BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:MYH7 mutations induce changes in single cell mechanobiology DTSTART:20221213T141500 DTEND:20221213T151500 DTSTAMP:20260407T091640Z UID:de4ed6235fe0e9c871a097fe8c9260d0e0c9a071db3d06165ed5536b CATEGORIES:Conferences - Seminars DESCRIPTION:Beth L. Pruitt\, Biological Engineering\, Mechanical Engineer ing\, and Biomolecular Science and Engineering\, University of California Santa Barbara (US)\nAbstract:\nHypertrophic Cardiomyopathy (HCM) is charac terized by thickening of the left ventricular wall and hypercontractility and has been linked to mutations in the sarcomere motor protein β-myosin (MYH7). Using single cell mechanobiology studies\, we examined how the eff ects of single point mutations propagate to change the contractile dynamic s and cellular morphology (sarcomere spacing\, spread area\, myofibril ali gnment) of human induced pluripotent stem cell derived cardiomyocytes (hiP SC-CMs). We micropattern islands of adhesive protein to constraining the s preading and alignment of hiPSC-CM on hydrogel substrates containing fluor escent microbeads as fiducial markers for traction force microscopy (TFM). We deployed substrate stiffnesses ranging from physiological (10 kPa) to heavily diseased/fibrotic (100 kPa) to test the role of increased “after load” in functional phenotypes. We use image and video analysis to asses s the contractile dynamics of the hiPSC-CM in terms of force\, power\, and velocities of relaxation and contraction. For example\, we assessed multi ple MYH7 mutations edited into the WTC line along with isogenic controls. Some lines carried an endogenously labeled alpha-actinin GFP reporter of s arcomere structure to enable visualization of sarcomere structure and dyna mics. We assessed the magnitude and dynamics of contractile force output f rom TFM video analysis and observed increased the contractile force when c ompared to the control hiPSC-CMs. We also measured significantly different dynamics in the relaxation or contraction velocities compared to control hiPSC-CMs. Interestingly\, not all HCM mutant lines presented a significan t increase in cell spread area\, a proxy for hypertrophy\, and this correl ated with culture conditions\, such as the size of the protein pattern con straining the cells or stiffness of the substrate. Taken together\, these results suggest a role for MYH7 mutations driving remodeling of structure and function at a cell-intrinsic level via changes in mechanosignaling.\n\ nBio:\nDr. Beth Pruitt graduated from the Massachusetts Institute of Techn ology (MIT) with an S.B. in mechanical engineering. She was supported by a Navy ROTC fellowship at MIT where she learned sailing\, leadership\, and perseverance. She earned an M.S. in Manufacturing Systems Engineering from Stanford University before serving as an officer in the U.S. Navy. Her fi rst tour was at the engineering headquarters of the Navy nuclear program p roviding engineering review and oversight to refueling operations. Her sec ond tour was as at the U.S. Naval Academy as an instructor teaching Syste ms Engineering during the academic year and offshore sailing in the summer . She earned her Ph.D. in Mechanical Engineering at Stanford University wh ere she specialized in MEMS and small-scale metrologies for electrical con tacts and was supported by a Hertz Foundation Fellowship. She was a postdo ctoral researcher at the Swiss Federal Institute of Technology Lausanne (E PFL) where she worked on polymer MEMS. Dr. Pruitt founded and led the Micr osystems Lab at Stanford for 15 years\, with research focused on small-sca le metrologies for interdisciplinary micromechanics problems in mechanobio logy\, biomechanics and sensing. She was a visiting professor in Prof. Vio la Vogel's Lab for Applied Mechanobiology in the Department of Health Scie nces and Technology at ETH\, Zurich in 2012. Dr. Pruitt moved to UC Santa Barbara in 2018 to help launch a biological engineering degree program and department. She has been Director of the Center for Bioengineering since 2019. She is an elected Fellow of BMES\, AIMBE\, and ASME and Senior Membe r of IEEE. She has been recognized by the NSF CAREER Award\, DARPA Young Faculty Award\, Denice Denton Leadership Award. LOCATION:SV 1717 https://plan.epfl.ch/?room==SV%201717 https://epfl.zoom.u s/j/66888282028 STATUS:CONFIRMED END:VEVENT END:VCALENDAR