Mast cells modulate the pathogenesis of elastase-induced abdominal aortic aneurysms in mice

Abdominal aortic aneurysm (AAA), an inflammatory disease, involves leukocyte recruitment, immune responses, inflammatory cytokine production, vascular remodeling, neovascularization, and vascular cell apoptosis, all of which contribute to aortic dilatation. This study demonstrates that mast cells, key participants in human allergic immunity, participate in AAA pathogenesis in mice. Mast cells were found to accumulate in murine AAA lesions. Mast cell–deficient KitW-sh/KitW-sh mice failed to develop AAA elicited by elastase perfusion or periaortic chemical injury. KitW-sh/KitW-sh mice had reduced aortic expansion and internal elastic lamina degradation; decreased numbers of macrophages, CD3+ T lymphocytes, SMCs, apoptotic cells, and CD31+ microvessels; and decreased levels of aortic tissue IL-6 and IFN-γ. Activation of mast cells in WT mice via C48/80 injection resulted in enhanced AAA growth while mast cell stabilization with disodium cromoglycate diminished AAA formation. Mechanistic studies demonstrated that mast cells participated in angiogenesis, aortic SMC apoptosis, and matrix-degrading protease expression. Reconstitution of KitW-sh/KitW-sh mice with bone marrow–derived mast cells from WT or TNF-α–/– mice, but not from IL-6–/– or IFN-γ–/– mice, caused susceptibility to AAA formation to be regained. These results demonstrate that mast cells participate in AAA pathogenesis in mice by releasing proinflammatory cytokines IL-6 and IFN-γ, which may induce aortic SMC apoptosis, matrix-degrading protease expression, and vascular wall remodeling, important hallmarks of arterial aneurysms

Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process

Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important disease-related optic nerve parameter. In 21,094 individuals of European ancestry and 6,784 individuals of Asian ancestry, we identify 10 new loci associated with variation in VCDR. In a separate risk-score analysis of five case-control studies, Caucasians in the highest quintile have a 2.5-fold increased risk of primary open-angle glaucoma as compared with those in the lowest quintile. This study has more than doubled the known loci associated with optic disc cupping and will allow greater understanding of mechanisms involved in this common blinding condition

Common variants near CAV1 and CAV2 are associated with primary openangle glaucoma.

l e t t e r s We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in 1,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q31 (rs4236601[A], odds ratio (OR) = 1.36, P = 5.0 × 10 −10 ). We then replicated the association in sample sets of 2,175 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = 1.18, P = 0.0015) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.0021). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal rim of the optic nerve and a characteristic visual field defect. It is distinct from other forms of optic neuropathy in that the neuro retinal rim of the optic nerve retains its normal pink color as it becomes progressively thinner, leading to an enlarged opticnerve cup. POAG is the most common form of glaucoma. Excluding rare primary juvenile glaucoma with age of onset between 10 and 35 years, POAG is arbitrarily divided into highpressure glaucoma (defined as ≥22 mmHg) and normalpressure glaucoma. POAG is thought to have a multifactorial etiology, with the main risk factors being age, elevated intraocular (IOP) pressure, family history, race, central corneal thickness (CCT), hypertension, diabetes and myopia. The familiality of POAG has been known for decades, and studies have revealed three to ninefold greater risk of POAG in firstdegree relatives of POAG cases than in the population in general 2 . Common variants near CAV1 and CAV2 are associated with primary openangle glaucom

18 Eye Clinic

We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in ,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q3 (rs423660[A], odds ratio (OR) = .36, P = 5.0 × 0 −0 ). We then replicated the association in sample sets of 2,75 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = .8, P = 0.005) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.002). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal rim of the optic nerve and a characteristic visual field defect. It is distinct from other forms of optic neuropathy in that the neuro retinal rim of the optic nerve retains its normal pink color as it becomes progressively thinner, leading to an enlarged opticnerve cup. POAG is the most common form of glaucoma. Excluding rare primary juvenile glaucoma with age of onset between 10 and 35 years, POAG is arbitrarily divided into highpressure glaucoma (defined as ≥22 mmHg) and normalpressure glaucoma. POAG is thought to have a multifactorial etiology, with the main risk factors being age, elevated intraocular (IOP) pressure, family history, race, central corneal thickness (CCT), hypertension, diabetes and myopia. The familiality of POAG has been known for decades, and studies have revealed three to ninefold greater risk of POAG in firstdegree relatives of POAG cases than in the population in general 2 . Common variants near CAV1 and CAV2 are associated with primary openangle glaucom

A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

Background High myopia (HM), defined as a spherical equivalent refractive error (SER) ≤ −6.00 diopters (D), is a leading cause of sight impairment, through myopic macular degeneration (MMD). We aimed to derive an improved polygenic score (PGS) for predicting children at risk of HM and to test if a PGS is predictive of MMD after accounting for SER. Methods The PGS was derived from genome-wide association studies in participants of UK Biobank, CREAM Consortium, and Genetic Epidemiology Research on Adult Health and Aging. MMD severity was quantified by a deep learning algorithm. Prediction of HM was quantified as the area under the receiver operating curve (AUROC). Prediction of severe MMD was assessed by logistic regression. Findings In independent samples of European, African, South Asian and East Asian ancestry, the PGS explained 19% (95% confidence interval 17–21%), 2% (1–3%), 8% (7–10%) and 6% (3–9%) of the variation in SER, respectively. The AUROC for HM in these samples was 0.78 (0.75–0.81), 0.58 (0.53–0.64), 0.71 (0.69–0.74) and 0.67 (0.62–0.72), respectively. The PGS was not associated with the risk of MMD after accounting for SER: OR = 1.07 (0.92–1.24). Interpretation Performance of the PGS approached the level required for clinical utility in Europeans but not in other ancestries. A PGS for refractive error was not predictive of MMD risk once SER was accounted fo

Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive error

Abstract: Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects on eye elongation. Implicated genes are involved in extracellular matrix organization, developmental process for body and eye, connective tissue cartilage and glycosylation protein activities. Our study provides insights into population-specific novel genes for corneal curvature, and their pleiotropic effect in regulating eye size or conferring susceptibility to myopia

Suppression of experimental abdominal aortic aneurysms in mice by treatment with pyrrolidine dithiocarbamate, an antioxidant inhibitor of nuclear factor-κB

ObjectiveProinflammatory cytokines and matrix metalloproteinases (MMPs) are prominent mediators of the connective tissue destruction that characterizes abdominal aortic aneurysms (AAAs), and nuclear factor (NF)-κB is a cytokine-responsive transcription factor that promotes macrophage MMP expression. The purpose of this study was to determine whether aneurysmal degeneration is influenced by pyrrolidine dithiocarbamate (PDTC), a pharmacologic inhibitor of NF-κB.MethodsAdult male C57BL/6 mice underwent transient elastase perfusion of the abdominal aorta to induce the development of AAAs. Animals were treated every 48 hours by intraperitoneal injection with either saline (n = 34) or PDTC 20 mg/kg (n = 49). Aortic diameter (AD) measurements were used to determine the extent of aortic dilatation before and immediately after elastase perfusion and again at day 14.ResultsAll saline-treated mice developed AAAs associated with mononuclear inflammation and destruction of medial elastin (overall increase in AD, mean ± SEM, 169.1% ± 7.5%). In contrast, the incidence of AAAs was only 63% in PDTC-treated mice, with a reduction in the overall increase in AD to 109.8% ± 4.2% (P < .0001 vs saline), decreased inflammation, and structural preservation of aortic wall connective tissue. Although aneurysm development in saline-treated mice was associated with a marked increase in aortic tissue NF-κB and activator protein 1 DNA-binding activities, both activities were substantially reduced in PDTC-treated animals. PDTC-treated mice also exhibited significantly lower serum and aortic wall concentrations of interleukin 1β and interleukin 6, as well as lower amounts of aortic wall MMP-9, as compared with saline-treated controls.ConclusionsTreatment with PDTC inhibits elastase-induced experimental AAAs in the mouse, along with suppression of aortic wall NF-κB and activator protein 1 transcription factor activities, reduced expression of proinflammatory cytokines, and suppression of MMP-9. NF-κB is therefore a potentially important therapeutic target for the suppression of aneurysmal degeneration.Clinical relevanceDevelopment and progression of human AAAs is associated with inflammation and enzymatic degradation of connective tissue proteins. MMP-9 is one of the enzymes involved in aneurysm disease, and its production may be induced in part by activation of the transcription factor NF-κB. In this mouse model, treatment with pyrrolidine dithiocarbamate (a pharmacologic inhibitor of NF-κB) acted to suppress MMP-9 and aneurysm development. It is hoped that treatment strategies that target NF-κB may eventually be shown to suppress the growth of small aortic aneurysms in patients