[The mechanism of SSO regulating SiO(2)-induced lipid metabolism disorders in macrophages was explored based on lipid metabolomics].

Objective: To investigate the mechanism of Sulfo-N-succinimidyloleate (SSO) regulating lipid metabolism disorder induced by silicon dioxide (SiO(2)) . Methods: In March 2023, Rat alveolar macrophages NR8383 were cultured in vitro and randomly divided into control group (C), SSO exposure group (SSO), SiO(2) exposure group (SiO(2)) and SiO(2)+SSO exposure group (SiO(2)+SSO). NR8383 cells were exposure separately or jointly by SSO and SiO(2) for 36 h to construct cell models. Immunofluorescence and BODIPY 493/ 503 staining were used to detect cluster of differentiation (CD36) and intracellular lipid levels, the protein expression levels of CD36, liver X receptors (LXR), P-mammalian target of rapamycin (P-mTOR) and cholinephosphotransferase 1 (CHPT1) were detected by Western blot, respectively, and lipid metabolomics was used to screen for different lipid metabolites and enrichment pathways. Single-factor ANOVA was used for multi-group comparison, and LSD test was used for pair-to-group comparison. Results: SiO(2) caused the expression of CD36 and P-mTOR to increase ( P =0.012, 0.020), the expression of LXR to decrease ( P =0.005), and the intracellular lipid level to increase. After SSO treatment, CD36 expression decreased ( P =0.023) and LXR expression increased ( P =0.000) in SiO(2)+SSO exposure group compared with SiO(2) exposure group. Metabolomics identified 87 different metabolites in the C group and SiO(2) exposure group, 19 different metabolites in the SiO(2) exposure group and SiO(2)+SSO group, and 5 overlaps of different metabolites in the two comparison groups, they are PS (22∶1/14∶0), DG (O-16∶0/18∶0/0∶0), PGP (i-13∶0/i-20∶0), PC (18∶3/16∶0), and Sphinganine. In addition, the differential metabolites of the two comparison groups were mainly concentrated in the glycerophospholipid metabolism and sphingolipid metabolism pathways. The differential gene CHPT1 in glycerophospholipid metabolic pathway was verified, and the expression of CHPT1 decreased after SiO(2) exposure. Conclusion: SSO may improve SiO(2)-induced lipid metabolism disorders by regulating PS (22∶1/14∶0), DG (O-16∶0/18∶0/0∶0), PGP (i-13∶0/i-20∶0), PC (18∶3/16∶0), SPA, glycerophospholipid metabolism and sphingolipid metabolism pathways.