Abstract
Purpose:
Angiogenin (ANG), a component of tear, is involved in the innate immune system and related with inflammatory disease. We investigate that ANG has the immune modulatory function in inflamed human corneal fibroblast (HCF) cells.
Methods:
HCF cells cultured in normal medium were exposed to media with tumor necrosis factor-alpha (TNF-α) or lipopolysaccharide (LPS). Then, the cells were treated in presence or absence of the ANG. Total RNA was isolated from cultures and the mRNA level was measured by real-time reverse transcription polymerase chain reaction (PCR). Protein levels were measured by immunodot blot assay. Immunocytochemistry was used to observe NF-κB expression in HCF cells.
Results:
While ANG decreased the mRNA level of interleukin-1beta (IL-1β), -6, -8, TNF-α receptor (TNFR) 1, 2, toll-like receptor (TLR) 4, myeloid differentiation primary response gene (MYD) 88, and complement components except for C1r and C1s, it elevated the mRNA expression of IL-4 and -10. Signal intensity of IL-6, -8 and monocyte chemotactic protein (MCP)-1 and -2 enlarged by was weakened by ANG treatment. ANG reduces the protein levels of IκB kinase epsilon (IKK-ε) and TANK-binding kinase (TBK) 1 production induced by TNF-α, not LPS was decreased by ANG. The expression of NF-κB in nuclei was decreased after ANG treatment.
Conclusions:
These results demonstrate that ANG reduced inflammatory response in HCF cells induced by TNF-α or LPS through commonly suppression of IKK-ε mediated NF-κB activation. We thought these findings support to targeting of immune-mediated inflammatory therapeutic substance and finding out the comprehension of immune-mediated inflammatory diseases.