Stem Cell Research & Therapy最新文献

Background: Acute liver failure (ALF) is a life-threatening syndrome characterized by rapid deterioration of liver function, resulting in high mortality and posing a substantial global health burden. Human embryonic stem cells (hESCs) possess unlimited self-renewal capacity and pluripotent differentiation potential. Transplantation of hESC-derived hepatocyte-like cells (HPLCs) represents a promising therapeutic strategy for ALF.

Methods: A good manufacturing practice (GMP)-compliant differentiation process was developed to generate HPLCs from hESCs, and their biological characteristics and functional properties were systematically evaluated. A comprehensive series of preclinical safety and efficacy studies was performed, including dose-escalation experiments, biodistribution analysis, comparative evaluation of administration routes, and carcinogenicity testing. The therapeutic efficacy and safety of HPLCs were assessed in a fatal rat model of D-galactosamine (D-gal) and lipopolysaccharide (LPS)-induced ALF. In addition, the HPLCs underwent quality evaluation by the National Institutes for Food and Drug Control (NIFDC), and an independent safety assessment was conducted.

Results: A high-efficiency system was established for the generation of qualified, clinical-grade HPLCs from hESCs under GMP-compliant conditions. The HPLCs exhibited multiple mature hepatocyte functions, including carbohydrate and lipid metabolism, hepatic synthetic and storage functions, inducible cytochrome P450 activity, albumin secretion, and urea production. The HPLCs met the certification standards of the NIFDC of China. Transplantation of HPLCs significantly improved survival in ALF rats, with survival rates of 72.4% following tail vein injection and 66.7% following intraperitoneal injection, compared with 6.67% in the control group. HPLC transplantation also promoted recovery of liver function, as reflected by improvements in biochemical and coagulation parameters. Preclinical safety evaluations confirmed the biosafety of HPLCs, with no evidence of acute toxicity or tumorigenicity. A Phase I clinical trial (ChiCTR2100052988) for the treatment of ALF and acute-on-chronic liver failure (ACLF) has been approved by the National Health Commission of the People's Republic of China (Filing Number: MR-43-21-014643) and has been initiated.

Conclusions: A novel multistage, GMP-compliant process was developed for the effective and reproducible differentiation of hESCs into hepatocytes. The resulting HPLCs demonstrated robust hepatocyte functions, therapeutic efficacy in an ALF animal model, and favorable biosafety profiles. These findings support the clinical translation of HPLCs, with an ongoing Phase I clinical trial designed to evaluate their safety and feasibility in patients with ALF and ACLF.

Background: Circadian rhythms are endogenous, transcription-translation feedback loops that align cellular activities with the 24-h light-dark cycle. Stem-cell populations across tissues exhibit circadian oscillations that influence their self-renewal, proliferation, and differentiation. Key developmental pathways (Wnt/β-catenin, Notch, and Hedgehog) are increasingly recognized as both regulators and targets of circadian machinery.

Objectives: This review synthesizes current knowledge on the bidirectional crosstalk between circadian clock components and major stem-cell regulatory pathways, and evaluates how this interplay shapes tissue homeostasis, regenerative capacity, and therapeutic potential.

Methods: Literature examining molecular interfaces between circadian clock genes and Wnt, Notch, and Hedgehog signaling was surveyed, with emphasis on transcriptional regulation, chromatin dynamics, post-translational control, and functional outcomes for stem-cell behavior and regeneration.

Results: Evidence indicates that core clock components modulate stem-cell pathways through direct transcriptional control, shared enhancer architecture, altered chromatin accessibility, and rhythmic protein modification. In turn, Wnt, Notch, and Hedgehog signals feed back onto clock genes, influencing circadian amplitude and phase within stem-cell niches. Perturbation of this reciprocal regulation disrupts tissue maintenance, diminishes regenerative responses, alters metabolic equilibrium, and may promote tumorigenesis.

Conclusions: Circadian oscillators act as temporal gatekeepers of stem-cell function. Mapping the molecular interfaces between clock genes and developmental signaling pathways reveals new opportunities to refine regenerative therapies. Chronotherapeutic strategies, i.e. timing interventions to intrinsic circadian phases may enhance the efficacy, precision, and safety of stem-cell-based treatments.

Tuberculosis (TB) remains a major global public health challenge, with drug-resistant tuberculosis (DR-TB) presenting a serious threat to TB management. Conventional treatment faces challenges such as significant drug toxicity, frequent emergence of drug resistance, and compromised host immune microenvironment. These limitations, particularly in DR-TB cases, often lead to poor treatment outcomes and heightened recurrence rates, underscoring the need for complementary strategies. Cell-based host-directed therapy (HDT) emerges as a novel therapeutic strategy that may complement conventional drugs by directly modulating pathological immune responses and facilitating the repair of damaged tissue. This narrative review synthesizes preclinical and clinical data on cell therapy for TB. We focus on two distinct strategic approaches: (1) mesenchymal stem cell (MSC)-based therapies, which primarily exert immunomodulatory and tissue-repair functions, and (2) T cell-based adoptive cell therapies (ACTs), which are designed to enhance antimicrobial immunity directly. Current evidence, while promising, predominantly remains in the early exploratory stages or lacks robust evidence-based support. To facilitate successful translation, future research should focus on standardizing cell products, conducting comprehensive safety assessments and implementing more rigorous clinical trials. This review critically assesses the therapeutic potential and translational challenges of cell therapy for TB.

Background: HC-HA/PTX3 (a complex formed by high molecular weight hyaluronan covalently linked to heavy chain 1 of inter-α-trypsin inhibitor and tightly bound to pentraxin 3) is a unique extracellular matrix from human amniotic membrane that exerts an anti-scarring action and reprograms human corneal fibroblasts (HCF) and myofibroblasts to corneal stromal keratocytes in the absence of transforming growth factor β1 (TGFβ1) by downregulating canonical Smad-mediated signaling and upregulating bone morphogenetic protein (BMP) signaling. It remains unclear whether HC-HA/PTX3 can further reprogram HCF into neural crest (NC) progenitors in the presence of TGFβ1.

Methods: Human corneal fibroblasts were seeded on plastic, immobilized hyaluronic acid (HA) or HC-HA/PTX3 or on plastic with or without soluble HA and HC-HA/PTX3 in DMEM + 10% fetal bovine serum (FBS), with or without various inhibitors with or without TGFβ1. Transcript expression of NC and signaling markers was determined by RT-qPCR. Immunostaining was performed to monitor cytolocalization of signaling markers and α-smooth muscle actin (α-SMA). Raft separation before Western blot was used to study protein distributions in both rafts. Western blot and ELISA were used to measure relative protein level.

Results: Herein, we show for the first time that in the presence of exogenous TGFβ1, HC-HA/PTX3 continues to reprogram HCF into NC progenitors by upregulating mRNA expression of NC markers, confirmed by successful induction into human corneal endothelial cells, highlighted by hexagonal shape, mRNA expression of corneal endothelial markers and junctional staining of corneal endothelial markers such as Na-K-ATPase, α-catenin, β-catenin, F-actin, N-cadherin, p120 and ZO-1 but the lack of fibrogenic marker S100A4. Such reprogramming requires suppression of TGFβ1 SMAD-mediated canonical signaling that starts from HC-HA/PTX3 binding with CD44 to sequester type II TGFβ receptor (TβRII) in lipid raft and ends with downregulation of TβRII by nuclear translocation of cyclin D1. Mechanistically, nuclear translocation of cyclin D1 is mediated by activation of transforming growth factor-beta-activated kinase 1-transcription factor Jun (TAK1-cJUN) noncanonical signaling because of type I TGFβ receptor (TβRI) and type III TGFβ receptor (TβRIII) (without TβRII) in non-lipid raft as well as by nuclear translocation of CD44 intracellular domain (CD44ICD) formed by Membrane Type 1 Matrix Metalloproteinase (MT1MMP)/γ-secretase cleavage to facilitate such reprogramming.

Conclusions: Thus, HC-HA/PTX3 from amniotic membrane can be deployed as a new strategy to reverse scar toward regeneration.

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.