The Study On Effect Of Hypoxia Inducing Factor-1α In A Murine Model Of Pseudomonas Aeruginosa Pneumonia

Objects: To investigate the expression of HIF-1α in mice lungtissue in the pseudomonas aeruginosa pneumonia model. To explore thecorrelation between HIF-1α and TNF-α, IL-8. To speculate the possiblerole of HIF-1α in Pseudomonas aeruginosa pneumonia. To find new ideasfor the treatment of Pseudomonas aeruginosa pneumonia. Methods: Themale kunming mice were randomly divided into two groups(n=120,pneumonia model group=60, control group=60). The pneumonia modelwas established by intratracheally injected pseudomonas aeruginosa andanother group of mice was received intratracheal normal saline as anegative control. Then each group were divided into three subgroups andmice were euthanized after3,9or24hours. The content of TNF-alpha,IL-8in serum were measured by Elisa. The pathological change of lungwas observed and HIF-1α protein expressions were measured byimmunohistochemistry. Meanwhile, the colonies in lung homogenateswere counted in each group. All statistical analyses were completed withSPSS17.0version software. Results:1. The mice of pneumonia modelgroup had obvious lung tissue pathology change and the24hourssubgroup was more serious compared with3,9hours. The alveolar andpulmonary interstitial structure were normal in the control group. Thelung homogenate of all the pneumonia model group were cultivated pseudomonas aeruginosa, and the lung homogenate colonies countexceed105CFU/g. But the control group was not cultivated bacteria.2.The expression of HIF-1α protein in pneumonia model group of eachtime point was significantly expression, and the expression of HIF-1αprotein in pneumonia model group rised at3hours, continued to rise at9hours, and arrived the highest at24hours. But there was no obviousexpression in the control group.3. The contents of TNF-α and IL-8inserum of pneumonia model group were significantly higher than those ofthe control group (P <0.05). The contents of TNF-α and IL-8all rised at3hours, continued to rise at9hours, and arrived the highest at24hours.4.The expression of HIF-1α protein and the contents of TNF-α waspositively correlated (r=0.827), and the expression of HIF-1α protein andthe contents of IL-8was positively correlated (r=0.974). Conclusions:1.HIF-1α may participates the inflammatory process of Pseudomonasaeruginosa pneumonia, and the more severe, the more obvious HIF-1αexpression.2. HIF-1α is an important part of the inflammatory cytokinenetworks. The interaction of HIF-1α, TNF-α and IL-8enhance thesynthesis and release of cytokine and magnify the inflammation inPseudomonas aeruginosa pneumonia.