Tractional force generation by human Muller cells: Growth factor responsiveness and integrin receptor involvement
Tractional force generation by human Muller cells: Growth factor responsiveness and integrin receptor involvement
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DOI：
10.1167/iovs.02-0046
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发表时间：
2003-03-01
影响因子：
4.4
通讯作者：
King, JL
中科院分区：
文献类型：
--
作者：
Guidry, C;Bradley, KM;King, JL
目的。评价人Muller细胞产生牵引力的能力，并确定生长因子和胶原结合整合素在这一过程中的作用。从木瓜蛋白酶酶消化的人视网膜中分离Muller细胞。通过免疫检测胶质纤维酸性蛋白（GFAP）、细胞视黄醛结合蛋白（CRALBP）、波形蛋白和α -平滑肌肌动蛋白（α - sma），确认细胞的身份和细胞表型的变化。牵引力的产生是通过组织培养试验来评估的，包括细胞在三维胶原凝胶上的孵育。将促收缩生长因子直接添加到培养基中，考察了促收缩生长因子的作用。通过免疫检测、RTPCR和亚单位特异性阻断抗体评估Muller细胞的表达和特异性整合素受体的参与。在维持培养过程中，人穆勒细胞采用能够产生牵引力的成纤维细胞样表型。胰岛素样生长因子I和血小板源性生长因子以剂量依赖性的方式刺激基质收缩。高浓度的转化生长因子(TGF)- β 1和- β 2对小鼠有适度的反应。Muler细胞表达构成胶原结合受体的所有四种整合素亚基，包括alpha1、alpha2、alpha3和beta1。抗受体亚单位alpha2和beta1的阻断抗体显著降低了基质收缩的总体速率。针对α 1亚基的抗体有适度抑制作用，而抗α 3的抗体无抑制作用。人Muller细胞在体外获得产生牵引力的能力，促收缩生长因子胰岛素样生长因子(IGF)- 1和血小板衍生生长因子（PDGF）是有效的刺激。Muller细胞产生牵引力主要涉及含有α 2和β 1亚基的整合素受体。
PURPOSE. To assess the ability of human Muller cells to generate tractional forces and to determine the role of growth factors and Collagen binding integrins in this process.METHODS. Muller cells were isolated from papain-DNase-digested human retina. Cell identity and changes in cell phenotype were confirmed by immunodetection of glial fibrillary acidic protein (GFAP), cellular retinaldehyde-binding protein (CRALBP), vimentin, and alpha-smooth muscle actin (alpha-SMA). Generation of tractional force was assessed with a tissue culture assay involving incubation of cells on three-dimensional collagen gels. The effects of contraction-promoting growth factors were examined by adding these directly to the culture medium. Muller cell expression and the involvement of specific integrin receptors were assessed by immunodetection, RTPCR, and subunit-specific blocking antibodies.RESULTS. During maintenance in culture, human Muller cells adopted a fibroblast-like phenotype capable of generating tractional forces. Matrix contraction was stimulated in a dose-dependent fashion by insulin-like growth factor I and platelet-derived growth factor. Modest responses were observed with high concentrations of transforming growth factor (TGF)-beta1 and -beta2. Muler cells express all four integrin subunits that comprise the collagen-binding receptors including alpha1, alpha2, alpha3, and beta1. Blocking antibodies against receptor subunits alpha2 and beta1 significantly reduced the overall rate of matrix contraction. Antibodies against the alpha1 subunit were modestly inhibitory, whereas anti-alpha3 was without effect.CONCLUSIONS. Human Muller cells acquire the capacity to generate tractional forces in vitro and the contraction-promoting growth factors insulin-like growth factor (IGF)-I and platelet-derived growth factor (PDGF) are potent stimuli. Generation of tractional force by Muller cells primarily involves integrin receptors containing alpha2 and beta1 subunits.