Abstract：OBJECTIVE: To study the role of cell adhesion molecule CD44 in the lung on airway inflammatory response in rats with asthma. METHODS: Thirty-two Sprague-Dawley rats were randomly divided into normal control and asthma groups. Asthma was induced by repeated inhalation of ovalbulium. CD44 expression in the lung was detected by semi-quantitatively reverse transcription-polymerase chain reaction (RT-PCR) and immuno-histochemical staining 1 week and 2 weeks after ovalbulium challenge. Differential leukocytes (mononuclear phagocytes, neutrophils, eosinophils, and lymphocytes) in bronchoalveolar lavage fluid (BALF) were counted. RESULTS: CD44 expression in the lung increased 1 week after ovalbulium challenge (P<0.05) and increased more significantly 2 weeks after ovalbulium challenge (P<0.01) compared with that in the control group. The percentages of lymphocytes and eosinophils in BALF increased, while the percentage of BALF mononuclear phagocytes decreased significantly 1 week and 2 weeks after ovalbulium challenge in the asthma group compared with those in the control group (P<0.05). An increased percentage of neutrophils was found 1 week after ovalbulium challenge in the asthma group compared with the control group (P<0.05). CD44 expression in the lung was positively correlated with the percentages of lymphocytes and eosinophils in BALF in the asthma group 1 week and 2 weeks after ovalbulium challenge, in contrast, lung CD44 expression was negatively correlated with the percentage of mononuclear phagocytes in the asthma group 1 week after ovalbulium challenge. CONCLUSIONS: CD44 was over-expressed in the lung and closely related to inflammatory infiltration in rats with asthma. CD44 may play an important role in the development of airway inflammatory in asthma.［Chin J Contemp Pediatr, 2009, 11 (2):142-145］
［3］Woodside DG, Vanderslice P. Cell adhesion antagonists: therapeutic potential in asthma and chronic obstructive pulmonary disease ［J］. BioDrugs, 2008, 22(2): 85-100.
［4］Borland G, Ross JA, Guy K. Forms and functions of CD44［J］. Immunology, 1998, 93（2）:139-48.
［5］Katoh S, Ishii N, Nobumoto A, Takeshita K, Dai SY, Shinonaga R, et al. Galectin-9 inhibits CD44-hyaluronan interaction and suppresses a murine model of allergic asthma ［J］. Am J Respir Crit Care Med, 2007, 176(1): 27-35.
［6］Katoh S, Matsumoto N, Kawakita K, Tominaga A, Kincade PW, Matsukura S. A role for CD44 in an antigen-induced murine model of pulmonary eosinophilia［J］. J Clin Invest, 2003, 111(10):1563-1570.
［7］Kopriva F, Szotkowská J, Ordeltová M, Zápalka M. Percentage of eosinophils with surface CD44 and levels of eosinophil cationic protein in the peripheral blood in children with bronchial asthma and their changes after montelukast therapy ［J］. Allergy Asthma Proc, 2006, 27(4): 378-82.
