Kun Yu1, Bin Zheng, Mei Han, Jin-kun Wen. 1. Key Laboratory of Neural and Vascular Biology, Department of Biochemistry and Molecular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China.
Abstract
AIMS: Krüppel-like factor 4 (KLF4) is implicated in all-trans retinoic acid (ATRA)-induced and platelet-derived growth factor-BB (PDGF-BB)-repressed SM22α expression in vascular smooth muscle cells (VSMCs). However, its exact mechanism of action remains unclear. We determined how KLF4 plays different roles in ATRA- and PDGF-BB-dependent regulation of the SM22α gene. METHODS AND RESULTS: ATRA and PDGF-BB induced KLF4 expression but exhibited an opposite effect on SM22α expression and VSMC proliferation. Chromatin immunoprecipitation and oligonucleotide pull-down assays showed that KLF4 was directly bound to the KLF4 binding sites 1 ((-263)CACCC(-259)) and 2 ((-136)GTGGG(-132)) of the SM22α promoter. ATRA increased the binding of KLF4 to site 2, whereas PDGF-BB decreased the binding of KLF4 to site 1. ATRA stimulated KLF4 acetylation by inducing KLF4 phosphorylation and increasing its interaction with p300 via activating c-Jun NH(2)-terminal kinase (JNK) and p38 pathways, and acetylated KLF4 increased its binding activity to site 2. PDGF-BB stimulated KLF4 deacetylation by inducing KLF4 dephosphorylation and increasing its interaction with histone deacetylase 2 (HDAC2) via activating extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase/Akt (PI3K/Akt) pathways, and deacetylated KLF4 dissociated from site 1. CONCLUSIONS: In VSMCs, ATRA activates and PDGF-BB represses SM22α expression through KLF4 binding to, or dissociating from, its different cis-elements in an acetylation-dependent manner.
AIMS: Krüppel-like factor 4 (KLF4) is implicated in all-trans retinoic acid (ATRA)-induced and platelet-derived growth factor-BB (PDGF-BB)-repressed SM22α expression in vascular smooth muscle cells (VSMCs). However, its exact mechanism of action remains unclear. We determined how KLF4 plays different roles in ATRA- and PDGF-BB-dependent regulation of the SM22α gene. METHODS AND RESULTS:ATRA and PDGF-BB induced KLF4 expression but exhibited an opposite effect on SM22α expression and VSMC proliferation. Chromatin immunoprecipitation and oligonucleotide pull-down assays showed that KLF4 was directly bound to the KLF4 binding sites 1 ((-263)CACCC(-259)) and 2 ((-136)GTGGG(-132)) of the SM22α promoter. ATRA increased the binding of KLF4 to site 2, whereas PDGF-BB decreased the binding of KLF4 to site 1. ATRA stimulated KLF4 acetylation by inducing KLF4 phosphorylation and increasing its interaction with p300 via activating c-Jun NH(2)-terminal kinase (JNK) and p38 pathways, and acetylated KLF4 increased its binding activity to site 2. PDGF-BB stimulated KLF4 deacetylation by inducing KLF4 dephosphorylation and increasing its interaction with histone deacetylase 2 (HDAC2) via activating extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase/Akt (PI3K/Akt) pathways, and deacetylated KLF4 dissociated from site 1. CONCLUSIONS: In VSMCs, ATRA activates and PDGF-BB represses SM22α expression through KLF4 binding to, or dissociating from, its different cis-elements in an acetylation-dependent manner.
Authors: Lei Song; Zachary M Zigmond; Laisel Martinez; Roberta M Lassance-Soares; Alejandro E Macias; Omaida C Velazquez; Zhao-Jun Liu; Alghidak Salama; Keith A Webster; Roberto I Vazquez-Padron Journal: Am J Physiol Heart Circ Physiol Date: 2019-08-23 Impact factor: 4.733