[Influence of sexual difference on expression of Toll-like receptor 4 and myeloid differential protein-2 mRNA in the lung in septic rats].
OBJECTIVE
To investigate the influence of gender on the gene expression of Toll-like receptor 4 (TLR4), myeloid differential protein-2 (MD-2) and tumor necrosis factor-alpha (TNF-alpha) in the lung in septic rats.


METHODS
The total RNA from normal and lipopolysaccharide (LPS)-challenged rats was extracted by Trizol reagent. The gene expressions of TLR4, MD-2 and TNF-alpha mRNA were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Plasma estradiol (E2) content was determined by radioimmunoassay.


RESULTS
The gene of TLR4, MD-2 and TNF-alpha were expressed in the lungs in normal rats, and there was no significant difference between male and female rats (P>0.05). After LPS challenge, the gene expression were markedly up-regulated at 2 hours, and the gene expressions of TLR4, MD-2 and TNF-alpha were significantly lower in female group than those in male group (all P<0.01).


CONCLUSIONS
There are marked difference in activation of TLR4 signal transduction in the lung when stimulated by LPS between male group and female group. The response to LPS is lower in female septic rats than in male septic rats, which might be associated to the effect of endogenous estrogen.
Du
Xiao-hui
XH
Department of General Surgery, The General Hospital of PLA, Beijing 100853, China.
Yao
Yong-ming
YM
Li
Rong
R
Shen
Chuan-an
CA
Yin
Hui-nan
HN
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D008168:Lung / Q000378:metabolism; D051218:Lymphocyte Antigen 96 / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018805:Sepsis / Q000378:metabolism*; D012737:Sex Factors; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D051218:Lymphocyte Antigen 96; D012333:RNA, Messenger; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha