Effects of Exendin-4 on the differentiation of neural stem cells from subventricular zone of adult mice in vitro / 中国应用生理学杂志

OBJECTIVE@#To study the effect of exendin-4(Ex-4) on the differentiation of neural stem cells(NSCs) in adult mouse subventricular zone(SVZ)and its mechanism .@*METHODS@#NSCs in the SVZ were derived from 5-week C57BL/6J mice and the expression of nestin was detected by immunofluorescence. The cell morphology was observed after the cells treatmed with 100 nmol/L Ex-4 for 14 days.The expressions of nestin and glucagon-like peptide-1 receptor (GLP-1R) were detected by immunofluorescence. GLP-1R was knocked down by using shRNA and the study was divided into four groups: control group, Ex-4 group, GLP-1R knockdown group, GLP-1R knockdown + Ex-4 group. After treatment with 100 nmol/L Ex-4 for 14 d, β-tublin III and glial fibrillary acidic protein (GFAP) were labeled by immunofluorescence and then the proportion of β-tublin III positive cells were counted. Western blot was used to detect the activation of cAMP-response element binding protein (CREB) in NSCs. In order to further study the effects of Ex-4 on mitogen-activated protein kinase(MAPK) and phosphatidylinositol 3-hydroxy kinase (PI3K) pathways, the cells were pretreated with MAPK inhibitor U0126 at a concentration of 0.07 μmol/L for 30 min or PI3K inhibitor LY294002 at 50 μmol for 2 h, respectively. The study was divided into six groups: control group, Ex-4 group, U0126 group, U0126 + Ex-4 group, LY294002 group, LY294002 + Ex-4 group. The activation of CREB in each group was detected by Western blot. The experiment was repeated three times independently.@*RESULTS@#NSCs were successfully extracted from SVZ of C57BL/6J mice. Immunofluorescence showed that nestin and GLP-1R were positive in NSCs. Compared with the control group, the proportion of neurons differentiated from Ex-4 group was higher. The percentage of neurons in GLP-1R knockdown + Ex-4 group was basically the same as that in control group (P＜0.01). The positive cells of beta-tublin III showed positive activation of GLP-1R and CREB. Western blot showed that CREB was significantly activated in the Ex-4 group, and knockdown of GLP-1R abolished its activation (P＜0.01). U0126 did not affect Ex-4-mediated CERB activation, and LY294002 significantly reduced Ex-4-mediated CREB activation (P＜0.01).@*CONCLUSION@#Ex-4 promotes the differentiation of NSCs into neurons in SVZ of adult mice through GLP-1R receptor, which may be achieved through PI3K/CREB pathway.

Effects of ibuprofen on the growth and development of oligodendrocytes / 天津医药

Objective To study the effects of ibuprofen on the growth and development of oligodendrocytes. Methods A total of 6 clean and healthy adult female SD (Sprague Dawley) rats were used for extracting and culturing of oligodendrocytes(OLs).Lysophosphatidic acid(LPA)was then added,and the morphological changes of OLs pre-treatment and post-treatment were observed. Then 6 newborn rats (born 24-48 h) were used for mixed glial cell extraction from the cortex, then the OPCs were inoculated into the culture plates and randomly divided into control group, ibuprofen group, lysophosphatidic acid(LPA)group and LPA+ibuprofen group.After the adhering of the cells in each group for three days, cell morphology was observed,and the drugs were added as interventions.The control group was treated with normal saline, and the other 3 groups were added with saline solution of ibuprofen(100 μmol/L),LPA(1.0 μmol/L)and the mixture of them. The cell morphological changes were observed after 7-day intervention.The morphology of OPCs and OLs were observed by immunofluorescence staining through OPCs'specific immune markers (platelet-derived growth factor receptor alpha, PDGFR-α)and OLs'specific immune markers(myelin basic protein,MBP)along with cell count of mature OLs.Western blot assay was used to detect the relative expression level of MBP in each group. Results After the treatment with LPA to the mature OLs,protrusions were shrinking and became very sparse.The morphology of cells developed well in each group after cell adhering for 3 days. After drug intervention for 7 days, more cell protrusions and branches were observed in ibuprofen group and LPA+ibuprofen group than those of the control group and LPA group.The results of cell count showed that the number of MBP positive cells was significantly higher in the ibuprofen group and LPA+ibuprofen group than that in the control group and LPA group(P<0.01).The results of Western blot assay showed that the MBP protein expression was significantly less in LPA group than the other three groups (P<0.01), and the expression was significantly higher in the ibuprofen group than that of LPA+ibuprofen group (P<0.01). Conclusion LPA has a toxic effect on the growth and development of OPCs, and it has an inhibitory effect on the normal growth of mature OLs. A certain concentration of ibuprofen can significantly inhibit the cytotoxicity of LPA on OPCs and OLs,and promote the formation and maintenance of mature OLs.