Histone deacetylase activity is measured using a continuous trypsin-coupled assay. For inhibitor characterization, measurements are performed in a reaction volume of 100 μL^-1 using 96-well assay plates in a fluorescence plate reader. For each isozyme, the HDAC protein in reaction buffer (50 mM HEPES, 100 mM KCl, 0.001% Tween-20, 5% DMSO, pH 7.4, supplemented with bovine serum albumin at concentrations of 0-0.05% ) is mixed with inhibitor at various concentrations and allowed to incubate for 15 min. Trypsin is added to a final concentration of 50 nM, and acetyl-Gly-Ala-(N-acetyl-Lys)-amino-4-methylcoumarin is added to a final concentration of 25-100 μM to initiate the reaction. After a 30 min lag time, the fluorescence is measured over a 30 min time frame using an excitation wavelength of 355 nm and a detection wavelength of 460 nm. The increase in fluorescence with time is used as the measure of the reaction rate. Inhibition constants K_i(app) are obtained using the program BatchK_i^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Tumor cell lines and human umbilical vein endothelial cells are cultured for at least two doubling times, and growth is monitored at the end of compound exposure using an Alamar Blue fluorometric cell proliferation assay as recommended by the manufacturer. Compounds (e.g.,PCI-34051) are assayed in triplicate wells in 96-well plates. The concentration required to inhibit cell growth by 50% (GI₅₀) and 95% confidence intervals are estimated from nonlinear regression using a four-parameter logistic equation^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Mice^[2]
A mouse model of asthma is utilized. Briefly, healthy female BALB/C mice (n=72) aged 6-8 weeks and weighing 18-22 g are used. Animals are housed independently in a pathogen-free room and provided ad libitum access to water and standard food. Animals are housed for 1 week prior to experiment onset. Mice are divided into six treatment groups: normal control, simple asthma, Dexamethasone, Tubastatin A HCl, PCI-34051, and Givinostat. Sensitization is carried out for mice in the last five groups on the 1st, 8th and 15th day using ovalbumin (OVA, 20 μg) and aluminum hydroxide gel (2 mg). 7 days after the last sensitization, OVA (20 mg/mL) atomization is performed using an ultrasonic atomizing device (3 mL/min for 30 min, 3 times/week for 8 weeks). Dexamethasone (2.0 mg/kg), TSA (0.5 mg/kg), PCI-34051 (0.5 mg/kg) and Givinostat (0.5 mg/kg) are administered via intraperitoneal injection 30 min before excitation. In the normal control group, normal saline is used instead of OVA.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Balasubramanian S, et al. A novel histone deacetylase 8 (HDAC8)-specific inhibitor PCI-34051 induces apoptosis in T-cell lymphomas. Leukemia. 2008 May;22(5):1026-34.  [Content Brief]

  [2]. Ren Y, et al. Therapeutic effects of histone deacetylase inhibitors in a murine asthma model. Inflamm Res. 2016 Dec;65(12):995-1008.  [Content Brief]