More than a Rumor Spreads in Parkinson's Disease

As Parkinson's disease progresses, a massive loss of dopaminergic neurons is accompanied by accumulation of alpha-Synuclein (αSyn) neuronal inclusions called Lewy bodies and Lewy neurites. Inclusions first appear in olfactory bulb and enteric neurons then in ascendant neuroanatomical interconnected areas, and finally, in late stages of the disease, Lewy bodies are observed in a substantia nigra pars compacta with clear signs of neuronal loss. It is believed that the spreading of Lewy bodies through the nervous system is a consequence of the cell-to-cell propagation of αSyn, that can occur via sequential steps of secretion and uptake. Certain pathological forms of transmitted αSyn are able to seed endogenous counterparts in healthy recipient cells, thus promoting the self-sustained cycle of inclusion formation, amplification and spreading, that ultimately underlies disease progression. Here we review the cell-to-cell propagation of αSyn focusing on its role in the progression of Parkinson’s disease

Survival, growth, and physiological responses of advanced juvenile freshwater crayfish (Cherax quadricarinatus), reared at low temperature and high salinities

The effects of stress caused by low temperature, high salinities, and a combination of both low temperatures and high salinities were evaluated in advanced (~. 5. g) juvenile freshwater crayfish (Cherax quadricarinatus). Ten animals were weighed and assigned to each of the following combination of two temperature and three salinity treatments: 27 °C (optimum for this species) or 20 °C and 0, 5, and 10. g/L salt concentrations. After 30. days in each treatment, oxygen consumption and weight were recorded, together with hemolymph levels of glucose, sodium, potassium, and free amino acids (FAA). Glycogen level was determined in hepatopancreas and abdominal muscle, while FAA levels were measured in abdominal muscle and hemolymph. A significant decrease of weight gain was seen at the combination of 20 °C and 10. g/L salinity. A marked hyperglycemia was seen at the lower temperature, at any salinity tested. At the same temperature, there was a concomitant decrease of glycogen, in both hepatopancreas and muscle. Both sodium and potassium hemolymphatic levels significantly increased with increasing salinity, but only at 20 °C. No changes were seen in hemolymphatic FAA levels, but they increased in abdominal muscle at higher salinities, in correspondence with the sodium hemolymphatic increase, in order to regulate cellular osmolarity. Although advanced juveniles of C. quadricarinatus did not exhibit reduced survival or growth at 20 °C or 10. g/L salinity, the combination of relatively low temperature and high salinity significantly reduces growth, suggesting that the combination of these two factors is a stressful condition for these crayfish juveniles.Fil: Prymaczok, Natalia Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Chaulet, Anouk. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Medesani, Daniel Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Rodriguez, Enrique Marcelo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentin

More than a rumor spreads in Parkinson’s disease

As Parkinson’s disease progresses, a massive loss of dopaminergic neurons is accompanied by accumulation of alpha-Synuclein (αSyn) neuronal inclusions called Lewy bodies and Lewy neurites. Inclusions first appear in olfactory bulb and enteric neurons then in ascendant neuroanatomical interconnected areas, and finally, in late stages of the disease, Lewy bodies are observed in a substantia nigra pars compacta with clear signs of neuronal loss. It is believed that the spreading of Lewy bodies through the nervous system is a consequence of the cell-to-cell propagation of αSyn, that can occur via sequential steps of secretion and uptake. Certain pathological forms of transmitted αSyn are able to seed endogenous counterparts in healthy recipient cells, thus promoting the self-sustained cycle of inclusion formation, amplification and spreading, that ultimately underlies disease progression. Here we review the cell-to-cell propagation of αSyn focusing on its role in the progression of Parkinson’s disease.Instituto Multidisciplinario de Biología Celula

Proteomics-based monitoring of pathway activity reveals that blocking diacylglycerol biosynthesis rescues from alpha-synuclein toxicity

Proteinaceous inclusions containing alpha-synuclein (α-Syn) have been implicated in neuronal toxicity in Parkinson’s disease, but the pathways that modulate toxicity remain enigmatic. Here, we used a targeted proteomic assay to simultaneously measure 269 pathway activation markers and proteins deregulated by α-Syn expression across a panel of 33 Saccharomyces cerevisiae strains that genetically modulate α-Syn toxicity. Applying multidimensional linear regression analysis to these data predicted Pah1, a phosphatase that catalyzes conversion of phosphatidic acid to diacylglycerol at the endoplasmic reticulum membrane, as an effector of rescue. Follow-up studies demonstrated that inhibition of Pah1 activity ameliorates the toxic effects of α-Syn, indicate that the diacylglycerol branch of lipid metabolism could enhance α-Syn neuronal cytotoxicity, and suggest a link between α-Syn toxicity and the biology of lipid droplets

Niveles de sodio en hemolinfa

<p><br></p

Levels of glucose and glycogen of C. quadricarinatus

<p>A) Hemolymphatic glucose levels; B) Glycogen levels in hepatopancreas and abdominal muscle, respectively, of crayfish injected with recombinant CHH under stressful conditions. Mean values ± standard error are indicated.<br></p

Cloning of the CHH

<p> RT-PCR to amplify CHH  cDNA from eyestalk (E). Muscle (M) and hepatopancreas (H) tissue were used as negative controls. MW: molecular weight marker (1KbPlus, Invitrogen), N: PCR negative control </p

Thermal and saline acclimation of freshwater juvenile crayfish Cherax quadricarinatus. Physiological role of the hyperglycemic hormone

En esta tesis estudiamos la respuesta fisiológica de individuos de C. quadricarinatus, una langosta de agua dulce originaria de los ríos del norte de Australia, expuestos a condiciones de estrés térmico, salino, o a la combinación de ambos factores. Demostramos que la combinación de ambos tratamientos produjo una inhibición en la ganancia de peso de los juveniles avanzados expuestos. El efecto de la temperatura sobre la fisiología del animal fue notable; la disminución de la temperatura impidió, en los juveniles expuestos, la eficiente regulación de los niveles de Na+ y K+ y generó incrementos superiores al 100 % en los niveles de glucosa, en hemolinfa. A su vez, la tasa metabólica varió levemente ante las diferentes condiciones ensayadas. Con el objetivo de estudiar la participación de la Hormona Hiperglucemiante de Crustáceos (CHH) en este tipo de estrés, medimos sus niveles de expresión por RT-PCR. Con ello demostramos que CHH se induce, bajo condiciones de estrés, en el tejido nervioso del pedúnculo ocular, sitio en el cual CHH es sintetizada, almacenada y secretada. Luego de producir CHH recombinante (rCqCHH) en bacterias, demostramos que la administración prolongada de esta hormona condujo a una disminución en los niveles de glucógeno en el hepatopáncreas y a un aumento de glucosa en la hemolinfa. Contrariamente, los niveles de glucógeno se mantuvieron estables en el músculo abdominal, luego de la administración de rCqCHH. Demostramos también que el aumento de los iones Na+ y K+ inducido por condiciones de alta salinidad, disminuyó por la administración de rCqCHH. Finalmente, las condiciones de estrés utilizadas en este trabajo condujeron a una desregulación en la expresión de PEPCK, enzima fundamental de la gluconeogénesis. En su conjunto, estos resultados sugieren una participación directa de la hormona CHH en el metabolismo energético asociado al mantenimiento de la homeostasis bajo condiciones de estrés térmico y salino. En línea con esta hipótesis, demostramos que bajo las condiciones de estrés mencionadas, los animales inyectados con rCqCHH poseen un significativo incremento en la ganancia de peso (200-300 %). El descubrimiento de la función de CHH como modulador del metabolismo energético en condiciones de estrés térmico y salino puede contribuir al desarrollo de nuevas tecnologías que puedan ser utilizadas para estimular el crecimiento de C. quadricarinatus en condiciones subóptimas, favoreciendo así la producción de la especie con fines comerciales.In this thesis we studied the physiological response of individuals of C. quadricarinatus, an Australian freshwater crayfish, to salinity, cold shock, or the combinatory of both kind of stress. We demonstrated that both treatments lead to an inhibition of weight gain, respect the controls. The effect of temperature on the physiology of the animal was remarkable; the decrease in temperature prevented, at the exposure animals, the efficient regulation of Na+ and K+ levels and increased more than 100% the glucose levels, in the hemolymph. In turn, the metabolic rate varied slightly in different conditions tested. With the aim of studying the involvement of the Crustacean Hyperglycemic Hormone (CHH) hormone in this kind of stress, its expression levels were quantified by RT-PCR. We found that CHH is induced by stress conditions in eyestalk, the organ in which CHH is synthesized and secreted. We produced recombinant CHH (rCqCHH) in bacteria and administrated in to C. quadricarinatus individuals; the long-term administration of CHH decreased the glycogen levels in hepatopancreas, but increased the glucose levels in hemolymph. Oppositely, the glycogen levels remained unchanged in abdominal muscle upon CHH administration. Also, we demonstrated that the high-salinity induced increase of Na+ y K+ ions is inhibited after recombinant CHH administration. Finally, the stress conditions used in this work lead to a deregulation of PEPCK, the main enzyme of glyconeogenesis. Overall, these results suggest a direct involvement of CHH in the energetic metabolic rate associated to the homeostasis maintenance upon salinity and cold shock stress. In accordance with this hypothesis, we demonstrated that the animals injected with CHH showed a significant increase of weight gain (200-300 %). The discovery of CHH as a modulator of the energetic metabolic rate in salinity and cold shock stress will contribute to the development of novel technologies used to stimulate the growth of C. quadricarinatus in suboptimal conditions, and to the improvement of the knowledge related to its culture for commercial aims.Fil: Prymaczok, Natalia Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina