Mechanism of de novo mutation in the MTUS1 gene involved in compaction of ventricular myocardium

Abstract:

Objective：To investigate the mechanism of de novo mutation in the microtubule-associated tumor suppressor 1（MTUS1） gene in the compaction of ventricular myocardium. Methods：Lentiviral vectors containing mutant MTUS1 gene or wild MTUS1 gene or empty vectors were co-infected into CP15-5a cells（mutation group，wild group，and vector group，respectively）. The mRNA expression of MTUS1 and small GTPase-ras homolog family member A（RhoA） was measured by real-time PCR. The protein expression of RhoA was measured by Western blot. The fluorescence intensity of α-tubulin was determined by immunofluorescence assay. Cell mi－gration activity was evaluated by wound-healing assay. Results：Lentiviral vectors containing mutant MTUS1 or wild MTUS1 or empty vectors were successfully co-infected into CP15-5a cells，which was confirmed by fluorescence staining and real-time PCR. Immuno-fluorescence assay results showed that the mutation group had a lower fluorescence intensity of α-tubulin than the wild group（P=0.006，P<0.01）. Real-time PCR and Western blot results showed that the mutation group had significantly higher mRNA and protein expression of RhoA compared with the wild group（P=0.005，P=0.01）. Wound-healing assay showed that the mutation group had sig－nificantly higher migration rates at 6 and 12 hours after scratch compared with the wild group（P=0.000，P=0.000）. Conclusion：A de novo mutation in the MTUS1 gene is a protective mutation for decreasing the incidence of noncompaction of ventricular myocardium via reducing the stability of microtubules in CP15-5a cells and increasing cell migration activity by regulating the expression of RhoA.