Jin-zheng Li

Endotoxin tolerance attenuates liver ischemia/reperfusion injury by down-regulation of interleukin-1 receptor-associated kinase 4 in kupffer cells.

AIM The aim of this study was to study the role of interleukin-1 receptor-associated kinase 4 (IRAK-4) in the formation of endotoxin tolerance (ET) in liver ischemia/reperfusion (I/R) injury. METHODS Animals were randomly divided into 3 groups: control group, I/R group, and ET group. Liver morphological changes were observed using optical microscopy with hematoxylin eosin (HE) staining. Alanine aminotransferase (ALT) was quantified to measure liver functional injury. The messenger RNA (mRNA) and protein expressions of IRAK-4 in Kupffer cells (KCs) isolated from recipients were detected using real-time polymerase chain reaction (PCR) and Western blot, respectively. The activities of NF-κB and the supernatant levels of tumor necrosis factor-alpha (TNF-α), IL-10 were assayed using enzyme-linked immunosorbent assay (ELISA). RESULTS Endotoxin preconditioning improved hepatic tissue injury as indicated by morphological analysis, whereas serum ALT levels were significantly decreased at various times (P < .05); concurrently, the expression of IRAK-4 and TNF-α in KCs was down-regulated (P < .05) and the secretion of IL-10 was enhanced (P < .05); NF-κB DNA-binding activity of KCs was also significantly inhibited by endotoxin preconditioning (P < .05). CONCLUSION Endotoxin preconditioning attenuated the liver I/R injury caused by transplantation. The expression of IRAK-4 in KCs may play an important role in the formation of ET.

Association Between Gene Polymorphisms of IRAK-M and the Susceptibility of Sepsis

The aim of this study was to explore the association between the single-nucleotide polymorphisms of interleukin-1 receptor-associated kinase-M (IRAK-M) gene and the susceptibility of sepsis. The allele frequency and genotype distribution of IRAK-M gene polymorphisms were assessed in 118 controls and 82 sepsis patients by semiquantitative polymerase chain reaction and restriction fragment length polymorphism (RFLP) analysis. The plasma levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were detected by enzyme-linked immunosorbent assay. Associations between IRAK-M polymorphisms and the susceptibility of sepsis were analyzed by Cox regression. Data were analyzed by the χ2 test and the Student’s t test, whenever appropriate. Statistical calculations were performed by using statistical package SPSS version 18.0. The genotype distribution of IRAK-M+22148 polymorphism significantly differed between the sepsis and control groups (P < 0.0001). The frequency of the G allele was remarkably more common in the sepsis group than that of the control group (P < 0.0001). However, the frequency of the A allele was significantly less common in the sepsis group than that of control group (P < 0.0001). Moreover, the plasma levels (in picograms per milliliter) of TNF-α and IL-6 in patients with G/G genotype were greatly higher than those with A/A genotype after lipopolysaccharide stimulation (P < 0.05). The genetic polymorphism of IRAK-M+22148 G>A is associated with the susceptibility of sepsis. The G/G genotype of IRAK-M increases the risk of developing sepsis, and the A/A genotype may play a protective role in the process of developing sepsis.

Dynamic Changes of Indoleamine 2,3-Dioxygenase of Kupffer Cells in Rat Liver Transplant Rejection and Tolerance

AIMS To study the dynamic changes and the immunologic role of indoleamine 2, 3-dioxygenase (IDO) in Kupffer cells (KCs) after rat liver transplantation. METHODS Animals were randomly divided into two groups: a rejection group (REJ; LEW to BN) and a tolerance group (TOL; BN to LEW). Liver morphological changes were observed optically with hematoxylin/eosin staining. KCs were isolated from recipients. mRNA and protein expressions of IDO were detected by real-time polymerase chain reaction and Western blotting at 1, 3, 5, and 7 days after transplantation. RESULTS The levels of IDO mRNA and protein in KCs of TOL groups were similar to those in REJ groups at day 1 posttransplantation. However, the expression of IDO mRNA and protein time-dependently increased to much higher levels in the TOL than the in REJ groups at 3, 5, and 7 days posttransplantation (P < .05). The peak was observed at 7 days. CONCLUSIONS The IDO level of KCs was closely associated with immune tolerance induction. IDO-mediated immune modulation appears to be an attractive means to assess transplant tolerance induction.

Advantages of Promoting Interleukin-10 by Silence of Histone Deacetylase 11 in Inducing Tolerance in Orthotopic Liver Transplantation in Rats

AIMS The aims of this study were to study the role of histone deacetylase 11 (HDAC11) in tolerance induction in orthotopic liver transplantation (OLT) in rats and to assess the advantages of gene therapy over the immunosuppressant FK506. METHODS Recipients were assigned to an acute rejection group (AcR; group I), an FK506 intervention group (group II), and a tolerance group (group III). Acute rejection (AcR) was graded by the Banff scheme and we examined postoperative survival. The messenger RNA (mRNA) and protein expressions of histone deacetylase 11 (HDAC11) and interleukin (IL) 10 in liver tissue were detected using real-time polymerase chain reaction (PCR) and Western blots, respectively. Plasma levels of tumor necrosis factor (TNF)-α, IL-2, and IL-10 were measured using enzyme-linked immunosorbent Assays. RESULTS Group I displayed severe, Group II had less, and Group III had no evidence of AR. The survivals among Group III were longer than those in Group I and Group II. IL-10 expression was promoted by HDAC11-shRNA at 7 days after OLT. Serum IL-2 and TNF-α levels were significantly lower among Group III compared with Groups I and II, whereas IL-10 showed the opposite result. CONCLUSIONS Silence of HDAC11 promotes IL-10 expression and leads to tolerance following OLT in rats. Thus HDAC11 is a promising target for gene therapy to induce tolerance with advantages over immunosuppressive drugs.

Correlation between augmenter of liver regeneration and IFN-γ expression in graft after rat orthotopic liver transplantation

BACKGROUND Previous data suggested that augmenter of liver regeneration (ALR) has immunomodulation function by suppressing liver-resident NK cell activity and reducing IFN-γ expression in human liver diseases. The correlation between ALR and IFN-γ expression in graft after rat orthotopic liver transplantation remains uncertain. METHODS A Lewis-to-BN (allograft group) and BN-to-BN (isograft group) rat liver transplantation model was used to investigate the ALR and IFN-γ expression in liver graft. Graft recipients were sacrificed at days 1, 3, 5, and 7 posttransplantation. The histopathologic changes of grafts were observed under light microscope and the intragraft expression of ALR and IFN-γ mRNA and protein was determined by real-time PCR and immunohistochemistry staining, respectively. Correlation between ALR and IFN-γ expression in graft was evaluated by Spearman rank correlation analysis. RESULTS The light microscope inspection revealed severe acute rejection in the allograft group but not in the isograft group at day 7 after liver transplantation. The intragraft ALR showed slight protein expression at day 1 after liver transplantation in both groups and it was significantly increased at days 3, 5, and 7 (P < 0.05). There was no significant difference in ALR mRNA expression between the allograft group and isograft group at day 1 (1.09 ± 0.12 and 1.13 ± 0.10, respectively; P > 0.05, n = 3). The ALR mRNA level was slightly reduced at day 3 in both groups compared with that at day 1 (0.81 ± 0.11 and 0.59 ± 0.10, respectively, P > 0.05). However, it was markedly increased at day 5 (2.86 ± 0.37) and day 7 (3.19 ± 0.33) in the isograft group and was 1.57 ± 0.27 and 1.98 ± 0.13 in the allograft group at days 5 and 7, respectively. IFN-γ protein and mRNA expression in the allograft group was increased at day 1 posttransplantation and reached a peak at day 3, and then it had a slight tendency of decline at day 5 and day 7. And they in the isograft group were at a low level at all times. The levels of ALR mRNA showed a negative correlation with levels of IFN-γ mRNA in the allograft group (r = -0.86, P < 0.05, y = -0.241x + 0.586), whereas there is no correlation between ALR and IFN-γ mRNA expression in the isograft group. CONCLUSION These data revealed an obviously negative correlation between ALR and IFN-γ levels intragraft, which indicated that ALR may participate in immunoregulation of acute rejection.

Glycogen synthase kinase 3 inhibitor attenuates endotoxin-induced liver injury

BACKGROUND/AIMS Endotoxin (lipopolysaccharide, LPS)-induced acute liver injury was attenuated by endotoxin tolerance (ET), which is characterized by phosphatidylinositol 3-kinase pathway/Akt signaling. Glycogen synthase kinase 3 (GSK-3) acts downstream of phosphatidylinositol 3-kinase pathway/Akt and GSK-3 inhibitor protects against organic injury. This study evaluates the hypothesis that ET attenuated LPS-induced liver injury through inhibiting GSK-3 functional activity and downstream signaling. METHODS Sprague-Dawley rats with or without low-dose LPS pretreatment were challenged with or without large dose of LPS and subsequently received studies. Serum tumor necrosis factor-alpha, interleukin-10, alanine aminotransferase, lactate dehydrogenase, and total bilirubin levels were analyzed, morphology of liver tissue was performed, glycogen content, myeloperoxidase content, phagocytosis activity of Kupffer cells, and the expression and inhibitory phosphorylation as well as kinase activity of GSK-3 were examined. Survival after LPS administration was also determined. RESULTS LPS induced significant increases of serum TNF-α, alanine aminotransferase, lactate dehydrogenase, and total bilirubin (P < 0.05), which were companied by obvious alterations in liver: the injury of liver tissue, the decrease of glycogen, the infiltration of neutrophils, and the enhancement of phagocytosis of Kupffer cells (P < 0.05). LPS pretreatment significantly attenuated these alterations, promoted the inhibitory phosphorylation of GSK-3 and inhibited its kinase activity, and improved the survival rate (P < 0.05). CONCLUSIONS ET attenuated LPS-induced acute liver injury through inhibiting GSK-3 functional activity and its downstream signaling.

Expression of Glucocorticoid-Induced Tumor Necrosis Factor Receptor Ligand in Rat Graft after Liver Transplantation

BACKGROUND Costimulation between the glucocorticoid-induced tumor necrosis factor receptor and its ligand (GITRL) breaks immunologic tolerance induced by regulatory T cells. The purpose of this research was to examine the involvement of GITRL during rat liver transplantation, the survival of which depends on interactions between regulatory T cells and Kupffer cells (KCs). METHODS Recipients were divided into 2 groups: The allograft group underwent orthotopic liver transplantation from male Lewis to Brown Norway (BN) rats and the isograft group, BN-to-BN liver transplantation. We evaluated 2-week survival rates, histologic changes, as well as serum and supernatant levels of tumor necrosis factor-α (TNF-α); GITRL, and TNF-α expressions in the graft, and GITRL expression by graft-derived KCs. RESULTS TNF-α levels were increased in plasma and in the supernates of KCs during allograft transplantation compared with isograft liver transplantation (P <.05). The expressions of TNF-α and GITRL in liver grafts were increased during acute rejection. Furthermore, the expression of GITRL on KCs derived from allografts was increased compared with isografts (P < .05). CONCLUSION GITRL expression on KCs may mediate acute rejection in liver transplantation.

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

ABSTRACT Purpose: Suppression of the Toll like receptor 4 (TLR4)-nuclear factor-κB (NF-κB) signaling was critical in protection against liver IRI. Previous studies revealed that Liver X receptors (LXRs) activation could antagonize TLR4-NF-κB signaling. The purpose of this study is to determine whether LXRs agonist GW3965 can suppress the TLR4-NF-κB signaling during liver transplantation and protect ischemia-reperfusion injury (IRI). Materials and Methods: Sprague Dawley (SD) rats were used to perform orthotropic liver transplantation. Donors were pretreatment with GW3965 (0.3 mg/kg) through caudal vein injection 30 min before the surgery. The followings were analyzed after transplantation: alanine aminotransferase (ALT), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) level in serum, ATP binding cassette transporter A1 (Abca1) expression, NF-κB transcriptional activity, apoptosis and histological injury. Results: GW3965 pretreatment significantly ameliorated the degree of IRI associated with the effects of upregulating Abca1 expression, inhibiting NF-κB transcriptional activity, and downregulating TNF-α and IL-6 level. Conclusion: LXRs activation attenuated hepatic IRI by preventing TLR4–NF-κB signaling.