REGULATION OF INDUCIBLE RAT SALIVARY CYSTATIN

胱抑素超家族的半胱氨酸蛋白酶抑制剂分为 根据分子结构分为三个家族。 家族1 胱抑素主要在细胞内发现， 许多老鼠组织的成分。 家族2半胱氨酸蛋白酶抑制剂主要存在于 细胞外液 激肽原是家族3胱抑素，主要存在于 血浆 家族1和家族3半胱氨酸蛋白酶抑制剂已被相当好地表征 但关于家族2可用信息非常有限 大鼠胱抑素 家族2半胱氨酸蛋白酶抑制剂最近已被纯化， 由我们从异丙肾上腺素的唾液和下颌下腺中测序 治疗的老鼠 相对于家族1半胱氨酸蛋白酶抑制剂， 大鼠组织成分中，家族2半胱氨酸蛋白酶抑制剂在正常大鼠中未检测到 组织中 虽然家族3半胱氨酸蛋白酶抑制剂（激肽原）也可作为急性期 反应物，它们也存在于正常大鼠血浆中。 这些观察结果表明，这三种细胞的生物合成和分泌 半胱氨酸蛋白酶抑制剂可能是不同的，每一种都可能具有重要的生理作用 玩 据推测，这些分子可能作为一种 针对内源性半胱氨酸浓度增加的保护措施 炎症过程中的蛋白酶。 由于家族2大鼠胱抑素在大鼠 下颌下腺不作为组成成分存在，但 异丙肾上腺素治疗后诱导，这提供了一种新的模型系统 为了研究这种分子在炎症条件下的生物合成和分泌， 条件 这项试验性研究旨在研究 通过不同促分泌素和试剂诱导家族2半胱氨酸蛋白酶抑制剂， 会对唾液腺造成伤害 建议的目的 研究是研究损伤产生试剂对 可诱导家族2半胱氨酸蛋白酶抑制剂的转录和翻译调控 从大鼠下颌下腺中提取的。 免疫化学技术将用于 研究大鼠唾液和下颌下半胱氨酸蛋白酶抑制剂的变化 在体内和体外刺激下颌下腺后。 cDNA 将分离对应于家族2半胱氨酸蛋白酶抑制剂的克隆， 研究转录调控。 为了准确地理解 半胱氨酸蛋白酶抑制剂的重要性，重要的是要了解它们的结构- 功能关系，并了解控制它们的机制 合成和分泌。 根据本试验中获得的信息， 研究中，我们希望将研究扩展到其他模型的唾液腺 腺泡和导管细胞损伤并了解这些控制机制 更详细地说。 这项工作的长期目标是使用 在大鼠模型中获得的信息作为研究 在正常和病理生理条件下的胱抑素。

Cysteine proteinase inhibitors of the cystatin superfamily are grouped into three families on the basis of their molecular structure. Family 1 cystatins are found mainly intracellularly and are present as constituative components of many rat tissues. Family 2 cystatins are mainly present in extracellular fluids. Kininogens are family 3 cystatins, present mainly in the plasma. Family 1 and 3 cystatins have been fairly well characterized in rat model system but very limited information is available on family 2 cystatins of rat. A family 2 cystatin has been very recently purified and sequenced by us from the saliva and submandibular glands of isoproterenol treated rats. As opposed to family 1 cystatins, which are constituative component of rat tissues, family 2 cystatin is not detected in normal rat tissues. Although family 3 cystatins (kininogens) also act as acute-phase reactants in rat plasma, they are also present in the normal rat plasma. These observations suggest that biosynthesis and secretion of the three cystatins may be different and each may have important physiological role to play. It is speculated that these molecules may be involved as a protective measure against increased concentration of endogenous cysteine proteinases during inflammation. Since family 2 rat cystatin in rat submandibular gland is not present as a constituative component, but is induced following isoproterenol treatment, this offers a novel model system to study the biosynthesis and secretion of this molecule under inflammatory conditions. This pilot study is designed to study the feasibility of induction of family 2 cystatins by different secretogogues and agents, known to produce injury to the salivary glands. The aim of the proposed research is to study the effects of the injury producing reagents on the transcriptional and translational regulation of inducible family 2 cystatin from rat submandibular glands. Immunochemical techniques will be used to study the changes in the salivary and submandibular cystatin in rats following in vivo and in vitro stimulation of submandibular glands. cDNA clones corresponding to family 2 cystatin will be isolated and used to study the transcriptional control. In order to understand precisely the importance of cystatins, it is important to understand their structure- function relationship and to understand the mechanism which control their synthesis and secretion. Based on the information achieved in this pilot study, we would like to extend the study to other models of salivary gland injury of acinar and ductal cells and to understand these control mechanism in greater details. The long term goal of this work is to use the information gained in the rat model as a basis for the study of role of cystatins in normal and pathophysiological conditions.