Development of proteomic tools to study protein adsorption on a biomaterial, titanium grafted with poly(sodium styrene sulfonate)

1 - ArticleIt is known that protein adsorption is the initial interaction between implanted biomaterials and biological environment. Generally, a complex protein layer will be formed on material surfaces within a few minutes and the composition of this layer at the interface determines the biological response to the implanted material, and therefore the long-term compatibility of the biomaterial. Despite different techniques exist to observe protein adsorption on biomaterials, none of them led to the identification of adsorbed proteins. In this paper, we report a chromatographic technique coupled to proteomics to analyse and identify proteins from complex biological samples adsorbed on biomaterial surfaces. This approach is based on (1) elaboration of the chromatographic support containing the biomaterial (2) a chromatography step involving adsorption of proteins on the biomaterial (3) the high-resolution separation of eluted proteins by 2-DE gel and (4) the identification of proteins by mass spectrometry. Experiments were performed with proteins from platelets rich plasma (PRP) adsorbed on a biomaterial which consist in titanium bioactivated with PolyNaSS. Our results show that chromatographic approach combined to 2-DE gels and mass spectrometry provides a powerful tool for the analysis and identification of proteins adsorbed on various surfaces

The CD95/CD95L Signaling Pathway: A Role in Carcinogenesis

International audienceApoptosis is a fundamental process contributing to tissue homeostasis, immune response, and development. CD95, also called Fas, is a member of the tumor necrosis factor receptor (TNFR) superfamily. Its ligand, CD95L, was initially detected at the plasma membrane of activated T-lymphocytes and natural killer (NK) cells where it contributes to the elimination of transformed and infected cells. Given its implication in immune homeostasis and immune surveillance combined with the fact that various lineages of malignant cells exhibit loss-of-function mutations, CD95 was initially classified as a tumor suppressor gene. Nonetheless, in different pathophysiological contexts, this receptor is able to transmit non-apoptotic signals and promote inflammation and carcinogenesis. Although the different non-apoptotic signaling pathways (NF-κB, MAPK, and PI3K) triggered by CD95 are known, the initial molecular events leading to these signals, the mechanisms by which the receptor switches from an apoptotic function to an inflammatory role, and, more importantly, the biological functions of these signals remain elusive. © Springer Nature Switzerland AG 2020