Hypertrophic stimuli induce transforming growth factor-beta 1 expression in rat ventricular myocytes.

N Takahashi, A Calderone, NJ Izzo… - The Journal of …, 1994 - Am Soc Clin Investig
N Takahashi, A Calderone, NJ Izzo, TM Mäki, JD Marsh, WS Colucci
The Journal of clinical investigation, 1994Am Soc Clin Investig
Transforming growth factor-beta 1 (TGF-beta 1) is a peptide growth factor that may play a
role in the myocardial response to hypertrophic stimuli. However, the cellular distribution,
mechanism of induction, and source of increased TGF-beta 1 in response to hypertrophic
stimuli are not known. We tested the hypothesis that the cardiac myocyte responds to
hypertrophic stimuli with the increased expression of TGF-beta 1. In adult rat ventricular
myocardium freshly dissociated into myocyte and nonmyocyte cellular fractions, the …
Transforming growth factor-beta 1 (TGF-beta 1) is a peptide growth factor that may play a role in the myocardial response to hypertrophic stimuli. However, the cellular distribution, mechanism of induction, and source of increased TGF-beta 1 in response to hypertrophic stimuli are not known. We tested the hypothesis that the cardiac myocyte responds to hypertrophic stimuli with the increased expression of TGF-beta 1. In adult rat ventricular myocardium freshly dissociated into myocyte and nonmyocyte cellular fractions, the preponderance of TGF-beta 1 mRNA visualized by Northern hybridization was in the nonmyocyte fraction. Abdominal aortic constriction (7 d) and subcutaneous norepinephrine infusion (36 h) each caused ventricular hypertrophy associated with 3.1-fold and 3.8-fold increases, respectively, in TGF-beta 1 mRNA in the myocyte fraction, but had no effect on the level of TGF-beta 1 mRNA in the nonmyocyte fraction. In ventricular myocytes, norepinephrine likewise caused a 4.1-fold increase in TGF-beta 1 mRNA associated with an increase in TGF-beta bioactivity. This induction of TGF-beta 1 mRNA occurred at norepinephrine concentrations as low as 1 nM and was blocked by prazosin, but not propranolol. NE did not increase the TGF-beta 1 mRNA level in nonmyocytes, primarily fibroblasts, cultured from neonatal rat ventricle. Thus, the cardiac myocyte responds to two hypertrophic stimuli, pressure overload and norepinephrine, with the induction of TGF-beta 1. These data support the view that TGF-beta 1, released by myocytes and acting in an autocrine and/or paracrine manner, is involved in myocardial remodeling by hypertrophic stimuli.
Images
The Journal of Clinical Investigation