[Effects of TNF alpha on the expression of SCAP and triglyceride contents in cultured steatotic hepatocytes].
OBJECTIVE
To explore the effects of TNF alpha on the expression of sterol regulatory element binding proteins cleavage activating protein (SCAP) and triglyceride contents in cells of a model of cultured steatotic hepatocytes.


METHODS
A steatotic hepatocytes model was established by treating L-02 cell strain with oleic acid. The cells were treated with TNF alpha and/or TNF alpha antibody. The cells were divided into six groups: a control group (C), a model group (F), a control group with TNF alpha (C1), a control group with TNFalpha antibody (C2), a model group with TNFalpha(F1) and a model group with TNFalpha antibody (F2). The expression of SREBP-1c mRNA was measured with RT-PCR; the protein expression of SCAP was measured by Western blot; lipid droplets in the hepatocytes were observed with oil red O staining; the contents of triglyceride in hepatocytes were measured with an analytical kit.


RESULTS
The mRNA expression of SCAP in the groups treated with TNF alpha were upregulated compared with those of the control group (C1 vs C increased 67%, F1 vs F increased 55%, F = 212.98), the protein expression of SCAP in the groups treated with TNF alpha was upregulated compared with those of the control group (C1 vs C increased 45%, F1 vs F increased 95%, F = 104.3), and triglyceride contents in hepatocytes of these groups were increased compared with those of the control group [C (2.02+/-0.67) mg/10(7) cells, F(7.79+/-1.35) mg/10(7) cells, F1(13.36+/-1.99) mg/10(7) cells, F = 82.94].


CONCLUSIONS
TNF alpha upregulates the expression of SCAP and promotes the synthesis of triglyceride; it probably participates in the process of developing steatosis of hepatocytes.
Yang
Lin-hui
LH
Department of Gastroenterology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, China.
Chen
Dong-feng
DF
D002460:Cell Line; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C102196:SREBP cleavage-activating protein; D014409:Tumor Necrosis Factor-alpha