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1.
Soc Indic Res ; 166(1): 85-103, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36687501

RESUMO

Using data from the 2018 National Financial Capability Study (NFCS), this study examined the relationships between poor financial behaviors, receiving government assistance, and financial satisfaction while accounting for adverse financial experiences. The logistic regression results showed that both poor financial behaviors and adverse financial experiences increased the likelihood of receiving government assistance. The OLS results indicated that receiving government assistance significantly increased levels of financial satisfaction, whereas poor financial behaviors significantly decreased levels of financial satisfaction. While the magnitude of these associations for both receiving government assistance and poor financial behaviors was small, adverse financial experiences had a stronger influence on the levels of financial satisfaction. When we combined poor financial behaviors and receiving government assistance into a categorical variable, we gained additional insights into the connections between these constructs that warrants further research.

2.
Soc Sci Med ; 317: 115572, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36473337

RESUMO

OBJECTIVE: The purpose of this study was to investigate associations between financial hardship and change in emotional well-being-positive and negative affect-before to during the COVID-19 pandemic among middle-aged and older Americans and to examine the extent to which associations were moderated by internal coping resources-dispositional mastery and optimism. METHOD: Data derived from the Leave-Behind Questionnaire in the 2016 and 2020 waves of the Health and Retirement Study, a nationally representative longitudinal survey of U.S. adults aged 51 and older (N = 1312). We estimated multivariate ordinary least squares regression models with interaction terms to evaluate prospectively the benefits of mastery and optimism as internal coping resources for middle-aged and older adults. RESULTS: Dispositional mastery moderated the effects of financial hardship on changes in negative and positive affect, respectively, before to during the COVID-19 pandemic; however, optimism did not significantly moderate the effects of financial hardship on change in negative and positive affect before to during the COVID-19 pandemic. CONCLUSIONS: Our findings have implications for interventions aimed at improving middle-aged and older adults' emotional well-being by promoting internal coping resources. Specifically, interventions should focus on financial hardship and mastery for vulnerable middle-aged and older adults in the context of public health crises.


Assuntos
COVID-19 , Estresse Financeiro , Pessoa de Meia-Idade , Humanos , Idoso , Pandemias , COVID-19/epidemiologia , Estudos Longitudinais , Adaptação Psicológica
3.
Acta Oncol ; 61(12): 1507-1511, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36369873

RESUMO

BACKGROUND: Transmembrane protein 27 (TMEM27/collectrin), a glycoprotein and homolog of angiotensin-converting enzyme 2 (ACE2), is a regulator of renal amino acid uptake in the proximal tubule and may have a protective role in hypertension. Two previous reports have shown that the absence of TMEM27 expression in clear cell renal cell carcinoma (ccRCC) correlates with poorer cancer-related survival. We report our findings of TMEM27 expression in ccRCC and clinical outcomes in an independent third cohort. MATERIAL AND METHODS: We conducted a retrospective analysis to identify all 321 cases of ccRCC diagnosed between 2010 and 2015 at the University of Rochester Medical Center. The intensity of TMEM27 immunostaining on tumor tissue was semi-quantitatively graded on a scale of 0, 0.5, 1, 1.5, 2, 2.5, and 3 by a single pathologist, and correlated with tumor characteristics and survival. RESULTS: There was evidence of metastasis at time of nephrectomy in 36 (11.2%) cases, and at the latest follow-up in 70 (21.8%) cases. As of Spring 2021, 82 (25.5%) had died. TMEM27 staining intensity correlated inversely with various tumor characteristics. Kaplan-Meier survival analysis showed worse overall all-cause mortality (p = 0.02) and disease-free survival (p = 0.028) for tumors without any TMEM27 staining (0) compared to 0.5 or higher by log-rank test. CONCLUSION: The absence of TMEM27 expression is associated with more aggressive tumor characteristics and poorer all-cause mortality and disease-free survival in ccRCC. TMEM27 may be a useful biomarker to assess cancer prognosis. Further studies are needed to better assess if TMEM27 is protective in RCC, and its potential role in active surveillance and prediction of response to target therapy.


Assuntos
Carcinoma de Células Renais , Carcinoma , Neoplasias Renais , Humanos , Biomarcadores Tumorais/metabolismo , Carcinoma/metabolismo , Carcinoma de Células Renais/patologia , Rim , Neoplasias Renais/patologia , Nefrectomia , Prognóstico , Estudos Retrospectivos
4.
Aquat Toxicol ; 249: 106225, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35724523

RESUMO

Due to increasing anthropogenic impacts, heatwaves and prolonged exposure to elevated concentrations of ammonia (HEA) may occur in aquatic environments as a single stressor or a combination thereof, potentially impacting the physiology of exposed animals. In the current study, common water fleas Daphnia magna were exposed for one week to either a 5°C increase in temperature, an increase of 300 µmol l-1 total environmental ammonia, or to both of these stressors simultaneously. Exposure to elevated temperature caused a decrease in MO2, ammonia excretion rates, a downregulation of mRNA coding for key Krebs cycle enzymes and the energy consuming Na+/K+-ATPase and V-type H+-ATPase, as well as the energy distributing crustacean hyperglycemic hormone Rh-protein. High environmental ammonia inflicted a lesser inhibitory effect on the energy metabolism of Daphnia, but initiated ammonia detoxification processes via urea synthesis evident by elevated urea excretion rates and a mRNA upregulation of arginase. Effects observed under the combined stressors resembled largely the effects seen after acclimation to elevated temperature alone, potentially due to the animals' capability to efficiently detoxify critical ammonia loads. The observed physiological effects and potential threats of the environmental stressor are discussed in detail.


Assuntos
Amônia , Poluentes Químicos da Água , Amônia/metabolismo , Animais , Daphnia/genética , Daphnia/metabolismo , Metabolismo Energético , Brânquias , Nitrogênio/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ureia/metabolismo , Poluentes Químicos da Água/toxicidade
5.
J Fam Econ Issues ; 42(1): 203-214, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32958989

RESUMO

This study investigated the implications that cash flow problems and resource intermingling between the family and the business had on small business recovery and resilience after a natural disaster. This study contributed to the literature by studying the impact of cash flow problems and resource intermingling on small businesses in two separate periods: right after the natural disaster (period 1) and eight years after the disaster (period 2). Period 1 determined whether the business was in operation directly following Hurricane Katrina. Period 2 investigated success of the small business after Katrina (compared to pre-Katrina success). Results showed that cash flow problems and resource intermingling did not affect operational status directly following Katrina, but did play a role in business resilience in the long run.

6.
Acta Neuropathol ; 138(6): 1013-1031, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31463572

RESUMO

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype-phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.


Assuntos
Proteínas de Ciclo Celular/genética , Doenças Cerebelares/genética , Proteínas do Citoesqueleto/genética , DNA Mitocondrial , Doenças Mitocondriais/genética , Distrofias Musculares/genética , Mutação , Adolescente , Adulto , Atrofia , Células Cultivadas , Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/patologia , Doenças Cerebelares/fisiopatologia , Criança , Variações do Número de Cópias de DNA , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Mitocondriais/diagnóstico por imagem , Doenças Mitocondriais/patologia , Doenças Mitocondriais/fisiopatologia , Músculos/patologia , Distrofias Musculares/diagnóstico por imagem , Distrofias Musculares/patologia , Distrofias Musculares/fisiopatologia , Fenótipo , Adulto Jovem
7.
Gerontologist ; 59(5): e512-e520, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31322654

RESUMO

BACKGROUND AND OBJECTIVES: This study examined how financial strain and changes in employment status affect subjective stressors over 12 months in 184 family caregivers of individuals with dementia. RESEARCH DESIGN AND METHODS: Subjective stressors of role overload and role captivity, and employment status were measured at baseline, 6-, and 12-months. Self-reports on financial strain were measured at baseline only. Caregivers were categorized into 3 groups based on changes in their employment status during the study over 12 months: (a) who were never employed, (b) who experienced some sort of employment status change, either going from employment to unemployment or vice versa, and (c) who were always employed. Growth curve analyses were conducted to examine within-person changes in role overload and role captivity, and associations with employment and financial strain. RESULTS: Caregivers with greater financial strain at baseline had higher levels of role overload and increasing role captivity over time. Caregivers who experienced a caregiving transition and had low financial strain at baseline showed greater decrease in role captivity over 12 months. Although caregivers who were consistently unemployed reported lower levels of role overload, they also showed steeper increase over time than those who were consistently employed. DISCUSSION AND IMPLICATIONS: Caregivers' perceptions of financial strain add to the long-term stress of the caregiving role. Changes in caregivers' employment status may have complex associations with their feelings of stress over time.


Assuntos
Cuidadores/economia , Cuidadores/psicologia , Demência/enfermagem , Emprego/psicologia , Estresse Psicológico/economia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos
8.
Clin Genet ; 93(2): 301-309, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28708278

RESUMO

The inherited peripheral neuropathies (IPNs) are characterized by marked clinical and genetic heterogeneity and include relatively frequent presentations such as Charcot-Marie-Tooth disease and hereditary motor neuropathy, as well as more rare conditions where peripheral neuropathy is associated with additional features. There are over 250 genes known to cause IPN-related disorders but it is estimated that in approximately 50% of affected individuals a molecular diagnosis is not achieved. In this study, we examine the diagnostic utility of whole-exome sequencing (WES) in a cohort of 50 families with 1 or more affected individuals with a molecularly undiagnosed IPN with or without additional features. Pathogenic or likely pathogenic variants in genes known to cause IPN were identified in 24% (12/50) of the families. A further 22% (11/50) of families carried sequence variants in IPN genes in which the significance remains unclear. An additional 12% (6/50) of families had variants in novel IPN candidate genes, 3 of which have been published thus far as novel discoveries (KIF1A, TBCK, and MCM3AP). This study highlights the use of WES in the molecular diagnostic approach of highly heterogeneous disorders, such as IPNs, places it in context of other published neuropathy cohorts, while further highlighting associated benefits for discovery.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Sequenciamento do Exoma , Sequenciamento de Nucleotídeos em Larga Escala , Doenças do Sistema Nervoso Periférico/genética , Acetiltransferases/genética , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/patologia , Exoma/genética , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Cinesinas/genética , Masculino , Mutação , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/patologia , Proteínas Serina-Treonina Quinases/genética
9.
Int J Pharm ; 528(1-2): 602-610, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28642200

RESUMO

Baicalein, wogonin, and oroxylin A are three major hydrophobic components in the extract of Radix scutellariae with wide spectrum of pharmacological applications. The purpose of this study was to enhance the solubility, dissolution rate and stability of baicalein, wogonin and oroxylin A by solid dispersion (SD) technique. SD of the extract with various polymers was prepared to select the best carrier. Solubility study, chemical stability study and dissolution study were performed to characterize the SD. The solubility of all three components, after forming solid dispersion with povidone K-30 (PVP K-30) was significantly increased in pH 6.8 medium at room temperature. Stability study conducted for 80days elucidated that the SD in powder state was fairly stable without the aid of Vitamin C (VC). VC was required as antioxidant to impart stability to baicalein in aqueous medium. The dissolution test of the SD of three components, admixed with VC at the weight ratio of 1:6 (Radix scutellariae extract: VC, w/w) exhibited faster dissolution rate with 100% release of all components. Pharmacokinetic study of baicalein solid dispersion revealed that AUC and Cmax significantly increased by solid dispersion preparation. Thus, the current developed method, being simple, economical and effective, can be useful for the production of soluble dosage forms of the extract of Radix scutellariae in commercial scale.


Assuntos
Flavanonas/química , Flavonoides/química , Scutellaria/química , Estabilidade de Medicamentos , Solubilidade
11.
Mol Psychiatry ; 22(3): 407-416, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27001618

RESUMO

Extensive evidence has indicated that a high rate of cholesterol biogenesis and abnormal neuronal energy metabolism play key roles in Alzheimer's disease (AD) pathogenesis. Here, for we believe the first time, we used osmotin, a plant protein homolog of mammalian adiponectin, to determine its therapeutic efficacy in different AD models. Our results reveal that osmotin treatment modulated adiponectin receptor 1 (AdipoR1), significantly induced AMP-activated protein kinase (AMPK)/Sirtuin 1 (SIRT1) activation and reduced SREBP2 (sterol regulatory element-binding protein 2) expression in both in vitro and in vivo AD models and in Adipo-/- mice. Via the AdipoR1/AMPK/SIRT1/SREBP2 signaling pathway, osmotin significantly diminished amyloidogenic Aß production, abundance and aggregation, accompanied by improved pre- and post-synaptic dysfunction, cognitive impairment, memory deficits and, most importantly, reversed the suppression of long-term potentiation in AD mice. Interestingly, AdipoR1, AMPK and SIRT1 silencing not only abolished osmotin capability but also further enhanced AD pathology by increasing SREBP2, amyloid precursor protein (APP) and ß-secretase (BACE1) expression and the levels of toxic Aß production. However, the opposite was true for SREBP2 when silenced using small interfering RNA in APPswe/ind-transfected SH-SY5Y cells. Similarly, osmotin treatment also enhanced the non-amyloidogenic pathway by activating the α-secretase gene that is, ADAM10, in an AMPK/SIRT1-dependent manner. These results suggest that osmotin or osmotin-based therapeutic agents might be potential candidates for AD treatment.


Assuntos
Proteínas de Plantas/uso terapêutico , Proteína de Ligação a Elemento Regulador de Esterol 2/antagonistas & inibidores , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Proteínas Quinases Ativadas por AMP/efeitos dos fármacos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Modelos Animais de Doenças , Humanos , Potenciação de Longa Duração/fisiologia , Transtornos da Memória/genética , Camundongos , Camundongos Transgênicos , Fosforilação , Proteínas de Plantas/farmacologia , Proteínas de Plantas/fisiologia , Receptores de Adiponectina/efeitos dos fármacos , Receptores de Adiponectina/metabolismo , Transdução de Sinais/genética , Sirtuína 1/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 2/efeitos dos fármacos
13.
Neuroradiology ; 58(10): 1035-1042, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27516098

RESUMO

INTRODUCTION: Infantile neuroaxonal dystrophy (INAD), an autosomal recessive neurodegenerative disorder due to PLA2G6 mutation, is classified both as a PLA2G6-associated neurodegeneration (PLAN) disorder and as one of the neurodegeneration with brain iron accumulation (NBIA) disorders. Age of onset and clinical presentation in INAD is variable. Typically described imaging features of cerebellar atrophy, cerebellar cortex bright FLAIR signal, and globus pallidus iron deposition are variable or late findings. We characterize clinical and neuroimaging phenotypes in nine children with confirmed PLA2G6 mutations and show a useful imaging feature, clava hypertrophy, which may aid in earlier identification of patients. Measurements of the clava confirm actual enlargement, rather than apparent enlargement due to volume loss of the other brain stem structures. METHODS: A retrospective clinical and MRI review was performed. Brain stem measurements were performed and compared with age-matched controls. RESULTS: We identified nine patients, all with novel PLA2G6 gene mutations. MRI, available in eight, showed clava hypertrophy, regardless of age or the absence of other more typically described neuroimaging findings. Brain autopsy in our cohort confirmed prominent spheroid bodies in the clava nuclei. CONCLUSION: Clava hypertrophy is an important early imaging feature which may aid in indentification of children who would benefit from specific testing for PLA2G6 mutations.


Assuntos
Biometria/métodos , Fosfolipases A2 do Grupo VI/genética , Imageamento por Ressonância Magnética/métodos , Distrofias Neuroaxonais/genética , Distrofias Neuroaxonais/patologia , Pré-Escolar , Diagnóstico Diferencial , Feminino , Predisposição Genética para Doença/genética , Humanos , Hipertrofia , Lactente , Masculino , Distrofias Neuroaxonais/diagnóstico por imagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Br J Dermatol ; 174(4): 723-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26708699

RESUMO

Buschke-Ollendorff syndrome (BOS) is a rare, often benign, autosomal skin disorder. BOS commonly presents with nontender connective tissue naevi and sclerotic bony lesions (osteopoikilosis [OPK]). Herein, we summarize the presenting features of BOS and potential associations by conducting a systematic review of the literature and summarizing a cohort seen at the Hospital for Sick Children (HSC), Toronto, Canada. PubMed was searched using the following terms: 'BOS'; 'dermatofibrosis lenticularis'; 'OPK'; 'LEMD3'; 'elastoma'; 'collagenoma'. Only case reports were included, without date or language restrictions. Cases were further narrowed to those where patients or their families had a combination of skin and bony lesions, or a positive genetic test. Data were summarized using frequencies. In total, 594 reports were discovered, of which 546 (92%) were excluded. The remaining 48 accounted for 164 cases. Skin lesions were noted in 24% of cases and bony lesions in 20%, while 54% of patients had both. In 1% of cases the diagnosis was made on genetic testing alone. A family history was noted in 92% of cases. All patients with spinal stenosis (2%) or shortened status (7%) had OPK. Six per cent of patients had neurological problems. However, 50% of the cohort from HSC had cognitive delays, and only cases from 2007 onwards reported cognitive delays (the prevalence was 17% among those cases). This review confirms the classical diagnostic features of BOS. In addition, it highlights a previously unreported association between a shortened stature and OPK, as well as a possible association with cognitive delays.


Assuntos
Osteopecilose/diagnóstico , Dermatopatias Genéticas/diagnóstico , Adolescente , Adulto , Distribuição por Idade , Idade de Início , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteopecilose/complicações , Dermatopatias Genéticas/complicações , Adulto Jovem
15.
Clin Genet ; 89(3): 275-84, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26283276

RESUMO

An accurate diagnosis is an integral component of patient care for children with rare genetic disease. Recent advances in sequencing, in particular whole-exome sequencing (WES), are identifying the genetic basis of disease for 25-40% of patients. The diagnostic rate is probably influenced by when in the diagnostic process WES is used. The Finding Of Rare Disease GEnes (FORGE) Canada project was a nation-wide effort to identify mutations for childhood-onset disorders using WES. Most children enrolled in the FORGE project were toward the end of the diagnostic odyssey. The two primary outcomes of FORGE were novel gene discovery and the identification of mutations in genes known to cause disease. In the latter instance, WES identified mutations in known disease genes for 105 of 362 families studied (29%), thereby informing the impact of WES in the setting of the diagnostic odyssey. Our analysis of this dataset showed that these known disease genes were not identified prior to WES enrollment for two key reasons: genetic heterogeneity associated with a clinical diagnosis and atypical presentation of known, clinically recognized diseases. What is becoming increasingly clear is that WES will be paradigm altering for patients and families with rare genetic diseases.


Assuntos
Exoma , Genes , Doenças Genéticas Inatas/diagnóstico , Mutação , Análise de Sequência de DNA , Canadá , Criança , Doenças Genéticas Inatas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
16.
Clin Genet ; 89(4): 501-506, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26497935

RESUMO

SHORT syndrome has historically been defined by its acronym: short stature (S), hyperextensibility of joints and/or inguinal hernia (H), ocular depression (O), Rieger abnormality (R) and teething delay (T). More recently several research groups have identified PIK3R1 mutations as responsible for SHORT syndrome. Knowledge of the molecular etiology of SHORT syndrome has permitted a reassessment of the clinical phenotype. The detailed phenotypes of 32 individuals with SHORT syndrome and PIK3R1 mutation, including eight newly ascertained individuals, were studied to fully define the syndrome and the indications for PIK3R1 testing. The major features described in the SHORT acronym were not universally seen and only half (52%) had four or more of the classic features. The commonly observed clinical features of SHORT syndrome seen in the cohort included intrauterine growth restriction (IUGR) <10th percentile, postnatal growth restriction, lipoatrophy and the characteristic facial gestalt. Anterior chamber defects and insulin resistance or diabetes were also observed but were not as prevalent. The less specific, or minor features of SHORT syndrome include teething delay, thin wrinkled skin, speech delay, sensorineural deafness, hyperextensibility of joints and inguinal hernia. Given the high risk of diabetes mellitus, regular monitoring of glucose metabolism is warranted. An echocardiogram, ophthalmological and hearing assessments are also recommended.

18.
Phys Chem Chem Phys ; 16(34): 18493-500, 2014 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-25073067

RESUMO

Amyloid proteins, implicated in numerous aging-related diseases, possess remarkable mechanical properties. Polymorphism leads to different arrangements of ß sheets in amyloid fibrils, which changes the characteristics of the hydrogen bond network that determines their mechanical properties and structural characteristics. We performed bending simulations using molecular dynamics methods under constant-velocity conditions in different bending directions. Two different fibril structures, parallel/homo and parallel/hetero, of hIAPP amyloids were considered. Though the bending configuration influences the toughness of the material, our results indicate that the basic material behavior is affected by the ß-sheet arrangement that is determined by the type of polymorphism in amyloid fibrils.


Assuntos
Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/ultraestrutura , Modelos Químicos , Simulação de Dinâmica Molecular , Nanofios/química , Nanofios/ultraestrutura , Anisotropia , Simulação por Computador , Módulo de Elasticidade , Conformação Proteica , Estresse Mecânico , Resistência à Tração
19.
Free Radic Res ; 48(9): 1100-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24917460

RESUMO

Transforming growth factor ß1 (TGF-ß1) induces Mv1Lu cell senescence through inactivating glycogen synthase kinase 3 (GSK3), thereby inactivating complex IV and increasing intracellular ROS. In the present study, we identified protein kinase C delta (PKCδ) as an upstream regulator of GSK3 inactivation in this mechanism of TGF-ß1-induced senescence. When Mv1Lu cells were exposed to TGF-ß1, PKCδ phosphorylation simultaneously increased with GSK3 phosphorylation, and then AKT and ERK were phosphorylated. AKT phosphorylation and Smad signaling were independent of GSK3 phosphorylation, but ERK phosphorylation was downstream of GSK3 inactivation. TGF-ß1-triggered GSK3 phosphorylation was blocked by inhibition of PKCδ, using its pharmacological inhibitor, Rottlerin, or overexpression of a dominant negative PKCδ mutant, but GSK3 inhibition with SB415286 did not alter PKCδ phosphorylation. Activation of PKCδ by PMA delayed cell growth and increased intracellular ROS level, but did not induce senescent phenotypes. In addition, overexpression of wild type or a constitutively active PKCδ mutant was enough to delay cell growth and decrease the mitochondrial oxygen consumption rate and complex IV activity, but weakly induce senescence. However, PMA treatment on Mv1Lu cells, which overexpress wild type and constitutively active PKCδ mutants, effectively induced senescence. These results indicate that PKCδ plays a key role in TGF-ß1-induced senescence of Mv1Lu cells through the phosphorylation of GSK3, thereby triggering mitochondrial complex IV dysfunction and intracellular ROS generation.


Assuntos
Senescência Celular/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Mitocôndrias/metabolismo , Proteína Quinase C-delta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Western Blotting , Linhagem Celular , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Citometria de Fluxo , Imunoprecipitação , Fosforilação , Transdução de Sinais/fisiologia , Transfecção , Fator de Crescimento Transformador beta1/metabolismo
20.
Cell Death Dis ; 5: e1150, 2014 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-24675468

RESUMO

Fetal alcohol syndrome is a neurological and developmental disorder caused by exposure of developing brain to ethanol. Administration of osmotin to rat pups reduced ethanol-induced apoptosis in cortical and hippocampal neurons. Osmotin, a plant protein, mitigated the ethanol-induced increases in cytochrome c, cleaved caspase-3, and PARP-1. Osmotin and ethanol reduced ethanol neurotoxicity both in vivo and in vitro by reducing the protein levels of cleaved caspase-3, intracellular [Ca(2+)]cyt, and mitochondrial transmembrane potential collapse, and also upregulated antiapoptotic Bcl-2 protein. Osmotin is a homolog of adiponectin, and it controls energy metabolism via phosphorylation. Adiponectin can protect hippocampal neurons against ethanol-induced apoptosis. Abrogation of signaling via receptors AdipoR1 or AdipoR2, by transfection with siRNAs, reduced the ability of osmotin and adiponectin to protect neurons against ethanol-induced neurodegeneration. Metformin, an activator of AMPK (adenosine monophosphate-activated protein kinase), increased whereas Compound C, an inhibitor of AMPK pathway, reduced the ability of osmotin and adiponectin to protect against ethanol-induced apoptosis. Osmotin exerted its neuroprotection via Bcl-2 family proteins and activation of AMPK signaling pathway. Modulation of AMPK pathways by osmotin, adiponectin, and metformin hold promise as a preventive therapy for fetal alcohol syndrome.


Assuntos
Apoptose , Encéfalo/patologia , Etanol/toxicidade , Degeneração Neural/tratamento farmacológico , Degeneração Neural/patologia , Fármacos Neuroprotetores/uso terapêutico , Proteínas de Plantas/uso terapêutico , Adenilato Quinase/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Células Cultivadas , Feminino , Imunofluorescência , Hipocampo/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Proteínas de Plantas/farmacologia , Ratos Sprague-Dawley , Receptores de Adiponectina/metabolismo
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