Abstract
Purpose :
Age-related maculopathy susceptibility 2 (ARMS2) is a small poorly characterized protein detected intracellularly in placenta, monocytes, microglia and human retina. The gene is located on chromosome 10q26 where variations have been consistently associated with risk and progression of age-related macular degeneration (AMD). Prior data from a yeast two-hybrid system suggested that ARMS2 might be involved in extracellular matrix homeostasis. Many studies have already demonstrated the contribution of ECM dysregulation to AMD pathogenesis. The present study identified ARMS2-interacting proteins and explored changes in ECM in overexpressing human retinal pigment epithelial cells (RPE).
Methods :
The impact of ARMS2 on ECM remodeling was assessed in overexpressing hTert-RPE1 cells by wound healing and transwell invasion assay, and protein abundance of TIMP1, MMP2 and MMP14 by Western blot. Cell viability was monitored by MTT assay. To determine ARMS2 interacting ECM-proteins we performed pull-down assays with tagged ARMS2 as a bait and supernatants from RPE cells as a prey, followed by a trypsin digestion and quantitative LC/MS-MS analysis.
Results :
ARMS2 overexpression resulted with significant increase in migration (26% ± 6.7%; p=0.034) and invasion (20% ± 4.8%, p=0.012) of RPE cells. At the same time, the abundance of ECM remodeling proteins like TIMP1, MMP2 and MMP14 was highly upregulated while cell viability remained unaffected. The pull down assay identified significant enriched ARMS2 binding partners known to be involved in ECM remodeling and cell migration like Collagen Type VI Alpha (COL6A3), Coactosin-Like 1 (COTL1), Desmoglein (DG1), Dystroglycan (DAG1) and Fibrinogen gamma (FGG).
Conclusions :
Our results expand current knowledge about ARMS2 by providing new protein interactors and confirming its function as a modulator of extracellular matrix homeostasis and cell migration. That could be a link between genetic associations and ECM changes found in AMD patients.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.