Key Role of STAT4 Deficiency in the Hematopoietic Compartment in Insulin Resistance and Adipose Tissue Inflammation

Figure 2

Adipose tissue morphometry and inflammation in STAT4 chimeras after 15 weeks on HFD. Adipocyte size distribution (a) and adipose tissue morphometry (b) were performed in 4 mice/group. Adipose tissue of STAT4−/− recipients displayed higher percentage of large adipocytes, increased average adipocyte size, and lower cellularity. Representative micrographs of epididymal adipose tissue sections are shown in (c). DNA was extracted from adipose tissue and amplified with specific primers to determine STAT4 positivity. Note that STAT4 is present in adipose tissue of both chimeras indicating significant infiltration of STAT4+/+ hematopoietic cells in the STAT4−/− recipients; histogram represents percentage of the donor cell genotype signal out of the total signal determined by densitometry of respective bands in agarose gels (d). Representative immunofluorescence pictures of the Mac-2 positive crown-like structures (e); morphometric analysis (f) was performed in mice/group. The number of crown-like structures is significantly correlated with adipocyte size ( mice). Gene array containing a panel of 72 genes involved in inflammation was performed in STAT4−/− and STAT4+/+ recipients (/group) (g). Histogram shows the three significantly increased genes in STAT4−/− recipients. Data represents average ± SD and the null hypothesis was rejected for . .

(a)

(b)

(c)

(d)

(e)

(f)

(g)