Simvastatin prevented myocardium of diabetes rats from apoptosis through inhibition of oxidative stress

doi:10.12047/j.cjap.5653.2018.096

Abstract

Abstract: Objective: To investigate the protective effects and the possible mechanisms of simvastatin on myocardial injury induced by diabetes.Methods: Twenty-four SD rats (180~220)g were randomly divided into control group (control, n=8) and modeled groups(n=16), the modeled groups were injected with streptozotocin intraperitoneally to induce diabetes. Then the modeled rats were randomly divided into diabetes mellitus group (DM group, n=8) and diabetes mellitus + simvastatin group (DM+S group, n=8). Rats in DM+S group were treated with simvastatin at the dose of 40 mg/(kg·d)by gavage for 4 weeks, and the other two groups were treated with the same amount of saline. At the end of experiments, the heart tissues were collected for further observation. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in heart tissues were measured by spectrophotometry; HE staining of rat heart slides was used to observe the pathological changes; TUNEL assay was used to determine the apoptosis index of myocardial cells in each groups; The distribution of p53 in the heart tissues was evaluated by immunohistochemistry; Western blot was used to detect the expressions of p53, p53-phospho-serine 15, Bax and Bcl-2 in the heart tissues. Results: ①Compared with control group, the content of malondialdehyde (MDA) was increased while the activity of superoxide dismutase (SOD) was decreased significantly in DM group (P<0.01). After simvastatin administration, the activity of SOD was increased and the content of MDA was decreased significantly (P<0.01). ② HE staining results showed that the myocardial cells in the DM group were disorganized, with unclear morphological structure and a large number of inflammatory cells infiltration. Compared with DM group, the myocardial morphology in DM+S group was improved significantly. ③TUNEL staining results showed that the apoptosis index of myocardial cells in DM group was increased significantly compared with that of control group, and the apoptosis index was decreased significantly after the treatment of simvastatin (P<0.01).④ Immunohistochemistry showed that compared with control group,the expression of p53 in DM group was increased significantly, and was expressed in both cytoplasm and nucleus, while the expression of p53 in DM+S group was decreased and the expression of p53 in nucleus was decreased significantly (P<0.01). ⑤ The results of Western blot showed that the expression levels of p53, p53-phospho-serine15 and Bax were higher than those in control group, and the expression of Bcl-2 was lower than that in control group (P<0.01). After simvastatin administration, the expression levels of p53,p53-phospho-serine 15 (P<0.01) and Bax were decreased significantly (P<0.05) and the expression of Bcl-2 was increased (P<0.05). Conclusion: Simvastatin exerted protective effects on myocardial injury caused by diabetes through improving the abnormal morphological changes of diabetic myocardium, alleviating oxidative stress and inhibiting apoptosis of myocardial cells. The mechanism is related to the regulation of apoptosis pathway mediated by p53.

Key words: SD rats, diabetes mellitus, heart, simvastatin, apoptosis, oxidative stress

LI Fan-lu, WAN Xin, WANG Xi, LIU Xin, WU Ya-li, CHEN Huan-zhen, CUI Xiang-li. Simvastatin prevented myocardium of diabetes rats from apoptosis through inhibition of oxidative stress[J]. CJAP, 2018, 34(5): 422-426.

References

[1] Chavali V, Tyagi SC, Mishra PK. Predictors and prevention of diabetic cardiomyopathy[J]. Diabetes Metab Syndr Obes, 2013, 6:151-160.
[2] Zhao MX, Zhou B, Ling L, et al. Salusin-beta contributes to oxidative stress and inflammation in diabetic cardiomyopathy[J]. Cell Death Dis, 2017, 8(3):e2690.
[3] Kumar S, Prasad S, Sitasawad SL. Multiple antioxidants improve cardiac complications and inhibit cardiac cell death in streptozotocin-induced diabetic rats[J]. PLoS One, 2013, 8(7):e67009.
[4] Crisby M. Modulation of the inflammatory process by statins[J]. Timely Top Med Cardiovasc Dis, 2005, 9:E3.
[5] Kumai T, Matsumoto N, Koitabashi Y, et al. Pleiotropic effects of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors:candidate mechanisms for anti-lipid deposition in blood vessels[J]. Curr Med Chem Cardiovasc Hematol Agents, 2005, 3(3):195-201.
[6] 王妍妍, 陈还珍, 李艳, 等. 辛伐他汀对糖尿病大鼠低血糖时血清炎症因子及血管内皮的影响[J]. 中西医结合心脑血管病杂志, 2013, 11(7):851-852.
[7] Li H, Zhao QQ, Liu R, et al. Protective effect and potential mechanism of simvastatin on myocardial injury induced by diabetes with hypoglycemia[J]. Exp Clin Endocrinol Diabetes, 2018, 126(3):148-161.
[8] 许良中, 杨文涛. 免疫组织化学反应结果的判断标准[J]. 中国癌症杂志, 1996(4):229-231.
[9] Huynh K, Bernardo BC, McMullen JR, et al. Diabetic cardiomyopathy:mechanisms and new treatment strategies targeting antioxidant signaling pathways[J]. Pharmacol Ther, 2014, 142(3):375-415.
[10] Chen YH, Feng B, Chen ZW. Statins for primary prevention of cardiovascular and cerebrovascular events in diabetic patients without established cardiovascular diseases:a meta-analysis[J]. Exp Clin Endocrinol Diabetes, 2012, 120(2):116-120.
[11] Olafsdottir E, Aspelund T, Sigurdsson G, et al. Similar decline in mortality rate of older persons with and without type 2 diabetes between 1993 and 2004 the Icelandic population-based Reykjavik and AGES-Reykjavik cohort studies[J]. BMC Public Health, 2013, 13:36.
[12] Silva S, Lourenço P, Paulo C, et al. Statin-induced low cholesterol is not associated with poor outcome in chronic heart failure[J]. J Cardiovasc Pharmcol Ther, 2012, 17(3):284-290.
[13] Koh GC, Vlaar AP, Hofstra JJ, et al. In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury:a cohort study[J]. Crit Care Med, 2012, 40(6):1835-1843.
[14] Janda S, Young A, Fitzgerald JM, et al. The effect of statins on mortality from severe infections and sepsis:a systematic review and meta-analysis[J]. J Crit Care, 2010, 25(4):656.
[15] Wemmelund H, H￠gh A, Hundborg HH, et al. Statin use and rupture of abdominal aortic aneurysm[J]. Br J Surg, 2014, 101(8):966-975.
[16] Yu Y, Ohmori K, Chen Y, et al. Effects of pravastatin on progression of glucose intolerance and cardiovascular remodeling in a type Ⅱ diabetes model[J]. J Am Coll Cardiol, 2004, 44(4):904-913.
[17] Ozaki T, Nakagawara A. p53:the attractive tumor suppressor in the cancer research field[J]. J Biomed Biotechnol, 2011, 2011:603925.
[18] Appella E, Anderson CW. Post-translational modifications and activation of p53 by genotoxic stresses[J]. Eur J Biochem, 2001, 268(10):2764-2772.
[19] Chen YW, Chenier I, Chang SY, et al. High glucose promotes nascent nephron apoptosis via NF-κB and p53 pathways[J]. Am J Physiol-Renal, 2011, 300(1):F147-156.
[20] Huang J, Li X, Li M, et al. Mitochondria-targeted antioxidant peptide SS31 protects the retinas of diabetic rats[J]. Curr Mol Med, 2013, 13(6):935-945.