Supplementary Material for: Pioglitazone Identifies a New Target for Aneurysm Treatment: Role of Egr1 in an Experimental Murine Model of Aortic Aneurysm Charolidi N. Pirianov G. Torsney E. Pearce S. Laing K. Nohturfft A. Cockerill G.W. 10.6084/m9.figshare.5128129.v1 https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Pioglitazone_Identifies_a_New_Target_for_Aneurysm_Treatment_Role_of_Egr1_in_an_Experimental_Murine_Model_of_Aortic_Aneurysm/5128129 Peroxisome proliferator-activated receptor γ agonists have been shown to inhibit angiotensin II (AngII)-induced experimental abdominal aortic aneurysms. Macrophage infiltration to the vascular wall is an early event in this pathology, and therefore we explored the effects of the peroxisome proliferator-activated receptor γ agonist pioglitazone on AngII-treated macrophages. Using microarray-based expression profiling of phorbol ester-stimulated THP-1 cells, we found that a number of aneurysm-related gene changes effected by AngII were modulated following the addition of pioglitazone. Among those genes, polycystic kidney disease 1 <i>(PKD1)</i> was significantly up-regulated (multiple testing corrected p < 0.05). The analysis of the <i>PKD1</i> proximal promoter revealed a putative early growth response 1 (EGR1) binding site, which was confirmed by chromatin immunoprecipitation (ChIP) and quantitative PCR. Further analysis of publicly available ChIP-sequencing data revealed that this putative binding site overlapped with a conserved EGR1 binding peak present in 5 other cell lines. Quantitative real-time PCR showed that EGR1 suppressed <i>PKD1</i>, while AngII significantly up-regulated <i>PKD1</i>, an effect counteracted by pioglitazone. Conversely, in EGR1 short hairpin RNA lentivirally transduced THP-1 cells, reduced EGR1 led to a significant up-regulation of <i>PKD1</i>, especially after treatment with pioglitazone. In vivo, deficiency of <i>Egr1</i> in the haematopoietic compartment of mice completely abolished the incidence of CaCl<sub>2</sub>-induced aneurysm formation. 2015-06-20 00:00:00 Aneurysm Angiotensin II Macrophage Pioglitazone Polycystic kidney disease