Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 328
Filtrar
1.
Nat Commun ; 11(1): 5794, 2020 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-33188181

RESUMO

Necrotizing enterocolitis (NEC) is a severe, currently untreatable intestinal disease that predominantly affects preterm infants and is driven by poorly characterized inflammatory pathways. Here, human and murine NEC intestines exhibit an unexpected predominance of type 3/TH17 polarization. In murine NEC, pro-inflammatory type 3 NKp46-RORγt+Tbet+ innate lymphoid cells (ILC3) are 5-fold increased, whereas ILC1 and protective NKp46+RORγt+ ILC3 are obliterated. Both species exhibit dysregulation of intestinal TLR repertoires, with TLR4 and TLR8 increased, but TLR5-7 and TLR9-12 reduced. Transgenic IL-37 effectively protects mice from intestinal injury and mortality, whilst exogenous IL-37 is only modestly efficacious. Mechanistically, IL-37 favorably modulates immune homeostasis, TLR repertoires and microbial diversity. Moreover, IL-37 and its receptor IL-1R8 are reduced in human NEC epithelia, and IL-37 is lower in blood monocytes from infants with NEC and/or lower birthweight. Our results on NEC pathomechanisms thus implicate type 3 cytokines, TLRs and IL-37 as potential targets for novel NEC therapies.


Assuntos
Enterocolite Necrosante/tratamento farmacológico , Enterocolite Necrosante/imunologia , Imunidade Adaptativa , Animais , Animais Recém-Nascidos , Biomarcadores/metabolismo , Enterocolite Necrosante/sangue , Enterocolite Necrosante/patologia , Homeostase , Humanos , Imunidade Inata , Recém-Nascido , Mediadores da Inflamação/metabolismo , Interleucina-1 , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Linfócitos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores Toll-Like/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(45): 28056-28067, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33097662

RESUMO

The Rac-GEF, P-Rex1, activates Rac1 signaling downstream of G protein-coupled receptors and PI3K. Increased P-Rex1 expression promotes melanoma progression; however, its role in breast cancer is complex, with differing reports of the effect of its expression on disease outcome. To address this we analyzed human databases, undertook gene array expression analysis, and generated unique murine models of P-Rex1 gain or loss of function. Analysis of PREX1 mRNA expression in breast cancer cDNA arrays and a METABRIC cohort revealed that higher PREX1 mRNA in ER+ve/luminal tumors was associated with poor outcome in luminal B cancers. Prex1 deletion in MMTV-neu or MMTV-PyMT mice reduced Rac1 activation in vivo and improved survival. High level MMTV-driven transgenic PREX1 expression resulted in apicobasal polarity defects and increased mammary epithelial cell proliferation associated with hyperplasia and development of de novo mammary tumors. MMTV-PREX1 expression in MMTV-neu mice increased tumor initiation and enhanced metastasis in vivo, but had no effect on primary tumor growth. Pharmacological inhibition of Rac1 or MEK1/2 reduced P-Rex1-driven tumoroid formation and cell invasion. Therefore, P-Rex1 can act as an oncogene and cooperate with HER2/neu to enhance breast cancer initiation and metastasis, despite having no effect on primary tumor growth.

3.
J Clin Invest ; 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33119550

RESUMO

The regulation of autophagy-dependent lysosome homeostasis in vivo is unclear. We show the inositol polyphosphate 5-phosphatase INPP5K regulates autophagic lysosome reformation (ALR), a lysosome recycling pathway, in muscle. INPP5K hydrolyses phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) to phosphatidylinositol 4-phosphate (PI(4)P) and INPP5K mutations cause muscular dystrophy by unknown mechanisms. We report loss of INPP5K in muscle causes severe disease, autophagy inhibition and lysosome depletion. Reduced PI(4,5)P2 turnover on autolysosomes in Inpp5k-/- muscle suppresses autophagy and lysosome repopulation via ALR inhibition. Defective ALR in Inpp5k-/- myoblasts was characterised by enlarged autolysosomes and the persistence of hyperextended reformation tubules, structures that participate in membrane-recycling to form lysosomes. Reduced disengagement of the PI(4,5)P2 effector clathrin was observed on reformation tubules which we propose interferes with ALR completion. Inhibition of PI(4,5)P2 synthesis, or expression of wild-type, but not INPP5K-disease mutants in INPP5K-depleted myoblasts restored lysosomal homeostasis. Therefore, bidirectional interconversion of PI(4)P/PI(4,5)P2 on autolysosomes is integral to lysosome replenishment and autophagy function in muscle. Activation of TFEB-dependent de novo lysosome biogenesis did not compensate for loss of ALR in Inpp5k-/- muscle, revealing a dependence on this lysosome recycling pathway. Therefore, in muscle, ALR is indispensable for lysosome homeostasis during autophagy and when defective is associated with muscular dystrophy.

4.
Cell ; 183(3): 636-649.e18, 2020 Oct 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.

5.
Mol Cell ; 80(2): 279-295.e8, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33065020

RESUMO

The PTEN tumor suppressor controls cell death and survival by regulating functions of various molecular targets. While the role of PTEN lipid-phosphatase activity on PtdIns(3,4,5)P3 and inhibition of PI3K pathway is well characterized, the biological relevance of PTEN protein-phosphatase activity remains undefined. Here, using knockin (KI) mice harboring cancer-associated and functionally relevant missense mutations, we show that although loss of PTEN lipid-phosphatase function cooperates with oncogenic PI3K to promote rapid mammary tumorigenesis, the additional loss of PTEN protein-phosphatase activity triggered an extensive cell death response evident in early and advanced mammary tumors. Omics and drug-targeting studies revealed that PI3Ks act to reduce glucocorticoid receptor (GR) levels, which are rescued by loss of PTEN protein-phosphatase activity to restrain cell survival. Thus, we find that the dual regulation of GR by PI3K and PTEN functions as a rheostat that can be exploited for the treatment of PTEN loss-driven cancers.


Assuntos
Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , PTEN Fosfo-Hidrolase/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Carcinogênese , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Dexametasona/farmacologia , Feminino , Humanos , Isoenzimas/metabolismo , Camundongos , Modelos Biológicos , Mutação/genética , Organoides/patologia , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Estabilidade Proteica , Proteoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
6.
J Extracell Vesicles ; 9(1): 1766822, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32922692

RESUMO

Alzheimer's disease is a progressive neurodegenerative disorder, with the strongest disease-associated changes observed at clinical or end-stage disease. Transcriptomic deregulation of miRNA expression can spread via "horizontal" RNA transfer through extracellular vesicles (EVs) to act in conjunction with proteins, leading to changes in mRNA, which can provide early signals to indicate forthcoming neuropathological changes in the brain. Here, we analysed the small RNA content, in particular, miRNA, contained in brain-derived EVs isolated from the frontal cortex of Alzheimer's subjects (n = 8) and neurological control subjects (n = 9). Brain-derived EVs were found to contain an upregulation of disease-associated miRNA. RNA species from brain-derived EVs were correlated with miRNA profiles obtained from matching total brain homogenate. These results provide a blueprint into the biological pathways potentially effected during disease that may be assisted by brain-derived EV RNA horizontal transfer.We also correlated the miRNA changes in the brain with those detected in peripheral EVs collected from serum of Alzheimer's disease patients (n = 23, and healthy controls, n = 23) and revealed a panel of miRNA that could be used as a liquid brain biopsy. Overall, our study provides the first interrogation of the small RNA contents in brain-derived EVs and how they could be used to understand the early pathological changes in Alzheimer's disease which will benefit the development of an early diagnostic blood test.

7.
Brain Commun ; 2(2): fcaa029, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32954317

RESUMO

Astrocytes are glial cells of the central nervous system that become reactive under conditions of stress. The functional properties of reactive astrocytes depend on their stimulus that induces the upregulation of specific genes. Reactive astrocytes are a neuropathological feature of prion disorders; however, their role in the disease pathogenesis is not well understood. Here, we describe our studies of one polarization state of reactive astrocytes, termed A1 astrocytes, in the frontal cortex region of 35 human sporadic Creutzfeldt-Jakob disease brains encompassing a range of molecular sub-types. Examination of two mRNA markers of A1 astrocytes, C3 and GBP2, revealed a strong linear correlation between the two following their log-normalization (P = 0.0011). Both markers were found upregulated in the sporadic Creutzfeldt-Jakob disease brain compared with age-matched control tissues (P = 0.0029 and 0.0002, for C3log and GBP2log, respectively), and stratifying samples based on codon 129 genotype revealed that C3log is highest in homozygous methionine and lowest in homozygous valine patients, which followed a linear trend (P = 0.027). Upon assessing other disease parameters, a significant positive correlation was found between GBP2log and disease duration (P = 0.031). These findings provide evidence for a divergence in the astrocytic environment amongst patients with sporadic Creutzfeldt-Jakob disease based on molecular sub-type parameters of disease. While more research will be needed to determine the global changes in the genomic profiles and resulting functional properties of reactive astrocytes in disease, considering the evidence demonstrating that A1 astrocytes harbour neurotoxic properties, the changes seen in C3log and GBP2log in the current study may reflect differences in pathogenic mechanisms amongst the sporadic Creutzfeldt-Jakob disease sub-types associated with the A1 polarization state.

8.
Eur J Hum Genet ; 2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-32862205

RESUMO

X-linked myotubular myopathy (XLMTM) is a severe congenital myopathy characterised by generalised weakness and respiratory insufficiency. XLMTM is associated with pathogenic variants in MTM1; a gene encoding the lipid phosphatase myotubularin. Whole genome sequencing (WGS) of an exome-negative male proband with severe hypotonia, respiratory insufficiency and centralised nuclei on muscle biopsy identified a deep intronic MTM1 variant NG_008199.1(NM_000252.2):c.1468-577A>G, which strengthened a cryptic 5' splice site (A>G substitution at the +5 position). Muscle RNA sequencing was non-diagnostic due to low read depth. Reverse transcription PCR (RT-PCR) of muscle RNA confirmed the c.1468-577A>G variant activates inclusion of a pseudo-exon encoding a premature stop codon into all detected MTM1 transcripts. Western blot analysis establishes deficiency of myotubularin protein, consistent with the severe XLMTM phenotype. We expand the genotypic spectrum of XLMTM and highlight benefits of screening non-coding regions of MTM1 in male probands with phenotypically concordant XLMTM who remain undiagnosed following exome sequencing.

9.
Inorg Chem ; 59(16): 11658-11669, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32799487

RESUMO

Alzheimer's disease is characterized by the presence of extracellular amyloid-ß plaques. Positron emission tomography (PET) imaging with tracers radiolabeled with positron-emitting radionuclides that bind to amyloid-ß plaques can assist in the diagnosis of Alzheimer's disease. With the goal of designing new imaging agents radiolabeled with positron-emitting copper-64 radionuclides that bind to amyloid-ß plaques, a family of bis(thiosemicarbazone) ligands with appended substituted stilbenyl functional groups has been prepared. The ligands form charge-neutral and stable complexes with copper(II). The new ligands can be radiolabeled with copper-64 at room temperature. Two lead complexes were demonstrated to bind to amyloid-ß plaques present in post-mortem brain tissue from subjects with clinically diagnosed Alzheimer's disease and crossed the blood-brain barrier in mice. The work presented here provides strategies to prepare compounds with radionuclides of copper that can be used for targeted brain PET imaging.

10.
J Natl Cancer Inst ; 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32778876

RESUMO

BACKGROUND: ASPirin in Reducing Events in the Elderly (ASPREE), a randomized double-blind placebo-controlled trial (RCT) of daily low-dose aspirin (100 mg) in older adults, showed an increase in all-cause mortality, primarily due to cancer. In contrast prior RCTs, mainly involving younger individuals, demonstrated a delayed cancer benefit with aspirin. We now report a detailed analysis of cancer incidence and mortality. METHODS: 19,114 Australian and U.S. community-dwelling participants aged 70+ years (U.S. minorities 65+ years) without cardiovascular disease, dementia or physical disability were randomized and followed for a median of 4.7 years. Fatal and non-fatal cancer events, a prespecified secondary endpoint, were adjudicated based on clinical records. RESULTS: 981 cancer events occurred in the aspirin and 952 in the placebo groups. There was no statistically significant difference between groups for all incident cancers (HR = 1.04, 95% CI = 0.95 to 1.14), hematological cancer (HR = 0.98, 95% CI = 0.73 to 1.30), or all solid cancers (HR = 1.05, 95% CI = 0.95 to 1.15), including by specific tumor type. However, aspirin was associated with an increased risk of incident cancer that had metastasized (HR = 1.19, 95% CI = 1.00 to 1.43) or was stage 4 at diagnosis (HR = 1.22, 95% CI = 1.02 to 1.45), and with higher risk of death for cancers that presented at stages 3 (HR = 2.11, 95% CI = 1.03 to 4.33) or 4 (HR = 1.31, 95% CI = 1.04 to 1.64). CONCLUSIONS: In older adults, aspirin treatment had an adverse effect on later stages of cancer evolution. These findings suggest that in older persons, aspirin may accelerate the progression of cancer and thus, suggest caution with its use in this age group.

11.
Artigo em Inglês | MEDLINE | ID: mdl-32664829

RESUMO

Nationwide surveillance of Creutzfeldt-Jakob disease and other human prion diseases is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR). National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period, considerable developments have occurred in pre-mortem diagnostics; in the delineation of new disease subtypes; and in a heightened awareness of prion diseases in healthcare settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR during 2019. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2019, 513 domestic CSF specimens were referred for 14-3-3 protein testing and 85 persons with suspected human prion disease were formally added to the national register. As of 31 December 2019, just under half (42 cases) of the 85 suspect case notifications remain classified as 'incomplete'; 16 cases were excluded through either detailed clinical follow-up (3 cases) or neuropathological examination (13 cases); 20 cases were classified as 'definite' and seven as 'probable' prion disease. For 2019, sixty-three percent of all suspected human prion disease related deaths in Australia underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified. Two possibly causal novel prion protein gene (PRNP) sequence variations were identified.

12.
J Neurochem ; 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32614980

RESUMO

Glutaminyl cyclases (QC) catalyze the formation of neurotoxic pGlu-modified amyloid-ß peptides found in the brains of people with Alzheimer's disease (AD). Reports of several-fold increases in soluble QC (sQC) expression in the brain and peripheral circulation of AD individuals has prompted the development of QC inhibitors as potential AD therapeutics. There is, however, a lack of standardized quantitative data on QC expression in human tissues, precluding inter-laboratory comparison and validation. We tested the hypothesis that QC is elevated in AD tissues by quantifying levels of sQC protein and activity in post-mortem brain tissues from AD and age-matched control individuals. We found a modest but statistically significant increase in sQC protein, which paralleled a similar increase in enzyme activity. In plasma samples sourced from the Australian Imaging, Biomarker and Lifestyle study we determined that QC activity was not different between the AD and control group, though a modest increase was observed in female AD individuals compared to controls. Plasma QC activity was further correlated with levels of circulating monocytes in AD individuals. These data provide quantitative evidence that alterations in QC expression are associated with AD pathology.

13.
Cells ; 9(7)2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32708779

RESUMO

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by the deposition of misfolded proteins in the motor cortex and motor neurons. Although a multitude of ALS-associated mutated proteins have been identified, several have been linked to small extracellular vesicles such as exosomes involved in cell-cell communication. This study aims to determine the proteome of extracellular vesicles isolated from the motor cortex of ALS subjects and to identify novel ALS-associated deregulated proteins. Motor cortex extracellular vesicles (MCEVs) were isolated from human postmortem ALS (n = 10) and neurological control (NC, n = 5) motor cortex brain tissues and the MCEVs protein content subsequently underwent mass spectrometry analysis, allowing for a panel of ALS-associated proteins to be identified. This panel consists of 16 statistically significant differentially packaged proteins identified in the ALS MCEVs. This includes several upregulated RNA-binding proteins which were determined through pathway analysis to be associated with stress granule dynamics. The identification of these RNA-binding proteins in the ALS MCEVs suggests there may be a relationship between ALS-associated stress granules and ALS MCEV packaging, highlighting a potential role for small extracellular vesicles such as exosomes in the pathogenesis of ALS and as potential peripheral biomarkers for ALS.

14.
Oncogene ; 39(30): 5267-5281, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32561850

RESUMO

Melanoma is a deadly form of skin cancer that accounts for a disproportionally large proportion of cancer-related deaths in younger people. Compared with most other skin cancers, a feature of melanoma is its high metastatic capacity, although the mechanisms that confer this are not well understood. The Hippo pathway is a key regulator of organ growth and cell fate that is deregulated in many cancers. To analyse the Hippo pathway in cutaneous melanoma, we generated a transcriptional signature of melanoma cells that overexpressed YAP, the key downstream Hippo pathway oncoprotein. YAP-mediated transcriptional activity varied in melanoma cell lines but did not cluster with known genetic drivers of melanomagenesis such as BRAF and NRAS mutations. Instead, it correlated strongly with published gene expression profiles linked to melanoma cell invasiveness and varied throughout the metastatic cascade in melanoma patient tumours. Consistent with this, YAP was both necessary and sufficient for melanoma cell invasion in vitro. In vivo, YAP promoted spontaneous melanoma metastasis, whilst the growth of YAP-expressing primary tumours was impeded. Finally, we identified the YAP target genes AXL, THBS1 and CYR61 as key mediators of YAP-induced melanoma cell invasion. These data suggest that YAP is a critical regulator of melanoma metastasis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Pulmonares/genética , Melanoma/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Neoplasias Cutâneas/genética , Fatores de Transcrição/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Doxorrubicina/farmacologia , Perfilação da Expressão Gênica/métodos , Humanos , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Melanoma/patologia , Melanoma/terapia , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
15.
Australas J Dermatol ; 2020 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-32363586

RESUMO

BACKGROUND/OBJECTIVES: Acral lentiginous melanoma (ALM) is a melanoma subtype associated with atypical locations on the hands and feet and advanced disease at diagnosis. There is a limited understanding of whether the survival is similar for nail, non-nail, lower limb and upper limb ALM patients. We therefore explored clinicopathologic characteristics and melanoma-specific survival of ALM patients according to tumour location. METHODS: A prospectively collected cohort study was performed of all primary invasive cutaneous acral lentiginous melanomas with known thickness and tumour location reviewed at a tertiary referral centre over 21 years. RESULTS: A total of 101 ALM patients were reviewed from 1994 until 2016. The majority of cases (82/101) occurred on the feet. Hand ALMs were thicker and more likely to be ulcerated than feet ALMs (P = 0.05 and 0.02, respectively); however, survival was not statistically different between these two groups (univariate HR 0.48 P = 0.11, 95% CI, 0.20-1.17; multivariate HR 0.67 P = 0.40, 95% CI, 0.27-1.69, respectively). Non-nail ALM patients had longer survival when compared to nail ALM on univariate analysis (HR 0.40, 95% CI, 0.17 to 0.90) which was accounted for by Breslow thickness and ulceration (multivariate HR 0.56, 95% CI, 0.24 to 1.34). CONCLUSIONS: The reduced melanoma-specific survival in nail ALM patients was likely due to their greater thickness and ulceration. Although hand ALMs are thicker and more frequently ulcerated, this is likely due to the higher proportion of nail ALMs present in this location.

16.
Mol Brain ; 13(1): 52, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228644

RESUMO

Pathogenic variants in the gene encoding the small GTPase Ras analogue in Brain 39b (RAB39B) are associated with early-onset parkinsonism. In this study we investigated the expression and localization of RAB39B (RNA and protein) in mouse brain tissue to gain a better understanding of its normal physiological function(s) and role in disease.We developed novel resources, including monoclonal antibodies directed against RAB39B and mice with Rab39b knockout, and performed real-time PCR and western blot analysis on whole brain lysates. To determine the spatial localization of Rab39b RNA and protein, we performed in-situ hybridization and immunohistochemistry on fresh frozen and fixed brain tissue. Our results show that RAB39B is localized throughout the cortex, hippocampus and substantia nigra of mice throughout postnatal life. We found high levels of RAB39B within MAP2 positive cortical and hippocampal neurons, and TH positive dopaminergic neurons in the substantia nigra pars compacta.Our studies support and extend current knowledge of the localization of RAB39B. We validate RAB39B as a neuron-enriched protein and demonstrate that it is present throughout the mouse cortex and hippocampus. Further, we observe high levels in the substantia nigra pars compacta, the brain region most affected in Parkinson's disease pathology. The distribution of Rab39b is consistent with human disease associations with parkinsonism and cognitive impairment. We also describe and validate novel resources, including monoclonal antibodies directed against RAB39B and mice with Rab39b knockout, both of which are valuable tools for future studies of the molecular function of RAB39B.

17.
J Med Imaging Radiat Oncol ; 64(6): 814-816, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32227569

RESUMO

Tumour thrombus is a complication that occurs when a malignancy invades into the vasculature, occluding its lumen. Here, we present a rare case of melanoma tumour thrombus of the great saphenous vein of the left thigh, which was diagnosed on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography and ultrasound-guided biopsy, and responded well to immunotherapy with pembrolizumab.

18.
J Med Genet ; 57(12): 835-842, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32179706

RESUMO

BACKGROUND: UBA5 is the activating enzyme of UFM1 in the ufmylation post-translational modification system. Different neurological phenotypes have been associated with UBA5 pathogenic variants including epilepsy, intellectual disability, movement disorders and ataxia. METHODS AND RESULTS: We describe a large multigenerational consanguineous family presenting with a severe congenital neuropathy causing early death in infancy. Whole exome sequencing and linkage analysis identified a novel homozygous UBA5 NM_024818.3 c.31C>T (p.Arg11Trp) mutation. Protein expression assays in mouse tissue showed similar levels of UBA5 in peripheral nerves to the central nervous system. CRISPR-Cas9 edited HEK (human embrionic kidney) cells homozygous for the UBA5 p.Arg11Trp mutation showed reduced levels of UBA5 protein compared with the wild-type. The mutant p.Arg11Trp UBA5 protein shows reduced ability to activate UFM1. CONCLUSION: This report expands the phenotypical spectrum of UBA5 mutations to include fatal peripheral neuropathy.

19.
Dalton Trans ; 49(14): 4559-4569, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32202264

RESUMO

Two tridentate ligand systems bearing N-heterocyclic carbene (NHC), amine and carboxylate donor groups coupled to benzothiazole- or stilbene-based amyloid binding moieties were synthesised. Reaction of the imidazolium salt containing pro-ligands with Re(CO)5Cl yielded the corresponding rhenium metal complexes which were characterised by NMR, and X-ray crystallography. These ligands are of interest for the potential preparation of technetium-99m imaging agents for Alzheimer's disease and the capacity of these rhenium complexes bind to amyloid fibrils composed of amyloid-ß peptide and amyloid plaques in human frontal cortex brain tissue was evaluated using fluorescence microscopy. These studies show that the complexes bound efficiently to amyloid-ß fibrils and some evidence of binding to amyloid-ß plaques.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/química , Complexos de Coordenação/química , Compostos de Organotecnécio/química , Aminas/química , Benzotiazóis/química , Sítios de Ligação , Ácidos Carboxílicos/química , Complexos de Coordenação/síntese química , Humanos , Ligantes , Estrutura Molecular , Compostos de Organotecnécio/síntese química , Córtex Pré-Frontal/patologia , Rênio/química , Estilbenos/química
20.
Alzheimers Res Ther ; 12(1): 22, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131891

RESUMO

BACKGROUND: The Centiloid scale was developed to standardise the results of beta-amyloid (Aß) PET. We aimed to determine the Centiloid unit (CL) thresholds for CERAD sparse and moderate-density neuritic plaques, Alzheimer's disease neuropathologic change (ADNC) score of intermediate or high probability of Alzheimer's Disease (AD), final clinicopathological diagnosis of AD, and expert visual read of a positive Aß PET scan. METHODS: Aß PET results in CL for 49 subjects were compared with post-mortem findings, visual read, and final clinicopathological diagnosis. The Youden Index was used to determine the optimal CL thresholds from receiver operator characteristic (ROC) curves. RESULTS: A threshold of 20.1 CL (21.3 CL when corrected for time to death, AUC 0.97) yielded highest accuracy in detecting moderate or frequent plaque density while < 10 CL was optimal for excluding neuritic plaque. The threshold for ADNC intermediate or high likelihood AD was 49.4 CL (AUC 0.98). Those cases with a final clinicopathological diagnosis of AD yielded a median CL result of 87.7 (IQR ± 42.2) with 94% > 45 CL. Positive visual read agreed highly with results > 26 CL. CONCLUSIONS: Centiloid values < 10 accurately reflected the absence of any neuritic plaque and > 20 CL indicated the presence of at least moderate plaque density, but approximately 50 CL or more best confirmed both neuropathological and clinicopathological diagnosis of Alzheimer's disease.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA