Campus Stem Cell Lab meeting, Tuesday, April 30 (NOTE: CHANGE OF VENUE!!!!)

[Sue Gilbert]

Our next talk this semester will be tomorrow, Tuesday, April 30, and will start at noon promptly. We will continue to meet 1360 Biotechnology Center (Note: Change of venue) 425 Henry Mall (PLEASE NOTE THE CHANGE OF VENUE FOR THIS WEEK), and will include pizza. starting at 11:50am (no beverages will be provided so if you want something to drink please bring your own.)

Date: Tuesday, April 30

Speaker: Daryl Nelson, Graduate Fellow, Cell and Regenerative Biology (Lyons lab)

Title: The Homeobox Transcription Factor, Irx4, Identifies a Mutipotent, Ventricular-specific Cardiac Progenitor

Abstract: Cardiac progenitors have been presented as potential cell therapeutics, due to their cardiogenic potency. Iroquois homeobox protein 4 (Irx4) is the earliest known marker of ventricular myocardium differentiation, and the transcription factor is restricted to the ventricles throughout embryogenesis and into adulthood. Our goal is to identify a multipotent, ventricular-specific cardiac progenitor. We have targeted the 3’ end of the Irx4 locus using a recombineering approach to insert fluorescence (mCherry), bioluminescence (luciferase), and antibiotic resistance (hph) cassettes. Six mESC clones were properly targeted Irx4luc-mCh-hph/wt ES cells. RT-PCR, western blot analysis, and immunofluorescence assays demonstrated the functional integration of the reporters during embryoid body (EB) differentiation. Following 4 days of differentiation of the Irx4luc-mCh-hph/wt cells in EBs, selection with hygromycin was carried out for 2 days, and day 6 cells were plated onto STO cell feeder layers for expansion. Selected Irx4+ cells are proliferative, expressing the cell cycle antigen, Ki67, and could be passaged more than 12 times. The Irx4+ cells express cKit, Flk1, and CXCR4 on the cell surface. Selected Irx4+ cells demonstrate cardiovascular potency when re-aggregated and differentiated in hanging drops resulted in ventricular myocyte-enriched cell preparations (65±3.7% cTnT+; 67±2.6% Myl2+, 22±3.1% SmMHC+, and 6±2% CD31+ cells. The selected Irx4+ population represents the first ventricular-specific multipotent progenitor population identified and holds promise for generating all cardiovascular lineages necessary to reconstitute infarcted myocardium.

Daryl Nelson¹, Joshua Trzebiatowski¹, Erin Willing¹, Pearl Hsu², Kevin Schoen¹, Kevin Liberko¹, Matthew Butzler¹, Pat Powers², Manorama John², Timothy Kamp¹, Gary Lyons¹

¹School of Medicine and Public Health, University of Wisconsin-Madison

²University of Wisconsin Biotechnology Center

In addition to the talk, WiSCR (the Wisconsin Stem Cell Roundtable) will be announcing their WiSCR SURF mentor-fellow pairs.

Reminder: If you are talking this Seminar Series for credit, please check in with Sue Gilbert at the back of the room.

Next talk: The last talk of the semester will be on Tuesday, May 7, we will be welcoming Dr. Samuel Rabkin, Associate Professor, Surgery/Microbiology and Molecular Genetics, Harvard Medical School who will be speaking on “Cancer Stem Cells in Glioblastoma”. The talk will be back at the Wisconsin Institutes of Discovery (WID) in the H.F. Deluca Forum in the Town Center on the first floor. We will continue to provide sandwiches and chips starting at 11:50am (water will be provided but if you want something else to drink please bring your own.)

 A list of the talks for the semester is found at: http://stemcells.wisc.edu/node/246

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