Celastrol attenuates pulmonary ischemia reperfusion injury in cardiopulmonary bypass via mitigating ER stress and inducing autophagy depend on Sirt1 activation in rat model.
作者单位：Clinical Medicine (Eight-year Program)Shanghai Medical CollegeFudan University Department of Physiology and PathophysiologySchool of Basic Medical ScienceFudan University
会议名称：《2019中国生理学会学术年会暨张锡钧基金第十五届全国青...》
会议日期：2019年
关 键 词：Celastrol Pulmonary ischemia reperfusion injury Cardiopulmonary bypass ER stress Autophagy Sirt1
摘 要：Objective: Cardiopulmonary bypass（CPB） carries a risk of lung ischemia reperfusion, leading to acute lung injury（ALI）.It is well known that abundant ROS production, overloaded calcium,exhausted ATP and acidosis in pulmonary epithelial cells induced by ischemia and reperfusion（I/R）result in endoplasmic reticulum stress（ERS） associated autophagy, which eventually cause lung injury.Silent information regulator 1（Sirt1） is a sort of histone deacetylase, which has the function of dual-directional control of autophagy.Studies suggest that the overexpression of Sirt1 in lung I/R can inhibit the level of ERS.Celastrol, a major active constituent of Tripterygium wilfordii with antioxidant, anti-inflammatory and autophagy-modulatory effects, has been shown to protect against ischemia/reperfusion（I/R） injury.This study aimed to investigate the protective effects of celastrol on alveolar tissue injury during cardiopulmonary bypass and to further explore whether its mechanism of action was associated with Sirt1-regulated ERS and autophagic level.Materials and methods: SD adult male rats were used, weighing 200-300 g.The rats were randomly divided into three groups: sham group, cardiopulmonary bypass（CPB） group, CPB + celastrol group, CPB +celastrol+EX 527（Sirt 1 antagonist） group and CPB + celastrol+SRT1720（Sirt 1 agonist） group（n=10 in each group）.Rats were subjected to CPB under anesthesia for 60 min.Celastrol（5 mg/kg）was administered via arterial inflow.The indexes of dynamic pulmonary function, including expiratory resistance（Re）, inspiratory resistance（Ri） and dynamic compliance（Cdyn） were recorded by using the plethysmographic measurement system.The wet weight（W）, and post-4 hours drying wet（D） of the lung was weighed.The total lung weight（TLW） and the wet and dry ratio（W/D） were calculated.The lung injury and pathological morphology were observed by HE staining under light microscope.The expression and localization of Sirt1, ERS marker GRP78 and autophagic marker LC3 in lung tissue were detected by immunohistochemistry and Western Blot.Ultrastructural damage of blood-air barrier and autophagy in alveolar epithelial cell were identified by transmission electron microscopic observation.Results: Compared to Sham group, both the Re and Ri was increased in CPB group, while the Cdyn was decreased（P0.05）;The lung edema related index W/D and TLW were increased in CPB group（P0.05）;Compared to CPB group, the Re and Ri was decreased in CPB + celastrol group, while the Cdyn was increased（P0.05）;Lung injuries related indexes W/D and TLW were decreased（P0.05）;Pathohistological examinations showed a significant inflammatory infiltration and edema in the lung tissue of CPB group, which were attenuated by celastrol treatment;Electron micrograph showed disruption of the mitochondria with derangement of the mitochondrial crests in alveolar epithelial cell of the CPB group, while increased number of autophagosomes were observed in CPB + celastrol group.Western bl