成年哺乳动物视网膜色素上皮细胞中的酪氨酸酶生物合成

Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells.

作者信息

Schraermeyer Ulrich, Kopitz Jürgen, Peters Swaantje, Henke-Fahle Sigrid, Blitgen-Heinecke Petra, Kokkinou Despina, Schwarz Tobias, Bartz-Schmidt Karl-Ulrich

机构信息

Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tubingen, Schleichstr. 12/1, D-72076 Tubingen, Germany.

出版信息

Exp Eye Res. 2006 Aug;83(2):315-21. doi: 10.1016/j.exer.2005.12.015. Epub 2006 Mar 31.

DOI:10.1016/j.exer.2005.12.015

PMID:16579986

Abstract

Tyrosinase (EC 1.14.18.1) is the rate limiting enzyme of melanogenesis and it is unclear whether it is synthesized in postnatal retinal pigment epithelium (RPE). Cultured RPE cells from cattle were fed with isolated rod outer segments (ROS). After phagocytosis, RPE cells were tested for tyrosinase presence and activity with three independent methods: (1) ultrastructural DOPA (l-3,4-dihydroxyphenylalanine) histochemistry (2) immunocytochemistry with anti-tyrosinase antibodies (3) measuring tyrosine hydroxylase activity using [(3)H]tyrosine. With all three methods tyrosinase was found in RPE cells after ROS-feeding but was absent without feeding. In contrast to the classical hypothesis, we demonstrated with three independent methods that the expression of tyrosinase and its enzymatic activity are induced in cultured adult RPE by phagocytosis of rod outer segments (ROS) in vitro.

摘要

酪氨酸酶（EC 1.14.18.1）是黑色素生成的限速酶，目前尚不清楚它是否在出生后视网膜色素上皮（RPE）中合成。用分离的视杆外段（ROS）喂养来自牛的培养RPE细胞。吞噬作用后，用三种独立的方法检测RPE细胞中酪氨酸酶的存在和活性：（1）超微结构多巴（l-3,4-二羟基苯丙氨酸）组织化学（2）用抗酪氨酸酶抗体进行免疫细胞化学（3）使用[（3）H]酪氨酸测量酪氨酸羟化酶活性。用这三种方法在ROS喂养后的RPE细胞中均发现了酪氨酸酶，但未喂养时则不存在。与经典假说相反，我们用三种独立的方法证明，在体外通过视杆外段（ROS）的吞噬作用，可诱导培养的成年RPE中酪氨酸酶的表达及其酶活性。