Connective tissue activation. XVIII. Stimulation of hyaluronic acid synthetase activity.
Connective tissue activation. XVIII. Stimulation of hyaluronic acid synthetase activity.
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结缔组织激活。
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
J. A. Klavons
中科院分区：
文献类型：
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作者：
J. Sisson;C. Castor;J. A. Klavons
人滑膜成纤维细胞合成透明质酸，这是一个可以被许多试剂刺激的过程。合成途径中的几个步骤可能是这些刺激物起作用的位点;选择由透明质酸合成酶促进的最后一步进行研究。透明质酸合成酶是将单糖单元转移到新生透明质酸链的酶系统。通过测量14 C-UDP-葡萄糖醛酸掺入透明质酸中，在培养的滑膜成纤维细胞的裂解物中测定酶的活性。透明质酸的合成率增加，通过添加CTAP-I或CTAP-III，DbcAMP，或前列腺素E2的培养物。在每种情况下，透明质酸合成酶活性以与透明质酸合成中所见相当的方式增强。在酶和产品的变化，观察到早在6小时后，培养物暴露于CTAP-III，这两个指数下降时，这种刺激剂被撤回24 hr. Although DbcAMP增加透明质酸合成酶活性的完整的成纤维细胞，它没有影响酶的细胞裂解物。在培养的细胞中，放线菌酮降低了基础水平的透明质酸合成酶活性，而透明质酸的合成可能是通过诱导透明质酸合成酶来实现的。
Human synovial fibroblasts synthesize hyaluronic acid, a process that can be stimulated by a number of agents. Several steps in the synthetic pathway could be the locus at which these stimulators act; the final step, promoted by hyaluronic acid synthetase, was selectd for study. Hyaluronic acid synthetase is an enzyme system that transfers monosaccharide units to nascent hyaluronic acid chains. Activities of the enzyme were determined in lysates of cultured synovial fibroblasts by measuring incorporation of 14C-UDP-glucuronic acid into hyaluronic acid. Rates of hyaluronic acid synthesis were increased by adding CTAP-I or CTAP-III, DbcAMP, or prostaglandin E2 to the cultures. In each instance, hyaluronic acid synthetase activity was enhanced in a manner comparable to that seen in hyaluronic acid synthesis. The changes in enzyme and product were observed as early as 6 hr after cultures were exposed to CTAP-III, and both indices declined when this stimulator was withdrawn for 24 hr. Although DbcAMP incrased the hyaluronic acid synthetase activity of intact fibroblasts, it had no effect on the enzyme in lysates of cells. In the cultured cells, cycloheximide reduced basal levels of synthetase activity and hyaluronic acid synthesis of hyaluronic acid may do so by inducing hyaluronic acid synthetase.