Disease-specific Protein Research Articles

Potential Role of Natural Polyphenols against Protein Aggregation Toxicity: In Vitro, In Vivo, and Clinical Studies.

One of the main features of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease is the amyloidogenic behavior of disease-specific proteins including amyloid β, tau, α-synuclein, and mutant Huntingtin which participate in the formation, accumulation, and deposition of toxic misfolded aggregates. Consequently, these proteins not only associated with the progress of their respective neurodegenerative pathologies but also qualify as disease-specific biomarkers. The aim of using natural polyphenols is to target amyloid-dependent proteopathies by decreasing free radical damage and inhibiting and dissolving amyloid fibrils. We explore the effectiveness of the polyphenols epigallocatechin-3-gallate, oleuropein aglycone, and quercetin on their ability to inhibit aggregation of amyloid β, tau, and α-synuclein and mitigate other pathological features for Alzheimer's disease and Parkinson's disease. The analysis was carried from in vitro and cell line studies to animal models and clinical trials. This Review describes the use of phytochemical compounds as prophylactic agents for Alzheimer's disease, Parkinson's disease, and other proteopathies.

Huntingtin Aggregates in the Olfactory Bulb in Huntington's Disease.

Olfactory deficits are an early and prevalent non-motor symptom of Huntington’s disease (HD). In other neurodegenerative diseases where olfactory deficits occur, such as Alzheimer’s disease and Parkinson’s disease, pathological protein aggregates (tau, β-amyloid, α-synuclein) accumulate in the anterior olfactory nucleus (AON) of the olfactory bulb (OFB). Therefore, in this study we determined whether aggregates are also present in HD OFBs; 13 HD and five normal human OFBs were stained for mutant huntingtin (mHtt), tau, β-amyloid, TDP-43, and α-synuclein. Our results show that mHtt aggregates detected with 1F8 antibody are present within all HD OFBs, and mHtt aggregate load in the OFB does not correlate with Vonsattel grading scores. The majority of the aggregates were located in the AON and in similar abundance in each anatomical segment of the AON. No mHtt aggregates were found in controls; 31% of HD cases also contained tau neurofibrillary tangles within the AON. This work demonstrates HD pathology in the OFB and indicates that disease-specific protein aggregation in the AON is a common feature of neurodegenerative diseases that show olfactory deficits.

Streaming-enhanced, chip-based biosensor with acoustically active, biomarker-functionalized micropillars: A case study of thrombin detection

Enzyme-linked immunosorbent assay is a widely used analytical technique for detecting and quantifying disease-specific protein biomarkers. Despite recent progresses in disease-specific protein biomarkers detection with microfluidic chips, many devices still suffer from the limited mass transport of target molecules, and consequently low detection efficiency or long incubation time. In this work, we present a novel strategy to significantly enhance the sensing efficiency of a chip-based biosensor by exploiting micro-streaming in an acoustofluidic device, which boosts intermolecular interactions and a hybridization chain reaction to increase the fluorescent signals. This device was made of a microfluidic chip that contains an array of PDMS micropillars in a ship-shaped microchannel. And the inner surface of the channel was functionalized with capture aptamers that bind with thrombin, chosen as a model target molecule. An ultrasonic transducer underneath the chip operating at 150 kHz generates circular micro-streaming flows around the pillars that significantly improves the binding efficiency of thrombin with capture aptamers by 1) increasing the retention time and 2) enhancing mass transport via local convection versus diffusion. The effects of ultrasound parameters, such as operating frequencies and voltages, on the distribution and magnitude of flows were optimized to obtain a better performance of the sensor chip. Under the optimized conditions, the detection limit was increased by one order of magnitude. Although this work has focused on the detection of thrombin as a model molecule, this streaming-enhanced, microstructure-based sensing strategy can be applied to detect a wide range of molecules or even cells.

Sensitive Signal Amplifying a Diagnostic Biochip Based on a Biomimetic Periodic Nanostructure for Detecting Cancer Exosomes.

Tumor-derived exosomes are emerging noninvasive biomarker reservoirs that reflect biological information from their parental cells, especially specific markers, including proteins, DNA fragments and RNAs. Recently, analytical methods of tumor-derived exosomes have been increasing growth. However, developing a convenient signal amplification technique to improve the sensitivity of exosomes detection still remains a challenge. Herein, an ultrasensitive and specific exosomes diagnostic biochip is constructed and further applied to circulating tumor exosomes detection in serum. Using an exosomes diagnostic biochip, signal amplification is achieved by combining the advantages of quantum dots with the biomimetic periodic nanostructure of photonic crystals. Glypican-1 (GPC1), a membrane-anchored protein that is overexpressed in exosomes from pancreatic cancer, is detected using nanosized molecular beacons with high luminescence efficiency; then the signal is amplified through photonic crystals. Moreover, the method allows the quantitative analysis of various disease-specific surface proteins on exosomes. We believe that this exosomes diagnostic biochip is likely to have potential as an effective bioassay, which may be helpful for quantification of disease-specific exosomes in clinical use.

Abstract PR12: Detection of EV-based signatures in prostate cancer using microflow cytometry and machine learning

Abstract Microflow cytometry (µFCM) has recently emerged as a viable technology to enumerate and quantify individual EVs from complex biologic fluids. This method is a promising alternative to biopsy collection because it is highly sensitive and allows for longitudinal assessment of patients. EVs are highly abundant and analysis by µFCM allows for sophisticated multiparametric analysis of organ-specific, disease-specific, and outcome-specific proteins, genes, or metabolites. Detection of EVs with µFCM requires very little sample yet provides exceptional specificity and sensitivity for low abundance events. By combining µFCM analysis of EVs with advanced machine learning approaches, we have developed a platform technology called ClarityDX to generate EV fingerprints that significantly improve the diagnosis of diseases such as prostate cancer using a few drops of blood. Here I will discuss the development and clinical validation of new blood tests for prostate cancer that utilize the ClarityDX platform. Prostate cancer is the most commonly diagnosed cancer and the third leading cause of cancer deaths in men. Screening has enabled the early detection of many latent prostate cancers, and it is estimated that up to 50% of new prostate cancer diagnoses detect a tumor that was unlikely to surface clinically in the absence of PSA screening. In the majority of cases, the treatment of indolent cancer causes a patient more harm than good. Consequently, there is an urgent need for a noninvasive test to detect clinically significant prostate cancer, or perhaps even more importantly, to detect metastatic disease. ClarityDX Prostate is a µFCM-based test to predict clinically significant prostate cancer prior to a prostate biopsy. A prospective clinical validation of ClarityDX Prostate was performed in a cohort of 377 Albertan men. The overall average AUC for ClarityDX Prostate in this population was 0.83, which was significantly higher than PSA alone. While PSA alone provided only 17% specificity for aggressive prostate cancer at a 95% sensitivity, ClarityDX Prostate was 56% specific for aggressive prostate cancer. We are now conducting a pivotal clinical validation study, in which up to 2,800 men will be enrolled to assess the performance of ClarityDX Prostate in a “real-world” clinical environment. Overall, we have established a robust µFCM EV platform for the development of novel and clinically viable diagnostic tests. Incorporating ClarityDX Prostate into routine prostate cancer screening could reduce the number of unnecessary biopsies by up to 40%. This abstract is also being presented as Poster B57. Citation Format: John D. Lewis, Robert J. Paproski, Desmond B. Pink, Catalina Vasquez, Eric Hyndman, Adrian Fairey, APCaRI. Detection of EV-based signatures in prostate cancer using microflow cytometry and machine learning [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr PR12.

Clinical Proteomics Profiling for Biomarker Identification Among Patients Suffering With Indian Post Kala Azar Dermal Leishmaniasis.

Background: Post Kala Azar Dermal Leishmaniasis (PKDL) is a non-fatal dermal sequel of Visceral Leishmaniasis (VL), affecting individuals worldwide. Available diagnostic tools lack sensitivity and specificity toward identifying macular (MAC) PKDL patients, due to low parasite load in patients' sample. Confirmatory test like punch biopsy are invasive and painful. Considering the rural nature of this disease and the prevailing situation of diagnostic scenario, PKDL patients mostly remains unattended from receiving proper medical care. They in turn act as “mobile parasite reservoir,” responsible for VL transmission among healthy individuals (HI). This study aims to identify PKDL disease specific glycated protein biomarkers, utilizing the powerful LC-MS/MS technology, which is the tool of choice to efficiently identify and quantify disease specific protein biomarkers. These identified PKDL disease specific novel glycoproteins could be developed in future as immunochromatographic based assay for efficient case detection.Methodology: Previously our lab had identified importance of glycated (Circulating Immune Complexes) CICs, among PKDL patients. This study aims to further characterize disease specific glycated protein biomarkers, among MAC PKDL patients for both diagnostic and prognostic evaluation of the disease. LC-MS/MS based comparative spectral count analysis of MAC PKDL to polymorphic (POLY) PKDL, HI, and Cured (CR) individuals were performed. Proteins level alterations among all study groups were confirmed by Western blot and enzyme-linked immunosorbant Assay (ELISA).Results: Among MAC PKDL patients 43, 60, 90 proteins were altered compared to POLY PKDL, HI, and CR groups, respectively. Filtering for the most significant proteins, Plasminogen (PLG) and Vitronectin (VTN) were identified which promisingly identified MAC PKDL cases. Active surveillance results from endemic districts of West Bengal revealed drastic rise of MAC PKDL cases, alarming the urgency for field adaptive efficient biomarker.Conclusion: This current study aims to establish PLG and VTN as novel diagnostic and prognostic protein biomarker for MAC and POLY PKDL cases management.

Traffic signaling: new functions of huntingtin and axonal transport in neurological disease.

Over the past twenty years there have been numerous advances in our understanding of Huntington's disease (HD) and other neurodegenerative proteopathies such as Alzheimer's disease and Parkinson's disease. In each case, disease-specific proteins are expressed and accumulate; what has been less clear is precisely what problems are caused by the accumulation. Recently we have begun to appreciate that increased protein levels or changes in the ratios of different isoforms affect the movement of molecules along the axon, thereby disrupting neuronal function. Huntingtin, the protein involved in HD, plays a special role in axonal transport, and very recent studies have found that its activity - and the movement of its cargoes - is altered not only in HD but in other neurological diseases. Here, we contextualize these studies and consider how modulating huntingtin activity could provide new avenues to therapy.

Development of a platform for screening patient-derived CD8+ T cell responses against autoantigens

Abstract Cytotoxic CD8+ T cells outnumber CD4+ T cells within multiple sclerosis (MS) lesions, yet the pathogenic role for these cells and the relevant target antigen(s) involved in neuropathology remain unknown. We predict that a subset of lesion-infiltrating CD8+ T cells are specific for neuronal antigens and contribute to axon or neuron injury, thereby driving disease progression and accumulation of disability. To test this, we are developing protocols to measure MS patient-derived T cell reactivity against neuronal and control antigens. Peripheral blood mononuclear cells (PBMCs) isolated from whole blood were incubated with GM-CSF and IL-4 to selectively expand dendritic cells (DCs) or with IL-7 to promote survival and maintenance of T cells. After resting, patient T cells were combined 1:1 with autologous DCs in the presence of vaccine antigens or peptides derived from common pathogens. We tested responses against a pool of cytomegalovirus, Epstein Barr virus, and influenza peptides (CEF) and against mumps viral protein extract. We also tested responses in T cells derived from patients with autoimmune neurological disorders following incubation with autologous DCs and disease-specific proteins. Activation profiles were assessed using CD69, CD44, and LFA-1 by conventional flow cytometry. Cellular responses were also assessed using mass cytometry (cytometry by time of flight; CyTOF). Our next steps include testing MS patient-derived T cell responses against neuronal and axonal protein libraries, with the goal of identifying potential autoantigens that underlie disease progression.

Targeting Inflammation, PHA-767491 Shows a Broad Spectrum in Protein Aggregation Diseases

Many protein aggregation diseases (PAD) affect the nervous system. Deposits of aggregated disease-specific proteins are found within or around the neuronal cells of neurodegenerative diseases. Although the main protein component is disease-specific, oligomeric aggregates are presumed to be the key agents causing the neurotoxicity. Evidence has shown that protein aggregates cause a chronic inflammatory reaction in the brain, resulting in neurodegeneration. Therefore, strategies targeting anti-inflammation could be beneficial to the therapeutics of PAD. PHA-767491 was originally identified as an inhibitor of CDC7/CDK9 and was found to reduce TDP-43 phosphorylation and prevent neurodegeneration in TDP-43 transgenic animals. We recently identified PHA-767491 as a GSK-3β inhibitor. In this study, we established mouse hippocampal primary culture with tau-hyperphosphorylation through the activation of GSK-3β using Wortmannin and GF109203X. We found that PHA-767491 significantly improved the neurite outgrowth of hippocampal primary neurons against the neurotoxicity induced by GSK-3β. We further showed that PHA-767491 had neuroprotective ability in hippocampal primary culture under oligomeric Aβ treatment. In addition, PHA-767491 attenuated the neuroinflammation in mouse cerebellar slice culture with human TBP-109Q agitation. Further study of SCA17 transgenic mice carrying human TBP-109Q showed that PHA-767491 ameliorated the gait ataxia and the inflammatory response both centrally and peripherally. Our findings suggest that PHA-767491 has a broad spectrum of activity in the treatment of different PAD and that this activity could be based on the anti-inflammation mechanism.

The disease-specific proteins in striatum of the mouse models of Parkinson's disease induced by rotenone and MPTP

The disease-specific proteins in striatum of the mouse models of Parkinson's disease induced by rotenone and MPTP

The disease-specific proteins in striatum of the mouse models of Parkinson's disease induced by rotenone and MPTP

The disease-specific proteins in striatum of the mouse models of Parkinson's disease induced by rotenone and MPTP

The role of prion strain diversity in the development of successful therapeutic treatments.

Prions are a self-propagating misfolded conformation of a cellular protein. Prions are found in several eukaryotic organisms with mammalian prion diseases encompassing a wide range of disorders. The first recognized prion disease, the transmissible spongiform encephalopathies (TSEs), affect several species including humans. Alzheimer's disease, synucleinopathies, and tauopathies share a similar mechanism of self-propagation of the prion form of the disease-specific protein reminiscent of the infection process of TSEs. Strain diversity in prion disease is characterized by differences in the phenotype of disease that is hypothesized to be encoded by strain-specific conformations of the prion form of the disease-specific protein. Prion therapeutics that target the prion form of the disease-specific protein can lead to the emergence of drug-resistant strains of prions, consistent with the hypothesis that prion strains exist as a dynamic mixture of a dominant strain in combination with minor substrains. To overcome this obstacle, therapies that reduce or eliminate the template of conversion are efficacious, may reverse neuropathology, and do not result in the emergence of drug resistance. Recent advancements in preclinical diagnosis of prion infection may allow for a combinational approach that treats the prion form and the precursor protein to effectively treat prion diseases.

Correction: Disease-specific protein corona sensor arrays may have disease detection capacity

Correction for ‘Disease-specific protein corona sensor arrays may have disease detection capacity’ by Giulio Caracciolo et al., Nanoscale Horiz., 2019, 4, 1063–1076.

Expression and functions of cellular prion proteins in immunocytes.

Prion diseases are fatal neurodegenerative processes caused by the accumulation of the pathological prion protein, PrPSc . While pathological lesions are limited to the central nervous system (CNS), disease-specific proteins accumulate and replicate in secondary lymphoid organs prior to neuroinvasion, and their replication there depends on the abundance of cellular prion protein (PrPC ). PrPC is expressed in both central and peripheral lymphoid tissues, and up- or downregulates innate and adaptive immune responses. In addition to prion diseases, PrPC is also immunologically involved in other neurological disorders and infectious diseases, including Alzheimer's disease and human immunodeficiency virus infection. Herein, we summarize the expression and functions of PrPC in various immunocytes, as well as its immunological and pathological roles in neurodegeneration and infection.

Targeted Multiple Reaction Monitoring Analysis of CSF Identifies UCHL1 and GPNMB as Candidate Biomarkers for ALS

The neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD) share some common molecular deficits including disruption of protein homeostasis leading to disease-specific protein aggregation. While insoluble protein aggregates are the defining pathological confirmation of diagnosis, patient stratification based on early molecular etiologies may identify distinct subgroups within a clinical diagnosis that would respond differently in therapeutic development programs. We are developing targeted multiple reaction monitoring (MRM) mass spectrometry methods to rigorously quantify CSF proteins from known disease genes involved in lysosomal, ubiquitin-proteasomal, and autophagy pathways. Analysis of CSF from 21 PD, 21 ALS, and 25 control patients, rigorously matched for gender, age, and age of sample, revealed significant changes in peptide levels between PD, ALS, and control. In patients with PD, levels of two peptides for chromogranin B (CHGB, secretogranin 1) were significantly reduced. In CSF of patients with ALS, levels of two peptides from ubiquitin carboxy-terminal hydrolase like protein 1 (UCHL1) and one peptide each for glycoprotein non-metastatic melanoma protein B (GPNMB) and cathepsin D (CTSD) were all increased. Analysis of patients with ALS separated into two groups based on length of survival after CSF sampling revealed that the increases in GPNMB and UCHL1 were specific for short-lived ALS patients. While analysis of additional cohorts is required to validate these candidate biomarkers, this study suggests methods for stratification of ALS patients for clinical trials and identifies targets for drug efficacy measurements during therapeutic development.

The Propagation Hypothesis of Prion-like Protein Agregates in Neurodegenerative Diseases

The most common neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, are known to be protein-misfolding diseases, and characterized by the presence of disease-specific protein aggregates in neuronal and glial cells. Recently, the propagation hypothesis of prion-like protein inclusions in neurodegenerative diseases has been proposed. Many studies have shown that aggregation-prone proteins such as tau, alpha-synuclein and TDP-43 can form aggregates in a seed-dependent and self-templating prion-like manner, and these aggregates can be transferred intercellularly to neighboring cells and seeded for further aggregation. Propagation of aggregated proteins in these diseases may therefore occur through mechanisms similar to those that underlie prion pathogenesis. If this hypothesis is verified in vivo, it will suggest new therapeutic strategies to block the propagation of aggregated proteins throughout the brain.

Proteins and microRNAs are differentially expressed in tear fluid from patients with Alzheimer\u2019s disease

Alzheimer’s disease (AD) is characterized by a progressive loss of neurons and cognitive functions. Therefore, early diagnosis of AD is critical. The development of practical and non-invasive diagnostic tests for AD remains, however, an unmet need. In the present proof-of-concept study we investigated tear fluid as a novel source of disease-specific protein and microRNA-based biomarkers for AD development using samples from patients with mild cognitive impairment (MCI) and AD. Tear protein content was evaluated via liquid chromatography-mass spectrometry and microRNA content was profiled using a genome-wide high-throughput PCR-based platform. These complementary approaches identified enrichment of specific proteins and microRNAs in tear fluid of AD patients. In particular, we identified elongation initiation factor 4E (eIF4E) as a unique protein present only in AD samples. Total microRNA abundance was found to be higher in tears from AD patients. Among individual microRNAs, microRNA-200b-5p was identified as a potential biomarker for AD with elevated levels present in AD tear fluid samples compared to controls. Our study suggests that tears may be a useful novel source of biomarkers for AD and that the identification and verification of biomarkers within tears may allow for the development of a non-invasive and cost-effective diagnostic test for AD.

Effect of Cell Age on Uptake and Toxicity of Nanoparticles: The Overlooked Factor at the Nanobio Interface.

Clinical translation of nanotechnologies has limited success, at least in part, due to the existence of several overlooked factors on the nature of the nanosystem (e.g., physicochemical properties of nanoparticles), nanobio interfaces (e.g., protein corona composition), and the cellular characteristics (e.g., cell type). In the past decade, several ignored factors including personalized and disease-specific protein corona (a layer of formed biomolecules at the surface of nanoparticles upon their entrance into a biological fluid), incubating temperature, local temperature gradient, cell shape, and cell sex has been introduced. Here, it was hypothesized and validated cell age as another overlooked factor in the field of nanomedicine. To test our hypothesis, cellular toxicity and uptake profiles of our model nanoparticles (i.e., PEGylated quantum dots, QDs) were probed in young and senescent cells (i.e., IMR90 fibroblast cells from human fetal lung and CCD841CoN epithelial cells from human fetal colon) and the outcomes revealed substantial dependency of cell-nanoparticles interactions to the cell age. For example, it was observed that the PEGylated QDs were acutely toxic to senescent IMR90 and CCD841CoN cells, leading to lysosomal membrane permeabilization which caused cell necrosis; in contrast, the young cells were resilient to the exact same amount of QDs and the same incubation time. It was also found that the formation of protein corona could delay the QDs' toxicity on senescent cells. These findings suggest that the cellular aging process have a capacity to cause deteriorative effects on their organelles and normal functions. The outcomes of this study suggest the proof-of-concept that cell age may have critical role in biosystem responses to nanoparticle technologies. Therefore, the effect of cell age should be carefully considered on the nanobio interactions and the information about cellular age (e.g., passage number and age of the cell donor) should be included in the nanomedicine papers to facilitate clinical translation of nanotechnologies and to help scientists to better design and produce safe and efficient diagnostic/therapeutic age-specific nanoparticles.

High-efficiency CRISPR induction of t(9;11) chromosomal translocations and acute leukemias in human blood stem cells

AbstractChromosomal rearrangements involving the mixed lineage leukemia (MLL) gene, also known as KMT2A, are often observed in human leukemias and are generally associated with a poor prognosis. To model these leukemias, we applied clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing to induce MLL chromosomal rearrangements in human hematopoietic stem and progenitor cells purified from umbilical cord blood. Electroporation of ribonucleoprotein complexes containing chemically modified synthetic single guide RNAs and purified Cas9 protein induced translocations between chromosomes 9 and 11 [t(9;11)] at an efficiency >1%. Transplantation of gene-edited cells into immune-compromised mice rapidly induced acute leukemias of different lineages and often with multiclonal origins dictated by the duration of in vitro culture prior to transplantation. Breakpoint junction sequences served as biomarkers to monitor clonal selection and progression in culture and in vivo. High-dimensional cell surface and intracellular protein analysis by mass cytometry (CyTOF) revealed that gene-edited leukemias recapitulated disease-specific protein expression observed in human patients and showed that MLL-rearranged (MLLr) mixed phenotype acute leukemias (MPALs) were more similar to acute myeloid leukemias (AMLs) than to acute lymphoblastic leukemias (ALLs). Therefore, highly efficient generation of MLL chromosomal translocations in primary human blood stem cells using CRISPR/Cas9 reliably models human acute MLLr leukemia and provides an experimental platform for basic and translational studies of leukemia biology and therapeutics.

Evidence of corticofugal tau spreading in patients with frontotemporal dementia.

Common neurodegenerative diseases feature progressive accumulation of disease-specific protein aggregates in selectively vulnerable brain regions. Increasing experimental evidence suggests that misfolded disease proteins exhibit prion-like properties, including the ability to seed corruptive templating and self-propagation along axons. Direct evidence for transneuronal spread in patients, however, remains limited. To test predictions made by the transneuronal spread hypothesis in human tissues, we asked whether tau deposition within axons of the corticospinal and corticopontine pathways can be predicted based on clinical syndromes and cortical atrophy patterns seen in frontotemporal lobar degeneration (FTLD). Sixteen patients with Pick's disease, 21 with corticobasal degeneration, and 3 with FTLD-MAPT were included, spanning a range of clinical syndromes across the frontotemporal dementia (FTD) spectrum. Cortical involvement was measured using a neurodegeneration score, a tau score, and a composite score based on semiquantitative ratings and complemented by an MRI-based cortical atrophy W-map based on antemortem imaging. Midbrain cerebral peduncle and pontine base descending fibers were divided into three subregions, representing prefrontopontine, corticospinal, and parieto-temporo-occipital fiber pathways. Tau area fraction was calculated in each subregion and related to clinical syndrome and cortical measures. Within each clinical syndrome, there were predicted relationships between cortical atrophy patterns and axonal tau deposition in midbrain cerebral peduncle and pontine base. Between syndromes, contrasting and predictable patterns of brainstem axonal tau deposition emerged, with, for example, greater tau in prefrontopontine fibers in behavioral variant FTD and in corticospinal fibers in corticobasal syndrome. Finally, semiquantitative and quantitative cortical degeneration scores predicted brainstem axonal tau deposition based on anatomical principles. Taken together, these findings provide important human evidence in support of axonal tau spreading in patients with specific forms of tau-related neurodegeneration.