UV-INDUCED COLLAGENASE--A MOLECULAR BASIS FOR PHOTOAGING

紫外线诱导的胶原酶——光老化的分子基础

• 批准号: 2080553
• 负责人: MARTA J PETERSEN
• 金额: $ 10.65万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-17 至 1997-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2080553
• 关键词: athymic mouse; cell age; collagenase; cytokine; disease /disorder proneness /risk; enzyme biosynthesis; extracellular matrix proteins; fibroblasts; gene expression; human subject; immunocytochemistry; in situ hybridization; keratinocyte; molecular pathology; northern blottings; protease inhibitor; radiation dosage; radiation hazard; skin transplantation; solar radiation; tissue /cell culture; ultraviolet radiation; western blottings

The studies outlined in this proposal will pursue the compelling finding that UVA irradiation stimulates collagenase production in cultured human skin fibroblasts and further elucidate the biochemical and molecular mechanisms of connective tissue damage in human skin caused by ultraviolet radiation (UVR). Photodamage is seen in most fair-skinned individuals by the fifth decade of life and is manifest clinically by wrinkled, lax and fragile skin and histologically by accumulation of elastotic material and collagen degradation. The biochemical mechanisms responsible for these connective tissue changes are poorly understood. Degradation of connective tissue is mediated, in part, by enzymes termed matrix metalloproteinases (MMPs), which include interstitial collagenase and type IV collagenases. Preliminary studies have demonstrated a dose dependent increase in interstitial collagenase and collagenase mRNA in cultured human skin fibroblasts irradiated with ultraviolet A. These preliminary data support the hypothesis that UVR induces expression of MMPs, resulting in connective tissue damage. This study will examine the effect of UVR on the synthesis of MMPs in vitro and in vivo. The effect of long- and short-wave UVR, as well as solar- simulating radiation, on the production and expression of MMPs, and their common inhibitor, tissue inhibitor of metalloproteinase (TIMP), by human fibroblasts and keratinocytes in culture will be investigated. A comprehensive examination of interstitial collagenase, 72-kD and 92-kD type IV collagenase and TIMP regulation in vitro will be undertaken using functional, immunological and molecular biological methods. Specific experiments will address these questions: a) Is cellular response dependent on cellular age or on past UVR exposure? b) Do extracellular matrix molecules alter the cellular response to UVR of MMPs and TIMP? c) Will inhibitors of collagenase production modify cellular responses to UVR? d) Does UVR indirectly regulate MMP and TIMP expression via cytokines? The effect of UVR on MMP and TIMP synthesis and gene expression in vivo will be studied in human skin irradiated with UVR using immunohistochemical and in situ hybridization techniques, as well as in human skin grafted onto athymic mice. The effect of topically applied inhibitors of collagenase and sunscreens on UV-induced MMP and TIMP expression will be studied in human subjects and the effect of orally administered inhibitors will be studied using the athymic mouse model.

本提案中概述的研究将追求令人信服的发现 UVA 照射刺激培养人类胶原酶的产生 皮肤成纤维细胞并进一步阐明其生化和分子 紫外线引起人体皮肤结缔组织损伤的机制 辐射（紫外线）。 大多数白皮肤的人都会出现光损伤 生命的第五个十年，临床上表现为皱纹、松弛和 脆弱的皮肤和组织学上的弹性材料的积累和 胶原蛋白降解。 负责这些的生化机制 人们对结缔组织的变化知之甚少。 结缔组织退化 组织部分由称为基质金属蛋白酶的酶介导 (MMP)，包括间质胶原酶和 IV 型胶原酶。 初步研究表明，剂量依赖性增加 培养人皮肤中的间质胶原酶和胶原酶 mRNA 用紫外线A照射成纤维细胞。这些初步数据支持 假设 UVR 诱导 MMP 表达，从而导致结缔组织 组织损伤。 本研究将探讨 UVR 对体外 MMP 合成的影响 和体内。 长波和短波 UVR 以及太阳光的影响 模拟辐射、MMP 的产生和表达及其作用 人类常见的抑制剂，金属蛋白酶组织抑制剂（TIMP） 将研究培养物中的成纤维细胞和角质形成细胞。 一个 间质胶原酶综合检查，72-kD 和 92-kD 型 IV 胶原酶和 TIMP 体外调节将使用 功能、免疫学和分子生物学方法。 具体的 实验将解决这些问题：a）细胞反应是 取决于细胞年龄或过去的紫外线照射？ b) 进行细胞外 基质分子改变 MMP 和 TIMP 对 UVR 的细胞反应？ c) 胶原酶产生的抑制剂会改变细胞对紫外线的反应吗？ d) UVR 是否通过细胞因子间接调节 MMP 和 TIMP 表达？ 这 UVR对体内MMP和TIMP合成及基因表达的影响 使用免疫组织化学方法对经 UVR 照射的人体皮肤进行研究 原位杂交技术，以及在人体皮肤上移植 无胸腺小鼠。 局部应用胶原酶抑制剂的作用 和防晒霜对紫外线诱导的 MMP 和 TIMP 表达的影响将在 人类受试者和口服抑制剂的效果将 使用无胸腺小鼠模型进行研究。