scholarly journals Improvement of Retinal Vascular Injury in Diabetic Rats by Statins Is Associated With the Inhibition of Mitochondrial Reactive Oxygen Species Pathway Mediated by Peroxisome Proliferator-Activated Receptor   Coactivator 1 

Diabetes ◽  
2010 ◽  
Vol 59 (9) ◽  
pp. 2315-2325 ◽  
Author(s):  
Z. Zheng ◽  
H. Chen ◽  
H. Wang ◽  
B. Ke ◽  
B. Zheng ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Vascular Injury ◽  
Reactive Oxygen ◽  
Diabetic Rats ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Peroxisome Proliferator Activated Receptor

scholarly journals Identification of a Functional Peroxisome Proliferator-Activated Receptor Response Element in the Rat Catalase Promoter

2002 ◽  
Vol 16 (12) ◽  
pp. 2793-2801 ◽  
Author(s):  
Geoffrey D. Girnun ◽  
Frederick E. Domann ◽  
Steven A. Moore ◽  
Mike E. C. Robbins
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factors ◽  
Inflammatory Response ◽  
Reactive Oxygen ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Response Element ◽  
Peroxisome Proliferator Activated Receptor ◽  
Promoter Deletion Analysis

Abstract Peroxisomal proliferator-activated receptor (PPAR)γ has been shown to decrease the inflammatory response via transrepression of proinflammatory transcription factors. However, the identity of PPARγ responsive genes that decrease the inflammatory response has remained elusive. Because generation of the reactive oxygen species hydrogen peroxide (H2O2) plays a role in the inflammatory process and activation of proinflammatory transcription factors, we wanted to determine whether the antioxidant enzyme catalase might be a PPARγ target gene. We identified a putative PPAR response element (PPRE) containing the canonical direct repeat 1 motif, AGGTGA-A-AGTTGA, in the rat catalase promoter. In vitro translated PPARγ and retinoic X receptor-α proteins were able to bind to the catalase PPRE. Promoter deletion analysis revealed that the PPRE was functional, and a heterologous promoter construct containing a multimerized catalase PPRE demonstrated that the PPRE was necessary and sufficient for PPARγ-mediated activation. Treatment of microvascular endothelial cells with PPARγ ligands led to increases in catalase mRNA and activity. These results demonstrate that PPARγ can alter catalase expression; this occurs via a PPRE in the rat catalase promoter. Thus, in addition to transrepression of proinflammatory transcription factors, PPARγ may also be modulating catalase expression, and hence down-regulating the inflammatory response via scavenging of reactive oxygen species.

scholarly journals Oxidative Stress Attenuates Lipid Synthesis and Increases Mitochondrial Fatty Acid Oxidation in Hepatoma Cells Infected with Hepatitis C Virus

2015 ◽  
Vol 291 (4) ◽  
pp. 1974-1990 ◽  
Author(s):  
Donna N. Douglas ◽  
Christopher Hao Pu ◽  
Jamie T. Lewis ◽  
Rakesh Bhat ◽  
Anwar Anwar-Mohamed ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Growth Arrest ◽  
Lipid Synthesis ◽  
Reactive Oxygen ◽  
Hcv Infection ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Peroxisome Proliferator Activated Receptor

Cytopathic effects are currently believed to contribute to hepatitis C virus (HCV)-induced liver injury and are readily observed in Huh7.5 cells infected with the JFH-1 HCV strain, manifesting as apoptosis highly correlated with growth arrest. Reactive oxygen species, which are induced by HCV infection, have recently emerged as activators of AMP-activated protein kinase. The net effect is ATP conservation via on/off switching of metabolic pathways that produce/consume ATP. Depending on the scenario, this can have either pro-survival or pro-apoptotic effects. We demonstrate reactive oxygen species-mediated activation of AMP-activated kinase in Huh7.5 cells during HCV (JFH-1)-induced growth arrest. Metabolic labeling experiments provided direct evidence that lipid synthesis is attenuated, and β-oxidation is enhanced in these cells. A striking increase in nuclear peroxisome proliferator-activated receptor α, which plays a dominant role in the expression of β-oxidation genes after ligand-induced activation, was also observed, and we provide evidence that peroxisome proliferator-activated receptor α is constitutively activated in these cells. The combination of attenuated lipid synthesis and enhanced β-oxidation is not conducive to lipid accumulation, yet cellular lipids still accumulated during this stage of infection. Notably, the serum in the culture media was the only available source for polyunsaturated fatty acids, which were elevated (2-fold) in the infected cells, implicating altered lipid import/export pathways in these cells. This study also provided the first in vivo evidence for enhanced β-oxidation during HCV infection because HCV-infected SCID/Alb-uPA mice accumulated higher plasma ketones while fasting than did control mice. Overall, this study highlights the reprogramming of hepatocellular lipid metabolism and bioenergetics during HCV infection, which are predicted to impact both the HCV life cycle and pathogenesis.

scholarly journals 15-Deoxy-Δ12-14-Prostaglandin-J2 Induces Hypertrophy and Loss of Contractility in Human Testicular Peritubular Cells: Implications for Human Male Fertility

Endocrinology ◽  
2010 ◽  
Vol 151 (3) ◽  
pp. 1257-1268 ◽  
Author(s):  
C. Schell ◽  
M. Albrecht ◽  
S. Spillner ◽  
C. Mayer ◽  
L. Kunz ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Smooth Muscle ◽  
Cell Size ◽  
Reactive Oxygen ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Peroxisome Proliferator Activated Receptor ◽  
Human Male ◽  
Peritubular Cells ◽  
Prostaglandin J2

The wall of the seminiferous tubules contains contractile smooth-muscle-like peritubular cells, thought to be important for sperm transport. Impaired spermatogenesis in men typically involves remodeling of this wall, and we now found that smooth muscle cell (SMC) markers, namely myosin heavy chain (MYH11) and smooth muscle actin (SMA) are often lost or diminished in peritubular cells of testes of men with impaired spermatogenesis. This suggests reduced contractility of the peritubular wall, which may contribute to sub- or infertility. In these cases, testicular expression of cyclooxygenase-2 (COX-2) implies formation of prostaglandins (PGs). When screening different PGs for their ability to target human testicular peritubular cells (HTPCs), only a PG metabolite, 15-deoxy-Δ12-14-prostaglandin-J2 (15dPGJ2), was effective. In primary cultures of HTPCs, 15dPGJ2 increased cell size in a reversible manner. Importantly, 15dPGJ2 treatment resulted in a loss of typical differentiation markers for SMCs, namely MYH11, calponin, and SMA, whereas fibroblast markers were unchanged. Collagen gel contraction assays revealed that this loss correlates with a reduced ability to contract. Experiments with an antagonist (bisphenol A diglycidyl ether) and agonist (troglitazone) for a cognate 15dPGJ2 receptor (i.e. peroxisome proliferator-activated receptor-γ) indicated that peroxisome proliferator-activated receptor-γ is not directly involved. Rather, the mode of action of 15dPGJ2 involves reactive oxygen species. The antioxidant N-acetylcysteine not only blocked ROS formation but also prevented the increase in cell size and the loss of contractility in HTPCs challenged with 15dPGJ2. We conclude that 15dPGJ2, via reactive oxygen species, influences SMC phenotype and contractility of human peritubular cells and possibly is involved in the development of human male sub-/infertility.

scholarly journals Evidence for the Important ¬Role of Oxidative Stress in the Pathogenesis of Acne

2019 ◽  
Vol 8 ◽  
pp. 1291
Author(s):  
Sina Kardeh ◽  
Seyed arman Moein ◽  
Mohammad Reza Namazi ◽  
Bahareh Kardeh
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Acne Vulgaris ◽  
Reactive Oxygen ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Oxidative Stress Biomarkers ◽  
Peroxisome Proliferator Activated Receptor ◽  
Oxidative Biomarkers

Acne vulgaris is a common inflammatory skin disorder which is recognizable by dermatological lesions and scars. In addition to some pathogenetic factors such as hyperkeratinization, upregulated sebum secretion, and immunoinflammatory reactions, recent studies have also connected oxidative stress to the pathogenesis of acne vulgaris. In this article, we will briefly review clinical studies that interrogated alterations in oxidative stress biomarkers by a systematic search conducted in PubMed, Web of Science, and Scopus using “acne”, “oxidative stress”, and “reactive oxygen species” keywords. Overall, studies have shown that oxidative biomarkers (e.g. lipid peroxidation final products) are higher in acne vulgaris lesions. A significant positive correlation has also been noted between acne severity and oxidative biomarkers. In contrast, diminished levels of antioxidant enzymes (e.g. superoxide dismutase and catalase) have been observed in acne. We propose four probable mechanisms for the role of reactive oxygen species (ROS) in acne pathogenesis. We believe that ROS can contribute significantly to the acne vulgaris pathobiology via toll-like receptor (TLR), peroxisome proliferator-activated receptor (PPAR), mTOR pathway, and innate immune system, resulting in inflammation by alterations in the generation of several proinflammatory cytokines including IL-1, IL-8, and TNF-a.[GMJ. 2019;8:e1291]

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