[Study on mechanism of Zhenwu Decoction against heart-kidney Yang deficiency-induced heart failure via cAMP/PKA signaling pathway].

摘要

This study aimed to investigate the effects of Zhenwu Decoction(ZWT) on cardiac fibrosis in mice with heart-kidney Yang deficiency-induced chronic heart failure(CHF). The research further explored the therapeutic mechanisms of ZWT in CHF treatment in the hope of providing novel insights for TCM approaches to managing heart-kidney Yang deficiency-induced heart failure. Sixty C57BL/6 mice were randomly divided into the following groups: the control group(normal untreated mice),the DOX group(doxorubicin-induced CHF model),the low-dose ZWT group(ZWT-L,4.7 g·kg~(-1)),the medium-dose ZWT group(ZWT-M,9.3 g·kg~(-1)),the high-dose ZWT group(ZWT-H,18.6 g·kg~(-1)),and the dopamine group(DA,positive control). The CHF mouse model was established over a 4-week period, which was followed by an additional 4-week treatment regimen. After 8 weeks, the spontaneous locomotor activity of mice was assessed, and TCM syndrome scoring was performed. Mouse serum samples were collected and analyzed to measure the levels of cardiac-specific biomarkers including cardiac troponin Ⅰ(cTn-Ⅰ),brain natriuretic peptide(BNP), creatine kinase-MB isoenzyme(CK-MB), creatine kinase(CK),lactate dehydrogenase(LDH),triiodothyronine(T3),succinate dehydrogenase(SDH) and myocardial cyclic adenosine monophosphate(cAMP). Cardiac tissue was collected for pathological examination. Western blot and real-time quantitative polymerase chain reaction(RT-PCR) were used to detect the expression of myocardial cAMP-dependent protein kinase catalytic subunit(PKA C),protein kinase A(PKA),ryanodine receptor 2(RyR2),phospholamban(PLB),B-cell lymphoma-2(Bcl-2),caspase-3,cleaved caspase-3 and Bcl-2-associated X protein(Bax). The experimental results indicated that, compared with the control group, the DOX group exhibited significantly elevated TCM syndrome scores accompanied by decreased heart rate, reduced body weight, and increased cardiac index(P<0.05); serum levels of CK, CK-MB, BNP, cTn-Ⅰ, LDH and myocardial cAMP were significantly increased(P<0.05), while SDH and T3 levels were decreased(P<0.05); meanwhile, myocardial interstitial fibrosis was aggravated and myocardial hypertrophy appeared; the expression of PKA C, PKA, caspase-3, cleaved caspase-3, Bax and phosphorylation of RyR2 were increased(P<0.05), the expression of Bcl-2 and phosphorylation of PLB were decreased compared with the DOX group, the ZWT treated groups demonstrated reduced TCM syndrome scores, increased heart rate, improved body weight, and decreased cardiac index. Additionally, serum levels of CK, CK-MB, BNP, cTn-Ⅰ, LDH and myocardial cAMP were decreased(P<0.05), while SDH and T3 levels were increased(P<0.05); myocardial hypertrophy and fibrosis were also improved; the expression of PKA C, PKA, Bax, caspase-3, cleaved caspase-3 and phosphorylation of RyR2 was reduced(P<0.05), and the expression of Bcl-2 and phosphorylation of PLB were increased(P<0.05). These findings suggested that ZWT may exert therapeutic effects on CHF by regulating sarcoplasmic reticulum calcium-related proteins, reducing apoptosis, and improving cardiac function.