scholarly journals Steroidogenic acute regulatory (StAR) protein (p25) and prohibitin (p28) from cultured rat ovarian granulosa cells

Reproduction ◽  
1997 ◽  
Vol 109 (2) ◽  
pp. 337-348 ◽  
Author(s):  
W. E. Thompson ◽  
A. Sanbuissho ◽  
G. Y. Lee ◽  
E. Anderson
Keyword(s):  
Granulosa Cells ◽  
Star Protein ◽  
Ovarian Granulosa Cells ◽  
Steroidogenic Acute Regulatory

scholarly journals Interactions among Peroxisome Proliferator Activated Receptor-γ, Insulin Signaling Pathways, and Steroidogenic Acute Regulatory Protein in Human Ovarian Cells

2007 ◽  
Vol 92 (6) ◽  
pp. 2232-2239 ◽  
Author(s):  
Donna Seto-Young ◽  
Dimiter Avtanski ◽  
Marina Strizhevsky ◽  
Grishma Parikh ◽  
Parini Patel ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Signaling Pathways ◽  
Granulosa Cells ◽  
Insulin Signaling ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Star Protein ◽  
Ppar Γ ◽  
Ovarian Cells ◽  
Steroidogenic Acute Regulatory

Abstract Context and Objective: Peroxisome proliferator activated receptor-γ (PPAR-γ) agonists thiazolidinediones (TZDs) are thought to ameliorate hyperandrogenism in polycystic ovary syndrome by reducing hyperinsulinemia. However, TZDs also exhibit direct effects in the human ovary. We examined interactions among PPAR-γ, insulin signaling pathways, and steroidogenic acute regulatory (StAR) protein in human ovarian cells. Materials and Methods: Mixed human ovarian tissue culture that contained granulosa, theca, and stromal cells, and a culture of purified granulosa cells obtained during in vitro fertilization, were established as previously described. Cells were cultured in the presence or absence of insulin, with or without 25 or 50 μm rosiglitazone or pioglitazone. Expression of PPAR-γ, insulin receptor, or insulin receptor substrate (IRS)-1 in both cell systems and of the StAR protein in granulosa cells was measured using immunoprecipitation and immunoblotting. Results: Rosiglitazone stimulated expression of PPAR-γ, insulin receptor α- and β-subunits, and IRS-1 up to 168% (P < 0.05), 679% (P < 0.006), 290% (P < 0.037), and 323% (P < 0.01) of baseline, respectively. Pioglitazone stimulated expression of PPAR-γ, insulin receptor α- and β-subunits, and IRS-1 up to 222% (P < 0.01), 362% (P < 0.001), 402% (P < 0.029), and 492% (P < 0.03), respectively. Insulin alone stimulated expression of PPAR-γ, α-subunit and β-subunit of insulin receptor, and IRS-1 up to 174% (P < 0.001), 692% (P < 0.014), 275% (P < 0.024), and 431% (P < 0.01), respectively. In purified granulosa cell culture, rosiglitazone stimulated expression of StAR protein up to 540% (P < 0.007), and pioglitazone stimulated expression of StAR protein up to 670% (P < 0.007). Insulin alone stimulated expression of StAR protein up to 600% (P < 0.012). Conclusions: Insulin and TZDs independently stimulate expression of PPAR-γ, insulin receptor, IRS-1, and StAR protein in human ovarian cells. Thus, PPAR-γ, insulin receptor with its signaling pathways, and StAR protein constitute a novel human ovarian regulatory system with complex interactions among its components.

scholarly journals The involvement of hypoxia-inducible factor 1α (HIF1α)-stabilising factors in steroidogenic acute regulatory (STAR) protein-dependent steroidogenesis in murine KK1 granulosa cells in vitro

2021 ◽  
Vol 33 (18) ◽  
pp. 865
Author(s):  
Tina Gysin ◽  
Mariusz P. Kowalewski
Keyword(s):  
Granulosa Cells ◽  
Hypoxia Inducible Factor ◽  
Severe Hypoxia ◽  
Prolyl Hydroxylases ◽  
Von Hippel Lindau ◽  
Star Protein ◽  
Functional Aspects ◽  
Functional Blocking ◽  
Steroidogenic Acute Regulatory

As a component of hypoxia-inducible factor1 (HIF1)-complexes, HIF1α regulates the expression of steroidogenic acute regulatory (STAR) protein in granulosa cells. However, severe hypoxia or exaggeratedly expressed HIF1α have detrimental effects. HIF1α is regulated by factor inhibiting HIF (FIH), prolyl hydroxylases (PHD1, 2, 3) and von Hippel-Lindau (VHL) suppressor protein. In this study, the expression of FIH, PHD1, 2, 3 and VHL was investigated in murine ovaries and immortalised KK1 granulosa cells. We found FIH, VHL and PHD2 transcripts predominantly in growing tertiary follicles. Functional aspects were assessed in KK1 cells exposed to decreasing O2 (20%, 10%, 1%), by determining HIF1α, FIH, VHL, PHD1–3 and STAR expression. The main findings indicated gradually increasing PHD2 under lowered O2. Functional blocking of PHDs revealed biphasic effects on STAR expression; concomitantly with increasing HIF1α, STAR expression, which was initially induced, decreased significantly when HIF1α was strongly stabilised. Finally, PHD2 in particular might act as a specific regulator of HIF1α and, thereby, of STAR availability in granulosa cells.

Effect of follicle size and atresia grade on mitochondrial membrane potential and steroidogenic acute regulatory protein expression in bovine granulosa cells

Zygote ◽  
2018 ◽  
Vol 26 (6) ◽  
pp. 476-484
Author(s):  
Angela Ostuni ◽  
Maria Pina Faruolo ◽  
Carmen Sileo ◽  
Agata Petillo ◽  
Raffaele Boni
Keyword(s):  
Membrane Potential ◽  
Protein Expression ◽  
Mitochondrial Membrane Potential ◽  
Granulosa Cells ◽  
Mitochondrial Membrane ◽  
Tunel Assay ◽  
Aromatase Activity ◽  
Star Protein ◽  
Follicle Atresia ◽  
Steroidogenic Acute Regulatory

SummaryDuring follicular development, granulosa cells undergo functional and structural changes affecting their steroidogenic activity. Oestrogen synthesis mainly occurs in the endoplasmic reticulum and relies on aromatase activity to convert androgens that arise from theca cells. In the present study, indicators of mitochondria-related steroidogenic capacity, as steroidogenic acute regulatory (StAR) protein expression and mitochondrial membrane potential (MMP), have been evaluated in bovine granulosa cells (GCs) and related to follicle growth and atresia. Atresia was estimated by morphological examination of follicle walls and cumulus–oocyte complexes (COC) and assessed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay for apoptosis detection. Bovine ovarian follicles were macroscopically classified according to their atresia grade and grouped into small, medium or large follicles. After follicle opening, the COCs were morphologically classified for follicle atresia and the GCs were collected. Granulosa cells were fixed for immunofluorescence (IF) and TUNEL assay, frozen for western blotting (WB) or freshly maintained for MMP analyses. StAR protein expression was assessed using both IF and WB analyses. The follicle atresia grade could be efficiently discriminated based on either follicle wall or COC morphological evaluations. Granulosa cells collected from small non-atretic follicles showed a higher (P <0.01) MMP and WB-based StAR protein expression than small atretic follicles. For IF analysis, StAR protein expression in large atretic follicles was higher (P <0.05) than that in large non-atretic follicles. These results suggest a role played by mitochondria in GC steroidogenic activity, which declines in healthy follicles along with their growth. In large follicles, steroidogenic activity increases with atresia and is possibly associated with progesterone production.

scholarly journals Lindane, a gap junction blocker, suppresses FSH and transforming growth factor β1-induced connexin43 gap junction formation and steroidogenesis in rat granulosa cells

2005 ◽  
Vol 184 (3) ◽  
pp. 555-566 ◽  
Author(s):  
Ferng-Chun Ke ◽  
Su-Huan Fang ◽  
Ming-Ting Lee ◽  
Shiow-Yhu Sheu ◽  
Si-Yi Lai ◽  
...  
Keyword(s):  
Growth Factor ◽  
Gap Junctions ◽  
Gap Junction ◽  
Granulosa Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Cell Periphery ◽  
Star Protein ◽  
Ovarian Granulosa Cells ◽  
Progesterone Production

The present study was designed to explore the role of gap junctions in follicle-stimulating hormone (FSH) and transforming growth factor β1 (TGFβ1)-stimulated steroidogenesis in ovarian granulosa cells of gonadotropin-primed immature rats. There were three specific aims. First, we investigated the effect of FSH and TGFβ1 as well as lindane (a general gap junction blocker) on the level of connexin43 (Cx43), the major gap junction constituent in granulosa cells, and on gap junction function. The second aim was to determine the effect of lindane on FSH and TGFβ1-stimulated progesterone production and the levels of two critical players, cytochrome P450 side-chain cleavage (P450scc) enzyme and steroidogenic acute regulatory (StAR) protein. The third aim was to further investigate the specific involvement of Cx43 gap junctions in FSH and TGFβ1-stimulated steroidogenesis using a Cx43 mimetic peptide blocker. Immunoblotting analysis showed that FSH plus TGFβ1 dramatically increased the levels of phosphorylated Cx43 without significantly influencing the level of nonphosphorylated Cx43, and this stimulatory effect was completely suppressed by lindane. Also, immunofluorescence analysis showed that Cx43 immuno-reactivity increased in the FSH plus TGFβ1-treated group and predominantly appeared in a punctate pattern at cell–cell contact sites, and lindane reduced such cell periphery immunostaining. Furthermore, TGFβ1 enhanced the FSH-induced gap junction intercellular communication and lindane completely suppressed this effect. In addition, lindane suppressed the FSH and TGFβ1-stimulated increases in progesterone production and the levels of P450scc enzyme and StAR protein. This study demonstrates a clear temporal association between the Cx43 protein level/gap junction communication and progesterone production in rat ovarian granulosa cells in response to FSH and TGFβ1 as well as lindane. Furthermore, a specific Cx43 gap junction blocker suppressed FSH plus TGFβ1-stimulated progesterone production. In conclusion, this study suggests that Cx43 gap junctions may play a critical role in FSH plus TGFβ1-stimulated progesterone production in rat ovarian granulosa cells.

cDNA cloning reveals the potential of human ovarian granulosa cells to secrete collagenase inhibitor

1989 ◽  
Vol 120 (3_Suppl) ◽  
pp. S138
Author(s):  
J. FREUDENSTEIN ◽  
J. MUCHA ◽  
G. RAPP ◽  
K. H. SHEIT
Keyword(s):  
Cdna Cloning ◽  
Granulosa Cells ◽  
Ovarian Granulosa Cells ◽  
Collagenase Inhibitor

C-myc promotes miR-92a-2-5p transcription in rat ovarian granulosa cells after cadmium exposure

2021 ◽  
Vol 421 ◽  
pp. 115536
Author(s):  
Yi Sun ◽  
Chaowei Zong ◽  
Jin Liu ◽  
Lingfeng Zeng ◽  
Qingyu Li ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Cadmium Exposure ◽  
Ovarian Granulosa Cells
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