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.

Suppression of PPAR-γ attenuates insulin-stimulated glucose uptake by affecting both GLUT1 and GLUT4 in 3T3-L1 adipocytes

2007 ◽  
Vol 293 (1) ◽  
pp. E219-E227 ◽  
Author(s):  
Wei Liao ◽  
M. T. Audrey Nguyen ◽  
Takeshi Yoshizaki ◽  
Svetlana Favelyukis ◽  
David Patsouris ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Insulin Signaling ◽  
Adipocyte Differentiation ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Tnf Α ◽  
Interfering Rna

Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays a critical role in regulating insulin sensitivity and glucose homeostasis. In this study, we identified highly efficient small interfering RNA (siRNA) sequences and used lentiviral short hairpin RNA and electroporation of siRNAs to deplete PPAR-γ from 3T3-L1 adipocytes to elucidate its role in adipogenesis and insulin signaling. We show that PPAR-γ knockdown prevented adipocyte differentiation but was not required for maintenance of the adipocyte differentiation state after the cells had undergone adipogenesis. We further demonstrate that PPAR-γ suppression reduced insulin-stimulated glucose uptake without affecting the early insulin signaling steps in the adipocytes. Using dual siRNA strategies, we show that this effect of PPAR-γ deletion was mediated by both GLUT4 and GLUT1. Interestingly, PPAR-γ-depleted cells displayed enhanced inflammatory responses to TNF-α stimulation, consistent with a chronic anti-inflammatory effect of endogenous PPAR-γ. In summary, 1) PPAR-γ is essential for the process of adipocyte differentiation but is less necessary for maintenance of the differentiated state, 2) PPAR-γ supports normal insulin-stimulated glucose transport, and 3) endogenous PPAR-γ may play a role in suppression of the inflammatory pathway in 3T3-L1 cells.

Rosiglitazone increases expression of steroidogenic acute regulatory protein and progesterone production through PPARγ–EGFR–ERK1/2 in human cumulus granulosa cells

2019 ◽  
Vol 31 (11) ◽  
pp. 1647
Author(s):  
Kristina Pogrmic-Majkic ◽  
Gordana Kosanin ◽  
Dragana Samardzija Nenadov ◽  
Svetlana Fa ◽  
Bojana Stanic ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Regulatory Protein ◽  
Growth Factor Receptor ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Peroxisome Proliferator Activated Receptor ◽  
Progesterone Production ◽  
Extracellular Signal ◽  
Epidermal Growth ◽  
Steroidogenic Acute Regulatory

The mechanism by which rosiglitazone (ROSI: a thiazolidinedione (TZD)) affects steroid production in undifferentiated human granulosa cells is not known. In this study, cultured human cumulus granulosa cells were exposed to ROSI and pharmacological inhibitors of the extracellular signal-regulated kinase 1/2 (ERK1/2), epidermal growth factor receptor (EGFR) and peroxisome proliferator-activated receptor gamma (PPARγ) signalling pathways. Expression of progesterone biosynthetic enzymes, PPARγ and PPARα, progesterone production and ERK1/2 activation were analysed. After 48h, 30μM ROSI increased STAR, 3βHSD and PPARγ mRNA and elevated progesterone production in human cumulus granulosa cells. Addition of ERK1/2 (U0126), EGFR (AG1478) and PPARγ (GW9662) inhibitors prevented the ROSI-induced STAR mRNA expression and progesterone production after 48h. Inhibition of PPARγ, but not EGFR or ERK1/2, decreased the PPARγ mRNA levels induced by ROSI in human cumulus granulosa cells after 48h. On the other hand, U0126 and GW9662 prevented the ROSI-induced increase in PPARγ transcripts after 6h. Western blot analysis showed that ROSI induced a rapid ERK1/2 activation, which was prevented by inhibition of ERK1/2, EGFR and PPARγ in human cumulus granulosa cells. Overall, these data suggested that PPARγ, EGFR and ERK1/2 were involved in the stimulatory effect of ROSI on STAR expression and progesterone production in undifferentiated human cumulus granulosa cells.

Involvement of peroxisome proliferator-activated receptor γ in gonadal steroidogenesis and steroidogenic acute regulatory protein expression

2009 ◽  
Vol 21 (7) ◽  
pp. 909 ◽  
Author(s):  
Mariusz P. Kowalewski ◽  
Matthew T. Dyson ◽  
Pulak R. Manna ◽  
Douglas M. Stocco
Keyword(s):  
Granulosa Cells ◽  
Promoter Activity ◽  
Combined Treatment ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Peroxisome Proliferator ◽  
Activator Protein 1 ◽  
Dibutyryl Camp ◽  
Peroxisome Proliferator Activated Receptor ◽  
Steroidogenic Acute Regulatory

Peroxisome proliferator-activated receptor (PPAR) γ belongs to the PPAR family of nuclear transcription factors whose ligands, such as eicosanoids, fatty acids and prostaglandins, are known to affect gonadal function. Although several of these enhance the expression of the steroidogenic acute regulatory protein (STAR) and steroid production, the role of PPARγ in regulating STAR-mediated steroidogenesis remains unclear. In the present study, we used ciglitazone to selectively activate PPARγ and examine its role in STAR-mediated steroidogenesis in immortalised KK1 mouse granulosa cells and MA-10 mouse Leydig tumour cells. Cotreatment with both dibutyryl-cAMP and ciglitazone revealed a dose-dependent, significant increase in progesterone synthesis, Star promoter activity, Star mRNA and STAR protein relative to either compound alone. The overexpression of PPARγ further increased Star-promoter activity. The ciglitazone-induced activity of the Star-promoter appears to be mediated through the cAMP-response element half-sites located within its proximal 151 bp. Combined treatment with ciglitazone and dibutyryl-cAMP significantly increased the expression and activity of transcriptional pathways impacted by the activator protein-1 family member c-JUN. The present study demonstrates that ciglitazone and dibutyryl-cAMP synergistically enhance STAR expression in MA-10 and KK1 cells. Ciglitazone-activated PPARγ appears to increase the sensitivity of Leydig and granulosa cells to cAMP stimulation, possibly via upregulation of c-JUN expression.

scholarly journals Andrographis paniculata and Its Main Bioactive Ingredient Andrographolide Decrease Alcohol Drinking and Seeking in Rats Through Activation of Nuclear PPARγ Pathway

2021 ◽  
Author(s):  
Serena Stopponi ◽  
Yannick Fotio ◽  
Carlo Cifani ◽  
Hongwu Li ◽  
Carolina L Haass-Koffler ◽  
...  
Keyword(s):  
Oral Administration ◽  
Alcohol Drinking ◽  
Andrographis Paniculata ◽  
Peroxisome Proliferator ◽  
Herbaceous Plant ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Treatment Administration ◽  
Dried Extract

Abstract Background and aims Andrographis paniculata is an annual herbaceous plant which belongs to the Acanthaceae family. Extracts from this plant have shown hepatoprotective, anti-inflammatory and antidiabetic properties, at least in part, through activation of the nuclear receptor Peroxisome Proliferator-Activated Receptor-gamma (PPAR γ). Recent evidence has demonstrated that activation of PPARγ reduces alcohol drinking and seeking in Marchigian Sardinian (msP) alcohol-preferring rats. Methods The present study evaluated whether A. paniculata reduces alcohol drinking and relapse in msP rats by activating PPARγ. Results Oral administration of an A. paniculata dried extract (0, 15, 150 mg/kg) lowered voluntary alcohol consumption in a dose-dependent manner and achieved ~65% reduction at the dose of 450 mg/kg. Water and food consumption were not affected by the treatment. Administration of Andrographolide (5 and 10 mg/kg), the main active component of A. paniculata, also reduced alcohol drinking. This effect was suppressed by the selective PPARγ antagonist GW9662. Subsequently, we showed that oral administration of A. paniculata (0, 150, 450 mg/kg) prevented yohimbine- but not cues-induced reinstatement of alcohol seeking. Conclusions Results point to A. paniculata-mediated PPARγactivation as a possible therapeutic strategy to treat alcohol use disorder.

scholarly journals Diet and PPARG2 Pro12Ala Polymorphism Interactions in Relation to Cancer Risk: A Systematic Review

Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 261
Author(s):  
Lieu Tran ◽  
Gerd Bobe ◽  
Gayatri Arani ◽  
Yang Zhang ◽  
Zhenzhen Zhang ◽  
...  
Keyword(s):  
Cancer Risk ◽  
Dietary Factors ◽  
Dietary Fats ◽  
Current Evidence ◽  
Peroxisome Proliferator ◽  
Allele Polymorphism ◽  
Peroxisome Proliferator Activated Receptor ◽  
Complex Relation ◽  
Ppar Γ ◽  
Pubmed Database

Peroxisome proliferator-activated receptor-γ2 gene Pro12Ala allele polymorphism (PPARG2 Pro12Ala; rs1801282) has been linked to both cancer risk and dietary factors. We conducted the first systematic literature review of studies published before December 2020 using the PubMed database to summarize the current evidence on whether dietary factors for cancer may differ by individuals carrying C (common) and/or G (minor) alleles of the PPARG2 Pro12Ala allele polymorphism. The inclusion criteria were observational studies that investigated the association between food or nutrient consumption and risk of incident cancer stratified by PPARG2 Pro12Ala allele polymorphism. From 3815 identified abstracts, nine articles (18,268 participants and 4780 cancer cases) covering three cancer sites (i.e., colon/rectum, prostate, and breast) were included. CG/GG allele carriers were more impacted by dietary factors than CC allele carriers. High levels of protective factors (e.g., carotenoids and prudent dietary patterns) were associated with a lower cancer risk, and high levels of risk factors (e.g., alcohol and refined grains) were associated with a higher cancer risk. In contrast, both CG/GG and CC allele carriers were similarly impacted by dietary fats, well-known PPAR-γ agonists. These findings highlight the complex relation between PPARG2 Pro12Ala allele polymorphism, dietary factors, and cancer risk, which warrant further investigation.

Sign in / Sign up

Export Citation Format

Share Document