Na-Na Liu1, Xue-Zhao Jia2, Jing Wang2, Guo-Qi Zhu3, Dan Li1, Qing-Ling Li1, Qiang Ma1. 1. Graduate School, Anhui University of Chinese Medicine, Hefei 230012, China. 2. College of Traditional Chinese Medicine, Anhui University of Chinese Medicine, Hefei 230012, China. 3. Xin'an Medicine, Key Laboratory of Chinese Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038.
Abstract
OBJECTIVE: To observe the effect of moxibustion on cardiac function and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and selective autophagy receptor signaling adaptor sequestosome 1 (SQSTM1/p62) in rats with chronic heart failure (CHF), so as to explore its underlying mechanisms in preventing and treating CHF. METHODS: Sixty male SD rats were randomly divided into normal, model, moxibustion, autophagy inhibitor 3-methyladenine (3-MA) and autophagy agonist rapamycin (RAPA) groups (n＝12 rats/group). The CHF model was established by intrape-ritoneal injection of adriamycin (ADR, 2 mg/kg, once every week for 12 weeks). Mild moxibustion was applied to bilateral "Feishu" (BL13) and "Xinshu" (BL15) for 20 min every time. Rats of the 3-MA group were treated by intraperitoneal injection of 3-MA suspension (15 mg/kg), and those of the RAPA group treated by gavage of RAPA suspension (2 mg/kg). All the treatments were given once a day for 3 weeks. The heart rate (HR), cardiac output (CO), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and maximum rising and lowering rates of left ventricular pressure (±dp/dtmax) were measured for assessing the cardiac performance. Histopathological changes of the left ventricular myocardium were observed by HE staining. The expression levels of LC3-Ⅰ， LC3-Ⅱ and p62 proteins of the left ventricle myocardium tissue were detected by Western blot. RESULTS: After modeling, the pathological changes of myocardium (as myocardial cell swelling with vacuoles, myocardial fibre breakage, etc.) were obvious, and the HR, LVEDP, LC3-Ⅱ and LC3-Ⅱ/Ⅰ protein expression levels were significantly increased in the model group compared with the normal group (P<0.01), while the CO, LVSP, ±dp/dtmax, and the expression of p62 protein were significantly down-regulated (P<0.01). Following the interventions, the myocardial injury was reduced, the HR, LVEDP, LC3-Ⅱ and LC3-Ⅱ/Ⅰ levels in both moxibustion and 3-MA groups were significantly decreased (P<0.05, P<0.01), while the CO, LVSP, ±dp/dtmax and p62 expression level were significantly increased relevant to the model group (P<0.05, P<0.01). In addition, the ratio of LC3-Ⅱ/Ⅰ was significantly increased, and the expression level of p62 significantly down-regulated in the RAPA group compared with the model group (P<0.01). CONCLUSION: Moxibustion can improve cardiac function in CHF rats, which may be related to its effects in down-regulating the ratio of LC3-Ⅱ/Ⅰ and up-regulating the expression of p62 protein to inhibit cardiomyocyte autophagy.
OBJECTIVE: To observe the effect of moxibustion on cardiac function and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and selective autophagy receptor signaling adaptor sequestosome 1 (SQSTM1/p62) in rats with chronic heart failure (CHF), so as to explore its underlying mechanisms in preventing and treating CHF. METHODS: Sixty male SD rats were randomly divided into normal, model, moxibustion, autophagy inhibitor 3-methyladenine (3-MA) and autophagy agonist rapamycin (RAPA) groups (n＝12 rats/group). The CHF model was established by intrape-ritoneal injection of adriamycin (ADR, 2 mg/kg, once every week for 12 weeks). Mild moxibustion was applied to bilateral "Feishu" (BL13) and "Xinshu" (BL15) for 20 min every time. Rats of the 3-MA group were treated by intraperitoneal injection of 3-MA suspension (15 mg/kg), and those of the RAPA group treated by gavage of RAPA suspension (2 mg/kg). All the treatments were given once a day for 3 weeks. The heart rate (HR), cardiac output (CO), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and maximum rising and lowering rates of left ventricular pressure (±dp/dtmax) were measured for assessing the cardiac performance. Histopathological changes of the left ventricular myocardium were observed by HE staining. The expression levels of LC3-Ⅰ， LC3-Ⅱ and p62 proteins of the left ventricle myocardium tissue were detected by Western blot. RESULTS: After modeling, the pathological changes of myocardium (as myocardial cell swelling with vacuoles, myocardial fibre breakage, etc.) were obvious, and the HR, LVEDP, LC3-Ⅱ and LC3-Ⅱ/Ⅰ protein expression levels were significantly increased in the model group compared with the normal group (P<0.01), while the CO, LVSP, ±dp/dtmax, and the expression of p62 protein were significantly down-regulated (P<0.01). Following the interventions, the myocardial injury was reduced, the HR, LVEDP, LC3-Ⅱ and LC3-Ⅱ/Ⅰ levels in both moxibustion and 3-MA groups were significantly decreased (P<0.05, P<0.01), while the CO, LVSP, ±dp/dtmax and p62 expression level were significantly increased relevant to the model group (P<0.05, P<0.01). In addition, the ratio of LC3-Ⅱ/Ⅰ was significantly increased, and the expression level of p62 significantly down-regulated in the RAPA group compared with the model group (P<0.01). CONCLUSION: Moxibustion can improve cardiac function in CHFrats, which may be related to its effects in down-regulating the ratio of LC3-Ⅱ/Ⅰ and up-regulating the expression of p62 protein to inhibit cardiomyocyte autophagy.