Stem Cell Research & Therapy最新文献

Background: Peripheral nerve injuries are associated with significant morbidity, particularly when primary surgical repair is delayed or impossible due to extensive nerve gaps. While advances in biomedical engineering have led to commercially available nerve guidance conduits tailored for such injuries, rates of sensory and motor recovery remain suboptimal following neurotmesis with gap defects beyond 3 cm. Cell therapy represents a promising treatment strategy to heal the injured peripheral nervous system, thought to promote tissue regeneration and enhance endogenous mechanisms of nerve repair to restore functionality. In this study, we explore the potential utility and efficacy of subcutaneous adipose tissue-derived neural stem cells in a nerve transection injury model.

Methods: Plp1-EGFP mice, which express GFP in Schwann cells, underwent surgical excision of a 5 mm segment of the left sciatic nerve. Nerves were then immediately repaired using silicone nerve guidance conduits with a residual 5 mm defect between nerve stumps. Conduits were loaded with cell culture media alone or with subcutaneous adipose tissue-derived neural stem cells harvested from Wnt1-tdTomato neural crest reporter mice, the latter enabling cell tracing post-transplantation.

Results: Subcutaneous adipose tissue-derived neural stem cells persisted through postoperative day 56 and contributed structurally to the reformed sciatic nerve. Integration between Wnt1-tdTomato neural stem cells and endogenous Plp1-EGFP Schwann cells occurred at the distal and proximal transection margins. Furthermore, neural stem cells predominantly differentiated into Schwann-like cells following transplantation, aiding in myelination of the reformed nerve, but not undesirable cell types such as neurons. Gait testing indicated that adipose-derived neural stem cells significantly improved hindlimb motor recovery compared to conduit repair alone by postoperative day 56.

Conclusions: Using cell tracer models, we confirm that adipose-derived neural stem cells can be therapeutically delivered to injured peripheral nerves, integrate with recipient axons and Schwann cells, and differentiate into myelinating Schwann-like cells to enhance motor recovery. These findings indicate that subcutaneous adipose tissue-derived neural stem cells could fill a critical gap in the treatment of peripheral nerve injuries, representing a readily available, autologous source of regenerative cells to optimize functional recovery after injury.

Background: Intestinal epithelial stem cells (SCs) and their transit-amplifying (TA) progeny are critical for mucosal repair and regeneration. However, their behaviour under chronic inflammatory conditions, such as those observed in Inflammatory Bowel Disease (IBD), remains incompletely understood.

Methods: We investigated the impact of chronic inflammation on intestinal stem/progenitor cells by integrating bulk RNA sequencing from the largest IBD biopsy cohort to date with single-cell transcriptomic analysis and experimental assays using patient-derived intestinal organoids.

Results: Active inflammation was associated with a reduction in canonical LGR5⁺ intestinal stem cells and a concurrent expansion of OLFM4⁺ populations, consistent with an inflammation-induced epithelial repair program. Notably, SC/TA cells from both inflamed and non-inflamed IBD tissues exhibited persistent transcriptional changes that were distinct from those in healthy controls. Single-cell analysis identified transcriptionally heterogeneous SC/TA subpopulations, including a previously uncharacterized inflammation-associated cluster enriched in immune signalling pathways. Pseudotime trajectory analysis demonstrated a shift in differentiation toward deep crypt secretory (Paneth-like) cell lineages under inflammatory conditions.

Conclusions: Chronic intestinal inflammation reshapes the epithelial stem and progenitor cell compartment, promoting altered differentiation and the emergence of immune-responsive epithelial states. These findings highlight the plasticity of the human intestinal epithelium in IBD and point to new avenues for therapeutic strategies aimed at maintaining epithelial integrity during chronic inflammation.

Background: Hereditary persistence of Fetal Hemoglobin (HPFH) is a benign condition known to mitigate symptoms in individuals with co-inherited β-hemoglobinopathies, such as β-thalassemia (BT) and sickle cell disease (SCD), through the reactivation of fetal hemoglobin (HbF). HPFH typically arises from deletions of varying sizes affecting the β-globin gene cluster or point mutations in the promoters of the γ-globin genes. While the therapeutic benefits of point mutations have been extensively studied, the potential of deletional forms of HPFH remains underexplored in preclinical settings.

Method: In this study, we generated benign deletional HPFH3 genotype in SCD and BT patient-derived HSPCs using CRISPR/Cas9 and showed that therapeutically relevant levels of HbF reactivation result in the alleviation of the pathological phenotypes.

Results: In edited cells derived from SCD patients, we observed reduced sickling and oxidative stress, while in edited from BT cells, restoration of the α-globin/β-globin ratio improved erythroid lineage maturation and reduced ROS levels. Importantly, HPFH3-edited HSPCs retained their genome integrity and showed no detrimental effect on their regeneration or differentiation into erythroid, myeloid, T, and B cell lineages in immunodeficient NBSGW mice post-xenotransplantation. Additionally, we showed a reduced interaction between the LCR and HBB, suggesting that the HPFH3 deletion specifically promoted LCR interactions with HBG1/2, likely due to the absence of the HBB locus.

Conclusions: Collectively, our preclinical findings suggest that the generation of the HPFH3 genotype has the potential to significantly enhance HbF levels, offering a promising universal therapeutic strategy for treating both SCD and β-thalassemia.

Human mesenchymal stem cells (MSCs) are characterized by their ability to differentiate into a variety of cell types, including osteocytes, chondrocytes, and adipocytes, making them promising candidates for cell-based therapies. Whilst the optimum method of clinical use is to use MSCs immediately after harvesting and expansion, there is often a need to cryostore MSCs before transplantation; this negatively impacts MSCs, affecting phenotypic marker expression, viability, differentiation potential, and other properties. There is consequently a requirement for methods to determine the biophysical state of MSCs post-thaw, in order to determine an optimum time for implantation after cells have recovered to a "normal" state. Typically, the primary method of assessing this is by measurement of cell viability; the cellular membrane is one of the key indicators of cell health and cell-cell interactions. Membrane-integrity dyes such as trypan blue are commonly used for binary viability checks, and ion tracking dyes offer insight into channel activation. However, these are typically expensive and time-consuming to use, limiting their efficacy in relatively high-throughput manufacturing scenarios. We used novel electrophysiological methods to assess MSC-health following freezing and thawing. Our results indicate that MSC health deviates significantly from its original phenotype immediately after thawing and only begins to resemble the pre-freezing state after three days. Notably, cell membrane capacitance does not fully recover to pre-freezing levels, even after this period. Results also suggest that the use of DMSO as a cryopreservant may be associated with the prolonged recovery period.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD), the most prevalent chronic liver disorder worldwide, exhibits complex pathogenesis and lacks effective targeted therapeutics. Existing animal models are limited by prolonged induction periods and interspecies discrepancies, while conventional monolayer hepatocyte cultures fail to recapitulate disease pathology due to inadequate polarization and functional immaturity.

Methods: To overcome these limitations, we established an in vitro MASLD model by treating human embryonic stem cell (hESC)-derived mature polarized hepatocyte organoids (P-hep-orgs) with free fatty acids (FFAs). Pathogenesis and progression of MASLD in this model were characterized using multiple assays, and its utility for drug screening was validated with three known antioxidant or lipid-lowering agents.

Results: P-hep-orgs derived from hESCs expressed mature hepatocyte markers (e.g., ALB), exhibited polarized architecture (e.g., MRP2) and demonstrated functionalities of mature hepatocytes (e.g., urea production). Moreover, we developed an in vitro MASLD model by treating P-hep-orgs with FFAs. This model recapitulated key pathological progression hallmarks, including disrupted glucose/lipid metabolism, oxidative stress, apoptosis, loss of polarization, impaired liver function, and ductular reaction. Furthermore, transcriptomic analysis revealed that P-hep-orgs treated with FFAs for 10 days shared similar molecular signatures with human MASH liver tissues (581 overlap DEGs). Finally, this model was used to assess the potential efficacy of established antioxidant or lipid-lowering agents (e.g., Vitamin E) in alleviating pathological phenotypes, including lipid accumulation and oxidative stress.

Conclusions: In summary, we established a novel in vitro MASLD model using hESC-derived P-hep-orgs. This model faithfully recapitulates key aspects of MASLD progression and serves as a valuable platform for investigating disease mechanisms and screening potential therapeutic compounds.

Background: Chronic lower extremity ulcers (CLEUs) remain a major clinical challenge due to their prolonged healing process and risk of amputation. Stem cell therapy (SCT) has emerged as a promising regenerative strategy, with various cell types being explored for their efficacy in treating CLEUs. This umbrella review aims to consolidate the existing evidence on stem cell interventions for CLEUs, providing a comprehensive overview of the current research landscape.

Methods: This umbrella review was conducted following the PRIOR and PRISMA guidelines. We searched across PubMed, Embase, Web of Science, and Cochrane Library databases for systematic reviews (SRs) and meta-analyses (MAs) that included randomized controlled trials (RCTs) on SCT for CLEUs. The methodological quality and evidence quality of the SRs/MAs were assessed by AMSTAR 2 and GRADE. A quantitative synthesis of all RCTs included in the SRs/MAs to obtain objective and updated conclusions.

Results: A total of 28 SRs/MAs involving 72 RCTs were included. Our updated meta-analysis reinforces that SCT offers potential therapeutic benefits for CLEUs, including improved healing rates, amelioration of tissue perfusion and pain-related indicators, and more favorable prognostic outcomes. No significant difference in all-cause mortality was observed between the SCT and control groups.

Conclusion: SCT represents a promising adjunctive therapy for CLEUs, with many studies demonstrating its safety and potential benefits. Since current evidence is limited by methodological flaws and study heterogeneity, high-quality RCTs in the future are crucial to prove the benefits of SCT for CLEUs truly.

Background: Kidney fibrosis is one of the pathological hallmarks of chronic kidney disease, likely contributing to the loss of kidney function. The mechanisms leading to kidney fibrosis and its reversibility is only partially understood, which hampers the development of therapeutic targets. Therefore, it is crucial to establish a robust human in vitro model that can be used to study kidney fibrosis and potential regeneration.

Methods: Human induced pluripotent stem cells (iPSC) were differentiated into kidney organoids. Fibrotic injury was induced by mimicking hypoxia (1% O₂ 48 h), inflammation (interleukin-1 beta (IL-1β) 96 h) or a combination (hypoxia and IL-1β). Organoids were harvested at injury onset and up to 2 weeks post-injury. Fibrosis was assessed by mRNA and protein expression of fibronectin (FN1) and collagen type I, regeneration was evaluated through the presence of CD133+ and CD24+ progenitor cells and markers for differentiated kidney cell types.

Results: The combination of hypoxia and IL-1β induced the strongest fibrotic response with significant upregulation of FN1 and collagen type I, and loss of tubular and glomerular markers. Over time, FN1 levels realigned with the control group, whereas collagen type I remained elevated. Tubular markers (Villin and ECAD) recovered to near-control levels, coinciding with increased CD133+ and CD24+ cell population and Ki67 expression. In contrast, PODXL+ glomerular structures showed limited recovery.

Conclusions: We present a reproducible human kidney organoid model that captures both fibrotic remodeling and tubular regeneration following clinically relevant injury. This platform offers a valuable tool for studying kidney-specific fibrosis dynamics and testing anti-fibrotic or pro-regenerative strategies.

Stepwise pancreatic β-cell differentiation protocols, designed to recapitulate key developmental milestones of pancreatic organogenesis-from definitive endoderm to mature, glucose-responsive β-cells-draw on insights from both rodent and human developmental biology. These protocols consist of three critical stages: the formation of definitive endoderm, the induction of pancreatic progenitors, and the maturation of functional β-cells. Here, we discuss human and rodent embryonic development together with stem-cell differentiation protocols in concert to identify gaps and bottlenecks that limit the practicality and scalability of current protocols. Ultimately, the aim of refining these processes is to produce functional β-cells from pluripotent stem cells to treat, and potentially cure, diabetes.