title: Wt1, the mesothelium and the origins and heterogeneity of visceral fat progenitors.
abstract: One major gap in adipocyte biology has been a lack of understanding of the developmental origins of the different visceral white adipose tissue (WAT) depots and subcutaneous WAT. In a recent study we showed that most visceral WAT but no subcutaneous WAT arises from cells expressing the Wilms' tumor 1 (Wt1) gene late in mouse gestation.(1) Wt1 continues to be expressed in visceral WAT progenitors into adult life. We also showed that visceral WAT is lined by a mesothelium and provided evidence that this structure is the source of adipocytes. Our study also adds to the growing body of evidence that there is heterogeneity in the visceral progenitors, such that there are Wt1-expressing and non-expressing subsets, the relative proportions of which vary between depots. This raises the enticing prospect that the adipocytes arising from these progenitor subsets may have different properties and our preliminary data support this notion. Finally, evidence from our study and one from Spiegelman's group(2) suggests that Wt1 is not just a marker but regulates visceral WAT identity and the progenitor population. We discuss the implications of this work and some of the questions and future directions that arise from it.
authors.affiliation: Medical Research Council Human Genetics Unit; Institute of Genetics and Molecular Medicine at the University of Edinburgh; Western General Hospital ; Edinburgh, UK.
authors.forename: You-Ying
authors.initials: YY
authors.lastname: Chau
authors.affiliation: Medical Research Council Human Genetics Unit; Institute of Genetics and Molecular Medicine at the University of Edinburgh; Western General Hospital ; Edinburgh, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Hastie
keywords: Wt1; adipocytes; adipose progenitors; developmental origins of visceral white adipose tissue; lineage tracing; mesothelium; mouse model; subcutaneous and visceral adipose tissue