title: Molecular and functional characterization of LRP1 promoter polymorphism c.1-25 C>G (rs138854007).
abstract: The transcription of the Low-density lipoprotein receptor-related protein (LRP1) is upregulated by aggregated LDL (agLDL) and angiotensin II (AngII) in human vascular smooth muscle cells (hVSMC). The polymorphism c.1-25C>G creates a new GC-box in the LRP1 promoter recognized by Sp1/Sp3 transcription factors. The aims of this study were 1) to evaluate the impact of c.1-25C>G polymorphism on LRP1 transcriptional activity and expression, and 2) to examine the response of c.1-25C>G LRP1 promoter to LDL and AngII. EMSA and Luciferase assays in HeLa cells showed that -25G promoter has enhanced basal transcriptional activity and specific Sp1/Sp3 binding. hVSMC with GG genotype (GG-hVSMC) had higher LRP1 mRNA and protein levels, respectively than CC genotype (CC-hVSMC). EMSA assays showed that the polymorphism determines scarce amount of SRE-B/SREBP-2 complex formation and the failure of agLDL to further reduce these SRE-B/SREBP-2 complexes. Taken together, these results suggest that c.1-25C>G, by difficulting SREBP-2 binding, prevents SREBP-2 displacement required for LRP1 promoter response to LDL. In contrast, c.1-25C>G strongly favours Sp1/Sp3 binding and AngII-induced activity in Sp1/Sp3 dependent manner in GG-hVSMC. This increase is functionally translated into a higher capacity of GG-hVSMC to become foam cells from agLDL in presence of AngII. These results suggest that c.1-25C>G determines a lack of response to agLDL and an exacerbated response to AngII. It is thus conceivable that the presence of the polymorphism would be easily translated to vascular alterations in the presence of the pro-hypertensive autacoid, AngII.
authors: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Autonomous University of Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain.
authors: R
authors: R
authors: Aledo
authors: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Autonomous University of Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain.
authors: P
authors: P
authors: Costales
authors: Biochemistry and Molecular Biology Department, School of Pharmacy, IBUB, University of Barcelona, Barcelona, Spain.
authors: C
authors: C
authors: Ciudad
authors: Biochemistry and Molecular Biology Department, School of Pharmacy, IBUB, University of Barcelona, Barcelona, Spain.
authors: V
authors: V
authors: Noé
authors: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Autonomous University of Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain. Electronic address: cllorente@csic-iccc.org.
authors: V
authors: V
authors: Llorente-Cortes
authors: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Autonomous University of Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain.
authors: L
authors: L
authors: Badimon
mesh_terms: D000804:Angiotensin II / Q000502:physiology; D001665:Binding Sites; D006367:HeLa Cells; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000096:biosynthesis / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D051705:Sp3 Transcription Factor / Q000378:metabolism*; D051782:Sterol Regulatory Element Binding Protein 2 / Q000096:biosynthesis; D015533:Transcriptional Activation
chemical_list: D008077:Lipoproteins, LDL; D026503:Low Density Lipoprotein Receptor-Related Protein-1; C497121:SP3 protein, human; C497390:SREBF2 protein, human; D016329:Sp1 Transcription Factor; D051782:Sterol Regulatory Element Binding Protein 2; D000804:Angiotensin II; D051705:Sp3 Transcription Factor
keywords: Aggregated LDL; Angiotensin II; Cardiovascular disease; Human vascular smooth muscle cells; In vitro transcriptional analysis; LRP1 gene; c.1-25 C>G polymorphism