Stem Cells International最新文献

Background: Stem cell-based regenerative approaches have been developed to treat osteoarthritis (OA) and repair cartilage defects. In the present study, we fabricated a three-dimensional (3D) collagen-based decellularized biological scaffold using human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) and analyzed its recellularization and subsequent differentiation potential toward chondrocytes. Methods: MSCs were isolated from human Wharton's jelly, characterized by flow cytometry, and differentiated toward osteogenic and adipogenic lineages. hWJ-MSCs were cultured in a 3D collagen scaffold. After the matrix was deposited by the cells, the scaffold was decellularized, and new hWJ-MSCs were cultured and differentiated into chondrocytes. The efficiency of the decellularization process was assessed using hematoxylin and eosin (H&E) staining, DNA quantification, scanning electron microscopy (SEM), and Raman spectroscopy. Immunohistochemical and transcriptional evaluation of chondrogenic markers, including collagen type II, aggrecan, and osteonectin, was performed. Results: Prepared decellularized scaffolds showed very low levels of nucleic materials compared to intact ones. The integrity and efficiency of the decellularization process were confirmed using SEM. Moreover, a comparison of Raman spectra of intact and decellularized scaffolds demonstrated a remarkable reduction in carbohydrate, lipid, and DNA content. Three weeks after recellularization in the presence of chondrogenic medium, the immunoreactivity and expression levels of specific chondrocyte markers, including collagen type II, aggrecan, and osteonectin, significantly increased compared to negative controls. Conclusion: hWJ-MSCs and their use in fabricating nucleic acid-free 3D collagen-based scaffolds represent a promising in vitro model for investigating how the extracellular matrix (ECM) contributes to specific cell microenvironments. Decellularized ECM can also be utilized to develop novel, cell-free biomedical products for regenerative medicine.

Dental mesenchymal stem cells (MSCs) play an essential role in the development of immature permanent teeth. Bacterial infection of the pulp and periapical tissues of immature permanent teeth, the associated oral pathogens, and their virulence factors affect the viability, proliferation, differentiation, and cytokine secretion of MSCs. Bacteria and virulence factors can also trigger an inflammatory response that induces pro-inflammatory cytokine secretion and destroys odontogenic MSCs in the pulp and periapical region, negatively affecting the development of immature permanent teeth. The present study explored the role and mechanisms of oral pathogens associated with pulpitis and apical periodontitis and their virulence factors concerning odontogenic MSCs. The findings can contribute to the clinical treatment of pulpitis and apical periodontitis of immature permanent teeth, providing a theoretical basis for improving its clinical efficacy.

Osteoarthritis (OA) is the leading joint disease that causes joint pain and disability. Despite increasing progress regarding the therapeutic potential of human umbilical cord mesenchymal stem cells (UC-MSCs) for OA, effective strategies for the treatment of OA using UC-MSCs have not yet been developed in clinical practice. Our present study has proven that the early stage in OA rats is the main development stage of nod-like receptor heat protein domain protein 3 (NLRP3)-mediated synovial inflammation. The middle stage in OA rats is the main development stage of chondrocyte apoptosis. The late stage in OA rats is the main development stage of synovial fibrosis. The treatment of UC-MSCs in the early and middle stages of OA significantly reduced cartilage damage in rats, and improved the pathological structure of the knee joint. In comparison, UC-MSCs effectively reduced chondrocyte apoptosis in the early and middle stages of OA rats, but they only effectively reduced NLRP3-mediated synovial inflammation in the early stages of OA rats. Experiments in vitro showed that UC-MSCs could inhibit NLRP3-mediated pyroptosis of rat primary synovial cells (Rat-scs). In conclusion, our findings suggest that UC-MSCs exert therapeutic effects on OA, at least in part, through inhibiting NLRP3-mediated synovial inflammation in the early stage of OA.

Objective: Postmenopausal osteoporosis (PMOP) is a common bone metabolic disorder in middle-aged and elderly women, yet its pathogenesis remains unclear. This study investigates the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) deficiency on bone homeostasis to provide insight into the mechanisms underlying PMOP. Methods: Sixteen female SD rats were randomly assigned to Sham and ovariectomized (OVX) groups. After 12 weeks, bone homeostasis disruption and Nrf2-mediated oxidative stress responses in bone tissue cells were assessed. Nrf2 expression was modulated in UMR-106 osteoblast-like cells and RAW264.7 macrophage-derived osteoclast precursor cells through knockdown or pharmacological activation. The effects on osteogenic function and osteoclast differentiation under oxidative stress were then evaluated. Results: The OVX group of rats exhibited a disruption in bone homeostasis, potentially attributable to the reduced expression of Nrf2 and its downstream antioxidant enzymes, coupled with elevated levels of oxidative stress. Nrf2 knockdown impaired osteogenic capacity in UMR-106 cells and enhanced osteoclast differentiation in RAW264.7 cells. In contrast, activation of Nrf2 using tert-butylhydroquinone (TBHQ) promoted bone formation and suppressed osteoclast differentiation and bone resorption. Conclusion: Nrf2 deficiency may contribute to PMOP by disrupting bone homeostasis. Activation of Nrf2 may represent a potential therapeutic strategy for restoring bone balance and treating PMOP.

Liver hepatocellular carcinoma (LIHC) is a prevalent and highly aggressive form of liver cancer, characterized by increasing rates of incidence and mortality globally. Although numerous treatment options currently exist, they frequently result in insufficient clinical outcomes for those diagnosed with LIHC. This highlights the urgent need to identify new biomarkers that can enhance prognostic evaluations and support the development of more effective therapeutic strategies for LIHC. Through the use of the SwissTargetPrediction tool, we precisely identified molecular targets related to Sorafenib. Furthermore, analysis of RNA sequencing data from the TCGA-LIHC cohort uncovered 24 genes associated with different patient prognoses following Sorafenib therapy. Employing a clustering-based analytical approach, we assessed the connections between gene expression profiles, clinical outcomes, immune cell infiltration levels, and tumor stage progression. A prognostic framework was constructed by applying various machine learning techniques and subsequently validated across several independent datasets. Utilizing the XgBoost algorithm, MAPK12 emerged as a key regulatory gene influencing the prognosis of individuals with LIHC. The results of in vitro experiments demonstrated that knockdown of MAPK12 reduced the proliferation, metastasis, and tumor stemness-related sphere-forming ability of LIHC cells. These results underscore the promise of MAPK12 as a potential prognostic biomarker for LIHC and offer valuable insights for crafting personalized treatment approaches.

Tumor surgery or trauma in the maxillofacial region may cause injuries to peripheral nerves, such as facial nerves. The gold standard of treatment for peripheral nerve injury has been autologous nerve grafting. Since new peripheral nerve regeneration technologies are required, three-dimensional (3D) structures fabricated only from cells by using Bio 3D printers are attracting attention. Dental pulp stem cells (DPSCs) are a promising option as a cell source because of their high clonogenic, proliferative, and multidifferentiation potentials. In this study, nerve conduits were fabricated from DPSCs using a Bio 3D printer, and their potential for nerve regeneration was evaluated in a rat facial nerve injury model. DPSCs were obtained from wisdomteeth of patients and cultured. A 5 mm Bio 3D conduit was fabricated by using a Bio 3D printer. Six F344 rnu-/rnu- rats with immune deficiency (10 weeks old, body weight: 190-240 g) were divided into two groups: a Bio 3D group (n = 3) and a silicone tube group (n = 3). The 5 mm Bio 3D conduits and silicone tubes were transplanted into 4 mm defects. Evaluation was performed at 12 weeks after the surgery. The whiskers of immunodeficient rats in both groups were moving. The number of myelinated axons was larger in the Bio 3D group than in the silicone group. Myelinated axon diameter (MAD) and myelin thickness (MT) of regenerated axons in the Bio 3D group were significantly greater than those in the silicone group (MAD: p  < 0.01, MT: p  < 0.05). In this study, we confirmed the nerve regeneration potential of Bio 3D structures fabricated from DPSCs that were transplanted into a rat model of facial nerve injury.

Background: Nonalcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease and is a comorbidity in type 2 diabetes (T2D) mellitus. Mesenchymal stem cell (MSC) is emerging as a potential therapeutic strategy for diabetes and NAFLD through mitochondrial transfer initiated by signaling from injured recipient cells. Thus, in this study, we investigated whether exogenous mitochondrial preconditioning of MSCs could exert superior effects on NAFLD and explore the role of MSCs-mediated mitochondrial transfer into hepatocyte. Methods: After free HepG2 mitochondria pretreated, umbilical cord-derived MSCs (UC-MSCs) (mito-MSCs), T2D model mice were infused with equal amounts of MSCs/mito-MSCs via the tail vein once a week for 4 weeks. Body weight and random blood glucose were monitored weekly. After the end of treatment, the mitochondrial transfer level of MSCs before and after pretreatment were monitored by fluorescence tracing. Blood and liver were collected for biochemical and histopathological examinations. The number, morphology, and function of mitochondria in liver tissue were evaluated by tissue electron microscopy and western blot analysis. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to monitor the expression of genes associated with lipid metabolism and regulation pathways. Results: Pretreatment of UC-MSCs enhanced the efficacy of MSCs in lowering blood glucose, liver transaminase, triglyceride levels, and reducing histological damage, which may be related to free mitochondria triggering autophagy of MSCs, which in turn promoted the entry of MSCs mitochondria into the liver tissue of diabetic mice. Conclusion: Exogenous mitochondria could enhance the therapeutic efficacy of MSCs in NAFLD via mediating mitochondrial transfer, which offers a novel strategy for the improving the outcomes of MSCs cell-therapy for diabetes-related NAFLD.

Acute and chronic neurodegenerative conditions (NDs) are major causes of disability and mortality worldwide. Acute NDs encompass conditions such as stroke, traumatic brain injury (TBI), and spinal cord injury (SCI). On the other hand, chronic NDs include Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS). Currently, no definitive cure exists for these diseases, and available therapies focus primarily on slowing the progression of symptoms. Mesenchymal stem cells (MSCs), due to their multilineage differentiation capacity, immunomodulatory abilities, and regenerative properties, have gained attention in regenerative medicine. In recent years, extracellular vesicles (EVs) derived from MSCs have shown great promise as a cell-free therapeutic approach, eliminating the risks associated with direct MSCs use, such as tumorigenicity and poor cell survival after transplantation. EVs have emerged as powerful mediators of intercellular communication and tissue repair, exhibiting immunomodulatory, anti-inflammatory, and proregenerative properties. However, limitations such as low EVs yield and reduced efficacy due to MSCs replicative senescence restrict their therapeutic potential. Preconditioning strategies, including hypoxia, 3D cultures, and biochemical priming, have been explored in other fields to enhance EVs properties, yet their specific application to NDs remains under-reported. This review aims to address this gap by analyzing the preconditioning methods used to boost the therapeutic potential of MSCs-derived EVs for neurodegenerative diseases. These preconditioning strategies may enhance EVs yield, functional cargo, and targeted therapeutic efficacy for treating acute and chronic NDs.

Aims: Inflammation is a key process involved in the early stages of periodontal regeneration, where immune cells are responsible for the recruitment of osteoblast to facilitate periodontal regeneration. The aim of the present study was to explore the effect of platelet-rich fibrin (PRF) on macrophage polarization, and thereafter to investigate its effect on osteoblast recruitment to enhance early-stage periodontal regeneration. Materials and Methods: The extracted liquids of PRF, produced using fixed-angled and horizontal centrifugation protocols, were utilized to stimulate Thp1 to study macrophage proliferation and polarization. Thereafter, the supernatants of Thp1 were collected and utilized to stimulate the migration of human bone marrow osteoblasts, to investigate the recruitment of osteoblast via macrophage polarization. Results: PRF stimulated the proliferation and recruitment of macrophages, with horizontal centrifugation protocols demonstrating significantly greater potential when compared to fixed-angled. Furthermore, PRF was able to enhance the recruitment of osteoblast via macrophage polarization, with horizontal platelet-rich fibrin (H-PRF) demonstrating the most significant increase. Conclusion: The present study explored a promising mechanism of the periodontal regeneration function of PRF, by inducing macrophage polarization, thereby enhancing osteoblast recruitment, with horizontal centrifugation significantly improving these findings.

Cardiac fibroblasts (CFs) are activated into cardiac myofibroblasts (CMFs) in myocardial infarction (MI) and promote fibrosis, playing a crucial role in deteriorating cardiac function and inducing fatal arrhythmias. Transplantation of bone marrow mesenchymal stem cells (BMSCs) has emerged as a promising therapeutic approach for ischemic heart diseases, including MI. Recent studies have indicated that BMSCs can modulate the survival, differentiation, and antifibrotic activity of CFs. Kruppel-like factor 5 (KLF5) is a significant transcription factor involved in maintaining stem cell properties. In this study, we aimed to investigate whether overexpression of KLF5 could enhance the cardioprotective characteristics of BMSCs, particularly in terms of mitigating structural and electrical remodeling. Our in vivo experiments revealed that transplantation of KLF5-overexpressing BMSCs in mice with MI led to a substantial reduction in ventricular fibrosis and the occurrence of ventricular arrhythmias (VAs). In vitro coculture experiments demonstrated that BMSCs could inhibit CFs activation and cytoskeleton protein bundling induced by hypoxia through paracrine effects, resulting in reduced expression of α-SMA and Collagen I. Furthermore, coculturing BMSCs significantly reduced the expression of connexin 43, alleviated hypoxia, increased the expression of inward-rectifier K⁺ current (Kir), and decreased voltage-dependent K⁺ (Kv) currents. Mechanistically, KLF5 enhanced the effects of BMSCs by facilitating the transfer of miR-152-3 p from BMSCs-derived exosomes to CFs. Overall, our findings show that BMSCs transplantation promotes the recovery of cardiac function and reduces the incidence of arrhythmias by inhibiting CFs activation and modulating CFs Kir current remodeling. Additionally, overexpression of KLF5 enhances the cardioprotective effects of BMSCs.