Fig. 2.

KLF15 inhibits cardiomyocyte hypertrophy in vitro. (A) KLF15 inhibits hypertrophic gene expression. NRVM were cultured for 24 h, infected with empty (Ad-GFP) or KLF15 adenovirus (Ad-GFP-KLF15) and total RNA was isolated for Northern blot analysis using indicated probes. (B) KLF15 inhibits basal and PE-induced ANF/BNP promoter activity. NRVMs overexpressing EV or KLF15 were transfected with −638 ANF-luc or −116 BNP-luc promoters. Luciferase activity (normalized to β-gal activity) was expressed as fold induction compared with empty vector (EV) (n = 9–12 per group). (C) KLF15 inhibits protein synthesis in NRVM as measured by leucine incorporation. Cells were treated with PE (50 μM) (+) or (−) [³H]leucine (2.5 μCi/ml) for 48 h (n = 9 per group). (D) KLF15 reduces myocyte size. NRVMs overexpressing EV or KLF15 were serum-starved for 48 h (+) or (−) PE (50 μM) and analyzed by using FACS in triplicate. The geometric mean of forward scatter (FSC) data were used as a correlate of cell size (Left). Representative micrographs of NRVM immunostained with anti-α-actinin antibodies (Right).