Tubastatin A hydrochloride

Biological Activity

Tubastatin A HCl is a potent and selective HDAC6 inhibitor with IC50 values of 15 nM. Tubastatin A was substantially more selective than the known HDAC6 inhibitor Tubacin at all isozymes except HDAC8. In addition, Tubastatin A displayed over 1000-fold selectivity against all HDAC isoforms excluding HDAC8, where it displayed 54-fold selectivity. This compound displayed dose-dependent protection against HCA induced neuronal cell death starting at 5 μM with near complete protection at 10 μM.

Protocol

Cell Experiment
Cell lines	Primary cortical neuron
Preparation method	Neuroprotection Assays Primary cortical neuron cultures were obtained from the cerebral cortex of fetal Sprague-Dawley rats (embryonic day 17) as described previously. All experiments were initiated 24 h after plating. Under these conditions, the cells are not susceptible to glutamate-mediated excitotoxicity. For cytotoxicity studies, cells were rinsed with warm PBS and then placed in minimum essential medium (Invitrogen) containing 5.5 g/liter glucose, 10% fetal calf serum, 2 mM L-glutamine, and 100 µM cystine. Oxidative stress was induced by the addition of the glutamate analog homocysteate (HCA; 5 mM) to the media. HCA was diluted from 100-fold concentrated solutions that were adjusted to pH 7.5. In combination with HCA, neurons were treated with either TSA or Tubastatin A at the indicated concentrations. Viability was assessed after 24 h by MTT assay (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) method.
Concentrations	0, 1, 2.5, 5.0, 7.5 and 10 μM
Incubation time	24 h

Animal Experiment
Animal models	dextran sodium sulfate (DSS) and adoptive transfer models of colitis
Formulation	DMSO
Dosages	0.5 mg/kg of body weight/day
Administration	i.p

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

Chemical Information

References

Actin filaments play a primary role for structural integrity and viscoelastic response in cells.
Ketene AN, et al. Integr Biol (Camb). 2012 May;4(5):540-9. PMID: 22446682.

Rational design and simple chemistry yield a superior, neuroprotective HDAC6 inhibitor, tubastatin A.
Butler KV, et al. J Am Chem Soc. 2010 Aug 11;132(31):10842-6. PMID: 20614936.