Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America.
PLoS One. 2012;7(4):e34309. doi: 10.1371/journal.pone.0034309. Epub 2012 Apr 4.
Fluid shear modulates many biological properties. How shear mechanosensing occurs in the extracellular matrix (ECM) and is transduced into cytoskeletal change remains unknown. Cochlin is an ECM protein of unknown function. Our investigation using a comprehensive spectrum of cutting-edge techniques has resulted in following major findings: (1) over-expression and down-regulation of cochlin increase and decrease intraocular pressure (IOP), respectively. The overexpression was achieved in DBA/2J-Gpnmb(+)/SjJ using lentiviral vectors, down-regulation was achieved in glaucomatous DBA/2J mice using targeted disruption (cochlin-null mice) and also using lentiviral vector mediated shRNA against cochlin coding region; (2) reintroduction of cochlin in cochlin-null mice increases IOP; (3) injection of exogenous cochlin also increased IOP; (4) increasing perfusion rates increased cochlin multimerization, which reduced the rate of cochlin proteolysis by trypsin and proteinase K; The cochlin multimerization in response to shear stress suggests its potential mechanosensing. Taken together with previous studies, we show cochlin is involved in regulation of intraocular pressure in DBA/2J potentially through mechanosensing of the shear stress.
流体剪切力调节许多生物学特性。细胞外基质 (ECM) 中的剪切力机械感受器如何发生以及如何转化为细胞骨架变化尚不清楚。Cochlin 是一种功能未知的细胞外基质蛋白。我们使用一系列先进的技术进行了全面的研究，得出了以下主要发现：(1) Cochlin 的过表达和下调分别增加和降低眼内压 (IOP)。过表达是在 DBA/2J-Gpnmb(+)/SjJ 中使用慢病毒载体实现的，下调是在青光眼 DBA/2J 小鼠中使用靶向敲除 (Cochlin-null 小鼠) 和慢病毒载体介导的针对 Cochlin 编码区的 shRNA 实现的；(2) Cochlin-null 小鼠中 Cochlin 的重新引入增加了 IOP；(3) 外源性 Cochlin 的注射也增加了 IOP；(4) 增加灌注速率增加 Cochlin 多聚化，从而降低胰蛋白酶和蛋白酶 K 对 Cochlin 的蛋白水解速度；剪切应力引起的 Cochlin 多聚化表明其具有潜在的机械感受器功能。结合以前的研究，我们表明 Cochlin 参与 DBA/2J 眼内压的调节，可能是通过对剪切力的机械感受器。
