钙调蛋白在人睫状肌及其他眼前节组织中的分布。

Calponin distribution in human ciliary muscle and other anterior segment tissues.

作者信息

Kashiwagi K, Lindsey J D, Kashiwagi F, Tsukahara S, Weinreb R N

机构信息

Glaucoma Center, University of California, San Diego, La Jolla 92093, USA.

出版信息

Invest Ophthalmol Vis Sci. 1997 Feb;38(2):349-56.

PMID:9040467

Abstract

PURPOSE

Calponins are a family of actin-binding proteins known to regulate aortic and tracheal smooth muscle contraction. This investigation was undertaken to assess the presence, subtype, and distribution of calponin proteins in human ciliary muscle, iris, and other anterior segment tissues as well as expression in ciliary muscle cells in vitro.

METHODS

The distribution of calponin immunoreactivity was assessed in paraffin sections of human anterior segment tissue. Human ciliary muscle proteins were analyzed by polyacrylamide gel electrophoresis and Western blotting. The regulation of calponin expression was compared with alpha-sm-actin expression in preconfluent and postconfluent ciliary muscle cell cultures by immunocytochemistry. To determine total cell counts, the cultures were counter-stained with ethidium homodimer. As control specimens, expression of calponin and alpha-sm-actin also was assessed in human Tenon fibroblast cultures.

RESULTS

Strong calponin immunoreactivity was present in ciliary muscle, iris dilator and sphincter muscles, and blood vessel smooth muscle. Fine immunostained strands also were observed in the scleral spur. This distribution was similar to alpha-sm-actin. Western blotting showed a single band of calponin with a molecular weight of 32 kDa. In the cultured ciliary muscle cells, calponin stained straight cable-like fibers running parallel along the long axis of the cells. Although the proportion of calponin immunoreactive cells was reduced substantially in preconfluent cultures, virtually all cells were stained in confluent primary through fourth-passage cultures. Cultured human Tenon fibroblasts did not show either calponin or alpha-sm-actin immunoreactivity.

CONCLUSIONS

Calponin is expressed in human ciliary muscle, iris smooth muscles, blood vessel smooth muscle, as well as within the scleral spur. In addition, calponin is expressed by ciliary smooth muscle cells in vitro. The role of calponin in contraction of these tissues should be investigated.

摘要

目的

钙调蛋白是一类肌动蛋白结合蛋白，已知其可调节主动脉和气管平滑肌收缩。本研究旨在评估钙调蛋白在人睫状肌、虹膜及其他眼前节组织中的存在情况、亚型和分布，以及其在体外睫状肌细胞中的表达。

方法

在人眼前节组织石蜡切片中评估钙调蛋白免疫反应性的分布。通过聚丙烯酰胺凝胶电泳和蛋白质印迹法分析人睫状肌蛋白。通过免疫细胞化学比较融合前和融合后睫状肌细胞培养物中钙调蛋白表达与α - 平滑肌肌动蛋白表达的调节情况。为确定细胞总数，培养物用乙锭同二聚体复染。作为对照标本，还在人Tenon成纤维细胞培养物中评估钙调蛋白和α - 平滑肌肌动蛋白的表达。

结果

在睫状肌、虹膜开大肌和括约肌以及血管平滑肌中存在强烈的钙调蛋白免疫反应性。在巩膜突中也观察到细的免疫染色条带。这种分布与α - 平滑肌肌动蛋白相似。蛋白质印迹显示钙调蛋白有一条分子量为32 kDa的单带。在培养的睫状肌细胞中，钙调蛋白染出沿细胞长轴平行排列的直的索状纤维。尽管在融合前培养物中钙调蛋白免疫反应性细胞的比例大幅降低，但在融合的原代至第四代培养物中几乎所有细胞均被染色。培养的人Tenon成纤维细胞未显示钙调蛋白或α - 平滑肌肌动蛋白免疫反应性。