title: miR-155 functions downstream of angiotensin II receptor subtype 1 and calcineurin to regulate cardiac hypertrophy.
abstract: Cardiac hypertrophy is characterized by maladaptive tissue remodeling that may lead to heart failure or sudden death. MicroRNAs (miRs) are negative regulators of angiotensin II and the angiotensin II receptor subtype 1 (AGTR1), which are two components involved in cardiac hypertrophy. In the present study, the interaction between angiotensin II receptor subtype 1 (AGTR1) signaling and miR-155 was investigated. Rat H9C2 (2-1) cardiomyocytes were transfected with miR-155 analogues or inhibitors, then stimulated with angiotensin II to induce cardiac hypertrophy. miR-155 expression was revealed to be altered following transfection with chemically-modified miR-155 analogues and inhibitors in rat cardiomyocytes. In cell cardiac hypertrophy models, the cell surface area, AGTR1, atrial natriuretic peptide and myosin heavy chain-β mRNA expression levels were revealed to be lower in cells stimulated with miR-155 analogue-transfected cells treated with angiotensin II compared with cells stimulated with angiotensin alone (P<0.05), as determined using reverse transcription-polymerase chain reaction (PCR), quantitative PCR and western blot analyses. Furthermore, calcineurin mRNA and protein, intracellular free calcium and nuclear factor of activated T-cells-4 proteins were downregulated in miR-155 analogue-transfected cells treated with angiotensin II, as compared with cells stimulated with angiotensin II alone (P<0.05). In conclusion, the current study indicates that miR-155 may improve cardiac hypertrophy by downregulating AGTR1and suppressing the calcium signaling pathways activated by AGTR1.
authors: Department of Cardiology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Yong
authors: Y
authors: Yang
authors: Department of Medical Oncology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Yong
authors: Y
authors: Zhou
authors: Department of Cardiology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Zheng
authors: Z
authors: Cao
authors: Department of Cardiology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Xin Zhu
authors: XZ
authors: Tong
authors: Department of Cardiology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Hua Qiang
authors: HQ
authors: Xie
authors: Department of Cardiology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Tao
authors: T
authors: Luo
authors: Department of Cardiology, Suizhou Central Hospital, Hubei University of Medicine, Suizhou, Hubei 441300, P.R. China.
authors: Xian Ping
authors: XP
authors: Hua
authors: Institute of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors: Han Qin
authors: HQ
authors: Wang
keywords: angiotensin II receptor type 1; cardiac hypertrophy; microRNA-155