Abstract
Purpose::
To evaluate the expression of inflammatory markers in diabetic rat retina exposed to ischemia-reperfusion injury.
Methods::
Diabetes was induced in female Wistar rats by an i.p. injection of streptozotocin. Eyes from diabetic and non-diabetic rats were exposed to retinal ischemia by ligation of the optic nerve and vessels behind the left eye bulb for 45 minutes, followed by a reperfusion for 24 hours. Retinas unexposed to ischemia-reperfusion injury from diabetic rats were compared to retinas from non-diabetic rats as well. Expressions of the inflammatory markers caspase-1, TNF-α, I-6, I-1ß, P-selectin, VCAM-1, and ICAM-1 were analyzed with real-time RT-PCR and related to the endogenous control cyclophilin B.
Results::
Diabetes increased the expressions of caspase-1 (2.8-fold, p=0.046), VCAM-1 (2.6-fold, p=0.027), and ICAM-1 (2.2-fold, p=0.016) in non-ischemic retinas. Ischemia/reperfusion increased the expressions in both non-diabetic and diabetic eyes of TNF-α 4.9-fold, (p=0.012) and 4.0-fold, (p=0.017), respectively, IL-1ß 8.9-fold, (p=0.017) and 26.9-fold, (p=0.012), respectively, ICAM-1 2.6-fold, (p=0.025) and 2.0-fold, (p=0.017), respectively and IL-6 5.6-fold, (p=0.012) and 22.2-fold, (p=0.012), respectively. The expressions of caspase-1, P-selectin and VCAM-1 were unchanged.Conclusion Diabetes triggers an increased expression of several inflammatory markers in rat retina, and ischemia-reperfusion injury induces considerably higher levels of expression.
Keywords: diabetic retinopathy • gene/expression • cytokines/chemokines