Altered ubiquitination and stability of aquaporin-1 in hypertonic stress

Aquaporin-1 (AQP1) water channel protein expression is increased by hypertonic stress. The contribution of changes in protein stability to hypertonic induction of AQP1 have not been described. Incubation of BALB/c fibroblasts spontaneously expressing AQP1 with proteasome inhibitors increased AQP1 expression, suggesting basal proteasome-dependent degradation of the protein. Degradation by the proteasome is thought to be triggered by polyubiquitination of a target protein. To determine whether AQP1 is ubiquitinated, immunoprecipitation with anti-AQP1 antibodies was performed, and the resultant samples were probed by protein immunoblot for the presence of ubiquitin. Immunoblots demonstrated ubiquitination of AQP1 under control conditions that increased after treatment with proteasome inhibitors (MG132, lactacystin). Exposure of cells to hypertonic medium for as little as 4 h decreased ubiquitination of AQP1, an effect that persisted through 24 h in hypertonic medium. Using metabolic labeling with [35S]methionine, the half-life of AQP1 protein under isotonic conditions was found to be <4 h. AQP1 protein half-life was markedly increased by exposure of cells to hypertonic medium. These observations provide evidence that aquaporins are a target for ubiquitination and proteasome-dependent degradation. Additionally, these studies demonstrate that reduced protein ubiquitination and increased protein stability lead to increased levels of AQP1 expression during hypertonic stress.

Evolution of genome–phenome diversity under environmental stress

The genomic era revolutionized evolutionary biology. The enigma of genotypic-phenotypic diversity and biodiversity evolution of genes, genomes, phenomes, and biomes, reviewed here, was central in the research program of the Institute of Evolution, University of Haifa, since 1975. We explored the following questions. (i) How much of the genomic and phenomic diversity in nature is adaptive and processed by natural selection? (ii) What is the origin and evolution of adaptation and speciation processes under spatiotemporal variables and stressful macrogeographic and microgeographic environments? We advanced ecological genetics into ecological genomics and analyzed globally ecological, demographic, and life history variables in 1,200 diverse species across life, thousands of populations, and tens of thousands of individuals tested mostly for allozyme and partly for DNA diversity. Likewise, we tested thermal, chemical, climatic, and biotic stresses in several model organisms. Recently, we introduced genetic maps and quantitative trait loci to elucidate the genetic basis of adaptation and speciation. The genome–phenome holistic model was deciphered by the global regressive, progressive, and convergent evolution of subterranean mammals. Our results indicate abundant genotypic and phenotypic diversity in nature. The organization and evolution of molecular and organismal diversity in nature at global, regional, and local scales are nonrandom and structured; display regularities across life; and are positively correlated with, and partly predictable by, abiotic and biotic environmental heterogeneity and stress. Biodiversity evolution, even in small isolated populations, is primarily driven by natural selection, including diversifying, balancing, cyclical, and purifying selective regimes, interacting with, but ultimately overriding, the effects of mutation, migration, and stochasticity.

Heat-Stress Response of Maize Mitochondria1

We have identified maize (Zea mays L. inbred B73) mitochondrial homologs of the Escherichia coli molecular chaperones DnaK (HSP70) and GroEL (cpn60) using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblots. During heat stress (42°C for 4 h), levels of HSP70 and cpn60 proteins did not change significantly. In contrast, levels of two 22-kD proteins increased dramatically (HSP22). Monoclonal antibodies were developed to maize HSP70, cpn60, and HSP22. The monoclonal antibodies were characterized with regard to their cross-reactivity to chloroplastic, cytosolic, and mitochondrial fractions, and to different plant species. Expression of mitochondrial HSP22 was evaluated with regard to induction temperature, time required for induction, and time required for degradation upon relief of stress. Maximal HSP22 expression occurred in etiolated seedling mitochondria after 5 h of a +13°C heat stress. Upon relief of heat stress, the HSP22 proteins disappeared with a half-life of about 4 h and were undetectable after 21 h of recovery. Under continuous heat-stress conditions, the level of HSP22 remained high. A cDNA for maize mitochondrial HSP22 was cloned and extended to full length with sequences from an expressed sequence tag database. Sequence analysis indicated that HSP22 is a member of the plant small heat-shock protein superfamily.

Cellular stress inhibits transposition of the yeast retrovirus-like element Ty3 by a ubiquitin-dependent block of virus-like particle formation.

Many stress proteins and their cognates function as molecular chaperones or as components of proteolytic systems. Viral infection can stimulate synthesis of stress proteins and particular associations of viral and stress proteins have been documented. However, demonstrations of functions for stress proteins in viral life cycles are few. We have initiated an investigation of the roles of stress proteins in eukaryotic viral life cycles using as a model the Ty3 retrovirus-like element of Saccharomyces cerevisiae. During stress, Ty3 transposition is inhibited; Ty3 DNA is not synthesized and, although precursor proteins are detected, mature Ty3 proteins and virus-like particles (VLPs) do not accumulate. The same phenotype is observed in the constitutively stressed ssa1 ssa2 mutant, which lacks two cytoplasmic members of the hsp70 family of chaperones. Ty3 VLPs preformed under nonstress conditions are degraded more rapidly if cells are shifted from 30 degrees C to 37 degrees C. These results suggest that Ty3 VLPs are destroyed by cellular stress proteins. Elevated expression of the yeast UBP3 gene, which encodes a protease that removes ubiquitin from proteins, allows mature Ty3 proteins and VLPs to accumulate in the ssa1 ssa2 mutant, suggesting that, at least under stress conditions, ubiquitination plays a role in regulating Ty3 transposition.

Persistent elevations of cerebrospinal fluid concentrations of corticotropin-releasing factor in adult nonhuman primates exposed to early-life stressors: implications for the pathophysiology of mood and anxiety disorders.

There is increasing evidence for an important role of adverse early experience on the development of major psychiatric disorders in adulthood. Corticotropin-releasing factor (CRF), an endogenous neuropeptide, is the primary physiological regulator of the mammalian stress response. Grown nonhuman primates who were exposed as infants to adverse early rearing conditions were studied to determine if long-term alterations of CRF neuronal systems had occurred following the early stressor. In comparison to monkeys reared by mothers foraging under predictable conditions, infant monkeys raised by mothers foraging under unpredictable conditions exhibited persistently elevated cerebrospinal fluid (CSF) concentrations of CRF. Because hyperactivity of CRF-releasing neurons has been implicated in the pathophysiology of certain human affective and anxiety disorders, the present finding provides a potential neurobiological mechanism by which early-life stressors may contribute to adult psychopathology.

Life satisfaction and health related quality of life during pregnancy and puerperium

Poster submitted to the 22nd International Conference Stress and Anxiety Research Society (STAR), Palma de Mallorca, July, 12-14, 2001.

Psychological Homelessness and Enculturative Stress among US-Deported Salvadorans: A Preliminary Study with a Novel Approach

The purpose of this study was to examine the construct psychological homelessness—feelings of not belonging in one’s home country—within the context of deported Salvadorans’ enculturation to El Salvador. Participants (n = 66) who had been deported from the United States completed a set of questionnaires related to their deportation experience. Results indicated that deportees, in various degrees, experienced the phenomenon of psychological homelessness and enculturative stress related to living in El Salvador. As hypothesized, enculturative stress related to re-adapting to life in El Salvador significantly correlated with psychological homelessness after controlling for time spent in the United States, acculturation, and enculturation. Additional analyses revealed that maladaptive cognitions related to the deportation experience also predicted psychological homelessness. Our findings suggest psychological homelessness appears to be a valid construct and is experienced by many undocumented immigrants.

Qualidade do sono e suas implicações ao nível da ansiedade, depressão e stress nos estudantes do ensino superior

O sono é imprescindível à existência humana, assumindo uma panóplia de funções cruciais nas diferentes faixas etárias. São inúmeros os fatores que podem contribuir para a sua alteração, sendo a vida universitária um deles. Tendo em conta os dados de incidência e prevalência de alterações neurocognitivas na população portuguesa, torna-se fundamental o estudo da qualidade do sono e as suas implicações a nível da ansiedade, depressão e stress nos estudantes de Ensino Superior do Instituto Politécnico de Bragança. Objetivou-se “Avaliar a qualidade do sono dos estudantes do ensino superior” e “Analisar os níveis de ansiedade, depressão e stress vivenciados pelos estudantes do ensino superior”. Face aos objetivos delineados optou-se por um estudo descritivo-correlacional inserido no paradigma quantitativo e num plano transversal, com uma amostragem não probabilística por conveniência de 358 estudantes representativos do Instituto Politécnico de Bragança. Para a colheita de dados utilizou-se uma Ficha Sociodemográfica, o Índice de Qualidade de Sono de Pittsburgh (IQSP) de Ramalho (2008) e a Escala de Ansiedade, Depressão e Stress (EADS-21) de Pais Ribeiro, Honrado e Leal (2004). Como principais resultados, destaca-se a qualidade de sono, evidenciando-se que 53,6% (192) dos estudantes apresenta má qualidade de sono e os restantes 46,4% (166) têm boa qualidade de sono. Os estudantes com má qualidade de sono apresentaram níveis médios de stress, ansiedade e depressão mais elevados que os estudantes com boa qualidade de sono. Os níveis de stress, ansiedade e depressão evidenciados nos estudantes foram considerados díspares entre eles, sendo que o stress foi o mais significativo. Ao constatarmos que a má qualidade de sono é frequente nos estudantes do ensino superior tendo esta repercussões na sua saúde física e mental, concluímos que estamos perante um risco de saúde pública.

Energy Signaling in the Regulation of Gene Expression during Stress

Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must have evolved to allow rapid perception of environmental cues and concomitant modification of growth and developmental patterns for adaptation and survival. Re-establishment of homeostasis in response to environmental perturbations requires reprogramming of metabolism and gene expression to shunt energy sources from growth-related biosynthetic processes to defense, acclimation, and, ultimately, adaptation. Failure to mount an initial 'emergency' response may result in nutrient deprivation and irreversible senescence and cell death. Early signaling events largely determine the capacity of plants to orchestrate a successful adaptive response. Early events, on the other hand, are likely to be shared by different conditions through the generation of similar signals and before more specific responses are elaborated. Recent studies lend credence to this hypothesis, underpinning the importance of a shared energy signal in the transcriptional response to various types of stress. Energy deficiency is associated with most environmental perturbations due to their direct or indirect deleterious impact on photosynthesis and/or respiration. Several systems are known to have evolved for monitoring the available resources and triggering metabolic, growth, and developmental decisions accordingly. In doing so, energy-sensing systems regulate gene expression at multiple levels to allow flexibility in the diversity and the kinetics of the stress response.

Vulnerabilidade ao stress : implicações no bem-estar e satisfação do professor

Enquadramento: O stress acompanha o indivíduo, tanto no trabalho como na vida social. Desencadeado por diversos fatores, o stress está, também,presente na vida do professor. Objetivos: Identificar os fatores que têm desencadeado situações de stress dos professores no Ensino Fundamental do município de Campo Grande-AL; Determinar os principais stressores no bem-estar e satisfação dos mesmos. Material e métodos: Optou-se pelo tipo de investigação quantitativo e não experimental, com corte transversal, descritivo e correlacional. A recolha de dados foi realizada através de protocolo constituído por questionário de caraterização sócio demográfica e escalas de: Satisfação Geral do Trabalho; Vulnerabilidade ao Stress; Afecto Positivo e Negativo; Apgar Familiar e Inventário de Qualidade de Vida. A amostra é não probabilística por conveniência constituída por 70 (setenta) professores do Ensino Fundamental. Resultados: Constatou-se que 50% dos participantes apresentaram vulnerabilidade ao stress, 28,5% boa relação com pessoas desconhecidas e 55% revelaram ter apoio dos amigos. Não foram identificados problemas familiares e 65% dos inquiridos referiram ter ajuda da família. Na satisfação do trabalho apenas 27% dos professores estão satisfeitos e 30% pensaram abandonar o trabalho. Conclusões:O desgaste em sala de aula envolve situações diárias dos professores, levando à necessidade de alertar os órgãos públicos, a fim de adotarem estratégias para o bem estar e satisfação dos professores, visando o sucesso desejado. Palavras-chave: Vulnerabilidade ao Stress; Professor; Bem-estar; Satisfação Profissional.

Qualidade de vida e vulnerabilidade ao stress dos cuidadores formais de uma unidade de cuidados continuados integrados do Alentejo

Viver um maior número de anos não significa necessariamente que se viva com qualidade. Devido às alterações demográficas verificadas nos últimos anos e face ao envelhecimento progressivo da população mundial e consequente aumento da esperança média de vida, ao acréscimo das doenças crónicas e à dependência a elas associada, surgem dificuldades que os doentes e os seus cuidadores enfrentam no seu quotidiano de internamento. Assim, surgiu a necessidade de equacionar a problemática da Qualidade de Vida e a Vulnerabilidade ao Stress dos Cuidadores Formais, que diariamente trabalham numa Unidade de Cuidados Continuados Integrados do Alentejo. Este trabalho foi desenvolvido numa Unidade de Cuidados Continuados Integrados com duas valências de internamento, a Média e a Longa Duração, com os Cuidadores Formais que nele aceitaram participar. Entre eles, encontram-se as mais diversas profissões, desde Auxiliares de Lar, Enfermeiros, Fisioterapeutas, Psicólogos, Animadores Socioculturais, Técnicos de Psicomotricidade, Terapeutas da Fala e Assistentes Sociais. Todos eles representam um papel muito importante no cuidado aos seus clientes, cada um na sua área. Ao delinear este estudo, o Problema prático identificado foi se existia uma relação entre a Qualidade de Vida e a Vulnerabilidade ao Stress dos Cuidadores Formais de uma Unidade de Cuidados Continuados Integrados do Alentejo. Este estudo foi desenvolvido com uma população de 63 elementos, todos Cuidadores Formais a desempenhar funções no local de estudo já referenciado. Foi utilizada a abordagem quantitativa, que é uma metodologia de investigação de vertente epistemológica positivista. Neste estudo, foram utilizados dois instrumentos para aplicar e recolher os dados: um destinado a medir a vulnerabilidade ao stress (23 QVS) dos cuidadores formais; outro para avaliar a qualidade de vida (WHOQOL-Bref), gentilmente cedidos pelos seus autores. Os dados recolhidos, após analisados apontaram no sentido de que à medida que a qualidade de vida aumentava nos diferentes domínios, diminuía a vulnerabilidade ao stress.

Compression Loading Induced Cellular Stress Response of Intervertebral Disc Cells in Organ Culture

Introduction: Mechanical stress is often associated to interverterbal disc (IVD) degeneration and the effect of mechanical loading on IVD has been studied and reviewed.1,2 Previously, expression of heat shock proteins, HSP70 and HSP27 has been found in pathological discs.3 However, there is no direct evidence on whether IVD cells respond to the mechanical loading by expression of HSPs. The objective of this study is to investigate the stress response of IVD cells during compressive loading in an organ culture. Materials and Methods: Fresh adult bovine caudal discs were cultured with compressive loading applied at physiological range. Effect of loading type (static and dynamic) and repeated loading (2 hours per day for 2 days) were studied. Nucleus pulposus (NP) and annulus fibrosus (AF) of the IVD were retrieved at different time points: right after loading and right after resting. Positive control discs were heat shocked (43°C). Cell activity was assessed and expression of stress response genes (HSP70 and HSF1) and matrix remodeling genes (ACAN, COL2, COL1, ADAMTS4, MMP3 and MMP13) were studied. Results: Cell activity was maintained in all groups. Both NP and AF expressed high level of HSP70 in heat shock groups, confirming their expression in response to stress. In NP, expression of HSP70 was up-regulated after static loading and dynamic loading with higher fold change was observed after static loading. During repeated loading, HSP70 appeared to be upregulated right after loading and decreased after resting. Such trend was not observed in AF and HSF1 levels. Expressions of matrix remodeling genes did not change significantly with loading except ADAMTS4 decreased in AF during static loading. Conclusion: This study demonstrated that NP cells upregulate expression of HSP70 in response to loading induced stress without changing cell activity and matrix remodeling significantly. Acknowledgments: This project was funded by AO Spine (AOSPN) (grant number: SRN_2011_14) and a fellowship exchange award by AO Spine Scientific Research Network (SRN).

Protein Hydrolysis and Nitrogen Remobilisation in Plant Life and Senescence

In plant cells, as in all other cells, proteins are submitted to permanent turnover, and the intracellular content of a given protein depends on its rate of both synthesis and degradation. The life time of most proteins is shorter than that of the cell. Thus, in young leaves of Lemna minor, the average half-life of protein was estimated to be 7 days, and it was shorter under stress conditions (Davies 1982). Such observations mean that nitrogen and amino acid fluxes are both cylic and permanent. Although protein turnover may appear wasteful, in terms of energy, numerous studies have shown that proteolysis provides multiple functions in cell physiology, and is an essential regulatory mechanism of cell metabolism and development.

A combined analysis of two randomized controlled trials evaluating the effect of Mindfulness-Based Stress Reduction on self-reported emotional experience and physiological symptoms among Veterans with Posttraumatic Stress Disorder

Thesis (Master's)--University of Washington, 2016-06

Examining the Relationship Between Secondary Traumatic Stress and Sickness Absenteeism within 9-1-1 Emergency Call Centers

Thesis (Master's)--University of Washington, 2016-06