Role of osteopontin in cardiac fibrosis and remodeling in angiotensin II-induced cardiac hypertrophy.
Osteopontin (OPN) is upregulated in several experimental models of cardiac fibrosis and remodeling. However, its direct effects remain unclear. We examined the hypothesis that OPN is important for the development of cardiac fibrosis and remodeling. Moreover, we examined whether the inhibitory effect of eplerenone (Ep), a novel aldosterone receptor antagonist, was mediated through the inhibition of OPN expression against cardiac fibrosis and remodeling. Wild-type (WT) and OPN-deficient mice were treated with angiotensin II (Ang II) for 4 weeks. WT mice receiving Ang II were divided into 2 groups: a control group and an Ep treatment group. Ang II treatment significantly elevated blood pressure and caused cardiac hypertrophy and fibrosis in WT mice. Ep treatment and OPN deficiency could reduce the Ang II-induced elevation of blood pressure and ameliorate the development of cardiac fibrosis, whereas Ep-only treatment abolished the development of cardiac hypertrophy. Most compelling, the reduction of cardiac fibrosis led to an impairment of cardiac systolic function and subsequent left ventricular dilatation in Ang II-treated OPN-deficient mice. These results suggest that OPN has a pivotal role in the development of Ang II-induced cardiac fibrosis and remodeling. Moreover, the effect of Ep on the prevention of cardiac fibrosis, but not cardiac hypertrophy, might be partially mediated through the inhibition of OPN expression.
Matsui
Yutaka
Y
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Jia
Nan
N
Okamoto
Hiroshi
H
Kon
Shigeyuki
S
Onozuka
Hisao
H
Akino
Masatoshi
M
Liu
Lizhi
L
Morimoto
Junko
J
Rittling
Susan R
SR
Denhardt
David
D
Kitabatake
Akira
A
Uede
Toshimitsu
T
D000450:Aldosterone / Q000502:physiology; D000804:Angiotensin II / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D006332:Cardiomegaly / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D048429:Cell Size; D000077545:Eplerenone; D005355:Fibrosis; D006339:Heart Rate / Q000187:drug effects; D017379:Hypertrophy, Left Ventricular / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology; D053495:Osteopontin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D013148:Spironolactone / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D014463:Ultrasonography; D020257:Ventricular Remodeling / Q000187:drug effects / Q000502:physiology*
D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D053495:Osteopontin; D000804:Angiotensin II; D013148:Spironolactone; D000450:Aldosterone; D000077545:Eplerenone