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1.
Int J Mol Sci ; 25(9)2024 May 03.
Article En | MEDLINE | ID: mdl-38732223

Alzheimer's disease (AD) is characterized by a loss of neurons in the cortex and subcortical regions. Previously, we showed that the progressive degeneration of subcortical monoaminergic (MAergic) neurons seen in human AD is recapitulated in the APPswe/PS1ΔE9 (APP/PS) transgenic mouse model. Because degeneration of cholinergic (Ach) neurons is also a prominent feature of AD, we examined the integrity of the Ach system in the APP/PS model. The overall density of Ach fibers is reduced in APP/PS1 mice at 12 and 18 months of age but not at 4 months of age. Analysis of basal forebrain Ach neurons shows no loss of Ach neurons in the APP/PS model. Thus, since MAergic systems show overt cell loss at 18 months of age, the Ach system is less vulnerable to neurodegeneration in the APP/PS1 model. We also examined whether the proximity to Aß deposition affected the degeneration of Ach and 5-HT afferents. We found that the areas closer to the edges of compact Aß deposits exhibit a more severe loss of afferents than the areas that are more distal to Aß deposits. Collectively, the results indicate that the APP/PS model recapitulates the degeneration of multiple subcortical neurotransmitter systems, including the Ach system. In addition, the results indicate that Aß deposits cause global as well as local toxicity to subcortical afferents.


Alzheimer Disease , Amyloid beta-Protein Precursor , Cholinergic Neurons , Disease Models, Animal , Plaque, Amyloid , Presenilin-1 , Animals , Humans , Mice , Alzheimer Disease/pathology , Alzheimer Disease/metabolism , Alzheimer Disease/genetics , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Cholinergic Neurons/metabolism , Cholinergic Neurons/pathology , Mice, Transgenic , Plaque, Amyloid/pathology , Plaque, Amyloid/metabolism , Presenilin-1/genetics , Presenilin-1/metabolism
2.
Nat Aging ; 4(3): 309-318, 2024 Mar.
Article En | MEDLINE | ID: mdl-38429379

Age remains the central risk factor for many neurodegenerative diseases including Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis. Although the mechanisms of aging are complex, the age-related accumulation of senescent cells in neurodegeneration is well documented and their clearance can alleviate disease-related features in preclinical models. Senescence-like characteristics are observed in both neuronal and glial lineages, but their relative contribution to aging and neurodegeneration remains unclear. Human pluripotent stem cell-derived neurons provide an experimental model system to induce neuronal senescence. However, the extensive heterogeneity in the profile of senescent neurons and the methods to assess senescence remain major challenges. Here, we review the evidence of cellular senescence in neuronal aging and disease, discuss human pluripotent stem cell-based model systems used to investigate neuronal senescence and propose a panel of cellular and molecular hallmarks to characterize senescent neurons. Understanding the role of neuronal senescence may yield novel therapeutic opportunities in neurodegenerative disease.


Neurodegenerative Diseases , Pluripotent Stem Cells , Humans , Aging , Cellular Senescence/physiology , Neurons
4.
Int J Mol Sci ; 24(14)2023 Jul 16.
Article En | MEDLINE | ID: mdl-37511300

The unfolded protein response (UPR), which comprises three branches: PERK, ATF6α, and IRE1, is a major mechanism for maintaining cellular proteostasis. Many studies show that the UPR is a major player in regulating neuron viability and function in various neurodegenerative diseases; however, its role in neurodegeneration is highly controversial. Moreover, while evidence suggests activation of the UPR in neurons under normal conditions, deficiency of individual branches of the UPR has no major effect on brain neurons in animals. It remains unclear whether or how the UPR participates in regulating neuronal proteostasis under normal and disease conditions. To determine the physiological role of the UPR in neurons, we generated mice with double deletion of PERK and ATF6α in neurons. We found that inactivation of PERK and ATF6α in neurons caused lysosomal dysfunction (as evidenced by decreased expression of the V0a1 subunit of v-ATPase and decreased activation of cathepsin D), impairment of autophagic flux (as evidenced by increased ratio of LC3-II/LC3-I and increased p62 level), and accumulation of p-tau and Aß42 in the hippocampus, and led to impairment of spatial memory, impairment of hippocampal LTP, and hippocampal degeneration in adult mice. These results suggest that the UPR is required for maintaining neuronal proteostasis (particularly tau and Aß homeostasis) and the viability and function of neurons in the hippocampus of adult mice.


Neurodegenerative Diseases , Proteostasis , Mice , Animals , Unfolded Protein Response , Neurodegenerative Diseases/metabolism , Hippocampus/metabolism , Neurons/metabolism
6.
Acta Neuropathol ; 145(5): 597-610, 2023 05.
Article En | MEDLINE | ID: mdl-36764943

α-Synuclein is a major component of Lewy bodies (LB) and Lewy neurites (LN) appearing in the postmortem brain of Parkinson's disease (PD) and other α-synucleinopathies. While most studies of α-synucleinopathies have focused on neuronal and synaptic alterations as well as dysfunctions of the astrocytic homeostatic roles, whether the bidirectional astrocyte-neuronal communication is affected in these diseases remains unknown. We have investigated whether the astrocyte Ca2+ excitability and the glutamatergic gliotransmission underlying astrocyte-neuronal signaling are altered in several transgenic mouse models related to α-synucleinopathies, i.e., mice expressing high and low levels of the human A53T mutant α-synuclein (G2-3 and H5 mice, respectively) globally or selectively in neurons (iSyn mice), mice expressing human wildtype α-synuclein (I2-2 mice), and mice expressing A30P mutant α-synuclein (O2 mice). Combining astrocytic Ca2+ imaging and neuronal electrophysiological recordings in hippocampal slices of these mice, we have found that compared to non-transgenic mice, astrocytes in G2-3 mice at different ages (1-6 months) displayed a Ca2+ hyperexcitability that was independent of neurotransmitter receptor activation, suggesting that the expression of α-synuclein mutant A53T altered the intrinsic properties of astrocytes. Similar dysregulation of the astrocyte Ca2+ signal was present in H5 mice, but not in I2-2 and O2 mice, indicating α-synuclein mutant-specific effects. Moreover, astrocyte Ca2+ hyperexcitability was absent in mice expressing the α-synuclein mutant A53T selectively in neurons, indicating that the effects on astrocytes were cell-autonomous. Consistent with these effects, glutamatergic gliotransmission was enhanced in G2-3 and H5 mice, but was unaffected in I2-2, O2 and iSyn mice. These results indicate a cell-autonomous effect of pathogenic A53T expression in astrocytes that may contribute to the altered neuronal and synaptic function observed in α-synucleinopathies.


Parkinson Disease , Synucleinopathies , Mice , Humans , Animals , alpha-Synuclein/genetics , alpha-Synuclein/metabolism , Synucleinopathies/pathology , Astrocytes/pathology , Mice, Transgenic , Parkinson Disease/pathology , Disease Models, Animal
7.
bioRxiv ; 2023 Dec 23.
Article En | MEDLINE | ID: mdl-38187538

Acetaminophen (APAP) overdose triggers a cascade of intracellular oxidative stress events culminating in acute liver injury. The clinically used antidote, N-acetylcysteine (NAC) has a narrow therapeutic window and early treatment is essential for satisfactory therapeutic outcome. For more versatile therapies that can be effective even at late-presentation, the intricacies of APAP-induced hepatotoxicity must be better understood. Accumulation of advanced glycation end-products (AGEs) and consequent activation of the receptor for AGEs (RAGE) are considered one of the key mechanistic features of APAP toxicity. Glyoxalase-1 (Glo-1) regulates AGE formation by limiting the levels of methylglyoxal (MEG). In this study, we studied the relevance of Glo-1 in APAP mediated activation of RAGE and downstream cell-death cascades. Constitutive Glo-1 knockout mice (GKO) and a cofactor of Glo-1, ψ-GSH, were employed as tools. Our findings show elevated oxidative stress, activation of RAGE and hepatocyte necrosis through steatosis in GKO mice treated with high-dose APAP compared to wild type controls. A unique feature of the hepatic necrosis in GKO mice is the appearance of microvesicular steatosis as a result of centrilobular necrosis, rather than inflammation seen in wild type. The GSH surrogate and general antioxidant, ψ-GSH alleviated APAP toxicity irrespective of Glo-1 status, suggesting that oxidative stress being the primary driver of APAP toxicity. Overall, exacerbation of APAP hepatotoxicity in GKO mice suggests the importance of this enzyme system in antioxidant defense against initial stages of APAP overdose.

8.
Acta Neuropathol Commun ; 10(1): 180, 2022 12 14.
Article En | MEDLINE | ID: mdl-36517890

Antisense oligonucleotide (ASO) therapy for neurological disease has been successful in clinical settings and its potential has generated hope for Alzheimer's disease (AD). We previously described that ablating SNCA encoding for α-synuclein (αSyn) in a mouse model of AD was beneficial. Here, we sought to demonstrate whether transient reduction of αSyn expression using ASOSNCA could be therapeutic in a mouse model of AD. The efficacy of the ASOSNCA was measured via immunocytochemistry, RT-qPCR and western blotting. To assess spatial learning and memory, ASOSNCA or PBS-injected APP and non-transgenic (NTG) mice, and separate groups of SNCA-null mice, were tested on the Barnes circular maze. Hippocampal slice electrophysiology and transcriptomic profiling were used to explore synaptic function and differential gene expression between groups. Reduction of SNCA transcripts alleviated cognitive deficits in male transgenic animals, but surprisingly, not in females. To determine the functional cause of this differential effect, we assessed memory function in SNCA-null mice. Learning and memory were intact in male mice but impaired in female animals, revealing that the role of αSyn on cognitive function is sex-specific. Transcriptional analyses identified a differentially expressed gene network centered around EGR1, a central modulator of learning and memory, in the hippocampi of SNCA-null mice. Thus, these novel results demonstrate that the function of αSyn on memory differs between male and female brains.


Alzheimer Disease , Cognition , alpha-Synuclein , Animals , Female , Male , Mice , alpha-Synuclein/genetics , alpha-Synuclein/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Disease Models, Animal , Gene Expression , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic
9.
J Med Chem ; 65(21): 14441-14455, 2022 11 10.
Article En | MEDLINE | ID: mdl-36353871

Addressing glycation-induced oxidative stress in Alzheimer's disease (AD) is an emerging pharmacotherapeutic strategy. Restoration of the brain glyoxalase enzyme system that neutralizes reactive dicarbonyls is one such approach. Toward this end, we designed, synthesized, and evaluated a γ-glutamyl transpeptidase-resistant glyoxalase substrate, ψ-GSH. Although mechanistically successful, the oral efficacy of ψ-GSH appeared as an area in need of improvement. Herein, we describe our rationale for the creation of prodrugs that mask the labile sulfhydryl group. In vitro and in vivo stability studies identified promising prodrugs that could deliver pharmacologically relevant brain levels of ψ-GSH. When administered orally to a mouse model generated by the intracerebroventricular injection of Aß1-42, the compounds conferred cognitive benefits. Biochemical and histological examination confirmed their effects on neuroinflammation and oxidative stress. Collectively, we have identified orally efficacious prodrugs of ψ-GSH that are able to restore brain glyoxalase activity and mitigate inflammatory and oxidative pathology associated with AD.


Alzheimer Disease , Lactoylglutathione Lyase , Prodrugs , Animals , Mice , Alzheimer Disease/drug therapy , Alzheimer Disease/pathology , Prodrugs/pharmacology , Prodrugs/therapeutic use , Oxidative Stress , Disease Models, Animal , Amyloid beta-Peptides/pharmacology
10.
Redox Biol ; 57: 102484, 2022 Nov.
Article En | MEDLINE | ID: mdl-36183541

Increased oxidative stress and inflammation are implicated in the pathogenesis of Alzheimer's disease. Treatment with hydrogen sulfide (H2S) and H2S donors such as sodium hydrosulfide (NaSH) can reduce oxidative stress in preclinical studies, however clinical benefits of such treatments are rather ambiguous. This is partly due to poor stability and bioavailability of the H2S donors, requiring impractically large doses that are associated with dose-limiting toxicity. Herein, we identified a bioavailable 3-mercaptopyruvate prodrug, sulfanegen, which is able to pose as a sacrificial redox substrate for 3-mercaptopyruvate sulfurtransferase (3MST), one of the H2S biosynthetic enzymes in the brain. Sulfanegen is able to mitigate toxicity emanating from oxidative insults and the Aß1-42 peptide by releasing H2S through the 3MST pathway. When administered to symptomatic transgenic mouse model of AD (APP/PS1; 7 and 12 months) and mice that were intracerebroventricularly administered with the Aß1-42 peptide, sulfanegen was able to reverse oxidative and neuroinflammatory consequences of AD pathology by restoring 3MST function. Quantitative neuropathological analyses confirmed significant disease modifying effect of the compound on amyloid plaque burden and brain inflammatory markers. More importantly, sulfanegen treatment attenuated progressive neurodegeneration in these mice, as evident from the restoration of TH+ neurons in the locus coeruleus. This study demonstrates a previously unknown concept that supplementation of 3MST function in the brain may be a viable approach for the management of AD. Finally, brought into the spotlight is the potential of sulfanegen as a promising AD therapeutic for future drug development efforts.

11.
Transl Neurodegener ; 11(1): 34, 2022 07 01.
Article En | MEDLINE | ID: mdl-35773715

BACKGROUND: Neuronal dysfunction and degeneration linked to α-synuclein (αS) pathology is thought to be responsible for the progressive nature of Parkinson's disease and related dementia with Lewy bodies. Studies have indicated bidirectional pathological relationships between αS pathology and tau abnormalities. We recently showed that A53T mutant human αS (HuαS) can cause post-synaptic and cognitive deficits that require microtubule-associated protein tau expression. However, the role of tau in the development of αS pathology and subsequent neuronal dysfunction has been controversial. Herein, we set out to determine the role of tau in the onset and progression of αS pathology (α-synucleinopathy) using a transgenic mouse model of α-synucleinopathy lacking mouse tau expression. METHODS: Transgenic mice expressing A53T mutant HuαS (TgA53T) were crossed with mTau-/- mice to generate TgA53T/mTau-/-. To achieve more uniform induction of α-synucleinopathy in mice, we used intramuscular injections of αS preformed fibrils (PFF) in non-transgenic (nTg), TgA53T, TgA53T/mTau-/-, and mTau-/- mice. Motor behavior was analyzed at 70 days post inoculation (dpi) of PFF and tissues for biochemical and neuropathological analysis were collected at 40 dpi, 70 dpi, and end stage. RESULTS: Loss of tau expression significantly delayed the onset of motor deficits in the TgA53T model and the progression of α-synucleinopathy disease, as evidenced by a significant reduction in histopathological and behavioral markers of neurodegeneration and disease, and a significant improvement in survival. In vitro application of PFF to primary mouse hippocampal neurons demonstrated no changes in PFF uptake and processing or pS129 αS aggregation as a function of tau expression. However, PFF-induced neurotoxicity, including morphological deficits in nTg neurons, was prevented with tau removal. CONCLUSIONS: Collectively, our data suggest that tau is likely acting downstream of αS pathology to affect neuronal homeostasis and survival. This work further supports the investigation of tau in α-synucleinopathies to identify novel disease-modifying therapeutic strategies.


Parkinson Disease , Synucleinopathies , tau Proteins , Animals , Disease Models, Animal , Hippocampus/metabolism , Hippocampus/pathology , Mice , Mice, Transgenic , Parkinson Disease/genetics , Parkinson Disease/pathology , Synucleinopathies/genetics , Synucleinopathies/metabolism , Synucleinopathies/pathology , alpha-Synuclein/genetics , alpha-Synuclein/metabolism , tau Proteins/biosynthesis , tau Proteins/deficiency , tau Proteins/genetics
12.
Diabetes Metab Res Rev ; 38(5): e3530, 2022 07.
Article En | MEDLINE | ID: mdl-35395144

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in patients with diabetes mellitus (DM) admitted with acute coronary syndrome (ACS) and treated with a drug-eluting stent (DES) remains unclear. This is a prespecified sub-study from the Randomised Evaluation of short-term DUal antiplatelet therapy in patients with acute Coronary syndromE treated with a new generation DES (REDUCE) trial that was designed to determine the efficacy and safety of short-term versus standard 12 months DAPT in diabetic patients with ACS undergoing percutaneous coronary intervention (PCI) using the COMBO stent. METHODS: In this study we included ACS diabetic patients enroled in the REDUCE trial treated with the COMBO stent and randomly assigned to either 3 or 12 months of DAPT. The primary study endpoint was the composite of all-cause mortality, myocardial infarction (MI), stent thrombosis (ST), stroke, target vessel revascularisation (TVR), and bleeding complications at 12 and 24 months follow-up. RESULTS: A total of 307 diabetic patients were included, of which 162 (52.8%) in the 3 months DAPT group and 145 (47.2%) in the 12 months DAPT group. Patient characteristics, PCI success, and number of stents used were similar in the 3 and 12 months DAPT groups. Occurrence of the primary study endpoint at 12 and 24 months follow-up was comparable between the two groups (3.1 vs. 3.5%, p = 0.865, and 15.8 vs. 14.9%, p = 0.824, respectively). Moreover, the prevalence of the specific clinical outcome parameters (all-cause mortality), MI, ST, stroke, TVR, and bleeding was similar in both study groups. CONCLUSIONS: This sub-analysis shows similar clinical outcomes following 3 months DAPT as compared to 12 months DAPT in diabetic patients undergoing PCI for ACS using the COMBO stent. These results suggest that, even in this particular subset of patients, short duration of DAPT might be considered safe. Future larger studies are warranted to provide more precise estimations in terms of safety and efficacy of short term DAPT in these high-risk patients.


Acute Coronary Syndrome , Diabetes Mellitus , Dual Anti-Platelet Therapy , Platelet Aggregation Inhibitors , Acute Coronary Syndrome/drug therapy , Diabetes Mellitus/drug therapy , Drug-Eluting Stents , Dual Anti-Platelet Therapy/adverse effects , Humans , Myocardial Infarction/epidemiology , Percutaneous Coronary Intervention/methods , Platelet Aggregation Inhibitors/adverse effects , Stroke/epidemiology , Treatment Outcome
13.
Neurooncol Adv ; 4(1): vdac001, 2022.
Article En | MEDLINE | ID: mdl-35156037

BACKGROUND: Modern molecular pathology workflows in neuro-oncology heavily rely on the integration of morphologic and immunohistochemical patterns for analysis, classification, and prognostication. However, despite the recent emergence of digital pathology platforms and artificial intelligence-driven computational image analysis tools, automating the integration of histomorphologic information found across these multiple studies is challenged by large files sizes of whole slide images (WSIs) and shifts/rotations in tissue sections introduced during slide preparation. METHODS: To address this, we develop a workflow that couples different computer vision tools including scale-invariant feature transform (SIFT) and deep learning to efficiently align and integrate histopathological information found across multiple independent studies. We highlight the utility and automation potential of this workflow in the molecular subclassification and discovery of previously unappreciated spatial patterns in diffuse gliomas. RESULTS: First, we show how a SIFT-driven computer vision workflow was effective at automated WSI alignment in a cohort of 107 randomly selected surgical neuropathology cases (97/107 (91%) showing appropriate matches, AUC = 0.96). This alignment allows our AI-driven diagnostic workflow to not only differentiate different brain tumor types, but also integrate and carry out molecular subclassification of diffuse gliomas using relevant immunohistochemical biomarkers (IDH1-R132H, ATRX). To highlight the discovery potential of this workflow, we also examined spatial distributions of tumors showing heterogenous expression of the proliferation marker MIB1 and Olig2. This analysis helped uncover an interesting and unappreciated association of Olig2 positive and proliferative areas in some gliomas (r = 0.62). CONCLUSION: This efficient neuropathologist-inspired workflow provides a generalizable approach to help automate a variety of advanced immunohistochemically compatible diagnostic and discovery exercises in surgical neuropathology and neuro-oncology.

14.
EuroIntervention ; 17(16): 1313-1317, 2022 Mar 18.
Article En | MEDLINE | ID: mdl-34387547

Clinical guidelines recommend the development of ST-elevation myocardial infarction (STEMI) networks at community, regional and/or national level to ideally offer primary coronary angioplasty, or at least the best available STEMI care to all patients. However, there is a discrepancy between this clinical recommendation and daily practice, with no coordinated care for STEMI patients in many regions of the world. While this can be a consequence of lack of resources, in reality it is more frequently a lack of organisational power. In this paper, the Stent - Save a Life! Initiative (www.stentsavealife.com) proposes a practical methodology to set up a STEMI network effectively in any region of the world with existing resources, and to develop the STEMI network continuously once it has been established.


Angioplasty, Balloon, Coronary , Myocardial Infarction , ST Elevation Myocardial Infarction , Humans , ST Elevation Myocardial Infarction/surgery , Stents
15.
Glia ; 70(2): 368-378, 2022 02.
Article En | MEDLINE | ID: mdl-34726298

Alzheimer's disease (AD) is associated with senile plaques of beta-amyloid (Aß) that affect the function of neurons and astrocytes. Brain activity results from the coordinated function of neurons and astrocytes in astroglial-neuronal networks. However, the effects of Aß on astroglial and neuronal network function remains unknown. Simultaneously monitoring astrocyte calcium and electric neuronal activities, we quantified the impact of Aß on sensory-evoked cortical activity in a mouse model of AD. At rest, cortical astrocytes displayed spontaneous hyperactivity that was related to Aß density. Sensory-evoked astrocyte responsiveness was diminished in AD mice, depending on the density and distance of Aß, and the responses showed altered calcium dynamics. Hence, astrocytes were spontaneously hyperactive but hypo-responsive to sensory stimulation. Finally, AD mice showed sensory-evoked electrical cortical hyperresponsiveness associated with altered astrocyte-neuronal network interplay. Our findings suggest dysfunction of astrocyte networks in AD mice may dysregulate cortical electrical activity and contribute to cognitive decline.


Alzheimer Disease , Amyloid beta-Peptides/pharmacology , Animals , Astrocytes , Disease Models, Animal , Mice , Mice, Transgenic , Neurons , Plaque, Amyloid
16.
AsiaIntervention ; 7(1): 54-59, 2021 Jul.
Article En | MEDLINE | ID: mdl-34913003

AIMS: The aim of the study was to report the clinical experience, 30-day mortality and acute outcomes of patients undergoing transcatheter aortic valve implantation (TAVI) in the Asia Pacific region. METHODS AND RESULTS: The Asia Pacific TAVI registry is an international, multicentre, prospective, observational registry managed under the auspices of the Asian Pacific Society of Interventional Cardiology (APSIC). Patients undergoing TAVI in seven centres from Hong Kong, Japan, Philippines, Singapore and Taiwan, treated with TAVI devices for severe symptomatic aortic stenosis, were assessed. This first review presents the acute results and 30-day mortality. A multivariable analysis was also performed to identify independent predictors of early all-cause mortality. The enrolment was from 2009 to 2017 and a total of 1,125 patients were recruited. The 30-day mortality rate was 2.5%. Baseline logistic EuroSCORE more than 16 was independently associated with a 2.8-times increased risk of 30-day all-cause mortality (p=0.016). Post-procedural stroke (HR 4.9, p=0.008) was also associated with increased mortality. CONCLUSIONS: This initial report of the Asia Pacific TAVI registry demonstrated good acute success and low 30-day mortality. The preprocedural logistic EuroSCORE and post-procedural stroke incidence were strongly associated with acute mortality. Further attempts to reduce post-procedural stroke should be explored.

17.
Antioxidants (Basel) ; 10(11)2021 Nov 10.
Article En | MEDLINE | ID: mdl-34829667

Oxidative stress in Alzheimer's disease (AD) is mediated, in part, by the loss of glutathione (GSH). Previous studies show that γ-glutamyl transpeptidase (GGT)-resistant GSH analog, Ψ-GSH, improves brain GSH levels, reduces oxidative stress markers in brains of APP/PS1 transgenic mice, a mouse model of AD, and attenuates early memory deficits in the APP/PS1 model. Herein, we examined whether Ψ-GSH can attenuate the disease progression when administered following the onset of AD-like pathology in vivo. Cohorts of APP/PS1 mice were administered Ψ-GSH for 2 months starting at 8 month or 12 months of age. We show that Ψ-GSH treatment reduces indices of oxidative stress in older mice by restoration of enzyme glyoxalase-1 (Glo-1) activity and reduces levels of insoluble Aß. Quantitative neuropathological analyses show that Ψ-GSH treatment significantly reduces Aß deposition and brain inflammation in APP/PS1 mice compared to vehicle-treated mice. More importantly, Ψ-GSH treatment attenuated the progressive loss of cortical TH+ afferents and the loss of TH+ neurons in the locus coeruleus (LC). Collectively, the results show that Ψ-GSH exhibits significant antioxidant activity in aged APP/PS1 mice and chronic Ψ-GSH treatment administered after the onset of AD pathology can reverse/slow further progression of AD-like pathology and neurodegeneration in vivo.

18.
Cell Rep ; 37(2): 109817, 2021 10 12.
Article En | MEDLINE | ID: mdl-34644566

Pancreatic neuroendocrine neoplasms (PNENs) are biologically and clinically heterogeneous. Here, we use a multi-omics approach to uncover the molecular factors underlying this heterogeneity. Transcriptomic analysis of 84 PNEN specimens, drawn from two cohorts, is substantiated with proteomic profiling and identifies four subgroups: Proliferative, PDX1-high, Alpha cell-like and Stromal/Mesenchymal. The Proliferative subgroup, consisting of both well- and poorly differentiated specimens, is associated with inferior overall survival probability. The PDX1-high and Alpha cell-like subgroups partially resemble previously described subtypes, and we further uncover distinctive metabolism-related features in the Alpha cell-like subgroup. The Stromal/Mesenchymal subgroup exhibits molecular characteristics of YAP1/WWTR1(TAZ) activation suggestive of Hippo signaling pathway involvement in PNENs. Whole-exome sequencing reveals subgroup-enriched mutational differences, supported by activity inference analysis, and identifies hypermorphic proto-oncogene variants in 14.3% of sequenced PNENs. Our study reveals differences in cellular signaling axes that provide potential directions for PNEN patient stratification and treatment strategies.


Biomarkers, Tumor , Neuroendocrine Tumors/genetics , Neuroendocrine Tumors/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/metabolism , Proteome , Transcriptome , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cell Differentiation , Cell Proliferation , Co-Repressor Proteins/genetics , Co-Repressor Proteins/metabolism , Databases, Genetic , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Genetic Heterogeneity , Humans , Male , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Mutation , Neuroendocrine Tumors/pathology , Neuroendocrine Tumors/therapy , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/therapy , Prognosis , Proteomics , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Signal Transduction , Transcriptional Coactivator with PDZ-Binding Motif Proteins/genetics , Transcriptional Coactivator with PDZ-Binding Motif Proteins/metabolism , YAP-Signaling Proteins/genetics , YAP-Signaling Proteins/metabolism
19.
Cancers (Basel) ; 13(20)2021 Oct 13.
Article En | MEDLINE | ID: mdl-34680285

The overall survival of pancreatic ductal adenocarcinoma (PDAC) remains poor and its incidence is rising. Targetable mutations in PDAC are rare, thus novel therapeutic approaches are needed. Protein arginine methyltransferase 5 (PRMT5) overexpression is associated with worse survival and inhibition of PRMT5 results in decreased cancer growth across multiple cancers, including PDAC. Emerging evidence also suggests that altered RNA processing is a driver in PDAC tumorigenesis and creates a partial dependency on this process. PRMT5 inhibition induces altered splicing and this vulnerability can be exploited as a novel therapeutic approach. Three possible biological pathways underpinning the action of PRMT5 inhibitors are discussed; c-Myc regulation appears central to its action in the PDAC setting. Whilst homozygous MTAP deletion and symmetrical dimethylation levels are associated with increased sensitivity to PRMT5 inhibition, neither measure robustly predicts its growth inhibitory response. The immunomodulatory effect of PRMT5 inhibitors on the tumour microenvironment will also be discussed, based on emerging evidence that PDAC stroma has a significant bearing on disease behaviour and response to therapy. Lastly, with the above caveats in mind, current knowledge gaps and the implications and rationales for PRMT5 inhibitor development in PDAC will be explored.

20.
Curr Oncol ; 28(5): 3629-3648, 2021 09 21.
Article En | MEDLINE | ID: mdl-34590606

The 21st annual Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC) was held in Calgary, Alberta, 20-21 September 2019. The WCGCCC is an interactive multi-disciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists, pathologists, radiologists, and allied health care professionals such as dietitians and nurses participated in presentation and discussion sessions to develop the recommendations presented here. This consensus statement addresses current issues in the management of hepato-pancreato-biliary (HPB) cancers.


Gastrointestinal Neoplasms , Alberta , Consensus , Gastrointestinal Neoplasms/therapy , Humans , Manitoba , Saskatchewan
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