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Astrocytes play a critical role in the maintenance of a healthy central nervous system and astrocyte dysfunction has been implicated in various neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). There is compelling evidence that mouse and human ALS and ALS/FTD astrocytes can reduce the number of healthy wild-type motoneurons (MNs) in co-cultures or after treatment with astrocyte conditioned media (ACM), independently of their genotype. A growing number of studies have shown that soluble toxic factor(s) in the ACM cause non-cell autonomous MN death, including our recent identification of inorganic polyphosphate (polyP) that is excessively released from mouse primary astrocytes (SOD1, TARDBP, and C9ORF72) and human induced pluripotent stem cells (iPSC)-derived astrocytes (TARDBP) to kill MNs. However, others have reported that astrocytes carrying mutant TDP43 do not produce detectable MN toxicity. This controversy is likely to arise from the findings that human iPSC-derived astrocytes exhibit a rather immature and/or reactive phenotype in a number of studies. Here, we have succeeded in generating a highly homogenous population of functional quiescent mature astrocytes from control subject iPSCs. Using identical conditions, we also generated mature astrocytes from an ALS/FTD patient carrying the TDP43A90V mutation. These mutant TDP43 patient-derived astrocytes exhibit key pathological hallmarks, including enhanced cytoplasmic TDP-43 and polyP levels. Additionally, mutant TDP43 astrocytes displayed a mild reactive signature and an aberrant function as they were unable to promote synaptogenesis of hippocampal neurons. The polyP-dependent neurotoxic nature of the TDP43A90V mutation was further confirmed as neutralization of polyP in ACM derived from mutant TDP43 astrocytes prevented MN death. Our results establish that human astrocytes carrying the TDP43A90V mutation exhibit a cell-autonomous pathological signature, hence providing an experimental model to decipher the molecular mechanisms underlying the generation of the neurotoxic phenotype.
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Purpose: to determine lactose intolerance (LI) prevalence in women with Hashimoto's thyroiditis (HT) and assess the impact of LI on LT4 replacement dose. Methods. consecutive patients with HT underwent Lactose Breath Test and clinical/laboratory data collection. Unrelated gastrointestinal disorders were carefully ruled out. Lactose-free diet and shift to lactose-free LT4 were proposed to patients with LI. Results: we enrolled 58 females (age range, 23−72 years) with diagnosis of HT. In total, 15 patients were euthyroid without treatment, and 43 (74%) euthyroid under LT4 (30 of them with a LT4 formulation containing lactose). Gastrointestinal symptoms were present in 84.5% of patients, with a greater prevalence in change in bowel habits in lactose-intolerant patients (p < 0.0001). The cumulative LT4 dose required did not differ in patients with or without LI. No significant difference in both TSH values and LT4 dose were observed in patients shifted to lactose-free LT4 and diet at 3 and 6 months compared to baseline. Conclusion: the prevalence of LI in patients with HT was 58.6%, not different from global prevalence of LI. In the absence of other gastrointestinal disorders, LI seems not to be a major cause of LT4 malabsorption and does not affect the LT4 required dose in HT patients.
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Gastroenteropatias , Doença de Hashimoto , Intolerância à Lactose , Adulto , Idoso , Feminino , Gastroenteropatias/tratamento farmacológico , Doença de Hashimoto/tratamento farmacológico , Doença de Hashimoto/epidemiologia , Humanos , Lactose , Intolerância à Lactose/diagnóstico , Pessoa de Meia-Idade , Prevalência , Tiroxina/uso terapêutico , Adulto JovemRESUMO
In recent years, immune checkpoint inhibitors (ICIs), including nivolumab and pembrolizumab have revolutionized the treatment landscape in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). However, many patients do not respond to ICIs for reasons that remain largely unknown. For patients who progress on ICIs, chemotherapy and/or biologic therapies are the most widely used treatments based on the clinician's choice, with no defined sequence strategy. We report the experience of a patient with metastatic oropharyngeal squamous cell cancer p16 and human papillomavirus-DNA positive who received chemotherapy with weekly paclitaxel after progressing on nivolumab. Our patient presented a partial response to fourth line paclitaxel, which lasted more than 2 years, with an improvement of his quality of life too. These results support the hypothesis of synergism between immunotherapy and conventional chemotherapies. Even in the setting of immune-refractory disease, immunotherapy may affect tumor immune microenvironment thus leading to a synergistic effect with conventional chemotherapy and achieving unexpected results.
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Neoplasias de Cabeça e Pescoço , Nivolumabe , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Imunoterapia/métodos , Recidiva Local de Neoplasia/terapia , Nivolumabe/uso terapêutico , Paclitaxel , Qualidade de Vida , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Microambiente TumoralRESUMO
Non-cell-autonomous mechanisms contribute to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), in which astrocytes release unidentified factors that are toxic to motoneurons (MNs). We report here that mouse and patient iPSC-derived astrocytes with diverse ALS/FTD-linked mutations (SOD1, TARDBP, and C9ORF72) display elevated levels of intracellular inorganic polyphosphate (polyP), a ubiquitous, negatively charged biopolymer. PolyP levels are also increased in astrocyte-conditioned media (ACM) from ALS/FTD astrocytes. ACM-mediated MN death is prevented by degrading or neutralizing polyP in ALS/FTD astrocytes or ACM. Studies further reveal that postmortem familial and sporadic ALS spinal cord sections display enriched polyP staining signals and that ALS cerebrospinal fluid (CSF) exhibits increased polyP concentrations. Our in vitro results establish excessive astrocyte-derived polyP as a critical factor in non-cell-autonomous MN degeneration and a potential therapeutic target for ALS/FTD. The CSF data indicate that polyP might serve as a new biomarker for ALS/FTD.
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Esclerose Lateral Amiotrófica , Demência Frontotemporal , Esclerose Lateral Amiotrófica/genética , Animais , Astrócitos , Proteína C9orf72/genética , Meios de Cultivo Condicionados/farmacologia , Demência Frontotemporal/genética , Humanos , Camundongos , Neurônios Motores , PolifosfatosRESUMO
BACKGROUND: Hexanucleotide repeat expansions of the G4C2 motif in a non-coding region of the C9ORF72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Tissues from C9ALS/FTD patients and from mouse models of ALS show RNA foci, dipeptide-repeat proteins, and notably, widespread alterations in the transcriptome. Epigenetic processes regulate gene expression without changing DNA sequences and therefore could account for the altered transcriptome profiles in C9ALS/FTD; here, we explore whether the critical repressive marks H3K9me2 and H3K9me3 are altered in a recently developed C9ALS/FTD BAC mouse model (C9BAC). RESULTS: Chromocenters that constitute pericentric constitutive heterochromatin were visualized as DAPI- or Nucblue-dense foci in nuclei. Cultured C9BAC astrocytes exhibited a reduced staining signal for H3K9me3 (but not for H3K9me2) at chromocenters that was accompanied by a marked decline in the global nuclear level of this mark. Similar depletion of H3K9me3 at chromocenters was detected in astrocytes and neurons of the spinal cord, motor cortex, and hippocampus of C9BAC mice. The alterations of H3K9me3 in the hippocampus of C9BAC mice led us to identify previously undetected neuronal loss in CA1, CA3, and dentate gyrus, as well as hippocampal-dependent cognitive deficits. CONCLUSIONS: Our data indicate that a loss of the repressive mark H3K9me3 in astrocytes and neurons in the central nervous system of C9BAC mice represents a signature during neurodegeneration and memory deficit of C9ALS/FTD.
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Proteína C9orf72/metabolismo , Disfunção Cognitiva/genética , Epigênese Genética/genética , Histonas/genética , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Astrócitos/metabolismo , Disfunção Cognitiva/metabolismo , Metilação de DNA/genética , Dipeptídeos/metabolismo , Modelos Animais de Doenças , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Expressão Gênica , Hipocampo/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Transcriptoma/genéticaRESUMO
The symptomatic irreproducibility of data in biomedicine and biotechnology prompts the need for higher order measurements of cells in their native and near-native environments. Such measurements may support the adoption of new technologies as well as the development of research programs across different sectors including healthcare and clinic, environmental control and national security. With an increasing demand for reliable cell-based products and services, cellular metrology is poised to help address current and emerging measurement challenges faced by end-users. However, metrological foundations in cell analysis remain sparse and significant advances are necessary to keep pace with the needs of modern medicine and industry. Herein we discuss a role of metrology in cell and cell-related R&D activities to underpin growing international measurement capabilities. Relevant measurands are outlined and the lack of reference methods and materials, particularly those based on functional cell responses in native environments, is highlighted. The status quo and current challenges in cellular measurements are discussed in the light of metrological traceability in cell analysis and applications (e.g., a functional cell count). An emphasis is made on the consistency of measurement results independent of the analytical platform used, high confidence in data quality vs. quantity, scale of measurements and issues of building infrastructure for end-users.
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BACKGROUND: Neuroinflammation involves cytokine release, astrocyte reactivity and migration. Neuronal Thy-1 promotes DITNC1 astrocyte migration by engaging αVß3 Integrin and Syndecan-4. Primary astrocytes express low levels of these receptors and are unresponsive to Thy-1; thus, inflammation and astrocyte reactivity might be necessary for Thy-1-induced responses. METHODS: Wild-type rat astrocytes (TNF-activated) or from human SOD1G93A transgenic mice (a neurodegenerative disease model) were used to evaluate cell migration, Thy-1 receptor levels, signaling molecules, and reactivity markers. RESULTS: Thy-1 induced astrocyte migration only after TNF priming. Increased expression of αVß3 Integrin, Syndecan-4, P2X7R, Pannexin-1, Connexin-43, GFAP, and iNOS were observed in TNF-treated astrocytes. Silencing of ß3 Integrin prior to TNF treatment prevented Thy-1-induced migration, while ß3 Integrin over-expression was sufficient to induce astrocyte reactivity and allow Thy-1-induced migration. Finally, hSOD1G93A astrocytes behave as TNF-treated astrocytes since they were reactive and responsive to Thy-1. CONCLUSIONS: Therefore, inflammation induces expression of αVß3 Integrin and other proteins, astrocyte reactivity, and Thy-1 responsiveness. Importantly, ectopic control of ß3 Integrin levels modulates these responses regardless of inflammation.
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Astrócitos/fisiologia , Movimento Celular/fisiologia , Regulação da Expressão Gênica/genética , Integrina alfaVbeta3/metabolismo , Animais , Animais Geneticamente Modificados , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Células Cultivadas , Conexinas/genética , Conexinas/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Integrina alfaVbeta3/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Ratos , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Antígenos Thy-1/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Cicatrização/fisiologiaRESUMO
Amyotrophic lateral sclerosis is a fatal neurodegenerative disease and studies in vitro show that motoneuron degeneration is triggered by non-cell-autonomous mechanisms. However, whether soluble toxic factor(s) released by mutant superoxide dismutase 1 (SOD1) expressing astrocytes induces death of motoneurons and leads to motor dysfunction in vivo is not known. To directly test this, healthy adult rats were treated with conditioned media derived from primary mouse astrocytes (ACM) that express human (h) SOD1G93A (ACM-hG93A) via chronic osmotic pump infusion in the lumbar spinal cord. Controls included ACM derived from transgenic mice expressing hSOD1WT (ACM-hWT) or non-transgenic mouse SOD1WT (ACM-WT) astrocytes. Rats chronically infused with ACM-hG93A started to develop motor dysfunction at 8 days, as measured by rotarod performance. Additionally, immunohistochemical analyses at day 16 revealed reactive astrogliosis and significant loss of motoneurons in the ventral horn of the infused region. Controls did not show significant motor behavior alterations or neuronal damage. Thus, we demonstrate that factors released in vitro from astrocytes derived from ALS mice cause spinal motoneuron death and consequent neuromuscular dysfunction in vivo.
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Esclerose Lateral Amiotrófica/enzimologia , Astrócitos/enzimologia , Meios de Cultivo Condicionados/metabolismo , Atividade Motora , Neurônios Motores/metabolismo , Nervos Espinhais/metabolismo , Superóxido Dismutase-1/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Comportamento Animal , Morte Celular , Células Cultivadas , Modelos Animais de Doenças , Gliose , Humanos , Masculino , Camundongos Transgênicos , Neurônios Motores/patologia , Mutação , Cultura Primária de Células , Ratos Wistar , Teste de Desempenho do Rota-Rod , Nervos Espinhais/patologia , Superóxido Dismutase-1/genética , Fatores de TempoRESUMO
BACKGROUND: The multinational EDGE (Effectiveness of Diabetes control with vildaGliptin and vildagliptin/mEtformin) study assessed the effectiveness and tolerability of vildagliptin versus other oral antihyperglycemic drugs (OAD) when added to monotherapy in patients in the real-world setting. METHODS: Prospective, real-world observational study. The primary endpoint (PEP) was the proportion of patients achieving a reduction in HbA1c > 0.3% without peripheral edema, hypoglycemia, discontinuation, dueto gastrointestinal event, or weight gain > 5%. The secondary endpoint (SEP) was the proportion of patient achieving HbA1c < 7% (at month 12), without proven hypoglycemia or weight gain (≥ 3%). RESULTS: Of the 3,523 patients enrolled in Mexico, 2,847 were in the vildagliptin and 676 in the comparator cohort. The PEP was reached in 61.8 and 53.2% in the vildagliptin and comparator cohorts, respectively. The unadjusted odds ratio was 1.42 (95% CI: 1.19-1.68) in favor of vildagliptin. A similar advantage for vildagliptin-based therapies was seen for the SEP. The percentage was lower in the vildagliptin (n = 145; 5.0%) than in the comparator group (n = 95; 14.0%). CONCLUSION: Vildagliptin, added to a first-line OAD monotherapy, allows patients to reach target HbA1c without experiencing significant adverse events.
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Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Nitrilas/uso terapêutico , Pirrolidinas/uso terapêutico , Adamantano/efeitos adversos , Adamantano/uso terapêutico , Administração Oral , Adulto , Idoso , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Masculino , México , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Estudos Prospectivos , Pirrolidinas/efeitos adversos , Resultado do Tratamento , VildagliptinaRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which pathogenesis and death of motor neurons are triggered by non-cell-autonomous mechanisms. We showed earlier that exposing primary rat spinal cord cultures to conditioned media derived from primary mouse astrocyte conditioned media (ACM) that express human SOD1(G93A) (ACM-hSOD1(G93A)) quickly enhances Nav channel-mediated excitability and calcium influx, generates intracellular reactive oxygen species (ROS), and leads to death of motoneurons within days. Here we examined the role of mitochondrial structure and physiology and of the activation of c-Abl, a tyrosine kinase that induces apoptosis. We show that ACM-hSOD1(G93A), but not ACM-hSOD1(WT), increases c-Abl activity in motoneurons, interneurons and glial cells, starting at 60 min; the c-Abl inhibitor STI571 (imatinib) prevents this ACM-hSOD1(G93A)-mediated motoneuron death. Interestingly, similar results were obtained with ACM derived from astrocytes expressing SOD1(G86R) or TDP43(A315T). We further find that co-application of ACM-SOD1(G93A) with blockers of Nav channels (spermidine, mexiletine, or riluzole) or anti-oxidants (Trolox, esculetin, or tiron) effectively prevent c-Abl activation and motoneuron death. In addition, ACM-SOD1(G93A) induces alterations in the morphology of neuronal mitochondria that are related with their membrane depolarization. Finally, we find that blocking the opening of the mitochondrial permeability transition pore with cyclosporine A, or inhibiting mitochondrial calcium uptake with Ru360, reduces ROS production and c-Abl activation. Together, our data point to a sequence of events in which a toxic factor(s) released by ALS-expressing astrocytes rapidly induces hyper-excitability, which in turn increases calcium influx and affects mitochondrial structure and physiology. ROS production, mediated at least in part through mitochondrial alterations, trigger c-Abl signaling and lead to motoneuron death.
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BACKGROUND: Patients with history of colonic resection for cancer have an increased risk of the development of metachronous malignant and premalignant lesions. Scanty data are reported on detection rates of premalignant lesions during colonoscopy surveillance in this setting. OBJECTIVE: To assess the risk of metachronous precancerous lesions developing in patients with previous colonic surgery for cancer according to the resection type. DESIGN: Retrospective study. SETTING: Two academic centers in Italy. PATIENTS: A total of 441 patients; 256 with previous left-sided colectomy (LCR) (LCR group) and 185 with previous right-sided colectomy (RCR) (RCR group). INTERVENTIONS: Second surveillance colonoscopy. MAIN OUTCOME MEASUREMENTS: Polyp and adenoma detection rates. RESULTS: At least 1 adenoma was diagnosed in 76 of 256 patients (30% adenoma detection rate) and in 35 of 185 patients (19% adenoma detection rate) in the LCR and RCR groups, respectively (P=.014), yielding an odds ratio of 1.83 (95% confidence interval, 1.16-2.89). Corresponding figures for the polyp detection rate were 39% and 25%, respectively (P=.002; odds ratio 1.97; 95% confidence interval, 1.30-3.00). LIMITATIONS: Retrospective study with colonoscopy baseline information missing. CONCLUSIONS: Patients who have undergone LCR are at higher risk of the development of adenomas than those who have undergone RCR. If this result is confirmed by large prospective studies, surveillance programs could be targeted according to the type of colonic resection, with longer intervals for patients with previous RCR compared with LCR.
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Adenoma/diagnóstico , Colo/cirurgia , Neoplasias do Colo/diagnóstico , Pólipos do Colo/diagnóstico , Segunda Neoplasia Primária/diagnóstico , Adenoma/cirurgia , Idoso , Colectomia , Neoplasias do Colo/cirurgia , Colonoscopia , Feminino , Humanos , Masculino , Estudos RetrospectivosRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal paralytic disorder caused by dysfunction and degeneration of motor neurons. Multiple disease-causing mutations, including in the genes for SOD1 and TDP-43, have been identified in ALS. Astrocytes expressing mutant SOD1 are strongly implicated in the pathogenesis of ALS: we have shown that media conditioned by astrocytes carrying mutant SOD1(G93A) contains toxic factor(s) that kill motoneurons by activating voltage-sensitive sodium (Na v ) channels. In contrast, a recent study suggests that astrocytes expressing mutated TDP43 contribute to ALS pathology, but do so via cell-autonomous processes and lack non-cell-autonomous toxicity. Here we investigate whether astrocytes that express diverse ALS-causing mutations release toxic factor(s) that induce motoneuron death, and if so, whether they do so via a common pathogenic pathway. We exposed primary cultures of wild-type spinal cord cells to conditioned medium derived from astrocytes (ACM) that express SOD1 (ACM-SOD1(G93A) and ACM-SOD1(G86R)) or TDP43 (ACM-TDP43(A315T)) mutants; we show that such exposure rapidly (within 30-60 min) increases dichlorofluorescein (DCF) fluorescence (indicative of nitroxidative stress) and leads to extensive motoneuron-specific death within a few days. Co-application of the diverse ACMs with anti-oxidants Trolox or esculetin (but not with resveratrol) strongly improves motoneuron survival. We also find that co-incubation of the cultures in the ACMs with Na v channel blockers (including mexiletine, spermidine, or riluzole) prevents both intracellular nitroxidative stress and motoneuron death. Together, our data document that two completely unrelated ALS models lead to the death of motoneuron via non-cell-autonomous processes, and show that astrocytes expressing mutations in SOD1 and TDP43 trigger such cell death through a common pathogenic pathway that involves nitroxidative stress, induced at least in part by Na v channel activity.
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Amyotrophic lateral sclerosis (ALS) is a fatal motoneuron disease with no current effective treatment. Accumulation of abnormal protein inclusions containing SOD1, TARDBP, FUS, among other proteins, is a pathological hallmark of ALS. Autophagy is the major degradation pathway involved in the clearance of damaged organelles and protein aggregates. Although autophagy has been shown to efficiently degrade ALS-linked mutant protein in cell culture models, several studies suggest that autophagy impairment may also contribute to disease pathogenesis. In this report, we tested the potential use of trehalose, a disaccharide that induces MTOR-independent autophagy, in the development of experimental ALS. Administration of trehalose to mutant SOD1 transgenic mice significantly prolonged life span and attenuated the progression of disease signs. These effects were associated with decreased accumulation of SOD1 aggregates and enhanced motoneuron survival. The protective effects of trehalose were associated with increased autophagy levels in motoneurons. Cell culture experiments demonstrated that trehalose led to mutant SOD1 degradation by autophagy in NSC34 motoneuron cells and also protected primary motoneurons against the toxicity of conditioned media from mutant SOD1 transgenic astrocytes. At the mechanistic level, trehalose treatment led to a significant upregulation in the expression of key autophagy-related genes at the mRNA level including Lc3, Becn1, Sqstm1 and Atg5. Consistent with these changes, trehalose administration enhanced the nuclear translocation of FOXO1, an important transcription factor involved in the activation of autophagy in neurons. This study suggests a potential use of trehalose and enhancers of MTOR-independent autophagy for the treatment of ALS.
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Esclerose Lateral Amiotrófica/patologia , Autofagia/efeitos dos fármacos , Progressão da Doença , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/patologia , Trealose/farmacologia , Animais , Autofagia/genética , Sobrevivência Celular/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Longevidade/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios Motores/metabolismo , Mutação/genética , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/patologia , Estrutura Quaternária de Proteína , Ratos , Ratos Sprague-Dawley , Medula Espinal/patologia , Superóxido Dismutase/química , Superóxido Dismutase/genética , Transcrição Gênica/efeitos dos fármacos , Trealose/administração & dosagemRESUMO
Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by dysfunction and degeneration of motoneurons starting in adulthood. Recent studies using cell or animal models document that astrocytes expressing disease-causing mutations of human superoxide dismutase 1 (hSOD1) contribute to the pathogenesis of ALS by releasing a neurotoxic factor(s). Neither the mechanism by which this neurotoxic factor induces motoneuron death nor its cellular site of action has been elucidated. Here we show that acute exposure of primary wild-type spinal cord cultures to conditioned medium derived from astrocytes expressing mutant SOD1 (ACM-hSOD1(G93A)) increases persistent sodium inward currents (PC(Na)), repetitive firing, and intracellular calcium transients, leading to specific motoneuron death days later. In contrast to TTX, which paradoxically increased twofold the amplitude of calcium transients and killed motoneurons, reduction of hyperexcitability by other specific (mexiletine) and nonspecific (spermidine and riluzole) blockers of voltage-sensitive sodium (Na(v)) channels restored basal calcium transients and prevented motoneuron death induced by ACM-hSOD1(G93A). These findings suggest that riluzole, the only FDA-approved drug with known benefits for ALS patients, acts by inhibiting hyperexcitability. Together, our data document that a critical element mediating the non-cell-autonomous toxicity of ACM-hSOD1(G93A) on motoneurons is increased excitability, an observation with direct implications for therapy of ALS.
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Potenciais de Ação , Astrócitos/metabolismo , Neurônios Motores/efeitos dos fármacos , Mutação , Superóxido Dismutase/genética , Animais , Cálcio/metabolismo , Sinalização do Cálcio , Morte Celular , Células Cultivadas , Meios de Cultivo Condicionados/toxicidade , Humanos , Camundongos , Camundongos Transgênicos , Neurônios Motores/fisiologia , Ratos , Ratos Sprague-Dawley , Sódio/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologiaRESUMO
BACKGROUND: Dengue (DEN) is an infectious disease caused by the DEN virus (DENV), which belongs to the Flavivirus genus in the family Flaviviridae. It has a (+) sense RNA genome and is mainly transmitted to humans by the vector mosquito Aedes aegypti. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by one of four closely related virus serotypes (DENV-1, DENV-2, DENV-3 and DENV-4). Epidemiological and evolutionary studies have indicated that host and viral factors are involved in determining disease outcome and have proved the importance of viral genotype in causing severe epidemics. Host immune status and mosquito vectorial capacity are also important influences on the severity of infection. Therefore, an understanding of the relationship between virus variants with altered amino acids and high pathogenicity will provide more information on the molecular epidemiology of DEN. Accordingly, knowledge of the DENV serotypes and genotypes circulating in the latest DEN outbreaks around the world, including Mexico, will contribute to understanding DEN infections. RESULTS: 1. We obtained 88 isolates of DENV, 27 from Oaxaca and 61 from Veracruz. 2. Of these 88 isolates, 16 were serotype 1; 62 serotype 2; 7 serotype 3; and 2 serotype 4. One isolate had 2 serotypes (DENV-2 and -1). 3. Partial nucleotide sequences of the genes encoding C- prM (14 sequences), the NS3 helicase domain (7 sequences), the NS5 S-adenosyl methionine transferase domain (7 sequences) and the RNA-dependent RNA polymerase (RdRp) domain (18 sequences) were obtained. Phylogenetic analysis showed that DENV-2 isolates belonged to the Asian/American genotype. In addition, the Asian/American genotype was divided into two clusters, one containing the isolates from 2001 and the other the isolates from 2005-2006 with high bootstrap support of 94%. CONCLUSION: DENV-2 was the predominant serotype in the DF and DHF outbreak from 2005 to 2006 in Oaxaca State as well as in the 2006 outbreak in Veracruz State, with the Asian/American genotype prevalent in both states. Interestingly, DENV-1 and DENV-2 were the only serotypes related to DHF cases. In contrast, DENV-3 and DENV-4 were poorly represented according to epidemiological data reported in Mexico. We found that isoleucine was replaced by valine at residue 106 of protein C in the isolates from these 2005-2006 outbreaks and in those from the 1997, 1998 and 2001 outbreaks in the Caribbean islands. We suggested that this amino acid change may be used as a signature for isolates arising in the Caribbean islands and pertaining to the Asian/American genotype. Other amino acid changes are specific for the Asian/American, Asian and American strains.
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Vírus da Dengue/classificação , Vírus da Dengue/genética , Surtos de Doenças , Dengue Grave/epidemiologia , Dengue Grave/virologia , Aedes/virologia , Substituição de Aminoácidos , Animais , Marcadores Genéticos , Humanos , México/epidemiologia , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de Proteína , Sorotipagem , Proteínas Virais/genéticaRESUMO
The skin rash of Kawasaki syndrome is usually erythematous. A 23-month-old Costa Rican boy was admitted with a clinical picture compatible with Kawasaki syndrome, except for his skin lesions. He had diffuse, confluent, multiple sterile whitish pustular lesions on his chest, abdomen, neck, genitals, and thighs.