scholarly journals Peroxisome Proliferator-Activated Receptors and Shock State

2006 ◽  
Vol 6 ◽  
pp. 1770-1782 ◽  
Author(s):  
Emanuela Esposito ◽  
Salvatore Cuzzocrea ◽  
Rosaria Meli
Keyword(s):  
Transcription Factors ◽  
Energy Homeostasis ◽  
Hormone Receptors ◽  
Inflammatory Responses ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Shock State ◽  
Anti Inflammatory ◽  
Peroxisome Proliferator Activated Receptors ◽  
Inflammatory Molecules

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid, and thyroid hormone receptors. Three isotypes of PPARs have been identified: alpha, beta/delta, and gamma, encoded by different genes and distributed in various tissues. PPARs are implicated in the control of inflammatory responses and in energy homeostasis and, thus, can be defined as metabolic and anti-inflammatory transcription factors. They exert anti-inflammatory effects by inhibiting the induction of proinflammatory cytokines, adhesion molecules, and extracellular matrix proteins, or by stimulating the production of anti-inflammatory molecules. Moreover, PPARs modulate the proliferation, differentiation, and survival of immune cells. This review presents the current state of knowledge regarding the involvement of PPARs in the control of inflammatory response, and their potential therapeutic applications in several types of shock, as well as hemorrhagic, septic, and nonseptic shock.

scholarly journals Neuroprotective Mechanisms of PPARδ: Modulation of Oxidative Stress and Inflammatory Processes

PPAR Research ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Caroline I. Schnegg ◽  
Mike E. Robbins
Keyword(s):  
Energy Homeostasis ◽  
Peroxisome Proliferator ◽  
Cellular Processes ◽  
Wide Range ◽  
Inflammatory Processes ◽  
The Central Nervous System ◽  
Chronic Injuries ◽  
Neuroprotective Efficacy ◽  
Anti Inflammatory ◽  
Peroxisome Proliferator Activated Receptors

Peroxisome proliferator-activated receptors (PPARα,δ, andγ) are ligand-activated transcription factors that regulate a wide range of cellular processes, including inflammation, proliferation, differentiation, metabolism, and energy homeostasis. All three PPAR subtypes have been identified in the central nervous system (CNS) of rodents. While PPARαand PPARγare expressed in more restricted areas of the CNS, PPARδis ubiquitously expressed and is the predominant subtype. Although data regarding PPARδare limited, studies have demonstrated that administration of PPARδagonists confers neuroprotection following various acute and chronic injuries to the CNS, such as stroke, multiple sclerosis, and Alzheimer's disease. The antioxidant and anti-inflammatory properties of PPARδagonists are thought to underly their neuroprotective efficacy. This review will focus on the putative neuroprotective benefits of therapeutically targeting PPARδin the CNS, and specifically, highlight the antioxidant and anti-inflammatory functions of PPARδagonists.

Evolution of the nuclear receptor superfamily: early diversification from an ancestral orphan receptor

1997 ◽  
Vol 19 (3) ◽  
pp. 207-226 ◽  
Author(s):  
V Laudet
Keyword(s):  
Hormone Receptors ◽  
Steroid Receptors ◽  
Distance Matrix ◽  
Nuclear Hormone Receptor ◽  
Orphan Receptor ◽  
Peroxisome Proliferator ◽  
Orphan Receptors ◽  
Vitamin D Receptors ◽  
Peroxisome Proliferator Activated Receptors ◽  
X Receptors

From a database containing the published nuclear hormone receptor (NR) sequences I constructed an alignment of the C, D and E domains of these molecules. Using this alignment, I have performed tree reconstruction using both distance matrix and parsimony analysis. The robustness of each branch was estimated using bootstrap resampling methods. The trees constructed by these two methods gave congruent topologies. From these analyses I defined six NR subfamilies: (i) a large one clustering thyroid hormone receptors (TRs), retinoic acid receptors (RARs), peroxisome proliferator-activated receptors (PPARs), vitamin D receptors (VDRs) and ecdysone receptors (EcRs) as well as numerous orphan receptors such as RORs or Rev-erbs; (ii) one containing retinoid X receptors (RXRs) together with COUP, HNF4, tailless, TR2 and TR4 orphan receptors; (iii) one containing steroid receptors; (iv) one containing the NGFIB orphan receptors; (v) one containing FTZ-F1 orphan receptors; and finally (vi) one containing to date only one gene, the GCNF1 orphan receptor. The relationships between the six subfamilies are not known except for subfamilies I and IV which appear to be related. Interestingly, most of the liganded receptors appear to be derived when compared with orphan receptors. This suggests that the ligand-binding ability of NRs has been gained by orphan receptors during the course of evolution to give rise to the presently known receptors. The distribution into six subfamilies correlates with the known abilities of the various NRs to bind to DNA as homo- or heterodimers. For example, receptors heterodimerizing efficiently with RXR belong to the first or the fourth subfamilies. I suggest that the ability to heterodimerize evolved once, just before the separation of subfamilies I and IV and that the first NR was able to bind to DNA as a homodimer. From the study of NR sequences existing in vertebrates, arthropods and nematodes, I define two major steps of NR diversification: one that took place very early, probably during the multicellularization event leading to all the metazoan phyla, and a second occurring later on, corresponding to the advent of vertebrates. Finally, I show that in vertebrate species the various groups of NRs accumulated mutations at very different rates.

scholarly journals Role of Peroxisome Proliferator-Activated Receptors in Inflammation Control

2004 ◽  
Vol 2004 (3) ◽  
pp. 156-166 ◽  
Author(s):  
Jihan Youssef ◽  
Mostafa Badr
Keyword(s):  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Late Phase ◽  
Common Mechanism ◽  
Peroxisome Proliferator ◽  
Initiation Phase ◽  
Anti Inflammatory ◽  
Peroxisome Proliferator Activated Receptors

Peroxisome proliferator-activated receptors (PPARs) were discovered over a decade ago, and were classified as orphan members of the nuclear receptor superfamily. To date, three PPAR subtypes have been discovered and characterized (PPARα, β/δ, γ). Different PPAR subtypes have been shown to play crucial roles in important diseases and conditions such as obesity, diabetes, atherosclerosis, cancer, and fertility. Among the most studied roles of PPARs is their involvement in inflammatory processes. Numerous studies have revealed that agonists of PPARα and PPARγ exert anti-inflammatory effects both in vitro and in vivo. Using the carrageenan-induced paw edema model of inflammation, a recent study in our laboratories showed that these agonists hinder the initiation phase, but not the late phase of the inflammatory process. Furthermore, in the same experimental model, we recently also observed that activation of PPARδ exerted an anti-inflammatory effect. Despite the fact that exclusive dependence of these effects on PPARs has been questioned, the bulk of evidence suggests that all three PPAR subtypes, PPARα,δ,γ, play a significant role in controlling inflammatory responses. Whether these subtypes act via a common mechanism or are independent of each other remains to be elucidated. However, due to the intensity of research efforts in this area, it is anticipated that these efforts will result in the development of PPAR ligands as therapeutic agents for the treatment of inflammatory diseases.

scholarly journals PPARdelta in Affected Atopic Dermatitis and Psoriasis: A Possible Role in Metabolic Reprograming

2021 ◽  
Vol 22 (14) ◽  
pp. 7354
Author(s):  
Stefan Blunder ◽  
Petra Pavel ◽  
Deborah Minzaghi ◽  
Sandrine Dubrac
Keyword(s):  
Atopic Dermatitis ◽  
Hormone Receptors ◽  
Target Genes ◽  
Skin Diseases ◽  
Retinoic Acid Receptor ◽  
Skin Inflammation ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Keratinocyte Proliferation ◽  
Peroxisome Proliferator Activated Receptors

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors expressed in the skin. Three PPAR isotypes, α (NRC1C1), β or δ (NRC1C2) and γ (NRC1C3), have been identified. After activation through ligand binding, PPARs heterodimerize with the 9-cis-retinoic acid receptor (RXR), another nuclear hormone receptor, to bind to specific PPAR-responsive elements in regulatory regions of target genes mainly involved in organogenesis, cell proliferation, cell differentiation, inflammation and metabolism of lipids or carbohydrates. Endogenous PPAR ligands are fatty acids and fatty acid metabolites. In past years, much emphasis has been given to PPARα and γ in skin diseases. PPARβ/δ is the least studied PPAR family member in the skin despite its key role in several important pathways regulating inflammation, keratinocyte proliferation and differentiation, metabolism and the oxidative stress response. This review focuses on the role of PPARβ/δ in keratinocytes and its involvement in psoriasis and atopic dermatitis. Moreover, the relevance of targeting PPARβ/δ to alleviate skin inflammation is discussed.

scholarly journals The Role of Peroxisome Proliferator-Activated Receptors in Colorectal Cancer

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Joo-In Park ◽  
Jong-Young Kwak
Keyword(s):  
Colorectal Cancer ◽  
Dietary Fat ◽  
Energy Homeostasis ◽  
Hormone Receptors ◽  
Clinical Implications ◽  
Peroxisome Proliferator ◽  
Fat Intake ◽  
Nutrient Metabolism ◽  
Peroxisome Proliferator Activated Receptors

Colorectal cancer is one of the most common cancers in the world. Dietary fat intake is a major risk factor for colorectal cancer. Some nuclear hormone receptors play an important role in regulating nutrient metabolism and energy homeostasis. Among these receptors, special attention has been focused on the role of peroxisome proliferator-activated receptors (PPARs) in colorectal cancer, because PPARs are involved in regulation of lipid and carbohydrate metabolism. PPARs are ligand-activated intracellular transcription factors. The PPAR subfamily consists of three subtypes encoded by distinct genes named PPARα, PPARβ/δ, and PPARγ. PPARγis the most extensively studied subtype of PPARs. Even though many investigators have studied the expression and clinical implications of PPARs in colorectal cancer, there are still many controversies about the role of PPARs in colorectal cancer. In this paper, the recent progresses in understanding the role of PPARs in colorectal cancer are summarized.

scholarly journals Peroxisome Proliferator-Activated Receptors in Lung Cancer

PPAR Research ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Venkateshwar G. Keshamouni ◽  
ShouWei Han ◽  
Jesse Roman
Keyword(s):  
Lung Cancer ◽  
Cell Biology ◽  
Energy Homeostasis ◽  
Lung Tumor ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Cellular Mechanisms ◽  
Lung Carcinoma Cells ◽  
Tumor Cell Biology ◽  
Peroxisome Proliferator Activated Receptors

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights into the cellular mechanisms involved in the control of energy homeostasis; the regulation of cell differentiation, proliferation, and apoptosis; and the modulation of important biological and pathological processes related to inflammation, among others. Since then, PPARs have become an exciting therapeutic target for several diseases. PPARs are expressed by many tumors including lung carcinoma cells, and their function has been linked to the process of carcinogenesis in lung. Consequently, intense research is being conducted in this area with the hope of discovering new PPAR-related therapeutic targets for the treatment of lung cancer. This review summarizes the research being conducted in this area and focuses on the mechanisms by which PPARs are believed to affect lung tumor cell biology.

scholarly journals Lysosome-Dependent LXR and PPARδ Activation Upon Efferocytosis in Human Macrophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Carolina Mota ◽  
Monica Dominguez ◽  
Andreas Weigert ◽  
Ryan G. Snodgrass ◽  
Dmitry Namgaladze ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Target Genes ◽  
Inflammatory Responses ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Liver X Receptors ◽  
Human Macrophages ◽  
Sterol Regulatory Element ◽  
Peroxisome Proliferator Activated Receptors ◽  
X Receptors

Efferocytosis is critical for tissue homeostasis, as its deregulation is associated with several autoimmune pathologies. While engulfing apoptotic cells, phagocytes activate transcription factors, such as peroxisome proliferator-activated receptors (PPAR) or liver X receptors (LXR) that orchestrate metabolic, phagocytic, and inflammatory responses towards the ingested material. Coordination of these transcription factors in efferocytotic human macrophages is not fully understood. In this study, we evaluated the transcriptional profile of macrophages following the uptake of apoptotic Jurkat T cells using RNA-seq analysis. Results indicated upregulation of PPAR and LXR pathways but downregulation of sterol regulatory element-binding proteins (SREBP) target genes. Pharmacological inhibition and RNA interference pointed to LXR and PPARδ as relevant transcriptional regulators, while PPARγ did not substantially contribute to gene regulation. Mechanistically, lysosomal digestion and lysosomal acid lipase (LIPA) were required for PPAR and LXR activation, while PPARδ activation also demanded an active lysosomal phospholipase A2 (PLA2G15). Pharmacological interference with LXR signaling attenuated ABCA1-dependent cholesterol efflux from efferocytotic macrophages, but suppression of inflammatory responses following efferocytosis occurred independently of LXR and PPARδ. These data provide mechanistic details on LXR and PPARδ activation in efferocytotic human macrophages.

scholarly journals Unraveling the Complex Relationship Triad between Lipids, Obesity, and Inflammation

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Shahida A. Khan ◽  
Ashraf Ali ◽  
Sarah A. Khan ◽  
Solafa A. Zahran ◽  
Ghazi Damanhouri ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Pulmonary Inflammation ◽  
Lipid Mediators ◽  
Peroxisome Proliferator ◽  
Omega 3 ◽  
Mortality And Morbidity ◽  
Increased Risk ◽  
Omega 6 ◽  
Anti Inflammatory ◽  
Peroxisome Proliferator Activated Receptors

Obesity today stands at the intersection between inflammation and metabolic disorders causing an aberration of immune activity, and resulting in increased risk for diabetes, atherosclerosis, fatty liver, and pulmonary inflammation to name a few. Increases in mortality and morbidity in obesity related inflammation have initiated studies to explore different lipid mediated molecular pathways of attempting resolution that uncover newer therapeutic opportunities of anti-inflammatory components. Majorly the thromboxanes, prostaglandins, leukotrienes, lipoxins, and so forth form the group of lipid mediators influencing inflammation. Of special mention are the omega-6 and omega-3 fatty acids that regulate inflammatory mediators of interest in hepatocytes and adipocytes via the cyclooxygenase and lipoxygenase pathways. They also exhibit profound effects on eicosanoid production. The inflammatory cyclooxygenase pathway arising from arachidonic acid is a critical step in the progression of inflammatory responses. New oxygenated products of omega-3 metabolism, namely, resolvins and protectins, behave as endogenous mediators exhibiting powerful anti-inflammatory and immune-regulatory actions via the peroxisome proliferator-activated receptors (PPARs) and G protein coupled receptors (GPCRs). In this review we attempt to discuss the complex pathways and links between obesity and inflammation particularly in relation to different lipid mediators.

scholarly journals Activated PPARγTargets Surface and Intracellular Signals That Inhibit the Proliferation of Lung Carcinoma Cells

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Shou Wei Han ◽  
Jesse Roman
Keyword(s):  
Lung Cancer ◽  
Cell Biology ◽  
Cancer Biology ◽  
Energy Homeostasis ◽  
Lung Tumor ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Cellular Mechanisms ◽  
Lung Carcinoma Cells ◽  
Peroxisome Proliferator Activated Receptors

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights into the cellular mechanisms involved in the control of energy homeostasis, the regulation of cell differentiation, proliferation, and apoptosis, and the modulation of important biological and pathological processes related to inflammation and cancer biology, among others. Since then, PPARs have become an exciting target for the development of therapies directed at many disorders including cancer. PPARs are expressed in many tumors including lung cancer, and their function has been linked to the process of carcinogenesis. Consequently, intense research is being conducted in this area with the hope of discovering new PPAR-related therapeutic targets for the treatment of lung cancer. This review summarizes the research being conducted in this area, and focuses on the mechanisms by which a member of this family (PPARγ) is believed to affect lung tumor cell biology.

scholarly journals PPAR Regulation of Inflammatory Signaling in CNS Diseases

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
John J. Bright ◽  
Saravanan Kanakasabai ◽  
Wanida Chearwae ◽  
Sharmistha Chakraborty
Keyword(s):  
Hormone Receptors ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Signaling Networks ◽  
Peroxisome Proliferator ◽  
Inflammatory Signaling ◽  
Cns Diseases ◽  
Ppar Agonists ◽  
Peroxisome Proliferator Activated Receptors ◽  
Privileged Site

Central nervous system (CNS) is an immune privileged site, nevertheless inflammation associates with many CNS diseases. Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear hormone receptors that regulate immune and inflammatory responses. Specific ligands for PPAR, , and isoforms have proven effective in the animal models of multiple sclerosis (MS), Alzheimer's disease, Parkinson's disease, and trauma/stroke, suggesting their use in the treatment of neuroinflammatory diseases. The activation of NF-B and Jak-Stat signaling pathways and secretion of inflammatory cytokines are critical in the pathogenesis of CNS diseases. Interestingly, PPAR agonists mitigate CNS disease by modulating inflammatory signaling network in immune cells. In this manuscript, we review the current knowledge on how PPARs regulate neuroinflammatory signaling networks in CNS diseases.

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