Automated patch clamp screening of amiloride and 5-N,N-hexamethyleneamiloride (HMA) analogs identifies 6-iodoamiloride as a potent acid-sensing ion channel inhibitor.

Finol-Urdaneta, R. K.; McArthur, J. R.; Aboelela, A.; Bujaroski, R. S.; Majed, H. H.; Rangel, A.; Adams, D. J.; Ranson, M.; Kelso, M. J.; Buckley, B. J.

doi:10.1101/2022.03.12.484055

bioRxiv · 10.1101/2022.03.12.484055

Automated patch clamp screening of amiloride and 5-N,N-hexamethyleneamiloride (HMA) analogs identifies 6-iodoamiloride as a potent acid-sensing ion channel inhibitor.

Finol-Urdaneta, R. K.·McArthur, J. R.·Aboelela, A.·Bujaroski, R. S.·Majed, H. H.·Rangel, A.·Adams, D. J.·Ranson, M.·Kelso, M. J.·Buckley, B. J.

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Abstract

Acid-sensing ion channels (ASICs) are transmembrane sensors of extracellular acidosis and potential drug targets in several disease indications, including neuropathic pain and cancer metastasis. The K+-sparing diuretic amiloride is a moderate non-specific inhibitor of ASICs and has been widely used as a probe for elucidating ASIC function. In this work, we screened a library of 6-substituted and 5,6-disubstituted amiloride analogs using a custom-developed automated patch-clamp protocol and identified 6-iodoamiloride as a more potent ASIC1 inhibitor. Follow-up IC50 determinations in tsA-201 cells confirmed higher ASIC1 inhibitory potency for 6-iodoamiloride 97 (hASIC1 97 IC50 88 nM cf. amiloride 11 IC50 1.7 M). A similar improvement in activity was observed in ASIC3-mediated currents from rat small diameter dorsal root ganglion neurons (rDRG single-concentration 97 IC50 230 nM cf. 11 IC50 2.7 M). 6-iodoamiloride represents the amiloride analogue of choice for studying the effects of ASIC inhibition on cell physiology.

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Finol-Urdaneta, R. K., McArthur, J. R., Aboelela, A., Bujaroski, R. S., Majed, H. H., Rangel, A., Adams, D. J., Ranson, M., Kelso, M. J., Buckley, B. J.. 2022-03-14. Automated patch clamp screening of amiloride and 5-N,N-hexamethyleneamiloride (HMA) analogs identifies 6-iodoamiloride as a potent acid-sensing ion channel inhibitor.. https://doi.org/10.1101/2022.03.12.484055

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