Broad Proteomic Analysis of a Dehydrated Amnion Chorion Membrane

Background: Dehydrated amnion chorion membranes (dACM) have been shown to promote wound repair responses in vitro through their high content of a variety of growth factors and cytokines.

Purpose: We have previously reported concentrations of known factors present including anti-inflammatory, pro-angiogenic, and regenerative proteins.  To build on this characterization, we have used a high-throughput platform to test for the presence of 1000 proteins in dACM grafts (Kiloplex Array, RayBioTech, Norcross GA).

Methods: Over the 10 independent human donor grafts tested, 640 proteins were consistently found present. dACM was found to contain a variety of proteins with diverse localization and functional roles as determined by UniProt keyword analysis. Of the 640 proteins detected, about 30% were secreted, 21% were cell membrane related, 12% were cytoplasmic, and 4% were extracellular matrix proteins, among others. Receptors, hydrolases, proteases, and cytokines were the most highly represented molecular functions, with growth factors, kinases, and protease inhibitors also representing a significant number of proteins.

Results: The most abundant growth factors were platelet-derived endothelial cell growth factor, insulin-like growth factor-binding protein 3, and insulin-like growth factor-binding protein 1. The most abundant cytokines were nicotinamide phosphoribosyltransferase, platelet factor 4, and osteopontin. When considering the data set and how it relates to biological processes, cell adhesion was the most highly represented process, with inflammatory response, chemotaxis, and angiogenesis terms also highly represented. Unbiased gene set enrichment analysis (GSEA, Broad Institute) was also conducted using a pre-ranked list of the detected proteins sorted based on abundance. Multiple terms were identified to be enriched at the top of this list, including cell-substrate junction assembly, vascular endothelial growth receptor signaling, and endothelial cell differentiation as some of the most significantly enriched gene sets.  

Conclusion: This work provides a high-level, unbiased overview of the protein content of dACM, providing important insight into how these grafts might function.