Referenced in: none

Automatically associated channels: Cav3.1 , Cav3.2

Title: Delayed onset of beating and decreased expression of T-type Ca2+ channel in mouse ES cell-derived cardiocytes carrying human chromosome 21.

Authors: Einosuke Mizuta, Hitomi Furuichi, Yasuhiro Kazuki, Junichiro Miake, Shuichi Yano, Udin Bahrudin, Yasutaka Yamamoto, Osamu Igawa, Chiaki Shigemasa, Kyoko Hidaka, Takayuki Morisaki, Yasutaka Kurata, Haruaki Ninomiya, Masafumi Kitakaze, Yasuaki Shirayoshi, Mitsuo Oshimura, Ichiro Hisatome

Journal, date & volume: Biochem. Biophys. Res. Commun., 2006 Dec 8 , 351, 126-32

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17054917

Abstract
The mouse ES cell line hcgp7/#21, which carries a human chromosome 21 (hChr.21), was used as an in vitro model to examine the effects of hChr.21 on cardiomyocyte differentiation. Cardiomyocytes derived from hcgp7/#21 showed a significant delay in the onset of spontaneous beating. The number of Nkx2.5/GFP(+) cardiac progenitor cells was comparable to that in control ES cells and they also expressed comparable mRNA levels for mesodermal markers, cardiac specific transcription factors, contractile proteins, and L-type Ca(2+) channels. However, cells from hcgp7/#21 expressed significantly reduced levels of mRNA for Cav3.1 and Cav3.2, which was consistent with the decreased number of cells expressing T-type Ca(2+) channels and decreased T-type Ca(2+) channel currents. These findings suggest that the presence of human chromosome 21 suppresses expression of T-type Ca(2+) channels in cardiomyocytes during differentiation, which may be responsible for delayed onset of spontaneous beating.