糖尿病大鼠心肌损伤中程序性坏死通路相关蛋白的表达

目的 探讨程序性坏死（Necroptosis）通路相关蛋白在糖尿病心肌中的表达及其可能机制。方法 在大鼠高糖高脂饮食喂养基础上腹腔注射链脲佐菌素40 mg/kg制备糖尿病模型大鼠，其中正常组（CON组，n=6）、高脂高糖组（HC组，n=6）和糖尿病组（DM组，n=6）；10周后超声检测左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVESD）及左心室射血分数（LVEF）；处死大鼠后测量心质量（HW）、体质量（BW）、心体比（HW/BW）；ELISA法检测血液中肿瘤坏死因子-α（TNF-α）、白细胞介素6（IL-6）及丙二醇（MDA）水平；心尖部组织行Masson染色；RT-PCR及Western blotting检测心肌组织中RIPK1、RIPK3、MLKL的含量变化。结果 与CON组比，HC组HW、TNF-α、IL-6、MDA水平增加，RIPK1、RIPK3和MLKL的蛋白表达量增加（P < 0.05~P < 0.01），但MLKL的mRNA表达量无明显变化（P>0.05）；与HC组比较，DM组HW/BW升高，LVEF下降，TNF-α、IL-6及MDA水平增加，RIPK1、RIPK3、MLKL的mRNA及蛋白含量增加（P < 0.01），Masson染色蓝染加重。结论 高糖状态可诱导心肌损伤，增加心肌纤维化及氧化水平，可能与上调Necroptosis通路有关。

Expression of proteins associated with necroptosis pathways in myocardial injury in diabetic rats

Objective To investigate the expression of necroptosis pathway related protienin diabetic myocardium, and its possible mechanism.Methods The diabetic model of rats was prepared by intraperitoneal injection of 40mg/kg of streptozotocin on the basis of highcalories diet feeding, and divided into the normal group(CON group, n=6), highcalories group(HC group, n=6) and diabetes group(DM group, n=6).After 10 weeks, the left ventricular end diastolic diameter(LVEDD), left ventricular end systolic diameter(LVESD) and left ventricular ejection fraction(LVEF) were detected using ultrasound.The heart weight(HW), body weight(BW), and heart-body ratio(HW/BW) in three groups were measured after the rats were sacrificed.In three groups, the serum levels of tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) and maleic dialdehyde(MDA) were detected using ELISA method, the apical tissue were stained using Masson, and the changes of RIPK1, RIPK3 and MLKL in myocardial tissue were detected using RT-PCR and Western blotting.Results Compared with the CON group, the expression levels of HW, TNF-α, IL-6 and MDA increased, and the protein expression levels of RIPK1, RIPK3, and MLKL increased(P < 0.05 to P < 0.01), but the changes of the mRNA expression levels of MLKL were not obvious in HC group(P>0.05).Compared with the HC group, the HW/BW increased, the LVEF decreased, the levels of TNF-α, IL-6 and MDA expression increased, the mRNA and protein levels of RIPK1, RIPK3, and MLKL increased(P < 0.01), and the blue staining of Masson aggravated in DM group.Conclusions High glucose status can induce the myocardial injury, increase the myocardial fibrosis and oxidation level, which may be related to the upregulation of the necroptosis pathway.