scholarly journals PPARγExpression and Function in Mycobacterial Infection: Roles in Lipid Metabolism, Immunity, and Bacterial Killing

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Patricia E. Almeida ◽  
Alan Brito Carneiro ◽  
Adriana R. Silva ◽  
Patricia T. Bozza
Keyword(s):  
Molecular Mechanisms ◽  
Critical Role ◽  
Mycobacterial Infection ◽  
Receptor Activation ◽  
Host Cells ◽  
Current Evidence ◽  
Peroxisome Proliferator ◽  
Bacterial Killing ◽  
Peroxisome Proliferator Activated Receptor ◽  
And Function

Tuberculosis continues to be a global health threat, with drug resistance and HIV coinfection presenting challenges for its control.Mycobacterium tuberculosis, the etiological agent of tuberculosis, is a highly adapted pathogen that has evolved different strategies to subvert the immune and metabolic responses of host cells. Although the significance of peroxisome proliferator-activated receptor gamma (PPARγ) activation by mycobacteria is not fully understood, recent findings are beginning to uncover a critical role for PPARγduring mycobacterial infection. Here, we will review the molecular mechanisms that regulate PPARγexpression and function during mycobacterial infection. Current evidence indicates that mycobacterial infection causes a time-dependent increase in PPARγexpression through mechanisms that involve pattern recognition receptor activation. Mycobacterial triggered increased PPARγexpression and activation lead to increased lipid droplet formation and downmodulation of macrophage response, suggesting that PPARγexpression might aid the mycobacteria in circumventing the host response acting as an escape mechanism. Indeed, inhibition of PPARγenhances mycobacterial killing capacity of macrophages, suggesting a role of PPARγin favoring the establishment of chronic infection. Collectively, PPARγis emerging as a regulator of tuberculosis pathogenesis and an attractive target for the development of adjunctive tuberculosis therapies.

scholarly journals Essential Roles of PPARs in Lipid Metabolism during Mycobacterial Infection

2021 ◽  
Vol 22 (14) ◽  
pp. 7597
Author(s):  
Kazunari Tanigawa ◽  
Yuqian Luo ◽  
Akira Kawashima ◽  
Mitsuo Kiriya ◽  
Yasuhiro Nakamura ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Mycobacterial Infection ◽  
Host Cells ◽  
Peroxisome Proliferator ◽  
Host Immune System ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nutrient Sources ◽  
Cellular Environment ◽  
Ppar Signaling ◽  
Mycobacterial Cell Wall

The mycobacterial cell wall is composed of large amounts of lipids with varying moieties. Some mycobacteria species hijack host cells and promote lipid droplet accumulation to build the cellular environment essential for their intracellular survival. Thus, lipids are thought to be important for mycobacteria survival as well as for the invasion, parasitization, and proliferation within host cells. However, their physiological roles have not been fully elucidated. Recent studies have revealed that mycobacteria modulate the peroxisome proliferator-activated receptor (PPAR) signaling and utilize host-derived triacylglycerol (TAG) and cholesterol as both nutrient sources and evasion from the host immune system. In this review, we discuss recent findings that describe the activation of PPARs by mycobacterial infections and their role in determining the fate of bacilli by inducing lipid metabolism, anti-inflammatory function, and autophagy.

scholarly journals Enhanced Clearance of Pseudomonas aeruginosa by Peroxisome Proliferator-Activated Receptor Gamma

2016 ◽  
Vol 84 (7) ◽  
pp. 1975-1985 ◽  
Author(s):  
Brahmchetna Bedi ◽  
Zhihong Yuan ◽  
Myungsoo Joo ◽  
Susu M. Zughaier ◽  
Joanna B. Goldberg ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Nuclear Hormone Receptor ◽  
Host Cells ◽  
Peroxisome Proliferator ◽  
Bacterial Killing ◽  
Peroxisome Proliferator Activated Receptor ◽  
Content Type ◽  
Homoserine Lactones ◽  
Pparγ Agonist ◽  
Pparγ Agonists

The pathogenic profile ofPseudomonas aeruginosais related to its ability to secrete a variety of virulence factors. Quorum sensing (QS) is a mechanism wherein small diffusible molecules, specifically acyl-homoserine lactones, are produced byP. aeruginosato promote virulence. We show here that macrophage clearance ofP. aeruginosa(PAO1) is enhanced by activation of the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ). Macrophages treated with a PPARγ agonist (pioglitazone) showed enhanced phagocytosis and bacterial killing of PAO1. It is known that PAO1 QS molecules are inactivated by PON-2. QS molecules are also known to inhibit activation of PPARγ by competitively binding PPARγ receptors. In accord with this observation, we found that infection of macrophages with PAO1 inhibited expression of PPARγ and PON-2. Mechanistically, we show that PPARγ induces macrophage paraoxonase 2 (PON-2), an enzyme that degrades QS molecules produced byP. aeruginosa. Gene silencing studies confirmed that enhanced clearance of PAO1 in macrophages by PPARγ is PON-2 dependent. Further, we show that PPARγ agonists also enhance clearance ofP. aeruginosafrom lungs of mice infected with PAO1. Together, these data demonstrate thatP. aeruginosaimpairs the ability of host cells to mount an immune response by inhibiting PPARγ through secretion of QS molecules. These studies define a novel mechanism by which PPARγ contributes to the host immunoprotective effects during bacterial infection and suggest a role for PPARγ immunotherapy forP. aeruginosainfections.

scholarly journals Regulation of mitochondrial biogenesis

2010 ◽  
Vol 47 ◽  
pp. 69-84 ◽  
Author(s):  
François R. Jornayvaz ◽  
Gerald I. Shulman
Keyword(s):  
Mitochondrial Dysfunction ◽  
Mitochondrial Biogenesis ◽  
Molecular Mechanisms ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nuclear Respiratory Factor ◽  
Mitochondrial Transcription Factor ◽  
Nuclear Respiratory Factor 1 ◽  
And Function ◽  
Amp Activated Protein Kinase

Although it is well established that physical activity increases mitochondrial content in muscle, the molecular mechanisms underlying this process have only recently been elucidated. Mitochondrial dysfunction is an important component of different diseases associated with aging, such as Type 2 diabetes and Alzheimer’s disease. PGC-1α (peroxisome-proliferator-activated receptor γ co-activator-1α) is a co-transcriptional regulation factor that induces mitochondrial biogenesis by activating different transcription factors, including nuclear respiratory factor 1 and nuclear respiratory factor 2, which activate mitochondrial transcription factor A. The latter drives transcription and replication of mitochondrial DNA. PGC-1α itself is regulated by several different key factors involved in mitochondrial biogenesis, which will be reviewed in this chapter. Of those, AMPK (AMP-activated protein kinase) is of major importance. AMPK acts as an energy sensor of the cell and works as a key regulator of mitochondrial biogenesis. AMPK activity has been shown to decrease with age, which may contribute to decreased mitochondrial biogenesis and function with aging. Given the potentially important role of mitochondrial dysfunction in the pathogenesis of numerous diseases and in the process of aging, understanding the molecular mechanisms regulating mitochondrial biogenesis and function may provide potentially important novel therapeutic targets.

scholarly journals Peroxisome Proliferator-Activated Receptor Agonists: Do They Increase Cardiovascular Risk?

PPAR Research ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmad Aljada ◽  
Kshitij Ashwin Shah ◽  
Shaker A. Mousa
Keyword(s):  
Molecular Mechanisms ◽  
Review Article ◽  
Current Evidence ◽  
Peroxisome Proliferator ◽  
Cardiovascular Risks ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Agonists ◽  
Record Trial ◽  
Meta Analyses

Cardiovascular disease is a major cause of morbidity and mortality among people with type 2 diabetes mellitus. The peroxisome proliferator-activated receptor (PPAR) agonists have a significant role on glucose and fat metabolism. Thiazolidinediones (TZDs) are predominantly PPARγagonists, and their primary benefit appears to be the prevention of diabetic complications by improving glycemic control and lipid profile. Recently, the cardiovascular safety of rosiglitazone was brought to center stage following meta analyses and the interim analysis of the RECORD trial. Current evidence points to rosiglitazone having a greater risk of myocardial ischemic events than placebo, metformin, or sulfonylureas. This review article discusses the mechanism of action of PPAR agonists and correlates it with clinical and laboratory outcomes in the published literature. In addition, this review article attempts to discuss some of the molecular mechanisms regarding the association between TZDs therapy and the nontraditional cardiovascular risks.

scholarly journals The Potential of Resveratrol to Act as a Caloric Restriction Mimetic Appears to Be Limited: Insights from Studies in Mice

2020 ◽  
Author(s):  
Kathrin Pallauf ◽  
Ilka Günther ◽  
Gianna Kühn ◽  
Dawn Chin ◽  
Sonia de Pascual-Teresa ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Caloric Restriction ◽  
Gene Transcription ◽  
Molecular Mechanisms ◽  
Molecular Targets ◽  
Laboratory Animals ◽  
Current Evidence ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Age Related

ABSTRACT Caloric restriction (CR) has been shown repeatedly to prolong the lifespan in laboratory animals, with its benefits dependent on molecular targets forming part of the nutrient signaling network, including the NAD-dependent deacetylase silent mating type information regulation 2 homologue 1 (SIRT1). It has been hypothesized that the stilbene resveratrol (RSV) may counteract age- and obesity-related diseases similarly to CR. In yeast and worms, RSV-promoted longevity also depended on SIRT1. While it remains unclear whether RSV can prolong lifespans in mammals, some studies in rodents supplemented with RSV have reported lowered body weight (BW) and fat mass, improved insulin sensitivity, lowered cholesterol levels, increased fitness, and mitochondrial biogenesis. Molecular mechanisms possibly leading to such changes include altered gene transcription and activation of SIRT1, AMP-activated kinase (AMPK), and peroxisome proliferator–activated receptor gamma coactivator 1-alpha (PPARGC1A). However, some mouse models did not benefit from RSV treatment to the same extent as others. We conducted a literature search on PubMed (15 April, 2020) for trials directly comparing RSV application to CR feeding in mice. In most studies retrieved by this systematic PubMed search, mice supplemented with RSV did not show significant reductions of BW, glucose, or insulin. Moreover, in some of these studies, RSV and CR treatments affected molecular targets differently and/or findings on RSV and CR impacts varied between trials. We discuss those RSV-induced changes in gene transcription hypothesized to partly counteract age-related alterations. Although there may be a moderate effect of RSV supplementation on parameters such as insulin sensitivity toward a more CR-like profile in mice, data are inconsistent. Likewise, RSV supplementation trials in humans report controversial findings. While we consider that RSV may, under certain circumstances, moderately mimic some aspects of CR, current evidence does not fully support its use to prevent or treat age- or obesity-related diseases.

scholarly journals Mechanosensation and Mechanotransduction by Lymphatic Endothelial Cells Act as Important Regulators of Lymphatic Development and Function

2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Mechanical Forces ◽  
Lymphatic Endothelial Cells ◽  
Lymphatic Development ◽  
And Function ◽  
The Impact

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.

scholarly journals PPAR-gamma induced AKT3 expression increases levels of mitochondrial biogenesis driving prostate cancer

Oncogene ◽  
2021 ◽  
Vol 40 (13) ◽  
pp. 2355-2366
Author(s):  
Laura C. A. Galbraith ◽  
Ernest Mui ◽  
Colin Nixon ◽  
Ann Hedley ◽  
David Strachan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Biogenesis ◽  
Nuclear Export ◽  
Epithelial To Mesenchymal Transition ◽  
Ppar Gamma ◽  
Peroxisome Proliferator ◽  
Serine Threonine Kinase ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mesenchymal Transition ◽  
And Function

AbstractPeroxisome Proliferator-Activated Receptor Gamma (PPARG) is one of the three members of the PPAR family of transcription factors. Besides its roles in adipocyte differentiation and lipid metabolism, we recently demonstrated an association between PPARG and metastasis in prostate cancer. In this study a functional effect of PPARG on AKT serine/threonine kinase 3 (AKT3), which ultimately results in a more aggressive disease phenotype was identified. AKT3 has previously been shown to regulate PPARG co-activator 1 alpha (PGC1α) localisation and function through its action on chromosome maintenance region 1 (CRM1). AKT3 promotes PGC1α localisation to the nucleus through its inhibitory effects on CRM1, a known nuclear export protein. Collectively our results demonstrate how PPARG over-expression drives an increase in AKT3 levels, which in turn has the downstream effect of increasing PGC1α localisation within the nucleus, driving mitochondrial biogenesis. Furthermore, this increase in mitochondrial mass provides higher energetic output in the form of elevated ATP levels which may fuel the progression of the tumour cell through epithelial to mesenchymal transition (EMT) and ultimately metastasis.

scholarly journals Expression and function of Smad7 in autoimmune and inflammatory diseases

2021 ◽  
Author(s):  
Yiping Hu ◽  
Juan He ◽  
Lianhua He ◽  
Bihua Xu ◽  
Qingwen Wang
Keyword(s):  
Posttranscriptional Regulation ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Inflammatory Diseases ◽  
Kidney Diseases ◽  
Critical Role ◽  
Transforming Growth Factor Β ◽  
Negative Regulator ◽  
Signaling Mechanism ◽  
And Function

AbstractTransforming growth factor-β (TGF-β) plays a critical role in the pathological processes of various diseases. However, the signaling mechanism of TGF-β in the pathological response remains largely unclear. In this review, we discuss advances in research of Smad7, a member of the I-Smads family and a negative regulator of TGF-β signaling, and mainly review the expression and its function in diseases. Smad7 inhibits the activation of the NF-κB and TGF-β signaling pathways and plays a pivotal role in the prevention and treatment of various diseases. Specifically, Smad7 can not only attenuate growth inhibition, fibrosis, apoptosis, inflammation, and inflammatory T cell differentiation, but also promotes epithelial cells migration or disease development. In this review, we aim to summarize the various biological functions of Smad7 in autoimmune diseases, inflammatory diseases, cancers, and kidney diseases, focusing on the molecular mechanisms of the transcriptional and posttranscriptional regulation of Smad7.

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.

scholarly journals The Potential Applications of Peroxisome Proliferator-Activated ReceptorδLigands in Assisted Reproductive Technology

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Jaou-Chen Huang
Keyword(s):  
Assisted Reproductive Technology ◽  
Reproductive Function ◽  
Reproductive Technology ◽  
Embryonic Cell ◽  
Preimplantation Embryos ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Potential Applications ◽  
And Function

Peroxisome proliferator-activated receptorδ(PPARδ, also known as PPARβ) has ubiquitous distribution and extensive biological functions. The reproductive function of PPARδwas first revealed in the uterus at the implantation site. Since then, PPARδand its ligand have been discovered in all reproductive tissues, including the gametes and the preimplantation embryos. PPARδin preimplantation embryos is normally activated by oviduct-derived PPARδligand. PPARδactivation is associated with an increase in embryonic cell proliferation and a decrease in programmed cell death (apoptosis). On the other hand, the role of PPARδand its ligand in gamete formation and function is less well understood. This review will summarize the reproductive functions of PPARδand project its potential applications in assisted reproductive technology.

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