Effects of Five Chitosan Oligosaccharides on Nuclear Factor-kappa B Signaling Pathway

The effects of five chito-oligomers,from dimer to hexamer(chitobiose,chitotriose,chitotetraose,chitopentaose,chitohexaose)separated from chitosan oligosaccharides,on nuclear factor-kappaB(NF-κB)signaling pathway were investigated by using luciferase assay and laser scanning microscopy.The expression of NF-κB downstream genes(cyclin D1,TNFα and IL-6)were tested by real time PCR.We found that all five chitosan oligosaccharides increased NF-κB-dependent luciferase gene expression and NF-κB downstream genes transcription,and the most significant were chitotetraose and chitohexaose.In addition,laser scanning microscopy experiments showed that chitotetraose and chitohexaose also activated the p65 subunite of NF-κB translocating from cytoplasm to nucleus,which suggested that they were the most potent activators of NF-κB signaling pathway.