GENERATION OF TISSUE-SPECIFIC KNOCKOUT MICE

组织特异性基因敲除小鼠的产生

• 批准号: 7651569
• 负责人: John Joseph Kopchick
• 金额: $ 31.91万
• 依托单位: SOUTHERN ILLINOIS UNIVERSITY SCH OF MED
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7651569
• 关键词: Ablation; Acromegaly; Adipose tissue; Aging; Aging-Related Process; Animals; Body Composition; Body Weight; Characteristics; DNA; Data; Diabetes Mellitus; Disease; ES Cell Line; Elements; Endocrine; Excision; Fatty acid glycerol esters; Fibrinogen; GHR gene; Gene Expression; Generations; Genes; Glucose; Growth; Growth Hormone Receptor; Health; Hormone Responsive; Hormones; Human; Individual; Infiltration; Instruction; Insulin; Insulin Resistance; Insulin-Like Growth Factor I; Intervention; Knockout Mice; Laboratories; LacZ Genes; Lead; Leptin; Life; Life Extension; Liver; Longevity; Measures; Metabolic; Michigan; Molecular; Mus; Muscle; Nonesterified Fatty Acids; Obesity; Organ; Patients; Performance; Physiological; Pituitary Gland; Play; Production; Prolactin; Reporter; Reporting; Repression; Role; Signal Transduction; Somatomedins; Somatotropin; Specificity; Study Section; System; Testing; Time; Tissues; Transgenic Mice; Triglycerides; Universities; Yeasts; adiponectin; age related; disability; fly; homologous recombination; improved; insulin sensitivity; insulin signaling; insulin tolerance; macrophage; mouse model; reproductive; somatotropin-binding protein

Growth Hormone (GH) is a diabetogenic molecule, i.e., it inhibits insulin action resulting in insulin resistance and diabetes. The diabetogenic effect of GH can be seen in GH transgenic mice that express relatively high levels of GH. These animals also possess high levels of insulin like growth factor one (IGF-1) and insulin, are insulin resistant and have short life spans. In humans, patients with acromegaly possess elevated levels of GH and IGF-1, are typically insulin resistance and many will develop diabetes. Thus, elevated levels of GH in both mice and humans results in insulin resistance. Conversely, mice were developed in our laboratory that lack the GH receptor (GHR/BP-/- mice) and therefore GH action. These mice are dwarf, possess low levels of IGF-1 and insulin, are extremely insulin sensitive and have an extended life span. Furthermore, disruption of the insulin or IGF-1 signaling system also leads to extended life spans in worms, yeast, flies, and other mouse lines with reduced GH/IGF-1 signaling. Thus, one would predict that increasing insulin sensitivity through repression of GH/IGF-1 signaling will result in animals with increased life span. Three insulin and GH sensitive .tissues are the liver, white adipose tissue (WAT) and muscle. By increasing insulin sensitivity in these tissues, one may increase the animal's life span. We hypothesize that the life span extension seen in the GHR/BP-/- mouse is due to decreased GHaction and consequent increased insulin sensitivity in insulin responsive tissues. To test this hypothesis, we will selectively disrupt the GHR gene in liver, WAT, and muscle to determine their individual contributions to overall insulin sensitivity and longevity. We expect to find improved insulin sensitivity in the three tissue- specific gene disrupted mouse lines, which, in turn, will increase longevity. Once the three mouse lines are generated, we will also assess a variety of growth, endocrine, physiological and metabolic parameters. Collectively, this data will help establish the importance of individual tissues on overall insulin sensitivity as a contributing factor to increased life span. Also, the data will help advance the understanding of molecular and cellular changes that underlie the aging process. Finally, the results may lead to interventions to extend life or delay the onset of age-related diseases and/or disabilities. RELEVANCE (See instructions): The absence of GH action has been shown to improve insulin sensitivity and increase life span. Removal of GH action in liver, fat, and muscle, as outlined in this proposal will help identify organs that are important for improved insulin sensitivity and life extension.

生长激素（GH）是一种致糖尿病分子，也就是说，它抑制胰岛素的作用，导致胰岛素抵抗