PPAR-alpha activation as a preconditioning-like intervention in rats in vivo confers myocardial protection against acute ischaemia–reperfusion injury: involvement of PI3K–Akt

2012 ◽  
Vol 90 (8) ◽  
pp. 1135-1144 ◽  
Author(s):  
Táňa Ravingerová ◽  
Slávka Čarnická ◽  
Martina Nemčeková ◽  
Veronika Ledvényiová ◽  
Adriana Adameová ◽  
...  
Keyword(s):  
Target Genes ◽  
Left Ventricular ◽  
Metabolic Effects ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Akt Inhibitor ◽  
Ischaemia Reperfusion Injury ◽  
Acute Ischaemia ◽  
Ischaemia Reperfusion

Peroxisome proliferator-activated receptors (PPAR) regulate the expression of genes involved in lipid metabolism, energy production, and inflammation. Their role in ischaemia–reperfusion (I/R) is less clear, although research indicates involvement of PPARs in some forms of preconditioning. This study aimed to explore the effects of PPAR-α activation on the I/R injury and potential cardioprotective downstream mechanisms involved. Langendorff-perfused hearts of rats pretreated with the selective PPAR-α agonist WY-14643 (WY, pirinixic acid; 3 mg·(kg body mass)·day–1; 5 days) were subjected to 30 min ischaemia – 2 h reperfusion with or without the phosphatidylinositol 3-kinase (PI3K)–Akt inhibitor wortmannin for the evaluation of functional (left ventricular developed pressure, LVDP) recovery, infarct size (IS), and reperfusion-induced arrhythmias. A 2-fold increase in baseline PPAR-α mRNA levels (qPCR) in the WY-treated group and higher post-I/R PPAR-α levels compared with those in untreated controls were accompanied by similar changes in the expression of PPAR-α target genes PDK4 and mCPT-1, regulating glucose and fatty acid metabolism, and by enhanced Akt phosphorylation. Post-ischaemic LVDP restoration in WY-treated hearts reached 60% ± 9% of the pre-ischaemic values compared with 24% ± 3% in the control hearts (P < 0.05), coupled with reduced IS and incidence of ventricular fibrillation that was blunted by wortmannin. Results indicate that PPAR-α up-regulation may confer preconditioning-like protection via metabolic effects. Downstream mechanisms of PPAR-α-mediated cardioprotection may involve PI3K–Akt activation.

Delayed cardioprotective effects of WY-14643 are associated with inhibition of MMP-2 and modulation of Bcl-2 family proteins through PPAR-α activation in rat hearts subjected to global ischaemia–reperfusion

2013 ◽  
Vol 91 (8) ◽  
pp. 608-616 ◽  
Author(s):  
Eleftheria Barlaka ◽  
Veronika Ledvényiová ◽  
Eleftheria Galatou ◽  
Miroslav Ferko ◽  
Slávka Čarnická ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Matrix Metalloproteinase ◽  
Left Ventricular ◽  
Matrix Metalloproteinase 2 ◽  
Heme Oxygenase 1 ◽  
Mrna Levels ◽  
Acute Ischaemia ◽  
Ischaemia Reperfusion ◽  
Rat Hearts ◽  
Selective Ligand

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors regulating cardiac lipid metabolism and energy homeostasis. Although the activation of PPARs has been implicated in cardioprotection, the molecular mechanisms are largely unexplored. In this study, we aimed to investigate the effect of the PPAR-α agonist WY-14643 (WY), mimicking a delayed effect of preconditioning in rat hearts exposed to acute ischaemia–reperfusion (I/R) 24 h later, and to define whether antioxidative and antiapoptotic mechanisms are involved. Treatment with WY markedly attenuated post-ischaemic contractile dysfunction (as evidenced by the reduced infarct size), the higher left ventricular developed pressure (LVDP) recovery, and the decreased occurrence of arrhythmias. These effects were abolished in the presence of the PPAR-α antagonist MK886. Heme oxygenase-1, a key antioxidative enzyme implicated in cytoprotection, was upregulated in response to WY at baseline, but was markedly reduced after I/R, indicating reduced oxidative stress. WY treatment was also associated with decreased mRNA levels and enzymatic activity of matrix metalloproteinase-2, and increased ratios of Bcl-2:Bax proteins. These results indicate that PPAR-α activation by its selective ligand WY may confer delayed preconditioning-like protection in rat hearts subjected to I/R by modulating oxidative stress, activation of matrix metalloproteinase-2, and expression of Bcl-2 and Bax.

Thyroid hormone interacts with PPARα and PGC-1 during mitochondrial maturation in sheep heart

2005 ◽  
Vol 289 (5) ◽  
pp. H2258-H2264 ◽  
Author(s):  
Timothy D. McClure ◽  
Martin E. Young ◽  
Heinrich Taegtmeyer ◽  
Xue-Han Ning ◽  
Norman E. Buroker ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Cytochrome C ◽  
Target Genes ◽  
Steroid Receptors ◽  
Pyruvate Dehydrogenase Kinase ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Peroxisome Proliferator Activated Receptor ◽  
Postnatal Maturation

Thyroid hormone (TH) promotes cardiac mitochondrial maturation and substrate metabolism after birth. This regulation involves ligand-dependent binding of nuclear TH receptors to target gene elements. TH also putatively controls genes indirectly by modulating transcription and/or translation of other nuclear steroid receptors and coactivators, such as peroxisome proliferator-activated receptor-α (PPARα) and peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1). We tested the hypothesis that TH influences PPARα and PGC-1 regulation of metabolic genes during postnatal maturation in sheep heart in vivo. We measured their mRNAs and/or protein levels and downstream targets in left ventricle from lambs: fetal (F), 30-day-old after postnatal thyroidectomy (THY), and 30-day-old euthyroid (Con). Both PPARα and PGC-1 mRNA expression decreased from F to Con, while PGC-1 protein increased substantially and PPARα did not change. THY limited this mRNA response and attenuated the paradoxical postnatal PGC-1 protein elevation but did not alter mRNA levels for PPARα, nuclear respiratory factor-1 and hypoxia-inducible factor-1α. THY promotion in PPARα mRNA did not change PPARα protein or mRNA for PPARα target genes, pyruvate-dehydrogenase kinase 4 ( PDK4) and muscle type carnitine palmitoyltransferase I ( mCPTI). THY reduction in PGC-1 protein occurred, while reducing cytochrome c oxidase and cytochrome c content and decreasing cardiac maximal inherent respiratory capacity. These data imply that TH modulates mitochondrial maturation partly through posttranscriptional control of PGC-1, while any important regulation of PDK4 and mCPTI by change in PPARα protein expression remains doubtful. Also, the paradoxical expression pattern between mRNA and protein, particularly for PGC-1, suggests a feedback control mechanism.

Gene Silencing using siRNA for Preventing Liver Ischaemia-Reperfusion Injury

2018 ◽  
Vol 24 (23) ◽  
pp. 2692-2700 ◽  
Author(s):  
H. Susana Marinho ◽  
Paulo Marcelino ◽  
Helena Soares ◽  
Maria Luísa Corvo
Keyword(s):  
Gene Silencing ◽  
Reperfusion Injury ◽  
Therapeutic Potential ◽  
Major Complication ◽  
Ischaemia Reperfusion Injury ◽  
Small Interference Rna ◽  
Ischaemia Reperfusion ◽  
Promising Therapeutic Approach ◽  
Sirna Therapy

Background: Ischaemia-reperfusion injury (IRI), a major complication occurring during organ transplantation, involves an initial ischemia insult, due to loss of blood supply, followed by an inflammation-mediated reperfusion injury. A variety of molecular targets and pathways involved in liver IRI have been identified. Gene silencing through RNA interference (RNAi) by means of small interference RNA (siRNA) targeting mediators of IRI is a promising therapeutic approach. Objective: This study aims at reviewing the use of siRNAs as therapeutic agents to prevent IRI during liver transplantation. Method: We review the crucial choice of siRNA targets and the advantages and problems of the use of siRNAs. Results: We propose possible targets for siRNA therapy during liver IRI. Moreover, we discuss how drug delivery systems, namely liposomes, may improve siRNA therapy by increasing siRNA stability in vivo and avoiding siRNA off-target effects. Conclusion: siRNA therapeutic potential to preclude liver IRI can be improved by a better knowledge of what molecules to target and by using more efficient delivery strategies.

scholarly journals Extract of Wax Gourd Peel Prevents High-Fat Diet-Induced Hyperlipidemia in C57BL/6 Mice via the Inhibition of the PPARγPathway

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ming Gu ◽  
Shengjie Fan ◽  
Gaigai Liu ◽  
Lu Guo ◽  
Xiaobo Ding ◽  
...  
Keyword(s):  
Blood Glucose ◽  
High Fat Diet ◽  
Target Genes ◽  
Metabolic Diseases ◽  
Body Weight Gain ◽  
Fasting Blood Glucose ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
High Fat ◽  
Wax Gourd

Wax gourd is a popular vegetable in East Asia. In traditional Chinese medicine, wax gourd peel is used to prevent and treat metabolic diseases such as hyperlipidemia, hyperglycemia, obesity, and cardiovascular disease. However, there is no experimental evidence to support these applications. Here, we examined the effect of the extract of wax gourd peel (EWGP) on metabolic disorders in diet-induced C57BL/6 obese mice. In the preventive experiment, EWGP blocked body weight gain and lowered serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), liver TG and TC contents, and fasting blood glucose in mice fed with a high-fat diet. In the therapeutic study, we induced obesity in the mice and treated with EWGP for two weeks. We found that EWGP treatment reduced serum and liver triglyceride (TG) contents and fasting blood glucose and improved glucose tolerance in the mice. Reporter assay and gene expression analysis showed that EWGP could inhibit peroxisome proliferator-activated receptorγ(PPARγ) transactivities and could decrease mRNA levels of PPARγand its target genes. We also found that HMG-CoA reductase (HMGCR) was downregulated in the mouse liver by EWGP. Our data suggest that EWGP lowers hyperlipidemia of C57BL/6 mice induced by high-fat diet via the inhibition of PPARγand HMGCR signaling.

Cachectin/TNF or IL-1 alpha induces cachexia with redistribution of body proteins

1989 ◽  
Vol 256 (3) ◽  
pp. R659-R665 ◽  
Author(s):  
Y. Fong ◽  
L. L. Moldawer ◽  
M. Marano ◽  
H. Wei ◽  
A. Barber ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Muscle Protein ◽  
Interleukin 1 ◽  
Metabolic Effects ◽  
Liver Protein ◽  
Mrna Levels ◽  
Skeletal Muscle Protein ◽  
Male Wistar Rats

Macrophage secretory products are suspected to participate in the severe lean tissue wasting related to chronic illness. The protein metabolic effects of chronic, 7-day cachectin/tumor necrosis factor (cachectin) or interleukin 1 alpha (IL-1 alpha) administration in vivo were studied in male Wistar rats that were 1) freely fed, 2) pair fed, 3) total protein and calorie starved, 4) twice daily lipopolysaccharide (LPS) administered, 5) twice daily cachectin administered, and 6) twice daily IL-1 alpha administered. LPS, cachectin, or IL-1 alpha administration produced anorexia; weight loss in these groups was comparable to respective pair-fed animals. However, LPS, cachectin, or IL-1 alpha accelerated peripheral protein wasting while preserving liver protein content, unlike the pattern in the pair-fed or starved animals in which loss of liver proteins and relative preservation of skeletal muscle protein were observed. The decrease in skeletal muscle protein content in LPS- or cytokine-treated animals was associated with coordinate decreases in muscle mRNA levels for the myofibrillar proteins myosin heavy chain, myosin light chain, actin, and in the 18S and 28S subunits of ribosomal RNA. We conclude that chronic exposure to the cytokines, IL-1 alpha or cachectin, can simulate those body and muscle protein changes seen in experimental LPS administration or chronic disease and markedly differ from the pattern of protein redistribution due to caloric restriction.

scholarly journals Effects of mycophenolate mofetil on acute ischaemia-reperfusion injury in rats and its consequences in the long term

2009 ◽  
Vol 25 (5) ◽  
pp. 1443-1450 ◽  
Author(s):  
M. Sabbatini ◽  
F. Uccello ◽  
V. Serio ◽  
G. Troncone ◽  
V. Varone ◽  
...  
Keyword(s):  
Mycophenolate Mofetil ◽  
Reperfusion Injury ◽  
Ischaemia Reperfusion Injury ◽  
Acute Ischaemia ◽  
Ischaemia Reperfusion

trans-10, cis-12, but not cis-9,trans-11 CLA isomer, inhibits brown adipocyte thermogenic capacity

2002 ◽  
Vol 282 (6) ◽  
pp. R1789-R1797 ◽  
Author(s):  
Enrique Rodrı́guez ◽  
Joan Ribot ◽  
Andreu Palou
Keyword(s):  
Linoleic Acid ◽  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Equal Concentration ◽  
Brown Adipose ◽  
Cla Isomers ◽  
Thermogenic Capacity

Conjugated linoleic acid (CLA) is reported to have health benefits, including reduction of body fat. Previous studies have shown that brown adipose tissue (BAT) is particularly sensitive to CLA-supplemented diet feeding. Most of them use mixtures containing several CLA isomers, mainly cis-9, trans-11 and trans-10, cis-12 in equal concentration. Our aim was to characterize the separate effects of both CLA isomers on thermogenic capacity in cultured brown adipocytes. The CLA isomers showed opposite effects. Hence, on the one hand, trans-10, cis-12 inhibited uncoupling protein (UCP) 1 induction by norepinephrine (NE) and produced a decrease in leptin mRNA levels. These effects were associated with a blockage of CCAAT-enhancer-binding protein-α and peroxisome proliferator-activated receptor-γ2 mRNA expression. On the other hand, cis-9, trans-11 enhanced the UCP1 elicited by NE, an effect reported earlier for polyunsaturated fatty acids and also observed here for linoleic acid. These findings could explain, at least in part, the effects observed in vivo when feeding a CLA mixture supplemented diet as a result of the combined action of CLA isomers (reduction of adipogenesis and defective BAT thermogenesis that could be through trans-10, cis-12 and enhanced UCP1 thermogenic capacity through cis-9, trans-11).

scholarly journals Circular RNA CDR1as Exerts Oncogenic Properties Partially through Regulating MicroRNA 641 in Cholangiocarcinoma

2020 ◽  
Vol 40 (15) ◽  
Author(s):  
Dingyang Li ◽  
Zhe Tang ◽  
Zhiqiang Gao ◽  
Pengcheng Shen ◽  
Zhaochen Liu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Target Genes ◽  
Circular Rna ◽  
Tumor Xenograft ◽  
Mrna Levels ◽  
Cell Behaviors ◽  
Xenograft Growth ◽  
Tumor Xenograft Growth

ABSTRACT It has been found that the circular RNA (circRNA) CDR1as is upregulated in cholangiocarcinoma (CCA) tissues. In this study, we tried to explore the roles of CDR1as in CCA. CDR1as was overexpressed or knocked down in human CCA cells to assess the effects of CDR1as on cell behaviors and tumor xenograft growth. In vitro, the CDR1as level was significantly increased in CCA cell lines. The results showed that CDR1as promoted the cell proliferation, migration, invasion, and activation of the AKT3/mTOR pathway in CCA cells. Moreover, miR-641, a predicted target microRNA (miRNA) of CDR1as, could partially reverse the effects of CDR1as on cell behaviors in CCA cells. Furthermore, CDR1as improved tumor xenograft growth, and it could be attenuated by miR-641 in vivo. Additionally, CDR1as expression was inversely correlated with miR-641 in CCA cells, and miR-641 could directly bind with CDR1as and its target genes, the AKT3 and mTOR genes. Mechanistically, CDR1as could bind with miR-641 and accelerate miR-641 degradation, which possibly leads to the upregulation of the relative mRNA levels of AKT3 and mTOR in RBE cells. In conclusion, our findings indicated that CDR1as might exert oncogenic properties, at least partially, by regulating miR-641 in CCA. CDR1as and miR-641 could be considered therapeutic targets for CCA.

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