scholarly journals Regulation of Angiotensin Type 2 Receptor in Bovine Granulosa Cells

Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5004-5011 ◽  
Author(s):  
Valério M. Portela ◽  
Paulo B. D. Gonçalves ◽  
Angela M. Veiga ◽  
Edmir Nicola ◽  
José Buratini ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Theca Cells ◽  
Protein Levels ◽  
Estradiol Secretion ◽  
Morphogenetic Protein ◽  
Angiotensin Type 2 Receptor ◽  
Igf I ◽  
Follicle Atresia

Angiotensin II (AngII) is best known for its role in blood pressure regulation, but it also has documented actions in the reproductive system. There are two AngII receptors, type 1 (AGTR1) and type 2 (AGTR2). AGTR2 mediates the noncardiovascular effects of AngII and is expressed in the granulosa cell layer in rodents and is associated with follicle atresia. In contrast, expression of AGTR2 is reported to occur only in theca cells in cattle. The objective of the present study was to determine whether AngII also plays a role in follicle atresia in cattle. RT-PCR demonstrated AGTR2 mRNA in both granulosa and theca cells of bovine follicles. The presence of AGTR2 protein was confirmed by immunofluorescence. Abundance of AGTR2 mRNA in granulosa cells was higher in healthy compared with atretic follicles, whereas in theca cells, it did not change. Granulosa cells were cultured in serum-free medium, and treatment with hormones that increase estradiol secretion (FSH, IGF-I, and bone morphogenetic protein-7) increased AGTR2 mRNA and protein levels, whereas fibroblast growth factors inhibited estradiol secretion and AGTR2 protein levels. The addition of AngII or an AGTR2-specific agonist to granulosa cells in culture did not affect estradiol secretion or cell proliferation but inhibited abundance of mRNA encoding serine protease inhibitor E2, a protein involved in tissue remodeling. Because estradiol secretion is a major marker of nonatretic granulosa cells, these data suggest that AngII is not associated with follicle atresia in cattle but may have other specific roles during follicle growth.

scholarly journals Orexin A Enhances Pro-Opiomelanocortin Transcription Regulated by BMP-4 in Mouse Corticotrope AtT20 Cells

2021 ◽  
Vol 22 (9) ◽  
pp. 4553
Author(s):  
Satoshi Fujisawa ◽  
Motoshi Komatsubara ◽  
Naoko Tsukamoto-Yamauchi ◽  
Nahoko Iwata ◽  
Takahiro Nada ◽  
...  
Keyword(s):  
Stress Responses ◽  
Endocrine Function ◽  
Type I ◽  
Orexin A ◽  
Protein Levels ◽  
Bmp Receptors ◽  
Morphogenetic Protein ◽  
Crh Receptor Type 1

Orexin is expressed mainly in the hypothalamus and is known to activate the hypothalamic–pituitary–adrenal (HPA) axis that is involved in various stress responses and its resilience. However, the effects of orexin on the endocrine function of pituitary corticotrope cells remain unclear. In this study, we investigated the roles of orexin A in pro-opiomelanocortin (POMC) transcription using mouse corticotrope AtT20 cells, focusing on the bone morphogenetic protein (BMP) system expressed in the pituitary. Regarding the receptors for orexin, type 2 (OXR2) rather than type 1 (OX1R) receptor mRNA was predominantly expressed in AtT20 cells. It was found that orexin A treatment enhanced POMC expression, induced by corticotropin-releasing hormone (CRH) stimulation through upregulation of CRH receptor type-1 (CRHR1). Orexin A had no direct effect on the POMC transcription suppressed by BMP-4 treatment, whereas it suppressed Smad1/5/9 phosphorylation and Id-1 mRNA expression induced by BMP-4. It was further revealed that orexin A had no significant effect on the expression levels of type I and II BMP receptors but upregulated inhibitory Smad6/7 mRNA and protein levels in AtT20 cells. The results demonstrated that orexin A upregulated CRHR signaling and downregulated BMP-Smad signaling, leading to an enhancement of POMC transcription by corticotrope cells.

scholarly journals Expression of mRNA encoding IGF-I, IGF-II and type 1 IGF receptor in bovine ovarian follicles

2000 ◽  
Vol 165 (1) ◽  
pp. 101-113 ◽  
Author(s):  
DG Armstrong ◽  
CG Gutierrez ◽  
G Baxter ◽  
AL Glazyrin ◽  
GE Mann ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Granulosa Cells ◽  
Culture Media ◽  
Antral Follicles ◽  
Theca Cells ◽  
Stage Of Development ◽  
Igf I ◽  
Igf Receptor

IGFs regulate gonadotrophin-stimulated proliferation and differentiation of granulosa and theca cells in vitro. However, the detailed pattern of mRNA expression of IGFs in bovine follicles remains controversial. The objectives of this study were therefore to describe the temporal and spatial pattern of expression of mRNA encoding IGF-I, IGF-II and the type 1 IGF receptor in bovine follicles in vivo. The expression of mRNA encoding IGF-II was detected in theca tissue from around the time of antrum formation up to and during the development of dominance. No IGF-II mRNA expression was detected in granulosa cells. In the majority of follicles we were unable to detect mRNA encoding IGF-I in either granulosa or theca tissue from follicles at any stage of development. Occasionally low amounts of mRNA encoding IGF-I were detected in the theca externa and connective tissue surrounding some follicles. Type 1 IGF receptor mRNA was detected in both granulosa and theca cells of preantral and antral follicles. Expression was greater in granulosa tissue compared with theca tissue. We also measured IGF-I and -II mRNA in total RNA isolated from cultured granulosa and theca cells using reverse transcriptase PCR. In contrast to the in vivo results, IGF-II mRNA was detected in both granulosa and theca tissue. IGF-I mRNA was detected in theca tissue and in very low amounts in granulosa cells. Using a specific IGF-I RIA we were unable to detect IGF-I immunoreactivity in granulosa conditioned cell culture media. Using immunohistochemistry we detected IGF-I immunoreactivity in some blood vessels within the ovarian stroma. We conclude from these results that IGF-II is the principal intrafollicular IGF ligand regulating the growth of bovine antral follicles. In preantral follicles the expression of mRNA encoding type 1 IGF receptor but absence of endogenous IGF-I or -II mRNA expression, highlights a probable endocrine mechanism for the IGF regulation of preantral follicle growth.

Immunodetection and quantification of enzymatic markers in theca cells: the early process of ovarian steroidogenesis†

2019 ◽  
Author(s):  
P Asiabi ◽  
E C R Leonel ◽  
E Marbaix ◽  
M M Dolmans ◽  
C A Amorim
Keyword(s):  
Cytochrome P450 ◽  
Luteinizing Hormone ◽  
Granulosa Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Expression Intensity ◽  
Theca Cells ◽  
Perilipin 2 ◽  
Cytochrome P450c17

Abstract The association between theca cells (TCs) and granulosa cells is pivotal to steroid biosynthesis in the ovary. During the late secondary follicle stage, TCs form a layer around granulosa cells, after which their steroidogenic function falls under the control of luteinizing hormone (LH) that activates the cAMP signaling pathway via a G protein-coupled receptor. In addition to perilipin-2, a marker for lipid droplets containing esters as substrates for TCs to produce steroidogenic hormones, other essential proteins, like steroidogenic acute regulatory protein (StAR), cytochrome P450 11A1, cytochrome P450c17, 3 beta-hydroxysteroid dehydrogenase/delta 5 —> 4-isomerase type 1, and 3 beta-hydroxysteroid dehydrogenase/delta 5 —> 4-isomerase type 2, play a role in the cascade after luteinizing hormone–choriogonadotropic hormone receptor (LH/CG-R) occupation by LH. The aim of the present study was to assess expression levels and corresponding amounts of LH/CG-R, perilipin-2, and enzymes involved in the steroidogenic pathway of TCs based on follicle stage. Immunohistochemical analysis of each of these proteins was therefore performed on ovarian samples from nine adult women, most (n = 8) with BRCA1 and/or BRCA2 mutations undergoing prophylactic bilateral oophorectomy. Pictures were taken of the theca layer of secondary, small (<3000 μm), and large (>3000 μm) antral follicles and corpora lutea at 100× magnification. ImageJ software was used to analyze the surface area and expression intensity of each protein at each stage, known as the staining index. Overall, our data showed that LH/CG-R, perilipin-2, and StAR expression increased in the course of folliculogenesis and luteinization. Similarly, cytochrome P450 11A1, cytochrome P450c17, 3 beta-hydroxysteroid dehydrogenase/delta 5 —> 4-isomerase type 1, and 3 beta-hydroxysteroid dehydrogenase/delta 5 —> 4-isomerase type 2 expression were substantially elevated in TCs during folliculogenesis, evidenced by their coordinated action in terms of area covered and expression intensity. This study, conducted for the first time on human ovarian tissue, contributes to localizing and quantifying expression of key steroidogenic proteins at both intracellular and tissue levels. These findings may shed new light on pathological conditions involving the human ovary, such as androgen-secreting tumors of the ovary and other disorders associated with ovarian TCs in patients with polycystic ovary syndrome.

scholarly journals Activation of angiotensin type 2 receptor attenuates testosterone-induced hypertension and uterine vascular resistance in pregnant rats

2021 ◽  
Author(s):  
Jay S Mishra ◽  
Sathish Kumar
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Vascular Function ◽  
Uterine Artery ◽  
Artery Blood Flow ◽  
Protein Levels ◽  
Angiotensin Type 2 Receptor ◽  
Enos Protein ◽  
Angiotensin Type

Abstract Preeclampsia is a pregnancy-related hypertensive disorder with unclear mechanisms. While hypersensitivity to angiotensin II via vasoconstrictive angiotensin type-1 receptor (AT1R) is observed in preeclampsia, the importance of vasodilatory angiotensin type-2 receptor (AT2R) in the control of vascular dysfunction is less clear. We assessed whether AT1R, AT2R and eNOS expression is altered in placental vessels of preeclamptic women and tested if ex vivo incubation with AT2R agonist Compound 21 (C21; 1 μM) could restore AT1R, AT2R and eNOS balance. Further, using a rat model of gestational hypertension induced by elevated testosterone, we examined whether C21 (1 μg·kg−1·day−1, oral) could preserve AT1R and AT2R balance and improve blood pressure, uterine artery blood flow, and vascular function. Western blots revealed that AT1R protein level was higher while AT2R and eNOS protein were reduced in preeclamptic placental vessels, and AT2R agonist C21 decreased AT1R and increased AT2R and eNOS protein levels in preeclamptic vessels. In testosterone-dams, blood pressure was higher, and uterine artery blood flow was reduced, and C21 treatment reversed these levels similar to those in controls dams. C21 attenuated the exaggerated Ang II contraction and improved endothelium-dependent vasorelaxation in uterine arteries of testosterone-dams. These C21-mediated vascular effects were associated with decreased AT1R and increased AT2R and eNOS protein levels. C21 also increased serum nitrate/nitrite and bradykinin production in testosterone-dams and attenuated the feto-placental growth restriction. Thus, AT1R upregulation and AT2R downregulation is observed in preeclampsia and testosterone-model, and increasing AT2R activity could help restore AT1R and AT2R balance and improve gestational vascular function.

scholarly journals Bone morphogenetic protein-6 enhances gonadotrophin-dependent progesterone and inhibin secretion and expression of mRNA transcripts encoding gonadotrophin receptors and inhibin/activin subunits in chicken granulosa cells

Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Sara L Al-Musawi ◽  
Richard T Gladwell ◽  
Philip G Knight
Keyword(s):  
Bone Morphogenetic Protein ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Dependent Manner ◽  
Cell Type ◽  
Inhibin A ◽  
Theca Cells ◽  
Subunit Mrna ◽  
Morphogenetic Protein

The aims were to examine ovarian expression of bone morphogenetic protein (BMP) ligands/receptor mRNAs in the chicken and to test the hypothesis that theca-derived BMP(s) modulates granulosa cell function in a paracrine manner. RT-PCR revealed expression of multiple BMPs in granulosa and theca cells from prehierarchical and preovulatory follicles with greater expression in theca cells; both cell types expressed BMP receptors-IA, -IB and -II consistent with tissue responsiveness. Preovulatory granulosa cells (F1, F2 and F3/4) were cultured with BMP-6 (expressed by theca but not granulosa) in the presence/absence of LH, FSH or 8-Br-cAMP. BMP-6 increased ‘basal’ and gonadotrophin-induced inhibin-A and progesterone secretion by each cell type but did not enhance the effect of 8-Br-cAMP. This indicates that the observed synergism between BMP-6 and gonadotrophin might involve BMP-induced up-regulation of gonadotrophin receptors. In support of this, BMP-6 alone increased LH-receptor (LHR) mRNA in F1 cells and FSH-receptor (FSHR) mRNA in F1, F2 and F3/4 cells. BMP-6 also enhanced LH/FSH-induced LHR transcript amount in each cell type but did not raise FSHR transcript amounts above those induced by BMP-6 alone. To further explore BMP-6 action on inhibin-A secretion, we quantified inhibin/activin subunits (α, βA, βB) mRNAs. Consistent with its effect on inhibin-A secretion, BMP-6 enhanced ‘basal’ expression of α- and βA-subunit mRNA in F1, F2 and F3/4 cells, and βB-subunit mRNA in F3/4 cells. BMP-6 markedly enhanced FSH/LH-induced expression of α-subunit in all follicles and FSH-induced βA-subunit in F2 and F3/4 follicles but not in F1 follicles. Neither BMP-6 alone, nor FSH/LH alone, affected ‘basal’ βB mRNA abundance. However, co-treatment with gonadotrophin and BMP-6 greatly increased βB-subunit expression, the response being lowest in F1 follicles and greatest in F3/4 follicles. Collectively, these results support the hypothesis that intraovarian BMPs of thecal origin have a paracrine role in modulating granulosa cell function in the chicken in a preovulatory stage-dependent manner.

scholarly journals Zinc partitions IGFs from soluble IGF binding proteins (IGFBP)-5, but not soluble IGFBP-4, to myoblast IGF type 1 receptors

2004 ◽  
Vol 180 (2) ◽  
pp. 227-246 ◽  
Author(s):  
RH McCusker ◽  
J Novakofski
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Affinity Binding ◽  
Igf Binding Proteins ◽  
Igf I ◽  
Igf Binding ◽  
Igf Receptor ◽  
Igf Binding Protein

Zinc (Zn(2+)), a multifunctional micronutrient, was recently shown to lower the affinity of cell-associated insulin-like growth factor (IGF) binding protein (IGFBP)-3 and IGFBP-5 for both IGF-I and IGF-II, but to increase the affinity of the cell surface type 1 IGF receptor (IGF-1R) for the same two ligands. However, there is a need for data concerning the effects of Zn(2+) on soluble IGFBPs and the type 2 IGF receptor (IGF-2R). In the current work, we demonstrate that Zn(2+) affects the affinity of IGFBP-5 secreted by myoblasts but not IGFBP-4. Zn(2+), at physiological levels, depressed binding of both IGF-I and IGF-II to IGFBP-5, affecting (125)I-IGF-I more than (125)I-IGF-II. Both (125)I-IGF-I and (125)I-IGF-II bound to high and low affinity sites on IGFBP-5. Zn(2+) converted the high affinity binding sites of IGFBP-5 into low affinity binding sites. An IGF-I analog, (125)I-R(3)-IGF-I, did not bind to the soluble murine IGFBP-5. Zn(2+) also decreased the affinity of the IGF-2R on L6 myoblasts. In contrast, Zn(2+) increased IGF-I, IGF-II and R(3)-IGF-I binding to the IGF-1R by increasing ligand binding affinity on both P(2)A(2a)-LISN and L6 myoblasts. Soluble IGFBP-5 and IGFBP-4 depressed the binding of (125)I-IGF-I and (125)I-IGF-II to the IGF-1R, but did not affect binding of (125)I-R(3)-IGF-I. By depressing the association of the IGFs with soluble IGFBP-5, Zn(2+) partitioned (125)I-IGF-I and (125)I-IGF-II from soluble IGFBP-5 onto cell surface IGF-1Rs. This effect is not seen when soluble L6-derived IGFBP-4 is present in extracellular fluids. We introduce a novel mechanism by which the trace micronutrient Zn(2+) may alter IGF distribution, i.e. Zn(2+) acts to increase IGF-1R binding at the expense of IGF binding to soluble IGFBP-5 and the IGF-2R.

scholarly journals Regulation and action of fibroblast growth factor 17 in bovine follicles

2009 ◽  
Vol 202 (3) ◽  
pp. 347-353 ◽  
Author(s):  
M F Machado ◽  
V M Portela ◽  
C A Price ◽  
I B Costa ◽  
P Ripamonte ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Granulosa Cells ◽  
Cumulus Cells ◽  
Mrna Abundance ◽  
Fibroblast Growth ◽  
Theca Cells ◽  
Progesterone Secretion ◽  
Igf I

Fibroblast growth factor 17 (FGF17) is a member of the FGF8 subfamily that appears to be relevant to folliculogenesis and oogenesis, as the prototype member FGF8 is an oocyte-derived protein that signals to cumulus cells. FGF8 has structural and receptor-binding similarities to FGF17, whose expression in the ovary has not been reported. In this study, we demonstrate localization of FGF17 protein to the oocyte of preantral follicles, and to the oocyte and granulosa cells of antral follicles. Real-time PCR demonstrated the presence of mRNA in oocytes and, to a lesser extent, in granulosa and theca cells. FGF17 mRNA abundance was low in granulosa and theca cells from healthy follicles and increased significantly in atretic follicles. Addition of FSH or IGF-I to granulosa cells in vitro decreased FGF17 mRNA abundance, and treatment with FGF17 inhibited estradiol and progesterone secretion from granulosa cells in relation to control cultures without these additives. We conclude that FGF17 is a potential mediator of granulosa cell differentiation.

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