Anti-receptor Advanced Glycation End Products Decreases Inflammatory Pathways in Retinopathy Diabetics: In vivo Study

Abstract

BACKGROUND: Diabetic retinopathy is an emerging microvascular complication of diabetes mellitus and a causes of blindness in individuals between ages 30 and 70 years, which is characterized by increased proliferation of blood vessels, vascular occlusion, angiogenesis, loss of pericytes from retinal capillaries, microaneurysms, retinal bleeding, increased retinal capillary permeability, thickening of capillary basal membranes, and infarcts that affect the retina, induced to permanent blindness.

AIM: This study aimed to find the role of receptor advanced glycation end products (RAGE) inhibition in lowering the vascularization process which causes a decrease in retinal function on diabetic retinopathy.

MATERIALS AND METHODS: This research was an in vivo experimental study. A total of 30 male Wistar rats (200 ± 20 g) were obtained from Eureka Research Laboratory (Palembang, Indonesia). Experimental animals were placed in cages under controlled conditions (12 h of light/dark cycles with temperatures of 22 ± 1°C and humidity of 40–60%), fed and drank ad libitum. White rats were induced by diabetes mellitus using alloxan at a dose of 120 mg/kgBW, intraperitoneally, accompanied by drinking 10% glucose solution for 140 days. Furthermore, experimental animals were grouped into five groups (at eight animals per group), Group 1: Normal control, Group 2: Negative control (induced diabetics retinopathy and given intravenous aquadest), Group 3: Given anti-RAGE 1 ng/mL, Group 4: Given anti-RAGE 10 ng/mL, and Group 5: Given anti-RAGE 100 ng/mL. Giving anti-RAGE was done in a single dosage and intravitreal. After the rats were sacrificed by intraperitoneal injection of 10% chloral hydrate, the evacuation of the eye’s retinal tissue was then carried out, fixed in a 4% paraformaldehyde buffer for immunohistochemistry examination of the eye’s retinal tissue. Evaluation of the expression of nuclear factor-κβ (NF-kB) and intercellular adhesion molecule-1 (ICAM-1) used Image J Software so that the percentage of NF-kB and ICAM-1 expression would be obtained.

RESULTS: Negative control group showed an increase in NF-kB expression in the retinal tissue of diabetic retinopathy rats. Administration of anti-RAGE showed its potential to suppress NF-kB expression in retinal tissue of diabetic retinopathy white rats as well with an increase of anti-RAGE dose from 1 ng/mL to 100 ng/mL. Activation of NF-kB causes activation of the inflammatory cascade, which is characterized by the production of pro-inflammatory cytokines, one of which is ICAM-1. Giving anti-RAGE could suppress the expression of ICAM-1 along with an increase in anti-RAGE dose.

CONCLUSION: Anti-RAGE is able to block the inflammatory process, by inhibiting the expression of NF-kB and ICAM-1 in the retinal tissue of diabetics retinopathy in white rats.