Fig. 1: Generation and characterization of a mouse strain that lacks fortilin in macrophages (MФ, fortilin^KO-MФ).

LysM myeloid specific promoter, MФ macrophages, fortilin^WT-MΦ, LysM-Cre^–/–fortilin^fl/fl; fortilin^KO-MΦ, LysM-Cre^+/–fortilin^fl/fl, A.U. arbitrary unit, IB immunoblot, GAPDH glceraldehyde-3-phosphate dehydrogenase, α-GAPDH anti-GAPDH antibody, α-fortilin, anti-fortilin antibody, WT fortilin^WT-MФ, KO fortilin^KO-MФ, M.S. median survival, HC hypercholesterolemic, NC normal chow, LDL-C low density lipoprotein cholesterol, HDL-C high density lipoprotein cholesterol, VLDL-C very low density lipoprotein cholesterol. a Schematic diagram of the strategy of generating fortilin^WT-MФ and fortilin^KO-MФ mice. We first generated fortilin^flox/flox mice in which the fortilin gene was flanked by the LoxP sequence to allow tissue-specific deletion using the standard homologous recombination technique (a-1). These mice were then crossed with C57BL/6 J mice overexpressing the Cre transgene under the control of the LysM enhancer/promoter (a-2a) to generate LysM-Cre^+/–fortilin^flox/flox mice (fortilin^KO-MΦ mice), which is a mouse strain lacking fortilin in MΦ and other myeloid-lineage cells (a-3a) but not in other tissues (a-3b). Control mice (LysM-Cre^–/–fortilin^flox/flox mice or fortilin^WT-MΦ mice) were generated by crossing fortilin^flox/flox mice with C57BL/6 J mice lacking the Cre gene (a-2b). b RT-qPCR quantification of fortilin mRNA of peritoneal MФ from fortilin^WT-MФ and fortilin^KO-MФ mice. c Western blot analyses of tissues samples from fortilin^WT-MФ and fortilin^KO-MФ mice. d Survival analysis of fortilin^WT-MФ and fortilin^KO-MФ mice. e Placement of fortilin^KO-MФ and fortilin^WT-MФ on the HC genetic background. f Identification of fortilin^WT-MФ-HC (lanes 1–3) and fortilin^KO-MФ-HC (lanes 4–7) mice by PCR-based genotyping. Lane 8 shows the PCR results for DNA from LysM-Cre^–/–fortilin^flox/floxLdlr^+/+Apobec1^+/+ mouse. g Body weight of fortilin^WT-MФ-HC and fortilin^KO-MФ-HC mice at the time of sacrifice (10-months of age). h–l Lipid profile of fortilin^WT-MФ-HC and fortilin^KO-MФ-HC mice at the time of sacrifice. Data are mean ± s.d., P values determined by two-sided Student’s t test (b, g–l) are shown. The findings in (c) were confirmed in two independent experiments.