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1.
Am J Ind Med ; 67(2): 169-173, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38047323

RESUMO

BACKGROUND: Work is a social determinant of health that is often overlooked. There are major work-related differences in the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and death, but there have been few analyses of infection rates across industry groups. To date, only one national assessment of SARS-CoV-2 infection prevalence by industry based on self-report has been completed. No study has looked at seroprevalence of COVID-19 by industry. METHODS: During May-December 2021, blood donors with SARS-CoV-2 antinucleocapsid testing were sent an electronic survey about their work. Free-text industry responses were classified using the North American Industry Classification System. We estimated seroprevalence and 95% confidence intervals (CIs) of SARS-CoV-2 infection by industry. RESULTS: Of 57,726 donors, 7040 (12%, 95% CI: 11.9%-12.5%) had prior SARS-CoV-2 infection. Seroprevalence was highest among Accommodation & Food Services (19.3%, 95% CI: 17.1%-21.6%), Mining, Quarrying, and Oil and Gas Extraction (19.2%, 95% CI: 12.8%-27.8%), Healthcare & Social Assistance (15.6%, 95% CI: 14.9%-16.4%), and Construction (14.7%, 95% CI: 13.1%-16.3%). Seroprevalence was lowest among Management of Companies & Enterprises (6.5%, 95% CI: 3.5%-11.5%), Professional Scientific & Technical Services (8.4%, 95% CI: 7.7%-9.0%), and Information (9.9%, 95% CI: 8.5%-11.5%). CONCLUSIONS: While workers in all industries had serologic evidence of SARS-CoV-2 infection, certain sectors were disproportionately impacted. Disease surveillance systems should routinely collect work characteristics so public health and industry leaders can address health disparities using sector-specific policies.


Assuntos
Doadores de Sangue , COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Prevalência , Estudos Soroepidemiológicos , Autorrelato , Anticorpos Antivirais
2.
Occup Environ Med ; 81(2): 109-112, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-37932036

RESUMO

OBJECTIVES: To describe recent investigations of potential workplace cancer clusters. METHODS: We identified Health Hazard Evaluations (HHEs) of cancer concerns during 2001-2020. We described information about industry, requestors, cancer characteristics, investigative procedures, and determinations about the presence of a cluster (ie, presence of excess cases, unusual case distribution or exposure). RESULTS: Of 5754 HHEs, 174 included cancer concerns, comprising 1%-5% of HHEs per year. In 123 HHEs, the cancer cluster concerns involved different cancer primary sites. Investigation procedures varied but included record review (n=63, 36%) and site visits (n=22, 13%). Of 158 HHEs with a cluster determination by investigator(s), 151 (96%) were not considered cancer clusters. In seven HHEs, investigators found evidence of a cluster, but occupational exposure to a carcinogen was not identified. CONCLUSIONS: The proportion of HHEs on workplace cancer cluster concerns remained steady over time; most did not meet the definition of a cluster or uncover an occupational cause. Public health practitioners can use this information to provide updated context when addressing workplace cancer cluster concerns and as motivation to refine investigative approaches. More broadly, this review highlights an opportunity to identify best practices on how to apply community cluster investigation methods to the workplace.


Assuntos
Neoplasias , Exposição Ocupacional , Saúde Ocupacional , Humanos , Neoplasias/epidemiologia , Exposição Ocupacional/efeitos adversos , Local de Trabalho
3.
Neuron ; 110(19): 3106-3120.e7, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-35961320

RESUMO

Breakdown of the blood-central nervous system barrier (BCNSB) is a hallmark of many neuroinflammatory disorders, such as multiple sclerosis (MS). Using a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), we show that endothelial-to-mesenchymal transition (EndoMT) occurs in the CNS before the onset of clinical symptoms and plays a major role in the breakdown of BCNSB function. EndoMT can be induced by an IL-1ß-stimulated signaling pathway in which activation of the small GTPase ADP ribosylation factor 6 (ARF6) leads to crosstalk with the activin receptor-like kinase (ALK)-SMAD1/5 pathway. Inhibiting the activation of ARF6 both prevents and reverses EndoMT, stabilizes BCNSB function, reduces demyelination, and attenuates symptoms even after the establishment of severe EAE, without immunocompromising the host. Pan-inhibition of ALKs also reduces disease severity in the EAE model. Therefore, multiple components of the IL-1ß-ARF6-ALK-SMAD1/5 pathway could be targeted for the treatment of a variety of neuroinflammatory disorders.


Assuntos
Encefalomielite Autoimune Experimental , Proteínas Monoméricas de Ligação ao GTP , Esclerose Múltipla , Receptores de Ativinas/metabolismo , Animais , Sistema Nervoso Central/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Doenças Neuroinflamatórias , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais
4.
Hosp Pediatr ; 12(9): 760-783, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35670605

RESUMO

OBJECTIVES: To describe coronavirus disease 2019 (COVID-19)-related pediatric hospitalizations during a period of B.1.617.2 (Δ) variant predominance and to determine age-specific factors associated with severe illness. METHODS: We abstracted data from medical charts to conduct a cross-sectional study of patients aged <21 years hospitalized at 6 United States children's hospitals from July to August 2021 for COVID-19 or with an incidental positive severe acute respiratory syndrome coronavirus 2 test. Among patients with COVID-19, we assessed factors associated with severe illness by calculating age-stratified prevalence ratios (PR). We defined severe illness as receiving high-flow nasal cannula, positive airway pressure, or invasive mechanical ventilation. RESULTS: Of 947 hospitalized patients, 759 (80.1%) had COVID-19, of whom 287 (37.8%) had severe illness. Factors associated with severe illness included coinfection with respiratory syncytial virus (RSV) (PR 3.64) and bacteria (PR 1.88) in infants; RSV coinfection in patients aged 1 to 4 years (PR 1.96); and obesity in patients aged 5 to 11 (PR 2.20) and 12 to 17 years (PR 2.48). Having ≥2 underlying medical conditions was associated with severe illness in patients aged <1 (PR 1.82), 5 to 11 (PR 3.72), and 12 to 17 years (PR 3.19). CONCLUSIONS: Among patients hospitalized for COVID-19, factors associated with severe illness included RSV coinfection in those aged <5 years, obesity in those aged 5 to 17 years, and other underlying conditions for all age groups <18 years. These findings can inform pediatric practice, risk communication, and prevention strategies, including vaccination against COVID-19.


Assuntos
COVID-19 , Coinfecção , Infecções por Vírus Respiratório Sincicial , COVID-19/epidemiologia , COVID-19/terapia , Criança , Estudos Transversais , Hospitalização , Humanos , Lactente , Obesidade , Infecções por Vírus Respiratório Sincicial/epidemiologia , SARS-CoV-2 , Estados Unidos/epidemiologia
5.
MMWR Morb Mortal Wkly Rep ; 71(16): 574-581, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35446827

RESUMO

On October 29, 2021, the Food and Drug Administration expanded the Emergency Use Authorization for Pfizer-BioNTech COVID-19 vaccine to children aged 5-11 years; CDC's Advisory Committee on Immunization Practices' recommendation followed on November 2, 2021.* In late December 2021, the B.1.1.529 (Omicron) variant of SARS-CoV-2 (the virus that causes COVID-19) became the predominant strain in the United States,† coinciding with a rapid increase in COVID-19-associated hospitalizations among all age groups, including children aged 5-11 years (1). COVID-19-Associated Hospitalization Surveillance Network (COVID-NET)§ data were analyzed to describe characteristics of COVID-19-associated hospitalizations among 1,475 U.S. children aged 5-11 years throughout the pandemic, focusing on the period of early Omicron predominance (December 19, 2021-February 28, 2022). Among 397 children hospitalized during the Omicron-predominant period, 87% were unvaccinated, 30% had no underlying medical conditions, and 19% were admitted to an intensive care unit (ICU). The cumulative hospitalization rate during the Omicron-predominant period was 2.1 times as high among unvaccinated children (19.1 per 100,000 population) as among vaccinated¶ children (9.2).** Non-Hispanic Black (Black) children accounted for the largest proportion of unvaccinated children (34%) and represented approximately one third of COVID-19-associated hospitalizations in this age group. Children with diabetes and obesity were more likely to experience severe COVID-19. The potential for serious illness among children aged 5-11 years, including those with no underlying health conditions, highlights the importance of vaccination among this age group. Increasing vaccination coverage among children, particularly among racial and ethnic minority groups disproportionately affected by COVID-19, is critical to preventing COVID-19-associated hospitalization and severe outcomes.


Assuntos
COVID-19 , Vacina BNT162 , COVID-19/epidemiologia , Criança , Etnicidade , Hospitalização , Humanos , Grupos Minoritários , SARS-CoV-2 , Estados Unidos/epidemiologia
6.
Occup Environ Med ; 79(3): 184-191, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34750240

RESUMO

OBJECTIVES: To characterise heat-related acute kidney injury (HR-AKI) among US workers in a range of industries. METHODS: Two data sources were analysed: archived case files of the Occupational Safety and Health Administration's (OSHA) Office of Occupational Medicine and Nursing from 2010 through 2020; and a Severe Injury Reports (SIR) database of work-related hospitalisations that employers reported to federal OSHA from 2015 to 2020. Confirmed, probable and possible cases of HR-AKI were ascertained by serum creatinine measurements and narrative incident descriptions. Industry-specific incidence rates of HR-AKI were computed. A capture-recapture analysis assessed under-reporting in SIR. RESULTS: There were 608 HR-AKI cases, including 22 confirmed cases and 586 probable or possible cases. HR-AKI occurred in indoor and outdoor industries including manufacturing, construction, mail and package delivery, and solid waste collection. Among confirmed cases, 95.2% were male, 50.0% had hypertension and 40.9% were newly hired workers. Incidence rates of AKI hospitalisations from 1.0 to 2.5 hours per 100 000 workers per year were observed in high-risk industries. Analysis of overlap between the data sources found that employers reported only 70.6% of eligible HR-AKI hospitalisations to OSHA, and only 41.2% of reports contained a consistent diagnosis. CONCLUSIONS: Workers were hospitalised with HR-AKI in diverse industries, including indoor facilities. Because of under-reporting and underascertainment, national surveillance databases underestimate the true burden of occupational HR-AKI. Clinicians should consider kidney risk from recurrent heat stress. Employers should provide interventions, such as comprehensive heat stress prevention programmes, that include acclimatisation protocols for new workers, to prevent HR-AKI.


Assuntos
Injúria Renal Aguda , Transtornos de Estresse por Calor , Medicina do Trabalho , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Creatinina , Feminino , Transtornos de Estresse por Calor/epidemiologia , Transtornos de Estresse por Calor/etiologia , Humanos , Incidência , Masculino
7.
MMWR Morb Mortal Wkly Rep ; 70(5152): 1766-1772, 2021 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-34968374

RESUMO

During June 2021, the highly transmissible† B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, became the predominant circulating strain in the United States. U.S. pediatric COVID-19-related hospitalizations increased during July-August 2021 following emergence of the Delta variant and peaked in September 2021.§ As of May 12, 2021, CDC recommended COVID-19 vaccinations for persons aged ≥12 years,¶ and on November 2, 2021, COVID-19 vaccinations were recommended for persons aged 5-11 years.** To date, clinical signs and symptoms, illness course, and factors contributing to hospitalizations during the period of Delta predominance have not been well described in pediatric patients. CDC partnered with six children's hospitals to review medical record data for patients aged <18 years with COVID-19-related hospitalizations during July-August 2021.†† Among 915 patients identified, 713 (77.9%) were hospitalized for COVID-19 (acute COVID-19 as the primary or contributing reason for hospitalization), 177 (19.3%) had incidental positive SARS-CoV-2 test results (asymptomatic or mild infection unrelated to the reason for hospitalization), and 25 (2.7%) had multisystem inflammatory syndrome in children (MIS-C), a rare but serious inflammatory condition associated with COVID-19.§§ Among the 713 patients hospitalized for COVID-19, 24.7% were aged <1 year, 17.1% were aged 1-4 years, 20.1% were aged 5-11 years, and 38.1% were aged 12-17 years. Approximately two thirds of patients (67.5%) had one or more underlying medical conditions, with obesity being the most common (32.4%); among patients aged 12-17 years, 61.4% had obesity. Among patients hospitalized for COVID-19, 15.8% had a viral coinfection¶¶ (66.4% of whom had respiratory syncytial virus [RSV] infection). Approximately one third (33.9%) of patients aged <5 years hospitalized for COVID-19 had a viral coinfection. Among 272 vaccine-eligible (aged 12-17 years) patients hospitalized for COVID-19, one (0.4%) was fully vaccinated.*** Approximately one half (54.0%) of patients hospitalized for COVID-19 received oxygen support, 29.5% were admitted to the intensive care unit (ICU), and 1.5% died; of those requiring respiratory support, 14.5% required invasive mechanical ventilation (IMV). Among pediatric patients with COVID-19-related hospitalizations, many had severe illness and viral coinfections, and few vaccine-eligible patients hospitalized for COVID-19 were vaccinated, highlighting the importance of vaccination for those aged ≥5 years and other prevention strategies to protect children and adolescents from COVID-19, particularly those with underlying medical conditions.


Assuntos
COVID-19/terapia , Adolescente , COVID-19/epidemiologia , Vacinas contra COVID-19/administração & dosagem , Criança , Pré-Escolar , Coinfecção/epidemiologia , Feminino , Hospitalização , Hospitais , Humanos , Lactente , Masculino , Obesidade Infantil/epidemiologia , Resultado do Tratamento , Estados Unidos/epidemiologia , Vacinação/estatística & dados numéricos
8.
Ophthalmic Plast Reconstr Surg ; 34(2): 101-105, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28430707

RESUMO

PURPOSE: To review the clinical and histopathologic findings associated with subepidermal calcinosis of the eyelids. METHODS: A systematic review of the literature on subepidermal calcinosis of the eyelids was performed. Cases included were idiopathic in nature and met the histologic criteria for subepidermal calcinosis with calcium deposits in the dermis of the skin. RESULTS: Twenty-one publications presenting 53 cases of subepidermal calcinosis involving the eyelids were published between 1970 and 2016. Males were affected more than females (67% vs. 33%), and 89% of patients were 21 years of age or younger. A total of 63% were non-Caucasian. Most cases involved a single lesion (82%), and lesions were most frequently located on the upper eyelid (63%). In 81% of cases, the lesion was less than 5 mm in diameter. When reported, the treatment of choice was complete surgical excision. CONCLUSIONS: Subepidermal calcinosis should be considered in the differential diagnosis of idiopathic lesions on the eyelid, particularly in young males with no history of systemic disease or laboratory abnormalities. These nodules usually present as painless, small, firm, mobile solitary cutaneous lesions with a predilection for the upper eyelid. Diagnosis is confirmed by histopathology, and treatment is with surgical excision.


Assuntos
Calcinose/patologia , Doenças Palpebrais/patologia , Dermatopatias/patologia , Fatores Etários , Calcinose/etiologia , Diagnóstico Diferencial , Doenças Palpebrais/etiologia , Humanos , Fatores Sexuais , Dermatopatias/etiologia
9.
J Clin Invest ; 127(12): 4569-4582, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29058688

RESUMO

The devastating sequelae of diabetes mellitus include microvascular permeability, which results in retinopathy. Despite clinical and scientific advances, there remains a need for new approaches to treat retinopathy. Here, we have presented a possible treatment strategy, whereby targeting the small GTPase ARF6 alters VEGFR2 trafficking and reverses signs of pathology in 4 animal models that represent features of diabetic retinopathy and in a fifth model of ocular pathological angiogenesis. Specifically, we determined that the same signaling pathway utilizes distinct GEFs to sequentially activate ARF6, and these GEFs exert distinct but complementary effects on VEGFR2 trafficking and signal transduction. ARF6 activation was independently regulated by 2 different ARF GEFs - ARNO and GEP100. Interaction between VEGFR2 and ARNO activated ARF6 and stimulated VEGFR2 internalization, whereas a VEGFR2 interaction with GEP100 activated ARF6 to promote VEGFR2 recycling via coreceptor binding. Intervening in either pathway inhibited VEGFR2 signal output. Finally, using a combination of in vitro, cellular, genetic, and pharmacologic techniques, we demonstrated that ARF6 is pivotal in VEGFR2 trafficking and that targeting ARF6-mediated VEGFR2 trafficking has potential as a therapeutic approach for retinal vascular diseases such as diabetic retinopathy.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Retinopatia Diabética/metabolismo , Transdução de Sinais , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fator 6 de Ribosilação do ADP , Fatores de Ribosilação do ADP/genética , Linhagem Celular , Retinopatia Diabética/genética , Retinopatia Diabética/patologia , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Transporte Proteico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética
10.
Am J Ophthalmol ; 169: 162-167, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27349412

RESUMO

PURPOSE: To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency and chatter using a monitored forced infusion system. DESIGN: In vitro animal study. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. PROCEDURES: Formalin-soaked porcine lenses were divided into 2 mm cubes (tip diameter, 0.9 mm). Vacuum levels were tested at 200, 300, 400, and 500 mm Hg; aspiration rates at 20, 35, and 50 mL/min. Torsional power was set at 60% and intraocular pressure at 50 mm Hg. RESULTS: Increasing vacuum increased efficiency regardless of aspiration rates (R(2) = 0.92; P = .0004). Increasing aspiration further increased efficiency when vacuum was at 400 and 500 mm Hg (P = .004 for 20 vs 35 mL/min, P = .0008 for 35 vs 50 mL/min). At 200 and 300 mm Hg, efficiency only improved when increasing aspiration to 35 mL/min (P < .0001 with 20 vs 35 + 50 mL/min). Chatter improved with increasing vacuum, up to 400 mm Hg (P = .003 for 200 vs 300 mm Hg and P = .045 for 300 vs 500 mm Hg). A similar trend of improved chatter was seen with increasing levels of aspiration. CONCLUSIONS: Vacuum improved efficiency up to 500 mm Hg independent of flow. Flow has an additive effect on efficiency through 50 mL/min, when vacuum is at 400 mm Hg or higher, and only up to 35 mL/min at vacuums less than 400 mm Hg. Chatter correlated with both vacuum and flow such that increasing either parameter decreases chatter, up to 400 mm Hg with vacuum.


Assuntos
Cristalino/cirurgia , Facoemulsificação/métodos , Sucção , Vácuo , Animais , Catarata/patologia , Modelos Animais de Doenças , Ondas de Choque de Alta Energia , Infusões Parenterais , Pressão Intraocular/fisiologia , Monitorização Fisiológica , Facoemulsificação/instrumentação , Suínos
11.
Cancer Cell ; 29(6): 889-904, 2016 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-27265506

RESUMO

Activating mutations in Gαq proteins, which form the α subunit of certain heterotrimeric G proteins, drive uveal melanoma oncogenesis by triggering multiple downstream signaling pathways, including PLC/PKC, Rho/Rac, and YAP. Here we show that the small GTPase ARF6 acts as a proximal node of oncogenic Gαq signaling to induce all of these downstream pathways as well as ß-catenin signaling. ARF6 activates these diverse pathways through a common mechanism: the trafficking of GNAQ and ß-catenin from the plasma membrane to cytoplasmic vesicles and the nucleus, respectively. Blocking ARF6 with a small-molecule inhibitor reduces uveal melanoma cell proliferation and tumorigenesis in a mouse model, confirming the functional relevance of this pathway and suggesting a therapeutic strategy for Gα-mediated diseases.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Melanoma/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/administração & dosagem , Neoplasias Uveais/tratamento farmacológico , beta Catenina/metabolismo , Fator 6 de Ribosilação do ADP , Fatores de Ribosilação do ADP/antagonistas & inibidores , Fatores de Ribosilação do ADP/genética , Animais , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Citoplasma/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Melanoma/genética , Melanoma/metabolismo , Camundongos , Transplante de Neoplasias , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Neoplasias Uveais/genética , Neoplasias Uveais/metabolismo
12.
Clin Exp Ophthalmol ; 44(8): 710-713, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26999336

RESUMO

BACKGROUND: To evaluate the effect of varying levels of power on phacoemulsification efficiency using the CENTURION Vision System. METHODS: Formalin-soaked porcine lenses were divided into 2-mm cubes; 0.9-mm, balanced tips were used. Torsional power levels were tested from 10% to 100% at 10% intervals. Vacuum was set to 550 mmHg, aspiration to 50 ml/min, and intraocular pressure at 50 mmHg. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were determined. RESULTS: Increasing torsional power up to 60% increased efficiency. This effect was linear from 30 to 60% power (R2 = .90; P < 0.05). There were no significant differences in efficiency past 60%. Chatter was highest at 10% power and decreased linearly (R2 = .87; P = 0.007) as power was increased up to 60% power, and chatter did not improve above this power level. CONCLUSIONS: Power improved efficiency only up to a 60% power level, and then was negligible. Chatter correlated well with power up to the 60% level, so that as power was increased, chatter decreased. Because there are no additional benefits in efficiency past 60% power, and because chatter is minimal at 60% power, we recommend torsional ultrasound at 60% as the optimal power setting for using the CENTURION System for phacoemulsification.l.


Assuntos
Facoemulsificação/instrumentação , Torção Mecânica , Animais , Catarata/etiologia , Modelos Animais de Doenças , Drenagem/métodos , Pressão Intraocular/fisiologia , Cristalino/cirurgia , Facoemulsificação/métodos , Suínos , Vácuo
13.
Hum Mol Genet ; 23(23): 6223-34, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24990152

RESUMO

Cerebral cavernous malformation (CCM) is a disease of vascular malformations known to be caused by mutations in one of three genes: CCM1, CCM2 or CCM3. Despite several studies, the mechanism of CCM lesion onset remains unclear. Using a Ccm1 knockout mouse model, we studied the morphogenesis of early lesion formation in the retina in order to provide insight into potential mechanisms. We demonstrate that lesions develop in a stereotypic location and pattern, preceded by endothelial hypersprouting as confirmed in a zebrafish model of disease. The vascular defects seen with loss of Ccm1 suggest a defect in endothelial flow response. Taken together, these results suggest new mechanisms of early CCM disease pathogenesis and provide a framework for further study.


Assuntos
Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Proto-Oncogênicas/genética , Retina/patologia , Animais , Animais Geneticamente Modificados , Hemangioma Cavernoso do Sistema Nervoso Central/genética , Hemangioma Cavernoso do Sistema Nervoso Central/metabolismo , Humanos , Proteína KRIT1 , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Peixe-Zebra
14.
J Clin Invest ; 124(9): 3757-66, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25061876

RESUMO

The proteasome inhibiter bortezomib has been successfully used to treat patients with relapsed multiple myeloma; however, many of these patients become thrombocytopenic, and it is not clear how the proteasome influences platelet production. Here we determined that pharmacologic inhibition of proteasome activity blocks proplatelet formation in human and mouse megakaryocytes. We also found that megakaryocytes isolated from mice deficient for PSMC1, an essential subunit of the 26S proteasome, fail to produce proplatelets. Consistent with decreased proplatelet formation, mice lacking PSMC1 in platelets (Psmc1(fl/fl) Pf4-Cre mice) exhibited severe thrombocytopenia and died shortly after birth. The failure to produce proplatelets in proteasome-inhibited megakaryocytes was due to upregulation and hyperactivation of the small GTPase, RhoA, rather than NF-κB, as has been previously suggested. Inhibition of RhoA or its downstream target, Rho-associated protein kinase (ROCK), restored megakaryocyte proplatelet formation in the setting of proteasome inhibition in vitro. Similarly, fasudil, a ROCK inhibitor used clinically to treat cerebral vasospasm, restored platelet counts in adult mice that were made thrombocytopenic by tamoxifen-induced suppression of proteasome activity in megakaryocytes and platelets (Psmc1(fl/fl) Pdgf-Cre-ER mice). These results indicate that proteasome function is critical for thrombopoiesis, and suggest inhibition of RhoA signaling as a potential strategy to treat thrombocytopenia in bortezomib-treated multiple myeloma patients.


Assuntos
Complexo de Endopeptidases do Proteassoma/fisiologia , Trombopoese , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/fisiologia , Fator Plaquetário 4/fisiologia , Glicoproteína IIb da Membrana de Plaquetas/fisiologia , Inibidores de Proteassoma/farmacologia , Trombopoese/efeitos dos fármacos , Proteínas rho de Ligação ao GTP/fisiologia , Proteína rhoA de Ligação ao GTP
15.
Nature ; 492(7428): 252-5, 2012 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-23143332

RESUMO

The innate immune response is essential for combating infectious disease. Macrophages and other cells respond to infection by releasing cytokines, such as interleukin-1ß (IL-1ß), which in turn activate a well-described, myeloid-differentiation factor 88 (MYD88)-mediated, nuclear factor-κB (NF-κB)-dependent transcriptional pathway that results in inflammatory-cell activation and recruitment. Endothelial cells, which usually serve as a barrier to the movement of inflammatory cells out of the blood and into tissue, are also critical mediators of the inflammatory response. Paradoxically, the cytokines vital to a successful immune defence also have disruptive effects on endothelial cell-cell interactions and can trigger degradation of barrier function and dissociation of tissue architecture. The mechanism of this barrier dissolution and its relationship to the canonical NF-κB pathway remain poorly defined. Here we show that the direct, immediate and disruptive effects of IL-1ß on endothelial stability in a human in vitro cell model are NF-κB independent and are instead the result of signalling through the small GTPase ADP-ribosylation factor 6 (ARF6) and its activator ARF nucleotide binding site opener (ARNO; also known as CYTH2). Moreover, we show that ARNO binds directly to the adaptor protein MYD88, and thus propose MYD88-ARNO-ARF6 as a proximal IL-1ß signalling pathway distinct from that mediated by NF-κB. Finally, we show that SecinH3, an inhibitor of ARF guanine nucleotide-exchange factors such as ARNO, enhances vascular stability and significantly improves outcomes in animal models of inflammatory arthritis and acute inflammation.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Receptores de Interleucina/metabolismo , Fator 6 de Ribosilação do ADP , Adjuvantes Imunológicos/farmacologia , Animais , Artrite/patologia , Caderinas/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Linhagem Celular , Células Endoteliais/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Interleucina-1beta/farmacologia , NF-kappa B/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transporte Proteico/efeitos dos fármacos , Purinas/farmacologia , Transdução de Sinais , Tiofenos/farmacologia
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