Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variatio...Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood.In this study,treatment groups set as 1%(about 0.63g),3%,and 7%of total body weight(named F1,F3 and F7 groups respectively).The potential molecular mechanisms behind the functions of respiratory tree and body wall were investigated by RNA-Seq.A total of 52411 expressed genes were identified from 89342 expressed transcripts.The results showed 759,254 and 334 genes were up-regulated,and 334,445 and 992 genes were down-regulated in respiratory tree of F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Meanwhile,2070,1601 and 896 genes were up-regulated,and 1303,1337 and 1144 genes were down-regulated in body wall between F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Differentially expressed genes were enriched in salivary secretion and ECM-receptor interaction pathways in respiratory tree,and in various types of N-glycan biosynthesis,ribosome and sphingolipid metabolism pathways in body wall.These results suggested respiratory tree and body wall were involved in activation of respiratory metabolisms in response to different feeding rations.Our research provided valuable knowledge for physiological differences in res-piratory metabolism.展开更多
The sea cucumber Apostichopus japonicus plays important roles in marine benthic ecosystem as environmental cleaners,and it is the important aquaculture species in China.High water temperature poses critical threat for...The sea cucumber Apostichopus japonicus plays important roles in marine benthic ecosystem as environmental cleaners,and it is the important aquaculture species in China.High water temperature poses critical threat for the survival of A.japonicus,which has resulted in extensive death in summer.To explore the genes expression profiles under different levels of heat stress,the high-throughput RNA-seq was applied in this study.Our results revealed a total of 1371,1225 and 1408 differentially expressed genes(DEGs)in 26℃for 6 h,26℃for 48 h and 30℃for 6 h respectively in comparison with Control group.The pathway analysis suggested“Protein processing in endoplasmic reticulum(ER)”was significantly enriched in all these heat stress(HS)treatment groups.The expression results of key DEGs in this pathway(Hsp70,Derlin,NEF,PDI,GPR94 and ERP57)by qRT-PCR was in accordance with the RNA-seq data.The subcluster analysis of DEGs revealed that a variety of heat shock proteins(HSPs)and calcium ion binding proteins had an obvious up-regulated expression in 26℃for 6 h,comparatively low expression in 26℃for 48 h,and the highest expression in 30℃for 6 h.The other DEGs subcluster,consisting of critical components of extracellular matrix(ECM)and a subset of peptidases and proteases,showed significantly rising tendency in 30℃for 6 h.Additionally,the expression of matrix metalloproteases(MMP1,MMP16 and MMP19)was prominently affected by HS,and peaked in 30℃for 6 h.This study provides a series of candidate genes for further study about heat shock response in A.japonicus,especially genes associated with protein processing in ER and regulation of ECM,which also offers new insights into cellular homeostasis under stressful conditions in marine invertebrates.展开更多
Previous studies have shown that Vibrio splendidus infection causes mitochondrial damage in Apostichopus japonicus coelomocytes,leading to the production of excessive reactive oxygen species(ROS)and irreversible apopt...Previous studies have shown that Vibrio splendidus infection causes mitochondrial damage in Apostichopus japonicus coelomocytes,leading to the production of excessive reactive oxygen species(ROS)and irreversible apoptotic cell death.Emerging evidence suggests that mitochondrial autophagy(mitophagy)is the most effective method for eliminating damaged mitochondria and ROS,with choline dehydrogenase(CHDH)identified as a novel mitophagy receptor that can recognize non-ubiquitin damage signals and microtubule-associated protein 1 light chain 3(LC3)in vertebrates.However,the functional role of CHDH in invertebrates is largely unknown.In this study,we observed a significant increase in the mRNA and protein expression levels of A.japonicus CHDH(AjCHDH)in response to V.splendidus infection and lipopolysaccharide(LPS)challenge,consistent with changes in mitophagy under the same conditions.Notably,AjCHDH was localized to the mitochondria rather than the cytosol following V.splendidus infection.Moreover,AjCHDH knockdown using si RNA transfection significantly reduced mitophagy levels,as observed through transmission electron microscopy and confocal microscopy.Further investigation into the molecular mechanisms underlying CHDH-regulated mitophagy showed that AjCHDH lacked an LC3-interacting region(LIR)for direct binding to LC3 but possessed a FB1 structural domain that binds to SQSTM1.The interaction between AjCHDH and SQSTM1 was further confirmed by immunoprecipitation analysis.Furthermore,laser confocal microscopy indicated that SQSTM1 and LC3 were recruited by AjCHDH in coelomocytes and HEK293T cells.In contrast,AjCHDH interference hindered SQSTM1 and LC3 recruitment to the mitochondria,a critical step in damaged mitochondrial degradation.Thus,AjCHDH interference led to a significant increase in both mitochondrial and intracellular ROS,followed by increased apoptosis and decreased coelomocyte survival.Collectively,these findings indicate that AjCHDH-mediated mitophagy plays a crucial role in coelomocyte survival in A.japonicus following V.splendidus infection.展开更多
基金supported by the National Natural Science Foundation of China(No.31672657).
文摘Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood.In this study,treatment groups set as 1%(about 0.63g),3%,and 7%of total body weight(named F1,F3 and F7 groups respectively).The potential molecular mechanisms behind the functions of respiratory tree and body wall were investigated by RNA-Seq.A total of 52411 expressed genes were identified from 89342 expressed transcripts.The results showed 759,254 and 334 genes were up-regulated,and 334,445 and 992 genes were down-regulated in respiratory tree of F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Meanwhile,2070,1601 and 896 genes were up-regulated,and 1303,1337 and 1144 genes were down-regulated in body wall between F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Differentially expressed genes were enriched in salivary secretion and ECM-receptor interaction pathways in respiratory tree,and in various types of N-glycan biosynthesis,ribosome and sphingolipid metabolism pathways in body wall.These results suggested respiratory tree and body wall were involved in activation of respiratory metabolisms in response to different feeding rations.Our research provided valuable knowledge for physiological differences in res-piratory metabolism.
基金The National Natural Science Foundation of China under contract Nos 42276143 and 31902360the Shandong Provincial Natural Science Foundation under contract Nos ZR2022MC050 and ZR2022QD003the“First Class Fishery Discipline”Programme[(2020)3]in Shandong Province。
文摘The sea cucumber Apostichopus japonicus plays important roles in marine benthic ecosystem as environmental cleaners,and it is the important aquaculture species in China.High water temperature poses critical threat for the survival of A.japonicus,which has resulted in extensive death in summer.To explore the genes expression profiles under different levels of heat stress,the high-throughput RNA-seq was applied in this study.Our results revealed a total of 1371,1225 and 1408 differentially expressed genes(DEGs)in 26℃for 6 h,26℃for 48 h and 30℃for 6 h respectively in comparison with Control group.The pathway analysis suggested“Protein processing in endoplasmic reticulum(ER)”was significantly enriched in all these heat stress(HS)treatment groups.The expression results of key DEGs in this pathway(Hsp70,Derlin,NEF,PDI,GPR94 and ERP57)by qRT-PCR was in accordance with the RNA-seq data.The subcluster analysis of DEGs revealed that a variety of heat shock proteins(HSPs)and calcium ion binding proteins had an obvious up-regulated expression in 26℃for 6 h,comparatively low expression in 26℃for 48 h,and the highest expression in 30℃for 6 h.The other DEGs subcluster,consisting of critical components of extracellular matrix(ECM)and a subset of peptidases and proteases,showed significantly rising tendency in 30℃for 6 h.Additionally,the expression of matrix metalloproteases(MMP1,MMP16 and MMP19)was prominently affected by HS,and peaked in 30℃for 6 h.This study provides a series of candidate genes for further study about heat shock response in A.japonicus,especially genes associated with protein processing in ER and regulation of ECM,which also offers new insights into cellular homeostasis under stressful conditions in marine invertebrates.
基金supported by the National Natural Science Foundation of China (32102825)Natural Science Foundation of Zhejiang Province (LQ22C190003)。
文摘Previous studies have shown that Vibrio splendidus infection causes mitochondrial damage in Apostichopus japonicus coelomocytes,leading to the production of excessive reactive oxygen species(ROS)and irreversible apoptotic cell death.Emerging evidence suggests that mitochondrial autophagy(mitophagy)is the most effective method for eliminating damaged mitochondria and ROS,with choline dehydrogenase(CHDH)identified as a novel mitophagy receptor that can recognize non-ubiquitin damage signals and microtubule-associated protein 1 light chain 3(LC3)in vertebrates.However,the functional role of CHDH in invertebrates is largely unknown.In this study,we observed a significant increase in the mRNA and protein expression levels of A.japonicus CHDH(AjCHDH)in response to V.splendidus infection and lipopolysaccharide(LPS)challenge,consistent with changes in mitophagy under the same conditions.Notably,AjCHDH was localized to the mitochondria rather than the cytosol following V.splendidus infection.Moreover,AjCHDH knockdown using si RNA transfection significantly reduced mitophagy levels,as observed through transmission electron microscopy and confocal microscopy.Further investigation into the molecular mechanisms underlying CHDH-regulated mitophagy showed that AjCHDH lacked an LC3-interacting region(LIR)for direct binding to LC3 but possessed a FB1 structural domain that binds to SQSTM1.The interaction between AjCHDH and SQSTM1 was further confirmed by immunoprecipitation analysis.Furthermore,laser confocal microscopy indicated that SQSTM1 and LC3 were recruited by AjCHDH in coelomocytes and HEK293T cells.In contrast,AjCHDH interference hindered SQSTM1 and LC3 recruitment to the mitochondria,a critical step in damaged mitochondrial degradation.Thus,AjCHDH interference led to a significant increase in both mitochondrial and intracellular ROS,followed by increased apoptosis and decreased coelomocyte survival.Collectively,these findings indicate that AjCHDH-mediated mitophagy plays a crucial role in coelomocyte survival in A.japonicus following V.splendidus infection.
