TMEM88 Regμlates The Secretion Of Inflammatory Factors In Drug-induced Liver Injury Through Mediated Autophagy

Objective: Drug induced liver injury(DILI)refers to liver injury caused by an allergic reaction to the drug itself or its metabolites during drug use.Studies have shown that acetaminophen(APAP)is metabolized in the liver by cytochrome P450 enzyme2E1(CYP2EI)to an iminoquinone toxic metabolite(NAPQI),which can be inactivated or detoxified by binding to glutathione(GSH)in cells.However,when APAP is overdosed or in patients sensitive to it,excess NAPQI is produced in hepatocytes after depletion of glutathione in the body and binds to cysteine groups in hepatocyte proteins to form the toxic adduct APAP-protein adduct(APAP-AD),which causes abnormal mitochondrial function and leads to hepatocyte necrosis.IntracellμLar components released from hepatocytes include nuclear DNA,mitochondrial DNA and proteins that can act as relevant molecμLar patterns(DAMPs)and activate the formation of inflammatory vesicle complexes in various cells(e.g.Kupffer cells),thereby causing the release of pro-inflammatory cytokines.Transmembrane proteins(TMEM)are proteins that span biological membranes.The functions of the TMEM family collection are mostly unknown proteins.TMEM88 may be localized to the cytoplasm or plasma membrane.There is limited understanding of TMEM88 expression,subcellμLar localization and potential molecμLar mechanisms,and its potential applications are gradually gaining attention.The resμLts of our group’s previous study showed that TMEM88 coμLd promote alcohol-induced inflammatory factors in macrophages and regμLate the secretion of lipid anabolic cytokines in non-alcoholic fatty liver,demonstrating that TMEM88 woμLd play a regμLatory role in the development of liver diseases,whether TMEM88 has a regμLatory role in drug-induced liver injury has not been focused on.In this study,we investigated the effect of TMEM88 on inflammatory cytokine secretion in hepatocytes in AILI and inflammatory factor secretion in APAPinduced AML-12 cells,in addition to the function of autophagy in APAP-induced AML-12 cells.Methods: In vivo,the localization of TMEM88 in mouse AILI hepatocytes was examined after the construction of a mouse model of drug-induced liver injury(AILI)using 400 mg/kg APAP,followed by the detection of TMEM88 expression in AILI by tail vein injection into C57BL/6J mice with silencing effect of TMEM88 adenoassociated virus(AAV-TMEM88)and its control by tail vein injection into C57BL/6J mice.The expression of TMEM88 in AILI was subsequently examined.In vitro,mouse hepatocytes(AML-12)were induced with 20 mmol/L APAP.p EGFP-C1-TMEM88 and TMEM88 si RNA were used to overexpress and silence TMEM88,respectively,and the expression levels of IL-22,IL-1β and TNF-α were detected by Western blotting and RT-q PCR,respectively.The effect of TMEM88 on APAP-induced apoptosis of AML-12 cells was detected by flow-through;Electron microscopic observation of AML-12 cell morphology,mitochondrial structure and the nμmber of autophagic vesicles after APAP induction in AML-12 cells,and finally the specific regμLatory mechanism of TMEM88 on AILI was observed.ResμLts: This study found elevated expression of TMEM88 in APAP-induced drug-induced liver injury,and over expression of TMEM88 led to upregμLation of IL-22,IL-1β and TNF-α secretion,suggesting that TMEM88 may be associated with the onset,development and end of inflammation.In addition,silencing of TMEM88 also attenuated the expression levels of IL-22,IL-1β and TNF-α in AML-12 cells,which was detrimental to the regeneration of injured hepatocytes.Finally,we demonstrated that TMEM88 may be involved in the AILI process by regμLating the level of hepatocyte autophagy in AILI and subsequently affecting the secretion of inflammatory factors.Conclusions: These experimental resμLts suggest that TMEM88 may play a regμLatory role by regμLating APAP-induced secretion of inflammatory factors in AML-12 cells through the autophagic pathway.