Silverman Matthew D, Zamora David O, Pan Yuzhen, Texeira Paul V, Baek Seung-Hee, Planck Stephen R, Rosenbaum James T
Department of Ophthalmology, Casey Eye Institute, Oregon Health & Sciences University, Portland, Oregon 97201, USA.
Invest Ophthalmol Vis Sci. 2003 Apr;44(4):1608-15. doi: 10.1167/iovs.02-0233.
Fractalkine (FKN) is a dual-adhesion molecule-chemokine that plays a role in inflammation but has not been explored in the eye. In the current study, constitutive expression of FKN was identified in human iris and retina, and its regulation by various cytokines in endothelial cells (ECs) and stromal cells from human iris, retina, and choroid was investigated.
Human iris and retina explants were evaluated for FKN mRNA and protein expression using RT-PCR and immunohistochemistry, respectively. Cultured ocular ECs and stromal cells were stimulated with various inflammatory mediators (endotoxin; TNFalpha; interferon-gamma; interleukin (IL)-1alpha, -4, -10, -13, -17, and -18; and/or CD40 ligand, or combinations thereof), with FKN mRNA being subsequently evaluated by cDNA array and/or RT-PCR and FKN protein by enzyme-linked immunoculture assay (ELICA) and/or by Western blot analysis.
Iris and retina explants constitutively expressed FKN protein in microvascular ECs and also in several stromal cell types. Iris and retina both express FKN mRNA. TNFalpha upregulated FKN in iris explants. All ocular microvascular ECs and stromal cultures expressed low FKN mRNA and/or protein levels, which were variably upregulated by endotoxin, TNFalpha, interferon-gamma, IL-1alpha, and/or CD40 ligand, but not by IL-18. In ECs, the Th2 cytokines IL-4 and -13, but not IL-10, reduced TNFalpha-induced FKN protein. IL-17, usually considered proinflammatory, reduced TNFalpha-induced FKN protein in ocular ECs.
FKN is expressed in various ocular tissues and cells. Inflammatory mediator modulation of ocular FKN expression suggests that this adhesive chemokine may play important roles in regulating leukocyte efflux in inflammatory eye diseases, such as anterior uveitis and retinochoroiditis.
趋化因子（FKN）是一种双粘附分子趋化因子，在炎症中发挥作用，但尚未在眼部进行研究。在本研究中，在人虹膜和视网膜中鉴定出FKN的组成性表达，并研究了人虹膜、视网膜和脉络膜的内皮细胞（ECs）和基质细胞中各种细胞因子对其的调节作用。
分别使用逆转录聚合酶链反应（RT-PCR）和免疫组织化学评估人虹膜和视网膜外植体中FKN mRNA和蛋白的表达。用各种炎症介质（内毒素；肿瘤坏死因子α（TNFα）；干扰素γ；白细胞介素（IL）-1α、-4、-10、-13、-17和-18；和/或CD40配体，或其组合）刺激培养的眼部ECs和基质细胞，随后通过cDNA阵列和/或RT-PCR评估FKN mRNA，通过酶联免疫培养测定（ELICA）和/或蛋白质印迹分析评估FKN蛋白。
虹膜和视网膜外植体在微血管ECs以及几种基质细胞类型中组成性表达FKN蛋白。虹膜和视网膜均表达FKN mRNA。TNFα上调虹膜外植体中的FKN。所有眼部微血管ECs和基质培养物均表达低水平的FKN mRNA和/或蛋白，其水平被内毒素、TNFα、干扰素γ、IL-1α和/或CD40配体不同程度地上调，但未被IL-18上调。在ECs中，Th2细胞因子IL-4和-13而非IL-10降低了TNFα诱导的FKN蛋白。通常被认为具有促炎作用的IL-17降低了眼部ECs中TNFα诱导的FKN蛋白。
FKN在各种眼组织和细胞中表达。眼部FKN表达的炎症介质调节表明，这种粘附趋化因子可能在调节炎症性眼病（如前葡萄膜炎和视网膜脉络膜炎）中的白细胞外流中起重要作用。
