RESUMO
ATP-citrate lyase (ACLY) is a central metabolic enzyme and catalyses the ATP-dependent conversion of citrate and coenzyme A (CoA) to oxaloacetate and acetyl-CoA1-5. The acetyl-CoA product is crucial for the metabolism of fatty acids6,7, the biosynthesis of cholesterol8, and the acetylation and prenylation of proteins9,10. There has been considerable interest in ACLY as a target for anti-cancer drugs, because many cancer cells depend on its activity for proliferation2,5,11. ACLY is also a target against dyslipidaemia and hepatic steatosis, with a compound currently in phase 3 clinical trials4,5. Many inhibitors of ACLY have been reported, but most of them have weak activity5. Here we report the development of a series of low nanomolar, small-molecule inhibitors of human ACLY. We have also determined the structure of the full-length human ACLY homo-tetramer in complex with one of these inhibitors (NDI-091143) by cryo-electron microscopy, which reveals an unexpected mechanism of inhibition. The compound is located in an allosteric, mostly hydrophobic cavity next to the citrate-binding site, and requires extensive conformational changes in the enzyme that indirectly disrupt citrate binding. The observed binding mode is supported by and explains the structure-activity relationships of these compounds. This allosteric site greatly enhances the 'druggability' of ACLY and represents an attractive target for the development of new ACLY inhibitors.
Assuntos
ATP Citrato (pro-S)-Liase/antagonistas & inibidores , ATP Citrato (pro-S)-Liase/ultraestrutura , Compostos de Benzil/farmacologia , Microscopia Crioeletrônica , Inibidores Enzimáticos/farmacologia , ATP Citrato (pro-S)-Liase/química , ATP Citrato (pro-S)-Liase/metabolismo , Difosfato de Adenosina/metabolismo , Regulação Alostérica/efeitos dos fármacos , Compostos de Benzil/química , Sítios de Ligação/efeitos dos fármacos , Ácido Cítrico/metabolismo , Inibidores Enzimáticos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Relação Estrutura-AtividadeRESUMO
Simultaneous inhibition of the acetyl-CoA carboxylase (ACC) isozymes ACC1 and ACC2 results in concomitant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation and may favorably affect the morbidity and mortality associated with obesity, diabetes, and fatty liver disease. Using structure-based drug design, we have identified a series of potent allosteric protein-protein interaction inhibitors, exemplified by ND-630, that interact within the ACC phosphopeptide acceptor and dimerization site to prevent dimerization and inhibit the enzymatic activity of both ACC isozymes, reduce fatty acid synthesis and stimulate fatty acid oxidation in cultured cells and in animals, and exhibit favorable drug-like properties. When administered chronically to rats with diet-induced obesity, ND-630 reduces hepatic steatosis, improves insulin sensitivity, reduces weight gain without affecting food intake, and favorably affects dyslipidemia. When administered chronically to Zucker diabetic fatty rats, ND-630 reduces hepatic steatosis, improves glucose-stimulated insulin secretion, and reduces hemoglobin A1c (0.9% reduction). Together, these data suggest that ACC inhibition by representatives of this series may be useful in treating a variety of metabolic disorders, including metabolic syndrome, type 2 diabetes mellitus, and fatty liver disease.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Dislipidemias/tratamento farmacológico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Fígado Gorduroso/tratamento farmacológico , Pirimidinonas/farmacologia , Tiofenos/farmacologia , Acetil-CoA Carboxilase/metabolismo , Animais , Inibidores Enzimáticos/farmacocinética , Feminino , Células Hep G2/efeitos dos fármacos , Células Hep G2/metabolismo , Humanos , Resistência à Insulina , Masculino , Simulação de Acoplamento Molecular , Obesidade/tratamento farmacológico , Obesidade/etiologia , Multimerização Proteica/efeitos dos fármacos , Ratos Sprague-Dawley , Ratos Zucker , Relação Estrutura-AtividadeRESUMO
NDI-010976, an allosteric inhibitor of acetyl-coenzyme A carboxylases (ACC) ACC1 and ACC2, reduces hepatic de novo lipogenesis (DNL) and favorably affects steatosis, inflammation, and fibrosis in animal models of fatty liver disease. This study was a randomized, double-blind, placebo-controlled, crossover trial evaluating the pharmacodynamic effects of a single oral dose of NDI-010976 on hepatic DNL in overweight and/or obese but otherwise healthy adult male subjects. Subjects were randomized to receive either NDI-010976 (20, 50, or 200 mg) or matching placebo in period 1, followed by the alternate treatment in period 2; and hepatic lipogenesis was stimulated with oral fructose administration. Fractional DNL was quantified by infusing a stable isotope tracer, [1-13 C]acetate, and monitoring 13 C incorporation into palmitate of circulating very low-density lipoprotein triglyceride. Single-dose administration of NDI-010976 was well tolerated at doses up to and including 200 mg. Fructose administration over a 10-hour period stimulated hepatic fractional DNL an average of 30.9 ± 6.7% (mean ± standard deviation) above fasting DNL values in placebo-treated subjects. Subjects administered single doses of NDI-010976 at 20, 50, or 200 mg had significant inhibition of DNL compared to placebo (mean inhibition relative to placebo was 70%, 85%, and 104%, respectively). An inverse relationship between fractional DNL and NDI-010976 exposure was observed with >90% inhibition of fractional DNL associated with plasma concentrations of NDI-010976 >4 ng/mL. CONCLUSION: ACC inhibition with a single dose of NDI-010976 is well tolerated and results in a profound dose-dependent inhibition of hepatic DNL in overweight adult male subjects. Therefore, NDI-010976 could contribute considerable value to the treatment algorithm of metabolic disorders characterized by dysregulated fatty acid metabolism, including nonalcoholic steatohepatitis. (Hepatology 2017;66:324-334).
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Lipogênese/fisiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Sobrepeso/tratamento farmacológico , Acetil-CoA Carboxilase/administração & dosagem , Administração Oral , Adulto , Índice de Massa Corporal , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Medição de Risco , Resultado do TratamentoRESUMO
As the need for novel antibiotic classes to combat bacterial drug resistance increases, the paucity of leads resulting from target-based antibacterial screening of pharmaceutical compound libraries is of major concern. One explanation for this lack of success is that antibacterial screening efforts have not leveraged the eukaryotic bias resulting from more extensive chemistry efforts targeting eukaryotic gene families such as G protein-coupled receptors and protein kinases. Consistent with a focus on antibacterial target space resembling these eukaryotic targets, we used whole-cell screening to identify a series of antibacterial pyridopyrimidines derived from a protein kinase inhibitor pharmacophore. In bacteria, the pyridopyrimidines target the ATP-binding site of biotin carboxylase (BC), which catalyzes the first enzymatic step of fatty acid biosynthesis. These inhibitors are effective in vitro and in vivo against fastidious gram-negative pathogens including Haemophilus influenzae. Although the BC active site has architectural similarity to those of eukaryotic protein kinases, inhibitor binding to the BC ATP-binding site is distinct from the protein kinase-binding mode, such that the inhibitors are selective for bacterial BC. In summary, we have discovered a promising class of potent antibacterials with a previously undescribed mechanism of action. In consideration of the eukaryotic bias of pharmaceutical libraries, our findings also suggest that pursuit of a novel inhibitor leads for antibacterial targets with active-site structural similarity to known human targets will likely be more fruitful than the traditional focus on unique bacterial target space, particularly when structure-based and computational methodologies are applied to ensure bacterial selectivity.
Assuntos
Antibacterianos/química , Carbono-Nitrogênio Ligases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Antibacterianos/farmacologia , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/enzimologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/enzimologia , Moraxella catarrhalis/efeitos dos fármacos , Moraxella catarrhalis/enzimologia , Inibidores de Proteínas Quinases/química , Pirimidinas/química , Bibliotecas de Moléculas PequenasRESUMO
Cannabinoid-1 (CB(1)) receptor antagonists exhibit pharmacological properties favorable to treatment of obesity, caused by both centrally mediated effects on appetite and peripherally mediated effects on energy metabolism. However, the relative contribution of these effects to the weight loss produced by CB(1) receptor antagonists remains unclear. Here, we compare food intake-related and independent effects of the CB(1)-selective antagonist 1-(7-(2-chlorophenyl)-8-(4-chlorophenyl)-2-methylpyrazolo[1,5-a][1,3,5]triazin-4-yl)-3-(methylamino) azetidine-3-carboxamide (PF-95453) in obese cynomolgus monkeys. Monkeys were divided into three study groups (n = 10 each) and treated once daily for 8 weeks with either vehicle or PF-95453 as follows: 1, fed ad libitum and dosed orally with vehicle; 2, fed ad libitum and dosed orally with PF-95453 (0.5 mg/kg weeks 1-3, 1.0 mg/kg weeks 4-8); and 3, fed an amount equal to the amount consumed by the drug-treated group and dosed orally with vehicle (pair-fed). PF-95453 treatment significantly reduced food consumption by 23%, body weight by 10%, body fat by 39%, and leptin by 34% while increasing adiponectin by 78% relative to vehicle-treated controls. Pair-fed animals did not exhibit reductions in body weight or leptin but did show significantly reduced body fat (11%) and increased adiponectin (15%) relative to vehicle-treated controls but markedly less than after PF-95453 treatment. Indeed, significant differences were noted between the drug-treated and pair-fed groups with respect to body weight reduction, body fat reduction, increased adiponectin, and leptin reduction. Similar to humans, monkeys treated with the CB(1) receptor antagonist exhibited decreased body weight and body fat, a substantial portion of which seemed to be independent of the effects on food intake.
Assuntos
Adiposidade/efeitos dos fármacos , Fármacos Antiobesidade , Azetidinas/farmacologia , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Obesidade/tratamento farmacológico , Receptor CB1 de Canabinoide/antagonistas & inibidores , Triazinas/farmacologia , Adiponectina/metabolismo , Animais , Azetidinas/farmacocinética , Glicemia/metabolismo , Dieta , Cães , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Determinação de Ponto Final , Comportamento Alimentar/efeitos dos fármacos , Teste de Tolerância a Glucose , Leptina/metabolismo , Lipídeos/sangue , Macaca fascicularis , Masculino , Ratos , Ratos Sprague-Dawley , Triazinas/farmacocinética , Redução de Peso/efeitos dos fármacosRESUMO
Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of lipid and glucose metabolism. PPARgamma agonists improve insulin sensitivity and hyperglycemia and are effective in treating type 2 diabetes mellitus (T2DM), whereas PPARalpha agonists are used to treat dyslipidemia and atherosclerosis. The goal here was to examine the efficacy of a selective PPARalpha agonist {(S)-3-[3-(1-carboxy-1-methyl-ethoxy)-phenyl]-piperidine-1-carboxylic acid 4-trifluoromethyl-benzyl ester; CP-900691} on lipid, glycemic, and inflammation indices in 14 cynomolgus monkeys with spontaneous T2DM maintained on daily insulin therapy. Monkeys were dosed orally with either vehicle (n = 7) or CP-900691 (3 mg/kg, n = 7) daily for 6 weeks. CP-900691 treatment increased plasma high-density lipoprotein cholesterol (HDLC) (33 +/- 3 to 60 +/- 4 mg/dL, p < 0.001) and apolipoprotein A1 (96 +/- 5 to 157 +/- 5 mg/dL, p < 0.001), reduced plasma triglycerides (547 +/- 102 to 356 +/- 90 mg/dL, p < 0.01), and apolipoprotein B (62 +/- 3 to 45 +/- 3 mg/dL, p < 0.01), improved the lipoprotein index (HDL to non-HDLC ratio; 0.28 +/- 0.06 to 0.79 +/- 0.16, p < 0.001), decreased body weight (p < 0.01) and C-reactive protein (CRP) (1700 +/- 382 to 304 +/- 102 ng/ml, p < 0.01), and increased adiponectin (1697 +/- 542 to 4242 +/- 1070 ng/ml, p < 0.001) compared with baseline. CP-900691 treatment reduced exogenous insulin requirements by approximately 25% (p < 0.04) while lowering plasma fructosamine from 2.87 +/- 0.09 to 2.22 +/- 0.17 mM (p < 0.05), indicative of improved glycemic control. There were no changes in any of the aforementioned parameters in the vehicle group. Because low HDLC and high triglycerides are well established risk factors for cardiovascular disease, the marked improvements in these parameters, and in glycemic control, body weight, and CRP, suggest that CP-900691 may be of benefit in diabetic and obese or hyperlipidemic populations.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipolipemiantes , Lipídeos/sangue , Lipoproteínas/sangue , PPAR alfa/agonistas , Piperidinas/farmacologia , Propionatos/farmacologia , Adiponectina/sangue , Animais , Área Sob a Curva , Proteína C-Reativa/metabolismo , Diabetes Mellitus Tipo 2/genética , Relação Dose-Resposta a Droga , Teste de Tolerância a Glucose , Resistência à Insulina , Macaca fascicularis , Redução de Peso/efeitos dos fármacosRESUMO
Screening Pfizer's compound library resulted in the identification of weak acetyl-CoA carboxylase inhibitors, from which were obtained rACC1 CT-domain co-crystal structures. Utilizing HTS hits and structure-based drug discovery, a more rigid inhibitor was designed and led to the discovery of sub-micromolar, spirochromanone non-specific ACC inhibitors. Low nanomolar, non-specific ACC-isozyme inhibitors that exhibited good rat pharmacokinetics were obtained from this chemotype.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Inibidores Enzimáticos/farmacocinética , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Modelos Moleculares , Ratos , Bibliotecas de Moléculas Pequenas/farmacocinética , Relação Estrutura-AtividadeRESUMO
The incidence of hepatocellular carcinoma (HCC) is rapidly increasing due to the prevalence of obesity and non-alcoholic fatty liver disease, but the molecular triggers that initiate disease development are not fully understood. We demonstrate that mice with targeted loss-of-function point mutations within the AMP-activated protein kinase (AMPK) phosphorylation sites on acetyl-CoA carboxylase 1 (ACC1 Ser79Ala) and ACC2 (ACC2 Ser212Ala) have increased liver de novo lipogenesis (DNL) and liver lesions. The same mutation in ACC1 also increases DNL and proliferation in human liver cancer cells. Consistent with these findings, a novel, liver-specific ACC inhibitor (ND-654) that mimics the effects of ACC phosphorylation inhibits hepatic DNL and the development of HCC, improving survival of tumor-bearing rats when used alone and in combination with the multi-kinase inhibitor sorafenib. These studies highlight the importance of DNL and dysregulation of AMPK-mediated ACC phosphorylation in accelerating HCC and the potential of ACC inhibitors for treatment.
Assuntos
Acetil-CoA Carboxilase , Carcinoma Hepatocelular/metabolismo , Lipogênese , Neoplasias Hepáticas/metabolismo , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/fisiologia , Animais , Células Hep G2 , Humanos , Masculino , Camundongos , Fosforilação , Ratos , Ratos WistarRESUMO
Sterol regulatory element-binding proteins (SREBPs) are major transcriptional regulators of cholesterol, fatty acid, and glucose metabolism. Genetic disruption of SREBP activity reduces plasma and liver levels of cholesterol and triglycerides and insulin-stimulated lipogenesis, suggesting that SREBP is a viable target for pharmacological intervention. The proprotein convertase SREBP site 1 protease (S1P) is an important posttranscriptional regulator of SREBP activation. This report demonstrates that 10 microM PF-429242 (Bioorg Med Chem Lett 17:4411-4414, 2007), a recently described reversible, competitive aminopyrrolidineamide inhibitor of S1P, inhibits endogenous SREBP processing in Chinese hamster ovary cells. The same compound also down-regulates the signal from an SRE-luciferase reporter gene in human embryonic kidney 293 cells and the expression of endogenous SREBP target genes in cultured HepG2 cells. In HepG2 cells, PF-429242 inhibited cholesterol synthesis, with an IC(50) of 0.5 microM. In mice treated with PF-429242 for 24 h, the expression of hepatic SREBP target genes was suppressed, and the hepatic rates of cholesterol and fatty acid synthesis were reduced. Taken together, these data establish that small-molecule S1P inhibitors are capable of reducing cholesterol and fatty acid synthesis in vivo and, therefore, represent a potential new class of therapeutic agents for dyslipidemia and for a variety of cardiometabolic risk factors associated with diabetes, obesity, and the metabolic syndrome.
Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Lipogênese/fisiologia , Pró-Proteína Convertases/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas de Ligação a Elemento Regulador de Esterol/antagonistas & inibidores , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Animais , Células CHO , Linhagem Celular , Células Cultivadas , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Lipogênese/efeitos dos fármacos , Masculino , Camundongos , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Inibidores de Proteases/química , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/biossínteseRESUMO
Niemann-Pick C disease (NPC) is a fatal, neurovisceral genetic disorder. Cell culture studies showed that NPC1 or NPC2 mutations cause malfunctions in cellular cholesterol trafficking and lead to accumulation of cholesterol and other lipids in the late endo/lysosomes. Previous work showed that neuronal cholesterol accumulation occurs in the brains of young postnatal NPC1-/- mice. Here, to evaluate the potential of partial blockage of cholesterol biosynthesis as a therapy for the NPC disease, we first developed a simple method to monitor the relative rates of lipid biosynthesis in mice brains. We next administered squalene synthase inhibitor (SSI) CP-340868 to young mice. The results show that treating 8-day-old NPC1-/- mice with CP-340868 for 6 days significantly inhibits cholesterol biosynthesis in the mice brains. It reduces neuronal cholesterol accumulation, reduces GM3 ganglioside accumulation, and diminishes astrogliosis in the brain. These results suggest that neuronal cholesterol accumulation contributes to early pathogenesis in the NPC1-/- mice brains. The SSI treatment also reduced brain galactolipid content, suggesting that blocking endogenous cholesterol synthesis in the young mice brains may disrupt the normal myelin maturation processes. The methods described in the current work have general applicability for lipid metabolism studies in mice brains in various pathophysiological conditions.
Assuntos
Encéfalo , Colesterol/metabolismo , Inibidores Enzimáticos/farmacologia , Farnesil-Difosfato Farnesiltransferase/metabolismo , Neurônios/metabolismo , Proteínas/genética , Esteróis/metabolismo , Acetatos/metabolismo , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Farnesil-Difosfato Farnesiltransferase/antagonistas & inibidores , Ácidos Graxos/metabolismo , Gangliosídeos/metabolismo , Técnicas In Vitro , Peptídeos e Proteínas de Sinalização Intracelular , Fígado/efeitos dos fármacos , Fígado/metabolismo , Lovastatina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteína C1 de Niemann-Pick , Fatores de Tempo , Trítio/metabolismoRESUMO
Type 2 diabetes mellitus is a major health problem of increasing incidence. To better study the pathogenesis and potential therapeutic agents for this disease, appropriate animal models are needed. Old World nonhuman primates (NHPs) are a useful animal model of type 2 diabetes; like humans, the disease is most common in older, obese animals. Before developing overt diabetes, NHPs have a period of obesity-associated insulin resistance that is initially met with compensatory insulin secretion. When either a relative or absolute deficiency in pancreatic insulin production occurs, fasting glucose concentrations begin to increase and diabetic signs become apparent. Pathological changes in pancreatic islets are also similar to those seen in human diabetics. Initially there is hyperplasia of the islets with abundant insulin production typically followed by replacement of islets with islet-associated amyloid. Diabetic NHPs have detrimental changes in plasma lipid and lipoprotein concentrations, lipoprotein composition, and glycation, which may contribute to progression of atherosclerosis. As both the prediabetic condition (similar to metabolic syndrome in humans) and overt diabetes become better defined in monkeys, their use in pharmacological studies is increasing. Likely due to their genetic similarity to humans and the similar characteristics of the disease in NHPs, NHPs have been used to study recently developed agonists of the peroxisome proliferators-activated receptors. Importantly, agonists of the different receptor subclasses elicit similar responses in both humans and NHPs. Thus, Old World NHPs are a valuable animal model of type 2 diabetes to study disease progression, associated risk factors, and potential new treatments.
Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/veterinária , Modelos Animais de Doenças , Doenças dos Macacos/metabolismo , Estado Pré-Diabético/veterinária , Animais , Cercopithecidae , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Hipoglicemiantes/uso terapêutico , Resistência à Insulina/fisiologia , Masculino , Doenças dos Macacos/tratamento farmacológico , Doenças dos Macacos/fisiopatologia , Estado Pré-Diabético/metabolismo , Estado Pré-Diabético/fisiopatologiaRESUMO
Continuous de novo fatty acid synthesis is a common feature of cancer that is required to meet the biosynthetic demands of a growing tumor. This process is controlled by the rate-limiting enzyme acetyl-CoA carboxylase (ACC), an attractive but traditionally intractable drug target. Here we provide genetic and pharmacological evidence that in preclinical models ACC is required to maintain the de novo fatty acid synthesis needed for growth and viability of non-small-cell lung cancer (NSCLC) cells. We describe the ability of ND-646-an allosteric inhibitor of the ACC enzymes ACC1 and ACC2 that prevents ACC subunit dimerization-to suppress fatty acid synthesis in vitro and in vivo. Chronic ND-646 treatment of xenograft and genetically engineered mouse models of NSCLC inhibited tumor growth. When administered as a single agent or in combination with the standard-of-care drug carboplatin, ND-646 markedly suppressed lung tumor growth in the Kras;Trp53-/- (also known as KRAS p53) and Kras;Stk11-/- (also known as KRAS Lkb1) mouse models of NSCLC. These findings demonstrate that ACC mediates a metabolic liability of NSCLC and that ACC inhibition by ND-646 is detrimental to NSCLC growth, supporting further examination of the use of ACC inhibitors in oncology.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/biossíntese , Metabolismo dos Lipídeos/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Pirimidinonas/farmacologia , Tiofenos/farmacologia , Proteínas Quinases Ativadas por AMP , Acetiltransferases/antagonistas & inibidores , Regulação Alostérica , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células/genética , Humanos , Metabolismo dos Lipídeos/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Camundongos , Camundongos Knockout , Terapia de Alvo Molecular , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The inhibition of microsomal triglyceride transfer protein (MTP) blocks the hepatic secretion of very low density lipoproteins (VLDL) and the intestinal secretion of chylomicrons. Consequently, this mechanism provides a highly efficacious pharmacological target for the lowering of low density lipoprotein (LDL) cholesterol and reduction of postprandial lipemia. The combination of these effects could afford unprecedented benefit in the treatment of atherosclerosis and consequent cardiovascular disease. The promise of this therapeutic target has attracted widespread interest in the pharmaceutical industry. Independent efforts have yielded strikingly similar series of lipophilic amide inhibitors. The way in which the evolutionary paths of distinct inhibitor series have tended to converge through the course of robotics-assisted synthesis efforts is illustrated with candidates from Bristol-Myers Squibb and Pfizer. Hanging in the balance with the exceptional potency of the compounds presented are the potential adverse effects due to blockage of intestinal fat absorption and hepatic lipid secretion. Finding a degree of efficacy that can be safely tolerated defines the dilemma surrounding the advancement of these compounds to clinical practice.
Assuntos
Proteínas de Transporte/antagonistas & inibidores , Tecnologia Farmacêutica/métodos , Animais , Proteínas de Transporte/metabolismo , VLDL-Colesterol/antagonistas & inibidores , VLDL-Colesterol/sangue , VLDL-Colesterol/metabolismo , Humanos , Robótica/métodos , Robótica/tendências , Tecnologia Farmacêutica/tendênciasRESUMO
Metabolic syndrome is defined as a clustering of cardiovascular risk factors (abdominal obesity, hyperinsulinemia, atherogenic dyslipidemia, hypertension and hypercoagulability) that together increase the risk of developing coronary heart disease and type 2 diabetes. Inhibition of acetyl-CoA carboxylase (ACC), which results in inhibition of fatty acid synthesis and stimulation of fatty acid oxidation, has the potential to favorably affect a multitude of cardiovascular risk factors associated with metabolic syndrome. ACC exists as two tissue-specific isozymes, ACC1 present in lipogenic tissues (liver and adipose) and ACC2 present in oxidative tissues (liver, heart and skeletal muscle). Studies in both ACC2 knockout mice and animals administered isozyme-nonselective ACC inhibitors have demonstrated the utility of treating metabolic syndrome through this modality. An isozyme-non-selective ACC inhibitor may potentially provide the optimal therapeutic for beneficially affecting metabolic syndrome. However, demonstration of the full potential of isozyme-selective inhibitors, once identified, should reveal advantages and liabilities associated with single isozyme inhibition. While demonstrating clinical efficacy of an ACC inhibitor should be relatively straightforward, the heterogeneity of the patient population and the absence of established guidelines regarding approval endpoints for agents simultaneously affecting multiple aspects of metabolic syndrome will pose developmental challenges for initial market entries.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Síndrome Metabólica/tratamento farmacológico , Animais , Ácidos Graxos/metabolismo , Humanos , Isoenzimas/metabolismo , Malonil Coenzima A/metabolismo , Síndrome Metabólica/metabolismoRESUMO
Over the past decade and a half it has become increasingly clear that adipose tissue is a much more complex organ than was initially considered and that its metabolic functions extend well beyond the classical actions of thermoregulation and of storage and release of fatty acids. In fact, it is now well established that adipose tissue plays a critical role in maintenance of energy homeostasis through secretion of a large number of adipokines that interact with central as well as peripheral organs such as the brain, liver, pancreas, and skeletal muscle to control diverse processes, such as food intake, energy expenditure, carbohydrate and lipid metabolism, blood pressure, blood coagulation, and inflammation. While many of these adipokines are adipocyte-derived and have a variety of endocrine functions, others are produced by resident macrophages and interact in a paracrine fashion to control adipocyte metabolism. It is also abundantly clear that the dysregulation of adipokine secretion and action that occurs in obesity plays a fundamental role in the development of a variety of cardiometabolic disorders, including the metabolic syndrome, type 2 diabetes, inflammatory disorders, and vascular disorders, that ultimately lead to coronary heart disease. Described herein are the traditional as well as endocrine roles of adipose tissue in controlling energy metabolism and their dysregulation in obesity that leads to development of cardiometabolic disorders, with a focus on what is currently known regarding the characteristics and roles in both health and disease of the adipocyte-derived adipokines, adiponectin, leptin, resistin, and retinol binding protein 4, and the resident macrophage-derived adipokines, tumor necrosis factor-α and interleukin-6. This article is part of a Special Issue entitled 'Central Control of Food Intake'.
Assuntos
Adipócitos/fisiologia , Sistema Endócrino/citologia , Homeostase/fisiologia , Animais , Humanos , Doenças Metabólicas/metabolismo , Doenças Metabólicas/patologia , Neuropeptídeos/metabolismoRESUMO
Animal models are important for determining the pathogenesis of and potential treatments for obesity and diabetes. Nonhuman primates (NHPs) are particularly useful for studying these disorders. As in humans, type 2 diabetes mellitus is the most common form of diabetes in NHPs and occurs more often in older obese animals, with a metabolic progression from insulin resistance (IR) and impaired glucose tolerance to overt diabetes. Histopathologic changes in pancreatic islets are also similar to those seen in humans with diabetes. Initially, there is islet hyperplasia with abundant insulin production to compensate for IR, followed by insufficient insulin production with replacement of islets with islet-associated amyloid. Diabetic NHPs also have adverse changes in plasma lipid and lipoprotein concentrations, biomarkers of obesity, inflammation, and oxidative stress, and protein glycation that contribute to the numerous complications of the disease. Furthermore, sex hormones, pregnancy, and environmental factors (e.g., diet and stress) affect IR and can also contribute to diabetes progression in NHPs. Additionally, due to their similar clinical and pathologic characteristics, NHPs have been used in many pharmacological studies to assess new therapeutic agents. For these reasons, NHPs are particularly valuable animal models of obesity and diabetes for studying disease pathogenesis, risk factors, comorbidities, and therapeutic interventions.
Assuntos
Diabetes Mellitus Tipo 2 , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Comorbidade , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/terapia , Modelos Animais de Doenças , Progressão da Doença , Cães , Predisposição Genética para Doença , Humanos , Primatas , Prognóstico , Fatores de Risco , Especificidade da EspécieRESUMO
The incidence and severity of atherosclerotic vascular disease are increased in diabetic patients, in part because of increased production of reactive oxygen species (ROS). Previously, we found both increased atherosclerosis and arterial protein oxidation 6 months after streptozotocin-induced diabetes in monkeys fed an atherogenic diet, the pattern of which was indicative of redox-active transition metal involvement. The goal of this study was to determine if short-term (1 month) hyperglycemia increases oxidative stress and dysregulates iron metabolism before differences in atherosclerosis. Cynomolgus monkeys with preexisting atherosclerosis were stratified by dietary history and plasma lipids and received either streptozotocin (STZ-DM; n = 10) or vehicle (control; n = 10). One month after diabetes induction, blood and artery samples were collected. There were no differences in plasma lipoprotein cholesterol, arterial cholesterol, and atherosclerosis between control and STZ-DM. However, plasma lipid peroxides were elevated 137% (P < .01); arterial superoxide was increased 47% (P < .05); plasma ferritin, an indicator of whole-body iron stores, was 46% higher (P < .05); and iron deposition within aortic atherosclerotic lesions was more prevalent in STZ-DM compared with controls. Arterial levels of the antioxidant enzymes, superoxide dismutase, catalase, and heme oxygenase-1 were not higher in STZ-DM, although superoxide was higher, suggesting impaired antioxidant response. The increase in ROS before differences in atherosclerosis supports ROS as an initiating event in diabetic vascular disease. Further studies are needed to determine if increases in iron stores and arterial iron deposition promote hydroxyl radical formation from superoxide and accelerate diabetic vascular damage.
Assuntos
Artérias/metabolismo , Aterosclerose/metabolismo , Diabetes Mellitus Experimental/metabolismo , Hiperglicemia/metabolismo , Ferro/metabolismo , Superóxidos/metabolismo , Animais , Catalase/metabolismo , Dieta Aterogênica , Gorduras na Dieta , Ferritinas/sangue , Heme Oxigenase-1/metabolismo , Lipídeos/sangue , Macaca fascicularis , Estresse Oxidativo/fisiologia , Superóxido Dismutase/metabolismoAssuntos
Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Administração Cutânea , Administração Oral , Animais , Ensaios Clínicos como Assunto , Avaliação Pré-Clínica de Medicamentos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Insulina/administração & dosagem , Insulina/uso terapêutico , Transplante das Ilhotas Pancreáticas , Ratos , Ratos Zucker , Transplante de Células-TroncoRESUMO
CYP51 fulfills an essential requirement for all cells, by catalyzing three sequential mono-oxidations within the cholesterol biosynthesis cascade. Inhibition of fungal CYP51 is used as a therapy for treating fungal infections, whereas inhibition of human CYP51 has been considered as a pharmacological approach to treat dyslipidemia and some forms of cancer. To predict the interaction of inhibitors with the active site of human CYP51, a three-dimensional quantitative structure-activity relationship model was constructed. This pharmacophore model of the common structural features of CYP51 inhibitors was built using the program Catalyst from multiple inhibitors (n = 26) of recombinant human CYP51-mediated lanosterol 14alpha-demethylation. The pharmacophore, which consisted of one hydrophobe, one hydrogen bond acceptor, and two ring aromatic features, demonstrated a high correlation between observed and predicted IC(50) values (r = 0.92). Validation of this pharmacophore was performed by predicting the IC(50) of a test set of commercially available (n = 19) and CP-320626-related (n = 48) CYP51 inhibitors. Using predictions below 10 microM as a cutoff indicative of active inhibitors, 16 of 19 commercially available inhibitors (84%) and 38 of 48 CP-320626-related inhibitors (79.2%) were predicted correctly. To better understand how inhibitors fit into the enzyme, potent CYP51 inhibitors were used to build a Cerius(2) receptor surface model representing the volume of the active site. This study has demonstrated the potential for ligand-based computational pharmacophore modeling of human CYP51 and enables a high-throughput screening system for drug discovery and data base mining.
Assuntos
Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/química , Modelos Moleculares , Oxirredutases/antagonistas & inibidores , Amidas/química , Humanos , Indóis/química , Relação Quantitativa Estrutura-Atividade , Esterol 14-DesmetilaseRESUMO
The discovery and efficacy of a series of potent aminopyrrolidineamide-based inhibitors of sterol regulatory element binding protein site-1 protease is described.