WT1 in Adipose Tissue: From Development to Adult Physiology.

Karin M Kirschner,Holger Scholz

doi:10.3389/fcell.2022.854120

Abstract

Much of the fascination of the Wilms tumor protein (WT1) emanates from its unique roles in development and disease. Ubiquitous Wt1 deletion in adult mice causes multiple organ failure including a reduction of body fat. WT1 is expressed in fat cell progenitors in visceral white adipose tissue (WAT) but detected neither in energy storing subcutaneous WAT nor in heat producing brown adipose tissue (BAT). Our recent findings indicate that WT1 represses thermogenic genes and maintains the white adipose identity of visceral fat. Wt1 heterozygosity in mice is associated with molecular and morphological signs of browning including elevated levels of uncoupling protein 1 (UCP1) in epididymal WAT. Compared to their wild-type littermates, Wt1 heterozygous mice exhibit significantly improved whole-body glucose tolerance and alleviated hepatic steatosis under high-fat diet. Partial protection of heterozygous Wt1 knockout mice against metabolic dysfunction is presumably related to browning of their epididymal WAT. In the light of recent advancements, this article reviews the role of WT1 in the development of visceral WAT and its supposed function as a regulator of white adipose identity.

Highlights

Since the initial discovery that mice with homozygous disruption of the Wilms tumor gene 1 (Wt1) are embryonic lethal with a failure of kidney and gonad formation (Kreidberg et al, 1993), the knowledge of the role of the WT1 in development has steadily increased. (Hastie, 2017)
Visceral white adipose tissue (WAT) is a prime example for the complex role of WT1 reaching from embryogenesis to adulthood
Recent data suggest that WT1 is necessary for maintaining white adipose identity in visceral WAT. (Kirschner et al, 2022)

Summary

Introduction

Since the initial discovery that mice with homozygous disruption of the Wilms tumor gene 1 (Wt1) are embryonic lethal with a failure of kidney and gonad formation (Kreidberg et al, 1993), the knowledge of the role of the WT1 in development has steadily increased. (Hastie, 2017). Lineage tracing experiments in mice endorse the contribution of mesothelium-derived Wt1 expressing cells to all visceral WAT depots. (Chau et al, 2014) A recent lineage tracing study by Wilm et al shows that Wt1 expressing mesothelial cells in adult peritoneum do not contribute to the deeper stromal and parenchymal compartments in the abdominal cavity, but rather constitute the progenitor niche for visceral WAT.

Results

Conclusion