Stem Cell Research & Therapy最新文献

Objective: Heterotopic ossification (HO) is a pathological condition characterized by dysregulated regenerative processes in skeletal muscle, resulting in the formation of mature bone within ectopic sites. Accumulating studies indicate that M2 macrophages facilitate endothelial-mesenchymal transition (EndMT), which contributes centrally to HO pathogenesis. This study explored the mechanism of M2 macrophage involvement in EndMT-mediated HO and analyzed the underlying molecular pathways.

Methods: Clinical samples of immature, mature, and autologous cancellous bones were collected to analyze macrophage infiltration and the cellular origin of HO. Using the GEO and GeneCards databases, MSX2 was identified as a candidate regulatory factor. An endothelial-macrophage co-culture system was established to investigate the specific molecular mechanisms by which macrophages affect EndMT by modulating MSX2 expression. Achilles tendon incision surgery was performed in C57BL/6 mice to simulate trauma-induced HO. Histological examination, immunohistochemistry, immunofluorescence, and ELISA were performed to verify the role of macrophages in influencing HO progression via MSX2. The STRING database was used to predict LEF1 as a downstream target gene of MSX2. Regulatory interactions between MSX2 and LEF1 were examined using dual-luciferase reporter assays, western blotting, and quantitative real-time PCR.

Results: Compared to autologous cancellous bone, there was an increase in M2 macrophage infiltration in HO tissues, accompanied by the transformation of endothelial cells at the injury site into mesenchymal stem cells. The degree of HO positively correlated with elevated levels of BMP-2, SP, Act A, TGF-β, OSM, and NT-3 in the serum. In vitro experiments demonstrated that under co-culture conditions, M2 macrophages induced mouse aortic endothelial cells (MAOECs) to exhibit elevated expression of mesenchymal markers (N-cadherin, vimentin) and mesenchymal stem cell markers (CD44, CD90), while reducing levels of endothelial markers (E-cadherin, occludin). Moreover, M2 macrophage-driven EndMT activation further promoted the upregulation of chondrogenic (Sox9, SP7) and osteogenic (OPN, OCN, Runx2) markers. However, MSX2 depletion rescued M2 macrophage-induced EndMT activation. In vivo, MSX2 inhibition or macrophage depletion reduced the osteogenic capacity in mice and decreased HO formation, whereas injection of a lentivirus overexpressing MSX2 promoted HO formation. Mechanistically, MSX2 directly binds to the LEF1 promoter to enhance its transcriptional activity, thereby activating Wnt signaling and maintaining EndMT.

Conclusions: Our findings suggest that M2 macrophages regulate EndMT-driven osteogenesis through MSX2/LEF1/Wnt axis, providing new insights into future therapeutic strategies for HO.

Background: As a chronic inflammatory disease characterized by periodontal tissue destruction, periodontitis has a pathogenesis that remains incompletely understood. This study aimed to investigate the expression of upregulated vanin-2 (VNN2) in exosomes derived from dental pulp stem cells (DPSCs) and its effects on the function of periodontal ligament stem cells (PDLSCs) and the progression of periodontitis.

Methods: A total of 35 patients with periodontitis and 35 healthy individuals were enrolled for gingival tissue sample collection. DPSC-EXO-VNN2 was cultured with a 3D system and isolated by ultracentrifugation. The samples were then subjected to nanoparticle tracking analysis (NTA), western blot and transmission electron microscopy (TEM). In vitro, PDLSCs were treated with DPSC- EXO-VNN2 and LPS, and the expression of IL-6 and TNF-α and their osteogenic potential were evaluated. Furthermore, in vivo, experimental periodontitis was induced in rats, which were then divided into two groups and treated with either DPSC-EXO-VNN2 or PBS. The maxillae were subsequently collected for histological staining and micro-CT analysis.

Results: VNN2 was upregulated in periodontitis according to dataset analysis, western blot and immunofluorescence (P < 0.05). Higher expression levels of VNN2 were associated with greater periodontal parameters PD and CAL (P < 0.05). The production of DPSC-EXO in the 3D culture system surpassed that in the 2D system. In vitro, PDLSCs internalized 3D-DPSC-EXO-VNN2, which increased LPS-induced IL-6 and TNF-α production while reducing osteogenic differentiation, as shown by decreased ALP activity and mineralization. In vivo, DPSC-EXO-VNN2 administration worsened alveolar bone loss, as micro-CT revealed a significantly lower bone volume fraction (P < 0.01) than did the control treatment.

Conclusion: This study reveals for the first time that DPSC-EXO-VNN2 participates in the progression of periodontitis by regulating the inflammatory response and osteogenic differentiation ability of PDLSCs. Future research may further explore the potential application of targeting VNN2 in treating periodontitis.

Background: Extracellular vesicles derived from human induced mesenchymal stromal cells (hiEVs) constitute a promising cell-free therapeutic option for osteoarthritis. To facilitate transition to the clinic we evaluated the therapeutic effects of hiEVs for osteoarthritis treatment. Specifically, we compared the efficacy of hiEVs collected from serum-containing and serum-free, PurStem (PS), media in an osteoarthritis mouse model.

Methods: hiEVs were administered via intra-articular injection in a destabilization of the medial meniscus (DMM) mouse model, with or without hydrogel to determine added value of localized application and controlled hiEV-release. Fluorescence imaging was used to monitor the retention of IR780-labeled hiEVs in the joint cavity. Therapeutic effects were evaluated by scoring of damage as well as expression of Mmp13 and Col2, catabolic and anabolic markers respectively, in joint tissues. Subchondral bone changes were assessed with Micro-CT.

Results: Fluorescence imaging confirmed that hiEVs remained localized at the injection site without systemic migration. HiEVs demonstrated significant protective effects against joint tissue degeneration in the osteoarthritis DMM mouse model as evidenced by reduced damage scores, decreased Mmp13 expression, and increased Col2 expression independent of the medium used for hiEV collection. The hydrogel alone also showed beneficial therapeutic effects, illustrated by reduced damage scores, increased Col2, and reduced Mmp13 expression. These effects, however, were notably smaller than those achieved with hiEV treatment. Micro-CT analysis further showed that hiEV treatment attenuated DMM-induced subchondral bone sclerosis as reflected by normalization of the bone volume fraction and trabecular structure.

Conclusions: Together, our findings demonstrate that hiEVs from xeno-free conditions effectively prevent cartilage degradation and promote its repair. This paves the way for future clinical translation of hiEV-based therapies as a safe, scalable, and effective approach to treat osteoarthritis.

Lung cancer is the first leading cause of cancer death worldwide. oxysterol-binding protein-like 2 (OSBPL2), is a lipid transport protein regulating cholesterol homeostasis. Here, we clarified the previously unreported role of OSBPL2 in lung cancer stemness properties. We observed that OSBPL2 reduced cholesterol content by HPLC-MS. It inhibited the accumulation of lipid droplets (LDs) in lung cancer. OSBPL2-mediated lipid transportation significantly suppressed tumor sphere formation, stemness markers expression and in vivo tumorigenesis and tumor metastasis. In clinical specimens, we also demonstrated that OSBPL2 repressed the expression of Lung cancer stem-like cells (LCSCs) markers-ALDH1A1, CD133 and Nanog. The level of OSBPL2 was negatively correlated with malignant of lung cancer, such as tumor stage progression and lymph node metastasis. Taken together, these findings illustrated that OSBPL2-mediated lipid transportation inhibited the stemness and aggressiveness of lung cancer cells. OSBPL2 was a potential therapeutic target to develop novel cancer-preventive compound.

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by disrupted epidermal barrier function, immune dysregulation, and persistent inflammation. Affecting both children and adults, AD significantly impairs quality of life due to its visible symptoms and associated psychosocial and economic burdens. Traditional treatments such as application of topical corticosteroids, calcineurin inhibitors, moisturizers and antibiotics, while managing symptoms, often fall short of providing long-term solutions and can lead to adverse effects over time. This review explores innovative approaches to AD management, focusing on the therapeutic potential of the secretome. The secretome, a collection of bioactive molecules secreted by cells, has shown promise in promoting tissue regeneration and modulating immune responses. This study investigates how secretome therapy can restore the integrity of keratinocytes, the primary cells responsible for maintaining the skin barrier, which is severely compromised in AD. Using in vitro AD models, the secretome's potential to reduce inflammation and enhance skin barrier function is evaluated. By targeting the underlying mechanisms of AD, secretome-based therapies could offer a novel approach to treatment, providing both regenerative and anti-inflammatory benefits. The findings from this study may pave the way for more effective, non-invasive treatments that address the root causes of AD, potentially reducing the disease's impact and improving patient outcomes.

Background: Neurotmesis, remains a significant clinical challenge due to limited intrinsic regenerative capacity and suboptimal outcomes of current therapies. Mesenchymal stromal cells (MSCs) secretome has emerged as a promising cell-free alternative, providing neurotrophic and immunomodulatory factors to support nerve repair. This study aimed to evaluate the regenerative efficacy of primed adipose-derived MSC secretome in a rat model of sciatic nerve neurotmesis.

Methods: Human and rat adipose-derived MSCs were cultured and primed under hypoxic and inflammatory conditions. Secretomes were characterized by nanoparticle tracking analysis, proteomics, and total protein quantification. Neurotmesis was induced in Wistar rats, followed by repair with biomaterial alone or combined with human or rat secretome. Functional recovery was assessed by neurophysiological measurements at 6 months. Molecular and morphological regeneration was evaluated.

Results: Secretome priming enhanced the secretion of neurotrophic factors and immunomodulatory proteins, as confirmed by transcriptomic and proteomic analyses. In vivo, secretome-treated groups showed significantly improved neurophysiological recovery and increased NGF levels. qPCR revealed upregulation of myelination-associated genes in treated nerves. Histological and TEM analyses demonstrated robust axonal regeneration.

Conclusions: Primed MSC secretome markedly enhances structural and functional recovery after sciatic nerve neurotmesis, supporting its potential as a safe, effective, and scalable cell-free therapy for peripheral nerve repair.

Background: Human basal stem cells, with their self-renewal and multilineage differentiation capacity, are essential tools for modeling airway diseases and advancing regenerative medicine. However, existing culture systems often rely on undefined components like serum, bovine pituitary extract, or feeder cells, limiting reproducibility and clinical translation. To address this limitation, we developed a well-defined culture medium that enables the long-term expansion of human airway basal stem cells while preserving their proliferative and differentiation potential.

Methods: We formulated a novel medium (sfBSC) comprising 14 defined components, including basal media, supplements, growth factors (EGF, FGF10), and signaling inhibitors (Y-27632, A-83-01, DAPT, DMH1). Human bronchial and small airway epithelial cells were cultured over multiple passages in sfBSC and assessed for morphology, population doublings, marker expression, and differentiation capacity via air-liquid interface and organoid cultures. RNA-seq was performed to explore molecular changes across passages.

Results: Bronchial and small airway epithelial cells were expanded up to 17 and 24 passages, respectively, with stable morphology and consistent cell size (10-15 μm). Cells maintained expression of canonical BSC markers (TP63, KRT5, NGFR) throughout long-term culture. Differentiation assays confirmed the ability to generate ciliated, goblet, and club cells. Optimized concentrations of EGF (1 ng/mL) and FGF10 (0.4 ng/mL) were critical for sustained proliferation. RNA-seq revealed stable marker expression and metabolic changes over time.

Conclusions: sfBSC medium offers a defined, reproducible, and scalable platform for basal stem cell culture, enabling applications in disease modeling, regenerative medicine, and clinical-grade cell production.

Background: Endothelial cells (ECs) are crucial for tissue repair and wound healing but are prone to damage and apoptosis. When tissues or blood vessels are injured, endothelial progenitor cells (EPCs) are quickly activated, home to the site, and differentiate into ECs for endothelial integrity restoration. Apoptotic extracellular vesicles (Apo-EVs), released during apoptosis, have been found to regulate the micro environment, mediate intercellular communication, and participate in tissue repair, yet there's a lack of research on how EC-derived Apo-EVs, as intercellular communication media-tors, regulate EPCs' differentiation into ECs and promote angiogenesis and wound re-pair. Therefore, this study aims to explore whether EC-derived Apo-EVs can promote the differentiation of EPCs into ECs, facilitating wound angiogenesis, and to deeply analyze the underlying molecular mechanisms and key signaling pathways.

Methods: Human embryonic stem cells were differentiated into endothelial progenitor cells (EPCs) and endothelial cells (ECs), followed by phenotypic characterization. ECs were induced to undergo apoptosis for isolating EC-derived apoptotic extracellular vesicles (EC-Apo-EVs), which were co-cultured with EPCs to evaluate their pro-differentiation capacity. Integrative analysis of EPC transcriptome and EC-Apo-EV miRNA sequencing identified key mediating miRNAs and signaling pathways, validated in vitro. A murine skin wound model was established (randomized into control, EC-Apo-EV, and positive control groups) to assess EC-Apo-EVs' therapeutic efficacy in wound healing.

Results: In this study, we induced ECs apoptosis, extracted Apo-EVs for promoting angiogenesis and wound repair. The isolated Apo-EVs showed excellent ability to promote EPCs differentiation and angiogenesis in vitro and in vivo. In wound healing, Apo-EVs outperformed the positive control group. Mechanistically, miR-30a-5p in Apo-EVs inhibits Promyelocytic Leukemia (PML), activating the Epidermal Growth Factor Receptor/Phosphatidylinositol 3-Kinase/Protein Kinase B/Vascular Endothelial Growth Factor (EGFR/PI3K/AKT/VEGF) pathway in EPCs and exerting biological effects.

Conclusion: EC-derived Apo-EVs demonstrated excellent capacity to promote EPCs differentiation and angiogenesis both in vitro and in vivo, the mechanism is associated with miR-30a-5p within the vesicles inhibiting PML and activating the EGFR/PI3K/AKT/VEGF signaling pathway. This finding provides a new perspective for revealing the role of EC-derived Apo-EVs in tissue repair and offers potential strategies for the treatment of related diseases.

Adipose tissue-derived stromal vascular fraction (SVF) has rapidly emerged as a promising tool in regenerative medicine due to its accessibility, autologous origin, and potent reparative potential. However, despite encouraging preclinical outcomes, the clinical safety of SVF across organ systems remains insufficiently characterized. This comprehensive review synthesizes current evidence on the safety and tolerability of autologous SVF therapy in humans, organized by target organ systems including cardiovascular, pulmonary, hepatic, renal, musculoskeletal, cutaneous, neurological, and inflammatory applications. Across studies, SVF therapy appears technically feasible and generally well tolerated, with adverse events predominantly mild and procedure-related (e.g., transient pain, swelling, or local inflammation). Serious complications - including embolism, infection, fibrosis, or tumor formation - have not been reported to date in clinical settings. However, available studies suffer from major limitations: small and heterogeneous cohorts, non-randomized designs, variability in cell preparation and dosing, and short follow-up durations. The lack of standardized isolation protocols and absence of mechanistic endpoints further restrict interpretation. Overall, current data support the short-term safety of autologous SVF therapy, while underscoring the need for large-scale randomized controlled trials, harmonized methodologies, and long-term surveillance to fully establish its risk-benefit profile.