Loss of RNA-binding protein HuR leads to defective ependymal cells and hydrocephalus.

Multiciliated ependymal cells line the ventricle wall and generate cerebrospinal fluid flow through ciliary beating. Defects in ependymal cells cause hydrocephalus, however, there are still significant gaps in our understanding the molecular, cellular and developmental mechanisms involved in the pathogenesis of hydrocephalus. Here, we demonstrate that specific deletion of RNA-binding protein HuR in the mouse brain results in hydrocephalus and causes postnatal death. HuR deficiency leads to impaired ependymal cell development with defective motile ciliogenesis in both female and male mice. Transcriptome-wide analysis reveals that HuR binds to mRNA transcripts related to ciliogenesis, including cilia and flagella associated protein 52 (Cfap52), the effector gene of Foxj-1 and Rfx transcriptional factors. HuR deficiency accelerates the degradation of Cfap52 mRNA, while overexpression of Cfap52 is able to promote the development of HuR-deficient ependymal cells. Taken together, our results unravel the important role of HuR in posttranscriptional regulation of ependymal cell development by stabilizing Cfap52 mRNA.Significance StatementThis study identifies HuR as a genetic factor involved in the pathogenesis of hydrocephalus. Mechanistically, HuR regulates ependymal cell differentiation and ciliogenesis through stabilizing Cfap52 mRNA, the effector gene of Foxj-1 and Rfx transcriptional factors.