Zinc Supplementation Induced Transcriptional Changes in Primary Human Retinal Pigment Epithelium: A Single-Cell RNA Sequencing Study to Understand Age-Related Macular Degeneration.

Zinc supplementation has been shown to be beneficial to slow the progression of age-related macular degeneration (AMD). However, the molecular mechanism underpinning this benefit is not well understood. This study used single-cell RNA sequencing to identify transcriptomic changes induced by zinc supplementation. Human primary retinal pigment epithelial (RPE) cells could mature for up to 19 weeks. After 1 or 18 weeks in culture, we supplemented the culture medium with 125 µM added zinc for one week. RPE cells developed high transepithelial electrical resistance, extensive, but variable pigmentation, and deposited sub-RPE material similar to the hallmark lesions of AMD. Unsupervised cluster analysis of the combined transcriptome of the cells isolated after 2, 9, and 19 weeks in culture showed considerable heterogeneity. Clustering based on 234 pre-selected RPE-specific genes divided the cells into two distinct clusters, we defined as more and less differentiated cells. The proportion of more differentiated cells increased with time in culture, but appreciable numbers of cells remained less differentiated even at 19 weeks. Pseudotemporal ordering identified 537 genes that could be implicated in the dynamics of RPE cell differentiation (FDR < 0.05). Zinc treatment resulted in the differential expression of 281 of these genes (FDR < 0.05). These genes were associated with several biological pathways with modulation of ID1/ID3 transcriptional regulation. Overall, zinc had a multitude of effects on the RPE transcriptome, including several genes involved in pigmentation, complement regulation, mineralization, and cholesterol metabolism processes associated with AMD.

Genetic deficiency and pharmacological modulation of RORα regulate laser-induced choroidal neovascularization.

Choroidal neovascularization (CNV) causes acute vision loss in neovascular age-related macular degeneration (AMD). Genetic variations of the nuclear receptor RAR-related orphan receptor alpha (RORα) have been linked with neovascular AMD, yet its specific role in pathological CNV development is not entirely clear. In this study, we showed that Rora was highly expressed in the mouse choroid compared with the retina, and genetic loss of RORα in Staggerer mice (Rorasg/sg) led to increased expression levels of Vegfr2 and Tnfa in the choroid and retinal pigment epithelium (RPE) complex. In a mouse model of laser-induced CNV, RORα expression was highly increased in the choroidal/RPE complex post-laser, and loss of RORα in Rorasg/sg eyes significantly worsened CNV with increased lesion size and vascular leakage, associated with increased levels of VEGFR2 and TNFα proteins. Pharmacological inhibition of RORα also worsened CNV. In addition, both genetic deficiency and inhibition of RORα substantially increased vascular growth in isolated mouse choroidal explants ex vivo. RORα inhibition also promoted angiogenic function of human choroidal endothelial cell culture. Together, our results suggest that RORα negatively regulates pathological CNV development in part by modulating angiogenic response of the choroidal endothelium and inflammatory environment in the choroid/RPE complex.

Omega-3/Omega-6 Long-Chain Fatty Acid Imbalance in Phase I Retinopathy of Prematurity.

There is a gap in understanding the effect of the essential ω-3 and ω-6 long-chain polyunsaturated fatty acids (LCPUFA) on Phase I retinopathy of prematurity (ROP), which precipitates proliferative ROP. Postnatal hyperglycemia contributes to Phase I ROP by delaying retinal vascularization. In mouse neonates with hyperglycemia-associated Phase I retinopathy, dietary ω-3 (vs. ω-6 LCPUFA) supplementation promoted retinal vessel development. However, ω-6 (vs. ω-3 LCPUFA) was also developmentally essential, promoting neuronal growth and metabolism as suggested by a strong metabolic shift in almost all types of retinal neuronal and glial cells identified with single-cell transcriptomics. Loss of adiponectin (APN) in mice (mimicking the low APN levels in Phase I ROP) decreased LCPUFA levels (including ω-3 and ω-6) in retinas under normoglycemic and hyperglycemic conditions. ω-3 (vs. ω-6) LCPUFA activated the APN pathway by increasing the circulating APN levels and inducing expression of the retinal APN receptor. Our findings suggested that both ω-3 and ω-6 LCPUFA are crucial in protecting against retinal neurovascular dysfunction in a Phase I ROP model; adequate ω-6 LCPUFA levels must be maintained in addition to ω-3 supplementation to prevent retinopathy. Activation of the APN pathway may further enhance the ω-3 and ω-6 LCPUFA's protection against ROP.

miR-106b suppresses pathological retinal angiogenesis.

MicroRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression. We recently demonstrated that levels of miR-106b were significantly decreased in the vitreous and plasma of patients with neovascular age-related macular degeneration (AMD). Here we show that expression of the miR-106b-25 cluster is negatively regulated by the unfolded protein response pathway of protein kinase RNA-like ER kinase (PERK) in a mouse model of neovascular AMD. A reduction in levels of miR-106b triggers vascular growth both in vivo and in vitro by inducing production of pro-angiogenic factors. We demonstrate that therapeutic delivery of miR-106b to the retina with lentiviral vectors protects against aberrant retinal angiogenesis in two distinct mouse models of pathological retinal neovascularization. Results from this study suggest that miRNAs such as miR-106b have the potential to be used as multitarget therapeutics for conditions characterized by pathological retinal angiogenesis.

Brain PUFA Concentrations Are Differentially Affected by Interactions of Diet, Sex, Brain Regions, and Phospholipid Pools in Mice.

BACKGROUND: PUFAs play vital roles in the development, maintenance, and functioning of circuitries that regulate reward and social behaviors. Therefore, modulations in PUFA concentrations of these brain regions may disrupt reward and social circuitries contributing to mood disorders, developmental disabilities, and addictions. Though much is known about regional and phospholipid-pool-specific PUFA concentrations, less is known about the effects of dietary interventions that concurrently lowers n-6 PUFA and supplements n-3 PUFA, on brain PUFA concentrations. There is even less knowledge on the effects of sex on brain PUFA concentrations. OBJECTIVE: This study aimed to comprehensively examine the interaction effects of diet (D), sex (S), brain regions (BR), and phospholipid pools (PL) on brain PUFA concentrations. METHODS: Male and female C57BL/6J mice were fed 1 of 4 custom-designed diets varying in linoleic acid (LNA) (8 en% or 1 en%) and eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) (0.4 en% or 0 en%) concentrations from in utero to 15 weeks old. At 15 weeks old, the prefrontal cortex, dorsal striatum, and cerebellum were collected. Fatty acids of 5 major PL were quantified by GC-flame ionization detection. Repeated measures ANOVA was used to test for differences among the groups for D, S, BR, and PL. RESULTS: No significant 4-way interactions on PUFA concentrations. DHA, predominant n-3 PUFA, concentrations were dependent on significant D × BR × PL interactions. DHA concentration was not affected by sex. Arachidonic acid (ARA; predominant n-6 PUFA) concentrations were not dependent on 3-way interactions. However, significant 2-way D × PL, BR × PL, and D × Sinteractions affected ARA concentrations. Brain fatty acid concentrations were differentially affected by various combinations of D, S, BR, and PL interactions. CONCLUSION: Though DHA concentrations are not affected by sex, ARA concentrations are affected by interactions of the 4 variables examined. This study provides comprehensive references in the investigation of complex interactions between factors that affect brain PUFA concentrations in mice.

Why is Zeaxanthin the Most Concentrated Xanthophyll in the Central Fovea?

Diet-based xanthophylls (zeaxanthin and lutein) are conditionally essential polar carotenoids preferentially accreted in high concentrations (1 mM) to the central retina, where they have the capacity to impart unique physiologically significant biophysical biochemical properties implicated in cell function, rescue, and survival. Macular xanthophylls interact with membrane-bound proteins and lipids to absorb/attenuate light energy, modulate oxidative stress and redox balance, and influence signal transduction cascades implicated in the pathophysiology of age-related macular degeneration. There is exclusive transport, sequestration, and appreciable bioamplification of macular xanthophylls from the circulating carotenoid pool to the retina and within the retina to regions required for high-resolution sensory processing. The distribution of diet-based macular xanthophylls and the lutein metabolite meso-zeaxanthin varies considerably by retinal eccentricity. Zeaxanthin concentrations are 2.5-fold higher than lutein in the cone-dense central fovea. This is an ~20-fold increase in the molar ratio relative to eccentric retinal regions with biochemically detectable macular xanthophylls. In this review, we discuss how the differences in the specific properties of lutein and zeaxanthin could help explain the preferential accumulation of zeaxanthin in the most vulnerable region of the macula.

Effect of Adjunctive Estradiol on Schizophrenia Among Women of Childbearing Age: A Randomized Clinical Trial.

Importance: Several lines of evidence suggest that estradiol influences the course of schizophrenia, and a previous randomized controlled trial demonstrated that transdermal estradiol improved symptoms in female patients of childbearing age. However, many initial positive findings in schizophrenia research are not later replicated. Objective: To independently replicate the results of the effect of estradiol on schizophrenia in women of childbearing age. Design, Setting, and Participants: An 8-week randomized, placebo-controlled trial performed in the Republic of Moldova between December 4, 2015, and July 29, 2016, among 200 premenopausal women aged 19 to 46 years with schizophrenia or schizoaffective disorder as defined by the DSM-5. Intervention: Patients were randomized to receive a 200-µg estradiol patch or placebo patch changed twice a week added to their antipsychotic treatment. Main Outcomes and Measures: The primary outcome was the positive subscale of the Positive and Negative Syndrome Scale (PANSS; lower scores indicated fewer symptoms and higher scores indicated more symptoms), analyzed with mixed models for repeated measures on an intention-to-treat basis. Results: A total of 100 women (median age, 38 years; interquartile range, 34-42 years) were randomized to receive an estradiol patch and 100 women (median age, 38 years; interquartile range, 31-41 years) were randomized to receive a placebo patch; the median age at baseline for the entire group of 200 women was 38.0 years (range, 19.5-46.0 years). At baseline, the mean positive PANSS score was 19.6 for both groups combined; at week 8, the mean positive PANSS score was 14.4 in the placebo group and 13.4 in the estradiol group. Compared with placebo, participants receiving add-on estradiol patches had statistically significant improvements in the primary outcome measure, PANSS positive subscale points (-0.94; 95% CI, -1.64 to -0.24; P = .008; effect size = 0.38). Post hoc heterogeneity analyses found that this effect occurred almost entirely in 100 participants older than 38.0 years (46 in placebo group vs 54 in estradiol group; difference, -1.98 points on the PANSS positive subscale; 95% CI, -2.94 to -1.02; P < .001). Younger participants did not benefit from estradiol (difference, 0.08 points on the PANSS positive subscale; 95% CI, -0.91 to 1.07; P = .87). Breast tenderness was more common in the estradiol group (n = 15) than in the placebo group (n = 1) as was weight gain (14 in estradiol group vs 1 in placebo group). Conclusions and Relevance: The results independently replicate the finding that transdermal estradiol is an effective add-on treatment for women of childbearing age with schizophrenia and extend it, finding improvements in negative symptoms and finding that the effect could be specific to those older than 38 years. The results should be viewed in the context of the differences in the natural course of schizophrenia between females and males. Trial Registration: ClinicalTrials.gov identifier: NCT03848234.

Maternal fish consumption during pregnancy and smoking behavioural patterns.

n-3 Highly unsaturated fatty acids (HUFA), are essential components of neuronal membranes and mediate a range of complex bioactive properties including gene expression, myelination, cell-signalling and dopaminergic function. Deficits in n-3 HUFA have been linked to increased risks for addictive disorders, thus we posited that lower fish consumption would be associated with greater risks for perinatal smoking among 9640 mothers enroled in the Avon Longitudinal Study of Parents and Children. We used univariable and multivariable regression models to examine relationships between self-reported prenatal dietary intakes of n-3 HUFA-rich foods (fish and shellfish) and maternal smoking; outcomes included cessation and the number of cigarettes smoked per d. Both before and during pregnancy, there was consistent evidence (P<0·001) of protective fish intake-smoking associations; relative to mothers reporting no fish consumption, those who reported some fish consumption (<340 g/week) and high fish consumption (340 g+/week) at 32 weeks of gestation showed lower likelihoods of smoking (adjusted P values <0·001). Respective OR for these relationships were 0·87 (95% CI 0·77, 0·97) and 0·73 (95% CI 0·61, 0·86). Although the prevalence of smoking diminished, from a high of 31·6% (pre-pregnancy) to a low of 18·7% (second trimester), the magnitude of fish intake-smoking associations remained stable following adjustment for confounders. These observations suggest that greater fish or n-3 HUFA consumption should be evaluated as an intervention to reduce or prevent smoking in randomised clinical trials.

Meat Consumption During Pregnancy and Substance Misuse Among Adolescent Offspring: Stratification of TCN2 Genetic Variants.

BACKGROUND: Reducing meat consumption is often advised; however, inadvertent nutritional deficiencies during pregnancy may result in residual neurodevelopmental harms to offspring. This study assessed possible effects of maternal diets in pregnancy on adverse substance use among adolescent offspring. METHODS: Pregnant women and their 13-year-old offspring taking part in a prospective birth cohort study, the Avon Longitudinal Study of Parents and Children (ALSPAC), provided Food Frequency Questionnaire data from which dietary patterns were derived using principal components analysis. Multivariable logistic regression models including potential confounders evaluated adverse alcohol, cannabis, and tobacco use of the children at 15 years of age. RESULTS: Lower maternal meat consumption was associated with greater problematic substance use among 15-year-old offspring in dose-response patterns. Comparing never to daily meat consumption after adjustment, risks were greater for all categories of problem substance use: alcohol, odds ratio OR = 1.75, 95% CI = (1.23, 2.56), p < 0.001; tobacco use OR = 1.85, 95% CI = (1.28, 2.63), p < 0.001; and cannabis OR = 2.70, 95% CI = (1.89, 4.00), p < 0.001. Given the likelihood of residual confounding, potential causality was evaluated using stratification for maternal allelic variants that impact biological activity of cobalamin (vitamin B12) and iron. Lower meat consumption disproportionally increased the risks of offspring substance misuse among mothers with optimally functional (homozygous) variants (rs1801198) of the gene transcobalamin 2 gene (TCN2) which encodes the vitamin B12 transport protein transcobalamin 2 implicating a causal role for cobalamin deficits. Functional maternal variants in iron metabolism were unrelated to the adverse substance use. Risks potentially attributable to cobalamin deficits during pregnancy include adverse adolescent alcohol, cannabis, and tobacco use (14, 37, and 23, respectively). CONCLUSIONS: Lower prenatal meat consumption was associated with increased risks of adolescent substance misuse. Interactions between TCN2 variant status and meat intake implicate cobalamin deficiencies.

Adiponectin Mediates Dietary Omega-3 Long-Chain Polyunsaturated Fatty Acid Protection Against Choroidal Neovascularization in Mice.

Purpose: Neovascular age-related macular degeneration (AMD) is a major cause of legal blindness in the elderly. Diets with omega3-long-chain-polyunsaturated-fatty-acid (ω3-LCPUFA) correlate with a decreased risk of AMD. Dietary ω3-LCPUFA versus ω6-LCPUFA inhibits mouse ocular neovascularization, but the underlying mechanism needs further exploration. The aim of this study was to investigate if adiponectin (APN) mediated ω3-LCPUFA suppression of neovessels in AMD. Methods: The mouse laser-induced choroidal neovascularization (CNV) model was used to mimic some of the inflammatory aspect of AMD. CNV was compared between wild-type (WT) and Apn-/- mice fed either otherwise matched diets with 2% ω3 or 2% ω6-LCPUFAs. Vldlr-/- mice were used to mimic some of the metabolic aspects of AMD. Choroid assay ex vivo and human retinal microvascular endothelial cell (HRMEC) proliferation assay in vitro was used to investigate the APN pathway in angiogenesis. Western blot for p-AMPKα/AMPKα and qPCR for Apn, Mmps, and IL-10 were used to define mechanism. Results: ω3-LCPUFA intake suppressed laser-induced CNV in WT mice; suppression was abolished with APN deficiency. ω3-LCPUFA, mediated by APN, decreased mouse Mmps expression. APN deficiency decreased AMPKα phosphorylation in vivo and exacerbated choroid-sprouting ex vivo. APN pathway activation inhibited HRMEC proliferation and decreased Mmps. In Vldlr-/- mice, ω3-LCPUFA increased retinal AdipoR1 and inhibited NV. ω3-LCPUFA decreased IL-10 but did not affect Mmps in Vldlr-/- retinas. Conclusions: APN in part mediated ω3-LCPUFA inhibition of neovascularization in two mouse models of AMD. Modulating the APN pathway in conjunction with a ω3-LCPUFA-enriched-diet may augment the beneficial effects of ω3-LCPUFA in AMD patients.

RORα modulates semaphorin 3E transcription and neurovascular interaction in pathological retinal angiogenesis.

Pathological proliferation of retinal blood vessels commonly causes vision impairment in proliferative retinopathies, including retinopathy of prematurity. Dysregulated crosstalk between the vasculature and retinal neurons is increasingly recognized as a major factor contributing to the pathogenesis of vascular diseases. Class 3 semaphorins (SEMA3s), a group of neuron-secreted axonal and vascular guidance factors, suppress pathological vascular growth in retinopathy. However, the upstream transcriptional regulators that mediate the function of SEMA3s in vascular growth are poorly understood. Here we showed that retinoic acid receptor-related orphan receptor α (RORα), a nuclear receptor and transcription factor, is a novel transcriptional regulator of SEMA3E-mediated neurovascular coupling in a mouse model of oxygen-induced proliferative retinopathy. We found that genetic deficiency of RORα substantially induced Sema3e expression in retinopathy. Both RORα and SEMA3E were expressed in retinal ganglion cells. RORα directly bound to a specific ROR response element on the promoter of Sema3e and negatively regulated Sema3e promoter-driven luciferase expression. Suppression of Sema3e using adeno-associated virus 2 carrying short hairpin RNA targeting Sema3e promoted disoriented pathological neovascularization and partially abolished the inhibitory vascular effects of RORα deficiency in retinopathy. Our findings suggest that RORα is a novel transcriptional regulator of SEMA3E-mediated neurovascular coupling in pathological retinal angiogenesis.-Sun, Y., Liu, C.-H., Wang, Z., Meng, S. S., Burnim, S. B., SanGiovanni, J. P., Kamenecka, T. M., Solt, L. A., Chen, J. RORα modulates semaphorin 3E transcription and neurovascular interaction in pathological retinal angiogenesis.

miRNAs, single nucleotide polymorphisms (SNPs) and age-related macular degeneration (AMD).

Advanced age-related macular degeneration (AAMD) is a complex sight-threating disease of public health significance. Micro RNAs (miRNAs) have been proposed as biomarkers for AAMD. The presence of certain single nucleotide polymorphisms (SNPs) may influence the explanatory value of these biomarkers. Here we present findings from an integrated approach used to determine whether AAMD-associated SNPs have the capacity to influence miRNA-mRNA pairing and, if so, to what extent such pairing may be manifested in a discrete AAMD transcriptome. Using a panel of 8854 SNPs associated with AAMD at p-values ≤5.0E-7 from a cohort of >30,000 elderly people, we identified SNPs in miRNA target-encoding constituents of: (1) regulator of complement activation (RCA) genes (rs390679, CFHR1, p≤2.14E-214 | rs12140421, CFHR3, p≤4.63E-29); (2) genes of major histocompatibility complex (MHC) loci (rs4151672, CFB, p≤8.91E-41 | rs115404146, HLA-C, p≤6.32E-12 | rs1055821, HLA-B, p≤1.93E-9 | rs1063355, HLA-DQB1, p≤6.82E-14); and (3) genes of the 10q26 AAMD locus (rs1045216, PLEKHA1, p≤4.17E-142 | rs2672603, ARMS2, p≤7.14E-46). We used these findings with existing data on AAMD-related retinal miRNA and transcript profiles for the purpose of making inferences on SNP-mRNA-miRNA-AAMD relationships. Four of 12 miRNAs significantly elevated in AAMD retina (hsa-miR-155-5p, hsa-let-7a-5p, hsa-let-7b-5p hsa-let-7d-5p) also showed strong pairing capacity (TarBase 7.1 context++ score <-0.2, miRanda 3.3 pairing score >150) with miRNA target transcripts encoded by AAMD-associated SNPs resident in HLA-DQB1 (rs1063355, hsa-miR-155-5p) and TGFBR1 (rs868, hsa-let-7). Three of the 12 miRNAs overexpressed in AAMD retina are inducible by NFkB and have high affinity targets in the complement factor H (CFH) mRNA 3' UTR. We used ENSEMBL to identify polymorphic regions in the CFH mRNA 3' UTR with the capacity to disrupt miRNA-mRNA pairing. Two variants (rs766666504 and rs459598) existed in DNA sequence encoding the seed region of hsa-miR-146a-5p in the CFH mRNA 3' UTR - as this miRNA is also elevated in both vitreous and serum of people with AAMD, it shows great value as a biomarker. Our findings suggest that knowledge on the nature of DNA sequence variation may increase the explanatory power of miRNA biomarkers in genetically diverse populations, while yielding information with which to develop: (1) mechanistic tests on processes implicated in AMD pathogenesis; and, (2) site-specific small molecules (synthetic mimetics or anti-miRNAs) with preventive or therapeutic efficacy for AAMD.

Fenofibrate Inhibits Cytochrome P450 Epoxygenase 2C Activity to Suppress Pathological Ocular Angiogenesis.

Neovascular eye diseases including retinopathy of prematurity, diabetic retinopathy and age-related-macular-degeneration are major causes of blindness. Fenofibrate treatment in type 2 diabetes patients reduces progression of diabetic retinopathy independent of its peroxisome proliferator-activated receptor (PPAR)α agonist lipid lowering effect. The mechanism is unknown. Fenofibrate binds to and inhibits cytochrome P450 epoxygenase (CYP)2C with higher affinity than to PPARα. CYP2C metabolizes ω-3 long-chain polyunsaturated fatty acids (LCPUFAs). While ω-3 LCPUFA products from other metabolizing pathways decrease retinal and choroidal neovascularization, CYP2C products of both ω-3 and ω-6 LCPUFAs promote angiogenesis. We hypothesized that fenofibrate inhibits retinopathy by reducing CYP2C ω-3 LCPUFA (and ω-6 LCPUFA) pro-angiogenic metabolites. Fenofibrate reduced retinal and choroidal neovascularization in PPARα-/-mice and augmented ω-3 LCPUFA protection via CYP2C inhibition. Fenofibrate suppressed retinal and choroidal neovascularization in mice overexpressing human CYP2C8 in endothelial cells and reduced plasma levels of the pro-angiogenic ω-3 LCPUFA CYP2C8 product, 19,20-epoxydocosapentaenoic acid. 19,20-epoxydocosapentaenoic acid reversed fenofibrate-induced suppression of angiogenesis ex vivo and suppression of endothelial cell functions in vitro. In summary fenofibrate suppressed retinal and choroidal neovascularization via CYP2C inhibition as well as by acting as an agonist of PPARα. Fenofibrate augmented the overall protective effects of ω-3 LCPUFAs on neovascular eye diseases.

Retinal expression of small non-coding RNAs in a murine model of proliferative retinopathy.

Ocular neovascularization is a leading cause of blindness in proliferative retinopathy. Small non-coding RNAs (sncRNAs) play critical roles in both vascular and neuronal development of the retina through post-transcriptional regulation of target gene expression. To identify the function and therapeutic potential of sncRNAs in retinopathy, we assessed the expression profile of retinal sncRNAs in a mouse model of oxygen-induced retinopathy (OIR) with pathologic proliferation of neovessels. Approximately 2% of all analyzed sncRNAs were significantly altered in OIR retinas compared with normoxic controls. Twenty three microRNAs with substantial up- or down-regulation were identified, including miR-351, -762, -210, 145, -155, -129-5p, -150, -203, and -375, which were further analyzed for their potential target genes in angiogenic, hypoxic, and immune response-related pathways. In addition, nineteen small nucleolar RNAs also revealed differential expression in OIR retinas compared with control retinas. A decrease of overall microRNA expression in OIR retinas was consistent with reduced microRNA processing enzyme Dicer, and increased expression of Alu element in OIR. Together, our findings elucidated a group of differentially expressed sncRNAs in a murine model of proliferative retinopathy. These sncRNAs may exert critical post-transcriptional regulatory roles in regulating pathological neovascularization in eye diseases.

Cytochrome P450 Oxidase 2C Inhibition Adds to ω-3 Long-Chain Polyunsaturated Fatty Acids Protection Against Retinal and Choroidal Neovascularization.

OBJECTIVE: Pathological ocular neovascularization is a major cause of blindness. Increased dietary intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) reduces retinal neovascularization and choroidal neovascularization (CNV), but ω-3 LCPUFA metabolites of a major metabolizing pathway, cytochrome P450 oxidase (CYP) 2C, promote ocular pathological angiogenesis. We hypothesized that inhibition of CYP2C activity will add to the protective effects of ω-3 LCPUFA on neovascular eye diseases. APPROACH AND RESULTS: The mouse models of oxygen-induced retinopathy and laser-induced CNV were used to investigate pathological angiogenesis in the retina and choroid, respectively. The plasma levels of ω-3 LCPUFA metabolites of CYP2C were determined by mass spectroscopy. Aortic ring and choroidal explant sprouting assays were used to investigate the effects of CYP2C inhibition and ω-3 LCPUFA-derived CYP2C metabolic products on angiogenesis ex vivo. We found that inhibition of CYP2C activity by montelukast added to the protective effects of ω-3 LCPUFA on retinal neovascularization and CNV by 30% and 20%, respectively. In CYP2C8-overexpressing mice fed a ω-3 LCPUFA diet, montelukast suppressed retinal neovascularization and CNV by 36% and 39% and reduced the plasma levels of CYP2C8 products. Soluble epoxide hydrolase inhibition, which blocks breakdown and inactivation of CYP2C ω-3 LCPUFA-derived active metabolites, increased oxygen-induced retinopathy and CNV in vivo. Exposure to selected ω-3 LCPUFA metabolites of CYP2C significantly reversed the suppression of both angiogenesis ex vivo and endothelial cell functions in vitro by the CYP2C inhibitor montelukast. CONCLUSIONS: Inhibition of CYP2C activity adds to the protective effects of ω-3 LCPUFA on pathological retinal neovascularization and CNV.

Efficacy of omega-3 highly unsaturated fatty acids in the treatment of depression.

BACKGROUND: Trials evaluating efficacy of omega-3 highly unsaturated fatty acids (HUFAs) in major depressive disorder report discrepant findings. AIMS: To establish the reasons underlying inconsistent findings among randomised controlled trials (RCTs) of omega-3 HUFAs for depression and to assess implications for further trials. METHOD: A systematic bibliographic search of double-blind RCTs was conducted between January 1980 and July 2014 and an exploratory hypothesis-testing meta-analysis performed in 35 RCTs including 6665 participants receiving omega-3 HUFAs and 4373 participants receiving placebo. RESULTS: Among participants with diagnosed depression, eicosapentaenoic acid (EPA)-predominant formulations (>50% EPA) demonstrated clinical benefits compared with placebo (Hedge's G = 0.61, P<0.001) whereas docosahexaenoic acid (DHA)-predominant formulations (>50% DHA) did not. EPA failed to prevent depressive symptoms among populations not diagnosed for depression. CONCLUSIONS: Further RCTs should be conducted on study populations with diagnosed or clinically significant depression of adequate duration using EPA-predominant omega-3 HUFA formulations.

MicroRNA signatures in vitreous humour and plasma of patients with exudative AMD.

Age-related macular degeneration (AMD) is a leading cause of blindness worldwide affecting individuals over the age of 50. The neovascular form (NV AMD) is characterized by choroidal neovascularization (CNV) and responsible for the majority of central vision impairment. Using non-biased microRNA arrays and individual TaqMan qPCRs, we profiled miRNAs in the vitreous humour and plasma of patients with NV AMD. We identified a disease-associated increase in miR-146a and a decrease in miR-106b and miR-152 in the vitreous humour which was reproducible in plasma. Moreover, miR-146a/miR-106b ratios discriminated patients with NV AMD with an area under the Receiver Operating Characteristic curve (ROC AUC) of 0,977 in vitreous humour and 0,915 in plasma suggesting potential for a blood-based diagnostic. Furthermore, using the AMD Gene Consortium (AGC) we mapped a NV AMD-associated SNP (rs1063320) in a binding site for miR-152-3p in the HLA-G gene. The relationship between our detected miRNAs and NV AMD related genes was also investigated using gene sets derived from the Ingenuity Pathway Analysis (IPA). To our knowledge, our study is the first to correlate vitreal and plasma miRNA signatures with NV AMD, highlighting potential future worth as biomarkers and providing insight on NV AMD pathogenesis.

Nuclear receptor RORα regulates pathologic retinal angiogenesis by modulating SOCS3-dependent inflammation.

Pathologic ocular angiogenesis is a leading cause of blindness, influenced by both dysregulated lipid metabolism and inflammation. Retinoic-acid-receptor-related orphan receptor alpha (RORα) is a lipid-sensing nuclear receptor with diverse biologic function including regulation of lipid metabolism and inflammation; however, its role in pathologic retinal angiogenesis remains poorly understood. Using a mouse model of oxygen-induced proliferative retinopathy, we showed that RORα expression was significantly increased and genetic deficiency of RORα substantially suppressed pathologic retinal neovascularization. Loss of RORα led to decreased levels of proinflammatory cytokines and increased levels of antiinflammatory cytokines in retinopathy. RORα directly suppressed the gene transcription of suppressors of cytokine signaling 3 (SOCS3), a critical negative regulator of inflammation. Inhibition of SOCS3 abolished the antiinflammatory and vasoprotective effects of RORα deficiency in vitro and in vivo. Moreover, treatment with a RORα inverse agonist SR1001 effectively protected against pathologic neovascularization in both oxygen-induced retinopathy and another angiogenic model of very-low-density lipoprotein receptor (Vldlr)-deficient (Vldlr (-/-) ) mice with spontaneous subretinal neovascularization, whereas a RORα agonist worsened oxygen-induced retinopathy. Our data demonstrate that RORα is a novel regulator of pathologic retinal neovascularization, and RORα inhibition may represent a new way to treat ocular neovascularization.

Netrin-1 - DCC Signaling Systems and Age-Related Macular Degeneration.

We conducted a nested candidate gene study and pathway-based enrichment analysis on data from a multi-national 77,000-person project on the molecular genetics of age-related macular degeneration (AMD) to identify AMD-associated DNA-sequence variants in genes encoding constituents of a netrin-1 (NTN1)-based signaling pathway that converges on DNA-binding transcription complexes through a 3'-5'-cyclic adenosine monophosphate-calcineurin (cAMP-CN)-dependent axis. AMD-associated single nucleotide polymorphisms (SNPs) existed in 9 linkage disequilibrium-independent genomic regions; these included loci overlapping NTN1 (rs9899630, P ≤ 9.48 x 10(-5)), DCC (Deleted in Colorectal Cancer)--the gene encoding a primary NTN1 receptor (rs8097127, P ≤ 3.03 x 10(-5)), and 6 other netrin-related genes. Analysis of the NTN1-DCC pathway with exact methods demonstrated robust enrichment with AMD-associated SNPs (corrected P-value = 0.038), supporting the idea that processes driven by NTN1-DCC signaling systems operate in advanced AMD. The NTN1-DCC pathway contains targets of FDA-approved drugs and may offer promise for guiding applied clinical research on preventive and therapeutic interventions for AMD.

Dietary ω-3 polyunsaturated fatty acids decrease retinal neovascularization by adipose-endoplasmic reticulum stress reduction to increase adiponectin.

BACKGROUND: Retinopathy of prematurity (ROP) is a vision-threatening disease in premature infants. Serum adiponectin (APN) concentrations positively correlate with postnatal growth and gestational age, important risk factors for ROP development. Dietary ω-3 (n-3) long-chain polyunsaturated fatty acids (ω-3 LCPUFAs) suppress ROP and oxygen-induced retinopathy (OIR) in a mouse model of human ROP, but the mechanism is not fully understood. OBJECTIVE: We examined the role of APN in ROP development and whether circulating APN concentrations are increased by dietary ω-3 LCPUFAs to mediate the protective effect in ROP. DESIGN: Serum APN concentrations were correlated with ROP development and serum ω-3 LCPUFA concentrations in preterm infants. Mouse OIR was then used to determine whether ω-3 LCPUFA supplementation increases serum APN concentrations, which then suppress retinopathy. RESULTS: We found that in preterm infants, low serum APN concentrations positively correlate with ROP, and serum APN concentrations positively correlate with serum ω-3 LCPUFA concentrations. In mouse OIR, serum total APN and bioactive high-molecular-weight APN concentrations are increased by ω-3 LCPUFA feed. White adipose tissue, where APN is produced and assembled in the endoplasmic reticulum, is the major source of serum APN. In mouse OIR, adipose endoplasmic reticulum stress is increased, and APN production is suppressed. ω-3 LCPUFA feed in mice increases APN production by reducing adipose endoplasmic reticulum stress markers. Dietary ω-3 LCPUFA suppression of neovascularization is reduced from 70% to 10% with APN deficiency. APN receptors localize in the retina, particularly to pathologic neovessels. CONCLUSION: Our findings suggest that increasing APN by ω-3 LCPUFA supplementation in total parental nutrition for preterm infants may suppress ROP.