ABSTRACT
Diabetic retinopathy is the leading cause of blindness in the working-age population, in which diabetic macular edema(DME)is the most common reason resulting in the vision impairment. Studies showed that inflammation factors play an important role in the pathogenesis and development of DME. Chronic hyperglycemia activates several biochemical pathways, leading to retinal hypoxia, oxidative stress and chronic inflammation. Intraretinal inflammation-related cells, such as microglia, monocytes/macrophages, Müller cells and retinal pigment epithelial cells, become activated and release a large number of inflammation-related factors and mediators, including the complement system, vascular endothelial growth factor(VEGF), placental growth factor(PlGF), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-6 and IL-8, etc., resulting in the breakdown of the blood-retinal barrier and neuronal degeneration. In addition, up-regulatethe expression of intercellular adhesion molecule-1(ICAM-1)and vascular cell adhesion molecule-1(VCAM-1)by retinal vascular endothelial cells increased the adhesion of leukocyte and leukostasis, further aggravating retinal hypoxia and breakdown of the blood-retinal barrier, leading to the increased retinal vascular leakage and macular edema. Therefore, early treatment with anti-VEGF and anti-inflammatory are pivotal for the treatment of DME. In this review, we will discuss the role of inflammation factors in the pathogenesis of DME and the research status of the targeted drugs targeting inflammation, so as to provide reference for the treatment of DME.
ABSTRACT
Background Oxidative damage is a major cause of age-related cataracts,and the ubiquitinproteasome system is involved in lens differentiation and development.Ubiquitin carboxy-terminal hydrolase L1 (UCHL1),one of key enzymes of ubiquitin-proteasome system,was discovered to participate in the age related diseases and oxidative stress damage. Objective This study was to investigate the effects of UCHL1 on the formation and development of age-related cataract. Methods Lens capsule were collected from 24 patients with age-related cataract(including 12 cases of cortical cataract and 12 cases of nuclear cataract) during the surgery.Five normal lens capsule membranes were obtained from eye bank of Tongji University.Human lens epithelial cells (LECs) line (SRA01/04) was also collected in this study.Expression of UCHL1 in the lens epithelial layer of different samples was assayed using immunofluorescence technology.UCHL1 eukaryotic expressing vector was constructed and transfected into cultured SRA01/04 by liposome,and green fluorescent protein (GFP) eukaryotic expressing vector was transfected at the same method as the control group.UCHL1 over-expressing cells were then exposed to different concentrations (0.2,0.3,0.4 and 0.5 mol/L) of tert-butyl hydroperoxide (TBHP) for 24 hours and subsequently monitored for cell viability evaluation by MTT assay. Results Immunofluorescence showed that UCHL1 was expressed in human lens epithelial layer,but significantly different expressing levels were seen among normal lens capsular membrane,cortical cataract and nuclear cataract ( F =13.411,P =0.000),and UCHL1 expressing levels were lower in cortical cataract and nuclear cataract than the normal lens (P =0.000,P =0.000).No significant difference was found in UCHL1 expressing level between cortical cataract and nuclear cataract ( P =0.164).Western blot analysis verified that UCHL1 exhibited a stranger expression in the UCHL1 transfected group compared with the GFP transfected group,illuminating a successful transfection of UCHL1 in SRA01/04 cells.MMT assay revealed that the A570/630 value in UCHL1 transfected cells was significantly elevated in comparison with GFP transfected cells following the treatment of 0.3 mol/L TBHP. Conclusions UCHL1 has an antioxidative ability,and it might plays an important role in the progress of age-related cataract.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the possible involvement of erythr opoietin (EPO)/erythropoietin receptor (EPOR) system in neovascularization and vascular regeneration in diabetic retinopathy (DR).</p><p><b>METHODS</b>EPOR positive circulating progenitor cells (CPCs: CD34(+)) and endothelial progenitor cells (EPCs: CD34(+)KDR(+)) were assessed by flow cytometry in type 2 diabetic patients with different stages of DR. The cohort consisted of age- and sex-matched control patients with out diabetes ( n=7),non-proliferative DR (NPDR, n=7),non-proliferative DR (PDR, n=8), and PDR complicated with diabetic nephr opathy (PDR-DN, n=7).</p><p><b>RESULTS</b>The numbers of EPOR(+) CPCs and EPOR(+) EPCs were reduced remarkably in NPDR compared with the control group (both Pü0.01), whereas rebounded in PDR and PDR-DN groups in varyingdegrees. Similar changes were observed in respect of the proportion of EPOR(+)CPCs in CPCs (NPDR vs. control, Pü0.01) and that of EPOR(+) EPCs in EPCs (NPDR vs. control, Pü0.05).</p><p><b>CONCLUSION</b>Exogenous EPO, mediated via the EPO/EPOR system of EPCs, may alleviate the impaired vascular regeneration in NPDR, whereas it might aggravate retinal neovascularization in PDR due to a rebound of EPOR(+)EPCs associated with ischemia.</p>