Multiple microRNAs regulate tacrolimus metabolism through CYP3A5.

The CYP3A5 gene polymorphism accounts for the majority of inter-individual variability in tacrolimus pharmacokinetics. We found that the basal expression of CYP3A5 in donor grafts also played a significant role in tacrolimus metabolism under the same genetic conditions after pediatric liver transplantation. Thus, we hypothesized that some potential epigenetic factors could affect CYP3A5 expression and contributed to the variability. We used a high-throughput functional screening for miRNAs to identify miRNAs that had the most abundant expression in normal human liver and could regulate tacrolimus metabolism in HepaRG cells and HepLPCs. Four of these miRNAs (miR-29a-3p, miR-99a-5p, miR-532-5p, and miR-26-5p) were selected for testing. We found that these miRNAs inhibited tacrolimus metabolism that was dependent on CYP3A5. Putative miRNAs targeting key drug-metabolizing enzymes and transporters (DMETs) were selected using an in silico prediction algorithm. Luciferase reporter assays and functional studies showed that miR-26b-5p inhibited tacrolimus metabolism by directly regulating CYP3A5, while miR-29a-5p, miR-99a-5p, and miR-532-5p targeted HNF4α, NR1I3, and NR1I2, respectively, in turn regulating the downstream expression of CYP3A5; the corresponding target gene siRNAs markedly abolished the effects caused by miRNA inhibitors. Also, the expression of miR-29a-3p, miR-99a-5p, miR-532-5p, and miR-26b-5p in donor grafts were negatively correlated with tacrolimus C/D following pediatric liver transplantation. Taken together, our findings identify these miRNAs as novel regulators of tacrolimus metabolism.

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.

Long non-coding RNAs play regulatory roles in acetaminophen-induced liver injury.

OBJECTIVE: To explore the expression profile and role of hepatic long non-coding RNA (lncRNA) in acetaminophen-induced liver injury mouse model by analyzing lncRNA-mRNA co-expression. METHODS: Serum aminotransferase, liver pathology and inflammatory cells were analyzed in mice model at different time points after treated with acetaminophen 300 mg/kg. High-throughput RNA sequencing was performed to investigate hepatic expression profiles of messenger RNA (mRNA) and lncRNA. The relationship between the lncRNA and mRNA was delineated by the co-expression network using Cytoscape software. Differential mRNAs co-expressed with lncRNAs were analyzed using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment. Differential mRNAs and lncRNAs were selected for quantitative reverse transcription polymerase chain reaction validation, and the conservation of lncRNA between human and mouse was analyzed. RESULTS: Liver injury was more severe at 24 hours than at 6 hours. There was a substantial infiltration of monocytes instead of neutrophil and Kupffer cells at 24 hours compared with 6 hours. The mRNAs co-expressed with the differential lncRNAs at 24 vs 6 hours were mainly enriched in protein processing in endoplasmic reticulum, MAPK and PPAR signaling pathways. The co-expression network delineated with four lncRNAs and 94 mRNAs presented the core position of lncRNA in the network. A conservation analysis indicated that four differential mouse lncRNAs (NONMMUT023651.2, NONMMUT029382.2, NONMMUT029383.2 and NONMMUT102053.1) could all be mapped to the relevant human lncRNAs. CONCLUSION: Four lncRNAs may play regulatory roles through metabolic and apoptosis-related pathways during hepatic homeostasis maintenance and repair progress.

Impact of non-oncological factors on tumor recurrence after liver transplantation in hepatocellular carcinoma patients.

Hepatocellular carcinoma (HCC) is the most common primary neoplasm of the liver and is one of the leading causes of cancer-related death worldwide. Liver transplantation (LT) has become one of the best curative therapeutic options for patients with HCC, although tumor recurrence after LT is a major and unaddressed cause of mortality. Furthermore, the factors that are associated with recurrence are not fully understood, and most previous studies have focused on the biological properties of HCC, such as the number and size of the HCC nodules, the degree of differentiation, the presence of hepatic vascular invasion, elevated serum levels of alpha-fetoprotein, and the tumor stage outside of the Milan criteria. Thus, little attention has been given to factors that are not directly related to HCC (i.e., "non-oncological factors"), which have emerged as predictors of tumor recurrence. This review was performed to assess the effects of non-oncological factors on tumor recurrence after LT. The identification of these factors may provide new research directions and clinical strategies for the prophylaxis and surveillance of tumor recurrence after LT, which can help reduce recurrence and improve patient survival.