Project description:ObjectiveDiabetic nephropathy clusters in families, suggesting that genetic factors play a role in its pathogenesis. We investigated whether similar clustering exists for proliferative retinopathy in families with two or more siblings with type 1 diabetes.Research design and methodsThe FinnDiane Study has characterized 20% (4,800 patients) of adults with type 1 diabetes in Finland. In 188 families, there were at least two siblings with type 1 diabetes. Ophthalmic records were obtained for 369 of 396 (93%) and fundus photographs for 251 of 369 (68%) patients. Retinopathy was graded based on photographs and/or repeated ophthalmic examinations using the Early Treatment of Diabetic Retinopathy grading scale.ResultsMean age at onset of diabetes was 14.3 +/- 10.2 years, and mean duration was 25.9 +/- 11.8 years. Proliferative retinopathy was found in 115 of 369 patients (31%). The familial risk of proliferative retinopathy was estimated in 168 of 188 sibships, adjusted for A1C, duration, and mean blood pressure. Proliferative retinopathy in the probands (48 of 168) was associated with an increased risk (odds ratio 2.76 [95% CI 1.25- 6.11], P = 0.01) of proliferative retinopathy in the siblings of probands (61 of 182). The heritability of proliferative retinopathy was h(2) = 0.52 +/- 0.31 (P < 0.05).ConclusionsWe found a familial clustering of proliferative retinopathy in patients with type 1 diabetes. The observation cannot be accounted for by conventional risk factors, suggesting a genetic component in the pathogenesis of proliferative retinopathy in type 1 diabetes.
Project description:Proliferative diabetic retinopathy (PDR) is the most severe vision-threatening complication of diabetes. For investigation of genetic association between TCF7L2 and PDR in Caucasian type 2 diabetes mellitus (T2DM) and its functional consequences, 383 T2DM patients with PDR (T2DM-PDR) and 756 T2DM patients without diabetic retinopathy (T2DM-no DR) were genotyped with rs7903146 in TCF7L2. We found that risk allele (T) frequency of rs7903146 was significantly higher in T2DM-PDR patients (allelic P = 2.52E-04). In lymphoblastoid cells induced to undergo endoplasmic reticulum (ER) stress by treatment of tunicamycin, higher fold change of TCF7L2 and VEGFA mRNA levels were observed in rs7903146-TT cells than in rs7903146-CC cells (P = 0.02 for TCF7L2; P = 0.004 for VEGFA), suggesting that ER stress plays a role in PDR pathogenesis. Silencing TCF7L2 resulted in decreased mRNA levels of both TCF7L2 and VEGFA (P < 0.001). Retinas of oxygen-induced retinopathy mice (a model for PDR) had higher TCF7L2 and VEGFA mRNA levels than those of controls (P = 2.9E-04 for TCF7L2; P = 1.9E-07 for VEGFA). Together, data from our study show that TCF7L2-rs7903146 is associated with PDR in Caucasian T2DM and suggest that TCF7L2 promotes pathological retinal neovascularization via ER stress-dependent upregulation of VEGFA.
Project description:Several candidate genes have been so far implicated in the pathogenesis of proliferative diabetic retinopathy (PDR) in subjects with type 2 diabetes. Since the principal pathogenetic mechanisms for diabetic retinopathy (DR) and PDR are different, the main pathogenetic mechanism in DR is increased vascular permeability, whereas in PDR the crucial pathogenetic mechanisms are fibrosis and neoangiogenesis. Due to that fact, different candidate genes are expected to be involved in the development of either DR or PDR. None of the candidate genes, however, can be fully and solely responsible for the development of PDR and for DR progression into PDR. Epigenetic mechanisms are expected to be involved in the pathogenesis of PDR as well. Gene polymorphisms responsible for PDR and epigenetic mechanisms responsible for PDR are reviewed in this paper.
Project description:We identified lncRNA expression profiles in vitreous samples between proliferative diabetic retinopathy (PDR) patients and idiopathic macular hole (IMH) patients, and between PDR patients who had received preoperative anti-vascular endothelial growth factor (anti-VEGF) therapy and PDR patients who had received surgery alone. There had been the systemic expression differences in vitreous at the microarray level from PDR patients and IMH patients, and from PDR patients after anti-VEGF treatment and untreated PDR patients.
Project description:BackgroundProliferative diabetic retinopathy (PDR), a sight-threatening retinopathy, is the leading cause of irreversible blindness in adults. Despite strict control of systemic risk factors, a fraction of patients with diabetes develop PDR, suggesting the existence of other potential pathogenic factors underlying PDR. This study aimed to investigate the plasma metabotype of patients with PDR and to identify novel metabolite markers for PDR. Biomarkers identified from this study will provide scientific insight and new strategies for the early diagnosis and intervention of diabetic retinopathy.MethodsA total of 1024 patients with type 2 diabetes were screened. To match clinical parameters between case and control subjects, patients with PDR (PDR, n = 21) or those with a duration of diabetes of ≥10 years but without diabetic retinopathy (NDR, n = 21) were assigned to the present case-control study. Distinct metabolite profiles of serum were examined using liquid chromatography-mass spectrometry (LC-MS).ResultsThe distinct metabolites between PDR and NDR groups were significantly enriched in 9 KEGG pathways (P < 0.05, impact > 0.1), namely, alanine, aspartate and glutamate metabolism, caffeine metabolism, beta-alanine metabolism, purine metabolism, cysteine and methionine metabolism, sulfur metabolism, sphingosine metabolism, and arginine and proline metabolism. A total of 63 altered metabolites played important roles in these pathways. Finally, 4 metabolites were selected as candidate biomarkers for PDR, namely, fumaric acid, uridine, acetic acid, and cytidine. The area under the curve for these biomarkers were 0.96, 0.95, 1.0, and 0.95, respectively.ConclusionsThis study suggested that impairment in the metabolism of pyrimidines, arginine and proline were identified as metabolic dysregulation associated with PDR. And fumaric acid, uridine, acetic acid, and cytidine might be potential biomarkers for PDR. Fumaric acid was firstly reported as a novel metabolite marker with no prior reports of association with diabetes or diabetic retinopathy, which might provide insights into potential new pathogenic pathways for diabetic retinopathy.
Project description:Aims/hypothesisProliferative diabetic retinopathy (PDR) with retinal neovascularisation (NV) is a leading cause of vision loss. This study identified a set of metabolites that were altered in the vitreous humour of PDR patients compared with non-diabetic control participants. We corroborated changes in vitreous metabolites identified in prior studies and identified novel dysregulated metabolites that may lead to treatment strategies for PDR.MethodsWe analysed metabolites in vitreous samples from 43 PDR patients and 21 non-diabetic epiretinal membrane control patients from Japan (age 27-80 years) via ultra-high-performance liquid chromatography-mass spectrometry. We then investigated the association of a novel metabolite (creatine) with retinal NV in mouse oxygen-induced retinopathy (OIR). Creatine or vehicle was administered from postnatal day (P)12 to P16 (during induced NV) via oral gavage. P17 retinas were quantified for NV and vaso-obliteration.ResultsWe identified 158 metabolites in vitreous samples that were altered in PDR patients vs control participants. We corroborated increases in pyruvate, lactate, proline and allantoin in PDR, which were identified in prior studies. We also found changes in metabolites not previously identified, including creatine. In human vitreous humour, creatine levels were decreased in PDR patients compared with epiretinal membrane control participants (false-discovery rate <0.001). We validated that lower creatine levels were associated with vascular proliferation in mouse retina in the OIR model (p = 0.027) using retinal metabolomics. Oral creatine supplementation reduced NV compared with vehicle (P12 to P16) in OIR (p = 0.0024).Conclusions/interpretationThese results suggest that metabolites from vitreous humour may reflect changes in metabolism that can be used to find pathways influencing retinopathy. Creatine supplementation could be useful to suppress NV in PDR. Graphical abstract.
Project description:PurposeTo evaluate the effectiveness of sulodexide for the treatment of hard exudates (HE) in non-proliferative diabetic retinopathy (NPDR).MethodsThis was a randomized, placebo-controlled, multicenter trial involving 130 patients (65 for each group) who had mild-to-moderate NPDR with macular HE. Participants were given a daily dose of either 50 mg sulodexide or a matching dose of placebo orally for 12 months. Main outcome measure was an improvement in HE defined as a decrease in severity by at least two grades on a 10-grade severity scale. This was evaluated by fundus photography over 12-month period.ResultsThe sulodexide group showed significantly greater improvement in HE severity than that shown by the placebo group (39.0 % vs. 19.3 %; chi square, P = 0.005). Logistic regression analysis yielded an odds ratio of 2.790 (95 % confidence interval, 1.155-6.743; P = 0.023) for the effect of treatment once adjustments were made for demographic, prognostic and disease confounders. Intention to treat and per-protocol analysis yielded similar results. Sulodexide's safety was comparable to that of the placebo.ConclusionsOral sulodexide therapy over 12 months improved macular HE in patients with mild-to-moderate NPDR, without leading to detectable adverse events. The study protocol was registered on clinicaltrial.gov under identifier NCT01295775.
Project description:To establish adaptive optics scanning laser ophthalmoscopy as a method to detect and characterize microscopic signs of diabetic retinopathy in capillaries and cone photoreceptors in the parafovea.Recently, adaptive optics scanning laser ophthalmoscope (AOSLO) has enabled noninvasive assessment of photoreceptors, capillaries, and leukocytes in the retinas of live human subjects. Repeated application of AOSLO imaging along with comparison to fluorescein angiography was used to track individual capillaries near the foveal avascular zone (FAZ) from one eye affected with severe non-proliferative diabetic retinopathy. Fluorescein angiography was used to identify clinical signs of diabetic retinopathy, such as microaneurysms and intraretinal microvascular abnormalities, and corresponding regions were imaged and assessed using the AOSLO. In addition, the structural integrity of photoreceptors and the spatial distribution of leukocytes around the parafoveal capillary network were quantitatively assessed.Capillaries and cone photoreceptors were visualized using the AOSLO without the use of injected contrast agents. Although the majority of capillaries were stable over a period of 16 months, one capillary at the edge of the FAZ dropped out, leading to a small but significant increase in FAZ size. Longitudinal assessment of the capillaries also showed microaneurysm formation and disappearance as well as the formation of tiny capillary bends similar in appearance to intraretinal microvascular abnormalities. The leukocytes in the capillary network were found to preferentially travel through the same routes in all four visits, suggesting that these channels are robust against small changes to the surrounding capillaries. In this eye, cone photoreceptor spacing was increased in the fovea when compared with normal data but stable across all visits.AOSLO imaging can be used to longitudinally track capillaries, leukocytes, and photoreceptors in diabetic retinopathy. Capillary changes that can be detected include dropout of individual capillaries as well as formation and disappearance of microaneurysms.
Project description:Pleiotrophin (PTN), a secreted, multifunctional cytokine, is involved in angiogenic, fibrotic and neurodegenerative diseases. However, little is known about its effects on diabetic retinopathy, a neurovascular disease. To investigate the role of PTN in proliferative diabetic retinopathy (PDR), PTN concentration in the vitreous was evaluated in PDR patients and non-diabetic controls. PTN expression was observed in epiretinal membranes from patients. PTN knockdown was performed using small interfering (si)RNA, and the effects on retinal pigment epithelium (RPE) cells and human umbilical vascular endothelia cells (HUVECs) were observed in vitro under hyperglycemic and hypoxic conditions. Cell attachment, proliferation, migration, tube formation, cell cycle, apoptosis, extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation, and VEGF levels were studied. The vitreous PTN concentration in PDR patients was higher than that in non-diabetic controls, and PTN was highly expressed in the fibrovascular membranes of PDR patients. Under hyperglycemic and hypoxic conditions, PTN knockdown reduced cell attachment, proliferation, migration, and tube formation and induced cell cycle arrest and apoptosis in vitro. Mechanically, PTN depletion decreased ERK 1/2 phosphorylation. Recombinant PTN up regulated the concentration of VEGF in vitro, which can be attenuated by the ERK 1/2 inhibitor. Taken together, our results implied that elevated PTN in PDR patients might participate in the critical processes of the development of PDR, most likely playing roles in angiogenesis and proliferation, possibly by activating the ERK 1/2 pathway and regulating VEGF secretion. These findings provide new insight into the roles of PTN in PDR and suggest that PTN may become a new target for therapeutic intervention in PDR.
Project description:Background/aimsTo determine if anaemia and oxygen delivery-related co-morbidities (ODCs) affect progression from non-proliferative diabetic retinopathy (NPDR) to vision-threatening diabetic retinopathy (VTDR).MethodsThis is a retrospective cohort study using medical claims data from a large US insurer. Cohorts were created from all NPDR patients between 2002 and 2016. Primary exclusion criteria consisted of any previous diagnosis of proliferative diabetic retinopathy (PDR), diabetic macular oedema (DME) or treatment used in the care of VTDR. The main outcome was a new diagnosis of VTDR (DME or PDR), PDR, or DME. A time-dependent, multivariate Cox proportional hazard regression was used to determine the association between anaemia and other ODCs with NPDR progression.ResultsOf the total 69,982 NPDR patients included for analysis, 12,270, 2,162, and 10,322 progressed to VTDR, PDR and DME, respectively. Both mild and moderate/severe (mod/sev) anaemia were associated with an increased hazard for progression to VTDR (mild HR:1.10, 95% CI:1.04-1.16, p < 0.001; mod/sev HR:1.20, 95% CI:1.12-1.29, p < 0.001), PDR (mild HR:1.29, 95% CI:1.13-1.46, p < 0.001; mod/sev HR:1.43, 95% CI:1.21-1.69, p < 0.001), and DME (mild HR:1.06, 95% CI:1.00-1.13, p < 0.001; mod/sev HR:1.14, 95% CI:1.05-1.24, p < 0.001). ODCs such as chronic pulmonary disease and history of blood disorder/cancer were also significantly associated with an increased hazard for NPDR progression (HR > 1.00, p < 0.001 for all comparisons).ConclusionsAnaemia, independent of kidney disease, appears to play a significant role in progression from NPDR to VTDR, PDR, or DME. Concurrently, association of ODCs with NPDR progression lends support to the underlying mechanisms of anaemia in the pathogenesis of diabetic retinopathy.