Fig 1: Circulating parvalbumin suppresses M2 macrophage polarization in mice.a Parvalbumin protein expression in muscle and serum from WT and parvalbumin KO mice. b Representative M2 macrophage marker gene expression in scWAT and BAT of WT and parvalbumin KO mice. WT, n = 10; PVALB KO, n = 10. c Representative flow cytometry plots and (d) quantification demonstrate the numbers of M2 macrophages (CD206+/CD11C-) in the scWAT of WT and parvalbumin KO mice. WT, n = 13; PVALB KO, n = 13. e Male parvalbumin KO mice were intravenously injected with Ad-parvalbumin or Ad-GFP through the tail vein. Parvalbumin protein expression in the liver and serum were examined. f Representative M2 macrophage marker gene expression in scWAT and BAT of parvalbumin KO mice injected with Ad-GFP or Ad-parvalbumin. Adv-GFP, n = 8; adv-PVALB, n = 8. g Representative flow cytometry plots and (h) quantification demonstrate the numbers of M2 macrophages (CD206+/CD11C-) in the scWAT of parvalbumin KO mice injected with Ad-GFP and Ad-parvalbumin. Adv-GFP, n = 14; Ad-parvalbumin, n = 14. i Macrophage parvalbumin deficiency had no effect on M2 activation. Cd301, Cd206, and Tgm2 mRNA expression in WT and parvalbumin KO BMDM treated with IL4 and parvalbumin (100 ng/ml) (n = 3 per group). Data are represented as mean ± SEM. P values were determined by unpaired two-tailed Student’s t test (b, d, f, h, and i). Source data are provided as a Source Data file.