Hypoxia Up-regulates Expression of Peroxisome Proliferator-activated Receptor γ Angiopoietin-related Gene (PGAR) in Cardiomyocytes: Role of Hypoxia Inducible Factor 1α

2002 ◽  
Vol 34 (7) ◽  
pp. 765-774 ◽  
Author(s):  
Adam J. Belanger ◽  
Hsienwie Lu ◽  
Taro Date ◽  
Louis X. Liu ◽  
Karen A. Vincent ◽  
...  
2012 ◽  
Vol 287 (42) ◽  
pp. 35161-35169 ◽  
Author(s):  
Jundong Zhou ◽  
Shuyu Zhang ◽  
Jing Xue ◽  
Jori Avery ◽  
Jinchang Wu ◽  
...  

Activation of peroxisome proliferator-activated receptor α (PPARα) has been demonstrated to inhibit tumor growth and angiogenesis, yet the mechanisms behind these actions remain to be characterized. In this study, we examined the effects of PPARα activation on the hypoxia-inducible factor-1α (HIF-1α) signaling pathway in human breast (MCF-7) and ovarian (A2780) cancer cells under hypoxia. Incubation of cancer cells under 1% oxygen for 16 h significantly induced HIF-1α expression and activity as assayed by Western blotting and reporter gene analysis. Treatment of the cells with PPARα agonists, but not a PPARγ agonist, prior to hypoxia diminished hypoxia-induced HIF-1α expression and activity, and addition of a PPARα antagonist attenuated the suppression of HIF-1α signaling. Activation of PPARα attenuated hypoxia-induced HA-tagged HIF-1α protein expression without affecting the HA-tagged HIF-1α mutant protein level, indicating that PPARα activation promotes HIF-1α degradation in these cells. This was further confirmed using proteasome inhibitors, which reversed PPARα-mediated suppression of HIF-1α expression under hypoxia. Using the co-immunoprecipitation technique, we found that activation of PPARα enhances the binding of HIF-1α to von Hippel-Lindau tumor suppressor (pVHL), a protein known to mediate HIF-1α degradation through the ubiquitin-proteasome pathway. Following PPARα-mediated suppression of HIF-1α signaling, VEGF secretion from the cancer cells was significantly reduced, and tube formation by endothelial cells was dramatically impaired. Taken together, these findings demonstrate for the first time that activation of PPARα suppresses hypoxia-induced HIF-1α signaling in cancer cells, providing novel insight into the anticancer properties of PPARα agonists.


2015 ◽  
Vol 468 (3) ◽  
pp. 409-423 ◽  
Author(s):  
Caryn S. Gonsalves ◽  
Chen Li ◽  
Marthe-Sandrine Eiymo Mwa Mpollo ◽  
Vinod Pullarkat ◽  
Punam Malik ◽  
...  

We showed that erythropoietin (EPO)-mediated activation of hypoxia-inducible factor-1α (HIF-1α) increased the expression of placental growth factor (PlGF). Furthermore, miR-214 post-transcriptionally regulates PlGF expression. miR-214 itself is regulated by both peroxisome proliferator-activated receptor-α (PPARα) and HIF-1α, thus providing a novel approach for reduction in PlGF levels in sickle cell disease (SCD).


2014 ◽  
Vol 289 (52) ◽  
pp. 36031-36047 ◽  
Author(s):  
Chen Li ◽  
Marthe-Sandrine Eiymo Mwa Mpollo ◽  
Caryn S. Gonsalves ◽  
Stanley M. Tahara ◽  
Punam Malik ◽  
...  

Author(s):  
Rana A. Alaaeddine ◽  
Perihan A. Elzahhar ◽  
Ibrahim AlZaim ◽  
Wassim Abou-Kheir ◽  
Ahmed S.F. Belal ◽  
...  

: Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro-and anti-tumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarize the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 734
Author(s):  
Pietro Antonuccio ◽  
Herbert Ryan Marini ◽  
Antonio Micali ◽  
Carmelo Romeo ◽  
Roberta Granese ◽  
...  

Varicocele is an age-related disease with no current medical treatments positively impacting infertility. Toll-like receptor 4 (TLR4) expression is present in normal testis with an involvement in the immunological reactions. The role of peroxisome proliferator-activated receptor-α (PPAR-α), a nuclear receptor, in fertility is still unclear. N-Palmitoylethanolamide (PEA), an emerging nutraceutical compound present in plants and animal foods, is an endogenous PPAR-α agonist with well-demonstrated anti-inflammatory and analgesics characteristics. In this model of mice varicocele, PPAR-α and TLR4 receptors’ roles were investigated through the administration of ultra-micronized PEA (PEA-um). Male wild-type (WT), PPAR-α knockout (KO), and TLR4 KO mice were used. A group underwent sham operation and administration of vehicle or PEA-um (10 mg/kg i.p.) for 21 days. Another group (WT, PPAR-α KO, and TLR4 KO) underwent surgical varicocele and was treated with vehicle or PEA-um (10 mg/kg i.p.) for 21 days. At the end of treatments, all animals were euthanized. Both operated and contralateral testes were processed for histological and morphometric assessment, for PPAR-α, TLR4, occludin, and claudin-11 immunohistochemistry and for PPAR-α, TLR4, transforming growth factor-beta3 (TGF-β3), phospho-extracellular signal-Regulated-Kinase (p-ERK) 1/2, and nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) Western blot analysis. Collectively, our data showed that administration of PEA-um revealed a key role of PPAR-α and TLR4 in varicocele pathophysiology, unmasking new nutraceutical therapeutic targets for future varicocele research and supporting surgical management of male infertility.


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