Finding an Appropriate Mouse Model to Study the Impact of a Treatment for Friedreich Ataxia on the Behavioral Phenotype.

Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by a GAA repeat in the intron 1 of the frataxin gene (FXN) leading to a lower expression of the frataxin protein. The YG8sR mice are Knock-Out (KO) for their murine frataxin gene but contain a human frataxin transgene derived from an FRDA patient with 300 GAA repeats. These mice are used as a FRDA model but even with a low frataxin concentration, their phenotype is mild.

Prime editing strategies to mediate exon skipping in gene.

Duchenne muscular dystrophy is a rare and lethal hereditary disease responsible for progressive muscle wasting due to mutations in the gene. We used the CRISPR-Cas9 Prime editing technology to develop different strategies to correct frameshift mutations in gene carrying the deletion of exon 52 or exons 45 to 52. With optimized epegRNAs, we were able to induce the specific substitution of the GT nucleotides of the splice donor site of exon 53 in up to 32% of HEK293T cells and 28% of patient myoblasts.

Removal of the GAA repeat in the heart of a Friedreich's ataxia mouse model using CjCas9.

Most Friedreich ataxia (FRDA) cases are caused by the elongation of the GAA repeat (GAAr) sequence in the first intron of the FXN gene, leading to a decrease of the frataxin protein expression. Deletion of this GAAr with CRISPR/Cas9 technology leads to an increase in frataxin expression in vitro. We are therefore aiming to develop FRDA treatment based on the deletion of GAAr with CRISPR/Cas9 technology using a single AAV expressing a small Cas9 (CjCas9) and two single guide RNAs (sgRNAs) targeting the FXN gene.

Small-molecule inhibitors of proteasome increase CjCas9 protein stability.

The small size of CjCas9 can make easier its vectorization for in vivo gene therapy. However, compared to the SpCas9, the CjCas9 is, in general, less efficient to generate indels in target genes. The factors that affect its efficacity are not yet determined.

Serum extracellular vesicles for delivery of CRISPR-CAS9 ribonucleoproteins to modify the dystrophin gene.

Extracellular vesicles (EVs) mediate intercellular biomolecule exchanges in the body, making them promising delivery vehicles for therapeutic cargo. Genetic engineering by the CRISPR system is an interesting therapeutic avenue for genetic diseases such as Duchenne muscular dystrophy (DMD). We developed a simple method for loading EVs with CRISPR ribonucleoproteins (RNPs) consisting of SpCas9 proteins and guide RNAs (gRNAs).

CRISPR-SCReT (CRISPR-Stop Codon Read Through) method to control Cas9 expression for gene editing.

CRISPR/Cas9 has paved the way for the development of therapies that correct genetic mutations. However, constitutive expression of the Cas9 gene can increase off-target mutations and induce an immune response against the Cas9 protein. To limit the time during which the Cas9 nuclease is expressed, we proposed a simple drug inducible system.

Rotavirus and norovirus in children with severe diarrhea in Burkina Faso before rotavirus vaccine introduction.

Burkina Faso introduced rotavirus vaccine (RotaTeq) to the national immunization program in November 2013. This study describes the detection rates, clinical profiles, and molecular epidemiology of rotavirus and norovirus (NoV) infections among children <5 years hospitalized (n = 154) because of acute diarrhea in Ouagadougou, Burkina Faso, from December 2012 to November 2013, just before the start of vaccination. Overall, 44% and 23% of fecal samples were positive for rotavirus and NoV, respectively, most of them detected during the cold dry season (December-March).

Molecular Heterogeneity of Glucose-6-Phosphate Dehydrogenase Deficiency in Burkina Faso: G-6-PD Betica Selma and Santamaria in People with Symptomatic Malaria in Ouagadougou.

The G-6-PD deficiency has an important polymorphism with genotypic variants such as 202A/376G, 376G/542T and 376G/968T known in West African populations. It would confer protection against severe forms of malaria although there are differences between the various associations in different studies. In this study we genotyped six (06) variants of the G-6-PD gene in people with symptomatic malaria in urban areas in Burkina Faso.