Loss of RhoA in neural progenitor cells causes the disruption of adherens junctions and hyperproliferation

Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 05/2011; 108(18):7607-12. DOI: 10.1073/pnas.1101347108
Source: PubMed


The organization of neural progenitors in the developing mammalian neuroepithelium is marked by cadherin-based adherens junctions. Whereas RhoA, a founding member of the small Rho GTPase family, has been shown to play important roles in epithelial adherens junctions, its physiological roles in neural development remain uncertain due to the lack of specific loss-of-function studies. Here, we show that RhoA protein accumulates at adherens junctions in the developing mouse brain and colocalizes to the cadherin-catenin complex. Conditional deletion of RhoA in midbrain and forebrain neural progenitors using Wnt1-Cre and Foxg1-Cre mice, respectively, disrupts apical adherens junctions and causes massive dysplasia of the brain. Furthermore, RhoA-deficient neural progenitor cells exhibit accelerated proliferation, reduction of cell- cycle exit, and increased expression of downstream target genes of the hedgehog pathway. Consequently, both lines of conditional RhoA-deficient embryos exhibit expansion of neural progenitor cells and exencephaly-like protrusions. These results demonstrate a critical role of RhoA in the maintenance of apical adherens junctions and the regulation of neural progenitor proliferation in the developing mammalian brain.

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    • "RESEARCH ARTICLE Development (2014) 141, 4076-4086 doi:10.1242/dev.108282 DEVELOPMENT Katayama et al., 2011; Komada et al., 2008). mTOR-deficient progenitors show a failure of cell cycle re-entry. "
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    • "The Wnt1-Cre mouse transgenic line is widely used for interrogating gene function and cell lineage relationships in a variety of developmental contexts including early neural crest migration, secondary palate, calvaria, cardiac outflow tract, and midbrain development (Brewer et al., 2004; Chai et al., 2000; Ito et al., 2003; Jiang et al., 2000, 2002; Katayama et al., 2011; Merrill et al., 2006; Tallquist and Soriano, 2003; Yoshida et al., 2008). Its utility is based on the fact that the Wnt1 gene is highly expressed in the dorsal neural tube prior to the emigration of the neural crest and in the midbrain–hindbrain boundary (MHB) at the initiation of midbrain development. "
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