Activity-Regulated microRNAs: Modulators of Synaptic Growth at the Drosophila Neuromuscular Junction

It is well established that long-term changes in synaptic structure and function are mediated by rapid activity-dependent gene transcription and new protein synthesis. A growing body of evidence supports the involvement of the microRNA (miRNA) pathway in these processes. We have used the Drosophila neuromuscular junction (NMJ) as a model synapse to characterize activity-regulated miRNAs and their important mRNA targets. Here, we have identified five neuronal miRNAs (miRs-1, -8, -289, -314, and -958) that are significantly downregulated in response to neuronal activity. Furthermore we have discovered that neuronal misexpression of three of these miRNAs (miR-8, -289, and -958) is capable of suppressing new synaptic growth in response to activity suggesting that these miRNAs control the translation of biologically relevant target mRNAs. Putative targets of the activity-regulated miRNAs-8 and -289 are significantly enriched in clusters mapping to functional processes including axon development, pathfinding, and axon growth. We demonstrate that activity-regulated miR-8 regulates the 3'UTR of wingless, a presynaptic regulatory protein involved in the process of activity-dependent axon terminal growth. Additionally, we show that the 3'UTR of the protein tyrosine phosophatase leukocyte antengen related (lar), a protein required for axon guidance and synaptic growth, is regulated by activity-regulated miRNAs-8, -289, and -958 in vitro. Both wg and lar were identified as relevant putative targets for co-regulation based through our functional cluster analysis. One putative target of miR-289 is the Ca2+/calmodulin-dependent protein kinase II (CamKII). While CamKII is not predicted as a target for co-regulation by multiple activity-regulated miRNAs we identified it as an especially pertinent target for analysis in our system for two reasons. First, CamKII has an extremely well characterized role in postsynaptic plasticity, but its presynaptic role is less well characterized and bears further analysis. Second, local translation of CamKII mRNA is regulated in part by the miRNA pathway in an activity-dependent manner in dendrites. We find that the CamKII 3'UTR is regulated by miR-289 in-vitro and this regulation is alleviated by mutating the `seed region' of the miR-289 binding site within the CamKII 3'UTR. Furthermore, we demonstrate a requirement for local translation of CamKII in motoneurons in the process of activity-regulated axon terminal growth.

O efeito imediato da estimulação elétrica neuromuscular na função de deglutição em indivíduos com câncer de cabeça e pescoço após terapia antineoplásica

A estimulação elétrica neuromuscular (EENM) é uma recente técnica terapêutica no tratamento das disfagias orofaríngeas. Poucos estudos utilizaram a EENM em casos oncológicos, havendo muitas dúvidas sobre o método de aplicação e os resultados de diferentes condições de estimulação nessa população. Este trabalho teve por objetivo verificar o efeito imediato da EENM sensorial e motora, nas fases oral e faríngea da deglutição, em pacientes após tratamento do câncer de cabeça e pescoço. Para isso foi realizado um estudo transversal intervencional que incluiu 11 pacientes adultos e idosos (mediana de 59 anos) acometidos por câncer de cabeça e pescoço. Todos os indivíduos foram submetidos ao exame de videofluoroscopia da deglutição, no qual, de modo randomizado, foram solicitadas deglutições de 5 ml de alimentos nas consistências líquida, mel e pudim em três condições distintas: sem estimulação, com EENM sensorial, com EENM motora. Foi classificado o grau da disfunção da deglutição por meio da escala DOSS (Dysphagia Outcome and Severity Scale), a presença de estase de alimentos (escala de Eisenhuber), de penetração laríngea, aspiração laringotraqueal (Penetration and Aspiration Scale - PAS), além da medida do tempo de trânsito oral e faríngeo (em segundos). Para a comparação dos resultados, considerando os três estímulos aplicados, na escala de resíduos, na escala de penetração aspiração, na escala DOSS e no tempo de trânsito oral e faríngeo foi aplicado o teste de Friedman ou a análise de variância para medidas repetidas (de acordo com a distribuição dos dados). Para todos os testes foi adotado nível de significância de 5%. Os resultados demonstraram que houve melhora com a estimulação sensorial e motora na escala DOSS e na escala PAS para um paciente tratado de câncer de boca e outro de laringe e piora, em ambas as escalas, para dois pacientes (câncer de boca), sendo um para a estimulação motora e outro na sensorial. A aplicação da escala de Eisenhuber permitiu verificar que a EENM, tanto em nível sensorial como motor, modificou de forma variável a presença de resíduos para os casos de câncer de boca, enquanto para o paciente com câncer de laringe houve redução de resíduos em valécula/raiz da língua para a estimulação sensorial e motora, além de aumento de resíduos em parede posterior da faringe com o estímulo motor. Além disso, não foi encontrada diferença estatisticamente significante para o tempo de trânsito oral e faríngeo nas diferentes estimulações para todas as consistências testadas (p>0,05). Diante desses achados, concluiu-se que a EENM, em nível sensorial e motor, apresentou variável impacto imediato nas fases oral e faríngea da deglutição, podendo melhorar a função de deglutição de pacientes com significante disfagia após o tratamento para o câncer de cabeça e pescoço, no que se diz respeito ao grau da disfagia e à presença de penetração e aspiração.

Fatigue and efficiency: a study in industry

by Josephine Goldmark ; introduction by Frederic S. Lee ...

One year after the Youth Guarantee: Policy fatigue or signs of action? EPC Policy Brief, 27 May 2015

In April 2013, the EU Council called on EU member states to establish Youth Guarantee (YG) schemes, ensuring that “all young people under the age of 25 years receive a good-quality offer of employment, continued education, apprenticeship or traineeship within a period of four months of becoming unemployed or leaving formal education”. Implementation was meant to start more than a year ago, but political interest seems to have waned a bit. Is a ‘policy fatigue’ contaminating youth employment policies across the EU? Have some timid signs of economic recovery led to youth unemployment being less urgent or are we witnessing the usual policy developments whereby grand EU statements are worn down by political realities and resistance on the ground? In this Policy Brief, Claire Dhéret and Martina Morosi assess the implementation of the Youth Guarantee and provide suggestions on how to renew a sense of enthusiasm for such an ambitious tool across Europe.

Effect of material damping and stress distribution on the resonant fatigue strength of parts /

"Materials Laboratory Contract no. AF 33(038)-20840; Project no. 7360; Task no. 73604."

Blink rate as a measure of fatigue: a review.

Federal Aviation Administration, Washington, D.C.

Mental fatigue during continuous exercise of a single function /

Also published as thesis (Ph.D.) Columbia university, 1918.

Effects of hours of service regularity of schedules, and cargo loading on truck and bus driver fatigue. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

The effects of fatigue and alcohol on highway safety. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Energy versus stress theories for combined stress; a fatigue experiment using a rotating disc,

"Department of Army Project no. 5B99-01-004, Ordnance R and D Project no. TB2-0001. Office of Ordnance Research Project no. 1348 Contract no. DA-19-020-ORD-3520."

A theory for the effect of mean stress on fatigue of metals under combined torsion and axial load or bending.

"Department of Army Project no. 5B99-01-004, Ordnance R and D Project no. TB2-0001, Office of Ordnance Research Project no. 1348, Contract no. DA-19-020-ORD-3250."

Modern installation for testing of large assemblies under static and fatigue loading. Description of installation at Fritz Engineering laboratory, Lehigh University, Bethlehem, Pennsylvania,

"Not for publication."

Fatigue tests of plate joints and bolted lugs. ARO project. Final report, September 30, 1954.

Mode of access: Internet.

Modified theories of fatigue failure under combined stress,

Bibliography: leaves 21-23.