Fine tuning of the unfolded protein response by ISRIB improves neuronal survival in a model of amyotrophic lateral sclerosis.

Loss of protein folding homeostasis features many of the most prevalent neurodegenerative disorders. As coping mechanism to folding stress within the endoplasmic reticulum (ER), the unfolded protein response (UPR) comprises a set of signaling mechanisms that initiate a gene expression program to restore proteostasis, or when stress is chronic or overwhelming promote neuronal death. This fate-defining capacity of the UPR has been proposed to play a key role in amyotrophic lateral sclerosis (ALS). However, the several genetic or pharmacological attempts to explore the therapeutic potential of UPR modulation have produced conflicting observations. In order to establish the precise relationship between UPR signaling and neuronal death in ALS, we have developed a neuronal model where the toxicity of a familial ALS-causing allele (mutant G93A SOD1) and UPR activation can be longitudinally monitored in single neurons over the process of neurodegeneration by automated microscopy. Using fluorescent UPR reporters we established the temporal and causal relationship between UPR and neuronal death by Cox regression models. Pharmacological inhibition of discrete UPR processes allowed us to establish the contribution of PERK (PKR-like ER kinase) and IRE1 (inositol-requiring enzyme-1) mechanisms to neuronal fate. Importantly, inhibition of PERK signaling with its downstream inhibitor ISRIB, but not with the direct PERK kinase inhibitor GSK2606414, significantly enhanced the survival of G93A SOD1-expressing neurons. Characterization of the inhibitory properties of both drugs under ER stress revealed that in neurons (but not in glial cells) ISRIB overruled only part of the translational program imposed by PERK, relieving the general inhibition of translation, but maintaining the privileged translation of ATF4 (activating transcription factor 4) messenger RNA. Surprisingly, the fine-tuning of the PERK output in G93A SOD1-expressing neurons led to a reduction of IRE1-dependent signaling. Together, our findings identify ISRIB-mediated translational reprogramming as a new potential ALS therapy.

N-terminal acetylation mutants affect alpha-synuclein stability, protein levels and neuronal toxicity.

Alpha-synuclein (aSyn) protein levels are sufficient to drive Parkinson's disease (PD) and other synucleinopathies. Despite the biomedical/therapeutic potential of aSyn protein regulation, little is known about mechanisms that limit/control aSyn levels. Here, we investigate the role of a post-translational modification, N-terminal acetylation, in aSyn neurotoxicity. N-terminal acetylation occurs in all aSyn molecules and has been proposed to determine its lipid binding and aggregation capacities; however, its effect in aSyn stability/neurotoxicity has not been evaluated. We generated N-terminal mutants that alter or block physiological aSyn N-terminal acetylation in wild-type or pathological mutant E46K aSyn versions and confirmed N-terminal acetylation status by mass spectrometry. By optical pulse-labeling in living primary neurons we documented a reduced half-life and accumulation of aSyn N-terminal mutants. To analyze the effect of N-terminal acetylation mutants in neuronal toxicity we took advantage of a neuronal model where aSyn toxicity was scored by longitudinal survival analysis. Salient features of aSyn neurotoxicity were previously investigated with this approach. aSyn-dependent neuronal death was recapitulated either by higher aSyn protein levels in the case of WT aSyn, or by the combined effect of protein levels and enhanced neurotoxicity conveyed by the E46K mutation. aSyn N-terminal mutations decreased E46K aSyn-dependent neuronal death both by reducing protein levels and, importantly, by reducing the intrinsic E46K aSyn toxicity, being the D2P mutant the least toxic. Together, our results illustrate that the N-terminus determines, most likely through its acetylation, aSyn protein levels and toxicity, identifying this modification as a potential therapeutic target.

Comparison of audio vs. audio + video for the rating of shared decision making in oncology using the observer OPTION5 instrument: an exploratory analysis.

BACKGROUND: How non-verbal data may influence observer-administered ratings of shared decision making is unknown. Our objective for this exploratory analysis was to determine the effect of mode of data collection (audio+video vs. audio only) on the scoring of the OPTION5 instrument, an observer rated measure of shared decision making. METHODS: We analyzed recordings of 15 encounters between cancer patients and clinicians in which a clinical decision was made. Audio+video or audio only recordings of the encounters were randomly assigned to four trained raters, who reviewed them independently. We compared the adjusted mean scores of audio+video and audio only. RESULTS: Forty-one unique decisions were identified within the 15 encounters. The mean OPTION5 score for audio+video was 17.5 (95% CI 13.5, 21.6) and for audio only was 21.8 (95% CI 17.2, 26.4) with a mean difference of 4.28 (95% CI = 0.36, 8.21; p = 0.032). CONCLUSION: A rigorous and well established measure of shared decision making performs differently when the data source is audio only. Data source may influence rating of observer administered measures of shared decision making. This potential bias needs to be confirmed as video recording to examine communication behaviors becomes more common.

E46K α-synuclein pathological mutation causes cell-autonomous toxicity without altering protein turnover or aggregation.

α-Synuclein (aSyn) is the main driver of neurodegenerative diseases known as "synucleinopathies," but the mechanisms underlying this toxicity remain poorly understood. To investigate aSyn toxic mechanisms, we have developed a primary neuronal model in which a longitudinal survival analysis can be performed by following the overexpression of fluorescently tagged WT or pathologically mutant aSyn constructs. Most aSyn mutations linked to neurodegenerative disease hindered neuronal survival in this model; of these mutations, the E46K mutation proved to be the most toxic. While E46K induced robust PLK2-dependent aSyn phosphorylation at serine 129, inhibiting this phosphorylation did not alleviate aSyn toxicity, strongly suggesting that this pathological hallmark of synucleinopathies is an epiphenomenon. Optical pulse-chase experiments with Dendra2-tagged aSyn versions indicated that the E46K mutation does not alter aSyn protein turnover. Moreover, since the mutation did not promote overt aSyn aggregation, we conclude that E46K toxicity was driven by soluble species. Finally, we developed an assay to assess whether neurons expressing E46K aSyn affect the survival of neighboring control neurons. Although we identified a minor non-cell-autonomous component spatially restricted to proximal neurons, most E46K aSyn toxicity was cell autonomous. Thus, we have been able to recapitulate the toxicity of soluble aSyn species at a stage preceding aggregation, detecting non-cell-autonomous toxicity and evaluating how some of the main aSyn hallmarks are related to neuronal survival.

Análisis de las caídas en una residencia de ancianos y de la influencia del entorno / Analysis of the falls in a residence of elderly and the environmental influence

Introducción: La caída en el anciano es un síndrome geriátrico importante con una etiología multifactorial. Su porcentaje en instituciones es tres veces superior al que se da en la comunidad. Además, un 22% de estas se producen porque existen factores de riesgo extrínsecos, y en su mayoría evitables. Por ello, se debe trabajar en la adaptación de los factores ambientales. Objetivo: Analizar las caídas producidas en una residencia de ancianos durante 5 años describiendo los factores del entorno influyentes y explorar la asociación de las caídas con el riesgo de caídas medido con la escala de Tinetti. Metodología: Se realizó un estudio descriptivo retrospectivo con el que se obtuvo una muestra de 160 casos recogidos en los partes de caídas del centro. Resultados: El 73,1% de las personas que caían eran mujeres, con una media de edad de 85,73 años, sin que existan diferencias según sexo. El 73,1% de estas caídas coexistía con un riesgo alto según la escala de Tinetti. Es destacable que el 48,1% de las caídas se produjeron por la mañana; el lugar más habitual fue la habitación, con un 39,4%, y el tipo de suelo es el no antideslizante en un 79,4% de las ocasiones. Se obtuvieron diferencias significativas entre las categorías de las distintas variables. Conclusión: Se observó un mayor número de caídas cuando existe un riesgo alto según la escala de Tinetti y coexiste algún factor ambiental. Por lo tanto, sería deseable incidir en la disminución de los riesgos ambientales, puesto que son factores modificables

Background: An elderly fall is an important geriatric syndrome with a multifactorial etiology. The average in institutions is three times higher than in the community. Furthermore, 22% of them are caused by extrinsic risk factors, most of them avoidable. Therefore, we must work in environmental factors adjustment. Objective: Analyze the falls in an elderly care home during 5 years, and describe all the environmental factors involved. Furthermore, this study was designed to explore the association between the falls and the risk of falls measured with Tinetti scale. Methods: a retrospective study was carried out, with 160 incidents documented in the care home falls reports. Results: 73.1% of the falls happened to females, with an age average of 85.73 years considering the whole sample. 73.1% of the falls coexisted with a high risk in Tinetti scale. It’s remarkable that 48.1% of the falls happened during the morning, the residents room as the most usual place (39.4%), and the floor wasn’t non-slide in 79.4% of the incidents. Significant differences between categories of different variables were obtained. Conclusions: A larger number of drops are observed when a high risk is notified in Tinetti scale and it coexists with some environmental factors. Therefore, it would be desirable to influence the reduction of environmental risk, as they are modifiable factors