17β-Estradiol rapidly mobilizes intracellular calcium from ryanodine-receptor-gated stores via a PKC–PKA–Erk-dependent pathway in the human eccrine sweat gland cell line NCL-SG3

SummaryWe describe a novel rapid non-genomic effect of 17β-estradiol (E2) on intracellular Ca2+ ([Ca2+]i) signalling in the eccrine sweat gland epithelial cell line NCL-SG3. E2 had no observable effect on basal [Ca2+]i, however exposure of cells to E2 in the presence of the microsomal Ca2+ ATPase pump inhibitor, thapsigargin, produced a secondary, sustained increase in [Ca2+]i compared to thapsigargin treatment alone, where cells responded with a transient single spike-like increase in [Ca2+]i. The E2-induced increase in [Ca2+]i was not dependent on the presence of extracellular calcium and was completely abolished by ryanodine (100 μM). The estrogen receptor antagonist ICI 182,780 (1 μM) prevented the E2-induced effects suggesting a role for the estrogen receptor in the release of [Ca2+]i from ryanodine-receptor-gated stores. The E2-induced effect on [Ca2+]i could also be prevented by the protein kinase C δ (PKCδ)-specific inhibitor rottlerin (10 μM), the protein kinase A (PKA) inhibitor Rp-adenosine 3′,5′-cyclic monophosphorothioate (200 μM) and the MEK inhibitor PD98059 (10 μM). We established E2 rapidly activates the novel PKC isoform PKCɛ, PKA and Erk 1/2 MAPK in a PKCδ and estrogen-receptor-dependent manner. The E2-induced effect was specific to 17β-estradiol, as other steroids had no effect on [Ca2+]i. We have demonstrated a novel mechanism by which E2 rapidly modulates [Ca2+]i release from ryanodine-receptor-gated intracellular Ca2+ stores. The signal transduction pathway involves the estrogen receptor coupled to a PKC–PKA–Erk 1/2 signalling pathway.