Effects of Inflammatory Cytokines on Human Fetal RPE in vitro

视网膜色素上皮（RPE）通过运输液体和分泌包括细胞因子/趋化因子在内的多种分子，在维持眼后部的内稳态中起重要作用。在眼部炎症中，受促炎细胞因子升高的影响，RPE的生理特性如液体运输和趋化因子分泌可能发生改变，从而导致疾病的加重。为了研究这个问题，我们用tnf - α、ifn - γ和il -1 - β的混合物刺激培养的人胎儿RPE。顶部添加的混合物对Jv没有影响。相比之下，基础添加使净流体吸收率增加了8.6 1 2.9 ul7cm-27hr-1 （n=3）。两侧加入后Jv增加5.5 1 1.3 ul7cm-27hr-1 （n=3）。混合刺激可显著增加12种趋化因子和3种细胞因子的分泌。对于大多数分子，来自根尖侧的刺激比来自基侧的刺激有效得多，而且根尖侧的分泌量远远大于基侧。高度受影响的趋化因子为4种CC趋化因子（MCP-1、RANTES、MCP-2、MCP-3）和4种CXC趋化因子（gro - α、IL-8、IP-10、I-TAC）。在3个独立实验中（n=3），对于CC趋化因子，顶端刺激使MCP-1的根尖侧分泌从6.9 + 1.2 ng/孔增加到106.2 + 15.1 ng/孔，RANTES从0增加到10.5 + 0.6 ng/孔，MCP-2从69.1 + 1.2 pg/孔增加到17.1 + 0.7 ng/孔，MCP-3从6.5 + 1.4 pg/孔增加到11.2 + 0.7 ng/孔。对于CXC趋化因子，顶点刺激使GRO-alpha顶点侧的分泌从15.7 + 3.2 pg/孔增加到36.2 + 0.3 ng/孔，IL-8从140.6 + 9.6 pg/孔增加到55.4 + 9.6 ng/孔，IP-10从5.1 + 0.3 pg/孔增加到119.9 + 10.8 ng/孔，I-TAC从9.5 + 2.1 pg/孔增加到44.6 + 1.0 ng/孔。促炎细胞因子诱导的JV活化和大多数趋化因子/细胞因子向顶泡分泌的显著增加表明RPE在眼部炎症性疾病的急慢性发病过程中起关键作用。

The retinal pigment epithelium (RPE) plays an important role in maintenance of homeostasis in the back of the eye by transporting fluid and secreting a variety of molecules including cytokines/chemokines. In ocular inflammation, affected by the elevated pro-inflammatory cytokines, the physiologic properties of RPE such as fluid transport and chemokine secretion may change resulting in exacerbation of the diseases. To investigate this question, we stimulated the cultured human fetal RPE with a mixture of TNF-alpha, IFN-gamma and IL-1beta. Apical addition of the mixture produced no changes in Jv. In contrast, basal addition increased net fluid absorption by 8.6 1 2.9 ul7cm-27hr-1 (n=3). Jv increased by 5.5 1 1.3 ul7cm-27hr-1 (n=3) after addition to both sides. Stimulation with the mixture, profoundly increased the secretion of the tested 12 chemokines and 3 cytokines. For the majority of these molecules, stimulation from the apical side was much more effective than that from the basal side and the secretion from the apical side was greater by far than that from the basal side. The highly affected chemokines were four CC chemokines (MCP-1, RANTES, MCP-2, MCP-3) and four CXC chemokines (GRO-alpha, IL-8, IP-10, I-TAC). In 3 independent experiments (n=3), for CC chemokines, apical stimulation increased secretion on apical side from 6.9 + 1.2 ng/well to 106.2 + 15.1 ng/well for MCP-1, from 0 to 10.5 + 0.6 ng/well for RANTES, from 69.1 + 1.2 pg/well to 17.1 + 0.7 ng/well for MCP-2, from 6.5 + 1.4 pg/well to 11.2 + 0.7 ng/well for MCP-3. For CXC chemokines, apical stimulation increased secretion on apical side from 15.7 + 3.2 pg/well to 36.2 + 0.3 ng/well for GRO-alpha, from 140.6 + 9.6 pg/well to 55.4 + 9.6 ng/well for IL-8, from 5.1 + 0.3 pg/well to 119.9 + 10.8 ng/well for IP-10, from 9.5 + 2.1 pg/well to 44.6 + 1.0 ng/well for I-TAC. The pro-inflammatory-cytokine-induced activation of JV and the predominant increase of secretion of most chemokine/cytokines to the apical bath suggest a critical role of the RPE in the pathogenesis of acute and chronic phases of ocular inflammatory diseases.