Studies on the effects of anti-nerve growth factor antibody and expression levels of matrix metalloproteinase-9 in asthmatic guinea pig model / 解放军医学杂志

ABSTRACT

Objective To investigate the pathological features of airway remodeling and evaluate interventional effects of nerve growth factor (NGF) on the expression of matrix metalloproteinase-9 (MMP-9), an important mediator of airway remodeling, in guinea pig asthma model. Methods Guinea pigs were randomly divided into the control group, asthma group, and antibody NGF intervention group (each group had 8 guinea pigs). In the asthma group the animals were sensitized by repeated exposure to aerosolized ovalbumin combined with Al(OH)_3. The thickness of the smooth muscle of intrapulmonary bronchi was measured by image analysis system. The expression of MMP-9 in bronchi and lung tissues were assayed with immunohistochemistry combined with the micro-image analysis system. The levels of MMP-9 mRNA in bronchi and lung tissues were determined by RT-PCR. Results After repeated allergen challenge, obvious infiltration of inflammatory cells and proliferation of goblet cells and smooth muscle were demonstrated in guinea pig bronchi. Expression levels of MMP-9 in the epithelial cells of bronchi were significantly higher in asthmatic animals than those of control group animals. Compared with asthmatic group, there was mild inflammation reaction, and decrease in collagen deposition and expression of MMP-9 in antibody NGF group animals, and they were not significantly higher than that in control group animals. Conclusions Repeated exposure of allergen induced airway inflammation and remodeling. MMP-9 plays an important role in airway remodeling. Antibody NGF intervention could inhibit airway remodeling through inhibition of the expression of MMP-9.