Keywords
Published : 2026-08-14
Abstract
Immobilization-induced muscle wasting is notoriously hard to counter pharmacologically. We tested whether CRISPR-mediated knockdown of miR-146a could offer protection and asked what might explain such an effect. Four sgRNAs were designed against the mouse miR-146a precursor; the best performer (lentiCRISPR miR-146a-3#), which gave ~80% cleavage in T7EI assays, was packaged into lentivirus. Forty C57BL/6 mice were randomly assigned to receive either this editing construct or a control vector, then underwent sham surgery or hindlimb immobilization. Western blotting confirmed Cas9 expression, and qPCR verified miR-146a reduction. In immobilized mice, miR-146a rose markedly, accompanied by elevated Atrogin-1 and MuRF-1 mRNAs, reduced myofiber cross-sectional area, and diminished p-mTOR and p-Akt signals. By contrast, animals given the miR-146a-editing virus showed lower atrogene expression, larger fibers, and restored mTOR/Akt phosphorylation. These results suggest that CRISPR-based miR-146a ablation mitigates disuse atrophy, and this benefit appears to be linked to reactivation of the mTOR/Akt anabolic pathway.
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