Induced neural cells from human dental pulp ameliorate functional recovery in a murine model of cerebral infarction
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ABSTRACT: Human mesenchymal stem cells are a promising cell source for the treatment of stroke. Their primary mechanism of action occurs via neuroprotective effects by trophic factors, anti-inflammatory effects, and immunomodulation. However, the regeneration of damaged neuronal networks by cell transplantation remains still challenging. We hypothesized that cells induced to neural lineages would fit the niche, replace the lesion, and be more effective in improving symptoms compared with stem cells themselves. We investigated the characteristics of induced neural cells from human dental pulp tissue and compared the transplantation effects between these induced neural cells and uninduced dental pulp stem cells. Induced neural cells or dental pulp stem cells were intracerebrally transplanted 5 days after cerebral infarction induced by permanent middle cerebral artery occlusion in immunodeficient mice. Effects on functional recovery were also assessed through behavior testing. We used immunohistochemistry and neuron tracing to analyze the differentiation, axonal extension, and connectivity of transplanted cells to the host’s neural circuit. Transplantation of induced neural cells from human dental pulp ameliorated functional recovery after cerebral infarction compared with dental pulp stem cells. The induced neural cells comprised both neurons and glia and expressed functional voltage, and they were more related to neurogenesis in terms of transcriptomics. Induced neural cells had a higher viability than did dental pulp stem cells in hypoxic culture. We showed that induced neural cells from dental pulp tissue offer a novel therapeutic approach for recovery after cerebral infarction.
Project description:Transplantation of human cranial bone-derived mesenchymal stem cells (hcMSCs) in central nervous system disorders has the potential to improve motor function by highly expressing neurotrophic factors. However, the effects of hcMSCs cultured under microgravity (MG) conditions on cerebral infarction have not been investigated before. Thus, this study aimed to investigate the transplantation effects of hcMSCs cultured in a simulated MG environment on cerebral infarction model rats. Our results showed that neurological function was significantly improved after transplantation of hcMSCs cultured in the MG environment (MG group) compared with normal gravity environment (1G group). Protein expressions of nerve growth factor, fibroblast growth factor 2, and synaptophysin were significantly higher in the MG group than in the IG group, whereas sortilin 1 expression was significantly lower. MicroRNA analysis revealed that genes related to cell proliferation, angiogenesis, neurotrophy, anti-apoptosis, neural and synaptic organization, and cell differentiation inhibition were significantly upregulated in the MG group. In contrast, genes promoting microtubule and extracellular matrix formation and cell adhesion, signaling, and differentiation were downregulated. These results indicate that hcMSCs cultured in an MG environment may be a useful source of stem cells for recovery of neurological function after cerebral infarction.
Project description:Stem cell-based therapy is an alternative strategy for brain repair. Various cell types have been investigated and dental pulp stem cells (DPSC) have been identified as promising candidates. These multipotent stem cells are found in the dental pulp tissue of molar teeth. They are clinically easily obtained, have a high proliferative rate, and possess neurogenic potential due to their mesoectodermal origin. Here, overexpression of octamer-binding transcription factor 4 (OCT4) in combination with neural conditions was used to reprogram human DPSC along the neural lineage. Transcriptomic analysis of differentially-expressed genes highlighted the expression of genes associated with neural and neuronal functions in the OCT4-overexpressing DPSC following neural induction.
Project description:Wnt regulates various cell responses. In dental pulp cells, Wnt signaling control cell proliferation, apoptosis, migration and differentiation. Here, the differential gene expression of human dental pulp stem cells treated with Wnt ligands or Wnt agonist was examined using a high throughput RNA sequencing technique. Results demonstrated that Wnt ligands or Wnt agonist altered numerous gene expression in human dental pulp stem cells.
Project description:Transplantation of neural stem cells (NSCs) has been proved to promote functional rehabilitation of brain lesions including ischemic stroke. However, the therapeutic effects of NSC transplantation is limited by the low survival and differentiation rates of NSCs due to the harsh environment in the brain after ischemic stroke. Here, we employed NSCs derived from human induced pluripotent stem cells (iPSCs) together with exosomes extracted from NSCs to treat cerebral ischemia induced by middle cerebral artery occlusion/reperfusion (MCAO/R) in mice. The results showed that NSC-derived exosomes significantly reduced the inflammatory response, alleviated oxidative stress after NSC transplantation, and facilitated NSCs differentiation in vivo. The combination of NSCs with exosomes ameliorated the injury of brain tissue including cerebral infarct, neuronal death and glial scarring, and promoted the motor function recovery. To explore the underlying mechanisms, we analyzed the miRNA profiles of NSC-derived exosomes and the potential downstream genes. Our study provided the rationale for the clinical application of NSC-derived exosomes as a supportive adjuvant for NSC transplantation after stroke.
Project description:We have performed gene expression microarray analysis to profile transcriptomic signatures affected by EtOH in human dental pulp stem cells Established human dental pulp stem cells were treated with different dose of EtOH (0, 1, 5, 10, 20 and 50mM) for a different time periods (24 and 48 hrs). Total RNA was extracted and subjected to gene expression microarray analysis using Affymetrix human genome 2.0 plus array
Project description:Small molecules, BIO and Lithium chloride are widely used to activate Wnt signaling. It has been shown that these molecules induced beta-catenin accumulation and translocation, leading to the activation of Wnt signaling. These molecules also control various cell responses. Here, the differential gene expression of human dental pulp stem cells treated with BIO and Lithium chloride was examined using a high throughput RNA sequencing technique. Results demonstrated that BIO and Lithium chloride regulated the mRNA expression of various genes in human dental pulp stem cells.
Project description:The current understanding is that Schwann cell transplantation is ideal strategy for peripheral nerve regeneration instead of autograft. It is difficult to obtain the required amount of Schwann cells which are best transplant condition, and central nervous cells have been gained attention in recent years, but its regenerative mechanism remain unknown. Neural stem/progenitor cells (NSPC) can generate various type of neural lineage cells (NLCs), and NSPCs derived from pluripotent stem cells are promising cells for cell therapy for neurodegenerative diseases. However, more safe and accessible cell source of NSPCs are required. In this study, we aim to provide NLCs derived from human dental pulp stem cells (DPSCs), and reveal the mechanism involved in regeneration after NLCs transplantation into peripheral nerve defect. Here, characterization of NLCs, paracrine effects for endothelial cells and Schwann cells, in xenotransplant for rat 10mm sciatic nerve defect, the differentiation, the survival, and outcome of nerve regeneration were investigated. Induced NLCs consisted of neuronal lineage cells, astrocyte lineage cells, oligodendrocyte lineage cells, and neural crest lineage cells. Considering retrospectively, NLCs were possible derived from NSPCs. Microarray analysis revealed neural markers of primary embryological development were up-regulated in induced NLCs compared to DPSCs. Moreover, NLCs enhanced the activity of endothelial cells and Schwann cells by paracrine effects in vitro. Two weeks after transplantation, many transplanted NLCs differentiated into platelet-derived growth factor receptor alpha (PDGFRa) + oligodendrocyte progenitor cells (OPCs), and PDGFRa+/p75 neurotrophin receptor + Schwann cells derived from OPCs were observed. Twelve weeks after transplantation, NLCs promoted functional repair of peripheral nerve. A few human Schwann cells survived, but did not myelinate axon. These findings suggest that some of mechanism promoting for peripheral nerve regeneration by transplanted NLCs. Transplantation of NLCs derived from DPSCs into partial peripheral nerve defect may be widely used for further experiments.