Self-healing polysaccharide-based hydrogels as injectable carriers for neural stem cells.

Neurogenesis involves generation of new neurons through finely tuned multistep processes, such as neural stem cell (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and subventricular zone. Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders, including Alzheimer disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizures. However, the effects of ETH on adult hippocampal neurogenesis and the underlying cellular and molecular mechanism(s) are yet unexplored. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation and adult hippocampal neurogenesis in an amyloid β (Aβ) toxin-induced rat model of AD-like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampus-derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation and reduced Aβ toxin-mediated toxicity and neurodegeneration, leading to behavioral recovery in the rat AD model. ETH inhibited Aβ-mediated suppression of neurogenic and Akt/Wnt/β-catenin pathway gene expression in the hippocampus. ETH activated the PI3K·Akt and Wnt·β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K·Akt and Wnt·β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1, and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K·Akt and Wnt·β-catenin signaling.

To study the effects of total ginsenosides (TG) extract from Panax ginseng on neural stem cell (NSC) proliferation and differentiation and their underlying mechanisms. The migration of NSCs after treatment with various concentrations of TG extract (50, 100, or 200 µ g/mL) were monitored. The proliferation of NSCs was examined by a combination of cell counting kit-8 and neurosphere assays. NSC differentiation mediated by TG extract was evaluated by Western blotting and immunofluorescence staining to monitor the expression of nestin and microtubule associated protein 2 (MAP2). The GSK-3β/β-catenin pathway in TG-treated NSCs was examined by Western blot assay. The NSCs with constitutively active GSK-3β mutant were made by adenovirus-mediated gene transfection, then the proliferation and differentiation of NSCs mediated by TG were further verified. TG treatment significantly enhanced NSC migration (P<0.01 or P<0.05) and increased the proliferation of NSCs (P<0.01 or P<0.05). TG mediation also significantly upregulated MAP2 expression but downregulated nestin expression (P<0.01 or P<0.05). TG extract also significantly induced GSK-3β phosphorylation at Ser9, leading to GSK-3β inactivation and, consequently, the activation of the GSK-3β/β-catenin pathway (P<0.01 or P<0.05). In addition, constitutive activation of GSK-3β in NSCs by the transfection of GSK-3β S9A mutant was found to significantly suppress TG-mediated NSC proliferation and differentiation (P<0.01 or P<0.05). TG promoted NSC proliferation and neuronal differentiation by inactivating GSK-3β.

Ginsenoside-Rg1, the main active component of Panax notoginseng, exhibits a number of pharmacological functions, including promoting protein synthesis in the brain, increasing the number of synapses, improving memory and promoting recovery of brain function following injury. The effect of ginsenoside-Rg1 on proliferation and glial-like-directed differentiation in the cortical neural stem cells (NSCs) of embryonic rat brain was investigated. The present study used MTS assays to identify the optimum dose and window time of ginsenoside-Rg1 administration to stimulate the proliferation of cortical NSCs in the rat embryonic tissue. The oxygen glucose deprivation (OGD) set-up was used as a cell injury model. Immunofluorescent staining was used for identification of NSCs and subsequent observation of their proliferation and glial-like directed differentiation. Nestin expression was the marker for the presence of NSCs among the cortical cells of embryonic rat brain. The optimum dose of ginsenoside-Rg1 for proliferation of NSCs was 0.32 µg/ml. The optimum window time of 0.32 µg/ml ginsenoside-Rg1 administration on proliferation of NSCs was 6 h. Ginsenoside-Rg1 at 0.32 µg/ml concentration promoted incorporation of bromo-2-deoxyuridine, and expression of nestin and vimentin in primary and passaged NSCs, and NSCs following OGD. Ginsenoside-Rg1 had a role in promoting proliferation and glial-like-directed differentiation of cortical NSCs. The plausible explanation for these responses is that ginsenoside-Rg1 acts similarly to the growth factors to promote the proliferation and differentiation of NSCs.

Objective: Neural stem cells (NSCs) are essential for replenishing nerve cells, providing neuroprotection, and repairing damaged brain function, while mitophagy is critical for maintaining NSCs’ homeostasis. The study investigated whether pyruvate kinase M2 (PKM2) regulates NSCs’ proliferation and differentiation by modulating mitophagy. Method: This study established a model of excessive autophagy in neural stem cell mitochondria induced by cobalt chloride (CoCl2) and used plasmid transfection technology to knock down PKM2 expression, examining its effects on NSCs proliferation and differentiation. Additionally, potential mechanisms were explored by overexpressing phosphatase and tensin homolog-induced putative kinase 1 (PINK1) and adding the mitophagy inducer carbonyl cyanide m-chlorophenyl hydrazone (CCCP). Result: Treatment with CoCl2 significantly inhibited the proliferation of NSCs and their differentiation into neurons, induced excessive mitophagy, and activated the PKM2/PINK1/Parkin pathway. Knockdown of PKM2 markedly enhanced cell viability, promoted NSCs’ proliferation, and neuronal differentiation. Mechanistically, PKM2 knockdown not only decreased the protein levels of PINK1, Parkin, p-Parkin, Beclin1, and LC3 II/I but also increased p62 expression, thereby mitigating excessive mitophagy. Overexpression of PINK1 attenuated the inhibitory effect of PKM2 knockdown on CoCl2-induced mitophagy in NSCs. Moreover, PKM2 knockdown significantly reversed the detrimental effects of CCCP on mitochondrial function, cell survival, and neuronal differentiation, further confirming that PKM2 promotes NSC proliferation and neuronal differentiation by inhibiting mitophagy. Conclusion: Knocking down PKM2 could inhibit PINK1/Parkin-mediated excessive mitophagy, thereby promoting NSCs proliferation and neuronal differentiation.

Background: Curcumin, found in the rhizome of Curcuma longa, demonstrates anti-inflammatory and neuroprotective properties. Objectives: This study aims to assess its effects on the proliferation and differentiation of embryonic neural stem cells (NSCs). Methods: Female rats (n = 36) became pregnant, resulting in the formation of embryos (n = 176). Neural stem cells from female embryos (n = 50, embryonic day 15.5, E15.5) were cultured in a serum-free medium with growth factors (FGF-2 and EGF). Curcumin was then added at doses of 0.1, 0.5, and 1 µM. The proliferation of NSCs was assessed using the MTT colorimetric assay, nestin immunofluorescence labeling, and RT-PCR. NSC differentiation was compared using immunocytochemistry (ICC) and RT-PCR for nestin, glial fibrillary acidic protein (GFAP), and class III β-tubulin (Tuj-1). Results: Curcumin at concentrations of 0.1 and 0.5 µM increased the proliferation of NSCs, as indicated by an increase in neurosphere diameter. Similarly, the MTT assay showed that curcumin at doses of 0.1 and 0.5 µM enhanced the viability of NSCs. In the differentiation condition, no significant difference was observed. However, RT-PCR analysis showed that nestin and GFAP expressions reached their highest levels in cells treated with curcumin at a dose of 0.5 µM, while Tuj-1 expression significantly increased in cells treated with curcumin at a dose of 1 µM. Conclusions: Curcumin at lower doses may regulate the proliferation and differentiation of NSCs. Treating NSCs with curcumin could provide a promising option for pre-differentiation before cell therapy.

Low-intensity pulsed ultrasound regulates proliferation and differentiation of neural stem cells through notch signaling pathway

Objective To investigate the effect of active factor on proliferation and differentiation of neural stem cells(NSCs)in the hippocampal subgranular zone after traumatic brain injury(TBI)in rats. Methods SD rats were divided into sham-injured group (only left dura mater exposed), active factor group (sham injury+ active factor therapy), TBI group (unilateral fluid percussion was used to generate severe TBI), and TBI+ active factor group (TBI+ active factor therapy) according to the random number table (n=10 in each group). Hippocampal homogenates or brain tissues were harvested at 7 d postinjury. Expressions of BrdU and NeuN in the hippocampal subgranular zone were detected by immunofluorescence staining, and five consecutive sections were used to count BrdU and NeuN positive cells. Level of nuclear factor (NF)-κB p65 in hippocampus was detected by Western blot. Results Number of BrdU and NeuN positive cells in TBI group were greatly higher than that in sham-injured group (P 0.05). NF-κBp65 presented over-expression in TBI group (0.81±0.09) while reversed in TBI+ active factor group (1.46±0.13), when compared to sham-injured group (P 0.05). Conclusion Active factor therapy can promote proliferation and neuronal differentiation of NSCs in the hippocampal subgranular zone after TBI in rats and the possible mechanism may relate to activation of the NSCs and inhibition of over-expression of NF-κBp65. Key words: Craniocerebral trauma; Neural stem cells; Active factor

BackgroundEndogenous neurogenesis could promote stroke recovery. Furthermore, anti-inflammatory phenotypical microglia (M2-microglia) could facilitate Neural Stem Cell (NSC)-mediated neurogenesis following Ischemic Stroke (IS). Nonetheless, the mechanisms through which M2 microglia influence NSC-mediated neurogenesis post-IS remain unclear. On the other hand, M2 microglia-derived small Extracellular Vesicles (M2-sEVs) could exert phenomenal biological effects and play significant roles in cell-to-cell interactions, highlighting their potential involvement in NSC-mediated neurogenesis post-IS, forming the basis of this study.MethodsM2-sEVs were first isolated from IL-4-stimulated microglia. For in vivo tests, M2-sEVs were intravenously injected into mice every day for 14 days after transient Middle Cerebral Artery Occlusion (tMCAO). Following that, the infarct volume and neurological function, as well as NSC proliferation in the Subventricular Zone and dentate gyrus, migration, and differentiation in the infarct area, were examined. For in vitro tests, M2-sEVs were administered to NSC subjected to Oxygen-Glucose Deprivation (OGD) and then reoxygenation, after which NSC proliferation and differentiation were assessed. Finally, M2-sEVs were subjected to microRNA sequencing to explore the regulatory mechanisms.ResultsOur findings revealed that M2-sEVs reduced the infarct volume and increased the neurological score in mice post-tMCAO. Furthermore, M2-sEV treatment promoted NSC proliferation and neuronal differentiation both in vivo and in vitro. Additionally, microRNA sequencing revealed miR-93-5p and miR-25-3p enrichment in M2-sEVs. Inhibitors of these miRNAs prevented TGFBR, PTEN, and FOXO3 downregulation in NSC, reversing M2-sEVs’ beneficial effects on neurogenesis and sensorimotor recovery.ConclusionsM2-sEVs increased NSC proliferation and neuronal differentiation, and protected against IS, at least partially, via delivering miR-25-3p and miR-93-5p to downregulate TGFBR, PTEN, and FOXO3 expression in NSC.Graphical abstract

In this study, we investigated the impact of Nardosinone, a bioactive component in Nardostachys root, on the proliferation and differentiation of neural stem cells. The neural stem cells were isolated from cerebrums of embryonic day 14 CD1 mice. The proliferation of cells was monitored using the cell counting kit-8 assay, bromodeoxyuridine incorporation and cell cycle analysis. Cell migration and differentiation were investigated with the neurosphere assay and cell specific markers, respectively. The results showed that Nardosinone promotes cells proliferation and increases cells migration distance in a dose-dependent manner. Nardosinone also induces the selective differentiation of neural stem cells to neurons and oligodendrocytes, as indicated by the expression of microtubule-associated protein-2 and myelin basic protein, respectively. Nardosinone also increases the expression of phospho-extracellular signal-regulated kinase and phospho-cAMP response element binding protein during proliferation and differentiation. In conclusion, this study reveals the regulatory effects of Nardosinone on neural stem cells, which may have significant implications for the treatment of brain injury and neurodegenerative diseases.

Hydrogen sulfide promotes proliferation and neuronal differentiation of neural stem cells and protects hypoxia-induced decrease in hippocampal neurogenesis

Neural stem cell (NSC) possess the essential properties of pluripotency and self-renewal, making them promising candidates for the treatment of neurological disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and spinal cord injuries. While previous studies have identified the long non-coding RNAs (lncRNAs) Pnky as a regulator of NSC differentiation into neurons via RNA splicing, its role in NSC differentiation and proliferation through the Wnt/β-catenin pathway remains unclear. In this study, we investigated the mechanism by which Pnky influences the Wnt/β-catenin pathway to promote NSC differentiation into neurons. Using cck8 assays, western blot analysis, and quantitative polymerase chain reaction (qPCR), we found that Pnky knockdown significantly enhanced NSC proliferation and promoted their differentiation into neurons. Additionally, Pnky knockdown resulted in the downregulation of the neural stem cell marker Nestin and upregulation of the neuronal marker β3-Tubulin, through activation of the β-catenin signaling pathway. Conversely, inhibiting the β-catenin pathway hindered both NSC differentiation and proliferation. These findings suggest that targeting the Pnky-mediated Wnt/β-catenin pathway may offer novel strategies for the treatment, diagnosis, and drug development of central nervous system diseases.

Neural stem cells (NSCs) disrupt with aging, contributing to neurodegeneration. Ginsenoside Rg1 (Rg1), a compound found in Ginseng, is known for its anti-aging effects; however, its role in the progression of aging NSCs remains unclear. Therefore, this investigation explored the impact of Rg1 on the growth and maturation of aging NSC and elucidated its underlying molecular mechanisms. Initially, mouse models of brain aging were successfully established using D-galactose (D-gal) injection. Mice received Rg1 treatment along with D-gal administration. Brain tissues and NSCs were isolated and analyzed for pathological changes, gene expression, and cellular function. In vitro, experiments used aging NSCs treated with Rg1 to assess cell viability, proliferation, differentiation, and senescence markers. D-gal triggered aging-related pathological alterations in mouse brains, elevated acetylcholinesterase levels, upregulated senescence genes, and inhibited NSC proliferation (p < 0.05). However, Rg1 treatment mitigated D-gal-induced effects, delayed brain aging, and improved NSC function. In vitro, Rg1 significantly increased cell viability, promoted NSC proliferation and differentiation, reduced senescent neurons, and downregulated p53 and p21 genes (p < 0.05). Rg1 demonstrates anti-aging properties in D-gal-induced mouse brain aging, promoting the proliferation and differentiation of NSCs, and downregulating the p53-p21 signaling pathway.

Alzheimer's disease is the most frequent neurodegenerative disease and is characterized by progressive cognitive impairment and decline. NSCs (neural stem cells) serve as beneficial and promising adjuncts to treat Alzheimer's disease. This study aimed to determine the role of miR-153-3p expression in NSC differentiation and proliferation. We illustrated that miR-153-3p was decreased and GPR55 was upregulated during NSC differentiation. IL-1β can induce miR-153-3p expression. Luciferase reporter analysis noted that elevated expression of miR-153-3p significantly inhibited the luciferase value of the WT reporter plasmid but did not change the luciferase value of the mut reporter plasmid. Ectopic miR-153-3p expression suppressed GPR55 expression in NSCs and identified GPR55 as a direct target gene of miR-153-3p. Ectopic expression of miR-153-3p inhibited NSC growth and differentiation into astrocytes and neurons. Elevated expression of miR-153-3p induced the release of proinflammatory cytokines, such as TNF-α, IL-1β and IL-6, in NSCs. Furthermore, miR-153-3p inhibited NSC differentiation and proliferation by targeting GPR55 expression. These data suggested that miR-153-3p may act as a clinical target for the therapeutics of neurodegenerative diseases.

SummaryBackgroundThe transplantation of neural stem cells (NSCs) has been accepted as a promising therapeutic strategy for central nervous system disorders. However, the beneficial effect of NSC transplantation upon functional recovery is limited due to the unfavorable microenvironment (niche) at the site of trauma or degenerative disease in the brain. Combination of transplantation of NSCs with neurotrophins may overcome the hurdles of impaired cell survival and neuronal differentiation.Material/MethodsIn the current study, the neurotrophin-3 (NT-3) gene was transduced into cultured mouse embryonic cortical NSCs via an AAV vector (NSC-NT-3). The effect of NT-3 over-expression on cell proliferation and differentiation in NSCs was observed by immunohistochemistry, cell culture and organotypic hippocampal slice cultures.ResultsThe characteristics of self-renewal and multiple differentiation of NSCs were well-preserved. Cells in the NSC-NT-3 group proliferated faster and differentiated into more β-tubulin III-positive neurons compared to the control group in vitro. Furthermore, cells in the NSC-NT-3 group survived in a significantly higher percentage and undertook neuronal differentiation preferably in organotypic hippocampal slice cultures.ConclusionsOur results suggest that the transduction of NT-3 into NSCs could effectively promote NSCs survival, proliferation, and neuronal differentiation in vitro without change of the stemness of NSCs. This work also offers evidence to better understand the safety and efficiency of combined treatment with NT-3 and NSCs for the central nervous system disorders.

Comparison of effects of high- and low-frequency electromagnetic fields on proliferation and differentiation of neural stem cells