Walker's early research established that a variety of neurons are involved in the formation of Aβ plaques, one of the pathological hallmarks of Alzheimer's disease.[11][12][13] With Dale Schenk at Athena Neurosciences (later part of Élan Pharmaceuticals), he discovered that antibodies to the Aβ protein can enter the brain from the cerebrospinal fluid and selectively bind to Aβ plaques and cerebral Aβ-amyloid angiopathy (CAA).[14][15] Based on his work with animal models of Alzheimer's disease, Walker has proposed that humans are uniquely vulnerable to Alzheimer's disease.[16][17][18]
Prion-like properties of disease-causing proteins
Since the late 1990s, Walker's research has been directed toward the mechanisms that drive the misfolding and aggregation of the Aβ protein in the living brain. In collaboration with Mathias Jucker at the University of Tübingen, he discovered that the accumulation of Aβ can be initiated in transgenic mouse models by a prion-like mechanism in which 'seeds' of abnormal Aβ precipitate the formation of plaques and CAA.[19][20][6] In 2000, Walker and Harry LeVine introduced the term 'proteopathy' (also known as 'proteinopathy') to describe diseases characterized by the misfolding and aggregation of proteins.[21] This terminology has been applied to a number of neurodegenerative disorders and amyloidoses, including tauopathies such as Pick's disease, synucleinopathies such as Parkinson's disease and Lewy Body Dementia, systemicamyloidoses, and others.[22][23][24]
"Seeds of Dementia". Walker LC and Jucker M (2013). Scientific American 308: 52-57; PMID23627220.
"Mechanisms of protein seeding in neurodegenerative diseases" Walker LC, Diamond MI, Duff KE and Hyman BT (2013). JAMA Neurology 70: 304-310; PMID23599928, PMCID: PMC3665718.
"Self-propagation of pathogenic protein aggregates in neurodegenerative diseases". Jucker M and Walker LC (2013). Nature 501: 45-51; PMID24005412, PMCID: PMC3963807.
"Neurodegenerative diseases: Expanding the prion concept". Walker LC and Jucker M (2015). Annual Review of Neuroscience 38: 87-103; PMID25840008, PMCID: PMC4803040.
"Proteopathic strains and the heterogeneity of neurodegenerative diseases". Walker LC (2016). Annual Review of Genetics 50: 329-346; PMID27893962, PMCID: PMC6690197.
"Propagation and spread of pathogenic protein assemblies in neurodegenerative diseases". Jucker M, Walker LC (2018). Nature Neuroscience 21: 1341-1349; PMID30258241, PMCID: PMC6375686.
Selected research reports
"Augmented senile plaque load in aged female β-amyloid precursor protein transgenic mice". Callahan MJ, Lipinski WJ, Bian F, Durham RA, Pack A and Walker LC (2001). American Journal of Pathology 158: 1173-1177; PMID11238065, PMCID: PMC1850367.
"Exogenous induction of Aβ-amyloidogenesis is governed by intrinsic properties of agent and host". Meyer-Luehmann M, Coomaraswamy J, Bolmont T, Kaeser S, Schaefer C, Kilger E, Neuenschwander A, Abramowski D, Frey P, Jaton AL, Vigouret J, Paganetti P, Walsh DM, Mathews P, Ghiso J, Staufenbiel M, Walker LC and Jucker M (2006). Science 313: 1781-1784; PMID16990547.
"Deficient high-affinity binding of Pittsburgh Compound B in a case of Alzheimer's disease". Rosen RF, Ciliax BJ, Gearing M, Dooyema J, Wingo T, Lah JJ, Ghiso JA, LeVine III H and Walker LC (2010). Acta Neuropathologica 119: 221-233; PMID19690877, PMCID: PMC3045810.
"Exogenous seeding of cerebral β-amyloid deposition in βAPP-transgenic rats". Rosen RF, Fritz JJ, Dooyema J, Cintron AF, Hamaguchi T, Lah JJ, LeVine III H, Jucker M and Walker LC (2012). Journal of Neurochemistry 120: 660-666; PMID22017494, PMCID: PMC3293176.
"Amyloid polymorphisms constitute distinct clouds of conformational variants in different etiological subtypes of Alzheimer's disease". Rasmussen J, Mahler J, Beschorner N, Kaeser SA, Häsler LM, Baumann F, Nyström S, Portelius E, Blennow K, Lashley T, Fox NC, Sepulveda-Falla D, Glatzel M, Oblak AL, Ghetti B, Nilsson KPR, Hammarström P, Staufenbiel M, Walker LC and Jucker M (2017). Proceedings of the National Academy of Sciences USA 114: 13018-13023; PMID29158413, PMCID: PMC5724274.
"The neurobiology of aging in nonhuman primates". Walker LC and Cork LC (1999). In: Alzheimer Disease (ISBN0781715032), RD Terry, R Katzman, KL Bick and SS Sisodia, Eds., Lippincott Williams and Wilkins, Philadelphia, PA, pp 233-243.
"Pathogenic protein strains as diagnostic and therapeutic targets in Alzheimer's disease". Walker LC, Rosen RF and LeVine III H (2012). In: Alzheimer's Disease: Targets for New Clinical Diagnostic and Therapeutic Strategies (ISBN978-1-4398-2708-6), R Wegrzyn and AS Rudolph, Eds., CRC Press, Boca Raton, FL, pp 231-247.
"The prion-like properties of amyloid-β assemblies: Implications for Alzheimer's disease". Walker LC, Schelle J and Jucker M (2017). In: Prion Diseases (ISBN978-1-621820-10-9), SB Prusiner, Ed., Cold Spring Harbor Laboratory Press, pp 175-188.
"Prion-like protein seeding and the pathobiology of Alzheimer's disease". Walker LC (2018). In: Protein Folding Disorders in the Central Nervous System (ISBN978-981-3222-95-3), J. Ghiso and A. Rostagno, Eds., World Scientific Publishing Company, pp 57-82.
^Patrella, C; Grazia Di Certo, M; Barbato, C; Gabanella, F; Ralli, M; Greco, A; Possenti, R; Severini, C (2019). "Neuropeptides in Alzheimer's Disease: An Update". Current Alzheimer Research. 16 (6): 544–558. doi:10.2174/1567205016666190503152555. PMID31456515. S2CID201656098.
^Hof, Patrick R. (1997). "Morphology and Neurochemical Characteristics of the Vulnerable Neurons in Brain Aging and Alzheimer's Disease". European Neurology. 37 (2): 71–81. doi:10.1159/000117414. ISSN1750-1326. PMID9058061.
^Knowles, TP; Vendruscolo, M; Dobson, CM (2014). "The amyloid state and its association with protein misfolding diseases". Nature Reviews Molecular Cell Biology. 15 (6): 384–396. doi:10.1038/nrm3810. PMID24854788. S2CID46357173.