The Effects And Underlying Mechanisms Of Terminal Sialylation Of Airway Mucin Macromolecules On Mucin-pseudomonas Aeruginosa Interactions

Objectives:Studies have shown that hypersecretion and increased glycosylation levels of mucus and mucins occur in the processes of airway acute and chronic inflammation. Sialic acid, as one of the main kinds of terminal saccharide groups as well as bindalbe sugar receptor for various bacteria, its increase is closely related to the severity of infection. Furthermore, pathological changes, such as proliferation and hypertrophy of secretion cells which potentially facilitated to mucins hypersecretion and more terminal sialic acids, exist in some chronic airway inflammatory diseases like COPD. However, the significances of these changes still remain unclear completely and therefore need further studies. The aims of this study are: (1) to compare the difference of terminal sialic acid of mucin macromolecules of airway secretions from the patients between with COPD and with pneumonia; (2) to observe the effects of terminal sialic acids by in vitro interventions on the interactions between mucins and pseudomonas aeruginosa, and the changes between the two groups of specimens; (3) to compare the difference of the universal sialyltransferases mRNA levels of bronchial mucosa from the taintless patients between with COPD and with normal lung functions; (4) to value the effects of analogical in vivo interventions using experimental model of bacterial intratracheal inoculation on rats injuryed by hydrochloric acid. It hopes to identify anti-infection effects and mechanisms of carbohydrate antiadherents and to provide the experiment evidences for future therapeutic drugs research and development.Methods:(1) The airway secretions after tracheal intubation or tracheotomy were collected from 24 patients with COPD (COPD group) and with pneumonia but not complicated by any chronic respiratory diseases (pneumonia group). Mucin macromolecules were isolated and purified by multi-centrifugation and sepharose CL-2B gel-chromatography, then verificated by agarose gel electrophoresis and immunoblotting. Total contents of sialic acids were...