Direct Reprogramming of Fibroblasts into Cardiomyocytes G. Hasenfuss No conflict Heart Center Heart Research Center Göttingen Georg-August-University Göttingen
Cardiac Regeneration Options in 5/2011 Stem cell-based pharmacotherapy (angiogenesis etc.) Bone marrow cells Cardiomyocyte-based regeneration Cell cycle Activation of CMs Endogenous transdifferentiation of non-cms Application of exogenous cells and tissues - Neonatal CM - Cardiospheres - ESCs - Adult SC (SSCs, magscs) - ips cells
Transcription factors necessary for reprogramming somatic cells into ips cells Yu J, Thomson JA (2007): Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells. Science 318:1917-1920. Takahashi K, Yamanaka S (2007): Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factor. Cell 131:861-872. Oct3/4 Sox2 Nanog Lin28 Epigenetic Reprogramming Oct3/4 Sox2 Klf4 c-myc (not necessary, Nat Biotechnol 26:101-106, 2008)
Generation of ips cells Reprogramming of somatic cells Cell type Factors for reprogramming Blood Plasmid Virus Liver Skin Protein Small Molekule Analysis ips cells Cell Therapy Regeneration Drug Screening Pathophysiology
Guan et al 2010 ips Cells and Cardiac Cells from Patient Hair Keratinocytes from hair follicles ips-cell from keratinocytes ips-cell derived cardiomyoctyes Action potential Calcium transients
Problems associated with induced (reprogrammed) Pluripotent cells regarding regeneration Genertion Rejection Teratoma formation NK-Zelle Activating receptor Inhibitory receptor NKG2D No MHC Class I Stem cell Dressel et al., FASEB J 2010
More unresovled issues with ips cells Copy number variation and selection during reprogramming to pluripotency Hussein et al Nature, March 2011 Somatic coding mutations in human induced pluripotent stem cells Gore Nature, March 2011 Hotspots of aberrant epigenomic reprogramming in human induced pluripotent stem cells Lister et al Nature, March 2011
Reprogramming of Somatic Cells Xu et al., Nat Cell Biol 2011
Cardiomyocytes from Fibroblasts without a pluripotent state Conversion of mouse fibroblasts into cardiomyocytes using a direct reprogramming strategy Jem A. Efe1, Simon Hilcove1, Janghwan Kim1, Hongyan Zhou1, Kunfu Ouyang2, Gang Wang2, Ju Chen2 and Sheng Ding1,3 Nature Cell Biology 2011 Transient low level expression of Oct4 Sox2 Klf4 (c-myc)
Calcium cycling Efe et al., Nat Cell Biol 2011
Electrophysiology Efe et al., Nat Cell Biol 2011
Reprogramming of Somatic Cells 3 Transcription Factors: Gata4, Mef2C, Tbx5 Ieda et al Cell 2010 Xu et al., Nat Cell Biol 2011
Fibroblast Derived Cardiomyocytes Ieda et al., Cell 2010
Fibroblast Derived Cardiomyocytes Ieda et al., Cell 2010
Fibroblast Derived Cardiomyocytes Following intramyocardial injection of transfected fibroblasts with 3TF cardiomyocates develop in vivo Ieda et al., Cell 2010
Epigenetic modification of genes Histone octamere H3K27me3 H3K4 Histone modification -Acetylation -Phosphorylation -Methylation -Ubiqutination Promoter modification - Methylation Methylated cytosines H3K27 H3K4me3 Unmethylated cytosines Gene switched on : Active (open) chromatin
Histone Methylation Actin Ryanodine Receptor Troponin T Ieda et al., Cell 2010
DNA Methylation Natriuretic P. αmhc Ieda et al., Cell 2010
Reprogramming of Somatic Cells Xu et al., Nat Cell Biol 2011
Summary Direct reprogramming of fibroblasts into cardiomyocytes In vitro with subsequent cardiomyocyte transplantation - lower risk of tumors - no/little cell proliferation In vivo conversion of fibroblasts into cardiomyocytes - conversion of scar tissue into contractile tissue - procedure without retrovirus needed
Acknowledgements Kaomei Guan Frieder Wolf Alexander M. Becker Katrin Streckfuss-Boemeke Diana Kaiser Anke Cierpka Yvonne Hintz Bernhard Unsöld Lars Maier Stephan Wagner R. Dressesl Collaborators Institute of Human Genetics University of Göttingen Wolfgang Engel Indiana University School of Medicine, USA Loren Field Molecular Pharmacology, Univers. Göttingen W. Zimmermann M. Tiburcy This work was supported by a Heidenreich von Siebold-Program 2006 grant from University of Göttingen (K.G.), a Forschungs- und Berufungspool (Kapitel 06 08 TG 74) grant of Ministry for Science and Culture of Lower Saxony (G.H.), and a BMBF grant G3-11(G.H.). The authors declare no conflict of interest