Search Results (177)

Replicative or stress-induced senescence disrupts the functioning of multipotent mesenchymal stromal cells (MSCs) required for tissue renewal and regeneration. Aged MSCs demonstrate reduced proliferation, impaired differentiation, and aberrant secretory activity, defined as “senescence-associated secretory phenotype” (SASP). SASP is characterized by elevated secretion of proinflammatory cytokines and specific extracellular vesicles (SASP-EVs), which affect the cellular microenvironment and promote tissue dysfunction. However, molecular mechanisms responsible for senescent phenotype propagation remain largely obscure. Earlier, we demonstrated suppression of adipogenic differentiation and insulin sensitivity of young MSCs by SASP-EVs. In this study, we elucidated potential mechanisms underlying SASP-EVs’ effects on MSCs. Bioinformatic analysis revealed that insulin signaling components are the most probable targets of SASP-EVs microRNA cargo. We demonstrated that SASP-EVs downregulated intracellular AGO1 levels, but surprisingly, PTEN levels were upregulated. Specifically, the increase in PTEN content was provided by its nuclear fraction. We have found that the intracellular PTEN distribution in young MSCs treated by SASP-EVs was similar to senescent MSCs. Furthermore, PTEN upregulation was accompanied by increased PTENP1 expression—a molecular sponge for PTEN-targeting microRNAs. Our findings indicate that nuclear PTEN could be a hallmark of senescent MSCs, and SASP-EVs propagate the senescent phenotype in young MSCs by promoting PTEN nuclear localization. Full article

Skin aging is driven by cellular senescence, oxidative stress, and diminished regenerative capacity. In this study, we investigated the effects of PhytoCellTec™ Argan, an argan callus extract (PC), on primary human fibroblasts and adult stem cells. PC treatment (0.1% and 0.5%) significantly enhanced fibroblast proliferation, reduced senescence-associated β-galactosidase activity, and decreased the expression of p16, p21, and phosphorylated NFκB. PC treatment lowered intracellular ROS levels, increased ATP production, and promoted autophagy via LC3B-II accumulation and p62 reduction. In skin-derived precursor cells (SKPs), as well as mesenchymal stem cells (MSCs), PC treatment improved spheroid formation and growth while preserving the expression of key stemness markers, including Sox2, Oct4, and Nestin. Furthermore, PC exhibited antioxidant capacity (TEAC assay) and inhibited elastase, supporting its anti-aging potential. These findings suggest that PC is safe at concentrations below 1% and may serve as an effective natural compound to restore cellular homeostasis, reduce senescence and inflammation, and support stem cell health during aging. Full article

Mesenchymal stem cell-derived exosomes (MSC-Exos) play a key role in tissue repair, immune regulation, and cancer biology. Due to limitations in MSC expansion and source variability, interest has shifted to induced pluripotent stem cell-derived MSCs (iMSCs) as a promising alternative. This study compares effects of exosomes derived from iMSCs (iMSC-Exos) and Wharton’s jelly MSCs (WJMSC-Exos) on MCF7 and A549 cancer cells. Both types of exosomes reduced MCF7 proliferation and induced a senescence-like state, rather than apoptosis, although the antiproliferative effect was transient in A549 cells. Notably, WJMSC-Exos promoted migration in both MCF7 and A549, whereas iMSC-Exos did not exhibit this effect. Overall, WJMSC-Exos had a more robust impact on cancer cell proliferation and migration. These findings highlight the diverse effects of exosomes on cancer and the development of a senescence-like state as an important response to Exos exposure. Moreover, these findings invite for more careful evaluation of the therapeutic role of iMSC-derived Exos. Full article

Enhancement of glycolysis has been reported in tumor cells, and it is believed that this enhancement is important for maintaining the stemness of tumor cells and contributes to malignant phenotypes. Here, we investigated the effects of Oxamate, which inhibits glycolysis by blocking the conversion of pyruvate to lactate, on radiosensitivity and its molecular mechanisms in T98G glioblastoma cells. Oxamate significantly enhanced radiosensitivity by delaying DNA repair, as indicated by the persistence of γ-H2AX foci up to four days post-irradiation. Mechanistically, Oxamate suppressed the expression and phosphorylation of key DNA repair factors. Furthermore, Oxamate induced apoptosis and promoted cellular senescence, as evidenced by the accumulation of SA-β-gal and the upregulation of pS15-p53 and p21. In addition, Oxamate downregulated EGFR expression, reduced the levels of stem cell markers, and modulated epithelial–mesenchymal transition (EMT) markers, suggesting a potential suppression of EMT-related pathways. Together, these results demonstrate that Oxamate enhances radiosensitivity in glioblastoma cells through multiple mechanisms, including the inhibition of DNA repair, induction of apoptosis and senescence, and suppression of cancer stem cell properties and EMT. Our findings provide new insights into the potential use of Oxamate as a radiosensitizer and warrant further investigation of its clinical application in glioblastoma therapy. Full article

Diabetic kidney disease (DKD), a well-characterized microvascular complication associated with the progression of diabetes mellitus, has been identified as the leading etiological factor contributing to the global burden of end-stage kidney disease (ESKD). Historically, DKD research has predominantly centered on glomerular mechanisms; however, recent studies have increasingly emphasized the critical role of tubular dysfunction. Extensive evidence has elucidated the key pathological drivers of tubular injury in DKD, encompassing metabolic dysregulation, pro-inflammatory signaling pathways, diverse cellular stress responses, and epithelial–mesenchymal transition (EMT). Furthermore, emerging mechanistic studies reveal that autophagic flux impairment and epigenetic memory formation collaboratively drive cellular senescence in DKD. Regarding the treatment of DKD, various hypoglycemic drugs, as well as hypotensive drugs, and microcirculatory improvers have garnered significant attention. Recently, stem cell-based interventions and precision gene editing techniques have unveiled novel therapeutic paradigms for DKD, fundamentally expanding the treatment arsenal beyond conventional pharmacotherapy. This review synthesizes updated insights into the pathogenesis of tubular injury in DKD and highlights promising therapeutic strategies for managing this condition. Full article

Acute radiation syndrome (ARS) results from high-dose ionizing radiation (IR) exposure, with bone marrow (BM) being highly susceptible due to its proliferative activity. BM injury causes pancytopenia, leading to infections, anemia, and bleeding. Mesenchymal stem cells (MSCs) hold promise for ARS treatment because of their immunomodulatory, anti-inflammatory, and regenerative properties. However, challenges such as replicative senescence, poor survival, and engraftment in irradiated microenvironments limit their efficacy. This study evaluated rapamycin-preconditioned placenta-derived MSCs (rPD-MSCs) in a mouse ARS model. Rapamycin was selected for preconditioning due to its ability to induce autophagy and modulate cytokine secretion. We assessed rapamycin-dependent modulation of autophagy-related genes and proteins, as well as hematopoietic cytokines secretion in PD-MSCs, and evaluated morphological changes in blood and BM at 7 and 21 days post-irradiation in ICR/CD1 mice. Preconditioning with rapamycin alters the secretion of granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), and Fms-related tyrosine kinase 3 ligand (Flt3LG) in PD-MSCs without affecting cell viability. rPD-MSCs better enhance hematopoietic recovery, restore bone marrow cellularity, and increase peripheral blood cell counts by elevating the secretion of hematopoietic cytokines compared to non-preconditioned cells. These results highlight rapamycin preconditioning as a promising strategy to enhance MSCs therapeutic potential for ARS, supporting further preclinical and clinical exploration. Full article

Bone tissue engineering (BTE) emerged as a practical approach to tackle prosthetic industry limitations. We merge aspects from developmental biology, engineering and medicine with the aim to produce fully functional bone tissue. Mesenchymal stem cells have the capability of self-renewal and specific lineage differentiation. Herein lies their potential for BTE. Among MSCs, human dental pulp stem cells have a higher proliferation rate, shorter doubling times, lower cellular senescence, and enhanced osteogenesis than hBM-SCs under specific conditions. In addition, these cells are readily accessible and can be extracted through a subtle extraction procedure. Thus, they garner fewer moral concerns than most MSCs available and embody a promising cell source for BTE therapies able to replace hBM-MSCs. Interestingly, their study has been limited. Conversely, there is a need for their further study to harness their true value in BTE, with special emphasis in the design of bioprocesses able to produce viable, homogenous bone constructs in a clinical scale. Here, we study the osteogenic differentiation of hDPSCs encapsulated in alginate hydrogels under suspended culture in a novel perfusion bioreactor. The system is compared with traditional 3D static and fed-batch culture methodologies. The novel system performed better, producing higher alkaline phosphatase activity, and more homogeneous, dense and functional bone constructs. Additionally, cell constructs produced by the in-house-designed system were richer in mature osteoblast-like and mineralizing osteocyte-like cells. In conclusion, this study reports the development of a novel bioprocess able to produce hDPSC-based bone-like constructs, providing new insights into hDPSCs’ therapeutic potential and a system able to be transferred from the laboratory bench into medical facilities. Full article

Background and Objectives: Aging-related bone loss still lacks interventions. As bone marrow-derived mesenchymal stem cells (BMSCs) undergo aging, R-loop-induced DNA replication stress impairs the osteogenic ability of BMSCs. High-mobility group A-2 (Hmga2) acts as a DNA-binding protein, and the understanding of its underlying mechanisms is crucial for developing effective preventive and therapeutic strategies. Materials and Methods: Aging mice were used as the experimental model, and mouse BMSCs were isolated from their femurs. Hmga2 was achieved through specific gene delivery methods. R-loop formation was detected using dot blotting, chromatin immunoprecipitation (ChIP), and DNA–RNA immunoprecipitation (DRIP) assays. Osteogenic differentiation was evaluated. Results: R-loops were highly accumulated in aging BMSCs. Notably, the key regulator Hmga2 reversed the accumulation of R-loops in aging BMSCs. Hmga2 overexpression significantly decreased the senescence and improved the osteogenic differentiation of aging mBMSCs. Mechanistically, R-loop-forming sequence (RLFS) regions were confirmed in key osteogenesis-related genes, including runt-related transcription factor 2 (Runx2). Hmga2 bound to the RLFS region of Runx2 and promoted its expression by reducing the R-loop level. More, Hmga2 treatment delivered via the AAV system effectively decreased bone loss in aging mice and increased the serum bone turnover biomarkers and collagen remodeling. Conclusions: Our study demonstrates that Hmga2 acts as an activator of aging BMSCs, significantly promoting their osteogenic ability by eliminating the aging-induced DNA replication stress caused by R-loops. Our findings provide new insights into the mechanisms of aging-related bone loss, suggesting that Hmga2 may be a new strategy for alleviating the bone loss phenotype in aging individuals. Full article

Induced pluripotent stem cells (iPSCs) are rapidly emerging as a transformative resource in regenerative medicine. In a previous study, our laboratory achieved a significant milestone by successfully reprograming jaw periosteal cells (JPCs) into iPSCs, which were then differentiated into iPSC-derived mesenchymal stem cells (iMSCs). Using an optimized protocol, we generated iMSCs with a remarkable osteogenic potential while exhibiting lower expression levels of the senescence markers p16 and p21 compared to the original JPCs. This study aimed to explore the epigenetic landscape by comparing the DNA methylation and transcription profiles of iMSCs with their JPC precursors, seeking to uncover key differences. Additionally, this analysis provided an opportunity for us to investigate the potential rejuvenation effects associated with cellular reprogramming. To assess the safety of the generated cells, we evaluated their ability to form teratomas through subcutaneous injection into immunodeficient mice. Our findings revealed that, while the methylation profile of iMSCs closely mirrored that of JPCs, distinct iMSC-specific methylation patterns were evident. Strikingly, the application of DNA methylation (DNAm) clocks for biological age estimation showed a dramatic reduction in DNAm age to approximately zero in iPSCs—a rejuvenation effect that persisted in the derived iMSCs. This profound reset in biological age, together with our transcriptome data, indicate that iMSCs could possess an enhanced regenerative potential compared to adult MSCs. Future in vivo studies should validate this hypothesis. Full article

Spinal cord injury (SCI) remains a major clinical challenge, with limited therapeutic options for restoring lost neurological function. While efforts to mitigate secondary damage have improved early-phase management, achieving sustained neurorepair and functional recovery remains elusive. Advances in stem cell engineering and regenerative medicine have opened new avenues for targeted interventions, particularly through the transplantation of neural stem/progenitor cells (NSPCs), induced pluripotent stem cells (iPSCs), and mesenchymal stem cells (MSCs). However, patient-specific factors such as cellular senescence, genetic and epigenetic variability, injury microenvironment, and comorbidities influence the efficacy of stem cell therapies by affecting graft survival and differentiation. Overcoming these challenges necessitates cutting-edge technologies, including single-cell transcriptomics, CRISPR-mediated hypoimmunogenic engineering, and biomaterial-based delivery platforms, which enable personalized and precision-driven SCI repair. Leveraging these advancements may help stem cell therapies overcome translational barriers and establish clinically viable regenerative solutions. This review explores the intersection of patient-specific variability, bioengineering innovations, and transcriptomic-guided precision medicine to define the next frontier in SCI therapy. Full article

Mesenchymal stem cells (MSCs) are multipotent progenitors capable of self-renewal and differentiation into various cell lineages, making them essential for tissue repair and regenerative medicine. However, their regenerative potential is constrained by replicative senescence, an irreversible growth arrest that occurs after a finite number of cell divisions. In this study, we serially passaged human bone marrow-derived MSCs (bMSCs) and compared young, pre-senescent, and senescent cells. The onset of senescence was accompanied by progressive alterations in mitochondrial dynamics, leading to a decline in mitochondrial membrane potential, and increased reactive oxygen species (ROS) production, alongside a diminished cellular antioxidant capacity. These mitochondrial defects play a role in metabolic reprogramming in senescent bMSCs. Our findings underscore the intricate interplay between ROS, mitochondrial dysfunction, and replicative senescence, offering valuable insights to guide the development of therapeutic strategies for preserving MSC functionality in aging and MSC-based therapies. Full article

Background/Objectives: Mesenchymal stem cells (MSCs) are regarded as a promising cell type with significant therapeutic benefits owing to their ease of isolation, maintenance, and characterisation. However, repeated passages during cultural maintenance frequently result in cellular senescence, limiting their utility in regenerative medicine. Methods: We investigated the differentiation capability between early- (P3) and late-passage MSCs (>P15) and tested the potential of Wnt agonist 99021 to reverse MSCs using standard cell culture protocols that define minimal criteria for MSCs, primarily tri-lineage differentiation assays, biochemical staining gene expression analysis, and senescence assays. Results: We initially noticed distinct signs of morphological aging between early- (P3) and late-passage MSCs (>P15) and further examined the differentiation capability between early- (P3) and late-passage MSCs (>P15). We found a diminished differentiation potential in late-passage MSCs. Our senescence assay also revealed >P15 cells were able to absorb the senescence dye, indicating that >P15 MSCs underwent senescence. We further demonstrated that CHIR 99021 reversed the differentiation inhibitory potential-mediated impasse of late-passage MSCs by employing tri-lineage specific differentiation assays, biochemical labelling, and gene expression analysis. Senescence assays after CHIR 99021 treatment also revealed no senescence dye uptake at all. Conclusions: Our findings demonstrated that CHIR 99021 Wnt agonist maybe aids in the reversal of MSC aging-related differentiation inhibition glitches and offers a proven demonstrated protocol for rejuvenating late-passage MSCs. Thus, CHIR99021 treatment inherently reverts the tri-lineage potency in late-passage MSCs, and this method could be further employed to ensure a plentiful MSC source for clinical purposes. Full article

Regenerative medicine is gaining interest in the medical field due to the limitations of conventional treatments, which often fail to address the underlying cause of disease. In recent years, stem cell-based therapies have evolved as a promising alternative approach to treat those diseases that cannot be cured using conventional medicine. Adult stem cells, particularly the mesenchymal stem cells (MSCs), have attracted a lot of attention due to their ability to regenerate and repair human tissues and organs. MSCs isolated from adult tissues are well characterized and are currently the most common type of cells for use in regenerative medicine. However, their low number in adult donor tissues, donor-age and cell-source related heterogeneity, limited proliferative and differentiation potential, and early senescence in in vitro cultures, negatively affect MSC regenerative potential. These factors restrict MSC use for research as well as for clinical applications. To overcome these problems, MSCs with superior regenerative potential are required. Induced MSCs (iMSCs) are obtained from induced pluripotent stem cells (iPSCs). These cells are patient-specific, readily available, and have relatively superior regenerative potential and, therefore, can overcome the problems associated with the use of primary MSCs. In this review, the authors aim to discuss the characteristics, regenerative potential, and limitations of MSCs for regenerative medicine applications. The main methods to generate iMSCs from iPSCs have been discussed in detail. In addition, the proposed criteria for their molecular characterization, applications of iMSCs for disease modeling and drug discovery, as well as potential use in regenerative medicine have been explored in detail. Full article

(1) Background: this study investigates the short-term effects of coenzyme Q10 (CoQ10) on mitochondrial respiration, fatty acid metabolism, oxidative stress gene expression, and sirtuin activity in young (passage 5, P5) and aged (passage 16, P16) mesenchymal stem cells (MSCs). (2) Methods: Mitochondrial respiration was assessed by measuring oxygen consumption after 24 h of treatment. Gas chromatography–mass spectrometry (GC-MS) analysis assessed cellular fatty acid methyl ester profiles. Quantitative polymerase chain reaction (qPCR) demonstrated the passage-dependent expression of oxidative stress-related genes and sirtuins in response to CoQ10 treatment. (3) Results: CoQ10 enhanced basal respiration and spare respiratory capacity (SRC), particularly in older senescent cells. CoQ10 improved basal respiration and ATP-linked oxygen consumption in young MSCs and partially restored these functions in aged MSCs. Moreover, CoQ10 increased saturated fatty acids, particularly in young cells, and decreased monounsaturated fatty acids in aged cells. qPCR analysis revealed passage-dependent modifications in oxidative stress-related genes and sirtuin expression; CoQ10 exposure significantly influenced SIRT1 and SIRT3 activity, leading to an increase in PPARγ and CAT expression. (4) Conclusions: these results highlight CoQ10’s potential to alleviate mitochondrial dysfunction and metabolic shifts associated with cellular aging, underscoring its therapeutic value for age-related mitochondrial and metabolic disorders. Full article

Supernumerary tooth-derived pulp stem cells (SNTSCs) hold promise for endodontic regeneration, yet little is known about the similarities and diversities of SNTSCs relative to other dental-derived mesenchymal stem cells. Herein, we compare the biological characteristics of SNTSCs with dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED). Cell proliferation, migration, and odontogenic differentiation potential, as well as viability and aging-related phenotype after long-term storage, were evaluated. Additionally, gene expressions during induced odontogenic differentiation were profiled by transcriptome sequencing. Our findings indicated that the SNTSCs outperformed the DPSCs but were inferior to the SHED in cell proliferation. The SNTSCs exhibited comparable migratory capacity to the SHED and surpassed the DPSCs. Of particular interest, the odontogenic differentiation potential followed the pattern of SHED > SNTSCs > DPSCs. After two years of storage, the SNTSCs showed weakness in resistance to apoptosis induced by lipopolysaccharide, whereas difference between the SNTSCs and SHED in stemness and senescence was not obvious. Transcriptome analysis revealed that upregulated genes in the SNTSCs were particularly enriched in inflammatory signaling pathways compared to both the DPSCs and SHED. Collectively, SNTSCs share many satisfactory features in proliferation and differentiation with SHED, which may serve as a promising alternative cell source for endodontic regeneration. Full article