| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Circulation. 2007;115:2022-2032.)
© 2007 American Heart Association, Inc.
Molecular Cardiology |
From the Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine (Y.A., Y.K., M.T., N.Y., H.T., K.I., J.O., T.S., K.S., H.S.), and Biomedical Engineering Research Organization (N.M.), Tohoku University, Sendai, and Japan Science and Technology Agency, CREST, Tokyo (H.S.), Japan.
Correspondence to Yutaka Kagaya, MD, Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, 11 Seiryo-Machi, Aoba-Ku, Sendai 9808574, Japan. E-mail kagaya{at}cardio.med.tohoku.ac.jp
Received August 17, 2006; accepted February 16, 2007.
Background Erythropoietin (Epo) receptors (EpoRs) are expressed in the heart. We have recently demonstrated that the endogenous Epo-EpoR system plays an important protective role in myocardial ischemia in mice and humans. In the present study, we tested our hypothesis that the endogenous Epo-EpoR system in nonhematopoietic cells also plays a protective role against pressure overloadinduced cardiac dysfunction in vivo.
Methods and Results Transgene-rescued EpoR-null mutant mice (EpoR/rescued) that express EpoR exclusively in the hematopoietic cells were subjected to transverse aortic constriction (TAC). At 1 week after TAC, left ventricular weight and lung weight were significantly increased in EpoR/rescued mice compared with wild-type mice, although the fibrotic area was comparably increased after TAC in the 2 genotypes. In the EpoR/rescued mice with TAC, left ventricular end-diastolic diameter was significantly increased, left ventricular fractional shortening was significantly decreased, and survival rate was significantly decreased compared with wild-type mice with TAC. Phosphorylation of STAT3 at 5 hours and 1 week after TAC and that of p38 at 5 hours after TAC were significantly increased in wild-type mice but not in EpoR/rescued mice. Vascular endothelial growth factor protein expression and capillary density in left ventricular myocardium were significantly decreased in EpoR/rescued mice with TAC compared with wild-type mice with TAC.
Conclusions These results suggest that the endogenous Epo-EpoR system in the nonhematopoietic cells plays an important protective role against pressure overloadinduced cardiac dysfunction in vivo.
This article has been cited by other articles:
![]() |
T. Niizeki, Y. Takeishi, T. Kitahara, T. Arimoto, M. Ishino, O. Bilim, S. Suzuki, T. Sasaki, O. Nakajima, R. A. Walsh, et al. Diacylglycerol kinase-{varepsilon} restores cardiac dysfunction under chronic pressure overload: a new specific regulator of G{alpha}q signaling cascade Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H245 - H255. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2007 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |