Genes distinctly expressed in WAT depots may impart depot-dependent physiological functions.
Here, we report that newborn mice lacking PRLR have hypotrophic BAT depots that express low levels of adipocyte nuclear receptor PPARγ2, its coactivator PGC-1α, uncoupling protein 1 (UCP1) and the β3 adrenoceptor, reducing mouse viability during cold challenge.
Potential regulators of adipogenesis include microRNAs (miRNAs), small non-coding RNAs that have been recently shown related to adiposity and differentially expressed in fat depots.
In comparison, heart as well as gonadal, retroperitoneal, omental and inguinal white adipose tissue depots expressed barely detectable levels of DLK (Fig. 1 A).
Increased body weight and food intake were associated with a trend towards increased mass of dissected white adipose tissue depots (expressed as a percent of body weight) upon completion of the study at 38 days after rAAV injection.
To examine the effect of Y2 receptor deletion per se, independent of the effect of Dox, the weights of dissected WAT depots (expressed as a percent of body weight) in NPYCre/+ Y2−/− mice were normalised to corresponding values of Dox-injected wild type mice, and the results were compared to that of saline-injected NPYCre/+ Y2lox/lox mice relative to saline-injected wild type mice.
Of these 1344 and 1246 genes, 103 and 87 respectively had also been identified in the study of Tchkonia et al, which identified 920 transcripts to be differently expressed across fat depots in either differentiated or undifferentiated cells (overrepresentation p-values: 2.5 × 10-7 for SAT and 8.7 × 10-5 for VAT, Fisher's exact test assuming that 20,000 unique genes were tested in total).
There is also evidence that adipose tissue isolated from specific fat depots, such as visceral fat, may express higher levels of inflammatory markers such as IL-6 (7), MCP-1 (8), and plasminogen activator inhibitor type 1 (PAI-1) (9).
Normalized adipose volumes for each individual depot were expressed as percent of the total fat.
Although there are differences in the expression/production/secretion of the adipokines between subcutaneous and visceral adipose tissue, they are expressed in both fat depots altered production and/or release from either fat depot can lead to altered circulating adipokine levels and impaired insulin action in peripheral tissues (primarily muscle).
Here we demonstrated that PPARγ1 is preferentially expressed in catabolic fat depots while PPARγ2 presents itself at a higher level in browning-resistant depots.
