Skin regeneration relies on several sequential biological and molecular events, where cell-cell and cell-matrix interactions and signalling are major players. The extracellular matrices (ECM) produced by both human dermal fibroblasts (hDFB) and human adipose stem cells (hASCs) were shown to play a role inskin wound healing [1-3]. Despite this, it is still not clear if and how the differences and/or similarities of the ECM produced by both cell types influence that. Therefore, the goal of this work was to explore and unravel the ECM components of both hDFB and hASCs as a first to understand their role in wound healing.

Cells-self ECMs 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). The protein profile of the extracted ECM was obtained by SDS-gel electrophoresis while western blot was used to confirm the presence of the main ECM proteins. Quantification of total protein was obtained by the Bradford assay. Biocolor ECM quantification kits Sircol, Blyscan and Fastin were used to quantify collagen, glycosaminoglycan and elastin, respectively. The presence of specific ECM components as collagen I, III and IV, fibronectin, laminin, versican, tenascin C and vitronectin were further confirmed by immunocytochemistry. A slightly different protein profile for hDFB and hASCs was revealed in the SDS-gel. More defined and denser low molecular weight (Mw) bands for hASCs-derived ECM when compared with hDFB counterparts were observed in the 25-10kDa and 35-55kDa region. Western blot and 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 total protein, collagen, GAG and elastin content also revealed higher amounts in the hASCs-derived ECMs. These results showed that ECM’s major components of hDFB and hASCs are comparable, with slight differences in the amount of secreted proteins that could have a key role in skin healing.

Acknowledgements: This research was supported by ERC Consolidator Grant ECM_INK (ERC-2016-COG-726061), project Dressing4Scars (ERA-NET/CSA/JPI/M-ERANET) 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.