Objective To investigate the role of macrophage stimulating protein (MSP) in the pathogenesis of chronic obstructive pulmonary disease (COPD). Methods Ninety subjects were recruited from health examination center, outpatient or inpatient department in Affiliated Hospital of North Sichuan Medical College from July 2013 to December 2013. They were divided intoahealthy control group, a stable COPD group, and an acute exacerbation of COPD (AECOPD) group with 30 subjects in each group. The levels of MSP, interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in the plasma of all subjects, as well as the levels of MSP in the induced sputum of the AECOPD and the stable COPD patients were assessed by enzyme-linked-immuno-sorbent assay. Results The concentrations of MSP, IL-6, IL-8 and TNF-α in the plasma of the patients with COPD were obviously higher than those of the healthy controls (P<0.05) while much higher in AECOPD patients than those in stable COPD patients (P<0.01).The concentration of MSP in the induced sputum of the patients with AECOPD was higher than that in the stable COPD patients (P<0.01). The concentrations of MSP in the serum and induced sputum as well as serum levels of IL-6, IL-8 and TNF-α in the patients with COPD were negatively correlated with the level of FEV1%pred. The concentrations of MSP in the serum and induced sputum in the COPD patients were positively correlated with the concentrations of IL-6, IL-8 and TNF-α. Conclusions The concentrations of serum and induced sputum MSP, and the serum concentrations of IL-6, IL-8 and TNF-α in COPD patients are related to the severity of the disease. MSP may play an important role in the pathogenesis of COPD. The mechanism might be mainly involved in the regulation of airway inflammation.
ObjectiveTo investigate the role and mechanism of S100A8/A9 in rat model of chronic obstructive pulmonary disease (COPD). Methods Twelve Wistar rats were randomly divided into a normal control group and a COPD group. The COPD model was established by exposing the rats to cigarette smoke and injected lipopolysaccharide (LPS) in bronchus for 1 month. The pathological changes of the lung tissue were observed under light microscope, and the emphysema indexes of pulmonary mean linear intercept (MLI), mean alveolar numbers (MAN) and pulmonary alveolar area (PAA) were analyzed by image analysis system. The concentrations of S100A8/A9 in serum and bronchoalveolar lavage fluid (BALF) were measured by enzyme linked immunosorbent assay. The mRNA expression levels of S100A8, S100A9, Toll-like receptor-4 (TLR4) and myeloid differentiation factor 88 (MyD88) of lung tissues were measured by real time polymerase chain reaction. The protein expressions of S100A8/A9, TLR4 and MyD88 of lung tissues were detected by immunohistochemistry. Results After cigarette smoking and LPS injection for 1 month, the rat lung tissue appeared in accordance with the typical pathological changes of COPD. The MLI, MAN and PAA had obvious difference compared with the normal control group (P<0.05). The concentrations of S100A8/A9 protein in BALF and serum of the COPD group were obviously higher than those of the normal control group (P<0.05). The levels of S100A8, S100A9, TLR4 and MyD88 mRNA of lung tissues in the COPD group were obviously higher than those in the normal control group (P<0.05), and the expression levels of S100A8 and S100A9 mRNA were positively correlated with the expression levels of TLR4 and MyD88 mRNA respectively (P<0.05). The levels of S100A8/A9, TLR4 and MyD88 protein of lung tissues in COPD group were obviously higher than those in normal control group (P<0.05), and the levels of S100A8/A9 protein were positively correlated with the levels of MyD88 and TLR4 protein (P<0.05). Conclusions As a new inflammatory mediator, S100A8/A9 may be involved in the occurrence and development of COPD. By up-regulating the expression of TLR4 and MyD88, the classical TLR4-MyD88 inflammatory pathway is activated, thus promotes the occurrence and development of COPD.