Fig. 6: APOO regulated the saturation of fatty acyl chains of phosphatidylcholine (PC), which was correlated with cholesterol levels.

A–D Eight-week-old Apoo^−/− and Apoo^+/+ mice were randomly grouped and fed an HFD diet for 12 weeks, liver lipidomics were performed for lipid composition analysis (n = 8). A Global abundance of LPS, MGDG, CerG1, PG, Co, PS, SM, PE, DG, TG, and PC revealed by lipidomics, B)analysis of fatty acyl composition of PC by the total degree of unsaturation, C, D correlation levels between the selected lipid species that were analyzed and blood TC or LDL-C levels. E The proteome of livers from male HFD-fed Apoo^+/+ and Apoo^−/− mice (n = 3) were performed. Heatmap of the abundance profile of proteins related to mitochondrial function was shown. F Representative TEM images of the mitochondrion in male NCD-fed Apoo^+/+ and Apoo^−/− mice. Quantification represents numbers of CJs in one hundred arbitrarily chosen mitochondria per group. G Oxygen consumption rate (OCR) determined by XFe96 Seahorse in hepatocytes from Apoo^−/− and Apoo^+/+ mice. Measures of mitochondrial respiration were calculated from the OCR trace. H Volcano plot of cholesterol metabolism-related proteins of E. I Summary of the pathways regulating bile acid metabolism of (E); green arrows indicate downregulated proteins, while red arrows indicate upregulated proteins. LDLR low-density lipoprotein receptor, SR-BI scavenger receptor class B type I, CYP7A1 cytochrome P450 family 7 subfamily A member 1, UGT1A2 UDP-glucuronosyltransferase family 1, CA2 carbonic anhydrase 2, SLCO1A1 solute carrier organic anion transporter family member 1A1; SLCO1A4: Solute carrier organic anion transporter family member 1A4; HDL high-density lipoprotein; BA bile acid. J Significantly upregulated pathway enriched in differentially expressed proteins of (E). Values are represented as mean ± SEM. Unpaired two-tailed Student’s t-test (A, B), or Mann–Whitney test (F) or two-way ANOVA (G). *p < 0.05, **p < 0.01, ***p < 0.001. LPS lysophosphatidylserine, MGDG monogalactosyldiacylglycerol, CerG1 glucocerebroside, PG phosphatidylglycerol, Co coenzyme, PS phosphatidylserine; PE phosphatidylethanolamine. DG diglycerides, TG triglyceride, PC phosphatidylcholine, PL phospholipid; TM6SF2 transmembrane 6 superfamily member 2; FDPS farnesyl pyrophosphate synthase; NSDHL sterol-4-alpha-carboxylate 3-dehydrogenase, decarboxylating, LSS lanosterol synthase; DHCR7 7-dehydrocholesterol reductase, cAV1 Caveolin-1, ACLY ATP-citrate synthase.