Cell experiment:

Human umbilical vein ECs (HUVECs) are cultured in EGM-2. Subconfluent HUVECs are made quiescent by serum starvation [EBM-2 containing 0.1% fetal bovine serum (FBS)] for 4 h. The cells are pretreated with the PPARδ ligand L-165041 or GW501516 for 6 h followed by VEGF (10 ng/mL) induction[2].

Animal experiment:

LDLR–/– mice are divided into vehicle (0.1 N NaOH) and L-165041 (5 mg/kg/day) group (9 animals in each group). LDLR–/– mice receive either NaOH or L-165041 via daily intraperitoneal injection (i.p.) for 16 weeks with the Western diet. Body weight is measured once a week and the blood samples for a serum parameter analysis are collected using an eye-bleeding method every 4 weeks. At the end of the experiment, LDLR–/– mice are fasted for 24 h before sacrificed and the liver samples are either fixed in formalin or frozen at –70℃ for further analysis. All animals are housed in polycarbonate cages in a room with a 12-h light/12-h dark cycle, and maintained at a constant temperature of 22℃[3].

Ki: 6 nM for PPARγ

Peroxisome proliferator-activated receptor (PPARγ) is known to be expressed ubiquitously and involved in lipid and glucose metabolism. Studies have demonstrated that PPARγ is expressed in endothelial cells and plays a potential role in endothelial proliferation and survival. L-165041 is reported as a selective and potent PPARγ ligand.

In vitro: L-165041, which is a selective and potent PPARδligand, displayed in this specified transactivation system, apart from its highly efficacious PPARδ agonist activity, partial and full agonism at, respectively, PPARγ2 and PPARαsubtypes [1].

In vivo: L-165041 could drastically reduce lipid accumulation in the mouse liver, decreasing total hepatic triglyceride and cholesterol content compared to the vehicle group. Gene analysis demonstrated that L-165041 lowered hepatic expression of PPARγ, apolipoprotein B, IL-1β, and interleukin-6. In contrast, L-165041 increased hepatic expressions of PPARδ, lipoprotein lipase, and ATP-binding cassette transporter G1 (ABCG1) [2].

Clinical trial: Up to now, L-165041 is still in the preclinical development stage.

Reference:
[1] Wurch T, Junquero D, Delhon A, Pauwels J.  Pharmacological analysis of wild-type alpha, gamma and delta subtypes of the human peroxisome proliferator-activated receptor. Naunyn Schmiedebergs Arch Pharmacol. 2002 Feb;365(2):133-40.
[2] Lim HJ, Park JH, Lee S, Choi HE, Lee KS, Park HY.  PPARdelta ligand L-165041 ameliorates Western diet-induced hepatic lipid accumulation and inflammation in LDLR-/- mice. Eur J Pharmacol. 2009 Nov 10;622(1-3):45-51.