Search

Careful regulation of the complement system is critical for enabling complement proteins to titrate immune defense while also preventing collateral tissue damage from poorly controlled inflammation. In the eye, this balance between complement activity and inhibition is crucial, as a low level of basal complement activity is necessary to support ocular immune privilege, a prerequisite for maintaining vision. Dysregulated complement activation contributes to parainflammation, a low level of inflammation triggered by cellular damage that functions to reestablish homeostasis, or outright inflammation that disrupts the visual axis. Complement dysregulation has been implicated in many ocular diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD). In the last two decades, complement activity has been the focus of intense investigation in AMD pathogenesis, leading to the development of novel therapeutics for the treatment of atrophic AMD. This Review outlines recent advances and challenges, highlighting therapeutic approaches that have advanced to clinical trials, as well as providing a general overview of the complement system in the posterior segment of the eye and selected ocular diseases. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCT-A) allows noninvasive visualization of intraocular tissues with high resolution. Recently, an innovative use of this technology in studying neurodegenerative diseases has emerged with the neurosensory retina as a unique window into deeper brain tissues. Here, we discuss its role in identifying biomarkers of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Retinal degenerative diseases are a major cause of morbidity in modern society because visual impairment significantly decreases the quality of life of patients. A significant challenge in treating retinal degenerative diseases is their genetic and phenotypic heterogeneity. However, despite this diversity, many of these diseases share a common endpoint involving death of light-sensitive photoreceptors. Identifying common pathogenic mechanisms that contribute to photoreceptor death in these diverse diseases may lead to a unifying therapy for multiple retinal diseases that would be highly innovative and address a great clinical need. Because the retina and photoreceptors, in particular, have immense metabolic and energetic requirements, many investigators have hypothesized that metabolic dysfunction may be a common link unifying various retinal degenerative diseases. Here, we discuss a new area of research examining the role of NAD+ and sirtuins in regulating retinal metabolism and in the pathogenesis of retinal degenerative diseases. Indeed, the results of numerous studies suggest that NAD+ intermediates or small molecules that modulate sirtuin function could enhance retinal metabolism, reduce photoreceptor death, and improve vision. Although further research is necessary to translate these findings to the bedside, they have strong potential to truly transform the standard of care for patients with retinal degenerative diseases. [ABSTRACT FROM AUTHOR]

The article offers information on neurosensory retina is a complex ecosystem has composed of precisely layered and diverse neurons, multiple vascular plexuses, and glial cells. Topics include the environment are processed and conducted through the optic nerve to the visual cortex to create the vivid images that humans see, the relationship of the neurosensory retina to the brain is fascinating, and the only extension of the central nervous system that can be easily visualized.

The presence of retinal vasculopathy in the absence of typical predisposing factors should suggest a possible underlying hematologic abnormality. In such cases, a systemic investigation may reveal a potentially fatal hypercoagulability or hyperviscosity syndrome. Retinal vein occlusion is the most commonly encountered ophthalmic finding in such syndromes; however, abnormalities of the arterial system, the choroid, and the macula are also possible. Visual symptoms may be the only manifestation of the underlying process, making timely diagnosis by the ophthalmologist critical for both treatment and thrombotic prophylaxis. Moreover, as newer ophthalmic diagnostic technologies arise, there is an increasingly important role for eye physicians in the management of such syndromes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Drusen and atherosclerotic plaques share similar components. [•] Altered macrophage cholesterol efflux is a determinant pathogenic event in AMD and atherosclerosis. [•] Targeting macrophage-mediated inflammation is a relevant therapeutic approach. [ABSTRACT FROM AUTHOR]

Abstract: We have developed an assay that quantifies the potential of macrophages to regulate proliferation of endothelial cells. We show that young mice macrophages can be distinguished from old mice macrophages by their ability to inhibit vascular endothelial cell proliferation. While young mice macrophages robustly inhibit proliferation, old mice macrophages fail to do so and actually promote the proliferation of endothelial cells. In this report, we outline a technique that directly assesses the effect of macrophages on modulation of endothelial cell proliferation. This assay will help us in understanding the mechanisms of macrophage function in several disease states characterized by abnormal angiogenesis including cancers, angiogenic eye disease and atherosclerotic heart disease. [Copyright &y& Elsevier]

BACKGROUND. Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a rare, autosomal dominant, universally fatal disease without effective treatment options. This study explores the safety and preliminary efficacy of crizanlizumab, a humanized monoclonal antibody against P-selectin approved for the prevention of sickle cell crises, in slowing retinal nonperfusion and preserving vision in patients with RVCL-S. METHODS. Eleven patients with RVCL-S with confirmed exonuclease 3 prime repair exonuclease 1 (TREX1) mutations received monthly crizanlizumab infusions over 2 years. The study measured the nonperfusion index within 3 retinal zones and the total retina with fluorescein angiography, visual acuity, intraocular pressure (IOP), and optical coherence tomography central subfield thickness (CST) at baseline, 1 year, and 2 years. A mixed repeated-measures analysis was performed to assess the progression rates and changes from baseline. RESULTS. Eleven participants received crizanlizumab infusions. All of the participants tolerated crizanlizumab well, with 8 of 11 (72.7%) reporting mild adverse effects such as nausea, fatigue, and gastrointestinal symptoms. The change in total retinal nonperfusion was 7.22% [4.47, 9.97] in year 1 and –0.69% [–4.06, 2.68] in year 2 (P < 0.001). In the mid periphery, the change in nonperfusion was 10.6% [5.1, 16.1] in year 1 and –0.68% [–3.98, 5.35] in year 2 (P < 0.01), demonstrating a reduction in progression of nonperfusion in the second year of treatment. Visual acuity, IOP, and CST remained stable. CONCLUSION. Crizanlizumab has an acceptable safety profile. These results show promising potential for examining crizanlizumab in larger studies of RVCL-S and similar small-vessel diseases and for using the retina as a biomarker for systemic disease. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is a neurovascular complication of diabetes. Recent investigations have suggested that early degeneration of the neuroretina may occur prior to the appearance of microvascular changes; however, the mechanisms underlying this neurodegeneration have been elusive. Microglia are the predominant resident immune cell in the retina and adopt dynamic roles in disease. Here, we show that ablation of retinal microglia ameliorates visual dysfunction and neurodegeneration in a type I diabetes mouse model. We also provide evidence of enhanced microglial contact and engulfment of amacrine cells, ultrastructural modifications, and transcriptome changes that drive inflammation and phagocytosis. We show that CD200-CD200R signaling between amacrine cells and microglia is dysregulated during early DR and that targeting CD200R can attenuate high glucose-induced inflammation and phagocytosis in cultured microglia. Last, we demonstrate that targeting CD200R in vivo can prevent visual dysfunction, microglia activation, and retinal inflammation in the diabetic mouse. These studies provide a molecular framework for the pivotal role that microglia play in early DR pathogenesis and identify a potential immunotherapeutic target for treating DR in patients. [ABSTRACT FROM AUTHOR]

: PurposeTo report a case of presumed congenital hypertrophy of the retinal pigment epithelium in the fovea of an 88-year-old woman in the setting of geographic atrophy from age-related macular degeneration.: DesignObservational case report.: MethodsAn 88-year-old woman was examined.: ResultsBest-corrected visual acuity was 20/63 in the right eye and 20/50 in the left eye. Multifocal areas of geographic atrophy and large-sized drusen were seen in the maculae of both eyes. Biomicroscopic examination of the right eye showed hyperpigmentation consistent with congenital hypertrophy of the retinal pigment epithelium through the center of the macula. No prior photographic documentation of the retina was available.: ConclusionThis case suggests that foveal congenital hypertrophy of the retinal pigment epithelium may be seen in the setting of macular geographic atrophy. Although it is theoretically possible that the hyperpigmentation is reactive rather than congenital, the pigmentation is typical for congenital hypertrophy and is unlike any reactive pigmentation in our experience or described in a MEDLINE search of features of age-related macular degeneration. The case suggests that a hypertrophic process of the retinal pigment epithelium may coexist within or immediately adjacent to the anatomic boundaries of an atrophic process such as geographic atrophy from age-related macular degeneration. [Copyright &y& Elsevier]

Glaucoma is one of the leading causes of blindness globally, and is characterized by loss of retinal ganglion cells (RGCs). Because vision loss in glaucoma is not reversible, therapeutic interventions early in disease are highly desirable. However, owing to the current limitations in evaluating glaucomatous neurodegeneration, it is challenging to monitor the disease severity and progression objectively, and to design rational therapeutic strategies accordingly. Therefore, there is a clear need to identify quantifiable molecular biomarkers of glaucomatous neurodegeneration. As such, in our opinion, molecular biomarker(s) that specifically reflect stress or death of RGCs, and which correlate with disease severity, progression, and response to therapy, are highly desirable. [ABSTRACT FROM AUTHOR]

Many epithelial compartments undergo constitutive renewal in homeostasis but activate unique regenerative responses following injury. The clear corneal epithelium is crucial for vision and is renewed from limbal stem cells (LSCs). Using single-cell RNA sequencing, we profiled the mouse corneal epithelium in homeostasis, aging, diabetes, and dry eye disease (DED), where tear deficiency predisposes the cornea to recurrent injury. In homeostasis, we capture the transcriptional states that accomplish continuous tissue turnover. We leverage our dataset to identify candidate genes and gene networks that characterize key stages across homeostatic renewal, including markers for LSCs. In aging and diabetes, there were only mild changes with <15 dysregulated genes. The constitutive cell types that accomplish homeostatic renewal were conserved in DED but were associated with activation of cell states that comprise “adaptive regeneration.” We provide global markers that distinguish cell types in homeostatic renewal vs. adaptive regeneration and markers that specifically define DED-elicited proliferating and differentiating cell types. We validate that expression of SPARC, a marker of adaptive regeneration, is also induced in corneal epithelial wound healing and accelerates wound closure in a corneal epithelial cell scratch assay. Finally, we propose a classification system for LSC markers based on their expression fidelity in homeostasis and disease. This transcriptional dissection uncovers the dramatically altered transcriptional landscape of the corneal epithelium in DED, providing a framework and atlas for future study of these ocular surface stem cells in health and disease. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented concerning a rare case of resolution of an inflammation-associated epiretinal membranes that was associated with posterior vitreous detachment in a 16-year-old white man patient.

Background: Age-related macular degeneration (AMD) is the leading cause of blindness in people over 50 y of age in at least three continents. Choroidal neovascularization (CNV) is the process by which abnormal blood vessels develop underneath the retina. CNV develops in 10% of patients with AMD but accounts for up to 90% of the blindness from AMD. Although the precise etiology of CNV in AMD remains unknown, the macrophage component of the inflammatory response, which has been shown to promote tumor growth and support atherosclerotic plaque formation, is thought to stimulate aberrant angiogenesis in blinding eye diseases. The current theory is that macrophage infiltration promotes the development of neovascularization in CNV.Methods and Findings: We examined the role of macrophages in a mouse model of CNV. IL-10(-/-) mice, which have increased inflammation in response to diverse stimuli, have significantly reduced CNV with increased macrophage infiltrates compared to wild type. Prevention of macrophage entry into the eye promoted neovascularization while direct injection of macrophages significantly inhibited CNV. Inhibition by macrophages was mediated by the TNF family death molecule Fas ligand (CD95-ligand).Conclusions: Immune vascular interactions can be highly complex. Normal macrophage function is critical in controlling pathologic neovascularization in the eye. IL-10 regulates macrophage activity in the eye and is an attractive therapeutic target in order to suppress or inhibit CNV in AMD that can otherwise lead to blindness. [ABSTRACT FROM AUTHOR]

The central role of vascular endothelial growth factor (VEGF) signaling in regulating normal vascular development and pathological angiogenesis has been documented in multiple studies. Ocular anti-VEGF therapy is highly effective for treating a subset of patients with blinding eye disorders such as diabetic retinopathy and neovascular age-related macular degeneration (AMD). However, chronic VEGF suppression can lead to adverse effects associated with poor visual outcomes due to the loss of prosurvival and neurotrophic capacities of VEGF. In this review, we discuss emerging evidence for immune-related mechanisms that regulate ocular angiogenesis in a VEGF-independent manner. These novel molecular and cellular pathways may provide potential therapeutic avenues for a multitarget strategy, preserving the neuroprotective functions of VEGF in those patients whose disease is unresponsive to VEGF neutralization. [ABSTRACT FROM AUTHOR]

Calcium regulates the response sensitivity, kinetics and adaptation in photoreceptors. In striped bass cones, this calcium feedback includes direct modulation of the transduction cyclic nucleotide-gated (CNG) channels by the calcium-binding protein CNG-modulin. However, the possible role of EML1, the mammalian homolog of CNG-modulin, in modulating phototransduction in mammalian photoreceptors has not been examined. Here, we used mice expressing mutant Eml1 to investigate its role in the development and function of mouse photoreceptors using immunostaining, in-vivo and ex-vivo retinal recordings, and single-cell suction recordings. We found that the mutation of Eml1 causes significant changes in the mouse retinal structure characterized by mislocalization of rods and cones in the inner retina. Consistent with the fraction of mislocalized photoreceptors, rod and cone-driven retina responses were reduced in the mutants. However, the Eml1 mutation had no effect on the dark-adapted responses of rods in the outer nuclear layer. Notably, we observed no changes in the cone sensitivity in the Eml1 mutant animals, either in darkness or during light adaptation, ruling out a role for EML1 in modulating cone CNG channels. Together, our results suggest that EML1 plays an important role in retina development but does not modulate phototransduction in mammalian rods and cones. [ABSTRACT FROM AUTHOR]

Macrophages undergo programmatic changes with age, leading to altered cytokine polarization and immune dysfunction, shifting these critical immune cells from protective sentinels to disease promoters. The molecular mechanisms underlying macrophage inflammaging are poorly understood. Using an unbiased RNA sequencing (RNA-seq) approach, we identified Mir146b as a microRNA whose expression progressively and unidirectionally declined with age in thioglycollateelicited murine macrophages. Mir146b deficiency led to altered macrophage cytokine expression and reduced mitochondrial metabolic activity, two hallmarks of cellular aging. Single-cell RNA-seq identified patterns of altered inflammation and interferon gamma signaling in Mir146b-deficient macrophages. Identification of Mir146b as a potential regulator of macrophage aging provides novel insights into immune dysfunction associated with aging. [ABSTRACT FROM AUTHOR]

Leber congenital amaurosis type nine is an autosomal recessive retinopathy caused by mutations of the NAD+ synthesis enzyme NMNAT1. Despite the ubiquitous expression of NMNAT1, patients do not manifest pathologies other than retinal degeneration. Here we demonstrate that widespread NMNAT1 depletion in adult mice mirrors the human pathology, with selective loss of photoreceptors highlighting the exquisite vulnerability of these cells to NMNAT1 loss. Conditional deletion demonstrates that NMNAT1 is required within the photoreceptor. Mechanistically, loss of NMNAT1 activates the NADase SARM1, the central executioner of axon degeneration, to trigger photoreceptor death and vision loss. Hence, the essential function of NMNAT1 in photoreceptors is to inhibit SARM1, highlighting an unexpected shared mechanism between axonal degeneration and photoreceptor neurodegeneration. These results define a novel SARM1-dependent photoreceptor cell death pathway and identifies SARM1 as a therapeutic candidate for retinopathies. [ABSTRACT FROM AUTHOR]

Macrophages are important mediators of inflammation and tissue remodeling. Recent insights into the heterogeneity of macrophage subpopulations have renewed interest in their functional diversity in homeostasis and disease. In addition, their plasticity enables them to perform a variety of functions in response to changing tissue contexts, such as those imposed by aging. These qualities make macrophages particularly intriguing cells given their dichotomous role in protecting against, or accelerating, diseases of the cardiovascular system and the eye, two tissues that are particularly susceptible to the effects of aging. We review novel perspectives on macrophage biology, as informed by recent studies detailing the diversity of macrophage identity and function, as well as mechanisms influencing macrophage behavior that might offer opportunities for new therapeutic strategies. Recent studies combining single-cell transcriptomics, imaging, and functional assays provide mechanistic validation of prior observations indicating that murine macrophage heterogeneity contributes to diverse roles in healthy tissue and during disease response. Disease models in mice have identified subpopulations of macrophages with characteristic gene expression and behavior profiles that protect against or exacerbate disease phenotypes in the cardiovascular system and the eye. Analysis of multiple macrophage populations can reveal molecular mechanisms of macrophage plasticity and phenotype switching (or lack thereof) in response to context-dependent tissue changes. Mechanistic insights from basic research have spurred numerous translational and clinical studies exploring the measurement or modulation of human macrophage function and identity in improving disease outcomes. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction in adipose tissue is involved in the pathophysiology of obesity-induced systemic metabolic complications, such as type 2 diabetes, insulin resistance, and dyslipidemia. However, the mechanisms responsible for obesity-induced adipose tissue mitochondrial dysfunction are not clear. The aim of present study was to test the hypothesis that nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin-3 (SIRT3) in adipocytes plays a critical role in adipose tissue mitochondrial biology and obesity. We first measured adipose tissue SIRT3 expression in obese and lean mice. Next, adipocyte-specific mitochondrial Sirt3 knockout (AMiSKO) mice were generated and metabolically characterized. We evaluated glucose and lipid metabolism in adult mice fed either a regular-chow diet or high-fat diet (HFD) and in aged mice. We also determined the effects of Sirt3 deletion on adipose tissue metabolism and mitochondrial biology. Supporting our hypothesis, obese mice had decreased SIRT3 gene and protein expression in adipose tissue. However, despite successful knockout of SIRT3, AMiSKO mice had normal glucose and lipid metabolism and did not change metabolic responses to HFD-feeding and aging. In addition, loss of SIRT3 had no major impact on putative SIRT3 targets, key metabolic pathways, and mitochondrial function in white and brown adipose tissue. Collectively, these findings suggest that adipocyte SIRT3 is dispensable for maintaining normal adipose tissue mitochondrial function and whole body metabolism. Contrary to our hypothesis, loss of SIRT3 function in adipocytes is unlikely to contribute to the pathophysiology of obesity-induced metabolic complications. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction in adipose tissue is involved in the pathophysiology of obesity-induced systemic metabolic complications, such as type 2 diabetes, insulin resistance, and dyslipidemia. However, the mechanisms responsible for obesity-induced adipose tissue mitochondrial dysfunction are not clear. The aim of present study was to test the hypothesis that nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin-3 (SIRT3) in adipocytes plays a critical role in adipose tissue mitochondrial biology and obesity. We first measured adipose tissue SIRT3 expression in obese and lean mice. Next, adipocyte-specific mitochondrial Sirt3 knockout (AMiSKO) mice were generated and metabolically characterized. We evaluated glucose and lipid metabolism in adult mice fed either a regular-chow diet or high-fat diet (HFD) and in aged mice. We also determined the effects of Sirt3 deletion on adipose tissue metabolism and mitochondrial biology. Supporting our hypothesis, obese mice had decreased SIRT3 gene and protein expression in adipose tissue. However, despite successful knockout of SIRT3, AMiSKO mice had normal glucose and lipid metabolism and did not change metabolic responses to HFD-feeding and aging. In addition, loss of SIRT3 had no major impact on putative SIRT3 targets, key metabolic pathways, and mitochondrial function in white and brown adipose tissue. Collectively, these findings suggest that adipocyte SIRT3 is dispensable for maintaining normal adipose tissue mitochondrial function and whole body metabolism. Contrary to our hypothesis, loss of SIRT3 function in adipocytes is unlikely to contribute to the pathophysiology of obesity-induced metabolic complications. [ABSTRACT FROM AUTHOR]

Perturbations in WNT signaling are associated with congenital eye disorders, including familial exudative vitreoretinopathy and Norrie disease. More recently, activation of the WNT pathway has also been shown to be associated with age-related macular degeneration (AMD). In this study, we identified that in choroidal neovascular membranes from AMD patients, β-catenin is activated specifically in the vascular endothelium, suggesting that WNT promotes pathologic angiogenesis by directly affecting vascular endothelial cells. WNT7B has been shown to be important during eye development for regression of the fetal hyaloid vasculature. However, it has not yet been established whether WNT7A and/or WNT7B are involved in neovascular AMD pathogenesis. Here, we show that WNT7A and WNT7B increase the proliferation of human dermal microvascular endothelial cells in a dose-dependent manner. Both WNT7A and WNT7B also stimulated vascular sprouting from mouse choroidal explants in vitro . To evaluate in vivo relevance, we generated mice systemically deficient in Wnt7a and/or Wnt7b . Genetic deletion of both Wnt7a and Wnt7b decreased the severity of laser injury-induced choroidal neovascularization (CNV), while individual deletion of either Wnt7a or Wnt7b did not have a significant effect on CNV, suggesting that WNT7A and WNT7B have redundant pro-angiogenic roles in vivo . Cumulatively, these findings identify specific WNT isoforms that may play a pathologic role in CNV as observed in patients with neovascular AMD. Although the source of increased WNT7A and/or WNT7B in CNV requires further investigation, WNT signaling may be a potential target for therapeutic intervention if these results are demonstrated to be relevant in human disease. [ABSTRACT FROM AUTHOR]

Purpose To evaluate visual outcomes after vitrectomy for intraocular hemorrhages secondary to traumatic brain injury. Design Retrospective, observational case series. Participants A total of 28 eyes in 20 patients undergoing vitrectomy for Terson syndrome secondary to traumatic brain injury between 1997 and 2015. Methods We reviewed the records of patients undergoing a standard 20-gauge or 23-gauge pars plana vitrectomy for intraocular hemorrhages secondary to traumatic brain injury, and the timing of vitrectomy in relation to the inciting intracranial event was recorded. Main Outcome Measures The primary outcome measure was the change in the preoperative visual acuity score at postoperative month 1 and at the last noted clinic appointment. Results A total of 28 eyes in 20 patients (all male) underwent pars plana vitrectomy for intraocular hemorrhages secondary to traumatic brain injury. The mean preoperative baseline logarithm of the minimum angle of resolution (logMAR) (Snellen) best-corrected visual acuity (BCVA) was 1.81±0.56 (20/1290). At 1-month postoperative follow-up, the mean BCVA was 0.30±0.33 (20/40). At the date of the last follow-up, the mean BCVA was 0.15±0.24 (20/30) and the median BCVA was 0.00 (20/20). Although the difference between preoperative and postoperative BVCA was significantly different at 1 month and the final postoperative clinic visits ( P < 0.001), there was not a correlation between preoperative visual acuity as a predictor of final postoperative visual acuity outcome ( r =−0.32; P = 0.09; 95% confidence interval [CI] −0.62 – 0.06). At the date of the last follow-up, the differences in visual outcomes between the individuals undergoing vitrectomy within 3 months of the inciting event, 0.08±0.15 (20/25), were not significantly different than those undergoing surgical intervention after 3 months, 0.18±0.27 (20/30) ( P = 0.28). Three cases among those undergoing vitrectomy after 3 months were complicated by retinal detachment, none of which resulted in a BCVA worse than when the patient originally presented preoperatively. Conclusions In this retrospective series of patients without other ocular pathology, surgical intervention effectively provided rapid visual recovery in the majority of individuals with intraocular hemorrhages secondary to traumatic brain injury, irrespective of the timing of vitrectomy or of preoperative visual acuity. [ABSTRACT FROM AUTHOR]

Endothelial cells (ECs) express fibroblast growth factor receptors (FGFRs) and are exquisitely sensitive to FGF signals. However, whether the EC or another vascular cell type requires FGF signaling during development, homeostasis, and response to injury is not known. Here, we show that Flk1-Cre or Tie2-Cre mediated deletion of FGFR1 and FGFR2 {Fgfr½Flk1-Cre or FgfrV 2tie2-cre mice), which results in deletion in endothelial and hematopoietic cells, is compatible with normal embryonic development. As adults, Fgfr½Flk-1-Cre mice maintain normal blood pressure and vascular reactivity and integrity under homeostatic conditions. However, neovascularization after skin or eye injury was significantly impaired in both Fgfr½Flk-1-Cre and Fgfr½½Flk-1-CreTie2-Cre½Flk-1-Cre mice, independent of either hematopoietic cell loss of FGFR½ or vascular endothelial growth factor receptor 2 (Vegfr2) haploinsuf-ficiency. Also, impaired neovascularization was associated with delayed cutaneous wound healing. These findings reveal a key requirement for cell-autonomous EC FGFR signaling in injury-induced angiogenesis, but not for vascular homeostasis, identifying the EC FGFR signaling pathway as a target for diseases associated with aberrant vascular proliferation, such as age-related macular degeneration, and for modulating wound healing without the potential toxicity associated with direct manipulation of systemic FGF or VEGF activity. [ABSTRACT FROM AUTHOR]

The retina is one of the major energy consuming tissues within the body. In this context, synaptic transmission between light-excited rod and cone photoreceptors and downstream ON-bipolar neurons is a highly demanding energy consuming process. Sirtuin 6 (SIRT6), a NAD-dependent deacylase, plays a key role in regulating glucose metabolism. In this study, we demonstrate that SIRT6 is highly expressed in the retina, controlling levels of histone H3K9 and H3K56 acetylation. Notably, despite apparent normal histology, SIRT6 deficiency caused major retinal transmission defects concomitant to changes in expression of glycolytic genes and glutamate receptors, as well as elevated levels of apoptosis in inner retina cells. Our results identify SIRT6 as a critical modulator of retinal function, likely through its effects on chromatin. [ABSTRACT FROM AUTHOR]

Nicotinamide adenine dinucleotide (NAD+) is an enzyme cofactor or cosubstrate in many essential biological pathways. To date, the primary source of neuronal NAD+ has been unclear. NAD+ can be synthesized from several different precursors, among which nicotinamide is the substrate predominantly used in mammals. The rate-limiting step in the NAD+ biosynthetic pathway from nicotinamide is performed by nicotinamide phosphoribosyltransferase (Nampt). Here, we tested the hypothesis that neurons use intracellular Nampt-mediated NAD+ biosynthesis by generating and evaluating mice lacking Nampt in forebrain excitatory neurons (CaMKIIαNampt-/- mice). CaMKIIαNampt-/- mice showed hippocampal and cortical atrophy, astrogliosis, microgliosis, and abnormal CA1 dendritic morphology by 2-3 months of age. Importantly, these histological changes occurred with altered intrahippocampal connectivity and abnormal behavior; including hyperactivity, some defects in motor skills, memory impairment, and reduced anxiety, but in the absence of impaired sensory processes or long-term potentiation of the Schaffer collateral pathway. These results clearly demonstrate that forebrain excitatory neurons mainly use intracellular Nampt-mediated NAD+ biosynthesis to mediate their survival and function. Studying this particular NAD+ biosynthetic pathway in these neurons provides critical insight into their vulnerability to pathophysiological stimuli and the development of therapeutic and preventive interventions for their preservation. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is a major cause of blindness in the developed world. Oxidative stress and inflammation are implicated in AMD, but precise mechanisms remain poorly defined. Carboxyethylpyrrole (CEP) is an AMD-associated lipid peroxidation product. We previously demonstrated that mice immunized with CEP-modified albumin developed AMD-like degenerative changes in the outer retina. Here, we examined the kinetics of lesion development in immunized mice and the presence of macrophages within the interphotoreceptor matrix (IPM), between the retinal pigment epithelium and photoreceptor outer segments. We observed a significant and time-dependent increase in the number of macrophages in immunized mice relative to young age-matched controls prior to overt pathology. These changes were more pronounced in BALB/c mice than in C57BL/6 mice. Importantly, IPM-infiltrating macrophages were polarized toward the M1 phenotype but only in immunized mice. Moreover, when Ccr2-deficient mice were immunized, macrophages were not present in the IPM and no retinal lesions were observed, suggesting a deleterious role for these cells in our model. This work provides mechanistic evidence linking immune responses against oxidative damage with the presence of proinflammatory macrophages at sites of future AMD and experimentally demonstrates that manipulating immunity may be a target for modulating the development of AMD. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is a major cause of blindness in the developed world. Oxidative stress and inflammation are implicated in AMD, but precise mechanisms remain poorly defined. Carboxyethylpyrrole (CEP) is an AMD-associated lipid peroxidation product. We previously demonstrated that mice immunized with CEP-modified albumin developed AMD-like degenerative changes in the outer retina. Here, we examined the kinetics of lesion development in immunized mice and the presence of macrophages within the interphotoreceptor matrix (IPM), between the retinal pigment epithelium and photoreceptor outer segments. We observed a significant and time-dependent increase in the number of macrophages in immunized mice relative to young age-matched controls prior to overt pathology. These changes were more pronounced in BALB/c mice than in C57BL/6 mice. Importantly, IPM-infiltrating macrophages were polarized toward the M1 phenotype but only in immunized mice. Moreover, when Ccr2-deficient mice were immunized, macrophages were not present in the IPM and no retinal lesions were observed, suggesting a deleterious role for these cells in our model. This work provides mechanistic evidence linking immune responses against oxidative damage with the presence of proinflammatory macrophages at sites of future AMD and experimentally demonstrates that manipulating immunity may be a target for modulating the development of AMD. [ABSTRACT FROM AUTHOR]

Objective: Perform a cost-effectiveness analysis of the treatment of diabetic macular edema (DME) with ranibizumab plus prompt or deferred laser versus triamcinolone plus prompt laser. Data for the analysis were drawn from reports of the Diabetic Retinopathy Clinical Research Network (DRCRnet) Protocol I. Design: Computer simulation based on Protocol I data. Analyses were conducted from the payor perspective. Participants: Simulated participants assigned characteristics reflecting those seen in Protocol I. Methods: Markov models were constructed to replicate Protocol I''s 104-week outcomes using a microsimulation approach to estimation. Baseline characteristics, visual acuity (VA), treatments, and complications were based on Protocol I data. Costs were identified by literature search. One-way sensitivity analysis was performed, and the results were validated against Protocol I data. Main Outcome Measures: Direct cost of care for 2 years, change in VA from baseline, and incremental cost-effectiveness ratio (ICER) measured as cost per additional letter gained from baseline (Early Treatment of Diabetic Retinopathy Study). Results: For sham plus laser (S+L), ranibizumab plus prompt laser (R+pL), ranibizumab plus deferred laser (R+dL), and triamcinolone plus laser (T+L), effectiveness through 104 weeks was predicted to be 3.46, 7.07, 8.63, and 2.40 letters correct, respectively. The ICER values in terms of dollars per VA letter were $393 (S+L vs. T+L), $5943 (R+pL vs. S+L), and $20 (R+dL vs. R+pL). For pseudophakics, the ICER value for comparison triamcinolone with laser versus ranibizumab with deferred laser was $14 690 per letter gained. No clinically relevant changes in model variables altered outcomes. Internal validation demonstrated good similarity to Protocol I treatment patterns. Conclusions: In treatment of phakic patients with DME, ranibizumab with deferred laser provided an additional 6 letters correct compared with triamcinolone with laser at an additional cost of $19 216 over 2 years. That would indicate that if the gain in VA seen at 2 years is maintained in subsequent years, then the treatment of phakic patients with DME using ranibizumab may meet accepted standards of cost-effectiveness. For pseudophakic patients, first-line treatment with triamcinolone seems to be the most cost-effective option. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. [Copyright &y& Elsevier]

Background: Demyelinating polyneuropathy is a debilitating, poorly understood disease that can exist in acute (Guillain- Barré syndrome) or chronic forms. Interleukin-10 (IL-10), although traditionally considered an anti-inflammatory cytokine, has also been implicated in promoting abnormal angiogenesis in the eye and in the pathobiology of autoimmune diseases such as lupus and encephalomyelitis. Principal Findings: Overexpression of IL-10 in a transgenic mouse model leads to macrophage-mediated demyelinating polyneuropathy. IL-10 upregulates ICAM-1 within neural tissues, promoting massive macrophage influx, inflammationinduced demyelination, and subsequent loss of neural tissue resulting in muscle weakness and paralysis. The primary insult is to perineural myelin followed by secondary axonal loss. Infiltrating macrophages within the peripheral nerves demonstrate a highly pro-inflammatory signature. Macrophages are central players in the pathophysiology, as in vivo depletion of macrophages using clodronate liposomes reverses the phenotype, including progressive nerve loss and paralysis. Macrophage-mediate demyelination is dependent on Fas-ligand (FasL)-mediated Schwann cell death. Significance: These findings mimic the human disease chronic idiopathic demyelinating polyneuropathy (CIDP) and may also promote further understanding of the pathobiology of related conditions such as acute idiopathic demyelinating polyneuropathy (AIDP) or Guillain-Barré syndrome. [ABSTRACT FROM AUTHOR]

Aberrant angiogenesis in the eye is the most common cause of blindness. The current study examined the role of interleukin-10 (IL-10) in ischemia-induced pathological angiogenesis called neovascularization during postnatal development. IL-10 deficiency resulted in significantly reduced pathological retinal angiogenesis. In contrast to the choroicapillaris where IL-10 interferes with macrophage influx, IL-10 did not prevent anti-angiogenic macrophages from migrating to the retina in response to hypoxia. Instead, IL-10 promoted retinal angiogenesis by altering macrophage angiogenic function, as macrophages from wild-type mice demonstrated increased vascular endothelial growth factor (VEGF) and nitric oxide (NO) compared to IL-10 deficient macrophages. IL-10 appears to directly affect macrophage responsiveness to hypoxia, as macrophages responded to hypoxia with increased levels of IL-10 and STAT3 phosphorylation as opposed to IL-10 deficient macrophages. Also, IL-10 deficient macrophages inhibited the proliferation of vascular endothelial cells in response to hypoxia while wild-type macrophages failed to do so. These findings suggest that hypoxia guides macrophage behavior to a pro-angiogenic phenotype via IL-10 activated pathways. [ABSTRACT FROM AUTHOR]

Purpose: To define the role of intravitreal bevacizumab in individuals with choroidal neovascularization (CNV) resulting from Ocular Histoplasmosis syndrome (OHS). Design: Retrospective chart review of a surgical therapy. Methods: We reviewed the course of 28 eyes of 28 patients who underwent intravitreal injection of bevacizumab for treatment of CNV secondary to OHS. Outcome was measured by pretreatment and posttreatment visual acuity (VA). Results: The average pretreatment logarithm of the minimum angle of resolution (logMAR) VA was 0.65 (Snellen equivalent of 20/88). Mean follow-up was 22.43 weeks with an average of 1.8 intravitreal injections. Average final logMAR VA was 0.43 (Snellen equivalent of 20/54). Twenty eyes (71%) experienced an increase in central VA, whereas four eyes (14%) were unchanged and four eyes (14%) experienced a decrease in vision. Conclusions: Intravitreal bevacizumab may improve or stabilize VA in a significant majority of patients with neovascular complications of OHS (24 eyes [85.7%] in our study population). [Copyright &y& Elsevier]

Abnormal angiogenesis plays a key role in diseases of aging such as heart disease, certain cancers, and eye diseases including age-related macular degeneration. Macrophages have been shown previously to be both anti- and proangiogenic, and their role in regulating angiogenesis at sites of tissue injury is critical and complex. In this study, we analyzed cytokine gene expression patterns of mouse macrophages by real-time quantitative PCR and tested the functional effects of senescence on gene expression and macrophage polarization. Following laser injury to the retina, IL-10 was upregulated and Fas ligand (FasL), IL-12, and TNF-alpha were downregulated in ocular macrophages of old mice (>18 months of age). Downregulation of FasL on macrophages led to a loss of the antiangiogenic phenotype, as evidenced by the inability of these macrophages to inhibit vascular endothelial cells. Our results demonstrate that senescence, FasL, and IL-10 are key determinants of macrophage function that alter the growth of abnormal postdevelopmental blood vessels in disease processes including blinding eye disease. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the complement factor H (CFH) Y402H variant is associated with specific age-related macular degeneration (AMD) clinical phenotypes.Design: Retrospective, case-control study.Methods: One hundred and eighty-eight white subjects with AMD and 189 control subjects were genotyped for the T-to-C polymorphism in exon 9 of the CFH gene by restriction-fragment length analysis and deoxyribonucleic acid (DNA) sequencing using genomic DNA from mouthwash samples. AMD phenotypes were characterized by clinical examination, fundus photography, and fluorescein angiography.Results: Heterozygosity for the at-risk genotype (TC) increased the likelihood for AMD 2.1-fold (95% confidence interval [CI], 1.3 to 3.3), whereas homozygosity for the genotype (CC) increased the likelihood for AMD 6.5-fold (95% CI, 3.4 to 12.5) in our population. The C allele was associated significantly with predominantly classic choroidal neovascularization (odds ratio [OR], 2.01; 95% CI, 1.34 to 3.30). Neovascular lesion size was similar among the three genotypes (P = .67).Conclusions: The Y402H CFH variant carried a significantly increased risk for developing AMD in our population. Genotype and phenotype correlations regarding choroidal neovascular lesion type were observed. [ABSTRACT FROM AUTHOR]

Presents findings of a study which tested the effect of angiopoietin 2 (Ang2) on blood vessels. Impact of increased expression of Ang2 on mature retinal blood vessels; Contribution of Ang2 expression to stimulation of retinal neovascularization; Discussion on Ang2 inhibition of subretinal neovascularization in rho/vascular endothelial growth factor transgenic mice

Purpose: To report the trends in intraocular pressures (IOP) within the first week after intravitreal injection of triamcinolone acetonide (Kenalog) for the treatment of retinal disease. Design: Retrospective chart review. Methods: Review of 43 consecutive patients and 50 intravitreal injections of 4 mg triamcinolone acetonide. Analysis of the effect on IOP was performed. Results: The mean preinjection IOP was 14.60 ± 3.71 mm Hg (mean ± SD) (range, 9 to 26 mm Hg). The mean postinjection IOP (30 minutes after injection) was 19.64 ± 7.43 mm Hg (range, 5 to 45 mm Hg). Mean IOP change before and after injection was 4.83 ± 7.10 mm Hg. The mean IOP one to two days after injection was 15.32 ± 4.41. mm Hg (range, 6 to 27 mm Hg). The mean IOP five to seven days after injection was 15.94 ± 4.86 mm Hg (range, 5 to 28 mm Hg). Conclusions: Intravitreal triamcinolone acetonide injection in this limited series does not cause a marked increase in IOP within the first week after the procedure. [Copyright &y& Elsevier]

Purpose: To report two cases of a retinal pigment epithelial tear after intravitreal injection of pegaptanib sodium. To our knowledge, this is the first report of this finding after intraocular antivascular endothelial growth factor therapy.Design: Observational case reports.Methods: Two patients presented with occult choroidal neovascularization and associated serous pigment epithelial detachment that was a result of age-related macular degeneration. Both patients were treated with an intravitreal injection of pegaptanib sodium.Results: One patient developed a retinal pigment epithelium tear one week after the intravitreal injection. The second patient developed a retinal pigment epithelium tear eight weeks after treatment.Conclusions: Although these cases may represent natural history, there should be a high index of suspicion for retinal pigment epithelium tears in patients who report significant visual deterioration after intravitreal injection of pegaptanib sodium. Further studies are needed to determine whether angiographic subtypes of choroidal neovascular membranes are more susceptible to developing retinal pigment epithelium tears after treatment with antivascular endothelial growth factor agents. [ABSTRACT FROM AUTHOR]

Cell-autonomous endothelial cell (EC) fibroblast growth factor receptor (FGFR) signaling through FGFR1/2 is essential for injury-induced wound vascularization and pathologic neovascularization as in blinding eye diseases such as age-related macular degeneration. Which FGF ligand(s) is critical in regulating angiogenesis is unknown. Utilizing ex vivo models of choroidal endothelial sprouting and in vivo models of choroidal neovascularization (CNV), we demonstrate here that only FGF2 is the essential ligand. Though FGF-FGFR signaling can activate multiple intracellular signaling pathways, we show that FGF2 regulates pathogenic angiogenesis via STAT3 activation. The identification of FGF2 as a critical mediator in aberrant neovascularization provides a new opportunity for developing multi-target therapies in blinding eye diseases especially given the limitations of anti-VEGF monotherapy. • Fibroblast growth factor-2 (FGF-2) regulates choroidal neovascularization. • FGF-2 activates intracellular stat3. • The identification of the fgf-2/stat3 axis presents novel therapeutic opportunities. [ABSTRACT FROM AUTHOR]