scholarly journals Bis-allylic Deuterated DHA Alleviates Oxidative Stress in Retinal Epithelial Cells

Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 447 ◽  
Author(s):  
Rosell ◽  
Giera ◽  
Brabet ◽  
Shchepinov ◽  
Guichardant ◽  
...  

Oxidative stress plays a crucial role in developing and accelerating retinal diseases including age-related macular degeneration (AMD). Docosahexaenoic acid (DHA, C22:6, n-3), the main lipid constituent of retinal epithelial cell membranes, is highly prone to radical and enzymatic oxidation leading to deleterious or beneficial metabolites for retinal tissue. To inhibit radical oxidation while preserving enzymatic metabolism, deuterium was incorporated at specific positions of DHA, resulting in D2-DHA when incorporated at position 6 and D4-DHA when incorporated at the 6,9 bis-allylic positions. Both derivatives were able to decrease DHAs’ toxicity and free radical processes involved in lipid peroxidation, in ARPE-19 cells (Adult Retinal Pigment Epithelial cell line), under pro-oxidant conditions. Our positive results encouraged us to prepare lipophenolic-deuterated-DHA conjugates as possible drug candidates for AMD treatment. These novel derivatives proved efficient in limiting lipid peroxidation in ARPE-19 cells. Finally, we evaluated the underlying mechanisms and the enzymatic conversion of both deuterated DHA. While radical abstraction was affected at the deuterium incorporation sites, enzymatic conversion by the lipoxygenase 15s-LOX was not impacted. Our results suggest that site-specifically deuterated DHA could be used in the development of DHA conjugates for treatment of oxidative stress driven diseases, or as biological tools to study the roles, activities and mechanisms of DHA metabolites.

2009 ◽  
Vol 2 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Alexandra A. Herzlich ◽  
Xiaoyan Ding ◽  
Defen Shen ◽  
Robert J. Ross ◽  
Jingsheng Tuo ◽  
...  

Peroxisome proliferator-activated receptors (PPARs) play a role in oxidative stress and VEGF regulation, which are closely related to age-related macular degeneration (AMD). PPAR γ expression and its downstream molecules were examined in fat-1 mice (transgenic mice that convert n-6 to n-3 fatty acids), Ccl2-/-/Cx3cr1-/- mice (an AMD model), ARPE19 cells (a human retinal pigment epithelial cell line, RPE, a cell type with a critical role in AMD), and human eyes with and without AMD. PPAR α, β, and γ, VEGF and receptors were determined by immunohistochemistry in the mice models, humans, and ARPE19 cells. Transcripts of PPARs, VEGF, MMP-9 and HO-1 were determined by RQ-PCR. PPARs were constitutively expressed in normal neuroretina and RPE of humans and mice. PPAR γ expression was increased in fat-1 and Ccl2-/-/Cx3cr1-/- mice. VEGF was decreased in fat-1 mice but increased in Ccl2-/-/Cx3cr1-/- mice. VEGF receptors were stable. VEGF, MMP9 and HO-1 transcript levels were increased in ARPE19 cells under H2O2 - induced oxidative stress. Human AMD retinas exhibited higher PPAR γ. The findings of increased expression of PPAR γ and its downstream proteins (VEGF, MMP9, and HO-1) in H2O2-treated ARPE19 cells, Ccl2-/-/Cx3cr1-/- mice, and human AMD eyes, but decreased VEGF in fat-1 mice, suggest that PPAR γ may play a role in AMD.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 412 ◽  
Author(s):  
Hellinen ◽  
Pirskanen ◽  
Tengvall-Unadike ◽  
Urtti ◽  
Reinisalo

Retinal pigment epithelium (RPE) acts as an outer blood–retinal barrier that limits the access of circulating xenobiotics to the eye. In addition, the RPE limits posterior elimination of intravitreally injected drugs to circulation. Thus, permeation in the RPE has a significant effect on ocular pharmacokinetics. The RPE is also a potentially important drug target in age-related macular degeneration. Therefore, the cell models of the RPE are important tools in ocular drug development, but poor availability and problems in reproducibility limit the use of primary RPE cell cultures. Furthermore, the best and widely used human cell line ARPE19 requires specialized culture conditions and a long time for cellular differentiation. In this paper, we describe a cell population arisen from the ARPE19 culture, with fast differentiation and improved barrier properties. This cell line, LEPI, forms clear microvilli and rapidly displays RPE-like cobblestone morphology after subculture in simple culture conditions. The LEPI cells show RPE-specific functions and expression of RPE65, ezrin, and BEST1 proteins. On filter, the LEPI cells develop tighter barrier than the ex vivo bovine RPE-choroid: permeability coefficients of beta-blockers (atenolol, nadolol, timolol, pindolol, metoprolol, betaxolol) ranged from 0.4 × 10−6 cm/sec to 2.3 × 10−6 cm/sec depending on the drug lipophilicity. This rapidly differentiating cell line will be an asset in ocular studies since it is easily maintained, it grows and differentiates quickly and does not require specialized culture conditions for differentiation. Thus, this cell line is suitable for both small scale assays and high throughput screening in drug discovery and development.


2020 ◽  
Vol 88 (3) ◽  
pp. 30 ◽  
Author(s):  
Jarriaun Streets ◽  
Priyanka Bhatt ◽  
Deepak Bhatia ◽  
Vijaykumar Sutariya

Age-related macular degeneration (AMD) will be responsible for the vision impairment of more than five million late-aged adults in the next 30 years. Current treatment includes frequent intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents. However, there are methods of drug delivery that can decrease the frequency of intravitreal injections by sustaining drug release. MPEG-PCL ((methoxypoly(ethylene glycol) poly(caprolactone)) has been reported as biocompatible and biodegradable. Polymeric micelles of MPEG-PCL can be useful in efficiently delivering anti-VEGF drugs such as sunitinib to the posterior segment of the eye. In this study, the novel micellar formulation exhibited an average dynamic light scattering (DLS) particle size of 134.2 ± 2.3 nm with a zeta potential of −0.159 ± 0.07 mV. TEM imaging further confirmed the nanoscopic size of the micelles. A sunitinib malate (SM)-MPEG-PCL formulation exhibited a sustained release profile for up to seven days with an overall release percentage of 95.56 ± 2.7%. In addition to their miniscule size, the SM-MPEG-PCL formulation showed minimal cytotoxicity onto the ARPE-19 human retinal pigment epithelial cell line, reporting a percent viability of more than 88% for all concentrations tested at time intervals of 24 h. The SM-MPEG-PCL micelles also exhibited exceptional performance during an anti-VEGF ELISA that decreased the overall VEGF protein expression in the cells across a 24–72 h period. Furthermore, it can be concluded that this type of polymeric vehicle is a promising solution to symptoms caused by AMD and improving the management of those suffering from AMD.


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