Abstract
Purpose: :
To investigate the expression of TLR2,TLR4 and inflammatory cytokines in the corneas from patients with fungal keratitis (FK).
Methods: :
26 human corneas with FK were obtained from patients with penetrating keratoplasty and fungal cultures were performed to identify the species of infected fungi. 26 host corneal buttons with FK and 11 healthy corneas were evaluated for TLR2, TLR4, IL-1β and IL-10 mRNA by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The expression of TLR2 and TLR4 were assessed by western blot and immunohistochemistry. The corneas were also examined for histopathology with hematoxylin and eosin and periodic acid-Schiff staining.
Results: :
23 cases (with a positive rate of 88.5%) showed positive in smear microscopy. 10 cases of Fusarium infection and 5 cases of Aspergillus infection were identified. TLR2, TLR4, IL-1β and IL-10 mRNA expressions were observed in both healthy and FK human corneas. The mRNA of TLR2, TLR4 and IL-1β were downregulated, whereas the expression of IL-10 was upregulated in FK corneas. The immunohistochemistry and western blot showed that the expression of TLR2 and TLR4 were decreased in FK corneas.
Conclusions: :
Fusarium and Aspergillus species were the most common pathogens of fungal keratitis. The expression of TLR2 and TLR4 in the corneal ulcer tissue were decreased dramatically. The downregulation of proinflammatory cytokine IL-1β and upregulation of anti-inflammatory cyotkines IL-10 may contribute to the progression of fungi-triggerd inflammation.
Keywords: cornea: clinical science • cornea: basic science