Diabetic retinopathy ultrastructure

Fibrocellular membrane or epiretinal membrane (ERM) forms on the surface of the inner limiting membrane (ILM) in the inner retina and alters the structure and function of the retina. ERM formation is frequently observed in ocular inflammatory conditions, such as proliferative diabetic retinopathy (PDR) and retinal detachment (RD). Although peeling of the ERM is used as a surgical intervention, it can inadvertently distort the retina. Our goal is to design alternative strategies to tackle ERMs. As a first step, we sought to determine the composition of the ERMs by identifying the constituent cell-types and gene expression signature in patient samples...

Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus that leads to significant vision loss. Isoliquiritigenin (ISL) is a bioactive flavonoid found in the root of licorice with reported anti-oxidant and anti-inflammatory activities. In the present study, we evaluated the effect of ISL administration on diabetes-induced retinal injury. Diabetes was induced in male Sprague-Dawley rats using single intraperitoneal streptozotocin (STZ, 50 mg/kg) injection. Diabetic rats showed up-regulated retinal miR-195, reduced retinal levels of SIRT-1, and increased levels of oxidative stress, nuclear factor-κB (NF-κB), inflammatory cytokines, and endothelin-1...

Blood-retinal barrier breakdown is the main pathological characteristics of diabetic retinopathy (DR). Asymmetric dimethylarginine (ADMA) was reported to be elevated in DR patients. In this study, we observed the dynamic profile of ADMA, retinal morphology and permeability of BRB at 2, 4 or 8 week of diabetic rats induced by a single intraperitoneal injection of streptozocin (60 mg/kg) and in cultured rat retinal pericytes pretreated with D-glucose (30 mM) for 1, 3, 5 and 7 days or ADMA (3, 10, 30 μM) for 24, 48 and 72 h, trying to explore the effects of ADMA on blood-retinal barrier in DR...

Vision disorders are one of the most serious complications of diabetes mellitus (DM) affecting the quality of life of patients and eventually cause blindness. The ocular lesions in diabetes mellitus are located mainly in the blood vessels and retina layers. Different retina lesions could be grouped under the umbrella term of diabetic retinopathies (DMRP).We propose that one of the main causes in the etiopathogenesis of the DMRP consists of a progressive loss of the selective permeability of blood retinal barriers (BRB)...

Oxidative stress and blood-retinal barrier (BRB) damage induced by hyperglycemia are the principal processes involved in the early stages of diabetic retinopathy (DR). CXC chemokine receptor 3 (CXCR3)-mediated inflammatory infiltration exists in many disease models. The main objective of the present study was to determine whether AMG487, a CXCR3 antagonist, can ameliorate BRB disruption and reactive oxygen species generation in the DR model. The retinal endothelial cell and ganglion cell ultrastructures were observed using a transmission electron microscope...

PURPOSE: Diabetic retinopathy is one of the worst complications of diabetes and can threaten sight. The aim of our study is to compare the clinical outcomes and ultrastructural changes in diabetic retinopathy patients after intravitreal admission of either ranibizumab (Lucentis) or aflibercept (Eylea). METHODS: In our prospective study, 27 patients with PDR were enrolled. They were divided into two groups - 14 PDR patients treated with ranibizumab and 13 PDR patients treated with aflibercept...

BACKGROUND: To pursuit effective sustained release systems for insulin to treat diabetic retinopathy (DR), a novel insulin delivering system was developed via loading onto chitosan nanoparticles/poly(lactic-co-glycolic acid)-poly(ethylene glycol)-poly(lactic-co-glycolic acid) hydrogel (ICNPH). METHODS AND MATERIALS: Examinations including electroretinography, HE staining, transmission electron microscopy, terminal deoxynucleotidyl transferased UTP nick-end labeling, immunofluorescence, Western blot, and real-time polymerase chain reaction were performed to evaluate the neuroprotective efficacy of ICNPH on DR by a single subconjunctival injection...

Diabetic retinopathy (DR) has become the most frequent cause of impaired visual acuity and blindness in working-age population in developed countries. Here we use diabetic rats to clarify the role of Lycium barbarum polysaccharides (LBP) on DR. We treated diabetic rats with LBP (400 mg/kg/d or 200 mg/kg/d) orally for 20 weeks. Electroretinogram (ERGs) and Laser Doppler blood flow were measured to assess the retinal function, routine histology and ultrastructural studies were performed to evaluate the morphological alterations, and immunohistochemistry, western blotting, and RT-PCR were conducted to detect the protein and mRNA levels of pro- and antiangiogenic factors...

AIMS/HYPOTHESIS: Diabetic retinopathy is a common microvascular complication of diabetes mellitus and is initiated by inflammation and apoptosis-associated retinal endothelial cell damage. Prostaglandin E2 (PGE2 ) has emerged as a critical regulator of these biological processes. We hypothesised that modulating PGE2 and its E-prostanoid receptor (EP2 R) would prevent diabetes mellitus-induced inflammation and microvascular dysfunction. METHODS: In a streptozotocin (STZ)-induced rat model of diabetes, rats received intravitreal injection of PGE2 , butaprost (a PGE2 /EP2 R agonist) or AH6809 (an EP2 R antagonist)...

AIM: To investigate protective effects of a novel recombinant decoy receptor drug RC28-E on retinal damage in early diabetic rats. METHODS: The streptozotocin (STZ)-induced diabetic rats were randomly divided into 6 groups: diabetes mellitus (DM) group (saline, 3 µL/eye); RC28-E at low (0.33 µg/µL, 3 µL), medium (1 µg/µL, 3 µL), and high (3 µg/µL, 3 µL) dose groups; vascular endothelial growth factor (VEGF) Trap group (1 µg/µL, 3 µL); fibroblast growth factor (FGF) Trap group (1 µg/µL, 3 µL)...

Purpose: Recent clinical data suggest an increasing prevalence of obesity and type 2 diabetes in adolescents, placing them at high risk of developing diabetic retinopathy during adult working years. The present study was designed to characterize the early retinal and microvascular alterations in young Ossabaw pigs fed a Western diet, described as a model of metabolic syndrome genetically predisposed to type 2 diabetes. Methods: Four-month-old Ossabaw miniature pigs were divided into two groups, lean and diet-induced obesity...

ETHNOPHARMACOLOGICAL RELEVANCE: According to ancient traditional Chinese medicine, Typhae Pollen (TP) is commonly used to treat fundus haemorrhage because it improves blood circulation. AIMS OF THE STUDY: This study evaluated the role of the main TP component, polysaccharides (TPP), on diabetic retinopathy (DR) and its possible mechanisms of inhibiting inflammation and improving blood circulation. MATERIALS AND METHODS: After successful establishment of a diabetic rat model, TPP was administered to diabetic rats for treatment, and the rats were sacrificed at 12 weeks...

PURPOSE: To investigate the potential protective effects of curcumin on the retina in diabetic rats. METHODS: An experimental diabetic rat model was induced by a low dose of streptozotocin combined with a high-energy diet. Rats which had blood glucose levels ≥11.6 mmol/L were used as diabetic rats. The diabetic rats were randomly divided into 3 groups: diabetic rats with no treatment (DM), diabetic rats treated with 100 mg/kg curcumin (DM + Cur 100 mg/kg), and diabetic rats treated with 200 mg/kg curcumin (DM + Cur 200 mg/kg)...

Proliferative diabetic retinopathy (PDR) is a major diabetic microvascular complication characterized by pathological angiogenesis. Several retinopathy animal models have been developed to study the disease mechanisms and putative targets. However, knowledge on the human proliferative disease remains incomplete, relying on steady-state results from thin histological neovascular tissue sections and vitreous samples. New translational models are thus required to comprehensively understand the disease pathophysiology and develop improved therapeutic interventions...

BACKGROUND/AIMS: Blood-retinal barrier (BRB) breakdown and vascular leakage is the leading cause of blindness of diabetic retinopathy (DR). Hyperglycemia-induced oxidative stress and inflammation are primary pathogenic factors of this severe DR complication. An effective interventional modality against the pathogenic factors during early DR is needed to curb BRB breakdown and vascular leakage. This study sought to examine the protective effects of α-Melanocyte-stimulating hormone (α-MSH) on early diabetic retina against vascular hyperpermeability, electrophysiological dysfunction, and morphological deterioration in a rat model of diabetes and probe the mechanisms underlying the α-MSH's anti-hyperpermeability in both rodent retinas and simian retinal vascular endothelial cells (RF6A)...

The previous concept regarding diabetic retinopathy assigned a primary role to hyperglycemia-induced microvascular alterations, while neuronal and glial abnormalities were considered to be secondary to either ischemia or exudation. The aim of this study was to reveal the potential role of neuronal and glial cells in initial and advanced alterations of the retinopathy in human type 2 diabetes. Electron microscopy and histochemical studies were performed on 38 surgically removed human eyes (28 obtained from diabetic patients and 10 from non-diabetic patients)...

This review discusses recent advances towards understanding the sigma-1 receptor (S1R) as an endogenous neuro-protective mechanism in the retina , a favorable experimental model system. The exquisite architecture of the mammalian retina features layered and intricately wired neurons supported by non-neuronal cells. Ganglion neurons, photoreceptors , as well as the retinal pigment epithelium, are susceptible to degeneration that leads to major retinal diseases such as glaucoma , diabetic retinopathy , and age-related macular degeneration (AMD), and ultimately, blindness...

BACKGROUND: Biomarker", a merged word of "biological marker", refers to a broad subcategory of medical signs that objectively indicate the state of health, and well-being of an individual. Biomarkers hold great promise for personalized medicine as information gained from diagnostic or progression markers can be used to tailor treatment to the individual for highly effective intervention in the disease process. Optical coherence tomography (OCT) has proved useful in identifying various biomarkers in ocular and systemic diseases...

Diabetic nephropathy is the main cause of end-stage renal failure in the Western world. In diabetes, metabolic and haemodynamic perturbations disrupt the integrity of the glomerular filtration barrier, leading to ultrastructural alterations of the glomeruli, including podocyte foot process fusion and detachment, glomerular basement membrane thickening, reduced endothelial cell glycocalyx, and mesangial extracellular matrix accumulation and glomerulosclerosis, ultimately leading to albuminuria and end-stage renal disease...

Pathologic neovascularisation and ocular permeability are hallmarks of proliferative diabetic retinopathy and age-related macular degeneration. Current pharmacologic interventions targeting VEGF are effective in only 30-60% of patients and require multiple intraocular injections associated with iatrogenic infection. Thus, our goal is to develop novel small molecule drugs that are VEGF-independent are amenable to sustained ocular-release, and which reduce retinal angiogenesis and retinal vascular permeability...