Lipoxins, resolvins, and protectins in the prevention and treatment of diabetic macular edema and retinopathy

Anti-Inflammatory Effect of Specialized Proresolving Lipid Mediators on Mesenchymal Stem Cells: An In Vitro Study

An interconnection between tissue inflammation and regeneration has been established through the regulation of defense and repair mechanisms within diseased dental tissue triggered by the release of immune-resolvent mediators. To better our understanding of the role of specific pro-resolving mediators (SPMs) in inflamed human bone marrow-derived mesenchymal stem cells (hBMMSCs), we studied the effects of Resolvin E1 (RvE1) and Maresin 1 (MaR1) in lipopoly-saccharide (LPS) stimulated hBMMSCs. The hBMMSCs were divided into five different groups, each of which was treated with or without SPMs. Group-1: negative control (no LPS stimulation), Group-2: positive control (LPS-stimulated), Group-3: RvE1 100 nM + 1 μg/mL LPS, Group-4: MaR1 100 nM + 1 µg/mL LPS, and Group-5: RvE1 100 nM + MaR1100 nM + 1 μg/mL LPS. Cell proliferation, apoptosis, migration, colony formation, Western blotting, cytokine array, and LC/MS analysis were all performed on each group to determine the impact of SPMs on inflammatory stem cells. According to our data, RvE1 plus MaR1 effectively reduced inflammation in hBMMSCs. In particular, IL-4, 1L-10, and TGF-β1 activation and downregulation of RANKL, TNF-α, and IFN-γ compared to groups receiving single SPM were shown to be significantly different (Group 3 and 4). In addition, the LC/MS analysis revealed the differentially regulated peptide's role in immunological pathways that define the cellular state against inflammation. Inflamed hBMMSCs treated with a combination of Resolvin E1 (RvE1) and Maresin 1 (MaR1) promoted the highest inflammatory resolution compared to the other groups; this finding suggests a potential new approach of treating bacterially induced dental infections.

Dietary Intake and Diabetic Retinopathy: A Systematic Review of the Literature

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. The evidence connecting dietary intake and DR is emerging, but uncertain. We conducted a systematic review to comprehensively summarize the current understanding of the associations between dietary consumption, DR and diabetic macular edema (DME). We systematically searched PubMed, Embase, Medline, and the Cochrane Central Register of Controlled Trials between January 1967 to May 2022 for all studies investigating the effect of diet on DR and DME. Of the 4962 articles initially identified, 54 relevant articles were retained. Our review found that higher intakes of fruits, vegetables, dietary fibers, fish, a Mediterranean diet, oleic acid, and tea were found to have a protective effect against DR. Conversely, high intakes of diet soda, caloric intake, rice, and choline were associated with a higher risk of DR. No association was seen between vitamin C, riboflavin, vitamin D, and milk and DR. Only one study in our review assessed dietary intake and DME and found a risk of high sodium intake for DME progression. Therefore, the general recommendation for nutritional counseling to manage diabetes may be beneficial to prevent DR risk, but prospective studies in diverse diabetic populations are needed to confirm our findings and expand clinical guidelines for DR management.

Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life

The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.

Diabetic retinopathy and visual impairment in a Norwegian diabetic coast population with a high dietary intake of fish oils. An observational study

PURPOSE

To present retinal and visual findings in a Norwegian west coast diabetic population and to elucidate the effect of dietary intake of marine polyunsaturated fatty acids (PUFAs) on the development of diabetic retinopathy (DR).

METHODS

In an eye practice in an archipelago of 314 km², serving a population of about 40 000, we recorded the prevalence of visual impairment and DR in a referred diabetic population. 510 consecutive patients were included, 238 females and 272 males. 50 patients had type I and 460 had type II diabetes mellitus (DM). Self-reported medication, diet supplements, HbA1c and fish consumption were registered.

RESULTS

In the type I group, the median age was 44.5 and median DM duration 11.5 years [1-44]. 48% had photographic evidence of DR, 8 patients (16%) had proliferative retinopathy (PDR), and 6 patients (12%) had diabetic macular oedema (DME). All had best-corrected visual acuity (BCVA) of 0.5 (log MAR 0.3) or better in the best eye. In the type II group, the median DM duration was 8 years [1-53], and median age was 66. 98% had best eye BCVA at or better than 0.5 (log MAR 0.3) in the best eye.

CONCLUSION

None of the 510 patients had BCVA worse than 0.3 (log MAR 0.48) due to diabetic retinopathy. Compared to similar studies, we found a very low visual impairment rate. A possible protective effect of PUFA on the prevalence and progression of diabetic microangiopathy including retinopathy is discussed.

Neutrophils and neutrophil extracellular trap components: Emerging biomarkers and therapeutic targets for age-related eye diseases

Age-related eye diseases, including dry eye, glaucoma, age-related macular degeneration, and diabetic retinopathy, represent a major global health issue based on their increasing prevalence and disabling action. Unraveling the molecular mechanisms underlying these diseases will provide novel opportunities to reduce the burden of age-related eye diseases and improve eye health, contributing to sustainable development goals achievement. The impairment of neutrophil extracellular traps formation/degradation processes seems to be one of these mechanisms. These traps formed by a meshwork of DNA and neutrophil cytosolic granule proteins may exacerbate the inflammatory response promoting chronic inflammation, a pivotal cause of age-related diseases. In this review, we describe current findings that suggest the role of neutrophils and their traps in the pathogenesis of the above-mentioned age-related eye diseases. Furthermore, we discuss why these cells and their constituents could be biomarkers and therapeutic targets for dry eye, glaucoma, age-related macular degeneration, and diabetic retinopathy. We also examine the therapeutic potential of some neutrophil function modulators and provide several recommendations for future research in age-related eye diseases.

Possible roles of anti-type II collagen antibody and innate immunity in the development and progression of diabetic retinopathy

The pathogenesis of both diabetic retinopathy (DR) and rheumatoid arthritis (RA) has recently been considered to involve autoimmunity. Serum and synovial fluid levels of anti-type II collagen antibodies increase early after the onset of RA, thus inducing immune responses and subsequent hydrarthrosis and angiogenesis, which resemble diabetic macular edema and proliferative DR (PDR), respectively. We previously reported that DR is also associated with increased serum levels of anti-type II collagen antibodies. Retinal hypoxia in DR may induce pericytes to express type II collagen, resulting in autoantibody production against type II collagen. As the result of blood-retinal barrier disruption, anti-type II collagen antibodies in the serum come into contact with type II collagen around the retinal vessels. A continued loss of pericytes and type II collagen around the retinal vessels may result in a shift of the immune reaction site from the retina to the vitreous. It has been reported that anti-inflammatory M2 macrophages increased in the vitreous of PDR patients, accompanied by the activation of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a key regulator of innate immunity. M2 macrophages promote angiogenesis and fibrosis, which might be exacerbated and prolonged by dysregulated innate immunity.

Plasma amino acids and oxylipins as potential multi-biomarkers for predicting diabetic macular edema

To investigate the pathophysiologic characteristics of diabetic complications, we identified differences in plasma metabolites in subjects with type 2 diabetes (T2DM) with or without diabetic macular edema (DME) and a disease duration > 15 years. An cohort of older T2DM patients with prolonged disease duration was established, and clinical information and biospecimens were collected following the guidelines of the National Biobank of Korea. DME phenotypes were identified by ophthalmologic specialists. For metabolomics studies, propensity matched case and control samples were selected. To discover multi-biomarkers in plasma, non-targeted metabolite profiling and oxylipin profiling in the discovery cohort were validated in an extended cohort. From metabolomic studies, 5 amino acids (asparagine, aspartic acid, glutamic acid, cysteine, and lysine), 2 organic compounds (citric acid and uric acid) and 4 oxylipins (12-oxoETE, 15-oxoETE, 9-oxoODE, 20-carboxy leukotriene B4) were identified as candidate multi-biomarkers which can guide DME diagnosis among non-DME subjects. Receiver operating characteristic curves revealed high diagnostic value of the combined 5 amino acids and 2 organic compounds (AUC = 0.918), and of the 4 combined oxylipins (AUC = 0.957). Our study suggests that multi-biomarkers may be useful for predicting DME in older T2DM patients.

Role of resolvin D1 in psoriasis before and after narrowband ultraviolet B phototherapy: A case-control study

Resolvin D1 (RvD1) is an endogenous lipid mediator that originated from docosahexaenoic acid that stimulates a bimodal mechanism in the anti-inflammatory activity in addition to regulation of the inflammatory reaction. The study aimed at assessing the tissue level of RvD1 in psoriasis to study its role in the etiopathogenesis of psoriasis, studying the action of NB-UVB on the level of resolvin D1 in psoriasis, and raising the possibility of using resolvin D1 as a new therapy for psoriasis in the future. This case-control study included 20 psoriasis patients and 20 healthy controls. Patients took narrowband ultraviolet B (NB-UVB) for 36 sessions. Skin biopsies were taken before and after treatment from patients and from controls to assess the expression of RvD1 by a quantitative real-time polymerase chain reaction. Our findings revealed a statistically significant difference (P < .001) between psoriasis patients (either before or after treatment) and controls with lower levels of RvD1 in psoriasis patients. On comparing the RvD1 levels in psoriasis patients before and after treatment, a statistically significant increase was detected after treatment (P < .001). Tissue RvD1 levels in psoriasis patients were lower than healthy controls and increased after NB-UVB treatment in psoriasis patients. Thus, it is suggested that RvD1 might have a role in the etiopathogenesis of psoriasis. Moreover, the significantly up-regulated tissue levels of RvD1 in patients after treatment with NB-UVB highlighted a novel mechanism of phototherapy-mediated response in psoriasis by up-regulating RvD1 level.

Resolvin D1 Modulates the Intracellular VEGF-Related miRNAs of Retinal Photoreceptors Challenged With High Glucose

Stimulation of retinal photoreceptors with elevated glucose concentration (30 mM) for 96 h, served as diabetic retinopathy in vitro model to study Resolvin D1 (50 nM) effects on neovascularization. VEGF and anti-angiogenic miR-20a-3p, miR-20a-5p, miR-106a-5p, and miR-20b expression was assessed either in photoreceptors exposed to HG or in exosomes released by those cells. High glucose increased VEGF levels and concurrently decreased anti-angiogenic miRNAs content in photoreceptors and exosomes. RvD1 reverted the effects of glucose damage in photoreceptors and exosomal pro-angiogenic potential, tested with the HUVEC angiogenesis assay. By activating FPR2 receptor, RvD1 modulated both the expression of anti-angiogenic miRNA, which decrease VEGF, and the pro-angiogenic potential of exosomes released by primary retinal cells. HUVEC transfection with miR-20a-3p, miR-20a-5p, miR-106a-5p, and miR-20b antagomirs, followed by exposure to exosomes from photoreceptors, confirmed the VEGF-related miRNAs mechanism and the anti-angiogenic effects of RvD1.

Molecular Basis of the Beneficial Actions of Resveratrol

Resveratrol modulates the transcription factor NF-κB, cytochrome P450 isoenzyme CYP1A1, expression and activity of cyclooxygenase (COX) enzymes, Fas/Fas ligand mediated apoptosis, p53, mTOR and cyclins and various phospho-diesterases resulting in an increase in cytosolic cAMP levels. Cyclic AMP, in turn, activates Epac1/CaMKKβ/AMPK/SIRT1/PGC-1α pathway that facilitates increased oxidation of fatty acids, mitochondrial respiration and their biogenesis and gluconeogenesis. Resveratrol triggers apoptosis of activated T cells and suppresses tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17) and other pro-inflammatory molecules and inhibits expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) that may explain its anti-inflammatory actions. Polyunsaturated fatty acids (PUFAs) and their anti-inflammatory metabolites lipoxin A4, resolvins, protectins and maresins have a significant role in obesity, type 2 diabetes mellitus (T2DM), metabolic syndrome and cancer. We observed that PUFAs (especially arachidonic acid, AA) and BDNF (brain-derived neurotrophic factor) protect against the cytotoxic actions of alloxan, streptozotocin, benzo(a)pyrene (BP) and doxorubicin. Thus, there is an overlap in the beneficial actions of resveratrol, PUFAs and BDNF suggesting that these molecules may interact and augment synthesis and action of each other. This is supported by the observation that resveratrol and PUFAs modulate gut microbiota and influence stem cell proliferation and differentiation. Since resveratrol is not easily absorbed from the gut it is likely that it may act on endocannabinoid and light, odor, and taste receptors located in the gut, which, in turn, convey their messages to the various organs via vagus nerve.

Modulation of pro-inflammatory and pro-resolution mediators by γ-linolenic acid: an important element in radioprotection against ionizing radiation

INTRODUCTION

The current study explored the radio-protective property of γ-linolenic acid (GLA) in C57BL/6J mice against low linear energy transfer ionizing radiation (IR; X-rays) and its modulatory effect on the production of lipid mediators such as prostaglandin E₂ (PGE2), leukotriene E₄ and lipoxin A₄ (LXA4) in mice plasma.

METHODS

The effect of GLA pre-treatment on radiation induced inflammation was assessed by estimating plasma levels of high mobility group box 1 protein (HMGB1), TMOP/NO and various anti-oxidant enzymes.

RESULTS

γ-linolenic acid pre-treated mice exposed to lethal IR dose (7.5 Gy) showed a decrease in plasma levels of HMGB1, PGE2 and LXA4 and a fall in TMOP/NO ratio and improvement in anti-oxidant enzymes: catalase, glutathione transferase and glutathione peroxidase compared to IR mice, suggesting that GLA suppresses IR-induced inflammation and restores the pro- vs. anti-oxidant ratio to near normal, which could explain its radioprotective action.

CONCLUSIONS

GLA showed radioprotective action.

Mechanisms for Reducing Neuropathic Pain

Injury typically results in the development of neuropathic pain, but the pain normally decreases and disappears in paralleled with wound healing. The pain results from cells resident at, and recruited to, the injury site releasing pro-inflammatory cytokines and other mediators leading to the development of pro-inflammatory environment and causing nociceptive neurons to develop chronic ectopic electrical activity, which underlies neuropathic pain. The pain decreases as some of the cells that induce pro-inflammation, changing their phenotype leading to the blocking the release of pro-inflammatory mediators while releasing anti-inflammatory mediators, and blocking nociceptive neuron chronic spontaneous electrical activity. Often, despite apparent wound healing, the neuropathic pain becomes chronic. This raises the question of how chronic pain can be eliminated. While many of the cells and mediators contributing to the development and maintenance of neuropathic pain are known, a better understanding is required of how the injury site environment can be controlled to permanently eliminate the pro-inflammatory environment and silence the chronically electrically active nociceptive neurons. This paper examines how methods that can promote the transition of the pro-inflammatory injury site to an anti-inflammatory state, by changing the composition of local cell types, modifying the activity of pro- and anti-inflammatory receptors, inducing the release of anti-inflammatory mediators, and silencing the chronically electrically active nociceptive neurons. It also examines the hypothesis that factors released from platelet-rich plasma applied to chronic pain sites can permanently eliminate chronic inflammation and its associated chronic pain.

Resolvin D1 reduces mitochondrial damage to photoreceptors of primary retinal cells exposed to high glucose

No study has investigated the interaction of Resolvin D1 (RvD1) with mitochondrial damage of retinal cells caused by diabetes. This study aims to investigate the effects of RvD1 (50 nM) on morphological and biochemical indicators of mitochondrial damage in primary retinal cells exposed to 30 mM d-glucose high glucose (HG). HG-cells exhibited photoreceptor damage characterized by short and small mitochondria with prevalent mitochondrial disruption, fragmentation, and aggregation. The cells had low mitochondrial transporters TIMM44 and TOMM40, Connexin 43, NAD/NADH ratio, and ATP levels, whereas increased cytosolic cytochrome c. Moreover, they expressed high cytosolic metalloproteinase matrix metallopeptidase 9 (MMP-9) and MMP-2 activity. HG-cells treated with RvD1 (50 nM) showed reduced reactive oxygen species levels, improved mitochondrial morphology and function, promoted mitochondrial DNA repair by OGG1, and reduced cell apoptosis and metalloproteinase activity. Therefore, RvD1 induces protection from high glucose-load to the retinal cell and promotes their survival by decreasing cytosolic MMP and mitochondrial damage.

Anti-inflammatory effects of resolvins in diabetic nephropathy: Mechanistic pathways

The incidence of diabetes mellitus is growing rapidly. The exact pathophysiology of diabetes is unclear, but there is increasing evidence of the role of the inflammatory response in both developing diabetes as well as its complications. Resolvins are naturally occurring polyunsaturated fatty acids that are found in fish oil and sea food that have been shown to possess anti-inflammatory actions in several tissues including the kidneys. The pathways by which resolvins exert this anti-inflammatory effect are unclear. In this review we discuss the evidence showing that resolvins can suppress inflammatory responses via at least five molecular mechanisms through inhibition of the nucleotide-binding oligomerization domain protein 3 inflammasome, inhibition of nuclear factor κB molecular pathways, improvement of oxidative stress, modulation of nitric oxide synthesis/release and prevention of local and systemic leukocytosis. Complete understanding of these molecular pathways is important as this may lead to the development of new effective therapeutic strategies for diabetes and diabetic nephropathy.

Role of ω3 polyunsaturated fatty acids in diabetic retinopathy: a morphological and metabolically cross talk among blood retina barriers damage, autoimmunity and chronic inflammation

Vision disorders are one of the most serious complications of diabetes mellitus (DM) affecting the quality of life of patients and eventually cause blindness. The ocular lesions in diabetes mellitus are located mainly in the blood vessels and retina layers. Different retina lesions could be grouped under the umbrella term of diabetic retinopathies (DMRP).

We propose that one of the main causes in the etiopathogenesis of the DMRP consists of a progressive loss of the selective permeability of blood retinal barriers (BRB). The loss of selective permeability of blood retinal barriers will cause a progressive autoimmune process. Prolonged autoimmune injures in the retinal territory will triggers and maintains a low-grade chronic inflammation process, microvascular alterations, glial proliferation and subsequent fibrosis and worse, progressive apoptosis of the photoreceptor neurons.

Patients with long-standing DM disturbances in retinal BRBs suffer of alterations in the enzymatic pathways of polyunsaturated fatty acids (PUFAs), increase release of free radicals and pro-inflammatory molecules and subsequently incremented levels of vascular endothelial growth factor. These facts can produce retinal edema and photoreceptor apoptosis.

Experimental, clinical and epidemiological evidences showing that adequate metabolic and alimentary controls and constant practices of healthy life may avoid, retard or make less severe the appearance of DMRP. Considering the high demand for PUFAs ω3 by photoreceptor complexes of the retina, it seems advisable to take fish oil supplements (2 g per day). The cellular, subcellular and molecular basis of the propositions exposed above is developed in this article.

Synthesizer drawings the most relevant findings of the ultrastructural pathology, as well as the main metabolic pathways of the PUFAs involved in balance and disbalanced conditions are provided.

Human vitreous in proliferative diabetic retinopathy: Characterization and translational implications

Diabetic retinopathy (DR) is one of the leading causes of visual impairment in the working-age population. DR is a progressive eye disease caused by long-term accumulation of hyperglycaemia-mediated pathological alterations in the retina of diabetic patients. DR begins with asymptomatic retinal abnormalities and may progress to advanced-stage proliferative diabetic retinopathy (PDR), characterized by neovascularization or preretinal/vitreous haemorrhages. The vitreous, a transparent gel that fills the posterior cavity of the eye, plays a vital role in maintaining ocular function. Structural and molecular alterations of the vitreous, observed during DR progression, are consequences of metabolic and functional modifications of the retinal tissue. Thus, vitreal alterations reflect the pathological events occurring at the vitreoretinal interface. These events are caused by hypoxic, oxidative, inflammatory, neurodegenerative, and leukostatic conditions that occur during diabetes. Conversely, PDR vitreous can exert pathological effects on the diabetic retina, resulting in activation of a vicious cycle that contributes to disease progression. In this review, we recapitulate the major pathological features of DR/PDR, and focus on the structural and molecular changes that characterize the vitreal structure and composition during DR and progression to PDR. In PDR, vitreous represents a reservoir of pathological signalling molecules. Therefore, in this review we discuss how studying the biological activity of the vitreous in different in vitro, ex vivo, and in vivo experimental models can provide insights into the pathogenesis of PDR. In addition, the vitreous from PDR patients can represent a novel tool to obtain preclinical experimental evidences for the development and characterization of new therapeutic drug candidates for PDR therapy.

Specialized Pro-resolving Lipid Mediators: Modulation of Diabetes-Associated Cardio-, Reno-, and Retino-Vascular Complications

Diabetes and its associated chronic complications present a healthcare challenge on a global scale. Despite improvements in the management of chronic complications of the micro-/macro-vasculature, their growing prevalence and incidence highlights the scale of the problem. It is currently estimated that diabetes affects 425 million people globally and it is anticipated that this figure will rise by 2025 to 700 million people. The vascular complications of diabetes including diabetes-associated atherosclerosis and kidney disease present a particular challenge. Diabetes is the leading cause of end stage renal disease, reflecting fibrosis leading to organ failure. Moreover, diabetes associated states of inflammation, neo-vascularization, apoptosis and hypercoagulability contribute to also exacerbate atherosclerosis, from the metabolic syndrome to advanced disease, plaque rupture and coronary thrombosis. Current therapeutic interventions focus on regulating blood glucose, glomerular and peripheral hypertension and can at best slow the progression of diabetes complications. Recently advanced knowledge of the pathogenesis underlying diabetes and associated complications revealed common mechanisms, including the inflammatory response, insulin resistance and hyperglycemia. The major role that inflammation plays in many chronic diseases has led to the development of new strategies aiming to promote the restoration of homeostasis through the "resolution of inflammation." These strategies aim to mimic the spontaneous activities of the 'specialized pro-resolving mediators' (SPMs), including endogenous molecules and their synthetic mimetics. This review aims to discuss the effect of SPMs [with particular attention to lipoxins (LXs) and resolvins (Rvs)] on inflammatory responses in a series of experimental models, as well as evidence from human studies, in the context of cardio- and reno-vascular diabetic complications, with a brief mention to diabetic retinopathy (DR). These data collectively support the hypothesis that endogenously generated SPMs or synthetic mimetics of their activities may represent lead molecules in a new discipline, namely the 'resolution pharmacology,' offering hope for new therapeutic strategies to prevent and treat, specifically, diabetes-associated atherosclerosis, nephropathy and retinopathy.

Resolvin E1 Promotes Bone Preservation Under Inflammatory Conditions

Resolvins are endogenous lipid mediators derived from omega-3 fatty acids. Resolvin E1 (RvE1), derived from eicosapentaenoic acid (EPA), modulates osteoclasts and immune cells in periodontal disease models. The direct role of RvE1 in bone remodeling is not well understood. The objective of this study was to determine the impact of RvE1 on bone remodeling under inflammatory conditions. Our working hypothesis is that RvE1 downregulates bone resorption through direct actions on both osteoblast and osteoclast function in inflammatory osteoclastogenesis. A tumor necrosis factor-α induced local calvarial osteolysis model with or without the systemic administration of RvE1 was used. To evaluate osteoclastogenesis and NFκB signaling pathway activity, murine bone tissue was evaluated by Micro CT (μCT) analysis, TRAP staining, and immunofluorescence analysis. Mechanistically, to evaluate the direct role of RvE1 impacting bone cells, primary calvarial mouse osteoblasts were stimulated with interleukin (IL)-6 (10 ng/ml) and IL-6 receptor (10 ng/ml) and simultaneously incubated with or without RvE1 (100 nM). Expression of receptor activator of NFκB ligand (RANKL) and osteoprotegerin (OPG) was measured by ELISA. RNA sequencing (RNA-Seq) and differential expression analysis was performed to determine signaling pathways impacted by RvE1. The systemic administration of RvE1 reduced calvarial bone resorption as determined by µCT. Histologic analysis of calvaria revealed that osteoclastogenesis was reduced as determined by number and size of osteoclasts in TRAP-stained sections (p < 0.05). Immunofluorescence staining of calvarial sections revealed that RvE1 reduced RANKL secretion by 25% (p < 0.05). Stimulation of osteoblasts with IL-6 increased RANKL production by 30% changing the RANKL/OPG to favor osteoclast activation and bone resorption. The ratio changes were reversed by 100 nM RvE1. RvE1 decreased the production of RANKL maintaining an RANKL/OPG more favorable for bone formation. RNA-Seq and transcriptomic pipeline analysis revealed that RvE1 significantly downregulates osteoclast differentiation mediated by differential regulation of NFκB and PI3K-AKT pathways. RvE1 reduces inflammatory bone resorption. This action is mediated, at least in part, by direct actions on bone cells promoting a favorable RANKL/OPG ratio. Mediators of resolution in innate immunity also directly regulate bone cell gene expression that is modulated by RvE1 through at least 14 specific genes in this mouse model.

Dietary intake and diabetic retinopathy: A systematic review

INTRODUCTION

The evidence linking dietary intake with diabetic retinopathy (DR) is growing but unclear. We conducted a systematic review of the association between dietary intake and DR.

METHODS

We systematically searched PubMed, Embase, Medline, and the Cochrane Central register of controlled trials, for publications between January 1967 and January 2017 using standardized criteria for diet and DR. Interventional and observational studies investigating micro- and macro-nutrient intakes; food and beverage consumptions; and dietary patterns were included. Study quality was evaluated using a modified Newcastle-Ottawa scale for observational studies, and the Cochrane collaboration tool for interventional studies.

RESULTS

Of 4265 titles initially identified, 31 studies (3 interventional, 28 Observational) were retained. Higher intakes of dietary fibre, oily fish, and greater adherence to a Mediterranean diet were protective of DR. Conversely, high total caloric intake was associated with higher risk of DR. No significant associations of carbohydrate, vitamin D, and sodium intake with DR were found. Associations of antioxidants, fatty acids, proteins and alcohol with DR remain equivocal.

CONCLUSIONS

Dietary fibre, oily fish, a Mediterranean diet and a reduced caloric intake are associated with lower risk of DR. Longitudinal data and interventional models are warranted to confirm our findings and better inform clinical guidelines.

Role of disturbed fatty acids metabolism in the pathophysiology of diabetic erectile dysfunction

BACKGROUND

Vasculogenic erectile dysfunction (VED) is considered as a common complication among people with type 2 diabetes (T2D). We tested whether changes in fatty acid (FAs) classes measured in erythrocytes are associated with increased risk of diabetic VED along with related risk factors.

METHODS

We assessed erythrocyte FAs composition, lipid peroxidation parameters and inflammatory cytokines among 72 T2D men with VED, 78 T2D men without VED and 88 healthy volunteers with similar age. Biochemical, hepatic, lipid and hormonal profiles were measured.

RESULTS

T2D people with VED had significant decrease in the indexes of Δ6-desaturase and elongase activities compared to the other studied groups. The same group of participants displayed lower erythrocytes levels of dihomo-γ-linolenic acid (C20:3n-6) (P < .001), precursor of the messenger molecule PGE1 mainly involved in promoting erection. Moreover, absolute SFAs concentration and HOMA IR levels were higher in T2D people with VED when compared to controls and associated with impaired NO concentration (1.43 vs 3.30 ng/L, P < .001). Our results showed that IL-6 and TNF-α were significantly increased and positively correlated with MDA levels only in T2D people with VED (r = 0.884, P = .016 and r = 0.753, P = .035; respectively) suggesting a decrease in the relative availability of vasodilator mediators and an activation of vasoconstrictors release.

CONCLUSION

Our findings show that the deranged FAs metabolism represents a potential marker of VED in progress, or at least an indicator of increased risk within men with T2D.

A regulatory role for β-adrenergic receptors regarding the resolvin D1 (RvD1) pathway in the diabetic retina

Diabetic retinopathy is a visually debilitating disease with limited treatment options available. Compound 49b, a β-adrenergic receptor agonist, has been demonstrated to effectively reduce disease pathogenesis associated with diabetic retinopathy. While the exact mechanisms are not fully understood, previous studies have determined that it reduces the pro-inflammatory cytokine, TNF-α, and inhibits apoptosis of the retinal microvasculture. As inflammation becomes more recognized in driving disease pathogenesis, so does the regulation by pro-resolving pathways as therapeutic points of intervention. The current study sought to explore whether Compound 49b had any influence on pro-resolving pathways, thus contributing to improved disease outcome. Using in vivo (animal model of type 1 diabetes) and in vitro (retinal endothelial cells, Müller cells, neutrophils/PMN) techniques, it was determined that high glucose lowers pro-resolving lipid mediator, resolvin D1 (RvD1) levels and differentially alters required enzymes, 5-lipoxygenase (5-LOX), 15-LOX-1 and 15-LOX-2. RvD1 receptors formyl peptide receptor 2 (ALX/FPR2) and G-protein coupled receptor 32 (GPR32) were also downregulated in response to hyperglycemic conditions. Moreover, it was observed that β-adrenergic receptor activation restored high glucose-induced decreases in both enzyme activity and RvD1 levels observed in vivo and in vitro. The current study is the first to describe a regulatory role for β-adrenergic receptors on pro-resolving pathways.

Low dose aspirin increases 15-epi-lipoxin A4 levels in diabetic chronic kidney disease patients

BACKGROUND

Resolution of inflammation is regulated by endogenous lipid mediators, such as lipoxins and their epimers, including 15-epi-lipoxin A4 (15-epi-LXA4). However, there is no information on 15-epi-LXA4 and its in vivo regulation in chronic kidney disease (CKD) patients.

STUDY DESIGN

Open label randomized clinical trial.

SETTING AND PARTICIPANTS

50 participants with chronic kidney disease (CKD) stage 3 and 4 without prior cardiovascular disease (25 in the aspirin group and 25 in the standard group) followed for 46 months.

INTERVENTION

Aspirin (100mg/day) or standard treatment.

AIM

To analyze the effect of aspirin on plasma 15-epi-LXA4 levels and inflammatory markers in CKD patients.

RESULTS

Baseline plasma15-epi-LXA4 levels were lower in diabetic (1.22 ± 0.99ng/ml) than in non-diabetic CKD patients (2.05 ± 1.06ng/ml, p < 0.001) and inversely correlated with glycosylated hemoglobin levels (r = -0.303, p = 0.006). In multivariate analysis, diabetes was associated with lower 15-epi-LXA4 levels, adjusted for age, inflammatory markers and renal function (p = 0.005). In the whole study population, 15-epi-LXA4 levels tended to increase, but not significantly (p = 0.45), after twelve months on aspirin (from mean ± SD 1.84 ± 1.06 to 2.04 ± 0.75ng/ml) and decreased in the standard care group (1.60 ± 1.15 to 1.52 ± 0.68ng/ml, p = 0.04). The aspirin effect on 15-epi-LXA4 levels was more striking in diabetic patients, increasing from 0.94 ± 0.70 to 1.93 ± 0.74ng/ml, p = 0.017.

CONCLUSIONS

Diabetic patients with CKD have lower circulating 15-epi-LXA4 levels than non-diabetic CKD patients. Low dose aspirin for 12 months increased 15-epi-LXA4 levels in diabetic patients. Given its anti-inflammatory properties, this increase in 15-epi-LXA4 levels may contribute to the beneficial effects of low dose aspirin.

Annexin A1 and specialized proresolving lipid mediators: promoting resolution as a therapeutic strategy in human inflammatory diseases

INTRODUCTION

The timely resolution of inflammation is essential to restore tissue homeostasis and to avoid chronic inflammatory diseases. Resolution of inflammation is an active process modulated by various proresolving mediators, including annexin A1 (AnxA1) and specialized proresolving lipid mediators (SPMs), which counteract excessive inflammatory responses and stimulate proresolving mechanisms. Areas covered: The protective effects of AnxA1 and SPMs have been extensively explored in pre-clinical animal models. However, studies investigating the function of these molecules in human diseases are just emerging. This review highlights recent advances on the role of proresolving mediators, and pharmacological opportunities of promoting resolution pathways in preclinical models and patients with various human diseases. Expert opinion: Dysregulation or 'failure' in proresolving mechanisms might be involved in the pathogenesis of chronic inflammatory diseases. Altered levels of proresolving mediators were found in a wide range of human diseases. In some cases, AnxA1 and SPMs are up-regulated in human blood and tissues but fail to engage in proresolving signaling and, hence, to regulate excessive inflammation. Thus, the new concept of 'resolution pharmacology' could be applied to compensate deficiency of endogenous proresolving mediators' generation and/or possible failures in the engagement of resolution pathways observed in many chronic inflammatory diseases.

Is There a Role for Bioactive Lipids in the Pathobiology of Diabetes Mellitus?

Inflammation, decreased levels of circulating endothelial nitric oxide (eNO) and brain-derived neurotrophic factor (BDNF), altered activity of hypothalamic neurotransmitters (including serotonin and vagal tone) and gut hormones, increased concentrations of free radicals, and imbalance in the levels of bioactive lipids and their pro- and anti-inflammatory metabolites have been suggested to play a role in diabetes mellitus (DM). Type 1 diabetes mellitus (type 1 DM) is due to autoimmune destruction of pancreatic β cells because of enhanced production of IL-6 and tumor necrosis factor-α (TNF-α) and other pro-inflammatory cytokines released by immunocytes infiltrating the pancreas in response to unknown exogenous and endogenous toxin(s). On the other hand, type 2 DM is due to increased peripheral insulin resistance secondary to enhanced production of IL-6 and TNF-α in response to high-fat and/or calorie-rich diet (rich in saturated and trans fats). Type 2 DM is also associated with significant alterations in the production and action of hypothalamic neurotransmitters, eNO, BDNF, free radicals, gut hormones, and vagus nerve activity. Thus, type 1 DM is because of excess production of pro-inflammatory cytokines close to β cells, whereas type 2 DM is due to excess of pro-inflammatory cytokines in the systemic circulation. Hence, methods designed to suppress excess production of pro-inflammatory cytokines may form a new approach to prevent both type 1 and type 2 DM. Roux-en-Y gastric bypass and similar surgeries ameliorate type 2 DM, partly by restoring to normal: gut hormones, hypothalamic neurotransmitters, eNO, vagal activity, gut microbiota, bioactive lipids, BDNF production in the gut and hypothalamus, concentrations of cytokines and free radicals that results in resetting glucose-stimulated insulin production by pancreatic β cells. Our recent studies suggested that bioactive lipids, such as arachidonic acid, eicosapentaneoic acid, and docosahexaenoic acid (which are unsaturated fatty acids) and their anti-inflammatory metabolites: lipoxin A4, resolvins, protectins, and maresins, may have antidiabetic actions. These bioactive lipids have anti-inflammatory actions, enhance eNO, BDNF production, restore hypothalamic dysfunction, enhance vagal tone, modulate production and action of ghrelin, leptin and adiponectin, and influence gut microbiota that may explain their antidiabetic action. These pieces of evidence suggest that methods designed to selectively deliver bioactive lipids to pancreatic β cells, gut, liver, and muscle may prevent type 1 and type 2 DM.

ω-3 and ω-6 long-chain PUFAs and their enzymatic metabolites in neovascular eye diseases

Neovascular eye diseases, including retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration, threaten the visual health of children and adults. Current treatment options, including anti-vascular endothelial growth factor therapy and laser retinal photocoagulation, have limitations and are associated with adverse effects; therefore, the identification of additional therapies is highly desirable. Both clinical and experimental studies show that dietary ω-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs) reduce retinal and choroidal angiogenesis. The ω-3 LC-PUFA metabolites from 2 groups of enzymes, cyclooxygenases and lipoxygenases, inhibit [and the ω-6 (n-6) LC-PUFA metabolites promote] inflammation and angiogenesis. However, both of the ω-3 and the ω-6 lipid products of cytochrome P450 oxidase 2C promote neovascularization in both the retina and choroid, which suggests that inhibition of this pathway might be beneficial. This review summarizes our current understanding of the roles of ω-3 and ω-6 LC-PUFAs and their enzymatic metabolites in neovascular eye diseases.

The role of dyslipidemia in diabetic retinopathy

Diabetic retinopathy (DR) affects over 93million people worldwide and is the number one cause of blindness among working age adults. These indicators coupled with the projected rise of patients diagnosed with diabetes, makes DR a serious and prevalent vision threating disease. Data from recent clinical trials demonstrate that in addition to the well accepted role of hyperglycemia, dyslipidemia is an important, but often overlooked factor in the development of DR. The central aim of this review article is to showcase the critical role of dyslipidemia in DR progression as well as highlight novel therapeutic solutions that take advantage of the vital roles lipid metabolism plays in DR progression.

AT-RvD1 Promotes Resolution of Inflammation in NOD/ShiLtJ mice

Sjögren’s syndrome (SS) is a chronic inflammatory autoimmune disease characterized by diminished secretory function of the exocrine glands. Treatments for hyposalivation are limited to the use of saliva substitutes and medications that provide only temporary relief. In light of the high degree of need and the limitations of current therapies, development of alternative treatments to restore functioning is essential. Resolvins (Rv), which are highly potent lipid mediators, offer a viable alternative for better treating inflammatory diseases such as SS. The goal of this study was to determine whether systemic preventive treatment with Aspirin-triggered RvD1 (AT-RvD1) reduces inflammation and preserves secretory functioning in NOD/ShiLtJ SS-like mice. Our results indicate that systemic treatment with AT-RvD1 diminishes the progression of the disease in salivary epithelium from female mice as follows: (a) improves secretory function, (b) reduces pro-inflammatory molecule gene expression, (c) increases anti-inflammatory molecule gene expression and (d) induces M2 macrophage polarization. Finally, AT-RvD1 decreases lymphocytic infiltration into the salivary glands when used with small doses of the steroid, dexamethasone, and promotes the tissue healing process.

Diabetic macular edema, retinopathy and age-related macular degeneration as inflammatory conditions

Diabetic macular edema (DME) and diabetic retinopathy (DR) are complications affecting about 25% of all patients with long-standing type 1 and type 2 diabetes mellitus and are a major cause of significant decrease in vision and quality of life. Age-related macular degeneration (AMD) is not uncommon, and diabetes mellitus affects the incidence and progression of AMD through altering hemodynamics, increasing oxidative stress, accumulating advanced glycation end products, etc. Recent studies suggest that DME, DR and AMD are inflammatory conditions characterized by a breakdown of the blood-retinal barrier, inflammatory processes and an increase in vascular permeability. Key factors that seem to have a dominant role in DME, DR and AMD are angiotensin II, prostaglandins and the vascular endothelial growth factor and a deficiency of anti-inflammatory bioactive lipids. The imbalance between pro- and anti-inflammatory eicosanoids and enhanced production of pro-angiogenic factors may initiate the onset and progression of DME, DR and AMD. This implies that bioactive lipids that possess anti-inflammatory actions and suppress the production of angiogenic factors could be employed in the prevention and management of DME, DR and AMD.

Resolvins and aliamides: lipid autacoids in ophthalmology - what promise do they hold?

Resolvins are a novel class of lipid-derived endogenous molecules (autacoids) with potent immunomodulating properties, which regulate the resolution phase of an active immune response. These modulating factors are locally produced, influencing the function of cells and/or tissues, which are produced on demand and subsequently metabolized in the same cells and/or tissues. This review is focused on certain lipid autacoids with putative relevance for ophthalmology in general and for dry eye more specifically. We also briefly investigate the concept of aliamides and the role of palmitoylethanolamide in ophthalmology, and analyze in more detail the putative role and the preclinical and clinical development of resolvins as emerging treatments for dry eye and related disorders, with a focus on one of the lead resolvin derivatives – RX-10045.

Renin-angiotensin-aldosterone system in insulin resistance and metabolic syndrome

Obesity and its consequent complications such as hypertension and metabolic syndrome are increasing in incidence in almost all countries. Insulin resistance is common in obesity. Renin- angiotensin system (RAS) is an important target in the treatment of hypertension and drugs that act on RAS improve insulin resistance and decrease the incidence of type 2 diabetes mellitus, explaining the close association between hypertension and type 2 diabetes mellitus. RAS influences food intake by modulating the hypothalamic expression of neuropeptide Y and orexins via AMPK dephosphorylation. Estrogen reduces appetite by its action on the brain in a way similar to leptin, an anorexigenic action that seems to be mediated via hypothalamic pro-opiomelanocortin (POMC) neurons in the arcuate nucleus and synaptic plasticity in the arcuate nucleus similar to leptin. Estrogen stimulates lipoxin A₄, a potent vasodilator and platelet anti-aggregator. Since both RAS and estrogen act on the hypothalamic neuropeptides and regulate food intake and obesity, it is likely that RAS modulates LXA₄ synthesis. Thus, it is proposed that Angiotensin-II receptor blockers and angiotensin-converting enzymes and angiotensin-II antagonists may have the ability to augment LXA₄ synthesis and thus bring about their beneficial actions.

Advances in Local Drug Release and Scaffolding Design to Enhance Cell Therapy for Diabetes

Islet transplant is a curative treatment for insulin-dependent diabetes. However, challenges, including poor tissue survival and a lack of efficient engraftment, must be overcome. An encapsulating or scaffolding material can act as a vehicle for agents carefully chosen for the islet transplant application. From open porous scaffolds to spherical capsules and conformal coatings, greater immune protection is often accompanied by greater distances to microvasculature. Generating a local oxygen supply from the implant material or encouraging vessel growth through the release of local factors can create an oxygenated engraftment site. Intricately related to the vascularization response, inflammatory interaction with the cell supporting implant is a long-standing hurdle to material-based islet transplant. Modulation of the immune responses to the islets as well as the material itself must be considered. To match the post-transplant complexity, the release rate can be tuned to orchestrate temporal responses. Material degradation properties can be utilized in passive approaches or external stimuli and biological cues in active approaches. A combination of multiple carefully chosen factors delivered in an agent-specialized manner is considered by this review to improve the long-term function of islets transplanted in scaffolding and encapsulating materials.

In vitro effects of docosahexaenoic and eicosapentaenoic acid on human meibomian gland epithelial cells

To investigate the effect of ω-3 fatty acids on human meibomian gland epithelial cells (HMGECs, cell line) in vitro. HMGECs were stimulated with docosahexaenoic acid (DHA) or combinations with eicosapentaenoic acid (EPA) and acetyl sialic acid (ASA). Sudan III fat staining, viability and proliferation assays, electric cell-substrate impedance sensing, real-time PCR for gene expression of cyclooxygenase-2 and 15-lipoxygenase and ELISAs for resolvin D1 (RvD1), IFNγ, TNFα and IL-6 were applied. Lipid droplet accumulation and viability was increased by 100 μM DHA in the presence or absence of EPA in serum cultured HMGECs. In contrast, HMGECs cultured with DHA and EPA under serum-free conditions showed minimal lipid accumulation, decreased proliferation and viability. Normalized impedance was significantly reduced in serum-free cultured HMGECs when stimulated with DHA and EPA. HMGECs cultured in serum containing medium showed increased normalized impedance under DHA and EPA stimulation compared to DHA or EPA alone or controls. IL-6 and IFNγ were downregulated in HMGECs treated for 72 h with DHA and EPA. In general, TNFα, IFNγ and IL-6 levels were decreased after 72 h compared to 24 h in serum containing medium with or without DHA or EPA. The concentration of RvD1 was elevated 2-fold after DHA treatment. Cyclooxygenase-2 gene expression decreased compared to controls during DHA stimulation after 72 h. Treatment with DHA and ASA revealed a decreased 15-lipoxygenase gene expression which was reduced after three days of DHA incubation. DHA and EPA supplementation affected HMGECs in vitro and supported anti-inflammatory effects by influencing cytokine levels, decreasing COX-2 expression and increasing the production of RvD1.

Cytokines, angiogenic, and antiangiogenic factors and bioactive lipids in preeclampsia

Preeclampsia is a low-grade systemic inflammatory condition in which oxidative stress and endothelial dysfunction occurs. Plasma levels of soluble receptor for vascular endothelial growth factor (VEGFR)-1, also known as sFlt1 (soluble fms-like tyrosine kinase 1), an antiangiogenic factor have been reported to be elevated in preeclampsia. It was reported that pregnant mice deficient in catechol-O-methyltransferase (COMT) activity show a preeclampsia-like phenotype due to a deficiency or absence of 2-methoxyoestradiol (2-ME), a natural metabolite of estradiol that is elevated during the third trimester of normal human pregnancy. Additionally, autoantibodies (AT1-AAs) that bind and activate the angiotensin II receptor type 1 a (AT1 receptor) also have a role in preeclampsia. None of these abnormalities are consistently seen in all the patients with preeclampsia and some of them are not specific to pregnancy. Preeclampsia could occur due to an imbalance between pro- and antiangiogenic factors. VEGF, an angiogenic factor, is necessary for the transport of polyunsaturated fatty acids (PUFAs) to endothelial cells. Hence reduced VEGF levels decrease the availability of PUFAs to endothelial cells. This leads to a decrease in the formation of anti-inflammatory and angiogenic factors: lipoxins, resolvins, protectins, and maresins from PUFAs. Lipoxins, resolvins, protectins, maresins, and PUFAs suppress insulin resistance; activation of leukocytes, platelets, and macrophages; production of interleukin-6 and tumor necrosis factor-α; and oxidative stress and endothelial dysfunction; and enhance production of prostacyclin and nitric oxide (NO). Estrogen enhances the formation of lipoxin A4 and NO. PUFAs also augment the production of NO and inhibit the activity of angiotensin-converting enzyme and antagonize the actions of angiotensin II. Thus, PUFAs can prevent activation of angiotensin II receptor type 1 a (AT1 receptor). Patients with preeclampsia have decreased plasma phospholipid concentrations of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), the precursors of lipoxins (from AA), resolvins (from EPA and DHA), and protectins (from DHA) and prostaglandin E1 (PGE1 from DGLA: dihomo-γ-linolenic acid) and prostacyclin (PGI2 derived from AA). Based on these evidences, it is proposed that preeclampsia may occur due to deficiency of PUFAs and their anti-inflammatory products: lipoxins, resolvins, protectins, and maresins.

Potential role of polyunsaturated fatty acids in diabetic retinopathy

Diabetic retinopathy (DR) is a serious complication of long-standing diabetes mellitus. It affects about 25% of all patients with diabetes mellitus and causes a significant decrease in the quality of life. Despite many years of research, the exact pathway that leads to the development and progression of DR is not clear. Recent studies suggest that polyunsaturated fatty acids (PUFAs) and their metabolites could play a significant role in DR. There is evidence to suggest that an imbalance between pro- and anti-inflammatory eicosanoids and enhanced production of pro-angiogenic factors may initiate the onset and progression of DR. This implies that PUFAs and their metabolites that possess anti-inflammatory actions and suppress the production of angiogenic factors could be employed in the prevention and management of DR.

Endogenous expression pattern of resolvin D1 in a rat model of self-resolution of lipopolysaccharide-induced acute respiratory distress syndrome and inflammation

Resolvin D1 (RvD1), an endogenous lipid mediator derived from docosahexaenoic acid, has been reported to promote a biphasic activity in anti-inflammatory response and regulate inflammatory resolution. The present study aimed to determine the endogenous expression pattern of RvD1 in a rat model of self-resolution of lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) and inflammation. The ARDS model was induced by administrating LPS (2mg/kg) via tracheotomy in 138 male Sprague-Dawley rats. At specified time points, lung injury and inflammation were respectively assessed by lung histology and analysis of bronchoalveolar lavage fluid and cytokine levels. The expression of endogenous RvD1 was detected by high performance liquid chromatography and tandem mass spectrometry. The results showed that histological lung injury peaked between 6h (LPS6h) and day 3, followed by recovery over 4-10 days after LPS administration. Lung tissue polymorph nuclear cell (PMN) was significantly increased at LPS6h, and peaked between 6h to day 2. The levels of interleukin (IL)-6 and IL-10 were significantly increased at LPS6h and remained higher over day 10 as compared to baseline. Intriguingly, the endogenous RvD1 expression was decreased gradually during the first 3 days, followed by almost completely recovery over days 9-10. The finding indicated that endogenous RvD1 underwent a decrease in expression followed by gradual increase that was basically coincident with the lung injury recovery in a rat model of self-resolution LPS-induced ARDS and inflammation. Our results may help define the optimal therapeutic window for endogenous RvD1 to prevent or treat LPS-induced ARDS and inflammation.

Combination of bevacizumab and bromfenac therapy in age-related macular degeneration: a pilot study

Background

According to recent studies, the newest strategy for the treatment of exudative age-related macular degeneration is to combine anti-VEGF agents with non-steroid anti-inflammatory drugs (NSAIDs) such as nepafenac and bromfenac to decrease the frequency of intravitreal injections. Since most research has focused on ranibizumab, the aim of this study is to evaluate whether an alternative drug such as bevacizumab could lead to similar outcomes.

Material/Methods

The study was conducted on a group of 26 patients who were administered intravitreal bevacizumab and topical bromfenac (study group) and 26 patients with single bevacizumab therapy (control group). Cases that were not qualified for ranibizumab therapy were included in the study group.

Results

The study revealed that the visual acuity and parameters observed in OCT improved more in the study group than in the control group. However, the correlations between the above factors and the frequency of intravitreal injections were statistically significant only in visual acuity.

Conclusions

We recommend the combined therapy of bevacizumab and bromfenac as an alternative and beneficial method of treatment in patients with exudative AMD who do not qualify for ranibizumab therapy. This combined therapy might efficiently reduce the number of intravitreal injections of bevacizumab.

Effect of α-linolenic acid on streptozotocin-induced diabetic retinopathy indices in vivo

BACKGROUND AND AIMS

Both oxidative stress and inflammation play a significant role in the pathobiology of diabetic retinopathy. Increased consumption of polyunsaturated fatty acids (PUFAs) may prevent or postpone the occurrence of diabetic retinopathy. Hence, the effect of α-linolenic acid (ALA), an essential fatty acid, on oxidative stress, inflammatory indices and production of vascular endothelial growth factor (VEGF) in streptozotocin-induced diabetic retinopathy indices in vivo was studied.

METHODS

Serum and retina concentrations of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), plasma and retina concentrations of lipid peroxides and antioxidant enzymes were estimated in streptozotocin (STZ)-induced diabetic animals.

RESULTS

STZ-induced diabetic rats had significantly higher levels of VEGF in the serum and retina and IL-6 in the serum, whereas BDNF was lower in the serum, all of which reverted to near normal in ALA-treated diabetic animals. STZ treatment decreased serum glutathione peroxidase levels, which was restored to normal by both pre- and post-ALA treatment groups.

CONCLUSIONS

STZ-induced changes in serum glutathione peroxidase, BDNF, VEGF and IL-6 that reverted to near control by ALA treatment, especially in ALA + STZ group, lending support to the concept that both oxidative stress and inflammation participate in DR and ALA treatment is of benefit in its prevention.

Autism as a disorder of deficiency of brain-derived neurotrophic factor and altered metabolism of polyunsaturated fatty acids

Autism has a strong genetic and environmental basis in which inflammatory markers and factors concerned with synapse formation, nerve transmission, and information processing such as brain-derived neurotrophic factor (BDNF), polyunsaturated fatty acids (PUFAs): arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic acids (DHA) and their products and neurotransmitters: dopamine, serotonin, acetylcholine, γ-aminobutyric acid, and catecholamines and cytokines are altered. Antioxidants, vitamins, minerals, and trace elements are needed for the normal metabolism of neurotrophic factors, eicosanoids, and neurotransmitters, supporting reports of their alterations in autism. But, the exact relationship among these factors and their interaction with genes and proteins concerned with brain development and growth is not clear. It is suggested that maternal infections and inflammation and adverse events during intrauterine growth of the fetus could lead to alterations in the gene expression profile and proteomics that results in dysfunction of the neuronal function and neurotransmitters, alteration(s) in the metabolism of PUFAs and their metabolites resulting in excess production of proinflammatory eicosanoids and cytokines and a deficiency of anti-inflammatory cytokines and bioactive lipids that ultimately results in the development of autism. Based on these evidences, it is proposed that selective delivery of BDNF and methods designed to augment the production of anti-inflammatory cytokines and eicosanoids and PUFAs may prevent, arrest, or reverse the autism disease process.