The Effect of Sialic Acid on MiR-320a and Let-7e Expression in Human Glial Cell Line.

Abstract

Introduction: Sialic acid is pivotal in various critical physiological events at molecular and cellular levels and pathological processes. Changes in sialic acid concentration are observed in many pathological processes; for example, some available data exist on the evaluated level of sialic acid and neurodegenerative prevalence. Presumably, sialic acid can play a significant role in regulating a diverse range of uncovered neurodegeneration factors and downstream targets. matrix metalloproteinases 9 (MMP9) is one factor that changes the exposure of different concentrations of sialic acid solution. Hence, we aimed to examine the possible effect of sialic acid solution exposure on the glial cell line in the expression patterns of miR-320a and let-7e as two upstream factors.

Methods: Human glial cell line was prepared from the Pasteur Institute of Iran and cultured in a dulbecco's modified eagle medium (DMEM) with 10% fetal bovine serum (FBS). The IC₅₀ value of sialic acid was obtained by colorimetric assay for assessing cell metabolic activity 3-(4,5-Dimethylthiazol-2-yl (MTT), and the glial cell line was treated with sialic acid in 300, 500, 1000 μg/mL for 24 h to investigate the effect of the sialic acid ligand on the expression pattern of the miR-320a and let-7e. Total RNA was isolated from approximately 10×10⁶ glial cells and was used from each sample for complementary dna (cDNA) synthesis. For quantitative analysis of miR-320a and let-7e, we used real-time polymerase chain reaction (PCR), and for statistical analysis, the SPSS v. 21 software was applied.

Results: Analyzing the real-time data revealed that the expression of miR-320a and let-7e was significantly increased (P<0.0001) in 300, 500, and 1000 μg/mL treated glial cells by sialic acid compared to the control group.

Conclusion: A possible linkage of sialic acid on miR-320a and let-7e regulation was observed in the glial cell line as proinflammatory factors in the inflammation pathway.

Highlights: Differing in sialic acid concentration is seen in various pathological states.MicroRNAs play a role in numerous biological processes and human disorders.miR-320a and let-7e expression levels displayed a significant increase in different sialic acid concentrations.

Plain language summary: Inflammation in the nervous system occurs because of numerous factors. Sialic acid is an inflammatory factor that promotes cellular inflammation, particularly in the glial cells. That is why it could serve as a useful model for simulating several neurodegenerative diseases, including Parkinson's and Multiple sclerosis. Changes in sialic acid concentration are observed in many pathological states, which could be a useful marker for identifying the inflammatory process. The present study was carried out to examine the impact of different concentrations of sialic acid on two non-coding RNAs in glial cells. Our research shows that these two microRNAs greatly increased when responding to sialic acid. We suggest that these two microRNAs are contributed to the neuroinflammatory pathways related to sialic acid.