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1.
Respir Res ; 25(1): 153, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566174

RESUMO

BACKGROUND: Wnt/ß-catenin signaling is critical for lung development and AT2 stem cell maintenance in adults, but excessive pathway activation has been associated with pulmonary fibrosis, both in animal models and human diseases such as idiopathic pulmonary fibrosis (IPF). IPF is a detrimental interstitial lung disease, and although two approved drugs limit functional decline, transplantation is the only treatment that extends survival, highlighting the need for regenerative therapies. METHODS: Using our antibody-based platform of Wnt/ß-catenin modulators, we investigated the ability of a pathway antagonist and pathway activators to reduce pulmonary fibrosis in the acute bleomycin model, and we tested the ability of a WNT mimetic to affect alveolar organoid cultures. RESULTS: A WNT mimetic agonist with broad FZD-binding specificity (FZD1,2,5,7,8) potently expanded alveolar organoids. Upon therapeutic dosing, a broad FZD-binding specific Wnt mimetic decreased pulmonary inflammation and fibrosis and increased lung function in the bleomycin model, and it impacted multiple lung cell types in vivo. CONCLUSIONS: Our results highlight the unexpected capacity of a WNT mimetic to effect tissue repair after lung damage and support the continued development of Wnt/ß-catenin pathway modulation for the treatment of pulmonary fibrosis.


Assuntos
Fibrose Pulmonar Idiopática , beta Catenina , Adulto , Animais , Humanos , beta Catenina/metabolismo , Pulmão/metabolismo , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/tratamento farmacológico , Fibrose Pulmonar Idiopática/metabolismo , Via de Sinalização Wnt , Bleomicina/toxicidade
2.
Cell Mol Gastroenterol Hepatol ; 14(2): 435-464, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35569814

RESUMO

BACKGROUND AND AIMS: Current management of inflammatory bowel disease leaves a clear unmet need to treat the severe epithelial damage. Modulation of Wnt signaling might present an opportunity to achieve histological remission and mucosal healing when treating IBD. Exogenous R-spondin, which amplifies Wnt signals by maintaining cell surface expression of Frizzled (Fzd) and low-density lipoprotein receptor-related protein receptors, not only helps repair intestine epithelial damage, but also induces hyperplasia of normal epithelium. Wnt signaling may also be modulated with the recently developed Wnt mimetics, recombinant antibody-based molecules mimicking endogenous Wnts. METHODS: We first compared the epithelial healing effects of RSPO2 and a Wnt mimetic with broad Fzd specificity in an acute dextran sulfate sodium mouse colitis model. Guided by Fzd expression patterns in the colon epithelium, we also examined the effects of Wnt mimetics with subfamily Fzd specificities. RESULTS: In the DSS model, Wnt mimetics repaired damaged colon epithelium and reduced disease activity and inflammation and had no apparent effect on uninjured tissue. We further identified that the FZD5/8 and LRP6 receptor-specific Wnt mimetic, SZN-1326-p, was associated with the robust repair effect. Through a range of approaches including single-cell transcriptome analyses, we demonstrated that SZN-1326-p directly impacted epithelial cells, driving transient expansion of stem and progenitor cells, promoting differentiation of epithelial cells, histologically restoring the damaged epithelium, and secondarily to epithelial repair, reducing inflammation. CONCLUSIONS: It is feasible to design Wnt mimetics such as SZN-1326-p that impact damaged intestine epithelium specifically and restore its physiological functions, an approach that holds promise for treating epithelial damage in inflammatory bowel disease.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Modelos Animais de Doenças , Inflamação , Doenças Inflamatórias Intestinais/patologia , Camundongos , Regeneração , Via de Sinalização Wnt
3.
Nat Commun ; 12(1): 3247, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059688

RESUMO

The Wnt signaling pathway is intricately connected with bone mass regulation in humans and rodent models. We designed an antibody-based platform that generates potent and selective Wnt mimetics. Using this platform, we engineer bi-specific Wnt mimetics that target Frizzled and low-density lipoprotein receptor-related proteins and evaluate their effects on bone accrual in murine models. These synthetic Wnt agonists induce rapid and robust bone building effects, and correct bone mass deficiency and bone defects in various disease models, including osteoporosis, aging, and long bone fracture. Furthermore, when these Wnt agonists are combined with antiresorptive bisphosphonates or anti-sclerostin antibody therapies, additional bone accrual/maintenance effects are observed compared to monotherapy, which could benefit individuals with severe and/or acute bone-building deficiencies. Our data support the continued development of Wnt mimetics for the treatment of diseases of low bone mineral density, including osteoporosis.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Reabsorção Óssea/tratamento farmacológico , Fraturas do Fêmur/tratamento farmacológico , Osteoporose Pós-Menopausa/tratamento farmacológico , Proteínas Wnt/agonistas , Idoso , Envelhecimento/fisiologia , Animais , Densidade Óssea/efeitos dos fármacos , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/fisiopatologia , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Quimioterapia Combinada/métodos , Feminino , Fraturas do Fêmur/patologia , Fêmur/efeitos dos fármacos , Fêmur/lesões , Fêmur/patologia , Humanos , Camundongos , Osteoporose Pós-Menopausa/fisiopatologia , Via de Sinalização Wnt/efeitos dos fármacos , Adulto Jovem
4.
Sci Rep ; 10(1): 13951, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811902

RESUMO

R-spondin (RSPO) proteins amplify Wnt signaling and stimulate regeneration in a variety of tissues. To repair tissue in a tissue-specific manner, tissue-targeted RSPO mimetic molecules are desired. Here, we mutated RSPO (RSPO2 F105R/F109A) to eliminate LGR binding while preserving ZNRF3/RNF43 binding and targeted the mutated RSPO to a liver specific receptor, ASGR1. The resulting bi-specific molecule (αASGR1-RSPO2-RA) enhanced Wnt signaling effectively in vitro, and its activity was limited to ASGR1 expressing cells. Systemic administration of αASGR1-RSPO2-RA in mice specifically upregulated Wnt target genes and stimulated cell proliferation in liver but not intestine (which is more responsive to non-targeted RSPO2) in healthy mice, and improved liver function in diseased mice. These results not only suggest that a tissue-specific RSPO mimetic protein can stimulate regeneration in a cell-specific manner, but also provide a blueprint of how a tissue-specific molecule might be constructed for applications in a broader context.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Regeneração Hepática/efeitos dos fármacos , Regeneração Hepática/fisiologia , Animais , Receptor de Asialoglicoproteína/efeitos dos fármacos , Receptor de Asialoglicoproteína/metabolismo , Linhagem Celular , Proliferação de Células , Descoberta de Drogas/métodos , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Trombospondinas/metabolismo , Trombospondinas/uso terapêutico , Ubiquitina-Proteína Ligases/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/metabolismo
5.
F1000Res ; 5: 136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27081476

RESUMO

Gpr21 KO mice generated with Gpr21 KO ES cells obtained from Deltagen showed improved glucose tolerance and insulin sensitivity when fed a high fat diet. Further mRNA expression analysis revealed changes in Rabgap1 levels and raised the possibility that Rabgap1 gene may have been modified. To assess this hypothesis a new Gpr21 KO mouse line using TALENS technology was generated. Gpr21 gene deletion was confirmed by PCR and Gpr21 and Rabgap1 mRNA expression levels were determined by RT-PCR. The newly generated Gpr21 KO mice when fed a normal or high fat diet chow did not maintain their improved metabolic phenotype. In conclusion, Rabgap1 disturbance mRNA expression levels may have contributed to the phenotype of the originally designed Gpr21 KO mice.

6.
Methods Mol Biol ; 1438: 153-75, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27150090

RESUMO

Type 2 diabetes is a fast-growing epidemic in industrialized countries, associated with obesity, lack of physical exercise, aging, family history, and ethnic background. Diagnostic criteria are elevated fasting or postprandial blood glucose levels, a consequence of insulin resistance. Early intervention can help patients to revert the progression of the disease together with lifestyle changes or monotherapy. Systemic glucose toxicity can have devastating effects leading to pancreatic beta cell failure, blindness, nephropathy, and neuropathy, progressing to limb ulceration or even amputation. Existing treatments have numerous side effects and demonstrate variability in individual patient responsiveness. However, several emerging areas of discovery research are showing promises with the development of novel classes of antidiabetic drugs.The mouse has proven to be a reliable model for discovering and validating new treatments for type 2 diabetes mellitus. We review here commonly used methods to measure endpoints relevant to glucose metabolism which show good translatability to the diagnostic of type 2 diabetes in humans: baseline fasting glucose and insulin, glucose tolerance test, insulin sensitivity index, and body type composition. Improvements on these clinical values are essential for the progression of a novel potential therapeutic molecule through a preclinical and clinical pipeline.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Descoberta de Drogas , Hipoglicemiantes/uso terapêutico , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Resistência à Insulina , Camundongos , Obesidade/complicações
7.
PLoS One ; 11(2): e0147254, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26840340

RESUMO

Pancreatic amyloid formation by islet amyloid polypeptide (IAPP) is a hallmark pathological feature of type 2 diabetes. IAPP is stored in the secretory granules of pancreatic beta-cells and co-secreted with insulin to maintain glucose homeostasis. IAPP is innocuous under homeostatic conditions but imbalances in production or processing of IAPP may result in homodimer formation leading to the rapid production of cytotoxic oligomers and amyloid fibrils. The consequence is beta-cell dysfunction and the accumulation of proteinaceous plaques in and around pancreatic islets. Beta-site APP-cleaving enzyme 2, BACE2, is an aspartyl protease commonly associated with BACE1, a related homolog responsible for amyloid processing in the brain and strongly implicated in Alzheimer's disease. Herein, we identify two distinct sites of the mature human IAPP sequence that are susceptible to BACE2-mediated proteolytic activity. The result of proteolysis is modulation of human IAPP fibrillation and human IAPP protein degradation. These results suggest a potential therapeutic role for BACE2 in type 2 diabetes-associated hyperamylinaemia.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Linhagem Celular , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Humanos , Insulina/metabolismo , Insulina/farmacologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Espectrometria de Massas , Camundongos , Dados de Sequência Molecular , Mutação , Placa Amiloide/metabolismo , Proteólise/efeitos dos fármacos , Proteínas Recombinantes , Especificidade por Substrato
8.
EBioMedicine ; 2(3): 214-24, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26151067

RESUMO

The polarization of tissue resident macrophages toward the alternatively activated, anti-inflammatory M2 phenotype is believed to positively impact obesity and insulin resistance. Here we show that the soluble form of the extracellular domain (ECD) of C-type lectin-like receptor 2, CLEC2, regulates Kupffer cell polarization in the liver and improves glucose and lipid parameters in diabetic animal models. Over-expression of Fc-CLEC2(ECD) in mice via in vivo gene delivery, or injection of recombinant Fc-CLEC2(ECD) protein, results in a reduction of blood glucose and liver triglyceride levels and improves glucose tolerance. Furthermore, Fc-CLEC2(ECD) treatment improves cytokine profiles and increases both the M2 macrophage population and the genes involved in the oxidation of lipid metabolism in the liver. These data reveal a previously unidentified role for CLEC2 as a regulator of macrophage polarity, and establish CLEC2 as a promising therapeutic target for treatment of diabetes and liver disease.


Assuntos
Glucose/metabolismo , Células de Kupffer/metabolismo , Lectinas Tipo C/metabolismo , Metabolismo dos Lipídeos/fisiologia , Animais , Polaridade Celular , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Homeostase/efeitos dos fármacos , Humanos , Células de Kupffer/citologia , Células de Kupffer/efeitos dos fármacos , Lectinas Tipo C/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Estrutura Terciária de Proteína , Receptores Fc/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Solubilidade
9.
PLoS One ; 10(6): e0126924, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26083576

RESUMO

Trefoil factor 3 (TFF3), also called intestinal trefoil factor or Itf, is a 59 amino acid peptide found as a homodimer predominantly along the gastrointestinal tract and in serum. TFF3 expression is elevated during gastrointestinal adenoma progression and has been shown to promote mucosal wound healing. Here we show that in contrast to other trefoil factor family members, TFF1 and TFF2, TFF3 is highly expressed in mouse duodenum, jejunum and ileum and that its expression is regulated by food intake. Overexpression of TFF3 using a recombinant adeno-associated virus (AAV) vector, or daily administration of recombinant TFF3 protein in vivo improved glucose tolerance in a diet-induced obesity mouse model. Body weight, fasting insulin, triglyceride, cholesterol and leptin levels were not affected by TFF3 treatment. Induction of mucinous metaplasia was observed in mice with AAV-mediated TFF3 overexpression, however, no such adverse histological effect was seen after the administration of recombinant TFF3 protein. Altogether these results suggest that the therapeutic potential of targeting TFF3 to treat T2D may be limited.


Assuntos
Glicemia/metabolismo , Ingestão de Alimentos/genética , Vetores Genéticos/efeitos adversos , Metaplasia/genética , Mucinas/genética , Obesidade/genética , Animais , Colesterol/sangue , Dependovirus/genética , Dieta Hiperlipídica , Duodeno/metabolismo , Duodeno/patologia , Expressão Gênica , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Teste de Tolerância a Glucose , Humanos , Íleo/metabolismo , Íleo/patologia , Insulina/sangue , Jejuno/metabolismo , Jejuno/patologia , Leptina/sangue , Masculino , Metaplasia/etiologia , Metaplasia/metabolismo , Metaplasia/patologia , Camundongos , Mucinas/administração & dosagem , Mucinas/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Fator Trefoil-2 , Fator Trefoil-3 , Triglicerídeos/sangue
10.
Am J Physiol Endocrinol Metab ; 307(12): E1144-52, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25370851

RESUMO

Elucidating the role of secreted frizzled-related protein 5 (SFRP5) in metabolism and obesity has been complicated by contradictory findings when knockout mice were used to determine metabolic phenotypes. By overexpressing SFRP5 in obese, prediabetic mice we consistently observed elevated hyperglycemia and glucose intolerance, supporting SFRP5 as a negative regulator of glucose metabolism. Accordingly, Sfrp5 mRNA expression analysis of both epididymal and subcutaneous adipose depots of mice indicated a correlation with obesity. Thus, we generated a monoclonal antibody (mAb) against SFRP5 to ascertain the effect of SFRP5 inhibition in vivo. Congruent with SFRP5 overexpression worsening blood glucose levels and glucose intolerance, anti-SFRP5 mAb therapy improved these phenotypes in vivo. The results from both the overexpression and mAb inhibition studies suggest a role for SFRP5 in glucose metabolism and pancreatic ß-cell function and thus establish the use of an anti-SFRP5 mAb as a potential approach to treat type 2 diabetes.


Assuntos
Glucose/metabolismo , Células Secretoras de Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos Monoclonais/imunologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Imunoglobulina G/imunologia , Células Secretoras de Insulina/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/complicações , Obesidade/genética , Obesidade/metabolismo
11.
Expert Opin Ther Targets ; 18(11): 1253-64, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25287216

RESUMO

OBJECTIVE: Although the human genome encodes ∼ 20,000 protein-coding genes, only a very small fraction of these have been explored as potential targets for therapeutic development. The challenge of identifying and validating new protein targets has contributed to the significant reduction in the productivity of the pharmaceutical industry in the recent decade, highlighting the continued need to find new therapeutic targets. RESEARCH DESIGN AND METHODS: The traditional methods to discover new targets are expensive, low throughput and time consuming, usually taking years to validate or invalidate a target. To address these limitations, as a proof of concept, we explored the hydrodynamic tail vein (HTV) injection as a gene delivery method for direct in vivo phenotypic screening of novel secreted factor targets for Type II diabetes therapeutics. RESULTS: High levels and sustained expression of target proteins were observed in diabetic mouse models tested, allowing us to identify multiple novel hormones that may regulate glucose metabolism. CONCLUSIONS: These results suggest that HTV is a low-cost, high-throughput method for direct in vivo phenotypic drug screening in metabolic disorders and could be applicable to many other disease areas as well. This method if combined with other approaches such as human genetic studies could provide a significant value to future drug discovery.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Proteoma , Animais , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Descoberta de Drogas/métodos , Técnicas de Transferência de Genes , Glucose/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Humanos , Hidrodinâmica , Injeções Intravenosas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Cauda/irrigação sanguínea
12.
J Biol Chem ; 289(44): 30470-30480, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25204652

RESUMO

The role of fibroblast growth factor receptor 4 (FGFR4) in regulating bile acid synthesis has been well defined; however, its reported role on glucose and energy metabolism remains unresolved. Here, we show that FGFR4 deficiency in mice leads to improvement in glucose metabolism, insulin sensitivity, and reduction in body weight under high fat conditions. Mechanism of action studies in FGFR4-deficient mice suggest that the effects are mediated in part by increased plasma levels of adiponectin and the endocrine FGF factors FGF21 and FGF15, the latter of which increase in response to an elevated bile acid pool. Direct actions of increased bile acids on bile acid receptors, and other potential indirect mechanisms, may also contribute to the observed metabolic changes. The results described herein suggest that FGFR4 antagonists alone, or in combination with other agents, could serve as a novel treatment for diabetes.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Resistência à Insulina , Obesidade/metabolismo , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/genética , Adiponectina/sangue , Tecido Adiposo/metabolismo , Animais , Feminino , Fatores de Crescimento de Fibroblastos/administração & dosagem , Fatores de Crescimento de Fibroblastos/sangue , Glucose/metabolismo , Células HEK293 , Humanos , Íleo/metabolismo , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/etiologia , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/deficiência , Transcriptoma
13.
Mol Cell Endocrinol ; 369(1-2): 119-29, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23403053

RESUMO

FFA1 (GPR40) and GPR120 are G-protein-coupled receptors activated by long-chain fatty acids. FFA1 is expressed in pancreatic ß-cells, where it regulates glucose-dependent insulin secretion, and GPR120 has been implicated in mediating GLP-1 secretion. We show here that FFA1 co-localizes with GLP-1 in enteroendocrine cells and plays a critical role in glucose management by mediating GLP-1 secretion in vivo. Corn oil induces GLP-1 secretion in wild type mice and in GPR120-/- mice, but not in FFA1-/- mice. α-Linolenic acid, an endogenous ligand of FFA1, induces GLP-1 secretion in GLUTag cells and in primary fetal mouse intestinal cells. Synthetic partial FFA1 agonists do not stimulate GLP-1 secretion in mice, but partial and full agonists combined function cooperatively to enhance receptor activation and GLP-1 secretion both in vitro and in vivo. We conclude that allosterism at FFA1 can contribute to postprandial glucose management by stimulating insulin secretion via an extrapancreatic mechanism of action, and that GPR120 in GLP-1 secretion requires further investigation.


Assuntos
Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptores Acoplados a Proteínas G/fisiologia , Animais , Células CHO , Células Cultivadas , Clonagem Molecular , Cricetinae , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo
14.
J Lipid Res ; 54(2): 325-32, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23204296

RESUMO

Elevated triglyceride (TG) and cholesterol levels are risk factors for cardiovascular disease and are often associated with diabetes and metabolic syndrome. Recent reports suggest that fibroblast growth factor (FGF)19 and FGF21 can dramatically improve metabolic dysfunction, including hyperglycemia, hypertriglyceridemia, and hypercholesterolemia. Due to their similar receptor specificities and co-receptor requirements, FGF19 and FGF21 share many common properties and have been thought to be interchangeable in metabolic regulation. Here we directly compared how pharmacological administration of recombinant FGF19 or FGF21 proteins affect metabolism in B6.V-Lep(ob)/J leptin-deficient mice. FGF19 and FGF21 equally improved glucose parameters; however, we observed increased serum TG and cholesterol levels after treatment with FGF19 but not with FGF21. Increases in serum TGs were also observed after a 4-day treatment with FGF19 in C57BL6/J mice on a high-fat diet. This is in contrast to many literature reports that showed significant improvements in hyperlipidemia after chronic treatment with FGF19 or FGF21 in high-fat diet models. We propose that FGF19 has lipid-raising and lipid-lowering actions mediated through different FGF receptors and target tissues, and the results described here provide a potential mechanism that may explain the inconsistency in the reported effects of FGF19 on lipid metabolism.


Assuntos
Fatores de Crescimento de Fibroblastos/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Linhagem Celular , Colesterol/sangue , Dieta/efeitos adversos , Fatores de Crescimento de Fibroblastos/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Obesidade/sangue , Obesidade/etiologia , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/metabolismo , Triglicerídeos/sangue
15.
Sci Transl Med ; 4(162): 162ra153, 2012 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-23197570

RESUMO

Fibroblast growth factor 21 (FGF21) is a distinctive member of the FGF family with potent beneficial effects on lipid, body weight, and glucose metabolism and has attracted considerable interest as a potential therapeutic for treating diabetes and obesity. As an alternative to native FGF21, we have developed a monoclonal antibody, mimAb1, that binds to ßKlotho with high affinity and specifically activates signaling from the ßKlotho/FGFR1c (FGF receptor 1c) receptor complex. In obese cynomolgus monkeys, injection of mimAb1 led to FGF21-like metabolic effects, including decreases in body weight, plasma insulin, triglycerides, and glucose during tolerance testing. Mice with adipose-selective FGFR1 knockout were refractory to FGF21-induced improvements in glucose metabolism and body weight. These results in obese monkeys (with mimAb1) and in FGFR1 knockout mice (with FGF21) demonstrated the essential role of FGFR1c in FGF21 function and suggest fat as a critical target tissue for the cytokine and antibody. Because mimAb1 depends on ßKlotho to activate FGFR1c, it is not expected to induce side effects caused by activating FGFR1c alone. The unexpected finding of an antibody that can activate FGF21-like signaling through cell surface receptors provided preclinical validation for an innovative therapeutic approach to diabetes and obesity.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Fatores de Crescimento de Fibroblastos/imunologia , Glucuronidase/metabolismo , Obesidade/tratamento farmacológico , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Anticorpos Monoclonais/farmacologia , Peso Corporal/genética , Diabetes Mellitus/sangue , Epitopos/química , Glucose/metabolismo , Glucuronidase/imunologia , Humanos , Proteínas Klotho , Macaca fascicularis , Camundongos , Obesidade/sangue , Obesidade/complicações , Fosfatos/sangue , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/agonistas , Transdução de Sinais/efeitos dos fármacos , Triglicerídeos/sangue
16.
PLoS One ; 7(3): e33603, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22457778

RESUMO

Diabetes and associated metabolic conditions have reached pandemic proportions worldwide, and there is a clear unmet medical need for new therapies that are both effective and safe. FGF19 and FGF21 are distinctive members of the FGF family that function as endocrine hormones. Both have potent effects on normalizing glucose, lipid, and energy homeostasis, and therefore, represent attractive potential next generation therapies for combating the growing epidemics of type 2 diabetes and obesity. The mechanism responsible for these impressive metabolic effects remains unknown. While both FGF19 and FGF21 can activate FGFRs 1c, 2c, and 3c in the presence of co-receptor ßKlotho in vitro, which receptor is responsible for the metabolic activities observed in vivo remains unknown. Here we have generated a variant of FGF19, FGF19-7, that has altered receptor specificity with a strong bias toward FGFR1c. We show that FGF19-7 is equally efficacious as wild type FGF19 in regulating glucose, lipid, and energy metabolism in both diet-induced obesity and leptin-deficient mouse models. These results are the first direct demonstration of the central role of the ßKlotho/FGFR1c receptor complex in glucose and lipid regulation, and also strongly suggest that activation of this receptor complex alone might be sufficient to achieve all the metabolic functions of endocrine FGF molecules.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Glucose/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/fisiologia , Animais , Western Blotting , Linhagem Celular , Dependovirus/genética , Fatores de Crescimento de Fibroblastos/genética , Vetores Genéticos , Teste de Tolerância a Glucose , Fígado/metabolismo , Masculino , Camundongos , Ligação Proteica , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais
17.
J Mol Biol ; 418(1-2): 82-9, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22370560

RESUMO

Three fibroblast growth factor (FGF) molecules, FGF19, FGF21, and FGF23, form a unique subfamily that functions as endocrine hormones. FGF19 and FGF21 can regulate glucose, lipid, and energy metabolism, while FGF23 regulates phosphate homeostasis. The FGF receptors and co-receptors for these three FGF molecules have been identified, and domains important for receptor interaction and specificity determination are beginning to be elucidated. However, a number of questions remain unanswered, such as the identification of fibroblast growth factor receptor responsible for glucose regulation. Here, we have generated a variant of FGF23: FGF23-21c, where the C-terminal domain of FGF23 was replaced with the corresponding regions from FGF21. FGF23-21c showed a number of interesting and unexpected properties in vitro. In contrast to wild-type FGF23, FGF23-21c gained the ability to activate FGFR1c and FGFR2c in the presence of ßKlotho and was able to stimulate glucose uptake into adipocytes in vitro and lower glucose levels in ob/ob diabetic mice model to similar extent as FGF21 in vivo. These results suggest that ßKlotho/FGFR1c or FGFR2c receptor complexes are sufficient for glucose regulation. Interestingly, without the FGF23 C-terminal domain, FGF23-21c was still able to activate fibroblast growth factor receptors in the presence of αKlotho. This suggests not only that sequences outside of the C-terminal region may also contribute to the interaction with co-receptors but also that FGF23-21c may be able to regulate both glucose and phosphate metabolisms. This raises an interesting concept of designing an FGF molecule that may be able to address multiple diseases simultaneously. Further understanding of FGF/receptor interactions may allow the development of exciting opportunities for novel therapeutic discovery.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Glucuronidase/metabolismo , Proteínas de Membrana/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Adipócitos/metabolismo , Animais , Glicemia/efeitos dos fármacos , Linhagem Celular , Feminino , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/farmacologia , Glucose/metabolismo , Proteínas Klotho , Masculino , Camundongos , Camundongos Obesos
18.
Biochem Biophys Res Commun ; 418(1): 1-5, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22155242

RESUMO

GPR21 is an orphan G-protein-coupled receptor. We found that mice deficient for the GPR21 gene were resistant to diet-induced obesity. Knockout mice were leaner than their wildtype counterpart, despite that no difference was observed in food intake. No differences were observed in the respiratory exchange rate and thermogenesis. However, knockout mice were more active than wildtype littermates, and this level of activity may be an underlying reason for the difference in energy balance. Mutant mice were more sensitive to insulin than their wildtype control and showed an improved glucose tolerance. Several inflammatory markers MCP-1, CRP and IP-10 were decreased in mutant animals, suggesting that GPR21 may also mediate its effect through anti-inflammatory mechanisms. We found that GPR21 is widely expressed in all tissues, with the highest levels found in the brain and in the spleen. Overall, these findings suggest that GPR21 may play an important role in regulating body weight and glucose metabolism.


Assuntos
Resistência à Insulina/genética , Insulina/farmacologia , Obesidade/genética , Receptores Acoplados a Proteínas G/genética , Animais , Biomarcadores/metabolismo , Peso Corporal/genética , Proteína C-Reativa/metabolismo , Quimiocina CCL2/metabolismo , Quimiocina CXCL10/metabolismo , Dieta/efeitos adversos , Expressão Gênica , Glucose/metabolismo , Teste de Tolerância a Glucose , Camundongos , Camundongos Knockout , Obesidade/etiologia , Distribuição Tecidual
19.
Proc Natl Acad Sci U S A ; 107(32): 14158-63, 2010 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-20660733

RESUMO

FGF19 and FGF21 are distinctive members of the FGF family that function as endocrine hormones. Their potent effects on normalizing glucose, lipid, and energy homeostasis in disease models have made them an interesting focus of research for combating the growing epidemics of diabetes and obesity. Despite overlapping functions, FGF19 and FGF21 have many discrete effects, the most important being that FGF19 has both metabolic and proliferative effects, whereas FGF21 has only metabolic effects. Here we identify the structural determinants dictating differential receptor interactions that explain and distinguish these two physiological functions. We also have generated FGF19 variants that have lost the ability to induce hepatocyte proliferation but that still are effective in lowering plasma glucose levels and improving insulin sensitivity in mice. Our results add valuable insight into the structure-function relationship of FGF19/FGF21 and identify the structural basis underpinning the distinct proliferative feature of FGF19 compared with FGF21. In addition, these studies provide a road map for engineering FGF19 as a potential therapeutic candidate for treating diabetes and obesity.


Assuntos
Glicemia , Proliferação de Células , Fatores de Crescimento de Fibroblastos/fisiologia , Hepatócitos/citologia , Sequência de Aminoácidos , Animais , Diabetes Mellitus/tratamento farmacológico , Variação Genética , Resistência à Insulina , Camundongos , Obesidade/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes/farmacologia
20.
Methods Mol Biol ; 602: 135-55, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20012397

RESUMO

Type II diabetes is a fast-growing epidemic in industrialized countries. Many recent advances have led to the discovery and marketing of efficient novel therapeutic medications. Yet, because of side effects of these medications and the variability in individual patient responsiveness, unmet needs subsist for the discovery of new drugs. The mouse has proven to be a reliable model for discovering and validating new treatments for type II diabetes mellitus. We review here the most common mouse models used for drug discovery for the treatment of type II diabetes. The methods presented focus on measuring the equivalent end points in mice to the clinical values of glucose metabolism used for the diagnostic of type II diabetes in humans: i.e., baseline fasting glucose and insulin, glucose tolerance test, and insulin sensitivity index. Improvements on these clinical values are essential for the progression of a novel potential therapeutic molecule through a preclinical and clinical pipeline.


Assuntos
Diabetes Mellitus Tipo 2 , Modelos Animais de Doenças , Descoberta de Drogas , Hipoglicemiantes/uso terapêutico , Animais , Composição Corporal , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Avaliação Pré-Clínica de Medicamentos/métodos , Ácidos Graxos não Esterificados/sangue , Glucose/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL
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