Adaptive preconditioning in neurological diseases -­ therapeutic insights from proteostatic perturbations

International audienceIn neurological disorders, both acute and chronic neural stress can disrupt cellular proteostasis, resulting in the generation of pathological protein. However in most cases, neurons adapt to these proteostatic perturbations by activating a range of cellular protective and repair responses, thus maintaining cell function. These interconnected adaptive mechanisms comprise a 'proteostasis network' and include the unfolded protein response, the ubiquitin proteasome system and autophagy. Interestingly, several recent studies have shown that these adaptive responses can be stimulated by preconditioning treatments, which confer resistance to a subsequent toxic challenge - the phenomenon known as hormesis. In this review we discuss the impact of adaptive stress responses stimulated in diverse human neuropathologies including Parkinson´s disease, Wolfram syndrome, brain ischemia, and brain cancer. Further, we examine how these responses - and the molecular pathways they recruit - might be exploited for therapeutic gai

Efeito de práticas culturais na conversão e no balanço energéticos Effect of cultural practices on energy conversion and balance

Desenvolveu-se de 1997 a 2003, em Passo Fundo (RS), um experimento constituído de quatro sistemas de manejo de solo (plantio direto, cultivo mínimo, preparo convencional de solo com arado de discos e preparo convencional de solo com arado de aivecas) e de três sistemas de rotação de culturas: sistema I (trigo/soja); sistema II (trigo/soja e ervilhaca/milho ou sorgo) e sistema III (trigo/soja, ervilhaca/milho ou sorgo e aveia branca/soja). O delineamento experimental foi o de blocos ao acaso, com parcelas subdivididas e três repetições. A parcela principal foi constituída pelos sistemas de manejo de solo, e as subparcelas, pelos sistemas de rotação de culturas. Neste trabalho, apresentam-se a conversão energética (energia disponível/energia consumida) e o balanço energético (energia disponível - energia consumida) no período de 7 anos. No sistema plantio direto houve conversão e balanço energéticos (72,44 e 190.766 MJ ha-1) superiores ao cultivo mínimo (64,06 e 167.349 MJ ha-1), aos preparos convencionais de solo com arado de discos (54,35 e 134.982 MJ ha-1) e com arado de aivecas (52,02 e 128.159 MJ ha-1) respectivamente. O trigo em rotação de culturas foi mais eficiente energeticamente do que a monocultura desse cereal. Na cultura de milho foi observada maior eficiência energética.<br>The effects of soil management systems and crop rotations were assessed from 1997 to 2003, in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil management systems (no-tillage, minimum tillage, conventional tillage using disk plow, and conventional tillage using moldboard plow) and three crop rotation systems [system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean)] were compared. An experimental design of blocks at random with split-plots and three replications was used. The main plot consisted of soil management systems, while the split-plots consisted of crop rotation systems. Energy conversion (energy available/energy consumed) and balance (energy available - energy consumed) during a seven-year period is presented in this paper. No-tillage showed higher energy conversion and balance (72.44 and 190,766 MJ ha-1) than minimum tillage (64.06 and 167,349 MJ ha-1), conventional tillage using disk plow (54.35 and 134,982 MJ ha-1), and conventional tillage using moldboard (52.02 and 128,159 MJ ha-1), respectively. Wheat within crop rotations presented higher energy efficiency in energy than the monoculture of this cereal. The corn crop was observed the highest energy efficiency of this study