scholarly journals Peroxisome Proliferator-Activated Receptor Activation is Associated with Altered Plasma One-Carbon Metabolites and B-Vitamin Status in Rats

Nutrients ◽  
2016 ◽  
Vol 8 (1) ◽  
pp. 26 ◽  
Author(s):  
Vegard Lysne ◽  
Elin Strand ◽  
Gard Svingen ◽  
Bodil Bjørndal ◽  
Eva Pedersen ◽  
...  
PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0226069
Author(s):  
Vegard Lysne ◽  
Bodil Bjørndal ◽  
Mari Lausund Grinna ◽  
Øivind Midttun ◽  
Per Magne Ueland ◽  
...  

Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3271-3280 ◽  
Author(s):  
Istvan Szatmari ◽  
Daniel Töröcsik ◽  
Maura Agostini ◽  
Tibor Nagy ◽  
Mark Gurnell ◽  
...  

Abstract Activation of the lipid-regulated nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) modifies the immunophenotype of monocyte-derived dendritic cells (DCs). However it has not been analyzed in a systematic manner how lipid metabolism and immune regulation are connected at the transcriptional level via this receptor. Here we present the genome-wide expression analyses of PPARγ-instructed human DCs. Receptor activation was achieved by exogenous, synthetic as well as endogenous, natural means. More than 1000 transcripts are regulated during DC development by activation of PPARγ; half of the changes are positive effects. These changes appear to enhance and modulate the robust gene expression alterations associated with monocyte to DC transition. Strikingly, only genes related to lipid metabolism are overrepresented among early induced genes. As a net consequence, lipid accumulation appears to be diminished in these cells. In contrast, genes related to immune response are regulated after 24 hours, implying the existence of indirect mechanisms of modulation. Receptor dependence was established by using DCs of patients harboring a dominant-negative mutation of PPARγ. Our data show that PPARγ acts as a mostly positive transcriptional regulator in human developing DCs, acting primarily through controlling genes involved in lipid metabolism and via this, indirectly modifying the immune phenotype.


2011 ◽  
Vol 300 (2) ◽  
pp. E341-E349 ◽  
Author(s):  
Miki Tadaishi ◽  
Shinji Miura ◽  
Yuko Kai ◽  
Emi Kawasaki ◽  
Keiichi Koshinaka ◽  
...  

There are three isoforms of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) mRNA, which promotes mitochondrial biogenesis in skeletal muscles. Compared with PGC-1α-a mRNA, PGC-1α-b or PGC-1α-c mRNA is transcribed by a different exon 1 of the PGC-1α gene. In this study, effects of exercise intensity and 5-aminoimidazole-4-carboxamide-1β-d-ribofuranoside (AICAR) on isoform-specific expressions of PGC-1α were investigated. All isoforms were increased in proportion to exercise intensity of treadmill running (10–30 m/min for 30 min). Preinjection of β2-adrenergic receptor (AR) antagonist (ICI 118551) inhibited the increase in PGC-1α-b and PGC-1α-c mRNAs, but not the increase in PGC-1α-a mRNA, in response to high-intensity exercise. Although high-intensity exercise activated α2-AMP-activated protein kinase (α2-AMPK) in skeletal muscles, inactivation of α2-AMPK activity did not affect high-intensity exercise-induced mRNA expression of all PGC-1α isoforms, suggesting that activation of α2-AMPK is not mandatory for an increase in PGC-1α mRNA by high-intensity exercise. A single injection in mice of AICAR, an AMPK activator, increased mRNAs of all PGC-1α isoforms. AICAR increased blood catecholamine concentrations, and preinjection of β2-AR antagonist inhibited the increase in PGC-1α-b and PGC-1α-c mRNAs but not the increase in PGC-1α-a mRNA. Direct exposure of epitrochlearis muscle to AICAR increased PGC-1α-a but not the -b isoform. These data indicate that exercise-induced PGC-1α expression was dependent on the intensity of exercise. Exercise or AICAR injection increased PGC-1α-b and PGC-1α-c mRNAs via β2-AR activation, whereas high-intensity exercise increased PGC-1α-a expression by a multiple mechanism in which α2-AMPK is one of the signaling pathways.


PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Patricia E. Almeida ◽  
Alan Brito Carneiro ◽  
Adriana R. Silva ◽  
Patricia T. Bozza

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.


2007 ◽  
Vol 194 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Masaya Takeda ◽  
Fumio Otsuka ◽  
Hiroyuki Otani ◽  
Kenichi Inagaki ◽  
Tomoko Miyoshi ◽  
...  

Involvement of peroxisome proliferator-activated receptor-γ (PPAR-γ ) activation and bone morphogenetic protein (BMP) signaling in regulating cell proliferation and hormonal production of pituitary tumors has been reported, although the underlying mechanism remains poorly understood. Here, we investigated regulatory roles of PPARα and PPARγ in gonadotropin transcription and cell mitosis modulated by pituitary activin/BMP systems using a mouse gonadotropinoma cell line Lβ T2, which expresses activin/BMP receptors, transcription factor Smads, PPARα , and PPARγ . In Lβ T2 cells, BMP signaling shown by Smad1/5/8 phosphorylation and Id-1 transcription was readily activated by BMPs. A PPARγ agonist, pioglitazone significantly reduced BMP-induced DNA synthesis by Lβ T2; whereas the PPARα agonist, fenofibric acid, did not. In accordance with the effects on cell mitosis, pioglitazone but not fenofibric acid significantly decreased BMP-induced Id-1-Luc activation. Neither fenofibric acid nor pioglitazone affected activin signaling detected by (CAGA)9-Luc activity. Both PPARα and PPARγ ligands directly suppressed transcriptional activities of FSHβ , LHβ , and GnRHR. Activation of PPARα and PPARγ increased mRNA levels of follistatin, but did not affect the expression of follistatin-related gene. Thus, PPAR agonists not only directly suppress gonadotropin transcription and BMP signaling, but also inhibit the biological actions of activins which facilitate gonadotropin transcription through upregulating follistatin expression. In addition, pioglitazone increased BMP ligands mRNA, but decreased activin-β B mRNA in Lβ T2 cells. Collectively, PPAR activation differentially regulates gonadotrope cell proliferation and gonadotropin transcription in a ligand-dependent manner.


Endocrinology ◽  
2007 ◽  
Vol 148 (7) ◽  
pp. 3441-3448 ◽  
Author(s):  
Shinji Miura ◽  
Kentaro Kawanaka ◽  
Yuko Kai ◽  
Mayumi Tamura ◽  
Masahide Goto ◽  
...  

A single bout of exercise increases expression of peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α mRNA, which may promote mitochondrial biogenesis in skeletal muscle. In brown adipose tissue, cold exposure up-regulates PGC-1α expression via adrenergic receptor (AR) activation. Because exercise also activates the sympathetic nervous system, we examined whether exercise-induced increase in PGC-1α mRNA expression in skeletal muscle was mediated via AR activation. In C57BL/6J mice, injection of the β2-AR agonist clenbuterol, but not α-, β1-, or β3-AR agonists, increased PGC-1α mRNA expression more than 30-fold in skeletal muscle. The clenbuterol-induced increase in PGC-1α mRNA expression in mice was inhibited by pretreatment with the β-AR antagonist propranolol. In ex vivo experiments, direct exposure of rat epitrochlearis to β2-AR agonist, but not α-, β1-, and β3-AR agonist, led to an increase in levels of PGC-1α mRNA. Injection of β2-AR agonist did not increase PGC-1α mRNA expression in β1-, β2-, and β3-AR knockout mice (β-less mice). PGC-1α mRNA in gastrocnemius was increased 3.5-fold in response to running on a treadmill for 45 min. The exercise-induced increase in PGC-1α mRNA was inhibited by approximately 70% by propranolol or the β2-AR-specific inhibitor ICI 118,551. The exercise-induced increase in PGC-1α mRNA in β-less mice was also 36% lower than that in wild-type mice. These data indicate that up-regulation of PGC-1α expression in skeletal muscle by exercise is mediated, at least in part, by β-ARs activation. Among ARs, β2-AR may mediate an increase in PGC-1α by exercise.


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