human LPA1 ( pIC50 = 0.98 μM ); mouse LPA1 ( pIC50 = 0.73 μM )

AM095 suppresses the calcium flux that LPA causes in CHO cells that have been transfected with mouse or human LPA1. For human or mouse LPA1-transfected CHO cells, the IC50 for AM095 antagonism of LPA-induced calcium flux is 0.025 and 0.023 μM, respectively[1]. Compared to vehicle control, AM095 reduces LPA-induced vasorelaxation by approximately 90% at 10 μM[2]. AM095 inhibits human A2058 melanoma cells (IC50=233 nM) and mouse LPA1 (IC50=778 nM)-driven chemotaxis of CHO cells[3].

AM095 antagonism of LPA1 and significantly reduces bleomycin induced skin fibrosis [1] AM095 is well tolerated at the doses tested in rats and dogs following oral and intravenous dosing. It also has a high oral bioavailability and a moderate half-life. LPA-stimulated histamine release is dose-dependently reduced by AM095. AM095 reduces the bleomycin-induced rises in inflammatory cell infiltration, collagen, and protein in bronchalveolar lavage fluid. In a mouse unilateral ureteral blockage model, AM095 reduces kidney fibrosis[3].

In assays, both hLPA1/CHO and mLPA1/CHO cells are used. Protease inhibitors, 10 mM HEPES, pH 7.4, 1 mM dithiothreitol, and approximately 20 mL of ice-cold membrane buffer are added to a cell pellet of hLPA1/CHO or mLPA1/CHO cells. The cells are sonicated, and the cell lysate is centrifuged for 10 minutes at 4°C at 2000 rpm. Further centrifuging of the supernatant is done for 70 minutes at 4°C at 25,000 rpm. Using a Potter-Elvehjem tissue grinder, the membrane pellet is resuspended in 5 mL of ice-cold membrane buffer and homogenized. With the Bradford Protein Assay Kit, the final protein concentration is calculated. To 25 to 40 μg of hLPA1/CHO or mLPA1/CHO membranes and 0.1 nM [³⁵S]-GTPηS in buffer (50 mM HEPES, 0.1 mM NaCl, 10 mM MgCl₂, 50 μg/mL saponin, pH 7.5) containing 0.2% fatty acid-free human serum albumin and 5 μM GDP, known amounts of AM095 (diluted in dimethyl sulfoxide) or vehicle (dimethyl sulfoxide) are added. The capacity of AM095 to impede GTPγS binding stimulated by 900 nM LPA (18:1) is measured in order to assess LPA1 antagonist activity. As an alternative, the capacity of AM095 to promote GTPηS binding in the absence of LPA is assessed in order to assess agonist effects. Membranes are harvested onto glass filter binding plates and three times washed with cold buffer containing 50 mM HEPES, pH 7.4, 100 mM NaCl, and 10 mM MgCl₂ using a Brandel 96-tip cell harvester after reactions are incubated for 30 minutes at 30°C. After plates are dried, a Packard TopCount NXT microplate scintillation counter is used to measure cpm.

In vitro, AM095 was a potent LPA₁ receptor antagonist because it inhibited GTPγS binding to Chinese hamster ovary (CHO) cell membranes overexpressing recombinant human or mouse LPA₁ with IC₅₀ values of 0.98 and 0.73 μM, respectively, and exhibited no LPA₁ agonism. In functional assays, AM095 inhibited LPA-driven chemotaxis of CHO cells overexpressing mouse LPA₁ (IC₅₀= 778 nM) and human A2058 melanoma cells (IC₅₀ = 233 nM)[3].

Mice had their left kidney operated on either by UUO or sham surgery. To put it briefly, the left kidney is exposed by a longitudinal, upper left incision. A 6/0 silk thread is inserted between the renal artery and the ureter after the artery has been identified. To ensure complete ureter ligation, the thread is wound around the ureter and knotted three times. The skin is sutured shut, the kidney is returned to the abdomen, and staples are used to close the incision. The healthy control kidney was the contralateral (right) kidney. Oral gavage of AM095 (30 mg/kg) or the vehicle (water) is administered 1 to 4 hours prior to UUO and on an as-needed basis after that. The kidneys are removed and cut in half for histopathological and biochemical examination of the fibrosis after the mice are put to sleep for eight days using CO2 inhalation. A kidney sample is fixed in 10% neutral buffered formalin and stained with Masson's trichrome in order to measure the amount of fibrosis. To analyze the collagen content biochemically, the other half of the kidney is frozen at -80°C.

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Wild type (WT), and LPA₁-knockout (KO) and LPA₂-KO mice were injected subcutaneously with bleomycin or phosphate buffered saline (PBS) once daily for 28 days. Dermal thickness, collagen content, and numbers of cells positive for α-smooth muscle actin (α-SMA) or phospho-Smad2 were determined in bleomycin-injected and PBS-injected skin. In separate experiments, a novel selective LPA₁ antagonist AM095 or vehicle alone was administered by oral gavage to C57BL/6 mice that were challenged with 28 daily injections of bleomycin or PBS. AM095 or vehicle treatments were initiated concurrently with, or 7 or 14 days after, the initiation of bleomycin and PBS injections and continued to the end of the experiments. Dermal thickness and collagen content were determined in injected skin.[1]

In vivo, we demonstrated that AM095: 1) had high oral bioavailability and a moderate half-life and was well tolerated at the doses tested in rats and dogs after oral and intravenous dosing, 2) dose-dependently reduced LPA-stimulated histamine release, 3) attenuated bleomycin-induced increases in collagen, protein, and inflammatory cell infiltration in bronchalveolar lavage fluid, and 4) decreased kidney fibrosis in a mouse unilateral ureteral obstruction model. Despite its antifibrotic activity, AM095 had no effect on normal wound healing after incisional and excisional wounding in rats. These data demonstrate that AM095 is an LPA₁ receptor antagonist with good oral exposure and antifibrotic activity in rodent models. [3]

[1]. Amelioration of dermal fibrosis by genetic deletion or pharmacologic antagonism of lysophosphatidic acid receptor 1 in a mouse model of scleroderma. Arthritis Rheum. 2011 May;63(5):1405-15.

[2]. Lysophosphatidic acid induces vasodilation mediated by LPA1 receptors, phospholipase C, and endothelial nitric oxide synthase. FASEB J. 2014 Feb;28(2):880-90.

[3]. Pharmacokinetic and pharmacodynamic characterization of an oral lysophosphatidic acid type 1 receptor-selective antagonist. Journal of Pharmacology and Experimental Therapeutics (2011), 336(3), 693-700.

Objective: Scleroderma (systemic sclerosis [SSc]), is characterized by progressive multiorgan fibrosis. We recently implicated lysophosphatidic acid (LPA) in the pathogenesis of pulmonary fibrosis. The purpose of the present study was to investigate the roles of LPA and two of its receptors, LPA₁ and LPA₂, in dermal fibrosis in a mouse model of SSc. Methods: Wild type (WT), and LPA₁-knockout (KO) and LPA₂-KO mice were injected subcutaneously with bleomycin or phosphate buffered saline (PBS) once daily for 28 days. Dermal thickness, collagen content, and numbers of cells positive for α-smooth muscle actin (α-SMA) or phospho-Smad2 were determined in bleomycin-injected and PBS-injected skin. In separate experiments, a novel selective LPA₁ antagonist AM095 or vehicle alone was administered by oral gavage to C57BL/6 mice that were challenged with 28 daily injections of bleomycin or PBS. AM095 or vehicle treatments were initiated concurrently with, or 7 or 14 days after, the initiation of bleomycin and PBS injections and continued to the end of the experiments. Dermal thickness and collagen content were determined in injected skin. Results: The LPA₁ -KO mice were markedly resistant to bleomycin-induced increases in dermal thickness and collagen content, whereas the LPA₂-KO mice were as susceptible as the WT mice. Bleomycin-induced increases in dermal α-SMA+ and phospho-Smad2+ cells were abrogated in LPA₁-KO mice. Pharmacologic antagonism of LPA₁ with AM095 significantly attenuated bleomycin-induced dermal fibrosis when administered according to either a preventive regimen or two therapeutic regimens. Conclusion: These results suggest that LPA/LPA₁ pathway inhibition has the potential to be an effective new therapeutic strategy for SSc, and that LPA₁ is an attractive pharmacologic target in dermal fibrosis.[1]

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Lysophosphatidic acid (LPA) has been implicated as a mediator of several cardiovascular functions, but its potential involvement in the control of vascular tone is obscure. Here, we show that both LPA (18:1) and VPC31143 (a synthetic agonist of LPA1-3 receptors) relax intact mouse thoracic aorta with similar Emax values (53.9 and 51.9% of phenylephrine-induced precontraction), although the EC50 of LPA- and VPC31143-induced vasorelaxations were different (400 vs. 15 nM, respectively). Mechanical removal of the endothelium or genetic deletion of endothelial nitric oxide synthase (eNOS) not only diminished vasorelaxation by LPA or VPC31143 but converted it to vasoconstriction. Freshly isolated mouse aortic endothelial cells expressed LPA1, LPA2, LPA4 and LPA5 transcripts. The LPA1,3 antagonist Ki16425, the LPA1 antagonist AM095, and the genetic deletion of LPA1, but not that of LPA2, abolished LPA-induced vasorelaxation. Inhibition of the phosphoinositide 3 kinase-protein kinase B/Akt pathway by wortmannin or MK-2206 failed to influence the effect of LPA. However, pharmacological inhibition of phospholipase C (PLC) by U73122 or edelfosine, but not genetic deletion of PLCε, abolished LPA-induced vasorelaxation and indicated that a PLC enzyme, other than PLCε, mediates the response. In summary, the present study identifies LPA as an endothelium-dependent vasodilator substance acting via LPA1, PLC, and eNOS.[2]

C₂₇H₂₄N₂O₅

456.49

456.168

C, 71.04; H, 5.30; N, 6.14; O, 17.52

1228690-36-5

AM095; 1345614-59-6

46213949

White to off-white solid powder

1.3±0.1 g/cm3

641.9±55.0 °C at 760 mmHg

342.0±31.5 °C

0.0±2.0 mmHg at 25°C

1.629

4.94

2

6

8

34

666

1

O=C(O)CC1=CC=C(C2=CC=C(C3=C(NC(O[C@@H](C4=CC=CC=C4)C)=O)C(C)=NO3)C=C2)C=C1

LNDDRUPAICPXIN-GOSISDBHSA-N

InChI=1S/C27H24N2O5/c1-17-25(28-27(32)33-18(2)20-6-4-3-5-7-20)26(34-29-17)23-14-12-22(13-15-23)21-10-8-19(9-11-21)16-24(30)31/h3-15,18H,16H2,1-2H3,(H,28,32)(H,30,31)/t18-/m1/s1

2-[4-[4-[3-methyl-4-[[(1R)-1-phenylethoxy]carbonylamino]-1,2-oxazol-5-yl]phenyl]phenyl]acetic acid

AM095; AM 095; AM-095; AM095 free acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: ~67.3 mg/mL (~147.4 mM)

Solubility in Formulation 1: ≥ 2.25 mg/mL (4.93 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 22.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)