gw-3965 and Inflammation

The Liver X Receptors (LXRs) are oxysterol-activated transcription factors that upregulate a suite of genes that together promote coordinated mobilization of excess cholesterol from cells and from the body. The LXRs, like other nuclear receptors, are anti-inflammatory, inhibiting signal-dependent induction of pro-inflammatory genes by nuclear factor-κB, activating protein-1, and other transcription factors. Synthetic LXR agonists have been shown to ameliorate atherosclerosis and a wide range of inflammatory disorders in preclinical animal models. Although this has suggested potential for application to human disease, systemic LXR activation is complicated by hepatic steatosis and hypertriglyceridemia, consequences of lipogenic gene induction in the liver by LXRα. The past several years have seen the development of multiple advanced LXR therapeutics aiming to avoid hepatic lipogenesis, including LXRβ-selective agonists, tissue-selective agonists, and transrepression-selective agonists. Although several synthetic LXR agonists have made it to phase I clinical trials, none have progressed due to unforeseen adverse reactions or undisclosed reasons. Nonetheless, several sophisticated pharmacologic strategies, including structure-guided drug design, cell-specific drug targeting, as well as non-systemic drug routes have been initiated and remain to be comprehensively explored. In addition, recent studies have identified potential utility for targeting the LXRs during therapy with other agents, such as glucocorticoids and rexinoids. Despite the pitfalls encountered to date in translation of LXR agonists to human disease, it appears likely that this accelerating field will ultimately yield effective and safe applications for LXR targeting in humans.

Topics: Animals; Atherosclerosis; Benzoates; Benzylamines; Gene Expression Regulation; Humans; Hydrocarbons, Fluorinated; Inflammation; Liver X Receptors; Models, Biological; Molecular Targeted Therapy; Sulfonamides

Transglutaminase 2 (TG2) is a multifunctional protein that promotes clearance of apoptotic cells (efferocytosis) acting as integrin β

Topics: 3T3 Cells; Adipocytes; Adipose Tissue; Animals; Apoptosis; Benzoates; Benzylamines; Cytokines; Diet, High-Fat; Fatty Liver; GTP-Binding Proteins; Inflammation; Insulin Resistance; Liver X Receptors; Lysosomes; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Obesity; Protein Glutamine gamma Glutamyltransferase 2; Proto-Oncogene Proteins pp60(c-src); Signal Transduction; Transglutaminases; Triglycerides

Liver-X-receptors (LXRs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily. The two popular homologous receptor subtypes, LXRα and LXRβ, exhibit differential expression patterns, thereby probably playing different roles in different contexts. This study aimed to evaluate the different roles of the two LXR subtypes and the mechanisms underlying their protection of cardiomyocytes against high-glucose stress. Silencing of LXRα, but not LXRβ impaired normal LXR-mediated cardioprotective effects against high glucose-induced oxidative stress, apoptosis, and inflammation. Mechanistically, silencing of small ubiquitin-like modifier (SUMO)1 or SUMO2/3 did not affect LXR-mediated cardioprotective effects; however, these were impaired in response to nuclear receptor corepressor (NCoR) silencing. Together, these findings indicate that LXRα, but not LXRβ, protects against high glucose-induced cardiomyocyte injury, probably via the NCoR-dependent transrepression of downstream target genes.

Topics: Animals; Apoptosis; Benzoates; Benzylamines; Cells, Cultured; Glucose; Inflammation; Liver X Receptors; Myocytes, Cardiac; Oxidative Stress; Rats

Liver X receptors (LXRs) play an important role in the regulation of cholesterol, fatty acid and glucose metabolisms together with inflammatory processes. In the present study, the effects of LXR agonist GW3965 on vascular reactivity and expression of functional proteins in DOCA-Salt induced hypertension were examined.. Hypertension was induced through unilateral nephrectomy and deoxycorticosterone-acetate (DOCA) injection (20 mg/kg, twice a week) for 6 weeks in male Wistar albino rats (8 weeks old). An LXR agonist GW3965 (10 mg/kg/day, i.p.) was administered to animals for last seven days.. GW3965 treatment reduced systolic blood pressures in hypertensive rats. Acetylcholine-induced endothelium-dependent and sodium nitroprusside-induced endothelium-independent vasorelaxations were decreased in hypertensive rats but not affected by GW3965. GW3965 treatment enhanced plasma nitrite levels in normotensive rats. KCl and phenylephrine (Phe)-induced vasocontractions were reduced in hypertensive groups and increased with GW3965 treatment. Decreased sarco/endoplasmic reticulum Ca. The results of study indicate that the LXR agonist, GW3965, exhibited a beneficial effect on increased blood pressure and improved hypertension-induced impairment in contractile activity of vessel and inflammatory markers in vascular tissue. Therefore, these effects of LXR agonists on vessel should be taken into account in experimental or therapeutic approaches to hypertension.

Topics: Animals; Aorta; Benzoates; Benzylamines; Blood Pressure; Cardiovascular Diseases; Desoxycorticosterone Acetate; Disease Models, Animal; Hypertension; Inflammation; Liver X Receptors; Male; Nitroprusside; Rats; Rats, Wistar

Liver X receptor (LXR) signaling pathways regulate lipid metabolism and inflammation, which has generated widespread interest in developing synthetic LXR agonists as potential therapeutics for the management of atherosclerosis. In this study, it is demonstrated that nanoparticles (NPs) containing the synthetic LXR agonist GW3965 (NP-LXR) exert anti-inflammatory effects and inhibit the development of atherosclerosis without causing hepatic steatosis. These NPs are engineered through self-assembly of a biodegradable diblock poly(lactide-co-glycolide)-b-poly(ethylene glycol) (PLGA-b-PEG) copolymer. NP-LXR is significantly more effective than free GW3965 at inducing LXR-target gene expression and suppressing inflammatory factors in macrophages in vitro and in vivo. Additionally, the NPs elicit negligible lipogenic gene stimulation in the liver. Using the Ldlr (-/-) mouse model of atherosclerosis, abundant colocalization of fluorescently labeled NPs within plaque macrophages following systemic administration is seen. Notably, six intravenous injections of NP-LXR over 2 weeks markedly reduce the CD68-positive cell (macrophage) content of plaques (by 50%) without increasing total cholesterol or triglycerides in the liver and plasma. Together, these findings identify GW3965-encapsulated PLGA-b-PEG NPs as a promising nanotherapeutic approach to combat atherosclerosis, providing the benefits of LXR agonists without their adverse effects on hepatic and plasma lipid metabolism.

Topics: Animals; Anti-Inflammatory Agents; Atherosclerosis; Benzoates; Benzylamines; Cell Line; Gene Expression Regulation; Inflammation; Liver; Liver X Receptors; Male; Mice, Inbred C57BL; Nanoparticles; Orphan Nuclear Receptors; Plaque, Atherosclerotic

Liver X receptors (LXRs) attenuate inflammation by modulating the expression of key inflammatory genes, making LXRs and their ligands particularly attractive candidates for therapeutic intervention in cardiovascular, metabolic, and/or inflammatory diseases. Herein, enhanced proresolving activity of polymeric nanoparticles (NPs) containing the synthetic LXR agonist GW3965 (LXR-NPs) is demonstrated, developed from a combinatorial library of more than 70 formulations with variations in critical physicochemical parameters. In vitro studies on peritoneal macrophages confirm that LXR-NPs are significantly more effective than the free agonist at downregulating pro-inflammatory mediators (MCP-1 and TNFα), as well as inducing the expression of LXR target genes (ABCA1 and SREBP1c). Through a zymosan-induced acute peritonitis in vivo model, LXR-NPs are found to be more efficient than free GW3965 at limiting the recruitment of polymononuclear neutrophils (50% vs 17%), suppressing the gene expression and secretion of pro-inflammatory factors MCP-1 and TNFα in peritoneal macrophages, and decreasing the resolution interval up to 4 h. Furthermore, LXR-NPs suppress the secretion of MCP-1 and TNFα by monocytes and macrophages more efficiently than the commercial drug dexamethasone. Overall, these findings demonstrate that LXR-NPs are capable of promoting resolution of inflammation and highlight the prospect of LXR-based nanotherapeutics for inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Benzoates; Benzylamines; Disease Models, Animal; Inflammation; Liver X Receptors; Male; Mice; Mice, Inbred C57BL; Nanoparticles; Orphan Nuclear Receptors; Peritonitis; Polymers

To investigate the role of liver X receptor (LXR) in adipose tissue metabolism during obesity, ob/ob mice were treated for 5 weeks with the synthetic LXR agonist GW3965. MRI analysis revealed that pharmacological activation of LXR modified fat distribution by decreasing visceral (VS) fat and inversely increasing subcutaneous (SC) fat storage without affecting whole body fat content. This was concordant with opposite regulation by GW3965 of the lipolytic markers hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) in the two fat depots; moreover, the expression of genes involved in lipogenesis was significantly induced in SC fat. Lipidomic analysis suggested that changes in lipid composition in response to GW3965 also varied between VS and SC fat. In both depots, the observed alteration in lipid composition indicated an overall change toward less lipotoxic lipids. Flow cytometry analysis showed decreased immune cell infiltration in adipose tissue of ob/ob mice in response to GW3965 treatment, which in VS fat mainly affected the macrophage population and in SC fat the lymphocyte population. In line with this, the expression and secretion of proinflammatory markers was decreased in both fat deposits with GW3965 treatment.

Topics: Adipogenesis; Adipose Tissue; Animals; Benzoates; Benzylamines; Body Fat Distribution; Female; Inflammation; Lipolysis; Liver X Receptors; Macrophages; Mice; Obesity; Orphan Nuclear Receptors

Dyslipidemia is a frequent component of the metabolic disorder of diabetic patients contributing to organ damage. Herein, in low-density lipoprotein receptor-deficient hyperlipidemic and streptozotozin-induced diabetic mice, hyperglycemia and hyperlipidemia acted reciprocally, accentuating renal injury and altering renal function. In hyperglycemic-hyperlipidemic kidneys, the accumulation of Tip47-positive lipid droplets in glomeruli, tubular epithelia, and macrophages was accompanied by the concomitant presence of the oxidative stress markers xanthine oxidoreductase and nitrotyrosine, findings that could also be evidenced in renal biopsy samples of diabetic patients. As liver X receptors (LXRα,β) regulate genes linked to lipid and carbohydrate homeostasis and inhibit inflammatory gene expression in macrophages, the effects of systemic and macrophage-specific LXR activation were analyzed on renal damage in hyperlipidemic-hyperglycemic mice. LXR stimulation by GW3965 up-regulated genes involved in cholesterol efflux and down-regulated proinflammatory/profibrotic cytokines, inhibiting the pathomorphology of diabetic nephropathy, renal lipid accumulation, and improving renal function. Xanthine oxidoreductase and nitrotyrosine levels were reduced. In macrophages, GW3965 or LXRα overexpression significantly suppressed glycated or acetylated low-density lipoprotein-induced cytokines and reactive oxygen species. Specifically, in mice, transgenic expression of LXRα in macrophages significantly ameliorated hyperlipidemic-hyperglycemic nephropathy. The results demonstrate the presence of lipid droplet-induced oxidative mechanisms and the pathophysiologic role of macrophages in diabetic kidneys and indicate the potent regulatory role of LXRs in preventing renal damage in diabetes.

Topics: Animals; Benzoates; Benzylamines; Cytokines; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Endothelial Cells; Fibrosis; Humans; Hyperglycemia; Hyperlipidemias; Inflammation; Kidney; Kidney Function Tests; Lipid Metabolism; Liver X Receptors; Macrophages; Mesangial Cells; Mice; Mice, Inbred C57BL; Orphan Nuclear Receptors; Oxidative Stress; Podocytes

Liver X receptor (LXR) agonists are atheroprotective but often induce hypertriglyceridaemia and liver steatosis. We investigated the effect of a novel high-affinity LXR activator, AZ876, on plasma lipids, inflammation and atherosclerosis, and compared the effects with another LXR agonist, GW3965.. APOE*3Leiden mice were fed an atherogenic diet alone or supplemented with either AZ876 (5 or 20µmol·kg(-1) ·day(-1) ) or GW3965 (17µmol·kg(-1) ·day(-1) ) for 20 weeks. Total cholesterol and triglyceride levels were measured using commercial kits. Plasma cytokines were determined by using bead-based multiplex suspension array kits with the Luminex technology. Atherosclerosis was assessed histochemically and lesion composition was assessed by immunohistochemical methods.. Low-dose AZ876 had no effect on plasma or liver lipids, whereas high-dose AZ876 increased plasma triglycerides (+110%) and reduced cholesterol (-16%) compared with controls. GW3965 increased plasma triglycerides (+70%). Low-dose AZ876 reduced lesion area (-47%); and high-dose AZ876 strongly decreased lesion area (-91%), lesion number (-59%) and severity. In either dose, AZ876 did not affect lesion composition. GW3965 reduced atherosclerosis and collagen content of lesions (-23%; P < 0.01). High-dose AZ876 and GW3965, but not low-dose AZ876, reduced inflammation as reflected by lower cytokine levels and vessel wall activation.. We have identified a novel LXR agonist that when given in a low dose inhibits the progression of atherosclerosis without inducing anti-inflammatory effects, liver steatosis or hypertriglyceridaemia. Therefore, the primary protective action of a low-dose AZ876 is likely to be an increased reverse cholesterol transport.

Topics: Aniline Compounds; Animals; Apolipoprotein E3; Atherosclerosis; Benzoates; Benzylamines; Cholesterol; Cytokines; Dose-Response Relationship, Drug; Fatty Liver; Female; Humans; Hypertriglyceridemia; Inflammation; Lipid Metabolism; Lipids; Liver; Liver X Receptors; Mice; Mice, Inbred C57BL; Mice, Transgenic; Orphan Nuclear Receptors; Thiazoles; Triglycerides

The liver X receptors (LXRs) belong to the nuclear receptor superfamily and act as transcriptional regulators of cholesterol metabolism in several tissues. Recent work also has identified LXRs as potent antiinflammatory molecules in macrophages and other immune cells. Combined changes in lipid and inflammatory profiles are likely mediating the protective role of LXRs in models of chronic injury like atherosclerosis. These beneficial actions, however, have not been illustrated in other models of acute injury such as stroke in which inflammation is an important pathophysiological feature.. We have studied LXR expression and function in the course of experimental stroke caused by permanent middle cerebral artery occlusion in rats and mice. Here, we show that administration of the synthetic LXR agonists GW3965 or TO901317 after the ischemic occlusion improves stroke outcome as shown by decreased infarct volume area and better neurological scores in rats. Neuroprotection observed with LXR agonists correlated with decreased expression of proinflammatory genes in the brain and with reduced nuclear factor-kappaB transcriptional activity. Loss of function studies using LXRalpha,beta(-/-) mice demonstrated that the effect of LXR agonists is receptor specific. Interestingly, infarcted brain area and inflammatory signaling were significantly extended in LXRalpha,beta(-/-) mice compared with control animals, indicating that endogenous LXR signaling mediates neuroprotection in this setting.. This work highlights the transcriptional action of LXR as a protective pathway in brain injury and the potential use of LXR agonists as therapeutic agents in stroke.

Topics: Animals; Benzoates; Benzylamines; Brain; Brain Ischemia; DNA-Binding Proteins; Inflammation; Liver X Receptors; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Neuroprotective Agents; Orphan Nuclear Receptors; Rats; Rats, Inbred F344; Receptors, Cytoplasmic and Nuclear; Stroke