Cardiomyopathy as the first manifestation of Friedreich's ataxia

Rafael Tuzino Leite Neves Maffei; Giulio de los Santos Fortuna; Luca Campolino Rosso; Pedro Dragone Pires; Ivan Rondelli Autops Case Rep, vol.10, n3, e2020204, 2020; doi:10.4322/acr.2020.204 

 We present the case of a female patient diagnosed in childhood with Friedreich Ataxia (FA). At the age of 6, she developed left congestive heart failure with cardiomyopathy, as evident on echocardiogram. Neurologic signs only appeared at age 7, including marked loss of muscle mass, gait instability, muscle clonus, and Babinski's signal. At age 27, she had a stroke and was hospitalized; a few days later, she had a cardiorespiratory arrest with asystole, leading to death. The autopsy disclosed severe cardiomyopathy and significant myocardial replacement with fibrosis; therefore, the cause of death was assumed to be heart failure. Compared to the literature, our case has some unique features, such as cardiac disease as the presenting manifestation instead of gait instability, which is the major initial sign in most FA cases. Since our patient was submitted to an autopsy, it was an opportunity to retrieve important data to confirm the diagnosis and to evaluate the pathophysiology of this entity, such as myocardium fibrosis and cerebellar degeneration. In summary, our case demonstrates that cardiac disease can be the first manifestation of FA, with eventual diagnostic and prognostic implications. In addition, the autopsy provided findings of severe cardiomyopathy associated with FA.

Epigenetic Regulation of the Clinical Signs of Friedreich’s Disease

E. P. Nuzhny, N. Yu. Abramycheva, N. S. Nikolaeva, M. V. Ershova, S. A. Klyushnikov, S. N. Illarioshkin & E. Yu. Fedotova; Neurosci Behav Physi (2020). doi:10.1007/s11055-020-00998-9 

Studies of genetic-epigenetic interactions identified correlations between the extent of methylation of a series of CpG sites in the UP-GAA and DOWN-GAA and the number of GAA repeats in both expanded alleles of the FXN gene in patients with FD. We also found a link between methylation and the presence of the extraneural signs of FD: cardiomyopathy was more likely to be present when the CpG site of the promoter region was hypermethylated, while impairments to carbohydrate metabolism were more common in hypomethylation of CpG sites in the DOWN-GAA area. Conclusions. The data obtained here provide evidence that epigenetic modifications of the FXN gene make a significant contribution to forming the clinical picture of FD.

The Nrf2 induction prevents ferroptosis in Friedreich’s Ataxia

Piergiorgio La Rosa, Sara Petrillo, Riccardo Turchi, Francesco Berardinelli, Tommaso Schirinzi, Gessica Vasco, Daniele Lettieri-Barbato, Maria Teresa Fiorenza, Enrico S. Bertini, Katia Aquilano, Fiorella Piemonte, Redox Biology, 2020, 101791, doi:10.1016/j.redox.2020.101791.

Ferroptosis is an iron-dependent cell death caused by impaired glutathione metabolism, lipid peroxidation and mitochondrial failure. Emerging evidences report a role for ferroptosis in Friedreich’s Ataxia (FRDA), a neurodegenerative disease caused by the decreased expression of the mitochondrial protein frataxin. Nrf2 signalling is implicated in many molecular aspects of ferroptosis, by upstream regulating glutathione homeostasis, mitochondrial function and lipid metabolism. As Nrf2 is down-regulated in FRDA, targeting Nrf2-mediated ferroptosis in FRDA may be an attractive option to counteract neurodegeneration in such disease, thus paving the way to new therapeutic opportunities. In this study, we evaluated ferroptosis hallmarks in frataxin-silenced mouse myoblasts, in hearts of a frataxin Knockin/Knockout (KIKO) mouse model, in skin fibroblasts and blood of patients, particularly focusing on ferroptosis-driven gene expression, mitochondrial impairment and lipid peroxidation. The efficacy of Nrf2 inducers to neutralize ferroptosis has been also evaluated.

PPAR gamma agonist leriglitazone improves frataxin-loss impairments in cellular and animal models of Friedreich Ataxia

Laura Rodríguez-Pascau, Elena Britti, Pablo Calap-Quintana, Yi Na Dong, Cristina Vergara, Fabien Delaspre, Marta Medina, Jordi Tamarit, Federico V. Pallardó, Pilar Gonzalez-Cabo, Joaquim Ros, David R. Lynch, Marc Martinell, Pilar Pizcueta, Neurobiology of Disease, 2020, 105162, doi:10.1016/j.nbd.2020.105162. 

Here we assess whether MIN-102 (INN: leriglitazone), a novel brain penetrant and orally bioavailable PPARγ agonist with an improved profile for central nervous system (CNS) diseases, rescues phenotypic features in cellular and animal models of FRDA. In frataxin-deficient dorsal root ganglia (DRG) neurons, leriglitazone increased frataxin protein levels, reduced neurite degeneration and α-fodrin cleavage mediated by calpain and caspase 3, and increased survival. Leriglitazone also restored mitochondrial membrane potential and partially reversed decreased levels of mitochondrial Na+/Ca2+ exchanger (NCLX), resulting in an improvement of mitochondrial functions and calcium homeostasis. In frataxin-deficient primary neonatal cardiomyocytes, leriglitazone prevented lipid droplet accumulation without increases in frataxin levels. Furthermore, leriglitazone improved motor function deficit in YG8sR mice, a FRDA mouse model. In agreement with the role of PPARγ in mitochondrial biogenesis, leriglitazone significantly increased markers of mitochondrial biogenesis in FRDA patient cells. Overall, these results suggest that targeting the PPARγ pathway by leriglitazone may provide an efficacious therapy for FRDA increasing the mitochondrial function and biogenesis that could increase frataxin levels in compromised frataxin-deficient DRG neurons. Alternately, leriglitazone improved the energy metabolism by increasing the fatty acid β-oxidation in frataxin-deficient cardiomyocytes without elevation of frataxin levels. This could be linked to a lack of significant mitochondrial biogenesis and cardiac hypertrophy. The results reinforced the different tissue requirement in FRDA and the pleiotropic effects of leriglitazone that could be a promising therapy for FRDA.

Electrocardiogram in Friedreich's ataxia: A short‐term surrogate endpoint for treatment efficacy

Sandra Mastroianno MD Michele Germano MD Angela Maggio MD Raimondo Massaro MD Domenico Rosario Potenza MD Aldo Russo MD Massimo Carella PhD Giuseppe Di Stolfo MD, PhD; Ann Noninvasive Electrocardiol. 2020; 00:e12813. doi:10.1111/anec.12813 

We describe the case of a 21‐year‐old patient affected by Friedreich's ataxia on wheel‐chair, with initial cardiac involvement and electrocardiographic features characterized by thiamine treatment‐related negative T wave and QTc variations. We discuss plausible physiopathology and potential ECG role implications as an intermediate marker of treatment response in future clinical trials considering patients affected by Friedreich's ataxia.

Effect of Mitochondrial and Cytosolic FXN Isoform Expression on Mitochondrial Dynamics and Metabolism

Agrò, M.; Díaz-Nido, J. , Int. J. Mol. Sci. 2020, 21, 8251. doi:10.3390/ijms21218251 (registering DOI)

Alternative forms of frataxin have been described, with different cellular localization and tissue distribution, including a cerebellum-specific cytosolic isoform called FXN II. Here, we explored the functional roles of FXN II in comparison to the mitochondrial FXN I isoform, highlighting the existence of potential cross-talk between cellular compartments. To achieve this, we transduced two human cell lines of patient and healthy subjects with lentiviral vectors overexpressing the mitochondrial or the cytosolic FXN isoforms and studied their effect on the mitochondrial network and metabolism. We confirmed the cytosolic localization of FXN isoform II in our in vitro models. Interestingly, both cytosolic and mitochondrial isoforms have an effect on mitochondrial dynamics, affecting different parameters. Accordingly, increases of mitochondrial respiration were detected after transduction with FXN I or FXN II in both cellular models. Together, these results point to the existence of a potential cross-talk mechanism between the cytosol and mitochondria, mediated by FXN isoforms. A more thorough knowledge of the mechanisms of action behind the extra-mitochondrial FXN II isoform could prove useful in unraveling FRDA physiopathology.

European Investment Bank provides Minoryx with up to €25 million to support development of breakthrough therapies in orphan neurodegenerative diseases

Press release, 30 October 2020, Barcelona.

 The European Investment Bank (EIB) today announced that it has approved €25 million financing for Minoryx Therapeutics, a Phase 3 clinical stage biotech company focused on the development of differentiating treatment options for orphan central nervous system (CNS) disorders.

The EU bank will grant long-term financing to Minoryx to drive the company's research activities in orphan genetic diseases for which there are currently no approved drugs available. The EIB investments will specifically support the development of Minoryx's leriglitazone, a disease-modifying treatment (PPAR-γ agonist) currently being evaluated in three late-stage clinical trials:......Phase 2 FRAMES study in Friedreich's Ataxia (FRDA), a life threatening disease characterised by neurodegeneration resulting in loss of coordination, muscle strength, and cardiomyopathy.

EL BANCO EUROPEO DE INVERSIONES PROPORCIONA €25M A MINORYX PARA APOYAR EL DESARROLLO DE TERAPIAS INNOVADORAS EN ENFERMEDADES RARAS NEURODEGENERATIVAS.

Mataró (Barcelona, España) y Charleroi (Bélgica), 30 de octubre de 2020. Minoryx Therapeutics, una empresa biotecnológica en fase clínica III especializada en el desarrollo de tratamientos diferenciales para enfermedades raras del sistema nervioso central (CNS), ha anunciado hoy que el Banco Europeo de Inversiones (BEI) ha aprobado una financiación de 25 millones de euros. El banco de la UE concederá financiación a largo plazo a Minoryx para impulsar las actividades de investigación y desarrollo de la entidad en enfermedades genéticas huérfanas para las que actualmente no se dispone de medicamentos aprobados.

 Las inversiones del BEI apoyarán específicamente el desarrollo de la leriglitazona, un agonista PPAR gamma diferenciado y con potencial de modificar el curso de la enfermedad que actualmente se está evaluando en tres ensayos clínicos en fase avanzada. Estudio FRAMES de fase II en ataxia de Friedreich (FRDA).

30/10/2020. ACN Mataró.-El Banc Europeu d’Inversions (BEI) ha anunciat l’aprovació de 25 milions d’euros en finançament per a Minoryx Therapeutics, una empresa de biotecnologia amb seu a Mataró que es dedica al desenvolupament de noves opcions terapèutiques per a malalties del sistema nerviós central per a les que no hi ha medicaments aprovats, com l’adrenomieloneuropatia, l’adrenoleucodistròfia o l’atàxia de Friedreich. BEI da 25 millones a firma que desarrolla terapia para enfermedades genéticas. Barcelona, 30 oct (EFE).- 

El Banco Europeo de Inversiones (BEI) ha anunciado que financiará con 25 millones de euros a Minoryx Therapeutics, una empresa de biotecnología centrada en el desarrollo de nuevas terapias para enfermedades genéticas huérfanas del sistema nervioso central y con sede en el Tecnocampus de Mataró (Barcelona). El ensayo (FRAMES) estudia la ataxia de Friedreich (AF), una enfermedad potencialmente mortal caracterizada por una neurodegeneración que provoca pérdida de coordinación y de fuerza muscular y cardiomiopatía.

 

[4Fe-4S] cluster trafficking mediated by Arabidopsis mitochondrial ISCA and NFU proteins

Tamanna Azam, Jonathan Przybyla-Toscano, Florence Vignols, Jérémy Couturier, Nicolas Rouhier, and Michael K. Johnson, J. Biol. Chem. jbc.RA120.015726. doi:10.1074/jbc.RA120.015726

 The results demonstrate rapid, unidirectional and quantitative [4Fe-4S]2+ cluster transfer from ISCA1a/2 to NFU4 or NFU5 that further delineates their respective positions in the plant ISC machinery and their contributions to the maturation of client [4Fe-4S] cluster-containing proteins.

An Overview of the Ferroptosis Hallmarks in Friedreich’s Ataxia

Turchi, R.; Faraonio, R.; Lettieri-Barbato, D.; Aquilano, K. Biomolecules 2020, 10, 1489. doi:10.3390/biom10111489 

 Even though ferroptosis has been associated with various neurodegenerative diseases including FRDA, the mechanisms leading to disease onset/progression have not been demonstrated yet. We describe the molecular alterations occurring in FRDA that overlap with those characterizing ferroptosis. Major conclusions: The study of ferroptotic pathways is necessary for the understanding of FRDA pathogenesis, and anti-ferroptotic drugs could be envisaged as therapeutic strategies to cure FRDA.