Two micrograms http://www.selleckchem.com/products/chir-99021-ct99021-hcl.html of plasmid DNA and 8 l SuperFect reagent were used for transfection of 1 106 HMC 1 cells. Luciferase expression was monitored by chemiluminescence of cell lysates 24 hrs after transfec tions using the Enhanced Luciferase Assay Kit. Statistical analysis of the data All experiments were done in triplicate. The data were ana lyzed by Students two tailed t test using Statistica soft ware. All data were reported as means SE. A p value of less than 0. 05 was considered significant. Background Pseudomonas aeruginosa, an opportunistic pathogen, causes infections associated with high inci dences of morbidity and mortality in immunocomprom ised hosts. P. aeruginosa colonizes the lower respiratory tract in patients resulting in bronchiectasis, cystic fibrosis, and chronic obstructive pulmonary disease.
The pathogen has a broad host range, which produces a large number of extracellular products including elastase and alkaline protease, LasA protease, hemolysin, rhamnolipid, and pyocyanin. These extracellular products alter host cell function and may contribute to disease pathogenesis. Among recognized virulence factors, the redox active phenazine PCN, a blue redox active secondary metabol ite, plays an important role in invasive pulmonary infec tion. Early studies have shown that PCN causes multiple effects on human cells, such as inhibition of cell respiration, ciliary function, epidermal cell growth, and prostacyclin re lease. Furthermore, PCN alters calcium homeostasis, caus ing damage to human cells.
Recent studies have confirmed that PCN can alter the hosts immune response and in crease IL 1 and TNF secretion induced by monocytes. PCN can also inhibit the bodys specific immune response to clear out pathogens, extend the time limit or prevent the infection of bacterial clearance, and increase secretion of inflammatory mediators in the body that can produce ad verse reactions. Studies have also shown that PCN and its precursor, promethazine 1 carboxylic acid, change the hosts immune response by adjusting the RANTES and IL 8 levels, and that in a variety of respiratory cell lines and primary cell cultures, PCN stimulation can cause the release of IL 8, IL 1 and IL 6, accom panied by increased levels of IL 8 mRNA. PCN also acts in synergy with IL 1, IL 1B and TNF to induce IL 8 expression in human airway epithelial cell lines.
In contrast to its effects on IL 8 expression, PCN inhibits cytokine dependent expression of the monocyte macrophage T cell chemokine RANTES. It is possible that the inhibition could cause AV-951 inflammation of mononuclear macrophage and T cell influx to subside. Alveolar macrophages are significant defense cells and inflammation regulatory cells which switch on multipli city mediators of inflammation and cytokines and then cause acute lung injury.