A new tool for investigation platelet activation in endometriosis patients

Objectives: Endometriosis (EM) is a gynecological disease characterized by chronic inflammation, due to the interaction of inflammatory cells with ectopic endometrium (1). Platelets (PLTs), recruited by procoagulant factors released from endometriotic stromal cells, secrete angiogenetic factors and induce overexpression of genes involved in pro-survival/ anti-apoptotic propensity, inflammationand extracellular matrix remodeling (2). We aimed to develop a tool to measure PLT activation (by small extracellular vesicles, s-EVs) in EM peritoneal fluids, as a potential predictive marker of EM severity. Materials & methods: S-EVs were isolated from EM peritoneal fluids and characterized with imaging (Atomic Force Microscopy; AFM) and protein expression analyses (Western blot, WB) (3). We explored gene expression in peritoneum and EM lesions using EndometDB (4). Results: We demonstrated the presence of s-EVs isolated from EM peritoneal fluids by liquid AFM, as showed by contact angle vs diameter scatterplot (Fig.1A-B), and by WB detecting the s-EV markers CD63, CD9, and TSG101 (Fig.1C). Using Endomet-DB, we highlighted the differentially expressed genes between control and EM peritoneum samples (Fig.1D). The protein expression of a panel of biomarkers of PTL in s-EVs was further confirmed by WB (Fig.1E). Conclusions: We propose applying s-EV research to EM investigation, generating a novel biochemical tool for PLT activation assessment and for the development of new diagnostics and therapies.