P465L pparγ mutation confers partial resistance to the hypolipidemic action of fibrates.

Abstract

Familial partial lipodystrophic syndrome 3 (FPLD3) is associated with mutations in the transcription factor PPAR. The P467L mutant confers a dominant negative effect. We have previously investigated the pathophysiology of FPLD3 using a humanised mouse harbouring an equivalent mutation (P465L) in PPAR that recapitulated the human clinical phenotype. One of the key clinical manifestations observed in humans and mice is the accumulation of fat in the liver. Here, we dissect the molecular mechanisms that facilitate accumulation of lipids in the liver and characterise the negative effect of the PPAR mutation on the activation of PPAR in vivo by fibrates. P465L mice have increased insulin and FFAs, decreased secretion of VLDL when fed HFD and impaired hypolipidemic response to WY14643. Thus, the phenotype of PPAR mutations may synergise with defects on PPAR function, indicating that the phenotype of the FPLD3 patients may not only be attributed to the dysfunction of PPAR.