Chemoattractant activity of degradation products of fetal and adult skin extracellular matrix for keratinocyte progenitor cells

Abstract

Biologic scaffolds composed of naturally occurring extracellular matrix (ECM) have been utilized as templates for the constructive remodeling of numerous tissues in preclinical studies and human clinical applications. The mechanisms by which ECM induces constructive remodeling are not well understood, but it appears that the degradation products of ECM scaffolds may play key roles in cell recruitment and constructive remodeling. The objective of the present study was to investigate the effects of age and species of the tissue from which ECM is harvested on the chemoattractant activity of degradation products of ECM for human keratinocyte stem and progenitor cells. Adult human skin ECM, fetal human skin ECM, and adult porcine skin ECM were prepared, enzymatically digested, characterized by SDS-PAGE, and evaluated for in vitro chemoattractant activity for human keratinocyte progenitor and stem cells (HEKn). Degradation products of human fetal skin ECM showed greater chemoattractant activity than human adult skin ECM degradation products for the HEKn. Degradation products of porcine adult skin ECM showed greater chemoattractant activity than human adult skin ECM. The human fetal skin ECM degradation products showed the strongest chemoattractant activity for the HEKn. The findings of this study support the concept that the mechanism of ECM scaffold remodeling involves the recruitment of lineage-directed progenitor cells by scaffold degradation products and that both the age and species of the tissue from which the ECM is harvested have an effect upon this chemoattractant potential.

Epimorphic regeneration approach to tissue replacement in adult mammals

“…After peracetic acid, ethanol, deionized H 2 O, and PBS treatment (19), lyophilized sheets were comminuted and digested in pepsin and 0.01 M HCl for 48 h before neutralization and dilution in PBS to yield a 5 mg/ mL solution. The soluble protein concentration of ex vivo-generated ECM degradation products was found to be 1.68 ± 0.17 μg/mL, and SDS/PAGE of these products in previous studies demonstrated a heterogeneous population of peptides (13,21).…”

“…Because ECM scaffolds consist of various molecules such as collagen and fibronectin, proteoglycans, glycoproteins, growth factors, and cytokines (46), degradation of these ECM scaffolds releases a heterogeneous set of molecules (13,21), each with varying biologic properties in vivo. Subsets of these peptides have been found to have different bioactive properties in vitro (13,17,19,44,47,48). Although a subset of generated peptides is clearly chemotactic for stem cells, the overall contribution of these peptides to stem cell recruitment in vivo is as of yet unknown.…”

“…Bioactive peptide molecules derived from mammalian extracellular matrix (ECM) have been shown to have potent chemoattractive and mitogenic effects upon endogenous progenitor and stem cells (13)(14)(15)(16). Although full characterization of these bioactive peptides has not been completed to date, ex vivo enzymatic, chemical, and physical methods (17)(18)(19), and in vivo physiologic methods (20), have generated a heterogeneous population of ECM peptides (13,21) with both chemotactic and mitogenic properties for a variety of stem and progenitor cells.…”

“…Although full characterization of these bioactive peptides has not been completed to date, ex vivo enzymatic, chemical, and physical methods (17)(18)(19), and in vivo physiologic methods (20), have generated a heterogeneous population of ECM peptides (13,21) with both chemotactic and mitogenic properties for a variety of stem and progenitor cells.…”

Tissue-Specific Effects of Esophageal Extracellular Matrix

“…2,[4][5][6][7][8][9][10][11] The homologous ECM can preferentially maintain tissuespecific cell phenotypes, [4][5][6][7] promote cell proliferation, 6,8 induce tissue-specific differentiation, 9 and enhance the chemotaxis of stem cells. 2,10,12 However, the preference or necessity for tissue-specific ECM has not been shown for all therapeutic applications. [13][14][15] The objective of the present study was to compare the cellular response to esophageal ECM (eECM) versus small intestinal submucosa (SIS)-ECM and urinary bladder matrix (UBM) in vitro and in vivo.…”