Search Results (141)

Adult hematopoietic stem cells (HSCs) and bone marrow (BM) mesenchymal stem/stromal cells (MSCs) are essential for lifelong hematopoiesis, skeletal homeostasis, immune competence, and tissue regeneration. The use of electronic cigarettes (E-cigs) among women of reproductive age continues to rise, raising concerns about potential adverse developmental effects; however, the long-term consequences of maternal E-cig vaping on offspring BM stem cell function and hematopoietic homeostasis remain incompletely understood. Here, using a rat model of maternal E-cig exposure (containing nicotine) during gestation, combined with longitudinal in vivo analyses and complementary ex vivo studies of human cells, we show that prenatal E-cig exposure is associated with persistent alterations in offspring BM stem cell function and lineage commitment. Gestational E-cig exposure was associated with expansion of the CD11b/c⁺ myeloid-enriched compartment, increased CD90⁺ stromal cells, and impaired osteogenic differentiation in rat offspring. Complementary experiments using primary human cells showed that nicotine exposure was associated with reduced T-cell proliferation and impaired cytotoxic activity in a proof-of-principle co-culture assay. Mechanistically, transcriptomic profiling followed by Gene Ontology and pathway enrichment analyses identified alterations in molecular programs associated with KLF4–Notch1 signaling, mitochondrial biogenesis, inflammation, and stem cell regulation in the BM of E-cig-exposed rat offspring. Changes in CCL11, FTO, and RUNX2 were additionally associated with an inflammatory and aging-related molecular phenotype that persisted from early life into adulthood, although these findings do not establish a causal CCL11–FTO–RUNX2 signaling axis or direct cellular senescence. Collectively, our study provides a phenotypic and mechanistic framework for understanding how maternal E-cig exposure may influence long-term offspring hematopoietic, skeletal, and immune health while highlighting the need for further studies to establish causal molecular mechanisms and determine their relevance to maternal E-cig use in humans. Full article

Human liver stem cells (HLSCs) are a mesenchymal stromal cell (MSC)-like population isolated from adult liver biopsies. HLSCs share key characteristics with MSCs, including phenotype and differentiation capabilities. Previous studies have demonstrated that HLSCs promote regeneration in different experimental models of acute and chronic tissue injury and that HLSC-derived extracellular vesicles (HLSC-EVs) recapitulate the therapeutic effects of the cells of origin. This study aimed to determine whether HLSC-EVs, obtained and characterized under good manufacturing practice (GMP) conditions, can influence the progression of liver fibrosis in vivo. The EV production process was carried out under GMP conditions to generate batches of HLSC-EVs by tangential flow filtration. To assess their therapeutic potential, an in vivo model of hepatic fibrosis was established through administration of thioacetamide (TAA). In TAA-treated mice, EV administrations attenuated fibrosis progression. Molecular analyses showed a significant reduction in the expression levels of key pro-fibrotic genes. At the functional level, EV administration resulted in a significant reduction in plasma alanine aminotransferase levels and an increase in albumin levels, indicating improved liver function. These data indicate that HLSC-EVs, produced under GMP conditions, display antifibrotic effects in a chronic liver disease model, leading to improved liver function and histology. Full article

Background/Objectives: Sebaceous carcinomas (SebCAs) of the ocular adnexa, primarily arising from the Meibomian glands, are locally aggressive eyelid tumors with metastatic potential. Upregulation of the oncogene MYC has been demonstrated in SebCA, suggesting a role in tumor initiation and progression. In other epithelial tumors, the insulin and insulin-like growth factor (IGF) signaling (IIS) pathway has been implicated in stem cell renewal via MYC activation and stabilization. This study aimed to evaluate the effects of pharmacologic and genetic modulation of the IIS pathway on MYC expression in human Meibomian gland epithelial cells (HMGECs) and meibocytes of adult C57B6 mice. Methods: HMGECs were incubated with either IIS activators or inhibitors or were subject to transfection with either an IGF1R plasmid or siRNA before assessments of viability, proliferation, immunostaining, and MYC quantification were performed. Murine eyelids were treated topically with small-molecule IIS modulators prior to tissue harvest for histology, immunolabeling, and qPCR. Results: HMGECs treated with IIS activators demonstrated downregulated IGF1R and upregulated MYC expression, increased viability and proliferation, and reduced autophagy, while treatment with inhibitors yielded the inverse effects. Incubation with the selective insulin receptor agonist, demethylasterriquinone B1, yielded the most phenotypic variability. IGF1R-overexpressing HMGECs exhibited relative upregulation of both Akt and MYC. Murine eyelids treated with an IIS agonist demonstrated a more mesenchymal phenotype and significantly induced MYC expression. Conclusions: Collectively, these results suggest that the IIS pathway may represent a novel approach for regulating high MYC expression in SebCA. Full article

Peripheral inflammation is increasingly recognized as a critical driver of sustained neuroinflammation and cognitive dysfunction in neurodegenerative and inflammation-associated disorders. Systemic inflammatory mediators can compromise blood–brain barrier integrity, activate glial cells, and initiate maladaptive neuroimmune cascades that disrupt hippocampal–prefrontal circuits underlying learning and memory. Here, we investigated whether early systemic administration of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) mitigates inflammation-driven cognitive deficits in a chronic lipopolysaccharide (LPS) mouse model. Adult mice received daily LPS injections for seven days to induce persistent systemic and central inflammation, which was confirmed by serum and hippocampal cytokine analyses in a separate cohort at the time of MSC administration, followed by intravenous MSC treatment immediately after cessation of the inflammatory insult. Behavioral testing revealed significant impairments in spatial working memory, recognition memory, and associative learning. These deficits were accompanied by pronounced microglial activation, immune cell accumulation, astrocytosis, and a shift toward a pro-inflammatory cytokine milieu with suppression of IL-10 in the hippocampal CA1 region and medial prefrontal cortex. Early MSC treatment attenuated glial reactivity, reduced pro-inflammatory cytokines, restored IL-10 expression, and partially rescued cognitive performance. Collectively, these findings identify a post-inflammatory therapeutic window in which early MSC-based immunomodulation can rebalance neuroimmune signaling and limit inflammation-induced hippocampal–prefrontal circuit dysfunction, highlighting a clinically relevant strategy for targeting cognitive impairment associated with chronic systemic inflammation. Full article

Mesenchymal stem cells (MSCs) are multipotent adult cells that are highly valued for their immunomodulatory potential and intrinsic ability to home to inflamed sites. This study specifically utilized human dental pulp stem cells (hDPSCs), a unique MSC subtype derived from the neural crest, due to their reported superior anti-inflammatory capacity. To rigorously test their efficacy, we employed the AIRmax murine model, which exhibits a genetically determined high-inflammatory phenotype. Acute inflammation was induced by subcutaneous injection of the polyacrylamide suspension Biogel P-100. Two hours post-induction, AIRmax mice were treated intravenously with hDPSCs. Our results demonstrate that hDPSC treatment produced significant anti-inflammatory effects evident at 24 h. The treated group showed a pronounced reduction in leukocyte migration and decreased protein extravasation in the inflammatory exudate. Crucially, hDPSCs also modulated molecular mediators, significantly decreasing the pro-inflammatory cytokine TNF-alpha and reactive oxygen species (ROS) production. Furthermore, while hDPSCs efficiently and rapidly homed to the inflammation site within 2 h, their maximal therapeutic benefits only manifested after 24 h. This suggests that their robust capacity to modulate acute inflammatory responses relies not only on rapid migration but also on a paracrine “hit-and-run” mechanism that suppresses cellular infiltration and oxidative stress over time. This study reinforces the potential of hDPSCs as a powerful, multi-target therapeutic agent for inflammatory conditions, supporting further investigation into their precise mechanisms and clinical application. Full article

The process of aging is fundamentally driven by genomic instability and the accumulation of DNA damage, which progressively impair cellular and tissue function. In order to counteract these challenges, cells rely on the DNA damage response (DDR), a multilayered signaling and repair network that preserves genomic integrity and sustains homeostasis. Within this framework, nucleases and helicases have pivotal and complementary roles by remodeling aberrant DNA structures, generating accessible repair intermediates, and determining whether a cell achieves faithful repair, undergoes apoptosis, or enters senescence. Defects in these enzymes are exemplified in human progeroid syndromes, where inherited mutations lead to premature aging phenotypes. This phenomenon is also replicated in genetically engineered mouse models that exhibit tissue degeneration, stem cell exhaustion, and metabolic dysfunction. Beyond their canonical repair functions, helicases and nucleases also interface with the epigenome, as DNA damage-induced chromatin remodeling alters enzyme accessibility, disrupts transcriptional regulation, and drives progressive epigenetic drift and chronic inflammatory signaling. Moreover, their dysfunction accelerates the exhaustion of adult stem cell populations, such as hematopoietic, neural, and mesenchymal stem cells. As a result, tissue regeneration is undermined, establishing a self-perpetuating cycle of senescence, impaired repair, and organismal aging. Current research is focused on developing therapeutic strategies that target the DDR–aging axis on several fronts: by directly modulating repair pathways, by regulating the downstream consequences of senescence, or by preventing DNA damage from accumulating upstream. Taken together, evidence from human disease, animal models, molecular studies, and pharmacological interventions demonstrates that nucleases and helicases are not only essential for genome maintenance but also decisive in shaping aging trajectories. This provides valuable knowledge into how molecular repair pathways influence organismal longevity and age-related diseases. Full article

Background: Ewing sarcoma (EWS) is a rare cancer of the bone and soft tissue, most prevalent in children and young adults. The treatment of EWS has progressed relatively little in over 30 years. Survival rates for patients, particularly those with metastatic and/or relapsed disease remain poor, highlighting the urgent need for innovative treatment options. Methods: Here, we have explored the therapeutic potential of the oncolytic Maraba virus strain MG1 using various in vitro models of EWS, including established cell lines, doxorubicin-resistant derivatives, spheroid cultures and primary patient-derived Ewing sarcoma cell cultures. We examined the direct oncolytic activity of MG1 and its ability to stimulate the immune-mediated killing of EWS by human healthy donor peripheral blood mononuclear cells. Results: We show that MG1 undergoes productive replication and exerts direct oncolysis of established EWS cell lines, doxorubicin-resistant EWS cell lines and patient-derived Ewing sarcoma cell cultures more recently established from tumours. In contrast, primary mesenchymal stem cells (the likely cell of origin of EWS) were resistant to MG1, with IFN-I being a major determinant of tumour cell selectivity. MG1-treated PBMC produced IFN-I and killed EWS cells in vitro, in a natural killer (NK) cell-dependent manner. Conclusions: The ability of MG1 to kill EWS cells directly and stimulate NK cell cytotoxicity against this tumour suggests that MG1 may provide therapeutic benefit for EWS patients where the efficacy of conventional treatments is currently limited. Full article

Stem cell (SC)-based therapy exploits the ability of cells to migrate to damaged tissues and repair them. In this context, there is a strong interest in the use of mesenchymal stem cells (MSCs), multipotent SCs that are easy to obtain and are able to differentiate into various cell lineages. However, MSCs undergo cellular senescence during in vitro expansion, and may also become senescent in vivo, influenced by multiple molecular, cellular, and environmental interactions. Therefore, the development of in vitro cell models is crucial to study the mechanisms underlying senescence in MSCs. This study aimed to investigate the effects of tert-butyl hydroperoxide (t-BHP) as a senescence inducer in human dermal MSCs (hDMSCs), a promising tool for tissue repair. t-BHP induced a pro-senescent effect on hDMSCs greater than hydrogen peroxide (H₂O₂), as evidenced by ROS production, DNA damage, cell cycle arrest, inhibition of cell proliferation, changes in cellular and nuclear morphology, and cytoskeletal reorganization, as well as the increase in other senescence markers, including senescence-associated β-galactosidase (SA-β-Gal)-positive cells, and senescence-associated secretory phenotype (SASP). These results indicate that t-BHP could be a promising compound for inducing stress-induced premature senescence (SIPS) in hDMSCs, providing a valuable tool to investigate this process and evaluate the efficacy of senolytic compounds. Full article

Xylosyltransferase-I (XT-I) plays a crucial role in skeletal development and cartilage integrity. An XT-I deficiency is linked to severe bone disorders, such as Desbuquois dysplasia type 2. While animal models have provided insights into XT-I’s role during skeletal development, its specific effects on adult bone homeostasis, particularly in human mesenchymal stem cell (hMSC) differentiation, remain unclear. This study investigates how XT-I deficiency impacts the differentiation of hMSCs into chondrocytes, osteoblasts, and adipocytes—key processes in bone formation and repair. The aim of this study was to elucidate for the first time the molecular mechanisms by which XT-I deficiency leads to impaired bone homeostasis. Using CRISPR-Cas9-mediated gene editing, we generated XYLT1 knockdown (KD) hMSCs to assess their differentiation potential. Our findings revealed significant disruption in the chondrogenic differentiation in KD hMSCs, characterized by the altered expression of regulatory factors and extracellular matrix components, suggesting premature chondrocyte hypertrophy. Despite the presence of perilipin-coated lipid droplets in the adipogenic pathway, the overall leptin mRNA and protein expression was reduced in KD hMSCs, indicating a compromised lipid metabolism. Conversely, osteogenic differentiation was largely unaffected, with KD and wild-type hMSCs exhibiting comparable mineralization processes, indicating that critical aspects of osteogenesis were preserved despite the XYLT1 deficiency. In summary, these results underscore XT-I’s pivotal role in regulating differentiation pathways within the bone marrow niche, influencing cellular functions critical for skeletal health. A deeper insight into bone biology may pave the way for the development of innovative therapeutic approaches to improve bone health and treat skeletal disorders. 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

The adult human heart has a limited ability to regenerate after injury, leading to the formation of fibrotic scars and a subsequent loss of function. In fish, mice, and humans, cardiac remodeling after myocardial injury involves the activation of epicardial and endocardial cells, pericytes, stem cells, and fibroblasts. The heart’s extracellular matrix (ECM) plays a significant role in the regeneration and recovery process. The epicardium, endocardium, and pericytes reactivate the embryonic program in response to ECM stimulation, which leads to epithelial–mesenchymal transition, cell migration, and differentiation. This review analyzes the role of ECM in guiding the differentiation or dedifferentiation and proliferation of heart components by comparing significant findings in a zebrafish model with those of mammals. Full article

With alopecia affecting millions globally, recent advancements in the understanding of hair follicle biology have driven the development of novel therapies focused on hair regrowth. This review discusses two emerging therapeutic strategies: hair follicle neogenesis and the modulation of the Wnt/B-catenin signaling pathway. Hair follicle neogenesis, a frontier once considered impossible to achieve in adult humans, has recently gained traction due to advancements in stem cell biology and further understanding of the epithelial–mesenchymal interactions that are critical to hair follicle development. Such an approach shows significant potential for addressing conditions leading to hair loss, such as androgenetic and scarring alopecias. The Wnt/B-catenin signaling pathway, a critical intracellular pathway responsible for hair follicle cycles, has gained traction as a target for therapeutic interventions. Studies show that stimulating this pathway leads to hair follicle growth, while its inhibition prompts hair follicle regression. Investigations demonstrate clinical efficacy of small molecule inhibitors and peptides, such as PTD-DBM, which activates the Wnt/β-catenin pathway by interfering with CXXC5, a negative regulator that inhibits pathway activation. Such therapies show potential as more effective treatment options than existing solutions such as finasteride and minoxidil. Adjunctive therapies, such as low-level laser therapy, have also shown clinical efficacy, further highlighting how modulation of this pathway stimulates follicular regrowth. While these novel therapies require further research to validate their efficacy and to gain additional insight into their risk profile, it is clear that alopecia treatment is approaching a new frontier beyond traditional pharmacologic interviews, with regenerative medicine and pathway modulation paving the way forward. Full article

Background: Mesenchymal stem cell-based therapy may be indicated in ischaemic heart disease. The use of autologous adipose-derived mesenchymal stromal cells (AdMSCs) offers regenerative potential due to their paracrine effects. The aim of this study was to expand and characterise adult human thymus-derived MSCs harvested during open heart surgery with respect to their stem cell and paracrine properties. Methods: Enzymatically and non-enzymatically isolated human thymic AdMSCs (ThyAdMSCs) were cultured in xeno-free media containing pooled human platelet lysate (pPL). MSC characterisation was performed. Ex vivo expanded ThyAdMSCs were differentiated into three lineages. Proliferative capacity and immunomodulatory properties were assessed by proliferation assays and mixed lymphocyte reaction, respectively. Gene expression analysis was performed by qPCR. Results: Both isolation methods yielded fibroblast-like cells with plastic adherence and high proliferation. Flow cytometry revealed distinct expression of MSC markers in the absence of haematopoietic cell surface markers. Ex vivo expanded ThyAdMSCs could be differentiated into adipocytes, osteocytes, and chondrocytes. Activated peripheral blood mononuclear cells were significantly reduced when co-cultured with ThyAdMSCs, indicating their ability to inhibit immune cells in vitro. Gene expression analysis showed significantly less IFNγ and TNFα, indicating an alteration of the activated and pro-inflammatory state in the presence of ThyAdMSCs. Conclusions: These results demonstrate an efficient method to generate AdMSCs from human thymus. These MSCs have a strong immunomodulatory capacity and are, therefore, a promising cell source for regenerative medicine. The culture conditions are crucial for cells to proliferate in culture. Further research could explore the use of ThyAdMSCs or their secretome in surgical procedures. 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

The World Health Organization estimates that approximately 285 million people suffer from visual impairments, around 5% of which are caused by corneal pathologies. Currently, the most common clinical treatment consists of a corneal transplant (keratoplasty) from a human donor. However, worldwide demand for donor corneas amply exceeds the available supply. Lamellar keratoplasty (transplantation replacement of only one of the three layers of the cornea) is partially solving the problem of cornea undersupply. Obviously, cell therapy applied to every one of these layers will expand current therapeutic options, reducing the cost of ophthalmological interventions and increasing the effectiveness of surgery. Mesenchymal stem cells (MSCs) are adult stem cells with the capacity for self-renewal and differentiation into different cell lineages. They can be obtained from many human tissues, such as bone marrow, umbilical cord, adipose tissue, dental pulp, skin, and cornea. Their ease of collection and advantages over embryonic stem cells or induced pluripotent stem cells make them a very practical source for experimental and potential clinical applications. In this review, we focus on recent advances using MSCs from different sources to replace the damaged cells of the three corneal layers, at both the preclinical and clinical levels for specific corneal diseases. Full article