Progesterone increases nitric oxide synthesis in human vascular endothelial cells through activation of membrane progesterone receptor-α

Abstract

Pang Y, Dong J, Thomas P. Progesterone increases nitric oxide synthesis in human vascular endothelial cells through activation of membrane progesterone receptor-␣. Am J Physiol Endocrinol Metab 308: E899 -E911, 2015. First published March 24, 2015; doi:10.1152/ajpendo.00527.2014.-Progesterone exerts beneficial effects on the human cardiovascular system by inducing rapid increases in nitric oxide (NO) production in vascular endothelial cells, but the receptors mediating these nongenomic progesterone actions remain unclear. Using human umbilical vein endothelial cells (HUVECs) as a model, we show that progesterone binds to plasma membranes of HUVECs with the characteristics of membrane progesterone receptors (mPRs). The selective mPR agonist Org OD 02-0 had high binding affinity for the progesterone receptor on HUVEC membranes, whereas nuclear PR (nPR) agonists R5020 and medroxyprogesterone acetate displayed low binding affinities. Immunocytochemical and Western blot analyses confirmed that mPRs are expressed in HUVECs and are localized on their plasma membranes. NO levels increased rapidly after treatment with 20 nM progesterone, Org OD 02-0, and a progesterone-BSA conjugate but not with R5020, suggesting that this progesterone action is at the cell surface and initiated through mPRs. Progesterone and Org OD 02-0 (20 nM) also significantly increased endothelial nitric oxide synthase (eNOS) activity and eNOS phosphorylation. Knockdown of mPR␣ expression by treatment with small-interfering RNA (siRNA) blocked the stimulatory effects of 20 nM progesterone on NO production and eNOS phosphorylation, whereas knockdown of nPR was ineffective. Treatment with PI3K/ Akt and MAP kinase inhibitors blocked the stimulatory effects of progesterone, Org OD 02-0, and progesterone-BSA on NO production and eNOS phosphorylation and also prevented progesterone-and Org OD 02-0-induced increases in Akt and ERK phosphorylation. The results suggest that progesterone stimulation of NO production in HUVECs is mediated by mPR␣ and involves signaling through PI3K/Akt and MAP kinase pathways. membrane progesterone receptors; human vascular endothelial cells; rapid progesterone action; nitric oxide; nitric oxide synthase FEMALE REPRODUCTIVE HORMONES are widely considered to have beneficial effects on cardiovascular functions in women. The lower incidence of cardiovascular disease in middle-aged premenopausal women than in men and postmenopausal women has been attributed to the presence of female sex steroids in the circulation (22,27,41,47). Blood pressure is typically lower in women than in men and often drops during pregnancy when circulating levels of estrogens and progesterone are elevated (30,70,71). Furthermore, synthesis of a major regulator of vasodilation, nitric oxide (NO), is greater in women than in men (14). These sex differences in the occurrence of cardiovascular disease are due partly to the well-known beneficial effects of estrogens, which include upregulation of NO production in human endothelial cells (7,18,28,33). Numerous...

Epigenetic Regulation of the Nitric Oxide Pathway, 17-α Hydroxyprogesterone Caproate, and Recurrent Preterm Birth

“…12 Progesterone is known to stimulate nitric oxide synthesis via transcriptional and non-transcriptional pathways in human endothelial cells. 13–16 Nitric oxide expression generally increases during pregnancy and decreases before parturition, 17 and nitric oxide is known to regulate vasodilation, smooth muscle relaxation, and the inflammatory response during pregnancy. However, myometrial relaxation occurs in a cGMP-independent manner.…”

Participation of membrane progesterone receptor α in the inhibitory effect of progesterone on prolactin secretion

“…These actions are relatively unaffected by inhibitors of transcription, as mimicked by steroids coupled to nonpermeant cell membrane molecules and persist in cells that do not express the classic genomic progesterone receptor . The mPRs belong to the progestin and adipoQ receptor (PAQR) family and were first identified in teleost fish, although it was later discovered that 5 subtypes (mPRα, mPRβ, mPRγ, mPRδ and mPRε) are found in tissues of several mammalian species, including humans . These receptors contain 7 transmembrane domains, display high‐affinity progesterone binding and rapidly activate G proteins during their downstream signalling pathways following progestin binding .…”

Trimetazidine therapy for diabetic mouse hearts subjected to ex vivo acute heart failure

“…However, some found that physiologically high progesterone levels are associated with increased congestive heart failure prevalence [37], while the first clues of its role in energy metabolism only emerged more recently, i.e. mediating its effects via the progesterone receptor-α to subsequently activate PI3-K/AKT-1 and MAPK in addition to increased endothelial nitric oxide (eNOS) activity and NO production [38, 39]. …”