npj Regenerative Medicine最新文献

Leading gene therapy approaches for Duchenne muscular dystrophy (DMD) using AAV-mediated delivery of microdystrophin (µDys) have shown partial efficacy in patients, contrasting with the favorable outcomes observed in animal models. The identification of effective therapeutic strategies could be accelerated by using human high-throughput DMD models that replicate the molecular complexity driving pathology for accurate screening. To face this challenge, we develop MYOrganoids, an engineered muscle platform derived from patient-induced pluripotent stem cells (iPSC), recapitulating critical hallmarks of DMD, such as fibrosis and muscle dysfunction. We show that co-culture of fibroblasts with iPSC-derived muscle cells during organoid generation is pivotal for functional maturation and muscle force evaluation upon eccentric contractions. Notably, incorporation of DMD fibroblasts induced phenotypic exacerbation in DMD MYOrganoids by unraveling of fibrotic signature and fatiguability through cell-contact and paracrine mechanisms. We then exploited our system to interrogate gene therapy efficacy in this severe context. Although µDys gene transfer improves muscle resistance and partially restores membrane stability, it fails to reduce profibrotic signaling. These findings highlight the persistence of fibrotic activity post-gene therapy in our system, a limitedly explored aspect in DMD models, and provide the opportunity to study mechanisms of dysregulated cellular communication and empower gene therapy efficacy.

Pelvic organ prolapse (POP) due to weak support tissues is a common, debilitating condition typically treated with surgery. However, surgery is suboptimal due to associated risks and high prolapse recurrence rates. Therefore, there is a need for non-surgical therapies to restore supportive tissues, such as the vagina, following surgical intervention. In this study, we used patient induced pluripotent stem cells as a source to generate patient-specific progenitors of smooth muscle cells (pSMCs) and collected secretomes from these progenitor cells to examine their paracrine effects. Proteomic analysis of the conditioned media from pSMCs (pSMC-CM), which contain the secretomes, revealed proteins involved in extracellular matrix (ECM) remodeling. We assessed the paracrine effect of pSMC-CM using vaginal fibroblasts from POP patients and in a rat model of surgically injured vagina. pSMC-CM increased ECM protein expression in human vaginal fibroblasts and enhanced vaginal contractile function and ECM protein deposition in the surgically injured rat vagina. These findings suggest that pSMC-CM may promote vaginal contractile function and tissue extracellular matrix remodeling following surgical intervention.

Vascular network disruption caused by spinal cord injury (SCI) exacerbates secondary neuronal damage. Although vascular barrier disruption naturally restores over time, its underlying mechanism is not fully clarified. Here, we found that blood factors promote the proliferation of endothelial cells (ECs), which are essential for revascularization in the repair process after SCI. In vivo, endogenous IgG leakage into the spinal cord initiates EC proliferation at the lesion after injury. In vitro, adult mouse serum promotes mouse ECs proliferation through beta-2-microglobulin (B2M) via transforming growth factor beta receptor 2 (TGFBR2). Under EC-specific knockdown of Tgfbr2 in vivo, we observed exacerbated blood extravasation and increased inflammatory cell infiltration compared to controls. Additionally, suppression of endothelial Tgfbr2 impaired motor function recovery, axon regrowth, and regeneration in injured mice. These findings suggest that targeting the B2M-TGFBR2 axis could be a potential therapeutic approach to promoting functional recovery against vascular disruption after SCI.

Induced pluripotent stem cells (iPSCs) have demonstrated superior capacity to regenerate hyaline cartilage compared to mesenchymal stromal cells (MSCs). However, most previous animal studies have only conducted short-term assessments. We performed a long-term (8 weeks) in vitro chondrogenesis of human iPSC-derived multipotent progenitor cells (iMPCs) and human MSCs. The expression levels of hypertrophy-related genes were significantly lower in the iMPC group compared to the MSC group, such as collagen type X being 5-fold lower on day 56. In the animal study, implants from the iMPC group maintained more matrix than the MSC group at both short and long-term time points (12 and 48 weeks). Importantly, at 48 weeks, the native cartilage surrounding the defect areas in some rats from the MSC group showed severe degradation, which was not observed in the iMPC group. In conclusion, iMPCs represent a safe and effective cell source for long-term hyaline cartilage repair.

Osteoarthritis (OA) is a progressive joint disease characterized by cartilage degeneration. Although the current use of mesenchymal stromal cells (MSCs) treatment provides a novel therapeutic option, stem cell therapy is limited to the risk of immune rejection, and stem cell-derived extracellular vesicles (Exos) are emerging as a more potential choice. Antler is a truly regenerative organ with unprecedented regenerative capacity and chondrogenic potential, and its derived antler stem cells (ASCs) provide a unique and sustainable biological resource for obtaining bioactive ASC-Exos. In this study, we found that intra-articular injection of ASC-Exos can effectively promote cartilage repair. Further analysis indicated that the key functional component of these exosomes is mir-140, which functions by regulating its target, matrix metalloproteinase 13 (MMP13). Finally, we found that miR-140-engineered ASC-Exo promotes chondrocyte activity, reduces apoptosis both in vitro and in vivo, and alleviates inflammation while inhibiting cartilage matrix degradation. Therefore, this study provides a new regenerative medical strategy for the treatment of osteoarthritis.

Unlike rodents, ferrets have human-like distribution of submucosal glands expressing MUC5B, associated with idiopathic pulmonary fibrosis (IPF). We evaluated ferrets exposed to a single dose of bleomycin (5 U/kg) longitudinally, and found sustained restrictive physiology, increased opacification and fibrotic injury in the lungs through 22 weeks. Notably, these lungs had an aberrant "proximalization" repair phenotype indicated by increased proportion of smaller airways co-expressing club cell secretory protein and alpha-tubulin that was associated with extent of fibrotic injury. We also observed MUC5B-positive cystic structures in the distal lung suggestive of honeycombing, consistent with increase of MUC5B+ airways in combination with a size shift to smaller airways. We conclude that ferrets exhibit aberrant repair and pathologic features characteristic of human IPF, including proximalization of the distal airways that has not been recapitulated in rodents. Heightened MUC5B expression may play a key role in promoting airway remodeling and sustained lung injury in IPF.

Cell therapies, such as T cell immunotherapies, hold significant promise for treating complex diseases; however, their widespread adoption has been hindered by challenges related to monitoring cells during culture, which has affected their consistency, potency, and cost. Here, we present a compact, low-cost, label-free quantitative phase imaging (QPI) platform to enable continuous, non-destructive, in-line monitoring of T cell cultures within bioreactors. We further develop quantitative, image-based assays that accurately characterizes T cell culture viability and activation from over 50 independent donors-including therapeutically relevant CAR-T cells - while also preserving culture sterility and eliminating the need for disruptive sampling and endpoint assays. Our findings establish a QPI-pipeline for label-free, in-line cell monitoring and characterization which can significantly improve cell manufacturing processes.

Peripheral nerve injuries beyond 5 cm lack effective treatments. Functional nerve guidance conduits (NGCs) have emerged as transformative tools orchestrating regeneration by leveraging Schwann cell (SC)-centric mechanisms. This review comprehensively analyzes how NGC designs modulate SC behavior through three synergistic axes: physical cues, biochemical signaling, and bioelectric regulation. By enhancing microenvironmental regulation, next-generation NGCs aim to surpass autograft efficacy, offering scalable solutions for functional nerve recovery and improved patient outcomes.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with limited treatment options, partly due to a lack of effective disease models. This study presents a ferret model of pulmonary fibrosis (PF) induced by bleomycin, which replicates key characteristics of human IPF. The ferret model demonstrates an irreversible loss of pulmonary compliance, increased opacification, and structures resembling honeycomb cysts. Using single-nucleus RNA sequencing, we observed a significant shift in the distal lung epithelium toward a proximal phenotype. Cell trajectory analysis showed that AT2 cells transition into KRT8^high/KRT7^low/SOX4⁺ cells, and eventually into KRT8^high/KRT7^high/SFN⁺/TP63⁺/KRT5^low "basaloid-like" cells. These cells, along with KRT7 and KRT8 populations, are located over myofibroblasts in fibrotic areas, suggesting a role in fibrosis progression similar to that in human IPF. This model accurately reproduces the pathophysiological and molecular features of human IPF, making it a valuable tool for future research and therapeutic development.