Nuclear factor of activated T-cells (NFAT) regulation of IL-1ß-induced retinal vascular inflammation.

Chronic low-grade retinal inflammation is an essential contributor to the pathogenesis of diabetic retinopathy (DR). It is characterized by increased retinal cell expression and secretion of a variety of inflammatory cytokines; among these, IL-1ß has the reputation of being a major driver of cytokine-induced inflammation. IL-1ß and other cytokines drive inflammatory changes that cause damage to retinal cells, leading to the hallmark vascular lesions of DR; these include increased leukocyte adherence, vascular permeability, and capillary cell death. Nuclear factor of activated T-cells (NFAT) is a transcriptional regulator of inflammatory cytokines and adhesion molecules and is expressed in retinal cells. Consequently, it may influence multiple pathogenic steps early in DR. We investigated the NFAT-dependency of IL-1ß-induced inflammation in human Müller cells (hMC) and human retinal microvascular endothelial cells (hRMEC). Our results show that an NFAT inhibitor, Inhibitor of NFAT-Calcineurin Association-6 (INCA-6), decreased IL-1ß-induced expression of IL-1ß and TNFα in hMC, while having no effect on VEGF, CCL2, or CCL5 expression. We also demonstrate that INCA-6 attenuated IL-1ß-induced increases of IL-1ß, TNFα, IL-6, CCL2, and CCL5 (inflammatory cytokines and chemokines), and ICAM-1 and E-selectin (leukocyte adhesion molecules) expression in hRMEC. INCA-6 similarly inhibited IL-1ß-induced increases in leukocyte adhesion in both hRMEC monolayers in vitro and an acute model of retinal inflammation in vivo. Finally, INCA-6 rescued IL-1ß-induced permeability in both hRMEC monolayers in vitro and an acute model of retinal inflammation in vivo. Taken together, these data demonstrate the potential of NFAT inhibition to mitigate retinal inflammation secondary to diabetes.

A screen for deeply conserved non-coding GWAS SNPs uncovers a MIR-9-2 functional mutation associated to retinal vasculature defects in human.

Thousands of human disease-associated single nucleotide polymorphisms (SNPs) lie in the non-coding genome, but only a handful have been demonstrated to affect gene expression and human biology. We computationally identified risk-associated SNPs in deeply conserved non-exonic elements (CNEs) potentially contributing to 45 human diseases. We further demonstrated that human CNE1/rs17421627 associated with retinal vasculature defects showed transcriptional activity in the zebrafish retina, while introducing the risk-associated allele completely abolished CNE1 enhancer activity. Furthermore, deletion of CNE1 led to retinal vasculature defects and to a specific downregulation of microRNA-9, rather than MEF2C as predicted by the original genome-wide association studies. Consistent with these results, miR-9 depletion affects retinal vasculature formation, demonstrating MIR-9-2 as a critical gene underpinning the associated trait. Importantly, we validated that other CNEs act as transcriptional enhancers that can be disrupted by conserved non-coding SNPs. This study uncovers disease-associated non-coding mutations that are deeply conserved, providing a path for in vivo testing to reveal their cis-regulated genes and biological roles.

[Retinal vasculopathy with cerebral leukoencephalopathy carrying TREX1 mutation diagnosed by the intracranial calcification: a case report].

A 40-year-old woman with renal dysfunction for 2 years was admitted to our hospital suffering from a headache. Family history revealed that her mother had a headache, renal dysfunction, and brain infarction in younger age. She had a retinal hemorrhage, a retinal atrophy, pitting edema in her lower extremities. Her neurological findings were unremarkable. Brain imaging showed multiple white matter lesions accompanied with calcifications and slightly enhancement. Kidney biopsy showed the thrombotic microangiopathy, Gene analysis demonstrated a causative mutation in three-prime repair exonuclease-1 (TREX1) gene, c.703_704insG (p.Val235GlyfsX6), thereby we diagnosed her as retinal vasculopathy with cerebral leukoencephalopathy (RVCL). RVCL is an autosomal dominant condition caused by C-terminal frame-shift mutation in TREX1. TREX1 protein is a major 3' to 5' DNA exonuclease, which are important in DNA repair. While TREX1 mutations identified in Aicardi-Goutieres syndrome patients lead to a reduction of enzyme activity, it is suggested that mutations in RVCL alter an intracellular location of TREX1 protein. There are no treatments based evidences in RVCL. We administered cilostazol to protect endothelial function, and her brain lesions and renal function have not become worse for 10 months after. It is necessary to consider RVCL associated with TREX1 mutation if a patient has retinal lesions, white matter lesions accompanied with calcifications, and multiple organ dysfunction.

Circulating Endothelial Markers in Retinal Vasculopathy With Cerebral Leukoencephalopathy and Systemic Manifestations.

BACKGROUND AND PURPOSE: Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a monogenic small vessel disease, caused by C-terminal truncating TREX1 mutations, that can be considered a model for stroke and vascular dementia. The pathophysiology of RVCL-S is largely unknown, but systemic endothelial involvement has been suggested, leading to pathology in the brain and other highly vascularized organs. Here, we investigated circulating endothelial markers to confirm endothelial involvement and identify biomarkers for disease activity. METHODS: We measured circulating levels of von Willebrand factor (VWF) antigen, VWF propeptide, and angiopoietin-2 in members of 3 Dutch RVCL-S families and matched unrelated healthy controls. Stratified analyses based on symptomatology and age were performed. RESULTS: We found elevated levels of VWF antigen, VWF propeptide, and angiopoietin-2 in TREX1 mutation carriers (n=31) compared with family members without a TREX1 mutation (n=33) and unrelated healthy controls (n=31; Kruskal-Wallis test P<0.001 for all comparisons). Effects were most pronounced in mutation carriers with clinical manifestations aged ≥40 years (Mann-Whitney U test P<0.001 for all comparisons). Compared with healthy controls, levels of VWF antigen (P=0.02) and angiopoietin-2 (P=0.04) were also elevated in mutation carriers aged <40 years. All 3 markers showed moderate correlations with markers of kidney and liver disease and inflammation (ie, systemic symptoms of RVCL-S). CONCLUSIONS: Our results confirm an important role of the endothelium in RVCL-S pathophysiology. VWF antigen, VWF propeptide, and angiopoietin-2 might serve as early biomarkers of disease activity. Our findings might also help to understand the pathophysiology of common neurovascular disorders, such as stroke.

Papillophlebitis versus paediatric venous thrombosis. A case with 46C/T polymorphism in the F12 coagulation gene. / Papiloflebitis versus trombosis venosa pediátrica. Un caso con polimorfismo C46T del gen F12 de la coagulación.

CLINICAL CASE: An 8 year-old boy with no known diseases, with sudden loss of visual acuity (VA) in the left eye (LE). EXAMINATION: VA 1 in right eye, and 0.1 in LE, discrete left relative afferent pupil defect (RAPD). Normal biomicroscopy. Funduscopy: congestive papilla, venous tortuosity, peripapillary haemorrhages with macular oedema in LE. The systemic study only revealed A C46Tpolymorphism in the F12 coagulation gene. He had a VA of 1 and normal funduscopy 8 months later. DISCUSSION: Papillophlebitis is an inflammatory and non-ischaemic central retinal vein occlusion, ophthalmoscopically similar to central retinal vein thrombosis. The systemic study is essential to rule out underlying diseases.

VKORC1 C1173T and VKORC1 G-1639A gene polymorphisms in Turkish Behçet's patients with ocular and non-ocular involvement.

BACKGROUND: Behçet's disease (BD) is a multisystemic vasculitis with unknown etiology. Vitamin K epoxide reductase complex subunit 1 (VKORC1) is the key enzyme in the formation of active vitamin K that is a cofactor of various coagulation factors. Polymorphisms of the VKORC1 may affect the levels of active forms of vitamin K-dependent coagulation proteins and the tendency to thrombosis. The current study aimed to evaluate the role of VKORC1 gene polymorphisms in ocular and non-ocular Behçet's disease. METHODS: VKORC1 C1173T (rs 9934438) and G-1639A (rs 9923231) gene polymorphisms were evaluated by real-time polymerase chain reaction-based DNA analysis. The frequency of alleles and distribution of genotypes were assessed by the chi-squared test. Genotype distribution and Hardy-Weinberg equilibrium were tested with the χ(2) test for quality of fit. RESULTS: The distribution of GG, GA and AA and CC, CT, TT genotypes and the frequency of G,A and C,T alleles were not found to be different between patients and controls (p = 0.5651; p = 0.335 respectively), as well as patients with or without eye involvement (p = 0.9267; p = 0.384 respectively). CONCLUSION: VKORC1 polymorphisms seem not to be related with the thrombotic state of systemic and ocular Behçet's disease.