Platelet-Released Growth Factors and Platelet-Rich Fibrin Induce Expression of Factors Involved in Extracellular Matrix Organization in Human Keratinocytes

Abstract

<jats:p>Platelet-released growth factor (PRGF) is a thrombocyte concentrate lysate which, like its clinically equivalent variations (e.g., Vivostat PRF® (platelet-rich fibrin)), is known to support the healing of chronic and hard-to-heal wounds. However, studies on the effect of PRGF on keratinocytes remain scarce. This study aims to identify genes in keratinocytes that are significantly influenced by PRGF. Therefore, we performed a whole transcriptome and gene ontology (GO) enrichment analysis of PRGF-stimulated human primary keratinocytes. This revealed an increased expression of genes involved in extracellular matrix (ECM) organization. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) analysis confirmed the PRGF-mediated induction of selected ECM-related factors such as transforming growth factor beta-induced protein, fibronectin 1, matrix metalloproteinase-9, transglutaminase 2, fermitin family member 1, collagen type I alpha 1 and collagen type XXII alpha 1. PRGF-induced expression of the above factors was influenced by blockade of the epidermal growth factor receptor (EGFR), a receptor playing a crucial role in wound healing. A differential induction of the investigated factors was also detected in skin explants exposed to PRGF and in experimentally generated in vivo wounds treated with Vivostat PRF®. Together, our study indicates that the induction of ECM-related factors may contribute to the beneficial wound-healing effects of PRGF-based formulations.</jats:p>

Platelet-Released Growth Factors Induce Genes Involved in Extracellular Matrix Formation in Human Fibroblasts

“…In previous studies, we observed a relevant influence of the epidermal growth factor receptor (EGFR) on the PRGF-mediated induction of antimicrobial peptides and ECM-related factors in keratinocytes [ 5 , 6 , 7 , 10 ]. Therefore, in this study we aimed to analyze the influence of the EGFR on the observed PRGF-mediated induction of ECM-associated genes in fibroblasts.…”

“…Surprisingly, except for MMP-9, the PRGF-mediated induction of all investigated genes was not inhibited after blocking the EGFR and some factors were even higher induced. This is in contrast to keratinocytes, where the PRGF-mediated induction of FN1, TGM2 and FERMT1 was dependent on the EGFR [ 10 ] indicating functional differences of the EGFR in keratinocytes and fibroblasts.…”

“…Data on the influence of thrombocyte concentrate products on the ECM physiology are especially rare. Recently, we have shown that PRGF induced several factors in primary human keratinocytes that play a role in ECM formation and we speculated that this might be one reason for the beneficial wound healing properties of thrombocyte concentrate products [ 10 ]. In the present study, we demonstrate that PRGF also induces several ECM-related factors in primary human fibroblasts.…”

“…Thrombocyte concentrate products contain a variety of growth factors, cytokines, and chemokines [ 65 , 66 , 67 ]. As we have recently demonstrated, the induction of antimicrobial peptides [ 5 , 6 ] and several factors involved in the ECM formation [ 10 ] in keratinocytes are dependent on the EGFR; in this study, we asked if the EGFR influences also the induction of the analyzed factors in fibroblasts. Surprisingly, except for MMP-9, the PRGF-mediated induction of all investigated genes was not inhibited after blocking the EGFR and some factors were even higher induced.…”

“…In contrast, the proliferation of keratinocytes was inhibited by PRGF [ 9 ]. The beneficial effects of PRGF may also be attributed to its capacity to induce various factors in keratinocytes, which are essential for the formation of the extracellular matrix (ECM) during wound healing [ 10 ]. According to our previous results on keratinocytes, the aim of this study was to assess the influence of PRGF on human fibroblasts.…”