RESUMO
A coordinated functional genomics program was implemented to identify secreted polypeptides with therapeutic applications in the treatment of diabetes. Secreted factors were predicted from a diverse expressed-sequence tags (EST) database, representing >1,000 cDNA libraries, using a combination of bioinformatic algorithms. Subsequently, approximately 8,000 human proteins were screened in high-throughput cell-based assays designed to monitor key physiological transitions known to be centrally involved in the physiology of type 2 diabetes. Bone morphogenetic protein-9 (BMP-9) gave a positive response in two independent assays: reducing phosphoenolpyruvate carboxykinase (PEPCK) expression in hepatocytes and activating Akt kinase in differentiated myotubes. Purified recombinant BMP-9 potently inhibited hepatic glucose production and activated expression of key enzymes of lipid metabolism. In freely fed diabetic mice, a single subcutaneous injection of BMP-9 reduced glycemia to near-normal levels, with maximal reduction observed 30 hours after treatment. BMP-9 represents the first hepatic factor shown to regulate blood glucose concentration. Using a combination of bioinformatic and high-throughput functional analyses, we have identified a factor that may be exploited for the treatment of diabetes.
Assuntos
Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Perfilação da Expressão Gênica/métodos , Animais , Proteínas Morfogenéticas Ósseas/química , Proteínas Morfogenéticas Ósseas/uso terapêutico , Células Cultivadas , Diabetes Mellitus/tratamento farmacológico , Desenho de Fármacos , Glucose/metabolismo , Fator 2 de Diferenciação de Crescimento , Fatores de Diferenciação de Crescimento , Humanos , Rim/química , Rim/embriologia , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Valores de Referência , Alinhamento de Sequência/métodos , Análise de Sequência de Proteína/métodos , Integração de SistemasRESUMO
The primary therapeutic goal for the treatment of diabetes is maintenance of a long-term, near-normoglycemic condition and prevention of the onset or progression of the complications associated with the disease. Although several analogs of human insulin have been developed, the currently prescribed long-acting insulin analogs do not provide a stable basal glycemia for more than a few hours. Here, we report the development of Albulin, a long-acting insulin analog obtained by direct gene fusion of a single-chain human insulin to human serum albumin. Albulin showed an elimination t(1/2) of approximately 7 h in normoglycemic mice. In vitro pharmacodynamic profiles for Albulin characterized by receptor binding, inhibition of gluconeogenesis, induction of glucose uptake, and global regulation of gene expression in relevant cell types showed that Albulin produced similar activity profiles compared with that of recombinant human insulin. A single Albulin administration in vivo normalized blood glucose level in diabetic mice in a relatively peakless and sustained (24-h) fashion. A further reduction in glucose levels was achieved by administering a recombinant human insulin a few hours after Albulin injection in mice, indicating the potential for Albulin therapy in combination with available fast-acting insulin derivatives. In summary, Albulin displays characteristics of a potent long-acting insulin analog that can be evaluated for use as a novel insulin therapy for patients with insulin-dependent diabetes.