Coactosin-like protein 1 inhibits neuronal migration during mouse corticogenesis

Coactosin-like protein 1 (Cotl1), a member of the actin-depolymerizing factor (ADF)/cofilin family, was first purified from a soluble fraction of Dictyostelium discoideum cells. Neuronal migration requires cytoskeletal remodeling and actin regulation. Although Cotl1 strongly binds to F-actin, the role of Cotl1 in neuronal migration remains undescribed. In this study, we revealed that Cotl1 overexpression impaired migration of both early- and late-born neurons during mouse corticogenesis. Moreover, Cotl1 overexpression delayed, rather than blocked, neuronal migration in late-born neurons. Cotl1 expression disturbed the morphology of migrating neurons, lengthening the leading processes. This study is the first to investigate the function of Cotl1, and the results indicate that Cotl1 is involved in the regulation of neuronal migration and morphogenesis.

Construction and Validation of a Mammalian Expression Vector for in Utero Electroporation Study of miR-3099 in the Mouse Neocortex

@#Introduction: MiR-3099 was reported to play a role in neuronal cell differentiation/function in the brain during late embryonic and early neonatal development. To further explore its potential regulatory effects on embryonic brain development, this study aims to construct and validate an expression vector of miR-3099 for future gain-of-function and loss-of-function studies. Methods: pCAG-eGFP vector was modified to include IRES2 and miR-3099 with 150bp upstream and downstream genomic sequences. The newly constructed vector, pCAG-miR-3099-IRES2-eGFP, consists of CAG promoter. The in vitro expression level of miR-3099 was measured using stem-loop RT-qPCR after it was transfected into 293FT cell. Later, the vector was electroporated into the embryonic brain at E15.5. Three days later, the E18.5 embryonic brain was harvested and cryopreserved. Immunohistochemistry was performed by using antibody against eGFP to validate the in utero expression of the transgene in the neocortex of the brain. Results: Our finding showed that, the expression level of miR-3099 was significantly upregulated (p<0.001) in cells transfected with miR-3099 vector as compared to both negative and empty plasmid control groups. In addition, the expression of eGFP was noted in the brain section indicating that the vectors with or without miR-3099 transgene were successfully transfected into and expressed in the neocortex upon electroporation. Conclusion: The bicistronic expression vector of miR-3099 which was driven by the CAG promoter was successfully constructed, validated and sufficiently delivered to brain cells via the in utero electroporation approach. The regulatory roles of miR-3099 in embryonic brain development can be manipulated using similar approach.

NS4A protein of Zika virus influences the neuronal migration of mouse cortex / 基础医学与临床

Objective To determine the effect of NS3 and NS4A proteins of Zika virus on the neuronal migration in vivo.Methods To identify the coding sequence of NS3 and NS4A,the genome of Zika SZ01 was sequenced by rapid amplification of cDNA ends (RACE) and reverse-transcription PCR,then NS3 and NS4A was constructed in pCIG vector fused with Flag-tag to express these proteins.And then these plasmids was transfected into the embryo brain of E13.5 mice by in utero electroporation,the distribution of the cells which express these proteins in the cortex was detected by Flag,eGFP and TBR1 fluorescence in E18.5 mice through immunohistochemistry so as to assess the influence of viral proteins on the neuronal migration of mouse cortex.Results 1) Sequence results showed that the amino acid sequence of NS4A is consistent with NCBI data,while NS3 has 1 amino acid mutant.2) As the fluorescence of Flag and eGFP can co-localization,the eGFP fluorescence signal marks the cells that have expressed these virus proteins in cortex.3) TBR1 fluorescence shows the distribution of the cells that express NS4A in vivo are significantly different from pCIG control and NS3 (P＜0.001).Conclusions The NS4A protein of Zika virus may affect the neuronal migration in vivo.