Mini-Catalytically Inactive Cas13X-Derived RNA Base Editing of β-Catenin Attenuates Pulmonary Damage in a Murine Acute Lung Injury Model.

Acute lung injury (ALI) is characterized by a considerable mortality rate and currently lacks viable therapeutic strategies. Alveolar type II epithelial cells (AT2 cells) play a critical role in lung injury repair, potentially through activation of the Wnt/β-catenin signaling cascade, which may enhance regenerative ability of lung tissue. In this study, we developed a mini-catalytically inactive Cas13X (mini dCas13X)-based adenosine-to-inosine (A-to-I) RNA editing approach, designated as β-catenin T41 editing to treat alveolar type 2 cells (CARTEL), with the objective of alleviating lung damage in ALI. We found that CARTEL proficiently performed base editing on β-catenin, achieving a high A-to-I conversion rate with minimal off-target effects. Moreover, CARTEL significantly inhibited the degradation of β-catenin, amplified Wnt/β-catenin signaling activation and facilitated cellular proliferation. In a murine model of lipopolysaccharide (LPS)-induced ALI, a single adeno-associated virus (AAV)-mediated administration of CARTEL effectively and primarily transduced AT2 cells, resulting in attenuated lung injury, enhanced AT2 cell proliferation, and improved pulmonary function, with no detected long-term risks. Collectively, these findings revealed that CARTEL-mediated RNA editing represents a promising therapeutic strategy to counteract lung injury occurring in diverse settings.