Inhibition of cyclooxygenase activity by diclofenac inhibits varicose remodeling of mouse veins. Inhibition of cyclooxygenase activity by diclofenac inhibits varicose remodeling of mouse veins

BACKGROUND: As evidenced by epidemiological and etiological studies, the development of varicose veins is driven by risk-factors which support the development of venous hypertension and thus chronically augment circumferential stress of the venous wall (e.g. dysfunctional venous valves, pregnancy or obesity). We have previously verified the relevance of this biomechanical stimulus for the activation of venous endothelial as well as smooth muscle cells and the subsequent detrimental structural remodeling of the vein wall in experimental mouse models. METHODS: Here, transcriptome analyses revealed an increase in the expression of cyclooxygenase 2 (COX-2) in human venous endothelial cells upon exposure to biomechanical stress. Subsequently, we investigated the impact of diclofenac – a cyclooxygenase inhibitor – on responses of isolated mouse veins to augmented wall stress in vitro and on varicose-like venous remodeling in vivo. RESULTS: Diclofenac treatment decreased COX-2 protein abundance in mouse veins but had no significant impact on the expression of corresponding transcripts. Short-term exposure to elevated pressure levels stimulated the activity of matrix-metalloproteinase-2 (MMP-2) and mitogen activated protein kinases ERK1/2. Diclofenac decreased the level of activated MMP-2 and ERK1/2 in pressure-exposed mouse veins. Varikose-like remodeling of veins in the mouse auricle was significantly inhibited by transdermal application of diclofenac-containing phospholipid-micelles. This effect was associated with decreased COX-2 and MMP-2 abundance as well as cell proliferation. CONCLUSION: The cyclooxygenase inhibitor diclofenac interferes with short term activation of MAP-kinases and matrix-metalloproteinases in cells of the wall stress-exposed venous wall while attenuating venous remodeling in vivo. Thus, nonsteroidal anti-inflammatory drugs may be suitable to interfere with processes promoting the progression of varicose vein development and biomechanical activation of venous cells. Overall design: Comparison of HUVECs exposed to biomechanical stretch vs. static culture conditions

背景：流行病学与病因学研究证实，静脉曲张的发生由多种危险因素驱动，这些因素可促进静脉高压的形成，进而长期增加静脉壁的周向应力（例如静脉瓣膜功能不全、妊娠或肥胖）。本团队此前已在实验小鼠模型中验证了该生物力学刺激与静脉内皮细胞、平滑肌细胞激活，以及随后静脉壁病理性结构重塑的相关性。
方法：本研究通过转录组分析发现，人静脉内皮细胞暴露于生物力学应力后，环氧合酶2（cyclooxygenase 2，COX-2）的表达水平升高。随后，我们研究了双氯芬酸——一种环氧合酶抑制剂——对离体小鼠静脉在体外承受增强壁应力时的应答，以及其对体内静脉曲张样静脉重塑的影响。
结果：双氯芬酸处理可降低小鼠静脉中COX-2的蛋白丰度，但对其对应转录本的表达无显著影响。短期暴露于升高的压力水平可激活基质金属蛋白酶2（matrix-metalloproteinase-2，MMP-2）与丝裂原活化蛋白激酶ERK1/2的活性。双氯芬酸可降低经压力处理的小鼠静脉中活化型MMP-2与ERK1/2的水平。经皮给予含双氯芬酸的磷脂胶束，可显著抑制小鼠耳廓静脉的静脉曲张样重塑。该效应与COX-2、MMP-2丰度降低以及细胞增殖受抑相关。
结论：环氧合酶抑制剂双氯芬酸可干扰暴露于壁应力的静脉壁细胞中丝裂原活化蛋白激酶与基质金属蛋白酶的短期激活，并在体内抑制静脉重塑。因此，非甾体抗炎药或可干预促进静脉曲张进展以及静脉细胞生物力学激活的相关过程。
整体实验设计：对比暴露于生物力学牵拉的人脐静脉内皮细胞（human umbilical vein endothelial cells，HUVECs）与静态培养条件下的人脐静脉内皮细胞的转录组差异。