Article Title: Lack of miR-133a Decreases Contractility of Diabetic Hearts: A Role for Novel Cross Talk Between Tyrosine Aminotransferase and Tyrosine Hydroxylase
Figure Lengend Snippet: Regulatory role of miR-133a in diabetic hearts. miR-133a targets 3′UTR of TAT. A : The binding sequence of miR-133a with TAT 3′UTR in rat. B : The plasmid clone of TAT 3′UTR used for luciferase (Luc) reporter assay. The mutant plasmid is identical except the miR-133a binding site is deleted. CMV, cytomegalovirus; hLuc, humanized firefly luciferase; hRLuc, humanized renilla luciferase; SV40, simian vacuolating virus 40. The luciferase reporter assay results with TAT 3′UTR ( C ) and mutant TAT 3′UTR ( D ). miR, miR-133a; scm, scrambled. The relative luciferase activity is measured in CATH.a cells treated with 3′UTR and increasing doses of miR-133a. The values are mean ± SEM ( n = 6). E : miR-133a regulates contractility by targeting TAT in diabetic hearts. Schematic shows that the reduced level of miR-133a upregulates TAT in diabetic hearts. Elevated TAT inhibits TH, which decreases the cardiac NE (c-NE) level. It results in inactivation of β 1 -AR and β 2 -AR that decreases contractility in diabetic hearts. However, treatment with miR-133a mimic increases the miR-133a level in the diabetic heart that decreases TAT by binding to its 3′UTR. Decreased TAT increases the level of TH, which induces c-NE biosynthesis. The elevated level of c-NE induces β-AR and improves the contractility of diabetic hearts.
Article Snippet: miR-133a (cat #MmiR3445-MR03), scrambled miRNA (cat #CmiR0001-MR03), anti–miR-133a (cat #MmiR-AN0880-AM04), and TAT 3′-untranslated region (UTR) clones (WT 3′UTR: cat #RmiT048999-MT01; mutant 3′UTR: CS-RmiT048999-MT01-01) were purchased from GeneCopoeia, Rockville, MD.
Techniques: Binding Assay, Sequencing, Plasmid Preparation, Luciferase, Reporter Assay, Mutagenesis, Activity Assay