Search Results (120)

Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) are emerging as potent acellular therapeutics; however, their rapid clearance hinders their clinical translation. To address this issue, 3D-bioprinted genipin-crosslinked gelatin (GECL) was engineered for human health. GECL hydrogels were functionalised with human umbilical cord MSC-derived sEVs (hUCMSC-sEVs) to create a bioactive wound-healing platform. These hydrogels demonstrated favourable physicochemical, mechanical, and biodegradable properties while providing an extracellular matrix (ECM)-mimetic environment conducive to tissue regeneration. MSCs were isolated from the umbilical cords, and their small extracellular vesicles (sEVs) were extracted and incorporated into gelatin-based hydrogels via 3D bioprinting. These sEV-loaded scaffolds were embedded in full-thickness wounds in mice, and healing was evaluated through macroscopic observation, histological analysis, collagen deposition, and angiogenesis assessment. Compared with the untreated controls, both the hydrogel-only (B) and sEV-loaded hydrogel (BE) groups significantly accelerated in vivo wound healing. Notably, the BE group achieved complete wound closure within 14 days, restoring the skin architecture, which closely resembled the native tissue with well-organised epidermal and dermal layers, optimal thickness, and skin appendages. Histological and ultrastructural assessments revealed an increased collagen type I deposition, a reduced α-smooth muscle actin (α-SMA) expression, and a robust neovascularisation. The TEM revealed tight junctions and active cellular infiltration, indicating scaffold integration and functional remodelling. Immunohistochemistry further revealed an upregulated CD31 expression with a balanced α-smooth muscle actin (α-SMA) expression, reflecting coordinated angiogenesis and myofibroblast regulation. These results highlight sEV-functionalised GECL hydrogels as robust and clinically translatable acellular therapeutic green products for accelerated wound closure and functional skin regeneration, advancing the fields of regenerative medicine and life expectancy. Full article

Skeletal muscle regeneration declines with age despite the persistence of satellite cells (muscle stem cells, MuSCs), suggesting that regenerative impairment reflects functional dysregulation rather than MuSC depletion. Increasing evidence identifies early MuSC activation during the immediate post-injury period as a stress-sensitive, rate-limiting transition that is particularly vulnerable in aged muscle. Aged MuSCs exhibit elevated stress responses and reduced membrane remodeling capacity, accompanied by weakened activation-associated transcriptional induction. In contrast, proliferative and differentiation programs remain largely intact once activation is successfully initiated. These findings underscore that impaired coordination during early activation contributes to long-term regenerative decline in aging. Within this framework, MG53 (tripartite motif–containing protein 72, TRIM72), a muscle-enriched TRIM family E3 ubiquitin ligase originally identified as a mediator of sarcolemmal membrane repair, may also function as a stress-responsive regulator that stabilizes the early activation environment. Rather than directly determining cell fate, MG53 is proposed to facilitate activation by mitigating stress-associated membrane disruption and maintaining programmatic coordination under age-related physiological constraints. Most mechanistic evidence derives from rodent models, and direct validation in human aging muscle remains limited. These observations suggest that targeting early activation, rather than simply increasing proliferation, may better preserve regenerative capacity in aging skeletal muscle. Full article

The number of pet dogs is increasing, and the number of working dogs (e.g., guide dogs, police dogs) is also gradually increasing. Skin wounds are a common clinical problem in dogs and tend to be more common in the clinic as mechanical wounds. The healing process of skin wounds is often influenced by a variety of factors, including infection, nutritional status, and immune response, while wound healing is more difficult in dogs with diabetes or aging dogs. Mesenchymal stem cells (MSCs) play an important role in skin healing and regeneration with their multidirectional differentiation potential and immunomodulatory function. However, the application of MSCs alone for the treatment of skin wounds may have certain limitations, such as low cell survival and a lack of localization. Therefore, it is important to find methods that can enhance the therapeutic effect of MSCs. Secreted protein acidic and rich in cysteine (SPARC), an extracellular matrix protein widely involved in regulating biological processes such as cell proliferation, migration, and matrix production, may enhance the efficacy of MSCs in skin wound healing. This study aims to systematically evaluate the therapeutic efficacy of SPARC-overexpressing adipose-derived mesenchymal stem cells (ADSCs) in promoting skin wound healing by establishing wound models in normal, diabetic, and aged mice and dogs, thereby validating their potential under diverse physiological and pathological conditions. For in vitro validation, we used hydrogen peroxide (H₂O₂) to induce Human Umbilical Vein Endothelial Cell (HUVEC) and Human Keratinocyte Cell (HaCaT) injury. All animals were randomly assigned to six experimental groups as follows: (1) Model group: Untreated wound (negative control); (2) HY group: Hydrogel alone (vehicle control); (3) Con group: Control-ADSCs (cell control); (4) Con-Exo&HY group: Control-ADSC exosomes in hydrogel; (5) SPARC group: oe-SPARC-ADSCs (treatment); (6) SPARC-Exo&HY group: oe-SPARC-ADSC exosomes in hydrogel (treatment). Separately, HUVEC and HaCaT cells were assigned to four experimental conditions: a blank control group, a model group, a control-ADSC-treated group, and an oe-SPARC-ADSC-treated group. ADSCs modified by SPARC significantly promoted re-epithelialization integrity, collagen deposition, inflammation reduction, angiogenesis, and hair follicle regeneration during wound healing in dog skin. HUVEC and HaCaT cells proliferated after adding oe-SPARC-ADSCs cell supernatant. Meanwhile, quantitative proteomic sequencing data analysis showed that SPARC could promote skin wound healing by enhancing cell adhesion, hyaluronic acid binding, and vascular smooth muscle contraction of ADSCs. Both in vitro cellular assays and in vivo wound-healing models suggest that the combination of SPARC and ADSCs for the treatment of skin wounds has broad application prospects. Full article

Mutations in genes encoding sarcomeric proteins are a common cause of cardiomyopathy and sudden cardiac death in humans. We evaluated the hypothesis that myofilament dysfunction is coupled to morphological and functional alterations of cardiomyocyte nuclei in a Tnnc1-targeted knock-in (Tnnc1-p.A8V) mouse model of hypertrophic cardiomyopathy (HCM). Tnnc1 is the gene that codes for the isoform of the Ca²⁺-regulatory protein troponin C (cTnC) that is expressed in cardiomyocytes and slow skeletal muscle fibers and resides on thin filaments of sarcomeres in those muscles. This pathogenic mutation in a sarcomere gene alters many aspects of cardiomyocyte function, including sarcomere contractility, cytoplasmic Ca²⁺ buffering, and gene expression. Analysis of myocardial histological sections and isolated cardiomyocytes from adult Tnnc1-p.A8V mouse hearts revealed significantly smaller (cross-sectional area and volume) and rounder nuclei compared to those from age-matched, wild-type control mice. Changes in nuclear morphology could not be explained by differences in cardiomyocyte size or ploidy. Isolated wild-type and mutant cardiomyocyte nuclei, which are embedded centrally within myofibrils, undergo compression during contraction of the cardiomyocyte, indicating that during each heartbeat cardiomyocyte nuclei would be mechanically deformed as well as being exposed to elevated cytoplasmic Ca²⁺. Immunoblotting analysis indicated decreased nuclear localization of cardiac troponin C and decreased histone H4 expression in Tnnc1-p.A8V mouse hearts. Next, we investigated the influence of nucleocytoplasmic transport by immunofluorescence microscopy, and we could not confirm nuclear localization of cardiac troponin C in fixed myocardial tissue from adult mice. However, cardiac troponin C could be detected in healthy human-induced pluripotent stem cell-derived cardiomyocyte nuclei. We conclude that pathological myofilament dysfunction due to a pathogenic, cardiomyopathy-associated mutation can be linked to altered protein composition of cardiomyocyte nuclei and aberrant nuclear morphology. Full article

Thyroid eye disease (TED) is an autoinflammatory condition characterized by fibrosis in orbital fat and extraocular muscles, primarily driven by TSH receptor antibodies and inflammatory cytokines. While research has predominantly focused on the involvement of fat tissue, the understanding of myopathy in TED remains limited. This study developed a TED mouse model and isolated myoblasts from both control individuals and TED patients for analysis. Single-cell RNA sequencing was used to investigate myofiber type changes in TED and their alterations following treatment with human-derived mesenchymal stem cells. Key regulatory genes involved in myofiber differentiation and fibrosis in myofibroblasts were identified, and their expression balance was validated in myoblasts derived from both normal individuals and TED patients. Our analysis revealed a disease-associated shift in myofiber types and identified Six1 and Eya1 as central regulators of myofiber differentiation and fibrosis suppression. These regulatory effects were validated in primary myoblasts isolated from both control and TED patients. Collectively, our findings uncover a novel role for the Six1/Eya1 axis in modulating muscle remodeling and fibrosis in TED and provide a foundation for the development of targeted therapies for TED-associated myopathy. Full article

Osteosarcopenia is a widespread geriatric condition resulting from the coexistence of osteoporosis and sarcopenia, where the connection between bone and muscle is, in part, driven by bone–muscle crosstalk. Given the close, reciprocal influence of muscle on nerve, and vice versa, it is not surprising that there are corresponding aging changes in the biochemistry and morphology of the neuromuscular junction (NMJ). Indeed, degeneration of motor neurons and progressive disruption of the neuromuscular connectivity were observed in old age. Extracellular vesicles (EVs) derived from human amniotic fluid stem cells (hAFSC), exhibiting antioxidant properties, which can also explain their anti-aging and cytoprotective effects, can be considered as potential treatment for age-related diseases. To study cell interactions under both healthy and pathological conditions occurring in musculo–skeletal apparatus, we developed a three-culture system exploiting the use of well-known transwell supports. This system allows both myotubes and neurons, eventually treated with EVs, and osteoblasts, induced to osteoporosis, to interact physically and biochemically. Collectively, this method allowed us to understand how the modifications induced in osteoblasts during bone disorders trigger a cascade of detrimental effects in the muscle and neuron parts. Moreover, we demonstrated the efficacy of hAFSC-EVs in preventing NMJ dysfunction, muscle atrophy, and osteoblast impairment. Full article

Diabetes mellitus, both type 1 (T1D) and type 2 (T2D), has become the epidemic of the century and a major public health concern given its rising prevalence and the increasing adoption of a sedentary lifestyle globally. This multifaceted disease is characterized by impaired pancreatic beta cell function and insulin resistance (IR) in peripheral organs, namely the liver, skeletal muscle, and adipose tissue. Additional insulin target tissues, including cardiomyocytes and neuronal cells, are also affected. The advent of stem cell research has opened new avenues for tackling this disease, particularly through the regeneration of insulin target cells and the establishment of disease models for further investigation. Human-induced pluripotent stem cells (iPSCs) have emerged as a valuable resource for generating specialized cell types, such as hepatocytes, myocytes, adipocytes, cardiomyocytes, and neuronal cells, with diverse applications ranging from drug screening to disease modeling and, importantly, treating IR in T2D. This review aims to elucidate the significant applications of iPSC-derived insulin target cells in studying the pathogenesis of insulin resistance and T2D. Furthermore, recent differentiation strategies, protocols, signaling pathways, growth factors, and advancements in this field of therapeutic research for each specific iPSC-derived cell type are discussed. Full article

Skeletal muscle regeneration requires a reliable source of myogenic progenitor cells capable of forming new fibers and creating a self-renewing satellite cell pool. Human induced pluripotent stem cell (hiPSC)-derived teratomas have emerged as a novel in vivo platform for generating skeletal myogenic progenitors, although in vivo studies to date have provided only an early single-time-point snapshot. In this study, we isolated a specific population of CD82⁺ ERBB3⁺ NGFR⁺ cells from human iPSC-derived teratomas and verified their long-term in vivo regenerative capacity following transplantation into NSG-mdx^4Cv mice. Transplanted cells engrafted, expanded, and generated human Dystrophin⁺ muscle fibers that increased in size over time and persisted stably long-term. A dynamic population of PAX7⁺ human satellite cells was established, initially expanding post-transplantation and declining moderately between 4 and 8 months as fibers matured. MyHC isoform analysis revealed a time-based shift from embryonic to neonatal and slow fiber types, indicating a slow progressive maturation of the graft. We further show that these progenitors can be cryopreserved and maintain their engraftment potential. Together, these findings give insight into the evolution of teratoma-derived human myogenic stem cell grafts, and highlight the long-term regenerative potential of teratoma-derived human skeletal myogenic progenitors. Full article

Background: Duchenne muscular dystrophy (DMD), which affects 1 in 3500 to 5000 newborn boys worldwide, is characterized by progressive skeletal muscle weakness and degeneration. The reduced muscle regeneration capacity presented by patients is associated with increased fibrosis. Satellite cells (SCs) are skeletal muscle stem cells that play an important role in adult muscle maintenance and regeneration. The absence or mutation of dystrophin in DMD is hypothesized to impair SC asymmetric division, leading to cell cycle arrest. Methods: To overcome the limited availability of biopsies from DMD patients, we used our 3D skeletal muscle organoid (SMO) system, which delivers a stable population of myogenic progenitors (MPs) in dormant, activated, and committed stages, to perform SMO cultures using three DMD patient-derived iPSC lines. Results: The results of scRNA-seq analysis of three DMD SMO cultures versus two healthy, non-isogenic, SMO cultures indicate reduced MP populations with constant activation and differentiation, trending toward embryonic and immature myotubes. Mapping our data onto the human myogenic reference atlas, together with primary SC scRNA-seq data, indicated a more immature developmental stage of DMD organoid-derived MPs. DMD fibro-adipogenic progenitors (FAPs) appear to be activated in SMOs. Conclusions: Our organoid system provides a promising model for studying muscular dystrophies in vitro, especially in the case of early developmental onset, and a methodology for overcoming the bottleneck of limited patient material for skeletal muscle disease modeling. Full article

Cardiomyopathies are a heterogeneous group of heart muscle diseases that can lead to heart failure, arrhythmias, and sudden cardiac death. Traditional animal models and in vitro systems have limitations in replicating the complex pathology of human cardiomyopathies. Induced pluripotent stem cells (iPSCs) offer a transformative platform by enabling the generation of patient-specific cardiomyocytes, thus opening new avenues for disease modeling, drug discovery, and regenerative therapy. This process involves reprogramming somatic cells into iPSCs and subsequently differentiating them into functional cardiomyocytes, which can be characterized using techniques such as electrophysiology, contractility assays, and gene expression profiling. iPSC-derived cardiomyocyte (iPSC-CM) platforms are also being explored for drug screening and personalized medicine, including high-throughput testing for cardiotoxicity and the identification of patient-tailored therapies. While iPSC-CMs already serve as valuable models for understanding disease mechanisms and screening drugs, ongoing advances in maturation and bioengineering are bringing iPSC-based therapies closer to clinical application. Furthermore, the integration of multi-omics approaches and artificial intelligence (AI) is enhancing the predictive power of iPSC models. iPSC-based technologies are paving the way for a new era of personalized cardiology, with the potential to revolutionize the management of cardiomyopathies through patient-specific insights and regenerative strategies. Full article

Mammary intraductal macrophages (foam cells) in humans are the most commonly encountered cells in spontaneous breast nipple discharge, nipple aspirate fluid, and ductal lavage, yet their origin remains unproven. These cells, in both humans and murine model systems, increase in pregnancy, pseudopregnancy, and other conditions like proliferative fibrocystic disease and intraductal neoplasia, ductal carcinoma in situ (DCIS), where there is intraductal ectasia and obstruction. Previous immunocytochemical studies with macrophage (CD68, lysozyme), epithelial (cytokeratin, estrogen receptor), and myoepithelial (smooth muscle actin, CALLA, maspin) markers have indicated that intraductal foam cells are of macrophage lineage. These foam cells engage in phagocytosis of both endogenous and exogenous substances present within the ducts and are not proliferative. Although it has been suggested that foam cells could derive from tissue-specific and niche-specific precursors or circulating monocytes, to date no experimental nor clinical studies have provided direct proof of their origin. In this study, we provide evidence in both human and murine bone marrow transplant studies that intraductal foam cells are bone marrow-derived. We first studied a registry of sex-mismatched bone marrow transplant recipients who later in life had undergone breast biopsies for either proliferative fibrocystic disease, DCIS, or gynecomastia, and studied these biopsies by XY chromosome fluorescence in situ hybridization (FISH) and informative microsatellite polymorphic markers. The intraductal foam cells were of bone marrow donor-origin. Then, in the experimental bone marrow transplant murine studies, donor marrow from female ROSA26 containing the lacZ reporter were transplanted into either irradiated female recipient transgenic mice carrying the highly penetrant MMTV-pymT or FVB/N background mice, where induced pluripotent stem (iPS) cells derived from tail vein fibroblasts of FVB/N-Tg(MMTV-PyVT)634Mul/J mice were subsequently injected into their mammary fat pads. In all of the transplanted recipient mice, the intraductal foam cells expressed the β-galactosidase (lacZ) reporter and also co-expressed markers of myeloid–macrophage lineage. The number of donor-derived intraductal foam cells increased in pseudopregnancy 5-fold and in intraductal neoplasia 10-fold. Although macrophages of different origins and lineages are undoubtedly present within both the murine and human breasts, those macrophages that qualify as phagocytic intraductal foam cells are bone marrow-derived. Full article

Emery–Dreifuss muscular dystrophy type 1 (EDMD1) is a rare genetic disease caused by mutations in the EMD gene, which encodes the nuclear envelope protein emerin. Despite understanding the genetic basis of the disease, the molecular mechanism underlying muscle and cardiac pathogenesis remains elusive. Progress is restricted by the limited availability of patient-derived samples; therefore, there is an urgent need for human-specific cellular models. In this study, we present the generation and characterization of induced pluripotent stem cell (iPSC) lines derived from EDMD1 patients carrying EMD mutations that lead to truncated or absent emerin, together with iPSCs from healthy donor. The patient-specific iPSCs exhibit stable karyotypes, maintain appropriate morphology, express pluripotency markers, and demonstrate the ability to differentiate into three germ layers. To model EDMD1, these iPSCs were differentiated into myogenic progenitors, myoblasts, and multinucleated myotubes, which represent all stages of myogenesis. Each developmental stage was validated by the presence of stage-specific markers, ensuring the accuracy of the model. We present the first iPSC-based in vitro platform that captures the complexity of EDMD1 pathogenesis during myogenesis. This model can significantly contribute to understanding disease mechanisms and develop the targeted therapeutic strategies for EDMD1. Full article

The global issue of aging populations has become increasingly prominent, thus the research and development for anti-aging therapies to assure longevity as well as to ameliorate age-related complications is put high on the agenda. The young humoral milieu has been substantiated to impart youthful characteristics to aged cells or organs. Extracellular vesicles (EVs) are a heterogeneous group of cell-derived membrane-limited structures that serve as couriers of proteins and genetic material to regulate intercellular communication. Of note, EVs appeared to be an indispensable component of young blood in prolonging lifespans, and circulating EVs have been indicated to mediate the beneficial effect of a young milieu on aging. Human umbilical cord mesenchymal stem cell-derived EVs (HUCMSC-EVs), isolated from the youngest adult stem cell source, are speculated to reproduce the function of circulating EVs in young blood and partially revitalize numerous organs in old animals. Robust evidence has suggested HUCMSC-EVs as muti-target therapeutic agents in combating aging and alleviating age-related degenerative disorders. Here, we provide a comprehensive overview of the anti-aging effects of HUCMSC-EVs in brain, heart, vasculature, kidney, muscle, bone, and other organs. Furthermore, we critically discuss the current investigation on engineering strategies of HUCMSC-EVs, intending to unveil their full potential in the field of anti-aging research. Full article

In general, the nerve cells of the peripheral nervous system regenerate normally within a certain period after the physical damage of their axon. However, when peripheral nerves are transected by trauma or tissue extraction for cancer treatment, spontaneous nerve regeneration cannot occur. Therefore, it is necessary to perform microsurgery to connect the transected nerve directly or insert a nerve conduit to connect it. In this study, we applied human tonsillar mesenchymal stem cell (TMSC)-derived Schwann cell-like cells (TMSC-SCs) to facilitate nerve regeneration and prevent muscle atrophy after neurorrhaphy. The TMSC-SCs were manufactured in a good manufacturing practice facility and termed neuronal regeneration-promoting cells (NRPCs). A rat model of peripheral nerve injury (PNI) was generated and a mixture of NRPCs and fibrin glue was transplanted into the injured nerve after neurorrhaphy. The application of NRPCs and fibrin glue led to the efficient induction of sciatic nerve regeneration, with the sparing of gastrocnemius muscles and neuromuscular junctions. This sparing effect of NRPCs toward neuromuscular junctions might prevent muscle atrophy after neurorrhaphy. These results suggest that a mixture of NRPCs and fibrin glue may be a therapeutic candidate to enable peripheral nerve and muscle regeneration in the context of neurorrhaphy in patients with PNI. Full article

Idiopathic pulmonary fibrosis (IPF) is the most common type of fibrosis in lungs, characterized as a chronic and progressive interstitial lung disease involving pathological findings of fibrosis with a median survival of 3 years. Despite the knowledge accumulated regarding IPF from basic and clinical research, an effective medical therapy for the condition remains to be established. Thus, it is necessary for further research, including stem cell therapy, which will provide new insights into and expectations for IPF treatment. Recently, it has been reported that one of the new therapeutic candidates for IPF is adipose-derived mesenchymal stem cells (ADSCs), which have several benefits, such as easy accessibility and minimal morbidity compared to bone marrow-derived mesenchymal stem cells. Therefore, we investigated the possibility of ADSCs as a therapeutic candidate for IPF. Using human lung fibroblasts (LFs) from IPF patients, we demonstrated that human IPF LFs cocultured with ADSCs led to reduced fibrosis-related genes. Further analysis revealed that ADSCs prevented the activation of the ERK signaling pathway in IPF LFs via the upregulation of protein tyrosine phosphatase receptor-type R (PTPRR), which negatively regulates the ERK signaling pathway. Moreover, we demonstrated that intravascular administration of ADSCs improved the pathogenesis of bleomycin-induced pulmonary fibrosis with reduced collagen deposition in histology and hydroxyproline quantification and collagen markers such as the gene expression of types I and III collagen and α-smooth muscle actin (α-SMA) in a murine model. ADSC transfer was also investigated in a humanized mouse model of lung fibrosis induced via the infusion of human IPF LFs, because the bleomycin installation model does not fully recapitulate the pathogenesis of IPF. Using the humanized mouse model, we found that intravascular administration of ADSCs also improved fibrotic changes in the lungs. These findings suggest that ADSCs are a promising therapeutic candidate for IPF. Full article