Generation of Animal Models for Diabetes by Transgenic and Gene Targeting Technology

非胰岛素依赖型糖尿病（NIDDM）被认为是一种多基因疾病，其中胰岛素抵抗和胰岛素分泌缺陷是主要病因。胰岛素受体底物-1（IRS-1）基因敲除的纯合子小鼠表现出与胰岛素抵抗和代偿性高胰岛素血症相关的正常葡萄糖耐量。β细胞葡萄糖激酶（GK）基因敲除的杂合小鼠由于胰岛素分泌减少而表现出葡萄糖耐量受损。为了阐明胰岛素抵抗和胰岛素分泌缺陷在NIDDM发生过程中的相互作用，我们通过将IRS-1和β细胞GK基因分别敲除的小鼠进行杂交，产生了双敲除小鼠。双基因敲除小鼠出现了明显的糖尿病。腹腔内葡萄糖负荷（1.5mg/ g体重）120min后血糖水平为108（±±）。[)24（宽型），95(]SY.+-。[)26（IRS-1敲除），159(]SY.+-。[)68（GK敲除），210(]SY.+-。[)38（双敲除）mg/dl(平均[]SY.+-。[)SD)（双型vs野生型，IRS-1，或GK； P<0.01）。与IRS-1敲除小鼠相比，双基因敲除小鼠表现出空腹高胰岛素血症和β细胞的选择性增生(空腹胰岛素水平：0.38(]SY.+- -[)0.30（双基因敲除），0.35(]SY.+- [)0.27（IRS-1敲除）。0.25(]SY.+- .[)0.12（野生型）ng/ml)(胰岛素阳性细胞占胰腺面积的比例：1.18(]SY.+- . [)0.68%；P<0.01（双敲除），1.20(]SY.+- . [)0.95%；P < 0.05 (IRS-1击倒)vs。0.54（[SY.+-]] 0.26%（野生型）），但胰岛素对葡萄糖的分泌受损(负荷后前30min胰岛素与葡萄糖的增量比：31（双基因敲除）vs。163（野生型）或183（IRS-1敲除）ng胰岛素/mg葡萄糖× 103)。综上所述，基因异常，其中每一个本身都不是致糖尿病的，如果它们共存，就会导致过度糖尿病。本报告首次在小鼠中对NIDDM作为一种多基因疾病进行了基因重构。

Non-insulin-dependent diabetes mellitus(NIDDM)is considered a polygenic disorder in which insulin resistance and insulin secretory defect are the major etiologic factors. Homozygous mice with insulin receptor substrate-1(IRS-1)gene knockout showed normal glucose tolerance associated with insulin resistance and compensatory hyperinsulinemia. Heterozygous mice with beta-cell glucokinase(GK)gene knockout showed impaired glucose tolerance due to decreased insulin secretion to glucose. To elucidate the interplay between insulin resistance and insulin secretory defect for the development of NIDDM,we generated a double knockout mouse with ***ption of IRS-1 and beta-cell GK genes by crossing the mice with each of the single gene knockout. The double knockout mice developed overt diabetes. Blood glucose levels 120min after intraperitoneal glucose load(1.5mg/ g body weight)were 108(]SY.+-。[)24(wide-type), 95(]SY.+-。[)26(IRS-1 knockout), 159(]SY.+-。[)68(GK knockout), and 210(]SY.+-。[)38(double knockout) mg/dl(mean(]SY.+-。[)SD)(double vs. wild-type, IRS-1, or GK ; P<0.01). The double knockout mice showed fasting hyperinsulinemia and selective hyperplasia of the beta-cells as the IRS-1 knockout mice(fasting insulin levels : 0.38(]SY.+-。[)0.30(double knockout), 0.35(]SY.+-。[)0.27(IRS-1 knockout)vs. 0.25(]SY.+-。[)0.12(wild-type)ng/ml)(proportion of areas of insulin-positive cells to the pancreas : 1.18(]SY.+-。[)0.68% ; P<0.01(double knockout), 1.20(]SY.+-。[)0.95% ; P<0.05(IRS-1 knockout)vs. 0.54(]SY.+-。[)0.26%(wild-type)), but impaired insulin secreation to glucose(the ratio of increment of insulin to that of glucose during the first 30min after load : 31(double knockout)vs. 163(wild-type)or 183(IRS-1 knockout)ng insulin/mg glucose x 103). In conclusions, the genetic abnormalities, each of which is non-diabetogenic by itself, cause overtdiabetes if they coexist. This report provides the first genetic reconstitution of NIDDM as a polygenic disorder in mice.