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:

The actin cytoskeleton of kidney podocytes is a direct target of the antiproteinuric effect of cyclosporine A

Abstract

The immunosuppressive action of the calcineurin inhibitor cyclosporine A (CsA) stems from the inhibition of nuclear factor of activated T cells (NFAT) signaling in T cells. CsA is also used for the treatment of proteinuric kidney diseases. As it stands, the antiproteinuric effect of CsA is attributed to its immunosuppressive action. Here we show that the beneficial effect of CsA on proteinuria is not dependent on NFAT inhibition in T cells, but rather results from the stabilization of the actin cytoskeleton in kidney podocytes. CsA blocks the calcineurin-mediated dephosphorylation of synaptopodin, a regulator of Rho GTPases in podocytes, thereby preserving the phosphorylation-dependent synaptopodin–14-3-3β interaction. Preservation of this interaction, in turn, protects synaptopodin from cathepsin L–mediated degradation. These results represent a new view of calcineurin signaling and shed further light on the treatment of proteinuric kidney diseases. Novel calcineurin substrates such as synaptopodin may provide promising starting points for antiproteinuric drugs that avoid the serious side effects of long-term CsA treatment.

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: Synaptopodin specifically interacts with 14-3-3.
Figure 2: Identification of synaptopodin as calcineurin binding protein.
Figure 3: The synaptopodin–14-3-3 interaction is antagonistically regulated by PKA, CaMKII and calcineurin.
Figure 4: 14-3-3β, E64 and CsA block the CatL-mediated degradation of synaptopodin.
Figure 5: CsA and E64 ameliorate LPS-induced proteinuria by blocking the CatL-mediated degradation of synaptopodin.
Figure 6: Expression of Synpo-CM1+2 in podocytes protects against proteinuria, whereas activation of calcineurin in podocytes causes proteinuria.

Similar content being viewed by others

References

  1. Somlo, S. & Mundel, P. Getting a foothold in nephrotic syndrome. Nat. Genet. 24, 333–335 (2000).

    Article  CAS  Google Scholar 

  2. Tryggvason, K., Patrakka, J. & Wartiovaara, J. Hereditary proteinuria syndromes and mechanisms of proteinuria. N. Engl. J. Med. 354, 1387–1401 (2006).

    Article  CAS  Google Scholar 

  3. Tryggvason, K., Pikkarainen, T. & Patrakka, J. Nck links nephrin to actin in kidney podocytes. Cell 125, 221–224 (2006).

    Article  CAS  Google Scholar 

  4. Faul, C., Asanuma, K., Yanagida-Asanuma, E., Kim, K. & Mundel, P. Actin up: regulation of podocyte structure and function by components of the actin cytoskeleton. Trends Cell Biol. 17, 428–437 (2007).

    Article  CAS  Google Scholar 

  5. Mundel, P. et al. Synaptopodin: an actin-associated protein in telencephalic dendrites and renal podocytes. J. Cell Biol. 139, 193–204 (1997).

    Article  CAS  Google Scholar 

  6. Asanuma, K. et al. Synaptopodin regulates the actin-bundling activity of α-actinin in an isoform-specific manner. J. Clin. Invest. 115, 1188–1198 (2005).

    Article  CAS  Google Scholar 

  7. Huber, T.B. et al. Bigenic mouse models of focal segmental glomerulosclerosis involving pairwise interaction of CD2AP, Fyn and synaptopodin. J. Clin. Invest. 116, 1337–1345 (2006).

    Article  CAS  Google Scholar 

  8. Asanuma, K. et al. Synaptopodin orchestrates actin organization and cell motility via regulation of RhoA signalling. Nat. Cell Biol. 8, 485–491 (2006).

    Article  CAS  Google Scholar 

  9. Yanagida-Asanuma, E. et al. Synaptopodin protects against proteinuria by disrupting Cdc42-IRSp53-Mena signaling complexes in kidney podocytes. Am. J. Pathol. 171, 415–427 (2007).

    Article  CAS  Google Scholar 

  10. Aramburu, J., Heitman, J. & Crabtree, G.R. Calcineurin: a central controller of signalling in eukaryotes. EMBO Rep. 5, 343–348 (2004).

    Article  CAS  Google Scholar 

  11. Crabtree, G.R. & Olson, E.N. NFAT signaling: choreographing the social lives of cells. Cell 109 Suppl, S67–S79 (2002).

    Article  CAS  Google Scholar 

  12. Heit, J.J. et al. Calcineurin-NFAT signalling regulates pancreatic beta cell growth and function. Nature 443, 345–349 (2006).

    Article  CAS  Google Scholar 

  13. Horsley, V., Aliprantis, A.O., Polak, L., Glimcher, L.H. & Fuchs, E. NFATc1 balances quiescence and proliferation of skin stem cells. Cell 132, 299–310 (2008).

    Article  CAS  Google Scholar 

  14. Koga, T. et al. NFAT and Osterix cooperatively regulate bone formation. Nat. Med. 11, 880–885 (2005).

    Article  CAS  Google Scholar 

  15. Meyrier, A. Treatment of focal segmental glomerulosclerosis. Expert Opin. Pharmacother. 6, 1539–1549 (2005).

    Article  CAS  Google Scholar 

  16. Charbit, M. et al. Cyclosporin therapy in patients with Alport syndrome. Pediatr. Nephrol. 22, 57–63 (2007).

    Article  Google Scholar 

  17. Chen, D. et al. Cyclosporine A slows the progressive renal disease of alport syndrome (X-linked hereditary nephritis): results from a canine model. J. Am. Soc. Nephrol. 14, 690–698 (2003).

    Article  CAS  Google Scholar 

  18. Reiser, J. et al. Induction of B7–1 in podocytes is associated with nephrotic syndrome. J. Clin. Invest. 113, 1390–1397 (2004).

    Article  CAS  Google Scholar 

  19. Fu, H., Subramanian, R.R. & Masters, S.C. 14-3-3 proteins: structure, function and regulation. Annu. Rev. Pharmacol. Toxicol. 40, 617–647 (2000).

    Article  CAS  Google Scholar 

  20. Yaffe, M.B. et al. The structural basis for 14-3-3–phosphopeptide binding specificity. Cell 91, 961–971 (1997).

    Article  CAS  Google Scholar 

  21. Faul, C., Dhume, A., Schecter, A.D. & Mundel, P. Protein kinase A, Ca2+-calmodulin–dependent kinase II and calcineurin regulate the intracellular trafficking of myopodin between the Z-disc and the nucleus of cardiac myocytes. Mol. Cell. Biol. 27, 8215–8227 (2007).

    Article  CAS  Google Scholar 

  22. O'Keefe, S.J., Tamura, J., Kincaid, R.L., Tocci, M.J. & O'Neill, E.A. FK-506– and CsA-sensitive activation of the interleukin-2 promoter by calcineurin. Nature 357, 692–694 (1992).

    Article  CAS  Google Scholar 

  23. Yaffe, M.B. How do 14-3-3 proteins work? Gatekeeper phosphorylation and the molecular anvil hypothesis. FEBS Lett. 513, 53–57 (2002).

    Article  CAS  Google Scholar 

  24. Faul, C. et al. Promotion of importin α-mediated nuclear import by the phosphorylation-dependent binding of cargo protein to 14-3-3. J. Cell Biol. 169, 415–424 (2005).

    Article  CAS  Google Scholar 

  25. Muslin, A.J., Tanner, J.W., Allen, P.M. & Shaw, A.S. Interaction of 14-3-3 with signaling proteins is mediated by the recognition of phosphoserine. Cell 84, 889–897 (1996).

    Article  CAS  Google Scholar 

  26. Dougherty, M.K. & Morrison, D.K. Unlocking the code of 14-3-3. J. Cell Sci. 117, 1875–1884 (2004).

    Article  CAS  Google Scholar 

  27. Masters, S.C. & Fu, H. 14-3-3 proteins mediate an essential anti-apoptotic signal. J. Biol. Chem. 276, 45193–45200 (2001).

    Article  CAS  Google Scholar 

  28. Reiser, J. et al. Podocyte migration during nephrotic syndrome requires a coordinated interplay between cathepsin L and α3 integrin. J. Biol. Chem. 279, 34827–34832 (2004).

    Article  CAS  Google Scholar 

  29. Sever, S. et al. Proteolytic processing of dynamin by cytoplasmic cathepsin L is a mechanism for proteinuric kidney disease. J. Clin. Invest. 117, 2095–2104 (2007).

    Article  CAS  Google Scholar 

  30. Lohmuller, T. et al. Toward computer-based cleavage site prediction of cysteine endopeptidases. Biol. Chem. 384, 899–909 (2003).

    Article  Google Scholar 

  31. Cotelle, V. et al. 14-3-3s regulate global cleavage of their diverse binding partners in sugar-starved Arabidopsis cells. EMBO J. 19, 2869–2876 (2000).

    Article  CAS  Google Scholar 

  32. Baricos, W.H. et al. Evidence suggesting a role for cathepsin L in an experimental model of glomerulonephritis. Arch. Biochem. Biophys. 288, 468–472 (1991).

    Article  CAS  Google Scholar 

  33. Bosma, G.C., Custer, R.P. & Bosma, M.J. A severe combined immunodeficiency mutation in the mouse. Nature 301, 527–530 (1983).

    Article  CAS  Google Scholar 

  34. Schwarz, K. et al. Podocin, a raft-associated component of the glomerular slit diaphragm, interacts with CD2AP and nephrin. J. Clin. Invest. 108, 1621–1629 (2001).

    Article  CAS  Google Scholar 

  35. Kim, B.S. et al. Impact of cyclosporin on podocyte ZO-1 expression in puromycin aminonucleoside nephrosis rats. Yonsei Med. J. 46, 141–148 (2005).

    Article  Google Scholar 

  36. Shigehara, T. et al. Inducible podocyte-specific gene expression in transgenic mice. J. Am. Soc. Nephrol. 14, 1998–2003 (2003).

    CAS  PubMed  Google Scholar 

  37. Zheng, W. et al. Cellular stability of serotonin N-acetyltransferase conferred by phosphonodifluoromethylene alanine (Pfa) substitution for Ser-205. J. Biol. Chem. 280, 10462–10467 (2005).

    Article  CAS  Google Scholar 

  38. Kuwahara, K. et al. TRPC6 fulfills a calcineurin signaling circuit during pathologic cardiac remodeling. J. Clin. Invest. 116, 3114–3126 (2006).

    Article  CAS  Google Scholar 

  39. Winn, M.P. et al. A mutation in the TRPC6 cation channel causes familial focal segmental glomerulosclerosis. Science 308, 1801–1804 (2005).

    Article  CAS  Google Scholar 

  40. Reiser, J. et al. TRPC6 is a glomerular slit diaphragm–associated channel required for normal renal function. Nat. Genet. 37, 739–744 (2005).

    Article  CAS  Google Scholar 

  41. Moller, C.C. et al. Induction of TRPC6 channel in acquired forms of proteinuric kidney disease. J. Am. Soc. Nephrol. 18, 29–36 (2007).

    Article  CAS  Google Scholar 

  42. Halloran, P.F. Immunosuppressive drugs for kidney transplantation. N. Engl. J. Med. 351, 2715–2729 (2004).

    Article  CAS  Google Scholar 

  43. Goulet, B. et al. A cathepsin L isoform that is devoid of a signal peptide localizes to the nucleus in S phase and processes the CDP/Cux transcription factor. Mol. Cell 14, 207–219 (2004).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank C. Chiu and S. Ratner for excellent technical assistance and T. Reinheckel for the analysis of CatL cleavage sites. We thank the Mount Sinai School of Medicine Mouse Genetics Research Facility for performing pronuclear injections. We also thank J.B. Kopp (US National Institutes of Health) for providing the podocin-rtTA mice, H. Fu (Emory University) for yellow fluorescence protein–tagged difopein and E.N. Olson (The University of Texas Southwestern Medical Center at Dallas) for wild-type and constitutively active calcineurin cDNA constructs. Y.H.C. was supported by a research fellowship from the Albert Einstein College of Medicine, S.F. was supported by Karger Stiftung and J.D. was supported by the Deutsche Forschungsgemeinschaft. This work was supported by US National Institutes of Health grants DA18886, DK57683 and DK062472 and the George M. O'Brien Kidney Center grants DK064236 (to P.M.) and DK073495 (to J.R.).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Peter Mundel.

Supplementary information

Supplementary Text and Figures

Supplementary Figs. 1–3, Supplementary Table 1 and Supplementary Methods (PDF 1367 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Faul, C., Donnelly, M., Merscher-Gomez, S. et al. The actin cytoskeleton of kidney podocytes is a direct target of the antiproteinuric effect of cyclosporine A. Nat Med 14, 931–938 (2008). https://doi.org/10.1038/nm.1857

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nm.1857

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