THE TEAR FILM AND THE OCULAR SURFACE: VITAMIN A IN TEARS

泪膜和眼表面：眼泪中的维生素 A

• 批准号: 3260922
• 负责人: JOHN L UBELS
• 金额: $ 13.95万
• 依托单位: EYE AND EAR INSTITUTE OF PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3260922
• 关键词: all trans retinol; autoradiography; binding proteins; cornea disorder; corneal epithelium; eye agent; gel electrophoresis; high performance liquid chromatography; human tissue; hydrolysis; lacrimal apparatus; lacrimal disorder; laminin; membrane activity; messenger RNA; molecular cloning; protein biosynthesis; protein kinase A; receptor; retinoate; retinoid binding proteins; tear; tissue /cell culture; transport proteins; tritium; vitamin A deficiency; wound healing

Retinoids are secreted by the lacrimal gland. The proposed studies will test the hypothesis that the lacrimal gland is a specialized target tissue for Vitamin A which contains retinoid receptor proteins, enzymes for synthesis and hydrolysis of retinyl esters. and mechanisms for secretion of retinol into lacrimal gland fluid (LGF). It is proposed that a carrier protein in LGF, synthesized by the gland, transports retinol to the cells of the ocular surface, serving as a source of vitamin A for these cells. Specific Aims: 1. Storage, synthesis, and hydrolysis of retinyl esters in the lacrimal gland will be studied by radioautography and measurement of acyl-CoA:retinol transferase activity and retinyl ester hydrolase activity. 2. Mechanisms and control of retinoid secretion will be studied in vitro using dispersed lacrimal gland acini and cultured cells. 3. It will be determined whether a 20-kd protein in LGF which binds retinol is retinol binding protein (RBP) by cloning the cDNA for this protein and probing the gland for RBP mRNA. 4. It will be determined whether cellular retinol and retinoic acid binding proteins are present in lacrimal gland by probing the gland for their messenger RNAs. 5. It will be determined whether the tears are a source of vitamin A for the cornea by measuring retinoid levels in corneas of rabbits with normal or impaired tear secretion. 6. Mechanisms of action of retinoids in the cultured corneal epithelial cells will be tested by measuring cAMP-dependent Protein kinase activity, laminin synthesis, and cell adhesion. These studies will contribute to the understanding of the relationship of tear film abnormalities to ocular surface disease.

类视网膜类动物被泪腺分泌。 提出的研究 将测试泪腺是专业的假设 维生素A的靶组织，其中含有类维生素的受体 蛋白质，用于合成和水解视黄酯的酶。 和将视黄醇分泌为泪腺液的机制 （LGF）。 提出合成的LGF中的载体蛋白 通过腺体将视黄醇转运到眼部的细胞 表面，作为这些细胞的维生素A的来源。 具体目的： 1。视黄酯中的储存，合成和水解 将通过放射记录和测量来研究泪腺 酰基-COA：视黄醇转移酶活性和视黄酯 水解酶活性。 2。将研究类维生素分泌的机制和控制 在体外使用分散的泪腺和培养的细胞。 3。将确定是否在LGF中使用20 kd蛋白 通过克隆cDNA，结合视黄醇是视黄醇结合蛋白（RBP） 对于该蛋白质并探测RBP mRNA的腺体。 4。将确定蜂窝视黄醇和视黄醇是否 酸结合蛋白通过探测泪腺中存在 腺体为他们的Messenger RNA。 5。将确定眼泪是否是维生素的来源 A通过测量兔角膜的类视黄度水平来用于角膜 撕裂分泌正常或受损。 6。类视黄素在培养的角膜中的作用机理 上皮细胞将通过测量cAMP依赖性蛋白进行测试 激酶活性，层粘连蛋白合成和细胞粘附。 这些研究将有助于理解 泪膜异常与眼表疾病的关系。