Effects of pirfenidone on endotoxin-induced liver injury after partial hepatectomy in rats.

BACKGROUND: In living donor liver transplantation, restrictions on graft size are a serious obstacle to expand indications for adult recipients. The sequence of gram-negative infection, septicemia, and multiple-organ failure is a common cause of early mortality after liver transplantation. An effective therapy has not been established for endotoxemia following extended hepatectomy in donors or small-for-size grafts in recipients. Pirfenidone (PFD), a new experimental antifibrotic agent, was used to ameliorate on endotoxin-induced liver injury following partial hepatectomy. METHODS: Male Sprague-Dawley rats were intravenously administered lipopolysaccharide (LPS) 48 hours after 70% hepatectomy. Prior to LPS administration, PFD (300 mg/kg) or its vehicle (0.5% carboxymethylcellulose) was given orally twice. RESULTS: The survival rate of the PFD-treated group was markedly improved compared with that of the controls. PFD prevented the increases in the activities of serum enzymes (aspartate transaminase [AST], alanine transaminase [ALT], and lactate dehydrogenase [LDH]) and total bilirubin. The serum and liver tissue levels of inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, interferon-gamma, and interleukin-6, were significantly lower among the PFD than the control group. Furthermore, the degree of necrosis in the remnant liver was significantly decreased in the PFD-treated rats compared with controls. CONCLUSION: These results indicate that PFD alleviates endotoxin-induced liver injury after partial hepatectomy through the inhibition of production of inflammatory cytokines in the residual liver. PFD may be useful to prevent endotoxin-induced liver injury after hepatectomy.

Effect of hepatocyte growth factor on induction of cytokine-induced neutrophil chemoattractant in rat hepatocytes.

BACKGROUND: Restrictions on graft size are a serious obstacle to the expansion of indications for adult recipients in living donor liver transplantation. Hepatocyte growth factor (HGF) has a crucial role in regeneration following hepatic injury. Rat cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin-8 superfamily in humans, has been implicated in chronic liver diseases or development of liver ischemia-reperfusion injury. Studies were performed to examine whether HGF influences the induction of CINC in hepatocytes. METHODS: Primary cultures of rat hepatocytes were treated with or without recombinant human (rh) HGF. The release of CINC into the culture medium and levels of CINC mRNA were measured using an enzyme-linked immunosorbent assay and Northern blot analysis. Transcription of nuclear factor (NF)-kappa B was detected by electrophoretic mobility shift assays. RESULTS: rhHGF increased the release of CINC in the medium dose- and time-dependently, showing a maximal effect at 100 ng/mL. Genistein (100 mumol/L) blocked the release of CINC stimulated by rhHGF. Levels of CINC mRNA were also increased, reaching a maximum at 8 hours after addition of rhHGF. Electrophoretic mobility shift assays revealed rhHGF activated transcription factor, NF-kappa B. CONCLUSION: These results suggest that HGF stimulates the induction of CINC gene expression through activation of NF-kappa B. CINC may be involved in the function of HGF during liver regeneration.

Pirfenidone protects endotoxin-induced liver injury after hepatic ischemia in rats.

BACKGROUND: Pirfenidone (PFD), an experimental antifibrotic agent, was investigated for its effects on endotoxin-induced liver injury after hepatic ischemia-reperfusion. METHODS: Male Sprague-Dawley rats were subjected to 30 minutes of partial hepatic ischemia, followed by reperfusion for 24 hours. Lipopolysaccharide (LPS) was injected at 30 minutes of reperfusion. PFD (300 mg/kg) or its vehicle (0.5% carboxymethylcellulose) was given orally following LPS administration. RESULTS: PFD prevented the increase in activities of serum alanine transaminase, aspartate transaminase, and lactate dehydrogenase after reperfusion. PFD inhibited the increase of cytokine-induced neutrophil chemoattractant in serum and liver tissue. The number of neutrophils infiltrating the liver was significantly lower in the PFD-treated group than the control group. CONCLUSION: These results indicate that PFD prevents endotoxin-induced liver injury after hepatic ischemia-reperfusion, in part through the decrease of neutrophil infiltration to the liver.

Effect of pirfenidone on induction of chemokines in rat hepatocytes.

BACKGROUND: Hepatic ischemia-reperfusion results in a neutrophil-dependent liver injury. The process of neutrophil recruitment and activation in this injury is at least partially dependent on the induction of chemokines, such as cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 (MIP-2) in rats. In the liver, parenchymal cells (hepatocytes), in addition to nonparenchymal cells such as Kupffer cells, have been reported to produce chemokines in the regulation of hepatic inflammation. Pirfenidone (PFD) is a new experimental drug used as an antifibrotic agent. Studies were performed to determine whether PFD influences the production of CINC and MIP-2 stimulated by interleukin (IL)-1beta in a primary culture model of rat hepatocytes. METHODS: Primary cultures of rat hepatocytes were treated with IL-1beta in the presence and absence of PFD. The protein and mRNA of CINC and MIP-2 were analyzed using enzyme-linked immunosorbent assays and Northern blots. RESULTS: IL-1beta increased the release of CINC and MIP-2 into culture media in a dose- and time-dependent manner. PFD inhibited both CINC and MIP-2 release in dose-dependent fashion. However, PFD had no effect on the levels of CINC mRNA induced by IL-1beta. CONCLUSION: These results suggest that PFD inhibits the production of CINC and MIP-2 by IL-1beta at a posttranscriptional step in hepatocytes.

Induction of inducible nitric oxide synthase in hepatocytes isolated from rats with ischemia-reperfusion injury.

BACKGROUND: Recent evidence indicates that nitric oxide (NO) has a crucial role in hepatic ischemia-reperfusion (I/R) injury. However, little is known about how I/R influences the gene expression of inducible nitric oxide synthase (iNOS) in hepatocytes. Under inflammatory conditions, we compared the induction of iNOS in hepatocytes isolated from normal and I/R-treated rats. METHODS: Hepatocytes were isolated using the collagenase perfusion method from rats treated with I/R (30-minute ischemia of middle and left lobes, followed by 3-hour reperfusion) or sham operation (control): Primary cultures of rat hepatocytes were incubated with an inflammatory cytokine, interleukin-1beta (IL-1beta), to compare the iNOS induction/NO production between the 2 groups. RESULTS: Both control and I/R groups had no production of nitrite (a stable metabolite of NO) in the absence of IL-1beta. In the control group, IL-1beta stimulated dose- and time-dependent production of NO. The I/R group showed more than 2-fold increased levels of NO production. Western and Northern blot analyses revealed that the I/R group also showed increased levels of iNOS protein and its messenger RNA. CONCLUSION: These results suggest that I/R directly affects the inducibility of the iNOS gene in hepatocytes by IL-1beta. Increased NO may be associated with protective or toxic effects in hepatic I/R injury.