Characterization of Cre recombinase activity for in vivo targeting of adipocyte precursor cells.
Bottom Line: In particular, Fabp4-Cre is not effective to target APCs, nor is its activity restricted to these cells.PdgfRα-Cre directs recombination in the vast majority of APCs, but also targets other populations.In contrast, adipose expression of Prx1-Cre is chiefly limited to subcutaneous inguinal APCs, which will be valuable for dissection of APC functions among adipose depots.
Affiliation: Department of Pediatrics/Endocrinology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.Show MeSH
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Mentions: Prx1-Cre directs expression to the embryonic limb bud mesenchyme, flank mesoderm, and a subset of the cranial mesenchyme (Logan et al., 2002), as well as to uncommitted mesenchymal progenitors of several other tissues (Calo et al., 2010). Therefore, it was expected that recombination would be observed in many SVF cells of all adipose depots. However, in striking contrast to the other Cre lines examined, adipose Prx1-Cre activity is mostly restricted to iWAT APCs: we observed recombination in >82% of APCs in both males and females (Figures 4A and 4B). Intriguingly, modest recombination is observed in gWAT APCs of female mice (∼18%), as well as in SCA1−CD31− cells of either depot (14%–22%) (Figure 4B), but is absent in males (Figure 4A). Neither sex displays significant recombination in any BAT SVF cell type (Figures 4A and 4B). Thus, Prx1-Cre has unexpected specificity for APCs, and this is particularly evident in male mice. As expected, examination of cultured iWAT SVF or BMSCs revealed a strikingly high percentage of recombination, both prior to and after adipogenic induction (Figure 4C), which is consistent with previous data showing recombination in limb bud mesenchyme (Logan et al., 2002).
Affiliation: Department of Pediatrics/Endocrinology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.