Sialic acid (N-acetylneuraminic acid, NANA) is found at all cell surfaces of vertebrates. Although it is widely accepted that sialic acid is an essential substrate for brain development via a significant role in nerve transfers, structure of glycosides, and synaptogenesis phenomena, there are some reports on the elevated levels of sialic acid and prevalence of neurodegeneration. Matrix metalloproteases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) are involved in neuroinflammation disorders and produced by many cell types, including activated T cells, macrophages, neurons, astrocytes, and microglial cells. It can be hypothesized that sialic acid may have a potentially critical role in regulation of a wide range of uncovered neurodegeneration factors as its downstream targets. In this study, for the first time, we aimed to analyze the possible effect of the sialic acid solution exposure in the human C118 cell line, which was derived from a human brain astrocytoma (glial cells), on the expression patterns of miR-218, NF-kB, MMP-9, and TIMP-1. For MMP-9, protein levels were studied too. Half maximal inhibitory concentration (IC₅₀) value of NANA was obtained by MTT assay. Glial cell line was treated with sialic acid (300, 500, and 1000 µg/ml) for 24 h to investigate the effects of this ligand on the expression of miR-218, NF-kB, MMP-9, and TIMP-1 genes. Protein levels were checked by Western blotting, and by using zymography, the gelatinolytic activity of MMP-9 secreted into conditioned media was assayed. At 300 µM, 500 µM, and 1000 µM sialic acid treatments, the expression of miR-218 was downregulated; subsequently, the NF-kB, MMP-9, and TIMP-1 genes as well as their protein expressions were upregulated. More interestingly, the enzyme activity of secreted MMP-9 was upregulated too (p-values ≤ 0.05). This study could demonstrate the significant effect of sialic acid on miR-218, NF-kB, MMP-9 , and TIMP-1 expressions in gene and protein levels and also the levels of enzyme activity of secreted MMP-9. Therefore, provided information indicates the novel idea of a possible linkage between sialic acid species and regulation of these neuroinflammation genes in Glial cell line.

唾液酸（N-乙酰神经氨酸（NANA）存在于脊椎动物的所有细胞表面。尽管唾液酸通过在神经传递，糖苷结构和突触发生现象中起重要作用而被广泛接受，但它是大脑发育必不可少的底物，但是有一些关于唾液酸水平升高和神经退行性变的报道。基质金属蛋白酶（MMP）和金属蛋白酶组织抑制剂（TIMP）与神经炎症有关，并由多种细胞类型产生，包括活化的T细胞，巨噬细胞，神经元，星形胶质细胞和小胶质细胞。可以假设唾液酸可能在调节许多未发现的神经退行性因子作为其下游靶标方面具有潜在的关键作用。在这项研究中，这是第一次 我们旨在分析唾液酸溶液暴露于人脑星形细胞瘤（神经胶质细胞）衍生的人C118细胞系对miR-218，NF-kB，MMP-9，和TIMP-1。对于MMP-9，也研究了蛋白质水平。半数最大抑制浓度（IC通过MTT分析获得₅₀）的NANA值。用唾液酸（300、500和1000 µg / ml）处理胶质细胞系24小时，以研究该配体对miR-218，NF-kB，MMP-9和TIMP-1基因表达的影响。通过蛋白质印迹法检查蛋白质水平，并通过酶谱法分析分泌到条件培养基中的MMP-9的明胶分解活性。在300 µM，500 µM和1000 µM唾液酸处理下，miR-218的表达下调；随后，NF-kB，MMP-9和TIMP-1基因及其蛋白表达被上调。更有趣的是，分泌的MMP-9的酶活性也被上调（p值≤0.05）。这项研究可以证明唾液酸对miR-218，NF-kB，MMP-9和TIMP-1在基因和蛋白质水平表达以及分泌的MMP-9酶活性水平的显着影响。因此，提供的信息表明了唾液酸种类与神经胶质细胞系中这些神经炎症基因的调控之间可能存在联系的新想法。