Involvement of Chromogranin A and Its Derived Peptides to Fight Infections
Résumé
In this chapter, after the presentation of the expression of Chromogranin A and its antimicrobial derived peptides in circulation, we report a clinical analysis for Vasostatin-I (VS-I) and the preparation of antimicrobial coating with Cateslytin (CTL). In a clinical multicenter analysis of VS-I in the plasma of critically ill patients (481 patients and 13 healthy staff), we have shown for the first time, that an increase in the VS-I concentration was present on admission in non-selected critically ill patients and that it was associated with poor outcome at day 28 after admission. By using a combination of VS-I, lactate and age values, our assessment of prognosis was better than taking the parameters alone. Concerning the preparation of antimicrobial biomaterial we decided to use polysaccharide multilayer film based on CTL functionalized hyaluronic acid as polyanion and chitosan as polycation, (HA-CTL-C/CHI), with the aim of designing a self-defensive coating against both bacteria (Staphylococcus aureus) and yeast (Candida albicans). The ability of S. aureus and Candida species to degrade HA, by producing hyaluronidase, allows the active peptide to be released from film only in the presence of the pathogens. We have demonstrated the antimicrobial activities of HA-CTL in solution and HA-CTL-C/CHI films against S. aureus and C. albicans. We have shown the penetration of the fluorescently labeled HA FITC -CTL-C into the cell membrane of C. albicans and the cytotoxicity of HA-CTL-C/CHI films was tested through human gingival fibroblasts (HGFs) viability. Keywords Chromogranin A Expression and processing Antimicrobial peptides Innate immunity Biomarker of severity Sepsis SIRS Antimicrobial biomaterials