Potential mechanism underlying down-regulation of albumin expression induced by lipopolysaccharide in rat hepatocytes / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the potential molecular mechanism underlying down-regulation of albumin expression induced by lipopolysaccharide (LPS) in rat hepatocytes.</p><p><b>METHODS</b>The albumin mRNA expression and albumin protein levels in the supernatant were observed at 0, 2, 8, 12 and 24 hours after 1 micro g/ml LPS treatment. The albumin mRNA expression was determined by RT-PCR, and albumin protein levels were assayed with EIA in the supernatant of hepatocytes pretreated with specific inhibitors of extracellular signal-regulated kinase (PD98059) and p38 kinase (SB203580).</p><p><b>RESULTS</b>The albumin mRNA expression was reduced to 70% of baseline value, meanwhile, the albumin protein concentration in the supernatant was reduced by 50% compared with the controls after 24 hours of LPS treatment. Pretreatment with PD98059 and SB203580 did significantly inhibit the reduction of albumin by LPS at the given dose.</p><p><b>CONCLUSION</b>The results indicate that LPS can induce the reduction of albumin synthesis by down-regulation of albumin mRNA expression at transcription level, and the process may be related to the signal transducation of extracellular signal-regulated kinase and p38 kinase.</p>