The Effects of a Selective CK2 Inhibitor on Anti-glomerular Basement Membrane Glomerulonephritis in Rats.

Protein kinase CK2 ("casein kinase II") is a protein serine/threonine kinase that plays critical roles in biological processes such as cell growth, cell cycle progression, and apoptosis. So far, we have identified that one catalytic isozyme of CK2, CK2α, is over-expressed in the kidney during the progression of glomerulonephritis (GN). Moreover, we have shown that in vivo inhibition of CK2 by administration of CK2 inhibitors was effective in the treatment of experimental GN. Hence the development of potent CK2 inhibitors should be considered in therapeutic strategies for GN. In the present study we identified compound 13, a pyrazine derivative, as a potent CK2 inhibitor. By performing enzyme kinetics analysis in vitro, we characterized the inhibition of compound 13 toward each CK2 catalytic isozyme. Furthermore, in vivo, we demonstrated that compound 13 is effective in attenuating proteinuria, decreasing the enhanced level of blood urea nitrogen and serum creatinine, and ameliorating glomerular crescent formation in an experimental GN rat model. On the other hand, cellular apoptosis was detected in the rat testis following administration of compound 13. This study provides clues for new strategies for developing applicable compounds into CK2-targeted GN treatments.

Discovery of 1-oxa-4,9-diazaspiro[5.5]undecane-based trisubstituted urea derivatives as highly potent soluble epoxide hydrolase inhibitors and orally active drug candidates for treating of chronic kidney diseases.

We identified 1-oxa-4,9-diazaspiro[5.5]undecane-based trisubstituted ureas as highly potent soluble epoxide hydrolase (sEH) inhibitors and orally active agents for treating chronic kidney diseases. Compound 19 exhibited excellent sEH inhibitory activity and bioavailability. When administered orally at 30 mg/kg, 19 lowered serum creatinine in a rat model of anti-glomerular basement membrane glomerulonephritis but 2,8-diazaspiro[4.5]decane-based trisubstituted ureas did not. These results suggest that 19 is an orally active drug candidate for treating chronic kidney diseases.

Discovery of 2,8-diazaspiro[4.5]decane-based trisubstituted urea derivatives as highly potent soluble epoxide hydrolase inhibitors and orally active drug candidates for treating hypertension.

We identified 2,8-diazaspiro[4.5]decane-based trisubstituted urea derivatives as highly potent soluble epoxide hydrolase (sEH) inhibitors and orally active agents for treating hypertension. Docking studies using human and murine sEH X-ray crystal structures revealed steric hindrance around the side chain of Phe406 of murine sEH. The trifluoromethyl moiety (11) was replaced with a trifluoromethoxy moiety (12) to prevent steric clash, and improved murine sEH inhibitory activity was observed. The oral administration of 12, 20, and 37 at a dose of 30mg/kg reduced blood pressure in spontaneously hypertensive rat, but had little effect on blood pressure in normotensive rat.

Discovery and structure-activity relationship of 2,6-disubstituted pyrazines, potent and selective inhibitors of protein kinase CK2.

We report the discovery and structure-activity relationship of 2,6-disubstituted pyrazines, which are potent and selective CK2 inhibitors. Lead compound 1 was identified, and derivatives were prepared to develop potent inhibitory activity. As a result, we obtained compound 7, which was the smallest unit that retained potency. Then, introducing an aminoalkyl group at the 6-position of the indazole ring resulted in improved efficacy in both enzymatic and cell-based CK2 inhibition assays. Moreover, compound 13 showed selectivity against other kinases and in vivo efficacy in a rat nephritis model. These results show that 2,6-disubstituted pyrazines have potential as therapeutic agents for nephritis.

Nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors as promising new leads for Chagas disease chemotherapy.

A century after discovering that the Trypanosoma cruzi parasite is the etiological agent of Chagas disease, treatment is still plagued by limited efficacy, toxicity, and the emergence of drug resistance. The development of inhibitors of the major T. cruzi cysteine protease, cruzain, has been demonstrated to be a promising drug discovery avenue for this neglected disease. Here we establish that a nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitor substantially ameliorates symptoms of acute Chagas disease in a mouse model with no apparent toxicity. A high-resolution crystal structure confirmed the mode of inhibition and revealed key binding interactions of this novel inhibitor class. Subsequent structure-guided optimization then resulted in inhibitor analogues with improvements in potency despite minimal or no additions in molecular weight. Evaluation of the analogues in cell culture showed enhanced activity. These results suggest that nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors have the potential to fulfill the urgent need for improved Chagas disease chemotherapy.