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Unexpected requirement for ELMO1 in clearance of apoptotic germ cells in vivo


Apoptosis and the subsequent clearance of dying cells occurs throughout development and adult life in many tissues. Failure to promptly clear apoptotic cells has been linked to many diseases1,2,3. ELMO1 is an evolutionarily conserved cytoplasmic engulfment protein that functions downstream of the phosphatidylserine receptor BAI1, and, along with DOCK1 and the GTPase RAC1, promotes internalization of the dying cells4,5,6,7. Here we report the generation of ELMO1-deficient mice, which we found to be unexpectedly viable and grossly normal. However, they had a striking testicular pathology, with disrupted seminiferous epithelium, multinucleated giant cells, uncleared apoptotic germ cells and decreased sperm output. Subsequent in vitro and in vivo analyses revealed a crucial role for ELMO1 in the phagocytic clearance of apoptotic germ cells by Sertoli cells lining the seminiferous epithelium. The engulfment receptor BAI1 and RAC1 (upstream and downstream of ELMO1, respectively) were also important for Sertoli-cell-mediated engulfment. Collectively, these findings uncover a selective requirement for ELMO1 in Sertoli-cell-mediated removal of apoptotic germ cells and make a compelling case for a relationship between engulfment and tissue homeostasis in vivo.

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Figure 1: Disrupted seminiferous tubule architecture in ELMO1-deficient mice.
Figure 2: Requirement for ELMO1 in apoptotic cell clearance in vivo and in vitro.
Figure 3: ELMO1 functions in Sertoli-cell-mediated apoptotic germ cell clearance.
Figure 4: BAI1 participates as an engulfment receptor in Sertoli-cell-mediated engulfment.


  1. Henson, P. M. Dampening inflammation. Nature Immunol. 6, 1179–1181 (2005)

    Article  CAS  Google Scholar 

  2. Nagata, S., Hanayama, R. & Kawane, K. Autoimmunity and the clearance of dead cells. Cell 140, 619–630 (2010)

    Article  CAS  Google Scholar 

  3. Gregory, C. D. & Pound, J. D. in Phagocytosis of Dying Cells Vol. 1. (eds Krysko, D. V. & Vandenabeele, P.) 271–298 (Springer, 2009)

    Book  Google Scholar 

  4. Zhou, Z., Caron, E., Hartwieg, E., Hall, A. & Horvitz, H. R. The C. elegans PH domain protein CED-12 regulates cytoskeletal reorganization via a Rho/Rac GTPase signaling pathway. Dev. Cell 1, 477–489 (2001)

    Article  CAS  Google Scholar 

  5. Wu, Y. C., Tsai, M. C., Cheng, L. C., Chou, C. J. & Weng, N. Y. C. elegans CED-12 acts in the conserved crkII/DOCK180/Rac pathway to control cell migration and cell corpse engulfment. Dev. Cell 1, 491–502 (2001)

    Article  CAS  Google Scholar 

  6. Gumienny, T. L. et al. CED-12/ELMO, a novel member of the CrkII/Dock180/Rac pathway, is required for phagocytosis and cell migration. Cell 107, 27–41 (2001)

    Article  CAS  Google Scholar 

  7. Park, D. et al. BAI1 is an engulfment receptor for apoptotic cells upstream of the ELMO/Dock180/Rac module. Nature 450, 430–434 (2007)

    Article  CAS  ADS  Google Scholar 

  8. Lauber, K., Blumenthal, S. G., Waibel, M. & Wesselborg, S. Clearance of apoptotic cells: getting rid of the corpses. Mol. Cell 14, 277–287 (2004)

    Article  CAS  Google Scholar 

  9. Zhou, Z., Mangahas, P. M. & Yu, X. The genetics of hiding the corpse: engulfment and degradation of apoptotic cells in C. elegans and D. melanogaster. Curr. Top. Dev. Biol. 63, 91–143 (2004)

    Article  CAS  Google Scholar 

  10. deBakker, C. D. et al. Phagocytosis of apoptotic cells is regulated by a UNC-73/TRIO-MIG-2/RhoG signaling module and armadillo repeats of CED-12/ELMO. Curr. Biol. 14, 2208–2216 (2004)

    Article  CAS  Google Scholar 

  11. Cool, J. & Capel, B. Mixed signals: development of the testis. Semin. Reprod. Med. 27, 5–13 (2009)

    Article  CAS  Google Scholar 

  12. Loveland, K. L. et al. Drivers of germ cell maturation. Ann. NY Acad. Sci. 1061, 173–182 (2005)

    Article  CAS  ADS  Google Scholar 

  13. Griswold, M. D. The central role of Sertoli cells in spermatogenesis. Semin. Cell Dev. Biol. 9, 411–416 (1998)

    Article  CAS  Google Scholar 

  14. Bailey, R. W., Aronow, B., Harmony, J. A. & Griswold, M. D. Heat shock-initiated apoptosis is accelerated and removal of damaged cells is delayed in the testis of clusterin/ApoJ knock-out mice. Biol. Reprod. 66, 1042–1053 (2002)

    Article  CAS  Google Scholar 

  15. Braun, R. E. Every sperm is sacred–or is it? Nature Genet. 18, 202–204 (1998)

    Article  CAS  Google Scholar 

  16. Rotter, V. et al. Mice with reduced levels of p53 protein exhibit the testicular giant-cell degenerative syndrome. Proc. Natl Acad. Sci. USA 90, 9075–9079 (1993)

    Article  CAS  ADS  Google Scholar 

  17. Holstein, A. F. & Eckmann, C. Multinucleated spermatocytes and spermatids in human seminiferous tubules. Andrologia 18, 5–16 (1986)

    Article  CAS  Google Scholar 

  18. Lysiak, J. J., Zheng, S., Woodson, R. & Turner, T. T. Caspase-9-dependent pathway to murine germ cell apoptosis: mediation by oxidative stress, BAX, and caspase 2. Cell Tissue Res. 328, 411–419 (2007)

    Article  CAS  Google Scholar 

  19. Lysiak, J. J., Turner, S. D. & Turner, T. T. Molecular pathway of germ cell apoptosis following ischemia/reperfusion of the rat testis. Biol. Reprod. 63, 1465–1472 (2000)

    Article  CAS  Google Scholar 

  20. Holdcraft, R. W. & Braun, R. E. Androgen receptor function is required in Sertoli cells for the terminal differentiation of haploid spermatids. Development 131, 459–467 (2004)

    Article  CAS  Google Scholar 

  21. Brugnera, E. et al. Unconventional Rac-GEF activity is mediated through the Dock180-ELMO complex. Nature Cell Biol. 4, 574–582 (2002)

    Article  CAS  Google Scholar 

  22. Miyanishi, M. et al. Identification of Tim4 as a phosphatidylserine receptor. Nature 450, 435–439 (2007)

    Article  CAS  ADS  Google Scholar 

  23. Park, S.-Y. et al. Rapid cell corpse clearance by stabilin-2, a membrane phosphatidylserine receptor. Cell Death Differ. 15, 192–201 (2008)

    Article  CAS  Google Scholar 

  24. Shiratsuchi, A., Kawasaki, Y., Ikemoto, M., Arai, H. & Nakanishi, Y. Role of class B scavenger receptor type I in phagocytosis of apoptotic rat spermatogenic cells by Sertoli cells. J. Biol. Chem. 274, 5901–5908 (1999)

    Article  CAS  Google Scholar 

  25. Gillot, I. et al. Germ cells and fatty acids induce translocation of CD36 scavenger receptor to the plasma membrane of Sertoli cells. J. Cell Sci. 118, 3027–3035 (2005)

    Article  CAS  Google Scholar 

  26. Lu, Q. et al. Tyro-3 family receptors are essential regulators of mammalian spermatogenesis. Nature 398, 723–728 (1999)

    Article  CAS  ADS  Google Scholar 

  27. Chen, Y. et al. Functions of TAM RTKs in regulating spermatogenesis and male fertility in mice. Reproduction 138, 655–666 (2009)

    Article  CAS  Google Scholar 

  28. Hanayama, R. et al. Autoimmune disease and impaired uptake of apoptotic cells in MFG-E8-deficient mice. Science 304, 1147–1150 (2004)

    Article  CAS  ADS  Google Scholar 

  29. Akakura, S. et al. The opsonin MFG-E8 is a ligand for the alphavbeta5 integrin and triggers DOCK180-dependent Rac1 activation for the phagocytosis of apoptotic cells. Exp. Cell Res. 292, 403–416 (2004)

    Article  CAS  Google Scholar 

  30. A-Gonzalez, N. et al. Apoptotic cells promote their own clearance and immune tolerance through activation of the nuclear receptor LXR. Immunity 31, 245–258 (2009)

    Article  CAS  Google Scholar 

  31. Meyers, E. N., Lewandoski, M. & Martin, G. R. An Fgf8 mutant allelic series generated by Cre- and Flp-mediated recombination. Nature Genet. 18, 136–141 (1998)

    Article  CAS  Google Scholar 

  32. Lakso, M. et al. Efficient in vivo manipulation of mouse genomic sequences at the zygote stage. Proc. Natl Acad. Sci. USA 93, 5860–5865 (1996)

    Article  CAS  ADS  Google Scholar 

  33. Srinivas, S. et al. Cre reporter strains produced by targeted insertion of EYFP and ECFP into the ROSA26 locus. BMC Dev. Biol. 1, 4 (2001)

    Article  CAS  Google Scholar 

  34. Xiong, W. et al. Gas6 and the Tyro 3 receptor tyrosine kinase subfamily regulate the phagocytic function of Sertoli cells. Reproduction 135, 77–87 (2008)

    Article  CAS  Google Scholar 

  35. Lu, M. et al. PH domain of ELMO functions in trans to regulate Rac activation via Dock180. Nature Struct. Mol. Biol. 11, 756–762 (2004)

    Article  CAS  Google Scholar 

  36. Lysiak, J. J. et al. Essential role of neutrophils in germ cell-specific apoptosis following ischemia/reperfusion injury of the mouse testis. Biol. Reprod. 65, 718–725 (2001)

    Article  CAS  Google Scholar 

  37. Ogawa, T. Aréchaga, J. M., Avarbock, M. R. & Brinster, R. L. Transplantation of testis germinal cells into mouse seminiferous tubules. Int. J. Dev. Biol. 41, 111–122 (1997)

    CAS  PubMed  Google Scholar 

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We thank T. Turner, K. Tung and members of the Ravichandran and Lysiak groups for suggestions. We also thank L. Haney, A. C. Tosello-Trampont, J. Kim and S. Clugston for technical assistance. This work was supported by funding from the National Institutes of Health (to K.S.R. and J.J.L.) and the American Cancer Society (to M.R.E.). K.S.R. is a Bill Benter fellow of the American Asthma Foundation.

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The project was designed and the experiments planned by J.J.L., K.S.R and M.R.E. M.R.E. generated the Elmo1 knockout mice and performed and analysed most of the experiments in this study. S.Z. carried out the experiments using ELMO–GFP constructs. R.I.W. performed all of the immunohistochemistry, Sertoli cell extraction and sperm counts. M.A.R. performed the microbubble uptake experiments. I.J.J. performed the phagocytosis assays on non-Sertoli cells. D.P. performed phagocytosis assays and synthesized and characterized BAI1-TSR. Caenorhabditis elegans mismigration analysis using Elmo1 transgenes was conducted by J.M.K. J.Z. assisted with immunoblotting and quantitative PCR studies of Sertoli cells. J.J.L. performed intratesticular injections. M.R.E., K.S.R. and J.J.L. wrote the manuscript with input from the co-authors.

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Correspondence to Jeffrey J. Lysiak or Kodi S. Ravichandran.

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The authors declare no competing financial interests.

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Elliott, M., Zheng, S., Park, D. et al. Unexpected requirement for ELMO1 in clearance of apoptotic germ cells in vivo. Nature 467, 333–337 (2010).

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