Abstract
Purpose :
The photoreceptor specific enzyme ELOVL4 generates very long chain (>C28) polyunsaturated fatty acids n-3 (VLC-PUFAs, n-3). While ELOVL4 mutations are linked to vision loss and neuronal dysfunctions, the roles of VLC-PUFAs lipoxygenated product ELOVs (ELOVs) is just evolving (Bhattacharjee S, et al. Sci Adv. 2017; Jun B, et al. Sci Rep. 2017). The subject of this study is to investigate mechanisms and targets involved in ELVs mediated regulation of proinflammatory genes in RPE under-stress.
Methods :
72h grown human RPE or primary cultures of human RPE (h-RPE) were serum starved for 8h, oxidative-stress(UOS) was introduced by H2O2 (600µM) plus TNF- α (10ng/ml), and then challenged with 200nM concentrations of elovanoids for 6h. Western-blot analysis using 20-25ug protein was analyzed on a 4-12% agarose gel for 2h at 125 volts using the 6h treated cell extracts. Protein was transferred on nitrocellulose membrane, blocked 1h in 3% BSA solution, and probed with primary antibodies of COX-2 (Santa-Cruz Biotechnology, TX) and ASC (Millipore, Mass). All the proteins were detected using ECL kit (Amhersham).
Results :
Here we report that proinflammatory gene COX-2 and Picard protein ASC are upregulated under UOS in human RPE. Interestingly ELVs methyl esters: 32:6- Me, 34:6-Me and 34:6-Me-acetilenic attenuated the UOS mediated enhanced upregulation of the proteins (COX-2 and ASC) in RPE under stress. Our results suggest that ELVs may play an important role in downregulating the expression of proinflammatory genes in cell signaling.
Conclusions :
Inhibition of UOS –induced upregulation of COX-2 and ASC by ELOVs in h-RPE cells may play a mechanistic role as protector and modulator of the inflammatory response to foster RPE and photoreceptor cell survival.
Supported by NEI EY005121 and the Eye, Ear, Nose and Throat Foundation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.