炎症是身体对损伤的反应,这取决于许多监管因素。其中,miRNAs因其在多个水平上调节炎症基因表达的作用而备受关注。特别是,miR-21在炎症反应期间上调,据报道通过下调促炎介质参与炎症的消退。包括MyD88。在这里,我们在6-merHA寡糖诱导人软骨细胞炎症的体外模型中评估了miR-21对TLR-4/MyD88通路的调节作用.软骨细胞暴露于6-merHA诱导了TLR4/MyD88通路的激活,最终导致NF-kB激活。miR-21,TLR-4,MyD88,NLRP3炎性体的变化,IL-29,Caspase1,MMP-9,iNOS,实时定量PCR检测6聚体HA刺激的软骨细胞的COX-2mRNA表达。TLR-4,MyD88,NLRP3炎性体的蛋白质量,p-ERK1/2,p-AKT,IL-29,caspase1,MMP-9,p-NK-kBp65亚基,和IKB-a已通过ELISA试剂盒进行了评估。NO和PGE2水平已通过比色法和ELISA试剂盒测定,分别。HA寡糖诱导上述参数的表达显著增加,包括NF-kB活性。miR-21模拟物的使用减弱了MyD88表达水平和下游效应物。相反,用miR-21抑制剂治疗诱导相反效果。有趣的是,使用MyD88siRNA证实MyD88作为miR-21的作用靶点。我们的结果表明,miR-21表达可能会增加,以减少炎症反应。瞄准MyD88.
Inflammation is the body\'s response to injuries, which depends on numerous regulatory factors. Among them, miRNAs have gained much attention for their role in regulating inflammatory gene expression at multiple levels. In particular, miR-21 is up-regulated during the inflammatory response and reported to be involved in the resolution of inflammation by down-regulating pro-inflammatory mediators, including
MyD88. Herein, we evaluated the regulatory effects of miR-21 on the TLR-4/
MyD88 pathway in an in vitro model of 6-mer HA oligosaccharides-induced inflammation in human chondrocytes. The exposition of chondrocytes to 6-mer HA induced the activation of the TLR4/MyD88 pathway, which culminates in NF-kB activation. Changes in miR-21, TLR-4, MyD88, NLRP3 inflammasome, IL-29, Caspase1, MMP-9, iNOS, and COX-2 mRNA expression of 6-mer HA-stimulated chondrocytes were examined by qRT-PCR. Protein amounts of TLR-4,
MyD88, NLRP3 inflammasome, p-ERK1/2, p-AKT, IL-29, caspase1, MMP-9, p-NK-kB p65 subunit, and IKB-a have been evaluated by ELISA kits. NO and PGE2 levels have been assayed by colorimetric and ELISA kits, respectively. HA oligosaccharides induced a significant increase in the expression of the above parameters, including NF-kB activity. The use of a miR-21 mimic attenuated
MyD88 expression levels and the downstream effectors. On the contrary, treatment with a miR-21 inhibitor induced opposite effects. Interestingly, the use of a
MyD88 siRNA confirmed
MyD88 as the target of miR-21 action. Our results suggest that miR-21 expression could increase in an attempt to reduce the inflammatory response, targeting MyD88.