Stem Cell Research & Therapy最新文献

Human neural stem cells (hNSCs) are promising candidates for regenerative medicine due to their self-renewal capacity, differentiation potential, and ability to modulate inflammation. However, several reports showed that the regenerative properties of stem cells are tied to the extracellular vesicles (EVs) they secrete. This study aimed at characterizing hNSCs produced under Good Manufacturing Practice (GMP) conditions and at elucidating the molecular and functional properties of their secreted extracellular vesicles (hNSC-EVs). hNSCs were first assessed for proliferation, and differentiation potential, showing a stable growth profile and expression of neural stem cell markers. High-resolution proteomic analysis identified over 5000 proteins, with about 40% overlap with previous NSCs studies. hNSCs expressed mostly markers for different cell lineage precursors. The molecular characterization of hNSC-derived EVs (hNSC-EVs) showed a size distribution, as measured by nanoparticle tracking analysis, ranging from 140 to 200 nm and an enrichment in EV markers, detected by western blotting. Functional analyses showed that hNSC-EVs, reduce nitric oxide generation and inducible nitric oxide expression in LPS-treated microglial cells and inhibit caspase-1 activation in monocytic cell models through uptake-dependent and independent mechanism, respectively. Our findings show that hNSC possess a strong stemness signature and secrete EVs with immunomodulatory properties, suggesting the worth of hNSC-EVs as either alternative to cell-based therapies or primer to boost anti-inflammatory properties of hNSCs in the treatment of neurological disorders.

Friedreich's ataxia (FRDA) is an inherited, autosomal recessive, multisystem disorder that primarily manifests in children and affects the nervous system and the heart. FRDA is caused by an expansion of GAA repeats in the first intron of the frataxin (FXN) gene. The expansion disrupts transcription of FXN, resulting in significantly decreased FXN expression in FRDA patients' tissues. Frataxin is involved in biosynthesis of iron-sulfur (Fe-S) clusters, which are critical for the function of the electron transport chain and many metabolic enzymes. Frataxin deficiency leads to reduced energy production and accumulation of iron in mitochondria that exacerbates oxidative stress. Despite significant advancements in the field, FXN cellular functions and underlying pathological mechanisms of FXN deficiency in cell-type specific contexts remain to be elucidated. Inaccessibility to the most vulnerable cell types in FRDA patients, including neurons, cardiomyocytes, and β-cells, largely accounts for these limitations. Significant progress in recent years regarding the derivation and differentiation of human pluripotent stem cells (hPSCs), along with breakthroughs in gene editing technologies, enables the generation of patient-derived and isogenic control disease-relevant cell types and organoid-like structures as platforms for studying disease mechanisms and for drug discovery. Herein, we first provide an overview of hPSC derivation and intrinsic properties of these cells. We then discuss current advances and limitations of hiPSC-based cell models for FRDA. We also highlight the need to further refine and develop these in vitro cell models for pre-clinical advancement of therapeutic approaches for FRDA.

Background: Human umbilical cord mesenchymal stem cell-derived exosomes (HucMSC-Exo) have shown great therapeutic promise in the treatment of primary ovarian insufficiency (POI). Ferroptosis, a distinct form of cell death, has been associated with the pathogenesis of POI. However, whether HucMSC-Exo can mitigate POI by modulating ferroptosis remains unknown.

Methods: In a CTX-induced POI mouse model, HucMSC-Exo was administered. Ovarian function was assessed by monitoring the estrous cycle, hormone levels, ovarian index, fertility rate, and ovarian morphology. The molecular mechanisms underlying injury and repair were investigated through HucMSC-Exo tracing, immunohistochemical staining, western blot, and real-time polymerase chain reaction (PCR).

Results: HucMSC-Exo restored hormonal balance, preserved ovarian reserve, and reduced follicular atresia and developmental defects in a cyclophosphamide (CTX)-induced POI mouse model. Furthermore, HucMSC-Exo attenuated Fe²⁺ accumulation, oxidative stress, and ferroptosis in the granulosa cells (GCs) of atretic follicles in ovaries with POI. In vitro assays also demonstrated that HucMSC-Exo attenuated CTX-induced ferroptosis in GCs by alleviating Fe²-dependent oxidative damage. Interestingly, hucMSC-Exo specifically suppressed the CTX-induced upregulation of heme oxygenase-1 (HO-1), a key regulator of iron homeostasis, at the translational level. This suggests that post-translational modifications may play a regulatory role in HO-1 expression and iron homeostasis. Mechanistic studies revealed that HucMSC-Exo delivers SMURF1, an E3 ubiquitin ligase that promotes HO-1 degradation, thereby restoring iron homeostasis and inhibiting ferroptosis in GCs. Furthermore, HO-1 knockdown enhanced the protective effects of HucMSC-Exo against CTX-induced ferroptosis and cytotoxicity in GCs.

Conclusions: HucMSC-Exo delivers SMURF1 to promote HO-1 degradation, which in turn suppresses Fe²⁺ accumulation and lipid peroxidation, thereby preventing ferroptosis in GCs and ameliorating chemotherapy-induced POI.

Background: Our previous study revealed that intravenous administration of mesenchymal stromal cells (MSCs) increases local cell engraftment and improves heart function. This study aims to investigate whether MSCs overexpressing HLA-G1 have further increased local transplanted cells engraftment and improved heart function.

Methods: The mice were intravenously administered saline or human umbilical cord blood-derived MSCs (hUCB-MSCs) 7 days before myocardial infarction (MI) induction. Then, the MI mouse model was established by ligating the left anterior descending coronary artery. The mice were then subjected to intramyocardial transplantation of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) 30 min after MI induction. Echocardiographic analysis was carried out to assess heart function. Furthermore, in vivo fluorescent imaging analysis was performed to analyze cell engraftment. Moreover, flow cytometry of splenic regulatory T cells (Tregs) and natural killer (NK) cells was conducted to evaluate the immunomodulatory effect of hUCB-MSCs.

Results: The results showed that systemic intravenous administration of hUCB-MSCs substantially enhanced Tregs, decreased NK cells, and increased intramyocardially transplanted hiPSC-CMs' engraftment, thus improving heart function. Compared with hUCB-MSCs, HLA-G1 overexpressing hUCB-MSCs reduced systemic NK cells (7.13 ± 0.19% vs. 9.12 ± 0.06%, p < 0.05), increased Tregs (5.03 ± 0.17% vs. 3.36 ± 0.05%, p < 0.05), improved cell engraftment (Radiant efficiency: 3.01 ± 0.36 × 10⁹ vs. 2.19 ± 0.27 × 10⁹, p < 0.05) and heart function (LVEF: 73.00 ± 0.44 vs. 62.36 ± 1.01, p < 0.05). The in vitro assays revealed that HLA-G1 overexpressing hUCB-MSCs modulated the immune response by decreasing pro-inflammatory cytokines.

Conclusions: This study showed that systemic intravenous administration of HLA-G1 overexpressing hUCB-MSCs modulated immune response and increased transplanted hiPSC-CMs' engraftment to improve heart function following AMI.

To elucidate spatiotemporal dynamics of tissue renewal, we developed evProTracer, an enhanced dual-recombinase lineage tracing system for cumulative in vivo labeling of proliferating cells. Robust longitudinal tracing using evProTracer in murine tracheal epithelium revealed near-complete homeostatic turnover (91.6 ± 1.29% epithelial replacement over 25 weeks), while basal cell-specific ​Trp63-evProTracer​ uncovered a dorsally biased proliferation pattern​, contributing 33.88 ± 1.44% of total epithelial renewal over 6 months, with early differentiation bias toward club cells. These data demonstrate that ventral epithelial renewal is primarily mediated by non-basal facultative progenitors, revealing their constitutive activation during homeostasis. This study uncovers spatially stratified renewal hierarchies: dorsal basal stem cell reservoirs versus ventral facultative non-basal progenitors. evProTracer provides a versatile platform for investigating tissue plasticity hierarchies in regenerative organs.

Background: Pulmonary arterial hypertension (PAH) is a fatal condition characterized by progressive vascular remodeling in the pulmonary arteries, eventually leading to right heart failure and death. Dysregulated extracellular matrix (ECM) remodeling is central to PAH pathogenesis and represents a potential therapeutic target. Mesenchymal stromal cells (MSCs) have shown promise in preclinical studies; however, the optimal therapeutic window, dosing frequency, and mechanistic basis for their regulation of vascular ECM remain unclear.

Methods: We employed a monocrotaline (MCT)-induced rat model of PAH to evaluate different MSC treatment regimens, including early administration (day 1 post-MCT), delayed administration (days 7 and 14), and repeated dosing (days 1 and 11). Additionally, we combined in vivo and in vitro approaches to investigate how MSCs modulate the activation of pulmonary arterial adventitial fibroblasts (PAAFs) and influence ECM remodeling.

Results: Biodistribution studies indicated that MSC retention in lung tissue peaked within 24 h and gradually declined by day 21. A single early dose of MSCs (on day 1) significantly ameliorated PAH progression, increasing the 28-day survival rate, reducing right ventricular systolic pressure (RVSP), improving right ventricular function, and attenuating small pulmonary vascular remodeling, including reductions in medial thickening, excessive muscularization, and collagen deposition. Repeated MSC administration did not provide additive therapeutic benefit. Both in animal models and cell cultures, MSCs effectively suppressed PAAF activation and reduced ECM protein production. This anti-fibrotic effect was mediated, at least in part, via the pathway involving the upregulation of SOCS3 and consequent inhibition of STAT3 phosphorylation.

Conclusion: Our findings underscore the importance of early intervention in the PAH disease course for MSC-based therapy. MSCs attenuate vascular remodeling and disease progression, possibly through the SOCS3/STAT3 signaling pathway, by targeting PAAF activation and ECM dysregulation. These results offer a novel mechanistic foundation for MSC treatment in PAH.

Two international stem cell consortia, the International Stem Cell Initiative (ISCI) and the International Stem Cell Biobanking Initiative (ISCBI, www.iscbi.org ) held a workshop on June 15th 2025 in Hong Kong on genetic variants in human pluripotent stem cell (hPSC) lines and accurate and standardized documentation of donor/hPSC genetic information including ethnicity. The occurrence and detection of genetic variants is a key issue for assuring reproducible stem cell research data and the safety of stem cell derived medicinal products. Presentations by leading experts addressed the nature of hPSC genetic variants, their detection and accurate recording of genetic data and ethnicity. The audience of stem cell researchers, cell banking directors and experts in ethic, policy and stem cell databases, from 13 countries across the globe, discussed progression of the ISCI consortium's efforts in providing further data and thought leadership on the management of genetic variants, and the challenges for standardizing biobanking approaches for hPSC genetic data including ethnicity. This paper records the key elements of this discussion and the conclusions and consensus reached and ongoing work to provide guidance for hPSC biobanks.

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as promising cell-free therapeutic strategies for musculoskeletal regeneration. MSC-EVs, which are enriched with diverse cargos, exert multifaceted biological effects, including the modulation of inflammation, the promotion of angiogenesis, and the regulation of immune responses. They also activate key regenerative signaling pathways, such as the PI3K/Akt, Wnt/β-catenin, TGF-β/Smad, and NF-κB pathways, thereby promoting osteogenesis, chondrogenesis, tenogenesis, and muscle repair to support the repair of bone, cartilage, tendon, and muscle tissues. In addition to their intrinsic activity, advances in bioengineering, including surface modification, cargo engineering, and integration with biomaterial scaffolds, have further increased their therapeutic potential and delivery. Preclinical studies consistently demonstrate efficacy across diverse musculoskeletal tissues, and early clinical trials highlight their translational promise. Nevertheless, clinical application remains constrained by challenges in large-scale production, standardization, and long-term safety evaluation. This review summarizes current knowledge on the mechanisms, therapeutic applications, engineering strategies, delivery systems, and clinical progress of the use of MSC-EVs in musculoskeletal regeneration while highlighting critical obstacles and future directions for their clinical implementation.

Previous studies have confirmed that scald injuries can lead to disturbances in hepatic lipid metabolism, and bone marrow-derived mesenchymal stem cells (BMSCs) have emerged as a promising therapeutic strategy for alleviating such disorders. However, research focusing on the regulation and restoration of liver lipid metabolic processes remains limited. In this study, we investigated the effects of BMSCs on hepatic lipid metabolism disorders induced by scald injury in rats through integrated transcriptomic and metabolomic analyses. The results demonstrated that portal vein infusion of BMSCs markedly improved body weight recovery, reduced hepatic lipid accumulation, normalized serum lipid profiles, and attenuated liver injury following scalding. Combined transcriptomic and metabolomic data further suggested that the therapeutic mechanism may involve inhibition of NF-κB/Gadd45a signaling in hepatocytes, restoration of sphingolipid metabolism, enhancement of hepatic lipid conversion, and suppression of adipocyte lipolysis. Overall, this study provides a theoretical basis for the potential clinical application of BMSCs in treating hepatic lipid metabolism disorders secondary to severe burn injury.

Background: Spinal cord injury (SCI) leads to persistent neurological deficits partly by disruption of the blood-spinal cord barrier (BSCB). Small extracellular vesicles (sEVs) from human umbilical cord mesenchymal stem cells (hUC-MSCs) can promote BSCB repair, but their active components remain unclear. This study examined whether miR-149 carried by hUC-MSC-derived sEVs (hUC-MSCs-sEVs) protects the BSCB after SCI by targeting endothelin-1 (ET-1).

Methods: Human brain microvascular endothelial cells (HBMECs) were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to model barrier injury, and rats underwent a thoracic SCI. hUC-MSCs-sEVs were isolated and loaded with miR-149 mimics or inhibitors. Endothelial cell viability, paracellular permeability (FITC-dextran assay), and junction protein levels (ZO-1, Claudin-5, β-Catenin, Occludin) were measured by viability assays, Western blot, and immunofluorescence. ET-1 levels and PI3K/Akt pathway activation were measured by ELISA and Western blot. In SCI rats, sEVs (with or without the miR-149 inhibitor) were injected; motor function (BBB locomotor score), BSCB permeability (Evans blue/FITC-dextran leakage) and spinal cord histology were evaluated.

Results: hUC-MSCs-sEVs were internalized by HBMECs and significantly improved cell survival and barrier function after OGD/R. sEVs treatment restored tight and adherens junction proteins and suppressed OGD/R-induced ET-1 upregulation and PI3K/Akt activation. OGD/R reduced miR-149 expression, which was rescued by sEVs. sEVs loaded with miR-149 mimic further enhanced these protective effects, whereas a miR-149 inhibitor abolished them. Notably, co-administration of an ET-1 receptor antagonist reversed the barrier disruption caused by miR-149 inhibition. In vivo, hUC-MSCs-sEVs treatment improved locomotor recovery and reduced BSCB leakage and tissue damage, whereas miR-149 inhibition abolished these benefits.

Conclusions: hUC-MSC-derived exosomal miR-149 preserves BSCB integrity and promotes functional recovery after SCI by targeting ET-1 and inhibiting the PI3K/Akt pathway, thereby enhancing junctional protein expression. The miR-149/ET-1 axis may represent a promising therapeutic target for SCI.