title: [Study on the susceptibility of human corneal epithelial cells to Acanthamoeba in a hypoxia condition].
abstract: Objective:To investigate the regulation mechanism ofAcanthamoeba-induced immune responses of human corneal epithelial cells in a hypoxia condition.Methods:Telomerase-immortalized human epithelial cells (THCEs) challenged withAcanthamoeba(1×106/ml) were incubated under normoxic (21% O2) (control group) or hypoxic (1% O2) (experiment group) conditions respectively. The mRNA of toll-like receptor (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), interferon-β (IFN-β), and the protein level of TLR4, inhibitor of nuclear factor kappa-Bα (IκBα), phosphorylated extracellular-signal related kinase 1/2 (p-ERK1/2) and phosphorylated IκBα (p-IκBα) were detected. Enzyme-linked immunosorbent assay (ELISA) was used to detect the secretion of the inflammatory cytokines (TNF-α, IL-8 and IFN-β).Results:The mRNA levels ofAcanthamoeba-induced TLR4, MyD88, NF-κB, TNF-α, IFN-β and IL-8 in THCEs under hypoxia was down-regulated by 47%, 41%, 45%, 53%, 36% and 50% respectively, compared to control group. And the protein levels of p-IκBα and p-ERK1/2 were significantly down-regulated by 56% and 55%, respectively, while the protein expression of IκBα was increased. The secretions of TNF-α, IL-8 and IFN-β under hypoxia were reduced by 46%, 28% and 35%, respectively.Conclusion:Hypoxia might attenuated the inflammatory response of the human corneal epithelial cells againstAcanthamoebainfection by suppressing TLR4 signaling.
authors.affiliation: Department of Ophthalmology, Qilu Hospital, Shandong University, Jinan 250012, China.
authors.forename: K P
authors.initials: KP
authors.lastname: Pang
authors.forename: H
authors.initials: H
authors.lastname: Pan
mesh_terms: D000048:Acanthamoeba; D015687:Cell Hypoxia; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells; D016899:Interferon-beta; D016209:Interleukin-8; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D010766:Phosphorylation; D015398:Signal Transduction; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha
chemical_list: C508606:CXCL8 protein, human; D016209:Interleukin-8; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D016899:Interferon-beta