In vitro activity: TMP269 has no impact on the mitochondrial activity and/or the viability of human CD4+ T cells at 10 μM, and may be used as tools to identify the endogenous substrates of the class IIa HDAC enzymes. In IEC-18 intestinal epithelial cells, TMP269 prevents cell cycle progression, DNA synthesis, and proliferation induced in response to G protein-coupled receptor/PKD1 activation

Kinase Assay: Dose-response studies are done with ten concentrations in a threefold dilution series from a maximum final compound concentration of 100 μM in the reaction mixture and are conducted at Reaction Biology Corp. All assays are based on the same principle as the HDAC9 assay described above: the deacetylation of acetylated or trifluoroacetylated lysine residues on fluorogenic peptide substrates by HDAC. HDAC1, HDAC2, HDAC3, HDAC6, HDAC10 and HDAC11 used a substrate based on residues 379-382 of p53 (Arg-His-Lys-Lys(Ac)). For HDAC8, the diacetylated peptide substrate, based on residues 379–382 of p53 (Arg-His-Lys(Ac)-Lys(Ac)), is used. HDAC4, HDAC5, HDAC7 and HDAC9 assays used the class IIa HDAC–specific fluorogenic substrate (Boc-Lys(trifluoroacetyl)-AMC). All reactions are done with 50 μM HDAC substrate in assay buffer (50 mM Tris-HCl, pH 8.0, 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl2, 1 mg/mL BSA) containing 1% DMSO final concentration; incubated for 2 h at 30 °C; and developed with trichostatin A and trypsin.

Cell Assay: Human CD4+ T cells are isolated from whole blood via negative selection according to manufacturer's instructions (RosetteSep Human CD4+ T cell enrichment kit), re-suspended in T-cell culture medium (10% FBS, 2 mM L-glutamine, 1 mM pyruvate, 10 mM HEPES, 10 U/10 mg penicillin/streptomycin, 0.5% DMSO in RPMI) and plated at 50,000 cells/well with IL-2 (10 BRMP units/mL) and 100,000 human T-expander Dynabeads for 72 h. Determination of mitochondrial function or cell viability is done according to manufacturer’s instructions (Cell Proliferation Assay Kit I (MTT)) and is represented as a percent of control (no inhibitor) wells.

Nat Chem Biol. 2013 May;9(5):319-25; Am J Physiol Cell Physiol. 2014 May 15;306(10):C961-71.