Abstract:AIM: To study the influence of Lipoglycans from Mycobacterium Chelonae(Che)on the expression of IL-6 and IL-8 in human corneal epithelia cells and its possible signal transduction pathway.
METHODS: Lipoglycans was extracted by the Triton X-114 phase partitioning. Lipoglycans from Che were purified, by successive detergent and phenol extractions. Lipoglycans were separated by gel filtration on a Sephacryl 200 column and Sephacryl 100 column in series, followed by extensive dialisis. Purified Lipoglycans(50μg/mL)were added into culture medium to stimulate primary human corneal epithelial(HCE)cells. Cells and supernatant were collected at 0, 6, 12, 24h after the stimulation. The IL-6 and IL-8 expression at mRNA level was assayed by using real time RT-PCR and the secreted IL-6 and IL-8 in the supernatants was measured by ELISA. Immunochemistry was used to detect the expression and location of NF-κB in HCE cells.
RESULTS: After the treatment of Lipoglycans, the expression of IL-8 and IL-6 at mRNA level obviouly increased within 12h, and reached peak level at 6h(IL-8 was 36.8 times that of the blank control, and IL-6 was 32.7 times). Compared with the blank control group, the expression of IL-8 at protein level in the supernatant increased 2.8 folds at 6h(P>0.05), 13.4 folds at 12h(P<0.05), and 200.7 folds at 24h(P<0.05), and the expression of IL-6 also incresed 3.6 folds at 6h(P<0.05), 6.1 folds at 12h(P<0.05), and 7.0 folds at 24h(P<0.05), which was similar to changes in the positive control group(situmulated by LPS). In the blank control group, NF-κB was localized in the cytoplasm, while in lipoglycans treated group, NF-κB was activated and translocalized to the nucleus in HCE.
CONCLUSION: Lipoglycans from Che can induce HCE cells to produce inflammatory factors(IL-6 and IL-8), and its signal transduction pathway probably is mediated by NF-κB.