Regulation of Bovine Tumor Necrosis Factor-α-Induced Protein 6 in Ovarian Follicles during the Ovulatory Process and Promoter Activation in Granulosa Cells

Centre de Recherche en Reproduction Animale and the Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada J2S 7C6.
Endocrinology (Impact Factor: 4.5). 09/2008; 149(12):6213-25. DOI: 10.1210/en.2008-0459
Source: PubMed


To study the regulation of bovine TNFalpha-induced protein 6 (TNFAIP6) prior to ovulation, preovulatory follicles obtained after the treatment with human chorionic gonadotropin (hCG) were used. RT-PCR analyses showed that levels of TNFAIP6 mRNA were low before hCG but significantly increased after hCG treatment in follicles. Further analyses and immunohistochemistry indicated that this increase in transcript and protein levels occurred in theca and granulosa cells. To investigate molecular mechanisms involved in TNFAIP6 transactivation, the activity of bovine TNFAIP6 promoter was studied in granulosa cell cultures. Mutant studies identified the minimal region conferring full-length promoter activity, in which activator protein-1 (AP1) and cAMP response element (CRE) elements were required for promoter activity. Overexpression of dominant-negative AP1 and activating transcription factor/cAMP response element-binding protein (CREB) inhibited forskolin-inducible promoter activity. DNA binding assays demonstrated the importance of AP1 and CRE for activity and identified JunD, FosB, Fra2, CREB1, and CREB2 as being part of the AP1 complex, and FosB, Fra2, and CREB1 for the CRE complex. Chromatin immunoprecipitation assays confirmed binding of these proteins with endogenous TNFAIP6 promoter. Treatment with forskolin, prostaglandin E2, and catalytic subunit protein kinase (cPKA) stimulated, but H89, PKA inhibitor peptide, and indomethacin inhibited, TNFAIP6 promoter activity and gene expression in granulosa cells. Collectively, this study is the first to describe that the ovulatory process in cows is associated with a gonadotropin-dependent induction of TNFAIP6 in ovarian follicles and provide the molecular basis through which AP1 and CRE sites and PKA activation played important roles in the regulation of TNFAIP6 in granulosa cells.

14 Reads
  • Source
    • "The expression of TNFAIP6 was without any changes after bovine OCC were stimulated with EGF. This is not surprising, since Sayasith et al. (2008) demonstrated gonadotropindependent induction of TNFAIP6 in bovine ovarian follicles and provided the evidence that PKA activation plays an important role in the regulation of TNFAIP6 in bovine granulosa cells. "
    [Show abstract] [Hide abstract]
    ABSTRACT: It has been shown that following endogenous gonadotropin surge, oocyte-cumulus complexes (OCC) synthesize hyaluronan (HA) in a process called cumulus expansion. During this process, HA associates with proteins and proteoglycans to form the expanded HA-rich oocyte-cumulus extracellular matrix (ECM), where the heavy chains of the serum derived inter-α-trypsin inhibitor family (IαI) bind covalently to HA. No study has been performed on the occurrence and regulation of this process during oocyte maturation in species other than mouse and pig, although, the heavy chains (of IαI)-HA complex was purified from human amniotic membrane. The present review pointing out that: 1/ formation of expanded HA-rich oocyte-cumulus ECM is dependent on the presence of IαI molecules, 2/ the heavy chains of IαI molecules identified in the serum are covalently linked to HA during cumulus expansion in mouse and pig, 3/ the family of IαI molecules can freely cross the blood-follicle barrier, and the follicular fluid collected at any stage of folliculogenesis can be successfully used instead of serum to form expanded cumulus ECM in pig, and 4/ proteins of the IαI family can affect reproductive process by modulating the expression of a large number of cellular genes during a preovulatory period. Finally, this review provides clear evidence that IαI family members present in the serum or follicular fluid become responsible for cumulus expansion, as without these proteins, expanded cumulus HA-rich ECM is not formed and HA is released into medium. cumulus expansion, cumulus-extracellular matrix, hyaluronan, inter-α-trypsin inhibitor.
    Endocrine Regulations 02/2015; 49(1):37-45. DOI:10.4149/endo_2015_01_37
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study was designed to evaluate whether the alteration of aquaporin-9 (AQP-9) expression in granulosa cells (GCs) of patients with polycystic ovary syndrome (PCOS) was associated with the hyperandrogenism in follicular fluid (FF). We recruited infertile women with PCOS (n = 14) and infertile women with tubal blockage (controls, n = 31) for this study. We examined total testosterone (TT), free androgen index (FAI), sex hormone-binding globulin (SHBG), FSH, LH and estradiol in FF. Real-time PCR and western blotting were performed to assess AQP-9 expression in GCs, including effects of dihydrotestosterone (DHT) in vitro. AQP-9 protein was localized in the nucleus, cytoplasm and cell membrane of the human GCs. The TT, FAI and LH levels were all higher, and SHBG levels lower, in the FF of women with PCOS versus controls (P = 0.0145, 0.0001, 0.0191, 0.0001, respectively). AQP-9 mRNA level in GCs of patients with PCOS was tightly correlated with the TT, SHBG levels and FAI in FF (P = 0.0020, 0.0001, 0.0020, respectively). In vitro, DHT (10(-9) mol/l) decreased AQP-9 mRNA (lowest at 12 h) and protein levels in control GCs (P = 0.0005, 0.0247, respectively). The inhibitory effect of DHT on AQP-9 mRNA was attenuated by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor (P = 0.0013). Fifty micromolar 4-(hydroxymercuri) benzoic acid sodium salt (PMB) and 10(-9) mol/l DHT blunted the swelling of GCs in hypotonic medium, respectively (P = 0.0350, 0.0027). Hyperandrogenism in FF of women with PCOS inhibited AQP-9 in GCs through the PI3K pathway.
    Human Reproduction 04/2010; 25(6):1441-50. DOI:10.1093/humrep/deq078 · 4.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To identify reliable genomic biomarkers expressed in cumulus cells that accurately and non-invasively predict the oocyte developmental competence and reinforce the already used morphological criteria. Eight consenting patients were selected for ovarian stimulation and ICSI procedures. Cumulus-oocyte complexes were transvaginally punctured and individually selected based on both good morphological criteria and high zona pellucida birefringence. Following ICSI, two 3-day embryos per patient were transferred. Pregnancy outcome was recorded and proven implantation was thereafter confirmed. Differential gene expression was assessed using two microarray platforms. Further real-time PCR validation, Ingenuity pathways analysis and intra-patient analysis were performed on 17 selected candidates. Seven genes were differentially (p ≤ 0.05) associated to successful pregnancy and implantation. These biomarkers could be used to predict the oocyte developmental competence. These genomic markers are a powerful reinforcement of morphological approaches of oocyte selection. Their large-scale validation could increase pregnancy outcome and single embryo transfer efficiency.
    Journal of Assisted Reproduction and Genetics 10/2010; 28(2):173-88. DOI:10.1007/s10815-010-9491-7 · 1.72 Impact Factor
Show more


14 Reads