Studies On Liver Regional Immunomodulation Mechanisms Of Mitochondrial Cyclooxygenase 2 Regulatory Pathways Mediated Hepatocarcinogenesis And Its Targeted Intervention

Exposure to environmental factors induces the occurrence and development of hepatocellular carcinoma(HCC)via the regional immune microenvironment(RIME)of the liver,such as the prevention and control of HCC related to hepatitis B virus(HBV)infection,which has become an important public health problem in the world.Mitochondrial quality control(MQC)is involved in the biological processes that affect glucose and lipid metabolism,regulatory cell death(RCD),and immune-inflammatory response in liver RIME.Cyclooxygenase-2(COX-2)is an important regulator of inflammation induced by exposure to carcinogens.The organelle distribution of COX-2 plays an important role in RCD regulation.However,the molecular mechanism of mitochondrial COX-2(mito-COX-2)regulating RIME remodeling and mediating the occurrence and development of HCC remains to be elucidated.Therefore,in this study,long non-coding RNA(LncRNA)omics and molecular biology methods of exosomes(Exos)were used in HBx transgenic(HBx-Tg)mice,ex vivo and in vitro test models.To explore protein phosphatase 2A(PP2A)regulating mitochondrial dynamin-related protein 1(Drp1)dephosphorylation,influences the phenotype of HCC cells by interaction with mito-COX-2,and the molecular mechanism of mito-COX-2 mediated macrophage inflammation via Exos.Firstly,by studying the mechanism of PP2A-B56γ(B56γ)regulating the mitochondriallysosomal communication in HCC cells.It was found that Drpl-mediated mitochondrial fission promotes mitophagy.It was clarified that B56γ regulates p-Drp1Ser616 dephosphorylation and inhibits p-Drp1Ser616 interacting with ras-related protein 7(Rab7)to mediate mitochondrial-lysosomal communication-dependent mitophagy flux.It was revealed that targeted intervention of B56γ regulates p-Drp1Ser616 dephosphorylation and inhibits HCC cells growth.Secondly,the mitochondrial dynamics mechanism study of mito-COX-2 and p-Drp1Ser616 interaction regulating HCC occurrence was carried out.It was found that the expression of COX-2 and Drpl in HCC tumor tissues were up-regulated and positively correlated,and the co-localization distribution in HCC cells was enhanced,which was related to poor prognosis.It was clarified that COX-2 in HCC cells is translocated to mitochondria,mediates mitochondrial fission via the interaction of mito-COX-2 and p-Drp1Ser616,and participates in the inhibition of mitochondrial-dependent apoptosis.It was revealed that sirtuin 3(SIRT3)-mediated mito-COX-2 deacetylation enhances the sensitivity of HCC cells to platinum drugs-induced chemotherapy via regulating mitochondrial-dependent apoptosis.Thirdly,mito-COX-2 regulation of hepatocyte-derived Exos LncRNA SNHG14(SNHG14)mediated epigenetic regulation of NLRP3 in macrophages,it is found that mito-COX-2 in liver RIME may be via exos release,which is hepatocyte lipid metabolism reprogrammingdependent,to induce macrophage activation and hepatocyte malignant phenotype.Establishing a methionine-choline deficient dietary exposure model of HBx-Tg mice and using Exos LncRNA omics,it was found that the level of specific SNHG14 in HBxexpressing hepatocytes Exos was up-regulated,which clarified that SNHG14 was sorted into hepatocyte-derived Exos through hnRNPA2B1 and passed by miR133b molecules sponge effect to promote NLRP3 inflammasome activation-dependent pyroptosis in macrophages via the competitive endogenous RNA(ceRNA)mechanism.It is revealed that the mito-COX-2 regulatory pathway mediated by SNHG14/miR133b/NLRP3 signaling axis in the combined targeting of liver RIME is involved in HBx-induced inflammation-cancer transformation.In summary,this study successfully constructed B56y targeted regulation,site-directed mutation simulating high and low phosphorylation of Drp1 functional site(Ser616),COX-2 mitochondrial targeted distribution,and targeted intervention(gene and pharmacology)in vivo and in vitro test models.It was clarified that B56γ regulates p-Drp1Ser616 dephosphorylation mediates mitophagy of HCC cells,participate in the deacetylation of SIRT3 to regulate the interaction of mito-COX-2 and p-Drp1Ser616,and enhances mito-COX-2 regulatory pathway mediates mitochondrial-dependent apoptosis-related anti-tumor effects.This study further used the Exos of HBx-Tg mice liver tissue to carry out LncRNA transcriptomics screening.It was revealed that the specific sorting effect of SNHG14 in the mito-COX-2 regulatory pathway entered Exos,and clarified the ceRNA mechanism of SNHG14-mediated miR133b/NLRP3 epigenetic regulation.Targeted intervention mito-COX2/SNHG14/miR133b/NLRP3 signal axis provides clues for the prevention and control of RIME related to inflammation-cancer transformation in liver.It provides a new idea to explore the biomarker screening and targeted intervention of mito-COX-2 and exosomal SNHG14-mediated exposure to environmental factor(such as HBV/HBx)induced hepatocarcinogenesis.