JNK2在早期糖尿病小鼠视网膜中的表达及作用

Expression and role of JNK2 in early course of diabetic retinopathy of mice

目的探讨JNK2在早期糖尿病(diabetes mellitus,DM)小鼠视网膜的表达和作用,为进一步深入探讨糖尿病视网膜病变的发病机制及早期治疗研究提供理论依据。方法 C57BL/6雄性小鼠60只随机分为DM组42只及正常组18只,DM组一次性腹腔注射5g·L-1STZ(150mg·kg-1体质量)诱发DM模型,正常组腹腔注射同体积的0.1mol·L-1柠檬酸钠缓冲液,于造模成功后2周、4周、8周分别处死正常组小鼠各6只,DM组小鼠各14只,取双眼眼球用于实验。其中,左眼提取视网膜用于实时定量RT-PCR,检测JNK2基因的表达变化,右眼行HE染色和TUNEL染色,分别观察视网膜在各时间点的形态学改变及视网膜神经节细胞的凋亡情况。结果正常组2周、4周、8周时JNK2基因表达水平分别为(2.31±0.53)g·L-1、(2.54±0.42)g·L-1、(2.26±0.67)g·L-1,各时间点表达无明显差异(P>0.05);DM组各时间点JNK2基因表达水平分别为(2.34±0.56)g·L-1、(4.51±0.64)g·L-1、(11.43±0.37)g·L-1,表达量随病程的延长而增加(P<0.05)。各时间点神经节细胞凋亡率在正常组分别为(0.77±0.73)%、(0.72±0.38)%、(0.87±0.76)%,差异无统计学意义(P>0.05);在DM组分别为(0.22±0.47)%、(6.87±1.17)%、(21.65±2.95)%,随DM病程延长神经节细胞凋亡率增加(P<0.05)。各时间点每高倍视野视网膜神经节细胞数在正常组小鼠分别为(47.83±3.76)个、(48.17±3.81)个、(47.74±4.16)个,各期表达无明显差异(P>0.05);在DM组分别为(45.96±4.20)个、(34.20±2.25)个、(30.19±3.54)个,神经节细胞的数量随DM病程的延长逐渐减少(P<0.05),且视网膜形态出现组织学改变。结论 JNK2参与了小鼠早期视网膜神经节细胞的凋亡过程,且有促进视网膜神经节细胞凋亡的作用。

Objective To discuss the expression and role of JNK2 in the early course of diabetic retinopathy of mice,and provide the theoretical basis for exploring the pathogenesis and early treatment of diabetic retinopathy.Methods Sixty C57BL/6 male mice were randomly divided into diabetes mellitus（DM） group（42 cases） and normal group（18 cases）,the DM group were administered intraperitoneally with 5 g·L-1 STZ to induce the diabetes model,the control group were injected with doses of sodium citrate buffer,each 6 cases in normal group and 14 cases in DM group were sacrificed at 2 weeks,4 weeks and 8 weeks after operation,the dual eyeballs were taken out for experiment.The JNK2 mRNA expression in retinal extract of left eye was detected by real-time RT-PCR,HE staining and TUNEL methods performed in the eye right eye to observe the retinal morphology and retinal ganglion cell（RGC） apoptosis.Results JNK2 expression levels in the normal group at 2 weeks,4 weeks and 8 weeks were（2.31±0.53）g·L-1,（2.54±0.42）g·L-1,（2.26± 0.67）g·L-1,respectively,there was no significant difference（P0.05）;That in DM group were（2.34±0.56）g·L-1,（4.51±0.64）g·L-1,（11.43±0.37）g·L-1,respectively,the expression increased with the prolong of duration（P0.05）.The rate of RGC apoptosis in the normal group at 2 weeks,4 weeks and 8 weeks were（0.77±0.73）%,（0.72±0.38）%,（0.87±0.76） %,respectively,there was no statistical difference（P0.05）;That in DM group were（0.22±0.47）%,（6.87±1.17） %,（21.65±2.95）%,respectively,the rate of RGC apoptosis increased with the prolong of duration（P0.05）.The number of RGC in normal group at 2 weeks,4 weeks and 8 weeks were 47.83± 3.76,48.17±3.81,47.74±4.16,respectively,there was no significant difference（P0.05）;That in DM group were 45.96±4.20,34.20±2.25,30.19±3.54,respectively,the number of RGC decreased with the prolong of duration（P0.05）,and the histological changes in retinal morphology appeared.Conclusion JNK2 takes part in the RGC apoptosis at early stage,and can promote the RGC apoptosis.