[Study on molecular mechanisms of indirect suppression of albumin mRNA expression of hepatocytes by lipopolysaccharide in rat].
OBJECTIVE
To explore the molecular mechanisms of relationship between the decreased expression of albumin gene of the cultured hepatocytes by lipopolysaccharide (LPS) and cytokines.


METHODS
As an inhibitor of protein synthesis, cycloheximide (CHX) could inhibit the LPS-induced synthesis of cytokines. Therefore, the culture system pretreated with CHX could exclude the influence of cytokines on the regulation of albumin gene expression, then it might prove that LPS induced down-regulation of expression of albumin gene was a through cytokine-dependent pathway. The concentrations of interleukin (IL-6) and tumor necrosis factor-alpha(TNF -alpha) in the supernatant were also assayed.


RESULTS
The expression of albumin mRNA is inhibited significantly by LPS. CHX could block the pathway of LPS-induced down-regulation of expression of albumin gene at least at the transcription level. And the prevention was in a dose-related manner. The increase of IL-6 and TNF-alpha induced by LPS was inhibited by CHX(both P<0.05).


CONCLUSIONS
The results suggest that LPS can indirectly inhibit the transcription of albumin gene through cytokines such as IL-6 and TNF-alpha.
Research Institute of General Surgery, Jinling Hospital, Nanjing 210002, Jiangsu, China.
Xin-Ying
XY
Wang
Wei-Qin
WQ
Li
Ning
N
Li
Jie-Shou
JS
Li
D000418:Albumins / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000418:Albumins; D015850:Interleukin-6; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha