中文摘要：

目的：探讨开放ATP敏感性钾通道（K_（ATP）通道）能否抑制Toll样受体4（TLR4）/核因子-κB（NF-κB）通路对抗高糖（HG）引起的H9c2心肌细胞损伤和炎症。方法：应用Western blot测定TLR4和NF-κB p65的蛋白水平;应用ELISA法检测细胞培养液中白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）的水平;采用细胞计数试剂盒8（CCK-8）测定心肌细胞存活率;罗丹明123染色荧光显微镜照相法测定线粒体膜电位（MMP）;双氯荧光素染色荧光显微镜照相法测定细胞内活性氧簇（ROS）水平;Hoechst 33258核染色荧光显微镜照相法检测凋亡细胞数量。结果：H9c2心肌细胞经HG（35 mmol/L葡萄糖）处理24 h,胞内TLR4和磷酸化NF-κB p65（p-NF-κB p65）的蛋白水平明显增加,100μmol/L K_（ATP）通道开放剂二氮嗪（DZ）预处理30 min可抑制HG对TLR4和p-NF-κB p65蛋白水平的上调作用;此外,30μmol/L TAK-242（TLR4抑制剂）和HG共处理心肌细胞24 h也可减轻HG对p-NF-κB p65的上调作用。另一方面,100μmol/L DZ预处理有明确的心肌保护作用,可抑制HG引起的细胞毒性、炎症反应、线粒体损伤、氧化应激和细胞凋亡,使细胞存活率升高,并减少IL-1β和TNF-α分泌水平、MMP丢失、ROS生成及凋亡细胞数量;而30μmol/L TAK-242或100μmol/L PDTC（NF-κB抑制剂）共处理心肌细胞24 h也可发挥和DZ相类似的作用,能抑制HG引起的上述损伤和炎症反应。结论：开放K_（ATP）通道可通过抑制TLR4/NF-κB通路对抗HG引起的H9c2肌细胞损伤和炎症。

英文摘要：

AIM： To investigate whether the opening of ATP-sensitive K~＋（ K_（ATP）） channels protects H9c2 cardiac cells against high glucose（ HG）-induced injury and inflammation by inhibiting the Toll-like receptor 4（ TLR4）/nuclear factor-κB（ NF-κB） pathway. METHODS： The protein levels of TLR4 and NF-κB p65 were determined by Western blot. The levels of interleukin-1β（ IL-1β） and tumor necrosis factor-α（ TNF-α） were detected by ELISA. The cell viability was measured by CCK-8 assay. Mitochondrial membrane potential（ MMP） was examined by rhodamine 123（ Rh 123）staining followed by photofluorography. The intracellular levels of reactive oxygen species（ ROS） were detected by 2＇,7＇-dichlorfluorescein- diacetate（ DCFH-DA） staining followed by photofluorography. The number of apoptotic cells was observed by Hoechst 33258 nuclear staining followed by photofluorography. RESULTS： After the H9c2 cardiac cells were treated with HG（ 35 mmol/L glucose） for 24 h,the protein levels of TLR4 and phosphorylated NF-κB p65（ p-NF-κB p65） were significantly increased. Pretreatment of the cells with 100 μmol/L diazoxide（ DZ,a K_（ATP）channel opener） for30 min before exposure to HG considerably blocked the up-regulation of the TLR4 and p-NF-κB protein levels induced by HG. Moreover,co-treatment of the cells with 30 μmol/L TAK-242（ an inhibitor of TLR4） obviously inhibited the HG-induced up-regulation of the p-NF-κB p65 protein level. On the other hand,pretreatment of the cells with 100 μmol/L DZ had a clear myocardial protection effect,which attenuated the HG-induced cytotoxicity,inflammatory response,mitochondrial damage,oxidative stress and apoptosis,evidenced by an increase in the cell viability,and decreases in the levels of IL-1β and TNF-α,MMP loss,ROS generation and the number of apoptotic cells. Similarly,co-treatment of H9c2 cardiac cells with 30 μmol/L TAK-242 or 100 μmol/L PDTC（ an inhibitor of NF-κB） and HG for 24 h also obviously reduced the