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1.
Alzheimers Dement ; 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-39090679

ABSTRACT

INTRODUCTION: Triggering receptor expressed on myeloid cells 2 (TREM2) agonists are being clinically evaluated as disease-modifying therapeutics for Alzheimer's disease. Clinically translatable pharmacodynamic (PD) biomarkers are needed to confirm drug activity and select the appropriate therapeutic dose in clinical trials. METHODS: We conducted multi-omic analyses on paired non-human primate brain and cerebrospinal fluid (CSF), and stimulation of human induced pluripotent stem cell-derived microglia cultures after TREM2 agonist treatment, followed by validation of candidate fluid PD biomarkers using immunoassays. We immunostained microglia to characterize proliferation and clustering. RESULTS: We report CSF soluble TREM2 (sTREM2) and CSF chitinase-3-like protein 1 (CHI3L1/YKL-40) as PD biomarkers for the TREM2 agonist hPara.09. The respective reduction of sTREM2 and elevation of CHI3L1 in brain and CSF after TREM2 agonist treatment correlated with transient microglia proliferation and clustering. DISCUSSION: CSF CHI3L1 and sTREM2 reflect microglial TREM2 agonism and can be used as clinical PD biomarkers to monitor TREM2 activity in the brain. HIGHLIGHTS: CSF soluble triggering receptor expressed on myeloid cells 2 (sTREM2) reflects brain target engagement for a novel TREM2 agonist, hPara.09. CSF chitinase-3-like protein 1 reflects microglial TREM2 agonism. Both can be used as clinical fluid biomarkers to monitor TREM2 activity in brain.

2.
Nat Commun ; 15(1): 6873, 2024 Aug 11.
Article in English | MEDLINE | ID: mdl-39127721

ABSTRACT

Ribosomes are regulated by evolutionarily conserved ubiquitination/deubiquitination events. We uncover the role of the deubiquitinase OTUD6 in regulating global protein translation through deubiquitination of the RPS7/eS7 subunit on the free 40 S ribosome in vivo in Drosophila. Coimmunoprecipitation and enrichment of monoubiquitinated proteins from catalytically inactive OTUD6 flies reveal RPS7 as the ribosomal substrate. The 40 S protein RACK1 and E3 ligases CNOT4 and RNF10 function upstream of OTUD6 to regulate alkylation stress. OTUD6 interacts with RPS7 specifically on the free 40 S, and not on 43 S/48 S initiation complexes or the translating ribosome. Global protein translation levels are bidirectionally regulated by OTUD6 protein abundance. OTUD6 protein abundance is physiologically regulated in aging and in response to translational and alkylation stress. Thus, OTUD6 may promote translation initiation, the rate limiting step in protein translation, by titering the amount of 40 S ribosome that recycles.


Subject(s)
Drosophila Proteins , Protein Biosynthesis , Ribosomal Proteins , Ubiquitination , Animals , Ribosomal Proteins/metabolism , Ribosomal Proteins/genetics , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Drosophila melanogaster/metabolism , Drosophila melanogaster/genetics , Ribosomes/metabolism , Stress, Physiological , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics
3.
BMJ ; 386: e078918, 2024 07 24.
Article in English | MEDLINE | ID: mdl-39048132

ABSTRACT

OBJECTIVE: To evaluate the personal protective effects of wearing versus not wearing surgical face masks in public spaces on self-reported respiratory symptoms over a 14 day period. DESIGN: Pragmatic randomised superiority trial. SETTING: Norway. PARTICIPANTS: 4647 adults aged ≥18 years: 2371 were assigned to the intervention arm and 2276 to the control arm. INTERVENTIONS: Participants in the intervention arm were assigned to wear a surgical face mask in public spaces (eg, shopping centres, streets, public transport) over a 14 day period (mask wearing at home or work was not mentioned). Participants in the control arm were assigned to not wear a surgical face mask in public places. MAIN OUTCOME MEASURES: The primary outcome was self-reported respiratory symptoms consistent with a respiratory infection. Secondary outcomes included self-reported and registered covid-19 infection. RESULTS: Between 10 February 2023 and 27 April 2023, 4647 participants were randomised of whom 4575 (2788 women (60.9%); mean age 51.0 (standard deviation 15.0) years) were included in the intention-to-treat analysis: 2313 (50.6%) in the intervention arm and 2262 (49.4%) in the control arm. 163 events (8.9%) of self-reported symptoms consistent with respiratory infection were reported in the intervention arm and 239 (12.2%) in the control arm. The marginal odds ratio was 0.71 (95% confidence interval (CI) 0.58 to 0.87; P=0.001) favouring the face mask intervention. The absolute risk difference was -3.2% (95% CI -5.2% to -1.3%; P<0.001). No statistically significant effect was found on self- reported (marginal odds ratio 1.07, 95% CI 0.58 to 1.98; P=0.82) or registered covid-19 infection (effect estimate and 95% CI not estimable owing to lack of events in the intervention arm). CONCLUSION: Wearing a surgical face mask in public spaces over 14 days reduces the risk of self-reported symptoms consistent with a respiratory infection, compared with not wearing a surgical face mask. TRIAL REGISTRATION: ClinicalTrials.gov NCT05690516.


Subject(s)
COVID-19 , Masks , SARS-CoV-2 , Self Report , Humans , Female , Male , COVID-19/prevention & control , COVID-19/epidemiology , Middle Aged , Norway/epidemiology , Adult , Respiratory Tract Infections/prevention & control , Aged , Pandemics/prevention & control , Coronavirus Infections/prevention & control , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Pneumonia, Viral/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Betacoronavirus
4.
J Neurosci ; 44(24)2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38692735

ABSTRACT

Sterile alpha and TIR motif containing 1 (SARM1) is an inducible NADase that localizes to mitochondria throughout neurons and senses metabolic changes that occur after injury. Minimal proteomic changes are observed upon either SARM1 depletion or activation, suggesting that SARM1 does not exert broad effects on neuronal protein homeostasis. However, whether SARM1 activation occurs throughout the neuron in response to injury and cell stress remains largely unknown. Using a semiautomated imaging pipeline and a custom-built deep learning scoring algorithm, we studied degeneration in both mixed-sex mouse primary cortical neurons and male human-induced pluripotent stem cell-derived cortical neurons in response to a number of different stressors. We show that SARM1 activation is differentially restricted to specific neuronal compartments depending on the stressor. Cortical neurons undergo SARM1-dependent axon degeneration after mechanical transection, and SARM1 activation is limited to the axonal compartment distal to the injury site. However, global SARM1 activation following vacor treatment causes both cell body and axon degeneration. Context-specific stressors, such as microtubule dysfunction and mitochondrial stress, induce axonal SARM1 activation leading to SARM1-dependent axon degeneration and SARM1-independent cell body death. Our data reveal that compartment-specific SARM1-mediated death signaling is dependent on the type of injury and cellular stressor.


Subject(s)
Armadillo Domain Proteins , Cerebral Cortex , Cytoskeletal Proteins , Induced Pluripotent Stem Cells , Neurons , Armadillo Domain Proteins/metabolism , Armadillo Domain Proteins/genetics , Animals , Cytoskeletal Proteins/metabolism , Cytoskeletal Proteins/genetics , Mice , Neurons/metabolism , Neurons/pathology , Male , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Humans , Female , Induced Pluripotent Stem Cells/metabolism , Nerve Degeneration/pathology , Nerve Degeneration/metabolism , Nerve Degeneration/genetics , Cells, Cultured , Mice, Inbred C57BL , Stress, Physiological/physiology , Axons/metabolism , Axons/pathology , Mitochondria/metabolism
5.
Nicotine Tob Res ; 26(Supplement_2): S89-S95, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38817026

ABSTRACT

INTRODUCTION: Systemic racism and tobacco-industry targeting contribute to disparities in communities of color. However, understanding tobacco as a social justice issue and the industry's role in perpetuating inequities remains limited. This study explored youth and young adult awareness of tobacco marketing and perceptions of tobacco marketing as a social justice issue. AIMS AND METHODS: Focus groups were conducted with youth and young adults in 2020 and 2021, including individuals who used tobacco and e-cigarettes and those who did not use either. Online surveys were conducted in 2021 with youth (n = 1227) and young adults (n = 2643) using AmeriSpeak's nationally representative panel, oversampling for black and Hispanic Americans and people who smoke. Perceptions of flavor bans, social justice, and industry marketing were assessed. RESULTS: Most (>80%) survey respondents agreed that tobacco companies target youth. However, only 20% saw tobacco as a social justice issue. Focus group participants regardless of their tobacco or e-cigarette use, reported higher prevalence of tobacco advertising in their communities relative to survey respondents but did not view it as targeting communities of color. Black non-Hispanic (20.9%) and Hispanic (21.4%) survey respondents perceived tobacco as a social justice issue more than white non-Hispanic (16.1%) respondents. The majority (>60%) of survey respondents supported bans on menthol and flavored tobacco, regardless of race or ethnicity. CONCLUSIONS: Respondents broadly supported menthol and flavored tobacco bans and recognized tobacco-industry influence on youth. Low awareness of tobacco as a social justice issue highlights the need to raise awareness of the underlying factors driving tobacco-related disparities. IMPLICATIONS: The majority of young people see the tobacco industry as targeting them. Most young people support bans on menthol and flavored tobacco bans, with support across racial and ethnic groups. While few young respondents perceived tobacco as a social justice issue, some perceived tobacco companies as targeting low-income and communities of color. Black non-Hispanic and Hispanic respondents were more likely to perceive tobacco as a social justice issue than white non-Hispanic respondents. Efforts to raise awareness among young people of tobacco as a social justice issue may be key in addressing tobacco disparities and advancing support for flavor tobacco bans.


Subject(s)
Focus Groups , Marketing , Social Justice , Tobacco Industry , Humans , Young Adult , Adolescent , Male , Female , Adult , Electronic Nicotine Delivery Systems/statistics & numerical data , Hispanic or Latino/psychology , Hispanic or Latino/statistics & numerical data , Tobacco Products , Health Knowledge, Attitudes, Practice , Surveys and Questionnaires , Black or African American/psychology , Black or African American/statistics & numerical data
6.
J Neurosci Res ; 102(5): e25337, 2024 May.
Article in English | MEDLINE | ID: mdl-38680084

ABSTRACT

Hepatic encephalopathy (HE) is defined as decline in neurological function during chronic liver disease (CLD). Alcohol is a major etiological factor in the pathogenesis of fibrosis/cirrhosis and has also been documented to directly impact the brain. However, the role of alcohol in the development of HE in CLD remains unclear. Here, we investigated the impact of excessive alcohol administration on neurological deterioration in rats with CLD. Starting day 7 post-BDL surgery, rats were administered alcohol twice daily (51% v/v ethanol, 3 g/kg, via gavage) for 4 weeks. Motor coordination was assessed weekly using rotarod and anxiety-like behavior was evaluated with open field and elevated plus maze at 5 weeks. Upon sacrifice, brains were collected for western blot and immunohistochemical analyses to investigate neuronal integrity and oxidative stress status. Alcohol worsened motor coordination performance and increased anxiety-like behavior in BDL rats. Impairments were associated with decreased neuronal markers of NeuN and SMI311, increased apoptotic markers of cleaved/pro-caspase-3 and Bax/Bcl2, increased necroptosis markers of pRIP3 and pMLKL, decreased total antioxidant capacity (TAC), and increased 4-hydroxynonenal (4-HNE)modified proteins in the cerebellum of BDL-alcohol rats when compared to respective controls. Immunofluorescence confirmed the colocalization of cleaved caspase-3 and pMLKL in the granular neurons of the cerebellum of BDL-alcohol rats. Excessive alcohol consumption exacerbates HE which leads to associated apoptotic and necroptotic neuronal loss in the cerebellum of BDL-alcohol rats. Additionally, higher levels of 4-HNE and decreased TAC in the cerebellum of BDL-alcohol rats suggest oxidative stress is the triggering factor of apoptotic and necroptotic neuronal loss/injury.


Subject(s)
Ethanol , Hepatic Encephalopathy , Neurons , Oxidative Stress , Animals , Male , Hepatic Encephalopathy/pathology , Hepatic Encephalopathy/chemically induced , Hepatic Encephalopathy/metabolism , Ethanol/toxicity , Ethanol/adverse effects , Rats , Neurons/pathology , Neurons/drug effects , Neurons/metabolism , Oxidative Stress/drug effects , Oxidative Stress/physiology , Cell Death/drug effects , Rats, Sprague-Dawley , Apoptosis/drug effects , Anxiety/etiology
7.
JMIR Res Protoc ; 13: e54440, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38517464

ABSTRACT

BACKGROUND: Liver transplantation (LT) is indicated in patients with severe acute or chronic liver failure for which no other therapy is available. With the increasing number of LTs in recent years, liver centers worldwide must manage their patients according to their clinical situation and the expected waiting time for transplantation. The LT clinic at the Centre hospitalier de l'Université de Montréal (CHUM) is developing a new health care model across the entire continuum of pre-, peri-, and posttransplant care that features patient monitoring by an interdisciplinary team, including an accompanying patient; a digital platform to host a clinical plan; a learning program; and data collection from connected objects. OBJECTIVE: This study aims to (1) evaluate the outcomes following the implementation of a patient platform with connected devices and an accompanying patient, (2) identify implementation barriers and facilitators, (3) describe service outcomes in terms of health outcomes and the rates and nature of contact with the accompanying patient, (4) describe patient outcomes, and (5) assess the intervention's cost-effectiveness. METHODS: Six types of participants will be included in the study: (1) patients who received transplants and reached 1 year after transplantation before September 2023 (historical cohort or control group), (2) patients who will receive an LT between December 2023 and November 2024 (prospective cohort/intervention group), (3) relatives of those patients, (4) accompanying patients who have received an LT and are interested in supporting patients who will receive an LT, (5) health care professionals, and (6) decision makers. To describe the study sample and collect data to achieve all the objectives, a series of validated questionnaires, accompanying patient logbooks, transcripts of interviews and focus groups, and clinical indicators will be collected throughout the study. RESULTS: In total, 5 (steering, education, clinical-technological, nurse prescription, and accompanying patient) working committees have been established for the study. Recruitment of patients is expected to start in November 2023. All questionnaires and technological platforms have been prepared, and the clinicians, stakeholders, and accompanying patient personnel have been recruited. CONCLUSIONS: The implementation of this model in the trajectory of LT recipients at the CHUM may allow for better monitoring and health of patients undergoing transplantation, ultimately reducing the average length of hospital stay and promoting better use of medical resources. In the event of positive results, this model could be transposed to all transplant units at the CHUM and across Quebec (potentially affecting 888 patients per year) but could also be applied more widely to the monitoring of patients with other chronic diseases. The lessons learned from this project will be shared with decision makers and will serve as a model for other initiatives involving accompanying patients, connected objects, or digital platforms. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/54440.

8.
Rapid Commun Mass Spectrom ; 38(9): e9731, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38469943

ABSTRACT

RATIONALE: Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in North America. To investigate the effect of drug-induced liver injury (DILI) on circulating bile acid (BA) profiles, serum from ALF patients and healthy controls were analyzed using a semitargeted high-resolution mass spectrometry approach to measure BAs in their unconjugated and amidated forms and their glucuronide and sulfate conjugates. METHODS: Human serum samples from 20 healthy volunteers and 34 ALF patients were combined with deuterated BAs and extracted, prior to liquid chromatography high-resolution tandem mass spectrometry analysis. A mix of 46 standards helped assign 26 BAs in human serum by accurate mass and retention time matching. Moreover, other isomers of unconjugated and amidated BAs, as well as glucuronide and sulfate conjugates, were assigned by accurate mass filtering. In vitro incubations of standard BAs provided increased information for certain peaks of interest. RESULTS: A total of 275 BA metabolites, with confirmed or putative assignments, were measured in human serum samples. APAP overdose significantly influenced the levels of most BAs, promoting glycine conjugation, and, to a lesser extent, taurine conjugation. When patient outcome was considered, 11 BAs were altered significantly, including multiple sulfated species. Although many of the BAs measured did not have exact structures assigned, several putatively identified BAs of interest were further characterized using in vitro incubations. CONCLUSION: An optimized chromatographic separation tailored to BAs of ranging polarities was combined with accurate mass measurements to investigate the effect that DILI has on their complex profiles and metabolism to a much wider extent than previously possible. The analysis of complex BA profiles enabled in-depth analysis of the BA metabolism perturbations in ALF, including certain metabolites related to patient outcomes.


Subject(s)
Bile Acids and Salts , Chemical and Drug Induced Liver Injury , Humans , Acetaminophen/adverse effects , Glucuronides , Mass Spectrometry , Chemical and Drug Induced Liver Injury/etiology , Sulfates , Liver
9.
Brief Bioinform ; 25(3)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38555476

ABSTRACT

Antigen presentation on MHC class II (pMHCII presentation) plays an essential role in the adaptive immune response to extracellular pathogens and cancerous cells. But it can also reduce the efficacy of large-molecule drugs by triggering an anti-drug response. Significant progress has been made in pMHCII presentation modeling due to the collection of large-scale pMHC mass spectrometry datasets (ligandomes) and advances in machine learning. Here, we develop graph-pMHC, a graph neural network approach to predict pMHCII presentation. We derive adjacency matrices for pMHCII using Alphafold2-multimer and address the peptide-MHC binding groove alignment problem with a simple graph enumeration strategy. We demonstrate that graph-pMHC dramatically outperforms methods with suboptimal inductive biases, such as the multilayer-perceptron-based NetMHCIIpan-4.0 (+20.17% absolute average precision). Finally, we create an antibody drug immunogenicity dataset from clinical trial data and develop a method for measuring anti-antibody immunogenicity risk using pMHCII presentation models. Our model increases receiver operating characteristic curve (ROC)-area under the ROC curve (AUC) by 2.57% compared to just filtering peptides by hits in OASis alone for predicting antibody drug immunogenicity.


Subject(s)
Histocompatibility Antigens Class II , Peptides , Antigen Presentation , Histocompatibility Antigens Class II/chemistry , Neural Networks, Computer , Peptides/chemistry , Humans
10.
J Med Chem ; 67(2): 1262-1313, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38180485

ABSTRACT

The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Proteolysis Targeting Chimera , Heterografts , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line , Lung Neoplasms/genetics , Transcription Factors/genetics , DNA Helicases/genetics , Nuclear Proteins/genetics
11.
J Proteome Res ; 23(8): 2934-2947, 2024 Aug 02.
Article in English | MEDLINE | ID: mdl-38251652

ABSTRACT

Intelligent data acquisition (IDA) strategies, such as a real-time database search (RTS), have improved the depth of proteome coverage for experiments that utilize isobaric labels and gas phase purification techniques (i.e., SPS-MS3). In this work, we introduce inSeqAPI, an instrument application programing interface (iAPI) program that enables construction of novel data acquisition algorithms. First, we analyze biotinylated cysteine peptides from ABPP experiments to demonstrate that a real-time search method within inSeqAPI performs similarly to an equivalent vendor method. Then, we describe PairQuant, a method within inSeqAPI designed for the hyperplexing approach that utilizes protein-level isotopic labeling and peptide-level TMT labeling. PairQuant allows for TMT analysis of 36 conditions in a single sample and achieves ∼98% coverage of both peptide pair partners in a hyperplexed experiment as well as a 40% improvement in the number of quantified cysteine sites compared with non-RTS acquisition. We applied this method in the ABPP study of ligandable cysteine sites in the nucleus leading to an identification of additional druggable sites on protein- and DNA-interaction domains of transcription regulators and on nuclear ubiquitin ligases.


Subject(s)
Cysteine , Proteome , Proteomics , Proteome/analysis , Proteomics/methods , Cysteine/chemistry , Cysteine/metabolism , Cysteine/analysis , Humans , Reproducibility of Results , Algorithms , Peptides/chemistry , Peptides/analysis , Isotope Labeling/methods , Software
12.
Metab Brain Dis ; 39(3): 403-437, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37606786

ABSTRACT

Brain edema is considered as a common feature associated with hepatic encephalopathy (HE). However, its central role as cause or consequence of HE and its implication in the development of the neurological alterations linked to HE are still under debate. It is now well accepted that type A and type C HE are biologically and clinically different, leading to different manifestations of brain edema. As a result, the findings on brain edema/swelling in type C HE are variable and sometimes controversial. In the light of the changing natural history of liver disease, better description of the clinical trajectory of cirrhosis and understanding of molecular mechanisms of HE, and the role of brain edema as a central component in the pathogenesis of HE is revisited in the current review. Furthermore, this review highlights the main techniques to measure brain edema and their advantages/disadvantages together with an in-depth description of the main ex-vivo/in-vivo findings using cell cultures, animal models and humans with HE. These findings are instrumental in elucidating the role of brain edema in HE and also in designing new multimodal studies by performing in-vivo combined with ex-vivo experiments for a better characterization of brain edema longitudinally and of its role in HE, especially in type C HE where water content changes are small.


Subject(s)
Brain Edema , Hepatic Encephalopathy , Animals , Humans , Hepatic Encephalopathy/metabolism , Brain Edema/metabolism , Brain/metabolism , Models, Animal , Liver Cirrhosis/complications
13.
Cell Rep ; 42(12): 113515, 2023 12 26.
Article in English | MEDLINE | ID: mdl-38096048

ABSTRACT

Argonaute (AGO) proteins execute microRNA (miRNA)-mediated gene silencing. However, it is unclear whether all 4 mammalian AGO proteins (AGO1, AGO2, AGO3, and AGO4) are required for miRNA activity. We generate Ago1, Ago3, and Ago4-deficient mice (Ago134Δ) and find AGO1/3/4 to be redundant for miRNA biogenesis, homeostasis, or function, a role that is carried out by AGO2. Instead, AGO1/3/4 regulate the expansion of type 2 immunity via precursor mRNA splicing in CD4+ T helper (Th) lymphocytes. Gain- and loss-of-function experiments demonstrate that nuclear AGO3 interacts directly with SF3B3, a component of the U2 spliceosome complex, to aid global mRNA splicing, and in particular the isoforms of the gene Nisch, resulting in a dysregulated Nisch isoform ratio. This work uncouples AGO1, AGO3, and AGO4 from miRNA-mediated RNA interference, identifies an AGO3:SF3B3 complex in the nucleus, and reveals a mechanism by which AGO proteins regulate inflammatory diseases.


Subject(s)
MicroRNAs , RNA Precursors , Animals , Mice , Argonaute Proteins/genetics , Argonaute Proteins/metabolism , Imidazoline Receptors/genetics , Imidazoline Receptors/metabolism , Mammals/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA Interference , RNA Precursors/genetics , RNA Precursors/metabolism , RNA Splicing/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism
14.
JHEP Rep ; 5(12): 100904, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37942225

ABSTRACT

Background & Aims: Hepatic encephalopathy (HE) is defined as a reversible syndrome and therefore should resolve following liver transplantation (LT). However, neurological complications have been reported in up to 47% of LT recipients, which have been documented to be associated with a history of overt HE pre-LT. We hypothesise that multiple episodes of HE lead to permanent cell injury and exacerbate neurological dysfunction. Our goal was to evaluate the impact of cumulative HE episodes on neurological status and brain integrity in rats with chronic liver disease. Methods: Episodes of overt HE (loss of righting reflex) were induced following injection of ammonium acetate in bile duct ligation (BDL) rats (BDL-Ammonia) every 4 days starting at week 3 post-BDL. Neurobehaviour was evaluated after the last episode. Upon sacrifice, plasma ammonia, systemic oxidative stress, and inflammation markers were assessed. Neuronal markers including neuron-specific nuclear antigen and SMI311 (anti-neurofilament marker) and apoptotic markers (cleaved caspase-3, Bax, and Bcl2) were measured. Total antioxidant capacity, oxidative stress marker (4-hydroxynonenal), and proinflammatory cytokines (tumour necrosis factor-alpha and interleukin-1ß) were measured in brain (hippocampus, frontal cortex, and cerebellum). Proteomic analysis was conducted in the hippocampus. Results: In hippocampus of BDL-Ammonia rats, cleaved caspase-3 and Bax/Bcl2 ratio were significantly increased, whereas NeuN and SMI311 were significantly decreased compared with BDL-Vehicle rats. Higher levels of oxidative stress-induced post-translational modified proteins were found in hippocampus of BDL-Ammonia group which were associated with a lower total antioxidant capacity. Conclusions: Ammonia-induced episodes of overt HE caused neuronal cell injury/death in BDL rats. These results suggest that multiple bouts of HE can be detrimental on the integrity of the brain, translating to irreversibility and hence neurological complications post-LT. Impact and implications: Hepatic encephalopathy (HE) is defined as a reversible neuropsychiatric syndrome resolving following liver transplantation (LT); however, ∼47% of patients demonstrate neurological impairments after LT, which are associated with a previous history of overt HE pre-LT. Our study indicates that multiple episodes of overt HE can cause permanent neuronal damage which may lead to neurological complications after LT. Nevertheless, preventing the occurrence of overt HE episodes is critical for reducing the risk of irreversible neuronal injury in patients with cirrhosis.

15.
iScience ; 26(11): 108362, 2023 Nov 17.
Article in English | MEDLINE | ID: mdl-37965143

ABSTRACT

Heterozygous mutations in the granulin (GRN) gene are a leading cause of frontotemporal lobar degeneration with TDP-43 aggregates (FTLD-TDP). Polymorphisms in TMEM106B have been associated with disease risk in GRN mutation carriers and protective TMEM106B variants associated with reduced levels of TMEM106B, suggesting that lowering TMEM106B might be therapeutic in the context of FTLD. Here, we tested the impact of full deletion and partial reduction of TMEM106B in mouse and iPSC-derived human cell models of GRN deficiency. TMEM106B deletion did not reverse transcriptomic or proteomic profiles in GRN-deficient microglia, with a few exceptions in immune signaling markers. Neither homozygous nor heterozygous Tmem106b deletion normalized disease-associated phenotypes in Grn -/-mice. Furthermore, Tmem106b reduction by antisense oligonucleotide (ASO) was poorly tolerated in Grn -/-mice. These data provide novel insight into TMEM106B and GRN function in microglia cells but do not support lowering TMEM106B levels as a viable therapeutic strategy for treating FTD-GRN.

16.
Nat Biotechnol ; 2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37857725

ABSTRACT

The broad application of precision cancer immunotherapies is limited by the number of validated neoepitopes that are common among patients or tumor types. To expand the known repertoire of shared neoantigen-human leukocyte antigen (HLA) complexes, we developed a high-throughput platform that coupled an in vitro peptide-HLA binding assay with engineered cellular models expressing individual HLA alleles in combination with a concatenated transgene harboring 47 common cancer neoantigens. From more than 24,000 possible neoepitope-HLA combinations, biochemical and computational assessment yielded 844 unique candidates, of which 86 were verified after immunoprecipitation mass spectrometry analyses of engineered, monoallelic cell lines. To evaluate the potential for immunogenicity, we identified T cell receptors that recognized select neoepitope-HLA pairs and elicited a response after introduction into human T cells. These cellular systems and our data on therapeutically relevant neoepitopes in their HLA contexts will aid researchers studying antigen processing as well as neoepitope targeting therapies.

17.
Nat Commun ; 14(1): 6322, 2023 10 09.
Article in English | MEDLINE | ID: mdl-37813836

ABSTRACT

Microglial reactivity is a pathological hallmark in many neurodegenerative diseases. During stimulation, microglia undergo complex morphological changes, including loss of their characteristic ramified morphology, which is routinely used to detect and quantify inflammation in the brain. However, the underlying molecular mechanisms and the relation between microglial morphology and their pathophysiological function are unknown. Here, proteomic profiling of lipopolysaccharide (LPS)-reactive microglia identifies microtubule remodeling pathways as an early factor that drives the morphological change and subsequently controls cytokine responses. We find that LPS-reactive microglia reorganize their microtubules to form a stable and centrosomally-anchored array to facilitate efficient cytokine trafficking and release. We identify cyclin-dependent kinase 1 (Cdk-1) as a critical upstream regulator of microtubule remodeling and morphological change in-vitro and in-situ. Cdk-1 inhibition also rescues tau and amyloid fibril-induced morphology changes. These results demonstrate a critical role for microtubule dynamics and reorganization in microglial reactivity and modulating cytokine-mediated inflammatory responses.


Subject(s)
Cytokines , Microglia , Cytokines/metabolism , Microglia/metabolism , Lipopolysaccharides/pharmacology , Lipopolysaccharides/metabolism , Proteomics , Microtubules/metabolism
18.
J Evid Based Med ; 16(3): 285-293, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37725488

ABSTRACT

AIM: The aim was to evaluate the effect of the Informed Health Choices (IHC) educational intervention on secondary students' ability to assess health-related claims and make informed choices. METHODS: In a cluster-randomized trial, we randomized 80 secondary schools (students aged 13-17 years) in Uganda to the intervention or control (usual curriculum). The intervention included a 2-day teacher training workshop, 10 lessons accessed online by teachers and delivered in one school term. The lesson plans were developed for classrooms equipped with a blackboard or a blackboard and projector. The lessons addressed nine prioritized concepts. We used two multiple-choice questions for each concept to evaluate the students' ability to assess claims and make informed choices. The primary outcome was the proportion of students with a passing score (≥9 of 18 questions answered correctly). RESULTS: Eighty schools consented and were randomly allocated. A total of 2477 students in the 40 intervention schools and 2376 students in the 40 control schools participated in this trial. In the intervention schools, 1364 (55%) of students that completed the test had a passing score compared with 586 (25%) of students in the control schools (adjusted difference 33%, 95% CI 26%-39%). CONCLUSIONS: The IHC secondary school intervention improved students' ability to think critically and make informed choices. Well-designed digital resources may improve access to educational material, even in schools without computers or other information and communication technology (ICT). This could facilitate scaling-up use of the resources and help to address inequities associated with limited ICT access.

19.
J Evid Based Med ; 16(3): 321-331, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37735807

ABSTRACT

AIM: The aim of this prospective meta-analysis was to synthesize the results of three cluster-randomized trials of an intervention designed to teach lower-secondary school students (age 14-16) to think critically about health choices. METHODS: We conducted the trials in Kenya, Rwanda, and Uganda. The intervention included a 2- to 3-day teacher training workshop, digital resources, and ten 40-min lessons. The lessons focused on nine key concepts. We did not intervene in control schools. The primary outcome was a passing score on a test (≥9 of 18 multiple-choice questions answered correctly). We performed random effects meta-analyses to estimate the overall adjusted odds ratios. Secondary outcomes included effects of the intervention on teachers. RESULTS: Altogether, 244 schools (11,344 students) took part in the three trials. The overall adjusted odds ratio was 5.5 (95% CI: 3.0-10.2; p < 0.0001) in favor of the intervention (high certainty evidence). This corresponds to 33% (95% CI: 25-40%) more students in the intervention schools passing the test. Overall, 3397 (58%) of 5846 students in intervention schools had a passing score. The overall adjusted odds ratio for teachers was 13.7(95% CI: 4.6-40.4; p < 0.0001), corresponding to 32% (95% CI: 6%-57%) more teachers in the intervention schools passing the test (moderate certainty evidence). Overall, 118 (97%) of 122 teachers in intervention schools had a passing score. CONCLUSIONS: The intervention led to a large improvement in the ability of students and teachers to think critically about health choices, but 42% of students in the intervention schools did not achieve a passing score.


Subject(s)
Choice Behavior , Health Education , Humans , Adolescent , Health Education/methods , Prospective Studies , Schools , Uganda
20.
J Evid Based Med ; 16(3): 264-274, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37735809

ABSTRACT

AIM: The aim of this trial was to evaluate the effects of the Informed Health Choices intervention on the ability of students in Rwandan to think critically and make Informed Health Choices. METHODS: We conducted a two-arm cluster-randomized trial in 84 lower secondary schools from 10 districts representing five provinces of Rwanda. We used stratified randomization to allocate schools to the intervention or control. One class in each intervention school had ten 40-min lessons taught by a trained teacher in addition to the usual curriculum. Control schools followed the usual curriculum. The primary outcome was a passing score (≥ 9 out of 18 questions answered correctly) for students on the Critical Thinking about Health Test completed within 2 weeks after the intervention. We conducted an intention-to-treat analysis using generalized linear mixed models, accounting for the cluster design using random intercepts. RESULTS: Between February 25 and March 29, 2022, we recruited 3,212 participants. We assigned 1,572 students and 42 teachers to the intervention arm and 1,556 students and 42 teachers to the control arm. The proportion of students who passed the test in the intervention arm was 915/1,572 (58.2%) compared to 302/1,556 (19.4%) in the control arm, adjusted odds ratio 10.6 (95% CI: 6.3-17.8), p < 0.0001, adjusted difference 37.2% (95% CI: 29.5%-45.0%). CONCLUSIONS: The intervention is effective in helping students think critically about health choices. It was possible to improve students' ability to think critically about health in the context of a competence-based curriculum in Rwanda, despite challenging postpandemic conditions.

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