ABSTRACT
Heterozygous loss-of-function variants of FOXP4 are associated with neurodevelopmental disorders (NDDs) that exhibit delayed speech development, intellectual disability, and congenital abnormalities. The etiology of NDDs is unclear. Here we found that FOXP4 and N-cadherin are expressed in the nuclei and apical end-feet of radial glial cells (RGCs), respectively, in the mouse neocortex during early gestation. Knockdown or dominant-negative inhibition of Foxp4 abolishes the apical condensation of N-cadherin in RGCs and the integrity of neuroepithelium in the ventricular zone (VZ). Inhibition of Foxp4 leads to impeded radial migration of cortical neurons and ectopic neurogenesis from the proliferating VZ. The ectopic differentiation and deficient migration disappear when N-cadherin is over-expressed in RGCs. The data indicate that Foxp4 is essential for N-cadherin-based adherens junctions, the loss of which leads to periventricular heterotopias. We hypothesize that FOXP4 variant-associated NDDs may be caused by disruption of the adherens junctions and malformation of the cerebral cortex.
Subject(s)
Mice , Animals , Ependymoglial Cells/physiology , Cadherins , Neurons/metabolism , Cerebral Cortex/metabolism , Cell Differentiation , Cell MovementABSTRACT
Objective To study effects ofDanlong Xingnao Formula (DLXNF) on proliferation of neural stem cells (NSCs) and the expressions of Hes1 and Hes5 in sub ventricular zone (SVZ) in cerebral ischemia-reperfusion injury model rats; To explore the mechanism of promoting the proliferation of NSCsMethods Eighty male SD rats were randomly divided into sham-operation group, model group, edaravone group andDLXNF group. The focal cerebral ischemia reperfusion injury models were prepared by suture method, and 7 d after reperfusion, the SVZ brain tissue of ischemia side was taken. The proliferation of cells was detected by Brdu labeling fluorescence immunocytochemistry; Hes1, Hes5 mRNA and protein expressions were detected by fluorescence real-time quantitative PCR and Western blot method in each group.Results Compared with the sham-operation group, Brdu positive cell rate in other groups increased more obviously, and the expressions of Hes1, Hes5 mRNA and protein also increased significantly (P<0.01). Compared with the model group, Brdu positive cell rate increased significantly in edaravone group and DLXNF group, and the expressions of Hes1, Hes5 mRNA and protein increased significantly (P<0.01). The expression of Hes1 mRNA in DLXNF group was superior to that in edaravone group (P<0.01), and other indexes had no significant difference.Conclusion DLXNF can promote the proliferation of NSCs in SVZ in cerebral ischemia-reperfusion injury model rats, and up-regulate the expressions of Hes1 and Hes5, whose mechanism may be related to the activation of Notch signaling pathway.
ABSTRACT
Objective To explore an endogenous self-repair potentiality for injured cerebral white matter from both of subependymal ventricular zone and white matter cell cultures in neonatal rats with oxygen glucose deprivation (OGD) in vitro.Methods The white matter and subependymal ventricular zone tissues from the neonatal rats within 5 days old were separately used to prepare primary glia-derived cell cultures,and these cell cultures were randomly divided into the control group and the OGD group.The double-label fluorescent immunoanalysis was used to observe the proliferation and differentiation of the glia-derived cells came from both of subependymal ventricular zone and white matter activated by OGD.The Hoechst33342/propidium iodide (PI) staining and the flow cytometry technology were used to assess the apoptotic rates of the newborn cells.Results More apoptotic and necrotic cells appeared in the OGD group than those in the control group both in subependymal ventricular zone and white matter cell cultures in the flow cytometry test and Hoechst33342/PI staining at 24 h,48 h,72 h,7 d and 14 d after OGD (all P ＜ 0.01).Furthermore,fluorescence microscope showed that the number of the NG2 + progenitor cells,the O4 + oligodendrocyte precursor cells in the OGD group were all significantly more than those in the control group during 72 h after OGD (all P ＜ 0.05,0.01),while the number of the immature and mature oligodendrocytes in the OGD group decreased significantly compared with those in the control group on 7 d and 14 d after OGD (all P ＜ 0.05,0.01).Conclusions OGD may activate 2 endogenous self-repair pathways from subependymal ventricular zone and white matter in vitro.The activated subependymal ventricular zone and white matter-glial progenitor cells appear to proliferate markedly,and differentiate along an oligodendroglial pathway.However,only a few newly generated precursor cells can be differentiated into the immature or mature oligodendrocytes and OGD may induce the newborn cells to appear apoptotic and necrotic.