International journal of stem cells最新文献

Despite long-term research achievements, the development of cell therapy (CT) products remains challenging. This is because the risks experienced by the subject and therapeutic effects in the clinical trial stage are unclear due to the various uncertainties of CT when administered to humans. Nevertheless, as autologous cell products for systemic administration have recently been approved for marketing, CT product development is accelerating, particularly in the field of unmet medical needs. The human experience of CT remains insufficient compared with other classes of pharmaceuticals, while there are countless products for clinical development. Therefore, for many sponsors, understanding the rationale of human application of an investigational product based on the consensus and improving the ability to apply it appropriately for CT are necessary. Thus, defining the level of evidence for safety and efficacy fundamentally required for initiating the clinical development and preparing it using a reliable method for CT. Furthermore, the expertise should be strengthened in the design of the first-in-human trial, such as the starting dose and dose-escalation plan, based on a sufficiently acceptable rationale. Cultivating development professionals with these skills will increase the opportunity for more candidates to enter the clinical development phase.

Background and objectives: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease mainly affecting young women of childbearing age. SLE affects the skin, joints, muscles, kidneys, lungs, and heart. Cardiovascular complications are common causes of death in patients with SLE. However, the complexity of the cardiovascular system and the rarity of SLE make it difficult to investigate these morbidities. Patient-derived induced pluripotent stem cells (iPSCs) serve as a novel tool for drug screening and pathophysiological studies in the absence of patient samples.

Methods and results: We differentiated CMs from HC- and SLE-iPSCs using 2D culture platforms. SLE-CMs showed decreased proliferation and increased levels of fibrosis and hypertrophy marker expression; however, HC-and SLE-monolayer CMs reacted differently to SLE serum treatment. HC-iPSCs were also differentiated into CMs using 3D spheroid culture and anti-Ro autoantibody was treated along with SLE serum. 3D-HC-CMs generated more mature CMs compared to the CMs generated using 2D culture. The treatment of anti-Ro autoantibody rapidly increased the gene expression of fibrosis, hypertrophy, and apoptosis markers, and altered the calcium signaling in the CMs.

Conclusions: iPSC derived cardiomyocytes with patient-derived serum, and anti-Ro antibody treatment could serve in effective autoimmune disease modeling including SLE. We believe that the present study might briefly provide possibilities on the application of a combination of patient-derived materials and iPSCs in disease modeling of autoimmune diseases.

Background and objectives: RUNX2 plays an essential role during the odontoblast differentiation of dental pulp stem cells (DPSCs). RUNX2 Exon 5 is an alternative exon and essential for RUNX2 transcriptional activity. This study aimed to investigate the regulatory mechanisms of RUNX2 exon 5 alternative splicing in human DPSCs.

Methods and results: The regulatory motifs of RUNX2 exon 5 were analyzed using the online SpliceAid program. The alternative splicing of RUNX2 exon 5 in DPSCs during mineralization-induced differentiation was analyzed by RT-PCR. To explore the effect of splicing factor YBX1 on exon 5 alternative splicing, gaining or losing function of YBX1 was performed by transfection of YBX1 overexpression plasmid or anti-YBX1 siRNA in DPSCs. Human RUNX2 exon 5 is evolutionarily conserved and alternatively spliced in DPSCs. There are three potential YBX1 binding motifs in RUNX2 exon 5. The inclusion of RUNX2 exon 5 and YBX1 expression level increased significantly during mineralization- induced differentiation in DPSCs. Overexpression of YBX1 significantly increased the inclusion of RUNX2 exon 5 in DPSCs. In contrast, silence of YBX1 significantly reduced the inclusion of exon 5 and the corresponding RUNX2 protein expression level. Knockdown of YBX1 reduced the expression of alkaline phosphatase (ALP) and osteocalcin (OC) and the mineralization ability of DPSCs, while overexpression of YBX1 increased the expression of ALP and OC and the mineralization ability of DPSCs.

Conclusions: Human RUNX2 exon 5 is conserved evolutionarily and alternatively spliced in DPSCs. Splicing factor YBX1 promotes the inclusion of RUNX2 exon 5 and improves the mineralization ability of DPSCs.

Background and objectives: Many preclinical studies have been conducted using animal disease models to determine the effectiveness of human mesenchymal stem cells (hMSCs) for treating immune and inflammatory diseases based on the belief that hMSCs are not immunogenic across species. However, several researchers have suggested xenogeneic immune responses to hMSCs in animals, still without detailed features. This study aimed to investigate a xenogeneic humoral immune response to hMSCs in mice in detail.

Methods and results: Balb/c mice were intraperitoneally injected with adipose tissue-derived or Wharton's jelly-derived hMSCs. Sera from these mice were titrated for each isotype. To confirm specificity of the antibodies, hMSCs were stained with the sera and subjected to a flow cytometic analysis. Spleens were immunostained for proliferating cell nuclear antigen to verify the germinal center formation. Additionally, splenocytes were subjected to a flow cytometric analysis for surface markers including GL-7, B220, CD4, CD8, CD44, and CD62L. Similar experiments were repeated in C57BL/6 mice. The results showed increased IgG1 and IgG2a titers in the sera from Balb/c mice injected with hMSCs, and the titers were much higher in the secondary sera than in the primary sera. These antibodies were specifically stained the hMSCs. Germinal centers were observed in the spleen, and flow cytometric analysis of the splenocytes showed higher frequencies of centroblasts (B220⁺ GL7⁺) and memory T cells (CD62L⁺ CD44⁺) both in CD4⁺ and CD8⁺ subsets. Similar results were obtained for C57BL/6 mice.

Conclusions: hMSCs induced a humoral immune response in mice, with characters of T cell-dependent immunity.

Background and objectives: Epidemiological investigations have shown positive correlations between increased diesel exhaust particles (DEP) in ambient air and adverse health outcomes. DEP are the major constituent of particulate atmospheric pollution and have been shown to induce proinflammatory responses both in the lung and systemically. Here, we report the effects of DEP exposure on the properties of human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs), including stemness, regeneration, and immunomodulation.

Methods and results: Non-apoptotic concentrations of DEP (10 μg/ml) inhibited the migration and osteogenic differentiation capacity of WJ-MSCs. Gene expression profiling showed that DEP increased intracellular reactive oxygen species (ROS) and expression of pro-inflammatory and metabolic-process-related genes including cFos. Furthermore, WJ-MSCs cultured with DEP showed impaired suppression of T cell proliferation that was reversed by inhibition of ROS or knockdown of cFos. ERK inhibition assay revealed that DEP-induced ROS regulated cFos through activation of ERK but not NF-κB signaling. Overall, low concentrations of DEP (10 μg/ml) significantly suppressed the stemness and immunomodulatory properties of WJ-MSCs through ROS/ERK/cFos signaling pathways. Furthermore, WJ-MSCs cultured with DEP impaired the therapeutic effect of WJ-MSCs in experimental colitis mice, but was partly reversed by inhibition of ROS.

Conclusions: Taken together, these results indicate that exposure to DEP enhances the expression of pro-inflammatory cytokines and immune responses through a mechanism involving the ROS/ERK/cFos pathway in WJ-MSCs, and that DEP-induced ROS damage impairs the therapeutic effect of WJ-MSCs in colitis. Our results suggest that modulation of ROS/ERK/cFos signaling pathways in WJ-MSCs might be a novel therapeutic strategy for DEP-induced diseases.

Background and objectives: Despite advances in wound treatments, chronic diabetic wounds remain a significant medical challenge. Exosomes from mesenchymal stem cells (MSCs) and small molecule activators of nuclear factor erythroid 2-related factor 2 (Nrf2) have emerged as potential therapies for nonhealing diabetic wounds. This study aimed to evaluate the effects of exosomes from bone marrow-derived MSCs (BMSCs) alone, or in combination with a small molecule activator of Nrf2 on diabetic wound healing.

Methods and results: BMSCs and endothelial progenitor cells (EPCs) were isolated from the femur and tibia bone marrow of Sprague-Dawley (SD) rats and culture-expanded. Exosomes were harvested from the BMSC culture supernatants through ultracentrifugation. The effects of the exosomes and Nrf2 knockdown, alone or in combination, on EPC tube formation were evaluated. Streptozotocin-induced diabetic rats bearing a fresh full-thickness round wound were treated with the exosomes alone, or in combination with a lentiviral shRNA targeting Nrf2 (Lenti-sh-Nrf2) or tert-butylhydroquinone (tBHQ), a small molecule activator of Nrf2. Two weeks later, wound closure, re-epithelization, collagen deposition, neovascularization, and local inflammation were evaluated. BMSC exosomes promoted while Nrf2 knockdown inhibited EPC tube formation. BMSC exosomes accelerated wound closure, re-epithelization, collagen deposition, and neovascularization, and reduced wound inflammation in diabetic rats. These regenerative and anti-inflammatory effects of the exosomes were inhibited by Lenti-sh-Nrf2 but enhanced by tBHQ administration.

Conclusions: BMSC exosomes in combination with a small molecule Nrf2 activator hold promise as a new therapeutic option for chronic diabetic wounds.

Background and objectives: Neural stem cells (NSCs) remain in the mammalian brain throughout life and provide a novel therapeutic strategy for central nervous system (CNS) injury. Bone morphogenetic protein-6 (BMP-6) had shown a protective effect in different types of cells. However, the role of BMP-6 in NSCs is largely unclear. The present study was aimed to investigate whether BMP-6 could protect human NSCs (hNSCs) against the oxygen and glucose deprivation (OGD)-induced cell death.

Methods and results: Upon challenge with OGD treatment, cell viability was significantly decreased in a time-dependent manner, as indicated by the CCK-8 assay. BMP-6 could attenuate the OGD-induced cell injury in a dose-dependent manner and decrease the number of TUNEL-positive cells. Moreover, BMP-6 markedly weakened the OGD-induced alterations in the expression of procaspase-8/9/3 and reversed the expression of cleaved-caspase-3. Interestingly, noggin protein (the BMP-6 inhibitor) attenuated the neuroprotective effect of BMP-6 in cultured hNSCs. Furthermore, the p38 MAPK signaling pathway was activated by OGD treatment and BMP-6 markedly inhibited the phosphorylation of p38 in a concentration-dependent manner. Pretreatment with noggin abolished the effect of BMP-6 on p38 activation. SB239063, a selective p38 inhibitor, exerted similar effects with BMP-6 in protecting hNSCs against the OGD-induced apoptosis. These results indicated that blocking the phosphorylation of p38 might contribute to the neuroprotective effect of BMP-6 against the OGD-induced injury in hNSCs.

Conclusions: These findings suggested that BMP-6 might be a therapeutic target in the OGD-induced cell death, which provides a novel therapeutic strategy for enhancing host and graft NSCs survival in hypoxic-ischemic brain injury.

Background and objectives: Apoptosis is an outstanding determinant of glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH). Human umbilical cord mesenchymal stem cells (hUC-MSCs) have been demonstrated to be associated with apoptosis in diseases models. However, the role of hUC-MSCs in GC-induced ONFH via regulating apoptosis still needs further study.

Methods and results: In the present study, a GC-induced ONFH model was built in vivo through a consecutive injection with lipopolysaccharide (LPS) and methylprednisolone. The necrosis and apoptosis of the femoral head was evaluated by histological and Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) assay. The level of collagen and TRAP positive cells were determined by Masson and TRAP staining, respectively. M1 macrophage polarization was assessed using immunofluorescence assay. The level of proinflammatory cytokines including tumor necrosis factor (TNF)-α, Interleukin (IL)-1β and IL-6 of femoral head was determined by enzyme-linked immunosorbent assay (ELISA) kits. The protein expression of AKT, mTOR, p-AKT and p-mTOR was detected using western blot assay. The results showed that hUC-MSCs treatment prominently promoted the GC-induced the decrease of the collagen level and the increase of TRAP positive cells. Besides, hUC-MSCs treatment decreased necrosis and apoptosis, macrophage polarization, the level of TNF-α, IL-1β and IL-6, the protein expression of p-AKT and p-mTOR, and the radio of p-AKT to AKT and p-mTOR to mTOR of femoral head in vivo.

Conclusions: Therefore, the present study revealed that hUC-MSCs improved the necrosis and osteocyte apoptosis in GC-induced ONFH model through reducing the macrophage polarization, which was associated with the inhibition of AKT/mTOR signaling pathway.

Background and objectives: Stroke is the most common cause of human death and functional disability, resulting in more than 5 million deaths worldwide each year. Bone marrow mesenchymal stem cells (BMSCs) are a kind of stem cell that are able to self-renew and differentiate into many types of tissues. Therefore, BMSCs have the potential to replace damaged neurons and promote the reconstruction of nerve conduction pathways and connective tissue. However, it remains unknown whether transplanted BMSCs promote angiogenesis or improve the tissue microenvironment directly or indirectly through paracrine interactions. This study aimed to determine the therapeutic effect of BMSCs on ischemic stroke with hypertension in a rodent model and to explore the possible mechanisms underlying any benefits.

Methods and results: Middle cerebral artery occlusion was used to establish the experimental stroke model. The area of cerebral infarction, expression of vascular endothelial growth factor (VEGF) and glial cell line-derived neurotrophic factor (GDNF), and increment of astrocyte were measured by TTC staining, western blot, real-time quantitative polymerase chain reaction (RT-qPCR) and immunocytochemistry. The results showed a smaller area of cerebral infarction and improved neurological function scores in animals treated with BMSCs compared to controls. The results of RT-qPCR and western blot assays showed higher expression of VEGF and GDNF in BMSC-treated animals compared with controls. Our study also showed that one round of BMSCs transplantation significantly promoted the proliferation of subventricular zone and cortical cells, especially astrocytes, on the ischemic side following cerebral ischemia.

Conclusions: Above findings support that BMSCs have therapeutic effects for ischemic stroke complicated with hypertension, which may occur via up-regulated expression of VEGF and GDNF and reduction of neuronal apoptosis, thereby promoting the recovery of nerve function.

The ultimate goal of regenerative medicine is to replace damaged cells, tissues or whole organs, in order to restore their proper function. Stem cell related technologies promise to generate transplants from the patients' own cells. Novel approaches such as blastocyst complementation combined with genome editing techniques open up new perspectives for organ replacement therapies. This review summarizes recent advances in the field and highlights the challenges that still remain to be addressed.