Down-Regulation of p38 Mitogen-Activated Protein Kinases/Nuclear Factor Kappa Light Chain Enhancer of Activated B Cells (p38 MAPK/NF-κB) Signaling Pathway Promotes Bone Marrow Mesenchymal Stem Cells Differentiation into Neural Stem Cells in Healing Neurodegeneration

This study intends to promote bone marrow mesenchymal stem cells (BMSCs) differentiation into neural stem cells by down-regulating p38 MAPK/NF-κB to heal neurodegeneration. 26 patients with neurodegenerative diseases were enrolled from the Department of Neurology along with recruitment of 26 other healthy controls followed by analysis of p38 MAPK/NF-κB signaling pathway expression by ELISA. BMSCs were cultured and characterized by flow cytometry. Western blot and qRTPCR measured the p38 MAPK/NF-κB expression in the absence or presence of p38 MAPK/NF-κB inhibitors. p38 MAPK/NF-κB expression in 26 neurodegenerative patients was significantly higher than that of 26 healthy controls. The qRT-PCR and western blot results showed that the neural stem cell-specific proteins expression was increased as days went; after addition of p38 MAPK/NF-κB inhibitor, the expression of related specific genes were significantly decreased. In conclusion, inhibition of the expression of p38 MAPK/NF-κB signaling pathway can heal neurodegeneration by promoting the differentiation of BMSCs into neural stem cells.

Sustained correction of hippocampal neurogenic and cognitive deficits after a brief treatment by Nutlin-3 in a mouse model of Fragile X Syndrome

Background: Fragile X syndrome (FXS), the most prevalent inherited intellectual disability and one of the most common monogenic form of autism, is caused by a loss of FMRP translational regulator 1 (FMR1). We have previously shown that FMR1 represses the levels and activities of ubiquitin ligase MDM2 in young adult FMR1-deficient mice and treatment by a MDM2 inhibitor Nutlin-3 rescues both hippocampal neurogenic and cognitive deficits in FMR1-deficient mice when analyzed shortly after the administration. However, it is unknown whether Nutlin-3 treatment can have long-lasting therapeutic effects. Methods: We treated 2-month-old young adult FMR1-deficient mice with Nutlin-3 for 10 days and then assessed the persistent effect of Nutlin-3 on both cognitive functions and adult neurogenesis when mice were 6-month-old mature adults. To investigate the mechanisms underlying persistent effects of Nutlin-3, we analyzed proliferation and differentiation of neural stem cells isolated from these mice and assessed the transcriptome of the hippocampal tissues of treated mice. Results: We found that transient treatment with Nutlin-3 of 2-month-old young adult FMR1-deficient mice prevents the emergence of neurogenic and cognitive deficits in mature adult FXS mice at 6-month of age. We further found that the long-lasting restoration of neurogenesis and cognitive function might not be mediated by changing intrinsic properties of adult neural stem cells. Transcriptomic analysis of the hippocampal tissue demonstrated that transient Nultin-3 treatment leads to significant expression changes in genes related to extracellular matrix, secreted factors, and cell membrane proteins in FMR1-deficient hippocampus.

lncRNA NEAT1-let 7b-P21 axis mediates the proliferation of neural stem cells cultured in vitro promoted by radial extracorporeal shock wave

In previous studies, we found radial extracorporeal shock wave (rESW), can promote the proliferation of neural stem cells（NSCs）. Emerging evidence suggests that lncRNA NEAT1 can regulate NSCs proliferation. Whether lncRNA NEAT1 plays a role in the proliferation of NSC induced by shock waves is unclear. Cell Counting Kit-8（CCK 8） method was used to detect the proliferation of NSCs, and the relative protein and mRNA expression of related genes of Nestin, Cyclin D1 and P21 were detected by Western Blot and Quantitative real-time PCR（RT-qPCR）respectively. Immunofluorescence staining was used to observe the changes in the number of BrdU/nestin positive cells. Overexpression of NEAT1 and let 7b in cells were used to explore whether rESW can rescue the decreased number of NSCs.We found that the optimal dose of R15 transmitter promoting NSCs proliferation is 1.5 bar, 500 pulse, 2 Hz. 1.2-1.5bar showed a dose-dependent effect on the proliferation of NSCs, but it was negatively correlated with the proliferation effect of NSC when it was more than 1.5bar. We revealed that let 7b-P21 axis was involved in regulating the inhibition of NSC proliferation which was activated by NEAT1 in NSCs. In addition, we demonstrated that rESW treatment resulted in the decrease of NEAT1 expression, which was accompanied by the improved biological function including proliferation.Our results confirm that low-intensity rESW（1.5bar，500pulse，2Hz） can promote the proliferation of NSCs through NEAT1-let 7b-P21 axis.

Generation of Porcine Induced Neural Stem Cells Using the Sendai Virus

The reprogramming of cells into induced neural stem cells (iNSCs), which are faster and safer to generate than induced pluripotent stem cells, holds tremendous promise for fundamental and frontier research, as well as personalized cell-based therapies for neurological diseases. However, reprogramming cells with viral vectors increases the risk of tumor development due to vector and transgene integration in the host cell genome. To circumvent this issue, the Sendai virus (SeV) provides an alternative integration-free reprogramming method that removes the danger of genetic alterations and enhances the prospects of iNSCs from bench to bedside. Since pigs are among the most successful large animal models in biomedical research, porcine iNSCs (piNSCs) may serve as a disease model for both veterinary and human medicine. Here, we report the successful generation of piNSC lines from pig fibroblasts by employing the SeV. These piNSCs can be expanded for up to 40 passages in a monolayer culture and produce neurospheres in a suspension culture. These piNSCs express high levels of NSC markers (PAX6, SOX2, NESTIN, and VIMENTIN) and proliferation markers (KI67) using quantitative immunostaining and western blot analysis. Furthermore, piNSCs are multipotent, as they are capable of producing neurons and glia, as demonstrated by their expressions of TUJ1, MAP2, TH, MBP, and GFAP proteins. During the reprogramming of piNSCs with the SeV, no induced pluripotent stem cells developed, and the established piNSCs did not express OCT4, NANOG, and SSEA1. Hence, the use of the SeV can reprogram porcine somatic cells without first going through an intermediate pluripotent state. Our research produced piNSCs using SeV methods in novel, easily accessible large animal cell culture models for evaluating the efficacy of iNSC-based clinical translation in human medicine. Additionally, our piNSCs are potentially applicable in disease modeling in pigs and regenerative therapies in veterinary medicine.

Sensitive-stage embryo irradiation affects embryonic neuroblasts and adult motor function

Background Cranial radiation therapy for treating childhood malignancies in the central nervous system or accidental radiation exposure may result in neurological side effects in surviving adults. As tissue homeostasis is maintained by stem cells, understanding the effect of radiation on neural stem cells will provide clues for managing the neurological effects. Drosophila embryos were used as a model system whose sensitivity to irradiation-induced cell death changes from the sensitive to resistant stage during development. Objective Drosophila embryos at the radiation-sensitive stage were irradiated at various doses and the radiation sensitivity was tested regarding the appearance of apoptotic cells in the embryos and the embryonic lethality. Cell fates of the neural stem cells called neuroblasts (NBs) and adult motor function after irradiation were also investigated. Result Irradiation of Drosophila embryos at the radiation-sensitive stage resulted in a dose-dependent increase in the number of embryos containing apoptotic cells 75 min after treatment starting at 3 Gy. Embryonic lethality assayed by hatch rate was induced by 1 Gy irradiation, which did not induce cell death. Notably, no apoptosis was detected in NBs up to 2 h after irradiation at doses as high as 40 Gy. At 3 h after irradiation, as low as 3 Gy, the number of NBs marked by Dpn and Klu was decreased by an unidentified mechanism regardless of the cell death status of the embryo. Furthermore, embryonic irradiation at 3 Gy, but not 1 Gy, resulted in locomotor defects in surviving adults. Conclusion Embryonic NBs survived irradiation at doses as high as 40 Gy, while cells in other parts of the embryos underwent apoptosis at doses higher than 3 Gy within 2 h after treatment. Three hours after exposure to a minimum dose of 3 Gy, the number of NBs marked by Dpn and Klu decreased, and the surviving adults exhibited defects in locomotor ability.

GLI3 Is Required for OLIG2+ Progeny Production in Adult Dorsal Neural Stem Cells

The ventricular–subventricular zone (V-SVZ) is a postnatal germinal niche. It holds a large population of neural stem cells (NSCs) that generate neurons and oligodendrocytes for the olfactory bulb and (primarily) the corpus callosum, respectively. These NSCs are heterogeneous and generate different types of neurons depending on their location. Positional identity among NSCs is thought to be controlled in part by intrinsic pathways. However, extrinsic cell signaling through the secreted ligand Sonic hedgehog (Shh) is essential for neurogenesis in both the dorsal and ventral V-SVZ. Here we used a genetic approach to investigate the role of the transcription factors GLI2 and GLI3 in the proliferation and cell fate of dorsal and ventral V-SVZ NSCs. We find that while GLI3 is expressed in stem cell cultures from both dorsal and ventral V-SVZ, the repressor form of GLI3 is more abundant in dorsal V-SVZ. Despite this high dorsal expression and the requirement for other Shh pathway members, GLI3 loss affects the generation of ventrally-, but not dorsally-derived olfactory interneurons in vivo and does not affect trilineage differentiation in vitro. However, loss of GLI3 in the adult dorsal V-SVZ in vivo results in decreased numbers of OLIG2-expressing progeny, indicating a role in gliogenesis.

The effects of superparamagnetic iron oxide nanoparticle exposure on gene expression patterns in the neural stem cells under magnetic field

Background: Due to the excellent reliable traceability and superparamagnetic properties, superparamagnetic iron oxide nanoparticles (SPIOs) are widely used for the applications in the field of biomedicine, including tissue engineering and regenerative medicine. However, the regulation of SPIOs on the gene expressions in the stem cells is not clear. Methods: In this study, by RNA-Seq analysis, we analyzed the gene expression pattern in the neural stem cells (NSCs) treated with SPIOs in the presence or absence of static magnetic field (SMF). Results: It was found that SPIOs with SMF regulated more gene expression in NSCs, while most of these genes have been previously reported to play a crucial role in NSCs fate decision. Conclusions: Our findings reveal the ability of SPIOs and SMF in the regulation of gene expression in NSCs, which may provide an experimental basis for its applications.