科研之友
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摘要
Background The 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.
Methods Twenty 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.
Results The 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 a-actin mRNA (P<0.05).
Conclusions The 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.
- 出版日期2008-7-5
- 单位华中科技大学
