Analysis of MicroRNA Expression Profiling Involved in MC-LR-Induced Cytotoxicity by High-Throughput Sequencing

Abstract

In recent years, microRNAs (miRNAs) in toxicology have attracted great attention. However, the underlying mechanism of miRNAs in the cytotoxicity of microcystin-LR (MC-LR) is lacking. The objective of this study is to analyze miRNA profiling in HepG2 cells after 24 h of MC-LR-exposure to affirm whether and how miRNAs were involved in the cytotoxicity of MC-LR. The results showed that totally 21 and 37 miRNAs were found to be significantly altered in the MC-LR treated cells at concentrations of 10 and 50 μM, respectively, when compared to the control cells. In these two groups, 37,566 and 39,174 target genes were predicted, respectively. The further analysis showed that MC-LR-exposure promoted the expressions of has-miR-149-3p, has-miR-449c-5p, and has-miR-454-3p while suppressed the expressions of has-miR-4286, has-miR-500a-3p, has-miR-500a-5p, and has-miR-500b-5p in MC-LR-treated groups when compared to the control group. Moreover, the result of qPCR confirmed the above result, suggesting that these miRNAs may be involved in MC-LR-hepatotoxicity and they may play an important role in the hepatitis and liver cancer caused by MC-LR. The target genes for differentially expressed miRNAs in MC-LR treatment groups were significantly enriched to totally 23 classes of GO, in which three were significantly enriched in both 10 and 50 μM MC-LR groups. Moreover, the results of KEGG pathway analysis showed that MC-LR-exposure altered some important signaling pathways such as MAPK, biosynthesis of secondary metabolites, and pyrimidine and purine metabolism, which were possibly negatively regulated by the corresponding miRNAs and might play important role in MC-LR-mediated cytotoxicity in HepG2 cells.

miR-149 in Human Cancer: A Systemic Review

“…[50, 51] Exposure of MC-LR was found promoted the expression of miR-149-3p, promoting miR-149-3p may be involved in MC-LR-hepatotoxicity, hepatitis and liver carcinoma. 52 …”

MicroRNA‑665 promotes the proliferation of ovarian cancer cells by targeting SRCIN1

“…Mechanistically, miRNAs directly bind to the 3'untranslated region (UTR) of their target mRNAs, leading to the degradation of mRNA or inhibition of translation (7). The expression of miRNA is tightly controlled in normal cells, for instance, dysregulation of several key miRNAs resulted in the disruption of cell signaling networks in human diseases, including cancer (8)(9)(10). With microarray analysis, many differentially expressed miRNAs are detected between ovarian tumors and normal tissues (11,12).…”

Aberrant Expressional Profiling of Known MicroRNAs in the Liver of Silver Carp (Hypophthalmichthys molitrix) Following Microcystin-LR Exposure Based on samllRNA Sequencing

“…The qPCR results confirmed the above results, suggesting that these miRNAs may be involved in the hepatotoxicity of MC-LR. Ma et al confirmed that 21 and 37 miRNAs were altered in HepG2 cells after MC-LR exposure (10 and 50 µM) [35]. Yang reported that treatment of the HL7702 cell line with MC-LR (1, 2.5, 5, or 10 µM) clearly altered the expression of 3, 10, 9, and 99 miRNAs, respectively, when compared with control cells [34].…”

“…MCs are known to be widespread in freshwater where cyanobacteria bloom, and they are highly toxic to aquatic organisms and even humans [33]. Biological and pathological processes are assumed to be due to exposure to MC-LR and associated changes in miRNA expression levels, including metabolism, developmental timing, signal transduction, cell proliferation, differentiation, apoptosis, cancer progression, and tumorigenesis [34,35]. Meanwhile, miRNAs have been proven to regulate multiple molecular functions and have been correlated with various diseases [36,37].…”