NPY对LPS诱导的BV-2细胞系iNOS和COX-2表达的影响

Effects of NPY on the expression of iNOS and COX-2 in LPS-induced BV-2 cell line

通过观察神经肽Y（neuropeptide Y,NPY）对脂多糖（lipopolysaccharide,LPS）诱导的BV-2细胞促炎酶类表达的影响,以期探讨NPY在神经系统炎症的发生发展中的作用。首先利用MTT法检测NPY对BV-2细胞活性的影响,从而确定作用浓度。然后,利用荧光定量PCR和蛋白质印迹法,分别检测NPY对LPS诱导的BV-2细胞中一氧化氮合酶（i NOS）和环氧合酶-2（COX-2）表达的影响。其次,添加NPY受体阻断剂后,观测对NPY效应的影响。结果显示1～1 000 nmol/L的NPY对BV-2无细胞毒作用;NPY预处理1 h后LPS刺激6 h,NPY＋LPS组BV-2细胞中i NOS和COX-2 mRNA的表达水平和蛋白的含量显著低于LPS组;BV-2细胞系上检测到Y1受体、Y2受体、Y4受体和Y5受体的存在;加入Y1受体阻断剂后,对样品中i NOS和COX-2 mRNA的表达水平和蛋白的含量进行检测,发现NPY的抑炎作用消失。结果表明,NPY通过作用于Y1受体抑制LPS诱导的促炎酶类表达。

To investigate the role of neuropeptide Y in the development of inflammation in nervous system,the effects of neuropeptide Y on the expression of proinflammatory enzymes were ob- served in lipopolysaccharide-indueed BV-2 cells. First of all,in order to determine the effective con- centration, MTT assay was used to measure the effect of NPY on activated BV-2 cells. Then,the effect of NPY on the expression of mRNA and protein of COX-2 and iNOS genes were measured by realtime-PCR and Western blot. In addition, after blocking the NPY receptor through corre- sponding blocker,its effect was observed. These results showed that there is no cytotoxicity on BV-2 cells under 1-1 000 nmol/L NPY treatment. Pre-treated with NPY for 1 h,followed by LPS for 6 h,the expression of iNOS and COX-2 at protein and mRNA level was significantly lower in NPY and LPS-treated BV-2 cells in comparison with LPS group. NPY receptors,including Y1 ,Y2, Y4 and Y5, were be detected in BV-2 cells. The expression of COX-2 and iNOS mRNA and protein was measured after Y1 receptor blocking. The anti-inflammatory effect of NPY was found to be disappeared. The results indicated that NPY could inhibit the expression of LPS-induced proin- flammatory enzymes through activating Y1 receptor.