Articles by Guillaume Chouinard-Pelletier In JoVE (1) Permeabilization של תאים דבקו שימוש בגז אינרטי Jet Other Publications (2) Biomedical Engineering OnlineAngiogenesis Articles by Guillaume Chouinard-Pelletier in JoVE Bioengineering Permeabilization של תאים דבקו שימוש בגז אינרטי Jet Scott Cooper1, Paul Jonak1, Guillaume Chouinard-Pelletier1, Sylvain Coulombe1, Elizabeth Jones1, Richard L. Leask1,2 1Chemical Engineering, McGill University, 2Montreal Heart Institute פרוטוקול זה מתאר שיטה לpermeabilization הזמני של תאים חסיד באמצעות סילון גז אינרטי. טכניקה זו מאפשרת ההעברה של חומר וביומולקולות גנטיים לתאי יונקים חסיד על ידי הניצול של כוחות מכאניים כדי לשבש את קרום הפלזמה. Other articles by Guillaume Chouinard-Pelletier on PubMed Use of Inert Gas Jets to Measure the Forces Required for Mechanical Gene Transfection Biomedical Engineering Online. 2012 | Pubmed ID: 22963645 Transferring genes and drugs into cells is central to how we now study, identify and treat diseases. Several non-viral gene therapy methods that rely on the mechanical disruption of the plasma membrane have been proposed, but the success of these methods has been limited due to a lack of understanding of the mechanical parameters that lead to cell membrane permeability. Increased Shear Stress Inhibits Angiogenesis in Veins and Not Arteries During Vascular Development Angiogenesis. Jan, 2013 | Pubmed ID: 22941228 Vascular development is believed to occur first by vasculogenesis followed by angiogenesis. Though angiogenesis is the formation of new vessels, we found that vascular density actually decreases during this second stage. The onset of the decrease coincided with the entry of erythroblasts into circulation. We therefore measured the level of shear stress at various developmental stages and found that it was inversely proportional to vascular density. To investigate whether shear stress was inhibitory to angiogenesis, we altered shear stress levels either by preventing erythroblasts from entering circulation ("low" shear stress) or by injection of a starch solution to increase the blood plasma viscosity ("high" shear stress). By time-lapse microscopy, we show that reverse intussusception (merging of two vessels) is inversely proportional to the level of shear stress. We also found that angiogenesis (both sprouting and splitting) was inversely proportional to shear stress levels. These effects were specific to the arterial or venous plexus however, such that the effect on reverse intussusception was present only in the arterial plexus and the effect on sprouting only in the venous plexus. We cultured embryos under altered shear stress in the presence of either DAPT, a Notch inhibitor, or DMH1, an inhibitor of the bone morphogenetic protein (BMP) pathway. DAPT treatment phenocopied the inhibition of erythroblast circulation ("low" shear stress) and the effect of DAPT treatment could be partially rescued by injection of starch. Inhibition of the BMP signaling prevented the reduction in vascular density that was observed when starch was injected to increase shear stress levels.
