calpain and Diabetic-Retinopathy

Topics: Aneurysm; Animals; Aorta; Atherosclerosis; Calpain; Catalysis; Cell Communication; Cell Proliferation; Cholesterol, LDL; Diabetic Angiopathies; Diabetic Retinopathy; Endothelial Cells; Extracellular Matrix; Humans; Hypertension, Pulmonary; Inflammation; Isoenzymes; Janus Kinase 1; Lipoproteins, LDL; Macrophages; Mice; Mice, Transgenic; Neoplasms; Neovascularization, Pathologic; Nitric Oxide Synthase; Phenotype; Proteolysis; Signal Transduction; Vascular Diseases

CAPN5 Neovascular Inflammatory Vitreoretinopathy (CAPN5-NIV; OMIM 193235) is a poorly-understood rare, progressive inflammatory intraocular disease with limited therapeutic options. To profile disease effector proteins in CAPN5-NIV patient vitreous, liquid vitreous biopsies were collected from two groups: eyes from control subjects (n = 4) with idiopathic macular holes (IMH) and eyes from test subjects (n = 12) with different stages of CAPN5-NIV. Samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein expression changes were evaluated by principal component analysis, 1-way ANOVA (significant p-value < 0.05), hierarchical clustering, gene ontology, and pathway representation. There were 216 differentially-expressed proteins (between CAPN5-NIV and control vitreous), including those unique to and abundant in each clinical stage. Gene ontology analysis revealed decreased synaptic signaling proteins in CAPN5-NIV vitreous compared to controls. Pathway analysis revealed that inflammatory mediators of the acute phase response and the complement cascade were highly-represented. The CAPN5-NIV vitreous proteome displayed characteristic enrichment of proteins and pathways previously-associated with non-infectious posterior uveitis, rhegmatogenous retinal detachment (RRD), age-related macular degeneration (AMD), proliferative diabetic retinopathy (PDR), and proliferative vitreoretinopathy (PVR). This study expands our knowledge of affected molecular pathways in CAPN5-NIV using unbiased, shotgun proteomic analysis rather than targeted detection platforms. The high-levels and representation of acute phase response proteins suggests a functional role for the innate immune system in CAPN5-NIV pathogenesis.

Topics: Adult; Aged; Calpain; Chromatography, Liquid; Diabetic Retinopathy; Female; Humans; Male; Middle Aged; Proteome; Proteomics; Retinal Degeneration; Retinal Detachment; Retinal Perforations; Tandem Mass Spectrometry; Vitreoretinopathy, Proliferative; Vitreous Body

To compare the expression of calpain and caspase-12 in human lens epithelial cells (LECs) of cataract patients with or without diabetic retinopathy (DR).. Prospective, comparative case series.. Patients were divided into 4 groups: patients without diabetes mellitus (DM) (Group 1), patients with DM and without diabetic retinopathy (DR) (Group 2), diabetic patients with nonprolifeative DR (NPDR) (Group 3), and diabetic patients with proliferative DR (PDR) (Group 4). Data on DM duration and glycated hemoglobin (HbA1c) level were collected. The LECs were obtained during cataract surgery and immunohistochemical staining was performed for calpain and caspase-12. The reactivity score of each specimen was determined using confocal microscopy.. A total of 40 patients (40 eyes) were evaluated, and each group was composed of 10 patients. The expression of calpain and caspase-12 was highest in Group 4, followed by Group 3, Group 2, and Group 1 (P < .001). The expressions were significantly higher with a longer duration of DM, increased HbA1c level, or advanced DR.. Endoplasmic reticulum stress may be associated with apoptosis of LECs, resulting in cataract formation in diabetic patients.

Topics: Aged; Aged, 80 and over; Calpain; Caspase 12; Cataract; Diabetes Mellitus; Diabetic Retinopathy; Epithelial Cells; Fluorescent Antibody Technique, Indirect; Glycated Hemoglobin; Humans; Lens, Crystalline; Microscopy, Confocal; Middle Aged; Prospective Studies

To describe how a high fat diet (HFD) and hyperglycemia initiate a sequence of calpain activation and oxidative stress associated with neuro-degenerative changes in diabetic retinopathy (DR), hyperglycemia was induced with streptozotocin in mice lacking the gene for calpastatin (CAST KO), and in mice lacking the gene for the transcription factor NF-E2 related factor 2 (Nrf2 KO). All animals were fed a HFD. Retinal ganglion cell (RGC) density was estimated by labeling with fluorogold and immunohistochemistry. A potent calpain inhibitor, SNJ-1945, was administered daily until the animals were sacrificed. In vitro, oxidative stress-induced RGC loss was evaluated in a high glucose culture medium with and without SNJ-1945. Retinal mRNA of calpain-1 and calpain-2 was measured by quantitative RT-PCR. Pre-apoptotic substrates of cleaved α-fodrin and synaptophysin protein were quantified by immunoblot analysis. Axonal damage was examined in transverse sections of the optic nerve. A HFD and hyperglycemia significantly increased RGC and axonal degeneration 3 weeks into the experiment. Levels of cleaved α-fodrin were increased. In the CAST KO mice, the neurotoxicity was augmented significantly. Gene manipulation of CAST and orally administered SNJ-1945 successfully modified calpain levels in the retina and prevented RGC death. In vitro, a high-glucose culture of retinal cells without antioxidants showed more RGC death than that with antioxidant treatment. The expression of synaptophysin was significantly suppressed by SNJ-1945 treatment. These results suggest that calpain plays a crucial role in metabolic-induced RGC degeneration caused by hyperglycemia and oxidative stress. Antioxidant and calpain inhibition offers important opportunities for future neuroprotective treatment against RGC death in various metabolic stress-induced diseases including DR.

Topics: Animals; Calpain; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Diet, High-Fat; Glycoproteins; Immunoblotting; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Stress, Physiological

The association of the gene encoding calpain 10 with type 2 diabetes mellitus (T2DM) has been reported. In this study we aimed to evaluate the association of SNP-19,-44, and -63 polymorphisms of calpain 10 with type 2 diabetes and diabetic-related conditions, such as diabetic retinopathy, nephropathy, and neuropathy in a Turkish population. The study group included 202 patients (133 female and 69 male) with T2DM, while the control group included 80 nondiabetic people (44 female and 36 male). Genotyping was done by the polymerase chain reaction and restriction fragment length polymorphism method. Calpain 10 SNP-44 TC genotype was found to be significantly frequent in type 2 diabetic patients with respect to the control group (p < 0.01). Body mass index (BMI) was found to be significantly high in TC genotype with type 2 diabetic patients (p < 0.05). SNP-44 T allele frequency was found to be lower in type 2 diabetic patients compared with the controls (p < 0.01). We conclude that the calpain 10 SNP-44 gene polymorphism may be accepted as a risk factor in the development of T2DM and elevated BMI in type 2 diabetic patients in a Turkish population.

Topics: Alleles; Calpain; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Risk Factors; Turkey