RESUMO
Myocardial infarction (MI) is a frequent outcome of coronary artery disease (CAD) and the key factor contributing to worldwide disability and death. Genetic factors contribute to the pathogenesis of CAD/MI, and SNP rs6903956 in the ADTRP gene was first found associated with CAD/MI in the Chinese Han population, which was successfully replicated in other cohorts. However, whether rs6903956 is a functional SNP and its risk mechanism to CAD/MI remains unknown. The ADTRP gene-encoded androgen-dependent TFPI regulating protein regulates vascular endothelial cell function, endothelial-monocyte adhesion, and thrombosis. The allele A of rs6903956, in particular, is associated with lower ADTRP mRNA levels in lymphocytes. In the current study, we found that SNP rs6903956 exhibits allelic differences in transcriptional activity by interacting with GATA2. Also, the A allele conferred a greater risk of CAD and MI, lowered transcriptional activity, and GATA2 binding ability as compared to the G allele. Our findings provide details on how rs6903956 regulates the expression of ADTRP and may provide novel insights into CAD pathology and susceptibility.
Assuntos
Doença da Artéria Coronariana/genética , Fator de Transcrição GATA2/genética , Proteínas de Membrana/genética , Alelos , Células Cultivadas , Doença da Artéria Coronariana/epidemiologia , Epistasia Genética , Fator de Transcrição GATA2/metabolismo , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Predisposição Genética para Doença , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas de Membrana/metabolismo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de RiscoRESUMO
Coronary artery disease (CAD) is the leading cause of death worldwide. GWAS have identified >50 genomic loci for CAD, including ADTRP and MIA3/TANGO1. However, it is important to determine whether the GWAS genes form a molecular network. In this study, we have uncovered a novel molecular network between ADTRP and MIA3/TANGO1 for the pathogenesis of CAD. We showed that knockdown of ADTRP expression markedly down-regulated expression of MIA3/TANGO1. Mechanistically, ADTRP positively regulates expression of PIK3R3 encoding the regulatory subunit 3 of PI3K, which leads to activation of AKT, resulting in up-regulation of MIA3/TANGO1. Both ADTRP and MIA3/TANGO1 are involved in endothelial cell (EC) functions relevant to atherosclerosis. Knockdown of ADTRP expression by siRNA promoted oxidized-LDL-mediated monocyte adhesion to ECs and transendothelial migration of monocytes, inhibited EC proliferation and migration, and increased apoptosis, which was reversed by expression of constitutively active AKT1 and MIA3/TANGO1 overexpression, while the over-expression of ADTRP in ECs blunted these processes. Knockdown of MIA3/TANGO1 expression also promoted monocyte adhesion to ECs and transendothelial migration of monocytes, and vice versa for overexpression of MIA3/TANGO1. We found that ADTRP negatively regulates the levels of collagen VII and ApoB in HepG2 and endothelial cells, which are downstream regulatory targets of MIA3/TANGOI. In conclusion, we have uncovered a novel molecular signaling pathway for the pathogenesis of CAD, which involves a novel gene-gene regulatory network. We show that ADTRP positively regulates PIK3R3 expression, which leads to activation of AKT and up-regulation of MIA3/TANGO1, thereby regulating endothelial cell functions directly relevant to atherosclerosis.
Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto/biossíntese , Aterosclerose/metabolismo , Doença da Artéria Coronariana/metabolismo , Redes Reguladoras de Genes , Predisposição Genética para Doença , Células Endoteliais da Veia Umbilical Humana/metabolismo , Proteínas de Membrana/metabolismo , Transdução de Sinais , Translocador Nuclear Receptor Aril Hidrocarboneto/genética , Aterosclerose/genética , Aterosclerose/patologia , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/patologia , Regulação da Expressão Gênica/genética , Estudo de Associação Genômica Ampla , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Proteínas de Membrana/genética , Fosfatidilinositol 3-Quinases/biossíntese , Fosfatidilinositol 3-Quinases/genéticaRESUMO
The ADTRP gene encodes the androgen-dependent TFPI-regulating protein and is a susceptibility gene for contrary artery disease (CAD). We performed global gene expression profiling for ADTRP knock-down using microarrays in human HepG2 cells. Follow-up real-time RT-PCR analysis demonstrated that ADTRP knock-down regulates a diverse set of genes, including upregulation of seven histone genes, downregulation of multiple cell cycle genes (CCND1, CDK4, and CDKN1A), and upregulation of apoptosis genes (CASP7 and PDCD2) in HepG2 cells and endothelial cells. Consistently, ADTRP increases the number of S phase cells during cell cycle, promotes cell proliferation, and inhibits apoptosis. Our study provides novel insights into the function of ADTRP and biological pathways involving ADTRP, which may be involved in the pathogenesis of CAD.