Cytoprotective effect of ALG-1001 peptide (Luminate) on human retinal pigment epithelial cells exposed to oxidative injury. A novel functional-outcome for an anti-VEGF agent.

Abstract

Purpose : The main purpose of this study was to determine the cytoprotective effect of the ALG-1001 peptide on cultured retinal pigment epithelial cells exposed to oxidative stress.

Methods : Human retinal pigment epithelium cells (ARPE-19) were exposed to cellular damage conditions employing hydrogen peroxide (H₂O₂). For control conditions, cells were exposed to culture medium only, with or without ALG-1001 (1mg) or H₂O₂ (100 µM) for 24 h. For the ALG-1001 treatment, we followed two strategies: 1) cells culture were exposed to ALG-1001 (1mg) for 24 h, then the medium was remove and new medium with H₂O₂ (100 µM) without peptide was applied; 2) cells culture were exposed to H₂O₂ (100 µM) for 24 h, then the medium was remove and applied new medium with ALG-1001 (1mg) without H₂O₂. Number and the viability of cultured cells was measured using WST-8 and LDH assays. Students-t test was used for statistical analysis.

Results : Exposition to H₂O₂, decreased the number and viability of cultured cells in a 40 ± 1.0 % and 49 ± 1.3 %, respectively (P<0.05). However, LDH assay does not show a significant effect (8 ± 1.1%) under cellular damage conditions. When the ALG-1001 peptide was added 24 h before the H₂O₂ exposition, we did not observe a significant reduction in the number (5 ± 1.2 %) and viability (10 ± 1.5 %) of the cell exposed to H₂O₂. However, when the ALG-1001 was added 24 h after the H₂O₂ exposition, the cell number and viability, was reduce only 20 ± 1.1 % and 14 ± 1.0 % respectively.

Conclusions : Our findings showed a clear reduction in the toxic effect generated by oxidative stress exposure in cultured cells. Moreover, the compound cytoprotective effect is observed by maintaining cells survival, which is reflected in the number of cells and their metabolic activity. This effect is more evident when the ALG-1001 is applied previously to oxidative stress. Therefore, considering the viability markers used in this study, it is likely that the ALG-1001 acts modulating an anti-apoptotic pathway. The characterization of this cytoprotective function by ALG-1001 peptide allows, at the therapeutic level, not only to decrease the angiogenesis process, but also to maintain cell viability under pathological conditions, a feature that, to our knowledge, has not been observed on any other molecule with anti-integrin activity.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.