osteoprotegerin and Diabetic-Retinopathy

To identify and determine the association of SNP (rs2073618) of OPG gene in diabetics with and without retinopathy and in healthy controls.. Descriptive study. Place and Duration of the Study: Department of Biochemistry and Molecular Biology, Army Medical College, Rawalpindi in collaboration with Chemical Pathology Laboratory, Pak Emirates Military Hospital, Rawalpindi and Armed Forces Institute of Ophthalmology, Rawalpindi, from June 2021 to May 2022.. Participants aged 25-70 years were inducted and divided into three equal groups. Group I consisted of diabetics with retinopathy (n = 50), group II was diabetics without retinopathy (n = 50), and group III was healthy individuals (n = 50). DNA was extracted and allele specific PCR technique was adopted using specifically designed primers. Results were analysed using the software Statistical Package for Social Sciences (SPSS) version 22.0 and online bio-informatics tool SNPstats.. CC, CG, and GG genotypes were found to be present in 94%, 4%, and 2% in diabetics without retinopathy, 92%, 4%, and 4% in diabetics with retinopathy, respectively, and 100% presence of CC genotype only in healthy controls. C and G alleles were present in 96% and 4%, respectively, in diabetics without retinopathy, with 100% presence of only C allele in healthy subjects. The genotypic assessment using the models showed no significant association.. SNP rs2073618 of OPG gene was identified in all study groups without any significant distribution or association with the development of diabetic retinopathy. The major genotype C/C was found in the majority of subjects in all groups.. Allele specific PCR, Diabetic retinopathy, Single nucleotide polymorphism, Type 2 Diabetes mellitus.

Topics: Diabetes Mellitus, Type 2; Diabetic Retinopathy; Humans; Osteoprotegerin; Polymorphism, Single Nucleotide

We investigated the expression of the proinflammatory and proangiogenic factor osteoprotegerin (OPG) and its ligands, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and the receptor RANK in proliferative diabetic retinopathy (PDR).. Vitreous samples from PDR and nondiabetic control patients and epiretinal membranes from PDR patients were studied by enzyme-linked immunosorbent assay, immunohistochemistry, and Western blot analysis.. Vascular endothelial growth factor, OPG, and soluble RANK levels in vitreous samples from PDR patients were significantly higher than that in nondiabetic controls. Soluble TRAIL levels were significantly lower in PDR patients than that in nondiabetic control, whereas soluble RANKL levels did not differ significantly. RANKL, RANK, and TRAIL were expressed in vascular endothelial cells, myofibroblasts, and CD45-expressing leukocytes in PDR epiretinal membranes.. Dysregulated expression of OPG/RANKL/RANK pathway and TRAIL might be related to inflammation and angiogenesis in PDR.

Topics: Actins; Adult; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Blotting, Western; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Humans; Immunohistochemistry; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; TNF-Related Apoptosis-Inducing Ligand; Vitreous Body

Osteoprotegerin (OPG) is a novel regulator of endothelial cell function, angiogenesis, and vasculogenesis. We correlated expression levels of OPG with those of the angiogenic and inflammatory factors vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) in proliferative diabetic retinopathy (PDR). We also examined expression of OPG in retinas from diabetic rats and diabetic patients and measured production of OPG by human retinal microvascular endothelial cells (HRMEC) and investigated its angiogenic activity.. Vitreous samples from 47 PDR and 28 nondiabetic patients, epiretinal membranes from 14 patients with PDR, human retinas (10 from diabetic patients and 10 from nondiabetic subjects), and rat retinas and HRMEC were studied by using enzyme-linked immunosorbent assay, immunohistochemistry, immunofluorescence, Western blot analysis, and RT-PCR. In vitro and in vivo angiogenesis assays were performed.. We showed a significant increase in the expression of OPG, VEGF, and MCP-1/CCL2 in a comparison between vitreous samples from PDR patients and those from nondiabetic controls. Significant positive correlations were found between levels of OPG and levels of VEGF and MCP-1/CCL2. In epiretinal membranes, OPG was expressed in vascular endothelial cells and stromal cells. Significant increases of OPG mRNA and protein were detected in the retinas from diabetic patients. The proinflammatory cytokines TNF-α and IL-1β, but not VEGF, MCP-1/CCL2 or thrombin, induced upregulation of OPG in HRMEC. Osteoprotegerin induced ERK1/2 and Akt phosphorylation in HRMEC and stimulated their migration. Osteoprotegerin potentiated the angiogenic effect of VEGF in the in vivo protein gelatin plug assay.. These results suggest that OPG is involved in PDR angiogenesis.

Topics: Animals; Blotting, Western; Chemokine CCL2; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Endothelial Cells; Epiretinal Membrane; Humans; Immunohistochemistry; Inflammation; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Retina; Retinal Neovascularization; Retinal Vessels; Vascular Endothelial Growth Factor A; Vitreous Body

Osteoprotegerin (OPG) is an arterial calcification marker which has been associated with vascular damage. Elevated OPG concentrations associated with low-grade inflammatory processes are found in diabetic subjects.. The aim of the study was to assess concentrations of OPG in relation to the presence of diabetic complications in patients with diabetes type 1 (DM 1) participating in the Poznań Prospective Study (PoProStu).. The study included 74 patients with DM1 (48 men) with a median age of 39 years (interquartile range [IQR]: 34-43) and a median 15-year history (IQR: 14-16) of diabetes, who were participants in the PoProStu. Serum OPG concentration was measured using the ELISA method, and serum concentration of C-reactive protein was measured with a high sensitivity test (hsCRP). The visceral adipose index (VAI) was used to determine indirect markers of insulin resistance (IR). The prevalence of microangiopathic diabetes complications was assessed.. Retinopathy was diagnosed in 28 patients (38%), diabetic kidney disease (DKD) in 28 (38%) patients, and neuropathy in 17 (23%) patients. The median OPG level was 43.8 (28.0-74.0) pg/mL. Patients with retinopathy had higher levels of OPG than those without retinopathy: 47.5 (35.0-88.0) vs 35.4 (24.7-69.4) pg/mL (p = 0.04). Positive correlations were observed between OPG concentration and hsCRP (Rs = 0.53; p < 0.001), HbA1c level (Rs = 0.36; p = 0.002), VAI (Rs = 0.23; p = 0.04) and waist circumference (Rs = 0.24; p = 0.04).. Higher concentrations of osteoprotegerin in DM1 patients are related to the presence of retinopathy. The study results indicate that OPG might play a role in the pathogenesis of vascular complications in association with hyperglycemia and low-grade inflammatory processes.

Topics: Adult; C-Reactive Protein; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Female; Glycated Hemoglobin; Humans; Logistic Models; Male; Osteoprotegerin; Prospective Studies

Angiogenesis is involved in the pathogenesis of diabetic retinopathy. Osteoprotegerin, a recently identified glycoprotein belonging to the tumour necrosis factor receptor superfamily, has been implicated to be correlated with angiogenesis. This study aims to determine whether serum and vitreous concentrations of osteoprotegerin are associated with diabetic retinopathy.. This study consisted of 254 diabetic patients (100 without diabetic retinopathy, 64 with non-proliferative diabetic retinopathy and 90 with proliferative diabetic retinopathy) and 62 control subjects. Serum and vitreous concentrations of osteoprotegerin were evaluated using enzyme-linked immunosorbent assay method.. Serum and vitreous osteoprotegerin concentrations in proliferative diabetic retinopathy patients were significantly elevated compared with those of the other three groups. Non-proliferative diabetic retinopathy patients showed elevated concentrations of serum and vitreous osteoprotegerin compared with patients without diabetic retinopathy. In addition, control subjects had significantly lower serum and vitreous osteoprotegerin concentrations compared with diabetic patients without retinopathy, non-proliferative diabetic retinopathy patients and proliferative diabetic retinopathy patients.. Serum and vitreous osteoprotegerin concentrations are associated with the presence and severity of diabetic retinopathy.

Topics: Asian People; Biomarkers; China; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Female; Hospitals, University; Humans; Male; Middle Aged; Osteoprotegerin; Severity of Illness Index; Up-Regulation; Vitreous Body

Recent studies indicate that osteoprotegerin (OPG) acts as an important regulatory molecule in the vasculature. Also, a strong association was observed between circulation OPG and microvascular complication. By considering the possible role of OPG in diabetic retinopathy (DR) we examined two of the most studied polymorphisms of the OPG genes rs2073618 (located in exon I) and rs3134069 (located in the promoter region) and their relation to DR in Slovenian patients with type 2 diabetes. Logistic regression analysis demonstrated that the carriers of the CC genotype had a 2.2 higher risk for DR than those with either the CG genotype or the GG genotype (codominant model for rs2073618). Furthermore, the combined effect of single nucleotide polymorphisms (SNPs) rs2073618 and rs3134069 on the DR was stronger than that of each SNP alone. The odds ratio (OR) for individuals with CC genotype (rs2073618) and AA genotype (rs3134069) compared with carriers of CG/GG (rs2073618) + AA (rs3134069) was 2.54 (95% CI = 1.26-5.13, P = 0.01). To conclude, these results indicate that SNPs in the OPG gene may be implicated in the pathogenesis of DR.

Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Gene Frequency; Genetic Association Studies; Genetic Predisposition to Disease; Haplotypes; Humans; Male; Middle Aged; Osteoprotegerin; Polymorphism, Single Nucleotide; Risk Factors