Figure 5.

Effects of selected molecule 10h on ER Ca²⁺ release and store-operated calcium entry (SOCE) measured in HEK293 cells. (A) Time-lapse recording of cytosolic calcium concentration variation (evaluated by changes in normalized fluorescence F340/F380 ratio). Inhibition of 3-(N-2-hydroxyphenylmethylidene)amino-4-imino-3,5-dihydro-4H-chromeno[2,3-d]pyrimidine 10h on ER Ca⁺² release (B) and store-operated Ca⁺² entry (SOCE) (C). Tested compound 10h at a concentration ranging from 1.25 to 50 μM was added 5 min before recording intracellular Ca⁺² level variation. Endoplasmic (ER) Ca⁺² content is totally depleted in Ca⁺² free buffer by injection of 2 µM Thapsigargin (TG) and SOCE is next measured by the addition of 1.8 mM Ca⁺² in the extracellular medium. The magnitude of SOCE was estimated as the maximal values of the normalized F340/380 ratio following Ca⁺² re-addition. Effects on cytosolic calcium variations of the same compound 10h were also evaluated on a B cell line (PLP cell line) without detecting any inhibitory effects on SOCE and Ca²⁺ release.