Figure 7. SEL1L deficiency induces FGF21 secretion from skeletal muscle.

(A) Gene set enrichment analysis (GSEA) of upregulated pathways in female 8-week-old gastrocnemius muscle (n = 3 mice per genotype). (B) Volcano plot of transcriptomics data from 8-week-old gastrocnemius muscle (n = 3 mice per genotype). (C) qPCR analysis of Ffg21 in the gastrocnemius muscle of 4- to 8-week-old female mice (n = 6 mice per genotype). (D) Western blot of FGF21 in the gastrocnemius muscle and liver from mice under ad libitum conditions (n = 3 mice per genotype). (E) Western blot of FGF21 in the gastrocnemius muscle from mice under ad libitum conditions at 4, 8, and 12 weeks (n = 2 mice per genotype/time point). (F) Blood serum levels of FGF21 in adult male and female mice under ad libitum feeding conditions and serum FGF21 levels in WT animals starved for 24 hours (n = 3–8 mice per genotype). (G) Representative H&E staining of brown adipose tissue (BAT, top) and inguinal white adipose tissue (iWAT, bottom) from male 12-week-old Sel1L^fl/fl and Sel1L^MLC mice (n = 4 per genotype). (H) Western blot of UCP1 in BAT and iWAT from 12-week-old male mice (n = 3 mice per genotype). Data presented as mean ± SEM. **P < 0.01; ***P < 0.001; ****P < 0.0001 determined by 2-tailed, unpaired t test (C and F).