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

ABSTRACT 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‐ ca tenin T41 editing to t r ea t alv e o l ar 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.