Background: miRNAs are non-coding RNAs that regulate gene expression in a wide range of biological contexts, including a variety of diseases. The present study clarified the role of miR-214-5p in hepatic fibrogenesis using human clinical tissue samples, livers from rodent models, and cultured hepatic stellate cells. Methods: The expression of miR-214-5p and genes that are involved in liver fibrosis were analyzed in hepatitis C virus-infected human livers, rodent fibrotic livers, a human stellate cell line (LX-2), and the cells from intact mouse livers using real-time PCR. The effect of miR-214-5p overexpression in LX-2 cells on cell function was investigated. Twist-1 expression in the liver tissues of mouse models and primary-cultured stellate cells was also analyzed. Results: miR-214-5p was upregulated in human and mouse livers in a fibrosis progression–dependent manner. miR-214-5p expression increased during the culture-dependent activation of mouse primary stellate cells and was significantly higher in stellate cells than in hepatocytes. The overexpression of miR-214-5p in LX-2 cells increased the expression of fibrosis-related genes, such as matrix metalloproteinase (MMP)-2, MMP-9, α-smooth muscle actin, and transforming growth factor (TGF)-β1. TGF-β stimulation induced miR-214-5p in LX-2 cells. Twist-1 was increased in fibrotic mouse livers and induced during mouse stellate cell activation. Conclusion: miR-214-5p may play crucial roles in the activation of stellate cells and the progression of liver fibrosis. Twist-1 may regulate miR-214-5p expression in the liver, particularly in stellate cells.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and the second most common cause of cancer deaths worldwide. The top three causes of HCC are hepatitis B virus (HBV), hepatitis C virus (HCV), and alcoholic liver disease. Owing to recent advances in direct-acting antiviral agents, HCV can now be eradicated in almost all patients. HBV infection and alcoholic liver disease are expected, therefore, to become the leading causes of HCC in the future. However, the association between alcohol consumption and chronic hepatitis B in the progression of liver disease is less well understood than with chronic hepatitis C. The mechanisms underlying the complex interaction between HBV and alcohol are not fully understood, and enhanced viral replication, increased oxidative stress and a weakened immune response could each play an important role in the development of HCC. It remains controversial whether HBV and alcohol synergistically increase the incidence of HCC. Herein, we review the currently available literature regarding the interaction of HBV infection and alcohol consumption on disease progression.

Intracellular gap (iGap) formation in liver sinusoidal endothelial cells (LSECs) is caused by the destruction of fenestrae and appears under pathological conditions; nevertheless, their role in metastasis of cancer cells to the liver remained unexplored. We elucidated that hepatotoxin-damaged and fibrotic livers gave rise to LSECs-iGap formation, which was positively correlated with increased numbers of metastatic liver foci after intrasplenic injection of Hepa1-6 cells. Hepa1-6 cells induced interleukin-23–dependent tumor necrosis factor–α (TNF-α) secretion by LSECs and triggered LSECs-iGap formation, toward which their processes protruded to transmigrate into the liver parenchyma. TNF-α triggered depolymerization of F-actin and induced matrix metalloproteinase 9 (MMP9), intracellular adhesion molecule 1, and CXCL expression in LSECs. Blocking MMP9 activity by doxycycline or an MMP2/9 inhibitor eliminated LSECs-iGap formation and attenuated liver metastasis of Hepa1-6 cells. Overall, this study revealed that cancer cells induced LSEC-iGap formation via proinflammatory paracrine mechanisms and proposed MMP9 as a favorable target for blocking cancer cell metastasis to the liver.

Background: Interferon‐free, direct‐acting antiviral treatments can result in a sustained virologic response in nearly 100% of patients with chronic hepatitis C virus infection.Aims: The purpose of this study was to evaluate histological improvement after achieving a sustained virologic response to direct‐acting antiviral treatments in patients with chronic hepatitis C.Methods: Among 691 patients with chronic hepatitis C who achieved a sustained virologic response to direct‐acting antivirals, 51 underwent liver biopsy 41 ± 20 weeks after the end of treatment despite normal transaminase levels. In 20 patients, liver biopsy specimens obtained a median of 1.2 years before the start of treatment were available.Results: Among the 51 patients who underwent post‐sustained virologic response biopsies, the grade of inflammation was A0 in 18 patients, A1 in 24, A2 in eight, and A3 in one; the stage of fibrosis was F0 in three patients, F1 in 20, F2 in 15, F3 in nine, and F4 in four. Among the nine post‐sustained virologic response biopsy specimens with moderate‐to‐severe inflammation (≥A2), four showed S1‐to‐S3 steatosis (>5% of hepatocytes affected). In the 20 paired biopsy specimens, the inflammation grade significantly regressed (p = 0.0043), but the fibrosis stage did not (p = 0.45). Histological improvement, defined as a ≥ 2‐point decrease in the Knodell inflammatory score and no worsening of the fibrosis, was found in 11 (55%) patients. The iron accumulation had significantly regressed (p = 0.0093), but the steatosis had not (p = 0.10).Conclusions: Even if transaminases become normal after obtaining a sustained virologic response, significant histological inflammation of unknown cause was found in some patients. Additionally, improvement in liver fibrosis was not evident in the short term.