Uwe Meya, Guillem Pina, Silvia Pascual, Marc Cerrada-Gimenez, Pilar Pizcueta, Marc Martinell, David Eckland, Jeroen v.d. Wetering de Rooij
Neurology Apr 2020, 94 (15 Supplement)
Evaluation of the pharmacokinetic parameters of leriglitazone in plasma and urine after single and multiple oral administration in healthy male volunteers. Evaluation of pro-inflammatory biomarkers in plasma and CSF after oral administration of leriglitazone in healthy male volunteers.
Friday, May 1, 2020
Thursday, April 30, 2020
MIN102 (Leriglitazone), a Brain Penetrant PPAR Gamma Agonist for the Treatment of Friedreich’s Ataxia (4147)
Sonia Poli, Laura Rodríguez-Pascau, Elena Britti, Joaquim Ros, Pilar González-Cab, David Lynch, Marc Martinell, Pilar Pizcueta; Neurology Apr 2020, 94 (15 Supplement) 4147;
The preclinical results support the investigation of leriglitazone for the treatment of FRDA. Leriglitazone is currently in clinical phase 2/3 for the treatment of AMN, in phase 2 for cALD and in phase 2 for Friedreich’s Ataxia.
The preclinical results support the investigation of leriglitazone for the treatment of FRDA. Leriglitazone is currently in clinical phase 2/3 for the treatment of AMN, in phase 2 for cALD and in phase 2 for Friedreich’s Ataxia.
Monday, April 27, 2020
Neurologic outcomes in Friedreich ataxia
Massimo Pandolfo, Neurol Genet Jun 2020, 6 (3) e415; DOI: 10.1212/NXG.0000000000000415
The SARA is a sensitive outcome measure in ambulatory patients with FRDA and has an excellent correlation with functional capabilities. Ambulatory patients with onset before age 8 years showed the fastest measurable worsening. Loss of ambulation in high-risk patients is a disease milestone that should be considered as an end point in clinical trials.
The SARA is a sensitive outcome measure in ambulatory patients with FRDA and has an excellent correlation with functional capabilities. Ambulatory patients with onset before age 8 years showed the fastest measurable worsening. Loss of ambulation in high-risk patients is a disease milestone that should be considered as an end point in clinical trials.
Thursday, April 23, 2020
Making iron-sulfur cluster: structure, regulation and evolution of the bacterial ISC system
Corentin Baussier, Soufyan Fakroun, Corinne Aubert, Sarah Dubrac, Pierre Mandin, Béatrice Py, Frédéric Barras, Advances in Microbial Physiology, Academic Press, 2020, doi:10.1016/bs.ampbs.2020.01.001.
Iron sulfur (Fe-S) clusters rank among the most ancient and conserved prosthetic groups. Fe-S clusters containing proteins are present in most, if not all, organisms. Fe-S clusters containing proteins are involved in a wide range of cellular processes, from gene regulation to central metabolism, via gene expression, RNA modification or bioenergetics. Fe-S clusters are built by biogenesis machineries conserved throughout both prokaryotes and eukaryotes. We focus mostly on bacterial ISC machinery, but not exclusively, as we refer to eukaryotic ISC system when it brings significant complementary information. Besides covering the structural and regulatory aspects of Fe-S biogenesis, this review aims to highlight Fe-S biogenesis facets remaining matters of discussion, such as the role of frataxin, or the link between fatty acid metabolism and Fe-S homeostasis. Last, we discuss recent advances on strategies used by different species to make and use Fe-S clusters in changing redox environmental conditions.
Iron sulfur (Fe-S) clusters rank among the most ancient and conserved prosthetic groups. Fe-S clusters containing proteins are present in most, if not all, organisms. Fe-S clusters containing proteins are involved in a wide range of cellular processes, from gene regulation to central metabolism, via gene expression, RNA modification or bioenergetics. Fe-S clusters are built by biogenesis machineries conserved throughout both prokaryotes and eukaryotes. We focus mostly on bacterial ISC machinery, but not exclusively, as we refer to eukaryotic ISC system when it brings significant complementary information. Besides covering the structural and regulatory aspects of Fe-S biogenesis, this review aims to highlight Fe-S biogenesis facets remaining matters of discussion, such as the role of frataxin, or the link between fatty acid metabolism and Fe-S homeostasis. Last, we discuss recent advances on strategies used by different species to make and use Fe-S clusters in changing redox environmental conditions.
Monday, April 20, 2020
Characterization of the Interruptions of the GAA Expansion and Study of Their Influence on the Severity of Friedreich's Ataxia (INTREP-AF)
ClinicalTrials.gov Identifier: NCT04346238 Posted : April 15, 2020
To date, only the partial correlation between the size of the expansion and the age of onset of Friedreich's ataxia has been established. In particular, very atypical forms of AF with a late onset (after the age of 25) are in particular explained by the low number of repetitions in the expansion, typically between 100 and 500 repetitions. However, the presence of an interruption could stabilize the size of the expansion and, therefore, be mainly associated with expansions of small sizes and therefore with a late onset of the disease.
The objective of this study is therefore to analyse and caracterize the presence and the type of interruptions of the GAA expansions in a group of patients with FA ; this data will be correlated with the age at onset of FA.
To date, only the partial correlation between the size of the expansion and the age of onset of Friedreich's ataxia has been established. In particular, very atypical forms of AF with a late onset (after the age of 25) are in particular explained by the low number of repetitions in the expansion, typically between 100 and 500 repetitions. However, the presence of an interruption could stabilize the size of the expansion and, therefore, be mainly associated with expansions of small sizes and therefore with a late onset of the disease.
The objective of this study is therefore to analyse and caracterize the presence and the type of interruptions of the GAA expansions in a group of patients with FA ; this data will be correlated with the age at onset of FA.
Sunday, April 19, 2020
A Comprehensive Transcriptome Analysis Identifies FXN and BDNF as Novel Targets of miRNAs in Friedreich’s Ataxia Patients
Julia O. Misiorek, Anna M. Schreiber, Martyna O. Urbanek-Trzeciak, Magdalena Jazurek-Ciesiołka, Lauren A. Hauser, David R. Lynch, Jill S. Napierala & Marek Napierala; Mol Neurobiol (2020). doi:10.1007/s12035-020-01899-1
Further studies confirmed that miRNA-224-5p indeed targets FXN, resulting in decreases in mRNA and protein levels. We also validated the ability of miRNA-10a-5p to bind and regulate the levels of brain-derived neurotrophic factor (BDNF), an important modulator of neuronal growth. We observed a significant decrease in the levels of miRNA-10a-5p and increase in the levels of BDNF upon correction of FRDA cells via zinc-finger nuclease (ZFN)-mediated excision of expanded GAA repeats. Our comprehensive transcriptome analyses identified miRNA-224-5p and miRNA-10a-5p as negative regulators of the FXN and BDNF expression, respectively. These results emphasize not only the importance of miRNAs in the pathogenesis of FRDA but also their potential as therapeutic targets for this disease.
Further studies confirmed that miRNA-224-5p indeed targets FXN, resulting in decreases in mRNA and protein levels. We also validated the ability of miRNA-10a-5p to bind and regulate the levels of brain-derived neurotrophic factor (BDNF), an important modulator of neuronal growth. We observed a significant decrease in the levels of miRNA-10a-5p and increase in the levels of BDNF upon correction of FRDA cells via zinc-finger nuclease (ZFN)-mediated excision of expanded GAA repeats. Our comprehensive transcriptome analyses identified miRNA-224-5p and miRNA-10a-5p as negative regulators of the FXN and BDNF expression, respectively. These results emphasize not only the importance of miRNAs in the pathogenesis of FRDA but also their potential as therapeutic targets for this disease.
Friday, April 17, 2020
A Natural History Study to TRACK Brain and Spinal Cord Changes in Individuals With Friedreich Ataxia (TRACK-FA) ((TRACK-FA))
ClinicalTrials.gov Identifier: NCT04349514. Estimated Study Start Date :June 2020
The aim of TRACK-FA is to develop an FA neuroimaging dataset from brain and spinal cord that is suitable for assessing the potential value of neuroimaging biomarkers and providing a basis for instituting them in clinical trials. The dataset will comprise a range of neuroimaging measures to assess changes in spinal cord and brain regions that have previously shown to be compromised in individuals with FA. In addition to neuroimaging measures, TRACK-FA will also include clinical, cognitive data and biospecimen data. The TRACK-FA dataset will provide a unique opportunity for academic researchers in collaboration with industry partners to access the images, subsidiary data, and associated clinical data for community research.
The aim of TRACK-FA is to develop an FA neuroimaging dataset from brain and spinal cord that is suitable for assessing the potential value of neuroimaging biomarkers and providing a basis for instituting them in clinical trials. The dataset will comprise a range of neuroimaging measures to assess changes in spinal cord and brain regions that have previously shown to be compromised in individuals with FA. In addition to neuroimaging measures, TRACK-FA will also include clinical, cognitive data and biospecimen data. The TRACK-FA dataset will provide a unique opportunity for academic researchers in collaboration with industry partners to access the images, subsidiary data, and associated clinical data for community research.
Thursday, April 16, 2020
Oxidative Stress, a Crossroad Between Rare Diseases and Neurodegeneration
Espinós, C.; Galindo, M.I.; García-Gimeno, M.A.; Ibáñez-Cabellos, J.S.; Martínez-Rubio, D.; Millán, J.M.; Rodrigo, R.; Sanz, P.; Seco-Cervera, M.; Sevilla, T.; Tapia, A.; Pallardó, F.V.; Antioxidants 2020, 9, 313.
Oxidative stress is an imbalance between production and accumulation of oxygen reactive species and/or reactive nitrogen species in cells and tissues, and the capacity of detoxifying these products, using enzymatic and non-enzymatic components, such as glutathione. Oxidative stress plays roles in several pathological processes in the nervous system, such as neurotoxicity, neuroinflammation, ischemic stroke, and neurodegeneration. The concepts of oxidative stress and rare diseases were formulated in the eighties, and since then, the link between them has not stopped growing. The present review aims to expand knowledge in the pathological processes associated with oxidative stress underlying some groups of rare diseases: Friedreich’s ataxia, diseases with neurodegeneration with brain iron accumulation, Charcot-Marie-Tooth as an example of rare neuromuscular disorders, inherited retinal dystrophies, progressive myoclonus epilepsies, and pediatric drug-resistant epilepsies. Despite the discrimination between cause and effect may not be easy on many occasions, all these conditions are Mendelian rare diseases that share oxidative stress as a common factor, and this may represent a potential target for therapies.
Oxidative stress is an imbalance between production and accumulation of oxygen reactive species and/or reactive nitrogen species in cells and tissues, and the capacity of detoxifying these products, using enzymatic and non-enzymatic components, such as glutathione. Oxidative stress plays roles in several pathological processes in the nervous system, such as neurotoxicity, neuroinflammation, ischemic stroke, and neurodegeneration. The concepts of oxidative stress and rare diseases were formulated in the eighties, and since then, the link between them has not stopped growing. The present review aims to expand knowledge in the pathological processes associated with oxidative stress underlying some groups of rare diseases: Friedreich’s ataxia, diseases with neurodegeneration with brain iron accumulation, Charcot-Marie-Tooth as an example of rare neuromuscular disorders, inherited retinal dystrophies, progressive myoclonus epilepsies, and pediatric drug-resistant epilepsies. Despite the discrimination between cause and effect may not be easy on many occasions, all these conditions are Mendelian rare diseases that share oxidative stress as a common factor, and this may represent a potential target for therapies.
Tuesday, April 14, 2020
The repeat variant in MSH3 is not a genetic modifier for spinocerebellar ataxia type 3 and Friedreich’s ataxia
Wai Yan Yau, Mafalda Raposo, Conceição Bettencourt, Robyn Labrum, João Vasconcelos, Michael H Parkinson, Paola Giunti, Nicholas W Wood, Manuela Lima, Henry Houlden, , Brain, , awaa043, https://doi.org/10.1093/brain/awaa043
MSH3 is a DNA mismatch repair gene whose product is essential for CAG repeat expansion and whose inactivation limits the expansion (Dragileva et al., 2009). The study conducted by Flower et al. demonstrates that a three-repeat allele in the mismatch repair gene MSH3 has potential disease-modifying effect on Huntington’s disease and myotonic dystrophy type 1 (DM1) (Flower et al., 2019), both of which are CAG repeat expansion disorders with distinct phenotypic features. The authors postulated that these effects are mediated through the influence of the MSH3 variant on the rate of somatic expansion.
MSH3 is a DNA mismatch repair gene whose product is essential for CAG repeat expansion and whose inactivation limits the expansion (Dragileva et al., 2009). The study conducted by Flower et al. demonstrates that a three-repeat allele in the mismatch repair gene MSH3 has potential disease-modifying effect on Huntington’s disease and myotonic dystrophy type 1 (DM1) (Flower et al., 2019), both of which are CAG repeat expansion disorders with distinct phenotypic features. The authors postulated that these effects are mediated through the influence of the MSH3 variant on the rate of somatic expansion.
Monday, April 13, 2020
Frataxin-deficient cardiomyocytes present an altered thiol-redox state which targets actin and pyruvate dehydrogenase
Rosa Purroy, Marta Medina-Carbonero, Joaquim Ros, Jordi Tamarit; Redox Biology, Volume 32, 2020, 101520, doi:10.1016/j.redox.2020.101520.
We identified two proteins with altered redox status in frataxin-deficient NRVMs: electron transfer flavoprotein-ubiquinone oxidoreductase and dihydrolipoyl dehydrogenase (DLDH). As DLDH is involved in protein-bound lipoic acid redox cycling, we analyzed the redox state of this cofactor and we observed that lipoic acid from pyruvate dehydrogenase was more oxidized in frataxin-deficient cells. Also, by targeted proteomics, we observed a decreased content on the PDH A1 subunit from pyruvate dehydrogenase. Finally, we analyzed the consequences of supplementing frataxin-deficient NRVMs with the PDH cofactors thiamine and lipoic acid, the PDH activator dichloroacetate and the antioxidants N-acetyl cysteine and Tiron. Both dichloroacetate and Tiron were able to partially prevent lipid droplet accumulation in these cells. Overall, these results indicate that frataxin-deficient NRVMs present an altered thiol-redox state which could contribute to the cardiac pathology.
We identified two proteins with altered redox status in frataxin-deficient NRVMs: electron transfer flavoprotein-ubiquinone oxidoreductase and dihydrolipoyl dehydrogenase (DLDH). As DLDH is involved in protein-bound lipoic acid redox cycling, we analyzed the redox state of this cofactor and we observed that lipoic acid from pyruvate dehydrogenase was more oxidized in frataxin-deficient cells. Also, by targeted proteomics, we observed a decreased content on the PDH A1 subunit from pyruvate dehydrogenase. Finally, we analyzed the consequences of supplementing frataxin-deficient NRVMs with the PDH cofactors thiamine and lipoic acid, the PDH activator dichloroacetate and the antioxidants N-acetyl cysteine and Tiron. Both dichloroacetate and Tiron were able to partially prevent lipid droplet accumulation in these cells. Overall, these results indicate that frataxin-deficient NRVMs present an altered thiol-redox state which could contribute to the cardiac pathology.
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