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目的:探讨蛋白激酶Cβ2 (protein kinase Cβ2, PKCβ2）在高糖与缺氧/复氧（hypoxia/reoxygenation, HR）诱导的心肌细胞焦亡中的作用。方法:将培养的H9c2心肌细胞按随机数字表法分为5组（每组6孔）：低糖组（LG组）、低糖缺氧/复氧组（LG+HR组）、高糖组（HG组）、高糖缺氧/复氧组（HG+HR组）、高糖缺氧/复氧+PKCβ2抑制剂CGP53353 （1 μmol/L）治疗组（HG+HR+CGP组）。采用三气培养箱（5%COn 2、94%Nn 2、1%On 2）缺氧4 h，正常氧浓度复氧2 h构建细胞HR模型，细胞计数试剂盒（cell counting kit-8, CCK8）检测细胞存活率，ELISA法检测乳酸脱氢酶（lactate dehydrogenase, LDH）水平，Western blot法检测细胞PKCβ2及焦亡相关蛋白Nod样受体蛋白-3 (Nod-like receptor pyrin domain3, NLRP3）、IL-1β、半胱氨酸蛋白酶-1 (caspase-1）表达水平，JC-1染色评估H9c2细胞线粒体膜电位水平。n 结果:与LG组比较，HG组、LG+HR组、HG+HR组细胞存活率明显降低而LDH释放水平明显增加（n P<0.05），同时伴随PKCβ2活化及NLRP3、IL-1β、caspase-1表达上调（n P<0.05）；与HG组比较，HG+HR组LDH释放水平增加，细胞存活率明显降低（n P<0.05），JC-1单体细胞百分比及磷酸化PKCβ2 [phospho-PKCβ2 （Ser660）, P-PKCβ2]蛋白、NLRP3、IL-1β、caspase-1表达上调（n P<0.05）；与LG+HR组比较，HG+HR组LDH释放水平增加，细胞存活率明显降低（n P<0.05），P-PKCβ2表达明显增加，NLRP3、IL-1β、caspase-1表达上调（n P<0.05）。与HG+HR组比较，HG+HR+ CGP组细胞存活率明显增加，LDH释放水平、JC-1单体细胞百分比、P-PKCβ2、NLRP3、IL-1β、caspase-1表达下调（n P<0.05）。n 结论:选择性抑制PKCβ2过度活化可减轻心肌细胞高糖HR性损伤，其机制可能与降低细胞焦亡水平及减轻线粒体损伤有关。“,”Objective:To investigate the effects of protein kinase Cβ2 (PKCβ2) in the pyroptosis of cardiac myocytes induced by hypoxia/reoxygenation (HR).Methods:H9c2 myocardial cells were cultured and divided into the five groups according to the random number table method (n n=6): a low-glucose (LG) group, a low-glucose and hypoxia reoxygenation (LG+HR) group, a high-glucose (HG) group, a high-glucose and hypoxia reoxygenation (HG+HR) group and a hyperglycemic reoxygenation and PKCβ2 inhibitor CGP53353 (1 μmol/L) (HG+HR+CGP) group. A cell model of HR was established through hypoxia in a three-gas incubator (5%COn 2, 94%Nn 2, and 1%On 2) for 4 h followed by reoxygenation at a normal oxygen concentration for 2 h. The cell viability was evaluated by cell counting kit 8 (CCK8) and the level of lactate dehydrogenase (LDH) was determined by enzyme-linked immunosorbent assay (ELISA). The levels of PKCβ2, Nod-like receptor pyrin domain3 (NLRP3), interleukin-1β (IL-1β) and caspase-1 were detected by Western blot, while the mitochondrial membrane potential of H9c2 cells was evaluated by JC-1 staining.n Results:Compared with the LG group, the HG group, the LG+HR group and the HG+HR group showed significantly decreased cell survival rates but increased LDH release (n P<0.05), as well as up-regulation in phosphorylated PKCβ2 and the expression of NLRP3, IL-1β and caspase-1 (n P<0.05). Compared with the HG group, the HG+HR group showed increased LDH release and a decreased cell survival rate (n P<0.05), as well as up-regulation in JC-1 cell percentage and the expression of phosphorylated PKCβ2 [phospho-PKCβ2(Ser660), P-PKCβ2]protein, NLRP3, IL-1β, and caspase-1 (n P<0.05). Compared with the LG+ HR group, the HG+HR group showed increased LDH release and a decreased cell survival rate (n P<0.05), as well as significantly increased expression of P-PKCβ2 and up-regulated expression of NLRP3, IL-1β and caspase-1 (n P<0.05). Compared with the HG+HR group, the HG+HR+CGP group presented a significantly increased survival rate and decreased LDH release, as well as down-regulation in JC-1 cell percentage and the expression of P-PKCβ2, NLRP3, IL-1β and caspase-1 (n P<0.05).n Conclusions:Selective inhibition of PKCβ2 overactivation can relieve hyperglycemic HR injury in cardiomyocytes, which may be related to relieving pyroptosis and inhibiting mitochondrial damage.