TY - JOUR
T1 - Mice with cardiomyocyte-specific disruption of the endothelin-1 gene are resistant to hyperthyroid cardiac hypertrophy
AU - Shohet, Ralph V.
AU - Kisanuki, Yaz Y.
AU - Zhao, Xiao Song
AU - Siddiquee, Zakir
AU - Franco, Fatima
AU - Yanagisawa, Masashi
PY - 2004/2/17
Y1 - 2004/2/17
N2 - Endothelin 1 (ET-1), a potent vasoconstrictor peptide expressed by endothelium, is also produced in the heart in response to a variety of stresses. It induces hypertrophy in cultured cardiac myocytes but only at concentrations far greater than those found in plasma. We tested whether ET-1 generated by cardiac myocytes in vivo is a local signal for cardiac hypertrophy. To avoid the perinatal lethality seen in systemic ET-1-null mice, we used the Cre/IoxP system to generate mice with cardiac myocyte-specific disruption of the ET-1 gene. We used the α-myosin heavy chain promoter to drive expression of Cre and were able to obtain 75% reduction in ET-1 mRNA in cardiac myocytes isolated from these mice at baseline and after stimulation, in vivo, for 24 h with tri-iodothyronine (T3). Necropsy measurements of cardiac mass indexed for body weight showed a 57% reduction in cardiac hypertrophy in response to 16 days of exogenous T3 in mice homozygous for the disrupted ET-1 allele compared to siblings with an intact ET-1 gene. Moreover, in vivo MRI showed only a 3% increase in left ventricular mass indexed for body weight in mice with the disrupted allele after 3 weeks of T3 treatment versus a 27% increase in mice with an intact ET-1 gene. A reduced hypertrophic response was confirmed by planimetry of cardiac myocytes. We conclude that ET-1, produced locally by cardiac myocytes, and acting in a paracrine/autocrine manner, is an important signal for myocardial hypertrophy that facilitates the response to thyroid hormone.
AB - Endothelin 1 (ET-1), a potent vasoconstrictor peptide expressed by endothelium, is also produced in the heart in response to a variety of stresses. It induces hypertrophy in cultured cardiac myocytes but only at concentrations far greater than those found in plasma. We tested whether ET-1 generated by cardiac myocytes in vivo is a local signal for cardiac hypertrophy. To avoid the perinatal lethality seen in systemic ET-1-null mice, we used the Cre/IoxP system to generate mice with cardiac myocyte-specific disruption of the ET-1 gene. We used the α-myosin heavy chain promoter to drive expression of Cre and were able to obtain 75% reduction in ET-1 mRNA in cardiac myocytes isolated from these mice at baseline and after stimulation, in vivo, for 24 h with tri-iodothyronine (T3). Necropsy measurements of cardiac mass indexed for body weight showed a 57% reduction in cardiac hypertrophy in response to 16 days of exogenous T3 in mice homozygous for the disrupted ET-1 allele compared to siblings with an intact ET-1 gene. Moreover, in vivo MRI showed only a 3% increase in left ventricular mass indexed for body weight in mice with the disrupted allele after 3 weeks of T3 treatment versus a 27% increase in mice with an intact ET-1 gene. A reduced hypertrophic response was confirmed by planimetry of cardiac myocytes. We conclude that ET-1, produced locally by cardiac myocytes, and acting in a paracrine/autocrine manner, is an important signal for myocardial hypertrophy that facilitates the response to thyroid hormone.
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U2 - 10.1073/pnas.0307159101
DO - 10.1073/pnas.0307159101
M3 - Article
C2 - 14764893
AN - SCOPUS:1242341961
SN - 0027-8424
VL - 101
SP - 2088
EP - 2093
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 7
ER -