Article

ISSN 0006-2979, Biochemistry (Moscow), 2023, Vol. 88, No. 11, pp. 1763-1777 © Pleiades Publishing, Ltd., 2023.

Russian Text © The Author(s), 2023, published in Biokhimiya, 2023, Vol. 88, No. 11, pp. 2138-2155.

1763

REVIEW

Microgravity Effects and Aging Physiology:

Similar Changes or Common Mechanisms?

Andrey Yu. Ratushnyy

and Ludmila B. Buravkova

1,a

Institute of Biomedical Problems, Russian Academy of Sciences, 123007 Moscow, Russia

e-mail: buravkova@imbp.ru

Received July 18, 2023

Revised October 13, 2023

Accepted October 14, 2023

Abstract— Despite the use of countermeasures (including intense physical activity), cosmonauts and astronauts develop

muscle atony and atrophy, cardiovascular system failure, osteopenia, etc. All these changes, reminiscent of age-related

physiological changes, occur in a healthy person in microgravity quite quickly– within a few months. Adaptation to the

lost of gravity leads to the symptoms of aging, which are compensated after returning to Earth. The prospect of interplan-

etary flights raises the question of gravity thresholds, below which the main physiological systems will decrease their func-

tional potential, similar to aging, and affect life expectancy. An important role in the aging process belongs to the body’s

cellular reserve– progenitor cells, which are involved in physiological remodeling and regenerative/reparative processes

of all physiological systems. With age, progenitor cell count and their regenerative potential decreases. Moreover, their

paracrine profile becomes pro-inflammatory during replicative senescence, disrupting tissue homeostasis. Mesenchymal

stem/stromal cells (MSCs) are mechanosensitive, and therefore deprivation of gravitational stimulus causes serious changes

in their functional status. The review compares the cellular effects of microgravity and changes developing in senescent

cells, including stromal precursors.

DOI: 10.1134/S0006297923110081

Keywords: microgravity, aging, cell senescence, mesenchymal stem/stromal cells (MSCs)

Abbreviations: ECM, extracellular matrix; MSCs,mesenchymal stem/stromal cells; Rb,retinoblastoma protein; ROS,reactive

oxygen species; RPM,Random Positioning Machine; SMG,simulated microgravity

* To whom correspondence should be addressed.

INTRODUCTION

Despite the careful pre-flight selection, factors re-

lated to space flight, primarily weightlessness/micrograv-

ity, increase the risk of deterioration of the space travel-

er’s health [1-3]. In this regard, pinpointing fundamental

mechanisms of adaptation to microgravity-related effects

at tissue, cellular, and molecular levels is one of the most

essential scientific problems for space medicine. Resem-

blance of the physiological changes occurring during

space flight to the processes developing during human

aging is of special interest that raises a crucial question

about the similarity of underlying molecular and cellular

mechanisms. At the same time, restoration and normal-

ization of physiological processes in organs and tissues

is observed after returning to Earth, but aging leads to

unidirectional, progressive pathological changes [1,4].

It is recognized that in many physiological systems

the long-term space flights could result in emergence of

signs typical to aging [4-7]. Studies carried out on the

MIR orbital station and the International Space Station

revealed that the long-term stay in space results in de-

creased bone density [8-11], dysfunction of the immune

system [12], issues related to cardiovascular system func-

tioning [13, 14] as well as lowered skeletal muscle mass

and strength [15]. Furthermore, cartilage tissue in the

musculoskeletal system is also noted to be affected.

In addition, the size of chondrogenic pellets, synthe-

sis of proteoglycans, and dynamic stiffness of three-

dimensional cartilage constructs are reduced [7]. Final-

ly, moderate hypothyroidism, increased stress hormone

(mainly catecholamines) and decreased sex steroid lev-

els, insulin resistance, as well as systemic pro-inflam-

matory state could be observed as well [6, 16]. Similar

RATUSHNYY, BURAVKOVA176 4

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

changes occur upon aging under Earth’s gravity, which

develop, however, much faster in spaceflights.

Degenerative changes in the musculoskeletal system

pose one of the most important risks upon exposure to

microgravity. In this regard, a recent meta-review sum-

marized the data from 25 experimental papers that an-

alyzed post-flight bone density level as well as in-flight

and post-flight bone biochemical markers in 148 and

124 subjects, respectively. It turned out that compared

with the pre-flight level the cosmonauts who spent more

than 28 days in space were found to have lower extremity

bone density decreased by 5.4% (n = 96). After landing,

level of the bone resorption markers decreased, and the

balance shifted toward prevailing bone formation [11].

Some of the mechanisms underlying decline in

bone density during spaceflight could highly resemble

those related to osteoporosis developed in aging and/or

due to physical inactivity. The reduced bone mass and

osteoporosis has been observed both in older people as

well as in immobilized or bedridden patients of any age

[6] primarily highlighting a reduced mechanical load on

the musculoskeletal system. In addition, the decreased

level of sex hormones such as testosterone and estro-

gen should be noted. Interestingly, the male astronauts

demonstrate both decreased workload and lowered tes-

tosterone level (comparable to the older men) [6, 17].

It should be noted that neither daily physical tasks nor

mechanical loads can fully prevent osteopenia devel-

opment.

Similar data were also observed in the animal study

with 16-week-old female C57BL/6J mice exposed to mi-

crogravity for 15 days during the STS-131 mission. It was

shown that the bone volume fraction and bone thickness

decreased by 6.2% and 11.9%, respectively. A more de-

tailed analysis revealed elevated number of osteoclasts

along with higher expression of the bone matrix metal-

loproteinases (MMP-1, -3, and -10). At the same time,

osteoblast expression of the CDKN1a gene encoding p21

(one of the cell cycle inhibitors and crucial markers of

cellular senescence) was upregulated by 3.3-fold. Hence,

it could indicate that alterations in bone homeostasis

under microgravity conditions underlie osteocyte oste-

olysis and p21-mediated arrest in osteoblast cell cycle

[18]. Thus, phenomenology of the long-term impact of

space flight factors on bone tissue physiology allows to

draw some parallels with the age-related changes sug-

gesting existence of similar cellular mechanisms.

Recent studies with astronauts identify more links

between the alterations related to spaceflight and aging.

Modern molecular biological methods allow to assess

the state of genetic apparatus upon different damages.

Thus, American researchers analyzed temporal changes

in the telomere (the ends of chromosomes) length and

DNA damage response (DDR) in the peripheral blood

mononuclear cells from 11 astronauts on board of the

ISS before, during, and after the long-term spaceflights

(up to a year). In this regard, shortened telomeric regions

is considered as one of the classic signs of aging, which

will be discussed in more detail below. Despite that all

space travelers underwent strict medical selection having

no health complaints, they had shorter telomere length

and lower level of telomerase activity compared to the

control age-matched healthy subjects. Interestingly, the

telomere length increased slightly during space flights,

but rapidly decreased upon return to Earth [19]. Hence,

it was unveiled that despite of the individual differences

the post-flight telomere length was decreased in almost

all astronauts in comparison with the pre-flight length.

Furthermore, a positive correlation between the oxida-

tive stress and dynamically fluctuating telomere length

was established. Aside from this, increased prevalence

of the chromosomal inversions was observed during and

after the space flights. It was proposed that regardless of

telomerase activity in somatic cells the in-flight chronic

oxidative stress transiently activates an alternative path-

way for telomere length regulation [19].

Discussing the data on the telomere length in-

creased during space flights, it should be noted that the

cosmonauts and astronauts use physical activity (about

an hour daily) as a countermeasure of adverse effects

related to weightlessness. Analyzing the effects of run-

ning revealed its positive effect on peripheral blood mono-

nuclear cell telomere length [20], the telomere length

positively correlated with the performance level of ath-

letes [21].

Considering telomere length (or any other sign of

aging) as one of an “integrative markers” for cumulative

effect of genetic and external cues (environment and

lifestyle) on human aging, it is necessary to remember

that together with microgravity, a healthy person be-

comes affected by the elevated level of radiation, tran-

sient changes in spacecraft normoxic atmosphere (in-

creased CO

level, airborne organic impurities), altered

microbiome, as well as stressful situations (e.g., extra-

vehicular activities, failures of life support system ele-

ments, etc.), which should be taken into consideration

while analyzing impact of space flights on physiological

processes.

Interestingly, the level of blood plasma pro-inflam-

matory interleukins and chemokines in astronauts sig-

nificantly correlated with the telomere length and in-

creased during the long-term space flights. For instance,

the astronauts’ plasma samples contained higher level of

various cytokines including pro-inflammatory cues such

as TNFα, IL-8, IL-1ra, Tpo, VEGF, MCP-1, CCL4,

CXCL5 [12] that could be considered as a sign of chron-

ic (sterile) inflammation, one of the signs of aging.

Microgravity is a major element affecting health of

astronauts during space flight [22]. Because physiologi-

cal changes at an organismal level result from the mod-

ified cellular functioning, cellular changes related to ag-

ing and microgravity were compared.

MICROGRAVITY AND AGING-RELATED EFFECTS 1765

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

It is necessary to remember that the central regula-

tory processes such as fluctuated biorhythms, hormonal

status etc. affecting the cell state (and aging) in the con-

text of an integral unified system also greatly impact the

gravity-related physiological effects. These effects are the

subject of separate investigation. In particular, they being

considered in the Dilman’s neuroendocrine theory of ag-

ing and in the hypothesis suggested by A. M. Olovnikov

about potential molecular mechanisms for the develop-

ment and aging of multicellular organisms, including in-

volvement of neuroendocrine cells and gravitational ef-

fects. Moreover, perception of the gravitational infradian

rhythms by the animals, which could become disrupted

during space flight and, probably, result in accelerated

aging, has been also mentioned [23-27].

CELL SENESCENCE

Nowadays, aging is often envisioned as the loss of

body physiological integrity that proceeds over time re-

sulting in its impaired functions and elevated risk of

death. Hypotheses, theories, definitions of aging at var-

ious levels of life organization have been extensively dis-

cussed in the Biochemistry (Moscow) journal including the

Issue12-13, 2022. In this review we will solely refer to the

hallmark issues. It is also worth noting about an epigen-

etic “clock” of aging proposed in 2013 by Horvath [28]

and in 2017 by the scientific team headed by Dr.Gladyshev

[29]. However, a rather broad application of the “clock”

concept with regard to space biology needs to be further

assessed.

Currently, at the cellular level, altered intercellular

interaction, depleted stem cell pool, cellular aging, mi-

tochondrial dysfunction, metabolic disorders, impaired

proteostasis, genome instability, telomere shortening,

and epigenetic changes are referred to as signs of ag-

ing at the cellular level [30]. Cell aging (senescence) is

thought to be one of the essential arms in the host ag-

ing [31]. Such phenomenon is characterized by the irre-

versibly arrested cell cycle and could be accompanied by

the prominent phenotypic changes including increased

autophagic events, modulated metabolism, chromatin

remodeling, production of proinflammatory cytokines,

etc. [32-36]. Morphological changes including larger

cell size and flattening should be highlighted among

the most recognized markers of cell senescence [37].

In addition, the senescence-associated β-galactosidase

(SA-β-gal) activity also increases [38] along with the

frequency of emerging of heterochromatic γ-H2AX

foci[39]. To some extent, formation of a senescent cell

may be considered as a consequence and as a cause of

aging. On the one hand, it results from alterations at the

molecular level, translated into the senescence program

at the cell level, which is an elementary unit of life or-

ganization. On the other hand, the senescent cell phys-

iology transforms dramatically leading to the impaired

tissue and organ functioning in the long term.

Cell senescence is generally referred to as an an-

tagonistic trait that has both negative and positive sides.

It is generally accepted that activation of the senescence

state is the most crucial barrier to tumorigenesis. Uncon-

trolled tumor cell division and inability of the senescent

cell to divide seem to be opposite consequences resulting

from the same causes primarily represented by accumu-

lation of damages in the cell genetic material [40, 41].

Cell senescence also plays an essential role in wound

healing, where, e.g., upon skin wound healing, the ma-

tricellular protein CCN1 can induce senescence of fibro-

blasts or myofibroblasts and thereby reduce fibrosis[42].

Another aspect of the positive senescence-related effects

may also be presented as the changed intercellular cross-

talk. A number of paracrine mediators typical to senes-

cent secretome are even used for the stromal progenitor

cell priming in regenerative medicine. In recent years,

various approaches have been explored to extend capa-

bilities of the stromal progenitor cells that resulted in the

development of new cell products with improved poten-

tial for diverse clinical applications [43]. These studies

clearly illustrate ambiguity of negative and positive bi-

ological effects, which is also applicable to senescent

cells.

Today, replicative and stress-induced cellular se-

nescence are distinguished: the former is considered as

a cell condition in which proliferative activity becomes

irreversibly lost following a series of mitoses. The cell

cycle arrest (in this case) largely results from the short-

ening of telomeric regions, which can be considered as

a special case of genome instability. In 1961, cellular se-

nescence was first described as the progressive and irre-

versible loss of proliferative potential in human somatic

cells. It was shown that even under ideal culture condi-

tions, human embryonic fibroblasts are capable of divid-

ing only a limited number of times (50 ± 10) [44], the

phenomenon named after the author, who discovered

it– the “Hayflick limit”. In 1971 A. M. Olovnikov pro-

posed a hypothesis to explain this phenomenon based

on the data regarding the principles of DNA synthesis

in cells [45], this hypothesis was later confirmed ex-

perimentally. It states that with each cell division chro-

mosomes become slightly shortened due to underrepli-

cation of telomeric DNA region. Human telomeres are

the terminal regions of chromosomes that contain from

4 to 15 thousand base pairs and consist of TTAGGG

repetitive sequences. It is known that DNA polymerase

is unable to synthesize a daughter DNA copy from the

end of its chain – it can only add nucleotides to the

pre-existing 3′-hydroxyl group, i.e., requires an RNA

primer. Upon removal of the last primer at the 3′end,

the daughter strand will inevitably be shorter leading to

gradual loss of telomeric nucleotides during successive

cycles of DNA synthesis [46].

RATUSHNYY, BURAVKOVA1766

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

The stress-induced cellular senescence is also char-

acterized by irreversible cell cycle arrest. Unlike in the

case of replicative cellular senescence, it is not associat-

ed with the number of cell divisions. The stress-induced

senescence is triggered by the sublethal damages or on-

cogene activation [36, 47]. Most often, this condition

is related to oxidative stress, i.e., an imbalance between

the oxidants [usually reactive oxygen species (ROS)]

and antioxidant systems. An effect of ROS on DNA in-

cluding mtDNA induces formation of the products of

oxidative DNA base damage such as 8-hydroxy-2′-deox-

yguanosine (8OHdG) and could also lead to the strand

breaks [48]. Apart from this, mitochondrial ROS could

activate the c-Jun N-terminal kinase (JNK), which, in

turn, facilitates release of the chromatin fragments into

cytoplasm and activation of the pro-inflammatory se-

cretome [49]. Interestingly, oxidative stress could also

accelerate telomere shortening [50] probably owing to

high content of guanine (G), which is most vulnerable

to ROS [51].

The programs of replicative and stress-induced cel-

lular senescence are executed via similar mechanisms.

Relatively small DNA damage results in the temporary

arrest of the cell cycle. After successful DNA repair, a

cell can begin to divide again. By definition, this con-

dition cannot be called cell senescence. More profound

damage that cannot be repaired for a long time triggers

a chronically activated DDR signaling cascade, cell re-

sponse to the genetic material damage. The chronically

activated DDR usually occurs upon multiple DNA dam-

ages and represents a major hallmark of the senescent

state– stable cell cycle arrest. The latter is achieved via

activation of the p16INK4a/Rb and p53/p21CIP1 tu-

mor suppressor signaling cascades [47, 51] so that the

cell would never be able to start division again. Sup-

pression of activity of the relevant cyclin-dependent ki-

nases by both inhibitors, p21 and p16 (encoded by the

CDKN1A and CDKN2A genes, respectively), results in

hypophosphorylation of the retinoblastoma protein(Rb).

The hypophosphorylated Rb is able to bind E2F family

transcription factors regulating cell cycle [52,53]. By re-

versibly binding and, consequently, functionally inacti-

vating E2F proteins, Rb controls expression of the genes,

products of which are essential for regulating cell cycle

as well as blocking the G1-to-S phase transition. In this

scenario, the p53/p21 pathway is predominantly activat-

ed first by preventing proliferation of the cells with se-

rious DNA damage, whereas the p16/Rb-axis becomes

involved somewhat later [32]. However, based on the

cellular context, one or another may become preferable.

Cellular senescence could be affected by various

mechanical forces including shear stress, tension, and

pressure [54,55]. This raises the question whether mi-

crogravity could be considered as a factor causing cellu-

lar senescence or other similar changes in the cell phys-

iology?

SENESCENCE-ASSOCIATED

ALTERATIONS UNDER

SIMULATED MICROGRAVITY

During the space flight, human body is exposed to

multiple unfavorable stress factors noted above that can

aggravate development of the aging-associated signs.

At the cellular level, they may be presented by the

changed radiation background able to disrupt DNA in-

tegrity and promote oxidative stress. In this review, the

microgravity-related effects will be discussed in detail.

In this review, the senescence-associated chang-

es occurring in the diverse cell types will be assessed

in the simulated microgravity (SMG) settings. Due to

the technical limitations posed by experiments in space

missions, various ground-based models are common-

ly used. Usually, such models are aimed at gravitation-

al “unloading” to simulate some of the microgravity-

related effects. Ground-based experiments also allow to

avoid an impact from the increased background radia-

tion and other space flight-associated factors. To sim-

ulate microgravity effects on cell cultures, rotating wall

vessels (RWV) and 2D/3D clinostats such as a device

for randomizing object position relative to the gravity

vector (Random Positioning Machine, RPM) are used

most often. It is believed that the computer-controlled

RPM consisting of two frames rotating in two perpen-

dicular planes represents the most suitable approach for

simulating microgravity effects on the adherent cell cul-

tures. Using the RPM allows to randomize object’s po-

sition relative to the gravity vector. In standard operating

modes, the device simulates gravitational acceleration

equivalent to 10

–2

g [56-58].

Various cell cultures including immortalized lines,

endothelium, stromal precursors, etc. have been used in

the studies [59-63]. A wide range of changes demon-

strating direct gravity-related effects on the cellular

structures were revealed in the studies investigating

invitro cell morphofunctional state. A change in posi-

tion of the heavy organelles such as nucleus results in

redistributed load on the cytoskeleton followed by its

reorganization; modifications in the adhesion molecule

physical interaction between the cell and extracellular

matrix also occur. Altogether, it results in the altered

gene expression, changes in functioning of multiple

proteins, and overall modification of the cell functional

state [64-68].

Some studies using SMG attempted to identify

ac tivated senescence in the pheochromocytoma cells

(PC12), erythrocytes, skeletal muscle myoblasts, and

cardiomyocytes [59, 69-71]. Wang et al. [59] used SMG

to analyze early (6-96 h) effects on the rat neuro-

nal PC12 cell line. It was shown that the cell cycle

was arrested in the G1 phase along with the increased

SA-β-gal activity as well as activated p53 and p16 signal-

ing cascades associated with senescence. More detailed

MICROGRAVITY AND AGING-RELATED EFFECTS 1767

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

analysis revealed elevated level of ROS, which could

induce cellular senescence. Activity of the intracellu-

lar antioxidant enzymes such as superoxide dismutase

(SOD), glutathione peroxidase (GSH-Px), and catalase

(CAT) were markedly enhanced 12h later but decreased

96 h after onset of the experiment. Moreover, the an-

tioxidant N-acetylcysteine was able to profoundly block

the ROS-associated effects that prominently abrogated

the microgravity-related increase in the SA-β-gal activ-

ity. These data allowed to suggest that SMG exposure

elicits cellular senescence in the PC12 cells via enhanced

oxidative stress [59].

Modifications in the human erythrocyte structure

and functions were assessed by using a 3D clinostat.

For this, the erythrocyte structural parameters were

analyzed together with the cellular senescence-specific

metabolic parameters. The obtained data show that the

long-term microgravity exposure results in emergence of

the senescence-specific morphological patterns [69].

It was shown that SMG with the Zeromo 3D cli-

nostat accelerates senescence in the human skeletal

muscle myoblast culture. A markedly decreased prolifer-

ation, typical cytoskeletal remodeling, and hypertrophy

of the cell nuclei as well as upregulated SA-β-gal expres-

sion were demonstrated. Similar changes are observed

in the senescent myoblasts after several passages. It was

noted that such effects were sustained even after return-

ing to the normal gravitational conditions. Moreover,

the myoblasts exposed to SMG demonstrated a reduced

ability to differentiate into myotubes [70].

More recently, studies were conducted with the

human iPSC (induced pluripotent stem cell)-derived

cardiomyocytes. It was revealed that exposure to SMG

resulted in chromosomal reorganizations, downregulat-

ed mitochondrial function, elevated ROS level, as well

as other signs indicative of cellular senescence. It is

worth noting that the following study limitations were

specifically highlighted, which are difficult to disagree

with: (i) short-term SMG exposure (48 h), (ii) further

experiments assessing durability of the detected changes

are required [71].

Other researchers tend to believe that ROS are

involved in the DNA damage during SMG exposure.

Forinstance, it has been noted that SMG induces DNA

damage and mitochondria-mediated apoptosis via in-

creased ROS production in the human promyelocytic

leukemia cells [72]. Earlier studies already revealed that

clinorotation affects mitochondria, one of the main cel-

lular free radical producers, thereby inducing apopto-

sis in the thyroid cells. In particular, it was found out

that 24 h after the onset of experiment 10% of the thy-

roid carcinoma cells (ONCO-DG1 cell line) entered

the Fas-dependent apoptotic pathway. Mitochondrial

destruction and redistribution, disrupted microtubules,

and activated effector caspase-3 were detected. Clinoro-

tation was also elicited apoptosis in the normal thyroid

cells (HTU-5) as evidenced by the caspase-3 activation

and elevated Fas and Bax protein levels [73].

Investigation of the mouse embryonic stem cells

demonstrated enhancement of the ROS-associated ef-

fects under SMG conditions. The authors added hy-

drogen peroxide to the cells and the number of DNA

double-strand breaks was analyzed. It turned out that

24-hour-exposure of the treated cells to microgravity

substantially elevated the degree of DNA damage [74].

In 2003, similar data were reported by Greco et al. [75]

demonstrating that the frequency of chromosomal ab-

errations increased by around 1.2-2.8-fold in the post-

flight blood samples exposed to X-ray radiation in

comparison with the pre-flight blood samples. At the

same time, another work shows that the early response

to bleomycin-induced DNA damage (the number of

γ-H2AX foci) was similar in both cells exposed to mi-

crogravity and those under control static ground con-

ditions [76].

Thus, a set of studies indicate that exposure to

SMG could result in the development of some signs of

cell senescence. Moreover, a mechanism involving ox-

idative stress has been even suggested for this phenom-

enon, which, to some extent, is associated with mito-

chondrial dysfunction. Nonetheless, not a single study

is available to confirm permanent cell cycle arrest, i.e.,

there is no clear evidence that after SMG exposure cells

can no longer proliferate. Therefore, it is too early to

conclude unequivocally that cellular senescence is initi-

ated under exposure to SMG. We believe that the effect

of SMG is hardly strong enough to cause such a pro-

found damage at the cellular level.

SENESCENCE-ASSOCIATED STROMAL

PROGENITOR FUNCTIONAL STATE

IN SMG SETTINGS

Mesenchymal stromal/stem cells (MSCs) or stro-

mal progenitors, which play a major role in renewal and

regeneration, have been found in almost all body tissues.

MSCs are involved in maintaining bone tissue homeo-

stasis, hematopoiesis, regulated immunomodulation, and

angiogenesis, etc. MSCs are of considerable interest

both for basic science and applied regenerative medicine

including age-related pathologies. To date, a consensus

has been reached allowing to refer the MSC-associated

beneficial effects to production of various secreted fac-

tors including extracellular matrix components and cy-

tokines [77-80].

Some studies suggest that pathological changes in

astronauts could be associated with the stromal precur-

sor cell senescence. Further assessment of the micro-

gravity-related effect on MSC senescence contributes

to understanding of the role of senescent cells in the

development of physiological and pathological changes

RATUSHNYY, BURAVKOVA1768

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

under spaceflight conditions [81]. Aging of an organism

correlates with the decreased MSC functional activity.

It decreases the rate of tissue repair typical to aging.

For instance, osteoporotic bone fractures in older peo-

ple heal more slowly due to the decreased MSC func-

tions and their count [82].

As noted above, oxidative stress may be the main

cause underlying cell damage. Microgravity is a stressor

potentially able to induce ROS production, ultimately

resulting in various damages to subcellular compart-

ments [83]. Increased level of free radicals and mito-

chondrial dysfunction in MSCs have been noted in

the recent study. However, addition of the antioxidant

restored mitochondrial functions and reversed cell se-

nescence. Moreover, SMG promoted expression of YAP

(Yes-associated protein) and its translocation into the

nucleus. YAP is an important effector in the Hippo sig-

naling pathway that regulates development, homeosta-

sis, and regeneration [81, 84, 85]. It is known that YAP

could regulate cell senescence by acting on ATM (atax-

ia-telangiectasia mutated kinase), p53/p21, p16/CDK/

Rb, autophagy, AMPK, mTOR, and SIRT1 signaling

pathways [86-88]. Verteporfin (VP), YAP inhibitor, re-

stored the SMG-induced MSC mitochondrial dysfunc-

tion and senescence [81].

Some other studies also suggested that SMG causes

stromal progenitor cell senescence. Molecular changes

associated with stemness (OCT-4, SOX2, NANOG) and

cellular senescence (p19, p21, p53) in the MSCs isolat-

ed from the Wharton’s jelly were analyzed. The authors

supposed that the results of the study indicate cellular

adaptation occurring within the first hours after expo-

sure followed by loss of stemness and emergence of the

signs of molecular senescence program [89]. Bellow the

main physiological parameters of MSCs exposed to mi-

crogravity will be discuss in more detail.

Proliferation. Proliferation is one of the major cell

characteristics particularly in the context of senescence.

Firstly, MSC senescence is typically characterized by

permanent cell cycle arrest in the G1 phase, i.e., senes-

cent MSCs cannot proliferate and form colonies [36,

90, 91]. Several studies evidence, at least slightly decreas-

ed MSC proliferative potential upon SMG conditions.

For instance, over time (from 1h to 10 days) clinostating

resulted in lowered proliferation rate and changed mor-

phology of the cells, which became flatter and reached

confluency at lower density. When exposure period pro-

longed up to 20 days, proliferation rate also decreased,

while the number of large flat culture cells increased

[92, 93]. Such changes can also be the signs of senes-

cence. Study with the rat bone marrow MSCs confirms

the findings published previously [94]. It is noted that

SMG inhibits MSC growth at the G0/G1 phase of the

cell cycle.

Other studies not only failed to obtain similar re-

sults, but, on the contrary, observed the opposite effect.

Yuge et al. [95] showed that proliferation rate of the

human MSC in the 3D clinostat increased by almost

3-fold under SMG in comparison with the control

group. Hence, it was noted that SMG can be used to

enhance stem cell expansion in vitro. We investigated

functional status of the human adipose tissue-derived

MSCs under SMG conditions (96h) using RPM. It was

found that the cell count increased 1.5-2-fold, whereas

activity of the lysosomal compartment, cell size, and

granularity decreased. No change in the ROS levels or

mitochondrial transmembrane potential was observed.

Therefore, this study suggests lack of the signs associ-

ated with cell stress during MSCs culturing under SMG

settings [96].

Investigation of the more committed MSCs osteo-

blasts, showed that SMG did not affect cell growth or

viability. Cells were incubated in the 3D clinostat for

12-96 h. Twenty-four hours after the onset of the ex-

periment, the Bax/Bcl-2 mRNA level ratio (parameter

of apoptosis) increased up to 136% relative to the static

control. However, it was accompanied by the increase of

XIAP (anti-apoptotic molecule) mRNA level to 138% of

the static control. No DNA fragmentation was observed

and the level of the effector caspase-3 mRNA remained

unaltered [97].

Thus, it is at least premature to draw conclusions

about the lowered MSC proliferation or enhanced apop-

tosis under SMG conditions, which requires further

detailed investigated.

Differentiation. Reduced multipotency is consid-

ered as an important feature of senescent MSCs [90, 91],

which may weaken their reparative potential in all tissue

types. Shift in the balance between adipocyte and osteo-

cyte lineages has been observed, although a specific vec-

tor for it remains debatable. Some studies noted decline

in the osteogenic properties of MSC with increased du-

ration of the cells culturing or upon senescence [98-100].

Other studies revealed no such changes or even reported

elevated osteogenic potential [101, 102]. Such data ob-

tained in different studies are usually accounted for by

different methodological approaches and experimental

models, heterogeneity of the MSC populations, as well as

lack of assays accurately assessing osteogenic differentia-

tion [98, 103]. The most informative invitro marker of os-

teogenic potential is presented by relevant differentiation

pathway followed by detection of matrix mineralization.

At the same time, elevated level of cell death may result

in the false-positive data due to the large calcium ion re-

lease from the dying cells and its binding to extracellular

matrix [36, 90, 91]. Regarding the adipocyte potential,

we are getting closer to a consensus. A somewhat wide

range of data has been accumulated, however, majority of

the researchers come to the conclusion that adipogenic

potential wanes upon senescence [91].

Our own data clearly and unambiguously indicate

reduced adipogenic potential of the MSCs isolated from

MICROGRAVITY AND AGING-RELATED EFFECTS 1769

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

adipose tissue during replicative senescence. This is

manifested by lack of pronounced formation of lipid in-

clusions during differentiation. A markedly downregu-

lated expression of the gene encoding the key transcrip-

tional regulator PPARγ was detected, which probably

underlies this phenomenon. On the other hand, signs

pointing at the reciprocally elevated osteogenic poten-

tial, despite the downmodulated expression of the genes

coding for some positive regulators of the osteoblastic

pathway (BMP2, BMP6, IGF1, IL1B) were additionally

observed. In the process, intensity of the matrix calci-

fication and osteoprotegerin concentration during dif-

ferentiation increased, which may be essential in the

context of atherosclerotic plaque calcification in elderly

people. Transcriptional activity of the key osteogene-

sis regulator (RUNX2) and some analyzed marker genes

(SPARC, SPP1, COL1A1, BGLAP) remained stable dur-

ing the replicative senescence of MSCs [104]. Despite

potentiated calcification of the matrix, its morphology

differed in the “young” and senescent cell cultures that

may indicate false positive data due to calcium release

[36, 90, 91]. At the same time, increased osteoprotegerin

production observed in the study may indicate a pro-os-

teogenic paracrine activity in the senescent MSCs [104].

A greater consensus was achieved on the issue regard-

ing osteogenic differentiation under SMG setting results,

with vast majority of the studies agrees that microgravity

contributes to the reduced osteogenic potential in MSC

[105]. In particular, such effects were demonstrated in the

rat [94, 106] and human [107, 108] bone marrow MSCs,

which was confirmed by Saxena etal. [109] revealing that

SMG inhibits the MSC-related osteoblastogenesis and

enhances adipocytogenesis under osteogenic conditions.

The authors believed that this process involves decreased

RhoA activity and cofilin phosphorylation, disruption of

F-actin stress fibers, as well as decreased focal adhesion

kinase-mediated integrin signaling. Other studies reported

that the lowered osteoblastogenesis under SMG settings

is, at least in part, caused by downmodulated integrin/

MAPK signaling [110].

Transcriptome analysis using a genome-wide mi-

croarray showed that 882 genes were downregulated, and

505 genes were upregulated after 24-hour SMG expo-

sure. In particular, a significantly reduced expression of

the osteocytic and chondrocytic genes, as well as higher

expression level of the adipocyte genes was noted [111].

More recently, attention was attracted to non-

canonical pathways of cell differentiation. For instance,

SMG turned out to promote MSC differentiation into

neurons evidenced by the upregulated expression of sev-

eral relevant markers. Moreover, secretion of neurotro-

phins such as nerve growth factor (NGF), brain-derived

neurotrophic factor (BDNF), or ciliary neurotrophic

factor (CNTF) was elevated [112]. In another study, the

rat MSCs were cultured for 72 h or 10 days in a clinos-

tat followed by expansion in various differential culture

media. It was found that the short-term exposure (72h)

promoted endothelial, neuronal, and adipogenic dif-

ferentiation, whereas the long-term exposure (10 days),

unexpectedly, facilitated MSC differentiation into osteo-

blasts. In addition, the short-term SMG exposure pro-

foundly downregulated RhoA activity, which, however,

increased with prolonging SMG exposure. Hence, such

data demonstrated that the duration of SMG exposure

regulates MSC differentiation via the RhoA-associated

pathway [113], which corroborated the above-mentioned

data obtained by Saxena etal. [109].

Thus, SMG can largely affect MSC differentiation

potential. Such effect is of inhibitory nature, at least

with regard to osteogenic differentiation, which may ex-

plain similar physiological consequences related to the

impaired bone metabolism.

Secretory activity. It is assumed that the senescent

cells could contribute to maintenance of chronic inflam-

mation and development of aging-associated diseases,

hence, investigating the issue of paracrine regulation is

of great importance. Senescent cells continue to interact

with the surrounding environment and exert local and

systemic effects primarily through paracrine regulation.

The secretory activity changes dramatically, and this

phenotype was even named accordingly– SASP (senes-

cence-associated secretory phenotype). First of all, the

SASP is characterized by increased proinflammatory se-

cretome, although individual cues vary widely depend-

ing on the cell type and the way to induce senescence

[36, 90, 91, 114].

It was discovered that the level of one of the main

pro-inflammatory cytokines, IL-8, in the human bone

marrow-derived MSCs increased in the culture medium

during culturing in 2D clinostat by 1.4-3.2-fold (20-d

exposure), as well as 1.5-6-fold (10-d exposure) and

1.6-2.1-fold (20-d exposure) on average in the culture

subjected to RPM [115]. Later, studies with the human

adipose tissue-derived MSCs complemented these find-

ings. Assessing the changes in paracrine activity upon

96-hour exposure to RPM showed elevated production

of IL-8 accompanied by the decreased IL-6 level. At the

same time, higher production of VEGF, a key positive

angiogenesis regulator, was noted [96].

Our study demonstrated that the post-RPM MSC-

conditioned medium stimulated formation of the vas-

cular network in ovo, of the capillary-like network of

endothelial cells (ECs) in Matrigel, and the EC non-di-

rectional migration invitro. Such effects were explained

by the changed expression of the genes and proteins as-

sociated with angiogenesis, primarily by the higher level

of expression of the angiogenesis regulators SerpinE1,

SerpinF1, IGFBP, VEGF, and IL-8 along with upreg-

ulated transcription of the genes encoding proangiogen-

ic growth factors such as VEGF-c and VEGF-a. Hence,

such data demonstrate that microgravity may exert an

MSC-mediated effect on the EC functional state [63].

RATUSHNYY, BURAVKOVA1770

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

In addition, we found higher transcriptional activi-

ty of the brain-derived neurotrophic factor, BDNF [63],

corroborating the findings reported by Chen et al. [112]

about potentiated MSC differentiation into neuron-like

cells under SMG. Additionally, therapeutic efficacy of

the microgravity-cultured MSCs after spinal cord isch-

emia-reperfusion injury was assessed revealing high-

er count of the BDNF-positive and lower count of the

caspase-3-positive apoptotic astrocytes, as well as re-

stored cell motility, which implies existence of positive ef-

fect of the post-SMG MSCs on regenerative process [116].

From the viewpoint of assessing the senescent state

in progenitor cells, it is important to study the proin-

flammatory secretome. While analyzing the SMG-

related effect of the adipose tissue-derived MSCs on

the TNFα-mediated priming, it was shown that SMG

perse results in no changes in the surface expression of

ICAM-1 and HLA-ABC, which can be considered as

markers of pro-inflammatory cell activation. A weak-

ened MSC response to the TNFα priming upon SMG

exposure was documented in the process that was man-

ifested as downmodulated production of the TNFα-de-

pendent pleiotropic cytokines (IL-8 and MCP-1), ma-

trix remodeling proteases, and suppression of some

genes encoding growth factors and cytokines [117].

Along with the proinflammatory cytokines, a stim-

ulatory effect related to the 10-day exposure to micro-

gravity on paracrine activity of the osteocommitted and

intact MSCs was evaluated. It was found that the MSC

response to SMG depended on the degree of cell com-

mitment so that for the osteocommitted MSCs it was

less pronounced and manifested by higher production

of sclerostin, negative regulator of osteoblastogenesis.

In contrast, the intact MSCs were distinguished by low

osteoprotegerin production. Such SMG-related changes

may underlie shift of the bone homeostasis towards bone

resorption [118]. In this regard, it is worth reminding that

the osteoprotegerin level becomes increased during se-

nescence [104].

Thus, it may be noted that exposure to SMG leads

to elevated secretion of the pro-inflammatory cytokine

IL-8, which, in turn, could promote production of the

downstream cues such as VEGF. Experiments show that

the changes in the secretome could be considered for

application in regenerative medicine to enhance neuro-

and angiogenesis. It is known that the pro-inflammatory

SASP in the senescent cells could also positively affect

tissue regeneration, whereas potential negative conse-

quences could be realized only upon chronic exposure.

Nonetheless, it is still premature to suggest the existence

of similarities between the SMG exposure and senes-

cence in the context of secretome.

Extracellular matrix. In addition to cells perse and

relevant paracrine cues, extracellular matrix (ECM)

plays an important role in the body tissue functioning.

It varies greatly depending on localization and medi-

ates intercellular interactions. The cell-ECM crosstalk is

necessary for normal cell functioning including cell pro-

liferation and differentiation [119, 120]. Various ECM

components perform specific functions. Proteoglycans

retain water, deposit metabolites and growth factors

due to their molecular structure and large number of

charged groups [121]. On the other hand, collagen and

fibronectin as protein constituents ensure tissue me-

chanical properties that cells rely on to maintain their

own shape as well as to migrate. Together with other

ECM proteins such as elastin and laminin, they ensure

matrix elasticity.

Available publications point at changes of ECM in

the senescent cells associated with their catabolic phe-

notype. In particular, upregulated expression of proteo-

lytic enzymes (matrix metalloproteinases, adamalysins

(ADAMs), urokinases and cathepsins) and lowered

production of ECM structural components (collagens,

glycoproteins, proteoglycans) was demonstrated. Even-

tually, it results in the reduced tissue elasticity, basement

membrane damage, and increased ECM stiffness [122].

At the moment, studies are mainly focused on as-

sessing effects of the ECM produced by young and se-

nescent cells on functional activity of the cellular ele-

ments in the tissue niche. The study by Choi etal. [123]

showed that the senescent fibroblasts seeded on the

ECM derived from the early passage fibroblasts had

reduced SA-β-gal expression along with the decreased

free radical levels, restored mitochondrial potential, as

well as telomere elongation. And vice versa, decline in

proliferation of the “young” fibroblasts cultured on the

senescent cell-derived ECM was observed [123].

The study of bone marrow MSCs obtained from the

young (3 weeks) and old (18 weeks) animals described

altered ECM properties. For this, the MSCs from young

and old mice were seeded onto decellularized matrix

from the relevant cell groups. It turned out that the

ECM released from the young MSCs produced lowered

ROS level that decreased by 30-50% in both young and

senescent MSCs compared to the ECM derived from

the old MSCs or cells grown on plastic [124]. It was

also shown that cultivation of the synovial fluid-derived

senescent MSCs on the decellularized fetal matrix en-

hances the MSC potential to undergo chondro- and adi-

podifferentiation [125].

From the viewpoint of gravireception, the ECM–

integrin–cytoskeleton complex represents a mechano-

sensitive platform that coordinates cell and tissue func-

tional state in the gravitational field [68]. The Myoui’s

group assessed cell differentiation [106] while the rat

bone marrow MSCs were cultured for 2 weeks inside

the pores of calcium hydroxyapatite on a 3D clinostat.

It was discovered that compared with the control group,

alkaline phosphatase activity (a marker of osteoblastic

differentiation) reduced by 40%. The MSC-containing

composites implanted into the syngeneic rats revealed

MICROGRAVITY AND AGING-RELATED EFFECTS 1771

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

that bone formation was markedly lowered upon SMG

exposure. It is important to note that the lower amount

extracellular matrix was observed in the culture culti-

vated in clinostat, so these two events might be relat-

ed[106]. More recent work noted that exposure to SMG

resulted in elevated expression of the adhesion mole-

cules (ITGB1, CD44), MMP1 protease, as well as one

of the collagen types (ColIII) in the MSCs. MMP1 is

known to degrade interstitial collagens including ColIII.

It is likely that the authors observed a compensatory

reaction in this case. Expression of the FBN1 and VIM

genes was downregulated. FBN1 is an extracellular ma-

trix glycoprotein required for elastic fiber formation,

whereas VIM is the major intermediate filament in the

stromal progenitor cell cytoskeleton [126].

Recent studies in our laboratory complemented the

results obtained previously. It was shown that the 10-day

exposure to RPM results in the decreased level of col-

lagen components in ECM likely due to the decreased

collagen synthesis and protease activation. The present-

ed data demonstrate that the ECM-associated mole-

cules from both native and osteocommitted MSCs could

be involved in the bone matrix reorganization during

spaceflight [127].

Flight experiments on the Foton 10 spacecraft

demonstrated downregulated expression of the major

structural protein COL1A in the MG-63 osteoblast cell

line. In addition, the SJ-10 experiment showed that the

2-day-spaceflight was associated with the lowered level of

several genes encoding matrisome structural proteins and

elevated MMP1 expression in the bone marrow MSCs.

An inhibitory effect on the COL1A2 level was observed

additionally after 5 days of spaceflight. Based on the re-

sults of onboard experiments, it can be concluded that

the matrisome structural proteins are negatively affected

by microgravity at the transcriptional level [128,129].

It is easy to recognize certain similarities between

the changes occurring during activation of cellular se-

nescence and upon exposure to SMG. In both cases,

less amounts of the ECM constituents are produced,

which is accompanied by the higher protease activity.

Itis likely that the negative link between the matrix deg-

radation and osteogenic differentiation really exists.

CONCLUSION

Development of physiological/pathophysiological

alterations in humans during long-term space flights

may be a sign of the “atrophic syndrome” described re-

peatedly by G. Libertini [130]. This syndrome is char-

acterized by the lowered cell duplication capacity, de-

creased number of cells, substitution of specific cells

with nonspecific cells, hypertrophy of the remaining

specific cells, altered functioning of the cells with short-

ened telomeres, and altered cellular microenvironment

depending on the state of senescent cells [130]. The atro-

phic syndrome resulting from the unloading is consid-

ered reversible in the spaceflights by duration no more

than a year under condition when a fairly wide range of

preventive measures is performed on board of the or-

bital space stations. In our opinion, it is impossible to

determine whether there are some threshold values for

decline in gravity or a maximum permissible time spent

in the unloading environment without countermeasures,

below which the essential physiological systems would

lose own functional potential due to the processes simi-

lar to those occurring in aging. Moreover, almost noth-

ing is known about the microgravity-related effect on

the lifespan of different organisms including mammals.

Summarizing some experimental data of the micro-

gravity effects on the cells and comparing the identified

effects to the senescence-associated changes, it should be

noted that microgravity may probably trigger initial stag-

es of the stress-induced reactions. Some of the studies

discussed here directly suggest similar mechanisms un-

derlying the analogy response to microgravity and senes-

cence. Even upon the short-term exposure, such shifts

can cause lowered proliferation, skewed differentiation

pathway, altered secretory profile including paracrine

mediators and ECM-associated molecules. At the same

time, the question regarding reversibility of the chang-

es discovered during SMG remains open, because such

reversibility does not allow to infer senescence directly.

And, secondly, it should be noted that the vast majority

of experimental studies proving that the cellular senes-

cent state could be activated invitro rely on the short-

term microgravity exposures (24-72h), which is clearly

insufficient to enable the cell senescence program.

Contributions. L.B.B. proposed initial concept of

the study; L.B.B. and A.Yu.R. wrote the manuscript,

comparatively analyzed microgravity- and aging-related

effects discussed in the review.

Funding. The study was financially supported

equally by the program of fundamental research of

the State Scientific Center of the Russian Federation–

Institute of Biomedical Problems of the Russian Acade-

my of Sciences (Topic65.3) and by the Russian Science

Foundation (grant no.21-75-10117).

Ethics declarations. The authors declare no conflict

of interest in financial or any other sphere. The article

contains no description of studies with human subjects

or animals performed by any of the authors.

REFERENCES

1. Demontis, G. C., Germani, M. M., Caiani, E. G., Barra-

vecchia, I., Passino, C., and Angeloni, D. (2017) Human

pathophysiological adaptations to the space environment,

Front. Physiol., 8, 547, doi:10.3389/fphys.2017.00547.

RATUSHNYY, BURAVKOVA17 72

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

2. Tran, K. N., and Choi, J. I. (2022) Mimic microgravi-

ty effect on muscle transcriptome under ionizing radia-

tion, Life Sci. Space Res., 32, 96-104, doi: 10.1016/j.lssr.

2021.12.002.

3. Patel, S. (2020) The effects of microgravity and space

radiation on cardiovascular health: from low-Earth or-

bit and beyond, Int.J. Cardiol. Heart Vasc., 30, 100595,

doi:10.1016/j.ijcha.2020.100595.

4. Vernikos, J., and Schneider, V. S. (2010) Space, grav-

ity and the physiology of aging: parallel or convergent

disciplines? A mini-review, Gerontology, 56, 157-166,

doi:10.1159/000252852.

5. Wang, E. (1999) Age-dependent atrophy and micrograv-

ity travel: what do they have in common? FASEBJ., 13,

S167-S174, doi:10.1096/fasebj.13.9001.s167.

6. Biolo, G., Heer, M., Narici, M., and Strollo, F. (2003)

Microgravity as a model of ageing, Curr. Opin. Clin.

Nutr. Metab. Care, 6, 31-40, doi: 10.1097/00075197-

200301000-00006.

7. Strollo, F., Gentile, S., Strollo, G., Mambro, A., and

Vernikos, J. (2018) Recent progress in space physiol-

ogy and aging, Front. Physiol., 9, 1551, doi: 10.3389/

fphys.2018.01551.

8. Burger, E. H., and Klein-Nulend, J. (1998) Microgravity

and bone cell mechanosensitivity, Bone, 22, 127S-130S,

doi:10.1016/s8756-3282(98)00010-6.

9. Keune, J. A., Branscum, A. J., Iwaniec, U. T., and Turn-

er, R. T. (2015) Effects of spaceflight on bone microarchi-

tecture in the axial and appendicular skeleton in growing

ovariectomized rats, Sci. Rep., 5, 18671, doi: 10.1038/

srep18671.

10. Gerbaix, M., Gnyubkin, V., Farlay, D., Olivier, C.,

Ammann, P., Courbon, G., Laroche, N., Genthial, R.,

Follet, H., Peyrin, F., Shenkman, B., Gauquelin-Koch, G.,

and Vico, L. (2017) One-month spaceflight compromises

the bone microstructure, tissue-level mechanical prop-

erties, osteocyte survival and lacunae volume in mature

mice skeletons, Sci. Rep., 7, 2659, doi: 10.1038/s41598-

017-03014-2.

11. Stavnichuk, M., Mikolajewicz, N., Corlett, T., Morris, M.,

and Komarova, S. V. (2020) A systematic review and

meta-analysis of bone loss in space travelers, NPJ Micro-

gravity, 6, 13, doi:10.1038/s41526-020-0103-2.

12. Crucian, B., Simpson, R. J., Mehta, S., Stowe, R.,

Chouker, A., Hwang, S. A., Actor, J. K., Salam, A. P.,

Pierson, D., and Sams, C. (2014) Terrestrial stress an-

alogs for spaceflight associated immune system dysreg-

ulation, Brain Behav. Immun., 39, 23-32, doi: 10.1016/

j.bbi.2014.01.011.

13. Sofronova, S. I., Tarasova, O. S., Gaynullina, D., Borzykh,

A. A., Behnke, B. J., Stabley, J. N., McCullough, D.J.,

Maraj, J. J., Hanna, M., Muller-Delp, J. M., Vinogra-

dova, O.L., and Delp, M.D. (2015) Spaceflight on the

Bion-M1 biosatellite alters cerebral artery vasomotor and

mechanical properties in mice, J. Appl. Physiol., 118,

830-838, doi:10.1152/japplphysiol.00976.2014.

14. Hughson, R. L., Yee, N. J., and Greaves, D. K. (2016)

Elevated end-tidal Pco

during long-duration spaceflight,

Aerospace Med. Hum. Perform., 87, 894-897, doi:10.3357/

AMHP.4598.2016.

15. Shen, H., Lim, C., Schwartz, A. G., Andreev-Andrievskiy, A.,

Deymier, A. C., and Thomopoulos, S. (2017) Effects

of spaceflight on the muscles of the murine shoulder,

FASEBJ., 31, 5466-5477, doi:10.1096/fj.201700320R.

16. Novikov, V. E., and Ilyin, E. A. (1981) Age-related reac-

tions of rat bones to their unloading, Aviat. Space Environ.

Med., 52, 551-553.

17. Strollo, F., Riondino, G., Harris, B., Strollo, G., Casaro-

sa, E., Mangrossa, N., Ferretti, C., and Luisi, M. (1998)

The effect of microgravity on testicular androgen secre-

tion, Aviat. Space Environ. Med., 69, 133-136.

18. Blaber, E. A., Dvorochkin, N., Lee, C., Alwood, J. S.,

Yousuf, R., Pianetta, P., Globus, R.K., Burns, B.P., and

Almeida, E.A. (2013) Microgravity induces pelvic bone

loss through osteoclastic activity, osteocytic osteolysis, and

osteoblastic cell cycle inhibition by CDKN1a/p21, PLoS

One, 8, e61372, doi:10.1371/journal.pone.0061372.

19. Luxton, J. J., McKenna, M. J., Lewis, A., Taylor, L. E.,

George, K. A., Dixit, S. M., Moniz, M., Benegas, W.,

Mackay, M. J., Mozsary, C., Butler, D., Bezdan, D.,

Meydan, C., Crucian, B. E., Zwart, S. R., Smith, S. M.,

Mason, C. E., and Bailey, S. M. (2020) Telomere

Length dynamics and DNA damage responses associat-

ed with long-duration spaceflight, Cell Rep., 33, 108457,

doi:10.1016/j.celrep.2020.108457.

20. Zhuikova, S. E., and Nagovitsyn, R. S. (2021) Influence

of running on some physiological and molecular biologi-

cal markers of human aging, Hum. Physiol., 47, 587-594,

doi:10.1134/S0362119721050133.

21. Simoes, H. G., Sousa, C. V., Dos Santos Rosa, T., da

Silva Aguiar, S., Deus, L.A., Rosa, E. C. C. C., Amato,

A. A., and Andrade, R. V. (2017) Longer telomere length

in elite master sprinters: relationship to performance and

body composition, Int. J. Sports Med., 38, 1111-1116,

doi:10.1055/s-0043-120345.

22. Prasad, B., Grimm, D., Strauch, S. M., Erzinger, G. S., Co-

rydon, T.J., Lebert, M., Magnusson, N.E., Infanger, M.,

Richter, P., and Krüger, M. (2020) Influence of micro-

gravity on apoptosis in cells, tissues, and other systems

invivo and invitro, Int.J. Mol. Sci., 21, 9373, doi:10.3390/

ijms21249373.

23. Fernando, H. J., and Bowers, D. (2021) Neuroendocrine

Theory of Aging, in Encyclopedia of Gerontology and Pop-

ulation Aging (Gu, D., and Dupre, M.E., eds) Springer,

Cham, doi:10.1007/978-3-030-22009-9_673.

24. Dilman, V. M., Revskoy, S. Y., and Golubev, A.G. (1986)

Neuroendocrine-ontogenetic mechanism of aging: toward

an integrated theory of aging, Int. Rev. Neurobiol., 28,

89-156, doi:10.1016/s0074-7742(08)60107-5.

25. Olovnikov, A. (2005) Lunasensor, infradian rhythms, telo-

meres, and the chronomere program of aging, Ann. NY

Acad. Sci., 1057, 112-132, doi:10.1196/annals.1356.006.

MICROGRAVITY AND AGING-RELATED EFFECTS 1773

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

26. Olovnikov, A. M. (2015) Chronographic theory of devel-

opment, aging, and origin of cancer: role of chronomeres

and printomeres, Curr. Aging Sci., 8, 76-88, doi:10.2174/

1874609808666150422114916.

27. Olovnikov, A. M. (2022) Planetary metronome as a regu-

lator of lifespan and aging rate: the metronomic hypoth-

esis, Biochemistry (Moscow), 87, 1640-1650, doi:10.1134/

S0006297922120197.

28. Horvath, S. (2013) DNA methylation age of human tis-

sues and cell types, Genome Biol., 14, R115, doi:10.1186/

gb-2013-14-10-r115.

29. Petkovich, D. A., Podolskiy, D. I., Lobanov, A. V., Lee,

S.G., Miller, R.A., and Gladyshev, V.N. (2017) Using

DNA methylation profiling to evaluate biological age

and longevity interventions, Cell Metab., 25, 954-960.e6,

doi:10.1016/j.cmet.2017.03.016.

30. López-Otín, C., Blasco, M. A., Partridge, L., Serrano, M.,

and Kroemer, G. (2013) Thehallmarks of aging, Cell,153,

1194-1217, doi:10.1016/j.cell.2013.05.039.

31. McHugh, D., and Gil, J. (2018) Senescence and aging:

causes, consequences, and therapeutic avenues, J. Cell

Biol., 217, 65-77, doi:10.1083/jcb.201708092.

32. Campisi, J., and d’Adda di Fagagna, F. (2007) Cellular se-

nescence: when bad things happen to good cells, Nat. Rev.

Mol. Cell Biol., 8, 729-740, doi:10.1038/nrm2233.

33. Ratushnyy, A. Y., Rudimova, Y. V., and Buravkova, L.B.

(2020) Replicative senescence and expression of auto-

phagy genes in mesenchymal stromal cells, Biochemistry

(Moscow), 85, 1169-1177, doi:10.1134/S0006297920100053.

34. Kuilman, T., Michaloglou, C., Mooi, W. J., and Peeper,

D.S. (2010) Theessence of senescence, Genes Dev., 24,

2463-2479, doi:10.1101/gad.1971610.

35. Salama, R., Sadaie, M., Hoare, M., and Narita, M. (2014)

Cellular senescence and its effector programs, Genes Dev.,

28, 99-114, doi:10.1101/gad.235184.113.

36. Ratushnyy, A. Y., and Buravkova, L. B. (2020) Cell senes-

cence and mesenchymal stromal cells, Hum. Physiol., 46,

85-93, doi:10.1134/S0362119720010132.

37. Imai, S., and Guarente, L. (2014) NAD

and sirtu-

ins in aging and disease, Trends Cell Biol., 24, 464-471,

doi:10.1016/j.tcb.2014.04.002.

38. Dimri, G. P., Lee, X., Basile, G., Acosta, M., Scott, G.,

Roskelley, C., Medrano, E.E., Linskens, M., Rubelj, I.,

and Pereira-Smith, O. (1995) Abiomarker that identifies

senescent human cells in culture and in aging skin invivo,

Proc. Natl. Acad. Sci. USA, 92, 9363-9367, doi:10.1073/

pnas.92.20.9363.

39. Narita, M., Nũnez, S., Heard, E., Narita, M., Lin,

A.W., Hearn, S.A., Spector, D.L., Hannon, G.J., and

Lowe, S. W. (2003) Rb-mediated heterochromatin for-

mation and silencing of E2F target genes during cellular

senescence, Cell, 113, 703-716, doi: 10.1016/s0092-8674

(03)00401-x.

40. Collado, M., Blasco, M. A., and Serrano, M. (2007) Cel-

lular senescence in cancer and aging, Cell, 130, 223-233,

doi:10.1016/j.cell.2007.07.003.

41. Hanahan, D., and Weinberg, R. A. (2011) Hallmarks

of cancer: the next generation, Cell, 144, 646-674,

doi:10.1016/j.cell.2011.02.013.

42. Jun, J. I., and Lau, L. F. (2010) Thematricellular protein

CCN1 induces fibroblast senescence and restricts fibrosis

in cutaneous wound healing, Nat. Cell Biol., 12, 676-685,

doi:10.1038/ncb2070.

43. Noronha, N. C., Mizukami, A., Caliári-Oliveira, C.,

Cominal, J. G., Rocha, J. L. M., Covas, D.T., Swiech, K.,

and Malmegrim, K. C. R. (2019) Priming approaches to

improve the efficacy of mesenchymal stromal cell-based

therapies, Stem Cell Res. Ther., 10, 131, doi: 10.1186/

s13287-019-1224-y.

44. Hayflick, L., and Moorhead, P. S. (1961) Theserial cul-

tivation of human diploid cell strains, Exp. Cell Res.,

25, 585-621, doi:10.1016/0014-4827(61)90192-6.

45. Olovnikov, A. M. (1971) Principle of marginotomy in

template synthesis of polynucleotides, Dokl. Akad. Nauk

SSSR, 201, 1496-1499.

46. Victorelli, S., and Passos, J. F. (2017) Telomeres and cell

senescence– size matters not, EBioMedicine, 21, 14-20,

doi:10.1016/j.ebiom.2017.03.027.

47. De Magalhães, J. P., and Passos, J. F. (2018) Stress, cell

senescence and organismal ageing, Mech. Ageing Dev.,

170, 2-9, doi:10.1016/j.mad.2017.07.001.

48. Gruber, J., Schaffer, S., and Halliwell, B. (2008) Themi-

tochondrial free radical theory of ageing– where do we

stand? Front. Biosci., 13, 6554-6579, doi:10.2741/3174.

49. Vizioli, M. G., Liu, T., Miller, K. N., Robertson, N. A.,

Gilroy, K., Lagnado, A. B., Perez-Garcia, A., Kiourtis, C.,

Dasgupta, N., Lei, X., Kruger, P. J., Nixon, C., Clark, W.,

Jurk, D., Bird, T. G., Passos, J. F., Berger, S. L., Dou, Z.,

and Adams, P. D. (2020) Mitochondria-to-nucleus retro-

grade signaling drives formation of cytoplasmic chromatin

and inflammation in senescence, Genes Dev., 34, 428-445,

doi:10.1101/gad.331272.119.

50. Von Zglinicki, T. (2002) Oxidative stress shortens telo-

meres, Trends Biochem. Sci., 27, 339-344, doi: 10.1016/

s0968-0004(02)02110-2.

51. Campisi, J. (2013) Aging, cellular senescence, and can-

cer, Annu. Rev. Physiol., 75, 685-705, doi: 10.1146/

annurev-physiol-030212-183653.

52. Sherr, C. J., and Roberts, J. M. (1999) CDK inhibitors:

positive and negative regulators of G1-phase progression,

Genes Dev., 13, 1501-1512, doi:10.1101/gad.13.12.1501.

53. Sherr, C. J., and McCormick, F. (2002) TheRB and p53

pathways in cancer, Cancer Cell, 2, 103-112, doi:10.1016/

s1535-6108(02)00102-2.

54. Tharp, K. M., Higuchi-Sanabria, R., Timblin, G. A.,

Ford, B., Garzon-Coral, C., Schneider, C., Muncie, J. M.,

Stashko, C., Daniele, J. R., Moore, A. S., Frankino, P. A.,

Homentcovschi, S., Manoli, S. S., Shao, H., Richards,

A.L., Chen, K. H., Hoeve, J. T., Ku, G. M., Hellerstein, M.,

Nomura, D. K., etal. (2021) Adhesion-mediated mech-

anosignaling forces mitohormesis, Cell Metab., 33, 1322-

1341.e13, doi:10.1016/j.cmet.2021.04.017.

RATUSHNYY, BURAVKOVA17 74

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

55. Duan, J. L., Ruan, B., Song, P., Fang, Z. Q., Yue, Z.S.,

Liu, J. J., Dou, G. R., Han, H., and Wang, L. (2022)

Shear stress-induced cellular senescence blunts liver re-

generation through Notch-sirtuin 1-P21/P16 axis, Hepa-

tology, 75, 584-599, doi:10.1002/hep.32209.

56. Van Loon, J. W. A. (2007) Some history and use of the

random positioning machine, RPM, in gravity related

research, Adv. Space Res., 39, 1161-1165, doi: 10.1016/

j.asr.2007.02.016.

57. Kopp, S., Warnke, E., Wehland, M., Aleshcheva, G.,

Magnusson, N. E., Hemmersbach, R., Corydon, T. J.,

Bauer, J., Infanger, M., and Grimm, D. (2015) Mecha-

nisms of three-dimensional growth of thyroid cells during

long-term simulated microgravity, Sci. Rep., 5, 16691,

doi:10.1038/srep16691.

58. Wuest, S. L., Richard, S., Kopp, S., Grimm, D., and

Egli, M. (2015) Simulated microgravity: critical review

on the use of random positioning machines for mam-

malian cell culture, BioMed Res. Int., 2015, 971474,

doi:10.1155/2015/971474.

59. Wang, J., Zhang, J., Bai, S., Wang, G., Mu, L., Sun, B.,

Wang, D., Kong, Q., Liu, Y., Yao, X., Xu, Y., and Li, H.

(2009) Simulated microgravity promotes cellular senes-

cence via oxidant stress in rat PC12 cells, Neurochem. Int.,

55, 710-716, doi:10.1016/j.neuint.2009.07.002.

60. Kapitonova, M. Y., Muid, S., Froemming, G. R., Yusoff,

W. N., Othman, S., Ali, A. M., and Nawawi, H. M. (2012)

Real space flight travel is associated with ultrastructural

changes, cytoskeletal disruption and premature senescence

of HUVEC, Malays.J. Pathol., 34, 103-113.

61. Ulbrich, C., Wehland, M., Pietsch, J., Aleshcheva, G.,

Wise, P., van Loon, J., Magnusson, N., Infanger, M.,

Grosse, J., Eilles, C., Sundaresan, A., and Grimm, D.

(2014) Theimpact of simulated and real microgravity on

bone cells and mesenchymal stem cells, BioMed Res. Int.,

2014, 928507, doi:10.1155/2014/928507.

62. Winkelmaier, G., Jabbari, K., Chien, L. C., Grabham, P.,

Parvin, B., and Pluth, J. (2023) Influence of simulated

microgravity on mammary epithelial cells grown as 2D

and 3Dcultures, Int.J. Mol. Sci., 24, 7615, doi:10.3390/

ijms24087615.

63. Ratushnyy, A., Ezdakova, M., Yakubets, D., and Bu-

ravkova, L. (2018) Angiogenic activity of human adi-

pose-derived mesenchymal stem cells under simulated

microgravity, Stem Cells Dev., 27, 831-837, doi:10.1089/

scd.2017.0262.

64. Ingber, D. E. (2003) Mechanobiology and diseas-

es of mechanotransduction, Ann. Med., 35, 564-577,

doi:10.1080/07853890310016333.

65. Louis, F., Deroanne, C., Nusgens, B., Vico, L., and Guig-

nandon, A. (2015) RhoGTPases as key players in mam-

malian cell adaptation to microgravity, BioMed Res. Int.,

2015, 747693, doi:10.1155/2015/747693.

66. Mao, X., Chen, Z., Luo, Q., Zhang, B., and Song, G.

(2016) Simulated microgravity inhibits the migration of

mesenchymal stem cells by remodeling actin cytoskeleton

and increasing cell stiffness, Cytotechnology, 68, 2235-

2243, doi:10.1007/s10616-016-0007-x.

67. Ratushnyy, A. Y., and Buravkova, L. B. (2017) Expression

of focal adhesion genes in mesenchymal stem cells under

simulated microgravity, Dokl. Biochem. Biophys., 477,

354-356, doi:10.1134/S1607672917060035.

68. Buravkova, L., Larina, I., Andreeva, E., and Grigoriev, A.

(2021) Microgravity effects on the matrisome, Cells,10,

2226, doi:10.3390/cells10092226.

69. Dinarelli, S., Longo, G., Dietler, G., Francioso, A.,

Mosca, L., Pannitteri, G., Boumis, G., Bellelli, A., and

Girasole, M. (2018) Erythrocyte’s aging in microgravity

highlights how environmental stimuli shape metabolism

and morphology, Sci. Rep., 8, 5277, doi:10.1038/s41598-

018-22870-0.

70. Takahashi, H., Nakamura, A., and Shimizu, T. (2021)

Simulated microgravity accelerates aging of human skel-

etal muscle myoblasts at the single cell level, Biochem.

Biophys. Res. Commun., 578, 115-121, doi:10.1016/j.bbrc.

2021.09.037.

71. Acharya, A., Nemade, H., Papadopoulos, S., Heschel-

er, J., Neumaier, F., Schneider, T., Rajendra Prasad, K.,

Khan, K., Hemmersbach, R., Gusmao, E.G., Mizi, A.,

Papantonis, A., and Sachinidis, A. (2022) Microgravi-

ty-induced stress mechanisms in human stem cell-de-

rived cardiomyocytes, iScience, 25, 104577, doi:10.1016/

j.isci.2022.104577.

72. Singh, R., Rajput, M., and Singh, R. P. (2021) Simulated

microgravity triggers DNA damage and mitochondria-me-

diated apoptosis through ROS generation in human pro-

myelocytic leukemic cells, Mitochondrion, 61, 114-124,

doi:10.1016/j.mito.2021.09.006.

73. Kossmehl, P., Shakibaei, M., Cogoli, A., Infanger, M.,

Curcio, F., Schönberger, J., Eilles, C., Bauer, J., Picken-

hahn, H., Schulze-Tanzil, G., Paul, M., and Grimm, D.

(2003) Weightlessness induced apoptosis in normal thy-

roid cells and papillary thyroid carcinoma cells via extrin-

sic and intrinsic pathways, Endocrinology, 144, 4172-4179,

doi:10.1210/en.2002-0171.

74. Ran, F., An, L., Fan, Y., Hang, H., and Wang, S. (2016)

Simulated microgravity potentiates generation of reac-

tive oxygen species in cells, Biophys. Rep., 2, 100-105,

doi:10.1007/s41048-016-0029-0.

75. Greco, O., Durante, M., Gialanella, G., Grossi, G.,

Pugliese, M., Scampoli, P., Snigiryova, G., and Obe, G.

(2003) Biological dosimetry in Russian and Italian as-

tronauts, Adv. Space Res., 31, 1495-1503, doi: 10.1016/

s0273-1177(03)00087-5.

76. Lu, T., Zhang, Y., Kidane, Y., Feiveson, A., Stodieck, L.,

Karouia, F., Ramesh, G., Rohde, L., and Wu, H. (2017)

Cellular responses and gene expression profile changes

due to bleomycin-induced DNA damage in human fi-

broblasts in space, PLoS One, 12, e0170358, doi:10.1371/

journal.pone.0170358.

77. Murphy, M. B., Moncivais, K., and Caplan, A. I. (2013)

Mesenchymal stem cells: environmentally responsive

MICROGRAVITY AND AGING-RELATED EFFECTS 1775

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

therapeutics for regenerative medicine, Exp. Mol. Med.,

45, e54, doi:10.1038/emm.2013.94.

78. Spees, J. L., Lee, R. H., and Gregory, C.A. (2016) Mech-

anisms of mesenchymal stem/stromal cell function, Stem

Cell Res. Ther., 7, 125, doi:10.1186/s13287-016-0363-7.

79. Andreeva, E., Bobyleva, P., Gornostaeva, A., and Bu-

ravkova, L. (2017) Interaction of multipotent mesenchy-

mal stromal and immune cells: bidirectional effects, Cyto-

therapy, 19, 1152-1166, doi:10.1016/j.jcyt.2017.07.001.

80. Fujii, S., and Miura, Y. (2022) Immunomodulatory and

regenerative effects of MSC-derived extracellular ves-

icles to treat acute GVHD, Stem Cells, 40, 977-990,

doi:10.1093/stmcls/sxac057.

81. Lv, W., Peng, X., Tu, Y., Shi, Y., Song, G., and Luo, Q.

(2023) YAP inhibition alleviates simulated microgravi-

ty-induced mesenchymal stem cell senescence via tar-

geting mitochondrial dysfunction, Antioxidants, 12, 990,

doi:10.3390/antiox12050990.

82. Moretta, L., Uccelli, A., and Pistoia, V. (2015) Mesen-

chymal stromal cells and immunity: Introductory over-

view, Immunol. Lett., 168, 127-128, doi: 10.1016/j.imlet.

2015.08.010.

83. Yatagai, F., Honma, M., Dohmae, N., and Ishioka, N.

(2019) Biological effects of space environmental factors:

A possible interaction between space radiation and mi-

crogravity, Life Sci. Space Res., 20, 113-123, doi:10.1016/

j.lssr.2018.10.004.

84. Moya, I. M., and Halder, G. (2019) Hippo-YAP/TAZ

signalling in organ regeneration and regenerative medi-

cine, Nat. Rev. Mol. Cell Biol., 20, 211-226, doi:10.1038/

s41580-018-0086-y.

85. Pobbati, A. V., and Hong, W. (2020) Acombat with the

YAP/TAZ-TEAD oncoproteins for cancer therapy, Thera-

nostics, 10, 3622-3635, doi:10.7150/thno.40889.

86. Childs, B. G., Gluscevic, M., Baker, D. J., Laberge,

R.M., Marquess, D., Dananberg, J., and van Deursen,

J.M. (2017) Senescent cells: an emerging target for dis-

eases of ageing, Nat. Rev. Drug Discov., 16, 718-735,

doi:10.1038/nrd.2017.116.

87. Xie, Q., Chen, J., Feng, H., Peng, S., Adams, U., Bai,

Y., Huang, L., Li, J., Huang, J., Meng, S., and Yuan, Z.

(2013) YAP/TEAD-mediated transcription controls cellu-

lar senescence, Cancer Res., 73, 3615-3624, doi:10.1158/

0008-5472.CAN-12-3793.

88. Yeung, Y. T., Guerrero-Castilla, A., Cano, M., Muñoz,

M.F., Ayala, A., and Argüelles, S. (2019) Dysregulation of

the hippo pathway signaling in aging and cancer, Pharma-

col. Res., 143, 151-165, doi:10.1016/j.phrs.2019.03.018.

89. Pala, R., Cruciani, S., Manca, A., Garroni, G., El Faqir,

M. A., Lentini, V., Capobianco, G., Pantaleo, A., and

Maioli, M. (2023) Mesenchymal stem cell behavior un-

der microgravity: from stress response to a premature

senescence, Int. J. Mol. Sci., 24, 7753, doi: 10.3390/

ijms24097753.

90. Turinetto, V., Vitale, E., and Giachino, C. (2016) Se-

nescence in human mesenchymal stem cells: functional

changes and implications in stem cell-based therapy, Int.J.

Mol. Sci., 17, 1164, doi:10.3390/ijms17071164.

91. Li, Y., Wu, Q., Wang, Y., Li, L., Bu, H., and Bao, J. (2017)

Senescence of mesenchymal stem cells (Review), Int. J.

Mol. Sci., 39, 775-782, doi:10.3892/ijmm.2017.2912.

92. Merzlikina, N. V., Buravkova, L. B., and Romanov, Y. A.

(2004) The primary effects of clinorotation on cultured

human mesenchymal stem cells, J.Gravitat. Physiol., 11,

P193-P194.

93. Gershovich, J. G., and Buravkova, L. B. (2007) Morpho-

functional status and osteogenic differentiation potential

of human mesenchymal stromal precursor cells during

in vitro modeling of microgravity effects, Bull. Exp. Biol.

Med., 144, 608-613, doi:10.1007/s10517-007-0387-1.

94. Dai, Z. Q., Wang, R., Ling, S. K., Wan, Y. M., and Li,

Y. H. (2007) Simulated microgravity inhibits the pro-

liferation and osteogenesis of rat bone marrow mesen-

chymal stem cells, Cell Prolif., 40, 671-684, doi:10.1111 /

j.1365-2184.2007.00461.x.

95. Yuge, L., Kajiume, T., Tahara, H., Kawahara, Y., Ume-

da, C., Yoshimoto, R., Wu, S. L., Yamaoka, K., Asashi-

ma, M., Kataoka, K., and Ide, T. (2006) Microgravity

potentiates stem cell proliferation while sustaining the

capability of differentiation, Stem Cells Dev., 15, 921-929,

doi:10.1089/scd.2006.15.921.

96. Ratushnyy, A. Yu., and Buravkova, L. B. (2016) Func-

tional state of multipotent mesenchymal stromal cells

during modeling the effects of microgravity [in Russian],

Aviakosm. Ekol. Med., 50, 24-29.

97. Nakamura, H., Kumei, Y., Morita, S., Shimokawa, H.,

Ohya, K., and Shinomiya, K. (2003) Antagonism be-

tween apoptotic (Bax/Bcl-2) and anti-apoptotic (IAP)

signals in human osteoblastic cells under vector-averaged

gravity condition, Ann. NY Acad. Sci., 1010, 143-147,

doi:10.1196/annals.1299.023.

98. Kim, M., Kim, C., Choi, Y. S., Kim, M., Park, C., and

Suh, Y. (2012) Age-related alterations in mesenchymal

stem cells related to shift in differentiation from osteo-

genic to adipogenic potential: implication to age-associ-

ated bone diseases and defects, Mech. Ageing Dev., 133,

215-225, doi:10.1016/j.mad.2012.03.014.

99. Despars, G., Carbonneau, C. L., Bardeau, P., Coutu,

D.L., and Beauséjour, C.M. (2013) Loss of the osteogen-

ic differentiation potential during senescence is limited to

bone progenitor cells and is dependent on p53, PLoS One,

8, e73206, doi:10.1371/journal.pone.0073206.

100. Yang, Y. K., Ogando, C. R., Wang See, C., Chang, T.Y.,

and Barabino, G.A. (2018) Changes in phenotype and dif-

ferentiation potential of human mesenchymal stem cells

aging in vitro, Stem Cell Res. Ther., 9, 131, doi: 10.1186/

s13287-018-0876-3.

101. Wagner, W., Horn, P., Castoldi, M., Diehlmann, A.,

Bork,S., Saffrich, R., Benes, V., Blake, J., Pfister, S., Eck-

stein, V., and Ho, A.D. (2008) Replicative senescence of

mesenchymal stem cells: a continuous and organized pro-

cess, PLoS One, 3, e2213, doi:10.1371/journal.pone.0002213.

RATUSHNYY, BURAVKOVA1776

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

102. Digirolamo, C. M., Stokes, D., Colter, D., Phinney, D. G.,

Class, R., and Prockop, D. J. (1999) Propagation and

senescence of human marrow stromal cells in culture:

a simple colony-forming assay identifies samples with

the greatest potential to propagate and differentiate,

Br. J. Haematol., 107, 275-281, doi:10.1046/j.1365-2141.

1999.01715.x.

103. Cheng, H., Qiu, L., Ma, J., Zhang, H., Cheng, M., Li, W.,

Zhao, X., and Liu, K. (2011) Replicative senescence of hu-

man bone marrow and umbilical cord derived mesenchy-

mal stem cells and their differentiation to adipocytes and

osteoblasts, Mol. Biol. Rep., 38, 5161-5168, doi:10.1007/

s11033-010-0665-2.

104. Ratushnyy, A. Yu., and Buravkova, L. B. (2022) Differen-

tiation potential of the mesenchymal stromal cells during

replicative senescence [in Russian], Aviakosm. Ekol. Med.,

56, 64-69.

105. Buravkova, L. B., Gershovich, P. M., Gershovich, J.G.,

and Grigor’ev, A. I. (2010) Mechanisms of gravitation-

al sensitivity of osteogenic precursor cells, Acta Naturae,

2, 28-36, doi:10.32607/actanaturae.10734.

106. Nishikawa, M., Ohgushi, H., Tamai, N., Osuga, K.,

Uemura, M., Yoshikawa, H., and Myoui, A. (2005) Theef-

fect of simulated microgravity by three-dimensional clinos-

tat on bone tissue engineering, Cell Transplant., 14, 829-

835, doi:10.3727/000000005783982477.

107. Zayzafoon, M., Gathings, W. E., and McDonald, J.M.

(2004) Modeled microgravity inhibits osteogenic differen-

tiation of human mesenchymal stem cells and increases ad-

ipogenesis, Endocrinology, 145, 2421-2432, doi:10.1210/

en.2003-1156.

108. Buravkova, L. B., Gershovich, P. M., Gershovich, J.G.,

and Grigoriev, A.I. (2013) Microgravity and mesenchy-

mal stem cell response, Curr. Biotechnol., 2, 217-225,

doi:10.2174/22115501113029990016.

109. Saxena, R., Pan, G., and McDonald, J. M. (2007) Os-

teoblast and osteoclast differentiation in modeled micro-

gravity, Ann. NY Acad. Sci., 1116, 494-498, doi:10.1196/

annals.1402.033.

110. Meyers, V. E., Zayzafoon, M., Gonda, S. R., Gathings,

W. E., and McDonald, J. M. (2004) Modeled microgravity

disrupts collagen I/integrin signaling during osteoblastic

differentiation of human mesenchymal stem cells, J.Cell.

Biochem., 93, 697-707, doi:10.1002/jcb.20229.

111. Sheyn, D., Pelled, G., Netanely, D., Domany, E., and

Gazit, D. (2010) Theeffect of simulated microgravity on

human mesenchymal stem cells cultured in an osteogenic

differentiation system: a bioinformatics study, Tissue Eng.

PartA, 16, 3403-3412, doi:10.1089/ten.tea.2009.0834.

112. Chen, J., Liu, R., Yang, Y., Li, J., Zhang, X., Li, J.,

Wang, Z., and Ma, J. (2011) Thesimulated microgravity

enhances the differentiation of mesenchymal stem cells

into neurons, Neurosci. Lett., 505, 171-175, doi:10.1016/

j.neulet.2011.10.014.

113. Xue, L., Li, Y., and Chen, J. (2017) Duration of simulat-

ed microgravity affects the differentiation of mesenchymal

stem cells, Mol. Med. Rep., 15, 3011-3018, doi:10.3892/

mmr.2017.6357.

114. Coppé, J. P., Desprez, P. Y., Krtolica, A., and Campisi,J.

(2010) The senescence-associated secretory phenotype:

the dark side of tumor suppression, Annu. Rev. Pathol., 5,

99-118, doi:10.1146/annurev-pathol-121808-102144.

115. Gershovich, Iu. G., and Buravkova, L. B. (2009) Interleu-

kine production in culture of mesenchymal stromal cells

of humans during simulation of the microgravity effects

[in Russian], Aviakosm. Ecolog. Med., 43, 44-50.

116. Kurose, T., Takahashi, S., Otsuka, T., Nakagawa, K.,

Imura, T., Sueda, T., and Yuge, L. (2019) Simulated mi-

crogravity-cultured mesenchymal stem cells improve re-

covery following spinal cord ischemia in rats, Stem Cell

Res.,

41, 101601, doi:10.1016/j.scr.2019.101601.

117. Ratushnyy, A., Yakubets, D., Andreeva, E., and Bu-

ravkova, L. (2019) Simulated microgravity modulates

the mesenchymal stromal cell response to inflammatory

stimulation, Sci. Rep., 9, 9279, doi:10.1038/s41598-019-

45741-8.

118. Zhivodernikov, I. V., Ratushnyy, A. Y., and Buravkova,

L. B. (2021) Secretory activity of mesenchymal stromal

cells with different degree of commitment under condi-

tions of simulated microgravity, Bull. Exp. Biol. Med., 170,

560-564, doi:10.1007/s10517-021-05106-6.

119. Aamodt, J. M., and Grainger, D. W. (2016) Extra-

cellular matrix-based biomaterial scaffolds and the

host response, Biomaterials, 86, 68-82, doi: 10.1016/

j.biomaterials.2016.02.003.

120. Choudhury, D., Tun, H. W., Wang, T., and Naing, M.W.

(2018) Organ-derived decellularized extracellular matrix: a

game changer for bioink manufacturing? Trends Biotech-

nol., 36, 787-805, doi:10.1016/j.tibtech.2018.03.003.

121. Hospodiuk, M., Dey, M., Sosnoski, D., and Ozbolat, I. T.

(2017) Thebioink: Acomprehensive review on bioprint-

able materials, Biotechnol. Adv., 35, 217-239, doi:10.1016/

j.biotechadv.2016.12.006.

122. Mavrogonatou, E., Pratsinis, H., Papadopoulou, A.,

Karamanos, N. K., and Kletsas, D. (2019) Extracellu-

lar matrix alterations in senescent cells and their signifi-

cance in tissue homeostasis, Matrix Biol., 75-76, 27-42,

doi:10.1016/j.matbio.2017.10.004.

123. Choi, H. R., Cho, K. A., Kang, H. T., Lee, J. B., Kaeber-

lein, M., Suh, Y., Chung, I. K., and Park, S. C. (2011)

Restoration of senescent human diploid fibroblasts by

modulation of the extracellular matrix, Aging Cell, 10,

148-157, doi:10.1111/j.1474-9726.2010.00654.x.

124. Sun, Y., Li, W., Lu, Z., Chen, R., Ling, J., Ran, Q., Jilka,

R.L., and Chen, X.D. (2011) Rescuing replication and

osteogenesis of aged mesenchymal stem cells by exposure

to a young extracellular matrix, FASEBJ., 25, 1474-1485,

doi:10.1096/fj.10-161497.

125. Lynch, K., and Pei, M. (2014) Age associated communica-

tion between cells and matrix: a potential impact on stem

cell-based tissue regeneration strategies, Organogenesis,

10, 289-298, doi:10.4161/15476278.2014.970089.

MICROGRAVITY AND AGING-RELATED EFFECTS 1777

BIOCHEMISTRY (Moscow) Vol. 88 No. 11 2023

126. Ebnerasuly, F., Hajebrahimi, Z., Tabaie, S.M., and Dar-

bouy, M. (2018) Simulated microgravity condition alters

the gene expression of some ECM and adhesion mole-

cules in adipose derived stem cells, Int.J. Mol. Cell. Med.,

7, 146-157, doi:10.22088/IJMCM.BUMS.7.3.146.

127. Zhivodernikov, I., Ratushnyy, A., and Buravkova, L.

(2021) Simulated microgravity remodels extracellular ma-

trix of osteocommitted mesenchymal stromal cells, Int.J.

Mol. Sci., 22, 5428, doi:10.3390/ijms22115428.

128. Carmeliet, G., Nys, G., and Bouillon, R. (1997) Micro-

gravity reduces the differentiation of human osteoblastic

MG-63 cells, J.Bone Min. Res., 12, 786-794, doi:10.1359/

jbmr.1997.12.5.786.

129. Zhang, C., Li, L., Jiang, Y., Wang, C., Geng, B., Wang,Y.,

Chen, J., Liu, F., Qiu, P., Zhai, G., Chen, P., Quan, R.,

and Wang, J. (2018) Space microgravity drives transdiffer-

entiation of human bone marrow-derived mesenchymal

stem cells from osteogenesis to adipogenesis, FASEB J.,

32, 4444-4458, doi:10.1096/fj.201700208RR.

130. Libertini, G. (2014) The programmed aging paradigm:

how we get old, Biochemistry (Moscow), 79, 1004-1016,

doi:10.1134/S0006297914100034.