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
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Mentions: Using 6-week-old Prx1-Cre;R26R-mTmG male and female mice, we first asked whether mGFP reporter activity is detectable in the APCs of any depots. We fractionated the SVFs from the mature adipocytes in several depots and, from the SVF fractions, isolated CD31−;CD45−(Lin−);CD29+;CD34+;SCA1+ cells (Figure 1A), which are highly enriched for APCs (Rodeheffer et al., 2008; Sanchez-Gurmaches et al., 2012). In males, 12.5% of the APCs in asWAT are mGFP+, and similarly, the CD24+ and CD24− populations in this depot are 10.5% and 10.9% mGFP+, respectively, whereas no mGFP+ signal was detectable in the Lin+ pool (Figure 1B). In psWAT, the number of mGFP+ precursors is significantly greater, reaching nearly 75% in the APC, CD24+, and CD24− pools again with no mGFP+ signal detectable in the Lin+ pool (Figure 1C). Representative dot plots and distribution plots of the APC populations are shown in Figure S1. In contrast, few mGFP+ cells are detectable in male visceral WAT depots (rWAT and pgWAT) or BAT depots (iBAT and sBAT; Figures 1D–1G). In female mice, the Prx1-Cre labeling pattern in the subcutaneous WAT APC pool is similar to that in males: in asWAT, the mGFP+ population is slightly higher in the females at 21.4% and in psWAT nearly identical to the males at 75.8%, with the CD24+ and CD24− populations showing similar percentages in each depot and all Lin+ cells being tdTomato+ (Figures 1B and 1C). The labeling pattern in female mice is also largely similar to the males in visceral depots, except in pgWAT, in which a small percentage of APCs are mGFP+ (Figure 1E). Thus, in both genders, Prx1-Cre activates reporter gene expression in most white adipocyte progenitors in psWAT.
Affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.