Unravelling the differences between human dermal fibroblasts and adipose stem cells extracellular matrices

Skin regeneration relies on several sequential biological and molecular events, where cell-cell and cell-matrix interactions and signalling are major players. Several studies have been showing that the extracellular matrices (ECM) produced by both human dermal fibroblasts (hDFB) and human adipose stem cells (hASCs) play a role inskin healing purposes [1-3]. Despite this, the differences and/or similarities of the ECM produced by both cell types is still not clear. Therefore, the goal of this work was to explore and unravel the ECM components of both hDFB and hASCs.

Cells-self ECM from both hDFB and hASCs were obtained after protein extraction using several protocols: freeze-thaw (FT) cycles, Triton x-100 with NH₄OH (TB) and a combination of both protocols (FT+TB). All procedures were followed by DNase treatment. The protein profile of the extracted ECM was obtained by SDS-gel electrophoresis and the presence of specific ECM components as collagen I, III and IV, fibronectin and laminin were further confirmed by immunocytochemistry. Collagen, glycosaminoglycan and elastin content were quantified using Biocolor ECM quantification kits Sircol, Blyscan and Fastin, respectively. The SDS-gel revealed a slightly different protein profile for hDFB and hASCs. The low molecular weight (Mw) bands in the 25-10kDa and 35-55kDa regions were more defined and denser in the hASCs-derived ECM. Immunocytochemistry results confirmed the presence of the main ECM components in both the hASCs and fibroblasts-derived ECM but it seems that fibronectin is secreted in higher amounts by hASCs. Quantification of collagen, GAG and elastin content also revealed higher amounts in the hASCs-derived ECMs. These results showed that hDFB and hASCs ECM’s major components are comparable, with slight differences in protein expression that could have a key role in skin regeneration.

Acknowledgements: This research was supported by ERC Consolidator Grant –ECM_INK (ERC-2016-COG-726061) and the European Union for The Discoveries Centre for Regenerative and Precision Medicine (H2020-WIDESPREAD-2014-1-739572).

1. Cerqueira, M.T., et al., Acta Biomater, 2014. 10(7): p. 3145-55.

2. Cerqueira, M.T., et al., Biomacromolecules, 2013. 14(11): p. 3997-4008.

3. Yu, J., et al., Acta Biomater, 2018. 77: p. 191-200.