MicroRNA-29a-3p Prevents Drug-Induced Acute Liver Failure through Inflammation-Related Pyroptosis Inhibition.

OBJECTIVE: Little is known about the role of microRNA-29a-3p (miR-29a-3p) in inflammation-related pyroptosis, especially in drug-induced acute liver failure (DIALF). This study aimed to identify the relationship between miR-29a-3p and inflammation-related pyroptosis in DIALF and confirm its underlying mechanisms. METHODS: Thioacetamide (TAA)- and acetaminophen (APAP)-induced ALF mouse models were established, and human samples were collected. The expression levels of miR-29a-3p and inflammation and pyroptosis markers were measured by quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, or immunochemical staining in miR-29a-3p knock-in transgenic mouse (MIR29A(KI/KI)) DIALF models. In addition, RNA sequencing was conducted to explore the mechanisms. RESULTS: MiR-29a-3p levels were decreased in TAA- and APAP-induced DIALF models. MiR-29a-3p prevented DIALF caused by TAA and APAP. RNA sequencing and further experiments showed that the protective effect of miR-29a-3p on DIALF was mainly achieved through inhibition of inflammation-related pyroptosis, and the inhibition was dependent on activation of the PI3K/AKT pathway. In addition, miR-29a-3p levels were reduced, and pyroptosis was activated in both peripheral blood mononuclear cells and liver tissues of DIALF patients. CONCLUSION: The study supports the idea that miR-29a-3p inhibits pyroptosis by activating the PI3K/AKT pathway to prevent DIALF. MiR-29a-3p may be a promising therapeutic target for DIALF.

Parkin deficiency elevates hepatic ischemia/reperfusion injury accompanying decreased mitochondrial autophagy, increased apoptosis, impaired DNA damage repair and altered cell cycle distribution.

Hepatic ischemia/reperfusion injury (HIRI) serves a causative role in postoperative hepatocyte death; however, the mechanisms underlying HIRI remain unclear. Mitochondrial autophagy, with apoptosis, cell cycle distribution and DNA damage repair, may be regarded as a regulatory factor post­HIRI. Parkin, a novel ubiquitin ligase, has been reported to increase mitochondrial autophagy and decrease apoptosis. However, the association between Parkin, mitochondrial autophagy and other regulatory factors in HIRI is unclear. In the present study, the effects of Parkin on HIRI were investigated, using hepatocytes and livers from male Sprague Dawley rats subjected to simulated in vivo HIRI. The results of the present study demonstrated that Parkin expression and mitochondrial autophagy were upregulated post­HIRI, leading to decreased hepatocyte death. Parkin knockdown suppresses the level of mitochondrial autophagy and promotes hepatocyte apoptosis by suppressing apoptosis regulator Bcl­2 function post­HIRI. In addition, Parkin deficiency alters cell cycle distribution and impairs DNA damage repair post­HIRI. In conclusion, Parkin facilitates mitochondrial autophagy and DNA damage repair, inhibits apoptosis, and modulates the cell cycle, leading to increased hepatocyte survival, demonstrating that Parkin may act as a protective regulatory factor post HIRI.

Effects of TMEM9 gene on cell progression in hepatocellular carcinoma by RNA interference.

Hepatocellular carcinoma (HCC) is a malignant tumor that has become a global health issue. The aim of the present study was to examine the role of transmembrane protein 9 (TMEM9) in cell progression, such as cell growth, cell cycle, cell metastasis of hepatoma cells, and to discuss the TMEM9 gene­encoding protein as a potential therapy target of hepatoma. RT-qPCR was performed to examine TMEM9 expression in tumor tissues and adjacent tissues of patients with liver cancer. siRNAs were used to interfere TMEM9 in HepG2 and 7721 cells. A CCK-8 assay was performed to evaluate cell growth at 24, 48 and 72 h. Cell cycle and apoptosis were analyzed using flow cytometry. Transwell assays were used to determine cell invasion, migration and adhesion. The results showed that TMEM9 was expressed abnormally in liver cancers. TMEM9 expression increased significantly in the 34 examined patients. TMEM9 knockdown inhibited proliferation in the HepG2 and 7721 cells. The flow cytometric analysis revealed that TMEM9 knockdown by RNA interference resulted in G1 arrest and induced apoptosis. Cell invasion, migration and adhesion ability were also decreased. Western blotting indicated that expression of the cell cycle­related proteins CDK1, EIF3H, RPL10L, S100A10, CCNB1 and CCNB2 was significantly decreased. In conclusion, TMEM9 plays an important role in the cell growth of hepatoma cells.