Cardiac origin of smooth muscle cells in the inflow tract.
Multipotent Isl1(+) heart progenitors give rise to three major cardiovascular cell types: cardiac, smooth muscle, and endothelial cells, and play a pivotal role in lineage diversification during cardiogenesis. A critical question is pinpointing when this cardiac-vascular lineage decision is made, and how this plasticity serves to coordinate cardiac chamber and vessel growth. The posterior domain of the Isl1-positive second heart field contributes to the SLN-positive atrial myocardium and myocardial sleeves in the cardiac inflow tract, where myocardial and vascular smooth muscle layers form anatomical and functional continuity. Herein, using a new atrial specific SLN-Cre knockin mouse line, we report that bipotent Isl1(+)/SLN(+) transient cell population contributes to cardiac as well as smooth muscle cells at the heart-vessel junction in cardiac inflow tract. The Isl1(+)/SLN(+) cells are capable of giving rise to cardiac and smooth muscle cells until late gestational stages. These data suggest that the cardiac and smooth muscle cells in the cardiac inflow tract share a common developmental origin. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".
Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Haruko
H
Nakano
Estrelania
E
Williams
Masahiko
M
Hoshijima
Mika
M
Sasaki
Susumu
S
Minamisawa
Kenneth R
KR
Chien
Atsushi
A
Nakano
D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D042783:Endothelial Cells / Q000166:cytology; D055879:Gene Knock-In Techniques; D018398:Homeodomain Proteins / Q000235:genetics; D060850:LIM-Homeodomain Proteins; D051379:Mice; D008822:Mice, Transgenic; D009124:Muscle Proteins / Q000235:genetics; D032386:Myoblasts, Cardiac / Q000166:cytology / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000378:metabolism*; D011510:Proteolipids / Q000235:genetics; D014157:Transcription Factors
D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009124:Muscle Proteins; D011510:Proteolipids; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; C077258:sarcolipin