Altered surfactant protein A gene expression and protein homeostasis in rats with emphysematous changes.
- Author:
Qiong-jie HU
1
;
Sheng-dao XIONG
;
Hui-lan ZHANG
;
Xue-mei SHI
;
Yong-jian XU
;
Zhen-xiang ZHANG
;
Guo-hua ZHEN
;
Jian-ping ZHAO
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Blotting, Western; Emphysema; metabolism; pathology; Homeostasis; Immunohistochemistry; Male; Microscopy, Electron; Polymerase Chain Reaction; Pulmonary Surfactant-Associated Protein A; analysis; genetics; RNA, Messenger; analysis; Rats; Rats, Wistar
- From: Chinese Medical Journal 2008;121(13):1177-1182
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDThe decrease of surfactant protein (SP) secreted by the alveolar type II cell is one of the important causes of limiting air of pulmonary emphysema. However, the SP-A gene and protein changes in this disease are rarely studied. This study was undertaken to investigate alterations in SP-A gene activity and protein, and to explore their roles in the pathogenesis of emphysematous changes.
METHODSTwenty Wistar rats were divided randomly into a normal control group (n = 10) and a cigarette smoking (CS) + lipopolysaccharide (LPS) group (n = 10). Ultra-structural changes were observed under an electron microscope. The number of cells positive for SP-A was measured by immunohistochemistry. The mRNA expression and protein level of SP-A in the lung tissues were determined by quantitative polymerase chain reaction (qPCR) and Western blot separately. The protein level of SP-A in lavage fluid was determined by Western blot.
RESULTSThe number of cells positive for SP-A of the CS + LPS group (0.35 +/- 0.03) was lower than that of the blank control group (0.72 +/- 0.06, P < 0.05). The level of SP-A in the lung tissues of rats in the CS + LPS group (0.2765 +/- 0.0890) was lower than that in the blank control group (0.6875 +/- 0.1578, P < 0.05). The level of SP-A in the lavage fluid of rats in the CS + LPS group (0.8567 +/- 0.1458) was lower than that in the blank control group (1.3541 +/- 0.2475, P < 0.05). The lung tissues of rats in the CS + LPS group showed an approximate increase (0.4-fold) in SP-A mRNA levels relative to beta-actin mRNA (P < 0.05).
CONCLUSIONSThe changes of SP-A may be related to emphysematous changes in the lung. And cigarette smoke and LPS alter lung SP-A gene activity and protein homeostasis.