Angiotensin II Increases HMGB1 Expression in the Myocardium Through AT1 and AT2 Receptors When Under Pressure Overload.

Angiotensin II Increases HMGB1 Expression in the Myocardium Through AT1 and AT2 Receptors When Under Pressure Overload.
Int Heart J. 2021 Jan 16;:
Authors: Zhang L, Zhang B, Yu Y, Wang J, Wu J, Su Y, Jiang H, Zou Y, Ge J
Abstract
High-mobility group box 1 (HMGB1) is increased in the myocardium under pressure overload (PO) and is involved in PO-induced cardiac remodeling. The mechanisms of the upregulation of cardiac HMGB1 expression have not been fully elucidated. In the present study, a mouse transverse aortic constriction (TAC) model was used, and an angiotensin II (Ang II) type 1 (AT1) receptor inhibitor (losartan) or Ang II type 2 (AT2) receptor inhibitor (PD123319) was administrated to mice for 14 days. Cardiac myocytes were cultured and treated with Ang II for 5 minutes to 48 hours conditionally with the blockage of the AT1 or AT2 receptor. TAC-induced cardiac hypertrophy was observed at 14 days after the operation, which was partially reversed by losartan, but not by PD123319. Similarly, the upregulated HMGB1 expression levels observed in both the serum and myocardium induced by TAC were reduced by losartan. Elevated cardiac HMGB1 protein levels, but not mRNA or serum levels, were significantly decreased by PD123319. Furthermore, HMGB1 expression levels in culture media and cardiac myocytes were increased following Ang II treatment in vitro, positively associated with the duration of treatment. Similarly, Ang II-induced upregu...

Source: International Heart Journal - January 20, 2021 Category: Cardiology Tags: Int Heart J Source Type: research