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Tau (MAPT) drives neuronal dysfunction in Alzheimer disease (AD) and other tauopathies. To dissect the underlying mechanisms, we combined an engineered ascorbic acid peroxidase (APEX) approach with quantitative affinity purification mass spectrometry (AP-MS) followed by proximity ligation assay (PLA) to characterize Tau interactomes modified by neuronal activity and mutations that cause frontotemporal dementia (FTD) in human induced pluripotent stem cell (iPSC)-derived neurons. We established interactions of Tau with presynaptic vesicle proteins during activity-dependent Tau secretion and mapped the Tau-binding sites to the cytosolic domains of integral synaptic vesicle proteins. We showed that FTD mutations impair bioenergetics and markedly diminished Tau's interaction with mitochondria proteins, which were downregulated in AD brains of multiple cohorts and correlated with disease severity. These multimodal and dynamic Tau interactomes with exquisite spatial resolution shed light on Tau's role in neuronal function and disease and highlight potential therapeutic targets to block Tau-mediated pathogenesis.
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Mitocôndrias/metabolismo , Degeneração Neural/metabolismo , Mapas de Interação de Proteínas , Sinapses/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/genética , Aminoácidos/metabolismo , Biotinilação , Encéfalo/metabolismo , Encéfalo/patologia , Núcleo Celular/metabolismo , Progressão da Doença , Metabolismo Energético , Demência Frontotemporal/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Proteínas Mutantes/metabolismo , Mutação/genética , Degeneração Neural/patologia , Neurônios/metabolismo , Ligação Proteica , Domínios Proteicos , Proteômica , Índice de Gravidade de Doença , Frações Subcelulares/metabolismo , Tauopatias/genética , Proteínas tau/químicaRESUMO
Long-distance RNA transport enables local protein synthesis at metabolically-active sites distant from the nucleus. This process ensures an appropriate spatial organization of proteins, vital to polarized cells such as neurons. Here, we present a mechanism for RNA transport in which RNA granules "hitchhike" on moving lysosomes. In vitro biophysical modeling, live-cell microscopy, and unbiased proximity labeling proteomics reveal that annexin A11 (ANXA11), an RNA granule-associated phosphoinositide-binding protein, acts as a molecular tether between RNA granules and lysosomes. ANXA11 possesses an N-terminal low complexity domain, facilitating its phase separation into membraneless RNA granules, and a C-terminal membrane binding domain, enabling interactions with lysosomes. RNA granule transport requires ANXA11, and amyotrophic lateral sclerosis (ALS)-associated mutations in ANXA11 impair RNA granule transport by disrupting their interactions with lysosomes. Thus, ANXA11 mediates neuronal RNA transport by tethering RNA granules to actively-transported lysosomes, performing a critical cellular function that is disrupted in ALS.
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Anexinas/metabolismo , Transporte Axonal/fisiologia , Grânulos Citoplasmáticos/metabolismo , Lisossomos/metabolismo , RNA/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Animais , Animais Geneticamente Modificados , Anexinas/genética , Axônios/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Mutação , Ligação Proteica , Ratos/embriologia , Ratos Sprague-Dawley , Transfecção , Peixe-ZebraRESUMO
Although gene discovery in neuropsychiatric disorders, including autism spectrum disorder, intellectual disability, epilepsy, schizophrenia, and Tourette disorder, has accelerated, resulting in a large number of molecular clues, it has proven difficult to generate specific hypotheses without the corresponding datasets at the protein complex and functional pathway level. Here, we describe one path forward-an initiative aimed at mapping the physical and genetic interaction networks of these conditions and then using these maps to connect the genomic data to neurobiology and, ultimately, the clinic. These efforts will include a team of geneticists, structural biologists, neurobiologists, systems biologists, and clinicians, leveraging a wide array of experimental approaches and creating a collaborative infrastructure necessary for long-term investigation. This initiative will ultimately intersect with parallel studies that focus on other diseases, as there is a significant overlap with genes implicated in cancer, infectious disease, and congenital heart defects.
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Mapeamento Cromossômico/métodos , Transtornos do Neurodesenvolvimento/genética , Biologia de Sistemas/métodos , Redes Reguladoras de Genes/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Humanos , Neurobiologia/métodos , NeuropsiquiatriaRESUMO
Variants of UNC13A, a critical gene for synapse function, increase the risk of amyotrophic lateral sclerosis and frontotemporal dementia1-3, two related neurodegenerative diseases defined by mislocalization of the RNA-binding protein TDP-434,5. Here we show that TDP-43 depletion induces robust inclusion of a cryptic exon in UNC13A, resulting in nonsense-mediated decay and loss of UNC13A protein. Two common intronic UNC13A polymorphisms strongly associated with amyotrophic lateral sclerosis and frontotemporal dementia risk overlap with TDP-43 binding sites. These polymorphisms potentiate cryptic exon inclusion, both in cultured cells and in brains and spinal cords from patients with these conditions. Our findings, which demonstrate a genetic link between loss of nuclear TDP-43 function and disease, reveal the mechanism by which UNC13A variants exacerbate the effects of decreased TDP-43 function. They further provide a promising therapeutic target for TDP-43 proteinopathies.
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Esclerose Lateral Amiotrófica , Demência Frontotemporal , Proteinopatias TDP-43 , Processamento Alternativo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Códon sem Sentido , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Humanos , Proteínas do Tecido Nervoso , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Protein aggregates disrupt cellular homeostasis, causing toxicity linked to neurodegeneration. Selective autophagic elimination of aggregates is critical to protein quality control, but how aggregates are selectively targeted for degradation is unclear. We compared the requirements for autophagy receptor proteins: OPTN, NBR1, p62, NDP52, and TAX1BP1 in clearance of proteotoxic aggregates. Endogenous TAX1BP1 is recruited to and required for the clearance of stress-induced aggregates, whereas ectopic expression of TAX1BP1 increases clearance through autophagy, promoting viability of human induced pluripotent stem cell-derived neurons. In contrast, TAX1BP1 depletion sensitizes cells to several forms of aggregate-induced proteotoxicity. Furthermore, TAX1BP1 is more specifically expressed in the brain compared to other autophagy receptor proteins. In vivo, loss of TAX1BP1 results in accumulation of high molecular weight ubiquitin conjugates and premature lipofuscin accumulation in brains of young TAX1BP1 knockout mice. TAX1BP1 mediates clearance of a broad range of cytotoxic proteins indicating therapeutic potential in neurodegenerative diseases.
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Proteínas Reguladoras de Apoptose/deficiência , Autofagia , Encéfalo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Proteínas de Neoplasias/deficiência , Doenças Neurodegenerativas/metabolismo , Agregação Patológica de Proteínas/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Encéfalo/patologia , Feminino , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipofuscina/genética , Lipofuscina/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/patologia , Ratos , Ratos Sprague-Dawley , Ubiquitina/genética , Ubiquitina/metabolismoRESUMO
Defects in DNA repair frequently lead to neurodevelopmental and neurodegenerative diseases, underscoring the particular importance of DNA repair in long-lived post-mitotic neurons1,2. The cellular genome is subjected to a constant barrage of endogenous DNA damage, but surprisingly little is known about the identity of the lesion(s) that accumulate in neurons and whether they accrue throughout the genome or at specific loci. Here we show that post-mitotic neurons accumulate unexpectedly high levels of DNA single-strand breaks (SSBs) at specific sites within the genome. Genome-wide mapping reveals that SSBs are located within enhancers at or near CpG dinucleotides and sites of DNA demethylation. These SSBs are repaired by PARP1 and XRCC1-dependent mechanisms. Notably, deficiencies in XRCC1-dependent short-patch repair increase DNA repair synthesis at neuronal enhancers, whereas defects in long-patch repair reduce synthesis. The high levels of SSB repair in neuronal enhancers are therefore likely to be sustained by both short-patch and long-patch processes. These data provide the first evidence of site- and cell-type-specific SSB repair, revealing unexpected levels of localized and continuous DNA breakage in neurons. In addition, they suggest an explanation for the neurodegenerative phenotypes that occur in patients with defective SSB repair.
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Quebras de DNA de Cadeia Simples , Reparo do DNA , Elementos Facilitadores Genéticos/genética , Neurônios/metabolismo , 5-Metilcitosina/metabolismo , Linhagem Celular , DNA/biossíntese , Replicação do DNA , Humanos , Masculino , Metilação , Poli(ADP-Ribose) Polimerases/metabolismo , Análise de Sequência de DNARESUMO
A major function of TAR DNA-binding protein-43 (TDP-43) is to repress the inclusion of cryptic exons during RNA splicing. One of these cryptic exons is in UNC13A, a genetic risk factor for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The accumulation of cryptic UNC13A in disease is heightened by the presence of a risk haplotype located within the cryptic exon itself. Here, we revealed that TDP-43 extreme N-terminus is important to repress UNC13A cryptic exon inclusion. Further, we found hnRNP L, hnRNP A1, and hnRNP A2B1 bind UNC13A RNA and repress cryptic exon inclusion, independently of TDP-43. Finally, higher levels of hnRNP L protein associate with lower burden of UNC13A cryptic RNA in ALS/FTD brains. Our findings suggest that while TDP-43 is the main repressor of UNC13A cryptic exon inclusion, other hnRNPs contribute to its regulation and may potentially function as disease modifiers.
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Esclerose Lateral Amiotrófica , Demência Frontotemporal , Ribonucleoproteínas Nucleares Heterogêneas Grupo L , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Éxons/genética , Demência Frontotemporal/genética , Ribonucleoproteínas Nucleares Heterogêneas/genética , RNA , Proteínas do Tecido Nervoso/metabolismoRESUMO
[This corrects the article DOI: 10.1371/journal.pbio.3002028.].
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In frontotemporal lobar degeneration (FTLD), pathological protein aggregation in specific brain regions is associated with declines in human-specialized social-emotional and language functions. In most patients, disease protein aggregates contain either TDP-43 (FTLD-TDP) or tau (FTLD-tau). Here, we explored whether FTLD-associated regional degeneration patterns relate to regional gene expression of human accelerated regions (HARs), conserved sequences that have undergone positive selection during recent human evolution. To this end, we used structural neuroimaging from patients with FTLD and human brain regional transcriptomic data from controls to identify genes expressed in FTLD-targeted brain regions. We then integrated primate comparative genomic data to test our hypothesis that FTLD targets brain regions linked to expression levels of recently evolved genes. In addition, we asked whether genes whose expression correlates with FTLD atrophy are enriched for genes that undergo cryptic splicing when TDP-43 function is impaired. We found that FTLD-TDP and FTLD-tau subtypes target brain regions with overlapping and distinct gene expression correlates, highlighting many genes linked to neuromodulatory functions. FTLD atrophy-correlated genes were strongly enriched for HARs. Atrophy-correlated genes in FTLD-TDP showed greater overlap with TDP-43 cryptic splicing genes and genes with more numerous TDP-43 binding sites compared with atrophy-correlated genes in FTLD-tau. Cryptic splicing genes were enriched for HAR genes, and vice versa, but this effect was due to the confounding influence of gene length. Analyses performed at the individual-patient level revealed that the expression of HAR genes and cryptically spliced genes within putative regions of disease onset differed across FTLD-TDP subtypes.
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To achieve high-sensitivity cell measurements (<1 in 105 cells) by flow cytometry (FCM), the minimum number of acquired cells must be considered and conventional immunophenotyping protocols fall short of these numbers. The bulk lysis (BL) assay is a standardized erythrocyte lysing approach that allows the analysis of the millions of cells required for high-sensitivity measurable residual disease (MRD) detection. However, this approach has been associated with significant cell loss, along with potential over or underestimates of rare cells when using this method. The aim of this study was to evaluate bulk lysis protocols and compare them with minimal sample perturbation (MSP) protocols, which are reported to better preserve the native cellular state and avoid significant cell loss due to washing steps. To achieve this purpose, we first generated an MRD model by spiking fresh peripheral blood with K562 cells, stably expressing EGFP, at known percentages of EGFP positive cells to leukocytes. Samples were then prepared with BL and MSP protocols and analyzed using FCM. For all percentages of K562 cells established and evaluated, a significant decrease of this population was detected in BL samples compared with MSP samples, even at low K562 cell percentages. Significant decreases for non-necrotic cells were also observed in BL samples relative to MSP samples. In conclusion, the evaluation of the potential effects of BL protocols in obtaining the final count is of great interest, especially for over- or under-estimation of target cells, as in the case of measurable residual disease. Since conventional flow cytometry or minimal sample perturbation assays fall short in obtaining the minimum numbers required to reach high sensitivity measurements, significant efforts may be needed to improve bulk lysis solution reagents.
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Citometria de Fluxo , Humanos , Citometria de Fluxo/métodos , Células K562 , Imunofenotipagem/métodos , Neoplasia Residual , Eritrócitos/citologia , Leucócitos/citologia , Contagem de Células/métodosRESUMO
The ability of an octanuclear cubic coordination cage to catalyse a nucleophilic aromatic substitution reaction on a cavity-bound guest was studied with 2,4-dinitrofluorobenzene (DNFB) as the guest/substrate. It was found that DNFB undergoes a catalysed reaction with hydroxide ions within the cavity of the cubic cage (in aqueous buffer solution, pHâ 8.6). The rate enhancement of kcat/kuncat was determined to be 22, with cavity binding of the guest being required for catalysis to occur. The product, 2,4-dinitrophenolate (DNP), remained bound within the cavity due to electrostatic stabilisation and exerts two apparently contradictory effects: it initially auto-catalyses the reaction when present at low concentrations, but at higher concentrations inhibits catalysis when a pair of DNP guests block the cavity. When encapsulated, the UV/Vis absorption spectrum of DNP is red-shifted when compared to the spectrum of free DNP in aqueous solution. Further investigations using other aromatic guests determined that a similar red-shift on cavity binding also occurred for 4-nitrophenolate (4NP) at pHâ 8.6. The red-shift was used to determine the stoichiometry of guest binding of DNP and 4NP within the cage cavity, which was confirmed by structural analysis with X-ray crystallography; and was also used to perform catalytic kinetic studies in the solution-state.
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Chediak-Higashi syndrome (CHS) is a rare, autosomal recessive disorder caused by biallelic mutations in the lysosomal trafficking regulator (LYST) gene. Even though enlarged lysosomes and/or lysosome-related organelles (LROs) are the typical cellular hallmarks of CHS, they have not been investigated in human neuronal models. Moreover, how and why the loss of LYST function causes a lysosome phenotype in cells has not been elucidated. We report that the LYST-deficient human neuronal model exhibits lysosome depletion accompanied by hyperelongated tubules extruding from enlarged autolysosomes. These results have also been recapitulated in neurons differentiated from CHS patients' induced pluripotent stem cells (iPSCs), validating our model system. We propose that LYST ensures the correct fission/scission of the autolysosome tubules during autophagic lysosome reformation (ALR), a crucial process to restore the number of free lysosomes after autophagy. We further demonstrate that LYST is recruited to the lysosome membrane, likely to facilitate the fission of autolysosome tubules. Together, our results highlight the key role of LYST in maintaining lysosomal homeostasis following autophagy and suggest that ALR dysregulation is likely associated with the neurodegenerative CHS phenotype.
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Síndrome de Chediak-Higashi , Proteínas de Transporte Vesicular , Humanos , Proteínas de Transporte Vesicular/genética , Lisossomos/fisiologia , Organelas , Autofagia/fisiologia , Síndrome de Chediak-Higashi/genética , NeurôniosRESUMO
OBJECTIVES: Prehospital electrocardiogram (ECG) and administration of aspirin are evidence-based strategies for patients with acute coronary syndrome (ACS). However, emergency medical services (EMS) compliance in patients with suspected ACS varies widely. We sought to understand the barriers to prehospital ECG acquisition and aspirin administration for patients with suspected ACS. METHODS: In this qualitative study, we interviewed EMS clinicians at three geographically diverse United States (U.S.)-based EMS agencies. We interviewed practicing clinicians and quality and operations leaders at these agencies. Based on the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework, interviews were recorded, transcribed, and analyzed using a grounded qualitative approach with open coding. The Systems Engineering Initiative for Patient Safety (SEIPS) framework and a constant comparison technique were used to identify and refine themes. RESULTS: Twenty-five paramedics and 20 additional agency personnel participated. Median age was 41 (IQR: 34-51) years and 13 (29%) were female. Themes were organized using SEIPS and longitudinally through four phases of an EMS call. During the pre-arrival phase, staffing challenges, training quality, and dispatch may anchor EMS clinicians on a diagnosis. During the diagnosis and treatment phase, safety and communication barriers may take priority over care delivery. Additionally, EMS clinicians must allocate assets (e.g. whether to send an advanced life support unit) and financial resources; veteran EMS clinicians identified their experience whereas newer clinicians cited their recent education when making these decisions. Also, diagnostic uncertainty due to increasing patient complexity and atypical presentations contributed to diagnostic errors. During the response and transport phase, the scope of practice limits the use and interpretation of the ECG, with clinicians reporting that liberal use of ECG led to more rapid decision-making. Finally, in the after phase, personnel reported the "psychologically taxing" nature of the job contributing to biases, bad habits, and burnout. Performance feedback was desired for personal development, though currently perceived as infrequent and punitive. CONCLUSIONS: Multiple, interrelated themes underscored the complexities of delivering evidence-based care to prehospital patients with ACS. Education in ECG interpretation, resource allocation, bias, and enhancing feedback may serve as strategies to address the identified barriers.
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BACKGROUND: Despite efforts to enhance the quality of medication prescribing in outpatient settings, potentially inappropriate prescribing remains common, particularly in unscheduled settings where patients can present with infectious and pain-related complaints. Two of the most commonly prescribed medication classes in outpatient settings with frequent rates of potentially inappropriate prescribing include antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). In the setting of persistent inappropriate prescribing, we sought to understand a diverse set of perspectives on the determinants of inappropriate prescribing of antibiotics and NSAIDs in the Veterans Health Administration. METHODS: We conducted a qualitative study guided by the Consolidated Framework for Implementation Research and Theory of Planned Behavior. Semi-structured interviews were conducted with clinicians, stakeholders, and Veterans from March 1, 2021 through December 31, 2021 within the Veteran Affairs Health System in unscheduled outpatient settings at the Tennessee Valley Healthcare System. Stakeholders included clinical operations leadership and methodological experts. Audio-recorded interviews were transcribed and de-identified. Data coding and analysis were conducted by experienced qualitative methodologists adhering to the Consolidated Criteria for Reporting Qualitative Studies guidelines. Analysis was conducted using an iterative inductive/deductive process. RESULTS: We conducted semi-structured interviews with 66 participants: clinicians (N = 25), stakeholders (N = 24), and Veterans (N = 17). We identified six themes contributing to potentially inappropriate prescribing of antibiotics and NSAIDs: 1) Perceived versus actual Veterans expectations about prescribing; 2) the influence of a time-pressured clinical environment on prescribing stewardship; 3) Limited clinician knowledge, awareness, and willingness to use evidence-based care; 4) Prescriber uncertainties about the Veteran condition at the time of the clinical encounter; 5) Limited communication; and 6) Technology barriers of the electronic health record and patient portal. CONCLUSIONS: The diverse perspectives on prescribing underscore the need for interventions that recognize the detrimental impact of high workload on prescribing stewardship and the need to design interventions with the end-user in mind. This study revealed actionable themes that could be addressed to improve guideline concordant prescribing to enhance the quality of prescribing and to reduce patient harm.
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Antibacterianos , Anti-Inflamatórios não Esteroides , Prescrição Inadequada , Padrões de Prática Médica , Pesquisa Qualitativa , United States Department of Veterans Affairs , Humanos , Anti-Inflamatórios não Esteroides/uso terapêutico , Estados Unidos , Antibacterianos/uso terapêutico , Prescrição Inadequada/estatística & dados numéricos , Prescrição Inadequada/prevenção & controle , Padrões de Prática Médica/estatística & dados numéricos , Masculino , Feminino , Entrevistas como Assunto , Pessoa de Meia-Idade , Pacientes Ambulatoriais , TennesseeRESUMO
OBJECTIVE: Essential tremor (ET) is the most common movement disorder. Deep brain stimulation (DBS) targeting the ventral intermediate nucleus (VIM) is known to improve symptoms in patients with medication-resistant ET. However, the clinical effectiveness of VIM-DBS may vary, and other targets have been proposed. The authors aimed to investigate whether the same anatomical structure is responsible for tremor control both immediately after VIM-DBS and at later follow-up evaluations. METHODS: Of 68 electrodes from 41 patients with ET, the authors mapped the distances of the active contact from the VIM, the dentatorubrothalamic tract (DRTT), and the caudal zona incerta (cZI) and compared them using Friedman's ANOVA and the Wilcoxon signed-rank follow-up test. The same distances were also compared between the initially planned target and the final implantation site after intraoperative macrostimulation. Finally, the comparison among the three structures was repeated for 16 electrodes whose active contact was changed after a mean 37.5 months follow-up to improve tremor control. RESULTS: After lead implantation, the VIM was statistically significantly closer to the active contact than both the DRTT (p = 0.008) and cZI (p < 0.001). This result did not change if the target was moved based on intraoperative macrostimulation. At the last follow-up, the active contact distance from the VIM was always significantly less than that of the cZI (p < 0.001), but the distance from the DRTT was reduced and even less than the distance from the VIM. CONCLUSIONS: In patients receiving VIM-DBS, the VIM itself is the structure driving the anti-tremor effect and remains more effective than the cZI, even years after implantation. Nevertheless, the role of the DRTT may become more important over time and may help sustain the clinical efficacy when the habituation from the VIM stimulation ensues.
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Estimulação Encefálica Profunda , Tremor Essencial , Núcleos Ventrais do Tálamo , Zona Incerta , Humanos , Tremor Essencial/terapia , Tremor Essencial/cirurgia , Estimulação Encefálica Profunda/métodos , Zona Incerta/cirurgia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Núcleos Ventrais do Tálamo/cirurgia , Resultado do Tratamento , Adulto , Seguimentos , Idoso de 80 Anos ou maisRESUMO
INTRODUCTION: Variants of uncertain significance (VUS) surged with affordable genetic testing, posing challenges for determining pathogenicity. We examine the pathogenicity of a novel VUS P93S in Annexin A11 (ANXA11) - an amyotrophic lateral sclerosis/frontotemporal dementia-associated gene - in a corticobasal syndrome kindred. Established ANXA11 mutations cause ANXA11 aggregation, altered lysosomal-RNA granule co-trafficking, and transactive response DNA binding protein of 43 kDa (TDP-43) mis-localization. METHODS: We described the clinical presentation and explored the phenotypic diversity of ANXA11 variants. P93S's effect on ANXA11 function and TDP-43 biology was characterized in induced pluripotent stem cell-derived neurons alongside multiomic neuronal and microglial profiling. RESULTS: ANXA11 mutations were linked to corticobasal syndrome cases. P93S led to decreased lysosome colocalization, neuritic RNA, and nuclear TDP-43 with cryptic exon expression. Multiomic microglial signatures implicated immune dysregulation and interferon signaling pathways. DISCUSSION: This study establishes ANXA11 P93S pathogenicity, broadens the phenotypic spectrum of ANXA11 mutations, underscores neuronal and microglial dysfunction in ANXA11 pathophysiology, and demonstrates the potential of cellular models to determine variant pathogenicity. HIGHLIGHTS: ANXA11 P93S is a pathogenic variant. Corticobasal syndrome is part of the ANXA11 phenotypic spectrum. Hybridization chain reaction fluorescence in situ hybridization (HCR FISH) is a new tool for the detection of cryptic exons due to TDP-43-related loss of splicing regulation. Microglial ANXA11 and related immune pathways are important drivers of disease. Cellular models are powerful tools for adjudicating variants of uncertain significance.
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Leukemic stem cells (LSCs) possess similar characteristics to normal hematopoietic stem cells, including self-renewal capacity, quiescence, ability to initiate leukemia, and drug resistance. These cells play a significant role in leukemia relapse, persisting even after apparent remission. LSCs were first described in 1994 by Lapidot et al. Although they have been extensively studied in acute leukemia, more LSC research is still needed in chronic lymphocytic leukemia (CLL) to understand if reduced apoptosis in mature cells should still be considered as the major cause of this disease. Here, we provide new evidence suggesting the existence of stem-like cell populations in CLL, which may help to understand the disease as well as to develop effective treatments. In this study, we identified a potential leukemic stem cell subpopulation using the tetraploid CLL cell line I83. This subpopulation is characterized by diploid cells that were capable of generating the I83 tetraploid population. Furthermore, we adapted a novel flow cytometry analysis protocol to detect CLL subpopulations with stem cell properties in peripheral blood samples and primary cultures from CLL patients. These cells were identified by their co-expression of CD19 and CD5, characteristic markers of CLL cells. As previously described, increased alkaline phosphatase (ALP) activity is indicative of stemness and pluripotency. Moreover, we used this method to investigate the potential synergistic effect of curcumin in combination with fludarabine and ibrutinib to deplete this subpopulation. Our results confirmed the effectiveness of this ALP-based analysis protocol in detecting and monitoring leukemic stem-like cells in CLL. This analysis also identified limitations in eradicating these populations using in vitro testing. Furthermore, our findings demonstrated that curcumin significantly enhanced the effects of fludarabine and ibrutinib on the leukemic fraction, exhibiting synergistic effects (combination drug index, CDI 0.97 and 0.37, respectively). Our results lend support to the existence of potential stem-like populations in CLL cell lines, and to the idea that curcumin could serve as an effective adjuvant in therapies aimed at eliminating these populations and improving treatment efficacy.
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Adenina/análogos & derivados , Curcumina , Leucemia Linfocítica Crônica de Células B , Piperidinas , Vidarabina/análogos & derivados , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Curcumina/farmacologia , Curcumina/uso terapêutico , TetraploidiaRESUMO
OBJECTIVE: (1) Evaluate the accuracy of computed tomography (CT) scans for localization of liver masses. (2) Assess the agreement between radiologists on localization. (3) Determine if location influences the accuracy of localization and histopathologic diagnosis. (4) Determine what lobar vasculature radiologists found most useful for localization. STUDY DESIGN: Retrospective. ANIMALS: A total of 67 client-owned dogs with a total of 75 hepatic masses. METHODS: Records were reviewed for relevant data. Localization for each hepatic mass was performed by four radiologists (JH, EH, ML, JF) independently. RESULTS: Overall accuracy of mass localization was 217/292 (74.3%) by lobe and 264/300 (88%) by division. Accuracy for the quadrate lobe (11/27, 40.7%) was lower (p < .05) than for the caudate process of the caudate lobe (19/24, 79.2%), left medial lobe (47/64, 73.4%) and left lateral lobe (95/101, 89.6%). Accuracy for the right lateral lobe (17/35, 48.6%) was lower (p < .05) lower than for the left lateral lobe (95/101, 89.6%). Accuracy of localization was 173/192 (90.1%) for masses located in the left division, 37/48 (77.1%) in the central division, and 53/60 (88.3%) for the right division. The agreement (kappa) between radiologists was good (0.61-0.8) to excellent (0.81-1) for division and moderate (0.41-0.6) to good for lobe localization. CONCLUSION: CT localization was more accurate for division than lobe localization of canine hepatic masses. Similarly, radiologists had a better agreement for division than lobe localization. CLINICAL SIGNIFICANCE: This study supports CT as a useful modality for liver mass localization based on division. CT localization to specific lobes should be interpreted with some caution.