[Mechanism of tanshinone II A inhibiting myocardial remodeling by Galectin-3].

Objective: To explore the effect of tanshinone II A on myocardial remodeling in ischemia/reperfusion (I/R)-induced heart failure of rodent model.

Methods: (1) In vivo, 30 SD rats were randomly divided into sham operation, heart failure and tanshinone II A treatment group, with 10 rats in each group. The I/R model was established by ligating the left coronary artery until ST segment elevation for 30 minutes, then the ligation was removed for 2 hours as reperfusion. In the sham operation group, the rat chest was opened without artery ligation. Three days after model establishment, tanshinone II A (10 mg/kg) were given intraperitoneal injected in tanshinone II A group for 9 weeks. In the other two groups, normal saline was administrated in the same way. The behavioral manifestations of the rats in each group were observed; hemodynamic indexes were evaluated; Masson staining was performed to observe the degree of myocardial fibrosis; enzyme linked immunosorbent assay (ELISA) was used to detect the content of Galectin-3 in myocardial tissue; quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the expressions of collagen III, collagen I, matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase (TIMP-1). (2) In vitro, rats primary cardiac fibroblasts were extracted and isolated, and divided into blank control group, angiotensin II group (7-10 mmol/L angiotensin II) and angiotensin II + tanshinone II A group (7-10 mmol/L angiotensin II + 5-10 mmol/L tanshinone II A). At 24 hours and 48 hours of culture, the cell proliferation in each group was detected by methyl thiazolyl tetrazolium (MTT); the expressions of collagen III, collagen I, MMP-2 and TIMP-1 were detected by qRT-PCR; the content of Galectin-3 in cardiac fibroblasts was detected by ELSIA.

Results: (1) In vivo, the rats' activity status, hair conformity and food intake were ranked from good to bad in order of sham operation group, tanshinone II A group and heart failure model group. Compared with the sham-operated group, the heart rate (HR) of the rats in the heart failure model group was significantly decreased and the heart function was significantly impaired. The mRNA and protein expression of collagen I, collagen III, TIMP-1 and Galectin-3 content were significantly increased, while the mRNA and protein expression of MMP-2 were significantly decreased. Compared with the heart failure model group, rats in the tanshinone II A group showed significantly higher HR and improved cardiac function, significantly lower mRNA expression of collagen I and collagen III, significantly lower mRNA and protein expression of TIMP-1 and Galectin-3, and significantly higher mRNA and protein expression of MMP-2, and the most obvious changes were in the 9th weeks of modeling [collagen I mRNA (2): 4.70±1.19 vs. 10.21±1.62, collagen III mRNA (2): 3.03±0.46 vs. 13.84±1.93, TIMP-1 mRNA (2): 1.90±0.19 vs. 4.55±0.43, TIMP-1/GAPDH: 0.33±0.04 vs. 0.67±0.05, Galectin-3 (ng/L): 489.93±79.30 vs. 821.72±94.09, MMP-2 mRNA (2): 0.37±0.07 vs. 0.03±0.01, MMP-2/GAPDH: 0.69±0.09 vs. 0.21±0.04, all P < 0.05]. Masson staining showed that myocardial tissue fibrosis was obvious in the heart failure group, and the degree of fibrosis in the tanshinone II A group was reduced. (2) In vitro, compared with the blank control group, the proliferation rate, collagen I, collagen III and TIMP-1 expression and Galectin-3 content of myocardial fibroblasts were significantly increased, and MMP-2 expression was significantly decreased in the angiotensin group at 24 h and 48 h of culture. Compared with the angiotensin group, the proliferation rate of cardiac fibroblasts and the expression of collagen I, collagen III and TIMP-1 and the content of Galectin-3 were significantly decreased, and the expression of MMP-2 mRNA was significantly increased in the angiotensin + tanshinone II A group, and the most significant changes were at 48 hours of culture [proliferation rate: (57.0±3.7)% vs. (67.0±2.4)%, collagen I mRNA (2): 551.43±67.10 vs. 871.48±12.25, collagen III mRNA (2): 233.76±18.73 vs. 385.51±31.35, TIMP-1 mRNA (2): 238.69±17.37 vs. 351.84±26.17, Galectin-3 (ng/L): 283.76±28.73 vs. 415.51±31.35, MMP-2 mRNA (2): 108.54±12.10 vs. 51.47±6.25, all P < 0.05].

Conclusions: Tanshinone II A can improve cardiac function, inhibit myocardial fibrosis and improve myocardial remodeling in rats with I/R-induced heart failure.