N2L,a novel lipoic acid-niacin dimer,attenu⁃ates ferroptosis and decreases lipid peroxida⁃tion in HT22 cells

摘要

OBJECTIVE N2L is a novel lipoic acid-niacin dimer regulating lipid metabolism with multifunction,including antioxidant effect.We investigated the protective effect of N2L and the underlying mechanisms under the ferroptosis inducer RAS-selective lethality 3(RSL3)treat⁃ment in HT22 cells.METHODS HT22 cells were pretreated with N2L and then were treated with RSL3 to establish a ferroptosis cell model.MTT assay was used to detect the cell survival rate.Free radical probe(dihydroethidium,DHE)and ferrous probe FerroOrange were used to detect the contents of free radicals and ferrous ions in cells.The ultrastructure of mitochondria of treat⁃ed cells was observed by transmission electron microscope.The expression of ferroptosis-relat⁃ed proteins acyl-CoA synthetase long-chain family member 4(ACSL4),glutathione peroxidase 4(GPX4),cyclooxygenase-2(COX-2),ferritin Heavy Chain 1(FTH1),nuclear factor E2-related factor 2/heme oxygenase-1,and phosphoryla⁃tion levels of the c-Jun N-terminal kinase(JNK)/extracellular regulated protein kinases(ERK)pathway were detected by Western blotting.RE⁃SULTS RSL3 decreased the cell viability and induced excessive accumulation of(reactive oxy⁃gen species)ROS in HT22 cells.N2L pretreat⁃ment effectively protected HT22 cells against lipid peroxidation.What′s more,N2L recovered GPX4 protein expression and blocked the increase of COX-2 and ACSL4 expressions.Moreover,N2L also significantly prevented FTH1 from downregulation and maintained iron homeo⁃stasis.Finally,N2L pretreatment could decrease JNK/ERK activation induced by RSL3.CON⁃CLUSION N2L is an excellent ferroptosis inhibi⁃tor,and its anti-ferroptosis mechanism may be related to the reduction of lipid peroxidation and the regulation of iron homeostasis.