Organisms produce high levels of reactive oxygen species(ROS)to kill pathogens or act as signaling molecules to induce immune responses;however,excessive ROS can result in cell death.To maintain ROS balance and cell s...Organisms produce high levels of reactive oxygen species(ROS)to kill pathogens or act as signaling molecules to induce immune responses;however,excessive ROS can result in cell death.To maintain ROS balance and cell survival,mitophagy selectively eliminates damaged mitochondria via mitophagy receptors in vertebrates.In marine invertebrates,however,mitophagy and its functions remain largely unknown.In the current study,Vibrio splendidus infection damaged mitochondrial morphology in coelomocytes and reduced mitochondrial membrane potential(ΔΨm)and mitophagosome formation.The colocalization of mitochondria and lysosomes further confirmed that lipopolysaccharide(LPS)treatment increased mitophagy flux.To explore the regulatory mechanism of mitophagy,we cloned Bcl2/adenovirus E1 B 19 kDa protein-interacting protein 3(BNIP3),a common mitophagy receptor,from sea cucumber Apostichopus japonicus(Aj BNIP3)and confirmed that Aj BNIP3 was significantly induced and accumulated in mitochondria after V.splendidus infection and LPS exposure.At the mitochondrial membrane,Aj BNIP3 interacts with microtubule-associated protein 1 light chain 3(LC3)on phagophore membranes to mediate mitophagy.After Aj BNIP3 interference,mitophagy flux decreased significantly.Furthermore,Aj BNIP3-mediated mitophagy was activated by ROS following the addition of exogenous hydrogen peroxide(H2 O2),ROS scavengers,and ROS inhibitors.Finally,inhibition of BNIP3-mediated mitophagy by Aj BNIP3 small interfering RNA(si RNA)or high concentrations of lactate increased apoptosis and decreased coelomocyte survival.These findings highlight the essential role of Aj BNIP3 in damaged mitochondrial degradation during mitophagy.This mitophagy activity is required for coelomocyte survival in A.japonicus against V.splendidus infection.展开更多
目的观察LC3、LC3-II/LC3-I比值、Nrf2和Bcl2在柯萨奇病毒B组3型(coxsackievirus group B tyype 3, CV-B3)感染后引起的心肌炎和4种不同污染源气体颗粒物滴入气管后引起的SD大鼠心肌损害的不同变化,来探讨这些病理条件下心肌细胞自噬与...目的观察LC3、LC3-II/LC3-I比值、Nrf2和Bcl2在柯萨奇病毒B组3型(coxsackievirus group B tyype 3, CV-B3)感染后引起的心肌炎和4种不同污染源气体颗粒物滴入气管后引起的SD大鼠心肌损害的不同变化,来探讨这些病理条件下心肌细胞自噬与抗凋亡、抗心肌损害作用机制。方法将成年SD大鼠随机分为CV-B3感染组(20只)、汽车尾气组(20只)、煤烟组(20只)、燃烧秸秆组(20只)、大气组(20只)和对照组(20只);于实验12 h、48 h、5 d、10 d Western blot法检测大鼠LC3和Bcl2及Nrf2的表达。结果前3组大鼠以上指标均表达上调.CV-B3组出现的早,峰值高,恢复快,汽车尾气组大鼠上述指标出现晚,幅度低,煤烟组大鼠以上指标出现更晚,但变化幅度高于汽车尾气组、低于CV-B3组,汽车尾气组和煤烟组第10天Bcl2和Nrf2仍轻度增高;大气组大鼠48 h以上指标出现了短暂的上调表达,第5天恢复正常,秸秆组和对照组大鼠以上指标始终未出现明显变化。结论CV-B3诱导的急性病毒性心肌炎和汽车尾气、煤烟、大气颗粒物诱导的心肌损害的SD大鼠通过自噬激活、凋亡抑制和抗氧化机制来完成心肌细胞的的代谢、更新、修复、抗损伤的全过程。展开更多
基金supported by the National Natural Science Foundation of China(32073003,32102825)Natural Science Foundation of Zhejiang Province(LZ19C190001)+1 种基金Key Project from Science Technology Department of Zhejiang Province(2019R52016)K.C.Wong Magna Fund in Ningbo University。
文摘Organisms produce high levels of reactive oxygen species(ROS)to kill pathogens or act as signaling molecules to induce immune responses;however,excessive ROS can result in cell death.To maintain ROS balance and cell survival,mitophagy selectively eliminates damaged mitochondria via mitophagy receptors in vertebrates.In marine invertebrates,however,mitophagy and its functions remain largely unknown.In the current study,Vibrio splendidus infection damaged mitochondrial morphology in coelomocytes and reduced mitochondrial membrane potential(ΔΨm)and mitophagosome formation.The colocalization of mitochondria and lysosomes further confirmed that lipopolysaccharide(LPS)treatment increased mitophagy flux.To explore the regulatory mechanism of mitophagy,we cloned Bcl2/adenovirus E1 B 19 kDa protein-interacting protein 3(BNIP3),a common mitophagy receptor,from sea cucumber Apostichopus japonicus(Aj BNIP3)and confirmed that Aj BNIP3 was significantly induced and accumulated in mitochondria after V.splendidus infection and LPS exposure.At the mitochondrial membrane,Aj BNIP3 interacts with microtubule-associated protein 1 light chain 3(LC3)on phagophore membranes to mediate mitophagy.After Aj BNIP3 interference,mitophagy flux decreased significantly.Furthermore,Aj BNIP3-mediated mitophagy was activated by ROS following the addition of exogenous hydrogen peroxide(H2 O2),ROS scavengers,and ROS inhibitors.Finally,inhibition of BNIP3-mediated mitophagy by Aj BNIP3 small interfering RNA(si RNA)or high concentrations of lactate increased apoptosis and decreased coelomocyte survival.These findings highlight the essential role of Aj BNIP3 in damaged mitochondrial degradation during mitophagy.This mitophagy activity is required for coelomocyte survival in A.japonicus against V.splendidus infection.
文摘目的观察LC3、LC3-II/LC3-I比值、Nrf2和Bcl2在柯萨奇病毒B组3型(coxsackievirus group B tyype 3, CV-B3)感染后引起的心肌炎和4种不同污染源气体颗粒物滴入气管后引起的SD大鼠心肌损害的不同变化,来探讨这些病理条件下心肌细胞自噬与抗凋亡、抗心肌损害作用机制。方法将成年SD大鼠随机分为CV-B3感染组(20只)、汽车尾气组(20只)、煤烟组(20只)、燃烧秸秆组(20只)、大气组(20只)和对照组(20只);于实验12 h、48 h、5 d、10 d Western blot法检测大鼠LC3和Bcl2及Nrf2的表达。结果前3组大鼠以上指标均表达上调.CV-B3组出现的早,峰值高,恢复快,汽车尾气组大鼠上述指标出现晚,幅度低,煤烟组大鼠以上指标出现更晚,但变化幅度高于汽车尾气组、低于CV-B3组,汽车尾气组和煤烟组第10天Bcl2和Nrf2仍轻度增高;大气组大鼠48 h以上指标出现了短暂的上调表达,第5天恢复正常,秸秆组和对照组大鼠以上指标始终未出现明显变化。结论CV-B3诱导的急性病毒性心肌炎和汽车尾气、煤烟、大气颗粒物诱导的心肌损害的SD大鼠通过自噬激活、凋亡抑制和抗氧化机制来完成心肌细胞的的代谢、更新、修复、抗损伤的全过程。
