Friedreich's ataxia (FRDA) results from decreased levels of frataxin; thus, stabilization of the FXN mRNA already present in patient cells represents an attractive and unexplored therapeutic avenue. This work pursued a novel approach based on oligonucleotide-mediated targeting of FXN mRNA ends to extend its half-life and availability as a template for translation. This group demonstrated that oligonucleotides designed to bind to FXN 5' or 3' noncoding regions can increase FXN mRNA and protein levels. Simultaneous delivery of oligonucleotides targeting both ends increases efficacy of the treatment. The approach was confirmed in several FRDA fibroblast and induced pluripotent stem cell-derived neuronal progenitor lines. RNA sequencing and single-cell expression analyses confirmed oligonucleotide-mediated FXN mRNA upregulation. Mechanistically, a significant elongation of the FXN mRNA half-life without any changes in chromatin status at the FXN gene was observed upon treatment with end-targeting oligonucleotides, indicating that transcript stabilization is responsible for frataxin upregulation. These results identify a novel approach toward upregulation of steady-state mRNA levels via oligonucleotide-mediated end targeting that may be of significance to any condition resulting from transcription downregulation.

Read the Full article here
 

Request For Proposals: Pharmacodynamic Biomarker Development

FARA is issuing a request for proposals (RFP) to support clinical drug development programs in Friedreich’s ataxia (FRDA) by promoting the discovery of technologies to measure frataxin or surrogates of frataxin in inaccessible and disease relevant tissues.

This RFP supports the discovery and validation of non-invasive and quantitative methodologies to measure the following in FRDA affected tissues (brain, spinal cord or heart):

• Frataxin protein levels
• Biochemical activities dependent on/downstream of frataxin function that can be surrogates of frataxin in inaccessible tissues

Allowed budget will depend on stage and scope of research.

FARA will consider proof of concept and high-risk proposals, without preliminary data, provided they show a strong rationale for the proposed use and development of such biomarkers.

Informal inquiries regarding study relevance and interest to FARA are welcome and should be directed to grants@curefa.org.

Please click below to submit a Letter of Intent.The LOI submission deadline is December 1, 2021.

The objective of this study was to assess skeletal muscle oxidative metabolism in vivo in adults with FRDA as compared to adults without FRDA using chemical exchange saturation transfer (CrCEST) MRI, which measures free creatine (Cr) over time following an in-magnet plantar flexion exercise. Participants included adults with FRDA (n = 11) and healthy adults (n = 25). All underwent 3-Tesla CrCEST MRI of the calf before and after in-scanner plantar flexion exercise. Participants also underwent whole-body dual-energy X-ray absorptiometry (DXA) scans to measure body composition and completed questionnaires to assess physical activity. In adults with FRDA (vs. healthy adults), prolonged post-exercise exponential decline in CrCEST (τCr) in the lateral gastrocnemius (LG, 274 s vs. 138 s, p = 0.01) was observed, likely reflecting decreased OXPHOS capacity. Adults with FRDA (vs. healthy adults) also engaged different muscle groups during exercise, as indicated by muscle group-specific changes in creatine with exercise (∆CrCEST), possibly reflecting decreased coordination. Across all participants, increased adiposity and decreased usual physical activity were associated with smaller ∆CrCEST. In FRDA, CrCEST MRI may be a useful biomarker of muscle-group-specific decline in OXPHOS capacity that can be leveraged to track within-participant changes over time. Appropriate participant selection and further optimization of the exercise stimulus will enhance the utility of this technique.

Read the Full article here
 

Neuroinflammation is proposed to accompany, or even contribute to, neuropathology in Friedreich ataxia (FRDA), with implications for disease treatment and tracking. The purpose of this study was to examine brain glial activation and systemic immune dysfunction in people with FRDA and quantify their relationship with symptom severity, duration, and onset age. Fifteen individuals with FRDA and 13 healthy controls underwent brain positron emission tomography using the translocator protein (TSPO) radioligand [18 F]-FEMPA, a marker of glial activation, together with the quantification of blood plasma inflammatory cytokines. [18 F]-FEMPA binding was significantly increased in the dentate nuclei (d = 0.67), superior cerebellar peduncles (d = 0.74), and midbrain (d = 0.87), alongside increased plasma interleukin-6 (IL-6) (d = 0.73), in individuals with FRDA compared to controls. Increased [18 F]-FEMPA binding in the dentate nuclei, brainstem, and cerebellar anterior lobe correlated with earlier age of symptom onset (controlling for the genetic triplet repeat expansion length; all rpart < -0.6), and in the pons and anterior lobe with shorter disease duration (r = -0.66; -0.73). Neuroinflammation is evident in brain regions implicated in FRDA neuropathology. Increased neuroimmune activity may be related to earlier disease onset and attenuate over the course of the illness.

Read the Full article here