[Effect of nuclear factor-kappaB on peroxisome proliferator activated receptor gamma expression in Ana-1 cells].
OBJECTIVE
To determine the effects of nuclear factor-alpha B (NF-alpha B) on peroxisome proliferator activated receptor gamma (PPAR gamma) expression in the murine macrophage cell line Ana-1, based on the investigation of the PPAR gamma expression stimulated by lipopolysaccharide (LPS).


METHODS
Ana-1 cells were divided randomly into seven groups: control group, LPS groups (cells were activated by 0.1 mg/L LPS for 1, 2, 4, 8 hours respectively), SN50 group (cells were stimulated by 50 mg/L SN50 for 4 hours) and NF-alpha B high expression plasmid transfected group. PPAR gamma and tumor necrosis factor-alpha(TNF-alpha) mRNA levels were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and the TNF-alpha protein was measured by enzyme linked immunosorbent assay (ELISA) after being activated by LPS. The eukaryotic expression vector of murine NF-alpha B p65 gene was constructed and stably transfected into Ana-1 cells with DOTAP liposome . The PPAR gamma expression and NF-alpha B p65 translocation as stimulated by LPS and SN50 were assayed by Western blotting.


RESULTS
Expressions of both PPAR gamma mRNA and protein were downregulated when cells were stimulated by LPS, which were accompanied with the activity of NF-alpha B and TNF-alpha in Ana-1 cells (all P<0.05). The eukaryotic expression vectors containing murine p65 gene were successfully constructed and stably transfected into Ana-1 cells. LPS stimulation and NF-alpha B p65 gene overexpression resulting in upregulation of p65 could downregulate PPAR gamma expression in Ana-1 cells (r=-0.913, P<0.05).But downregulation of NF-alpha B by SN50 could upregulate PPAR gamma expression in the nucleus (r=-0.959, P<0.05).


CONCLUSIONS
LPS can markedly decrease the expression of PPAR gamma in Ana-1 cells, which may be related to its activity of enhancing NF-alpha B. NF-alpha B p65 gene can control PPAR gamma expression in the reverse direction in Ana-1 cells.
Xiao
Bo
B
Institute of Respiratory Diseases of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
Wang
Jian-chun
JC
Wang
Guan-song
GS
Ji
Fu-yun
FY
Xu
Jing
J
D000818:Animals; D002460:Cell Line; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics
D008070:Lipopolysaccharides; D016328:NF-kappa B; D047495:PPAR gamma; D012333:RNA, Messenger