Discovery and pharmacological characterization of a novel potent inhibitor of diacylglycerol‐sensitive TRPC cation channels

T Maier, M Follmann, G Hessler… - British journal of …, 2015 - Wiley Online Library
T Maier, M Follmann, G Hessler, HW Kleemann, S Hachtel, B Fuchs, N Weissmann, W Linz…
British journal of pharmacology, 2015Wiley Online Library
Background and Purpose The cation channel transient receptor potential canonical (TRPC)
6 has been associated with several pathologies including focal segmental
glomerulosclerosis, pulmonary hypertension and ischaemia reperfusion‐induced lung
oedema. We set out to discover novel inhibitors of TRPC6 channels and investigate the
therapeutic potential of these agents. Experimental Approach A library of potential TRPC
channel inhibitors was designed and synthesized. Activity of the compounds was assessed …
Background and Purpose
The cation channel transient receptor potential canonical (TRPC) 6 has been associated with several pathologies including focal segmental glomerulosclerosis, pulmonary hypertension and ischaemia reperfusion‐induced lung oedema. We set out to discover novel inhibitors of TRPC6 channels and investigate the therapeutic potential of these agents.
Experimental Approach
A library of potential TRPC channel inhibitors was designed and synthesized. Activity of the compounds was assessed by measuring intracellular Ca2+ levels. The lead compound SAR7334 was further characterized by whole‐cell patch‐clamp techniques. The effects of SAR7334 on acute hypoxic pulmonary vasoconstriction (HPV) and systemic BP were investigated.
Key Results
SAR7334 inhibited TRPC6, TRPC3 and TRPC7‐mediated Ca2+ influx into cells with IC50s of 9.5, 282 and 226 nM, whereas TRPC4 and TRPC5‐mediated Ca2+ entry was not affected. Patch‐clamp experiments confirmed that the compound blocked TRPC6 currents with an IC50 of 7.9 nM. Furthermore, SAR7334 suppressed TRPC6‐dependent acute HPV in isolated perfused lungs from mice. Pharmacokinetic studies of SAR7334 demonstrated that the compound was suitable for chronic oral administration. In an initial short‐term study, SAR7334 did not change mean arterial pressure in spontaneously hypertensive rats (SHR).
Conclusions and Implications
Our results confirm the role of TRPC6 channels in hypoxic pulmonary vasoregulation and indicate that these channels are unlikely to play a major role in BP regulation in SHR. SAR7334 is a novel, highly potent and bioavailable inhibitor of TRPC6 channels that opens new opportunities for the investigation of TRPC channel function in vivo.
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