Diacylglycerol Kinase ζ Is Involved In Early Development Of The Rat Embryonic Neural Tube

Objective:To investigate the relationship among diacylglycerol kinaseζ(DGKζ),cytoskeleton and neural tube development by detecting their expression changes during the formation of rat embryonic neural tube.Methods:Transverse serial sections of six rat embryos from E9.5 to E12 were stained by immunohistochemistry to detect the expression of glial fibrillary acidic protein(GFAP),Nestin and DGKζin the neural tube.And the positive cell rate of GFAP or Nestin was statistically analyzed.Immunofluorescent double staining was used to detect the coexpression of DGKζ,fibros actin(F-actin)and phosphorylated protein kinase Cδ,(p-PKCδ)in the neuroepithelial cells.Results:1.Immunohistochemistry staining and cell counting results showed that the neural stem cells(NSCs)marker GFAP,earlier to Nestin,was expressed in the neuroepithelium at E9.75.With the increase of embryonic day,the GFAP immunointensity became weakened,and the positive cell rate decreased gradually.Nestin was expressed in the neuroepithelium since E10.25.After E11,with the neural groove closure and the brain vesicles development,the expression of Nestin increased gradually from cranial to caudal,and the positive cell rate increased significantly.2.Immunohistochemistry staining also showed that DGKζwas expressed in the neuroepithelium of E9.75～E12 embryos.However,the staining intensity and subcellular localization of DGKζchanged with embryonic days and sites.At E9.75 and E10,DGKζwas expressed in the cytoplasm and nucleus of most neuroepithelial cells,but only in the nucleus of M-band cells,which are in the mitotic phase.From E10.25 to E12,DGKζwas strongly expressed in the cytoplasm and nucleus,and was mostly located in the nucleus of the neuroepithelium in areas,such as dorsolateral hinge points,where the shaping of the neural tube was actively undergoing.3.Immunofluorescent double staining showed that F-actin was mainly expressed in the nucleus of neuroepithelium.DGKζand p-PKCδwere distributed on F-actin-positive microfilaments.Conclusion:During the rat neural tube developing,the proportion of Nestin~+cells in NSCs increased gradually.The expression of DGKζis shuttled betwwen the nucleus and cytoplasm of NSCs.Nucleus DGKζmay regulate the function of F-actin via DAG/PKC δ pathway.