Fig. 4: Ablation of hepatic Xbp1 causes a lipidome-wide impairment in the phosphatidylcholine (PC)-lysophosphatidylcholine (LPC) cycle pathway.
From: XBP1 links the 12-hour clock to NAFLD and regulation of membrane fluidity and lipid homeostasis
a The overall heatmap of the essential metabolites and lipid species in the indicated mouse livers at 15- and 30 weeks of age by the standard AbsoluteIDQ p180-based targeted metabolomics of whole liver extracts (left panel). The indicated PC and LPC cycle lipid species (right panel) were identified as the top impaired cluster in the AlbCre;Xbp1flx/flx mouse livers (n = 4 per age/group). b–e Univariate analysis identified lysoPC a C16:0 and lysoPC a C16:1 as the two most important features in the AlbCre;Xbp1flx/flx mouse livers of the two indicated age groups (n = 4 per age/group). One-way ANOVA was performed in (b) to tell the important features with p value threshold 0.05 indicated as the dotted horizontal line, followed by post hoc Fisher’s least significant difference method (Fisher’s LSD). Individual box plots for the two indicated lysoPC features in the two age groups were shown in (c) and (d) (the y axis represents the average normalized levels). The bar plots show the normalized values (mean ± SEM). The boxes range from 25 and 75% percentiles; the 5 and 95% percentiles are indicated as error bars. Medians are indicated by horizontal lines within each box. Significant features identified by the discriminant analysis (sPLS-DA) are shown in (e) (the x axis represents the absolute loading values of the ranking features). f, g Top metabolites and lipid species correlated with the two most important features in the AlbCre;Xbp1flx/flx mouse livers, lysoPC a C16:0 (f), and lysoPC a C16:1 (g).
