Forkhead-box protein P1 (FOXP1) is part of the forkhead-box family of transcription factors that is crucial for embryonic development. De novo disruptions of FOXP1 gene cause haploinsufficiency of FOXP1 that results in global developmental delay, intellectual disability, language impairment and autistic features. Prior literature has already reported 34 private mutations and seven mutations present in unrelated individuals. The majority of the pathogenic missense and in-frame mutations are located in the DNA-binding domain of FOXP1. Structural analyses have shown that these mutations can either disturb amino acids that are necessary for binding to DNA or interfere with the domain that mediates FOXP1 dimerization.
Our group has expertise in generating patient-derived induced pluripotent stem cell (iPSC) lines that can be further differentiated to various cell types and used for basic research on disease molecular biology, disease modelling and as a therapeutic platform. Moreover the past few year our group implemented in the iPSC line of research, in vitro 3D disease modeling with brain organoids. 3D brain organoids are more complex structures than 2D neurons as they reflect better some features of the human brain development. FOXP1 syndrome is a neurodevelopmental disease and brain organoids would be a great cell model to investigate disease mechanisms, possible disease phenotype and ultimately therapeutic options.
Our FOXP1 research in bullets:
- Generation of FOXP1 iPSC lines. To achieve this we will use CRISPR/Cas9 technology to introduce a point mutation c.1541G>A(p.Arg514His) and also generate FOXP1 heterozygous an homozygous knock-out lines.
- 3D-disease modelling with brain organoids. FOXP1 syndrome affects primarily the striatum. Using control and FOXP1 iPSC lines we will generate striatal organoids. We will use various downstream analysis methods, such as immunofluorescent stainings, gene expression analysis and RNA sequencing. Brain organoids will help us determine the role of FOXP1 protein during development and the disease mechanism.
- DNA therapy development. We will investigate the therapeutic potential of Adenine Base Editors (ABEs) in correcting the point mutation c.1541G>A(p.Arg514His), by converting the A nucleotide to G.