Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
Skip to main content

Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+-releasing second messenger known to date, but the precise NAADP/Ca2+ signalling mechanisms are still controversial. We report the synthesis of small-molecule inhibitors of NAADP-induced Ca2+ release based upon the nicotinic acid motif. Alkylation of nicotinic acid with a series of bromoacetamides generated a diverse compound library. However, many members were only weakly active or had poor physicochemical properties. Structural optimisation produced the best inhibitors that interact specifically with the NAADP/Ca2+ release mechanism, having no effect on Ca2+ mobilized by the other well-known second messengers D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] or cyclic adenosine 5'-diphospho-ribose (cADPR). Lead compound (2) was an efficient antagonist of NAADP-evoked Ca2+ release in vitro in intact T lymphocytes and ameliorated clinical disease in vivo in a rat experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Compound (3) (also known as BZ194) was synthesized as its bromide salt, confirmed by crystallography, and was more membrane permeant than 2. The corresponding zwitterion (3a), was also prepared and studied by crystallography, but 3 had more desirable physicochemical properties. 3 Is potent in vitro and in vivo and has found widespread use as a tool to modulate NAADP effects in autoimmunity and cardiovascular applications. Taken together, data suggest that the NAADP/Ca2+ signalling mechanism may serve as a potential target for T cell- or cardiomyocyte-related diseases such as multiple sclerosis or arrhythmia. Further modification of these lead compounds may potentially result in drug candidates of clinical use.

Original publication

DOI

10.1038/s41598-018-34917-3

Type

Journal article

Journal

Sci Rep

Publication Date

13/11/2018

Volume

8