Deletion Of Reelin Affecting Cortical Lamination And Cellular Polarization In Mice

Cell differentiation and changes of its polarity is a hotpot in life science and medical research. It has bi g significance in understanding development of body, diseases and even cancer. At present, we still have litt le knowledge about how key molecules and its mechanism in the microenvironment regulate cell differentia tion and change of polarity. Reelin is a kind of extracellular matrix glycoprotein that secreted from CR cells during the development of cerebral cortex. Reelin is combined with Apolipopretein E Receptor2 and Very Low Density Lipoprotein Receptor, then it induce the phosphorylation of Dab1 and guides neurons in migr ation to break away from radial glial cells, the neurons settles at according position on cortical plate. So Re elin is a key factor in regulating the formation of cerebral cortex layers. Research shows Reelin plays an im portant role as go signal, stop signal and in regulating and secreting special substance in migration of nerve cells. Lack of Reelin can cause cortex stratification and cell polarity in disorder in reeler mice. It shows that Reelin may be an important role in regulating cell differentiation and change of polarity. So in order to veri fy the relation between Reelin and cell differentiation and change of polarity, we use the immune histology technology, Nissl staining techniques and DiI tracer technique to study the difference between cell different iation and change of polarity in microenvironment of central nervous system of WT mice and reeler mice. We also studied the function of Reelin as signal transduction molecule in migration of nerve cells, cell diffe rentiation and change of polarity. Thus studying the regulation of Reelin in cell differentiation and change o f polarity has tremendous significance in revealing the pathogenesis of major disease.Aims: Our study aims at to investigate the role of Reelin in the cortical lamination, cell differentiation and polarization. In the meantime, the regulatory effects of Reelin signaling pathways will be discussed as well.Methods: Wild-type(WT) and reeler mice from E17(Embryonic day 17) to P21(postnatal day 21) were used for immunofluorescent labeling, Nissl staining,Brd U assay and DiI tracing method, therefore, the radial glial cells, neural stem cells, polarity protein could be visualized. Finally, the polarity of pyramidal cells in cerebral cortex and hippocampus also be measured.Results: Comparing with WT mice, in reeler mice, the cortical lamination was disorder due to the lack of Reelin, a stop signal. Moreover, the orientations of radial glial cells were disorder with number decrease, and molecular layer became narrow. BrdU positive cells were arranged in dispersion with number increase.Conclusion: Reelin plays an important role in the development of neuronal migration, neural proliferation and cortical lamination, especially for polarity of pyramidal cells.