Nodinitib-1 (CID-1088438) is a potent and selective NOD1 inhibitor with an IC50 of 0.56 μM.

ML130 has shown selective inhibition of NOD1-induced NF-κB activation in HEK293 cells with no cytotoxicity and is selected as a probe candidate molecule. ML130 is also confirmed in secondary assays by selectively inhibiting NOD1-dependent IL-8 secretion and also selectively inhibiting the NOD1-dependent pathway to NF-κB activation. [1] In another research, ML130 is proved to cause conformational changes of NOD1 in vitro and alter NOD1 subcellular targeting in cells, providing chemical probes for interrogating mechanisms regulating NOD1 activity and tools for exploring the roles of NOD1 in various infectious and inflammatory diseases. [2]

NOD1 Dose Response assay: Day 1 Procedure 1) Harvest HEK-293-T NFKB-Luc at 100% confluency at 100% confluency. 2) Add NOD assay media with Multidrop. 3) Spin down plates at 1000 rpm for 1 min in centrifuge. 4) Serial compound dilutions. 5) Add gamma-tri-DAP to cell suspension at 0.75 ug/mL. 6) Seed 13000 cells/well in 4 uL/well to full plate HEK-293-T NFKB-Luc to TC-treated plate. 7) Spin down plates 500 RPM for 5 min on centrifuge. 8) Lid Plates. Sandwich 4 plates between 2 lidded 384 plates filled with Water. 9) Wrap plates securely in single layer of Plastic Wrap. 10) Incubate overnight (14 hours) in 37 ℃ and 5% CO2 incubator. Day 2 Procedure 1) Add 3 ul/well of SteadyGlo solution with Multidrop. 2) Shake plates on a plate shaker for 20 min. 3) Spin plates 1000 RPM for 1 min using centrifuge. 4) Read luminescence.IC50 values are calculated using GraphPad Prism 5.0.The average Z' for the screen is 0.6, the signal to background is 11.1, signal to noise is 78.6 and signal to window is 6.0.

Hepatic toxicity of compounds is determined with Fa2N-4 immortalized human hepatocytes using the ATP-lite 1-step assay. Fa2N-4 cells are seeded at 50,000 cells/well, and incubated with a range of concentrations of the test compound (0.01 μM-50 μM) in MFE support medium for 24 h at 37 ℃, 5% CO2. At the end of the experiment D-luciferin and luciferase are added. The emitted luminescent signal produced as a result of the reaction with cellular ATP is captured on the Infinite M200 plate reader. The concentration of each compound that killed 50% of the cells (LC50) is calculated by non-linear regression analysis using a log (inhibitior) vs response equation with a variable slope, using the statistic software package Prism4.(Only for Reference)