GPER acts through the cAMP/Epac/JNK/AP-1 pathway to induce transcription of alpha 2C adrenoceptor in human microvascular smooth muscle cells.

Fardoun, Manal; Nasser, Suzanne A; El-Yazbi, Ahmed F; Eid, Ali H

Abstract

Raynaud's phenomenon (RP), which results from exaggerated cold-induced vasoconstriction, is more prevalent in females than males. We previously showed that estrogen increases the expression of alpha 2C-adrenoceptors (α2C-AR), the sole mediator of cold-induced vasoconstriction. This effect of estrogen is reproduced by the cell-impermeable form of the hormone (E2:BSA), suggesting a role of the membrane estrogen receptor, GPER, in E2-induced α2C-AR expression. We also previously reported that E2 upregulates α2C-AR in microvascular smooth muscle cells (VSMCs) via the cAMP/Epac/Rap/JNK/AP-1 pathway, and that E2:BSA elevates cAMP levels. We, therefore, hypothesized that E2 employs GPER to upregulate α2C-AR through the cAMP/Epac/JNK/AP-1 pathway. Our results show that G15, a selective GPER antagonist, attenuates the E2-induced increase in α2C-AR transcription. G-1, a selective GPER agonist, induced α2C-AR transcription, which was concomitant with elevated cAMP levels and JNK activation. Pretreatment with ESI09, an Epac inhibitor, abolished both G-1-induced α2C-AR upregulation and JNK activation. Moreover, pretreatment with SP600125, a JNK specific inhibitor, but not H89, a PKA specific inhibitor, abolished G-1-induced α2C-AR upregulation. In addition, transient transfection of an Epac dominant negative mutant (Epac-DN) attenuated G-1-induced activation of α2C-AR promoter. This inhibitory effect of Epac-DN on α2C-AR promoter was overridden by the co-transfection of constitutively active JNK mutant. Furthermore, mutation of AP-1 site in the α2C-AR promoter abrogated G1-induced expression. Collectively, these results indicate that GPER upregulates α2C-AR through the cAMP/EPAC/ JNK/AP-1 pathway. These findings unravel GPER as a new mediator of cold-induced vasoconstriction, and present it as a potential target for treating RP in estrogen-replete females. [Abstract copyright: Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.]

Citation

Fardoun, M., Nasser, S. A., El-Yazbi, A. F., & Eid, A. H. (2023). GPER acts through the cAMP/Epac/JNK/AP-1 pathway to induce transcription of alpha 2C adrenoceptor in human microvascular smooth muscle cells. Journal of Cardiovascular Pharmacology, 82(6), 470-479. https://doi.org/10.1097/FJC.0000000000001489

• Journal Article Type: Article
• Acceptance Date: Sep 17, 2023
• Online Publication Date: Sep 28, 2023
• Publication Date: 2023-12
• Deposit Date: Oct 23, 2023
• Publicly Available Date: Sep 29, 2024
• Journal: Journal of cardiovascular pharmacology
• Print ISSN: 0160-2446
• Electronic ISSN: 1533-4023
• Publisher: Lippincott, Williams & Wilkins
• Peer Reviewed: Peer Reviewed
• Volume: 82
• Issue: 6
• Pages: 470-479
• DOI: https://doi.org/10.1097/FJC.0000000000001489
• Keywords: Raynaud's phenomenon; estrogen; vascular smooth muscle; alpha 2C adrenoceptor; G-protein estrogen receptor; peripheral vascular disease