l-165041 and Inflammation

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors, which is composed of three members encoded by distinct genes: PPARα, PPARβ/δ, and PPARγ. The biological actions of PPARα and PPARγ and their potential as a cardiovascular therapeutic target have been extensively reviewed, whereas the biological actions of PPARβ/δ and its effectiveness as a therapeutic target in the treatment of hypertension remain less investigated. Preclinical studies suggest that pharmacological PPARβ/δ activation induces antihypertensive effects in direct [spontaneously hypertensive rat (SHR), ANG II, and DOCA-salt] and indirect (dyslipemic and gestational) models of hypertension, associated with end-organ damage protection. This review summarizes mechanistic insights into the antihypertensive effects of PPARβ/δ activators, including molecular and functional mechanisms. Pharmacological PPARβ/δ activation induces genomic actions including the increase of regulators of G protein-coupled signaling (RGS), acute nongenomic vasodilator effects, as well as the ability to improve the endothelial dysfunction, reduce vascular inflammation, vasoconstrictor responses, and sympathetic outflow from central nervous system. Evidence from clinical trials is also examined. These preclinical and clinical outcomes of PPARβ/δ ligands may provide a basis for the development of therapies in combating hypertension.

Topics: Animals; Antihypertensive Agents; Blood Pressure; Endothelium, Vascular; Fatty Acids; Gene Expression Regulation; Humans; Hypertension; Inflammation; Phenoxyacetates; PPAR delta; PPAR-beta; Rats; Rats, Inbred SHR; RGS Proteins; Sympathetic Nervous System; Thiazoles; Vasoconstriction; Vasodilation

Topics: Animals; Diabetes Mellitus; Drug Design; Humans; Hyperlipidemias; Hypertension; Inflammation; Ligands; Models, Molecular; Neoplasms; Nuclear Proteins; Obesity; Receptors, Cytoplasmic and Nuclear; Transcription Factors

Hyperglycemia-induced advanced glycation end products (AGEs) and receptor for AGEs (RAGE) production play major roles in progression of diabetic nephropathy. Anti-RAGE effect of peroxisome proliferator-activated receptor-delta (PPARδ) agonists was shown in previous studies. PPARδ agonists also stimulate glucagon-like peptide-1 (GLP-1) secretion from human intestinal cells.. In this study, the individual and synergic anti-inflammatory effects of GLP-1 receptor (exendin-4) and PPARδ (L-165,041) agonists in AGE-treated rat mesangial cells (RMC) were investigated.. The results showed both exendin-4 and L-165,041 significantly attenuated AGE-induced IL-6 and TNF-α production, RAGE expression, and cell death in RMC. Similar anti-inflammatory potency was seen between 0.3 nM exendin-4 and 1 μM L-165,041. Synergic effect of exendin-4 and L-165,041 was shown in inhibiting cytokines production, but not in inhibiting RAGE expression or cell death.. These results suggest that both GLP-1 receptor and PPARδ agonists have anti-inflammatory effect on AGE-treated rat mesangial cells.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Cell Survival; Cells, Cultured; Exenatide; Glucagon-Like Peptide-1 Receptor; Glycation End Products, Advanced; Inflammation; Interleukin-6; Mesangial Cells; Peptides; Phenoxyacetates; PPAR delta; Rats; Tumor Necrosis Factor-alpha; Venoms

Phytochemical study on the roots of Asarum sieboldii resulted in the isolation of one new compound, (1R,2S,5R,6R)-5'-O-methylpluviatilol (1) and 12 known compounds (2-13). Their structures were determined by extensive spectroscopic methods, including 1D and 2D NMR, and MS spectra. The absolute configuration of compound 1 was established using CD spectrum. Compounds 4, 5, and 12/13 significantly inhibited TNFα-induced NF-κB transcriptional activity in HepG2 cells in a dose-dependent manner, with IC(50) values ranging from 6.4 to 9.4 μM. Furthermore, the transcriptional inhibitory function of these compounds was confirmed based on decreases in COX-2 and iNOS gene expression in HepG2 cells. Compounds 1-3, 6,7, 10, and 11 significantly activated the transcriptional activity of PPARs in a dose-dependent manner, with EC(50) values ranging from 1.7 to 20.9 μM. Compounds 7, 10, and 11 exhibited significant dose-dependent PPARα transactivational activity, with EC(50) values of 19.5, 15.7, and 4.0 μM, respectively. Compounds 1, 6, 7, 10, and 11 activated PPARγ transcriptional activity, with EC(50) values ranging from 3.6 to 22.6 μM, whereas compounds 10 and 11 significantly increased PPARβ(δ) transactivational activity, with EC(50) values of 22.6 and 4.9 μM, respectively. These results provide a scientific support for the use of the roots of A. sieboldii and warrant further studies to develop new agents for the prevention and treatment of the inflammatory and metabolic diseases.

Topics: Anti-Inflammatory Agents; Asarum; Cyclooxygenase 2; Dose-Response Relationship, Drug; Furans; Hep G2 Cells; Humans; Inflammation; Magnetic Resonance Spectroscopy; Mass Spectrometry; NF-kappa B; Nitric Oxide Synthase Type II; Phenols; Plant Roots; PPAR alpha; Republic of Korea; Transcription, Genetic; Transcriptional Activation; Tumor Necrosis Factor-alpha

Activation of peroxisome proliferator-activated receptor δ (PPARδ) plays board beneficial effects in treating metabolic syndrome. The aim of this study is to examine whether PPARδ alters the expression of the receptor for advanced glycation end products (RAGE) and downstream pro-inflammatory cytokines in diabetic nephropathy. Streptozotocin-induced diabetic mice (STZ mice) were injected with a PPARδ agonist, L-165041 (5 μM/kg, intraperitoneal) once daily for 10 days and high glucose-treated cultured HEK cells were also used. After L-165041 treatment, serum TNFα, IL-6 and IL-1 levels were significantly decreased in STZ mice. RAGE mRNA and protein expression were both decreased by L-165041 in kidney tissues of STZ mice. The high glucose incubation increased NF-κB, RAGE and IL-6 expressions in HEK293 cells. These effects were inhibited by L-165041 and specific RAGE siRNA transfection. This study demonstrated that PPARδ may play a beneficial role in preventing diabetic nephropathy. Its downstream signaling may include RAGE and NF-κB pathway. Target on PPARδ will provide new meaningful therapies to patients with diabetic nephropathy.

Topics: Animals; Cytokines; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Down-Regulation; Glycation End Products, Advanced; HEK293 Cells; Humans; Inflammation; Kidney; Male; Mice; Mice, Inbred BALB C; Models, Animal; NF-kappa B; Phenoxyacetates; PPAR delta; Signal Transduction

This protocol describes microsphere-based protease assays for use in flow cytometry and high-throughput screening. This platform measures a loss of fluorescence from the surface of a microsphere due to the cleavage of an attached fluorescent protease substrate by a suitable protease enzyme. The assay format can be adapted to any site or protein-specific protease of interest and results can be measured in both real time and as endpoint fluorescence assays on a flow cytometer. Endpoint assays are easily adapted to microplate format for flow cytometry high-throughput analysis and inhibitor screening.

Topics: Animals; Biotinylation; Flow Cytometry; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; High-Throughput Screening Assays; Humans; Inflammation; Kinetics; Microspheres; Peptide Hydrolases; Peptides; Reproducibility of Results; Temperature

Although peroxisome proliferator-activated receptor delta (PPARdelta) has been implicated in energy metabolism and lipid oxidation process, detailed roles of PPARdelta in lipid homeostasis under pathologic conditions still remain controversial. Thus, we investigated the effect of PPARdelta ligand L-165041 on Western diet-induced fatty liver using low-density lipoprotein receptor-deficient (LDLR(-/-)) mice. LDLR(-/-) mice received either L-165041 (5mg/kg/day) or vehicle (0.1N NaOH) with Western diet for 16 weeks. According to our data, L-165041 drastically reduced lipid accumulation in the liver, decreasing total hepatic cholesterol and triglyceride content compared to the vehicle group. Gene expression analysis demonstrated that L-165041 lowered hepatic expression of PPARgamma, apolipoprotein B, interleukin 1 beta (IL-1beta), and interleukin-6. In contrast, L-165041 increased hepatic expressions of PPARdelta, lipoprotein lipase (LPL), and ATP-binding cassette transporter G1 (ABCG1). Our data suggest that L-165041 might be effective in preventing Western diet-induced hepatic steatosis by regulating genes involved in lipid metabolism and the inflammatory response.

Topics: Animals; Apolipoproteins B; Cholesterol; Cytokines; Diet; Female; Gene Expression Regulation; Inflammation; Ligands; Lipid Metabolism; Liver; Mice; Phenoxyacetates; PPAR delta; Receptors, LDL; RNA, Messenger; Triglycerides

Ischemic acute renal failure is characterized by damages to the proximal straight tubule in the outer medulla. Lesions include loss of polarity, shedding into the tubule lumen, and eventually necrotic or apoptotic death of epithelial cells. It was recently shown that peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) increases keratinocyte survival after an inflammatory reaction. Therefore, whether PPARbeta/delta could contribute also to the control of tubular epithelium death after renal ischemia/reperfusion was tested. It was found that PPARbeta/delta+/- and PPARbeta/delta-/- mutant mice exhibited much greater kidney dysfunction and injury than wild-type counterparts after a 30-min renal ischemia followed by a 36-h reperfusion. Conversely, wild-type mice that were given the specific PPARbeta/delta ligand L-165041 before renal ischemia were completely protected against renal dysfunction, as indicated by the lack of rise in serum creatinine and fractional excretion of Na+. This protective effect was accompanied by a significant reduction in medullary necrosis, apoptosis, and inflammation. On the basis of in vitro studies, PPARbeta/delta ligands seem to exert their role by activating the antiapoptotic Akt signaling pathway and, unexpectedly, by increasing the spreading of tubular epithelial cells, thus limiting potentially their shedding and anoikis. These results point to PPARbeta/delta as a remarkable new target for preconditioning strategies.

Topics: Acetates; Animals; Apoptosis; Blotting, Western; Cells, Cultured; Creatinine; Dose-Response Relationship, Drug; Epithelial Cells; Humans; In Situ Nick-End Labeling; Inflammation; Ischemia; Keratinocytes; Kidney; Kidney Tubules; Ligands; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Fluorescence; Necrosis; Neutrophils; Peroxidase; Phenols; Phenotype; Phenoxyacetates; PPAR delta; PPAR-beta; Proto-Oncogene Proteins c-akt; Renal Insufficiency; Signal Transduction; Sodium; Time Factors