Click chemistry extracellular vesicle/peptide/chemokine nanocarriers for treating central nervous system injuries

Central nervous system (CNS) injuries, including stroke, traumatic brain injury, and spinal cord injury, are essential causes of death and long-term disability and are difficult to cure, mainly due to the limited neuron regeneration and the glial scar formation. Herein, we apply extracellular vesicles (EVs) secreted by M2 microglia to improve the differentiation of neural stem cells (NSCs) at the injured site, and simultaneously modify them with the injured vascular targeting peptide (DA7R) and the stem cell recruiting factor (SDF-1) on their surface via copper-free click chemistry to recruit NSCs, inducing their neuronal differentiation, and serving as the nanocarriers at the injured site (Dual-EV). Results prove that the Dual-EV could target human umbilical vascular endothelial cells (HUVECs), recruit NSCs, and promote the neuronal differentiation of NSCs in vitro. Furthermore, 10 miRNAs are found to be upregulated in Dual-M2-EVs compared to Dual-M0-EVs via bioinformatic analysis, and further NSC differentiation experiment by flow cytometry reveals that among these miRNAs, miR30b-3p, miR-222-3p, miR-129-5p, and miR-155-5p may exert effect of inducing NSC to differentiate into neurons. In vivo experiments show that Dual-EV nanocarriers achieve improved accumulation in the ischemic area of stroke model mice, potentiate NSCs recruitment, and increase neurogenesis. This work provides new insights for the treatment of neuronal regeneration after CNS injuries as well as endogenous stem cells, and the click chemistry EV/peptide/chemokine and related nanocarriers for improving human health.

Impacts of cadmium on mouse neural stem cells based on dose-response metabomics / 环境与职业医学

Background Cadmium (Cd) is a ubiquitous and toxic heavy metal that can accumulate in human body. Previous studies have shown that Cd exposure can induce neurotoxicity, but the underlying mechanism remains unclear. Objective To investigate the metabolic impacts of multiple doses of Cd on mouse neural stem cells (NSCs), and to explore the potential mechanism and biomarkers of its neurotoxicity. Methods The NSCs were obtained from the subventricular zone (SVZ) of 1-day-old neonatal C57BL/6 mice. The passage 3 (P3) NSCs were exposed to CdCl2 at designed doses (0, 0.5, 1.0, and 1.5 μmol·L−1). The cells were treated with seven replicates, of which one plate was for cell counting. After 24 h of exposure, the intracellular and extracellular metabolites were extracted respectively and then detected by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS). The orthogonal partial least-squares discriminant analysis (OPLS-DA) was applied to visualize the alterations of metabolomic profiles and to identify the differential metabolites (DMs) based on their variable importance for the projection (VIP) value >1 and P<0.05. The metabolite set enrichment analysis (MSEA) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed to recognize the significantly altered metabolite sets and pathways. The dose-response relationships were established and the potential biomarkers of Cd exposure were identified by 10% up-regulated or 10% down-regulated effective concentration (EC) of target metabolites. Results A total of 1201 metabolites were identified in the intracellular metabolomic samples and 1207 for the extracellular metabolomic samples. The intracellular and extracellular metabolome of Cd-treated NSCs were distinct from that of the control group, and the difference grew more distant as the Cd dosage increased. At 0.5, 1.0, and 1.5 μmol·L−1 dosage of Cd, 87, 83, and 185 intracellular DMs and 161, 176, and 166 extracellular DMs were identified, respectively. Within the significantly changed metabolites among the four groups, 176 intracellular DMs and 167 extracellular DMs were identified. Both intracellular and extracellular DMs were enriched in multiple lipid metabolite sets. Intracellular DMs were mainly enriched in taurine and hypotaurine metabolism, glycerophospholipid metabolism, and glycerolipid metabolism pathways. Extracellular DMs changed by Cd were mainly enriched in glycerophospholipid metabolism, steroid hormone biosynthesis, and cysteine and methionine metabolism pathways. Among intracellular DMs, 125 metabolites were fitted with dose-response relationships, of which 108 metabolites showed linear changes with the increase of Cd dosage. And 134 metabolites were fitted with dose-response relationships among extracellular DMs, of which 86 metabolites showed linear changes. The intracellular DMs with low EC values were hypotaurine, ethanolamine, phosphatidylethanolamine, and galactose, while the extracellular DMs with low EC values were acetylcholine and 1,5-anhydrosorbitol. Conclusion Cd treatment can significantly alter the intracellular and extracellular metabolome of mouse NSCs in a dose-dependent manner. The neurotoxicity of Cd may be related to glycerophospholipid metabolism. Acetylcholine, ethanolamine, and phosphatidylethanolamine involved in glycerophospholipid metabolism pathway might be potential biomarkers of Cd-induced neurotoxicity.

Short-term voluntary exercise enhances the activation of endogenous neural stem cells inintracerebral hemorrhage mice with hyperlipidemia / 西安交通大学学报(医学版)

【Objective】 To investigate the improvement of motor function recovery and the activation of endogenous neural stem cells (eNSCs) via voluntary exercise in mice with hyperlipidemia after intracerebral hemorrhage (ICH). 【Methods】 Four-month-old male Nestin-CreERT2: tdTomato transgenic mice were fed with high-fat diet (HFD) for eight weeks. Type Ⅳ collagenase was micro-injected into the corpus striatum to construct mouse ICH model with the help of stereotaxic apparatus. Voluntary exercise (wheel running) was initiated on the second day after ICH and monitored daily for seven days. Neurological severity score (NSS) and beam walking test were applied to evaluate motor function and coordination. Liver and brain tissues were collected at day 9 after ICH and sliced for staining. Then the Nestin-labeled cells, Ki67+, and doublecortin (DCX)+ in subventricular zone (SVZ) were counted to evaluate eNSCs activation. 【Results】 ① Compared with those of mice fed by chow diet (CD), the body weight, blood glucose level, concentration of lipid metabolism factors and the number of Nile Red positive cells in liver tissue were significantly higher in HFD-fed mice, confirming hyperlipidemia. ② Compared with the sham group, NSS score increased and the distance of cross-beam walking of ICH mice significantly decreased, showing the deficiency of motor function. It could be rescued by 7-day wheel running, as shown by a lower NSS score and a longer cross-beam walking distance. ③ Compared with the sham group, the number of Nestin+/Ki67+ cells decreased and Nestin+/DCX+ cells increased after ICH. After 7-day voluntary exercise, the number of Nestin+/Ki67+ cells decreased but that of Nestin+/DCX+ cells further increased significantly. However, compared with ICH, the increase of Nestin+/DCX+ cells in ICH+Ex was not significant. 【Conclusion】 Short-term voluntary exercise during the acute stage of ICH improved the recovery of motor function and enhance the proliferation of eNSCs in mice with hyperlipidemia. This provides a new idea for further developing ICH accelerated rehabilitation strategy based on eNSCs.

Effects of paraquat on proliferation and neurogenesis of neural stem cells by promoting secretion of IL-1β by microglia / 环境与职业医学

Background Paraquat (PQ) is a widely used herbicide that exerts neurotoxicity. The effects of PQ on neural stem cells (NSCs) through microglia mediated neuroinflammation remain limitedly studied. Objective To investigate the effects of PQ on the proliferation and neurogenesis of NSCs through neuroinflammation mediated by microglia. Methods Microglial cell lines (BV2 cells) and primary NSCs were used. BV2 cells were exposed to 0, 1, 3.3, 10, 33, and 100 μmol·L−1 of PQ for 6 h followed by viability assessment. The highest PQ concentration that had no effect on cell viability was selected as the final exposure concentration (33 μmol·L−1). To exclude the direct effect of PQ on NSCs, after the BV2 cells were cultured in complete medium containing 33 μmol·L−1 PQ for 6 h, the BV2 culture medium was replaced by NSCs complete medium without PQ for 24 h. The concentration of interleukin-1β (IL-1β) in supernatant was detected by enzyme-linked immune sorbent assay. Besides, in order to detect the effects of IL-1β on NSCs proliferation and neurogenesis, NSCs isolated from hippocampus of adult mice were cultured in the supernatant obtained above and divided into four groups: control supernatant + control antibody, control supernatant + IL-1β neutralizing antibody (10 ng·mL−1), PQ supernatant + control antibody, PQ supernatant + IL-1β neutralizing antibody (10 ng·mL−1). Proportion of Ki67-positive NSCs was detected by flow cytometry (FCS) and immunofluorescence after 24 h culture, and neurogenesis was detected by FCS and immunofluorescence after 3-7 d of culture. Results The IL-1β concentration in the supernatant of BV2 cells was significantly increased after the 33 μmol·L−1 PQ exposure compared with the control group (t=3.020, P<0.05). After the NSCs were cultured with the supernatant of PQ-treated BV2 cells, the proportion of Ki67-positive NSCs (t=9.129, P<0.01) and the proportion of newborn neurons (t=4.638, P<0.01) were significantly decreased compared to the control group. After neutralizing IL-1β, the proportion of Ki67-positive NSCs (t=22.05, P<0.01) and the proportion of newborn neurons (t=11.09, P<0.01) were significantly higher than those in the un-neutralized group. The results of immunofluorescence detection also showed that after neutralizing IL-1β secreted by 33 μmol·L−1 PQ-treated BV2 cells, the number of Ki67-positive NSCs and the number of newborn neurons were significantly higher than those in the un-neutralized group. Conclusion The secretion of IL-1β by microglia is increased after PQ treatment, resulting in a decrease in the proliferation and neurogenesis of NSCs. These results suggest that neuroinflammation is involved in NSCs damage caused by PQ.

Total Ginsenoside Extract from Panax ginseng Enhances Neural Stem Cell Proliferation and Neuronal Differentiation by Inactivating GSK-3β / 中国结合医学杂志

OBJECTIVE@#To study the effects of total ginsenosides (TG) extract from Panax ginseng on neural stem cell (NSC) proliferation and differentiation and their underlying mechanisms.@*METHODS@#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.@*RESULTS@#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).@*CONCLUSION@#TG promoted NSC proliferation and neuronal differentiation by inactivating GSK-3β.

Effect of electroacupuncture on proliferation of hippocampal neural stem cells in young mice with Alzheimer's disease / 中国针灸

OBJECTIVE@#To observe the effect of electroacupuncture (EA) on the proliferation of endogenous neural stem cells in the hippocampus of young mice with Alzheimer's disease (AD), so as to explore its mechanisms underlying improvement of AD.@*METHODS@#Forty 1.5-month-old APP/PS1 transgenic male mice were randomly divided into an EA group and a model group, 20 mice in each group, and other 20 C57BL/6J male mice of the same age were used as the normal control group. EA (intermittment wave 10 Hz, 2 mA) was applied to "Baihui" (GV 20), "Fengfu" (GV 16) and "Shenshu" (BL 23) for 20 min, once a day, 6 days a week for 16 weeks. H.E. staining was used to assess histopathological changes of neurons of the hippocampal dentate gyrus. Immunohistochemical stain was used to detect the expression of 5-bromodeoxyuridine (BrdU)-positive in the hippocampus, and immunofluorescence double-labeled technique was used to detect the number of proliferated positive neurons of hippocampal neural stem cells. The expression levels of brain derived neurotrophic factor (BDNF) and Nestin mRNA and protein were detected by using real-time PCR and Western blot, separately.@*RESULTS@#The immunoactivity of BrdU, and the expression levels of BDNF and Nestin mRNA and protein in the hippocampus in the model group were significantly lower than in the normal control group (P<0.01, P<0.05), and considerably higher in the EA group than in the model group (P<0.01, P<0.05). The number of BrdU/NeuN dual labeled neurons was slightly increased in the model group than in the normal control group (P>0.05), and evidently increased in the EA group relevant to the model group (P<0.05), suggesting a proliferation of hippocampal neural stem cells. After modeling, the neurons of hippocampal dentate gyrus were arranged loosely and irregularly and their structure was fuzzy, with an appearance of different degrees of nuclear pyknosis, whereas in the EA group, the neuronal contour was clear and the nuclear structure was relatively distinct.@*CONCLUSION@#EA can activate the proliferation of neural stem cells in the hippocampus in AD mice, which may contribute to its function in improving the neuronal structure by upregulating the expression of BDNF.

Mechanism of Danhong injection in improving therapeutic effect of neural stem cell transplantation for cerebral ischemia injury / 器官移植

Objective To investigate whether Danhong injection can enhance the therapeutic effect of neural stem cell (NSC) transplantation in repairing cerebral ischemia injury by regulating the nuclear factor E2-related factor 2 (Nrf2) signaling pathway. Methods Forty male SD rats were randomly divided into the NSC transplantation group (NSC group), Danhong injection group (DH group), NSC+ Danhong injection group (N+D group), NSC+ Danhong injection group +ML385 group(N+D+M group) and PBS control group (PBS group), 8 rats in each group. All rat models of cerebral ischemia were established by embolization of the middle cerebral artery. Reperfusion was performed at 1.5 h after embolization. All rats in each group received corresponding interventions at 3 d after reperfusion. The neurological function score was evaluated before and 1, 2, 4 weeks after NSC transplantation. All rats were sacrificed at 4 weeks after NSC transplantation. The parameters related to oxidative stress were detected. The expression levels of neuron-specific nuclear protein (NeuN) and von Willebrand factor (vWF) were determined by immunofluorescence staining. Results Before NSC transplantation, the neurological function scores did not significantly differ among different groups (all P > 0.05). At postoperative 1, 2 and 4 weeks, the neurological function scores in the NSC, DH and N+D groups were significantly lower than those in the PBS and N+D+M groups (all P < 0.05). Compared with the PBS and N+D+M groups, the malondialdehyde (MDA) levels were significantly decreased, whereas the superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels were considerably increased in the NSC, DH and N+D groups (all P < 0.05). The GPX level in the N+D+M group was significantly lower than that in the PBS group (P < 0.05). Immunofluorescence staining showed that the transplant NSC in the rat brain migrated to the surrounding area of cerebral infarction and survived, and expressed neuronal marker NeuN and neovascularization marker vWF. However, the number of living NSC in the N+D+M group was significantly lower compared with those in the remaining groups. Conclusions Danhong injection may improve the microenvironment of stem cell transplantation, enhance the survival rate of transplant NSC and improve the therapeutic effect of NSC transplantation for cerebral ischemia injury probably by regulating the Nrf2 signaling pathway.

Effect of Notch signaling pathway on nerve regeneration after cerebral ischemia in rats with neural stem cells transplantation / 解剖学报

Objective To investigate the mechanism of inhibiting the Notch signaling pathway in promoting neural regeneration after neural stem cells (NSCs) transplantation in rats with cerebral ischemia. Methods The model of focal cerebral ischemia was established by middle cerebral artery occlusion (MCAO) method . NSCs were cultured in vitro and transplanted into the striatum ischemic area. In the experiment, 40 SD rats were divided into sham operation group, model group, transplantation group (transplanted neural stem cells), and N-[N-(3, 5-difluorohenacetyl )-L-alanyl ]-S-phenylglycinet-butyl ester( DAPT) + transplantation group. The degree of neuronal damage in each group was observed by HE staining. The expressions of Notchl, Hesl and Hes5 in the brain tissue of each group were detected by immunohistochemistry and Western blotting. Results Compared with the sham operation group, the neuron injury in the model group was severe, and nuclear pyknosis and nuclear lysis were observed. The Notchl, Hesl and Hes5 positive cells increased significantly, and the expression of Notchl, Hesl and Hes5 proteins were significantly up-regulated (P<0. 05). Compared with the model group, the neuronal damage in the transplantation group and the DAPT+ transplantation group were all relieved, and the Notchl, Hesl and Hes5 positive cells were partially expressed, and the expression of each protein decreased (P<0. 05). The DAPT+ transplantation group neurons were compared. The damage was obviously restored, and the expression of protein-positive cells and protein further decreased (P<0. 05). Conclusion Inhibition of Notch signaling pathway can promote nerve regeneration after neural stem cell transplantation in rats with cerebral ischemia. The mechanism is mainly related to down-regulation of Notch 1 , Hesl and Hes5 expression.

Penetrative needling of scalp-points improves neurological function by promoting stem cell proli-feration and activating Shh/Gil1 signaling in intracerebral hemorrhage rats / 针刺研究

OBJECTIVE: To observe the effect of penetrative needling from "Baihui" (GV20) to "Qubin" (GB7) on neural stem cell proliferation and sonic hedgehog (Shh) signaling in subventricular zone (SVZ) in intracerebral hemorrhage (ICH) rats so as to explore its mechanisms underlying improvement of ischemic injury of brain. METHODS: Male SD rats were randomly divided into blank control, model, acupuncture and agonist (Purmorphamine, an activator of Shh signaling pathway) groups (n＝18 in each group, 6 for H．E. stain, 6 for examining neuronal cell proliferation, and 6 for immunohistochemistry). The ICH model was established by injecting autogenous blood (50 µL) into the right caudate nucleus. The neurological defect was scored with refe-rence to Bederson's method. Penetrative needling from GV20 to GB7 was performed by manipulating the needle for 6 min (repeated 3 times in 30 min), once daily for 7 days. Intraperitoneal injection of Purmorphamine (1 mg/mL, 1 mg/kg) was performed, once daily for 7 days. Histopathological changes of the hemorrhagic penumbra region were observed under microscope after H．E. stain, the newborn neural stem cell proliferation (BrdU＋/Nestin＋ double labeled cells) in the SVZ was observed by immunofluorescence after intraperitoneal injection of BrdU (50 mg/kg), and the expression of Shh and glioma-associated hemolog-1 (Gli1) detected by immunohistochemistry. RESULTS: After modeling, the neurological score and expression levels of Shh and Gil1 proteins were significantly increased in the model group relevant to the blank control group (P0.05). Outcomes of H．E. stain showed obvious edema, disordered arrangement of cells, infiltration of inflammatory cells and red blood cells with glial cell hyperplasia around the hematoma area in the model group, which was relatively milder in both acupuncture and agonist groups such as in basic disappearance of edema and inflammatory reaction. CONCLUSION: Penetrative needling from GV20 to GB7 can obviously improve neurological function in ICH rats, which is related to its effects in activating Shh/Gil1 signaling and in further promoting neural stem cell proliferation in the SVZ region.

Effect of different courses of electroacupuncture intervention on recognition memory and proliferation and differentiation of hippocampal neural stem cells in mice with radiation-induced brain injury / 针刺研究

OBJECTIVE: To observe the influence of different courses of electroacupuncture (EA) intervention on recognition memory and the proliferation and differentiation of hippocampal neural stem cells in mice with radiation-induced brain injury, so as to explore its mechanisms underlying improving radiation-induced brain injury. METHODS: Se-venty 30-day old C57BL/6J mice were randomly divided into control, model and EA groups, and the latter two groups were further divided into 1 week (W), 2 W and 3 W subgroups (n=10 in the control group and each subgroup). The ra-diation-induced brain injury model was established by radiating the mouse' left head at a dose of 8 Gy for 10 min by using a radiation linear accelerator. EA (1.5 V, 2 Hz/10 Hz) was applied to "Baihui" (GV20), "Fengfu" (GV14) and bilateral "Shenshu" (BL23) for 30 min, once daily for 1, 2 and 3 weeks, respectively. The learning-cognition memory ability was detected by using novel object recognition test in an open test box to record the time for exploring a novel object (TN) and a familiar object and to calculate the recognition index (RI). The neural stem cells' proliferation and differentiation in the hippocampus tissues were evaluated by counting the number of bromodeoxyuridine (BrdU)-labeled cells, neuronal nuclei (NeuN)/BrdU-positive cells and BrdU/glia fibrillary acidic protein (GFAP)-positive cells under microscope after immunofluorescence stain. RESULTS: After modeling, the TN at 90 min and 24 h and RI of the model subgroup 3 W at 90 min and RI of the model subgroup 1, 2 and 3 W at 24 h were significantly decreased in comparison with those of the control group (P<0.01, P<0.05). Moreover, the number of BrdU-positive cells in the model subgroup 1 W and 2 W, the BrdU/NeuN double-labeled cells in the 3 model subgroups and BrdU/GFAP double-labeled cells in the model subgroup 1 W and 3 W were significantly decreased (P<0.01, P<0.05). Following EA interventions, the TN in the 3 EA subgroups at both 90 min and 24 h, and RI of EA subgroup 3 W at 90 min and EA subgroup 2 W and 3 W at 24 h were considerably increased compared with those of the corresponding 3 model subgroups (P<0.05, P<0.01). The numbers of BrdU-positive cells as well as BrdU/NeuN and BrdU/GFAP double-labeled cells were significantly increased in the 3 EA subgroups (P<0.05, P<0.01, P<0.001). CONCLUSION: EA of GV20, GV14 and BL23 can improve the recognition memory ability of mice with radiation-induced brain injury, which may be related to its effect in promoting the proliferation and differentiation of stem cells in the hippocampus.

Nac-1 is required for maintenance of multipotency in neural stem/progenitor cells / 西安交通大学学报(医学版)

Objective: To study the regulatory mechanism of Nac-1 on the self-renewal of neural stem/progenitor cells (NSPCs). Methods: The expression level of Nac-1 was detected by using ESCs-derived NSPCs as the cell model. RNA interference was used to reduce the expression of Nac-1; the interference efficiency was detected by quantitative RT-PCR and Western blot. The proliferation and apoptosis of NSPCs were detected by cell counting and flow cytometry. Luciferase assay was used to detect the transcriptional regulation of Nac-1 on c-Myc. Results: Nac-1 was highly expressed in NSPCs, and its mRNA level decreased by 77% after differentiation. Compared with that in the control group, the mRNA level of Nac-1 in the NSPCs of the experimental group was significantly decreased, and the interference efficiency was 69% and 66%, respectively. NSPCs with Nac-1 knockdown showed slow proliferation, increased apoptosis and tended to differentiate, and the mRNA level of c-Myc decreased by 46% and 57% in two Nac-1 knockdown groups, respectively. Luciferase assay showed that the transcriptional activity of c-Myc promoter decreased by 24% and 36%, respectively, suggesting that Nac-1 could regulate the promoter activity of c-Myc gene. Conclusion: Nac-1 can promote the proliferation of NSPCs and inhibit their differentiation by regulating the transcription of c-Myc.

Research Progress on Regulation of Proliferation and Differentiation of Neural Stem Cells by Traditional Chinese Medicine / 中国实验方剂学杂志

Neural stem cells (NSCs) have the potential of self-renewing and differentiation into neurons,astrocyte,as well as oligodentrocyte.Nowadays,neurogenesis and NSCs transplantation have become new strategies for the treatment of nervous system diseases.However,the disadvantages of NSCs transplantation also limit their progress,including low survival rate,difficulty in differentiation,tumorigenesis and difficulty in penetrating scar tissues.It is a novel issue on how to regulate the proliferation and differentiation of endogenous NSCs in adult neurogenesis.Drug-induced endogenous NSCs proliferation and differentiation is the potential strategy for the regenerative medicine,repairing damaged nerves and treating central nervous system diseases.As a traditional medicine in China,Chinese medicine has the characteristics of multi-target,multi-link and multi-channel treatment,and has unique advantages and broad prospects in promoting nerve regeneration.More and more studies have shown that Chinese herbal medicine could indirectly or directly regulate the proliferation and differentiation of NSCs through extracellular signaling pathways (such as Notch,Wnt/β-catenin,the Sonic Hedgehog (Shh) pathway),intracellular transcription factors,together with changing the microenvironment (neurotrophic factor BNDF).In this review,we focus on the traditional Chinese medicine formulae,Chinese patent medicine,single medicine,as well as their monomers,which regulate the proliferation and differentiation of NSCs,so as to provide a new strategy for the prevention and treatment of central nervous system diseases by traditional Chinese medicine.

The advance of endogenous neural stem cell features for retinal Müller cell / 中华眼底病杂志

Neural stem cell is a kind of stem cells that can differentiate into neural and glial cells. While Müller cells, the main endogenous neural stem cell in retina,have the features to reentry into the cell cycle and differentiate into neural cells after retinal damage. Although it is highly effective for retinal Müller cell differentiation spontaneously after retinal injury in vertebrates, this feature is rigorous restricted in mammals. Recently, some transcription factors,such as Ascl1, Sox2, Lin28, Atoh7, are sufficient to drive quiescent Müller cells back in proliferation to generate new retinal neurons. Moreover, combining Ascl1 expression with a histone deacetylase inhibitor can bypass the limitation and increase the generation of new neurons in the adult retina. These regenerated neurons integrate the existing neuronal network and are able to respond to light, indicating that they can likely be used to restore vision. While these results are extremely promising, the regenerative response is still limited, likely because the proliferative capacity of mammalian Müller cells is low compared to their zebrafish counterparts. It is indeed necessary to identify new factors increasing the efficiency of the regenerative response.

MicroRNA-132 in the Adult Dentate Gyrus is Involved in Opioid Addiction Via Modifying the Differentiation of Neural Stem Cells / 神经科学通报·英文版

MicroRNA-132 (miR-132), a small RNA that regulates gene expression, is known to promote neurogenesis in the embryonic nervous system and adult brain. Although exposure to psychoactive substances can increase miR-132 expression in cultured neural stem cells (NSCs) and the adult brain of rodents, little is known about its role in opioid addiction. So, we set out to determine the effect of miR-132 on differentiation of the NSCs and whether this effect is involved in opioid addiction using the rat morphine self-administration (MSA) model. We found that miR-132 overexpression enhanced the differentiation of NSCs in vivo and in vitro. Similarly, specific overexpression of miR-132 in NSCs of the adult hippocampal dentate gyrus (DG) during the acquisition stage of MSA potentiated morphine-seeking behavior. These findings indicate that miR-132 is involved in opioid addiction, probably by promoting the differentiation of NSCs in the adult DG.

Effects of timosaponin B-II on differentiation of rat neural stem cells into tyrosine hydroxylase posi-tive neurons in vitro / 中华行为医学与脑科学杂志

Objective To explore the effect of timosaponin B-II ( TB-II) on the differentiation of neural stem cells (NSCs) into tyrosine hydroxylase (TH) positive neurons in neonatal rats. Methods The biological functions of self-proliferation and multi-differentiation of NSCs were identified by primary culture, cell proliferation counting,morphological observation and immunology. NSCs of SD rats were cultured in vitro and treated with different concentrations of TB-II (10 μg/ml,30 μg/ml ,100 μg/ml) for 7 days. Immuno-histochemistry was used to detect the effect of TB-II on the differentiation of NSCs into TH-positive neurons, and Western blot was used to detect the expression of TH protein in neurons. Results ( 1) The cultured cells had the ability to self-proliferation,expressed nestin protein and differentiated into neurons and glial cells. So the cultured cells were conformed to the biological function of neural stem cells. (2)Compared with the control group,the TH positive cell ratio of TB-II 30 μg/ml group and TB-II 100 μg/ml group increased ((10. 03± 1. 36)%),( 20. 01± 3. 37)%),(31. 32± 3. 98)%) ,the difference was significant ( t=6. 15, 16. 54,both P<0. 05). There was no significant difference between TB-II 10 μg/ml group and control group (P>0. 05). (3)Western results showed that the relative expression of TH protein in TB-II 30 g/ml group and TB-II 100 μg/ml group was higher than that in control group,the difference was statistically significant (con-trol group: (1. 02±0. 24),TB-II 30μg/ml group: (3. 64±1. 78),TB-II 100 μg/ml group: (5. 88±2. 34);t=12. 58,9. 15,both P<0. 05). There was no significant difference between TB-II 10 μg/ml group and con-trol group (P>0. 05). Conclusion TB-II can promote the differentiation of NSCs into TH-positive neurons.

Neurogenesis and Regulation of Olfactory Epithelium

The olfactory epithelium is capable of structural and functional recovery after injury through neurogenesis. Neurogenesis occurs via stem cells in the olfactory epithelium. Horizontal basal cells and globose basal cells in the basal layer of the epithelium have the characteristics of stem cells and progenitor cells of olfactory neurons. In order for the horizontal basal cells and globose basal cells to differentiate into olfactory neurons, distinct transcriptional factors are required at each stage. These transcription factors inhibit or synergize with each other or cells at each differentiation stage, regulating olfactory neurogenesis. Recently, the regulation of neurogenesis and development through epigenetic controls that change gene expression without changing the gene sequence have been studied. Studies of olfactory epithelium have helped to elucidate complex neurological systems including spinal cord and brain. In particular, features of neurogenesis will lead to medical advances in the treatment of central nervous diseases, which until this time have been considered impossible.

H3K27me3 Signal in the Cis Regulatory Elements Reveals the Differentiation Potential of Progenitors During Drosophila Neuroglial Development / 基因组蛋白质组与生物信息学报·英文版

Drosophila neural development undergoes extensive chromatin remodeling and precise epigenetic regulation. However, the roles of chromatin remodeling in establishment and maintenance of cell identity during cell fate transition remain enigmatic. Here, we compared the changes in gene expression, as well as the dynamics of nucleosome positioning and key histone modifications between the four major neural cell types during Drosophila neural development. We find that the neural progenitors can be separated from the terminally differentiated cells based on their gene expression profiles, whereas nucleosome distribution in the flanking regions of transcription start sites fails to identify the relationships between the progenitors and the differentiated cells. H3K27me3 signal in promoters and enhancers can not only distinguish the progenitors from the differentiated cells but also identify the differentiation path of the neural stem cells (NSCs) to the intermediate progenitor cells to the glial cells. In contrast, H3K9ac signal fails to identify the differentiation path, although it activates distinct sets of genes with neuron-specific and glia-related functions during the differentiation of the NSCs into neurons and glia, respectively. Together, our study provides novel insights into the crucial roles of chromatin remodeling in determining cell type during Drosophila neural development.

The protective effect of nerve function of Buyang Huanwu decoction on cerebral ischemia/reperfusion rats after neural stem cell transplantation / 中国药理学通报

To explore the protective effect of nerve function of Buyang Huanwu Decoction on cerebral ischemia/reperfusion rats after the transplantation of neural stem cells (NSCs) . Methods Thread bolt method was used to establish middle cerebral artery occlusion model. Drug groups were given Buyang Huanwu Decoction (14. 8 g kg"1 d " 1) by gavage after the rats being sober. NSCs were transplanted to rat brain after making the model 24 hours later. Zea Longa neurobehavioral behavioral score was used to observe neural function defect, and TTC staining to detect the volume of cerebral infarction, and Nissl staining to detect Nissl body integrated optical density (IOD), and Immunohistochemical staining to detect expression of Bcl-2 and Bax. Results Compared with sham operation group, the nerve function defect appeared, and the volume of cerebral infarction increased significantly, the integral optical density of Nissl body was reduced and the ratio of Bcl-2 to Bax was reduced in model group (P < 0. 05) . Compared with model group, the nerve function defect was reduced, the volume of cerebral infarction was reduced, the integral optical density of Nissl body increased, and the ratio of Bcl-2 to Bax increased in BYHWD group, Transplant group and BYHWD + Transplant group (P < 0. 05). Compared with transplant group, the nerve function defect was reduced, the volume of cerebral infarction was reduced , the integrated optical density of Nissl body increased , and the ratio of Bcl-2 to Bax increased in BYHWD + Transplant group (P < 0. 05). Conclusions Buyang Huanwu Decoction can enhance the neuroprotective effect after NSCs transplantation in cerebral ischemia/reperfusion rats.

Insulin-like Growth Factor-1 Receptor Dictates Beneficial Effects of Treadmill Training by Regulating Survival and Migration of Neural Stem Cell Grafts in the Injured Spinal Cord

Survival and migration of transplanted neural stem cells (NSCs) are prerequisites for therapeutic benefits in spinal cord injury. We have shown that survival of NSC grafts declines after transplantation into the injured spinal cord, and that combining treadmill training (TMT) enhances NSC survival via insulin-like growth factor-1 (IGF-1). Here, we aimed to obtain genetic evidence that IGF-1 signaling in the transplanted NSCs determines the beneficial effects of TMT. We transplanted NSCs heterozygous (+/−) for Igf1r, the gene encoding IGF-1 receptor, into the mouse spinal cord after injury, with or without combining TMT. We analyzed the influence of genotype and TMT on locomotor recovery and survival and migration of NSC grafts. In vitro experiments were performed to examine the potential roles of IGF-1 signaling in the migratory ability of NSCs. Mice receiving +/− NSC grafts showed impaired locomotor recovery compared with those receiving wild-type (+/+) NSCs. Locomotor improvement by TMT was more pronounced with +/+ grafts. Deficiency of one allele of Igf1r significantly reduced survival and migration of the transplanted NSCs. Although TMT did not significantly influence NSC survival, it substantially enhanced the extent of migration for only +/+ NSCs. Cultured neurospheres exhibited dynamic motility with cytoplasmic protrusions, which was regulated by IGF-1 signaling. IGF-1 signaling in transplanted NSCs may be essential in regulating their survival and migration. Furthermore, TMT may promote NSC graft-mediated locomotor recovery via activation of IGF-1 signaling in transplanted NSCs. Dynamic NSC motility via IGF-1 signaling may be the cellular basis for the TMT-induced enhancement of migration.

Comparative study on extraction and culture method of neural stem cells / 中国药理学通报

Aim To explore the best method of neural stem cellextraction and culture, and provide a technical reference for thebasic research of neural stem cells. Methods Different extractionand culture methods of neural stem cells were compared.The rate of ball of neural stem cells and the stability of neuralstem cells in undifferentiated state were observed by extraction offetal and neonatal rats cortex, using different types of medium,different inoculation density, different culture methods, differentmethods of changing liquid and different passage methods. Neuralstem cells' activities were detected by Varioskan LUX MultimodeMicroplate Reader. Results ① The brain cortex of fetalrats of 14 d had higher proportion of neural stem cells, less othercells and more neurospheres than newborn rats of 24 h. ② Neuralstem cells could be stabilized in undifferentiated state by usingserum-free medium, while most of the neural stem cellswere differentiated into neurons and glial cells by using serummedium. ③ Neural stem cells, seeding at 1. 0 ×109 ·L-1 , hada large number of neurosperes and were in good condition. ④Suspension culture was beneficial to form a stable neurosphereand keep the neural stem cells in an undifferentiated state thanadherent culture. ⑤ The state of neurosphere by changing halfof the medium and adding medium without discarding was betterthan that by replacing all medium. ⑥ The neurospheres couldbe separated into single cells by mechanical blow in primary generationand the second generation of neurospheres cultured in serum-free medium. While the percentage of viable cells in neuralstem cells was the highest digested with stem cell lysates afterthree generations and the neurospheres re-formed were better. ⑦Neural stem cells' activity of 14 d fetal rat in Accutase digestiongroup was significantly higher than that of the other threegroups, and the difference was significant (P <0. 05). ConclusionsNeural stem cells proliferate and divide well, with highrate of ball formation and good neurosphere condition, which canmaintain a stable undifferentiated state by extracting the cerebralcortex of 14 d fetal rats, using serum-free medium, inoculatinginto a 25 cm2 flask at a density of 1. 0 × 109 ·L-1 , and takingthe suspension culture (adding the medium 1 ~ 1. 5 mL every 2~3 d and passage every 6 ~8 d ).