Potent Peroxisome Proliferator-activated Receptor Research Articles

Prospective de novo drug design with deep interactome learning

De novo drug design aims to generate molecules from scratch that possess specific chemical and pharmacological properties. We present a computational approach utilizing interactome-based deep learning for ligand- and structure-based generation of drug-like molecules. This method capitalizes on the unique strengths of both graph neural networks and chemical language models, offering an alternative to the need for application-specific reinforcement, transfer, or few-shot learning. It enables the “zero-shot" construction of compound libraries tailored to possess specific bioactivity, synthesizability, and structural novelty. In order to proactively evaluate the deep interactome learning framework for protein structure-based drug design, potential new ligands targeting the binding site of the human peroxisome proliferator-activated receptor (PPAR) subtype gamma are generated. The top-ranking designs are chemically synthesized and computationally, biophysically, and biochemically characterized. Potent PPAR partial agonists are identified, demonstrating favorable activity and the desired selectivity profiles for both nuclear receptors and off-target interactions. Crystal structure determination of the ligand-receptor complex confirms the anticipated binding mode. This successful outcome positively advocates interactome-based de novo design for application in bioorganic and medicinal chemistry, enabling the creation of innovative bioactive molecules.

Impact of Phytochemicals on PPAR Receptors: Implications for Disease Treatments.

Peroxisome proliferator-activated receptors (PPARs) are members of the ligand-dependent nuclear receptor family. PPARs have attracted wide attention as pharmacologic mediators to manage multiple diseases and their underlying signaling targets. They mediate a broad range of specific biological activities and multiple organ toxicity, including cellular differentiation, metabolic syndrome, cancer, atherosclerosis, neurodegeneration, cardiovascular diseases, and inflammation related to their up/downstream signaling pathways. Consequently, several types of selective PPAR ligands, such as fibrates and thiazolidinediones (TZDs), have been approved as their pharmacological agonists. Despite these advances, the use of PPAR agonists is known to cause adverse effects in various systems. Conversely, some naturally occurring PPAR agonists, including polyunsaturated fatty acids and natural endogenous PPAR agonists curcumin and resveratrol, have been introduced as safe agonists as a result of their clinical evidence or preclinical experiments. This review focuses on research on plant-derived active ingredients (natural phytochemicals) as potential safe and promising PPAR agonists. Moreover, it provides a comprehensive review and critique of the role of phytochemicals in PPARs-related diseases and provides an understanding of phytochemical-mediated PPAR-dependent and -independent cascades. The findings of this research will help to define the functions of phytochemicals as potent PPAR pharmacological agonists in underlying disease mechanisms and their related complications.

GW9662, a peroxisome proliferator-activated receptor gamma antagonist, attenuates the development of non-alcoholic fatty liver disease

Background and aimsInsulin resistance is among the key risk factors for the development of non-alcoholic fatty liver disease (NAFLD). Recently, it has been reported that GW9662, shown to be a potent peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, may improve insulin sensitivity in settings of type 2 diabetes. Here, we determined the effects of GW9662 on the development of NAFLD and molecular mechanisms involved. MethodsFemale C57BL/6J mice were pair-fed either a liquid control diet (C) or a fat-, fructose- and cholesterol-rich diet (FFC) for 8 weeks while either being treated with GW9662 (1 mg/kg body weight; C+GW9662 and FFC+GW9662) or vehicle (C and FFC) i.p. three times weekly. Indices of liver damage and inflammation, parameters of glucose metabolism and portal endotoxin levels were determined. Lipopolysaccharide (LPS)-challenged J774A.1 cells were treated with 10 μM GW9662. ResultsDespite similar caloric intake the development of NAFLD and insulin resistance were significantly attenuated in FFC+GW9662-treated mice when compared to FFC-fed animals. Bacterial endotoxin levels in portal plasma were almost similarly increased in both FFC-fed groups while expressions of toll-like receptor 4 (Tlr4), myeloid differentiation primary response 88 (Myd88) and interleukin 1 beta (Il1b) as well as nitrite (NO2−) concentration in liver were significantly higher in FFC-fed mice than in FFC+GW9662-treated animals. In J774A.1 cells, treatment with GW9662 significantly attenuated LPS-induced expression of Il1b, interleukin 6 (Il6) and inducible nitric oxide synthase (iNos) as well as NO2− formation. ConclusionIn summary, our data suggest that the PPARγ antagonist GW9662 attenuates the development of a diet-induced NAFLD and that this is associated with a protection against the activation of the TLR4 signaling cascade.

Small-Molecule Modulation of PPARs for the Treatment of Prevalent Vascular Retinal Diseases.

Vascular-related retinal diseases dramatically impact quality of life and create a substantial burden on the healthcare system. Age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity are leading causes of irreversible blindness. In recent years, the scientific community has made great progress in understanding the pathology of these diseases and recent discoveries have identified promising new treatment strategies. Specifically, compelling biochemical and clinical evidence is arising that small-molecule modulation of peroxisome proliferator-activated receptors (PPARs) represents a promising approach to simultaneously address many of the pathological drivers of these vascular-related retinal diseases. This has excited academic and pharmaceutical researchers towards developing new and potent PPAR ligands. This review highlights recent developments in PPAR ligand discovery and discusses the downstream effects of targeting PPARs as a therapeutic approach to treating retinal vascular diseases.

Label-free quantitative proteomics identifies transforming growth factor \u03b21 (TGF-\u03b21) as an inhibitor of adipogenic transformation in OP9-DL1 cells and primary thymic stromal cells

BackgroundAdipocyte accumulation is a predominant feature of age-related thymic involution, but the mechanisms responsible for thymic adipogenesis remain to be elucidated. The aim of this study was to identify key regulators in thymic adipogenesis. We used rosiglitazone, a potent peroxisome proliferator-activated receptor γ (PPARγ) agonist, to induce adipogenic differentiation of OP9-DL1 cells, and investigated the differentially expressed proteins during adipogenic differentiation by using label-free quantitative proteomics. Furthermore, the effects of transforming growth factor β1 (TGF-β1) on rosiglitazone-induced adipogenic differentiation of OP9-DL1 cells as well as the underlying mechanisms were also investigated.ResultsProteomic analysis identified 139 proteins differed significantly in rosiglitazone-treated cells compared with dimethyl sulphoxide (DMSO)-treated cells. Rosiglitazone-induced adipogenic differentiation was inhibited by TGF-β1 treatment in OP9-DL1 cells and primary thymic stromal cells. Real-time PCR analysis showed significant increases in PPARγ and fatty acid binding protein 4 mRNA levels in rosiglitazone-treated cells, which were inhibited by TGF-β1 treatment. TGF-β1 down-regulated PPARγ expression at both mRNA and protein levels in OP9-DL1 cells. Chromatin immunoprecipitation analysis demonstrated that TGF-β1 enhanced the binding of Smad2/3 and histone deacetylase 1, but reduced the binding of H3K14ac to the promoter of PPARγ gene. TGF-β1 partially reversed the inhibitory effects of rosiglitazone on the expression of Axin2 and β-catenin protein levels. TGF-β1 inhibited rosiglitazone-induced adipogenic transformation in OP9-DL1 cells by down-regulation of PPARγ and activation of the canonical Wnt/β-catenin signaling pathway.ConclusionTaken together, activation of TGF-β pathway may serve as a useful strategy to prevent thymic adiposity in age-related thymic involution.

Notch1 Inhibits Rosiglitazone-Induced Adipogenic Differentiation in Primary Thymic Stromal Cells.

Adipocyte deposition is believed to be a primary characteristic of age-related thymic involution. Herein, we cultured primary thymic stromal cells (TSCs), used rosiglitazone, a potent peroxisome proliferator-activated receptor γ (PPARγ) agonist, to induce adipogenic differentiation, and investigated the differentially expressed genes during adipogenic differentiation by using RNA-sequencing analysis. Furthermore, the effects of Notch1 on rosiglitazone-induced adipogenic differentiation of TSCs as well as the underlying mechanisms were also investigated. As a result, we identified a total of 1737 differentially expressed genes, among which 965 genes were up-regulated and 772 genes were down-regulated in rosiglitazone-treated cells compared with control cells. Gene ontology (GO) enrichment analysis showed that the GO terms were enriched in metabolic process, intracellular, and protein binding. Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that a number of pathways, including ubiquitin mediated proteolysis, PPAR signaling pathway, and mammalian target of rapamycin (mTOR) signaling pathway were predominantly over-represented. Meanwhile, overexpression of Notch1 suppressed and inhibition of Notch1 promoted rosiglitazone-induced adipogenic differentiation in TSCs, and the pro-adipogenic effects of the Notch inhibitor DAPT were associated with the activation of autophagy. Taken together, our results suggest that Notch1 is a key regulator in thymic adipogenesis and may serve as a potential target to hinder thymic adiposity in age-related thymic involution.

Enantioselective Synthesis of a Novel Thiazoline Core as a Potent Peroxisome Proliferator-Activated Receptor δ Agonist.

The convergent and enantioselective synthesis of a highly potent human peroxisome proliferator-activated receptor delta agonist is presented. More specifically, the thiazoline structure, which constitutes the biosynthetically distinctive core structure of pulicatin (a secondary metabolite of symbiotic bacteria), was synthesized from a commercially available and inexpensive chiral pool of l-threonine.

Peroxisome Proliferator-Activated Receptor α Activation Is Not the Main Contributor to Teratogenesis Elicited by Polar Compounds from Oxidized Frying Oil.

We previously reported that polar compounds (PO) in cooking oil are teratogenic and perturbed retinoic acid (RA) metabolism. Considering PO as a potent peroxisome proliferator-activated receptor α (PPARα) activator, this study aimed to investigate the role of PPARα in PO-induced teratogenesis and disturbance of RA metabolism. Female PPARα knockout or wild type mice were mated with males of the same genotype. Pregnant mice were fed a diet containing 10% fat from either fresh oil (FO) or PO from gestational day1 to day18, and killed at day18. The PO diet significantly increased the incidence of teratogenesis and fetal RA concentrations, regardless of genotype. Though PPARα deficiency disturbed maternal RA homeostasis, itself did not contribute to teratogenesis as long as FO diet was given. The mRNA profile of genes involved in RA metabolism was differentially affected by diet or genotype in mothers and fetuses. Based on hepatic mRNA levels of genes involved in xenobiotic metabolism, we inferred that PO not only activated PPARα, but also altered transactivity of other xenobiotic receptors. We concluded that PO-induced fetal anomalies and RA accumulation were independent of PPARα activation.

Untargeted metabolomics analysis of adipogenic transformation in OP9-DL1 cells using liquid chromatography-mass spectrometry: Implications for thymic adipogenesis.

Adipocyte deposition is a key feature of age-related thymic involution, but the underlying mechanisms responsible for thymic adiposity remain to be elucidated. In the present study, we utilized rosiglitazone, a potent peroxisome proliferator-activated receptor γ agonist, to induce adipogenic differentiation of OP9-DL1 cells, and detected the metabolomics alterations during adipogenic differentiation by using liquid chromatography-mass spectrometry. The obtained metabolites were further processed by multivariate statistical analysis, including principal component analysis, partial least squares discriminant analysis, and orthogonal projection on latent-structures discriminant analysis. As a result, we identified a total of 33 significantly differential metabolites between dimethyl sulphoxide- and rosiglitazone-treated OP9-DL1 cells, which were closely related to the dysregulation of phospholipid metabolism pathway, oxidative stress, and associated amino acid metabolism. Meanwhile, two pathways including glycerophospholipid metabolism and nitrogen metabolism were significantly perturbed (P < 0.05). Collectively, our results may provide some heuristic guidance for addressing the underlying mechanism of thymic adipogenesis, and future studies are warranted to unravel the functions of these altered metabolites in thymic adipogenesis.

Rosiglitazone attenuates inflammation and CA3 neuronal loss following traumatic brain injury in rats

Rosiglitazone, a potent peroxisome proliferator-activated receptor (PPAR)-γ agonist, has been shown to confer neuroprotective effects in stroke and spinal cord injury, but its role in the traumatic brain injury (TBI) is still controversial. Using a controlled cortical impact model in rats, the current study was designed to determine the effects of rosiglitazone treatment (6 mg/kg at 5 min, 6 h and 24 h post injury) upon inflammation and histological outcome at 21 d after TBI. In addition, the effects of rosiglitazone upon inflammatory cytokine transcription, vestibulomotor behavior and spatial memory function were determined at earlier time points (24 h, 1–5 d, 14–20 d post injury, respectively). Compared with the vehicle-treated group, rosiglitazone treatment suppressed production of TNFα at 24 h after TBI, attenuated activation of microglia/macrophages and increased survival of CA3 neurons but had no effect on lesion volume at 21 d after TBI. Rosiglitazone-treated animals had improved performance on beam balance testing, but there was no difference in spatial memory function as determined by Morris water maze. In summary, this study indicates that rosiglitazone treatment in the first 24 h after TBI has limited anti-inflammatory and neuroprotective effects in rat traumatic injury. Further study using an alternative dosage paradigm and more sensitive behavioral testing may be warranted.

Pan-PPAR Modulation Effectively Protects APP/PS1 Mice from Amyloid Deposition and Cognitive Deficits

Alzheimer’s disease (AD) is a neurodegenerative condition that leads to neuronal death and memory dysfunction. In the past, specific peroxisome proliferator-activated receptor (PPAR)γ-agonists, such as pioglitazone, have been tested with limited success to improve AD pathology. Here, we investigated the therapeutic efficacy of GFT1803, a novel potent PPAR agonist that activates all the three PPAR isoforms (α/δ/γ) in the APP/PS1 mouse model in comparison to the selective PPARγ-agonist pioglitazone. Both compounds showed similar brain/plasma partitioning ratios, although whole body and brain exposure to GFT1803 was significantly lower as compared to pioglitazone, at doses used in this study. Oral treatment of APP/PS1 mice with GFT1803 decreased microglial activation, amyloid β (Aβ) plaque area, Aβ levels in sodium dodecyl sulfate- and formic acid-soluble fractions in a concentration-dependent manner. With a single exception of Aβ38 and Aβ40 levels, measured by ELISA, these effects were not observed in mice treated with pioglitazone. Both ligands decreased glial fibrillary acidic protein (GFAP) expression to similar extent and did not affect ApoE expression. Finally, GFT1803 increased insulin-degrading enzyme expression. Analysis of spatial memory formation in the Morris water maze demonstrated that both compounds were able to partially revert the phenotype of APP/PS1 mice in comparison to wild-type mice with GFT1803 being most effective. As compared to pioglitazone, GFT1803 (pan-PPAR agonist) produced both quantitatively superior and qualitatively different therapeutic effects with respect to amyloid plaque burden, insoluble Aβ content, and neuroinflammation at significantly lower whole body and brain exposure rates.

Evaluation of the dual peroxisome proliferator–activated receptor α/γ agonist aleglitazar to reduce cardiovascular events in patients with acute coronary syndrome and type 2 diabetes mellitus: Rationale and design of the AleCardio trial

Peroxisome proliferator-activated receptors (PPARs) regulate transcription of genes involved in glucose uptake, lipid metabolism, and inflammation. Aleglitazar is a potent dual PPAR agonist with insulin-sensitizing and glucose-lowering actions and favorable effects on lipid profiles and biomarkers of cardiovascular risk. The AleCardio trial examines whether the addition of aleglitazar to standard medical therapy reduces the risk of cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus and recent acute coronary syndrome. AleCardio is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. A total of 7,228 patients were randomized to aleglitazar 150 μg or placebo daily in addition to standard medical therapy. The primary efficacy end point is time to the first event of cardiovascular death, myocardial infarction, or stroke. Principal safety end points are hospitalization due to heart failure and changes in renal function. Treatment will continue until 7,000 patients are followed up for at least 2.5 years and 950 primary end point events are adjudicated. AleCardio will establish whether the PPAR-α/γ agonist aleglitazar improves cardiovascular outcomes in patients with diabetes and high-risk coronary disease.

Synthesis and Structure–Activity Relationships of Novel Zwitterionic Compounds as Peroxisome Proliferator Activated Receptor α/γ Dual Agonists with Improved Physicochemical Properties

We describe herein the design, syntheses and structure-activity relationships (SAR) of novel zwitterionic compounds as non-thiazolidinedion (TZD) based peroxisome proliferator activated receptor (PPAR) α/γ dual agonists. In the previous report, we obtained compound 1 showing potent PPARα/γ dual agonistic activities, together with a great glucose lowering effect in the db/db mice. However, this compound possessed fatal issues such as potent cytochrome P450 (CYP)3A4 direct inhibitory activity. Thus, we carried out the medicinal optimization to improve these while maintaining the potent PPAR agonistic activity. As a result, the issues were addressed by changing the furan ring to a low lipophilic 1,3,4-oxadiazole ring. Additionally, these oxadiazole derivatives exhibited a significant decrease in plasma glucose and plasma triglyceride levels without marked weight gain.

Docking and Molecular Dynamics Simulations of Peroxisome Proliferator Activated Receptors Interacting with Pan Agonist Sodelglitazar

PPAR (peroxisome proliferator-activated receptor) pan agonists play a critical role in treating metabolic diseases, especially the Type-2 diabetes mellitus (T2DM). GlaxoSmithKline's sodelglitazar (GW677954) is one of the potent PPAR pan agonists, which is currently being investigated in Phase II clinical trials for the treatment of T2DM and its complications. The present study was aimed at investigation into the effect of sodelglitazar at the binding pockets of PPARs. The Schrodinger Suite program (2009) was used for the molecular docking, while the GROMACS program used for the molecular dynamics (MD) simulations. The results thus obtained showed that sodelglitazar being docked well in the active site of PPARs. It was revealed by the MD simulations that the structures of the receptors remained quite stable during the simulations and that the important AF-2 helix showed less flexibility after binding with sodelglitazar. Also, it was observed that sodelglitazar could periodically form hydrogen bonds with the AF-2 helix of PPARs to stabilize the AF-2 helix in an active conformation. Our findings have confirmed that GlaxoSmithKline's sodelglitazar can activate the PPARs, which is quite consistent with the previous biological studies.

Abstract 1311: Disposition and biotransformation of [14C]-radiolabeled CS-7017 in healthy male subjects

Abstract Background: CS-7017 is a novel, oral, highly potent and selective peroxisome proliferator-activated receptor gamma agonist with demonstrated anticancer activity in preclinical models. Currently, CS-7017 is in phase 2 trials for the treatment of non-small cell lung and colorectal cancer. CS-7017 disposition and biotransformation were investigated in healthy male subjects following oral administration of [14C]-radiolabeled CS-7017. Methods: Blood, plasma, urine, and fecal samples were collected and analyzed for radioactive levels to determine CS-7017 disposition following a single 0.5 mg oral dose containing approximately 50 µCi of [14C]-radiolabeled CS-7017 in 6 healthy male subjects. Metabolite separation, identification, and quantification were performed using radio/HPLC followed by LC-ESI/MS and LC-MS/MS. Plasma samples were also analyzed using LC-MS/MS for CS-7017 and by accelerator mass spectrometry for metabolite profiling. Results: CS-7017 was rapidly absorbed (plasma Tmax: 1.52 h) and steadily eliminated following oral administration. The majority of radioactivity was eliminated in feces (∼70% vs ∼20% in urine). In blood, the radioactivity was mainly distributed in plasma with little or no association with blood cells, as indicated by a blood to plasma ratio of 0.5. The parent molecule is the main circulating analyte in plasma contributing 60-70% of the total exposure. R-239457 (dearyl form) and its sulphate were the two highest circulating metabolites contributing 4.5% and 6.3% of the total radioactivity at 12 h post-dose, respectively. Several other radioactive peaks (∼12) were detected in plasma at a low level (&amp;lt;2.5%). In both urine and feces, several metabolites such as N-glucuronide of CS-7017, and R-239457 and its sulphate and glucuronide forms were observed, whereas little or no parent CS-7017 was detected. Conclusion: CS-7017 was rapidly absorbed and steadily eliminated with the parent molecule contributing the majority of the exposure; this indicates that CS-7017 itself contributes toward in vivo pharmacological activity. Traces of the parent molecule in urine and feces indicate that the majority of the drug is eliminated by metabolism. Therefore, CS-7017 exposure may be impacted by hepatic impairment, but may not be significantly changed in subjects with impaired renal function as renal excretion contributes to a relatively low proportion of clearance (∼20%). Based on the metabolite profiles, the metabolic routes in human and animals (rats and monkeys) are similar. The two highest metabolites detected in human plasma were also present in the plasma of at least one of the preclinical toxicology species, therefore, safety concerns raised by the metabolites would be minimal in humans. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1311. doi:10.1158/1538-7445.AM2011-1311

Peroxisome proliferator-activated receptor agonists with phenethylphenylphthalimide skeleton derived from thalidomide-related liver X receptor antagonists: Relationship between absolute configuration and subtype selectivity

Introduction of an alkylcarboxylic acid unit, which is a partial structure of endogenous peroxisome proliferator-activated receptor (PPAR) ligands, into a phenethylphenylphthalimide skeleton, which possesses liver X receptor (LXR) antagonistic activity, afforded novel PPAR ligands. The results of structure–activity relationship analysis and docking studies led us to the potent PPAR agonists 13c– e. The absolute configuration of 13c– e affects the PPAR subtype selectivity.

The Role of CaMKII in Calcium-Activated Death Pathways in Bone Marrow B Cells

Calcium is an essential signaling molecule in developing B cells, thus altering calcium dynamics represents a potential target for toxicant effects. GW7845, a tyrosine analog and potent peroxisome proliferator-activated receptor γ agonist, induces rapid mitogen-activated protein kinase (MAPK)-dependent apoptosis in bone marrow B cells. Changes in calcium dynamics are capable of mediating rapid initiation of cell death; therefore, we investigated the contribution of calcium to GW7845-induced apoptosis. Treatment of a nontransformed murine pro/pre-B cell line (BU-11) with GW7845 (40 μM) resulted in intracellular calcium release. Multiple features of GW7845-induced cell death were suppressed by the calcium chelator BAPTA, including MAPK activation, loss of mitochondrial membrane potential, cytochrome c release, caspase-3 activation, and DNA fragmentation. A likely mechanism for the calcium-mediated effects is activation of CaMKII, a calcium-dependent MAP4K. We observed that three CaMKII isoforms (β, γ, and δ) are expressed in lymphoid tissues and bone marrow B cells. Treatment with GW7845 increased CaMKII activity. All features of GW7845-induced cell death, except loss of mitochondrial membrane potential, were suppressed by CaMKII inhibitors (KN93 and AIP-II), suggesting the activation of multiple calcium-driven pathways. To determine if CaMKII activation is a common feature of early B cell death following perturbation of Ca(2+) flux, we dissected tributyltin (TBT)-induced death signaling. High-dose TBT (1 μM) is known to activate calcium-dependent death. TBT induced rapid apoptosis that was associated with intracellular calcium release, CaMKII activation and MAPK activation, and was inhibited by AIP-II. Thus, we show that early B cells are susceptible to calcium-triggered cell death through a CaMKII/MAPK-dependent pathway.

Structural Basis for the Improved Potency of Peroxisome Proliferator‐Activated Receptor (PPAR) Agonists

The need to develop safer and more effective antidiabetic drugs is essential owing to the growth worldwide of the diabetic population. Targeting the PPAR receptor is one strategy for the treatment of diabetes; the PPAR agonists rosiglitazone and pioglitazone are already on the market. Here we report the identification of a potent PPAR agonist, 15, whose PPARγ activation was more than 20 times better than that of rosiglitazone. Compound 15 was designed to incorporate an indole head with a carboxylic acid group, and 4-phenylbenzophenone tail to achieve a PPARγ EC(50) of 10 nM. Compound 15 showed the most potent PPARγ agonist activity among the compounds we investigated. To gain molecular insight into the improved potency of 15, a structural biology study and binding energy calculations were carried out. Superimposition of the X-ray structures of 15 and agonist 10 revealed that, even though they have the same indole head part, they adopt different conformations. The head part of 15 showed stronger interactions toward PPARγ; this could be due to the presence of the novel tail part 4-phenylbenzophenone, which could enhance the binding efficiency of 15 to PPARγ.

The synergistic anticancer effect of troglitazone combined with aspirin causes cell cycle arrest and apoptosis in human lung cancer cells

Troglitazone (TGZ) is a synthetic thiazolidinedione drug belonging to a group of potent peroxisome proliferator-activated receptor gamma (PPAR gamma) agonists known to inhibit proliferation, alter cell cycle regulation, and induce apoptosis in various cancer cell types. TGZ is an oral anti-type II diabetes drug that can reverse insulin resistance. For more then 100 yr, aspirin, a nonselective cyclooxygenase (COX) inhibitor, has been successfully used as an anti-inflammatory drug. Recently, Aspirin (ASA) and some other nonsteroidal anti-inflammatory drugs (NSAIDs) have drawn much attention for their protective effects against colon cancer and cardiovascular disease; it has been observed that ASA's anti-tumor effect can be attributed to inhibition of cell cycle progression, induction of apoptosis, and inhibition of angiogenesis. In this report we demonstrate for the first time that, when administered in combination, TGZ and ASA can produce a strong synergistic effect in growth inhibition and G(1) arrest in lung cancer CL1-0 and A549 cells. Examination by colony formation assay revealed an even more profound synergy. In Western blot, combined TGZ and ASA also could downregulate Cdk2, E2F-1, cyclin B1, cyclin D3 protein, and the ratio of phospho-Rb/Rb. Importantly, apoptosis was synergistically induced by the combination treatment, as evidenced by caspase-3 activation and PARP cleavage. The involvement of PI3K/Akt inhibition and p27 upregulation, as well as hypophosphorylation of Rac1 at ser71, were demonstrated. Taken together, these results suggest that clinically achievable concentrations of TGZ and ASA used in combination may produce a strong anticancer synergy that warrants further investigation for its clinical applications.

Pharmacokinetics, disposition and lipid-modulating activity of 5-{2-[4-(3,4-difluorophenoxy)-phenyl]-ethylsulfamoyl}-2-methyl-benzoic acid, a potent and subtype-selective peroxisome proliferator-activated receptor α agonist in preclinical species and human

5-{2-[4-(3,4-Difluorophenoxy)-phenyl]-ethylsulfamoyl}-2-methyl-benzoic acid (1) is a novel, potent, and selective agonist of the peroxisome proliferator-activated receptor alpha (PPAR-α).In preclinical species, compound 1 demonstrated generally favourable pharmacokinetic properties. Systemic plasma clearance (CLp) after intravenous administration was low in Sprague–Dawley rats (3.2 ± 1.4 ml min−1 kg−1) and cynomolgus monkeys (6.1 ± 1.6 ml min−1 kg−1) resulting in plasma half-lives of 7.1 ± 0.7 h and 9.4 ± 0.8 h, respectively. Moderate bioavailability in rats (64%) and monkeys (55%) was observed after oral dosing. In rats, oral pharmacokinetics were dose-dependent over the dose range examined (10 and 50 mg kg−1).In vitro metabolism studies on 1 in cryopreserved rat, monkey, and human hepatocytes revealed that 1 was metabolized via oxidation and phase II glucuronidation pathways. In rats, a percentage of the dose (approximately 19%) was eliminated via biliary excretion in the unchanged form.Studies using recombinant human CYP isozymes established that the rate-limiting step in the oxidative metabolism of 1 to the major primary alcohol metabolite M1 was catalysed by CYP3A4.Compound 1 was greater than 99% bound to plasma proteins in rat, monkey, mouse, and human.No competitive inhibition of the five major cytochrome P450 enzymes, namely CYP1A2, P4502C9, P4502C19, P4502D6 and P4503A4 (IC50’s > 30 μM) was discerned with 1.Because of insignificant turnover of 1 in human liver microsomes and hepatocytes, human clearance was predicted using rat single-species allometric scaling from in vivo data. The steady-state volume was also scaled from rat volume after normalization for protein-binding differences. As such, these estimates were used to predict an efficacious human dose required for 30% lowering of triglycerides.In order to aid human dose projections, pharmacokinetic/pharmacodynamic relationships for triglyceride lowering by 1 were first established in mice, which allowed an insight into the efficacious concentrations required for maximal triglyceride lowering. Assuming that the pharmacology translated in a quantitative fashion from mouse to human, dose projections were made for humans using mouse pharmacodynamic parameters and the predicted human pharmacokinetic estimates.First-in-human clinical studies on 1 following oral administration suggested that the human pharmacokinetics/dose predictions were in the range that yielded a favourable pharmacodynamic response.