npj Regenerative Medicine最新文献

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.

The mammalian heart retains regenerative capacity during the early postnatal period, but this ability declines as it matures. Enhancing cardiomyocyte proliferation represents a key therapeutic approach to promote heart regeneration and repair, yet the molecular mechanisms remain elusive. Here, we identified LncBAR (BAF complex-associated lncRNA) as a critical regulator of cardiac regeneration. LncBAR expression declines during heart development but is upregulated following cardiac injury. Loss of LncBAR impairs cardiomyocyte growth, suppresses cell cycle gene expression, and diminishes heart regeneration, as evidenced by reduced cytokinesis and cardiac function. Conversely, cardiac specific overexpression of LncBAR restores cardiomyocyte proliferation and enhances cardiac regeneration, especially in adult myocardial infarction model. Mechanistically, LncBAR interacts with Brg1, stabilizing BRG1 protein level and activating cell cycle progression to drive cardiomyocytes proliferation. Collectively, our study identified LncBAR as a crucial regulator for heart regeneration, highlighting the LncBAR-BRG1 axis as a promising therapeutic strategy for cardiac repair.

Distal injuries in human fingertips can regenerate almost fully, yet the process of human fingertip regeneration has hardly been characterized on a cellular and molecular level. A silicone finger cap, comprising a puncturable reservoir, was used to treat 22 human fingertip amputations. In all patients, subcutaneous tissue, nailbed and skin regenerated with excellent outcomes. Through the clinical assessment of the wounds, the regenerative process was divided into four distinct phases. Proteomic data from wound fluid samples collected at regular intervals, confirmed robust and unbiasedly distinct proteomic signatures, characteristic processes, and active regulatory networks in each phase. Moreover, this human dataset provides important insights, showing clear divergences from findings in regenerative animal models. The longitudinal and comprehensive analysis presented here unveils the complex orchestration of four clinically and proteomically-distinct phases of human fingertip regeneration. Further analyses of this proteomic data will allow for the identification of candidates orchestrating human fingertip regeneration and serving as a framework for comparative and regenerative medicine studies. This clinical trial was registered at ClinicalTrials.gov Identifier: NCT03089060 on March 17, 2017.

Cyclin A2 (CCNA2), a master cell cycle regulator silenced in postnatal cardiomyocytes, promotes cardiac repair in animal models. However, its effect on cytokinesis in adult human cardiomyocytes was previously unknown. We engineered a replication-deficient adenoviral vector encoding human CCNA2 under the cardiac Troponin T promoter and delivered it to freshly isolated cardiomyocytes from adult human hearts. Time-lapse live imaging revealed the induction of complete cytokinesis with preservation of sarcomeres and calcium mobilization in redifferentiated daughter cardiomyocytes. Single-nucleus transcriptomic profiling of CCNA2-transgenic and non-transgenic mouse hearts uncovered a cardiomyocyte subpopulation characterized by enrichment of cytokinesis, proliferation, and reprogramming gene signatures. Ultra-deep bulk RNA sequencing of adult and fetal human hearts further highlighted reprogramming pathways relevant to CCNA2-induced effects. Together, these findings demonstrate that CCNA2 can reinitiate cytokinesis in adult human cardiomyocytes, illuminating conserved molecular programs that support its promise as a regenerative gene therapy for the heart.