Roles of #fibronectin isoforms in #neonatal #vascular development and matrix integrity.

Kumra H¹, Sabatier L¹, Hassan A¹, Sakai T², Mosher DF³, Brinckmann J⁴, Reinhardt DP^1,5.

Abstract

#Fibronectin (FN) exists in two forms-plasma FN (pFN) and cellular FN (cFN). Although the role of FN in #embryonic #bloodvessel development is well established, its function and the contribution of individual isoforms in early #postnatal vascular development are poorly understood. Here, we employed a #tamoxifen-dependent cFN inducible knockout (cFN iKO) mouse model to study the consequences of #postnatal cFN deletion in smooth #musclecells (SMCs), the major cell type in the #vascularwall. Deletion of cFN influences collagen deposition but does not affect life span. Unexpectedly, pFN translocated to the aortic wall in the cFN iKO and in control mice, possibly rescuing the loss of cFN. Postnatal pFN deletion did not show a histological #aorticphenotype. Double knockout (dKO) mice lacking both, cFN in SMCs and pFN, resulted in postnatal lethality. These data demonstrate a safeguard role of pFN in vascular stability and the dispensability of the individual FN isoforms in postnatal vascular development.