Dataset Information

LRP1 protects the vasculature by regulating levels of connective tissue growth factor and HtrA1.

ABSTRACT: Low-density lipoprotein receptor-related protein 1 (LRP1) is a large endocytic and signaling receptor that is abundant in vascular smooth muscle cells. Mice in which the lrp1 gene is deleted in smooth muscle cells (smLRP1(-/-)) on a low-density lipoprotein receptor-deficient background display excessive platelet derived growth factor-signaling, smooth muscle cell proliferation, aneurysm formation, and increased susceptibility to atherosclerosis. The objectives of the current study were to examine the potential of LRP1 to modulate vascular physiology under nonatherogenic conditions.We found smLRP1(-/-) mice to have extensive in vivo aortic dilatation accompanied by disorganized and degraded elastic lamina along with medial thickening of the arterial vessels resulting from excess matrix deposition. Surprisingly, this was not attributable to excessive platelet derived growth factor-signaling. Rather, quantitative differential proteomic analysis revealed that smLRP1(-/-) vessels contain a 4-fold increase in protein levels of high-temperature requirement factor A1 (HtrA1), which is a secreted serine protease that is known to degrade matrix components and to impair elastogenesis, resulting in fragmentation of elastic fibers. Importantly, our study discovered that HtrA1 is a novel LRP1 ligand. Proteomics analysis also identified excessive accumulation of connective tissue growth factor, an LRP1 ligand and a key mediator of fibrosis.Our findings suggest a critical role for LRP1 in maintaining the integrity of vessels by regulating protease activity as well as matrix deposition by modulating HtrA1 and connective tissue growth factor protein levels. This study highlights 2 new molecules, connective tissue growth factor and HtrA1, which contribute to detrimental changes in the vasculature and, therefore, represent new target molecules for potential therapeutic intervention to maintain vessel wall homeostasis.

SUBMITTER: Muratoglu SC

PROVIDER: S-EPMC3892666 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

LRP1 protects the vasculature by regulating levels of connective tissue growth factor and HtrA1.

Muratoglu Selen C SC Belgrave Shani S Hampton Brian B Migliorini Mary M Coksaygan Turhan T Chen Ling L Mikhailenko Irina I Strickland Dudley K DK

Arteriosclerosis, thrombosis, and vascular biology 20130718 9

<h4>Objective</h4>Low-density lipoprotein receptor-related protein 1 (LRP1) is a large endocytic and signaling receptor that is abundant in vascular smooth muscle cells. Mice in which the lrp1 gene is deleted in smooth muscle cells (smLRP1(-/-)) on a low-density lipoprotein receptor-deficient background display excessive platelet derived growth factor-signaling, smooth muscle cell proliferation, aneurysm formation, and increased susceptibility to atherosclerosis. The objectives of the current st ...[more]

PMID: 23868935

Similar Datasets

Project description:BackgroundConnective tissue growth factor (CCN2; CTGF) is a newly identified growth factor, which is involved in the regulation of wound repair and fibrosis. Because there is variation among individuals with respect to tissue response to injury, genetic factors might be involved in the final outcome of tissue repair or scarring. For example, polymorphisms in the promoter region of genes, such as those encoding transforming growth factor beta1 (TGF-beta1), interleukin 10 (IL-10), and tumour necrosis factor alpha (TNF-alpha), influence transcriptional responses and are thought to contribute to the dysregulation of these genes in pathological conditions.AimTo investigate whether the promoter region of the ccn2 (ctgf) gene contains polymorphic sequences that might account for differential expression.Materials/methodsSeventy seven human DNA samples were sequenced-45 were from healthy controls and 32 were from patients with ischaemic heart disease (IHD)-using M13 tailed sequence specific ccn2 (ctgf) primers for amplification of a 600 bp fragment upstream of the transcription start site. Amplicons were bidirectionally sequenced with a dye primer M13 forward and reverse sequencing kit.ResultsA C to G substitution was identified at position -132 in one of the patients with IHD. Moreover, in five of the 32 patients with IHD and in six of the 45 healthy controls, a G to C polymorphism was found at position -447. These substitutions at -132 and -447 are thought to lie within predicted binding domains for the transcription factors Pbx-1 and MZF1, respectively. In addition, insertions at position -43 (G), -47 (C), -71 (G) and a C to T substitution at position -198 were found in all DNA samples compared with the published ccn2 (ctgf) promoter sequence. These corrections do not involve sequences predicted to function as transcription factor binding sites.ConclusionSequence analysis of the ccn2 (ctgf) promoter of 77 human DNA samples has revealed corrections and polymorphic sites. The latter lie within putative regulatory elements.

Dataset Information

LRP1 protects the vasculature by regulating levels of connective tissue growth factor and HtrA1.

Publications

LRP1 protects the vasculature by regulating levels of connective tissue growth factor and HtrA1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets