Liver X Receptors Activation Attenuates Ischemia Reperfusion Injury of Liver Graft in Rats

LncRNA Snhg1 Plays an Important Role via Sequestering rno-miR-139-5p to Function as a ceRNA in Acute Rejection After Rat Liver Transplantation Based on the Bioinformatics Analysis

In order to explore the molecular mechanism of acute rejection after liver transplantation (ARLT) in rats, we employed the GSE36798 data set in the Gene Expression Omnibust (GEO) database to construct a related ceRNA network. This dataset contained a total of 16 samples (8 graft samples and 8 plasma samples). Each kind of sample was divided into acute rejection (AR) groups and non-acute rejection (NR) groups, and each group had 4 replicates. First, we performed principal component analysis (PCA) with downloaded data to compare the difference between samples in a macroscopic way. Then, we used the “limma” R package to screen out differentially expressed miRNAs among different groups and used the “pheatmap” R package to perform bidirectional hierarchical clustering analysis for these differentially expressed miRNAs. The miRWalk database and the LncBase V.2 database were applied to predict downstream target genes and upstream-related lncRNAs, respectively. Meanwhile, the String database was used to predict the relationship between target genes, and the aforementioned results were processed for visualization by Cytoscape software. In addition, we exhibited the ultimate ceRNA network, including two lncRNAs, two miRNAs, and 77 mRNAs. Finally, we constructed a rat model of ARLT and applied graft specimens to relevant experimental verification. We found that the lncRNA Snhg1/rno-miR-139-5p axis might be involved in the regulation of ARLT in rats. In short, we demonstrated the differentially expressed miRNA profile, constructed a related ceRNA network, and screened out a possible regulatory axis. In view of the conservation of genes among species, this work was expected to provide a new strategy for the treatment and prevention of ARLT in the clinical setting.

IL-4 Alleviates Ischaemia-Reperfusion Injury by Inducing Kupffer Cells M2 Polarization via STAT6-JMJD3 Pathway after Rat Liver Transplantation

Background

Liver ischaemia-reperfusion injury (IRI) remains a problem in liver transplantation. Interleukin-4 (IL-4) has been found to reduce liver IRI, but the exact mechanism remains unclear.

Methods

Donor livers were infused with recombinant IL-4 or normal saline during cold storage, and the hepatocellular apoptosis and the inflammatory response were detected. The effect of IL-4 treatment on Kupffer cells (KCs) polarization and expression of the STAT6-JMJD3 pathway was evaluated in vivo and in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs.

Results

IL-4 treatment decreased sALT and sAST levels and alleviated hepatocellular apoptosis and inflammation at 6 h after liver transplantation. IL-4 treatment induced KCs alternatively activated (M2) polarization in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs. in vivo and in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs.

Conclusions

IL-4 treatment-induced KCs M2 polarization was dependent on the STAT6-JMJD3 pathway and protected liver grafts from IRI after liver transplantation.

α-ketoglutarate attenuates ischemia-reperfusion injury of liver graft in rats

OBJECTIVE

The α-ketoglutarate (αKG), a metabolite of glutaminolysis, is reported to orchestrate macrophages activation. This study aims to clarify whether the αKG / glutaminolysis metabolism can suppress Kupffer cells (KCs) activation during liver transplantation and attenuate hepatic ischemia-reperfusion injury (IRI).

METHODS

Donor livers were perfused with DM-αKG (a cell-permeable analog of αKG) or BPTES (an inhibitor of glutaminase 1) via portal vein during cold preservation, and controls were perfused with UW solution. Then, a rat model of liver transplantation was performed. Serum levels of alanine transaminase (ALT), total bilirubin (TBIL) and inflammatory cytokines, as well as histology, were analyzed after 24 h. KCs were isolated from grafts. RT-PCR and immunofluorescence were used to evaluate polarization-specific marker genes. Western bolt was employed to assess the expression of phosphorylation of glycogen synthase kinase 3β (p-GSK3β) and suppressor of cytokine signaling 1 (SOCS1). EMSA was utilized to quantify the NF-κB transcriptional activity.

RESULTS

Compared with controls, DM-αKG perfusion decreased ALT and TBIL levels, alleviated liver damage, and reduced apoptosis, while BPTES group showed higher ALT and TBIL levels, severe damage and more apoptosis. Furthermore, DM-αKG perfusion suppressed NF-κB activity, up-regulated the expression of p-GSK3β and SOCS1 in KCs, and shifted the M1/M2 balance toward an anti-inflammatory profile. Besides, DM-αKG suppressed serum pro-inflammatory cytokines secretion and increased IL-10.

CONCLUSIONS

αKG produced by glutaminolysis protects liver graft from IRI by regulating the inflammatory response and modifying the polarization of KCs.