Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thu...Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thus impacting aquatic animal survival.However,the adaptative mechanisms underlying fish responses to environmental hypoxia remain largely unknown.Here,we used large yellow croaker(Larimichthys crocea)and large yellow croaker fry(LYCF)cells to investigate the roles of the Hif-1α/Hsf1/Hsp70 signaling pathway in the regulation of cellular redox homeostasis,and apoptosis.We confirmed that hypoxia induced the expression of Hif-1α,Hsf1,and Hsp70 in vivo and in vitro.Genetic Hsp70 knockdown/overexpression indicated that Hsp70 was required for maintaining redox homeostasis and resisting oxidative stress in LYCF cells under hypoxic stress.Hsp70 inhibited caspase-dependent intrinsic apoptosis by maintaining normal mitochondrial membrane potential,enhancing Bcl-2 mRNA and protein expression,inhibiting Bax and caspase3 mRNA expression,and suppressing caspase-3 and caspase-9 activation.Hsp70 suppressed caspaseindependent intrinsic apoptosis by inhibiting nuclear translocation of apoptosis-inducing factor(AIF)and disturbed extrinsic apoptosis by inactivating caspase-8.Genetic knockdown/overexpression of Hif-1αand dual-luciferase reporter assay indicated that Hif-1αactivated the Hsf1 DNA promoter and enhanced Hsf1 mRNA transcription.Hsf1 enhanced Hsp70 mRNA transcription in a similar manner.In summary,the Hif-1α/Hsf1/Hsp70 signaling pathway plays an important role in regulating redox homeostasis and anti-apoptosis in L.crocea under hypoxic stress.展开更多
基金This work was supported by the National Key Research and Development Program of China(2018YFC1406300)NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(U1809212)+4 种基金Scientific and Technical Project of Zhejiang Province(2021C02069-1,2016C02055-7)Scientific and Technical Project of Ningbo City(2021Z002,2015C110005)Ningbo Science and Technology Plan Projects(2018A610228)Teaching and Research Project of Ningbo University(XYL19023)Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture,K.C.Wong Magna Fund in Ningbo University。
文摘Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thus impacting aquatic animal survival.However,the adaptative mechanisms underlying fish responses to environmental hypoxia remain largely unknown.Here,we used large yellow croaker(Larimichthys crocea)and large yellow croaker fry(LYCF)cells to investigate the roles of the Hif-1α/Hsf1/Hsp70 signaling pathway in the regulation of cellular redox homeostasis,and apoptosis.We confirmed that hypoxia induced the expression of Hif-1α,Hsf1,and Hsp70 in vivo and in vitro.Genetic Hsp70 knockdown/overexpression indicated that Hsp70 was required for maintaining redox homeostasis and resisting oxidative stress in LYCF cells under hypoxic stress.Hsp70 inhibited caspase-dependent intrinsic apoptosis by maintaining normal mitochondrial membrane potential,enhancing Bcl-2 mRNA and protein expression,inhibiting Bax and caspase3 mRNA expression,and suppressing caspase-3 and caspase-9 activation.Hsp70 suppressed caspaseindependent intrinsic apoptosis by inhibiting nuclear translocation of apoptosis-inducing factor(AIF)and disturbed extrinsic apoptosis by inactivating caspase-8.Genetic knockdown/overexpression of Hif-1αand dual-luciferase reporter assay indicated that Hif-1αactivated the Hsf1 DNA promoter and enhanced Hsf1 mRNA transcription.Hsf1 enhanced Hsp70 mRNA transcription in a similar manner.In summary,the Hif-1α/Hsf1/Hsp70 signaling pathway plays an important role in regulating redox homeostasis and anti-apoptosis in L.crocea under hypoxic stress.
