Article Title: A long non-coding RNA protects the heart from pathological hypertrophy
Figure Lengend Snippet: Mhrt inhibits chromatin targeting and gene regulation by Brg1 a, Gel electrophoresis and quantitation of nucleosomal 5SrDNA, Myh6 promoter and Neo DNA. Arrowheads: DNA-histone complex. Arrows: naked DNA. Nucleosome assembly efficiency is defined as the fraction of DNA bound to histones (arrowheads). P-value: Student’s t-test. Error bar: standard error of the mean (SEM). b-d, Quantification of amylose pull-down of MBP-D1D2 (D1D2) with nucleosomal and naked Myh6 promoter DNA ( b ), with nucleosomal Myh6 promoter, Neo , and 5SrDNA ( c ), or with nucleosomal Myh6 promoter in the presence of Mhrt779 ( d ). P-value: Student’s t-test. Error bar: SEM. e, Amylose pull-down of MBP-D1D2 and histone 3. Anti-histone 3 and anti-MBP antibodies were used for western blot analysis. f, ChIP analysis of Brg1 on chromatinized and naked Myh6 promoter in rat ventricular cardiomyocytes. GFP: green fluorescence protein control. P-value: Student’s t-test. Error bar: SEM. g, h, Luciferase reporter activity of Brg1 on naked Myh6 promoter ( g ) or of helicase-deficient Brg1 on chromatinized Myh6 promoter ( h ) in rat ventricular cardiomyocytes. ΔD1: Brg1 lacking amino acid 774–913; ΔD2: Brg1 lacking 1086–1246. GFP: green fluorescence protein control. ChIP: H-10 antibody recognizing N-terminus, non-disrupted region of Brg1. P-value: Student’s t-test. Error bar: SEM. i, j, ChIP analysis in SW13 cells of chromatinized Myh6 promoter in the presence of Mhrt779 ( i ) or helicase-deficient Brg1 ( j ). Vector: pAdd2 empty vector. Mhrt : pAdd2- Mhrt779 . P-value: Student’s t-test. Error bar: SEM. k, Schematic illustration and PCR of human MHRT. MHRT originates from MYH7 and is transcribed into MYH7. MYH7 e xons and introns are indicated. R1 and R2 are strand-specific PCR primers; F1 and R1 target MHRT and MYH7 ; F2 and R2 are specific for MHRT . l, Quantification of MHRT in human heart tissues. Ctrl: control. LVH: left ventricular hypertrophy. ICM: ischemic cardiomyopathy. IDCM: idiopathic dilated cardiomyopathy. P-value: Student’s t-test. Error bar: SEM. m, Working model of a Brg1- Mhrt negative feedback circuit in the heart. Brg1 represses Mhrt transcription, whereas Mhrt prevents Brg1 from recognizing its chromatin targets. Brg1 functions through two distinct promoter elements to bidirectionally repress Myh6 and Mhrt expression. n , Molecular model of how Brg1 binds to its genomic DNA targets. Brg1 helicase (D1D2) binds chromatinized DNA, C-terminal extension (CTE) binds histone 3 (H3), and bromodomain binds acetylated (Ac) histone 3 or 4 (H4).
Article Snippet: In brief, recombinant human core histone octamer, which consist of the 2:1 mix of histone H2A/H2B dimer and histone H3.1/H4 tetramer, were mixed with purified 5SrDNA (208bp, N1202S, NEB), Neo (512bp, amplified from pST18-Neo , 1175025, Roche), Myh6 core promoter (596bp, −426 to +170) and Mhrt core promoter (a3a4, 596bp, −2290 to −1775) DNA at 2 M NaCl.
Techniques: Nucleic Acid Electrophoresis, Quantitation Assay, Western Blot, Chromatin Immunoprecipitation, Fluorescence, Luciferase, Activity Assay, Plasmid Preparation, Polymerase Chain Reaction, Expressing