Figure 3: Myc targets Btg2, which is transiently upregulated in cardiomyocytes under adrenergic stimulation.
From: Btg2 is a Negative Regulator of Cardiomyocyte Hypertrophy through a Decrease in Cytosolic RNA
(A) Highly ranked genes in quantified RNA Pol II enrichment score under Ad-Myc transduction conditions in the replicated experiments. (B) Mapped reads for Myc and Pol II at the Btg2 locus and the primer locations used for the quantitative real-time PCR. The numbers at X-axis indicate the relative genomic location (bp) to the Btg2 transcription start site (left). Quantitative real-time PCR evaluation of Myc and Pol II binding at the Btg2 locus in ChIP analysis (right, n = 3, mean ± SD). #p < 0.001 vs Ad-LacZ. (C) Primary cultured rat neonatal cardiomyocytes were starved for 12 h and treated with PE for the indicated time (left). Cardiomyocytes were transfected with shRNA directed against either LacZ or Btg2 (#1 and #2). Twenty-four hours after transduction, cells were starved for 12 h, then treated by PE for 1 h (right). Endogenous Btg2 in cardiomyocytes at each condition was detected by western blotting. Tubulin was used as a loading control. (D) mRNA levels of BTG/TOB family genes were determined by quantitative real-time PCR in cardiomyocytes treated with PE for 1 h (n = 3, mean ± SD). #p < 0.01. (E) Acute pressure overload was induced by transaortic constriction (TAC) in murine hearts. Forty-eight hours after TAC, heart tissues were isolated and the heart weight (HW) normalized to body weight (BW) was measured (n = 4 each, mean ± SD). #p < 0.01. (F) mRNA expression levels for indicated genes in ventricular heart tissues isolated as in (E) were evaluated by quantitative real-time PCR (n = 4 each, mean ± SD). #p < 0.01. ##p < 0.05. (G) Cardiomyocytes were transfected with siRNA directed against Myc or with control siRNA. Twenty-four hours after transfection, cardiomyocytes were starved for 12 h, and treated with PE for the indicated time. Myc and Btg2 mRNA levels at each time point were determined by quantitative real-time PCR (n = 3, mean ± SD). *p < 0.01 vs no treatment with si control. #p < 0.05, ##p < 0.01 vs si control.
