MicroRNA‑122 regulation of the morphology and cytoarchitecture of hepatoma carcinoma cells

Integrated analysis of expression profiles with meat quality traits in cattle

MicroRNAs (miRNAs) play a vital role in improving meat quality by binding to messenger RNAs (mRNAs). We performed an integrated analysis of miRNA and mRNA expression profiling between bulls and steers based on the differences in meat quality traits. Fat and fatty acids are the major phenotypic indices of meat quality traits to estimate between-group variance. In the present study, 90 differentially expressed mRNAs (DEGs) and 18 differentially expressed miRNAs (DEMs) were identified. Eighty-three potential DEG targets and 18 DEMs were used to structure a negative interaction network, and 75 matching target genes were shown in this network. Twenty-six target genes were designated as intersection genes, screened from 18 DEMs, and overlapped with the DEGs. Seventeen of these genes enriched to 19 terms involved in lipid metabolism. Subsequently, 13 DEGs and nine DEMs were validated using quantitative real-time PCR, and seven critical genes were selected to explore the influence of fat and fatty acids through hub genes and predict functional association. A dual-luciferase reporter and Western blot assays confirmed a predicted miRNA target (bta-miR-409a and PLIN5). These findings provide substantial evidence for molecular genetic controls and interaction among genes in cattle.

Aquaporin-9 is involved in the lipid-lowering activity of the nutraceutical silybin on hepatocytes through modulation of autophagy and lipid droplets composition

Hepatic steatosis is the hallmark of non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome and insulin resistance with potential evolution towards non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Key roles of autophagy and oxidative stress in hepatic lipid accumulation and NAFLD progression are recognized. Here, we employed a rat hepatoma cell model of NAFLD progression made of FaO cells exposed to oleate/palmitate followed or not by TNFα treatment to investigate the molecular mechanisms through which silybin, a lipid-lowering nutraceutical, may improve hepatic lipid dyshomeostasis. The beneficial effect of silybin was found to involve amelioration of the fatty acids profile of lipid droplets, stimulation of the mitochondrial oxidation and upregulation of a microRNA of pivotal relevance in hepatic fat metabolism, miR-122. Silybin was also found to restore the levels of Aquaporin-9 (AQP9) and glycerol permeability while reducing the activation of the oxidative stress-dependent transcription factor NF-κB, and autophagy turnover. In conclusion, silybin was shown to have molecular effects on signaling pathways that were previously unknown and potentially protect the hepatocyte. These actions intersect TG metabolism, fat-induced autophagy and AQP9-mediated glycerol transport in hepatocytes.

Paternal Exposure to Environmental Chemical Stress Affects Male Offspring's Hepatic Mitochondria

Preconceptional paternal exposures may affect offspring's health, which cannot be explained by mutations in germ cells, but by persistent changes in the regulation of gene expression. Therefore, we investigated whether pre-conceptional paternal exposure to benzo[a]pyrene (B[a]P) could alter the offspring's phenotype. Male C57BL/6 mice were exposed to B[a]P by gavage for 6 weeks, 3× per week, and were crossed with unexposed BALB-c females 6 weeks after the final exposure. The offspring was kept under normal feeding conditions and was sacrificed at 3 weeks of age. Analysis of the liver proteome by 2D-gel electrophoresis and mass spectrometry indicated that proteins involved in mitochondrial function were significantly downregulated in the offspring of exposed fathers. This down-regulation of mitochondrial proteins was paralleled by a reduction in mitochondrial DNA copy number and reduced activity of citrate synthase and β-hydroxyacyl-CoA dehydrogenase, but in male offspring only. Surprisingly, analysis of hepatic mRNA expression revealed a male-specific up-regulation of the genes, whose proteins were downregulated, including Aldh2 and Ogg1. This discrepancy could be related to several selected microRNA (miRNA)'s that regulate the translation of these proteins; miRNA-122, miRNA-129-2-5p, and miRNA-1941 were upregulated in a gender-specific manner. Since mitochondria are thought to be a source of intracellular reactive oxygen species, we additionally assessed oxidatively-induced DNA damage. Both 8-hydroxy-deoxyguanosine and malondialdehyde-dG adduct levels were significantly reduced in male offspring of exposed fathers. In conclusion, we show that paternal exposure to B[a]P can regulate mitochondrial metabolism in offspring, which may have profound implications for our understanding of health and disease risk inherited from fathers.

Effect of formaldehyde on miRNA122 and its downstream molecules a disintegrin and metalloproteinase 10 and serum response factor in the liver of mice

AIM: To investigate the effect of formaldehyde on miRNA122 and its downstream molecules a disintegrin and metalloproteinase 10 (ADAM10) and serum response factor (SRF) in the liver of mice.

METHODS: Forty female Kunming mice were randomly divided into three formaldehyde groups (low-, medium- and high-concentration groups) and a control group. The three formaldehyde groups were intraperitoneally injected with different concentrations of formaldehyde at 9:00 am daily. The control group was injected with equal volume of normal saline. After 30 d, the expression of miRNA122 in the liver was examined by real-time quantitative PCR (qRT-PCR). Immunohistochemistry was performed to observe the expression of ADAM10 and SRF in the liver.

RESULTS: The relative expression levels of miRNA122 in the control group, low-, medium-, and high-concentration groups were 0.99 ± 0.005, 0.94 ± 0.074, 0.72 ± 0.062, and 0.38 ± 0.091, respectively. There were significant differences between different groups (F = 22.988, P < 0.01). Formaldehyde significantly reduced the expression of miRNA122 in a dose-dependent manner. The expression of ADAM10 and SRF was significantly higher in the three formaldehyde groups than in the control group (H = 21.484, P = 0.000; H = 31.566, P = 0.000, respectively). The relative expression of miRNA122 showed a negative association with ADAM10, as well as SRF (r = -0.975, P = 0.025; r = -0.799, P = 0.02, respectively).

CONCLUSION: Formaldehyde can significantly reduce the expression of miRNA122 in the liver in a dose-dependent manner. Formaldehyde may induce hepatocellular carcinoma by increasing the expression of ADAM10 and SRF.

MicroRNAs involved with hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is one of the most common malignancies, which accounts for 90% of primary liver cancer. HCC usually presents with poor outcomes due to the high rates of tumor recurrence and widespread metastasis. However, the underlying mechanism of HCC initiation and progression, which significantly hindered the development of valid approaches for early detection and treatment remain to be elucidated. As a group of small non-coding RNAs, microRNAs (miRNAs) have been demonstrated to be involved in many types of diseases especially human malignancies. Numerous miRNAs are deregulated in HCC, which may shed some light on current investigations. Since miRNAs are stable and detected easily, their ectopic expression has been reported in HCC tissues, serum/plasma and cell lines. As previously described, miRNAs serve as tumor suppressors or oncogenes, indicating that miRNAs may be useful as diagnostic, therapeutic and prognostic markers of HCC. In the present review, we assessed the latest data regarding dysregulated miRNAs in HCC and reviewed the reported functions of these miRNAs as they apply to the diagnosis and prognosis of HCC.