In vivo CRISPR/Cas9 inhibition of hepatic LDH as treatment of Primary Hyperoxaluria.

Genome editing strategies, specially CRISPR/Cas9 systems, have substantially increased the efficiency of innovative therapeutic approaches for many unmet clinical needs, including a significant number of inherited monogenic diseases such as primary hyperoxalurias (PH), a group of autosomal rare metabolic disorders, characterized by defects in enzymes of the glyoxylate metabolism. In our group we are interested in the use of CRISPR/Cas9 systems as therapeutic approaches for PH. We have previously demonstrated that CRISPR/Cas9-mediated reduction of glycolate oxidase represents a promising therapeutic option for PH1. Here, we extended our work evaluating the efficacy of liver-specific inhibition of lactate dehydrogenase (LDH), a key enzyme responsible for converting glyoxylate to oxalate, strategy that would be not limited to PH1, being applicable for other PH subtypes. In this work we demonstrated that CRISPR/Cas9-mediated LDH inhibition after single administration of AAV8 vectors drastically reduced LDH levels in the liver of PH1 and PH3 mice, reducing urine oxalate levels and kidney damage without signs of toxicity. Off-target analysis revealed the safety of this approach with no indel detection in the liver of treated animals. Altogether, our data provides evidence that in vivo genome editing technologies would represent valuable tools for improved and universal therapeutic approaches for PH.