Small-molecule inhibitors of store-operated calcium entry.

Controlled variation in intracellular calcium concentration is a key component of the immune response signaling pathway in lymphocytes. Store-operated calcium entry (SOCE) in these cells provides a prolonged increase in cytoplasmic Ca(2+) concentrations and ultimately leads to the production of pro-inflammatory cytokines. Molecules that inhibit SOCE could therefore be useful immunomodulating agents for the treatment of rheumatoid arthritis, psoriasis, inflammatory bowel disease, and other conditions. Although the presence of the SOCE signaling pathway in lymphocytes and other cells involved in the immune response has been known for many years, key proteins involved in SOCE were identified only recently. The identification of these proteins may further enable the identification of agents that inhibit SOCE without affecting other cellular processes. This contribution documents representative examples of the small-molecule inhibitors of SOCE that have been reported to date. Where possible, methods that were used to characterize the mechanism of action of the inhibitors are also described.