G protein-coupled estrogen receptor inhibits the P2Y receptor-mediated Ca(2+) signaling pathway in human airway epithelia.
P2Y receptor activation causes the release of inflammatory cytokines in the bronchial epithelium, whereas G protein-coupled estrogen receptor (GPER), a novel estrogen (E2) receptor, may play an anti-inflammatory role in this process. We investigated the cellular mechanisms underlying the inhibitory effect of GPER activation on the P2Y receptor-mediated Ca(2+) signaling pathway and cytokine production in airway epithelia. Expression of GPER in primary human bronchial epithelial (HBE) or 16HBE14o- cells was confirmed on both the mRNA and protein levels. Stimulation of HBE or 16HBE14o- cells with E2 or G1, a specific agonist of GPER, attenuated the nucleotide-evoked increases in [Ca(2+)]i, whereas this effect was reversed by G15, a GPER-specific antagonist. G1 inhibited the secretion of two proinflammatory cytokines, interleukin (IL)-6 and IL-8, in cells stimulated by adenosine 5'-(γ-thio)triphosphate (ATPγS). G1 stimulated a real-time increase in cAMP levels in 16HBE14o- cells, which could be inhibited by adenylyl cyclase inhibitors. The inhibitory effects of E2 or G1 on P2Y receptor-induced increases in Ca(2+) were reversed by treating the cells with a protein kinase A (PKA) inhibitor. These results demonstrated that the inhibitory effects of G1 or E2 on P2Y receptor-mediated Ca(2+) mobilization and cytokine secretion were due to GPER-mediated activation of a cAMP-dependent PKA pathway. This study has reported, for the first time, the expression and function of GPER as an anti-inflammatory component in human bronchial epithelia, which may mediate through its opposing effects on the pro-inflammatory pathway activated by the P2Y receptors in inflamed airway epithelia.
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Yuan
Y
Hao
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Alison W
AW
Chow
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Wallace C
WC
Yip
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Chi H
CH
Li
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Tai F
TF
Wan
School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.
Benjamin C
BC
Tong
School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.
King H
KH
Cheung
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Wood Y
WY
Chan
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Yangchao
Y
Chen
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong. chkcheng@cuhk.edu.hk.
Christopher H
CH
Cheng
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong. whko@cuhk.edu.hk.
Wing H
WH
Ko
D001980:Bronchi / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D058470:Receptors, Purinergic P2Y / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
D004967:Estrogens; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled; D058470:Receptors, Purinergic P2Y; D017868:Cyclic AMP-Dependent Protein Kinases; D002118:Calcium
Calcium signaling; GPER; Human bronchial epithelial cells; P2Y receptor signaling pathway; cAMP