LRP5 promotes adipose progenitor cell fitness and adipocyte insulin sensitivity
WNT signalling is a developmental pathway which plays an important role in post-natal bone accrual. We have previously shown, that in addition to exhibiting extreme high bone mass, subjects with rare gain-of-function (GoF) mutations in the WNT co-receptor LRP5 also display increased lower-body fat mass. Here, we demonstrate using human physiological studies in GoF LRP5 mutation carriers and glucose uptake assays in LRP5 knockdown (KD) adipocytes that LRP5 promotes adipocyte insulin sensitivity. We also show that a low frequency missense variant in LRP5 shown to be associated with low heel bone mineral density in a genome wide association study meta-analysis, is associated with reduced leg fat mass. Finally, using genome wide transcriptomic analyses and in vitro functional studies in LRP5-KD adipose progenitors (APs) we demonstrate that LRP5 plays an essential role in maintaining AP fitness i.e. functional characteristics. Pharmacological activation of LRP5 signalling in adipose tissue provides a promising strategy to prevent the redistribution of adipose tissue and metabolic sequela associated with obesity and ageing.