The Changes of Irisin and Inflammatory Cytokines in the Age-Related Macular Degeneration and Retinal Vein Occlusion

Abstract

PurposeAge-related macular degeneration (AMD) and retinal vein occlusion (RVO) are irreversible chorioretinal diseases, which might induce severe damage in visual function. The metabolic factor and inflammatory factors might play important roles in the pathogenesis of AMD and RVO. The levels of irisin and 14 cytokines were analyzed in aqueous humor of AMD and RVO eyes to evaluate the roles of irisin and inflammatory factors.MethodsWe collected aqueous humor samples from patients with AMD (n = 27), RVO (n = 30), and cataract (as control, n = 23) eyes. Samples were assayed using ELISA kit for irisin and a multiplex immunoassay kit for 14 cytokines. The macular thickness (MT) was measured with OCT in all included eyes.ResultsMT in the RVO group is significantly higher than that in the AMD or control group. Irisin levels in the aqueous samples of AMD and RVO eyes were both significantly lower than that in the control. Furthermore, a positive correlation was found between irisin and MT in the RVO. Compared with the controls, AMD eyes had significantly higher levels of BDNF, VEGF-A, VEGF-R1, VEGF-R2, IL-10, TNF-α, VCAM-1, IP-10, and MCP-1. Similarly, RVO eyes had significantly higher levels of BDNF, VEGF-A, VEGF-R1, VEGF-R2, IL-6, IL-8, IL-10, TNF-α, ICAM-1, VCAM-1, IP-10, and MCP-1. However, there was no significant difference between the levels of PDGF-BB or TNF-β in these three groups. A negative correlation was found between VEGF-A and MT in AMD, as well as in control. Furthermore, a positive correlation was found between IL-6 and MT in the 80 included eyes, as well as in RVO. A positive correlation was found between ICAM-1 and MT in the 80 included eyes, as well as in RVO.ConclusionsThe metabolic factor, irisin levels in the aqueous humor are decreased in AMD and RVO eyes and show a positive correlation between irisin and MT in RVO eyes, prompting researchers to explore the relationship between irisin and macular edema. We also identified the higher expression of vascular growth factors (VEGF-A, VEGF-R1, and PDGF-BB), inflammatory cytokines (IL-6, IL-8, IL-10, and TNF-α), and chemokines (ICAM-1, VCAM-1, IP-10, and MCP-1) in AMD and RVO eyes.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

“…Based on the consequences, a study ( 9 ) proved that caspase-9 also damaged the optic nerve cell in iCRVO. Further studies of other factors such as LPA, carotid plaque, irisin and Circular RNAs all show involvement in the occurrence of RVO ( 29 , 53 , 87 , 191 ). The study of etiological factors behind RVO is also extremely important in bettering treatment, prognosis as well as prevention.…”

Voluntary exercise preserves visual function and reduces inflammatory response in an adult mouse model of autosomal dominant retinitis pigmentosa

“…IP-10 labeling was abundant in the connective tissue matrix associated with choroidal neovascularization as well as neovascular endothelial cells in postmortem retinal tissues from AMD subjects 48 . Elevated expression of IP-10 and vascular growth factors VEGF and platelet derived growth factor (PDGF) have also been reported in the aqueous humor of AMD patients 50 .…”

Combination Therapy Using Anti-Vascular Endothelial Growth Factor (VEGF) Drugs and Steroids for Macular Edema in Retinal Vein Occlusions

“…Therefore, anti-VEGF drugs have become the first-line treatment for ME, and have been found to be effective in improving vision [ 14 ]. However, in some cases, the inflammatory factors might also play crucial roles in the pathogenesis of RVO occurrence [ 15 ]. Anti-inflammatory drugs may be another treatment for RVO-ME, and DEX I was approved for treatment of ME associated with RVO.…”