Bach1-induced suppression of angiogenesis is dependent on the BTB domain
Li Jiang,
Mengping Jia,
Xiangxiang Wei,
Jieyu Guo,
Shengyu Hao,
Aihong Mei,
Xiuling Zhi,
Xinhong Wang,
Qinhan Li,
Jiayu Jin,
Jianyi Zhang,
Shanqun Li,
Dan Meng
Affiliations
Li Jiang
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Mengping Jia
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Xiangxiang Wei
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Jieyu Guo
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Shengyu Hao
Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China
Aihong Mei
Department of Respiratory Medicine, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
Xiuling Zhi
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Xinhong Wang
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Qinhan Li
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Jiayu Jin
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
Jianyi Zhang
Department of Biomedical Engineering, School of Medicine, University of Alabama at Birmingham, Birmingham 35294, USA
Shanqun Li
Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Corresponding author at: 180 Fenglin Rd., Shanghai, 200032, China.
Dan Meng
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; Co-corresponding author at: 138 Yixueyuan Rd, P.O. Box: 224, Shanghai 200032, China.
The transcription factor Bach1 impairs angiogenesis after ischemic injury by suppressing Wnt/β-catenin signaling; however, the specific domains responsible for the anti-angiogenic effects of Bach1 remain unclear. This study determined the role of the BTB domain of Bach1 in ischemic angiogenesis. Bach1 is highly expressed in circulating endothelial cells from acute myocardial infarction patients and is the early induction gene after ischemia. Mice were treated with adenoviruses coding for GFP (AdGFP), Bach1 (AdBach1), or a Bach1 mutant lacking the BTB domain (AdBach1-ΔBTB) after surgically induced hind-limb ischemia. Measures of blood-flow recovery, capillary density, and the expression of vascular endothelial growth factor (VEGF) and heme oxygenase-1 (HO-1) were significantly lower and ROS levels were higher in the AdBach1 group, but not in AdBach1-ΔBTB animals. Furthermore, transfection with AdBach1, but not AdBach1-ΔBTB, in human endothelial cells was associated with significant declines in 1) capillary density and hemoglobin content in the Matrigel-plug assay, 2) proliferation, migration, tube formation, and VEGF and HO-1 expression in endothelial cells. Bach1 binds directly with TCF4, and this interaction is mediated by residues 81–89 of the Bach1 BTB domain and the N-terminal domain of TCF4. Bach1, but not Bach1-ΔBTB, also co-precipitated with histone deacetylase 1 (HDAC1), while the full-length HDAC1 proteins, but not HDAC1 mutants lacking the protein-interaction domain, co-precipitated with Bach1. Collectively, these results demonstrate that the anti-angiogenic activity of Bach1 is crucially dependent on molecular interactions that are mediated by the protein's BTB domain, and this domain could be a drug target for angiogenic therapy. Keywords: Angiogenesis, Bach1, The BTB domain, VEGF, TCF4
