title: PGF2α modulates the output of chemokines and pro-inflammatory cytokines in myometrial cells from term pregnant women through divergent signaling pathways.
abstract: Prostaglandin F2α (PGF2α) plays a critical role in the initiation and process of parturition. Since human labor has been described as an inflammatory event, we investigated the role of PGF2α in the inflammatory process using cultured human uterine smooth muscle cells (HUSMCs) isolated from term pregnant women as a model. Using a multiplex assay, HUSMCs treated with PGF2α changed their output of a number of cytokines and chemokines, with a distinct response pattern that differed between HUSMCs isolated from the upper and lower segment region of the uterus. Confirmatory enzyme-linked immunosorbent assays (ELISAs) showed that PGF2α stimulated increased output of interleukin (IL) 1β, IL6, IL8 (CXCL8) and monocyte chemotactic protein-1 (MCP1, also known as chemokine (c-c motif) ligand 2, CCL2) by HUSMCs isolated from both upper and lower uterine segments. In contrast, PGF2α inhibited tumor necrosis factor α (TNFα) release by HUMSCs from the lower uterine segment while the output of TNFα was undetectable in the upper segment. Small interfering (si) RNA mediated knockdown of the PGF2α receptor prevented the changes in cytokine and chemokine output by the HUSMCs. Since the PGF2α receptor (PTGFR) couples via the Gq protein and subsequently activates the phospholipase C (PLC) and protein kinase C (PKC) signaling pathways, we examined the role of these pathways in PGF2α modulation of the cytokines. Inhibition of PLC and PKC reversed the effects of PGF2α. PGF2α activated multiple signaling pathways including extracellular signal-regulated kinases (ERK) 1/2, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), P38, calcineurin/nuclear factor of activated T-cells (NFAT) and NF-κB signaling. Inhibition of ERK reversed PGF2α-induced IL1β, IL6 and CCL2 output, while inhibition of PI3K blocked the effect of PGF2α on IL6, CXCL8 and CCL2 output and inhibition of NF-κB reversed PGF2α-induced IL1β and CCL2 output. NFAT was involved in PGF2α modulation of CCL2 and TNFα output. In conclusion, our results support a role of PGF2α in creating an inflammatory environment during the late stage of human pregnancy.
authors.affiliation: Department of Physiology, Second Military Medical University, Shanghai 200433, China Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada.
authors.forename: Chen
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Physiology, Second Military Medical University, Shanghai 200433, China.
authors.forename: Weina
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Physiology, Second Military Medical University, Shanghai 200433, China.
authors.forename: Xingji
authors.initials: X
authors.lastname: You
authors.affiliation: Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada.
authors.forename: Kelycia
authors.initials: K
authors.lastname: Leimert
authors.affiliation: Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada.
authors.forename: Krystyn
authors.initials: K
authors.lastname: Popowycz
authors.affiliation: Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada.
authors.forename: Xin
authors.initials: X
authors.lastname: Fang
authors.affiliation: Department of Obstetrics and Gynecology, University of Calgary, Calgary T2N1N4, Canada.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Wood
authors.affiliation: Department of Obstetrics and Gynecology, University of Calgary, Calgary T2N1N4, Canada Departments of Physiology and Pharmacology, University of Calgary, Calgary T2N1N4, Canada.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Slater
authors.affiliation: Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Gu
authors.affiliation: Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada nixin@smmu.edu.cn david.olson@ualberta.ca.
authors.forename: David M
authors.initials: DM
authors.lastname: Olson
authors.affiliation: Department of Physiology, Second Military Medical University, Shanghai 200433, China nixin@smmu.edu.cn david.olson@ualberta.ca.
authors.forename: Xin
authors.initials: X
authors.lastname: Ni
mesh_terms: D018925:Chemokines / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D006801:Humans; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009215:Myometrium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D018925:Chemokines; D016207:Cytokines; D015237:Dinoprost
keywords: PGF2α; inflammation; labor; myometrium; pregnancy