Proteomic characterization of platelet gel releasate from adult peripheral and cord blood

Purpose: Activated platelet gel (PG) derived from adult peripheral blood (APB) has been extensively used for topical therapy of various clinical conditions. Conversely, few observations on PG from umbilical cord blood (CB) have been reported so far. Although PG preparations are known to contain a high concentration of a large number of biological factors involved in inflammation and tissue repair, their comprehensive characterization is still missing. The innovative goal of our research was to use proteomics technologies in order to profile biologically active components in these blood derivatives. Experimental design: Supernatants recovered from three independent APB and CB-derived PGs, prepared using batroxobin, were enriched for low-abundance proteins with ProteoMiner and subsequently analyzed by GeLC-MS/MS. Results: The 751 and 760 proteins were identified in the APB and CB-derived PG releasates, respectively. A core dataset including only proteins found in 2/3 and 3/3 biological replicates was generated and functionally characterized by gene ontology. Searching against Vesiclepedia database showed that 33% of our dataset consists of novel releasate proteins. Comparison between the two types of PG secretomes revealed that 117 proteins are present only in the APB-derived samples, 104 proteins are distinctive of the CB-derived samples, and 229 are in common. Conclusion and clinical relevance: Our study highlighted a differential content of proteins supporting tissue repair and regeneration between APB and CB-derived PGs. These findings may help better identifying future appropriate clinical applications.