Deletion of Serglycin Proteoglycan Gene in Mice

描述（由申请人提供）：该项目的长期目标是了解serglycin蛋白聚糖的功能。除了红系造血细胞、内皮细胞、胚胎干细胞和小鼠子宫蜕膜外，所有细胞的分泌颗粒中都含有这种蛋白多糖。据推测，舍甘氨酸的作用包括与分泌蛋白络合并将其包装成颗粒，调节其组成或在细胞活化过程中的释放，以及调节其活性和向靶细胞的递送。serglycin蛋白聚糖本身在与细胞或细胞外基质相互作用方面可能具有特定的功能。与舍甘氨酸相互作用的分泌蛋白包括趋化因子、细胞因子、细胞外基质蛋白和一些蛋白酶。因此，舍甘氨酸可能调节由这些分泌蛋白介导的重要生理活动，如凝血、免疫功能、炎症、早期胚胎发育和胚胎着床。在体外进行的许多研究表明，serglycin蛋白聚糖及其糖胺聚糖链在这些过程中的重要性。然而，serglycin在包装过程中的真正功能，以及最终将这些蛋白质引导到它们的细胞靶点，只能在体内确定。因此，我们建议产生具有全局、条件或细胞特异性缺失serglycin基因的小鼠。首先，利用我们制备的靶向载体，电穿孔到胚胎细胞中，我们将获得胚胎干细胞克隆，用于产生杂合子和纯合子serglycin无小鼠。其次，我们将生成一个靶向载体，包含serglycin基因关键区域两侧的loxP位点。用这种载体靶向的胚胎干细胞可以用来产生小鼠，这些小鼠将来可以与含有诱导型或细胞特异性ere重组酶的小鼠杂交，以获得诱导型或细胞特异性敲除serglycin基因。这些动物可以反过来与血栓性或动脉粥样硬化性疾病的小鼠模型繁殖。实验将最终描述谢尔甘霉素在正常和疾病状态下调节各种关键生理功能中的作用。

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the function of the serglycin proteoglycan. This proteoglycan is contained in the secretory granules of all but erythroid hematopoietic cells, endothelial cells, embryonic stem cells, and murine uterine decidua during pregnancy. The putative roles of serglycin include complexing with and packaging secretory proteins into granules, regulating their release either constitutively or during cell activation, and modulating their activity and delivery to target cells. The serglycin proteoglycan itself may have specific functions in terms of interaction with cells or extracellular matrices. The secretory proteins which interact with serglycin include chemokines, cytokines, extracellular matrix proteins, and a number of proteases. Thus serglycin may modulate important physiologic activities mediated by these secreted proteins such as blood coagulation, immune function, inflammation, early embryonic development, and embryonic implantation. Many studies which have been performed in vitro suggest the importance of the serglycin proteoglycan and its glycosaminoglycan chains in these processes. However, the true function of serglycin in the course of packaging and ultimately directing these proteins to their cellular targets can only be determined in vivo. Therefore we are proposing to generate mice with global, conditional, or cell-specific deletion of the serglycin gene. First, using a targeting vector which we have prepared and electroporated into embryonic cells, we will obtain embryonic stem cell clones which will be used to generate heterozygous and then homozygous serglycin null mice. Second, we will generate a targeting vector containing loxP sites flanking critical regions of the serglycin gene. Embryonic stem cells targeted with this vector can be used to generate mice which can in the future be crossbred with mice containing either inducible or cell-specific ere recombinase in order to obtain inducible or cell-specific knockouts of the serglycin gene. These animals can in turn be bred with mouse models of thrombotic or atherosclerotic disease. The experiments will ultimately delineate the role of serglycin in modulating a variety of critical physiologic functions in normal and disease states.