Highly selective in vivo labeling of subcutaneous white adipocyte precursors with Prx1-Cre.
Bottom Line: Here, we show that the majority of the precursor and mature subcutaneous white adipocytes in adult C57Bl/6 mice are labeled by Prx1-Cre.In sharp contrast, few to no brown adipocytes or visceral white adipocytes are marked by Prx1-Cre.This suggests that Prx1-Cre-mediated recombination may be useful for making depot-restricted genetic manipulations in subcutaneous white adipocyte precursor cells, particularly when targeting genes with fat-specific functions.
Affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.Show MeSH
Mentions: To gauge the potential utility of using Prx1-Cre to selectively target subcutaneous white adipocytes, we compared the mRNA expression of mGFP between adipose tissues and non-adipose tissues as a measure of past or present Prx1-Cre recombinase activity. Consistent with the imaging results, mGFP reporter expression among the fat depots is highest in psWAT, with only asWAT and paBAT, as predicted, showing significantly higher expression above background (Figure 4A). Among skeletal muscles, the level of mGFP expression is generally low (Figure 4A); mGFP reporter fluorescence was not detectable in any mature muscle fibers in the quadriceps or gastrocnemius muscles by our direct imaging strategy (Figure 4B). Slightly higher than baseline levels of mGFP expression were detected in lung and brain tissue, indicating a few cells in these tissues might also be marked by Prx1-Cre. Notably, we did not detect significant Cre mRNA expression in any whole fat depot (not shown), suggesting that Prx1-Cre recombinase activity may be active in only a small number of cells or that it was active before 6 weeks of age. We verified fat depot identity by analyzing Ucp1 and Perilipin1 mRNA expression. Ucp1 most highly expresses in BAT depots with only a very low level of expression in asWAT and psWAT and little if any in the visceral WAT (Figure S2A). Perilipin1 highly expresses in all of the fat depots (Figure S2B).
Affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.