Exploring RNA-binding repeat proteins as tools for splicing modulation / Characterization of an in vivo critical-sized bone defect regeneration using bioactively coated osteogenic ceramic granules

Transcriptome editing has opened a variety of possibilities for new therapeutic strategies, including the modulation of mRNA splicing using antisense oligonucleotides (ASOs), a treatment already approved for spinal muscular atrophy (SMA). However, the use of ASOs presents some disadvantages, and is important to explore alternative strategies, such as engineered RNA-binding repeat proteins. These proteins, such as the pentatricopeptide (PPR) and the Pumilio and FBF (PUF) families, can selectively bind specific RNA sequences based on an amino acid code, with each repeat recognizing a single base. This allows for the design of modular proteins programmed to bind a target sequence with elevated affinity and specificity.

In this project, we design and characterize a PPR and a PUF protein that specifically bind a sequence in SMN2 mRNA to induce exon 7 inclusion as a therapeutic strategy to correct splicing in SMA.

These newly engineered proteins modulate SMN2 splicing and are promising tools for transcriptome editing in additional splicing-related disorders.

Critical-sized bone defects are defined as those that will not heal spontaneously within a patient’s lifetime. These non-union bone defects are common in cases of major orthopaedic fracture and bone loss (particularly those resulting from trauma) and they have an increasing prevalence when considering the rise in osteoporosis cases. In fact, over 2 million surgical cases require bone graft to repair these defects each year worldwide. However, current products and clinical practice have their limitations.

Bioengineered bone graft systems need to be able to guide the regrowth of new bone into substantial voids and, therefore, implants pre-seeded with mineralizing cells are of significant clinical interest. To facilitate this process and improve bone regeneration, the EU-funded HEALIKICK project is working on a novel combinatorial approach that employs a granular graft material with a highly osteogenic coating. In this context, our group implements the multiscale characterization of biological tissues, paying special attention to the biomaterial-tissue interface.