Physical activity in the prevention of human diseases: role of epigenetic modifications

Elisa Grazioli, Ivan Dimauro, Neri Mercatelli, Guan Wang, Yannis Pitsiladis, Luigi Di Luigi and Daniela Caporossi; BMC Genomics 201718 (Suppl 8):802, doi:10.1186/s12864-017-4193-5

This review highlights the most significant findings from epigenetic studies involving physical activity/exercise interventions known to benefit chronic diseases such as metabolic syndrome, diabetes, cancer, cardiovascular and neurodegenerative diseases.

In conclusion, PA promises to be an important tool to be used alone or in combination with traditional therapies to improve the efficacy of strategies for disease prevention and treatment based on epigenetic modification. In this context, exercise remains an essential factor promoting important biological adaptations with profound implications for public health. Future collaborative studies may identify epigenetic markers with translational significance in identifying individuals for whom a personalized exercise regime could significantly alter the epigenomic signature and thus the risk of disease development or progression.

Differentially Regulated Cell-Free MicroRNAs in the Plasma of Friedreich's Ataxia Patients and Their Association with Disease Pathology

Subrahamanyam Dantham, Achal K. Srivastava, Sheffali Gulati, Moganty R. Rajeswari; Neuropediatrics 2017 Nov 27. DOI: 10.1055/s-0037-1607279

Friedreich's ataxia (FRDA) is a multisystem disease affecting the predominately nervous system, followed by muscle, heart, and pancreas. Current research focused on therapeutic interventions aimed at molecular amelioration, but there are no reliable noninvasive signatures available to understand disease pathogenesis. The present study investigates the alterations of plasma cell-free microRNAs (miRNAs) in FRDA patients and attempts to find the significance in relevance with the pathogenesis. Total RNA from the plasma of patients and healthy controls were subjected to miRNA microarray analysis using Agilent Technologies microarray platform. Differentially regulated miRNAs were validated by SYBR-green real-time polymerase chain reaction (Thermo Fisher Scientific). The study identified 20 deregulated miRNAs (false discovery rate < 0.01, fold change ≥ 2.0 ≤) in comparison with healthy controls; out of which 17 miRNAs were upregulated, and 3 miRNAs were downregulated. Target and pathway analysis of these miRNAs have shown association with neurodegenerative and other clinical features in FRDA. Further validation (n = 21) identified a set of significant (p < 0.05) deregulated miRNAs; hsa-miR-15a-5p, hsa-miR-26a-5p, hsa-miR-29a-3p, hsa-miR-223–3p, hsa-24–3p, and hsa-miR-21–5p in comparison with healthy controls. These miRNAs were reported to influence various pathological features associated with FRDA. The present study is expected to aid in the understanding of disease pathogenesis.

Do whole body vibration exercises affect lower limbs neuromuscular activity in populations with a medical condition? A systematic review

Dionello, Carla Fontouraa; de Souza, Patrícia Lopesa; Sá-Caputo, Danubiaa; Morel, Danielle Soaresa; Moreira-Marconi, Eloáb; Paineiras-Domingos, Laisa Lianea; Frederico, Eric Heleno Freire Ferreirab; Guedes-Aguiar, Elianeb; Paiva, Patricia de Castrob; Taiar, Redhah | Chiementin, Xavierh; Marín, Pedro J.i; Bernardo-Filho, Mariob; Restorative Neurology and Neuroscience, vol. 35, no. 6, pp. 667-681, 2017 DOI:10.3233/RNN-170765

The use of surface electromyography (sEMG) to evaluate muscle activation when executing whole body vibration exercises (WBVE) in studies provide neuromuscular findings, in healthy and diseased populations. Objectives:Perform a systematic review of the effects of WBVE by sEMG of lower limbs in non-healthy populations.
The group of Herrero evaluated muscle activation during WBVE of FA patients. The protocol consisted of two familiarization sessions and one working session that comprised six bouts of 3 min WBVE treatments on a tilt-table.

Patients organizations and new drug approval in the US. Eteplirsen and Duchenne muscular dystrophy case

Dal-Ré R, Lopez de Munain A, Ayuso C; Rev Neurol. 2017 Oct 16;65(8):373-380. [Article in Spanish]

INTRODUCTION:

In 2016 the US Food and Drug Administration (FDA) granted the marketing authorization for eteplirsen for Duchenne muscular dystrophy. This has been a very controversial decision since it happened after a negative assessment from both the Advisory Committee and the technical FDA evaluation team. The FDA's Center for Drug Evaluation and Research (CDER) director was who ultimately approved the product, while the FDA Commissioner did not overrule that decision.
AIM:

To report about the most relevant events regarding the approval of eteplirsen by the US FDA.
DEVELOPMENT:

All relevant facts that occurred during the clinical development and evaluation phase following 'accelerated approval' procedure of eteplirsen are discussed in detail. The technical FDA evaluation team reasons supporting that the drug has not proven clinical benefit, the attitude of patient advocacy groups and the post-approval FDA requirements to the marketing authorization holder are discussed. Finally, we reflect on what is the situation Spanish patients face once eteplirsen is on the US market.
CONCLUSIONS:

This is a unique case in the history of drug authorizations in western countries, that shows the difficulties that current regulations on accelerated approval of new medicines could have when interpreting scarce and low quality clinical development data, when dealing with rare diseases with no available therapies.

Oxidative stress and loss of Fe-S proteins in Friedreich ataxia induced pluripotent stem cell-derived PSNs can be reversed by restoring FXN expression with a benzamide HDAC inhibitor.

Amelie Hu, Myriam Rai, Simona Donatello, Massimo Pandolfo; bioRxiv 221242; doi:10.1101/221242 (This article is a preprint and has not been peer-reviewed)
We generated PSNs from induced pluripotent stem cells (iPSCs) from FRDA patients and showed that they recapitulate the key pathogenic events in FRDA, including low FXN levels, loss of Fe-S proteins and impaired antioxidant responses. We also showed that FXN deficiency in these cells may be partially corrected by a pimelic benzamide histone deacetylase inhibitor, a class of potential therapeutics for FRDA. We generated and validated a cellular model of the most vulnerable neurons in FRDA, which can be used for further studies on pathogenesis and treatment approaches.

Voyager Therapeutics "update"

CAMBRIDGE, Mass., Nov. 16, 2017 (GLOBE NEWSWIRE) -- Voyager Therapeutics, Inc. (NASDAQ:VYGR), a clinical-stage gene therapy company focused on developing life-changing treatments for severe neurological diseases, today at its R&D Day highlighted recent progress and plans for VY-AADC for advanced Parkinson’s disease, and progress with testing novel adeno-associated virus (AAV) capsids and delivery optimization efforts, along with its ALS, Huntington’s disease, Friedreich’s ataxia, anti-Tau antibody and severe chronic pain preclinical programs.

"Preclinical data from its Friedreich’s ataxia (FA) program in a transgenic mouse model of FA, with a one-time intravenous (IV) dosing of an AAV vector composed of a novel capsid and a frataxin transgene, together with intracerebral dosing of an AAV vector with the same transgene, that led to a rapid halting and reduction of FA disease progression in multiple functional tests of motor behavior. Additional preclinical studies are underway at Voyager including steps to identify a lead clinical candidate for the treatment of FA during 2018."

Proactive Ethical Design for Neuroengineering, Assistive and Rehabilitation Technologies: the Cybathlon Lesson

Marcello Ienca, Reto W. Kressig, Fabrice Jotterand and Bernice Elger; ournal of NeuroEngineering and Rehabilitation 201714:115 doi:10.1186/s12984-017-0325-z

As the fields of assistive technology and neuroengineering are entering a new phase of clinical and commercial maturity, there is an increasing need to address the ethical implications associated with the design and development of novel assistive and rehabilitative technological solutions. After reviewing various ethically-sensitive approaches to the design of NART, we proposed a framework for ethical design and development, which we call the Proactive Ethical Design (PED) framework. This framework is characterized by the convergence of user-centered and value-sensitive approaches to product design through a proactive mode of ethical evaluation. Four basic normative requirements are necessary for the realization of this framework: minimization of power imbalances, compliance with biomedical ethics, translationality and social awareness.

RESONANCIA MAGNÉTICA CARDIACA EN ATAXIA DE FRIEDREICH: SEGUIMIENTO CARDIACO DE LAS TERAPIAS ANTIOXIDANTES

Emilio Cuesta López. Tesis doctoral, UNIVERSIDAD AUTONOMA DE MADRID FACULTAD DE MEDICINA DEPARTAMENTO DE MEDICINA, Madrid 2017

Early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in the KIKO mouse model of Friedreich ataxia

Hong Lin, Jordi Magrane, Amy Rattelle, Anna Stepanova, Alexander Galkin, Elisia M. Clark, Yi Na Dong, Sarah M. Halawani, David R. Lynch; Disease Models & Mechanisms 2017 10: 1343-1352; doi: 10.1242/dmm.030502

Friedreich ataxia (FRDA), the most common recessive inherited ataxia, results from deficiency of frataxin, a small mitochondrial protein crucial for iron-sulphur cluster formation and ATP production. Frataxin deficiency is associated with mitochondrial dysfunction in FRDA patients and animal models; however, early mitochondrial pathology in FRDA cerebellum remains elusive. Using frataxin knock-in/knockout (KIKO) mice and KIKO mice carrying the mitoDendra transgene, we show early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in this FRDA model. At asymptomatic stages, the levels of PGC-1α (PPARGC1A), the mitochondrial biogenesis master regulator, are significantly decreased in cerebellar homogenates of KIKO mice compared with age-matched controls. Similarly, the levels of the PGC-1α downstream effectors, NRF1 and Tfam, are significantly decreased, suggesting early impaired cerebellar mitochondrial biogenesis pathways. Early mitochondrial deficiency is further supported by significant reduction of the mitochondrial markers GRP75 (HSPA9) and mitofusin-1 in the cerebellar cortex. Moreover, the numbers of Dendra-labeled mitochondria are significantly decreased in cerebellar cortex, confirming asymptomatic cerebellar mitochondrial biogenesis deficits. Functionally, complex I and II enzyme activities are significantly reduced in isolated mitochondria and tissue homogenates from asymptomatic KIKO cerebella. Structurally, levels of the complex I core subunit NUDFB8 and complex II subunits SDHA and SDHB are significantly lower than those in age-matched controls. These results demonstrate complex I and II deficiency in KIKO cerebellum, consistent with defects identified in FRDA patient tissues. Thus, our findings identify early cerebellar mitochondrial biogenesis deficits as a potential mediator of cerebellar dysfunction and ataxia, thereby providing a potential therapeutic target for early intervention of FRDA.

Insights on the conformational dynamics of human frataxin through modifications of loop-1

Martín E. Noguera, Martín Aran, Clara Smal, Diego S. Vazquez, María Georgina Herrera, Ernesto A. Roman, Nadine Alaimo, Mariana Gallo, Javier Santos; Archives of Biochemistry and Biophysics, Available online 31 October 2017, ISSN 0003-9861, doi:10.1016/j.abb.2017.10.022.

Human frataxin (FXN) is a highly conserved mitochondrial protein involved in iron homeostasis and activation of the iron-sulfur cluster assembly. FXN deficiency causes the neurodegenerative disease Friedreich's Ataxia. Here, we investigated the effect of alterations in loop-1, a stretch presumably essential for FXN function, on the conformational stability and dynamics of the native state. We generated four loop-1 variants, carrying substitutions, insertions and deletions. All of them were stable and well-folded proteins. Fast local motions (ps-ns) and slower long-range conformational dynamics (μs-ms) were altered in some mutants as judged by NMR. Particularly, loop-1 modifications impact on the dynamics of a distant region that includes residues from the β-sheet, helix α1 and the C-terminal. Remarkably, all the mutants retain the ability to activate cysteine desulfurase, even when two of them exhibit a strong decrease in iron binding, revealing a differential sensitivity of these functional features to loop-1 perturbation. Consequently, we found that even for a small and relatively rigid protein, engineering a loop segment enables to alter conformational dynamics through a long-range effect, preserving the native-state structure and important aspects of function.