Caspr4Interaction With LNX2Modulates The Proliferation And Differentiation Of Neural Progenitor Cells

Objective:To investigate the function of Caspr4and LNX2in neural precursor cells（NPCs）during cerebral cortex development.Methods:The neural progenitor cells（NPCs）were isolated from the subventricular zone ofC57BL/6E14mice. Immunofluorescence staining, RT-PCR and Western-blot analysiswere used to detect the expression of Caspr4and LNX2in the NPCs of C57BL/6mice. Toinvestigate the function of Caspr4and LNX2in the proliferation of NPCs, we transfectedSiRNA into NPCs by using electroporation and performed BrdU incorporation assay. Theplasmids encoding Caspr4, LNX2, Caspr4shRNA, LNX2shRNA and C4ICD weretransfected into NPCs by using electroporation and performed differentiation assay. Thecolocalization and interaction between Caspr4and LNX2were also examined by doubleimmunofluoresence staining and co-immunoprecipitation（Co-IP）, respectively.Results:1）Caspr4and LNX2colocalizein NPCs.2）Caspr4promotes neuronal differentiation while it inhibits proliferation of NPCs invitro.3）The intracellular domain of Caspr4（C4ICD）is required for the function of Caspr4on promoting neuronal differentiation of NPCs.4）Co-IP showed that Caspr4associates with LNX2.5）LNX2promotes neuronal differentiation of NPCs while it inhibits proliferation ofNPCs in vitro.6）C4ICD failed to promote neural differentiation of NPCs in absence of LNX2.7）LNX2promotes neural precursor cells to differentiate into neurons in absence ofCaspr4. Conclusion:In the early stage of neurogenic phase, LNX2as the downstream element of Caspr4signaling could positively modulates neurogenesis.