Mycophenolate mofetil prevents lethal acute liver failure in mice induced by bacille Calmette‐Guérin and lipopolysaccharide

Abstract

To investigate the effect of mycophenolate mofetil (MMF) on acute liver injury induced by bacille Calmette-Guérin (BCG) and lipopolysaccharide (LPS). Acute liver failure was induced in male Kunming strain mice by injecting the animals with BCG 2.5 mg per mouse, and LPS 10 microg per mouse 10 days later. The mice in the treatment groups were given MMF 2 h before, simultaneous with, or 2 h after administration of LPS, and the mice in the control group were given the same dose of saline. The 24-h survival rate, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels were compared. Serum levels of tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and interleukin 6 (IL-6) were measured and the expressions of TNF-alpha, IFN-gamma, and IL-6 mRNA in the liver tissue were determined by reverse transcription-polymerase chain reaction (RT-PCR). Concanavalin A (Con A)-induced splenocyte proliferation were determined by methods of methyl thiazolyl tetrazolium. Injecting a small dose of LPS into BCG-primed mice caused a lethal hepatic injury mimicking acute hepatitis, from which 16 of the 20 mice died within 24 h (20% survival rate). Massive necrosis of parenchymal hepatocytes with marked inflammatory cell infiltration was observed by histological examination. In parallel, serum ALT and TNF-alpha, IFN-gamma, and IL-6 levels were increased. Expression of TNF-alpha, IFN-gamma, and IL-6 mRNA in the liver were significantly increased also. Treatment with MMF markedly reduced the death rate in a dose-dependent manner. It reached its maximal effect at the dosage of 150 mg per kg of body weight when pretreated 2 h before LPS injection, with improvement of histological feather and survival rate (84.2%, 16/19). MMF significantly inhibited serum levels of TNF-alpha, IFN-gamma, and IL-6, and significantly reduced TNF-alpha, IFN-gamma, and IL-6 expression in the liver, which increased after BCG and LPS injection. Moreover, splenocyte proliferation response induced by Con A was also inhibited by MMF treatment. Treatment with MMF has a protective effect on endotoxin-induced fatal liver failure by regulating the production of inflammatory cytokines and T-cell proliferation.