Concentrations of matrix metalloproteinase-2 and interleukin-1 β in the aqueous humor of dogs with normal and cataractous eyes

Concentração de metaloprotease-2 e de interleucina-1 β no humor aquoso de cães com olhos normais e cataratosos

ABSTRACT:

We aimed to determine the concentration of MMP-2 and IL-1β in the aqueous humor of dogs with healthy eyes (n=8) and in those with mature (n=8) and hyper mature cataracts (n=8). Correlations between cytokines, cytokines, and intraocular pressure (IOP), as well as cytokines with ages of patients of each group, were also assessed. In patients with cataract, aqueous humor was collected at the end of the electroretinographic procedure. In healthy dogs, aqueous humor was collected before elective surgeries. Cytokine levels were determined using ELISA. IOP was assessed by applanation tonometry. IOP of patients with mature and hyper mature cataracts were lower than the ones measured in normal eyes (P=0.158). MMP-2 aqueous humor concentration was higher in patients with hyper mature cataracts, in comparisons with healthy patients (P=0.04). Average IL-1 β aqueous concentration was higher in patients with cataracts (P<0.0001). Significant higher values of IL-1 β were observed in patients with hyper mature, than in the ones with mature cataracts (P=0.0085). Correlations between MMP-2 and IL-1 β (r=-0.38, P=0.06), MMP-2 and IOP (r=-0.149, P=0.484), and IL-1 β and the ages of patients were not observed (P>0.05). IL-1 β and IOP correlated negatively (r=-0.42, P=0.04). MMP-2 and the ages of patients correlated only in dogs with mature cataracts (r=0.772, P=0.02). It can be concluded that the increment in the aqueous humor concentration of IL-1 β found in dogs with mature and hyper mature cataracts, in addition to the negative relationship of this cytokine with IOP, suggests that IL-1 β is involved in the pathogenesis of LIU. Despite dogs with hypermature cataracts presented significant higher concentrations of MMP-2 in the aqueous humor, such cytokine did not correlate with IL-1 β and IOP. In our study, a relationship between aqueous humor cytokines and the ages of patients was only confirmed between MMP-2 and the ages of dogs with mature cataracts.

INDEX TERMS:
Metalloproteinase-2; interleukin-1 β; dogs; cataractous; eyes; lens-induced uveitis; inflammatory cytokines; capsular fibrosis; lens