Fyn knock-down prevents levodopa-induced dyskinesia in a mouse model of parkinson’s disease

Dopamine replacement by levodopa (L-DOPA) is the most widely used therapy for Parkinson’s disease (PD), however patients often develop side effects, known as L-DOPA-induced dyskinesia (LID), that usually need therapeutic intervention. There are no suitable therapeutic options for LID, except for the use of the NMDA receptor (NMDA-R) antagonist amantadine, which has limited efficacy. The NMDA-R is indeed the most plausible target to manage LID in PD and recently the kinase Fyn, one of its key regulators, became a new putative molecular target involved in LID. The aim of this work was to reduce Fyn expression to alleviate LID in a mouse model of PD. We performed intrastriatal delivery of a designed micro-RNA against Fyn (miRNA-Fyn) in 6-OHDA-lesioned mice treated with L-DOPA. The miRNA-Fyn was delivered either before or after L-DOPA exposure to assess its ability to prevent or revert dyskinesia. Preadministration of miRNA-Fyn reduced LID with a concomitant reduction of FosB-DFosB protein levels, a marker of LID, as well as decreased phosphorylation of the NR2B-NMDA subunit, which is a main target of Fyn. On the other hand, post-L-DOPA delivery of miRNA-Fyn was less effective to revert already established dyskinesia, suggest-ing that early blocking of Fyn activity might be a more efficient therapeutic approach. Together, our results provide proof of concept about Fyn as a plausible therapeutic target to manage LID, and validate RNA si-lencing as a potential approach to locally reduce striatal Fyn, rising new perspectives for RNA therapy interventions in PD.Fil: Bordone, Melina Paula. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Damianich, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bernardi, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Eidelman, Tomas. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanz Blasco, Sara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Gershanik, Oscar Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Avale, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ferrario, Juan Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Mixed-Methods Evaluation of Real-Time Safety Reporting by Hospitalized Patients and Their Care Partners:The MySafeCare Application

OBJECTIVE: To evaluate the amount and content of data patients and carepartners reported using a real-time electronic safety tool compared to other reporting mechanisms, and understand their perspectives on safety concerns and reporting in the hospital. METHODS: Mixed-methods study including 20 month pre- and post-implementation trial evaluating MySafeCare, a web-based application which allows hospitalized patients/carepartners to report safety concerns in real-time. Comparison of MySafeCare submission rates for three hospital units (oncology acute care; vascular intermediate care; medical intensive care) to submissions rates of Patient Family Relations (PFR) Department, a hospital service to address patient/family concerns. Triangulation of quantitative data with thematic analysis of safety concern submissions and patient/carepartner interviews to understand submission content and perspectives on safety reporting. RESULTS: Thirty-two MySafeCare submissions were received with an average rate of 1.7 submissions per 1,000 patient-days and a range of 0.3 to 4.8 submissions per 1,000 patient-days across all units, indicating notable variation between units. MySafeCare submission rates were significantly higher than PFR submission rates during the post-intervention period on the vascular unit (4.3 [95% CI 2.8 – 6.5] versus 1.5 [95% CI 0.7 – 3.1], Poisson) (P=0.01). Overall trends indicated a decrease in PFR submissions after MySafeCare implementation. Triangulated data indicated patients preferred to report anonymously and did not want concerns submitted directly to their care team. CONCLUSIONS: MySafeCare evaluation confirmed the potential value of providing an electronic, anonymous reporting tool in the hospital to capture safety concerns in real-time. Such applications should be tested further as part of patient safety programs

Behavioral sensitization to different dopamine agonists in a parkinsonian rodent model of drug-induced dyskinesias

Repeated treatment with dopamine (DA) receptor agonists strongly potentiates contralateral turning behavior due to selective stimulation of D1 or D2-class receptors in 6-hydroxydopamine (6-OHDA)-lesioned rats. This phenomenon, referred to as sensitization, is believed to be related to the motor response complications (dyskinesias, on-off states) that occur during chronic administration of levodopa in Parkinson’s disease patients. In recent years a new method for the evaluation of abnormal involuntary movements (AIMs) secondary to dopaminergic stimulation in 6-OHDA-lesioned rats was described. These AIMs resemble dyskinesias as seen in parkinsonian patients under levodopa therapy. Our objective was to evaluate the effects of repeated treatment with different regimes of DA agonists on turning behavior and on an AIMs scale in 6-OHDA lesioned rats, with the aim of discriminating between drugs with different dyskinesia-inducing potential. In addition, we explored the effects of a previous exposure to a DA agonist (priming) on the behavioral response to the subsequent administration of a DA agonist with the same or different pharmacologic profile. Our results show that in apomorphine-treated rats, rotational behavior and AIMs run a parallel course of enhancement, while in those receiving quinpirole there is a dissociation, suggesting that they could be mediated by different mechanisms. The finding of a significant priming effect on subsequent testing of 6-OHDA lesioned rats should be borne in mind as the use of these pharmacological tests in the screening of well lesioned animals could lead to an erroneous interpretation of further results on dyskinesias and rotational behavior.Fil: Delfino MA. ININFA; Argentina. ININFA; ArgentinaFil: Stefano AV. ININFA; ArgentinaFil: Ferrario, Juan Esteban. ININFA; ArgentinaFil: Taravini, Irene Rita Eloisa. ININFA; ArgentinaFil: Murer, Mario Gustavo. FACULTAD DE MEDICINA; ArgentinaFil: Gershanik OS. ININFA; Argentin

Regulation of Pleiotrophin and Fyn in the striatum of rats undergoing L-DOPA-induced dyskinesia

L-DOPA is the gold standard pharmacological therapy for symptomatic treatment of Parkinson´s disease (PD), however, its long-term use is associated with the emergence of L-DOPA-induced dyskinesia (LID). Understanding the underlying molecular mechanisms of LID is crucial for the development of newer and more effective therapeutic approaches. In previous publications, we have shown that Pleiotrophin (PTN), a developmentally regulated trophic factor, is up-regulated by L-DOPA in the striatum of dopamine denervated rats. We have also shown that both mRNA and protein levels of RPTPζ/β, a PTN receptor, were upregulated in the same experimental condition and expressed in striatal medium spiny neurons. The PTN-RPTPζ/β intracellular pathway has not been fully explored and it might be implicated in the striatal plastic changes triggered by L-DOPA treatment. RPTPζ/β is part of the postsynaptic density zone and modulates Fyn, a Src tyrosine kinase that regulates the NR2A and NR2B subunits of the NMDA receptor and has been singled out as a key molecule in the development of LID. In this study, we evaluated the changes in PTN and Fyn protein levels and Fyn phosphorylation status in the 6-OHDA rat model of PD rendered dyskinetic with L-DOPA. We found an increase in the number of PTN immunoreactive neurons, no changes in the amount of total Fyn but a significant increase in Fyn phosphorylation in the dorsolateral striatum of dyskinetic rats. Our results support the idea that both PTN and Fyn may be involved in the development of LID, further contributing to the understanding of its molecular mechanisms.Fil: Gomez, Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Saborido, Mariano Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Bernardi, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Gershanik, Oscar Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Taravini, Irene Rita Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: Ferrario, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentin

Cabergoline and pramipexole fail to modify already established dyskinesias in an animal model of parkinsonism

Levodopa-induced dyskinesias are one of the major limiting side effects encountered in the treatment of Parkinson's disease. Dopamine agonists of the D2 family are less prone to induce these abnormal involuntary movements (AIMs), and in some instances it has been proposed that they could counteract them once already established. As differences in the plasma half-life of a given DA agonist could be related with a greater or lesser propensity to induce or to counteract AIMs, we compared the effects of two D2 agonists (cabergoline and pramipexole) with different half-lives, and levodopa, at doses producing similar improvement in purposeful forelimb use, in rats with severe nigrostriatal lesion, previously sensitized to levodopa. The same therapeutic regime was subsequently used in pharmacologically naïve rats. We found that: (i) prior induction of AIMs by levodopa administration primes rats for the occurrence of AIMs during mono-therapy with pramipexole (but not with cabergoline); (ii) an intervening period of D2 agonist mono-therapy does not modify the severity of AIMs induced by subsequent mono-therapy with levodopa; iii. de novo treatment with D2 agonists is associated with a lower risk of AIMs (regardless of the severity of the lesion) and does not modify AIMs during subsequent mono-therapy with levodopa. An unexpected finding was that prior levodopa therapy sensitized rats to the therapeutic effects of D2 agonists given in mono-therapy. In summary, the use of the rat with nigrostriatal lesion to model relevant therapeutic conditions does not support that D2 agonists prevent the development of AIMs during subsequent levodopa mono-therapy or can revert the dysfunction underlying it. © 2008 Elsevier B.V. All rights reserved.Fil: Larramendy, Celia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Taravini, Irene Rita Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Saborido, Mariano Diego. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiología de Circuitos Neuronales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ferrario, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Murer, Mario Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Gershanik, Oscar Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentin

Resultados bioquímicos, histológicos y conductuales del silenciamiento de Fyn en un modelo murino de disquinesias y Enfermedad de Parkinson: Efecto del tratamiento con un microRNA contra Fyn administrado en ratones hemiparkinsonianos antes o después de un primer desafío con levodopa

Las disquinesias inducidas por levodopa (LIDs) son un efecto secundario incapacitante del tratamiento en la enfermedad de Parkinson (EP). Al día de hoy, las LIDs carecen de un tratamiento farmacológico efectivo, excepto por el uso de inhibidores del receptor NMDA (NMDA-R), que tienen una eficacia limitada y pueden desencadenar efectos secundarios adversos. La tirosín quinasa FYN es un regulador clave de la función del NMDA-R y un blanco terapéutico potencial para el control de las LIDs. Los datos que aquí se presentan se utilizaron para demostrar que el tratamiento con un ARN de interferencia es efectivo para reducir la cantidad de ARNm de FYN en el cerebro adulto y prevenir las LIDs en un modelo de EP en ratón, estableciendo las bases para futuras intervenciones biomédicas para el tratamiento de las LID en la EP.Fil: Bordone, Melina Paula. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Damianich, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bernardi, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Eidelman, Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional.; ArgentinaFil: Sanz Blasco, Sara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Gershanik, Oscar Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Avale, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ferrario, Juan Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentin

Immunodetection of heparin-binding growth associated molecule (pleiotrophin) in striatal interneurons

Pleiotrophin (PTN), a developmentally-regulated trophic factor, is over-expressed in the striatum of parkinsonian rats. Because striatal PTN can provide trophic support to dopamine neurons, we identified the cellular types containing PTN in the striatum of adult rats. By means of fluorescent double-immunolabeling, we found PTN to co-localize with a neuronal nuclei marker but not with glial fibrillary acidic protein. The number, distribution, and morphology of the PTN-immunolabeled cells suggested that they were interneurons. Further double-immunolabeling studies ruled out PTN localization to calretinin- and parvalbumin-containing interneurons. Instead, ∼40% of the PTN-immunolabeled neurons contained nitric oxide synthase or somatostatin and ∼60% expressed the vesicular acetylcholine transporter, supporting that they were GABAergic nitric oxide synthase/somatostatin-containing and cholinergic interneurons. Further work is necessary to determine if PTN from striatal interneurons can provide trophic support to dopamine neurons.Fil: Taravini, Irene Rita Eloisa.Fil: Ferrario, Juan Esteban.Fil: Jean Delbe.Fil: Laure Ginestet.Fil: Thomas Debeir.Fil: José Courty.Fil: M. Gustavo Murer. FACULTAD DE MEDICINA; ArgentinaFil: Gershanik, Oscar Samuel. ININFA; ArgentinaFil: Rita Raisman-Vozari

Differential gene expression induced by chronic levodopa treatment in the striatum of rats with lesions of the nigrostriatal system

Levodopa, the major treatment for patients with Parkinson's disease, has been shown to induce a variety of compensatory effects, including facilitation of sprouting by dopaminergic neurons, in experimental animals with lesions leading to denervation of the striatum. To better understand the cellular and molecular environment where most of these compensatory changes take place, in particular elements that might contribute to the recovery of dopaminergic innervation, we have constructed a differential expression library enriched in transcripts from the striata of rats with lesions of the medial forebrain bundle treated with levodopa for 6 months. We have used this library to screen an expression array of rat genes representing the major cell functions, and have identified several that are involved in neurotrophic mechanisms and plasticity. We have confirmed the differential expression of selected transcripts by non‐radioactive in situ hybridization, and report that the growth factor pleiotrophin, myelin basic protein and calmodulin are overexpressed in the denervated striatum of levodopa‐treated rats.Fil: Ferrario, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentina. ININFA; ArgentinaFil: Taravini, Irene Rita Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Mourlevat S. Inserm U289, Hôpital de la Salpêtrière de Paris; Francia. HOSPITAL SALPETRIE FRANCIA; ArgentinaFil: Stefano A. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentina. ININFA; ArgentinaFil: Delfino M. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentina. ININFA; ArgentinaFil: Raisman-Vozari R. Inserm U289, Hôpital de la Salpêtrière de Paris; Francia. HOSPITAL SALPETRIE FRANCIA; ArgentinaFil: Murer, Mario Gustavo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. FACULTAD DE MEDICINA; ArgentinaFil: Ruberg M. Inserm U289, Hôpital de la Salpêtrière de Paris; Francia. HOSPITAL SALPETRIE FRANCIA; ArgentinaFil: Gershanik, Oscar Samuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentina. ININFA; Argentin