Fig. 2: BRD4-regulated Gdf3 induces inflammatory phenotype of ATM through SMAD2/3 signaling axis in the aged.
a–f, Old (23–24-month-old) female WT mice were intraperitoneally injected with JQ1 (12.5 mg kg−1) or vehicle and LPS (0.1 mg kg−1): vehicle-injected, n = 10; JQ1-injected, n = 11; a schematic of the experimental design (a); the Gdf3 expression in VAT (b); the frequency of CD11c+, CD206+ (c) and CCR2+ (d) ATMs in VAT; the inflammatory gene expression in VAT (e); and the mean core BT after LPS injection (f). g,h, The BMDMs isolated from old (24-month) female WT mice were treated with LPS (1 µg ml−1) 4 h before vehicle or JQ1 (1 µM) treatment: a schematic of the experimental design (g) and the Gdf3 and Il1b expression in BMDMs (h). i, The pSMAD2/3, total SMAD2/3 (tSMAD2/3) and β-actin by western blot of whole VAT from young (3-month-old) or old (24-month-old) female WT and GDF3 KO mice injected with 0.1 mg kg−1 LPS. The pSMAD2/3, tSMAD2/3 and β-actin were run on separate gels. j, The fibrotic gene expression in VAT from old control (n = 5) and old mKO (n = 5) male mice injected with 0.1 mg kg−1 LPS. The dotted line represents the young control. k, The quantification of pSMAD2/3 normalized to Ponceau S staining of SVF or adipocytes from young (3-month-old) and old (22-month-old) female WT mice injected with 0.1 mg kg−1 LPS (Extended Data Fig. 5a). l, The MFI of pSMAD2/3 in T cells, B cells and ATMs in VAT from old (24-month-old) female WT mice (n = 3). m, The pSMAD2/3 MFI in CD11c+ or CD11c− ATMs from young (4-month-old) and old (23-month-old) female WT mice. Young, n = 3; old, n = 8. n–p, The positively selected ATMs from VAT of old (24-month-old, n = 6) female WT mice were treated with vehicle or rGDF3 (20 ng ml−1) in vitro: a schematic of the experimental design (n), pSMAD2/3 MFI in CD11c+ or CD206+ ATMs (o) and the frequency of CD11c+ ATMs (p). All the data are presented as means ± s.e.m. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. See Extended Data Figs. 4 and 5 for more details. n.s., not significant.
