{"doi":"10.1021/acsptsci.5c00172","title":"Differential Sensitivity of TRPC- and ORAI-Mediated Calcium Entries to 1-[2-(4-Methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl]imidazole Chloride (SKF-96365)","abstract":"High Resolution Image Download MS PowerPoint Slide Background and Purpose: SKF-96365 is widely used as a broad-spectrum inhibitor of calcium entry. It was initially identified as a Receptor-Operated Ca 2+ Entry (ROCE) blocker and was later shown to inhibit ORAI1–STIM1-mediated Store-Operated Ca 2+ Entry (SOCE). However, its selectivity for TRPC versus the ORAI channels remains unclear. Experimental Approach: To examine the selectivity of SKF-96365, we evaluated its effects on SOCE and ROCE in wild-type and TRPC hepta-KO mouse embryonic fibroblasts (MEFs), as well as on TRPC-mediated OAG-induced calcium entry in HEK293 cells overexpressing TRPC3, TRPC6, or TRPC7. Additional assays were conducted on HEK293 cells expressing the muscarinic M5 receptor (M5R). Half-maximal inhibitory concentration (IC 50 ) values were determined under all conditions. Key Results: SKF-96365 suppressed thapsigargin (Tg)-induced SOCE similarly in wild-type and TRPC hepta-KO MEFs, with IC 50 values around 4–5 μM. Comparable inhibition was observed for carbachol (CCh)-activated ROCE in TRPC-deficient cells. In contrast, OAG-activated Ca 2+ entry by TRPC3/6/7 was only weakly inhibited, with IC 50 values exceeding 100 μM. Notably, TRPC-mediated Ca 2+ entry was unaffected by CRAC channel blockers or ORAI coexpression, confirming its independence of SOCE mechanisms Conclusions and Implications: Our findings demonstrate that ORAI-mediated SOCE is approximately 25-fold more sensitive to SKF-96365 than TRPC-mediated calcium entry. GSK-7975A further confirmed the ORAI selectivity by blocking SOCE without affecting TRPC channels. These results clarify the pharmacological profile of SKF-96365, confirming its primary action on ORAI channels and highlight the need for concentration-aware interpretation in calcium signaling studies, particularly in the context of CRAC channel-related disorders.","journal":"ACS Pharmacology & Translational Science","year":2025,"id":581737,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9553,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":405479,"name":"Karina Formoso","orcid":"0000-0003-4890-8547","position":1,"is_corresponding":false},{"id":1493629,"name":"Julieta Mansilla Ricartti","orcid":null,"position":2,"is_corresponding":false},{"id":331049,"name":"Marc Freichel","orcid":"0000-0003-1387-2636","position":3,"is_corresponding":false},{"id":110422,"name":"Lutz Birnbaumer","orcid":"0000-0002-0775-8661","position":4,"is_corresponding":false},{"id":405480,"name":"Sebastián Susperreguy","orcid":"0000-0001-7532-4825","position":0,"is_corresponding":true}],"reference_count":58,"raw_metadata":null,"created_at":"2026-07-19T02:58:51.328454Z","pmid":"41409173","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}