TY - JOUR
T1 - Adolescent feline heart contains a population of small, proliferative ventricular myocytes with immature physiological properties
AU - Chen, Xiongwen
AU - Wilson, Rachel M.
AU - Kubo, Hajime
AU - Berretta, Remus M.
AU - Harris, David M.
AU - Zhang, Xiaoying
AU - Jaleel, Naser
AU - MacDonnell, Scott M.
AU - Bearzi, Claudia
AU - Tillmanns, Jochen
AU - Trofimova, Irina
AU - Hosoda, Toru
AU - Mosna, Federico
AU - Cribbs, Leanne
AU - Leri, Annarosa
AU - Kajstura, Jan
AU - Anversa, Piero
AU - Houser, Steven R.
PY - 2007/3
Y1 - 2007/3
N2 - Recent studies suggest that rather than being terminally differentiated, the adult heart is a self-renewing organ with the capacity to generate new myocytes from cardiac stem/progenitor cells (CS/PCs). This study examined the hypotheses that new myocytes are generated during adolescent growth, to increase myocyte number, and these newly formed myocytes are initially small, mononucleated, proliferation competent, and have immature properties. Ventricular myocytes (VMs) and cKit (stem cell receptor) CS/PCs were isolated from 11- and 22-week feline hearts. Bromodeoxyuridine incorporation (in vivo) and p16 immunostaining were measured to assess myocyte cell cycle activity and senescence, respectively. Telomerase activity, contractions, Ca transients, and electrophysiology were compared in small mononucleated (SMMs) and large binucleated (LBMs) myocytes. Heart mass increased by 101% during adolescent growth, but left ventricular myocyte volume only increased by 77%. Most VMs were binucleated (87% versus 12% mononucleated) and larger than mononucleated myocytes. A greater percentage of SMMs was bromodeoxyuridine positive (SMMs versus LBMs: 3.1% versus 0.8%; P
AB - Recent studies suggest that rather than being terminally differentiated, the adult heart is a self-renewing organ with the capacity to generate new myocytes from cardiac stem/progenitor cells (CS/PCs). This study examined the hypotheses that new myocytes are generated during adolescent growth, to increase myocyte number, and these newly formed myocytes are initially small, mononucleated, proliferation competent, and have immature properties. Ventricular myocytes (VMs) and cKit (stem cell receptor) CS/PCs were isolated from 11- and 22-week feline hearts. Bromodeoxyuridine incorporation (in vivo) and p16 immunostaining were measured to assess myocyte cell cycle activity and senescence, respectively. Telomerase activity, contractions, Ca transients, and electrophysiology were compared in small mononucleated (SMMs) and large binucleated (LBMs) myocytes. Heart mass increased by 101% during adolescent growth, but left ventricular myocyte volume only increased by 77%. Most VMs were binucleated (87% versus 12% mononucleated) and larger than mononucleated myocytes. A greater percentage of SMMs was bromodeoxyuridine positive (SMMs versus LBMs: 3.1% versus 0.8%; P
KW - Calcium
KW - Cardiac stem cells
KW - New ventricular myocytes
KW - T-type calcium current
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U2 - 10.1161/01.RES.0000259560.39234.99
DO - 10.1161/01.RES.0000259560.39234.99
M3 - Article
C2 - 17272809
AN - SCOPUS:33947507392
VL - 100
SP - 536
EP - 544
JO - Circulation Research
JF - Circulation Research
SN - 0009-7330
IS - 4
ER -