Morphological study of tooth development in podoplanin-deficient mice

Abstract

Podoplanin is a mucin-type highly O-glycosylated glycoprotein identified in several somatyic cells: podocytes, alveolar epithelial cells, lymphatic endothelial cells, lymph node stromal fibroblastic reticular cells, osteocytes, odontoblasts, mesothelial cells, glia cells, and others. It has been reported that podoplanin-RhoA interaction induces cytoskeleton relaxation and cell process stretching in fibroblastic cells and osteocytes, and that podoplanin plays a critical role in type I alveolar cell differentiation. It appears that podoplanin plays a number of different roles in contributing to cell functioning and growth by signaling. However, little is known about the functions of podoplanin in the somatic cells of the adult organism because an absence of podoplanin is lethal at birth by the respiratory failure. In this report, we investigated the tooth germ development in podoplanin-knockout mice, and the dentin formation in podoplanin-conditional knockout mice having neural crest-derived cells with deficiency in podoplanin by the Wnt1 promoter and enhancer-driven Cre recombinase: Wnt1-Cre;PdpnΔ/Δmice. In the Wnt1-Cre;PdpnΔ/Δmice, the tooth and alveolar bone showed no morphological abnormalities and grow normally, indicating that podoplanin is not critical in the development of the tooth and bone.

CLEC-2 suppresses calcification in cultured osteoblasts

“…The podoplanin KO mice were established by Schacht et al in 2003 (24), but there were no reports of podoplanin conditional KO (cKO) mice until our report in 2018 (29). Podoplanin KO mice are lethal at birth due to respiratory failure (24,29).…”

“…This study aimed to investigate medullary cavity formation in conditionally podoplanin-deficient mice. All of the specimens were collected from euthanized mice and the manuscript was prepared following the ARRIVE guidelines (29). The protocol of experiments for animal use was approved by the Animal Experiment Committee of Fukuoka Dental College in accordance with the principles of the Helsinki Declaration.…”

“…The podoplanin KO mice were established by Schacht et al in 2003 (24), but there were no reports of podoplanin conditional KO (cKO) mice until our report in 2018 (29). Podoplanin KO mice are lethal at birth due to respiratory failure (24,29). The podoplanin KO mouse fetus do not have alveolar sacs at the end of the alveolar duct (29), and alveoli consisting of alveolar ducts with TTF-1 positive type II alveolar epithelial cells but lack alveolar sacs with type I alveolar epithelial cells.…”

“…Podoplanin KO mice are lethal at birth due to respiratory failure (24,29). The podoplanin KO mouse fetus do not have alveolar sacs at the end of the alveolar duct (29), and alveoli consisting of alveolar ducts with TTF-1 positive type II alveolar epithelial cells but lack alveolar sacs with type I alveolar epithelial cells. The flat and thin type I alveolar cells function as an air-blood barrier and type II alveolar cells differentiate into type I alveolar cells.…”

“…The flat and thin type I alveolar cells function as an air-blood barrier and type II alveolar cells differentiate into type I alveolar cells. The podoplanin-deficient type II alveolar cells appear unable to differentiate into type I lung cells, resulting in lung atrophy (29). All our attempts to generate cKO mice by embryos obtained from TIGM and EUCCOM have failed, it is believed that it is very difficult to become integrated in the germ line transmission of the podoplanin-targeted ES cells in the chimeric mice.…”