Mesenchymal Stem Cell Senescence during Aging:From Mechanisms to Rejuvenation Strategies

Cationic microbubbles loading shFOXO4/SDF1 rejuvenate the aged heart and alleviate myocardial ischemia-reperfusion injury in the elderly

Aging is a significant risk factor for cardiovascular diseases, with ischemic heart disease (IHD) being the leading cause of cardiovascular-related mortality. Inhibition of FOXO4, which selectively eliminates senescent cells, offers protective effects on the aging myocardium. However, the removal of senescent cells may lead to a reduction in tissue cell density, thereby exacerbating tissue space formation and perivascular fibrosis. Therefore, selectively eliminating senescent cells in the aging heart, while simultaneously replenishing therapeutic bone marrow-derived mesenchymal stem cells (BMSCs), holds substantial therapeutic potential for synergistically combating cardiac aging. This study proposes a promising cardiac rejuvenation strategy using ultrasound-targeted microbubble destruction (UTMD)-mediated delivery of shFOXO4/SDF1 to eliminate cellular senescence and enhance BMSC homing. Transcriptomic analysis identified FOXO4 as a pivotal transcription factor in cardiac aging, with FOXO4 protein predominantly expressed in cardiac fibroblasts (CFs) and vascular endothelial cells in the myocardium of aged rats. Knockdown of FOXO4 in aging CFs reversed cellular senescence, and co-culturing these rejuvenated CFs with BMSCs further enhanced the reversal of senescence and bolstered resistance to oxidative stress. The use of UTMD for delivering shFOXO4/SDF1 in dual-gene therapy significantly enhanced BMSC homing, ameliorating cardiac aging, oxidative stress, and inflammation. In an ischemia-reperfusion injury (MIRI) model, pretreatment with shFOXO4/SDF1 effectively reduced cardiomyocyte apoptosis, promoted neovascularization, reduced infarct size, and improved cardiac function. The combined removal of senescent cells and enhanced BMSC homing synergistically ameliorated cardiac aging and improved post-MIRI prognosis in aging hearts. These findings provide novel insights and potential therapeutic strategies for addressing cardiac aging and age-related heart diseases.

Age-associated changes in the heart: implications for COVID-19 therapies

Cardiac aging involves progressive structural, functional, cellular, and molecular changes that impair heart function. This review explores key mechanisms, including oxidative stress, mitochondrial dysfunction, impaired autophagy, and chronic low-grade inflammation. Excess reactive oxygen species (ROS) damage heart muscle cells, contributing to fibrosis and cellular aging. Mitochondrial dysfunction reduces energy production and increases oxidative stress, accelerating cardiac decline. Impaired autophagy limits the removal of damaged proteins and organelles, while inflammation activates signaling molecules that drive tissue remodeling. Gender differences reveal estrogen's protective role in premenopausal women, with men showing greater susceptibility to heart muscle dysfunction and injury. After menopause, women lose this hormonal protection, increasing their risk of cardiovascular conditions. Ethnic disparities, particularly among underserved minority populations, emphasize how social factors such as access to care, environment, and chronic stress contribute to worsening cardiovascular outcomes. The coronavirus disease pandemic has introduced further challenges by increasing the incidence of heart damage through inflammation, blood clots, and long-term heart failure, especially in older adults with existing metabolic conditions like diabetes and high blood pressure. The virus's interaction with receptors on heart and blood vessel cells, along with a weakened immune response in older adults, intensifies cardiac aging. Emerging therapies include delivery of therapeutic extracellular vesicles, immune cell modulation, and treatments targeting mitochondria. In addition, lifestyle strategies such as regular physical activity, nutritional improvements, and stress reduction remain vital to maintaining cardiac health. Understanding how these biological and social factors intersect is critical to developing targeted strategies that promote healthy aging of the heart.

The interplay of cellular senescence and reprogramming shapes the biological landscape of aging and cancer revealing novel therapeutic avenues

Cellular senescence and cellular reprogramming represent two fundamentally intertwined processes that profoundly influence aging and cancer. This paper explores how the permanent cell-cycle arrest of senescent cells and the identity-resetting capacity of reprogramming jointly shape biological outcomes in later life and tumor development. We synthesize recent findings to show that senescent cells, while halting the proliferation of damaged cells, can paradoxically promote tissue dysfunction and malignancy via their secretory phenotype. Conversely, induced reprogramming of somatic cells-exemplified by Yamanaka factors-resets cellular age and epigenetic marks, offering a potential to rejuvenate aged cells. Key findings highlight shared mechanisms (e.g., DNA damage responses and epigenetic remodeling) and bidirectional crosstalk between these processes: senescence signals can facilitate neighboring cell plasticity, whereas reprogramming attempts can trigger intrinsic senescence programs as a barrier. In aging tissues, transient (partial) reprogramming has been shown to erase senescence markers and restore cell function without inducing tumorigenesis, underlining a novel strategy to combat age-related degeneration. In cancer, we discuss how therapy-induced senescence of tumor cells may induce stem-cell-like traits in some cells and drive relapse, revealing a delicate balance between tumor suppression and tumor promotion. Understanding the interplay between senescence and reprogramming is crucial for developing innovative therapies. By targeting the senescence-reprogramming axis-for instance, via senolytic drugs, SASP inhibitors, or safe reprogramming techniques-there is significant therapeutic potential to ameliorate aging-related diseases and improve cancer treatment. Our findings underscore that carefully modulating cellular senescence and rejuvenation processes could pave the way for novel regenerative and anti-cancer strategies.

Bone marrow mesenchymal stem cells senescence induced by LCCP through activation of cGAS-STING-mediated inflammation

The pollution issue of chlorinated paraffins has garnered widespread attention, with short-chain chlorinated paraffins (SCCPs) being comprehensively banned by the Stockholm Convention due to environmental contamination concerns. Currently, long-chain chlorinated paraffins (LCCPs) are widely used, necessitating an assessment of their toxicological impact. Bone marrow mesenchymal stem cells (MSCs) are a type of multipotent stem cell with self-renewal, immunoregulatory, and tissue repair capabilities, exhibiting important biological functions. In this study, MSCs were used as a model to evaluate the toxicological effects of LCCP. Initially, cell proliferation experiments were conducted to assess the impact of LCCP on MSC proliferation. The results indicated a significant reduction in cell proliferation capacity. Further work revealed that LCCP treatment induced cell senescence, as evidenced by Sa-β-gal staining and the evaluation of senescence markers, including p16, p21, and p53. Furthermore, LCCP treatment led to inflammation and oxidative stress, as analyzed by corresponding marker molecules, and ultimately resulted in cell death. Based on these findings, we investigated the molecular mechanisms underlying LCCP-induced MSC senescence. In summary, this paper is the first study to systematically investigate the toxicological effects of LCCPs on stem cells. The current study demonstrates that LCCP induces MSC senescence, highlighting its potential toxicity. This research lays the foundation for further elucidating the toxicology of LCCP. This finding suggests that the use of LCCPs should be strictly controlled under rigorous regulation.

Mangiferin protects mesenchymal stem cells against DNA damage and cellular aging via SIRT1 activation

The protective effects of mangiferin (MAG) against etoposide- and high glucose (HG)-induced DNA damage and aging were investigated in human bone marrow-mesenchymal stem cells (hBM-MSCs). Etoposide, a topoisomerase II inhibitor, was used to induce double-strand breaks (DSBs) in hBM-MSCs, resulting in increased genotoxicity, elevated levels of the DNA damage sensor ATM and CDKN1A, and decreased levels of the aging markers H3 and H4. MAG activated AMPK and SIRT1, thus protecting against DSB-induced damage. Following long-term exposure to HG, MAG significantly mitigated DNA damage and delayed cellular aging, as evidenced by the preservation of H3, H4, LMNB1, and SIRT1 mRNA levels and reduction in γ-H2AX foci and DSBs. Furthermore, MAG improved genome stability, as indicated by decreased LINE1 expression and increased levels of the heterochromatin marker TRIM28, thereby maintaining H3K9me3 levels. MAG and metformin treatment enhanced cell proliferation, reduced senescence-associated β-galactosidase staining, and lowered the levels of the senescence-associated secretory phenotype factors IL-1A, IL-1B, IL-6, IL-8, CCL2, and CCL20 and senescence marker CDKN1A, CDKN2A and p53. MAG may reduce DNA damage and delay aging in hBM-MSCs under HG conditions, highlighting their potential as therapeutic agents for aging-related diseases.

Comparative analysis of transcriptomic profiles of mesenchymal stem cells at the onset of senescence and after exposure to acute exogenous oxidative stress

Cellular senescence can be triggered by a wide range of stress-inducing factors, including environmental and internal damaging events, such as oxidative stress. Moreover, stressed and senescent cells exhibit modifications in their transcriptional expression profile, but little is known regarding the common genes and pathways regulating these processes. Here, we analyzed the effects of long-term culture as well as exogenous acute oxidative stress on the transcriptional program of Wharton's jelly mesenchymal stem cells (WJ-MSCs). We demonstrate that, exposure to H2O2 compromised genomic stability and mitochondrial function in early passage WJ-MSCs, potentially initiating senescence to prevent cellular transformation. On the other hand, prolonged in vitro expansion of WJ-MSCs activated processes linked to integrins and extracellular matrix organization, possibly indicating the unfavorable consequences that senescence has on tissue integrity. Additionally, cells entering senescence and oxidative stressed young WJ-MSCs over-activated transcription factors related to permanent proliferative arrest and suppressed anti-senescence factors. Common differentially expressed genes in the late passage and H2O2-treated WJ-MSCs were implicated in DNA damage response and cell cycle arrest, which are known to trigger a senescent phenotype. Notably, the TP53INP1 gene emerged as a significantly upregulated gene in both late passage and H2O2-treated young WJ-MSCs, marking it as a potent senescence indicator. Silencing TP53INP1 mitigated the senescent phenotype, a role that appeared to be facilitated by autophagy regulation. Taken together, our results shed light on how transcriptomic changes govern MSCs' senescence program and identify key molecular drivers that could prove crucial for WJ-MSCs-based clinical applications.

The role of GATA4 in mesenchymal stem cell senescence: A new frontier in regenerative medicine

The Mesenchymal Stem Cell (MSC) is a multipotent progenitor cell with known differentiation potential towards various cell lineage, making it an appealing candidate for regenerative medicine. One major contributing factor to age-related MSC dysfunction is cellular senescence, which is the hallmark of relatively irreversible growth arrest and changes in functional properties. GATA4, a zinc-finger transcription factor, emerges as a critical regulator in MSC biology. Originally identified as a key regulator of heart development and specification, GATA4 has since been connected to several aspects of cellular processes, including stem cell proliferation and differentiation. Accumulating evidence suggests that the involvement of GATA4-nuclear signalizing in the process of MSC senescence-related traits may contribute to age-induced alterations in MSC behavior. GATA4 emerged as the central player in MSC senescence, interacting with several signaling pathways. Studies have shown that GATA4 expression is reduced with age in MSCs, which is associated with increased expression levels of senescence markers and impaired regenerative potential. At the mechanistic level, GATA4 regulates the expression of genes involved in cell cycle regulation, DNA repair, and oxidative stress response, thereby influencing the senescence phenotype in MSCs. The findings underscore the critical function of GATA4 in MSC homeostasis and suggest a promising new target to restore stem cell function during aging and disease. A better understanding of the molecular mechanisms that underlie GATA4 mediated modulation of MSC senescence would provide an opportunity to develop new therapies to revitalize old MSCs to increase their regenerative function for therapeutic purposes in regenerative medicine.

Youthful Stem Cell Microenvironments: Rejuvenating Aged Bone Repair Through Mitochondrial Homeostasis Remodeling

Extracellular matrix (ECM) derived from mesenchymal stem cells regulates antioxidant properties and bone metabolism by providing a favorable extracellular microenvironment. However, its functional role and molecular mechanism in mitochondrial function regulation and aged bone regeneration remain insufficiently elucidated. This proteomic analysis has revealed a greater abundance of proteins supporting mitochondrial function in the young ECM (Y-ECM) secreted by young bone marrow-derived mesenchymal stem cells (BMMSCs) compared to the aged ECM (A-ECM). Further studies demonstrate that Y-ECM significantly rejuvenates mitochondrial energy metabolism in adult BMMSCs (A-BMMSCs) through the promotion of mitochondrial respiratory functions and amelioration of oxidative stress. A-BMMSCs cultured on Y-ECM exhibited enhanced multi-lineage differentiation potentials in vitro and ectopic bone formation in vivo. Mechanistically, silencing of silent information regulator type 3 (SIRT3) gene abolished the protective impact of Y-ECM on A-BMMSCs. Notably, a novel composite biomaterial combining hyaluronic acid methacrylate hydrogel microspheres with Y-ECM is developed, which yielded substantial improvements in the healing of bone defects in an aged rat model. Collectively, these findings underscore the pivotal role of Y-ECM in maintaining mitochondrial redox homeostasis and present a promising therapeutic strategy for the repair of aged bone defects.

Donor age and breed determine mesenchymal stromal cell characteristics

BACKGROUND

Mesenchymal stromal cells (MSCs) hold significant potential for various applications in regenerative medicine and tissue engineering. Initially considered as a single cell type with defined characteristics, MSCs are now known as a heterogeneous cell population with remarkable differences in their properties. No consensus exists on how donor age affects MSC characteristics, like proliferation. Additionally, differences in differentiation capacities and immunophenotype could arise when MSCs are isolated from different animals breeds, which is relevant for experimental and preclinical studies of MSC-based treatments.

METHODS

In this study, we isolated bovine adipose tissue-derived MSCs from three age categories, i.e. fetal, calf, and adult, and of two different breeds, i.e. Holstein Friesian (HF) and Belgian Blue (BB). MSC characterization included tri-lineage differentiation, proliferation and senescence assays, and immunophenotyping using multi-color flow cytometry.

RESULTS

Especially fetal and calf HF-MSCs showed a high proliferation capacity, where 4 and 6 out of 7 donors, respectively, could surpass 30 population doublings. Adipogenic differentiation potential was higher for fetal and adult HF-MSCs. Furthermore, breed, but not age, affected their osteogenic differentiation potential, with BB-MSCs performing better. Evaluation of cell surface marker expression revealed a breed effect, as calf HF-MSCs showed a higher percentage of Cluster of Differentiation (CD)34+ cells compared to calf BB-MSCs, which was correlated with both osteogenic differentiation and proliferation potential.

CONCLUSIONS

Our findings clearly show the impact of donor characteristics such as age and breed on MSC proliferation, immunophenotype, and differentiation potential, illustrating the importance of selecting the appropriate MSC donor for MSC-based treatments when allogeneic MSCs are considered.

Combination of rapamycin and adipose-derived mesenchymal stromal cells enhances therapeutic potential for osteoarthritis

BACKGROUND

The regenerative potential of mesenchymal stromal/stem cells (MSCs) has been extensively studied in clinical trials in the past decade. However, despite the promising regenerative properties documented in preclinical studies, for instance in osteoarthritis (OA), the therapeutic translation of these results in patients has not been fully conclusive. One factor contributing to this therapeutic barrier could be the presence of senescent cells in OA joints.

METHODS

This study evaluated a novel approach to OA treatment by combining adipose tissue-derived MSCs (AD-MSCs) with rapamycin, a clinically approved immunosuppressive drug with anti-senescence properties. First, rapamycin effects on senescence and fibrosis markers were investigated in freshly isolated OA chondrocytes by immunostaining. Next, the in vitro differentiation capacities of AD-MSCs, their regulatory immune functions on activated immune cells and their regenerative effects on OA chondrocyte signature were assessed in the presence of rapamycin.

RESULTS

In OA chondrocytes, rapamycin reduced the senescence marker p15INK4B and the fibrosis marker COL1A1 without affecting the expression of the master chondrogenic markers SOX9 and COL2. Rapamycin also enhanced AD-MSC differentiation into chondrocytes and reduced their differentiation into adipocytes. In addition, rapamycin improved AD-MSC immunoregulatory functions by promoting the expression of immunosuppressive factors, such as IDO1, PTGS2 and also CD274 (encoding PD-L1). Finally, RNA sequencing analysis showed that in the presence of rapamycin, AD-MSCs displayed improved chondroprotective regenerative effects on co-cultured OA chondrocytes.

CONCLUSIONS

Our findings suggest that the rapamycin and AD-MSC combination enhances the therapeutic efficacy of these cells in senescence-driven degenerative diseases such as OA, notably by improving their anti-fibrotic and anti-inflammatory properties.

LncRNA H19 improves mesenchymal characteristics of buffalo (Bubalus bubalis) bone marrow-derived mesenchymal stem cells under hypoxic conditions

As adult stem cells with various advantages, Bone marrow-derived mesenchymal stem cells (BMSCs) are valuable resources for veterinary treatment and animal reproduction. Previous studies have shown that hypoxia can induce epithelial-mesenchymal transition (EMT) and improve mesenchymal characteristics of BMSCs in vitro culture. However, the mechanism by which hypoxia improves the interstitial characteristics of buffalo BMSCs (bBMSCs) remains unclear. In this study, the effects of hypoxia on the mesenchymal characteristics of bBMSCs and the expression level of lncRNA H19 were examined, and then the effects of lncRNA H19 on maintaining the mesenchymal characteristics of bBMSCs under hypoxic culture conditions (5 % oxygen) as well as its mechanism also were explored, so as to further understand the molecular mechanism of mesenchymal characteristics maintenance of bBMSCs. The results showed that hypoxic culture conditions promoted EMT of bBMSCs, with lncRNA H19 expression up-regulated. When lncRNA H19 was knocked down in hypoxia, the expression level of Vimentin was down-regulated, the expression level of E-Cadherin was up-regulated, and EMT was inhibited. Meanwhile, the genes (p-PI3K and p-AKT1) involved in PI3K/AKT signaling pathway were inhibited by lncRNA H19 Knockdown. IGF-1 (10 ng/mL), an activator of PI3K/AKT signaling pathway, was added to rescued the inhibition of PI3K/AKT signaling pathway caused by lncRNA H19 Knockdown, with the effects of lncRNA H19 on EMT related genes also partially reversed. These findings not only provide theoretical guidance to elucidate the detailed regulation mechanism of hypoxia on mesenchymal nature maintenance of bBMSCs, but also provide positive support to further establish the stable in vitro culture system of bBMSCs.

Targeting cellular senescence in kidney diseases and aging: A focus on mesenchymal stem cells and their paracrine factors

Cellular senescence is a phenomenon distinguished by the halting of cellular division, typically triggered by DNA injury or numerous stress-inducing factors. Cellular senescence is implicated in various pathological and physiological processes and is a hallmark of aging. The presence of accumulated senescent cells, whether transiently (acute senescence) or persistently (chronic senescence) plays a dual role in various conditions such as natural kidney aging and different kidney disorders. Elevations in senescent cells and senescence-associated secretory phenotype (SASP) levels correlate with decreased kidney function, kidney ailments, and age-related conditions. Strategies involving senotherapeutic agents like senolytics, senomorphics, and senoinflammation have been devised to specifically target senescent cells. Mesenchymal stem cells (MSCs) and their secreted factors may also offer alternative approaches for anti-senescence interventions. The MSC-derived secretome compromises significant therapeutic benefits in kidney diseases by facilitating tissue repair via anti-inflammatory, anti-fibrosis, anti-apoptotic, and pro-angiogenesis effects, thereby improving kidney function and mitigating disease progression. Moreover, by promoting the clearance of senescent cells or modulating their secretory profiles, MSCs could potentially reverse some age-related declines in kidney function.This review article intends to shed light on the present discoveries concerning the role of cellular senescence in kidney aging and diseases. Furthermore, it outlines the role of senotherapeutics utilized to alleviate kidney damage and aging. It also highlights the possible impact of MSCs secretome on mitigating kidney injury and prolonging lifespan across various models of kidney diseases as a novel senotherapy.

Antisenescence Expansion of Mesenchymal Stem Cells Using Piezoelectric β-Poly(vinylidene fluoride) Film-Based Culture

Regenerative therapies based on mesenchymal stem cells (MSCs) show promise in treating a wide range of disorders. However, the replicative senescence of MSCs during in vitro expansion poses a challenge to obtaining a substantial quantity of high-quality MSCs. In this investigation, a piezoelectric β-poly(vinylidene fluoride) film-based culture plate (β-CP) was developed with an antisenescence effect on cultured human umbilical cord-derived MSCs. Compared to traditional tissue culture plates (TCPs) and α-poly(vinylidene fluoride) film-based culture plates, the senescence markers of p21, p53, interleukin-6 and insulin-like growth factor-binding protein-7, stemness markers of OCT4 and NANOG, and telomere length of MSCs cultured on β-CPs were significantly improved. Additionally, MSCs at passage 18 cultured on β-CPs showed significantly better multipotency and pro-angiogenic capacities in vitro, and higher wound healing abilities in a mouse model. Mechanistically, β-CPs rejuvenated senescent MSCs by improving mitochondrial functions and mitigating oxidative and glycoxidative stresses. Overall, this study presents β-CPs as a promising approach for efficient and straightforward antisenescence expansion of MSCs while preserving their stemness, thereby holding great potential for large-scale production of MSCs for clinical application in cell therapies.

The Matrix Protein Tropoelastin Prolongs Mesenchymal Stromal Cell Vitality and Delays Senescence During Replicative Aging

Cellular senescence leads to the functional decline of regenerative cells such as mesenchymal stromal/stem cells (MSCs), which gives rise to chronic conditions and contributes to poor cell therapy outcomes. Aging tissues are associated with extracellular matrix (ECM) dysregulation, including loss of elastin. However, the role of the ECM in modulating senescence is underexplored. In this work, it is shown that tropoelastin, the soluble elastin precursor, is not only a marker of young MSCs but also actively preserves cell fitness and delays senescence during replicative aging. MSCs briefly exposed to tropoelastin exhibit upregulation of proliferative genes and concurrent downregulation of senescence genes. The seno-protective benefits of tropoelastin persist during continuous, long-term MSC culture, and significantly extend the MSC replicative lifespan. Tropoelastin-expanded MSCs further maintain youth-associated phenotype and function compared to age-matched controls, including preserved clonogenic potential, minimal senescence-associated beta-galactosidase activity, maintained cell sizes, reduced expression of senescence markers, suppressed secretion of senescence-associated factors, and increased production of youth-associated proteins. This work points to the utility of exogenously-supplemented tropoelastin for manufacturing MSCs that robustly maintain regenerative potential with age. It further reveals the active role of classical structural ECM proteins in driving cellular age-associated fitness, potentially leading to future interventions for aging-related pathologies.

Artificial mitochondrial transplantation (AMT) reverses aging of mesenchymal stromal cells and improves their immunomodulatory properties in LPS-induced synoviocytes inflammation

Nowadays, regenerative medicine techniques are usually based on the application of mesenchymal stromal cells (MSCs) for the repair or restoration of injured damaged tissues. However, the effectiveness of autologous therapy is limited as therapeutic potential of MSCs declines due to patient's age, health condition and prolonged in vitro cultivation as a result of decreased growth rate. For that reason, there is an urgent need to develop strategies enabling the in vitro rejuvenation of MSCs prior transplantation in order to enhance their in vivo therapeutic efficiency. In presented study, we attempted to mimic the naturally occurring mitochondrial transfer (MT) between neighbouring cells and verify whether artificial MT (AMT) could reverse MSCs aging and improve their biological properties. For that reason, mitochondria were isolated from healthy donor equine adipose-derived stromal cells (ASCs) and transferred into metabolically impaired recipient ASCs derived from equine metabolic syndrome (EMS) affected horses, which were subsequently subjected to various analytical methods in order to verify the cellular and molecular outcomes of the applied AMT. Mitochondria recipient cells were characterized by decreased apoptosis, senescence and endoplasmic reticulum stress while insulin sensitivity was enhanced. Furthermore, we observed increased mitochondrial fragmentation and associated PARKIN protein accumulation, which indicates on the elimination of dysfunctional organelles via mitophagy. AMT further promoted physioxia and regulated autophagy fluxes. Additionally, rejuvenated ASCs displayed an improved anti-inflammatory activity toward LPS-stimulated synoviocytes. The presented findings highlight AMT as a promising alternative and effective method for MSCs rejuvenation, for potential application in autologous therapies in which MSCs properties are being strongly deteriorated due to patients' condition.

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

Senolytics ameliorate the failure of bone regeneration through the cell senescence-related inflammatory signalling pathway

Stress-induced premature senescent (SIPS) cells induced by various stresses deteriorate cell functions. Dasatinib and quercetin senolytics (DQ) can alleviate several diseases by eliminating senescent cells. α-tricalcium phosphate (α-TCP) is a widely used therapeutic approach for bone restoration but induces bone formation for a comparatively long time. Furthermore, bone infection exacerbates the detrimental prognosis of bone formation during material implant surgery due to oral cavity bacteria and unintentional contamination. It is essential to mitigate the inhibitory effects on bone formation during surgical procedures. Little is known that DQ improves bone formation in Lipopolysaccharide (LPS)-contaminated implants and its intrinsic mechanisms in the study of maxillofacial bone defects. This study aims to investigate whether the administration of DQ ameliorates the impairments on bone repair inflammation and contamination by eliminating SIPS cells. α-TCP and LPS-contaminated α-TCP were implanted into Sprague-Dawley rat calvaria bone defects. Simultaneously, bone formation in the bone defects was investigated with or without the oral administration of DQ. Micro-computed tomography and hematoxylin-eosin staining showed that senolytics significantly enhanced bone formation at the defect site. Histology and immunofluorescence staining revealed that the levels of p21- and p16-positive senescent cells, inflammation, macrophages, reactive oxygen species, and tartrate-resistant acid phosphatase-positive cells declined after administering DQ. DQ could partially alleviate the production of senescent markers and senescence-associated secretory phenotypes in vitro. This study indicates that LPS-contaminated α-TCP-based biomaterials can induce cellular senescence and hamper bone regeneration. Senolytics have significant therapeutic potential in reducing the adverse osteogenic effects of biomaterial-related infections and improving bone formation capacity.

Rosa roxburghii Fruit Extracts Upregulate Telomerase Activity and Ameliorate Cell Replicative Senescence

Anti-aging functional foods benefit the elderly. Telomeres are chromosomal ends that maintain genome stability extended by telomerase catalytic subunit TERT. Due to the end-replication problem, telomeres shorten after each cell cycle without telomerase in most human cells, and eventually the cell enters the senescence stage. Natural products can attenuate the aging process by increasing telomerase activity, such as TA-65. However, TA-65 is expensive. Other Chinese natural products may achieve comparable effects. Here, we found that Rosa roxburghii fruit extracts effectively increase TERT expression and telomerase activity in cultured human mesenchymal stem cells. Both R. roxburghii fruit extracts obtained by freeze-drying and spray-drying increased the activity of telomerase. R. roxburghii fruit extracts were able to reduce reactive oxygen species levels, enhance superoxide dismutase activity, and reduce DNA damage caused by oxidative stress or radiation. R. roxburghii fruit extracts promoted cell proliferation, improved senescent cell morphology, delayed replicative cellular senescence, attenuated cell cycle suppressors, and alleviated the senescence-associated secretory phenotype. Transcriptome and metabolic profiling revealed that R. roxburghii fruit extracts promote DNA replication and telomere maintenance pathways and decrease triglyceride levels. Overall, we provide a theoretical basis for the application of R. roxburghii fruit as an anti-aging product.

Pazopanib stimulates senescence of renal carcinoma cells through targeting nuclear factor E2-related factor 2 (Nrf2)

Renal cell carcinoma (RCC) is the most common kidney cancer with high mortality rate. Pazopanib has been approved for the treatment of RCC. However, the underlying mechanism is not clear. Here, we report a novel finding by showing that treatment with Pazopanib could promote cellular senescence of the human RCC cell line ACHN. Cells were stimulated with 5, 10, and 20 μM Pazopanib, respectively. Cellular senescence was measured using senescence-associated β-galactosidase (SA-β-Gal) staining. Western blot analysis and real-time polymerase chain reaction were used to measure the mRNA and protein expression of nuclear factor E2-related factor 2 (Nrf2), γH2AX, human telomerase reverse transcriptase (hTERT), telomeric repeat binding factor 2 (TERF2), p53 and plasminogen activator inhibitor (PAI). First, we found that exposure to Pazopanib reduced the cell viability of ACHN cells. Additionally, Pazopanib induced oxidative stress  by increasing the production of reactive oxygen species, reducing the levels of glutathione peroxidase, and promoting nuclear translocation of Nrf2. Interestingly, Pazopanib exposure resulted in DNA damage by increasing the expression of γH2AX. Importantly, Pazopanib increased cellular senescence and reduced telomerase activity. Pazopanib also reduced the gene expression of hTERT but increased the gene expression of TERF2. Correspondingly, we found that Pazopanib increased the expression of p53 and PAI at both the mRNA and protein levels. To elucidate the underlying mechanism, the expression of Nrf2 was knocked down by transduction with Ad- Nrf2 shRNA. Results indicate that silencing of Nrf2 in ACHN cells abolished the effects of Pazopanib in stimulating cellular senescence and reducing telomerase activity. Consistently, knockdown of Nrf2 restored the expression of p53 and PAI in ACHN cells. Based on these results, we explored a novel mechanism whereby which Pazopanib displays a cytotoxicity effect in RCC cells through promoting cellular senescence mediated by Nrf2.

Epitranscriptomic modifications in mesenchymal stem cell differentiation: advances, mechanistic insights, and beyond

RNA modifications, known as the "epitranscriptome", represent a key layer of regulation that influences a wide array of biological processes in mesenchymal stem cells (MSCs). These modifications, catalyzed by specific enzymes, often termed "writers", "readers", and "erasers", can dynamically alter the MSCs' transcriptomic landscape, thereby modulating cell differentiation, proliferation, and responses to environmental cues. These enzymes include members of the classes METTL, IGF2BP, WTAP, YTHD, FTO, NAT, and others. Many of these RNA-modifying agents are active during MSC lineage differentiation. This review provides a comprehensive overview of the current understanding of different RNA modifications in MSCs, their roles in regulating stem cell behavior, and their implications in MSC-based therapies. It delves into how RNA modifications impact MSC biology, the functional significance of individual modifications, and the complex interplay among these modifications. We further discuss how these intricate regulatory mechanisms contribute to the functional diversity of MSCs, and how they might be harnessed for therapeutic applications. The review also highlights current challenges and potential future directions in the study of RNA modifications in MSCs, emphasizing the need for innovative tools to precisely map these modifications and decipher their context-specific effects. Collectively, this work paves the way for a deeper understanding of the role of the epitranscriptome in MSC biology, potentially advancing therapeutic strategies in regenerative medicine and MSC-based therapies.

Cellular microenvironment: a key for tuning mesenchymal stem cell senescence

Mesenchymal stem cells (MSCs) possess the ability to self-renew and differentiate into multiple cell types, making them highly suitable for use as seed cells in tissue engineering. These can be derived from various sources and have been found to play crucial roles in several physiological processes, such as tissue repair, immune regulation, and intercellular communication. However, the limited capacity for cell proliferation and the secretion of senescence-associated secreted phenotypes (SASPs) pose challenges for the clinical application of MSCs. In this review, we provide a comprehensive summary of the senescence characteristics of MSCs and examine the different features of cellular microenvironments studied thus far. Additionally, we discuss the mechanisms by which cellular microenvironments regulate the senescence process of MSCs, offering insights into preserving their functionality and enhancing their effectiveness.

Comprehensive analysis of PRPF19 immune infiltrates, DNA methylation, senescence-associated secretory phenotype and ceRNA network in bladder cancer

Background

Pre-mRNA processing factor 19 (PRPF19) is an E3 ligase that plays a crucial role in repairing tumor-damaged cells and promoting cell survival. However, the predictive value and biological function of PRPF19 in bladder urothelial carcinoma (BLCA) require further investigation.

Methods

In this study, we utilized transcriptomic data and bladder cancer tissue microarrays to identify the high expression of PRPF19 in BLCA, suggesting its potential as a prognostic biomarker. To gain a better understanding of the role of PRPF19 in the immune microenvironment of BLCA, we performed single cell analysis and employed the LASSO method. Additionally, we examined the methylation profiles of PRPF19 using the SMART website. Our investigation confirmed the correlation between PRPF19 and BLCA cell senescence and stemness. Furthermore, we constructed a PRPF19-miR-125a-5p-LINC02693-MIR4435-2HG ceRNA network using the ENCORI and miRWALK databases.

Results

Our comprehensive analysis reveals that PRPF19 can serve as a prognostic marker for BLCA and is significantly associated with various immune-infiltrating cells in BLCA. Moreover, our findings suggest that PRPF19 influences cellular senescence through the regulation of stemness. Finally, we developed a ceRNA network that has the potential to predict the prognosis of BLCA patients.

Conclusion

We confirmed the prognostic value and multiple biological functions of PRPF19 in BLCA. Furthermore, the specific ceRNA network can be used as a potential therapeutic target for BLCA.

Non-pharmacological and drug treatment of autonomic dysfunction in multiple system atrophy: current status and future directions

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.