John Q Trojanowski's research while affiliated with University of Pennsylvania and other places

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Publications (989)


MSUT2 expression is associated with human tau pathology. a Immunofluorescence co-staining of frontal cortical human brain sections with antibodies against neurons (NeuN), astrocytes (GFAP), microglia (IBA1), oligodendrocytes (SOX10) and MSUT2. Scale bar = 50 µm. b Measurement of MSUT2 and cellular fluorescent signal co-localization in a. *P < 0.05 by one-way ANOVA followed by Tukey’s post hoc test, n = 3. The error bars represent the standard deviation. c Representative images of non-tauopathy control (CTR), Alzheimer’s disease (AD), Corticobasal degeneration (CBD), and Progressive supranuclear palsy (PSP) patient brain sections (frontal cortex) co-stained with MSUT2 and p-tau (PHF1) antibodies to reveal MSUT2 protein and tau pathology. Scale bar = 5 µm. d–f Quantification of MSUT2 immunoreactivity (MFI = mean fluorescence intensity) in non-tauopathy control (CTR) vs. diseased brain sections as exemplified in c. MSUT2 area is normalized to the neuron counts. Four random images of the cortical region were used for the quantification of each case. *P < 0.05, **P < 0.01, n.s., not significant, by t-test when comparing CTR (n = 9) vs. AD (n = 17), CBD (n = 6), or PSP (n = 5). The error bars represent the standard deviation. g Correlation of MSUT2 expression and tau pathology (PHF1 immunoreactivity) quantified from sections as exemplified in c. R² = 0.2256, P = 0.0030 by normal linear regression. Four random images of the cortical region/case were used for the quantification of both MSUT2 and PHF1. Each dot represents the mean value from one individual case. Both MSUT2 and tau pathology level was presented by the integrated mean fluorescence intensity of PHF1 staining. h Representative immunoblots of MSUT2 and p-tau levels in human brains and cellular homogenates probed with MSUT2, PHF1, and GAPDH antibodies. Samples include CTR, MCI (mild cognitive impairment), AD, CBD, and PSP brains. The CTR, MCI, and AD cases were separated and run on separate blots due to lane limitations. In addition, for the gels involving CTR cases in CBD and PSP, the control (CTR) cases were randomly selected from within the same CTR group. Three isoforms of MSUT2 are indicated using QBI HEK-293 cell lysate samples. i–l Quantification of MSUT2 immunoreactivity in immunoblot samples as depicted in h. All samples were normalized to GAPDH to gain the relative quantity (RQ). All three isoforms were included for quantification. n.s., not significant, *P < 0.05, **P < 0.01 by t-test, n = 14 CTR vs. 12 MCI, n = 14 CTR vs. 12 AD, n = 7 CTR vs. 6 CBD, n = 8 CTR vs. 5 PSP. The error bars represent the standard deviation
MSUT2 modulates the spatiotemporal spreading of tau pathology induced by human-derived AD-tau seeds. a Schematic picture of the experimental paradigm: AD-tau seeds were enriched from postmortem AD brains and stereotactically injected into the hippocampi of MSUT2 KO mice and wild-type (WT) littermates at 3 months of age. Mouse brains were collected at different time points (from 3 days to 12 months post-injection time; m.p.i.) and analyzed by immunohistochemistry and biochemistry. b Representative images of AD-tau-injected mouse hippocampi at 1 to 12 m.p.i. AD-tau-seeded MSUT2 KO and WT mouse tau pathology was revealed with a S199/T205-p-tau antibody (AT8). Scale bar = 60 and 15 (inset) µm. c Quantification of neurofibrillary tangles (NFTs) in the ipsilateral hippocampal region of the AD-tau-injected MSUT2 KO and WT mouse brains. **P < 0.01, ***P < 0.001 by two-way ANOVA followed by Bonferroni’s post hoc test, n = 6 per group. The error bars represent the standard deviation. d MSUT2 KO and WT mouse brains were injected with AD-tau and analyzed at 3 m.p.i. Proteins were extracted and fractionated from the ipsilateral hippocampi. Soluble fractions were probed with a mouse tau (m-tau) antibody T49 and GAPDH antibody as the loading control. Insoluble fractions were probed with T49 antibody. e, f Quantification of T49-positive optical density from immunoblots in d. Relative Quantities (RQ) were determined by normalizing T49 to GAPDH signals in the soluble fraction. n.s., not significant, ***P < 0.001 by t-test, WT vs. MSUT2 KO n = 4 per group. The error bars represent the standard deviation. g Representative images showing T231-p-tau pathology in the AD-tau-injected (12 m.p.i.) WT and MSUT2 KO mouse brains. Mouse brain sections were stained with a p-tau antibody (AT180). Scale bar = 60 and 15 (inset) µm. h Quantification of AT180-positive area in the ipsilateral hippocampi of the mice as depicted in g. *P < 0.05 by t-test, WT vs. MSUT2 KO, n = 6 per group. The error bars represent the standard deviation. i Representative images showing S396/S404-p-tau pathology in the AD-tau-injected (12 m.p.i.) WT and MSUT2 KO mouse brains. Mouse brain sections were stained with a p-tau antibody (PHF1). Scale bar = 60 and 15 (inset) µm. j Quantification of PHF1-positive area in the ipsilateral hippocampi of the mice as depicted in i. *P < 0.05 by t-test, WT vs. MSUT2 KO, n = 6 per group. The error bars represent the standard deviation. k Heatmap of tau pathology at 12 m.p.i. in different brain regions of MSUT2 KO and WT mice aligned in high (top) to low (bottom) anterograde connectivity strength to the injection site. Color hue indicates the abundance of tau pathology (Tau). n = 4 per group. l Heatmap of tau pathology at 12 m.p.i. in different brain regions of MSUT2 KO and WT mice aligned in high (top) to low (bottom) retrograde connectivity strength to the injection site. Color hue indicates the abundance of tau pathology (Tau). n = 4 per group. m, n Fold-change (WT/KO) in tau pathology based on different levels of anterograde and retrograde connectivity strength. High = 1st–25th ranked regions, Medium = 26th–50th ranked regions, Low = 89th–113th ranked regions (lowest 25 regions). n.s., not significant, *P < 0.05 by one-way ANOVA followed by Tukey’s post hoc test, high vs. medium vs. low connectivity region, n = 25 per connectivity category. The error bars represent the standard deviation
MSUT2 modulates tau pathology but not Aβ or α-synuclein pathology. a Representative images of AT8-positive tau pathology in CBD-tau-injected MSUT2 KO (KO) and wild-type (WT) mouse brains. Mice were injected with CBD-tau at 3 months of age and brains were collected, sectioned, and stained with AT8 antibody for tau pathology at 6 m.p.i. iHP = ipsilateral hippocampus; NFTs = neurofibrillary tangles; APs = astrocytic plaques (arrows). Scale bar = 50 μm. b, c Quantification of NFTs and APs (count) in sections stained as in a. *P < 0.05, n.s., not significant by t-test, MSUT2 KO (KO) vs. wild-type (WT) mouse, n = 6 mice per group. Error bars represent the standard deviation. d Representative images of AT8-positive tau pathology in PSP-tau-injected MSUT2 KO (KO) and wild-type (WT) mouse brains. Mice were injected with PSP-tau at 3 months of age and brains were collected, sectioned, and stained with AT8 antibody for tau pathology at 6 m.p.i. iHP = ipsilateral hippocampus; NFTs = neurofibrillary tangles; TAs = tufted astrocytes (arrowheads). Scale bar = 50 μm. e, f Quantification of NFTs and TAs (count) in sections stained as in d. *P < 0.05, n.s., not significant by t-test, MSUT2 KO (KO) vs. wild-type (WT) mouse, n = 6 mice per group. Error bars represent the standard deviation. g Representative images of Aβ plaque pathology in the brains of 5xFAD/MSUT2 KO (5xKO) and 5xFAD/MSUT2 wild-type (5xWT) mice. Mice were sacrificed at 8 months of age. Mouse brain sections were stained with H31L21 (Aβ42) antibody to reveal the Aβ plaques. Scale bar = 100 µm. h Quantification of Aβ plaque-positive area (H31L21 immunoreactivity) in 5xKO and 5xWT mouse brains in sections stained as in g. n.s., not significant by t-test, 5xFAD vs. 5xKO, n = 6 mice per group. Error bars represent the standard deviation. i Counts of Aβ plaque numbers in 5xKO and 5xWT mice in sections stained as in g. n.s., not significant by t-test, 5xFAD vs. 5xKO, n = 6 mice per group. Error bars represent the standard deviation. j Representative images of ipsilateral hippocampal regions of MSUT2 KO (KO) mice and wild-type (WT) littermates injected with mouse-α-synuclein preformed fibrils (mSyn-pffs) at 1 m.p.i. Mouse brain sections were stained with EP1536Y antibody to reveal α-synuclein pathology. Scale bar = 200 μm. k Quantification of α-synuclein pathology area (EP1536Y immunoreactivity) in the ipsilateral hippocampal regions of mSyn-pffs-injected MSUT2 KO (KO) mice and wild-type (WT) littermates in sections stained as in j. n.s., not significant by t-test, MSUT2 KO (KO) vs. wild-type (WT) mouse, n = 4 mice per group. Error bars represent the standard deviation. l 5xKO and 5xWT were injected with AD-tau at 7 months of age. Mouse brains were collected, sectioned and stained for neuritic plaque (NP) tau pathology with AT8 antibody at 1 m.p.i. representative images show ipsilateral hippocampal regions of injected mouse brains. Scale bar = 500 µm. m Quantification of NP tau pathology area in AD-tau-injected 5xKO and 5xWT mice at 1 m.p.i. in sections stained as in l. *P < 0.05 by t-test, 5xFAD vs. 5xKO, n = 6 mice per group. Error bars represent the standard deviation. n Brain sections from aged (12–15-month-old) AD-tau-injected MSUT2 KO (KO) and wild-type (WT) littermates at 3 m.p.i. were probed with AT8 antibody for tau pathology. Representative images show AT8-positive staining in the caudal hilus regions of the injected mouse brains. Scale bar = 500 µm. o Neurofibrillary tangles were counted in the ipsilateral hippocampal regions of AD-tau-injected aged MSUT2 and wild-type littermates at 3 m.p.i. in sections stained as in n. *P < 0.05, ***P < 0.001 by one-way ANOVA followed by Newman-Keuls’ post hoc test, MSUT2 KO (KO) vs. wild-type (WT) mouse, n = 6 mice per group. Error bars represent the standard deviation. p AT8-positive tau pathology area was quantified in the ipsilateral hippocampal regions of AD-tau-injected aged MSUT2 KO (KO) and wild-type (WT) littermates in sections stained as in n. n.s., not significant, *P < 0.05 by one-way ANOVA followed by Newman-Keuls’ post hoc test, WT vs. KO, n = 6 mice per group. Error bars represent the standard deviation
MSUT2 modulates the internalization of pathogenic tau seeds in neurons. a Representative images showing wild-type mouse primary neurons that were immunocytochemically stained with R2295M antibody (mouse tau, green) and DAPI (blue) to assess the amount of mouse tau pathology induced by human tau seeds. Wild-type mouse primary neurons were pretreated with antisense oligonucleotides (ASOs) against MSUT2 or scrambled control ASO (SCR) at DIV2 and human-derived tau seeds or mSyn-pffs were added at DIV7. Cells were extracted with detergent to remove soluble proteins and fixed at DIV21. Scale bar = 250 µm. b Quantification of R2295M immunoreactivity of each condition represented in a. Data were quantified using the fluorescent density x area of occupancy/DAPI count and normalized to the PBS-treated samples (as 100%). *P < 0.05, **P < 0.01, ***P < 0.001, n.s., not significant by two-way ANOVA followed by Tukey’s multiple comparisons test, n = 3 biologic repeats per group. Data were normalized to PBS-treated neurons in each group. Error bars represent the standard deviation. c Representative images showing neurons treated with MSUT2 ASOs (ASOs) or scrambled control ASO (SCR) at DIV2 and treated with pHrodo red dye (PhR)-labeled amplified AD-tau seeds (ADT40P1) at DIV7. PhR dye was detected at 2, 8, 18, and 48 h after the addition of ADT40P1. Scale bar = 5 µm. d Quantification of pHrodo red signal intensities from neurons treated as in c. Data are present as density x area/neuron count (DxA/Neuron count). The dashed line delineates the region corresponding to the neuron’s outline, as indicated by the brightfield channel. **P < 0.01, ***P < 0.001 by two-way ANOVA followed by Tukey’s multiple comparisons test, n = 3 biologic repeats per group. Error bars represent the standard deviation. e Representative images show MSUT2 KO and wild-type mouse primary neurons treated with pHrodo red (PhR)-labeled ADT40P1 at DIV7 and live imaged at 24 h post-treatment time. Scale bar = 25 µm. f Quantification of pHrodo red signal in neurons treated as in e. Data are present as density x area coverage/neuron count and normalized to WT neurons. **P < 0.01 by t-test, wild-type (WT) vs. MSUT2 KO (KO), n = 5 biologic repeats per group. Error bars represent the standard deviation. g Representative images show the uptake of fluorescently labeled tau seeds in MSUT2 KO and wild-type mouse brains in vivo. Mice were stereotactically-injected with pHrodo red-labeled ADT40P1 at 3 months of age. Mouse brains were quickly dissected at 2 d.p.i., sectioned, and imaged using live imaging microscopy. Representative images show the dorsal hippocampal regions of injected mice. Scale bar = 500 µm (overview) and 100 µm (insets). h Quantification of pHrodo red signal density x area of occupancy (DxA) in the hippocampal regions of the ADT40P1-injected MSUT2 KO and wild-type mice in sections stained as in g. **P < 0.01 by t-test, wild-type (WT) vs. MSUT2 KO (KO), n = 5 mice per group. Error bars represent the standard deviation. i Representative images showing wild-type primary neurons that were treated with MSUT2 ASOs (ASOs) or scramble controls (SCR) at DIV2 and treated with bodipy (BDY)-labeled mSyn-pffs (mSyn-pffs), Alexa594 (A594)-labeled transferrin, or fluorescein (FL)-labeled dextran (500 kDa) at DIV7, with imaging 24 h later. Internalized proteins were revealed using live cell microscopy. Extracellular bodipy and fluorescein fluorescence were quenched by 500 mM trypan blue before imaging. Representative images show fluorescent signals for bodipy, Alexa594, and fluorescein as well as fluorescence images merged with bright field images. Scale bar = 5 µm. j–l Quantification of fluorescent signal intensities (DxA) in each condition in neurons stained as in i. n.s., not significant, *P < 0.05 by t-test, MSUT2 ASOs (ASOs) vs. scramble controls (SCR), n = 4–5 biologic repeats per group. Error bars represent the standard deviation
MSUT2 modulates tau pathogenesis via adenosine signaling. a UMAP plot shows distinct cell populations in scNT-sequencing of wild-type and MSUT2 KO primary neuron cultures at DIV 10. Cell populations were determined by expression levels of multiple genes in each cell type. Ex = excitatory neurons, Inh = inhibitory neurons, MG = microglia, OPC = oligodendrocyte precursor cells, RG_Astro = radial glia astrocytes. b Volcano plot showing differentially expressed genes (DEGs) in wild-type (WT) and MSUT2 KO (KO) excitatory neurons identified by scNT-seq. WT and KO primary neurons were cultured and collected at DIV10 in single-cell resuspension and sequenced using scNT-seq. DEGs are shown as WT vs. KO neurons. DEGs with adjusted p < 0.01 are shown on the graph. Increased DEGs (KO greater than WT) are in red while decreased DEGs are in blue. c Heatmaps showing the total RNA level, synthesis rate (syn) and degradation rate (deg) changes of DEGs in excitatory neurons with (WT) or without (KO) expression of MSUT2. Values of DEGs in WT neurons were set as 0. The color hue indicates the level of changes, with red indicating increases (greater in KO than WT) and blue indicating decreases. d Immunoblots show VCP, HSP70 and A1AR protein expression levels in MSUT2 KO (KO) and wild-type (WT) littermates at 3 months of age. GAPDH was used as the loading control. n = 5 mice per group. e–g Quantification of VCP, HSP70, A1AR optical density from immunoblots as depicted in d. Data were normalized to the GAPDH signal. *P < 0.05 by t-test, MSUT2 KO (KO) vs. wild-type (WT) mice, n = 5 mice per group. Error bars represent the standard deviation. h Representative images showing mouse tau pathology induced by AD-tau in neurons treated with PBS, ASOs for A1AR, or scrambled control ASO. Primary neurons were transfected with ASOs at DIV2 and treated with AD-tau at DIV7. Insoluble mouse tau aggregates were revealed with R2295M antibody. DAPI reveals nuclei. Scale bar = 50 µm. i Quantification of mouse tau pathology (area x density/DAPI count) in primary neurons as depicted in h. *P < 0.05, **P < 0.01, ***P < 0.001 by one-way ANOVA followed by Tukey’s multiple comparison, n = 4 biologic repeats/condition. Error bars represent the standard deviation. j Representative time-lapse live images of internalized tau seeds in primary neurons treated with PBS, scrambled control ASOs (SCR), MSUT2 ASOs (MSUT2), A1AR ASOs (A1AR) at DIV2, or adenosine at DIV6, with pHrodo red-labeled ADT40P1 added at DIV7. Time in the figures is the interval after the addition of labeled ADT40P1. Scale bar = 5 µm. k Quantification of internalized pHrodo red signal (area x density/cell count) as a function of time, as depicted in j. n = 4 biologic repeats/condition. Error bars show standard errors

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MSUT2 regulates tau spreading via adenosinergic signaling mediated ASAP1 pathway in neurons
  • Article
  • Full-text available

March 2024

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81 Reads

Acta Neuropathologica

Hong Xu

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Virginia M.-Y. Lee

Inclusions comprised of microtubule-associated protein tau (tau) are implicated in a group of neurodegenerative diseases, collectively known as tauopathies, that include Alzheimer’s disease (AD). The spreading of misfolded tau “seeds” along neuronal networks is thought to play a crucial role in the progression of tau pathology. Consequently, restricting the release or uptake of tau seeds may inhibit the spread of tau pathology and potentially halt the advancement of the disease. Previous studies have demonstrated that the Mammalian Suppressor of Tauopathy 2 (MSUT2), an RNA binding protein, modulates tau pathogenesis in a transgenic mouse model. In this study, we investigated the impact of MSUT2 on tau pathogenesis using tau seeding models. Our findings indicate that the loss of MSUT2 mitigates human tau seed-induced pathology in neuron cultures and mouse models. In addition, MSUT2 regulates many gene transcripts, including the Adenosine Receptor 1 (A1AR), and we show that down regulation or inhibition of A1AR modulates the activity of the “ArfGAP with SH3 Domain, Ankyrin Repeat, and PH Domain 1 protein” (ASAP1), thereby influencing the internalization of pathogenic tau seeds into neurons resulting in reduction of tau pathology. Supplementary Information The online version contains supplementary material available at 10.1007/s00401-024-02703-3.

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Polypathologic Associations with Gray Matter Atrophy in Neurodegenerative Disease

November 2023

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13 Reads

The Journal of Neuroscience : The Official Journal of the Society for Neuroscience

Mixed pathologies are common in neurodegenerative disease; however, antemortem imaging rarely captures copathologic effects on brain atrophy due to a lack of validated biomarkers for non-Alzheimer’s pathologies. We leveraged a dataset comprising antemortem MRI and postmortem histopathology to assess polypathologic associations with atrophy in a clinically heterogeneous sample of 125 human dementia patients (41 female, 84 male) with T1-weighted MRI ≤ 5 years before death and postmortem ordinal ratings of amyloid- ${\bi \beta }$ , tau, TDP-43, and ${\bi \alpha }$ -synuclein. Regional volumes were related to pathology using linear mixed-effects models; approximately 25% of data were held out for testing. We contrasted a polypathologic model comprising independent factors for each proteinopathy with two alternatives: a model that attributed atrophy entirely to the protein(s) associated with the patient’s primary diagnosis and a protein-agnostic model based on the sum of ordinal scores for all pathology types. Model fits were evaluated using log-likelihood and correlations between observed and fitted volume scores. Additionally, we performed exploratory analyses relating atrophy to gliosis, neuronal loss, and angiopathy. The polypathologic model provided superior fits in the training and testing datasets. Tau, TDP-43, and ${\bi \alpha }$ -synuclein burden were inversely associated with regional volumes, but amyloid- ${\bi \beta }$ was not. Gliosis and neuronal loss explained residual variance in and mediated the effects of tau, TDP-43, and ${\bi \alpha }$ -synuclein on atrophy. Regional brain atrophy reflects not only the primary molecular pathology but also co-occurring proteinopathies; inflammatory immune responses may independently contribute to degeneration. Our findings underscore the importance of antemortem biomarkers for detecting mixed pathology.


α-Synuclein aggregates amplified from patient-derived Lewy bodies recapitulate Lewy body diseases in mice

October 2023

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156 Reads

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5 Citations

Nature Communications

Extraction of α-Synuclein (αSyn) aggregates from Lewy body disease (LBD) brains has been widely described yet templated fibrillization of LB-αSyn often fails to propagate its structural and functional properties. We recently demonstrated that aggregates amplified from LB-αSyn (ampLB) show distinct biological activities in vitro compared to human αSyn preformed fibrils (hPFF) formed de novo. Here we compare the in vivo biological activities of hPFF and ampLB regarding seeding activity, latency in inducing pathology, distribution of pathology, inclusion morphology, and cell-type preference. Injection of ampLB into mice expressing only human αSyn (male Thy1: SNCA / Snca –/– mice) induced pathologies similar to those of LBD subjects that were distinct from those induced by hPFF-injection or developing spontaneously with aging. Importantly, αSyn aggregates in ampLB-injected Thy1: SNCA / Snca –/– mice maintained the unique biological and conformational features of original LB-αSyn. These results indicate that ampLB-injection, rather than conventional PFF-injection or αSyn overexpression, faithfully models key aspects of LBD.



Demographic, clinical, and speech characteristics of participants: Mean (SD)
Clinical diagnosis, CSF, and autopsy pathology for 30 naPPA participants 1
Perceptual judgments of features of AOS in naPPA by 2 judges, rated on a scale of 0 to 4 1 : Mean (SD)
Interrater reliability of judgments of features of AOS in naPPA by two judges
Apraxia of Speech in the Spontaneous Speech of Nonfluent/Agrammatic Primary Progressive Aphasia

June 2023

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71 Reads

Journal of Alzheimer s Disease Reports

Background: Apraxia of speech (AOS) is a core feature of nonfluent/agrammatic primary progressive aphasia (naPPA), but its precise characteristics and the prevalence of AOS features in spontaneous speech are debated. Objective: To assess the frequency of features of AOS in the spontaneous, connected speech of individuals with naPPA and to evaluate whether these features are associated with an underlying motor disorder such as corticobasal syndrome or progressive supranuclear palsy. Methods: We examined features of AOS in 30 patients with naPPA using a picture description task. We compared these patients to 22 individuals with behavioral variant frontotemporal dementia and 30 healthy controls. Each speech sample was evaluated perceptually for lengthened speech segments and quantitatively for speech sound distortions, pauses between and within words, and articulatory groping. We compared subgroups of naPPA with and without at least two features of AOS to assess the possible contribution of a motor impairment to speech production deficits. Results: naPPA patients produced both speech sound distortions and other speech sound errors. Speech segmentation was found in 27/30 (90%) of individuals. Distortions were identified in 8/30 (27%) of individuals, and other speech sound errors occurred in 18/30 (60%) of individuals. Frequent articulatory groping was observed in 6/30 (20%) of individuals. Lengthened segments were observed rarely. There were no differences in the frequencies of AOS features among naPPA subgroups as a function of extrapyramidal disease. Conclusion: Features of AOS occur with varying frequency in the spontaneous speech of individuals with naPPA, independently of an underlying motor disorder.


Demographic, clinical, and speech characteristics of participants: Mean (SD)
Perceptual judgments of features of AOS in naPPA by 2 judges, rated on a scale of 0 to 4 1 : Mean (SD)
Interrater reliability of judgments of features of AOS in naPPA by two judges
Apraxia of Speech in the Spontaneous Speech of Nonfluent/Agrammatic Primary Progressive Aphasia

May 2023

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59 Reads

Background: Apraxia of speech (AOS) is a core feature of nonfluent/agrammatic primary progressive aphasia (naPPA), but its precise characteristics and the prevalence of AOS features in spontaneous speech are debated. Objective: To assess the frequency of features of AOS in the spontaneous, connected speech of individuals with naPPA and to evaluate whether these features are associated with an underlying motor disorder such as corticobasal syndrome or progressive supranuclear palsy. Methods: We examined features of AOS in 30 patients with naPPA using a picture description task. We compared these patients to 22 individuals with behavioral variant frontotemporal dementia and 30 healthy controls. Each speech sample was evaluated perceptually for lengthened speech segments and quantitatively for speech sound distortions, pauses between and within words, and articulatory groping. We compared subgroups of naPPA with and without at least two features of AOS to assess the possible contribution of a motor impairment to speech production deficits. Results: naPPA patients produced both speech sound distortions and other speech sound errors. Speech segmentation was found in 27/30 (90%) of individuals. Distortions were identified in 8/30 (27%) of individuals, and other speech sound errors occurred in 18/30 (60%) of individuals. Frequent articulatory groping was observed in 6/30 (20%) of individuals. Lengthened segments were observed rarely. There were no differences in the frequencies of AOS features among naPPA subgroups as a function of extrapyramidal disease. Conclusion: Features of AOS occur with varying frequency in the spontaneous speech of individuals with naPPA, independently of an underlying motor disorder.


Figure 4. Network and hub analysis between disease phases. Weak edges (blue lines) found transitioning between nodes from epicenter to other phases in Panel (A) and sequentially from an earlier phase to a subsequent phase in Panel (B) for FTLD-tau and FTLD-TDP. Node colors represent regions associated with each phase. Connections are shown as projections onto the left lateral view. Shown in Panels (C) and (D) are comparisons of the percentage of these weak edges that were connected to HC hubs, per subject, during the transitioning from the epicenter or in adjacent phases, respectively. Asterisks (*p<.05 and **p< .01) indicate phases with significant differences found between the two pathology groups using a Welch's t-test. (Phases transitions [1-2]: t(39) = -2.46, p < 0.05; [1-3]: t(39) = -2.64, p < 0.05; [1-4]: t(39) = 1.38, p > 0.05; [1-5]: t(39) = -1.12, p > 0.05; [2-3]: t(39) = -3.03, p < 0.01; [3-4]: t(39) = -0.27, p > 0.05;[4-5]: t(39) = 1.61, p > 0.05; n = 28 FTLD-tau, 13 FTLD-TDP) 99x121mm (300 x 300 DPI)
Antemortem network analysis of spreading pathology in autopsy-confirmed frontotemporal degeneration

May 2023

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58 Reads

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2 Citations

Brain Communications

Despite well-articulated hypotheses of spreading pathology in animal models of neurodegenerative disease, the basis for spreading neurodegenerative pathology in humans has been difficult to ascertain. In this study, we used graph theoretic analyses of structural networks in antemortem, multimodal MRI from autopsy-confirmed cases to examine spreading pathology in sporadic frontotemporal lobar degeneration. We defined phases of progressive cortical atrophy on T1-weighted MRI using a published algorithm in autopsied frontotemporal lobar degeneration with tau inclusions (FTLD-tau) or with TDP-43 inclusions (FTLD-TDP). We studied global and local indices of structural networks in each of these phases, focusing on the integrity of gray matter hubs and white matter edges projecting between hubs. We found that global network measures are compromised to an equal degree in patients with FTLD-tau and FTLD-TDP compared to healthy controls. While measures of local network integrity were compromised in both FTLD-tau and FTLD-TDP, we discovered several important characteristics that distinguished between these groups. Hubs identified in controls were degraded in both patient groups, but degraded hubs were associated with the earliest phase of cortical atrophy (i.e. epicenters) only in FTLD-tau. Degraded edges were significantly more plentiful in FTLD-tau than in FTLD-TDP, suggesting that the spread of tau pathology involves more significant white matter degeneration. Weakened edges were associated with degraded hubs in FTLD-tau more than in FTLD-TDP, particularly in the earlier phases of disease, and phase-to-phase transitions in FTLD-tau were characterized by weakened edges in earlier phases projecting to diseased hubs in subsequent phases of disease. When we examined the spread of pathology from a region diseased in an earlier phase to physically adjacent regions in subsequent phases, we found greater evidence of disease spreading to adjacent regions in FTLD-TDP than in FTLD-tau. We associated evidence of degraded gray matter hubs and weakened white matter edges with quantitative measures of digitized pathology from direct observations of patients’ brain samples. We conclude from these observations that spread of pathology from diseased regions to distant regions via weakened long-range edges may contribute to spreading disease in FTD-tau, while spread of pathology to physically adjacent regions via local neuronal connectivity may play a more prominent role in spreading disease in FTLD-TDP.



Post-translational modifications of soluble α-synuclein regulate the amplification of pathological α-synuclein

January 2023

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354 Reads

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36 Citations

Nature Neuroscience

Cell-to-cell transmission and subsequent amplification of pathological proteins promote neurodegenerative disease progression. Most research on this has focused on pathological protein seeds, but how their normal counterparts, which are converted to pathological forms during transmission, regulate transmission is less understood. Here we show in cultured cells that phosphorylation of soluble, nonpathological α-synuclein (α-Syn) at previously identified sites dramatically affects the amplification of pathological α-Syn, which underlies Parkinsonʼs disease and other α-synucleinopathies, in a conformation- and phosphorylation site-specific manner. We performed LC–MS/MS analyses on soluble α-Syn purified from Parkinsonʼs disease and other α-synucleinopathies, identifying many new α-Syn post-translational modifications (PTMs). In addition to phosphorylation, acetylation of soluble α-Syn also modified pathological α-Syn transmission in a site- and conformation-specific manner. Moreover, phosphorylation of soluble α-Syn could modulate the seeding properties of pathological α-Syn. Our study represents the first systematic analysis how of soluble α-Syn PTMs affect the spreading and amplification of pathological α-Syn, which may affect disease progression. Pathological α-synuclein (α-Syn) spreading is critical for the progression of many neurodegenerative diseases. The authors demonstrate that soluble α-Syn post-translational modifications (PTMs) dramatically modulate pathological α-synuclein spreading.


Multinomial logistic regression analyses for CSF cholesterol efflux capacity (CEC). The predictions were evaluated for MCI and AD groups against CN. CSF cholesterol efflux capacity was measured in CN (n = 50), MCI (n = 18), and AD (n = 40). The CEC values were normalized to a standard CSF sample that was run on each plate to account for inter-assay variability. We then log normalized the data prior to regression analysis. A Multinomial logistic regression analysis showed N9 CEC has a significant prediction of MCI. B Multinomial logistic regression analysis showed SHSY-5Y CEC has a significant prediction of MCI Detailed statistics are shown in the lower part of the figure. CN, cognitively normal; MCI, mild cognitive impairment; AD, Alzheimer’s disease; CSF, cerebrospinal fluid; CEC, cholesterol efflux capacity
Multivariate linear regression of CSF CEC and apolipoproteins CSF. CSF cholesterol efflux capacity was measured in CN (n = 50), MCI (n = 18), and AD (n = 40). Association between ApoA1, ApoE, and ApoJ with both CEC in human microglial and neuronal cells (N9 and SH-SY5Y, respectively). Association between ApoA1 significantly associated with N9 microglial and SH-SY5Yneuronal cell CEC (**P < 8.96e−11 and ***P < 3.244e−06, respectively), ApoJ is significantly associated with N9 microglial and SH-SY5Yneuronal cell CEC (**P < 2.22e−05 and *P < 1.22e−02, respectively). ApoE is not associated with either CEC measurement
Heat map and hierarchical clustering of CSF CEC with apolipoproteins and biomarkers of AD. CSF CEC is closely associated with ApoA-I and Clusterin. Aβ1-42 is associated with ApoE, and pTau, TTau, and pTau/Aβ1-42 ratio
Multinomial logistic regression analyses for CSF apolipoproteins and AD diagnosis. Apolipoproteins were measured in CN (n = 50), MCI (n = 18), and AD (n = 40). A Apo A1 displayed significant prediction of MCI diagnosis. B ApoE is significantly lower in AD (**P < 0.01). C ApoJ (Clusterin) is significantly lower in MCI (**P < 0.01) AD denotes Alzheimer’s disease, CSF cerebrospinal fluid, ApoA1 apolipoprotein A-I, ApoE apolipoprotein E, ApoJ/Clusterin, PL phosphorylated lipid, and Aβ1-42 42 amino acid form of beta amyloid
ApoJ/Clusterin concentrations are determinants of cerebrospinal fluid cholesterol efflux capacity and reduced levels are associated with Alzheimer’s disease

December 2022

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5 Citations

Alzheimer's Research & Therapy

Background Alzheimer’s disease (AD) shares risk factors with cardiovascular disease (CVD) and dysregulated cholesterol metabolism is a mechanism common to both diseases. Cholesterol efflux capacity (CEC) is an ex vivo metric of plasma high-density lipoprotein (HDL) function and inversely predicts incident CVD independently of other risk factors . Cholesterol pools in the central nervous system (CNS) are largely separate from those in blood, and CNS cholesterol excess may promote neurodegeneration. CEC of cerebrospinal fluid (CSF) may be a useful measure of CNS cholesterol trafficking. We hypothesized that subjects with AD and mild cognitive impairment (MCI) would have reduced CSF CEC compared with Cognitively Normal (CN) and that CSF apolipoproteins apoA-I, apoJ, and apoE might have associations with CSF CEC. Methods We retrieved CSF and same-day ethylenediaminetetraacetic acid (EDTA) plasma from 108 subjects (40 AD; 18 MCI; and 50 CN) from the Center for Neurodegenerative Disease Research biobank at the Perelman School of Medicine, University of Pennsylvania. For CSF CEC assays, we used N9 mouse microglial cells and SH-SY5Y human neuroblastoma cells, and the corresponding plasma assay used J774 cells. Cells were labeled with [ ³ H]-cholesterol for 24 h, had ABCA1 expression upregulated for 6 h, were exposed to 33 μl of CSF, and then were incubated for 2.5 h. CEC was quantified as percent [ ³ H]-cholesterol counts in medium of total counts medium+cells, normalized to a pool sample. ApoA-I, ApoJ, ApoE, and cholesterol were also measured in CSF. Results We found that CSF CEC was significantly lower in MCI compared with controls and was poorly correlated with plasma CEC. CSF levels of ApoJ/Clusterin were also significantly lower in MCI and were significantly associated with CSF CEC. While CSF ApoA-I was also associated with CSF CEC, CSF ApoE had no association with CSF CEC. CSF CEC is significantly and positively associated with CSF Aβ. Taken together, ApoJ/Clusterin may be an important determinant of CSF CEC, which in turn could mitigate risk of MCI and AD risk by promoting cellular efflux of cholesterol or other lipids. In contrast, CSF ApoE does not appear to play a role in determining CSF CEC.


Citations (88)


... Progressive neurodegenerative disease Parkinson's disease (PD) is typified by dopaminergic neuronal death in the substantia nigra pars compacta (Chen et al., 2020). A key clinical feature of the condition, Lewy bodies are intraneuronal collections of fibrillar a-synuclein (Uemura et al., 2023). In the serum of people with Parkinson's disease (PD), Zhou et al., ...

Reference:

Molecular Crossfires between Inflammasome Signalling and Dietary Small Molecule Inhibitors in Neurodegenerative Diseases: Implications for Medical Nutrition Therapy
α-Synuclein aggregates amplified from patient-derived Lewy bodies recapitulate Lewy body diseases in mice

Nature Communications

... These circuits may have particular clinical relevance given that a recent neuroimaging study in FTD found a closer link between long-range white matter tracts and executive dysfunction than shorter-range tracts. 106 Neuroimaging studies and network modeling have implicated long-range neuronal pathways in FTLD-tau previously, 107,108 in addition to histologic studies examining large-scale networks that connect cortex to brainstem and spinal structures. For example, we found a predilection for tau-mediated degeneration of noradrenergic neurons in the locus coeruleus compared to TDP-43 pathology in FTLD, 109 and tau inclusions have been shown to preferentially spread along corticospinal and corticopontine fibers in FTLD. ...

Antemortem network analysis of spreading pathology in autopsy-confirmed frontotemporal degeneration

Brain Communications

... Epigenetic mechanisms in PD, including post-translational modifications, are receiving increased interest as highlighted in recent studies [4,5,[181][182][183][184]. As PADs may be a promising target in PD therapeutics, roles for the different isozymes must be better understood for the development of therapeutics utilising pan-PAD or PAD isozyme-specific targeting. ...

Post-translational modifications of soluble α-synuclein regulate the amplification of pathological α-synuclein

Nature Neuroscience

... They had been prompted by Previous studies have shown that apoA-1 deficiency contributes to the cerebral accumulation of amyloid and memory deficits, and that the overexpression of apoA-1 attenuates neuroinflammation in vivo 44,45) , implicating the contribution of the role of HDL in Alzheimer's pathogenesis. Their results indicated attenuated CEC in the cerebral fluid of individuals with Alzheimer's disease, suggesting the potential involvement of altered cholesterol homeostasis in this disease 46) . ...

ApoJ/Clusterin concentrations are determinants of cerebrospinal fluid cholesterol efflux capacity and reduced levels are associated with Alzheimer’s disease

Alzheimer's Research & Therapy

... Whole blood samples were collected and analyzed as previously described. 30,31 Briefly, samples were collected in ethylenediamine tetraacetic acid (EDTA) tubes, spun, and stored at −80 • C prior to analysis using the SiMoA HD-X platform (Quanterix, Billerica, MA, USA). ...

Plasma phosphorylated tau181 predicts cognitive and functional decline
Annals of Clinical and Translational Neurology

Annals of Clinical and Translational Neurology

... 12 These and other proteomic studies of neurodegeneration have been biased toward GM, though WM changes are known components of disease pathogenesis. 11,[27][28][29][30] Thus, we aimed to identify and compare GM and WM proteomic alterations in human tauopathy to more fully understand tau-mediated neurodegeneration. We hypothesized that WM would share many changes with GM, while also demonstrating unique disease-associated changes. ...

Digital Histological Study of Neocortical Grey and White Matter Tau Burden Across Tauopathies
  • Citing Article
  • October 2022

Journal of Neuropathology and Experimental Neurology

... Synaptic homeostasis alteration and degeneration are early pathological events common in many neurodegenerative diseases, including AD. This makes synaptic proteins that reflect synaptic dysfunction interesting early biomarkers [22]. Disruption of sleep and circadian rhythm is believed to happen with ageing and contribute to development of neurodegenerative diseases in part through synaptic dysfunction [23]. ...

Cerebrospinal fluid biomarker panel of synaptic dysfunction in Alzheimer's disease and other neurodegenerative disorders

... 3 Traditionally, AD pathology can be assessed using biomarkers such as cerebrospinal fluid assays or neuroimaging techniques like positron emission tomography (PET) and magnetic resonance imaging (MRI). [4][5][6][7] Several studies have explored these modalities to predict conversion from MCI to dementia. [8][9][10][11][12] Although these techniques provide useful information, they are invasive and expensive, limiting their applicability to well-resourced places and lacking the scalability and accessibility needed for low-and middle-income countries. ...

Increasing participant diversity in AD research: Plans for digital screening, blood testing, and a community‐engaged approach in the Alzheimer's Disease Neuroimaging Initiative 4
Alzheimer's & Dementia

Alzheimer's & Dementia

... Consistent with a role in our model, TBI induces Rock1-dependent neurodegeneration [65] and phosphorylation at three sites in JIP-3:Ser 318 , Ser 368 , and Ser 369 [66], resulting in JNK activation. Gap43 is well known as a primary JNK-targeted axonal phospho-protein [67] with elevations in AD CSF associated with tauopathy that predict progression [68]. Gab1 is also an adaptor protein with phospho-site-mediated coupling to SHP2 upstream of excitatory neuronal ERK activation and synaptic plasticity [69]; it is implicated in cognitive deficits in AD [69]. ...

Association of CSF GAP-43 With the Rate of Cognitive Decline and Progression to Dementia in Amyloid-Positive Individuals
  • Citing Article
  • October 2022

Neurology

... According to a recent survey, a TREM2 response occurs early in the amyloid cascades [73] . Several rare variants in TREM2, such as TREM2R47H have emerged, which significantly increase the risk by 2-to 4-fold, comparable to the increased risk associated with having one copy of APOEε4, which impairs ligand binding and curtails microglia activation in humans and AD mouse models [74] . From a recent autopsy-confirmed cohort, Kim et al found that TREM2 variant cases were more frequently associated with non-amnestic clinical syndromes and contributed to clinical and pathologic AD heterogeneity by altering the distribution of neurofibrillary degeneration and tau-dependent microglial dystrophy, resulting in hippocampalsparing and non-amnestic AD phenotypes [75] . ...

TREM2 risk variants are associated with atypical Alzheimer’s disease

Acta Neuropathologica