Ghouzali Ibtissem, Azhar Saïda, Bôle-Feysot Christine, Ducrotté Philippe, Déchelotte Pierre, Coëffier Moïse
Normandie Univ, INSERM Unit 1073, Nutrition, Inflammation and Gut-Brain Axis, Rouen, France; University of Rouen, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.
Normandie Univ, INSERM Unit 1073, Nutrition, Inflammation and Gut-Brain Axis, Rouen, France; University of Rouen, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France; Department of Gastroenterology, Rouen University Hospital, Rouen, France.
Cytokine. 2016 Oct;86:41-46. doi: 10.1016/j.cyto.2016.07.014. Epub 2016 Jul 25.
Protease activated receptors (PARs) and the ubiquitin-proteasome system (UPS) regulate inflammatory response in intestinal cells. We aimed to elucidate putative connections between PARs and UPS pathways in intestinal epithelial cells. Caco-2 cells were treated by agonist peptides of PARs and/or IL-1β and/or proteasome inhibitors, bortezomib or MG132. Inflammatory response was evaluated by measuring IL-8 production. Proteasome activities were also evaluated. We showed that PAR-1 and -2 activation increased release of IL-8 compared with vehicle and independently of IL-1β. In contrast, PAR-4 agonist peptide had no effect. Caspase-like and chymotrypsin-like proteasomal activities were increased by PAR-2 activation only in the presence of IL-1β. Interestingly, in polarized Caco-2 cells, the release of IL-8 was predominantly upregulated in the side where PAR-2 agonist peptide was added, apical or basalolateral. In contrast, proteasome activities were only affected when PAR-2 agonist peptide was added in the apical side. Proteasome inhibitors, bortezomib and MG132, enhanced IL-8 production in both sides, apical and basolateral. In conclusion, PAR-2 activation alone did not affect proteasome but needed inflammatory stimulus IL-1β to synergistically increase chymotrypsin-like activity in intestinal epithelial cells. However, proteasome inhibition led to exacerbate inflammatory response induced by PAR-2 activation.
蛋白酶激活受体（PARs）和泛素-蛋白酶体系统（UPS）调节肠道细胞中的炎症反应。我们旨在阐明肠道上皮细胞中PARs与UPS途径之间的潜在联系。用PARs的激动剂肽和/或白细胞介素-1β（IL-1β）和/或蛋白酶体抑制剂硼替佐米或MG132处理人结肠腺癌细胞（Caco-2细胞）。通过测量IL-8的产生来评估炎症反应。还评估了蛋白酶体活性。我们发现，与溶媒对照相比，PAR-1和PAR-2的激活增加了IL-8的释放，且与IL-1β无关。相比之下，PAR-4激动剂肽没有作用。仅在存在IL-1β的情况下，PAR-2的激活才增加了类半胱天冬酶样和类胰凝乳蛋白酶样蛋白酶体活性。有趣的是，在极化的Caco-2细胞中，添加PAR-2激动剂肽的一侧（顶端或基底外侧）IL-8的释放主要上调。相比之下，仅当在顶端添加PAR-2激动剂肽时蛋白酶体活性才受到影响。蛋白酶体抑制剂硼替佐米和MG132在顶端和基底外侧均增强了IL-8的产生。总之，单独激活PAR-2不会影响蛋白酶体，但需要炎症刺激物IL-1β来协同增加肠道上皮细胞中的类胰凝乳蛋白酶样活性。然而，蛋白酶体抑制导致PAR-2激活诱导的炎症反应加剧。
