[go: up one dir, main page]
Jump to content

Tauopathy

From Wikipedia, the free encyclopedia
Tauopathy
Diagram of a normal microtubule and one affected by tauopathy
SpecialtyNeurology Edit this on Wikidata

Tauopathies are a class of neurodegenerative diseases characterized by the aggregation of abnormal tau protein.[1] Hyperphosphorylation of tau proteins causes them to dissociate from microtubules and form insoluble aggregates called neurofibrillary tangles.[2] Various neuropathologic phenotypes have been described based on the anatomical regions and cell types involved as well as the unique tau isoforms making up these deposits. The designation 'primary tauopathy' is assigned to disorders where the predominant feature is the deposition of tau protein. Alternatively, diseases exhibiting tau pathologies attributed to different and varied underlying causes are termed 'secondary tauopathies'. Some neuropathologic phenotypes involving tau protein are Alzheimer's disease, frontotemporal dementia, progressive supranuclear palsy, and corticobasal degeneration.[1]

Tau protein

[edit]

Tau protein, also called tubulin associated unit or microtubule-associated protein tau (MAPT), is a microtubule-associated protein that promotes polymerization and stabilization into microtubules by binding to tubulin. Variants of Tau isoforms, spanning from 352 to 441 amino acids, arise through the alternative splicing of exons 2,3 and 10 within the MAPT gene. The six isoforms are differentiated by the inclusion and exclusion of inserts of either 29 or 58 amino acids in the N-terminus domain. Furthermore, the isoforms are categorized based on the presence of either three (3R tau isoforms) or four (4R tau isoforms) tandem repeat sequences each consisting of 31 or 32 amino acids.[3]

Biomarkers

[edit]

Neuroimaging

[edit]

Positron emission tomography (PET) is one type of biomarker capable of identifying elevated levels of tau in patients with Alzheimer's disease. PET is a great tool that can supplement information such as regions with higher neuropathologic burden than others. But it needs to be eligible, and have more positive outcomes than negative, such as exposure to radioactivity.[4]

Biofluid

[edit]

The analysis of cerebrospinal fluid (CSF) represents a potential avenue for the development of biomarkers in tauopathies. Substantial data on CSF biomarkers is available for Alzheimer's disease (AD), focusing on measures related to total and phosphorylated forms of tau and amyloid-beta (Aβ) protein. Elevated CSF tau and decreased Aβ levels constitute the characteristic CSF signature of AD, allowing differentiation from controls.[5] This signature may also assist in distinguishing atypical forms of AD pathology associated with clinical frontotemporal dementia (FTD) from those with underlying frontotemporal lobar degeneration (FTLD)-Tau pathology.[6]

Alzheimer's disease

[edit]

Alzheimer's disease (AD) is clinically characterized by a progressive decline in memory and cognitive functions, leading to severe dementia. Microscopically, AD is identified by the presence of two types of insoluble fibrous materials: (1) extracellular amyloid (Aβ) protein forming senile plaques and (2) intracellular neurofibrillary lesions (NFL) composed of abnormally and hyperphosphorylated tau protein. While AD is not strictly considered a prototypical tauopathy, as tau pathology coexists with Aβ protein deposition, the 'amyloid cascade hypothesis' posits that Aβ accumulation is the primary factor driving AD pathogenesis.[7][8] Nevertheless, AD neurofibrillary lesions were the first to undergo ultrastructural and biochemical analysis, thus laying the foundation for in-depth studies on tau protein deposition in various tauopathies.[9]

Neuropathologic phenotypes

[edit]

Frontotemporal dementia

[edit]

Frontotemporal dementia is a part of a diverse spectrum of disorders clinically marked by dysfunction in the frontal and temporal lobes, collectively referred to as frontotemporal lobar degeneration (FTLD). The primary histological characteristics include profound neuronal loss, enlarged neurons, and distinctive spherical argyrophilic inclusions known as Pick bodies (PBs). These PBs primarily consist of hyperphosphorylated tau protein, with tau protein presenting as two major bands at 60 and 64 kDa and a variable, minor band at 69 kDa. Filamentous tau deposits in nerve cells are predominantly composed of 3R tau isoforms.[10]

Progressive supranuclear palsy

[edit]

Progressive supranuclear palsy (PSP) is a type of tauopathy, but the cause is not yet discovered. For PSP unusual phosphorylation for tau protein causes vital protein filaments in the nerve cells to destruct, a phenomenon called "neurofibrillary" degeneration. Typical symptoms of PSP would be abnormal speech, balance impairment and overcognitive and memory impairment. As CBD, PSP is also classified as a 4R tauopathy, and because of that PSP will often be selected for trials regarding anti-tau therapeutics.[11][12]

Corticobasal degeneration

[edit]

Corticobasal degeneration (CBD) is an increasingly acknowledged neurodegenerative disorder characterized by both motor and cognitive dysfunction. In affected regions, histological examination reveals pronounced neuronal loss accompanied by spongiosis and gliosis, cortical ballooned cells, and notable intracytoplasmic filamentous tau pathology in both glial and neuronal cells. Biochemically, the distinctive tau profile in CBD cases manifests as a prominent tau doublet at 64 and 68 kDa, which is variably identified. These bands predominantly consist of hyperphosphorylated 4R tau isoforms, leading to the classification of CBD as a 4R tauopathy.[13]

Tau therapeutics

[edit]

Currently, there are no specific treatments for tauopathies. Up till now, attempts have been made to target neurotransmitter disturbances to relieve disease symptoms. For AD a specific treatment is difficult because the pathological changes both early compared to the symptoms showing.[14] Even though there is no current treatment for tauopathies, there are treatments that can relieve symptoms. Speech therapy can be beneficial for aphasia symptoms, symptoms such as depression and apathy frequently engaged with pharmaceuticals. For physical challenges, physical therapy has proven helpful in extending motor function for patients.[15]

Other diseases

[edit]

See also

[edit]

References

[edit]
  1. ^ a b Kovacs, Gabor G. (2018). "Tauopathies". In Gabor G. Kovacs; Irina Alafuzoff (eds.). Handbook of Clinical Neurology, volume 145. Handbook of Clinical Neurology. pp. 355–368. doi:10.1016/B978-0-12-802395-2.00025-0. ISBN 978-0-12-802395-2. PMID 28987182.
  2. ^ Goedert M, Spillantini MG (May 2017). "Propagation of Tau aggregates". Molecular Brain. 10 (1): 18. doi:10.1186/s13041-017-0298-7. PMC 5450399. PMID 28558799.
  3. ^ Goedert, M.; Spillantini, M.G.; Jakes, R.; Rutherford, D.; Crowther, R.A. (October 1989). "Multiple isoforms of human microtubule-associated protein tau: sequences and localization in neurofibrillary tangles of Alzheimer's disease". Neuron. 3 (4): 519–526. doi:10.1016/0896-6273(89)90210-9. PMID 2484340.
  4. ^ Moloney, Christina M.; Labuzan, Sydney A.; Crook, Julia E.; Siddiqui, Habeeba; Castanedes-Casey, Monica; Lachner, Christian; Petersen, Ronald C.; Duara, Ranjan; Graff-Radford, Neill R.; Dickson, Dennis W.; Mielke, Michelle M.; Murray, Melissa E. (March 2023). "Phosphorylated tau sites that are elevated in Alzheimer's disease fluid biomarkers are visualized in early neurofibrillary tangle maturity levels in the post mortem brain". Alzheimer's & Dementia. 19 (3): 1029–1040. doi:10.1002/alz.12749. ISSN 1552-5260. PMC 9895127. PMID 35920592.
  5. ^ Shaw, Leslie M.; Vanderstichele, Hugo; Knapik-Czajka, Malgorzata; Clark, Christopher M.; Aisen, Paul S.; Petersen, Ronald C.; Blennow, Kaj; Soares, Holly; Simon, Adam; Lewczuk, Piotr; Dean, Robert; Siemers, Eric; Potter, William; Lee, Virginia M.-Y.; Trojanowski, John Q. (April 2009). "Cerebrospinal fluid biomarker signature in Alzheimer's disease neuroimaging initiative subjects". Annals of Neurology. 65 (4): 403–413. doi:10.1002/ana.21610. PMC 2696350. PMID 19296504.
  6. ^ Irwin, David J.; McMillan, Corey T.; Toledo, Jon B.; Arnold, Steven E.; Shaw, Leslie M.; Wang, Li-San; Van Deerlin, Vivianna; Lee, Virginia M.-Y.; Trojanowski, John Q.; Grossman, Murray (1 August 2012). "Comparison of Cerebrospinal Fluid Levels of Tau and Aβ 1-42 in Alzheimer Disease and Frontotemporal Degeneration Using 2 Analytical Platforms". Archives of Neurology. 69 (8): 1018–1025. doi:10.1001/archneurol.2012.26. PMC 3528180. PMID 22490326.
  7. ^ Hardy, John; Selkoe, Dennis J. (19 July 2002). "The Amyloid Hypothesis of Alzheimer's Disease: Progress and Problems on the Road to Therapeutics". Science. 297 (5580): 353–356. doi:10.1126/science.1072994. PMID 12130773.
  8. ^ Nussbaum, Robert L.; Ellis, Christopher E. (3 April 2003). "Alzheimer's Disease and Parkinson's Disease". New England Journal of Medicine. 348 (14): 1356–1364. doi:10.1056/NEJM2003ra020003. PMID 12672864.
  9. ^ Tolnay, Markus; Probst, Alphonse (June 2003). "The Neuropathological Spectrum of Neurodegenerative Tauopathies". IUBMB Life. 55 (6): 299–305. doi:10.1080/1521654032000114348. PMID 12938731.
  10. ^ Tolnay, Markus; Probst, Alphonse (June 2003). "The Neuropathological Spectrum of Neurodegenerative Tauopathies". IUBMB Life. 55 (6): 299–305. doi:10.1080/1521654032000114348. PMID 12938731.
  11. ^ Coughlin, David G.; Litvan, Irene (April 2020). "Progressive supranuclear palsy: Advances in diagnosis and management". Parkinsonism & Related Disorders. 73: 105–116. doi:10.1016/j.parkreldis.2020.04.014. PMC 7462164. PMID 32487421.
  12. ^ "Progressive Supranuclear Palsy - Symptoms, Causes, Treatment | NORD". rarediseases.org.
  13. ^ Tolnay, Markus; Probst, Alphonse (June 2003). "The Neuropathological Spectrum of Neurodegenerative Tauopathies". IUBMB Life. 55 (6): 299–305. doi:10.1080/1521654032000114348. PMID 12938731.
  14. ^ Khan, Sahil; Barve, Kalyani H.; Kumar, Maushmi S. (2020). "Recent Advancements in Pathogenesis, Diagnostics, and Treatment of Alzheimer's Disease". Current Neuropharmacology. 18 (11): 1106–1125. doi:10.2174/1570159X18666200528142429. PMC 7709159. PMID 32484110.
  15. ^ Orr, Miranda E.; Sullivan, A. Campbell; Frost, Bess (July 2017). "A Brief Overview of Tauopathy: Causes, Consequences, and Therapeutic Strategies". Trends in Pharmacological Sciences. 38 (7): 637–648. doi:10.1016/j.tips.2017.03.011. PMC 5476494. PMID 28455089.
  16. ^ Santa-Maria I, Haggiagi A, Liu X, Wasserscheid J, Nelson PT, Dewar K, Clark LN, Crary JF (November 2012). "The MAPT H1 haplotype is associated with tangle-predominant dementia". Acta Neuropathologica. 124 (5): 693–704. doi:10.1007/s00401-012-1017-1. PMC 3608475. PMID 22802095.
  17. ^ Jellinger KA, Attems J (February 2007). "Neurofibrillary tangle-predominant dementia: comparison with classical Alzheimer disease". Acta Neuropathologica. 113 (2): 107–17. doi:10.1007/s00401-006-0156-7. PMID 17089134. S2CID 5655388.
  18. ^ McKee AC, Cairns NJ, Dickson DW, Folkerth RD, Keene CD, Litvan I, Perl DP, Stein TD, Vonsattel JP, Stewart W, Tripodis Y, Crary JF, Bieniek KF, Dams-O'Connor K, Alvarez VE, Gordon WA (January 2016). "The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy" (PDF). Acta Neuropathologica. 131 (1): 75–86. doi:10.1007/s00401-015-1515-z. PMC 4698281. PMID 26667418.
  19. ^ Roberts GW (1988). "Immunocytochemistry of neurofibrillary tangles in dementia pugilistica and Alzheimer's disease: evidence for common genesis". Lancet. 2 (8626–8627): 1456–8. doi:10.1016/S0140-6736(88)90934-8. PMID 2904573. S2CID 32662671.
  20. ^ Williams DR, Lees AJ (March 2009). "Progressive supranuclear palsy: clinicopathological concepts and diagnostic challenges". The Lancet. Neurology. 8 (3): 270–9. doi:10.1016/S1474-4422(09)70042-0. PMID 19233037. S2CID 1417930.
  21. ^ Tolnay, Markus; Probst, Alphonse (June 2003). "The Neuropathological Spectrum of Neurodegenerative Tauopathies". IUBMB Life. 55 (6): 299–305. doi:10.1080/1521654032000114348. PMID 12938731.
  22. ^ Selkoe DJ, Podlisny MB (2002). "Deciphering the genetic basis of Alzheimer's disease". Annual Review of Genomics and Human Genetics. 3: 67–99. doi:10.1146/annurev.genom.3.022502.103022. PMID 12142353.
  23. ^ Darwich NF, Phan JM, et al. (2020). "Autosomal dominant VCP hypomorph mutation impairs disaggregation of PHF-tau". Science. 370 (6519): eaay8826. doi:10.1126/science.aay8826. PMC 7818661. PMID 33004675.
  24. ^ Hof PR, Nimchinsky EA, Buée-Scherrer V, Buée L, Nasrallah J, Hottinger AF, Purohit DP, Loerzel AJ, Steele JC, Delacourte A (1994). "Amyotrophic lateral sclerosis/parkinsonism-dementia complex of Guam: quantitative neuropathology, immunohistochemical analysis of neuronal vulnerability, and comparison with related neurodegenerative disorders". Acta Neuropathologica. 88 (5): 397–404. doi:10.1007/BF00389490. PMID 7847067. S2CID 2821768.
  25. ^ Brat DJ, Gearing M, Goldthwaite PT, Wainer BH, Burger PC (June 2001). "Tau-associated neuropathology in ganglion cell tumours increases with patient age but appears unrelated to ApoE genotype". Neuropathology and Applied Neurobiology. 27 (3): 197–205. doi:10.1046/j.1365-2990.2001.00311.x. PMID 11489139. S2CID 36482221.
  26. ^ Halper J, Scheithauer BW, Okazaki H, Laws ER (July 1986). "Meningio-angiomatosis: a report of six cases with special reference to the occurrence of neurofibrillary tangles". Journal of Neuropathology and Experimental Neurology. 45 (4): 426–46. doi:10.1097/00005072-198607000-00005. PMID 3088216. S2CID 663552.
  27. ^ Paula-Barbosa MM, Brito R, Silva CA, Faria R, Cruz C (November 1979). "Neurofibrillary changes in the cerebral cortex of a patient with subacute sclerosing panencephalitis (SSPE)". Acta Neuropathologica. 48 (2): 157–60. doi:10.1007/BF00691159. PMID 506699. S2CID 36105401.
  28. ^ Wisniewski K, Jervis GA, Moretz RC, Wisniewski HM (March 1979). "Alzheimer neurofibrillary tangles in diseases other than senile and presenile dementia". Annals of Neurology. 5 (3): 288–94. doi:10.1002/ana.410050311. PMID 156000. S2CID 25649751.
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Tauopathy&oldid=1253202860"