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Abstract：
The aim of the present study is to investigate the role of c-Jun N-terminal kinase (JNK) and matrix metalloproteinase-2 (MMP-2) in mediating the effects of interleukin-1β (IL-1β) on the function of lacrimal gland myoepithelial cells (MECs). MECs isolated from an α-smooth muscle actin-green fluorescent protein (SMA-GFP) transgenic mouse were treated with IL-1β alone or in the presence of SP600125, a JNK inhibitor, or ARP100, an MMP-2 inhibitor. The GFP intensity and the cell size/area were measured, and on day 7, the SMA, calponin, and pro-MMP-2 protein levels and the MEC contraction were assessed. At baseline, the control and treated cells showed no differences in GFP intensity or cell size. Starting on day 2 and continuing on days 4 and 7, the GFP intensity and cell size were significantly lower in the IL-1β-treated samples, and these effects were alleviated following inhibition of either JNK or MMP-2. Compared with the control, the levels of SMA and calponin were lower in the IL-1β-treated samples, and both the JNK and MMP-2 inhibitors reversed this trend. The pro-MMP-2 protein level was elevated in the IL-1β-treated samples, and this effect was abolished by the JNK inhibitor. Finally, oxytocin-induced MEC contraction was diminished in the IL-1β-treated samples, and both the JNK and MMP-2 inhibitors reversed this effect. Our data suggest that IL-1β uses the JNK/MMP-2 pathways to alter MEC functions, which might account for the diminished tears associated with aqueous-deficient dry eye disease.
摘要：
本研究的目的是研究c-Jun氨基末端激酶（JNK）和基质金属蛋白酶-2（MMP-2）在介导白细胞介素-1β（IL-1β）对泪腺肌上皮细胞（MECs）功能的影响中的作用。分离自α-平滑肌肌动蛋白-绿色荧光蛋白（SMA-GFP）转基因小鼠的MEC单独用IL-1β处理或在存在JNK抑制剂SP600125的情况下处理，或ARP100，一种MMP-2抑制剂。测量GFP强度和细胞大小/面积，在第七天，SMA，Calponin,和pro-MMP-2蛋白水平和MEC收缩进行评估。在基线,对照和处理的细胞在GFP强度或细胞大小方面没有差异。从第2天开始，并在第4天和第7天继续，在IL-1β处理的样品中，GFP强度和细胞大小显着降低，这些作用在抑制JNK或MMP-2后得到缓解。与对照相比，在IL-1β处理的样品中，SMA和钙蛋白的水平较低，JNK和MMP-2抑制剂逆转了这一趋势。IL-1β处理的样品中pro-MMP-2蛋白水平升高,JNK抑制剂消除了这种作用。最后,催产素诱导的MEC收缩在IL-1β处理的样品中减少，JNK和MMP-2抑制剂都逆转了这种作用。我们的数据表明，IL-1β使用JNK/MMP-2途径来改变MEC功能，这可能是与缺乏房水的干眼症相关的眼泪减少的原因。
