Stem Cell Research & Therapy最新文献

Background: Hyperglycemia, a hallmark of diabetes mellitus, is a metabolic condition that highly affects the nervous system. While evidence from epidemiological and animal studies links diabetes to dopaminergic dysfunction and an increased risk of Parkinson's disease, the underlying mechanisms remain unclear. Here, we examined the effects of high glucose on human iPSC-derived dopaminergic neurons and glial cells to better understand the pathogenic alterations that lead to neurotoxicity. Previous implication of neurotrophins in the neurological manifestations of diabetes prompted us to focus on the role of p75NTR neurotrophin receptor (p75NTR) in dopaminergic neurodegeneration under hyperglycemic conditions.

Methods: iPSC-derived dopaminergic neurons, astrocytes and microglia were treated with high glucose (50mM, 100mM) for 48 h to simulate hyperglycemia. Cytotoxicity assays, RNA sequencing and DNA damage assessments were employed to investigate the pathological alterations induced by high glucose exposure in neurons. Pharmacological targeting of p75NTR activity allowed investigation of its involvement in glucose neurotoxicity. Glial-mediated neurotoxicity was evaluated using conditioned media and inflammatory marker analysis.

Results: High glucose treatment led to DNA damage, activation of JNK signaling and cell death in neurons. Importantly, we observed upregulation of p75NTR and its pro-apoptotic ligand pro-NGF, suggesting activation of the pro-NGF/p75NTR axis in high glucose-treated neurons. Inhibition of p75NTR activity rescued neuronal cell death, identifying p75NTR as a central mediator of glucose neurotoxicity. Furthermore, glucose overload sensitized neurons to 6-hydroxydopamine (6-OHDA), increasing their vulnerability to neurotoxic insults-an effect reversed by p75NTR blockade. Treatment with BNN27, a synthetic NGF mimetic, prevented neuronal loss through p75NTR and TrkA receptors, suggesting neurotrophin signaling as a potential therapeutic target for combating high glucose-induced neuronal damage. Finally, we demonstrated the contribution of glial cells to neurodegeneration since high glucose treatment of iPSC-derived astrocytes and microglia enhanced their inflammatory potential and triggered the release of neurotoxic factors, causing pro-apoptotic effects on neurons.

Conclusions: Our findings show that high glucose impairs human dopaminergic neuron survival through activation of the pro-NGF/p75NTR axis and indirect glia-mediated mechanisms. Targeting p75NTR signaling may offer neuroprotective benefits in diabetes-related neurodegeneration, particularly for patients at risk of Parkinson's disease.

Diabetic retinopathy (DR), the most prevalent ocular complication of diabetes, progresses from non-proliferative (NPDR) to sight-threatening proliferative (PDR) stages. Current interventions-including retinal photocoagulation, intravitreal anti-VEGF agents, and surgery-address advanced disease, often require repeated administration, and carry risks like retinal injury. Safer, more effective, and longer-lasting treatments are needed, especially for early-stage DR. Mesenchymal stem cells (MSCs) and their derivatives offer a promising alternative, with advantages including low immunogenicity, paracrine signaling, and the ability to mitigate inflammation and vascular permeability. However, challenges in delivery efficiency and targeting specificity remain. Hydrogel-based scaffold materials are increasingly important due to their superior biocompatibility and ability to overcome ocular barriers. Recent advances include novel injectable hydrogels that can be combined with drugs or stem cells, enabling targeted delivery to retinal layers, prolonging therapeutic retention, and significantly improving bioavailability for sustained treatment of DR.

Background: Mesenchymal stromal cells (MSCs) are widely used in regenerative medicine, but their clinical utility is limited by replicative senescence. Strategies that reverse aging while maintaining MSC identity are urgently needed.

Methods: We developed a non-integrating, temperature-sensitive Sendai virus (SeV)-mediated rejuvenation protocol transiently expressing hTERT, BMI1, and SV40T in human MSCs. Following SeV removal, we evaluated proliferation, telomere length, karyotype stability, transcriptomic reset, producing heterogeneity, and differentiation potential.

Results: Rejuvenated MSCs (rej-MSCs) demonstrated extended proliferation beyond 100 days, telomere elongation, and normal karyotypes after SeV clearance. Transcriptomic profiling showed a reset of senescence-associated programs while retaining mesenchymal identity. Functional analyses revealed clone-specific heterogeneity, including HGF-driven angiogenic activity. Multilineage differentiation capacity was preserved across rej-MSCs.

Conclusions: This transient, non-integrating rejuvenation strategy establishes an operational definition of rej-MSCs and provides a transcriptionally diverse and scalable platform for MSC manufacturing and precision therapy design.

Aim: Periodontitis can impair the osteogenic function of periodontal ligament stem cells (PDLSCs), thereby compromising their capacity for periodontal tissue regeneration. In this study, we explored the impact of a synthetic small molecule, DS96432529 (DS), on the osteogenic differentiation potential of PDLSCs and its underlying mechanism.

Methods: The viability of DS was assessed by cell proliferation assays and apoptosis analysis. Osteogenic potential was evaluated through alkaline phosphatase (ALP) activity staining and Alizarin Red S (ARS) staining for mineralized nodule formation. Inflammatory injury was induced using recombinant tumor necrosis factor-alpha (TNF-α). RNA sequencing analyzed signaling pathways involved in DS-enhanced osteogenic differentiation. Western blotting quantified key pathway protein expression. Specific small molecule inhibitors and agonists modulated relevant signaling pathways. Therapeutic efficacy was evaluated in a ligature-induced rat periodontitis model.

Results: DS inhibited cell proliferation at lower concentrations but did not induce significant apoptosis at concentrations up to 250 nM. Across tested concentrations, DS significantly enhanced ALP activity and accelerated mineralized nodule formation in PDLSCs. DS upregulated mitophagy-related protein expression under both inflammatory and non-inflammatory conditions. Additionally, DS restored TNF-α-inhibited ALP activity and attenuated TNF-α-induced activation of the RIG-I-like receptor (RLR) signaling pathway. The RIG-I activator Poly(I: C) counteracted DS-mediated repair of inflammatory injury during osteogenesis. Mitophagy inhibition diminished DS's beneficial effects on osteogenic differentiation under inflammation and reduced its suppression of RIG-I expression. DS alleviated ligation-induced alveolar bone loss in rats with periodontitis.

Conclusions: DS enhances the osteogenic potential of PDLSCs in association with the activation of mitophagy-related processes. It mitigates inflammation-impaired osteogenesis, potentially via modulation of the RIG-I-mediated RLR signaling pathway, in association with increased mitophagy-related activity. DS represents a potent therapeutic small molecule for ameliorating periodontitis-induced bone loss.

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a curative option for children with refractory, relapsed, or high-risk acute lymphoblastic leukemia (ALL). Conditioning regimens are critical for ensuring engraftment and reducing post-transplantation relapse. Cladribine is a purine nucleoside analogue with antileukemic activity and central nervous system penetration. However, its role in conditioning regimens for pediatric ALL remains insufficiently defined.

Methods: We conducted a retrospective cohort study of 66 pediatric patients with ALL who underwent their first allo-HSCT at Sun Yat-sen Memorial Hospital between August 2018 and December 2023. Patients were stratified according to whether cladribine was incorporated into the conditioning regimen (CLAD + vs. CLAD-). Survival outcomes, relapse incidence, regimen-related toxicity, graft-versus-host disease (GVHD), and post-transplantation complications were compared. Sensitivity analyses were performed by restricting the control group to patients receiving non-total body irradiation, chemotherapy-based conditioning. Competing-risk methods were applied where appropriate.

Results: Among the 66 children who underwent allo-HSCT, 38 patients received CLAD+ conditioning and 28 received CLAD- regimens. Conditioning intensity scores were significantly lower in the CLAD+ group (4.0 [3.0, 5.0] vs. 4.5 [4.0, 4.5], p < 0.001). Two-year overall survival or transplantation-related mortality did not differ significantly between the two groups. However, the 2-year relapse-free survival was significantly higher in the CLAD+ group (94.44% vs. 81.16%, p = 0.019), with a significantly lower 2-year cumulative incidence of relapse. These findings remained directionally consistent in sensitivity analyses that accounted for regimen heterogeneity and competing risks. Hematopoietic engraftment, the incidence of acute and chronic GVHD, and major post-transplantation complications were comparable between the two groups, while renal and gastrointestinal toxicities were significantly less frequent in the CLAD+ group.

Conclusion: Incorporation cladribine into conditioning regimens for pediatric ALL is associated with improved relapse-free survival and significantly lower frequencies of renal and gastrointestinal toxicities, without increasing the risk of transplant-related complications. Given the retrospective design and limited number of events, these promising findings warrant prospective validation in future studies.

Acute gastroenteritis viruses, such as rotavirus, human norovirus, human astrovirus, human adenovirus, human sapovirus, represent significant threats to global public health. Research on these pathogens has long been hampered by the limitations of conventional models. Animal and cell-based systems, widely used in virological studies, show limited efficiency in supporting rotavirus replication, while noroviruses remain largely non-cultivable in these settings. Organoids-complex, three-dimensional multicellular structures derived from stem cells-exhibit organ-specific characteristics and spatial organization, making them promising tools for viral research. Intestinal organoids, in particular, recapitulate key features of the gut epithelium and have emerged as versatile platforms for investigating viral pathogenesis and developing intervention strategies. This review systematically outlines the cultivation and functional properties of human intestinal organoids, as well as the evolution and progress of their application in studying acute gastroenteritis viruses. However, current intestinal organoid models are primarily composed of epithelial cells and lack immune and other non-epithelial components, thereby limiting their ability to fully simulate host-pathogen interactions and immune responses following infection. Future efforts should focus on incorporating emerging technologies, such as CRISPR/Cas9 gene editing, to develop more physiologically relevant intestinal models that better mimic in vivo conditions.

Background: Variants in OTUD5 are associated with neurodevelopmental disorders (NDDs), yet the underlying molecular mechanisms remain unclear. This study aimed to investigate the pathogenicity of a novel OTUD5 variant (c.697G > A, p.Val233Met) and elucidate its regulatory role in neural progenitor cell (NPC) proliferation and differentiation, thereby uncovering the function of OTUD5 in neurodevelopment.

Methods: The OTUD5 variant was identified in two NDD patients via exome sequencing. Patient-derived induced pluripotent stem cells (iPSCs) and CRISPR/Cas9-corrected isogenic controls were generated. NPC proliferative activity was assessed by Ki67 immunofluorescence staining, cell-cycle distribution was analyzed by flow cytometry, and neuronal differentiation was evaluated by Tuj1/MAP2 immunofluorescence staining. Substrate screening was conducted in HEK293T cells using co-immunoprecipitation (Co-IP) and mass spectrometry. Deubiquitination capacity and protein stability were validated through ubiquitination assays and cycloheximide (CHX) chase experiments.

Results: The p.Val233Met variant, located within the catalytic OTU domain, induced a marked conformational alteration in the OTUD5 protein. Functionally, the variant caused aberrant NPC proliferation (1.8-fold increase in Ki67⁺ cells, accompanied by release of G1 arrest) and impaired neuronal differentiation (60% reduction in Tuj⁺ cells). Mechanistically, wild-type OTUD5 stabilized GSK3β by removing K48-linked ubiquitin chains, whereas the mutant isoform exhibited diminished deubiquitinase activity, accelerating GSK3β degradation and shortening its half-life by 40%.

Conclusion: This study establishes a novel disease mechanism whereby OTUD5 mutations disrupt NPC homeostasis through GSK3β destabilization, highlighting the critical role of ubiquitination regulation in neurodevelopment. Our iPSC model provides a platform for testing GSK3β-targeted therapies in OTUD5-related NDDs.

Neuroinflammation is a key pathogenic factor for neurodegenerative diseases. Mesenchymal stem cell (MSC) transplantation, as a potential strategy for regulating neuroinflammation, has received extensive attention. Our previous research revealed that compared with ordinary MSC, MSC pretreated with tanshinone IIA (TIIA), referred to as TIIA-MSC, exhibited superior anti-neuroinflammatory activity, but the mechanism of action remains unclear. To clarify the underlying mechanism, this study integrated in vitro and in vivo experiments and evaluated the therapeutic effect of TIIA-MSC in a triple-transgenic Alzheimer's disease mouse model (3×Tg-AD mice) and explored its mechanism of action in a lipopolysaccharide (LPS)-induced BV2 microglial cell inflammation model. The results showed that TIIA-MSC could significantly improve the cognitive function of 3×Tg-AD mice, increase brain glucose metabolism levels, promote the recovery of synaptic and mitochondrial structures, and effectively alleviate neuroinflammatory responses. In vitro experiments further verified the superior inhibitory effect of TIIA-MSC on microglial cell activation and proinflammatory factor release. Mechanistic studies have indicated that the triggering receptor expressed on myeloid cells 2 (TREM2) is the key molecule that mediates this process. The knockdown of TREM2 expression significantly weakened the anti-inflammatory effect of TIIA-MSC, suggesting that TREM2 plays a central role in this process. Further analysis revealed that by activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway downstream of TREM2, TIIA-MSC may promote the transformation of the functional state of microglia from mainly proinflammatory to having neuroprotective and repair properties. This study systematically revealed the molecular mechanism by which TIIA-MSC regulate microglial cell phenotypic transformation through the TREM2/PI3K/Akt pathway and exert anti-neuroinflammatory effects, providing new ideas and an experimental basis for expanding the application of MSC in the treatment of neurodegenerative diseases.

Background: Alcoholic hepatic fibrosis (AHF) ultimately leads to liver cirrhosis and even hepatocellular carcinoma. The aim of this study was to investigate the specific mechanism by which high mobility group protein B1 (HMGB1) regulated the activation of hepatic stellate cells (HSCs) in AHF.

Methods: CCK-8, EdU staining and flow cytometry assays were utilized to evaluate the viability, proliferation and apoptosis of LX-2 cells stimulated by ethanol. The effect of HMGB1 on cell glycolysis was assessed by cellular energy metabolism assays. The levels of Fe²⁺/Fe³⁺, ROS, GSH and MDA were detected to evaluate the effect of HMGB1 on ferroptosis. In addition, clinical liver tissue samples and an AHF mouse model were employed to further investigate the effect of HMGB1 on AHF.

Results: Ethanol stimulation significantly upregulated HMGB1 and HSC activation markers, enhanced glycolysis, and inhibited ferroptosis in LX-2 cells. Knockdown of HMGB1 suppressed ethanol-induced effects, including HSC activation and glycolysis promotion. However, these effects of HMGB1 knockdown were negated by an oxidative phosphorylation inhibitor. Furthermore, a ferroptosis inducer impeded ethanol-induced HSC activation. Overexpression of HMGB1 decreased the ferroptosis level in ethanol-stimulated LX-2 cells, which was reversed by a glycolysis inhibitor. These in vitro findings demonstrated that upregulated HMGB1 inhibited ferroptosis by enhancing glycolysis, thereby promoting HSC activation. In vivo validation data further confirmed that HMGB1 knockdown inhibited glycolysis, increased ferroptosis level, reduced HSC activation, and alleviated liver fibrosis in AHF mice. Ferroptosis inhibitor counteracted the impacts of HMGB1 knockdown on ferroptosis, HSC activation and liver fibrosis in AHF mice.

Conclusion: In summary, HMGB1 promoted the metabolism of HSCs towards glycolysis to inhibit ferroptosis, which eventually led to the activation of HSCs and the progression of AHF.

Intervertebral disc (IVD) degenerative disease is a prevalent and debilitating spinal disease. Current treatments only focus on symptomatic relief but fail to halt disease progression or restore the native biomechanical function of the spine. Regenerative medicine strategies, particularly those harnessing endogenous progenitor cells, offer a promising avenue for achieving biological repair and functional homeostasis. The identification of intervertebral disc progenitor cells (IVD-PCs) has unveiled a potential cellular reservoir for self-repair, given their demonstrated stemness attributes, including clonogenicity and multipotent differentiation. However, the clinical translation of IVD-PCs is significantly hampered by an incomplete understanding of their inherent heterogeneity, hierarchical organization, and, most critically, the dynamic interplay with their unique microenvironment, which dictates their fate decisions. This review synthesizes recent advances in deciphering the molecular signatures and functional plasticity of IVD-PCs. We place a particular emphasis on how key physicochemical, mechanical, and cellular cues within the IVD niche orchestrate progenitor cell behavior-ranging from maintenance and activation to aberrant differentiation-during both homeostasis and degeneration. Furthermore, we propose forward-looking insights to bridge critical knowledge gaps, aiming to propel the development of novel progenitor cell-based therapeutics for IVD degeneration.