Upregulation of TNF-alpha and IL-6 mRNA in mouse liver induced by bacille Calmette-Guerin plus lipopolysaccharide.
OBJECTIVE
To investigate the mechanism of immunological liver injury induced by bacille Calmette-Guerin (BCG) plus lipopolysaccharide (LPS).


METHODS
Mice were injected via the tail vein with 125 mg/kg BCG, and 12 d later, the mice were injected intravenously with different doses of LPS (125, 250, or 375 microg/kg). Serum alanine aminotransferase (ALT) activity and liver pathological changes were examined. The expression of tumor necrosis factor (TNF)- alpha, interleukin (IL)-6, lipopolysaccharide binding protein (LBP) and CD14 mRNA, and NF-kappaB and IkappaB-alpha protein in mouse liver at different time points after BCG and LPS injection were measured using RT-PCR, immunohistochemistry and Western blotting analysis, respectively.


RESULTS
The activity of serum ALT in mice treated with BCG and LPS was significantly increased. Different degrees of liver injury, such as inflammatory cell infiltration, spotty necrosis, piecemeal necrosis, even bridging necrosis, could be seen in liver sections from mice after BCG and LPS administration. Furthermore, the levels of TNF-alpha and IL-6 mRNA in mouse liver were significantly elevated after administration of BCG plus LPS (P<0.05). The levels of LBP and CD14 mRNA in mouse liver were markedly upregulated after treatment with BCG and LPS, and treatment with BCG alone led to an increase in CD14 mRNA in mouse liver. Finally, immunoreactivity for NF-kappaB p65 was predominantly detected in hepatocyte nuclei from mice treated with BCG plus LPS, compared with the normal group. Protein levels of IkappaB-alpha were strikingly decreased by LPS or BCG plus LPS treatment, compared with the normal group or BCG group.


CONCLUSIONS
TNF-alpha and IL-6 mRNA were partially involved in early immunological liver injury induced by challenge with small doses of LPS after BCG priming. Upregulation of TNF-alpha and IL-6 mRNA might be related to increases in LBP and CD14 mRNA expression and activation of NF-kappaB. Furthermore, BCG priming in immunological liver injury may occur via upregulation of CD14 mRNA expression in mononuclear cell infiltration into the liver.
Liu
Dao-Fang
DF
Institute of Clinical Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology in Anhui Province, Key Laboratory of Research and Development of Chinese Medicine in Anhui Province, Anhui Medical University, Hefei 230032, China.
Wei
Wei
W
Song
Li-Hua
LH
D000209:Acute-Phase Proteins / Q000096:biosynthesis / Q000235:genetics; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D020672:I-kappa B Proteins / Q000378:metabolism; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis / Q000235:genetics; D008070:Lipopolysaccharides; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009163:Mycobacterium bovis; D000072000:NF-KappaB Inhibitor alpha; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051996:Transcription Factor RelA / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D000410:Alanine Transaminase; D002352:Carrier Proteins; D020672:I-kappa B Proteins; D015850:Interleukin-6; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D000072000:NF-KappaB Inhibitor alpha; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D000099231:Lipopolysaccharide-Binding Protein; C000606205:Nfkbia protein, mouse