硫化氢对局灶性脑缺血损伤大鼠脑组织炎性细胞因子的影响

Effects of hydrogen sulfide on inflammatory factors in brain tissues of rats with focal cerebral ischemia injury

目的观察硫化氢(H 2S)对局灶性脑缺血损伤大鼠脑组织核转录因子-κB(NF-κB)活性及其下游的炎性因子肿瘤坏死因子α(TNF-α)、白介素-1β(IL-1β)和白介素-10(IL-10)的影响,从炎性细胞因子方面探讨H 2S对局灶性脑缺血损伤的作用及机制。方法健康雄性SD大鼠共40只,随机分为5组,每组8只,分别为假手术组、缺血模型组、H 2S低剂量组、H 2S中剂量组、H 2S高剂量组。10%的水合氯醛350 mg/kg麻醉大鼠,采用线栓法复制大鼠大脑中动脉闭塞模型。H 2S低、中、高剂量组分别于大鼠脑缺血3 h时腹腔注射0.7 mg/kg、1.4 mg/kg和2.8 mg/kg的硫氢化钠(NaHS),假手术组和缺血模型组注射等容量的0.9%氯化钠溶液。5组大鼠均于缺血24 h腹主动脉取血并断头取脑,ELISA法测定血清、脑组织中TNF-α、IL-1β和IL-10的含量。免疫组织化学染色和Western blot分析脑组织中NF-κB的表达。结果与缺血模型组比较,H 2S低、中、高剂量组大鼠的血清中IL-1β、TNF-α水平显著降低,IL-10水平显著升高(P<0.05或P<0.01),H 2S中、高剂量组大鼠脑组织匀浆中IL-1β、TNF-α水平显著降低,IL-10水平显著升高(P<0.01)。H 2S中、高剂量组大鼠脑组织中NF-κB从细胞浆向细胞核的移位被明显抑制(P<0.01),NF-κB的表达也明显降低。结论H 2S可明显抑制局灶性脑缺血损伤后脑组织NF-κB的核移位,减少其蛋白表达,下调TNF-α、IL-1β,上调IL-10炎症相关细胞因子的表达,从而减轻局灶性脑缺血损伤。

Objective To investigate the effects of H 2S on inflammatory factors including NF-κB,TNF-α,IL-1βand IL-10 in brain tissues of rats with focal cerebral ischemia injury,and to explore the possible action mechanisms.Methods Forty male SD rats(weigh 250~280g)were randomly divided into five groups:sham operation group,ischemia model group,H 2S low,middle and high dose groups,with 8 rats in each group.The rats were anesthetized by 10%chloral hydrate at 350mg/kg,and the animal models with focal cerebral ischemia were established by inserting cranially a nylon thread with rounded tip into internal carotid artery.The rats in sham oeration group and ischemia model group were injected with 0.9%sodium chloride solution.The rats in H 2S low,middle and high dose groups were intraperitoneally injected with H 2S 0.7mg,1.4 mg,2.8mg/kg,respectively at 3h after ischemia.All the rats were sacrificed at 24h after ischemia.The levels of TNF-α,IL-1βand IL-10 were measured by enzyme-linked immunosorbent assay(ELISA).The expression levels of nuclear factor-κB(NF-кB)in the brain tissue of rats were detected by immunohistochemisty and Western Blot.Results As compared with those in ischemia model group,the levels of TNF-αand IL-1βin serum and brain tissue of rats were significantly decreased in H 2S low,middle and high dose groups,however,the levels of IL-10 in serum and brain tissue were significantly increased in the three medication groups(P<0.05 or P<0.01).The levels of TNF-αand IL-1βin serum and brain tissue of rats were significantly decreased in H 2S middle and high dose groups,however,the levels of IL-10 in serum and brain tissue were significantly increased in H 2S middle and high dose groups(P<0.01).Moreover the NF-κB translocation was obviously inhibited in H 2S middle and high dose groups(P<0.01),and the expression levels of NF-κB in the nuclei were significantly decreased,as compared with those in ischemia model group(P<0.05).Conclusion The application of H 2S can obviously inhibit NF-κB nuclear transposition,down-regulate the expressions of TNF-αand IL-1β,increase the expression of IL-10,which may be one of the molecular mechanisms of its neuroprotection.