RESUMO
Oviduct, uterus, and vagina are derived from Müllerian ducts. But only in the vagina, the epithelium differentiates into stratified layers. Organ-specific secreted factors derived from the stroma of a neonatal mouse induce epithelial differentiation in the female reproductive tracts. However, the effects of the components and mechanical property of extracellular matrix (ECM) on the regulation of gene expression in the mesenchymal cells of neonatal stroma and differentiation of epithelium in the female reproductive tracts have been overlooked. In the present study, we have developed a simple 3D neonatal vaginal model using clonal cell lines to study the effect of ECM's components and stiffness on the epithelial stratification. Transcriptome analysis was performed by DNA-microarray to identify the components of ECM involved in the differentiation of vaginal epithelial stratification. The knockdown experiment of the candidate genes relating to vaginal epithelial stratification was focused on fibromodulin (Fmod), a collagen cross-linking protein. FMOD was essential for the expression of Bmp4, which encodes secreted factors to induce the epithelial stratification of vaginal mesenchymal cells. Furthermore, stiffer ECM as a scaffold for epithelial cells is necessary for vaginal epithelial stratification. Therefore, the components and stiffness of ECM are both crucial for the epithelial stratification in the neonatal vagina.
Assuntos
Proteína Morfogenética Óssea 4/genética , Diferenciação Celular , Células Epiteliais/fisiologia , Fibromodulina/genética , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Mesenquimais/fisiologia , Vagina/embriologia , Animais , Proteína Morfogenética Óssea 4/metabolismo , Elasticidade , Epitélio/embriologia , Matriz Extracelular/metabolismo , Feminino , Fibromodulina/metabolismo , CamundongosRESUMO
Intramuscular motor innervation is an essential process in neuromuscular development. Recently, mutations in COL25A1, encoding CLAC-P/collagen XXV, have been linked to the development of a congenital cranial dysinnervation disorder (CCDD). Yet the molecular mechanisms of intramuscular innervation and the etiology of CCDD related to COL25A1 have remained elusive. Here, we report that muscle-derived collagen XXV is indispensable for intramuscular innervation. In developing skeletal muscles, Col25a1 expression is tightly regulated by muscle excitation. In vitro and cell-based assays reveal a direct interaction between collagen XXV and receptor protein tyrosine phosphatases (PTPs) σ and δ. Motor explant assays show that expression of collagen XXV in target cells attracts motor axons, but this is inhibited by exogenous PTPσ/δ. CCDD mutations attenuate motor axon attraction by reducing collagen XXV-PTPσ/δ interaction. Overall, our study identifies PTPσ/δ as putative receptors for collagen XXV, implicating collagen XXV and PTPσ/δ in intramuscular innervation and a developmental ocular motor disorder.