Expression of TLR4-MyD88 and NF-κB in the Iris during Endotoxin-Induced Uveitis

PURPOSE To observe the expression of Toll-like receptor-4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor kappa B p65 (NF-κB p65) in iris tissue during endotoxin-induced uveitis (EIU) and evaluate the significance of these factors in uveitis. METHODS Wistar rats were randomly divided into 5 groups (0  h, 12  h, 24  h, 48  h, and 72  h, n = 10/group). Animal model of acute anterior uveitis was established by a hind footpad injection of 200  μg Cholera vibrio LPS. Expression of TLR4, MyD88, and NF-κB p65 in iris ciliary body tissue was detected through immunohistochemical staining. RESULTS Expression of TLR4 was not detected in normal iris-ciliary body complex, TLR4 positive cells with round morphology appeared in the iris stroma 12 hours after injection, significantly increased (P < .001) 48 hours after injection, and decreased gradually 72 hours after injection. Expression of MyD88 and NF-κB p65 is consistent with the change of the TLR4. CONCLUSIONS The increased expression of TLR4 and its downstream signal transduction moleculesMyD88, NF-κB p65 indicate the potential role of pathway in the pathogenesis of acute anterior uveitis (AAU).