RESUMO
The use of nicotinic acid to treat dyslipidemia is limited by induction of a "flushing" response, mediated in part by the interaction of prostaglandin D(2) (PGD(2)) with its G-protein coupled receptor, DP1 (Ptgdr). The impact of DP1 blockade (genetic or pharmacologic) was assessed in experimental murine models of atherosclerosis. In Ptgdr(-/-)ApoE(-/-) mice versus ApoE(-/-) mice, both fed a high-fat diet, aortic cholesterol content was modestly higher (1.3- to 1.5-fold, P < 0.05) in Ptgdr(-/-)ApoE(-/-) mice at 16 and 24 weeks of age, but not at 32 weeks. In multiple ApoE(-/-) mouse studies, a DP1-specific antagonist, L-655, generally had a neutral to beneficial effect on aortic lipids in the presence or absence of nicotinic acid treatment. In a separate study, a modest increase in some atherosclerotic measures was observed with L-655 treatment in Ldlr(-/-) mice fed a high-fat diet for 8 weeks; however, this effect was not sustained for 16 or 24 weeks. In the same study, treatment with nicotinic acid alone generally decreased plasma and/or aortic lipids, and addition of L-655 did not negate those beneficial effects. These studies demonstrate that inhibition of DP1, with or without nicotinic acid treatment, does not lead to consistent or sustained effects on plaque burden in mouse atherosclerotic models.
Assuntos
Técnicas de Silenciamento de Genes , Niacina/farmacologia , Placa Aterosclerótica/tratamento farmacológico , Placa Aterosclerótica/metabolismo , Receptores Imunológicos/antagonistas & inibidores , Receptores Imunológicos/genética , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Prostaglandina/genética , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Apolipoproteínas E/deficiência , Colesterol/metabolismo , Interações Medicamentosas , Determinação de Ponto Final , Feminino , Humanos , Masculino , Camundongos , Niacina/uso terapêutico , Placa Aterosclerótica/genética , Receptores Imunológicos/deficiência , Receptores de LDL/deficiência , Receptores de Prostaglandina/deficiência , Receptores de Tromboxano A2 e Prostaglandina H2/metabolismoRESUMO
In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profiles in 24 models. These included five mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profiles, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study.
Assuntos
Modelos Animais de Doenças , Dislipidemias/sangue , Lipídeos/sangue , Animais , Cricetinae , Cães , Dislipidemias/tratamento farmacológico , Ácidos Graxos/sangue , Humanos , Camundongos , Primatas , Sinvastatina/uso terapêutico , Triglicerídeos/sangueRESUMO
Bombesin receptor subtype 3 (BRS-3) is an orphan G-protein coupled receptor expressed primarily in the hypothalamus which plays a role in the onset of both diabetes and obesity. We report herein our progress made towards identifying a potent, selective bombesin receptor subtype-3 (BRS-3) agonist related to the previously described MK-7725(1) Chobanian et al. (2012) that would prevent atropisomerization through the increase of steric bulk at the C-2 position. This would thereby make clinical development of this class of compounds more cost effective by inhibiting racemization which can occur over long periods of time at room/elevated temperature.
Assuntos
Benzodiazepinas/química , Desenho de Fármacos , Receptores da Bombesina/agonistas , Sulfonamidas/química , Sulfonamidas/síntese química , Animais , Humanos , Camundongos , Ligação Proteica , Ratos , Receptores da Bombesina/metabolismo , Estereoisomerismo , Sulfonamidas/farmacocinética , TemperaturaRESUMO
Reducing circulating LDL-cholesterol (LDL-c) reduces the risk of cardiovascular disease in people with hypercholesterolemia. Current approaches to reduce circulating LDL-c include statins, which inhibit cholesterol synthesis, and ezetimibe, which blocks cholesterol absorption. Both elevate serum PCSK9 protein levels in patients, which could attenuate their efficacy by reducing the amount of cholesterol cleared from circulation. To determine whether PCSK9 inhibition could enhance LDL-c lowering of both statins and ezetimibe, we utilized small interfering RNAs (siRNAs) to knock down Pcsk9, together with ezetimibe, rosuvastatin, and an ezetimibe/rosuvastatin combination in a mouse model with a human-like lipid profile. We found that ezetimibe, rosuvastatin, and ezetimibe/rosuvastatin combined lower serum cholesterol but induce the expression of Pcsk9 as well as the Srebp-2 hepatic cholesterol biosynthesis pathway. Pcsk9 knockdown in combination with either treatment led to greater reductions in serum non-HDL with a near-uniform reduction of all LDL-c subfractions. In addition to reducing serum cholesterol, the combined rosuvastatin/ezetimibe/Pcsk9 siRNA treatment exhibited a significant reduction in serum APOB protein and triglyceride levels. Taken together, these data provide evidence that PCSK9 inhibitors, in combination with current therapies, have the potential to achieve greater reductions in both serum cholesterol and triglycerides.
Assuntos
Anticolesterolemiantes/uso terapêutico , Azetidinas/uso terapêutico , Fluorbenzenos/uso terapêutico , Pirimidinas/uso terapêutico , Serina Endopeptidases/metabolismo , Sulfonamidas/uso terapêutico , Animais , Apolipoproteínas B/sangue , Colesterol/sangue , LDL-Colesterol/sangue , Ensaio de Imunoadsorção Enzimática , Ezetimiba , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/terapia , Camundongos , Camundongos Endogâmicos C57BL , Pró-Proteína Convertase 9 , Pró-Proteína Convertases , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rosuvastatina Cálcica , Serina Endopeptidases/genética , Triglicerídeos/sangueRESUMO
The use of stable isotopically labeled substrates and analysis by mass spectrometry have provided substantial insight into rates of synthesis, disposition, and utilization of lipids in vivo. The information to be gained from such studies is of particular benefit to therapeutic research where the underlying causes of disease may be related to the production and utilization of lipids. When studying biology through the use of isotope tracers, care must be exercised in interpreting the data to ensure that any response observed can truly be interpreted as biological and not as an artifact of the experimental design or a dilutional effect on the isotope. We studied the effects of dosing route and tracer concentration on the mass isotopomer distribution profile as well as the action of selective inhibitors of microsomal tri-glyceride transfer protein (MTP) in mice and diacylglycerol acyltransferase 1 (DGAT1) in nonhuman primates, using a stable-isotopically labeled approach. Subjects were treated with inhibitor and subsequently given a dose of uniformly ¹³C-labeled oleic acid. Samples were analyzed using a rapid LC-MS technique, allowing the effects of the intervention on the assembly and disposition of triglycerides, cholesteryl esters, and phospholipids to be determined in a single 3 min run from just 10 µl of plasma.
Assuntos
Proteínas de Transporte/metabolismo , Ésteres do Colesterol/sangue , Diacilglicerol O-Aciltransferase/metabolismo , Metabolismo dos Lipídeos , Lipoproteínas/sangue , Ácido Oleico , Triglicerídeos/sangue , Animais , Proteínas de Transporte/antagonistas & inibidores , Chlorocebus aethiops , Cromatografia Líquida , Vias de Administração de Medicamentos , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Feminino , Marcação por Isótopo/métodos , Isótopos/análise , Isótopos/sangue , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Ácido Oleico/metabolismo , Ácido Oleico/farmacologiaRESUMO
The enzyme 11beta-hydroxysteroid dehydrogenase (HSD) type 1 converts inactive cortisone into active cortisol in cells, thereby raising the effective glucocorticoid (GC) tone above serum levels. We report that pharmacologic inhibition of 11beta-HSD1 has a therapeutic effect in mouse models of metabolic syndrome. Administration of a selective, potent 11beta-HSD1 inhibitor lowered body weight, insulin, fasting glucose, triglycerides, and cholesterol in diet-induced obese mice and lowered fasting glucose, insulin, glucagon, triglycerides, and free fatty acids, as well as improved glucose tolerance, in a mouse model of type 2 diabetes. Most importantly, inhibition of 11beta-HSD1 slowed plaque progression in a murine model of atherosclerosis, the key clinical sequela of metabolic syndrome. Mice with a targeted deletion of apolipoprotein E exhibited 84% less accumulation of aortic total cholesterol, as well as lower serum cholesterol and triglycerides, when treated with an 11beta-HSD1 inhibitor. These data provide the first evidence that pharmacologic inhibition of intracellular GC activation can effectively treat atherosclerosis, the key clinical consequence of metabolic syndrome, in addition to its salutary effect on multiple aspects of the metabolic syndrome itself.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Adamantano/análogos & derivados , Arteriosclerose/tratamento farmacológico , Azepinas/administração & dosagem , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/administração & dosagem , Resistência à Insulina , Triazóis/administração & dosagem , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adamantano/administração & dosagem , Animais , Aorta/metabolismo , Arteriosclerose/complicações , Arteriosclerose/enzimologia , Glicemia/efeitos dos fármacos , Cortisona/metabolismo , Dieta Aterogênica , Modelos Animais de Doenças , Ácidos Graxos/sangue , Hidrocortisona , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Síndrome , Triglicerídeos/sangueRESUMO
Bombesin receptor subtype-3 (BRS-3) is an orphan G protein-coupled receptor implicated in the regulation of energy homeostasis. Here, we report the biologic effects of a highly optimized BRS-3 agonist, (2S)-1,1,1-trifluoro-2-[4-(1H-pyrazol-1-yl)phenyl]-3-(4-{[1-(trifluoromethyl)cyclopropyl]methyl}-1H-imidazol-2-yl)propan-2-ol (MK-5046). Single oral doses of MK-5046 inhibited 2-h and overnight food intake and increased fasting metabolic rate in wild-type but not Brs3 knockout mice. Upon dosing for 14 days, MK-5046 at 25 mg · kg(-1) · day(-1) reduced body weight of diet-induced obese mouse by 9% compared with vehicle-dosed controls. In mice, 50% brain receptor occupancy was achieved at a plasma concentration of 0.34 ± 0.23 µM. With chronic dosing, effects on metabolic rate, rather than food intake, seem to be the predominant mechanism for weight reduction by MK-5046. The compound also effectively reduced body weight in rats and caused modest increases in body temperature, heart rate, and blood pressure. These latter effects on temperature, heart rate, and blood pressure were transient in nature and desensitized with continued dosing. MK-5046 is the first BRS-3 agonist with properties suitable for use in larger mammals. In dogs, MK-5046 treatment produced statistically significant and persistent weight loss, which was initially accompanied by increases in body temperature and heart rate that abated with continued dosing. Our results demonstrate antiobesity efficacy for MK-5046 in rodents and dogs and further support BRS-3 agonism as a new approach to the treatment of obesity.
Assuntos
Fármacos Antiobesidade/farmacologia , Imidazóis/farmacologia , Pirazóis/farmacologia , Receptores da Bombesina/agonistas , Animais , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Receptores da Bombesina/análiseRESUMO
BACKGROUND: Lipidomic biomarkers will facilitate the development of novel anti-atherosclerotic therapies. OBJECTIVE: To evaluate the responses of circulating biomarkers to simvastatin treatment. METHODS: A randomized, cross-over study in men with mixed dyslipidaemia was used to compare effects of simvastatin 40 mg/day with placebo. RESULTS: Plasma concentrations of nine fatty acids (FA; of 33 evaluated) were reduced significantly by simvastatin. No changes in the rates of FA synthesis or in hepatic lipase or lipoprotein lipase activities were apparent. Circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) levels increased. CONCLUSION: We identified lipidomic biomarkers of simvastatin treatment effect that are consistent with statin inhibition of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase (ClinicalTrials.gov: NCT00935259).
Assuntos
Dislipidemias/tratamento farmacológico , Sinvastatina/administração & dosagem , Adulto , Idoso , Biomarcadores/sangue , Estudos Cross-Over , Método Duplo-Cego , Ácidos Graxos/sangue , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Pró-Proteína Convertase 9 , Pró-Proteína Convertases , Serina Endopeptidases/sangue , Sinvastatina/farmacologia , Resultado do TratamentoRESUMO
A series of six-membered heterocycle carboxamides were synthesized and evaluated as cholecystokinin 1 receptor (CCK1R) agonists. A pyrimidine core proved to be the best heterocycle, and SAR studies resulted in the discovery of analog 5, a potent and structurally diverse CCK1R agonist.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Receptor de Colecistocinina A/agonistas , Amidas/química , Animais , Células Cultivadas , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Humanos , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Ligação Proteica/efeitos dos fármacos , Pirimidinas/química , Relação Estrutura-AtividadeRESUMO
We report the discovery of piperazine urea based compound 1, a potent, selective, orally bioavailable melanocortin subtype-4 receptor partial agonist. Compound 1 shows anti-obesity efficacy without potentiating erectile activity in the rodent models.
Assuntos
Piperazinas/química , Receptor Tipo 4 de Melanocortina/agonistas , Ureia/análogos & derivados , Administração Oral , Animais , Disponibilidade Biológica , Modelos Animais de Doenças , Cães , Avaliação Pré-Clínica de Medicamentos , Ingestão de Alimentos/efeitos dos fármacos , Haplorrinos , Camundongos , Obesidade/tratamento farmacológico , Piperazinas/farmacocinética , Piperazinas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Relação Estrutura-Atividade , Ureia/química , Ureia/farmacocinética , Ureia/uso terapêuticoRESUMO
Treatment of rodents with a bombesin receptor subtype-3 (BRS-3) agonist reduces food intake and increases fasting metabolic rate, causing weight loss with continued treatment. In small mammals, core body temperature (T(b)) is regulated in part by nutritional status, with a reduced T(b) during fasting. We report that fed Brs3 knockout mice have a lower T(b), which is discordant with their nutritional status. Treatment of wild-type mice with a BRS-3 agonist increased T(b), more so when the baseline T(b) was reduced such as by fasting or during the inactive phase of the light cycle. With repeated BRS-3 agonist dosing, the T(b) increase attenuated despite continued weight loss efficacy. The increase in T(b) was not prevented by inhibitors of prostaglandin E (PGE) production but was partially reduced by a ß-adrenergic blocker. These results demonstrate that BRS-3 has a role in body temperature regulation, presumably secondary to its effect on energy metabolism, including effects on sympathetic tone. By making use of this phenomenon, the reversal of the fasting T(b) reduction was developed into a sensitive single-dose pharmacodynamic assay for BRS-3 agonism and other antiobesity compounds acting by various mechanisms, including sibutramine, cannabinoid-1, and melanin-concentrating hormone-1 receptor blockers, and melanocortin, ß3-adrenergic, and cholecystokinin-1 receptor agonists. These drugs increased both the fasted T(b) and the fasted, resting metabolic rates. The T(b) assay is a robust, information-rich assay that is simpler and has a greater throughput than measuring metabolic rate and is a practical, effective tool for drug discovery.
Assuntos
Fármacos Antiobesidade/farmacologia , Regulação da Temperatura Corporal/efeitos dos fármacos , Obesidade/tratamento farmacológico , Receptores da Bombesina/agonistas , Animais , Relação Dose-Resposta a Droga , Ingestão de Alimentos/fisiologia , Metabolismo Energético/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Obesidade/metabolismo , Obesidade/fisiopatologia , Receptores da Bombesina/metabolismo , Redução de Peso/fisiologiaRESUMO
The synthesis, SAR and binding affinities of cannabinoid-1 receptor (CB1R) inverse agonists based on furo[2,3-b]pyridine scaffolds are described. Food intake, mechanism specific efficacy, pharmacokinetic, and metabolic evaluation of several of these compounds indicate that they are effective orally active modulators of CB1R.
Assuntos
Desenho de Fármacos , Furanos/síntese química , Piridinas/síntese química , Receptor CB1 de Canabinoide/agonistas , Animais , Benzopiranos , Cães , Furanos/química , Furanos/farmacologia , Haplorrinos , Humanos , Concentração Inibidora 50 , Camundongos , Camundongos Knockout , Estrutura Molecular , Piridinas/química , Piridinas/farmacologia , Ratos , Receptor CB1 de Canabinoide/genética , Relação Estrutura-AtividadeRESUMO
Synthesis and structure-activity relationships of cannabinoid-1 receptor (CB1R) inverse agonists based on dihydro-pyrano[2,3-b] pyridine and tetrahydro-1,8-naphtyridine scaffolds are presented. Rat food intake and pharmacokinetic evaluation of 13g, 13i, 13k and 17a revealed these compounds to be highly efficacious orally active modulators of CB1R.
Assuntos
Naftiridinas/química , Piridinas/química , Receptor CB1 de Canabinoide/agonistas , Redução de Peso/efeitos dos fármacos , Administração Oral , Animais , Ingestão de Alimentos , Humanos , Naftiridinas/síntese química , Naftiridinas/farmacologia , Farmacocinética , Piridinas/síntese química , Piridinas/farmacologia , Ratos , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
We report an SAR study of MC4R analogs containing spiroindane heterocyclic privileged structures. Compound 26 with N-Me-1,2,4-triazole moiety possesses exceptional potency at MC4R and potent anti-obesity efficacy in a mouse model. However, the efficacy is not completely mediated through MC4R. Additional SAR studies led to the discovery of compound 32, which is more potent at MC4R. Compound 32 demonstrates MC4R mediated anti-obesity efficacy in rodent models.
Assuntos
Obesidade/tratamento farmacológico , Receptor Tipo 4 de Melanocortina/agonistas , Triazóis/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Camundongos , Camundongos Knockout , Estrutura Molecular , Ratos , Receptor Tipo 4 de Melanocortina/genética , Relação Estrutura-Atividade , Triazóis/química , Triazóis/uso terapêuticoRESUMO
We report a series of potent and selective MC4R agonists based on spiroindane amide privileged structures for potential treatments of obesity. Among the synthetic methods used, Method C allows rapid synthesis of the analogs. The series of compounds can afford high potency on MC4R as well as good rodent pharmacokinetic profiles. Compound 1r (MK-0489) demonstrates MC4R mediated reduction of food intake and body weight in mouse models. Compound 1r is efficacious in 14-day diet-induced obese (DIO) rat models.
Assuntos
Amidas/química , Fármacos Antiobesidade/química , Obesidade/tratamento farmacológico , Pirrolidinas/química , Receptor Tipo 4 de Melanocortina/agonistas , Compostos de Espiro/química , Amidas/farmacocinética , Amidas/uso terapêutico , Animais , Fármacos Antiobesidade/farmacocinética , Fármacos Antiobesidade/uso terapêutico , Peso Corporal/efeitos dos fármacos , Humanos , Camundongos , Camundongos Knockout , Pirrolidinas/farmacocinética , Pirrolidinas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Receptor Tipo 4 de Melanocortina/metabolismo , Compostos de Espiro/farmacocinética , Compostos de Espiro/uso terapêutico , Relação Estrutura-AtividadeRESUMO
Design, synthesis, and SAR of a series of 3H-spiro[isobenzofuran-1,4'-piperidine] based compounds as potent, selective and orally bioavailable melanocortin subtype-4 receptor (MC4R) agonists are disclosed.
Assuntos
Piperidinas/química , Receptor Tipo 4 de Melanocortina/agonistas , Administração Oral , Animais , Encéfalo/metabolismo , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Humanos , Conformação Molecular , Piperidinas/síntese química , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor Tipo 4 de Melanocortina/metabolismo , Compostos de Espiro/química , Relação Estrutura-AtividadeRESUMO
We report the design, synthesis and properties of spiroindane based compound 1, a potent, selective, orally bioavailable, non-peptide melanocortin subtype-4 receptor agonist. Compound 1 shows excellent erectogenic activity in the rodent models.
Assuntos
Disfunção Erétil/tratamento farmacológico , Indanos/química , Indanos/uso terapêutico , Receptor Tipo 4 de Melanocortina/agonistas , Receptor Tipo 4 de Melanocortina/metabolismo , Compostos de Espiro/química , Compostos de Espiro/uso terapêutico , Animais , Células CHO , Cricetinae , Cricetulus , Cães , Haplorrinos , Humanos , Indanos/farmacocinética , Indanos/farmacologia , Masculino , Camundongos , Estrutura Molecular , Ligação Proteica , Ratos , Compostos de Espiro/farmacocinética , Compostos de Espiro/farmacologia , Relação Estrutura-AtividadeRESUMO
We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.
Assuntos
Descoberta de Drogas , Imidazóis/química , Imidazóis/farmacologia , Receptores da Bombesina/agonistas , Animais , Disponibilidade Biológica , Humanos , Imidazóis/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
Reverse cholesterol transport promoted by HDL-apoA-I is an important mechanism of protection against atherosclerosis. We have previously identified apoA-I mimetic peptides by synthesizing analogs of the 22 amino acid apoA-I consensus sequence (apoA-I(cons)) containing non-natural aliphatic amino acids. Here we examined the effect of different aliphatic non-natural amino acids on the structure-activity relationship (SAR) of apoA-I mimetic peptides. These novel apoA-I mimetics, with long hydrocarbon chain (C(5-8)) amino acids incorporated in the amphipathic α helix of the apoA-I(cons), have the following properties: (i) they stimulate in vitro cholesterol efflux from macrophages via ABCA1; (ii) they associate with HDL and cause formation of pre-ß HDL particles when incubated with human and mouse plasma; (iii) they associate with HDL and induce pre-ß HDL formation in vivo, with a corresponding increase in ABCA1-dependent cholesterol efflux capacity ex vivo; (iv) at high dose they associate with VLDL and induce hypertriglyceridemia in mice. These results suggest our peptide design confers activities that are potentially anti-atherogenic. However a dosing regimen which maximizes their therapeutic properties while minimizing adverse effects needs to be established.
Assuntos
Apolipoproteína A-I/química , Lipoproteínas de Alta Densidade Pré-beta/biossíntese , Lipoproteínas HDL/efeitos dos fármacos , Fragmentos de Peptídeos/química , Triglicerídeos/biossíntese , Animais , Lipoproteínas de Alta Densidade Pré-beta/efeitos dos fármacos , Humanos , Lipoproteínas HDL/metabolismo , Camundongos , Mimetismo Molecular , Fragmentos de Peptídeos/farmacologia , Relação Estrutura-Atividade , Triglicerídeos/metabolismoRESUMO
Proprotein convertase substilisin-like/kexin type 9 (PCSK9) is a serine protease involved in a protein-protein interaction with the low-density lipoprotein (LDL) receptor that has both human genetic and clinical validation. Blocking this protein-protein interaction prevents LDL receptor degradation and thereby decreases LDL cholesterol levels. Our pursuit of small-molecule direct binders for this difficult to drug PPI target utilized affinity selection/mass spectrometry, which identified one confirmed hit compound. An X-ray crystal structure revealed that this compound was binding in an unprecedented allosteric pocket located between the catalytic and C-terminal domain. Optimization of this initial hit, using two distinct strategies, led to compounds with high binding affinity to PCSK9. Direct target engagement was demonstrated in the cell lysate with a cellular thermal shift assay. Finally, ligand-induced protein degradation was shown with a proteasome recruiting tag attached to the high-affinity allosteric ligand for PCSK9.