Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Soluble CPG15 expressed during early development rescues cortical progenitors from apoptosis

Abstract

The balance between proliferation and apoptosis is critical for proper development of the nervous system. Yet, little is known about molecules that regulate apoptosis of proliferative neurons. Here we identify a soluble, secreted form of CPG15 expressed in embryonic rat brain regions undergoing rapid proliferation and apoptosis, and show that it protects cultured cortical neurons from apoptosis by preventing activation of caspase 3. Using a lentivirus-delivered small hairpin RNA, we demonstrate that endogenous CPG15 is essential for the survival of undifferentiated cortical progenitors in vitro and in vivo. We further show that CPG15 overexpression in vivo expands the progenitor pool by preventing apoptosis, resulting in an enlarged, indented cortical plate and cellular heterotopias within the ventricular zone, similar to the phenotypes of mutant mice with supernumerary forebrain progenitors. CPG15 expressed during mammalian forebrain morphogenesis may help balance neuronal number by countering apoptosis in specific neuroblasts subpopulations, thus influencing final brain size and shape.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: cpg15 mRNA expression is biphasic.
Figure 2: CPG15 is predominantly expressed in a soluble secreted form.
Figure 3: Soluble CPG15 rescues cortical neurons from apoptosis induced by growth factor deprivation (starvation).
Figure 4: A lentivirus-delivered cpg15 small hairpin RNA (shRNA) knocks down CPG15 expression.
Figure 5: Endogenous CPG15 is required for cortical progenitor survival in vitro.
Figure 6: In vivo knockdown of endogenous CPG15 causes shrinkage of the cortical plate and increased apoptosis of cortical neurons.
Figure 7: In vivo CPG15 overexpression in the embryonic brain results in an expanded cortical plate and heterotopic cell masses in the ventricular zone.
Figure 8: CPG15 overexpression reduces apoptosis in the progenitor pool but does not affect mitotic index or cell cycle exit.

Similar content being viewed by others

References

  1. Rakic, P. A small step for the cell, a giant leap for mankind: a hypothesis of neocortical expansion during evolution. Trends Neurosci. 18, 383–388 (1995).

    Article  CAS  Google Scholar 

  2. Takahashi, T., Nowakowski, R.S. & Caviness, V.S.J. The mathematics of neocortical neuronogenesis. Dev. Neurosci. 19, 17–22 (1997).

    Article  CAS  Google Scholar 

  3. Caviness, V.S.J., Takahashi, T. & Nowakowski, R.S. Numbers, time and neocortical neuronogenesis: a general developmental and evolutionary model. Trends Neurosci. 18, 379–383 (1995).

    Article  CAS  Google Scholar 

  4. Haydar, T.F., Kuan, C-Y., Flavell, R.A. & Rakic, P. The role of cell death in regulating the size and shape of the mammalian forebrain. Cereb. Cortex 9, 621–626 (1999).

    Article  CAS  Google Scholar 

  5. Kuan, C.-H., Roth, K.A., Flavell, R.A. & Rakic, P. Mechanisms of programmed cell death in the developing brain. Trends Neurosci. 23, 291–297 (2000).

    Article  CAS  Google Scholar 

  6. de la Rosa, E.J. & de Pablo, F. Cell death in early neural development: beyond the neurotrophic theory. Trends Neurosci. 23, 454–458 (2000).

    Article  CAS  Google Scholar 

  7. Pompeiano, M., Blaschke, A.J., Flavell, R.A., Srinivasan, A. & Chun, J. Decreased apoptosis in proliferative and postmitotic regions of the caspase 3-deficient embryonic central nervous system. J. Comp. Neurol. 423, 1–12 (2000).

    Article  CAS  Google Scholar 

  8. Blaschke, A.J., Staley, K. & Chun, J. Widespread programmed cell death in proliferative and postmitotic regions of the fetal cerebral cortex. Development 122, 1165–1174 (1996).

    CAS  PubMed  Google Scholar 

  9. Thomaidou, D., Mione, M.C., Cavanagh, J.F.R. & Parnavelas, J.G. Apoptosis and its relation to the cell cycle in the developing cerebral cortex. J. Neurosci. 17, 1075–1085 (1997).

    Article  CAS  Google Scholar 

  10. Blaschke, A.J., Weiner, J.A. & Chun, J. Programmed cell death is a universal feature of embryonic and postnatal neuroproliferative regions throughout the central nervous system. J. Comp. Neurol. 396, 39–50 (1998).

    Article  CAS  Google Scholar 

  11. Kuida, K. et al. Decreased apoptosis in the brain and premature lethality in CPP32-deficient mice. Nature 384, 368–372 (1996).

    Article  CAS  Google Scholar 

  12. Kuida, K. et al. Reduced apoptosis and cytochrome c-mediated caspase activation in mice lacking caspase 9. Cell 94, 325–337 (1998).

    Article  CAS  Google Scholar 

  13. Hakem, R. et al. Differential requirement for caspase 9 in apoptotic pathways in vivo. Cell 94, 339–352 (1998).

    Article  CAS  Google Scholar 

  14. Cecconi, F., Alvarez-Bolado, G., Meyer, B.I., Roth, K.A. & Gruss, P. Apaf1 (CED-4 Homolog) regulates programmed cell death in mammalian development. Cell 94, 727–737 (1998).

    Article  CAS  Google Scholar 

  15. Yoshida, H. et al. Apaf1 is required for mitochondrial pathways of apoptosis and brain development. Cell 94, 739–750 (1998).

    Article  CAS  Google Scholar 

  16. Nedivi, E., Hevroni, D., Naot, D., Israeli, D. & Citri, Y. Numerous candidate plasticity-related genes revealed by differential cDNA cloning. Nature 363, 718–722 (1993).

    Article  CAS  Google Scholar 

  17. Hevroni, D. et al. Hippocampal plasticity involves extensive gene induction and multiple cellular mechanisms. J. Mol. Neurosci. 10, 75–98 (1998).

    Article  CAS  Google Scholar 

  18. Naeve, G.S. et al. Neuritin: a gene induced by neural activity and neurotrophins that promotes neuritogenesis. Proc. Natl Acad. Sci. USA 94, 2648–2653 (1997).

    Article  CAS  Google Scholar 

  19. Nedivi, E., Wu, G.Y. & Cline, H.T. Promotion of dendritic growth by CPG15, an activity-induced signaling molecule. Science 281, 1863–1866 (1998).

    Article  CAS  Google Scholar 

  20. Cantallops, I., Haas, K. & Cline, H.T. Postsynaptic CPG15 promotes synaptic maturation and presynaptic axon arbor elaboration in vivo. Nat. Neurosci. 3, 1004–1011 (2000).

    Article  CAS  Google Scholar 

  21. Corriveau, R., Shatz, C.J. & Nedivi, E. Dynamic regulation of cpg15 during activity-dependent synaptic development in the mammalian visual system. J. Neurosci. 19, 7999–8008 (1999).

    Article  CAS  Google Scholar 

  22. Lee, W.C.A. & Nedivi, E. Extended plasticity of visual cortex in dark-reared animals may result from prolonged expression of genes like cpg15. J. Neurosci. 22, 1807–1815 (2002).

    Article  CAS  Google Scholar 

  23. Hooper, N.M. Determination of glycosyl-phosphatidylinositol membrane protein anchorage. Proteomics 1, 748–755 (2001).

    Article  CAS  Google Scholar 

  24. Lois, C., Hong, E.J., Pease, S., Brown, E.J. & Baltimore, D. Germline transmission and tissue-specific expression of transgenes delivered by lentiviral vectors. Science 295, 868–872 (2002).

    Article  CAS  Google Scholar 

  25. Rubinson, D.A. et al. A lentivirus-based system to functionally silence genes in primary mammalian cells, stem cells and transgenic mice by RNA interference. Nat. Genet. 33, 401–406 (2003).

    Article  CAS  Google Scholar 

  26. McManus, M.T. & Sharp, P.A. Gene silencing in mammals by small interfering RNAs. Nat. Rev. Genet. 3, 737–747 (2002).

    Article  CAS  Google Scholar 

  27. Chenn, A. & Walsh, C.A. Increased neuronal production, enlarged forebrains and cytoarchitectural distortions in β-catenin overexpressing transgenic mice. Cereb. Cortex 13, 599–606 (2003).

    Article  Google Scholar 

  28. Motoyama, N. et al. Massive cell death of immature hematopoietic cells and neurons in Bcl-x-deficient mice. Science 267, 1506–1510 (1995).

    Article  CAS  Google Scholar 

  29. Roth, K.A. et al. Epistatic and independent functions of Caspase-3 and Bcl-XL in developmental programmed cell death. Proc. Natl Acad. Sci. USA 97, 466–471 (2000).

    Article  CAS  Google Scholar 

  30. Shindler, K.S., Latham, C.B. & Roth, K.A. bax deficiency prevents the increased cell death of immature neurons in bcl-x-deficient mice. J. Neurosci. 17, 3112–3119 (1997).

    Article  CAS  Google Scholar 

  31. Knudson, C.M., Tung, K.S.K., Tourtellotte, W.G., Brown, G.A.J. & Korsmeyer, S.J. Bax-deficient mice with lymphoid hyperplasia and male germ cell death. Science 270, 96–99 (1995).

    Article  CAS  Google Scholar 

  32. White, F.A., Keller-Peck, C.R., Knudson, C.M., Korsmeyer, S.J. & Snider, W.D. Widespread elimination of naturally occurring neuronal death in Bax-deficient mice. J. Neurosci. 18, 1428–1439 (1998).

    Article  CAS  Google Scholar 

  33. Chenn, A. & Walsh, C.A. Regulation of cerebral cortical size by control of cell cycle exit in neural precursors. Science 297, 365–369 (2002).

    Article  CAS  Google Scholar 

  34. Ortega, S., Ittmann, M., Tsang, S.H., Ehrlich, M. & Basilico, C. Neuronal defects and delayed wound healing in mice lacking fibroblast growth factor 2. Proc. Natl Acad. Sci. USA 95, 5672–5677 (1998).

    Article  CAS  Google Scholar 

  35. Dono, R., Texido, G., Dussel, R., Ehmke, H. & Zeller, R. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice. EMBO J. 17, 4213–4225 (1998).

    Article  CAS  Google Scholar 

  36. Vaccarino, F.M. et al. Changes in cerebral cortex size are governed by fibroblast growth factor during embryogenesis. Nat. Neurosci. 2, 246–253 (1999).

    Article  CAS  Google Scholar 

  37. Suh, J., Lu, N., Nicot, A., Tatsuno, I. & DiCicco-Bloom, E. PACAP is an anti-mitogenic signal in developing cerebral cortex. Nat. Neurosci. 4, 123–124 (2001).

    Article  CAS  Google Scholar 

  38. Kingsbury, M.A., Rehen, S.K. & Contos, J.J.A. Higgins, C.M.a. & Chun, J. Non-proliferative effects of lysophosphatidic acid enhance cortical growth and folding. Nat. Neurosci. 6, 1292–1299 (2003).

    Article  CAS  Google Scholar 

  39. Barnabé-Heider, F. & Miller, F.D. Endogenously produced neurotrophins regulate survival and differentiation of cortical progenitors via distinct signaling pathways. J. Neurosci. 23, 5149–5160 (2003).

    Article  Google Scholar 

  40. Brunstrom, J.E., Gray-Swain, M.R., Osborne, P.A. & Pearlman, A.L. Neuronal heterotopias in the developing cerebral cortex produced by neurotrophin-4. Neuron 18, 505–517 (1997).

    Article  CAS  Google Scholar 

  41. Ernfors, P., Merlio, J.-P. & Persson, H. Cells expressing mRNA for neurotrophins and their receptors during embryonic rat development. Eur. J. Neurosci. 4, 1140–1158 (1992).

    Article  Google Scholar 

  42. Conover, J.C. & Yancopoulos, G.D. Neurotrophin regulation of the developing nervous system: analyses of knockout mice. Rev. Neurosci. 8, 13–27 (1997).

    Article  CAS  Google Scholar 

  43. Götz, M. Doublecortin finds its place. Nat. Neurosci. 6, 1245–1247 (2003).

    Article  Google Scholar 

  44. Corbo, J.C. et al. Doublecortin is required in mice for lamination of the hippocampus but not the neocortex. J. Neurosci. 22, 7548–7557 (2002).

    Article  CAS  Google Scholar 

  45. Bai, J. et al. RNAi reveals doublecortin is required for radial migration in rat neocortex. Nat. Neurosci. 6, 1277–1282 (2003).

    Article  CAS  Google Scholar 

  46. Gleeson, J.G. et al. Doublecortin, a brain-specific gene mutated in human X-linked lissencephaly and double cortex syndrome, encodes a putative signaling protein. Cell 92, 63–72 (1998).

    Article  CAS  Google Scholar 

  47. Zhou, J. & Tang, X.C. Huperzine A attenuates apoptosis and mitochondria-dependent caspase-3 in rat cortical neurons. FEBS Lett. 526, 21–25 (2002).

    Article  CAS  Google Scholar 

  48. Ghosh, A. & Greenberg, M.E. Distinct roles for bFGF and NT-3 in the regulation of cortical neurogenesis. Neuron 15, 89–103 (1995).

    Article  CAS  Google Scholar 

  49. Walsh, C. & Cepko, C.L. Widespread dispersion of neuronal clones across functional regions of the cerebral cortex. Science 255, 434–440 (1992).

    Article  CAS  Google Scholar 

  50. Sambrook, J., Fritsch, E.F. & Maniatis, T. Molecular Cloning: A Laboratory Manual. (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989).

    Google Scholar 

Download references

Acknowledgements

We thank members of the Nedivi laboratory and P. Garrity, J. Hoch, and J. Mintern for helpful comments on the manuscript, J. Cottrell for initiating and help with shRNA cloning and testing, C. Lois for advice on construction and use of lentivirus vectors, C. Walsh and E. Olson for guidance on embryonic injections, and J. Pungor for help with cell counts. This work was sponsored by grants from National Eye Institute and the Ellison Medical Foundation to E. Nedivi. U. Putz was supported by a postdoctoral fellowship from the Deutsche Forschungsgemeinschaft, and C. Harwell by a Ford Foundation predoctoral fellowship.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Elly Nedivi.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Putz, U., Harwell, C. & Nedivi, E. Soluble CPG15 expressed during early development rescues cortical progenitors from apoptosis. Nat Neurosci 8, 322–331 (2005). https://doi.org/10.1038/nn1407

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nn1407

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing