Figure 6.

Tamoxifen-inducible cardiac-specific disruption of PIMT (TmcsPIMT^−/−) in adult mice causes dilated cardiomyopathy. Mice were killed 14 days after first tamoxifen injection in the experiments. (A) Representative photographs of adult hearts after tamoxifen-inducible heart-specific Cre mediated PIMT deletion. It is evident that TmcsPIMT^−/− mouse heart is bigger than that of TmcsPIMT^fl/fl mouse. Lower panel in (A) shows H&E cross sections of TmcsPIMT^−/− and TmcsPIMT^fl/fl hearts; (B) Relative PIMT mRNA expression in TmcsPIMT^fl/fl (WT) and TmcsPIMT^−/− (KO) mouse heart. (C) Western blot analysis of PIMT in TmcsPIMT^fl/fl and TmcsPIMT^−/− hearts. Total proteins from the heart tissues of appropriate mice were prepared as described (see Materials and Methods). They were then Western immunoblotted and probed with an anti-PIMT antibody (Bethyl IHC-00467, 1:1000); (D,E) Representative profiles of M-mode echocardiographic analyses of TmcsPIMT^−/− and littermate control mice; (F,G) represent ejection fraction and fractional shortening respectively. Data were derived from (D,E); (H) Relative mRNA levels of BNP (Nppb) in TmcsPIMT^fl/fl and TmcsPIMT^−/− mouse hearts. The day of initial injection of Tamoxifen was counted as day 1. Results are expressed as the mean ± SD. * p < 0.05, ** p < 0.01.