system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: ADAM Proteins, Animals, CD146 Antigen, Cell Movement, Cell Proliferation, Cell Survival, Cells, Cultured, Disease Models, Animal, Endothelial Progenitor Cells, Fas-Associated Death Domain Protein, Hindlimb, Ischemia, Matrix Metalloproteinases, Membrane-Associated, Membrane Microdomains, Mice, Muscle Proteins, Muscle, Skeletal, Neovascularization, Physiologic, Nitric Oxide Synthase Type III, Phosphorylation, Presenilin-1, Protein Isoforms, Proteolysis, Regeneration, Signal Transduction, Time Factors, Vascular Endothelial Growth Factor Receptor-1, Vascular Endothelial Growth Factor Receptor-2, bcl-X Protein.
user
Does soluble CD146 boost therapeutic effect of endothelial progenitors through proteolytic processing of short CD146 isoform? Context: Endothelial colony-forming cells (ECFC) constitute an endothelial progenitor fraction with a promising interest for the treatment of ischaemic cardiovascular diseases. As soluble CD146 (sCD146) is a new factor promoting angiogenesis, we examined whether sCD146 priming could improve the therapeutic potential of ECFC and defined the involved mechanism. We investigated the effects of sCD146 priming on regenerative properties of ECFC in vivo. In a mouse model of hindlimb ischaemia, the homing of radiolabelled cells to ischaemic tissue was assessed by SPECT-CT imaging. Soluble CD146 priming did not modify the number of engrafted ECFC but improved their survival capacity, leading to an enhanced revascularization. The mechanism of action of sCD146 on ECFC was studied in vitro. We showed that sCD146 acts in ECFC through a signalosome, located in lipid rafts, containing angiomotin, the short isoform of CD146 (shCD146), VEGFR1, VEGFR2, and presenilin-1. Soluble CD146 induced a sequential proteolytic cleavage of shCD146, with an extracellular shedding followed by an intramembrane cleavage mediated by matrix metalloprotease (MMP)/ADAM and presenilin-1, respectively. The generated intracellular part of shCD146 was directed towards the nucleus where it associated with the transcription factor CSL and modulated the transcription of genes involved in cell survival (FADD, Bcl-xl) and angiogenesis (eNOS). This effect was dependent on both VEGFR1 and VEGFR2, which were rapidly phosphorylated by sCD146.
assistant
These findings establish that activation of the proteolytic processing of shCD146, in particular by sCD146, constitutes a promising pathway to improve endothelial progenitors' regenerative properties for the treatment of cardiovascular diseases. Final Decision: yes