Fig. 4

Healthy visceral WAT expansion in obesity depends on mural Pparg expression. a Pdgfrb^rtTA; TRE-Cre; Pparg^loxP/loxP (Mural-Pparg^KO) mice are generated by breeding the Pdgfrb^rtTA transgenic mice to animals expressing Cre recombinase under the control of the tet-reponse element (TRE-Cre) and carrying floxed Pparg alleles (Pparg^loxP/loxP). Littermates carrying only Pdgfrb^rtTA and Pparg^−loxP/loxP alleles (i.e. Cre⁻) were used as the control animals. b Control and Mural-Pparg^KO mice were fed a standard chow diet until 8 weeks of age before being switched to dox-containing HFD for another 20 weeks. Body weights were measured weekly. Control-HFD, n = 14; Mural-Pparg^KO-HFD, n = 13. Data points represent mean + s.e.m. c Fat mass and lean mass (normalized to body weight) of control and Mural-Pparg^KO mice after 20 weeks of dox-diet feeding. n = 7 per genotype. Bars represent mean + s.e.m. d Fat pad weight (normalized to body weight) of control and Mural-Pparγ^KO mice after 20 weeks of dox-HFD feeding. * denotes p < 0.05 from Student’s t-test. Control-HFD, n = 14; Mural-Pparg^KO-HFD, n = 13. Bars represent mean + s.e.m. e–h Representative immunofluorescence staining of Perilipin (green) and Mac-2 (red) in e, f gonadal and g, h perirenal WAT paraffin sections obtained from control and Mural-Pparg^KO mice after 20 weeks of dox-diet feeding. Scale bar, 200 μm. i–l Representative trichrome staining of i, j gonadal and k, l perirenal WAT paraffin sections obtained from control and Mural-Pparg^KO mice after 20 weeks of dox-diet feeding. Scale bar, 200 μm. m Number of crown-like structures (Mac-2 positive) in the indicated depots obtained from control and Mural-Pparg^KO mice after 20 weeks of dox-HFD feeding. * denotes p < 0.05 from Welch’s t-test. n = 24 randomly chosen ×10 magnification fields from six individual animals. Bars represent mean + s.e.m. n Average adipocyte size in indicated fat depots from control and Mural-Pparg^KO mice after 20 weeks of dox-HFD feeding. * denotes p < 0.05 from Student’s t-test. Control-HFD, n = 8; Mural-Pparg^KO -HFD, n = 7. Bars represent mean + s.e.m. o, p Relative mRNA levels of indicted genes in o gonadal and p perirenal WAT obtained from control and Mural-Pparg^KO mice after 20 weeks of dox-chow diet feeding. * denotes p < 0.05 from Welch’s t-test. n = 6 per genotype. Bars represent mean + s.e.m.