Synthesis, Structure−Activity Relationships, and Biological Evaluation of Fatty Alcohol Phosphates as Lysophosphatidic Acid Receptor Ligands, Activators of PPARγ, and Inhibitors of Autotaxin

Abstract

We previously reported that fatty alcohol phosphates (FAP) represent a minimal pharmacophore required to interact with lysophosphatidic acid (LPA) receptors. To improve the activity of the first-generation saturated FAP series, a structure−activity relationship (SAR) study was carried out that includes modifications to the headgroup and alkyl side chain of the FAP pharmacophore. A series of unsaturated (C10−C18) FAP, headgroup-modified hydrolytically stable saturated (C10−C18) alkyl phosphonates, and saturated and unsaturated (C10−C18) thiophosphate analogues were synthesized and evaluated for activity in RH7777 cells transfected with individual LPA1 - 3 receptors, in PC-3 cells and in human platelets that endogenously express all three isoforms. In this series we identified several LPA1- and LPA3-selective antagonists with IC50 values in the nanomolar range. Oleoyl-thiophosphate (15g) was shown to be a pan-agonist, whereas tetradecyl-phosphonate (16c) was identified as a pan-antagonist. These compounds were also tested for the ability to activate the transcription factor PPARγ, an intracellular receptor for LPA, in CV1 cells transfected with the PPRE-Acox-Rluc reporter gene. All the FAP tested, along with the previously reported LPA GPCR antagonists dioctanoyl glycerol pyrophosphate (2), Ki16425 (6), and the agonist OMPT (3), were activators of PPARγ. The pan-agonist oleoyl-thiophosphate (15g) and pan-antagonist tetradecyl-phosphonate (16c) mimicked LPA in inhibiting autotaxin, a secreted lysophospholipase D that produces LPA in biological fluids.

Regulatory Effect of Lysophosphatidic Acid on Lymphocyte Migration

“…57) The involvement of LPA receptors was confirmed with oleyl thiophosphate, which is a partial agonist for LPA 1 and LPA 3 , and a potent and full agonist for LPA 2 . 35) Our finding that oleyl thiophosphate could suppress CCL21-induced chemotaxis of splenic lymphocytes is further evidence of the involvement of some LPA receptors in the regulation of chemokine signaling. To determine which receptors are responsible for this effect, further studies are required.…”

“…35) We observed that oleyl thiophosphate inhibited CCL21-induced lymphocyte chemotaxis at 0.1 mM (Fig. 3).…”

α‐Substituted Phosphonate Analogues of Lysophosphatidic Acid (LPA) Selectively Inhibit Production and Action of LPA

“…[29] Briefly, rat hepatoma RH7777 cells stably expressing human LPA 1 , LPA 2 , or LPA 3 , and CHO cells stably expressing LPA 4 , were loaded with Fura-2 AM (Molecular Probes). Using a FLEXStation (Molecular Devices, Sunnyvale, CA), changes in intracellular Ca 2+ concentration were monitored.…”

“…Several groups have reported the characterization of the LPA agonists and antagonists. [20][21][22][23][24][25][26][27][28][29] Appropriately validated compounds are essential to advance in vivo studies, particularly in view of potential off-target effects. The development of more selective, more stable, more potent, and more druglike agonists and antagonists is eagerly awaited, and is the bottleneck in therapeutic exploration.…”

Sulfonylureas and Glinides Exhibit Peroxisome Proliferator-Activated Receptor γ Activity: A Combined Virtual Screening and Biological Assay Approach

“…The compound classes shown or predicted here to be PPAR␥ ligands, sulfonylureas [4, RЈ ϭ (substituted) amino] and N-acylsulfonamides [4, RЈ ϭ (substituted) alkyl or aryl, pK a values of ϳ5] smoothly fit into this picture. Other compound classes exhibiting similar or higher acidity and similar H acceptor ability of their anions were recently shown to be PPAR␥ ligands [oxazolidinediones (Momose et al, 2002b), tetrazoles (Momose et al, 2002a), phosphates, and thiophosphates (Durgam et al, 2005)]. Circumstantial evidence for our views is provided by the observation that the succinimide analog of an antihyperglycemic thiazolidinedione (2, but S replaced by CH 2 , pK a 9.7), as well as the corresponding N-methylthiazolidinedione, are both inactive (Cantello et al, 1994).…”