Virtual Screening for LPA₂-Specific Agonists Identifies a Nonlipid Compound with Antiapoptotic Actions

Abstract

Lysophosphatidic acid (LPA) is a highly potent endogenous lipid mediator that protects and rescues cells from programmed cell death. Earlier work identified the LPA 2 G proteincoupled receptor subtype as an important molecular target of LPA mediating antiapoptotic signaling. Here we describe the results of a virtual screen using single-reference similarity searching that yielded compounds 2-((9-oxo-9H-fluoren-2-yl) carbamoyl)benzoic acid (NSC12404), 2-((3-(1,3-dioxo-1H-benzo- [de]isoquinolin-2(3H)-yl)propyl)thio)benzoic acid (GRI977143), 4,5-dichloro-2-((9-oxo-9H-fluoren-2-yl)carbamoyl)benzoic acid (H2L55-47924), and 2-((9,10-dioxo-9,10-dihydroanthracen-2-yl)carbamoyl) benzoic acid (H2L5828102), novel nonlipid and drug-like compounds that are specific for the LPA 2 receptor subtype. We characterized the antiapoptotic action of one of these compounds, GRI977143, which was effective in reducing activation of caspases 3, 7, 8, and 9 and inhibited poly(ADP-ribose)polymerase 1 cleavage and DNA fragmentation in different extrinsic and intrinsic models of apoptosis in vitro.Furthermore, GRI977143 promoted carcinoma cell invasion of human umbilical vein endothelial cell monolayers and fibroblast proliferation. The antiapoptotic cellular signaling responses were present selectively in mouse embryonic fibroblast cells derived from LPA 1&2 double-knockout mice reconstituted with the LPA 2 receptor and were absent in vector-transduced control cells. GRI977143 was an effective stimulator of extracellular signal-regulated kinase 1/2 activation and promoted the assembly of a macromolecular signaling complex consisting of LPA 2 , Na ϩ -H ϩ exchange regulatory factor 2, and thyroid receptor interacting protein 6, which has been shown previously to be a required step in LPA-induced antiapoptotic signaling. The present findings indicate that nonlipid LPA 2 -specific agonists represent an excellent starting point for development of lead compounds with potential therapeutic utility for preventing the programmed cell death involved in many types of degenerative and inflammatory diseases.

Combined Mitigation of the Gastrointestinal and Hematopoietic Acute Radiation Syndromes by an LPA 2 Receptor-Specific Nonlipid Agonist

“…1b). Because GRI977143 is both a selective agonist of the LPA 2 receptor and a weak antagonist of LPA 3 (Kiss, et al, 2012), we also examined whether DBIBB had antagonist or allosteric modulatory action on LPA 1/3/4/5 GPCR. The pharmacological characterization of DBIBB at LPA 2 showed that had nanomolar potency (IC 50 ~100 nM, a 33-fold increase over GRI977143); it was a specific agonist without activating or inhibiting LPA 1/3/4/5 receptors.…”

“…Thus, improved non-lipid, drug-like analogs specific to the LPA 2 GPCR could provide drug candidates suitable for the treatment of ARS. In silico drug discovery has identified 2-((3-(1,3-dioxo-1 H -benzo[ de ]isoquinolin-2(3 H )-yl)propyl)thio)-benzoic acid ( GRI977143 ) nonlipid compound that activates LPA 2 selectively although not specifically (Kiss, et al, 2012). GRI977143 , however, lacks the desired drug-like potency; it also has compromised specificity because it is an antagonist of LPA 3 .…”

Lysophosphatidic Acid and Sphingosine-1-Phosphate: A Concise Review of Biological Function and Applications for Tissue Engineering

“…The ability of LPA and LPA receptor agonists to protect multiple cell types against SD/H, 104 combined with the relatively low cost, makes them ideal for many cell delivery applications. Micromolar concentrations of LPA protect neuronal precursors, 105 osteoblasts, osteoclasts, 88 rat and human MSCs, 4,5 and other cell types against SD/ H-and endoplasmic reticulum-stress induced apoptosis in vitro in a pertussis toxin-and PI3K-dependent manner.…”

From Three-Dimensional GPCR Structure to Rational Ligand Discovery

“…Some of these hit optimization studies have been driven by structure-based design Congreve et al 2012;Lin et al 2012;Becker et al 2006;Wacker et al 2010). One of the most frequently observed steps in a VS hit exploration is the search for close analogues of one or more hit compounds (Carlsson et al 2010(Carlsson et al , 2011Langmead et al 2012;Kim et al 2012;Kiss et al 2012) or to synthesize a small series around one or more hit compounds Yrjola et al 2013) (Table 7.2). The experimental validation of compound 8, an AA2AR-selective VS hit from Carlsson et al (2010), was followed by an analogue search which yielded 5 equally selective analogues but all with a lower affinity.…”