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The elucidation of factors that activate the regeneration of the adult mammalian heart is of major scientific and therapeutic importance. Here we found that epicardial cells contain a potent cardiogenic activity identified as follistatin-like 1 (Fstl1). Epicardial Fstl1 declines following myocardial infarction and is replaced by myocardial expression. Myocardial Fstl1 does not promote regeneration, either basally or upon transgenic overexpression. Application of the human Fstl1 protein (FSTL1) via an epicardial patch stimulates cell cycle entry and division of pre-existing cardiomyocytes, improving cardiac function and survival in mouse and swine models of myocardial infarction. The data suggest that the loss of epicardial FSTL1 is a maladaptive response to injury, and that its restoration would be an effective way to reverse myocardial death and remodelling following myocardial infarction in humans.

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  • 23 September 2015

    Reference 11 was updated.


  1. 1.

    , , & Cardiac regeneration from activated epicardium. PLoS ONE 7, e44692 (2012)

  2. 2.

    et al. A myocardial lineage derives from Tbx18 epicardial cells. Nature 454, 104–108 (2008)

  3. 3.

    & Rebuilding the coronary vasculature: hedgehog as a new candidate for pharmacologic revascularization. Trends Cardiovasc. Med. 17, 77–83 (2007)

  4. 4.

    et al. Retinoic acid stimulates myocardial expansion by induction of hepatic erythropoietin which activates epicardial Igf2. Development 138, 139–148 (2011)

  5. 5.

    et al. Platelet-derived growth factor receptor beta signaling is required for efficient epicardial cell migration and development of two distinct coronary vascular smooth muscle cell populations. Circ. Res. 103, 1393–1401 (2008)

  6. 6.

    et al. Myocardial regeneration: expanding the repertoire of thymosin beta4 in the ischemic heart. Ann. NY Acad. Sci. 1269, 92–101 (2012)

  7. 7.

    et al. tcf21+ epicardial cells adopt non-myocardial fates during zebrafish heart development and regeneration. Development 138, 2895–2902 (2011)

  8. 8.

    et al. Adult mouse epicardium modulates myocardial injury by secreting paracrine factors. J. Clin. Invest. 121, 1894–1904 (2011)

  9. 9.

    et al. The effect of bioengineered acellular collagen patch on cardiac remodeling and ventricular function post myocardial infarction. Biomaterials 34, 9048–9055 (2013)

  10. 10.

    et al. DIP2 disco-interacting protein 2 homolog A (Drosophila) is a candidate receptor for follistatin-related protein/follistatin-like 1–analysis of their binding with TGF-β superfamily proteins. FEBS J. 277, 4278–4289 (2010)

  11. 11.

    et al. Identification of Follistatin-Like 1 by expression cloning as an activator of the growth differentiation factor 15 gene and a prognostic biomarker in acute coronary syndrome. Clin. Chem. 58, 1233–1241 (2012)

  12. 12.

    , & Developmental expression of mouse Follistatin-like 1 (Fstl1): Dynamic regulation during organogenesis of the kidney and lung. Gene Expr. Patterns 7, 491–500 (2007)

  13. 13.

    et al. Cardiac myocyte follistatin-like 1 functions to attenuate hypertrophy following pressure overload. Proc. Natl Acad. Sci. USA 108, E899–E906 (2011)

  14. 14.

    et al. Follistatin-Like 1 Is an Akt-regulated cardioprotective factor that is secreted by the heart. Circulation 117, 3099–3108 (2008)

  15. 15.

    et al. Therapeutic impact of follistatin-like 1 on myocardial ischemic injury in preclinical models. Circulation 126, 1728–1738 (2012)

  16. 16.

    et al. Identification of cardiomyocyte nuclei and assessment of ploidy for the analysis of cell turnover. Exp. Cell Res. 317, 188–194 (2011)

  17. 17.

    et al. Temporally regulated and tissue-specific gene manipulations in the adult and embryonic heart using a tamoxifen-inducible Cre protein. Circ. Res. 89, 20–25 (2001)

  18. 18.

    et al. Cardiac progenitor cells from adult myocardium: homing, differentiation, and fusion after infarction. Proc. Natl Acad. Sci. USA 100, 12313–12318 (2003)

  19. 19.

    et al. A dynamic epicardial injury response supports progenitor cell activity during zebrafish heart regeneration. Cell 127, 607–619 (2006)

  20. 20.

    , & Cardiac muscle regeneration: lessons from development. Genes Dev. 25, 299–309 (2011)

  21. 21.

    , , & Neuregulin1/ErbB4 signaling induces cardiomyocyte proliferation and repair of heart injury. Cell 138, 257–270 (2009)

  22. 22.

    , & Electrophysiological challenges of cell-based myocardial repair. Circulation 120, 2496–2508 (2010)

  23. 23.

    et al. Mammalian heart renewal by pre-existing cardiomyocytes. Nature 493, 433–436 (2013)

  24. 24.

    et al. Dedifferentiation and proliferation of mammalian cardiomyocytes. PLoS ONE 5, e12559 (2010)

  25. 25.

    et al. Zebrafish heart regeneration occurs by cardiomyocyte dedifferentiation and proliferation. Nature 464, 606–609 (2010)

  26. 26.

    , , , & Ultrarapid engineering of biomimetic materials and tissues: fabrication of nano- and microstructures by plastic compression. Adv. Funct. Mater. 15, 1762–1770 (2005)

  27. 27.

    et al. Role of epicardial mesothelial cells in the modification of phenotype and function of adult rat ventricular myocytes in primary coculture. Circ. Res. 71, 40–50 (1992)

  28. 28.

    et al. Lentiviral vectors and protocols for creation of stable hESC lines for fluorescent tracking and drug resistance selection of cardiomyocytes. PLoS ONE 4, e5046 (2009)

  29. 29.

    et al. Deletion of the β2-adrenergic receptor prevents the development of cardiomyopathy in mice. J. Mol. Cell Cardiol. 63, 155–164 (2013)

  30. 30.

    et al. Visualizing spatiotemporal dynamics of multicellular cell-cycle progression. Cell 132, 487–498 (2008)

  31. 31.

    & High-throughput screening for modulators of stem cell differentiation. Methods Enzymol. 414, 300–316 (2006)

  32. 32.

    et al. High throughput drug risk assessment in human cardiomyocytes by kinetic image cytometry. J. Pharm. Toxicol. Methods 66, 246–256 (2012)

  33. 33.

    et al. Reduced hydraulic permeability of three-dimensional collagen scaffolds attenuates gel contraction and promotes the growth and differentiation of mesenchymal stem cells. Acta Biomater. 6, 3978–3987 (2010)

  34. 34.

    , , & Fibroblast contractility and growth in plastic compressed collagen gel scaffolds with microstructures correlated with hydraulic permeability. J. Biomed. Mater. Res. A 96, 609–620 (2011)

  35. 35.

    , , , & Use of multiple unconfined compression for control of collagen gel scaffold density and mechanical properties. Soft Matter 2, 986–992 (2006)

  36. 36.

    et al. Embryonic cardiomyocytes beat best on a matrix with heart-like elasticity: scar-like rigidity inhibits beating. J. Cell Sci. 121, 3794–3802 (2008)

  37. 37.

    et al. Biomaterial strategies for alleviation of myocardial infarction. J. Royal Soc. Interface 9, 1–19 (2012)

  38. 38.

    et al. Expression and function of alpha-smooth muscle actin during embryonic-stem-cell-derived cardiomyocyte differentiation. J. Cell Sci. 120, 229–238 (2007)

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We thank L. M. Brill for spectrometry, F. Cerignolli for providing valuable cells, S. Metzler and P. Kim for help with imaging, and P. Shah for assistance in mouse and pig experiments. This work was supported by NIH grants to P.R.-L. (HL065484 and R01 HL086879); M.Me. (HL113601, HL108176, P01 HL098053); P30 AR061303 and P30 CA030199 for shared services and by the California Institute for Regenerative Medicine (CIRM, RC1-00132) to M.Me. K.We. and C.H. were SBMRI CIRM postdoctoral fellows (TG2-0116). V.S. was an Oak Foundation postdoctoral fellow. Support was also provided by NIH/NHLBI 5UM1 HL113456 to P.C.Y; HL116591 to K.Wa., M.J.B. was supported by the NIH (K08 AI079268) and the Stanford BioX Interdisciplinary Initiatives Program and NSF NSEC(PHY-0830228). B.Z. was supported by the National Basic Research Program of China (2013CB945302 and 2012CB945102) and the National Natural Science Foundation of China (91339104, 31271552, and 31222038). A Seed Grant to P.R.-L. from the Stanford Cardiovascular Institute supported the swine study.

Author information

Author notes

    • Ke Wei
    •  & Vahid Serpooshan

    These authors contributed equally to this work.


  1. Department of Bioengineering, University of California, San Diego, La Jolla, California 92037, USA

    • Ke Wei
    • , Cecilia Hurtado
    • , Marta Diez-Cuñado
    • , Wenhong Zhu
    • , Paul Bushway
    • , Wenqing Cai
    • , Alex Savchenko
    •  & Mark Mercola
  2. Sanford-Burnham-Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, USA

    • Ke Wei
    • , Cecilia Hurtado
    • , Marta Diez-Cuñado
    • , Wenhong Zhu
    • , Paul Bushway
    • , Wenqing Cai
    • , Alex Savchenko
    •  & Mark Mercola
  3. Stanford Cardiovascular Institute and Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA

    • Vahid Serpooshan
    • , Marta Diez-Cuñado
    • , Mingming Zhao
    • , Giovanni Fajardo
    • , Andrew Wang
    • , Yuka Matsuura
    • , Morteza Mahmoudi
    • , Manish J. Butte
    • , Phillip C. Yang
    • , Daniel Bernstein
    •  & Pilar Ruiz-Lozano
  4. Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, USA

    • Sonomi Maruyama
    • , Kazuto Nakamura
    •  & Kenneth Walsh
  5. Imperial College London, Faculty of Medicine, Imperial Centre for Translational and Experimental Medicine, Du Cane Road, London W12 0NN, UK

    • Michela Noseda
    •  & Michael D. Schneider
  6. Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China

    • Xueying Tian
    • , Qiaozhen Liu
    •  & Bin Zhou
  7. Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, 1417613151 Tehran, Iran

    • Morteza Mahmoudi
  8. Academic Medical Center. Dept Anatomy, Embryology and Physiology. Meibergdreef 15. 1105AZ Amsterdam, The Netherlands

    • Maurice J. B. van den Hoff
  9. CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China

    • Bin Zhou


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K.We. and W.C. performed experiments on EMCs and mESCs. K.We. generated mCMsESC, and performed cardiomyogenic and proliferation assays on mCMsESC, proliferation assays on NRVC. K.We. and W.Z. performed mass spectrometry experiments. M.D.-C. performed immunostaining of Fstl1. K.We. and A.S. performed calcium transient experiment. V.S. generated cardiac patch. V.S., A.W., and M.J.B. performed biomechanical analysis of cardiac patch biomaterial. M.Z. and V.S. performed mouse MI experiments and echocardiography. Y.M. and P.C.Y. performed MRI analysis. K.We. and W.C. performed immunostaining of α-actinin, pH3 and aurora B. K.We. performed GFP, TUNEL and f4/80 staining. K.We. and P.B. performed analysis of high throughput imaging results. M.Mh. analysed the release of Fstl1 from the patch in vitro. V.S. and G.F. performed assays of adult mouse cardiomyocytes. K.Wa., K.N. and S.M. performed experiments with Fstl1-TG mice. B.Z. performed experiments with adult mouse epicardium-conditioned media. X.T., Q.L. and B.Z. performed Wt1CreERT2 lineage tracing studies and experiments with adult mouse epicardium conditioned medium. K.Wa. and S.M. provided data on systemic delivery of FSTL1. M.N. and M.D.S. provided data on myocyte progenitors. M.J.B. supervised AFM studies. D.B. supervised and coordinated in vivo mouse physiology experiments. V.S., Y.M., and P.C.Y. conducted the preclinical swine study. C.H. performed FSTL1 overexpression and western blot experiments. K.We., V.S., M.Me. and P.R.-L. designed experiments and prepared the manuscript. M.J.B.v.d.H. provided materials.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Pilar Ruiz-Lozano.

Extended data

Supplementary information

PDF files

  1. 1.

    Supplementary Figure

    This file contains uncropped western blot scans with size marker indications.

Excel files

  1. 1.

    Supplementary Table

    This table contains a list of primers used in Q-RT-PCR.


  1. 1.

    Autonomous contraction of mCMsESC

    Bright field real time video of confluent mCMsESC culture, showing autonomous contraction of the cardiomyocytes.

  2. 2.

    Autonomous calcium transient of mCMsESC

    Fluo4 NW calcium transient of mCMsESC culture, imaged by KIC, showing autonomous calcium transient of the cardiomyocytes.

  3. 3.

    MI-only mouse at week 4 after surgery

    MRI video taken from representative study on MI-only mouse at week 4 after surgery

  4. 4.

    MI+Patch mouse at week 4 after surgery

    MRI video taken from representative study on MI+Patch mouse at week 4 after surgery

  5. 5.

    MI+Patch+FSTL1 mouse at week 4 after surgery

    MRI video taken from representative study on MI+Patch+FSTL1 mouse at week 4 after surgery.

  6. 6.

    3-D rendering of Aurora B (red) and α-actinin (green) immunostaining captured by Apotome (Fig. 3m) were processed with ImageJ Z-function to rotate the image Z-Stack. Note the Aurora B+ (red) cleavage furrow between α-actinin+ (green) cardiomyocytes.

    3-D rendering of Aurora B (red) and α-actinin (green) immunostaining captured by Apotome (Fig. 3m) were processed with ImageJ Z-function to rotate the image Z-Stack.  Note the Aurora B+ (red) cleavage furrow between α-actinin+ (green) cardiomyocytes.

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