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:

Sequential formation of different layers of dystrophic neurites in Alzheimer’s brains

Abstract

Alzheimer’s disease (AD) is characterized by the presence of neuritic plaques in which dystrophic neurites (DNs) are typical constituents. We recently showed that DNs labeled by antibodies to the tubular endoplasmic reticulum (ER) protein reticulon-3 (RTN3) are enriched with clustered tubular ER. However, multi-vesicle bodies are also found in DNs, suggesting that different populations of DNs exist in brains of AD patients. To understand how different DNs evolve to surround core amyloid plaques, we monitored the growth of DNs in AD mouse brains (5xFAD and APP/PS1ΔE9 mice) by multiple approaches, including two-dimensional and three-dimensional (3D) electron microscopy (EM). We discovered that a pre-autophagosome protein ATG9A was enriched in DNs when a plaque was just beginning to develop. ATG9A-positive DNs were often closer to the core amyloid plaque, whereas RTN3 immunoreactive DNs were mostly located in the outer layers of ATG9A-positive DNs. Proteins such as RAB7 and LC3 appeared in DNs at later stages during plaque growth, likely accumulated as a part of large autophagy vesicles, and were distributed relatively furthest from the core amyloid plaque. Reconstructing the 3D structure of different morphologies of DNs revealed that DNs in AD mouse brains were constituted in three layers that are distinct by enriching different types of vesicles, as validated by immune-EM methods. Collectively, our results provide the first evidence that DNs evolve from dysfunctions of pre-autophagosomes, tubular ER, mature autophagosomes, and the ubiquitin proteasome system during plaque growth.

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

Access options

Buy this article

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Braak H, Braak E. Neuropathological stageing of Alzheimer-related changes. Acta Neuropathol. 1991;82:239–59.

    Article  CAS  Google Scholar 

  2. Price JL, Morris JC. Tangles and plaques in nondemented aging and “preclinical” Alzheimer’s disease. Ann Neurol. 1999;45:358–68.

    Article  CAS  Google Scholar 

  3. Selkoe DJ. Alzheimer’s disease is a synaptic failure. Science. 2002;298:789–91. https://doi.org/10.1126/science.1074069

    Article  CAS  PubMed  Google Scholar 

  4. Trojanowski JQ, Lee VM. Brain degeneration linked to “fatal attractions” of proteins in Alzheimer’s disease and related disorders. J Alzheimers Dis. 2001;3:117–9.

    Article  CAS  Google Scholar 

  5. Fukumoto H, et al. Amyloid beta protein deposition in normal aging has the same characteristics as that in Alzheimer’s disease. Predominance of A beta 42(43) and association of A beta 40 with cored plaques. Am J Pathol. 1996;148:259–65.

    CAS  PubMed  PubMed Central  Google Scholar 

  6. Joachim CL, Morris JH, Selkoe DJ. Diffuse senile plaques occur commonly in the cerebellum in Alzheimer’s disease. Am J Pathol. 1989;135:309–19.

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Dickson DW, et al. Ubiquitin immunoelectron microscopy of dystrophic neurites in cerebellar senile plaques of Alzheimer’s disease. Acta Neuropathol. 1990;79:486–93.

    Article  CAS  Google Scholar 

  8. Lenders MB, et al. Dystrophic neuropeptidergic neurites in senile plaques of Alzheimer’s disease precede formation of paired helical filaments. Acta Neurol Belg. 1989;89:279–85.

    CAS  PubMed  Google Scholar 

  9. Onorato M, et al. Alteration of neuritic cytoarchitecture in Alzheimer disease. Prog Clin Biol Res. 1989;317:781–9.

    CAS  PubMed  Google Scholar 

  10. Dickson TC, King CE, McCormack GH, Vickers JC. Neurochemical diversity of dystrophic neurites in the early and late stages of Alzheimer’s disease. Exp Neurol. 1999;156:100–10. S0014-4886(98)97010-8 [pii] https://doi.org/10.1006/exnr.1998.7010

    Article  CAS  Google Scholar 

  11. Masliah E, et al. An antibody against phosphorylated neurofilaments identifies a subset of damaged association axons in Alzheimer’s disease. Am J Pathol. 1993;142:871–82.

    CAS  PubMed  PubMed Central  Google Scholar 

  12. Vickers JC, et al. Dystrophic neurite formation associated with age-related beta amyloid deposition in the neocortex: clues to the genesis of neurofibrillary pathology. Exp Neurol. 1996;141:1–11. S0014-4886(96)90133-8 [pii] https://doi.org/10.1006/exnr.1996.0133

    Article  CAS  Google Scholar 

  13. Hu X, et al. Transgenic mice overexpressing reticulon 3 develop neuritic abnormalities. EMBO J. 2007;26:2755–67. doi:7601707 [pii] https://doi.org/10.1038/sj.emboj.7601707

    Article  CAS  Google Scholar 

  14. Sharoar MG, et al. Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer’s disease. Mol Psychiatry. 2015. https://doi.org/10.1038/mp.2015.181 mp2015181 [pii].

    Article  Google Scholar 

  15. Friedman JR, Webster BM, Mastronarde DN, Verhey KJ, Voeltz GK. ER sliding dynamics and ER-mitochondrial contacts occur on acetylated microtubules. J Cell Biol. 2010;190:363–75. https://doi.org/10.1083/jcb.200911024 jcb.200911024 [pii]

    Article  CAS  Google Scholar 

  16. Noda T. Autophagy in the context of the cellular membrane-trafficking system: the enigma of Atg9 vesicles. Biochem Soc Trans. 2017;45:1323–31. https://doi.org/10.1042/BST20170128BST20170128 [pii]

    Article  CAS  Google Scholar 

  17. Bordi M, et al. Autophagy flux in CA1 neurons of Alzheimer hippocampus: increased induction overburdens failing lysosomes to propel neuritic dystrophy. Autophagy. 2016;12:2467–83. https://doi.org/10.1080/15548627.2016.1239003

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Lee S, Sato Y, Nixon RA. Lysosomal proteolysis inhibition selectively disrupts axonal transport of degradative organelles and causes an Alzheimer’s-like axonal dystrophy. J Neurosci. 2011;31:7817–30. https://doi.org/10.1073/JNEUROSCI.6412-10.201131/21/7817 [pii]

    Article  CAS  Google Scholar 

  19. Klionsky DJ, et al. A unified nomenclature for yeast autophagy-related genes. Dev Cell. 2003;5:539–45. S1534-5807(03)00296-X [pii]

    Article  CAS  Google Scholar 

  20. Mizushima N. Autophagy: process and function. Genes Dev. 2007;21:2861–73. doi:21/22/2861 [pii] https://doi.org/10.1101/gad.1599207

    Article  CAS  Google Scholar 

  21. Shintani T, Klionsky DJ. Autophagy in health and disease: a double-edged sword. Science. 2004;306:990–5. doi:306/5698/990 [pii] https://doi.org/10.1126/science.1099993

    Article  CAS  Google Scholar 

  22. Klionsky DJ. Autophagy: from phenomenology to molecular understanding in less than a decade. Nat Rev Mol Cell Biol. 2007;8:931–7. doi:nrm2245 [pii] https://doi.org/10.1038/nrm2245

    Article  CAS  Google Scholar 

  23. Sadleir KR, et al. Presynaptic dystrophic neurites surrounding amyloid plaques are sites of microtubule disruption, BACE1 elevation, and increased Abeta generation in Alzheimer’s disease. Acta Neuropathol. 2016;132:235–56. https://doi.org/10.1007/s00401-016-1558-910.1007/s00401-016-1558-9 [pii]

    Article  CAS  Google Scholar 

  24. Tammineni P, Cai Q. Defective retrograde transport impairs autophagic clearance in Alzheimer disease neurons. Autophagy. 2017;13:982–4. https://doi.org/10.1080/15548627.2017.1291114

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Sanchez-Varo R, et al. Abnormal accumulation of autophagic vesicles correlates with axonal and synaptic pathology in young Alzheimer’s mice hippocampus. Acta Neuropathol. 2012;123:53–70. https://doi.org/10.1007/s00401-011-0896-x

    Article  PubMed  Google Scholar 

  26. Gowrishankar S, et al. Massive accumulation of luminal protease-deficient axonal lysosomes at Alzheimer’s disease amyloid plaques. Proc Natl Acad Sci USA. 2015;112:E3699–3708. https://doi.org/10.1073/10.1073/pnas.15103291121510329112 [pii]

    Article  CAS  Google Scholar 

  27. Nixon RA, et al. Extensive involvement of autophagy in Alzheimer disease: an immuno-electron microscopy study. J Neuropathol Exp Neurol. 2005;64:113–22.

    Article  Google Scholar 

  28. Nixon RA. Autophagy, amyloidogenesis and Alzheimer disease. J Cell Sci. 2007;120:4081–91. doi:120/23/4081 [pii] https://doi.org/10.1242/jcs.019265

    Article  CAS  Google Scholar 

  29. He W, et al. Reticulon family members modulate BACE1 activity and amyloid-beta peptide generation. Nat Med. 2004;10:959–65. https://doi.org/10.1038/nm1088nm1088 [pii]

    Article  CAS  Google Scholar 

  30. Shi Q, et al. Impact of RTN3 deficiency on expression of BACE1 and amyloid deposition. J Neurosci. 2014;34:13954–62. https://doi.org/10.1073/JNEUROSCI.1588-14.201434/42/13954 [pii]

    Article  Google Scholar 

  31. Schindelin J, et al. Fiji: an open-source platform for biological-image analysis. Nat Methods. 2012;9:676–82. https://doi.org/10.1038/nmeth.2019nmeth.2019 [pii]

    Article  CAS  Google Scholar 

  32. Fiala JC, Harris KM. Extending unbiased stereology of brain ultrastructure to three-dimensional volumes. J Am Med Inform Assoc. 2001;8:1–16.

    Article  CAS  Google Scholar 

  33. Parzych KR, Klionsky DJ. An overview of autophagy: morphology, mechanism, and regulation. Antioxid Redox Signal. 2014;20:460–73. https://doi.org/10.1089/ars.2013.5371

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Mari M, et al. An Atg9-containing compartment that functions in the early steps of autophagosome biogenesis. J Cell Biol. 2010;190:1005–22. https://doi.org/10.1083/jcb.200912089jcb.200912089 [pii]

    Article  CAS  Google Scholar 

  35. Yamamoto H, et al. Atg9 vesicles are an important membrane source during early steps of autophagosome formation. J Cell Biol. 2012;198:219–33. https://doi.org/10.1083/jcb.201202061jcb.201202061 [pii]

    Article  CAS  Google Scholar 

  36. Karanasios E, et al. Autophagy initiation by ULK complex assembly on ER tubulovesicular regions marked by ATG9 vesicles. Nat Commun. 2016;7:12420. https://doi.org/10.1038/ncomms12420ncomms12420 [pii]

    Article  CAS  Google Scholar 

  37. Jager S, et al. Role for Rab7 in maturation of late autophagic vacuoles. J Cell Sci. 2004;117:4837–48. https://doi.org/10.1242/jcs.01370jcs.01370 [pii]

    Article  Google Scholar 

  38. Borchelt DR, et al. Familial Alzheimer’s disease-linked presenilin 1 variants elevate Abeta1-42/1-40 ratio in vitro and in vivo. Neuron. 1996;17:1005–13. doi:S0896-6273(00)80230-5 [pii]

    Article  CAS  Google Scholar 

  39. Feng Y, Klionsky DJ. Autophagic membrane delivery through ATG9. Cell Res. 2017;27:161–2. https://doi.org/10.1038/cr.2017.4cr20174 [pii]

    Article  CAS  Google Scholar 

  40. Orsi A, et al. Dynamic and transient interactions of Atg9 with autophagosomes, but not membrane integration, are required for autophagy. Mol Biol Cell. 2012;23:1860–73. https://doi.org/10.1091/mbc.E11-09-0746mbc.E11-09-0746 [pii]

    Article  CAS  Google Scholar 

  41. Noda T, et al. Apg9p/Cvt7p is an integral membrane protein required for transport vesicle formation in the Cvt and autophagy pathways. J Cell Biol. 2000;148:465–80.

    Article  CAS  Google Scholar 

  42. Yamada T, et al. Endothelial nitric-oxide synthase antisense (NOS3AS) gene encodes an autophagy-related protein (APG9-like2) highly expressed in trophoblast. J Biol Chem. 2005;280:18283–90. doi:M413957200 [pii] https://doi.org/10.1074/jbc.M413957200

    Article  CAS  Google Scholar 

  43. Reggiori F, Tooze SA. Autophagy regulation through Atg9 traffic. J Cell Biol. 2012;198:151–3. https://doi.org/10.1083/jcb.201206119jcb.201206119 [pii]

    Article  CAS  Google Scholar 

  44. Young AR, et al. Starvation and ULK1-dependent cycling of mammalian Atg9 between the TGN and endosomes. J Cell Sci. 2006;119:3888–3900. doi:jcs.03172 [pii] https://doi.org/10.1242/jcs.03172

    Article  CAS  Google Scholar 

  45. Imai K, et al. Atg9A trafficking through the recycling endosomes is required for autophagosome formation. J Cell Sci. 2016;129:3781–91. jcs.196196 [pii] https://doi.org/10.1242/jcs.196196

    Article  CAS  Google Scholar 

  46. Rao A, Simmons D, Sorkin A. Differential subcellular distribution of endosomal compartments and the dopamine transporter in dopaminergic neurons. Mol Cell Neurosci. 2011;46:148–58. https://doi.org/10.1016/j.mcn.2010.08.016S1044-7431(10)00207-1 [pii]

    Article  CAS  Google Scholar 

  47. Wang ZX, Tan L, Yu JT. Axonal transport defects in Alzheimer’s disease. Mol Neurobiol. 2015;51:1309–21. https://doi.org/10.1007/s12035-014-8810-x

    Article  CAS  PubMed  Google Scholar 

  48. Morfini GA, et al. Axonal transport defects in neurodegenerative diseases. J Neurosci. 2009;29:12776–86. https://doi.org/10.1073/JNEUROSCI.3463-09.200929/41/12776 [pii]

    Article  CAS  Google Scholar 

  49. Roy S, Zhang B, Lee VM, Trojanowski JQ. Axonal transport defects: a common theme in neurodegenerative diseases. Acta Neuropathol. 2005;109:5–13. https://doi.org/10.1007/s00401-004-0952-x

    Article  PubMed  Google Scholar 

  50. Reggiori F, et al. Early stages of the secretory pathway, but not endosomes, are required for Cvt vesicle and autophagosome assembly in Saccharomyces cerevisiae. Mol Biol Cell. 2004;15:2189–204. https://doi.org/10.1091/mbc.e03-07-0479E03-07-0479 [pii]

    Article  CAS  Google Scholar 

  51. Zoppino FC, Militello RD, Slavin I, Alvarez C, Colombo MI. Autophagosome formation depends on the small GTPase Rab1 and functional ER exit sites. Traffic. 2010;11:1246–61. https://doi.org/10.1111/j.1600-0854.2010.01086.xTRA1086 [pii]

    Article  CAS  Google Scholar 

  52. Bader CA, Shandala T, Ng YS, Johnson IR, Brooks DA. Atg9 is required for intraluminal vesicles in amphisomes and autolysosomes. Biol Open. 2015;4:1345–55. https://doi.org/10.1242/bio.013979bio.013979 [pii]

    Article  CAS  Google Scholar 

  53. Yamaguchi J, et al. Atg9a deficiency causes axon-specific lesions including neuronal circuit dysgenesis. Autophagy. 2018;14:764–77. https://doi.org/10.1080/15548627.2017.1314897

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank Dr. Graham Kidd (Cleveland Clinic Lerner Research Institute) for capturing 3D EM images and Dr. Maya Yankova (UConn Health EM core facility) for immuno-EM. This work is partially supported by National Institute of Health (NIH) grants to RY (AG025493, NS074256, RFAG058261, and AG046929), and an award from the Alzheimer’s Association to MGS (AARF-17–504724).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Riqiang Yan.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sharoar, M.G., Hu, X., Ma, XM. et al. Sequential formation of different layers of dystrophic neurites in Alzheimer’s brains. Mol Psychiatry 24, 1369–1382 (2019). https://doi.org/10.1038/s41380-019-0396-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41380-019-0396-2

This article is cited by

Search

Quick links