title: Regulation of cyclooxygenase-2 expression in rat oviductal epithelial cells: Evidence for involvement of GPR30/Src kinase-mediated EGFR signaling.
abstract: The oviduct plays a crucial role in female reproduction by regulating gamete transport, providing a specific microenvironment for fertilization and early embryonic development. Cyclooxygenase (COX)-derived prostaglandins play essential role in carrying out these oviduct-specific functions. Estrogen upregulates COX-2 expression in rat oviduct; however, the mechanisms responsible for regulation of COX-2 expression in rat oviductal epithelial cells (OECs) remain unclear. In the present study, we proposed that estrogen induces COX-2 expression via G-protein coupled receptor i.e., GPR30 in OECs. To investigate this hypothesis, we examined the effects of E2-BSA, ICI 182,780, GPR30 agonist and GPR30 antagonist on COX-2 expression and explored potential signaling pathway leading to COX-2 expression. Co-localization experiments revealed GPR30 to be primarily located in the peri-nuclear space, which was also the site of E2-BSA-fluorescein isothiocyanate (E2-BSA-FITC) binding. The E2-BSA induced-COX-2 and prostaglandin release were subjected to regulation by both EGFR and PI3K signaling as inhibitors of c-Src kinase (PP2), EGFR (EGFR inhibitor) and PI-3 kinase (LY294002) attenuated E2-BSA mediated effect. These results suggest that EGFR transactivation leading to activation of PI-3K/Akt pathway participates in COX-2 expression in rat OECs. Interestingly, E2-BSA induced COX-2 expression and subsequent prostaglandin release were abolished by NF-κB inhibitor. In addition, E2-BSA induced the nuclear translocation of p65-NF-κB and up-regulated the NF-κB promoter activity in rat OECs. Taken together, results demonstrated that E2-BSA induced the COX-2 expression and consequent PGE2 and PGF2α release in rat OECs. These effects are mediated through GPR30-derived EGFR transactivation and PI-3K/Akt cascade leading to NF-κB activation.
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Pooja
authors.initials: P
authors.lastname: Popli
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Sirohi
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Murli
authors.initials: M
authors.lastname: Manohar
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Vinay
authors.initials: V
authors.lastname: Shukla
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Jyoti Bala
authors.initials: JB
authors.lastname: Kaushal
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India.
authors.forename: Kanchan
authors.initials: K
authors.lastname: Gupta
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, UP, India. Electronic address: anila.dwivedi@rediffmail.com.
authors.forename: Anila
authors.initials: A
authors.lastname: Dwivedi
mesh_terms: D000818:Animals; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D010057:Oviducts / Q000166:cytology / Q000201:enzymology*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D015398:Signal Transduction; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: C520305:Gper1 protein, rat; D043562:Receptors, G-Protein-Coupled; D051546:Cyclooxygenase 2; D066246:ErbB Receptors; D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt
keywords: COX-2; EGFR; GPR30; Oviductal epithelial cells; Src kinase