RESUMO
PURPOSE: The function of FAM177A1 and its relationship to human disease is largely unknown. Recent studies have demonstrated FAM177A1 to be a critical immune-associated gene. One previous case study has linked FAM177A1 to a neurodevelopmental disorder in 4 siblings. METHODS: We identified 5 individuals from 3 unrelated families with biallelic variants in FAM177A1. The physiological function of FAM177A1 was studied in a zebrafish model organism and human cell lines with loss-of-function variants similar to the affected cohort. RESULTS: These individuals share a characteristic phenotype defined by macrocephaly, global developmental delay, intellectual disability, seizures, behavioral abnormalities, hypotonia, and gait disturbance. We show that FAM177A1 localizes to the Golgi complex in mammalian and zebrafish cells. Intersection of the RNA sequencing and metabolomic data sets from FAM177A1-deficient human fibroblasts and whole zebrafish larvae demonstrated dysregulation of pathways associated with apoptosis, inflammation, and negative regulation of cell proliferation. CONCLUSION: Our data shed light on the emerging function of FAM177A1 and defines FAM177A1-related neurodevelopmental disorder as a new clinical entity.
RESUMO
BACKGROUND: Since 2010, patients and physicians have collaborated to understand unmet needs of patients with mast cell diseases, incorporating mastocytosis and mast cell activation disorders, which include mast cell activation syndromes. OBJECTIVE: This Open Innovation in Science project aims to expand understanding of the needs of patients affected by mast cell diseases, and encourage global communication among patient advocacy groups, physicians, researchers, industry, and government. A major aim is to support the scientific community's efforts to improve diagnosis, management, therapy, and patients' quality of life by addressing unmet needs. METHODS: In collaboration with mast cell disease specialists, 13 patient advocacy groups from 12 countries and regions developed lists of top patient needs. A core team of leaders from patient advocacy groups collected and analyzed the data and proposed possible actions to address patient needs. RESULTS: Findings identified similarities and differences among participating countries in unmet needs between patients with mastocytosis and those with mast cell activation syndromes. Issues emphasized struggles relating to the nature and rarity of mast cell diseases, their impact on quality of life, the diagnostic process, access to appropriate care, more effective treatment, and the need for research. CONCLUSIONS: Solutions vary across countries because situations differ, in particular regarding the existence of and access to centers of excellence and reference centers. Multifaceted mast cell activation syndrome barriers necessitate innovative approaches to improve access to appropriate care. The outcomes of this project should greatly support scientists and clinicians in their efforts to improve diagnosis, management, and treatment of patients with mastocytosis and mast cell activation disorders.
Assuntos
Transtornos da Ativação de Mastócitos , Mastocitose , Humanos , Mastócitos , Mastocitose/diagnóstico , Mastocitose/terapia , Qualidade de VidaRESUMO
Decreased sequencing costs have led to an explosion of genetic and genomic data. These data have revealed thousands of candidate human disease variants. Establishing which variants cause phenotypes and diseases, however, has remained challenging. Significant progress has been made, including advances by the National Institutes of Health (NIH)-funded Undiagnosed Diseases Network (UDN). However, 6000-13,000 additional disease genes remain to be identified. The continued discovery of rare diseases and their genetic underpinnings provides benefits to affected patients, of whom there are more than 400 million worldwide, and also advances understanding the mechanisms of more common diseases. Platforms employing model organisms enable discovery of novel gene-disease relationships, help establish variant pathogenicity, and often lead to the exploration of underlying mechanisms of pathophysiology that suggest new therapies. The Model Organism Screening Center (MOSC) of the UDN is a unique resource dedicated to utilizing informatics and functional studies in model organisms, including worm (Caenorhabditis elegans), fly (Drosophila melanogaster), and zebrafish (Danio rerio), to aid in diagnosis. The MOSC has directly contributed to the diagnosis of challenging cases, including multiple patients with complex, multi-organ phenotypes. In addition, the MOSC provides a framework for how basic scientists and clinicians can collaborate to drive diagnoses. Customized experimental plans take into account patient presentations, specific genes and variant(s), and appropriateness of each model organism for analysis. The MOSC also generates bioinformatic and experimental tools and reagents for the wider scientific community. Two elements of the MOSC that have been instrumental in its success are (1) multidisciplinary teams with expertise in variant bioinformatics and in human and model organism genetics, and (2) mechanisms for ongoing communication with clinical teams. Here we provide a position statement regarding the central role of model organisms for continued discovery of disease genes, and we advocate for the continuation and expansion of MOSC-type research entities as a Model Organisms Network (MON) to be funded through grant applications submitted to the NIH, family groups focused on specific rare diseases, other philanthropic organizations, industry partnerships, and other sources of support.
Assuntos
Doenças não Diagnosticadas , Animais , Drosophila melanogaster , Humanos , Fenótipo , Doenças Raras/diagnóstico , Doenças Raras/genética , Peixe-ZebraRESUMO
OBJECTIVES: Head and neck (H&N) cancer patients experience significant acute side effects from treatment. This study evaluates prospectively collected patient-reported outcomes (PROs) in H&N patients undergoing radiotherapy (RT) to assess feasibility of electronically collecting PROs and to objectively document symptom acuity and trajectory during RT. MATERIALS AND METHODS: H&N patients undergoing radical RT at our multicentre institution completed a 12-item partial survey of the Vanderbilt Head & Neck Symptom Survey 2.0 prior to RT and weekly on RT. Between October 2016 and October 2018, 318 of 333 patients completed a baseline survey and at least one weekly survey. RESULTS: The average number of weekly questionnaires completed was 5 (range 1-8). The mean maximum symptom scores were highest for dysgeusia (5.8/10), pain (5.4/10), mucositis (4.8/10), weight loss due to swallowing (4.5/10) and mucus causing choking/gagging (4.3/10). On multivariate analysis, female gender, sinonasal, nasopharynx and oropharynx primaries were associated with a greater risk of moderate-severe pain (p < 0.05). Sinonasal, nasopharynx, oral cavity, oropharynx and thyroid primaries were associated with a greater risk of moderate-severe mucositis during radiation (p < 0.0001). Salivary gland, sinonasal, nasopharynx and oropharynx primaries and higher radiation dose were associated with a greater risk of moderate-severe dysgeusia (all p < 0.05). CONCLUSIONS: Electronic PRO collection during H&N cancer RT is feasible. H&N cancer patients experience significant symptoms during RT, and the most severe symptoms reported were dysgeusia, pain and mucositis. Oropharynx cancer patients reported the highest symptom scores during RT.
Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Medidas de Resultados Relatados pelo Paciente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
The purpose of this study is to extend the Sabin et al's. (Am J Public Health 105(9):1831-1841, 2015. https://doi.org/10.2105/AJPH.2015.302631) findings to examine the extent to which religiosity and/or geographic region is predictive of negative attitudes or beliefs toward lesbian, gay, bisexual, and asexual (LGB+) individuals. Secondary data from the Sexuality Implicit Association Test were analyzed. Data included only participants from 2013 to 2015 who identified "Healthcare - Diagnosing and Treating Practitioners" as their occupation (n = 1376). The results of a factorial ANOVA revealed significant group differences accounting for 22.4% of the variance in attitudes toward LGB+ individuals. Religiosity was a significant factor in determining negative attitudes toward LGB+ individuals. However, the study was underpowered (5.8%) to detect an effect of geographic location in determining negative attitudes toward LGB+ individuals. It is important to validate a tool that can adequately measure the common assumptions associated with both religion and geographic region. Additionally, medical educators need to learn how to recognize and address negative attitudes among their students.
Assuntos
Atitude do Pessoal de Saúde , Bissexualidade , Pessoal de Saúde/psicologia , Homossexualidade , Área de Atuação Profissional , Religião , Adulto , Feminino , Homofobia , Humanos , Masculino , Pessoa de Meia-Idade , Preconceito , Minorias Sexuais e de GêneroRESUMO
INTRODUCTION: Many prognostic factors have been studied in carpal tunnel decompression, but most studies consider only a subset of variables. METHODS: Three thousand three hundred thirty-two operations were used to develop prognostic models, and 885 operations were used for validation. Outcome recorded on a Likert scale was dichotomized into success or failure. Modeling was performed with both logistic regression and artificial neural networks using 87 candidate variables. RESULTS: Both approaches produced predictive multivariate models for outcome with areas under a receiver operating characteristic curve of 0.7 in the validation data set. Patients with moderately severe nerve conduction abnormalities, night waking, a family history of carpal tunnel syndrome, a good response to corticosteroid injection, and women have better outcomes. Greater functional impairment, diabetes, hypertension, and surgery on the dominant hand are associated with poorer outcomes. DISCUSSION: A multivariate model partially predicts the outcome of carpal tunnel surgery, aids decision making, and helps to manage patient expectations. Muscle Nerve 58:784-789, 2018.
Assuntos
Síndrome do Túnel Carpal , Descompressão Cirúrgica/métodos , Modelos Neurológicos , Medidas de Resultados Relatados pelo Paciente , Resultado do Tratamento , Adulto , Idoso , Idoso de 80 Anos ou mais , Síndrome do Túnel Carpal/diagnóstico , Síndrome do Túnel Carpal/psicologia , Síndrome do Túnel Carpal/cirurgia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Condução Nervosa/fisiologia , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , Reino Unido , Adulto JovemRESUMO
OBJECTIVES: To examine the prevalence, determinants, and impact of local school health management committees on implementation of minimum-recommended school health services delivery among basic and secondary schools in Ghana. METHODS: National level cross-sectional data from the first-ever assessment of Ghana Global-School Health Policies and Practices Survey was utilized. Complex sample analyses were used to quantify school-level implementation of recommended minimum package for health services delivery. RESULTS: Of 307 schools, 98% were basic and government run, and 33% offered at least half of the recommended health service delivery areas measured. Schools with a school health management committee (53%) were 4.8 (95% CI = 3.23-5.18) times as likely to offer at least 50% of the minimum health services package than schools that did not. CONCLUSIONS: There is significant deficit concerning delivery of school health services in schools across Ghana. However, school health management committees positively impact implementation of health service delivery. POLICY IMPLICATIONS: School health management committees provide a significant impact on delivery of school health services; thus, it is recommended that policy makers and programmers place greater emphasis on the value and need for these advisory boards in all Ghanaian schools.
RESUMO
Background: Adjuvant therapies can prevent/delay bone metastasis development in breast cancer. We investigated whether serum bone turnover markers in early disease have clinical utility in identifying patients with a high risk of developing bone metastasis. Methods: Markers of bone formation (N-terminal propeptide of type-1 collagen [P1NP]) and bone resorption (C-telopeptide of type-1 collagen [CTX], pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen [1-CTP]) were measured in baseline (pretreatment blood samples from 872 patients from a large randomized trial of adjuvant zoledronic acid (AZURE-ISRCTN79831382) in early breast cancer. Cox proportional hazards regression and cumulative incidence functions (adjusted for factors having a statistically significant effect on outcome) were used to investigate prognostic and predictive associations between recurrence events, bone marker levels, and clinical variables. All statistical tests were two-sided. Results: When considered as continuous variables (log transformed), P1NP, CTX, and 1-CTP were each prognostic for future bone recurrence at any time (P = .006, P = .009, P = .008, respectively). Harrell's c-indices were a P1NP of 0.57 (95% confidence interval [CI] = 0.51 to 0.63), CTX of 0.57 (95% CI = 0.51 to 0.62), and 1-CTP of 0.57 (95% CI = 0.52 to 0.63). In categorical analyses based on the normal range, high baseline P1NP (>70 ng/mL) and CTX (>0.299 ng/mL), but not 1-CTP (>4.2 ng/mL), were also prognostic for future bone recurrence (P = .03, P = .03, P = .10, respectively). None of the markers were prognostic for overall distant recurrence; that is, they were bone metastasis specific, and none of the markers were predictive of treatment benefit from zoledronic acid. Conclusions: Serum P1NP, CTX, and 1-CTP are clinically useful, easily measured markers that show good prognostic ability (though low-to-moderate discrimination) for bone-specific recurrence and are worthy of further study.
Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Osso e Ossos/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Desenvolvimento Ósseo , Neoplasias Ósseas/sangue , Neoplasias Ósseas/prevenção & controle , Remodelação Óssea , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/normas , Progressão da Doença , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Infusões Intravenosas , Pessoa de Meia-Idade , Prognóstico , Padrão de Cuidado , Reino Unido , Ácido Zoledrônico/administração & dosagemRESUMO
BACKGROUND: The tAnGo trial was designed to investigate the potential role of gemcitabine when added to anthracycline and taxane-containing adjuvant chemotherapy for early breast cancer. When this study was developed, gemcitabine had shown significant activity in metastatic breast cancer, and there was evidence of a favourable interaction with paclitaxel. METHODS: tAnGo was an international, open-label, randomised, phase 3 superiority trial that enrolled women aged 18 years or older with newly diagnosed, early-stage breast cancer who had a definite indication for chemotherapy, any nodal status, any hormone receptor status, Eastern Cooperative Oncology Group performance status of 0-1, and adequate bone marrow, hepatic, and renal function. Women were recruited from 127 clinical centres and hospitals in the UK and Ireland, and randomly assigned (1:1) to one of two treatment regimens: epirubicin, cyclophosphamide, and paclitaxel (four cycles of 90 mg/m2 intravenously administered epirubicin and 600 mg/m2 intravenously administered cyclophosphamide on day 1 every 3 weeks, followed by four cycles of 175 mg/m2 paclitaxel as a 3 h infusion on day 1 every 3 weeks) or epirubicin, cyclophosphamide, and paclitaxel plus gemcitabine (the same chemotherapy regimen as the other group, with the addition of 1250 mg/m2 gemcitabine to the paclitaxel cycles, administered intravenously as a 0·5 h infusion on days 1 and 8 every 3 weeks). Patients were randomly assigned by a central computerised deterministic minimisation procedure, with stratification by country, age, radiotherapy intent, nodal status, and oestrogen receptor and HER-2 status. The primary endpoint was disease-free survival and the trial aimed to detect 5% differences in 5-year disease-free survival between the treatment groups. Recruitment completed in 2004 and this is the final, intention-to-treat analysis. This trial is registered with EudraCT (2004-002927-41), ISRCTN (51146252), and ClinicalTrials.gov (NCT00039546). FINDINGS: Between Aug 22, 2001, and Nov 26, 2004, 3152 patients were enrolled and randomly assigned to epirubicin, cyclophosphamide, paclitaxel, and gemcitabine (gemcitabine group; n=1576) or to epirubicin, cyclophosphamide, and paclitaxel (control group; n=1576). 11 patients (six in the gemcitabine group and five in the control group) were ineligible because of pre-existing metastases and were therefore excluded from the analysis. At this protocol-specified final analysis (median follow-up 10 years [IQR 10-10]), 1087 disease-free survival events and 914 deaths had occurred. Disease-free survival did not differ significantly between the treatment groups at 10 years (65% [63-68] in the gemcitabine group vs 65% [62-67] in the control group), and median disease-free survival was not reached (adjusted hazard ratio 0·97 [95% CI 0·86-1·10], p=0·64). Toxicity, dose intensity, and a detailed safety substudy showed both regimens to be safe, deliverable, and tolerable. Grade 3 and 4 toxicities were reported at expected levels in both groups. The most common were neutropenia (527 [34%] of 1565 patients in the gemcitabine group vs 412 [26%] of 1567 in the control group), myalgia and arthralgia (207 [13%] vs 186 [12%]), fatigue (207 [13%] vs 152 [10%]), infection (202 [13%] vs 141 [9%]), vomiting (143 [9%] vs 108 [7%]), and nausea (132 [8%] vs 102 [7%]). INTERPRETATION: The addition of gemcitabine to anthracycline and taxane-based adjuvant chemotherapy at this dose and schedule confers no therapeutic advantage in terms of disease-free survival in early breast cancer, although it can cause increased toxicity. Therefore, gemcitabine has not been added to standard adjuvant chemotherapy in breast cancer for any subgroup. FUNDING: Cancer Research UK core funding for Clinical Trials Unit at the University of Birmingham, Eli Lilly, Bristol-Myers Squibb, and Pfizer.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/química , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Ciclofosfamida/administração & dosagem , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Intervalo Livre de Doença , Epirubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Análise de Intenção de Tratamento , Metástase Linfática , Mastectomia Segmentar , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Radioterapia , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Taxa de Sobrevida , GencitabinaRESUMO
The mechanism and magnitude by which the mammalian kidney generates and maintains its proximal tubules, distal tubules, and collecting ducts remain controversial. Here, we use long-term in vivo genetic lineage tracing and clonal analysis of individual cells from kidneys undergoing development, maintenance, and regeneration. We show that the adult mammalian kidney undergoes continuous tubulogenesis via expansions of fate-restricted clones. Kidneys recovering from damage undergo tubulogenesis through expansions of clones with segment-specific borders, and renal spheres developing in vitro from individual cells maintain distinct, segment-specific fates. Analysis of mice derived by transfer of color-marked embryonic stem cells (ESCs) into uncolored blastocysts demonstrates that nephrons are polyclonal, developing from expansions of singly fated clones. Finally, we show that adult renal clones are derived from Wnt-responsive precursors, and their tracing in vivo generates tubules that are segment specific. Collectively, these analyses demonstrate that fate-restricted precursors functioning as unipotent progenitors continuously maintain and self-preserve the mouse kidney throughout life.
Assuntos
Células-Tronco Embrionárias/fisiologia , Rim/fisiologia , Regeneração/fisiologia , Animais , Diferenciação Celular/fisiologia , Linhagem da Célula , Células-Tronco Embrionárias/citologia , Feminino , Rim/citologia , Rim/crescimento & desenvolvimento , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
PURPOSE: The purpose of this study is to compare patient outcomes between a therapeutic versus a prophylactic gastrostomy tube (GT) placement approach in patients treated with concurrent systemic and radiation (SRT) therapy for head and neck cancer (HNC). METHODS: Outcomes were compared between all HNC patients treated with concurrent SRT from January 2001 to June 2009 from a center that only places GTs therapeutically when clinically necessary (center A) versus a center that generally places them prophylactically (center B). RESULTS: A total of 445 patients with HNC were identified, with 63 % from center A. As anticipated, GTs were placed less commonly in center A compared to B (31 versus 88 %; p < 0.001). Center B had a significantly higher number of GT complications (p < 0.001), including infection (16 versus 5 %), leakage (10 versus 2 %), and blockage (3 versus 1 %). Conversely, center A had a higher admission rate (27 versus 13 %, p = 0.001), most prominent for GT-related issues (15 versus 6 %). Center B had higher GT dependence at 90 days post-radiation therapy (34 versus 12 %; p < 0.001), but not at 1 year (11 versus 10 %; p = 0.74). There was no significant difference in the proportion of head and neck patients who had a 10 % weight loss at 1 year (compared to baseline) between centers A and B (42 versus 53 %, p = 0.07). There was no significant difference in the overall survival (A versus B, HR = 0.99; p = 0.96). CONCLUSION: A prophylactic GT approach results in exposing higher number of patients to GT complications. The higher rate of hospitalizations using a therapeutic approach suggests that patients are sicker when GTs are required. Given the similar weight loss and survival, a therapeutic approach at an earlier stage of need may be a preferable approach, when access to prompt GT placement is available.
Assuntos
Gastrostomia/métodos , Neoplasias de Cabeça e Pescoço/terapia , Intubação Gastrointestinal/métodos , Apoio Nutricional/métodos , Cuidados Paliativos/métodos , Idoso , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Cetuximab , Cisplatino/uso terapêutico , Feminino , Fluoruracila/administração & dosagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Redução de PesoRESUMO
Since the discovery of neural stem cells in the mammalian brain, there has been significant interest in understanding their contribution to tissue homeostasis at both the cellular and molecular level. Wnt/ß-catenin signaling is crucial for development of the central nervous system and has been implicated in stem cell maintenance in multiple tissues. Based on this, we hypothesized that the Wnt pathway likely controls neural stem cell maintenance and differentiation along the entire developmental continuum. To test this, we performed lineage tracing experiments using the recently developed tamoxifen-inducible Cre at Axin2 mouse strain to follow the developmental fate of Wnt/ß-catenin-responsive cells in both the embryonic and postnatal mouse brain. From as early as embryonic day 8.5 onwards, Axin2(+) cells can give rise to spatially and functionally restricted populations of adult neural stem cells in the subventricular zone. Similarly, progeny from Axin2(+) cells labeled from E12.5 contribute to both the subventricular zone and the dentate gyrus of the hippocampus. Labeling in the postnatal brain, in turn, demonstrates the persistence of long-lived, Wnt/ß-catenin-responsive stem cells in both of these sites. These results demonstrate the continued importance of Wnt/ß-catenin signaling for neural stem and progenitor cell formation and function throughout developmental time.
Assuntos
Células-Tronco Adultas/citologia , Proteína Axina/metabolismo , Linhagem da Célula , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Células-Tronco Adultas/metabolismo , Animais , Animais Recém-Nascidos , Giro Denteado/citologia , Giro Denteado/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Integrases/metabolismo , Camundongos , Neuroglia/citologia , Neuroglia/metabolismo , Coloração e Rotulagem , Fatores de TempoRESUMO
The mammary epithelium undergoes extensive growth and remodeling during pregnancy, suggesting a role for stem cells. Yet their origin, identity, and behavior in the intact tissue remain unknown. Using an Axin2(CreERT2) allele, we labeled and traced Wnt/ß-catenin-responsive cells throughout mammary gland development. This reveals a switch in Wnt/ß-catenin signaling around birth and shows that, depending on the developmental stage, Axin2(+) cells contribute differently to basal and luminal epithelial cell lineages of the mammary epithelium. Moreover, an important difference exists between the developmental potential tested in transplantation assays and that displayed by the same cell population in situ. Finally, Axin2(+) cells in the adult build alveolar structures during multiple pregnancies, demonstrating the existence of a Wnt/ß-catenin-responsive adult stem cell. Our study uncovers dynamic changes in Wnt/ß-catenin signaling in the mammary epithelium and offers insights into the developmental fate of mammary gland stem and progenitor cells.
Assuntos
Linhagem da Célula , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Células-Tronco/citologia , Via de Sinalização Wnt , Animais , Proteína Axina/metabolismo , Proliferação de Células , Células Clonais , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Epitélio/crescimento & desenvolvimento , Epitélio/metabolismo , Feminino , Glândulas Mamárias Animais/embriologia , Camundongos , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/metabolismo , Gravidez , Maturidade Sexual , Transplante de Células-Tronco , Células-Tronco/metabolismo , Fatores de TempoRESUMO
Nanosecond pulsed electric field (nsPEF) is a novel modality for permeabilization of membranous structures and intracellular delivery of xenobiotics. We hypothesized that oxidative effects of nsPEF could be a separate primary mechanism responsible for bioeffects. ROS production in cultured cells and media exposed to 300-ns PEF (1-13 kV/cm) was assessed by oxidation of 2',7'-dichlorodihydrofluoresein (H(2)DCF), dihidroethidium (DHE), or Amplex Red. When a suspension of H(2)DCF-loaded cells was subjected to nsPEF, the yield of fluorescent 2',7'-dichlorofluorescein (DCF) increased proportionally to the pulse number and cell density. DCF emission increased with time after exposure in nsPEF-sensitive Jurkat cells, but remained stable in nsPEF-resistant U937 cells. In cell-free media, nsPEF facilitated the conversion of H(2)DCF into DCF. This effect was not related to heating and was reduced by catalase, but not by mannitol or superoxide dismutase. Formation of H(2)O(2) in nsPEF-treated media was confirmed by increased oxidation of Amplex Red. ROS increase within individual cells exposed to nsPEF was visualized by oxidation of DHE. We conclude that nsPEF can generate both extracellular (electrochemical) and intracellular ROS, including H(2)O(2) and possibly other species. Therefore, bioeffects of nsPEF are not limited to electropermeabilization; concurrent ROS formation may lead to cell stimulation and/or oxidative cell damage.
Assuntos
Permeabilidade da Membrana Celular , Eletroporação , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Células CHO , Linhagem Celular , Membrana Celular/metabolismo , Sobrevivência Celular , Sistema Livre de Células/metabolismo , Cricetinae , Eletroporação/métodos , Fluoresceínas/análise , Fluoresceínas/metabolismo , Corantes Fluorescentes/análise , Corantes Fluorescentes/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Células Jurkat , OxirreduçãoRESUMO
Previous studies have found that nanosecond pulsed electric field (nsPEF) exposure causes long-term permeabilization of the cell plasma membrane. In this study, we utilized the whole-cell patch-clamp method to study the nsPEF effect on currents of voltage-gated (VG) Ca(2+) and Na(+) channels (I(Ca) and I(Na)) in cultured GH3 and NG108 cells. We found that a single 300 or 600 ns pulse at or above 1.5-2 kV/cm caused prolonged inhibition of I(Ca) and I(Na). Concurrently, nsPEF increased a non-inactivating "leak" current (I(leak)), presumably due to the formation of nanoelectropores or larger pores in the plasma membrane. The nsPEF effects were similar in cells that were exposed intact and subsequently brought into the whole-cell recording configuration, and in cells that were first brought into the whole-cell configuration and then exposed. Although both I(leak) and the inhibition of VG currents were enhanced at higher E-field levels, these two nsPEF effects showed relatively weak correlation with each other. In some cells, I(leak) increased 10-fold or more while VG currents remained unchanged. At longer time intervals after exposure (5-15 min), I(Ca) and I(Na) could remain inhibited although I(leak) had largely recovered. The causal relation of nsPEF inhibitory effects on VG currents and permeabilization of the plasma membrane is discussed.
Assuntos
Canais de Cálcio/metabolismo , Condutividade Elétrica , Canais de Sódio/metabolismo , Animais , Linhagem Celular , Permeabilidade da Membrana Celular , Camundongos , Canais de Potássio/metabolismo , Ratos , Fatores de TempoRESUMO
Genetic alterations in the Wnt/ß-catenin/TCF-signaling pathway are commonly found in human tumors, but not in glioblastomas. In this issue of Cancer Cell, Zhang et al. report that FoxM1 mediates ß-catenin nuclear translocation in glioblastoma, suggesting a novel mechanism for glioblastoma progression in the absence of conventional Wnt/ß-catenin pathway activation.
RESUMO
BACKGROUND: Electroporation is a method of disrupting the integrity of cell membrane by electric pulses (EPs). Electrical modeling is widely employed to explain and study electroporation, but even most advanced models show limited predictive power. No studies have accounted for the biological consequences of electroporation as a factor that alters the cell's susceptibility to forthcoming EPs. METHODOLOGY/PRINCIPAL FINDINGS: We focused first on the role of EP rate for membrane permeabilization and lethal effects in mammalian cells. The rate was varied from 0.001 to 2,000 Hz while keeping other parameters constant (2 to 3,750 pulses of 60-ns to 9-µs duration, 1.8 to 13.3 kV/cm). The efficiency of all EP treatments was minimal at high rates and started to increase gradually when the rate decreased below a certain value. Although this value ranged widely (0.1-500 Hz), it always corresponded to the overall treatment duration near 10 s. We further found that longer exposures were more efficient irrespective of the EP rate, and that splitting a high-rate EP train in two fractions with 1-5 min delay enhanced the effects severalfold. CONCLUSIONS/SIGNIFICANCE: For varied experimental conditions, EPs triggered a delayed and gradual sensitization to EPs. When a portion of a multi-pulse exposure was delivered to already sensitized cells, the overall effect markedly increased. Because of the sensitization, the lethality in EP-treated cells could be increased from 0 to 90% simply by increasing the exposure duration, or the exposure dose could be reduced twofold without reducing the effect. Many applications of electroporation can benefit from accounting for sensitization, by organizing the exposure either to maximize sensitization (e.g., for sterilization) or, for other applications, to completely or partially avoid it. In particular, harmful side effects of electroporation-based therapies (electrochemotherapy, gene therapies, tumor ablation) include convulsions, pain, heart fibrillation, and thermal damage. Sensitization can potentially be employed to reduce these side effects while preserving or increasing therapeutic efficiency.
Assuntos
Eletricidade , Eletroporação , Transporte Biológico , Linhagem Celular , Membrana Celular/metabolismo , Sobrevivência Celular , Humanos , Propídio/metabolismo , Fatores de TempoRESUMO
Islet neogenesis associated protein (INGAP) stimulates experimental pancreatic islet growth, as evidenced by elevated markers of beta cell mass, in rodents, dogs and primates. Previous analyses of mice that have a transgenic expression of INGAP targeted to the exocrine pancreas have indicated additional biological activity attributed to INGAP. In this study we report on mice with a targeted expression of INGAP to the islet beta cell. The beta cell transgenic mice (IP-INGAP) showed enhanced normalization of blood glucose during IPGTT. Further, IP-INGAP mice had a significant delay in development of hyperglycemia following a diabetogenic dose of streptozotocin. INGAP conferred beta cell protection and enhanced islet function. Analysis of oxidative stress genes in IP-INGAP mice revealed a decrease in islet expression of the NADPH oxidase, NOX1, in both basal state and in response to pro-inflammatory cytokine stimulation. These data are consistent with a pleiotropic role for INGAP and reveal new pathways to target in the discovery of improved diabetic therapies.