Assuntos
Linfócitos B/metabolismo , Diferenciação Celular/imunologia , Imunoglobulinas/história , Fatores de Transcrição/história , Dedos de Zinco , Sequência de Aminoácidos , Animais , Linfócitos B/imunologia , Sequência de Bases , Diferenciação Celular/genética , Linhagem Celular Tumoral , Clonagem Molecular , História do Século XX , Imunoglobulinas/biossíntese , Imunoglobulinas/genética , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Camundongos , Dados de Sequência Molecular , Fator 1 de Ligação ao Domínio I Regulador Positivo , Fatores de Transcrição/fisiologia , Transfecção/história , Dedos de Zinco/genética , Dedos de Zinco/imunologiaRESUMO
PURPOSE: Mucolipidosis II and III (ML II; ML III) are lysosomal storage diseases characterized by a deficiency in GlcNAc-1-phosphotransferase. Patients with ML III have retinal disease, but in cases of the more clinically severe ML II, human ophthalmic studies are limited. In this study, retinal function and overall disease were assessed in mice lacking GNPTAB, the gene mutated in patients with ML II. METHODS: Mice deficient in GNPTAB were generated from Omnibank, a sequence-tagged gene-trap library of >270,000 mouse embryonic stem cell clones as part of a large-scale effort to knock out, phenotypically screen, and thereby validate pharmaceutically tractable genes for drug development. Routine diagnostics, expression analysis, histopathology, and ERG analyses were performed on mice lacking GNPTAB. In addition, measurements of serum lysosomal enzymes were performed. RESULTS: Severe retinal degeneration was observed in mice deficient in GNPTAB. Heterozygous mice were phenotypically normal and in situ hybridization showed expression across the neural retina. Compared to wild-type mice, the GNPTAB homozygous mice were smaller, had elevated levels of serum lysosomal enzymes, exhibited cartilage defects, and had cytoplasmic alterations in secretory cells of several exocrine glands. CONCLUSIONS: Mice deficient in GNPTAB exhibited severe retinal degeneration. Additional features observed in patients with ML II, a lysosomal storage disease, are also present in these mice. Understanding underlying mechanisms of this gene in the eye will increase its therapeutic potential for the treatment of retinal diseases.
Assuntos
Glândulas Exócrinas/patologia , Transtornos do Crescimento/enzimologia , Mucolipidoses/enzimologia , Degeneração Retiniana/enzimologia , Transferases (Outros Grupos de Fosfato Substituídos)/fisiologia , Animais , Catepsina D/metabolismo , Modelos Animais de Doenças , Eletrorretinografia , Genótipo , Glicosídeo Hidrolases/sangue , Transtornos do Crescimento/sangue , Transtornos do Crescimento/fisiopatologia , Hibridização In Situ , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucolipidoses/sangue , Mucolipidoses/fisiopatologia , Fotografação , Retina/fisiopatologia , Degeneração Retiniana/sangue , Degeneração Retiniana/fisiopatologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
One of the major challenges for the pharmaceutical industry is to develop innovative drugs to new targets from the human genome. A systematic approach for target selection could significantly increase the rate of successful new drug development, thereby enhancing industry productivity. It has previously been shown that mouse knockout phenotypes for the targets of the 100 best-selling pharmaceutical drugs correlate well with known drug efficacy. Furthermore, physiological validation of novel pipeline targets of the pharmaceutical industry has been provided using mouse knockout data. These data demonstrate an excellent correlation between knockout phenotype and anticipated drug efficacy, establishing an important marker for superior new drug targets from the genome.