CAJ | 학술논문

目的：探讨褪黑素( MT )是否能减轻由博来霉素( BLM)诱发小鼠肺纤维化早期的内质网应激反应。方法将成年健康♂ ICR小鼠随机分为对照组、MT组、BLM组和MT+BLM组。 MT组小鼠给予生理盐水前30 min经腹腔注射MT(10 mg·kg-1),并在给予生理盐水后按每24 h一次经腹腔注射MT(10 mg·kg-1),BLM组小鼠经气管插管单次给予BLM(5 mg·kg-1),MT+BLM组小鼠在给予BLM(5 mg·kg-1)前30min经腹腔注射给予MT(10 mg·kg-1),并在给予BLM后按每24 h一次经腹腔注射给予MT(10 mg· kg-1),对照组小鼠经气管插管给予等容积的生理盐水。各组分别在BLM处理后不同时间点(24、72 h)剖杀小鼠并取材,肺组织进行病理切片,HE染色法观察肺部炎性细胞浸润情况,Western blot检测内质网( ER)应激相关蛋白( GRP78、p-eIF2α和p-IRE1α)的表达水平,免疫组化检测ER应激相关蛋白(GRP78、p-IRE1α、ATF6α和p-PERK)的分布。结果成功构建了小鼠肺纤维化急性炎症模型；在BLM处理后,肺重、肺重比和肺炎性细胞浸润明显增加,并呈明显时间-效应关系；MT可明显降低BLM引起的肺重和肺重比增加,减轻肺部炎性细胞浸润；Western blot显示, MT处理后明显对抗BLM引起的ER应激敏感蛋白GRP78蛋白的上调,抑制BLM引起的UPR通路相关蛋白eIF2α和IRE1α磷酸化；免疫组化结果显示,MT可降低BLM诱导的ER应激相关蛋白GRP78、p-IRE1α、ATF6α和 p-PERK的表达。结论 MT可减轻BLM诱发的小鼠肺纤维化早期ER应激反应。
목적：탐토퇴흑소( MT )시부능감경유박래매소( BLM)유발소서폐섬유화조기적내질망응격반응。방법장성년건강♂ ICR소서수궤분위대조조、MT조、BLM조화MT+BLM조。 MT조소서급여생리염수전30 min경복강주사MT(10 mg·kg-1),병재급여생리염수후안매24 h일차경복강주사MT(10 mg·kg-1),BLM조소서경기관삽관단차급여BLM(5 mg·kg-1),MT+BLM조소서재급여BLM(5 mg·kg-1)전30min경복강주사급여MT(10 mg·kg-1),병재급여BLM후안매24 h일차경복강주사급여MT(10 mg· kg-1),대조조소서경기관삽관급여등용적적생리염수。각조분별재BLM처리후불동시간점(24、72 h)부살소서병취재,폐조직진행병리절편,HE염색법관찰폐부염성세포침윤정황,Western blot검측내질망( ER)응격상관단백( GRP78、p-eIF2α화p-IRE1α)적표체수평,면역조화검측ER응격상관단백(GRP78、p-IRE1α、ATF6α화p-PERK)적분포。결과성공구건료소서폐섬유화급성염증모형；재BLM처리후,폐중、폐중비화폐염성세포침윤명현증가,병정명현시간-효응관계；MT가명현강저BLM인기적폐중화폐중비증가,감경폐부염성세포침윤；Western blot현시, MT처리후명현대항BLM인기적ER응격민감단백GRP78단백적상조,억제BLM인기적UPR통로상관단백eIF2α화IRE1α린산화；면역조화결과현시,MT가강저BLM유도적ER응격상관단백GRP78、p-IRE1α、ATF6α화 p-PERK적표체。결론 MT가감경BLM유발적소서폐섬유화조기ER응격반응。
Aim To investigate whether melatonin ( MT) can alleviate endoplasmic reticulum( ER) stress at an early stage of bleomycin( BLM)-induced lung fi-brosis in mice. Methods Adult healthy male ICR mice were divided randomly into control group, MT group, BLM group and MT + BLM group. In MT group, mice had saline treatment 30 minutes after hav-ing the intraperitoneal injection of MT (10 mg·kg-1 ) and had been intraperitoneally injected with MT once in the following every 24 hours. In BLM group, mice were intratracheally injected with a single dose of BLM (5 mg·kg-1). In MT+BLM group, mice had been intraperitoneally injected with BLM 30 minutes after having MT and had been injected with MT once in the following every 24 hours. In control group, mice re-ceived the same level of saline treatment in the same manner. All mice were dissected for collecting the tis-sue of lungs at different time points (24h, 72h) after BLM treatment. Inflammatory cell infiltration of lungs was determined by HE staining. The level of ER stress related proteins ( GRP78 , p-eIF2α, p-IRE1α) in lungs was determined using Western blot. The distribu-tion of ER stress related proteins ( GRP78 , p-IRE1α, ATF6α, p-PERK) in lungs was detected by immuno-histochemistry. Results The model of BLM-induced acute inflammation of lung fibrosis in mice had been successfully constructed. After BLM treatment, lung weight, lung weight ratio and inflammatory cell infiltra-tion were significantly increased with a significant cor-relation between time and effectiveness. After MT treatment, lung weight, lung weight ratio and inflam-matory cell infiltration were significantly reduced. The results of Western blot showed that MT pretreatment not only prevented the increase of BLM-induced GRP78 protein significantly, but also restrained the phosphorylation of eIF2α and IRE1α in mouse lungs. Immunohistochemistry also showed that MT pretreat-ment reduced the expression of GRP78 , p-IRE1α, ATF6α and p-PERK. Conclusion MT alleviates ER stress effectively at an early stage of BLM-induced lung fibrosis in mice.