Skip to main content

Thank you for visiting 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.

Tsc1 (hamartin) confers neuroprotection against ischemia by inducing autophagy


Previous attempts to identify neuroprotective targets by studying the ischemic cascade and devising ways to suppress it have failed to translate to efficacious therapies for acute ischemic stroke1. We hypothesized that studying the molecular determinants of endogenous neuroprotection in two well-established paradigms, the resistance of CA3 hippocampal neurons to global ischemia2 and the tolerance conferred by ischemic preconditioning (IPC)3, would reveal new neuroprotective targets. We found that the product of the tuberous sclerosis complex 1 gene (TSC1), hamartin, is selectively induced by ischemia in hippocampal CA3 neurons. In CA1 neurons, hamartin was unaffected by ischemia but was upregulated by IPC preceding ischemia, which protects the otherwise vulnerable CA1 cells. Suppression of hamartin expression with TSC1 shRNA viral vectors both in vitro and in vivo increased the vulnerability of neurons to cell death following oxygen glucose deprivation (OGD) and ischemia. In vivo, suppression of TSC1 expression increased locomotor activity and decreased habituation in a hippocampal-dependent task. Overexpression of hamartin increased resistance to OGD by inducing productive autophagy through an mTORC1-dependent mechanism.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Hamartin expression is selectively induced in the CA3 hippocampal area following ischemia.
Figure 2: Hamartin regulates neuronal susceptibility to OGD-induced cell death.
Figure 3: Resistance of CA3 neurons to ischemia is mediated by upregulation of hamartin in vivo.
Figure 4: Hamartin promotes neuronal survival by inhibiting mTORC1 and inducing productive autophagy.

Accession codes


NCBI Reference Sequence


  1. O'Collins, V.E. et al. 1,026 experimental treatments in acute stroke. Ann. Neurol. 59, 467–477 (2006).

    Article  CAS  Google Scholar 

  2. Kirino, T. Delayed neuronal death in the gerbil hippocampus following ischemia. Brain Res. 239, 57–69 (1982).

    Article  CAS  Google Scholar 

  3. Dirnagl, U., Becker, K. & Meisel, A. Preconditioning and tolerance against cerebral ischaemia: from experimental strategies to clinical use. Lancet Neurol. 8, 398–412 (2009).

    Article  CAS  Google Scholar 

  4. Petito, C.K., Feldmann, E., Pulsinelli, W.A. & Plum, F. Delayed hippocampal damage in humans following cardiorespiratory arrest. Neurology 37, 1281–1286 (1987).

    Article  CAS  Google Scholar 

  5. Chen, J. et al. Expression of the apoptosis-effector gene, Bax, is up-regulated in vulnerable hippocampal CA1 neurons following global ischemia. J. Neurochem. 67, 64–71 (1996).

    Article  CAS  Google Scholar 

  6. Ouyang, Y.B., Voloboueva, L.A., Xu, L.J. & Giffard, R.G. Selective dysfunction of hippocampal CA1 astrocytes contributes to delayed neuronal damage after transient forebrain ischemia. J. Neurosci. 27, 4253–4260 (2007).

    Article  CAS  Google Scholar 

  7. Sun, H.S. et al. Suppression of hippocampal TRPM7 protein prevents delayed neuronal death in brain ischemia. Nat. Neurosci. 12, 1300–1307 (2009).

    Article  CAS  Google Scholar 

  8. Zhang, Q.G. et al. Akt inhibits MLK3/JNK3 signaling by inactivating Rac1: a protective mechanism against ischemic brain injury. J. Neurochem. 98, 1886–1898 (2006).

    Article  CAS  Google Scholar 

  9. Shioda, N., Han, F., Morioka, M. & Fukunaga, K. Bis(1-oxy-2-pyridinethiolato)oxovanadium(IV) enhances neurogenesis via phosphatidylinositol 3-kinase/Akt and extracellular signal regulated kinase activation in the hippocampal subgranular zone after mouse focal cerebral ischemia. Neuroscience 155, 876–887 (2008).

    Article  CAS  Google Scholar 

  10. Endo, H., Nito, C., Kamada, H., Yu, F. & Chan, P.H. Akt/GSK3β survival signaling is involved in acute brain injury after subarachnoid hemorrhage in rats. Stroke 37, 2140–2146 (2006).

    Article  CAS  Google Scholar 

  11. Gozal, E. et al. Proteomic analysis of CA1 and CA3 regions of rat hippocampus and differential susceptibility to intermittent hypoxia. J. Neurochem. 83, 331–345 (2002).

    Article  CAS  Google Scholar 

  12. Kawagoe, J. et al. Distributions of heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 mRNAs after transient focal ischemia in rat brain. Brain Res. 587, 195–202 (1992).

    Article  CAS  Google Scholar 

  13. Kinouchi, H. et al. Induction of 70-kDa heat shock protein and hsp70 mRNA following transient focal cerebral ischemia in the rat. J. Cereb. Blood Flow Metab. 13, 105–115 (1993).

    Article  CAS  Google Scholar 

  14. Colbourne, F., Li, H., Buchan, A.M. & Clemens, J.A. Continuing postischemic neuronal death in CA1: influence of ischemia duration and cytoprotective doses of NBQX and SNX-111 in rats. Stroke 30, 662–668 (1999).

    Article  CAS  Google Scholar 

  15. Choo, A.Y. et al. Glucose addiction of TSC null cells is caused by failed mTORC1-dependent balancing of metabolic demand with supply. Mol. Cell 38, 487–499 (2010).

    Article  CAS  Google Scholar 

  16. Di Nardo, A. et al. Tuberous sclerosis complex activity is required to control neuronal stress responses in an mTOR-dependent manner. J. Neurosci. 29, 5926–5937 (2009).

    Article  CAS  Google Scholar 

  17. Tavazoie, S.F., Alvarez, V.A., Ridenour, D.A., Kwiatkowski, D.J. & Sabatini, B.L. Regulation of neuronal morphology and function by the tumor suppressors Tsc1 and Tsc2. Nat. Neurosci. 8, 1727–1734 (2005).

    Article  CAS  Google Scholar 

  18. Andersen, M.B., Zimmer, J. & Sams-Dodd, F. Postischemic hyperactivity in the Mongolian gerbil correlates with loss of hippocampal neurons. Behav. Neurosci. 111, 1205–1216 (1997).

    Article  CAS  Google Scholar 

  19. Kesner, R.P. Behavioral functions of the CA3 subregion of the hippocampus. Learn. Mem. 14, 771–781 (2007).

    Article  Google Scholar 

  20. Mileson, B.E. & Schwartz, R.D. The use of locomotor activity as a behavioral screen for neuronal damage following transient forebrain ischemia in gerbils. Neurosci. Lett. 128, 71–76 (1991).

    Article  CAS  Google Scholar 

  21. Tee, A.R., Manning, B.D., Roux, P.P., Cantley, L.C. & Blenis, J. Tuberous sclerosis complex gene products, tuberin and hamartin, control mTOR signaling by acting as a GTPase-activating protein complex toward Rheb. Curr. Biol. 13, 1259–1268 (2003).

    Article  CAS  Google Scholar 

  22. Malagelada, C., Jin, Z.H., Jackson-Lewis, V., Przedborski, S. & Greene, L.A. Rapamycin protects against neuron death in in vitro and in vivo models of Parkinson's disease. J. Neurosci. 30, 1166–1175 (2010).

    Article  CAS  Google Scholar 

  23. Yang, S.S. et al. Rapamycin protects heart from ischemia/reperfusion injury independent of autophagy by activating PI3 kinase-Akt pathway and mitochondria K(ATP) channel. Pharmazie 65, 760–765 (2010).

    CAS  PubMed  Google Scholar 

  24. Chauhan, A., Sharma, U., Jagannathan, N.R., Reeta, K.H. & Gupta, Y.K. Rapamycin protects against middle cerebral artery occlusion induced focal cerebral ischemia in rats. Behav. Brain Res. 225, 603–609 (2011).

    Article  CAS  Google Scholar 

  25. Gabryel, B., Kost, A. & Kasprowska, D. Neuronal autophagy in cerebral ischemia—a potential target for neuroprotective strategies? Pharmacol. Rep. 64, 1–15 (2012).

    Article  CAS  Google Scholar 

  26. Klionsky, D.J. et al. Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy 4, 151–175 (2008).

    Article  CAS  Google Scholar 

  27. Zheng, Y.Q., Liu, J.X., Li, X.Z., Xu, L. & Xu, Y.G. RNA interference-mediated downregulation of Beclin1 attenuates cerebral ischemic injury in rats. Acta Pharmacol. Sin. 30, 919–927 (2009).

    Article  CAS  Google Scholar 

  28. Wen, Y.D. et al. Neuronal injury in rat model of permanent focal cerebral ischemia is associated with activation of autophagic and lysosomal pathways. Autophagy 4, 762–769 (2008).

    Article  CAS  Google Scholar 

  29. Carloni, S., Buonocore, G. & Balduini, W. Protective role of autophagy in neonatal hypoxia-ischemia induced brain injury. Neurobiol. Dis. 32, 329–339 (2008).

    Article  CAS  Google Scholar 

  30. Wang, P. et al. Induction of autophagy contributes to the neuroprotection of nicotinamide phosphoribosyltransferase in cerebral ischemia. Autophagy 8, 77–87 (2012).

    Article  CAS  Google Scholar 

  31. Liu, C., Gao, Y., Barrett, J. & Hu, B. Autophagy and protein aggregation after brain ischemia. J. Neurochem. 115, 68–78 (2010).

    Article  CAS  Google Scholar 

  32. Sheng, R. et al. Autophagy activation is associated with neuroprotection in a rat model of focal cerebral ischemic preconditioning. Autophagy 6, 482–494 (2010).

    Article  CAS  Google Scholar 

  33. van den Ouweland, A.M. et al. Characterisation of TSC1 promoter deletions in tuberous sclerosis complex patients. Eur. J. Hum. Genet. 19, 157–163 (2011).

    Article  CAS  Google Scholar 

  34. Pulsinelli, W.A. & Buchan, A.M. The four-vessel occlusion rat model: method for complete occlusion of vertebral arteries and control of collateral circulation. Stroke 19, 913–914 (1988).

    Article  CAS  Google Scholar 

  35. Guillemin, I. et al. A subcellular prefractionation protocol for minute amounts of mammalian cell cultures and tissue. Proteomics 5, 35–45 (2005).

    Article  CAS  Google Scholar 

  36. Xu, D. et al. Novel MMP-9 substrates in cancer cells revealed by a label-free quantitative proteomics approach. Mol. Cell. Proteomics 7, 2215–2228 (2008).

    Article  CAS  Google Scholar 

  37. Vogiatzi, T., Xilouri, M., Vekrellis, K. & Stefanis, L. Wild type alpha-synuclein is degraded by chaperone-mediated autophagy and macroautophagy in neuronal cells. J. Biol. Chem. 283, 23542–23556 (2008).

    Article  CAS  Google Scholar 

  38. Xilouri, M., Vogiatzi, T., Vekrellis, K., Park, D. & Stefanis, L. Abberant alpha-synuclein confers toxicity to neurons in part through inhibition of chaperone-mediated autophagy. PLoS ONE 4, e5515 (2009).

    Article  Google Scholar 

  39. Kaur, J., Zhao, Z., Geransar, R.M., Papadakis, M. & Buchan, A.M. Prior deafferentation confers long term protection to CA1 against transient forebrain ischemia and sustains GluR2 expression. Brain Res. 1075, 201–212 (2006).

    Article  CAS  Google Scholar 

  40. Jiang, Y., Deacon, R., Anthony, D.C. & Campbell, S.J. Inhibition of peripheral TNF can block the malaise associated with CNS inflammatory diseases. Neurobiol. Dis. 32, 125–132 (2008).

    Article  CAS  Google Scholar 

Download references


This work was supported by the UK Medical Research Council grant G0500495 and by the Dunhill Medical Trust. A.M.B. is a senior investigator of the UK National Institute for Health Research (NIHR) and received funding from Fondation Leducq for neurovascular coupling. G.H. was funded through the NIHR Integrated Academic Training Programme and Oxford University Clinical Academic Graduate School. B.K. and C.W.D. were supported by the NIHR Biomedical Research Centre. S.N. was supported by the Deutsche Forschungsgemeinschaft. G.T. and S.M.W. received funding from National Health Service Blood and Transplant and the NIHR under its Programme Grants Scheme (NIHR Programmes RP-PG-0310-10001 and -10003). We would also like to thank R. Deacon from the Department of Experimental Psychology, University of Oxford, for providing us with the open-field apparatus and for his guidance with the behavioral experiments. We thank E. Martin Rendon for her input concerning the lentiviral vectors and J. Peeling for his evaluation of the manuscript. We dedicate this paper to the memory of our colleague and mentor, John P. MacManus.

Author information

Authors and Affiliations



M.P. initiated and designed the study, carried out the proteomic and biochemical analyses, performed part of the in vitro and in vivo shRNA lentiviral studies and part of the in vitro overexpression studies and their analysis, and wrote the manuscript. G.H. carried out the subcellular fractionation and immunoblotting experiments for Figures 1 and 4. M.X. produced the overexpression lentiviral particles and helped with the analysis of long-lived protein degradation assays. L.C.H. carried out the rat surgeries for the IPC studies and contributed to the development of the subcellular fractionation protocol. S.N. assisted with the rat surgeries and immunofluorescence experiments and contributed in the interpretation of the proteomic data sets. G.T. assisted with the cortical culture experiments. S.M.W. supervised the National Health Service Blood and Transplant collaborative studies and critically reviewed and edited the manuscript. C.W.D. assisted with the IPA. R.C. assisted in the behavioral testing. Z.Z. carried out the rat surgeries to generate the tissue for the proteomic experiments and time course studies. M.M.M. and M.J.A.W. assisted with the design and conduct of the lentiviral overexpression experiments. B.K. supervised and helped with the proteomic analysis. K.V. contributed to the primary culture lentiviral studies, assisted with the in vivo shRNA experiments and designed, carried out and assisted in the analysis of protein degradation, autophagy and necrosis assays and supervised the collaboration. A.M.B. initiated and supervised the whole project. All authors edited the manuscript.

Corresponding author

Correspondence to Alastair M Buchan.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–13, Supplementary Tables 1–9 and Supplementary Results and Discussion (PDF 3125 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Papadakis, M., Hadley, G., Xilouri, M. et al. Tsc1 (hamartin) confers neuroprotection against ischemia by inducing autophagy. Nat Med 19, 351–357 (2013).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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