[The expression of scavenger receptor class A in the lung in mice with acute lung injury induced by lipopolysaccharide].
OBJECTIVE
To investigate the expression of scavenger receptor class A (SR-A) in lung tissue and alveolar macrophage (AM) in mice with acute lung injury (ALI) induced by lipopolysaccharide (LPS).


METHODS
The model of ALI was reproduced by intraperitoneal (ip) injection of LPS (5 mg/kg), and the expression of SR-A was observed in lung tissue and AM, and the expression and distribution of J774 A.1 were also studied by using mouse macrophage line.


RESULTS
Partial pressure of oxygen in artery (PaO(2)) of lung tissue in LPS groups was significantly lower while wet/dry weight (W/D) ratio was higher than those in normal saline control group (both P<0.01). SR-A was widely expressed in murine lung, including AM, pulmonary vascular endothelial cells, vascular smooth muscle cells, lung epithelial cells and polymorphonuclear neutrophils. Immunohistochemical staining showed that, during the course of development of ALI in mice, the expression of SR-A was gradually down-regulated with the elapse of time after ip injection of LPS, The same result was seen in the isolated AM, and especially marked in group 4 hours and group 8 hours. In vitro, the expression of SR-A on J774 A.1 cells decreased was also down-regulated when treated with LPS.


CONCLUSIONS
SR-A was widely expressed in murine lung. During the course of ALI, the expression of SR-A in the murine lung and AM is down-regulated, which may be induced by LPS.
Tian
Yu-Heng
YH
Institute of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
Xu
Jian-Cheng
JC
Qian
Gui-Sheng
GS
Gong
Chuan-Ming
CM
Chen
Wei-Zhong
WZ
Li
Shu-Ping
SP
D055371:Acute Lung Injury / Q000378:metabolism*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D008070:Lipopolysaccharides / Q000633:toxicity*; D008168:Lung / Q000378:metabolism*; D016676:Macrophages, Alveolar / Q000378:metabolism; D008297:Male; D051379:Mice; D011897:Random Allocation; D051117:Scavenger Receptors, Class A / Q000378:metabolism*
D008070:Lipopolysaccharides; C495140:Msr1 protein, mouse; D051117:Scavenger Receptors, Class A