The ribosome as novel target for stress-induced small regulatory RNAs

Small non-protein-coding RNA (ncRNA) molecules represent major contributors to regulatory networks in controlling gene expression in a highly efficient manner. All of the recently discovered regulatory ncRNAs that act on translation (e.g. microRNAs, siRNAs or antisense RNAs) target the mRNA rather than the ribosome. To address the question, whether small ncRNA regulators exist that are capable of modulating the rate of protein production by directly interacting with the ribosome, we have analyzed the small ncRNA interactomes of ribosomes Deep-sequencing and subsequent bioinformatic analyses revealed thousands of putative ribosome-associated ncRNAs in various model organisms (1,2). For a subset of these ncRNA candidates we have gathered experimental evidence that they associate with ribosomes in a stress-dependent manner and are capable of regulating gene expression by fine-tuning the rate of protein biosynthesis (3,4). Many of the investigated ribosome-bound small ncRNA appear to be processing products from larger functional RNAs, such as tRNAs (2,3) or mRNAs (3). Post-transcriptional cleavage of RNA molecules to generate smaller fragments is a widespread mechanism that enlarges the structural and functional complexity of cellular RNomes. Our data reveal the ribosome as a target for small regulatory ncRNAs and demonstrate the existence of a yet unknown mechanism of translation regulation. Ribosome-associated ncRNAs (rancRNAs) are found in all domains of life and represent a prevalent but so far largely unexplored class of regulatory molecules (5). Future work on the small ncRNA interactomes of ribosomes in a variety of model systems will allow deeper insight into the conservation and functional repertoire of this emerging class of regulatory ncRNA molecules.

REGULATION OF BRAIN NORADRENERGIC-RECEPTOR FUNCTION BY ADRENOCORTICOTROPHIN AND ANTIDEPRESSANT DRUGS (ADRENERGIC RECEPTOR, CYCLIC-AMP, ADENYLATE CYCLASE, IMIPRAMINE, STRESS)

Human behavior appears to be regulated in part by noradrenergic transmission since antidepressant drugs modify the number and function of (beta)-adrenergic receptors in the central nervous system. Affective illness is also known to be associated with the endocrine system, particularly the hypothalamic-pituitary-adrenal axis. The aim of the present study was to determine whether hormones, in particular adrencorticotrophin (ACTH) and corticosterone, may influence behavior by regulating brain noradrenergic receptor function.^ Chronic treatment with ACTH accelerated the increase or decrease in rat brain (beta)-adrenergic receptor number induced by a lesion of the dorsal noradrenergic bundle or treatment with the antidepressant imipramine. Chronic administration of ACTH alone had no effect on (beta)-receptor number although it reduced norepinephrine stimulated cyclic AMP accumulation in brain slices. Treatment with imipramine also reduced the cyclic AMP response to norepinephrine but was accompanied by a decrease in (beta)-adrenergic receptor number. Both the imipramine and ACTH treatments reduced the affinity of (beta)-adrenergic receptors for norepinephrine, but only the antidepressant modified the potency of the neurotransmitter to stimulate second messenger production. Neither ACTH nor imipramine treatment altered Gpp(NH)p- or fluoride-stimulated adenylate cyclase, cyclic AMP, cyclic GMP, or cyclic GMP-stimulated cyclic AMP phosphodiesterase, or the activity of the guanine nucleotide binding protein (Gs). These findings suggested that post-receptor components of the cyclic nucleotide generating system are not influenced by the hormone or antidepressant. This conclusion was verified by the finding that neither treatment altered adenosine-stimulated cyclic AMP accumulation in brain tissue.^ A detailed examination of the (alpha)- and (beta)-adrenergic receptor components of norepinephrine-stimulated cyclic AMP production revealed that ACTH, but not imipramine, administration reduced the contribution of the (alpha)-receptor mediated response. Like ACTH treatment, corticosterone diminished the (alpha)-adrenergic component indicating that adrenal steroids probably mediate the neurochemical responses to ACTH administration. The data indicate that adrenal steroids and antidepressants decrease noradrenergic receptor function by selectively modifying the (alpha)- and (beta)-receptor components. The functional similarity in the action of the steroid and antidepressants suggests that adrenal hormones normally contribute to the maintenance of receptor systems which regulate affective behavior in man. ^

Family stress, coping, communication, and adaptation in unintended adolescent pregnancy

Objective. This study examines post-crisis family stress, coping, communication, and adaptation using the Double ABC-X Model of Family Adaptation in families with a pregnant or postpartum adolescent living at home. ^ Methods. Ninety-eight pregnant and parenting adolescents between ages 14 and 18 years (Group 1 at 20 or more weeks gestation; Group 2 at delivery and 8 weeks postpartum) and their parent(s) completed instruments congruent with the model to measure family stress, coping, communication, and adaptation. Descriptive family data was obtained. Mother-daughter data was analyzed for differences between subjects and within subjects using paired t-tests. Correlational analysis was used to examine relationships among variables. ^ Results. More than 90% of families were Hispanic. There were no significant differences between mother and daughter mean scores for family stress or communication. Adolescent coping was not significantly correlated to family coping at any interval. Adolescent family adaptation scores were significantly lower than mothers' scores at delivery and 8 weeks postpartum. Mean individual ratings of family variables did not differ significantly between delivery and 8 weeks postpartum. Simultaneous multiple regression analysis showed that stress, coping, and communication significantly influenced adaptation for mothers and daughters at all three intervals. The relative contributions of the three independent variables exhibited different patterns for mothers and daughters. Parent-adolescent communication accounted for most of the variability in adaptation for daughters at all three intervals. Daughters' family stress ratings were significant for adaptability (p = .01) during the pregnancy and for cohesion (p = .03) at delivery. Adolescent coping (p = .03) was significant for cohesion at 8 weeks postpartum. Family stress was a significant influence at all three intervals for mothers' ratings of family adaptation. Parent-adolescent communication was significant for mother's perception of both family cohesion (p < .001) and adaptability (p < .001) at delivery and 8 weeks, but not during pregnancy. ^ Conclusions. Mothers' and daughters' ratings of family processes were similar regarding family stress and communication, but were significantly different for family adaptation. Adolescent coping may not reflect family coping. Family communication is a powerful component in family functioning and may be an important focus for interventions with adolescents and parents. ^

Salivary cortisol, psychological stress and depressive symptoms among patients undergoing colon cancer screenings

As the second leading cause of cancer-related deaths in the United States, colon cancer has a high cure rate if detected early by a colonoscopy (U.S. Cancer Statistics Working Group, 2007). However, more than 41 million at-risk Americans are not properly receiving colonoscopy screenings according to the recommendations of the Center for Disease Control. This study provides insight into the physiological and psychological benefits of the colonoscopy procedure over and above cancer detection and prevention. Thirty-six patients receiving colonoscopic screening at the University of Connecticut Health Center participated in this study. A questionnaire battery that assessed perceived stress, depressive symptoms, colon cancer related worry, and social support, and optional saliva sampling was completed 2 weeks prior to and post colonoscopy. It was hypothesized that salivary cortisol concentrations, perceived stress, and self-reported depressive symptoms would show significant decreases from pre to post colonoscopy, and that these variables would all be positively correlated with one another. Results showed significant, positive correlations between depressive symptoms and both salivary cortisol (r (34)= .348, p< .05) and perceived stress (r (34)= .635, p< .01). Morning salivary cortisol levels decreased significantly from pre to post colonoscopy to levels below the population mean (t (16)=-3.711, p<. 01). No such differences were observed in either perceived stress or depressive symptoms. These results indicate that by decreasing cortisol concentrations to levels below that of the population mean, the colonoscopy provided physiological health benefits to patients beyond cancer screening. From a health psychology standpoint, this may encourage some of the 41 million Americans not receiving proper colon cancer screenings to adopt this potentially life-saving health behavior.

Induction of endoplasmic reticular stress by bortezomib: A novel therapeutic strategy for pancreatic cancer

Bortezomib (VELCADE™, formerly known as PS-341) is a selective and potent inhibitor of the proteasome that was recently FDA-approved for the treatment of multiple myeloma. Despite its success in multiple myeloma and progression into clinical trials for other malignancies, bortezomib's exact mechanism of action remains undefined. The major objective of this study was to evaluate the anticancer activity of this drug using in vitro and in vivo pancreatic cancer models and determine whether bortezomib-induced apoptosis occurs via induction of endoplasmic reticular (ER) stress. The investigation revealed that bortezomib inhibited tumor cell proliferation via abrogation of cdk activity and induced apoptosis in pancreatic cancer cell lines. I hypothesized that bortezomib-induced apoptosis was triggered by a large accumulation ubiquitin-conjugated proteins that resulted in ER stress. My data demonstrated that bortezomib induced a unique type of ER stress in that it inhibited PKR-like ER kinase (PERK) and subsequent phosphorylation of eukaryotic initiation factor 2α (eif2α), a key event in translational suppression. The combined effects of proteasome inhibition and the failure to attenuate translation resulted in an accumulation of aggregated proteins (proteotoxicity), JNK activation, cytochrome c release, caspase-3 activation, and DNA fragmentation. Bortezomib also enhanced apoptosis induced by other agents that stimulated the unfolded protein response (UPR), demonstrating that translational suppression is a critical cytoprotective mechanism during ER stress. Tumor cells attempt to survive bortezomib-induced ER stress by sequestering aggregated proteins into large structures, termed aggresomes. Since histone deacetylase 6 (HDAC6) is essential for aggresome formation, tumor cells may be sensitized to bortezomib-induced apoptosis by blocking HDAC function. My results demonstrated that HDAC inhibitors disrupted aggresome formation and synergized with bortezomib to induce apoptosis in pancreatic cancer or multiple myeloma cells in vitro and in orthotopic pancreatic tumors in vivo. Taken together, my data establish a mechanistic link between bortezomib-induced aggresome formation, ER stress, and apoptosis and identify a novel therapeutic strategy for the treatment of pancreatic cancer and other hematologic and solid malignancies. ^

Synchrotron strain scanning for residual stress measurement in cold-drawn steel rods

Cold-drawn steel rods and wires retain significant residual stresses as a consequence of the manufacturing process. These residual stresses are known to be detrimental for the mechanical properties of the wires and their durability in aggressive environments. Steel makers are aware of the problem and have developed post-drawing processes to try and reduce the residual stresses on the wires. The present authors have studied this problem for a number of years and have performed a detailed characterization of the residual stress state inside cold-drawn rods, including both experimental and numerical techniques. High-energy synchrotron sources have been particularly useful for this research. The results have shown how residual stresses evolve as a consequence of cold-drawing and how they change with subsequent post-drawing treatments. The authors have been able to measure for the first time a complete residual strain profile along the diameter in both phases (ferrite and cementite) of a cold-drawn steel rod.

Techniques to accelerate convergence of stress-controlled molecular dynamics simulations of dislocation motion

Dislocation mobility —the relation between applied stress and dislocation velocity—is an important property to model the mechanical behavior of structural materials. These mobilities reflect the interaction between the dislocation core and the host lattice and, thus, atomistic resolution is required to capture its details. Because the mobility function is multiparametric, its computation is often highly demanding in terms of computational requirements. Optimizing how tractions are applied can be greatly advantageous in accelerating convergence and reducing the overall computational cost of the simulations. In this paper we perform molecular dynamics simulations of ½ 〈1 1 1〉 screw dislocation motion in tungsten using step and linear time functions for applying external stress. We find that linear functions over time scales of the order of 10–20 ps reduce fluctuations and speed up convergence to the steady-state velocity value by up to a factor of two.

QUALIDADE DE VIDA E STRESS DE CRIANÇAS E ADOLESCENTES COM CÂNCER EM ESTÁGIO DE REMISSÃO E RECIDIVA

O câncer em crianças até cerca de duas décadas, era considerado uma doença crônica, com prognóstico desfavorável, resultando na maioria dos casos, em morte. Atualmente, tem-se apresentado como uma doença com melhores perspectivas, onde 70% das crianças acometidas por essa doença podem ser curadas, quando diagnosticadas precocemente, e tratadas em centros especializados¹. Este estudo teve como objetivo, avaliar a qualidade de vida e o stress de crianças e adolescentes com câncer, em remissão e recidiva. Trata-se de um estudo correlacional, quali-quantitativo, transversal. Foi desenvolvido no ambulatório de oncologia pediátrica da Faculdade de Medicina do ABC, e na enfermaria do Hospital Mário Covas. Contou com a colaboração de 40 sujeitos, com idades entre 06 a 14 anos, de ambos os sexos. Como instrumento para medir a qualidade de vida, foi utilizado o Child Health Questionnaire (CHQ-PF50), que possui 15 conceitos em saúde, abrangendo aspectos físicos e psicossociais e para medir o stress, a Escala de Stress Infantil (ESI), que tem como objetivo, avaliar o stress da criança, através de reações físicas e psicológicas. Os resultados indicaram que no domínio físico (PhS), as crianças em situação clínica de recidiva e remissão não apresentam diferenças significativas em relação às variáveis: qualidade de vida e stress, porém, no domínio psicossocial (PsS), houve diferença estatisticamente significante, indicando que os meninos apresentam melhor qualidade de vida e menor stress, se comparados com as meninas, mostrando que o emocional interfere nesse resultado.(AU)

QUALIDADE DE VIDA E STRESS DE CRIANÇAS E ADOLESCENTES COM CÂNCER EM ESTÁGIO DE REMISSÃO E RECIDIVA

O câncer em crianças até cerca de duas décadas, era considerado uma doença crônica, com prognóstico desfavorável, resultando na maioria dos casos, em morte. Atualmente, tem-se apresentado como uma doença com melhores perspectivas, onde 70% das crianças acometidas por essa doença podem ser curadas, quando diagnosticadas precocemente, e tratadas em centros especializados¹. Este estudo teve como objetivo, avaliar a qualidade de vida e o stress de crianças e adolescentes com câncer, em remissão e recidiva. Trata-se de um estudo correlacional, quali-quantitativo, transversal. Foi desenvolvido no ambulatório de oncologia pediátrica da Faculdade de Medicina do ABC, e na enfermaria do Hospital Mário Covas. Contou com a colaboração de 40 sujeitos, com idades entre 06 a 14 anos, de ambos os sexos. Como instrumento para medir a qualidade de vida, foi utilizado o Child Health Questionnaire (CHQ-PF50), que possui 15 conceitos em saúde, abrangendo aspectos físicos e psicossociais e para medir o stress, a Escala de Stress Infantil (ESI), que tem como objetivo, avaliar o stress da criança, através de reações físicas e psicológicas. Os resultados indicaram que no domínio físico (PhS), as crianças em situação clínica de recidiva e remissão não apresentam diferenças significativas em relação às variáveis: qualidade de vida e stress, porém, no domínio psicossocial (PsS), houve diferença estatisticamente significante, indicando que os meninos apresentam melhor qualidade de vida e menor stress, se comparados com as meninas, mostrando que o emocional interfere nesse resultado.(AU)

Estratégias de enfrentamento e avaliação de stress em adolescentes atletas

O presente estudo teve por objetivos: a) descrever estratégias de enfrentamento (coping) utilizados por adolescentes atletas participantes de competições; b) descrever e relacionar os tipos de enfrentamento desses adolescentes segundo a prática esportiva individual e coletiva c) identificar o nível de stress desses atletas; d) relacionar as estratégias de enfrentamento com grau de stress. Selecionou-se por critério aleatório e conveniência, uma amostra de 141 atletas-adolescentes, estudantes, com idades entre 15 e 18 anos, sendo 66 meninas e 75 meninos. Estes eram estudantes do ensino médio de escolas privadas da região da Grande São Paulo, atletas que treinavam e participavam de competições esportivas de âmbito escolar e alto rendimento em categorias de base. Utilizou-se uma escala auto-aplicável de enfrentamento (coping) para adolescentes, composta por 80 itens, e um inventário de stress composto por 44 itens. Os resultados indicaram qure na amostra geral houve maior emprego da estratégia de aproximação; porém, numa separação em sub-grupos foram verificadas diferenças quanto ao gênero, pois as houve predomínio da estratégia de evitação entre as meninas. Quanto ao tipo de esporte coletivo e individual não se encontraram diferenças significativas, mestre entre meninos e meninas. O grau de stress esteve em média normal na amostra geral, porém quando se separa meninos e meninas, observou-se maior presença de sintomas entre os meninos e entre atletas praticantes da modalidade individual - xadrez. Também não foram encontradas diferenças significativas na correlação entre enfrentamento e stress. Entendeu-se que esse tipo de investigação pode auxiliar na compreensão desses jovens praticantes de esporte, bem como se levanta a hipótese de que a prática esportiva escolar, ainda que em nível de competição, pode ter uma influência positiva, tanto no enfrentamento quanto na administração do stress entre esses jovens.

Estratégias de enfrentamento e avaliação de stress em adolescentes atletas

O presente estudo teve por objetivos: a) descrever estratégias de enfrentamento (coping) utilizados por adolescentes atletas participantes de competições; b) descrever e relacionar os tipos de enfrentamento desses adolescentes segundo a prática esportiva individual e coletiva c) identificar o nível de stress desses atletas; d) relacionar as estratégias de enfrentamento com grau de stress. Selecionou-se por critério aleatório e conveniência, uma amostra de 141 atletas-adolescentes, estudantes, com idades entre 15 e 18 anos, sendo 66 meninas e 75 meninos. Estes eram estudantes do ensino médio de escolas privadas da região da Grande São Paulo, atletas que treinavam e participavam de competições esportivas de âmbito escolar e alto rendimento em categorias de base. Utilizou-se uma escala auto-aplicável de enfrentamento (coping) para adolescentes, composta por 80 itens, e um inventário de stress composto por 44 itens. Os resultados indicaram qure na amostra geral houve maior emprego da estratégia de aproximação; porém, numa separação em sub-grupos foram verificadas diferenças quanto ao gênero, pois as houve predomínio da estratégia de evitação entre as meninas. Quanto ao tipo de esporte coletivo e individual não se encontraram diferenças significativas, mestre entre meninos e meninas. O grau de stress esteve em média normal na amostra geral, porém quando se separa meninos e meninas, observou-se maior presença de sintomas entre os meninos e entre atletas praticantes da modalidade individual - xadrez. Também não foram encontradas diferenças significativas na correlação entre enfrentamento e stress. Entendeu-se que esse tipo de investigação pode auxiliar na compreensão desses jovens praticantes de esporte, bem como se levanta a hipótese de que a prática esportiva escolar, ainda que em nível de competição, pode ter uma influência positiva, tanto no enfrentamento quanto na administração do stress entre esses jovens.

A INFLUÊNCIA DO STRESS NA EXPRESSÃO CLÍNICA DA ASMA INFANTIL

A asma é a doença crônica mais freqüente na infância e o stress é considerado um dos agentes desencadeantes e agravantes do broncoespasmo nesses pacientes. O objetivo deste trabalho foi investigar a influência do stress na expressão clínica da asma e sua associação com as crises em crianças. Para verificar a presença de stress, utilizou-se a Escala de Stress Infantil (LIPP E LUCARELLI, 1998) e por meio de um questionário aplicado aos pais, observou-se freqüência de sintomas e crises de asma, as alterações do sono, o absenteísmo escolar, as limitações à prática de atividade física, a freqüência de uso de broncodilatador, as condutas dos pais durante as crises de asma, os fatores associados ao desencadeamento das crises, o poder aquisitivo e o grau de instrução do chefe da família. Observou-se que as crianças com asma estavam mais estressadas que as crianças do grupo controle, principalmente aquelas com maior gravidade da doença. Os resultados indicam que a presença de stress pode intensificar a freqüência de sintomas da asma, a limitação à atividade física, o absenteísmo escolar e as interrupções do sono. O maior tempo de diagnóstico de asma implicou em menor ocorrência de stress, sugerindo a existência de um fator de adaptação à doença. Conclui-se que o stress é um fator importante no desencadeamento e agravamento das crises de asma nas crianças e observa-se a necessidade de maiores pesquisas na aérea para aprofundar os conhecimentos sobre esse assunto.

A INFLUÊNCIA DO STRESS NA EXPRESSÃO CLÍNICA DA ASMA INFANTIL

A asma é a doença crônica mais freqüente na infância e o stress é considerado um dos agentes desencadeantes e agravantes do broncoespasmo nesses pacientes. O objetivo deste trabalho foi investigar a influência do stress na expressão clínica da asma e sua associação com as crises em crianças. Para verificar a presença de stress, utilizou-se a Escala de Stress Infantil (LIPP E LUCARELLI, 1998) e por meio de um questionário aplicado aos pais, observou-se freqüência de sintomas e crises de asma, as alterações do sono, o absenteísmo escolar, as limitações à prática de atividade física, a freqüência de uso de broncodilatador, as condutas dos pais durante as crises de asma, os fatores associados ao desencadeamento das crises, o poder aquisitivo e o grau de instrução do chefe da família. Observou-se que as crianças com asma estavam mais estressadas que as crianças do grupo controle, principalmente aquelas com maior gravidade da doença. Os resultados indicam que a presença de stress pode intensificar a freqüência de sintomas da asma, a limitação à atividade física, o absenteísmo escolar e as interrupções do sono. O maior tempo de diagnóstico de asma implicou em menor ocorrência de stress, sugerindo a existência de um fator de adaptação à doença. Conclui-se que o stress é um fator importante no desencadeamento e agravamento das crises de asma nas crianças e observa-se a necessidade de maiores pesquisas na aérea para aprofundar os conhecimentos sobre esse assunto.

Ras Regulates the Polarity of the Yeast Actin Cytoskeleton through the Stress Response Pathway

Polarized growth in yeast requires cooperation between the polarized actin cytoskeleton and delivery of post-Golgi secretory vesicles. We have previously reported that loss of the major tropomyosin isoform, Tpm1p, results in cells sensitive to perturbations in cell polarity. To identify components that bridge these processes, we sought mutations with both a conditional defect in secretion and a partial defect in polarity. Thus, we set up a genetic screen for mutations that conferred a conditional growth defect, showed synthetic lethality with tpm1Δ, and simultaneously became denser at the restrictive temperature, a hallmark of secretion-defective cells. Of the 10 complementation groups recovered, the group with the largest number of independent isolates was functionally null alleles of RAS2. Consistent with this, ras2Δ and tpm1Δ are synthetically lethal at 35°C. We show that ras2Δ confers temperature-sensitive growth and temperature-dependent depolarization of the actin cytoskeleton. Furthermore, we show that at elevated temperatures ras2Δ cells are partially defective in endocytosis and show a delocalization of two key polarity markers, Myo2p and Cdc42p. However, the conditional enhanced density phenotype of ras2Δ cells is not a defect in secretion. All the phenotypes of ras2Δ cells can be fully suppressed by expression of yeast RAS1 or RAS2 genes, human Ha-ras, or the double disruption of the stress response genes msn2Δmsn4Δ. Although the best characterized pathway of Ras function in yeast involves activation of the cAMP-dependent protein kinase A pathway, activation of the protein kinase A pathway does not fully suppress the actin polarity defects, suggesting that there is an additional pathway from Ras2p to Msn2/4p. Thus, Ras2p regulates cytoskeletal polarity in yeast under conditions of mild temperature stress through the stress response pathway.

Molecular control of vertebrate iron metabolism: mRNA-based regulatory circuits operated by iron, nitric oxide, and oxidative stress.

As an essential nutrient and a potential toxin, iron poses an exquisite regulatory problem in biology and medicine. At the cellular level, the basic molecular framework for the regulation of iron uptake, storage, and utilization has been defined. Two cytoplasmic RNA-binding proteins, iron-regulatory protein-1 (IRP-1) and IRP-2, respond to changes in cellular iron availability and coordinate the expression of mRNAs that harbor IRP-binding sites, iron-responsive elements (IREs). Nitric oxide (NO) and oxidative stress in the form of H2O2 also signal to IRPs and thereby influence cellular iron metabolism. The recent discovery of two IRE-regulated mRNAs encoding enzymes of the mitochondrial citric acid cycle may represent the beginnings of elucidating regulatory coupling between iron and energy metabolism. In addition to providing insights into the regulation of iron metabolism and its connections with other cellular pathways, the IRE/IRP system has emerged as a prime example for the understanding of translational regulation and mRNA stability control. Finally, IRP-1 has highlighted an unexpected role for iron sulfur clusters as post-translational regulatory switches.