RESUMO
OBJECTIVES: To determine the incidence, demographics and injury patterns involved in E-Scooter-related hospital admissions due to significant trauma compared with bicycle-related trauma within England and Wales. To compare morbidity and mortality between groups. DESIGN: A retrospective cohort study based on data which has been prospectively collected and submitted to the UK Trauma Audit and Research Network (TARN) registry. SETTING: Major trauma centres and trauma units within England and Wales. PARTICIPANTS: Patients of any age who were admitted to hospitals in England and Wales with injuries following E-Scooter or bicycle incidents between the dates 1 January 2021-31 December 2021. All patients must have met TARN database inclusion criteria. OUTCOMES: In-hospital mortality, critical care admission and length of stay (LoS), hospital LoS and discharge destination. RESULTS: There were 293 E-Scooter trauma incidents compared with 2538 bicycle incidents. E-Scooter users were more likely to be admitted to a major trauma centre (p=0.019) or a critical care unit (p<0.001). Serious head and limb trauma (Abbreviated Injury Scale >2) occurred more frequently among the E-Scooter cohort (35.2% vs 19.7%, p<0.001 and 39.9% vs 27.2%, p<0.001, respectively) while serious chest and pelvic trauma were greater among bicycle users (p<0.001 and p=0.003, respectively). Over one-third of E-Scooter injuries were incurred outside the current legislation by patients who were intoxicated by alcohol and drugs (26%, 75/293) or under the age of 17 (14%, 41/293). CONCLUSIONS: These early results suggest a greater relative incidence of serious trauma and an alternative pattern of injury among E-Scooter users compared with bicycles. TRIAL REGISTRATION NUMBER: TARN210101.
Assuntos
Ciclismo , Dispositivos de Proteção da Cabeça , Humanos , Estudos de Coortes , Estudos Retrospectivos , Ciclismo/lesões , Hospitalização , Acidentes de Trânsito/prevenção & controleAssuntos
Anestesia Local , Anestésicos Locais , Extremidade Superior , Humanos , Anestesia Local/métodos , Anestésicos Locais/administração & dosagem , Metanálise como Assunto , Procedimentos Ortopédicos/métodos , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/instrumentação , Torniquetes/efeitos adversos , Extremidade Superior/cirurgia , Revisões Sistemáticas como AssuntoRESUMO
Blood and ectoparasitic ticks were collected from migratory seabirds in New Zealand, including Australasian gannets (n = 13) from two sites and red-billed gulls (n = 9) and white-fronted terns (n = 2) from a third location. Blood smears were screened for parasite presence by microscopy, while DNA from blood samples was subjected to PCR for the presence of tick-transmitted protozoan haemoparasites belonging to the order Piroplasmida. Parasites were identified by comparing small subunit ribosomal RNA (18S rDNA) gene sequences to related sequences on GenBank. Analyses indicated that nine birds were infected with unknown variants of a Babesia poelea-like parasite (recorded as genotypes I and II), while four harboured a piroplasm that was genetically similar to Babesia kiwiensis. There was no parasite stratification by bird species; both the gannets and gulls were positive for all three parasites, while the terns were positive for the B. kiwiensis-like and the B. poelea-like (genotype I) parasites. The B. kiwiensis-like parasite found in the birds was also found in two species of ticks: Carios capensis and Ixodes eudyptidis. This represents the first report of Babesia-positive ticks parasitising seabirds in New Zealand. The lack of host specificity and evidence of wide ranging distributions of the three piroplasm genotypes suggests there is a high degree of haemoparasite transmission occurring naturally between New Zealand seabird populations and species.
Assuntos
Babesia/classificação , Babesiose/parasitologia , Doenças das Aves/parasitologia , Charadriiformes/parasitologia , Migração Animal , Animais , Vetores Aracnídeos/parasitologia , Argasidae/parasitologia , Babesia/genética , Babesiose/epidemiologia , Doenças das Aves/epidemiologia , Aves , Citocromos b/genética , DNA de Protozoário/sangue , DNA de Protozoário/química , DNA Ribossômico/sangue , DNA Ribossômico/química , Feminino , Genótipo , Ixodes/parasitologia , Masculino , Nova Zelândia/epidemiologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/genética , Análise de Sequência de DNA/veterinária , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterináriaRESUMO
Basal cell carcinoma (BCC) is the most common form of skin cancer. BCCs are seldom reported on the sole of the foot due to a lack of exposure to UV radiation which is the main risk factor. We present a brief literature review and case report of a 42-year-old female with a non-resolving lesion on the mid-arch of her left foot over a 20-year period. Tissue diagnosis identified the lesion as a BCC. Disease-free control was achieved but the patient experienced significant morbidity resulting in three separate procedures to diagnose, excise and reconstruct the defect. When evaluating lesions on the sole clinicians should consider BCC as a differential, particularly in those which do not respond to initial treatment.
RESUMO
Obesity and its related comorbidities are major public health concerns in the United States with over two-thirds of adults and one-third of children classified as overweight or obese. The prevalence of type 2 diabetes mellitus (T2DM) has similarly risen to an estimated 25.8 million, which accounts for a staggering $174 billion in annual healthcare costs. Identification of dietary interventions that protect against the development of T2DM would markedly reduce the medical and economic consequences of the disease. Hence, we review current evidence supporting a role of (n-3) PUFA in T2DM and explore potential therapeutic implications of stearidonic acid (SDA). The low consumption of fish in the US along with a reduced efficiency to interconvert most plant (n-3) PUFA highlights a need to find alternative sources of (n-3) PUFA. The efficient biological conversion of SDA to EPA underscores the potential implications of SDA as a source of (n-3) PUFA. The full therapeutic efficacy of SDA remains to be further determined. However, recent data have suggested a protective role of SDA consumption on markers of dyslipidemia and inflammation. The AHA recommends that healthy individuals consume oily fish at least twice per week and individuals with a history of cardiovascular disease consume 1 g of EPA+DHA/d. These goals will likely not be met by the typical American diet. Therefore, SDA may represent a sustainable alternative to marine-based (n-3) PUFA and may have novel therapeutic efficacy regarding the development of T2DM.
Assuntos
Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/prevenção & controle , Ácidos Graxos Ômega-3/administração & dosagem , Diabetes Mellitus Tipo 2/metabolismo , Suplementos Nutricionais , Óleos de Peixe/administração & dosagem , Humanos , Política Nutricional , Óleos de Plantas/administração & dosagem , Estados UnidosRESUMO
Alpha-synuclein (SNCA) is a predominantly neuronal protein involved in the control of neurotransmitter release. The levels of SNCA expression are closely linked to the pathogenesis of Parkinson's disease; however, the biochemical pathways and transcriptional elements that control SNCA expression are not well understood. We previously used the model system of neurotrophin-mediated PC12 cell neuronal differentiation to examine these phenomena. Although these studies were informative, they were limited to the use of a cell line; therefore, in the current work, we have turned our attention to cultured primary rat cortical neurons. In these cultures, SNCA expression increased with time in culture, as the neurons mature. Luciferase assays based on transient transfections of fusion constructs encoding components of the transcriptional control region of SNCA identified various promoter areas that have a positive or negative effect on SNCA transcription. Intron 1, previously identified by us as an important regulatory region in the PC12 cell model, cooperates with regions 5' to exon 1 to mediate gene transcription. Using selective pharmacological tools, we find that tyrosine kinase receptors and the phosphatidyl-inositol 3 kinase signaling pathway are involved in mediating these effects. The exogenous application of the neurotrophin brain-derived neurotrophic factor (BDNF) is sufficient on its own to promote the transcriptional activation of SNCA through this pathway, but a neutralizing antibody against BDNF failed to affect SNCA transcription in maturing cultures, suggesting that BDNF is not the main factor involved in maturation-induced SNCA transcription in this model. Further in vivo studies are needed to establish the role of neurotrophin signaling in the control of SNCA transcription.
Assuntos
Córtex Cerebral/citologia , Regulação da Expressão Gênica/fisiologia , Neurônios/metabolismo , alfa-Sinucleína/metabolismo , Análise de Variância , Animais , Anticorpos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/imunologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Células Cultivadas , Esquema de Medicação , Interações Medicamentosas , Embrião de Mamíferos , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Fatores de Tempo , Transfecção/métodos , alfa-Sinucleína/genéticaRESUMO
BACKGROUND: Collagens require the hydroxylation of proline (Pro) residues in their triple-helical domain repeating sequence Xaa-Pro-Gly to function properly as a main structural component of the extracellular matrix in animals at physiologically relevant conditions. The regioselective proline hydroxylation is catalyzed by a specific prolyl 4-hydroxylase (P4H) as a posttranslational processing step. RESULTS: A recombinant human collagen type I α-1 (rCIα1) with high percentage of hydroxylated prolines (Hyp) was produced in transgenic maize seeds when co-expressed with both the α- and ß- subunits of a recombinant human P4H (rP4H). Germ-specific expression of rCIα1 using maize globulin-1 gene promoter resulted in an average yield of 12 mg/kg seed for the full-length rCIα1 in seeds without co-expression of rP4H and 4 mg/kg seed for the rCIα1 (rCIα1-OH) in seeds with co-expression of rP4H. High-resolution mass spectrometry (HRMS) analysis revealed that nearly half of the collagenous repeating triplets in rCIα1 isolated from rP4H co-expressing maize line had the Pro residues changed to Hyp residues. The HRMS analysis determined the Hyp content of maize-derived rCIα1-OH as 18.11%, which is comparable to the Hyp level of yeast-derived rCIα1-OH (17.47%) and the native human CIa1 (14.59%), respectively. The increased Hyp percentage was correlated with a markedly enhanced thermal stability of maize-derived rCIα1-OH when compared to the non-hydroxylated rCIα1. CONCLUSIONS: This work shows that maize has potential to produce adequately modified exogenous proteins with mammalian-like post-translational modifications that may be require for their use as pharmaceutical and industrial products.
Assuntos
Colágeno Tipo I/metabolismo , Plantas Geneticamente Modificadas/genética , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Zea mays/genética , Sequência de Aminoácidos , Western Blotting , Cromatografia Líquida , Colágeno Tipo I/química , Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I , Humanos , Hidroxilação , Hidroxiprolina/química , Hidroxiprolina/metabolismo , Dados de Sequência Molecular , Pichia , Plantas Geneticamente Modificadas/metabolismo , Pró-Colágeno-Prolina Dioxigenase/química , Pró-Colágeno-Prolina Dioxigenase/genética , Engenharia de Proteínas , Estabilidade Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sementes/genética , Sementes/metabolismo , Alinhamento de Sequência , Espectrometria de Massas em Tandem , Zea mays/metabolismoRESUMO
A considerable number of cells expressing typical immature neuronal markers including doublecortin (DCX+) are present around layer II in the cerebral cortex of young and adult guinea pigs and other larger mammals, and their origin and biological implication await further characterization. We show here in young adult guinea pigs that these DCX+ cells are accompanied by in situ cell division around the superficial cortical layers mostly in layer I, but they co-express proliferating cell nuclear antigen (PCNA) and an early neuronal fate determining factor, PAX6. A small number of these DCX+ cells also colocalize with BrdU following administration of this mitotic indicator. Cranial X-ray irradiation causes a decline of DCX+ cells around layer II, and novel environmental exploration induces c-Fos expression among these cells in several neocortical areas. Together, these data are compatible with a notion that DCX+ cortical neurons around layer II might derive from proliferable neuronal precursors around layer I in young adult guinea pig cerebrum, and that these cells might be modulated by experience under physiological conditions.
Assuntos
Cérebro/fisiologia , Neocórtex/fisiologia , Neurogênese , Animais , Divisão Celular , Cérebro/citologia , Cérebro/efeitos da radiação , Proteínas do Domínio Duplacortina , Proteínas do Olho/análise , Cobaias , Proteínas de Homeodomínio/análise , Proteínas Associadas aos Microtúbulos/metabolismo , Neocórtex/citologia , Neocórtex/efeitos da radiação , Proteínas do Tecido Nervoso/análise , Neuropeptídeos/metabolismo , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/análise , Antígeno Nuclear de Célula em Proliferação/análise , Proteínas Proto-Oncogênicas c-fos/análise , Proteínas Repressoras/análiseRESUMO
The fusion oncogene RUNX1/RUNX1T1 encodes an aberrant transcription factor, which plays a key role in the initiation and maintenance of acute myeloid leukemia. Here we show that the RUNX1/RUNX1T1 oncogene is a regulator of alternative RNA splicing in leukemic cells. The comprehensive analysis of RUNX1/RUNX1T1-associated splicing events identifies two principal mechanisms that underlie the differential production of RNA isoforms: (i) RUNX1/RUNX1T1-mediated regulation of alternative transcription start site selection, and (ii) direct or indirect control of the expression of genes encoding splicing factors. The first mechanism leads to the expression of RNA isoforms with alternative structure of the 5'-UTR regions. The second mechanism generates alternative transcripts with new junctions between internal cassettes and constitutive exons. We also show that RUNX1/RUNX1T1-mediated differential splicing affects several functional groups of genes and produces proteins with unique conserved domain structures. In summary, this study reveals alternative splicing as an important component of transcriptome re-organization in leukemia by an aberrant transcriptional regulator.
Assuntos
Processamento Alternativo , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Regulação Leucêmica da Expressão Gênica , Leucemia Mieloide/genética , Proteínas de Fusão Oncogênica/genética , Proteína 1 Parceira de Translocação de RUNX1/genética , Doença Aguda , Linhagem Celular Tumoral , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Perfilação da Expressão Gênica/métodos , Humanos , Leucemia Mieloide/patologia , Modelos Genéticos , Proteínas de Fusão Oncogênica/metabolismo , Interferência de RNA , Isoformas de RNA/genética , Isoformas de RNA/metabolismo , Proteína 1 Parceira de Translocação de RUNX1/metabolismo , Sítio de Iniciação de TranscriçãoRESUMO
Alzheimer's disease (AD) is the most common dementia-causing disorder in the elderly; it may be related to multiple risk factors, and is characterized pathologically by cerebral hypometabolism, paravascular ß-amyloid peptide (Aß) plaques, neuritic dystrophy, and intra-neuronal aggregation of phosphorylated tau. To explore potential pathogenic links among some of these lesions, we examined ß-secretase-1 (BACE1) alterations relative to Aß deposition, neuritic pathology and vascular organization in aged monkey and AD human cerebral cortex. Western blot analyses detected increased levels of BACE1 protein and ß-site-cleavage amyloid precursor protein C-terminal fragments in plaque-bearing human and monkey cortex relative to controls. In immunohistochemistry, locally elevated BACE1 immunoreactivity (IR) occurred in AD but not in control human cortex, with a trend for increased overall density among cases with greater plaque pathology. In double-labeling preparations, BACE1 IR colocalized with immunolabeling for Aß but not for phosphorylated tau. In perfusion-fixed monkey cortex, locally increased BACE1 IR co-existed with intra-axonal and extracellular Aß IR among virtually all neuritic plaques, ranging from primitive to typical cored forms. This BACE1 labeling localized to swollen/sprouting axon terminals that might co-express one or another neuronal phenotype markers (GABAergic, glutamatergic, cholinergic, or catecholaminergic). Importantly, these BACE1-labeled dystrophic axons resided near to or in direct contact with blood vessels. These findings suggest that plaque formation in AD or normal aged primates relates to a multisystem axonal pathogenesis that occurs in partnership with a potential vascular or metabolic deficit. The data provide a mechanistic explanation for why senile plaques are present preferentially near the cerebral vasculature.
Assuntos
Envelhecimento/patologia , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Vasos Sanguíneos/patologia , Córtex Cerebral/enzimologia , Córtex Cerebral/patologia , Animais , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/ultraestrutura , Complexo IV da Cadeia de Transporte de Elétrons , Feminino , Regulação da Expressão Gênica/fisiologia , Humanos , Macaca mulatta , Masculino , Peso Molecular , NADPH Desidrogenase , Proteínas do Tecido Nervoso/metabolismo , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Placa Amiloide/ultraestrutura , Mudanças Depois da Morte , Terminações Pré-Sinápticas/metabolismo , Terminações Pré-Sinápticas/patologia , Coloração pela Prata/métodos , Estatísticas não Paramétricas , Proteínas tau/metabolismoRESUMO
Cerebral hypometabolism and amyloid accumulation are principal neuropathological manifestations of Alzheimer's disease (AD). Whether and how brain/neuronal activity might modulate certain pathological processes of AD are interesting topics of recent clinical and basic research in the field, and may be of potential medical relevance in regard to both the disease etiology and intervention. Using the Tg2576 transgenic mouse model of AD, this study characterized a promotive effect of neuronal hypoactivity associated with functional deprivation on amyloid plaque pathogenesis in the olfactory pathway. Unilateral naris-occlusion caused beta-secretase-1 (BACE1) elevation in neuronal terminals in the deprived relative to the non-deprived bulb and piriform cortex in young adult mice. In parallel with the overall age-related plaque development in the forebrain, locally increased BACE1 immunoreactivity co-occurred with amyloid deposition first in the piriform cortex then within the bulb, more prominent on the deprived relative to the non-deprived side. Biochemical analyses confirmed elevated BACE1 protein levels, enzymatic activity and products in the deprived relative to non-deprived bulbs. Plaque-associated BACE1 immunoreactivity in the bulb and piriform cortex was localized preferentially to swollen/sprouting glutamatergic axonal terminals, with Abeta immunoreactivity occurring inside as well as around these terminals. Together, these findings suggest that functional deprivation or neuronal hypoactivity facilitates amyloid plaque formation in the forebrain in a transgenic model of AD, which operates synergistically with age effect. The data also implicate an intrinsic association of amyloid accumulation and plaque formation with progressive axonal pathology.
Assuntos
Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Bulbo Olfatório/metabolismo , Condutos Olfatórios/metabolismo , Placa Amiloide/metabolismo , Fatores Etários , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Modelos Animais de Doenças , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , NADPH Desidrogenase/metabolismo , Neurônios/metabolismo , Nariz/patologia , Bulbo Olfatório/patologia , Condutos Olfatórios/patologia , Terminações Pré-Sinápticas/metabolismo , Regulação para CimaRESUMO
Alpha-synuclein (SNCA) is an abundant neuronal protein involved in synaptic neurotransmission. SNCA expression levels have been strongly implicated in Parkinson's disease pathogenesis. We have previously demonstrated that in the PC12 cell line elements in intron 1 may mediate SNCA transcriptional regulation in response to neurotrophins. We have now identified transcription factor (TF) binding sites in intron 1 and the 5'-promoter of SNCA. A binding site for the TF zinc finger and SCAN domain containing (ZSCAN)21 in the 5'-region of intron 1 is required for intron 1 transcriptional activity. Small interfering RNA against ZSCAN21 inhibits activation in the luciferase assay and diminishes SNCA protein levels in naïve and neurotrophin-treated PC12 cells and in primary cultured cortical neurons, demonstrating that ZSCAN21 is a novel transcriptional regulator of SNCA in neuronal cells. The 5'-promoter of SNCA has a complex architecture, including multiple binding sites for the TF zinc finger protein (ZNF)219, which functions as both an activator and a repressor. Targeting ZSCAN21 or other TFs controlling SNCA transcriptional activity may provide novel therapeutic avenues not only for Parkinson's disease but also for other synucleopathies.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica/fisiologia , Fatores de Transcrição Kruppel-Like/fisiologia , Regiões Promotoras Genéticas/fisiologia , Transcrição Gênica/fisiologia , Dedos de Zinco/genética , alfa-Sinucleína/genética , Animais , Sítios de Ligação/genética , Células Cultivadas , Humanos , Íntrons/genética , Camundongos , Fatores de Crescimento Neural/fisiologia , Células PC12 , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Transativadores , alfa-Sinucleína/metabolismoRESUMO
The presence of neuritic plaques is a pathological hallmark of Alzheimer's disease (AD). However, the origin of extracellular beta-amyloid peptide (Abeta) deposits and the process of plaque development remain poorly understood. The present study attempted to explore plaque pathogenesis by localizing beta-secretase-1 (BACE1) elevation relative to Abeta accumulation and synaptic/neuritic alterations in the forebrain, using transgenic mice harboring familial AD (FAD) mutations (5XFAD and 2XFAD) as models. In animals with fully developed plaque pathology, locally elevated BACE1 immunoreactivity (IR) coexisted with compact-like Abeta deposition, with BACE1 IR occurring selectively in dystrophic axons of various neuronal phenotypes or origins (GABAergic, glutamatergic, cholinergic or catecholaminergic). Prior to plaque onset, localized BACE1/Abeta IR occurred at swollen presynaptic terminals and fine axonal processes. These BACE1/Abeta-containing axonal elements appeared to undergo a continuing process of sprouting/swelling and dystrophy, during which extracellular Abeta IR emerged and accumulated in surrounding extracellular space. These data suggest that BACE1 elevation and associated Abeta overproduction inside the sprouting/dystrophic axonal terminals coincide with the onset and accumulation of extracellular amyloid deposition during the development of neuritic plaques in transgenic models of AD. Our findings appear to be in harmony with an early hypothesis that axonal pathogenesis plays a key or leading role in plaque formation.
Assuntos
Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Axônios/fisiologia , Placa Amiloide/fisiologia , Prosencéfalo/fisiopatologia , Sinapses/fisiologia , Envelhecimento , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Axônios/patologia , Espaço Extracelular/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mutação , Neurônios/patologia , Neurônios/fisiologia , Placa Amiloide/patologia , Presenilina-1/genética , Terminações Pré-Sinápticas/patologia , Terminações Pré-Sinápticas/fisiologia , Prosencéfalo/patologia , Nexinas de Proteases , Receptores de Superfície Celular/genética , Sinapses/patologiaRESUMO
C57BL/6 mice were given 0.2% cuprizone (CPZ) for 2 to 6 weeks while controls ate the same diet without CPZ. At various time points the animals were subjected to behavioral tests and their brains were analyzed. Mice exposed to CPZ for 2 and 3 weeks displayed more climbing behavior and lower prepulse inhibition, suggesting an increase in central nervous system activity and impaired sensorimotor gating. In addition, they showed lower activities of monoamine oxidase and dopamine beta hydroxylase in the hippocampus and prefrontal cortex, and had higher dopamine but lower norepinephrine levels in the prefrontal cortex. Mice exposed to CPZ for 4 to 6 weeks had less social interaction, which is an animal correlate of social withdrawal of patients with schizophrenia. Also, these CPZ-exposed mice showed evident brain demyelination, myelin break down, and loss of oligodendrocytes. At all time points the CPZ-exposed mice spent more time in the open arms of an elevated plus maze and exhibited spatial working memory impairment. These data are in line with evidence from human studies suggesting a putative role of white matter abnormality in the pathophysiology of schizophrenia.
Assuntos
Comportamento Animal/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Cuprizona/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Inibição Neural/efeitos dos fármacos , Análise de Variância , Animais , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Química Encefálica/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Doenças Desmielinizantes/induzido quimicamente , Dopamina beta-Hidroxilase/metabolismo , Eletroquímica/métodos , Comportamento Exploratório/efeitos dos fármacos , Relações Interpessoais , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Monoaminoxidase/metabolismo , Proteína Básica da Mielina/metabolismo , Inibição Neural/fisiologia , Fatores de TempoRESUMO
Cerebral hypometabolism, mitochondrial dysfunction, and beta-amyloid peptide (Abeta) accumulation are well-characterized manifestations of Alzheimer's disease (AD). beta-Secretase (BACE) is a prerequisite for amyloidogenesis, and it is up-regulated in sporadic AD. To explore a potential in vivo mechanism by which Abeta production is modulated by neuronal activity and/or oxidative metabolism, we compared BACE expression with cytochrome c oxidase (CO) or succinic dehydrogenase (SDH) activity in normal and functionally deprived adult rat olfactory bulb. In normal bulb, BACE was expressed predominantly in the glomerular layer, but labeling intensity within individual glomeruli varied substantially. A strong negative correlation existed between BACE labeling intensity and CO or SDH activity among individual glomeruli. Unilateral naris occlusion resulted in elevated glomerular BACE labeling in the deprived bulbs relative to the nondeprived counterparts, which was correlated with decreased CO activity in the same anatomic location. Enhanced BACE labeling was confirmed by measurements of elevated protein levels, enzymatic activity, and beta-site cleavage products of amyloid precursor protein in bulb extracts. Our findings reveal a negative regulation of BACE expression by physiological neuronal activity and an intrinsic inverse correlation between BACE expression and oxidative metabolism at the first synapse on the olfactory pathway. The results point to a biological role of BACE in synapse function and plasticity as well as a potential mechanism whereby reduced neuronal activity or metabolism could lead to amyloid overproduction in synaptic terminals.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Obstrução Nasal/enzimologia , Bulbo Olfatório/enzimologia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Western Blotting , Citocromo-c Peroxidase/antagonistas & inibidores , Citocromo-c Peroxidase/metabolismo , Glicosilação , Imuno-Histoquímica , Masculino , Obstrução Nasal/metabolismo , Bulbo Olfatório/metabolismo , Oxirredução , Presenilinas/metabolismo , Ratos , Ratos Sprague-Dawley , Succinato Desidrogenase/metabolismo , Distribuição Tecidual , Regulação para CimaRESUMO
Ethanol from lignocellulosic biomass is being pursued as an alternative to petroleum-based transportation fuels. To succeed in this endeavour, efficient digestion of cellulose into monomeric sugar streams is a key step. Current production systems for cellulase enzymes, i.e. fungi and bacteria, cannot meet the cost and huge volume requirements of this commodity-based industry. Transgenic maize (Zea mays L.) seed containing cellulase protein in embryo tissue, with protein localized to the endoplasmic reticulum, cell wall or vacuole, allows the recovery of commercial amounts of enzyme. E1 cellulase, an endo-beta-1,4-glucanase from Acidothermus cellulolyticus, was recovered at levels greater than 16% total soluble protein (TSP) in single seed. More significantly, cellobiohydrolase I (CBH I), an exocellulase from Trichoderma reesei, also accumulated to levels greater than 16% TSP in single seed, nearly 1000-fold higher than the expression in any other plant reported in the literature. The catalytic domain was the dominant form of E1 that was detected in the endoplasmic reticulum and vacuole, whereas CBH I holoenzyme was present in the cell wall. With one exception, individual transgenic events contained single inserts. Recovery of high levels of enzyme in T2 ears demonstrated that expression is likely to be stable over multiple generations. The enzymes were active in cleaving soluble substrate.
Assuntos
Celulose 1,4-beta-Celobiosidase/biossíntese , Plantas Geneticamente Modificadas/enzimologia , Sementes/enzimologia , Trichoderma/genética , Zea mays/enzimologia , Agrobacterium tumefaciens/genética , Celulase/genética , Celulase/metabolismo , Celulose 1,4-beta-Celobiosidase/economia , Celulose 1,4-beta-Celobiosidase/genética , Marcação de Genes , Vetores Genéticos , Plantas Geneticamente Modificadas/microbiologia , Transformação Genética , Trichoderma/enzimologia , Zea mays/genética , Zea mays/microbiologiaRESUMO
Gamma-secretase is a multimeric enzyme important for normal cell/neuronal proliferation, differentiation and plasticity. Determining in vivo gamma-secretase expression and activity remains a challenge because its subunit proteins can exist in immature and preassembled forms, but may execute cellular roles irrelevant to gamma-site cleavage. In this study, we characterized [3H]-L-685,458 as a radiotracer for the detection of active gamma-secretase in adult rat brain. In vitro autoradiography indicated that [3H]-L-685,458 binding was saturatable, displaceable by peptidomimetic and small molecule gamma-secretase inhibitors, and exhibited rapid association and dissociation kinetics. In cultured hippocampal slices, [3H]-L-685,458 binding density correlated with Abeta reduction following in-dish dosing of this radioligand or a non-radioactive gamma-secretase inhibitor. [3H]-L-685,458 binding sites in the adult brain were differentially distributed across regions and laminas, with heavy binding localized to the olfactory glomeruli, hippocampal CA3 and cerebellar molecular layer, and moderate binding in the cerebral cortex, amygdala and selected subcortical regions. All of these regions showed labeling for presenilin-1 N-terminal fragments (PS1-NTFs). A distinct correlation of dense binding sites with abundant presence of PS1-NTFs was verified in hippocampal mossy fiber terminals and olfactory bulb glomeruli, suggestive of a rich expression of gamma-secretase in the synapses at these locations that are characteristic of dynamic plasticity. Together, [3H]-L-685,458 is an excellent radiotracer for mapping active gamma-secretase complex, and may serve as a useful tool for studying the enzyme in vivo and in vitro.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/biossíntese , Mapeamento Encefálico/métodos , Carbamatos/metabolismo , Dipeptídeos/metabolismo , Presenilina-1/metabolismo , Ensaio Radioligante/métodos , Secretases da Proteína Precursora do Amiloide/análise , Animais , Animais Recém-Nascidos , Sítios de Ligação/fisiologia , Ligação Competitiva/efeitos dos fármacos , Ligação Competitiva/fisiologia , Encéfalo/anatomia & histologia , Encéfalo/enzimologia , Carbamatos/farmacocinética , Células Cultivadas , Dipeptídeos/farmacocinética , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Feminino , Masculino , Fibras Musgosas Hipocampais/enzimologia , Bulbo Olfatório/enzimologia , Técnicas de Cultura de Órgãos , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/metabolismo , Presenilina-1/análise , Ratos , Ratos Sprague-Dawley , Trítio/metabolismoRESUMO
Serotonin (5-HT) has been shown to exert antiepileptic effects in a variety of generalized convulsive seizure models, particularly the genetically epilepsy-prone rat (GEPR). The present study was designed to identify the region/site(s) where 5-HT exerts anticonvulsant effects in the GEPR-9, a model in which sound-evoked generalized tonic-clonic seizures (GTCS) are highly sensitive to manipulations in 5-HT concentration. Because the 5-HT reuptake inhibitor, fluoxetine, was known to exert anticonvulsant effects in GEPR-9s via a 5-HT-dependent mechanism, we utilized selective regional 5-HT depletion in combination with systemic fluoxetine administration to find the site where a 5-HT deficit would prevent the anticonvulsant action of fluoxetine. Widespread destruction of serotonergic terminal fields or regionally specific terminal field destruction was achieved using intracerebroventricular and more target specific infusions of 5,7-dihydroxytryptamine. The capacity of fluoxetine to suppress seizures in GEPR-9s following a loss of 5-HT was then examined. The present findings show the anticonvulsant action of fluoxetine is markedly attenuated following the loss of midbrain 5-HT, particularly in the region of the superior colliculus, while forebrain and spinal cord 5-HT do not appear to play a role in the action of fluoxetine. The importance of the deep layers of the SC was confirmed by demonstrating that direct microinfusion of fluoxetine into the SC can suppress seizures in rats pretreated with the 5-HT(1A) receptor antagonist pindolol.
Assuntos
Epilepsia/genética , Ratos Mutantes , Serotonina/fisiologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Di-Hidroxitriptaminas/farmacologia , Epilepsia/fisiopatologia , Epilepsia Reflexa/fisiopatologia , Feminino , Fluoxetina/administração & dosagem , Fluoxetina/farmacologia , Infusões Parenterais , Masculino , Ratos , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Medula Espinal/fisiologia , Medula Espinal/fisiopatologia , Colículos Superiores/efeitos dos fármacos , Colículos Superiores/fisiopatologiaRESUMO
Manganese peroxidase (MnP) has been implicated in lignin degradation and thus has potential applications in pulp and paper bleaching, enzymatic remediation and the textile industry. Transgenic plants are an emerging protein expression platform that offer many advantages over traditional systems, in particular their potential for large-scale industrial enzyme production. Several plant expression vectors were created to evaluate the accumulation of MnP from the wood-rot fungus Phanerochaete chrysosporium in maize seed. We showed that cell wall targeting yielded full-length MnP, whereas cytoplasmic localization resulted in multiple truncated peroxidase polypeptides as detected by immunoblot analysis. In addition, the use of a seed-preferred promoter dramatically increased the expression levels and reduced the negative effects on plant health. Multiple independent transgenic lines were backcrossed with elite inbred corn lines for several generations with the maintenance of high-level expression, indicating genetic stability of the transgene.