scholarly journals Cross-talk between Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) and Peroxisome Proliferator-activated Receptor-α (PPARα) Signaling Pathways

1999 ◽  
Vol 274 (5) ◽  
pp. 2672-2681 ◽  
Author(s):  
Yuan-Chun Zhou ◽  
David J. Waxman
Keyword(s):  
Signaling Pathways ◽  
Cross Talk ◽  
Janus Kinase ◽  
Peroxisome Proliferator ◽  
Signal Transducer ◽  
Peroxisome Proliferator Activated Receptor

scholarly journals The role of signal transducer and activator of transcription 5 in the inhibitory effects of GH on adipocyte differentiation

2003 ◽  
Vol 30 (2) ◽  
pp. 139-150 ◽  
Author(s):  
HE Richter ◽  
T Albrektsen ◽  
N Billestrup
Keyword(s):  
Tyrosine Phosphorylation ◽  
Janus Kinase ◽  
Peroxisome Proliferator ◽  
Transactivation Domain ◽  
Signal Transducer ◽  
Inhibitory Effects ◽  
Preadipocyte Differentiation ◽  
Peroxisome Proliferator Activated Receptor ◽  
Fatty Acid Binding

GH inhibits primary rat preadipocyte differentiation and expression of late genes required for terminal differentiation. Here we show that GH-mediated inhibition of fatty acid-binding protein aP2 gene expression correlates with the activation of the Janus kinase-2/signal transducer and activator of transcription (STAT)-5 signalling pathway. Within minutes of treatment, GH induced the tyrosine phosphorylation, nuclear localization and DNA binding of STAT5. Importantly, there was no evidence that STAT5 acted via an interaction with peroxisome proliferator-activated receptor gamma. To further understand the mechanism of STAT5 action, we reconstituted the inhibition of aP2 in a non-adipogenic cell line. Using this system, we showed that the ability of GH to inhibit a 520 bp aP2 reporter was largely dependent upon the presence of either STAT5A or STAT5B. Mutant analysis confirmed that the tyrosine phosphorylation of STAT5 was essential for this signalling. However, STAT5's C-terminal transactivation domain was fully dispensable for this inhibition. Taken together, these data confirm a key regulatory role of STAT5 in adipose tIssue and point to STAT5 as the repressing modulator of GH-mediated inhibition in primary preadipocytes.

scholarly journals Growth Hormone Inhibits Apoptosis in Human Colonic Cancer Cell Lines: Antagonistic Effects of Peroxisome Proliferator Activated Receptor-γ Ligands

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3353-3362 ◽  
Author(s):  
Fausto Bogazzi ◽  
Federica Ultimieri ◽  
Francesco Raggi ◽  
Dania Russo ◽  
Renato Vanacore ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Colonic Cancer ◽  
Cancer Cell Lines ◽  
Peroxisome Proliferator ◽  
Signal Transducer ◽  
Peroxisome Proliferator Activated Receptor ◽  
Antiapoptotic Effect ◽  
Pparγ Expression ◽  
Colonic Cells

Abstract GH has antiapoptotic effects on several cells. However, the antiapoptotic mechanisms of GH on colonic mucosa cells are not completely understood. Peroxisome proliferator activated receptor-γ (PPARγ) activation enhances apoptosis, and a link between GH and PPARγ in the colonic epithelium of acromegalic patients has been suggested. We investigated the effects of GH and of PPARγ ligands on apoptosis in colonic cancer cell lines. Colonic cells showed specific binding sites for GH, and after exposure to 0.05–50 nm GH, their apoptosis reduced by 45%. The antiapoptotic effect was due to either GH directly or GH-dependent local production of IGF-1. A 55–85% reduction of PPARγ expression was observed in GH-treated cells, compared with controls (P < 0.05). However, treatment of the cells with 1–50 μm ciglitazone (cig), induced apoptosis and reverted the antiapoptotic effects of GH by increasing the programmed cell death up to 3.5-fold at 30 min and up to 1.7-fold at 24 h. Expression of Bcl-2 and TNF-related apoptosis-induced ligand was not affected by either GH or cig treatment, whereas GH reduced the expression of Bax, which was increased by cig treatment. In addition, GH increased the expression of signal transducer and activator of transcription 5b, which might be involved in the down-regulation of PPARγ expression. In conclusion, GH may exert a direct antiapoptotic effect on colonic cells, through an increased expression of signal transducer and activator of transcription 5b and a reduction of Bax and PPARγ. The reduced GH-dependent apoptosis can be overcome by PPARγ ligands, which might be useful chemopreventive agents in acromegalic patients, who have an increased colonic polyps prevalence.

scholarly journals High Sugar Intake and Development of Skeletal Muscle Insulin Resistance and Inflammation in Mice: A Protective Role for PPAR-δAgonism

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Elisa Benetti ◽  
Raffaella Mastrocola ◽  
Mara Rogazzo ◽  
Fausto Chiazza ◽  
Manuela Aragno ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Signaling Pathways ◽  
Gastrocnemius Muscle ◽  
Metabolic Diseases ◽  
Whole Body ◽  
Intercellular Adhesion Molecule ◽  
Fibroblast Growth Factor 21 ◽  
Peroxisome Proliferator ◽  
Intercellular Adhesion Molecule 1 ◽  
Peroxisome Proliferator Activated Receptor

Peroxisome Proliferator Activated Receptor (PPAR)-δagonists may serve for treating metabolic diseases. However, the effects of PPAR-δagonism within the skeletal muscle, which plays a key role in whole-body glucose metabolism, remain unclear. This study aimed to investigate the signaling pathways activated in the gastrocnemius muscle by chronic administration of the selective PPAR-δagonist, GW0742 (1 mg/kg/day for 16 weeks), in male C57Bl6/J mice treated for 30 weeks with high-fructose corn syrup (HFCS), the major sweetener in foods and soft-drinks (15% wt/vol in drinking water). Mice fed with the HFCS diet exhibited hyperlipidemia, hyperinsulinemia, hyperleptinemia, and hypoadiponectinemia. In the gastrocnemius muscle, HFCS impaired insulin and AMP-activated protein kinase signaling pathways and reduced GLUT-4 and GLUT-5 expression and membrane translocation. GW0742 administration induced PPAR-δupregulation and improvement in glucose and lipid metabolism. Diet-induced activation of nuclear factor-κB and expression of inducible-nitric-oxide-synthase and intercellular-adhesion-molecule-1 were attenuated by drug treatment. These effects were accompanied by reduction in the serum concentration of interleukin-6 and increase in muscular expression of fibroblast growth factor-21. Overall, here we show that PPAR-δactivation protects the skeletal muscle against the metabolic abnormalities caused by chronic HFCS exposure by affecting multiple levels of the insulin and inflammatory cascades.

scholarly journals Mesoporous Silica Nanoparticles Trigger Liver and Kidney Injury and Fibrosis Via Altering TLR4/NF-κB, JAK2/STAT3 and Nrf2/HO-1 Signaling in Rats

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 528 ◽  
Author(s):  
Ayman M. Mahmoud ◽  
Ekram M. Desouky ◽  
Walaa G. Hozayen ◽  
May Bin-Jumah ◽  
El-Shaymaa El-Nahass ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Signaling Pathways ◽  
Mesoporous Silica Nanoparticles ◽  
Kidney Injury ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Liver And Kidney

Mesoporous silica nanoparticles (MSNs) represent a promising inorganic platform for multiple biomedical applications. Previous studies have reported MSNs-induced hepatic and renal toxicity; however, the toxic mechanism remains unclear. This study aimed to investigate MSNs-induced hepatic and nephrotoxicity and test the hypothesis that altered TLR4/MyD88/NF-κB, JAK2/STAT3, and Nrf2/ARE/HO-1 signaling pathways mediate oxidative stress, inflammation, and fibrosis induced by MSNs. Rats were administered 25, 50, 100, and 200 mg/kg MSNs for 30 days, and samples were collected for analyses. MSNs induced functional and histologic alterations, increased the levels of reactive oxygen species (ROS), lipid peroxidation and nitric oxide, suppressed antioxidants, and Nrf2/HO-1 signaling in the liver and kidney of rats. MSNs up-regulated the expression of liver and kidney TLR4, MyD88, NF-κB p65, and caspase-3 and increased serum pro-inflammatory cytokines. In addition, MSNs activated the JAK2/STAT3 signaling pathway, down-regulated peroxisome proliferator activated receptor gamma (PPARγ), and promoted fibrosis evidenced by the increased collagen expression and deposition. In conclusion, this study conferred novel information on the role of ROS and deregulated TLR4/MyD88/NF-κB, JAK2/STAT3, PPARγ, and Nrf2/ARE/HO-1 signaling pathways in MSNs hepatic and nephrotoxicity. These findings provide experimental evidence for further studies employing genetic and pharmacological strategies to evaluate the safety of MSNs for their use in nanomedicine.

scholarly journals Rosiglitazone Inhibits Adrenocortical Cancer Cell Proliferation by Interfering with the IGF-IR Intracellular Signaling

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
Giulia Cantini ◽  
Adriana Lombardi ◽  
Elisabetta Piscitelli ◽  
Giada Poli ◽  
Elisabetta Ceni ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Phosphatidyl Inositol ◽  
Inhibitory Effect ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Adrenocortical Cancer ◽  
Peroxisome Proliferator Activated Receptor ◽  
Igf I

Rosiglitazone (RGZ), a thiazolidinedione ligand of the peroxisome proliferator-activated receptor (PPAR)-γ, has been recently described as possessing antitumoral properties. We investigated RGZ effect on cell proliferation in two cell line models (SW13 and H295R) of human adrenocortical carcinoma (ACC) and its interaction with the signaling pathways of the activated IGF-I receptor (IGF-IR). We demonstrate a high expression of IGF-IR in the two cell lines and in ACC. Cell proliferation is stimulated by IGF-I in a dose- and time-dependent manner and is inhibited by RGZ. The analysis of the main intracellular signaling pathways downstream of the activated IGF-IR, phosphatidyl inositol 3-kinase (PI3K)-Akt, and extracellular signal-regulated kinase (ERK1/2) cascades reveals that RGZ rapidly interferes with the Akt and ERK1/2 phosphorylation/activation which mediates IGF-I stimulated proliferation. In conclusion, our results suggest that RGZ exerts an inhibitory effect on human ACC cell proliferation by interfering with the PI3K/Akt and ERK1/2 signaling pathways downstream of the activated IGF-IR.

Sign in / Sign up

Export Citation Format

Share Document