Protective Role of microRNA-31 in Acetaminophen-Induced Liver Injury: A Negative Regulator of c-Jun N-Terminal Kinase (JNK) Signaling Pathway.

BACKGROUND & AIMS: Sustained c-Jun N-terminal kinase (JNK) activation plays a major role in drug-induced liver injury (DILI). Stress-responsive microRNA-31 (miR-31) has been implicated in regulating different cellular damage, and JNK activation could induce miR-31 expression. However, the regulatory role of miR-31 in DILI has not been studied previously. We aimed to investigate whether miR-31 could ameliorate DILI and ascertain potential molecular mechanism. METHODS: miR-31 gene knockout (31-KO) and wild-type C57BL/6J mice were used to construct an acetaminophen (APAP)-induced DILI model. Primary mouse hepatocytes, as well as alpha mouse liver 12 (AML-12) cell lines, were used for in vitro experiments. Argonaute 2-associated RNA immunoprecipitation combined with high-throughput sequencing were performed to identify specific targets of miR-31. RESULTS: 31-KO mice showed a higher mortality rate, liver transaminase levels, and hepatic necrosis compared with those in wild-type mice after APAP-induced hepatotoxicity. The protective role of miR-31 on hepatocytes has been analyzed via constructing bone marrow chimeric mice. Mechanistically, we found that hepatic JNK phosphorylation increased significantly in 31-KO mice. This caused mitochondrial phosphorylated Src (p-Src) inactivation and more reactive oxygen species production, which directly amplifies hepatocyte necrotic cell death, while administration of JNK-specific inhibitor SP600125 could abrogate the differences. Moreover, bioinformatics analysis of RNA immunoprecipitation combined with high-throughput sequencing identified that guanosine triphosphatase, cell division cycle protein 42 (Cdc42), the upstream molecule of JNK signaling, was the specific target of miR-31 and could form a miR-31/Cdc42/phosphorylated mixed-lineage kinase 3 (p-MLK3) negative feedback loop to restrict JNK overactivation. Clinically, both miR-31 and phosphorylated JNK (p-JNK) were highly increased in liver tissues of DILI patients with different etiologies. CONCLUSIONS: miR-31 can down-regulate Cdc42 to restrict overactivation of reactive oxygen species/JNK/mitochondria necrotic death loop in hepatocytes of APAP-induced DILI, which might provide a new therapeutic target for alleviating JNK overactivation-based liver injury.

Cavitation effect in two-dimensional ultrasonic rolling process.

The ultrasonic cavitation effect can improve the machining quality. In order to study the formation process of cavitation in two-dimensional ultrasonic rolling process (TDUR) and its influence on processing, a simulation and experimental study of cavitation in TDUR was conducted to further improve the processing quality. The pressure distribution model and the cavitation model of the two-phase mixed flow around the roller in TDUR were constructed by combining the ideal bubble dynamics theory. And the cavitation intensity was evaluated by the vapor volume fraction (VVF). The formation process of cavitation effect in the flow field was analyzed by finite element analysis, and the effects of different inlet pressures and different pipe structures on the cavitation were studied. TDUR experiments were carried out to study the changes of surface roughness and residual stress of the workpiece under the effect of ultrasonic cavitation, and the positive effect of cavitation effect was verified. The simulation results show that the cavitation effect mainly occurs in the left half of the roller and the rolling area, and the cavitation in the left half of the roller changes from transient cavitation to steady-state cavitation as the inlet pressure increases. Different inlet pressures in the rolling region always show periodic transient cavitation, with obvious cavitation bubbles generation, expansion and collapse processes. The lower the inlet pressures in the straight and inverted trumpet pipe, the stronger the transient cavitation effect. The experimental results show that the cavitation effect can further improve the surface strengthening quality of the workpiece. Under the same process parameters, the surface roughness of the workpiece can be reduced by up to 47.7% and the residual compressive stress of the surface can be increased by up to 10.2%. Therefore, the cavitation effect can be applied in ultrasonic rolling process to further improve the surface strengthening quality, and the straight pipe at atmospheric inlet pressure is preferred in TDUR.

Impact of EBV infection and immune function assay for lymphoproliferative disorder in pediatric patients after liver transplantation: A single-center experience.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) is a lethal complication after pediatric liver transplantation, but information regarding risk factors for the development of PTLD remains unclear. This study was to identify characteristics and risk factors of PTLD. METHODS: A total of 705 pediatric patients who underwent liver transplantation between January 2017 and October 2018 were studied. Impact of clinical characteristics and Epstein-Barr virus (EBV) infection on the development of PTLD was evaluated. In addition, ImmuKnow assay was adopted in partial patients to analyze the immune status. RESULTS: Twenty-five (3.5%) patients suffered from PLTD with a median time of 6 months (3-14 months) after transplantation. Extremely high tacrolimus (TAC) level was found in 2 fatal cases at PTLD onset. EBV infection was found in 468 (66.4%) patients. A higher peak EBV DNA loads (>9590 copies/mL) within 3 months was a significant indicator for the onset of PTLD. In addition, the ImmuKnow assay demonstrated that overall immune response was significantly lower in patients with EBV infection and PTLD (P<0.0001). The cumulative incidence of PTLD was also higher in patients with lower ATP value (≤187 ng/mL, P<0.05). CONCLUSIONS: A careful monitoring of EBV DNA loads and tacrolimus concentration might be supportive in prevention of PTLD in pediatric patients after liver transplantation. In addition, application of the ImmuKnow assay may provide guidance in reducing immunosuppressive agents in treatment of PTLD.

Application of a novel liquid biopsy in patients with hepatocellular carcinoma undergoing liver transplantation.

Circulating tumor cells (CTCs) serves a primary function in metastasis and recurrence of hepatocellular carcinoma (HCC). In the present study, in order to evaluate the analytical performance and clinical value of the liquid biopsy-based platform, a novel integrated subtraction enrichment and immunostaining-fluorescence in situ hybridization (iFISH®) platform was applied to analyze CTCs in patients with HCC undergoing liver transplantation (LT). In total, 30 patients with HCC undergoing LT and 10 healthy volunteers were enrolled. CTCs in peripheral blood that were obtained from each patient prior to LT and 3 months thereafter were detected using the iFISH® platform, and CellSearch® system was performed for each subject for comparison. Using iFISH® and CellSearch®, the percentage of CTCs in patients with pre-operative HCC were 70.00% and 26.67%, respectively. CTCs counted using iFISH® (iFISH-CTCs) were increased compared with CellSearch® (Cellsearch-CTCs) (P<0.01). A significant decrease in iFISH-CTCs was observed 3 months following LT (3.04±0.93/7.5 to 1.0±0.53/7.5 ml, P<0.05). Furthermore, patients with lower preoperative iFISH-CTCs level (<5/7.5 ml) had markedly increased recurrence-free survival compared with iFISH-CTCs (>5/7.5 ml, 15 vs. 5.5 months; P<0.01. iFISH® platform exhibits an increased analytical sensitivity, and may be used as a dynamic monitoring tool for CTCs, and CTCs may be a good prognostic indicator for patients with HCC undergoing LT.