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1.
Intensive Crit Care Nurs ; : 103694, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38653631

RESUMO

INTRODUCTION: Early recognition and prompt, appropriate management may reduce mortality in patients with sepsis. The Surviving Sepsis Campaign's guidelines suggest the use of dynamic measurements to guide fluid resuscitation in sepsis; although these methods are rarely employed to monitor cardiac output in response to fluid administration outside intensive care units. This service evaluation investigated the introduction of a nurse led protocolised goal-directed fluid management using a non-invasive cardiac output monitor to the standard assessment of hypotensive ward patients. METHODS: We introduced the use of a goal-directed fluid management protocol into our critical care outreach teams' standard clinical assessment. Forty-nine sequential patients before and thirty-nine after its introduction were included in the assessment. RESULTS: Patients in the post-intervention cohort received less fluid in the 6 h following outreach assessment (750mls vs 1200mls). There were no differences in clinical background or rates of renal replacement therapy, but rates of invasive and non-invasive ventilation were reduced (0% vs 31%). Although the groups were similar, the post-intervention patients had lower recorded blood pressures. CONCLUSION: IV fluid therapy in the patient with hypotension complicating sepsis can be challenging. Excessive IV fluid administration is commonplace and associated with harm, and the use of advanced non-invasive haemodynamic monitoring by trained nurses can provide objective evaluation of individualised response to treatment. Avoiding excessive IV fluid and earlier institution of appropriate vasopressor therapy may improve patient outcomes. IMPLICATIONS FOR CLINICAL PRACTICE: Adoption of dynamic measures of cardiac output outside of critical care by trained critical care nurses is feasible and may translate into improved patient outcomes. In hospitals with a nurse-led critical care outreach service, consideration should be given to such an approach.

2.
Sci Rep ; 14(1): 5929, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467696

RESUMO

The copper compound CuII(atsm) has progressed to phase 2/3 testing for treatment of the neurodegenerative disease amyotrophic lateral sclerosis (ALS). CuII(atsm) is neuroprotective in mutant SOD1 mouse models of ALS where its activity is ascribed in part to improving availability of essential copper. However, SOD1 mutations cause only ~ 2% of ALS cases and therapeutic relevance of copper availability in sporadic ALS is unresolved. Herein we assessed spinal cord tissue from human cases of sporadic ALS for copper-related changes. We found that when compared to control cases the natural distribution of spinal cord copper was disrupted in sporadic ALS. A standout feature was decreased copper levels in the ventral grey matter, the primary anatomical site of neuronal loss in ALS. Altered expression of genes involved in copper handling indicated disrupted copper availability, and this was evident in decreased copper-dependent ferroxidase activity despite increased abundance of the ferroxidases ceruloplasmin and hephaestin. Mice expressing mutant SOD1 recapitulate salient features of ALS and the unsatiated requirement for copper in these mice is a biochemical target for CuII(atsm). Our results from human spinal cord indicate a therapeutic mechanism of action for CuII(atsm) involving copper availability may also be pertinent to sporadic cases of ALS.


Assuntos
Esclerose Amiotrófica Lateral , Complexos de Coordenação , Doenças Neurodegenerativas , Tiossemicarbazonas , Humanos , Camundongos , Animais , Cobre/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo , Doenças Neurodegenerativas/metabolismo , Camundongos Transgênicos , Medula Espinal/metabolismo , Ceruloplasmina/metabolismo , Modelos Animais de Doenças
3.
Mol Neurodegener ; 19(1): 14, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317225

RESUMO

BACKGROUND: Ferroptosis is a form of regulated cell death characterised by lipid peroxidation as the terminal endpoint and a requirement for iron. Although it protects against cancer and infection, ferroptosis is also implicated in causing neuronal death in degenerative diseases of the central nervous system (CNS). The precise role for ferroptosis in causing neuronal death is yet to be fully resolved. METHODS: To elucidate the role of ferroptosis in neuronal death we utilised co-culture and conditioned medium transfer experiments involving microglia, astrocytes and neurones. We ratified clinical significance of our cell culture findings via assessment of human CNS tissue from cases of the fatal, paralysing neurodegenerative condition of amyotrophic lateral sclerosis (ALS). We utilised the SOD1G37R mouse model of ALS and a CNS-permeant ferroptosis inhibitor to verify pharmacological significance in vivo. RESULTS: We found that sublethal ferroptotic stress selectively affecting microglia triggers an inflammatory cascade that results in non-cell autonomous neuronal death. Central to this cascade is the conversion of astrocytes to a neurotoxic state. We show that spinal cord tissue from human cases of ALS exhibits a signature of ferroptosis that encompasses atomic, molecular and biochemical features. Further, we show the molecular correlation between ferroptosis and neurotoxic astrocytes evident in human ALS-affected spinal cord is recapitulated in the SOD1G37R mouse model where treatment with a CNS-permeant ferroptosis inhibitor, CuII(atsm), ameliorated these markers and was neuroprotective. CONCLUSIONS: By showing that microglia responding to sublethal ferroptotic stress culminates in non-cell autonomous neuronal death, our results implicate microglial ferroptotic stress as a rectifiable cause of neuronal death in neurodegenerative disease. As ferroptosis is currently primarily regarded as an intrinsic cell death phenomenon, these results introduce an entirely new pathophysiological role for ferroptosis in disease.


Assuntos
Esclerose Amiotrófica Lateral , Doenças Neurodegenerativas , Camundongos , Animais , Humanos , Microglia/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Superóxido Dismutase-1/metabolismo , Doenças Neurodegenerativas/metabolismo , Morte Celular , Modelos Animais de Doenças
4.
Metallomics ; 16(1)2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38178638

RESUMO

Demyelination within the central nervous system (CNS) is a significant feature of debilitating neurological diseases such as multiple sclerosis and administering the copper-selective chelatorcuprizone to mice is widely used to model demyelination in vivo. Conspicuous demyelination within the corpus callosum is generally attributed to cuprizone's ability to restrict copper availability in this vulnerable brain region. However, the small number of studies that have assessed copper in brain tissue from cuprizone-treated mice have produced seemingly conflicting outcomes, leaving the role of CNS copper availability in demyelination unresolved. Herein we describe our assessment of copper concentrations in brain samples from mice treated with cuprizone for 40 d. Importantly, we applied an inductively coupled plasma mass spectrometry methodology that enabled assessment of copper partitioned into soluble and insoluble fractions within distinct brain regions, including the corpus callosum. Our results show that cuprizone-induced demyelination in the corpus callosum was associated with decreased soluble copper in this brain region. Insoluble copper in the corpus callosum was unaffected, as were pools of soluble and insoluble copper in other brain regions. Treatment with the blood-brain barrier permeant copper compound CuII(atsm) increased brain copper levels and this was most pronounced in the soluble fraction of the corpus callosum. This effect was associated with significant mitigation of cuprizone-induced demyelination. These results provide support for the involvement of decreased CNS copper availability in demyelination in the cuprizone model. Relevance to human demyelinating disease is discussed.


Assuntos
Cuprizona , Doenças Desmielinizantes , Humanos , Animais , Camundongos , Cuprizona/efeitos adversos , Corpo Caloso , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/tratamento farmacológico , Cobre/farmacologia , Oligodendroglia , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Bainha de Mielina
5.
J Geriatr Oncol ; 15(2): 101678, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38113756

RESUMO

INTRODUCTION: Population aging longevity and advances in robotic surgery suggest that increasing numbers of older women having gynaeoncological surgery is likely. Postoperative morbidity and mortality are more common in older than younger women with the age-associated characteristics of multimorbidity and frailty being generally predictive of worse outcome. Priorities that inform treatment decisions change during the life course: older patients often place greater' value on quality-of-life-years gained than on life expectancy following cancer treatments. However, data on post-operative cognition, frailty, or functional independence is sparse and not routinely collected. This study aimed to describe the clinical characteristics and trajectory of functional change of older women in the 12 months following gynaeoncological surgery and to explore the associations between them. MATERIALS AND METHODS: The prospective observational cohort study recruited consecutive women aged 65 or over scheduled for major gynaeoncologic surgery between July 2017 and April 2019. Baseline data on cancer stage, multimorbidity, and geriatric syndromes including cognition, frailty, and functional abilities were collected using standardised tools. Delirium and post-operative morbidity were recorded. Post hospital assessments were collected at 3-, 6-, and 12-months. RESULTS: Overall, of 103 eligible participants assessed pre-operatively, most (77, 70%) remained independent in personal care at all assessments from discharge to 12 months. Functional trajectories varied widely over the 12 months but overall there was no significant decline or improvement for the 85 survivors. Eleven experienced a clinically significant decline in function at six months. This was associated with baseline low mood (P < 0.05), albeit with small numbers (6 of 11). Cognitive impairment and frailty were associated with lower baseline function but not with subsequent functional decline. DISCUSSION: There was no clear clinical profile to identify the minority of older adults who experienced a clinically significant decline six months after surgery and for most, the decline was transient. This may be helpful in enabling informed patient consent. Assessment for geriatric syndromes and frailty may improve individual care but our findings do not indicate criteria for segmenting the patient population for selective attention. Future work should focus on causal pathways to potentially avoidable decline in those patients where this is not determined by the cancer itself.


Assuntos
Disfunção Cognitiva , Fragilidade , Neoplasias , Idoso , Humanos , Feminino , Fragilidade/complicações , Estudos Prospectivos , Avaliação Geriátrica , Disfunção Cognitiva/complicações , Envelhecimento , Neoplasias/complicações
6.
J Neurochem ; 167(3): 337-346, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37800457

RESUMO

Since the first description of Parkinson's disease (PD) over two centuries ago, the recognition of rare types of atypical parkinsonism has introduced a spectrum of related PD-like diseases. Among these is progressive supranuclear palsy (PSP), a neurodegenerative condition that clinically differentiates through the presence of additional symptoms uncommon in PD. As with PD, the initial symptoms of PSP generally present in the sixth decade of life when the underpinning neurodegeneration is already significantly advanced. The causal trigger of neuronal cell loss in PSP is unknown and treatment options are consequently limited. However, converging lines of evidence from the distinct neurodegenerative conditions of PD and amyotrophic lateral sclerosis (ALS) are beginning to provide insights into potential commonalities in PSP pathology and opportunity for novel therapeutic intervention. These include accumulation of the high abundance cuproenzyme superoxide dismutase 1 (SOD1) in an aberrant copper-deficient state, associated evidence for altered availability of the essential micronutrient copper, and evidence for neuroprotection using compounds that can deliver available copper to the central nervous system. Herein, we discuss the existing evidence for SOD1 pathology and copper imbalance in PSP and speculate that treatments able to provide neuroprotection through manipulation of copper availability could be applicable to the treatment of PSP.


Assuntos
Neuroquímica , Doenças Neurodegenerativas , Doença de Parkinson , Paralisia Supranuclear Progressiva , Humanos , Paralisia Supranuclear Progressiva/diagnóstico , Paralisia Supranuclear Progressiva/patologia , Cobre , Doenças Neurodegenerativas/terapia , Superóxido Dismutase-1 , Doença de Parkinson/patologia
8.
Neuroscience ; 509: 125-131, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36436699

RESUMO

CuII(atsm) is a blood-brain barrier permeant copper(II) compound that is under investigation in human clinical trials for the treatment of neurodegenerative diseases of the central nervous system (CNS). Imaging in humans by positron emission tomography shows the compound accumulates in affected regions of the CNS in patients. Most therapeutic studies to date have utilised oral administration of CuII(atsm) in an insoluble form, as either solid tablets or a liquid suspension. However, two pre-clinical studies have demonstrated disease-modifying outcomes following transdermal application of soluble CuII(atsm) prepared in dimethyl sulphoxide. Whether differences in the method of administration lead to different degrees of tissue accumulation of the compound has never been examined. Here, we compare the two methods of administration in wild-type mice by assessing changes in tissue concentrations of copper. Both administration methods resulted in elevated copper concentrations in numerous tissues, with the largest increases evident in the liver, brain and spinal cord. In all instances where treatment with CuII(atsm) resulted in elevated tissue copper, transdermal application of soluble CuII(atsm) led to higher concentrations of copper. In contrast to CuII(atsm), an equivalent dose of copper(II) chloride resulted in minimal changes to tissue copper concentrations, regardless of the administration method. Data presented herein provide quantitative insight to transdermal application of soluble CuII(atsm) as a potential alternative to oral administration of the compound in an insoluble formulation.


Assuntos
Compostos Organometálicos , Tiossemicarbazonas , Camundongos , Humanos , Animais , Compostos Organometálicos/uso terapêutico , Cobre , Tiossemicarbazonas/uso terapêutico , Medula Espinal/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Tomografia por Emissão de Pósitrons
10.
Elife ; 112022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36472367

RESUMO

Improving muscle function has great potential to improve the quality of life. To identify novel regulators of skeletal muscle metabolism and function, we performed a proteomic analysis of gastrocnemius muscle from 73 genetically distinct inbred mouse strains, and integrated the data with previously acquired genomics and >300 molecular/phenotypic traits via quantitative trait loci mapping and correlation network analysis. These data identified thousands of associations between protein abundance and phenotypes and can be accessed online (https://muscle.coffeeprot.com/) to identify regulators of muscle function. We used this resource to prioritize targets for a functional genomic screen in human bioengineered skeletal muscle. This identified several negative regulators of muscle function including UFC1, an E2 ligase for protein UFMylation. We show UFMylation is up-regulated in a mouse model of amyotrophic lateral sclerosis, a disease that involves muscle atrophy. Furthermore, in vivo knockdown of UFMylation increased contraction force, implicating its role as a negative regulator of skeletal muscle function.


Assuntos
Proteoma , Proteômica , Camundongos , Animais , Humanos , Proteoma/metabolismo , Qualidade de Vida , Músculo Esquelético/metabolismo , Fenótipo
11.
Crit Care Clin ; 38(3): 473-489, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35667738

RESUMO

Initial reporting suggested that kidney involvement following COVID-19 infection was uncommon but this is now known not to be the case. Acute kidney injury (AKI) may arise through several mechanisms and complicate up to a quarter of patients hospitalized with COVID-19 infection being associated with an increased risk for both morbidity and death. Mechanisms of injury include direct kidney damage predominantly through tubular injury, although glomerular injury has been reported; the consequences of the treatment of patients with severe hypoxic respiratory failure; secondary infection; and exposure to nephrotoxic drugs. The mainstay of treatment remains the prevention of worsening kidney damage and in some cases they need for renal replacement therapies (RRT). Although the use of other blood purification techniques has been proposed as potential treatments, results to-date have not been definitive.


Assuntos
Injúria Renal Aguda , COVID-19 , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , COVID-19/complicações , COVID-19/terapia , Humanos , Terapia de Substituição Renal , SARS-CoV-2
12.
Chem Sci ; 12(30): 10321-10333, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34476052

RESUMO

Tumours are abnormal growths of cells that reproduce by redirecting essential nutrients and resources from surrounding tissue. Changes to cell metabolism that trigger the growth of tumours are reflected in subtle differences between the chemical composition of healthy and malignant cells. We used LA-ICP-MS imaging to investigate whether these chemical differences can be used to spatially identify tumours and support detection of primary colorectal tumours in anatomical pathology. First, we generated quantitative LA-ICP-MS images of three colorectal surgical resections with case-matched normal intestinal wall tissue and used this data in a Monte Carlo optimisation experiment to develop an algorithm that can classify pixels as tumour positive or negative. Blinded testing and interrogation of LA-ICP-MS images with micrographs of haematoxylin and eosin stained and Ki67 immunolabelled sections revealed Monte Carlo optimisation accurately identified primary tumour cells, as well as returning false positive pixels in areas of high cell proliferation. We analysed an additional 11 surgical resections of primary colorectal tumours and re-developed our image processing method to include a random forest regression machine learning model to correctly identify heterogenous tumours and exclude false positive pixels in images of non-malignant tissue. Our final model used over 1.6 billion calculations to correctly discern healthy cells from various types and stages of invasive colorectal tumours. The imaging mass spectrometry and data analysis methods described, developed in partnership with clinical cancer researchers, have the potential to further support cancer detection as part of a comprehensive digital pathology approach to cancer care through validation of a new chemical biomarker of tumour cells.

13.
Cell Mol Life Sci ; 78(19-20): 6605-6630, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34476545

RESUMO

Motor neurone disease (MND) is a neurodegenerative disorder characterised by progressive destruction of motor neurons, muscle paralysis and death. The amyloid precursor protein (APP) is highly expressed in the central nervous system and has been shown to modulate disease outcomes in MND. APP is part of a gene family that includes the amyloid precursor-like protein 1 (APLP1) and 2 (APLP2) genes. In the present study, we investigated the role of APLP2 in MND through the examination of human spinal cord tissue and by crossing APLP2 knockout mice with the superoxide dismutase 1 (SOD1-G37R) transgenic mouse model of MND. We found the expression of APLP2 is elevated in the spinal cord from human cases of MND and that this feature of the human disease is reproduced in SOD1-G37R mice at the End-stage of their MND-like phenotype progression. APLP2 deletion in SOD1-G37R mice significantly delayed disease progression and increased the survival of female SOD1-G37R mice. Molecular and biochemical analysis showed female SOD1-G37R:APLP2-/- mice displayed improved innervation of the neuromuscular junction, ameliorated atrophy of muscle fibres with increased APP protein expression levels in the gastrocnemius muscle. These results indicate a sex-dependent role for APLP2 in mutant SOD1-mediated MND and further support the APP family as a potential target for further investigation into the cause and regulation of MND.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Doença dos Neurônios Motores/metabolismo , Superóxido Dismutase-1/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Animais , Sistema Nervoso Central/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neurônios Motores/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Junção Neuromuscular/metabolismo , Fenótipo , Medula Espinal/metabolismo
14.
Stroke ; 52(9): 2930-2938, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34015938

RESUMO

Background and Purpose: The circle of Willis (CoW) and leptomeningeal anastomoses play an important role in transforming infarct topography following middle cerebral artery occlusion. Their role in infarct topography following anterior cerebral artery occlusion is not well understood. The aim of this study was to evaluate the role of the CoW and leptomeningeal anastomoses in modifying regional variation in infarct topography following occlusion of the anterior cerebral artery and its branches. Methods: Perfusion and magnetic resonance imaging of patients with anterior cerebral artery stroke and evidence of vessel occlusion were segmented and manually registered to standard brain template for voxel-wise comparison. Next, a computer model of the cerebral arteries was formulated as network of nodes connected by cylindrical pipes. The experiments included occlusion of successive branches of the anterior cerebral artery while the configurations of the CoW were varied. Results: Forty-seven patients with a median age of 77.5 years (interquartile range, 68.0­84.5 years) were studied. The regions with the highest probabilities of infarction were the superior frontal gyrus (probability =0.26) and anterior cingulate gyrus (probability =0.24). The regions around the posterior cingulate gyrus (probability =0.08), paracentral lobule (probability =0.05), precuneus and superior parietal lobule (probability =0.03) had a low probability of infarction. Following occlusions distal to the anterior communicating artery, the computer model demonstrated an increase in flow (>30%) in neighboring cortical arteries with leptomeningeal anastomoses. Conclusions: Traditionally the CoW has been regarded as the primary collateral system. However, our computer model shows that the CoW is only helpful in redirecting flow following proximal vessel occlusions (pre-anterior communicating artery). More important are leptomeningeal anastomoses, which play an essential role in distal vessel occlusions, influencing motor outcome by modifying the posterolateral extent of infarct topography.


Assuntos
Artéria Cerebral Anterior/patologia , Estenose das Carótidas/patologia , Círculo Arterial do Cérebro/patologia , Infarto da Artéria Cerebral Anterior/patologia , Idoso , Idoso de 80 Anos ou mais , Artéria Cerebral Anterior/fisiopatologia , Encéfalo/patologia , Circulação Cerebrovascular/fisiologia , Circulação Colateral/fisiologia , Feminino , Humanos , Infarto da Artéria Cerebral Anterior/fisiopatologia , Infarto da Artéria Cerebral Média/patologia , Masculino , Pessoa de Meia-Idade
15.
Angew Chem Int Ed Engl ; 60(17): 9215-9246, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-32144830

RESUMO

Cu/Zn superoxide dismutase (SOD1) is a frontline antioxidant enzyme catalysing superoxide breakdown and is important for most forms of eukaryotic life. The evolution of aerobic respiration by mitochondria increased cellular production of superoxide, resulting in an increased reliance upon SOD1. Consistent with the importance of SOD1 for cellular health, many human diseases of the central nervous system involve perturbations in SOD1 biology. But far from providing a simple demonstration of how disease arises from SOD1 loss-of-function, attempts to elucidate pathways by which atypical SOD1 biology leads to neurodegeneration have revealed unexpectedly complex molecular characteristics delineating healthy, functional SOD1 protein from that which likely contributes to central nervous system disease. This review summarises current understanding of SOD1 biology from SOD1 genetics through to protein function and stability.


Assuntos
Antioxidantes/metabolismo , Doenças do Sistema Nervoso Central/metabolismo , Superóxido Dismutase-1/metabolismo , Biocatálise , Estabilidade Enzimática , Humanos , Superóxido Dismutase-1/deficiência , Superóxido Dismutase-1/genética , Superóxidos/metabolismo
16.
Life (Basel) ; 10(11)2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33158182

RESUMO

The blood-brain barrier permeant, copper-containing compound, CuII(atsm), has successfully progressed from fundamental research outcomes in the laboratory through to phase 2/3 clinical assessment in patients with the highly aggressive and fatal neurodegenerative condition of amyotrophic lateral sclerosis (ALS). The most compelling outcomes to date to indicate potential for disease-modification have come from pre-clinical studies utilising mouse models that involve transgenic expression of mutated superoxide dismutase 1 (SOD1). Mutant SOD1 mice provide a very robust mammalian model of ALS with high validity, but mutations in SOD1 account for only a small percentage of ALS cases in the clinic, with the preponderant amount of cases being sporadic and of unknown aetiology. As per other putative drugs for ALS developed and tested primarily in mutant SOD1 mice, this raises important questions about the pertinence of CuII(atsm) to broader clinical translation. This review highlights some of the challenges associated with the clinical translation of new treatment options for ALS. It then provides a brief account of pre-clinical outcomes for CuII(atsm) in SOD1 mouse models of ALS, followed by an outline of additional studies which report positive outcomes for CuII(atsm) when assessed in cell and mouse models of neurodegeneration which do not involve mutant SOD1. Clinical evidence for CuII(atsm) selectively targeting affected regions of the CNS in patients is also presented. Overall, this review summarises the existing evidence which indicates why clinical relevance of CuII(atsm) likely extends beyond the context of cases of ALS caused by mutant SOD1.

17.
Cell ; 183(3): 636-649.e18, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33031745

RESUMO

Cytoplasmic accumulation of TDP-43 is a disease hallmark for many cases of amyotrophic lateral sclerosis (ALS), associated with a neuroinflammatory cytokine profile related to upregulation of nuclear factor κB (NF-κB) and type I interferon (IFN) pathways. Here we show that this inflammation is driven by the cytoplasmic DNA sensor cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS) when TDP-43 invades mitochondria and releases DNA via the permeability transition pore. Pharmacologic inhibition or genetic deletion of cGAS and its downstream signaling partner STING prevents upregulation of NF-κB and type I IFN induced by TDP-43 in induced pluripotent stem cell (iPSC)-derived motor neurons and in TDP-43 mutant mice. Finally, we document elevated levels of the specific cGAS signaling metabolite cGAMP in spinal cord samples from patients, which may be a biomarker of mtDNA release and cGAS/STING activation in ALS. Our results identify mtDNA release and cGAS/STING activation as critical determinants of TDP-43-associated pathology and demonstrate the potential for targeting this pathway in ALS.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Membrana/metabolismo , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Nucleotidiltransferases/metabolismo , Alarminas/metabolismo , Esclerose Amiotrófica Lateral/patologia , Animais , Citoplasma/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Inflamação/metabolismo , Interferon Tipo I/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Degeneração Neural/patologia , Fosfotransferases (Aceptor do Grupo Álcool) , Subunidades Proteicas/metabolismo , Transdução de Sinais
18.
Front Neurol ; 11: 773, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849226

RESUMO

Endovascular clot retrieval, often referred to as mechanical thrombectomy, has transformed the treatment of patients with ischemic stroke based on an underlying large cerebral vessel occlusion, ranging from the extracranial internal carotid artery (ICA) to the M1 (proximal) segment of the middle cerebral artery (MCA). The aim of this study was to evaluate the effect of a progressive occlusion of the extracranial portion of the ICA on the cerebral blood flow either with a conventional guiding catheter or a balloon-guiding catheter, which enables the operator to completely occlude the parent artery by inflating the balloon around the tip of this type of guiding catheter. We evaluated the impact of flow reduction in the ICA in the setting of ipsilateral MCA occlusion given the different configurations of the circle of Willis (CoW). The computer model of cerebral arteries was based on anatomical works by Rhoton (1) and van der Eecken (2). The interactive experimental results are available on the web at https://gntem3.shinyapps.io/ecrsim. In the setting of left MCA occlusion, compensation from the anterior and posterior communicating artery preserved the flow in the left anterior cerebral artery (ACA) but not the left MCA branches. Under selected CoW configurations, such as classic, missing Acom, or missing A1 segment of the ACA and concurrent right ICA occlusion, there was a progressive decrease of flow in the left ACA to a minimum of 78% when the simulated catheter fully occluded the left ICA. Flow collapsed (<10%) in the left ACA and MCA branches under CoW configurations, such as bilateral fetal PCA. In summary, compensatory flow collapsed under certain clot retrieval scenarios and unusual configurations of CoW.

19.
Anal Bioanal Chem ; 411(3): 603-616, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30218126

RESUMO

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of µ-droplets is becoming an attractive alternative for detecting and quantifying elements in biological samples. With minimal sample preparation required and detection limits comparable to solution nebulisation ICP-MS, µ-droplets have substantial advantages over traditional elemental detection, particularly for low volumes, such as aliquots taken from samples required for multiple independent biochemical assays, or fluids and tissues where elements of interest exist at native concentrations not suited to the necessary dilution steps required for solution nebulisation ICP-MS. However, the characteristics of µ-droplet residue deposition are heavily dependent on the matrix, and potential effects on signal suppression or enhancement have not been fully characterised. We present a validated and flexible high-throughput method for quantification of elements in µ-droplets using LA-ICP-MS imaging and matrix-matched external calibrants. Imaging the entire µ-droplet area removes analytical uncertainty arising from the often-heterogenous distribution when compared to radial or bisecting line scans that capture only a small portion of the droplet residue. We examined the effects of common matrices found in a standard biochemistry workflow, including native protein and salt contents, as well as reagents used in typical preparation steps for concurrent biochemical assays, such as total protein quantification and enzyme activity assays. We found that matrix composition results in systemic, concentration-dependent signal enhancement and suppression for carbon, whereas high sodium content has a specific space-charge-like suppression effect on high masses. We confirmed the accuracy of our method using both a certified serum standard (Seronorm™ L1) and independent measurements of analysed samples by solution nebulisation ICP-MS, then tested the specificity and reproducibility by examining spinal cord tissue homogenates from SOD1-G93A transgenic mice with a known molecular phenotype of increased copper- and zinc-binding superoxide dismutase-1 expression and altered copper-to-zinc stoichiometry. The method presented is rapid and transferable to multiple other biological matrices and allows high-throughput analysis of low-volume samples with sensitivity comparable to standard solution nebulisation ICP-MS protocols. Graphical Abstract ᅟ.


Assuntos
Elementos Químicos , Espectrometria de Massas/métodos , Oligoelementos/análise , Animais , Terapia a Laser/métodos , Limite de Detecção , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Reprodutibilidade dos Testes , Tamanho da Amostra , Medula Espinal/química , Oligoelementos/sangue , Fluxo de Trabalho
20.
Exp Neurol ; 307: 118-128, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29906423

RESUMO

Mutations to the copper-dependent enzyme Cu/Zn-superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS) in humans, and transgenic overexpression of mutant SOD1 represents a robust murine model of the disease. We have previously shown that the copper-containing compound CuII(atsm) phenotypically improves mutant SOD1 mice and delivers copper to copper-deficient SOD1 in the CNS to restore its physiological function. CuII(atsm) is now in clinical trials for the treatment of ALS. In this study, we demonstrate that cuproenzyme dysfunction extends beyond SOD1 in SOD1G37R mice to also affect the endogenous copper-dependent ferroxidase ceruloplasmin. We show that SOD1 and ceruloplasmin both accumulate progressively in the SOD1G37R mouse spinal cord as the animals' ALS-like symptoms progress, yet the biochemical activity of the two cuproenzymes does not increase commensurately, indicating that, as per mutant SOD1, ceruloplasmin accumulates in a copper-deficient form. Consistent with this finding, we show that expression of the human copper transporter 1 (hCTR1) in SOD1G37R mice increases copper levels in the spinal cord and concurrently restores SOD1 and ceruloplasmin activity. Soluble misfolded SOD1, a proposed driver of pathology in this model, is readily detectable in the SOD1G37R mouse spinal cord. However, misfolded SOD1G37R levels do not change in abundance with disease progression and are less abundant than misfolded SOD1 in the spinal cords of age-matched transgenic SOD1WT mice which do not exhibit an evident ALS-like phenotype. Collectively, these outcomes support a copper malfunction phenomenon in mutant SOD1 mouse models of ALS and a copper-related mechanism of action for the therapeutic agent CuII(atsm).


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Proteínas de Transporte de Cátions/biossíntese , Modelos Animais de Doenças , Superóxido Dismutase/biossíntese , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Animais , Proteínas de Transporte de Cátions/genética , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Transportador de Cobre 1 , Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Medula Espinal/metabolismo , Medula Espinal/patologia , Superóxido Dismutase/genética
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