VEGF-R2/CAV-1 Interaction Induced by Resveratrol/Eicosapentaenoic Acid/Docosahexaenoic Acid-Enriched Formulation through Functional Detergent-Resistant Membranes Is Associated with Decreased VEGF-A Release in ARPE-19 Cells.

SCOPE: Omega-3 fatty acids (O3FAs) and resveratrol (RSV) are known to be beneficial for certain eye diseases, such as age-related macular degeneration (AMD). Neovascular AMD is characterized by abnormal blood vessel formation due to the excessive synthesis of vascular endothelial growth factor (VEGF) by retinal pigment epithelium (RPE) cells. The study investigates whether a formulation based on eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and RSV is capable of counteracting VEGF-A secretion, and elucidates the molecular mechanism. METHODS AND RESULTS: The study finds, using ELISA, that O3FAs/RSV reduces VEGF-A secretion in human RPE cells. This phenomenon is related to the increased interaction between VEGF-receptor 2 (VEGF-R2) and caveolin-1 (CAV-1), a protein of detergent-resistant membranes (DRMs), as determined by co-immunoprecipitation and proximity ligation assay. Using microscale thermophoresis, the study confirms that O3FAs/RSV causes a high-affinity interaction. Isolation and analysis of DRMs reveal that this interaction is concomitant with VEGF-R2 relocalization in DRMs. The depletion of DRMs by a cholesterol-chelating agent blocks the VEGF-R2/CAV-1 interaction and EPA/DHA/RSV-mediated impairment of VEGF production. CONCLUSION: This specific interaction can provide a new strategy for countering VEGF-A production in human RPE cells and, consequently, reducing neovascularization in AMD. Further preclinical studies involving O3FAs and polyphenols are warranted.

Red Wine Extract Prevents Oxidative Stress and Inflammation in ARPE-19 Retinal Cells.

Age-related macular degeneration (AMD) is one of the most commonly occurring ocular diseases worldwide. This degenerative condition affects the retina and leads to the loss of central vision. The current treatments are focused on the late stage of the disease, but recent studies have highlighted the importance and benefits of preventive treatments and how good dietary habits can reduce the risk of progression to an advanced form of the disease. In this context, we studied whether resveratrol (RSV) or a polyphenolic cocktail, red wine extract (RWE), are able to prevent the initiating events of AMD (i.e., oxidative stress and inflammation) in human ARPE-19 retinal pigment epithelial (RPE) cells and macrophages. This study highlights that RWE and RSV can prevent hydrogen peroxide (H2O2) or 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative stress and can subsequently prevent DNA damage via the inhibition of the ATM (ataxia telangiectasia-mutated)/Chk2 (checkpoint kinase 2) or Chk1 signaling pathways, respectively. Moreover, ELISA assays show that RWE and RSV can prevent the secretion of proinflammatory cytokines in RPE cells and in human macrophages. Interestingly, RWE exhibits a greater protective impact compared to RSV alone, even though RSV was more concentrated when used alone than in the red wine extract. Our results suggest that RWE and RSV may have potential interest as preventive nutritional supplementations against AMD.

Resvega, a Nutraceutical Preparation, Affects NFκB Pathway and Prolongs the Anti-VEGF Effect of Bevacizumab in Undifferentiated ARPE-19 Retina Cells.

Age-related macular degeneration (AMD) is an irreversible chronic degenerative pathology that affects the retina. Despite therapeutic advances thanks to the use of anti-vascular endothelial growth factor (VEGF) agents, resistance mechanisms have been found to accentuate the visual deficit. In the present study, we explored whether a nutraceutical formulation composed of omega-3 fatty acids and resveratrol, called Resvega®, was able to disrupt VEGF-A secretion in human ARPE-19 retina cells. We found that Resvega® inhibits VEGF-A secretion through decreases in both the PI3K-AKT-mTOR and NFκB signaling pathways. In NFκB signaling pathways, Resvega® inhibits the phosphorylation of the inhibitor of NFκB, IκB, which can bind NFκB dimers and sequester them in the cytoplasm. Thus, the NFκB subunits cannot migrate to the nucleus where they normally bind and stimulate the transcription of target genes such as VEGF-A. The IκB kinase complex (IKK) is also affected by Resvega® since the nutraceutical formulation decreases both IKKα and IKKß subunits and the IKKγ subunit which is required for the stimulation of IKK. Very interestingly, we highlight that Resvega® could prolong the anti-angiogenic effect of Avastin®, which is an anti-VEGF agent typically used in clinical practice. Our results suggest that Resvega® may have potential interest as nutritional supplementation against AMD.