Keratin 1 (Figure 7(a)) and keratin 10 (Figure 7(b)) gene expression was slightly but not significantly reduced by Vivostat PRF treatment.
Therefore, we analyzed gene expression patterns of early differentiation markers (keratin 1 and keratin 10) and late differentiation markers (transglutaminase-1 and involucrin) in keratinocytes [18-23, 34].
We observed that in vitro treatment of primary keratinocytes with PRGF pronounced late differentiation processes in primary human keratinocytes as documented by a PRGF-mediated decrease of keratin 1 and keratin 10 gene expression paralleled by an increase of transglutaminase-1 and involucrin gene expression.
As keratinocyte differentiation was demonstrated to be EGFR dependent [36-38], we analyzed the influence of the EGFR on the PRGF-mediated alteration of keratin 1, keratin 10, transglutaminase-1, and involucrin gene expression in human keratinocytes by blocking the EGFR via a monoclonal antibody (cetuximab).
Lane, "Monospecific monoclonal antibodies to keratin 1 carboxy terminal (synthetic peptide) and to keratin 10 as markers of epidermal differentiation," The British Journal of Dermatology, vol.
Smart, "C/EBPbeta modulates the early events of keratinocyte differentiation involving growth arrest and keratin 1 and keratin 10 expression," Molecular and Cellular Biology, vol.
PRGF stimulation of primary keratinocytes over 24 hours caused a dose-dependent decrease of keratin 1 (a) and keratin 10 (b) gene expression paralleled by a dose-dependent increase of transglutaminase-1 (c) and involucrin (d) gene expression (real-time PCR analysis, * P <0.05, ** P <0.01, *** P < 0.001, ns = not significant, one-way ANOVA with Tukey's multiple comparison test).
PRGF stimulation (1:10) of primary keratinocytes caused a time-dependent decrease of keratin 1 (a) and keratin 10 (b) gene expression paralleled by a time-dependent increase of transglutaminase-1 (c) and involucrin (d) gene expression.
Analyzing the capacity of PRGF from 14 different donors (PRGF number 1-PRGF number 14), we observed a strong and interindividually different effect of the used PRGF on the expression of keratin 1, keratin 10, transglutaminase-1, and involucrin in primary keratinocytes (a, c, e, g).
Caption: Figure 4: The epidermal growth factor receptor (EGFR) partially mediated the keratin 1, keratin 10, transglutaminase-1, and involucrin gene expression in keratinocytes stimulated with PRGF.