RESUMO
Identification and characterization of genes expressed preferentially in pancreatic beta-cells will clarify the mechanisms involved in the specialized properties of these cells, as well as providing new markers of the development of type 1 diabetes. Despite major efforts, relatively few beta-cell-specific genes have been characterized. We applied representational difference analysis to identify genes expressed selectively in the pancreatic beta-cell line betaTC1 compared with the pancreatic alpha-cell line alphaTC1 and isolated 26 clones expressed at higher levels in the beta-cells than in the alpha-cells. DNA sequencing revealed that 14 corresponded to known genes (that is, present in GenBank). Only four of those genes had been shown previously to be expressed at higher levels in beta-cells (insulin, islet amyloid polypeptide, neuronatin, and protein kinase A regulatory subunit [RIalpha]). The known genes include transcription factors (STAT6) and mediators of signal transduction (guanylate cyclase). The remaining 12 genes are absent from the GenBank database or are present as expressed sequence tag (EST) sequences (4 clones). Some of the genes are expressed in a highly specific pattern-expression in betaTC1 and islet cells and in relatively few of the non-beta-cell types examined; others are expressed in most cell types tested. The identification of these differentially expressed genes may aid in attaining a clearer understanding of the mechanisms involved in beta-cell function and of the possible immunogens involved in development of type 1 diabetes.
Assuntos
Regulação da Expressão Gênica , Ilhotas Pancreáticas/metabolismo , Proteínas/genética , Transcrição Gênica , Amiloide/genética , Animais , Encéfalo/metabolismo , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/genética , Diabetes Mellitus Tipo 1/genética , Enzimas/genética , Insulina/genética , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Pulmão/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Especificidade de Órgãos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testículo/metabolismoRESUMO
The rationale for multi-target drugs has been strengthened both on theoretical and empirical grounds. Serious diseases that are intractable to treatment were found to have multiple pathogenic factors and examples of successful drugs were shown to affect multiple disease targets. The salient features of multiple-target drugs, low target affinity and rapid binding kinetics, have been responsible for their late discovery and slow development. We predicted that peptides from the ligand-binding domains of chemokine (CK) receptors could be used to modulate the activities of disease-related chemokines (CKs) for therapeutic effect. We developed innovative technologies to produce, screen and optimize low affinity, chemokine-binding peptides (CBPs) derived from chemokine receptors (CRs). The peptides were found to have therapeutic activity in animal models of disease, confirming our prediction and validating the related technologies.