硫化氢对青光眼大鼠视网膜细胞的保护作用及机制研究

目的研究硫化氢(H2S)对青光眼大鼠视网膜细胞的保护作用及作用机制。方法雄性SD大鼠随机分为对照组、模型组和低、高剂量实验组,每组25只。模型组及低、高剂量实验组大鼠均用光凝法建立青光眼大鼠模型,造模成功后,低、高剂量实验组大鼠分别腹腔注射50,100μmol·kg^-1·d^-1硫氢化钠(NaHS)溶液(H2S供体),对照组与模型组腹腔注射等量生理盐水,连续干预2周。用动物眼压计测量各组大鼠干预后眼内压,以原位末端标记染色法检测视网膜神经节细胞(RGCs)凋亡情况,用蛋白质印迹法检测各组大鼠视网膜组织中磷酸化原癌基因蛋白Jun氨基末端激酶(p-JNK)、磷酸化细胞外调节蛋白激酶(p-ERK)及磷酸化丝裂原活化蛋白激酶p38(p-p38 MAPK)蛋白相对表达量。结果对照组、模型组和低、高剂量实验组大鼠干预后眼内压分别为(18.55±3.02),(37.11±2.62),(29.34±3.22),(23.87±1.68)mmHg,RGCs凋亡指数分别为(3.24±1.12)%,(59.03±5.92)%,(23.26±3.87)%,(12.52±2.33)%,视网膜组织中p-JNK蛋白相对表达量分别为0.10±0.04,0.81±0.13,0.19±0.05,0.15±0.06,p-ERK蛋白相对表达量分别为0.22±0.05,0.89±0.08,0.32±0.09,0.27±0.06,p-p38 MAPK蛋白相对表达量分别为0.40±0.06,0.94±0.06,0.51±0.11,0.45±0.08。模型组及低、高剂量实验组以上各指标与对照组比较,差异均有统计学意义(均P<0.05);低、高剂量实验组以上各指标与模型组相比,差异均有统计学意义(均P<0.05)。结论 H2S具有降低青光眼大鼠眼内压,改善视网膜组织病变,保护RGCs的作用,其作用机制可能与抑制MAPK信号转导通路有关。

Protective effect and mechanism of hydrogen sulfide on retinal cells in glaucoma rats

Objective To investigate the protective effect and mechanism of hydrogen sulfide(H2S) on retinal cells in glaucoma rats. Methods A total of 100 male Sprague-Dawley rats were randomly divided into control group, model group and experimental-L, experimental-H groups, 25 rats in each group. In model group and experimental-L, experimental-H groups, the glaucoma rat model was established by photocoagulation method. After successful modeling, the rats in experimental-L, experimental-H groups were injected intraperitoneally with 50, 100 μmol·kg^-1·d^-1 sodium hydrosulfide solution(hydrogen sulfide donor), control group and model group were intraperitoneally injected with the same amount of normal saline for 2 weeks. The intraocular pressure after intervention in each group of rats was measured using an animal tonometer;apoptosis of retinal ganglion cells( RGCs) were detected by TdT-mediated dUTP Nick-End Labeling( TUNEL) staining;the relative expression levels of proto oncogene protein Jun N-terminal kinase( p-JNK),phosphorylation extracellular regulated protein Kinases( p-ERK),and phosphorylation mitogen activated protein kinases p38( p-p38 MAPK) protein protein in retinal tissue of each group rats were detected by Western blotting( WB) method. Results Intraocular pressure in control group,model group and experimental-L,experimental-H groups were( 18. 55 ± 3. 02),( 37. 11 ± 2. 62),( 29. 34 ± 3. 22),( 23. 87 ± 1. 68) mm Hg,the apoptotic indexes of RGCs were( 3. 24 ± 1. 12) %,( 59. 03 ± 5. 92) %,( 23. 26 ± 3. 87) % and( 12. 52 ± 2. 33) %,the relative expression levels of p-JNK protein in retinal tissue were0. 10 ± 0. 04,0. 81 ± 0. 13,0. 19 ± 0. 05,0. 15 ± 0. 06,the relative expression levels of p-ERK protein were 0. 22 ± 0. 05,0. 89 ± 0. 08,0. 32 ± 0. 09,0. 27 ± 0. 06,the relative expression levels of p-p38 MAPK protein were 0. 40 ± 0. 06,0. 94 ± 0. 06,0. 51 ± 0. 11 and 0. 45 ± 0. 08,compared with control group,the above indexes in model group and experimental-L,experimental-H groups were with significant difference;Compared with model group,the above indexes in experimental-L,experimental-H groups were with significant difference( all P < 0. 05).Conclusion H2S can reduce intraocular pressure in glaucoma rats,improve retinal tissue lesions and protect RGCs,and its mechanism may be related to the inhibition of MAPK signal transduction pathways.