? ? Smad3 Katzel et al. JOR 2011 Differentiation Matrix - PowerPoint PPT Presentation

5/10/2013 Smad3 Regulates Tendon Matrix Organization and Binds We have nothing to disclose Key Tendon Transcription Factors Ellora Berthet, Carol Chen, Kristin Butcher, Richard A. Schneider, Tamara Alliston, Mohana Amirtharajah TGF β signaling in tendon Current challenges to tendon repair development and repair • Flexor tendon injury remains a significant problem TGFβ • Repair complicated by adhesion and re-rupture T β RI T β RII • “Biologic” Solution Pryce et al. Dev. 2009 • Limited knowledge of pathways of normal tendon development ? ? Smad3 Katzel et al. JOR 2011 Differentiation Matrix Production Injury & Repair How can we apply a molecular understanding of tendon Tenocytes Tenocytes Tendon Progenitors development to improve tendon healing? 1

5/10/2013 Smad3 is essential for the formation Matrix production is regulated by of normal tendon architecture tissue specific transcription factors H & E SHG Scx Mkx WT ) Dispersion Angle (° Collagen1 Collagen1 Tenomodulin Tenomodulin Smad3 -/- Léjard et al. JBC 2007 Liu et al. Molec Cell Bio 2010 Shukunami et al. Dev Bio 2006 Mkx -/- Scx -/- WT WT Smad3 -/- Murchison et al. Dev 2007 Smad3 is required for normal matrix Smad3 is required for normal gene protein expression in tendon expression in tendon Col1 Tnc IgG WT Smad3 -/- 2

5/10/2013 Smad3 binds the critical tendon Smad3 modulates the activity of transcription factors Scx and Mkx tissue specific transcription factors - + + + Smad3-HA + - + + Scx-HA-FLAG � Smad3 α-Smad3 Smad3 Smad3 ? HA IP: FLAG Smad3 α-Scx � Scx-HA Scx ??? HA � Smad3 Flag α-Smad3 Scx/Mkx Collagen I WCE � Scx-HA α-Scx Tendon HDAC4/5 CBP Smad3 Smad3 X Runx2 Osteocalcin Sox9 Collagen II Cartilage Bone Smad3 binds the critical tendon transcription factors Scx and Mkx Conclusions • Smad3 is a critical + - + + Smad3-FLAG + - + + Mkx-Myc TGFβ regulator of tendon � Mkx-Myc Mkx α-Myc My formation � IgG TβRII c TβRI IP: FLAG Smad3 � Smad3 α-Smad3 Flag • Smad3 regulates gene and protein expression � Mkx-Myc α-Myc WCE in mature tendon � Smad3 Smad3 Smad3 α-Smad3 • Smad3 can bind Mkx Scx Scleraxis and Mohawk Collagen1 Tenascin-C Matrix Production 3

5/10/2013 Acknowledgements • Mohana Amirtharajah • Tamara Alliston • Richard Schneider • Carol Chen • Kristin Butcher • Alliston Lab • Funding: – American Society for Surgery of the Hand – NIH NIDCR – UCSF Department of Orthopedic Surgery 4