Deletion of the GAA repeats from the human frataxin gene using the CRISPR-Cas9 system in YG8R-derived cells and mouse models of Friedreich ataxia

The Friedreich ataxia is a monogenic disease due to a hyperexpanded GAA triplet located within the first intron of the frataxin gene that causes transcriptional issues. The resulting frataxin protein deficiency leads to a Fe-S cluster biosynthesis dysfunction in the mitochondria and to oxidative stress and cell death. Here we use the CRISPR-Cas9 system to remove the mutated GAA expansion and restore the frataxin gene transcriptional activity and protein level. Both YG8R and YG8sR mouse models and cell lines derived from these mice were used to CRISPR-edited successfully the GAA expansion in vitro and in vivo. Nevertheless, our results suggest the YG8sR as a better and more suitable model for the study of the CRISPR-Cas9 edition of the mutated frataxin gene.

Prediction of magnetoresistance using a magnetic field and correlation between the magnetic and electrical properties of La0.7Bi0.05Sr0.15Ca0.1Mn1−xInxO3 (0 ≤ x ≤ 0.3) manganite

In this paper, we have systematically investigated the effect of In doping on the magnetic and magnetocaloric effect (MCE) in La_0.7Bi_0.05Sr_0.15Ca_0.1Mn_1−xIn_xO₃ (0 ≤ x ≤ 0.3) manganite.

Development of an AAV9 coding for a 3XFLAG-TALEfrat#8-VP64 able to increase in vivo the human frataxin in YG8R mice

Artificially designed transcription activator-like effector (TALE) proteins fused to a transcription activation domain (TAD), such as VP64, are able to activate specific eukaryotic promoters. They thus provide a good tool for targeted gene regulation as a therapy. However, the efficacy of such an agent in vivo remains to be demonstrated as the majority of studies have been carried out in cell culture. We produced an adeno-associated virus 9 (AAV9) coding for a TALEfrat#8 containing 13 repeat variable diresidues able to bind to the proximal promoter of human frataxin (FXN) gene. This TALEfrat#8 was fused with a 3XFLAG at its N terminal and a VP64 TAD at its C terminal, and driven by a CAG promoter. This AAV9_3XFLAG-TALEfrat#8-VP64 was injected intraperitoneally to 9-day-old and 4-month-old YG8R mice. After 1 month, the heart, muscle and liver were removed and their FXN mRNA and FXN protein were analyzed. The results show that the AAV9_3XFLAG-TALEfrat#8-VP64 increased the FXN mRNA and FXN protein in the three organs studied. These results corroborate our previous in vitro studies in the FRDA human fibroblasts. Our study indicates that an AAV coding for a TALE protein coupled with a TAD may be used to increase gene expression in vivo as a possible treatment not only for FRDA but also for other haploinsufficiency diseases.

Transfusion strategy for primary knee and hip arthroplasty: impact of an algorithm to lower transfusion rates and hospital costs

BACKGROUND

Blood transfusion strategies should reduce both blood transfusion and costs. Possible solutions include autologous donation for selected patients and the prescription of erythropoietin (EPO).

METHODS

We conducted a quality improvement program to examine the effect of a transfusion strategy algorithm in primary knee (TKA) and hip arthroplasty (THA). Our algorithm is presented as a diagram and is based on tolerated and expected blood losses. Patient characteristics, blood loss, transfusions given, autologous blood wastage, and costs were examined during an initial evaluation and after implementation of the algorithm.

RESULTS

Analysis of 302 (initial evaluation) and 173 (post-implementation) arthroplasties demonstrated a 55% reduction in the prescription of autologous blood donation. The proportion of EPO prescriptions increased from 6.6% to 17.3% (P<0.05). There was a 56% overall reduction in transfusions to fewer autologous (32% vs 12%, P<0.0001) and allogeneic transfusions (21% vs 13%, NS). There were 50% fewer wasted autologous blood units (P=0.002) and a 50% reduction in hospital costs (euro345 vs 169) with no significant change in overall costs (euro439 vs 407). Anaesthetists applied the algorithm in 97% of patients, and it is still in use 1 yr after evaluation.

CONCLUSIONS

In this study, the implementation of an algorithm for transfusion strategy changed practice and improved quality of care. The costs for EPO, its administration, and monitoring outside hospital were offset by the reduction in hospital transfusion costs.