RESUMEN
BACKGROUND AND PURPOSE: Nonalcoholic fatty liver disease refers to liver pathologies, ranging from steatosis to steatohepatitis, with fibrosis ultimately leading to cirrhosis and hepatocellular carcinoma. Although several mechanisms have been suggested, including insulin resistance, oxidative stress, and inflammation, its pathophysiology remains imperfectly understood. Over the last decade, a dysfunctional unfolded protein response (UPR) triggered by endoplasmic reticulum (ER) stress emerged as one of the multiple driving factors. In parallel, growing evidence suggests that insulin-degrading enzyme (IDE), a highly conserved and ubiquitously expressed metallo-endopeptidase originally discovered for its role in insulin decay, may regulate ER stress and UPR. EXPERIMENTAL APPROACH: We investigated, by genetic and pharmacological approaches, in vitro and in vivo, whether IDE modulates ER stress-induced UPR and lipid accumulation in the liver. KEY RESULTS: We found that IDE-deficient mice display higher hepatic triglyceride content along with higher inositol-requiring enzyme 1 (IRE1) pathway activation. Upon induction of ER stress by tunicamycin or palmitate in vitro or in vivo, pharmacological inhibition of IDE, using its inhibitor BDM44768, mainly exacerbated ER stress-induced IRE1 activation and promoted lipid accumulation in hepatocytes, effects that were abolished by the IRE1 inhibitors 4µ8c and KIRA6. Finally, we identified that IDE knockout promotes lipolysis in adipose tissue and increases hepatic CD36 expression, which may contribute to steatosis. CONCLUSION AND IMPLICATIONS: These results unravel a novel role for IDE in the regulation of ER stress and development of hepatic steatosis. These findings pave the way to innovative strategies modulating IDE to treat metabolic diseases.
RESUMEN
Peroxisome proliferator-activated receptors (PPARs) play a major role in regulating inflammatory processes, and dual or pan-PPAR agonists with PPARγ partial activation have been recognised to be useful to manage both metabolic syndrome and metabolic dysfunction-associated fatty liver disease (MAFLD). Previous works have demonstrated the capacity of 2-prenylated benzopyrans as PPAR ligands. Herein, we have replaced the isoprenoid bond by hydrazone, a highly attractive functional group in medicinal chemistry. In an attempt to discover novel and safety PPAR activators, we efficiently prepared benzopyran hydrazone/hydrazine derivatives containing benzothiazole (series 1) or 5-chloro-3-(trifluoromethyl)-2-pyridine moiety (series 2) with a 3- or 7-carbon side chain at the 2-position of the benzopyran nucleus. Benzopyran hydrazones 4 and 5 showed dual hPPARα/γ agonism, while hydrazone 14 exerted dual hPPARα/δ agonism. These three hydrazones greatly attenuated inflammatory markers such as IL-6 and MCP-1 on the THP-1 macrophages via NF-κB activation. Therefore, we have discovered novel hits (4, 5 and 14), containing a hydrazone framework with dual PPARα/γ or PPARα/δ partial agonism, depending on the length of the side chain. Benzopyran hydrazones emerge as potential lead compounds which could be useful for treating metabolic diseases.
Asunto(s)
Benzopiranos , PPAR alfa , Humanos , PPAR alfa/agonistas , Benzopiranos/química , Hidrazonas/farmacología , Hipoglucemiantes , PPAR gamma/agonistas , AntiinflamatoriosRESUMEN
A novel series of potent agonists of the bile acid receptor TGR5 bearing a dihydropyridone scaffold was developed from a high-throughput screen. Starting from a micromolar hit compound, we implemented an extensive structure-activity-relationship (SAR) study with the synthesis and biological evaluation of 83 analogues. The project culminated with the identification of the potent nanomolar TGR5 agonist 77A. We report the GLP-1 secretagogue effect of our lead compound ex vivo in mouse colonoids and in vivo. In addition, to identify specific features favorable for TGR5 activation, we generated and optimized a three-dimensional quantitative SAR model that contributed to our understanding of our activity profile and could guide further development of this dihydropyridone series.
Asunto(s)
Relación Estructura-Actividad Cuantitativa , Factores de Transcripción , Animales , Ratones , Péptido 1 Similar al Glucagón , Ácidos y Sales BiliaresRESUMEN
BACKGROUND AND PURPOSE: Selective peroxisome proliferator-activated receptors (PPARs) are widely used to treat metabolic complications; however, the limited effect of PPARα agonists on glucose metabolism and the adverse effects associated with selective PPARγ activators have stimulated the development of novel pan-PPAR agonists to treat metabolic disorders. Here, we synthesized a new prenylated benzopyran (BP-2) and evaluated its PPAR-activating properties, anti-inflammatory effects and impact on metabolic derangements. EXPERIMENTAL APPROACH: BP-2 was used in transactivation assays to evaluate its agonism to PPARα, PPARß/δ and PPARγ. A parallel-plate flow chamber was employed to investigate its effect on TNFα-induced leukocyte-endothelium interactions. Flow cytometry and immunofluorescence were used to determine its effects on the expression of endothelial cell adhesion molecules (CAMs) and chemokines and p38-MAPK/NF-κB activation. PPARs/RXRα interactions were determined using a gene silencing approach. Analysis of its impact on metabolic abnormalities and inflammation was performed in ob/ob mice. KEY RESULTS: BP-2 displayed strong PPARα activity, with moderate and weak activity against PPARß/δ and PPARγ, respectively. In vitro, BP-2 reduced TNFα-induced endothelial ICAM-1, VCAM-1 and fractalkine/CX3CL1 expression, suppressed mononuclear cell arrest via PPARß/δ-RXRα interactions and decreased p38-MAPK/NF-κB activation. In vivo, BP-2 improved the circulating levels of glucose and triglycerides in ob/ob mice, suppressed T-lymphocyte/macrophage infiltration and proinflammatory markers in the liver and white adipose tissue, but increased the expression of the M2-like macrophage marker CD206. CONCLUSION AND IMPLICATIONS: BP-2 emerges as a novel pan-PPAR lead candidate to normalize glycemia/triglyceridemia and minimize inflammation in metabolic disorders, likely preventing the development of further cardiovascular complications.
Asunto(s)
Enfermedades Metabólicas , PPAR delta , PPAR-beta , Ratones , Animales , PPAR gamma/metabolismo , PPAR alfa/metabolismo , PPAR-beta/metabolismo , Factor de Necrosis Tumoral alfa , Benzopiranos , FN-kappa B , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Inflamación/tratamiento farmacológicoRESUMEN
Insulin degrading enzyme (IDE) is a zinc metalloprotease that cleaves numerous substrates among which amyloid-ß and insulin. It has been linked through genetic studies to the risk of type-2 diabetes (T2D) or Alzheimer's disease (AD). Pharmacological activation of IDE is an attractive therapeutic strategy in AD. While IDE inhibition gave paradoxal activity in glucose homeostasis, recent studies, in particular in the liver suggest that IDE activators could be also of interest in diabetes. Here we describe the discovery of an original series of IDE activators by screening and structure-activity relationships. Early cellular studies show that hit 1 decreases glucose-stimulating insulin secretion. Docking studies revealed it has an unprecedented extended binding to the polyanion-binding site of IDE. These indole-based pharmacological tools are activators of both Aß and insulin hydrolysis by IDE and could be helpful to explore the multiple roles of IDE.
Asunto(s)
Indoles/farmacología , Insulisina/metabolismo , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Humanos , Indoles/química , Ratones , Modelos Moleculares , Estructura Molecular , Proteínas Recombinantes/metabolismo , Relación Estructura-ActividadRESUMEN
PEGylation of therapeutic agents is known to improve the pharmacokinetic behavior of macromolecular drugs and nanoparticles. In this work, we performed the conjugation of polyethylene glycols (220-5000 Da) to a series of non-steroidal small agonists of the bile acids receptor TGR5. A suitable anchoring position on the agonist was identified to retain full agonistic potency with the conjugates. We describe herein an extensive structure-properties relationships study allowing us to finely describe the non-linear effects of the PEG length on the physicochemical as well as the in vitro and in vivo pharmacokinetic properties of these compounds. When appending a PEG of suitable length to the TGR5 pharmacophore, we were able to identify either systemic or gut lumen-restricted TGR5 agonists.
Asunto(s)
Hipoglucemiantes/síntesis química , Hipoglucemiantes/farmacología , Receptores Acoplados a Proteínas G/agonistas , Animales , Barrera Hematoencefálica/metabolismo , Células CACO-2 , Células HEK293 , Humanos , Hipoglucemiantes/farmacocinética , Masculino , Ratones , Ratones Endogámicos C57BL , Microsomas Hepáticos/metabolismo , Polietilenglicoles/química , Receptores Acoplados a Proteínas G/química , Relación Estructura-ActividadRESUMEN
The role of the G-protein-coupled bile acid receptor TGR5 in various organs, tissues, and cell types, specifically in intestinal endocrine L-cells and brown adipose tissue, has made it a promising therapeutical target in several diseases, especially type-2 diabetes and metabolic syndrome. However, recent studies have shown deleterious on-target effects of systemic TGR5 agonists. To avoid these systemic effects while stimulating glucagon-like peptide-1 (GLP-1) secreting enteroendocrine L-cells, we have designed TGR5 agonists with low intestinal permeability. In this article, we describe their synthesis, characterization, and biological evaluation. Among them, compound 24 is a potent GLP-1 secretagogue, has low effect on gallbladder volume, and improves glucose homeostasis in a preclinical murine model of diet-induced obesity and insulin resistance, making the proof of concept of the potential of topical intestinal TGR5 agonists as therapeutic agents in type-2 diabetes.
Asunto(s)
Péptido 1 Similar al Glucagón/metabolismo , Glucosa/metabolismo , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Imidazoles/química , Imidazoles/farmacología , Receptores Acoplados a Proteínas G/agonistas , Aminación , Animales , Células CACO-2 , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Prueba de Tolerancia a la Glucosa , Humanos , Hipoglucemiantes/farmacocinética , Imidazoles/farmacocinética , Absorción Intestinal , Mucosa Intestinal/metabolismo , Ratones Endogámicos C57BL , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
Whereas the anti-inflammatory properties and mechanisms of action of long chain ω3 PUFAs have been abundantly investigated, research gaps remain regarding the respective contribution and mechanisms of action of their oxygenated metabolites collectively known as oxylipins. We conducted a dose-dependent and comparative study in human primary macrophages aiming to compare the anti-inflammatory activity of two types of DHA-derived oxylipins including the well-described protectins (NPD1 and PDX), formed through lipoxygenase pathway and the neuroprostanes (14-A4t- and 4-F4t-NeuroP) formed through free-radical mediated oxygenation and expected to be new anti-inflammatory mediators. Considering the potential ability of these DHA-derived oxylipins to bind PPARs and knowing the central role of these transcription factors in the regulation of macrophage inflammatory response, we performed transactivation assays to compare the ability of protectins and neuroprostanes to activate PPARs. All molecules significantly reduced mRNA levels of cytokines such as IL-6 and TNF-α, however not at the same doses. NPD1 showed the most effect at 0.1µM (-14.9%, p<0.05 for IL-6 and -26.7%, p<0.05 for TNF-α) while the three other molecules had greater effects at 10µM, with the strongest result due to the cyclopentenone neuroprostane, 14-A4t-NeuroP (-49.8%, p<0.001 and -40.8%, p<0.001, respectively). Part of the anti-inflammatory properties of the DHA-derived oxylipins investigated could be linked to their activation of PPARs. Indeed, all tested oxylipins significantly activated PPARγ, with 14-A4t-NeuroP leading to the strongest activation, and NPD1 and PDX also activated PPARα. In conclusion, our results show that neuroprostanes and more especially cyclopentenone neuroprostanes have potent anti-inflammatory activities similar or even more pronounced than protectins supporting that neuroprostanes should be considered as important contributors to the anti-inflammatory effects of DHA.
Asunto(s)
Antiinflamatorios/farmacología , Ácidos Docosahexaenoicos/farmacología , Macrófagos/inmunología , Neuroprostanos/farmacología , Oxilipinas/farmacología , Animales , Células COS , Células Cultivadas , Chlorocebus aethiops , Citocinas/genética , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Expresión Génica/efectos de los fármacos , Humanos , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismoRESUMEN
BACKGROUND: Atherosclerosis is characterized by lipid accumulation and chronic inflammation in the arterial wall. Elevated levels of apolipoprotein (apo) B-containing lipoproteins are a risk factor for cardiovascular disease (CVD). By contrast, plasma levels of functional high-density lipoprotein (HDL) and apoA-I are protective against CVD by enhancing reverse cholesterol transport (RCT). Activation of peroxisome proliferator-activated receptor-α (PPARα), a ligand-activated transcription factor, controls lipid metabolism, cellular cholesterol trafficking in macrophages and influences inflammation. OBJECTIVE: To study whether pharmacological activation of PPARα with a novel highly potent and selective PPARα modulator, pemafibrate, improves lipid metabolism, macrophage cholesterol efflux, inflammation and consequently atherosclerosis development in vitro and in vivo using human apolipoprotein E2 Knock-In (apoE2KI) and human apoA-I transgenic (hapoA-I tg) mice. APPROACH AND RESULTS: Pemafibrate treatment decreases apoB secretion in chylomicrons by polarized Caco-2/TC7 intestinal epithelium cells and reduces triglyceride levels in apoE2KI mice. Pemafibrate treatment of hapoA-I tg mice increases plasma HDL cholesterol, apoA-I and stimulates RCT to feces. In primary human macrophages, pemafibrate promotes macrophage cholesterol efflux to HDL and exerts anti-inflammatory activities. Pemafibrate also reduces markers of inflammation and macrophages in the aortic crosses as well as aortic atherosclerotic lesion burden in western diet-fed apoE2KI mice. CONCLUSIONS: These results demonstrate that the novel selective PPARα modulator pemafibrate exerts beneficial effects on lipid metabolism, RCT and inflammation resulting in anti-atherogenic properties.
Asunto(s)
Aterosclerosis/tratamiento farmacológico , Benzoxazoles/farmacología , Butiratos/farmacología , Colesterol/metabolismo , Dislipidemias/tratamiento farmacológico , Inflamación/tratamiento farmacológico , PPAR alfa/antagonistas & inhibidores , Animales , Apolipoproteína A-I/química , Transporte Biológico , Células CACO-2 , Enfermedades Cardiovasculares/sangre , Epitelio/metabolismo , Femenino , Homocigoto , Humanos , Mucosa Intestinal/metabolismo , Ligandos , Metabolismo de los Lípidos , Lipoproteínas HDL/sangre , Lipoproteínas HDL/metabolismo , Macrófagos/metabolismo , Ratones , PPAR alfa/metabolismo , Factores de RiesgoRESUMEN
Insulin-degrading enzyme (IDE) is a protease that cleaves insulin and other bioactive peptides such as amyloid-ß. Knockout and genetic studies have linked IDE to Alzheimer's disease and type-2 diabetes. As the major insulin-degrading protease, IDE is a candidate drug target in diabetes. Here we have used kinetic target-guided synthesis to design the first catalytic site inhibitor of IDE suitable for in vivo studies (BDM44768). Crystallographic and small angle X-ray scattering analyses show that it locks IDE in a closed conformation. Among a panel of metalloproteases, BDM44768 selectively inhibits IDE. Acute treatment of mice with BDM44768 increases insulin signalling and surprisingly impairs glucose tolerance in an IDE-dependent manner. These results confirm that IDE is involved in pathways that modulate short-term glucose homeostasis, but casts doubt on the general usefulness of the inhibition of IDE catalytic activity to treat diabetes.
Asunto(s)
Ácidos Hidroxámicos/síntesis química , Insulisina/antagonistas & inhibidores , Triazoles/síntesis química , Animales , Células CACO-2 , Dominio Catalítico , Diabetes Mellitus/tratamiento farmacológico , Evaluación Preclínica de Medicamentos , Prueba de Tolerancia a la Glucosa , Humanos , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/uso terapéutico , Masculino , Ratones , Ratones Endogámicos C57BL , Microsomas Hepáticos , Terapia Molecular Dirigida , Distribución Aleatoria , Relación Estructura-Actividad , Triazoles/farmacología , Triazoles/uso terapéuticoRESUMEN
Metabolic diseases reach epidemic proportions. A better knowledge of the associated alterations in the metabolic pathways in the liver is necessary. These studies need in vitro human cell models. Several human hepatoma models are used, but the response of many metabolic pathways to physiological stimuli is often lost. Here, we characterize two human hepatocyte cell lines, IHH and HepaRG, by analysing the expression and regulation of genes involved in glucose and lipid metabolism. Our results show that the glycolysis pathway is activated by glucose and insulin in both lines. Gluconeogenesis gene expression is induced by forskolin in IHH cells and inhibited by insulin in both cell lines. The lipogenic pathway is regulated by insulin in IHH cells. Finally, both cell lines secrete apolipoprotein B-containing lipoproteins, an effect promoted by increasing glucose concentrations. These two human cell lines are thus interesting models to study the regulation of glucose and lipid metabolism.