[Truncated abstract] Our understanding of the actions of oestrogen on the vasculature has recently been questioned following the results of large clinical trials revealing a negative effect of hormone replacement therapy (HRT) on cardiovascular disease (CVD) risk amongst postmenopausal women. It is important to determine how a hormone with numerous positive effects on intermediate pathways of atherosclerosis fails to offer cardioprotection. Further investigation into the actions of oestrogen in the vasculature may add to our current understanding of the pathogenesis of atherosclerosis and oestrogen biology. The primary aim of this thesis was to investigate involvement of the oestrogen receptors (ERs) in atherosclerotic CVD and to provide further insight into the actions of oestrogen on the vasculature by studying the actions of oestrogen on the regulation of an oestrogen-responsive gene within human vascular cells. Following confirmation of ERa and ERß expression at the RNA and protein level in human aorta sections, correlations of receptor expression with age and atherosclerosis were examined. Significantly strong negative relationships of ERa, androgen receptor (AR), and progesterone receptor (PR) with age in both males and females were detected. No trend was detected between ERß expression and age. These findings suggest that the receptor-mediated actions of hormones in the vasculature may change with age. Further, this thesis compared for the first time sex hormone receptor expression in normal and adjacent atherosclerotic aortic tissue providing a critical assessment of receptor differences due to atherosclerosis. Results revealed reductions of all hormone receptors in early atherosclerotic versus normal aorta tissue. ... These results suggest that the 3'-UTR SNPS may have more of an influence on carotid thickening when oestrogen levels are lower, suggesting the importance of both genetic variation of the ERß gene and oestrogen status on carotid thickening. Finally, this was the first study to investigate oestrogen-induced regulation of angiotensinogen (AGT), a candidate gene for CVD, in human vascular cells. Oestrogen influenced AGT transcription in a cell specific manner. The overall influence of oestrogen on AGT transcription in the vasculature is unknown. This thesis adds to the knowledge of oestrogen and atherosclerosis by suggesting the involvement of the sex hormone receptors (ERa, ERß, PR and AR) in atherosclerosis, presenting ERß as a potentially important candidate gene for atherosclerosis, revealing interactions between estrogen status and associations of ERß SNPs with carotid thickening, and demonstrating vascular cell-specific actions of oestrogen on the regulation of a candidate gene for CVD. These factors may have contributed to the lack of cardio-protection following HRT, as revealed by large clinical trials.

[Truncated thesis] Background & Aims- The determinants of atherosclerosis in elderly postmenopausal women are poorly understood. We do not know if the traditional coronary heart disease (CHD) risk factors remain important in this group. Despite the growing body of data relating to exogenous estrogen, we know very little about the relationship of endogenous estrogen with inflammation, CHD risk factors and subclinical atherosclerosis in elderly women. Genes that may play a role in post-menopausal cardiovascular disease (CVD)(ER-α and Apo E gene polymorphisms) have not been examined in this population for their effect on sub-clinical atherosclerosis and whether this effect is modified by the level of endogenous estrogen. We have examined the effect of established cardiovascular risk factors, endogenous estrogen and Apo E genotype on carotid artery atherosclerosis in a large group of women over the age of 70 years. In smaller sub-groups, we have examined the relationship between ER-α gene polymorphisms and atherosclerosis and the relationship between endogenous estrogen and CRP. Methods- We studied 1149 ambulatory elderly women who were recruited from the electoral role in Perth, Western Australia in 1998 and subsequently underwent carotid ultrasound assessment in 2001 according to a standardised protocol (for detection of focal plaque and measurement of intimal-medial thickness). The subjects had a mean age of 75 years (range 70 to 82 years) at baseline. We assessed the following variables in almost all subjects at baseline; time from menopause, FEI (molar ratio of plasma estradiol to sex hormone binding globulin (SHBG) x 1000), systolic and diastolic blood pressure, total cholesterol, LDL and HDL cholesterol, triglycerides, body mass index, glycated haemoglobin, homocysteine, apolipoprotein E (ApoE) genotype, history of smoking, diabetes, cardiovascular disease and medication use. Four hundred and thirty three women were analysed for estrogen receptor alpha (ERα) genotype and 100 underwent measurement of high sensitivity C-reactive protein.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Atherosclerosis preferentially develops in vascular regions of low or disturbed flow and high spatial gradients. Endothelial cells that line the vessel walls actively participate in translating mechanical stimuli, shear stress due to fluid flow, into intracellular signals to regulate cellular activities. Atherosclerosis is a chronic disease. During its development, a cascade of inflammatory signals alters the arterial endothelial homeostatic functions. Death-associated protein (DAP) kinase and its correlated pathway have been associated with cell apoptosis, turnover, and cytoskeleton remodeling in cellular networks, ultimately leading to changes in cell motility and vascular wall permeability. DAP-kinase is also highly regulated by inflammatory triggers such as TNF-α. This thesis investigates DAP-kinase modulation due to shear stress, and the role of DAP-kinase activity in endothelial responses toward applied shear stress. Using bovine aortic endothelial cells (BAEC), DAP-kinase expression is demonstrated in both sheared (10 dynes/cm2) and static conditions. Overall DAPK expression increased with extended shearing, while the presence of phosphorylated DAPK decreased with applied shear stress, as demonstrated in Western blot analysis. In correlation, DAPK RNA expression profiles were explored to understand pre-translational behavior and to understand just how shear stress influences DAPK expression over time. There is a temporal increase in DAPK mRNA, occurring at earlier time points when compared to DAPK protein expression, displaying the precedence of mRNA expression leading to increased translation into protein. From our apoptosis assay results, shear stress reduces apoptotic and late stage/necrotic cell fractions. The exposure of shear stress potentially plays a role in inhibiting apoptosis activation and TNF-α induced death cascade. Overall, the apoptosis activity influenced by shear further exhibits a possible connection between shear stress and apoptosis inhibition. The shear stress ultimately decreases overall apoptosis, while DAPK expression is increased. Therefore, DAPK may have a function in other possible mechano-transduction cascades, when endothelial cells are exposed to constant shear. Our data suggests shear stress modulation of DAP-kinase expression and activity, and the potential crosstalk of mechano-transduction and DAPK/apoptosis pathway, may lead to further understanding the responsibility of DAPK in endothelial cell function.

No description available.

Atherosclerotic cardiovascular disease is a leading cause of death in the United States and worldwide. While much progress has been made in investigating dyslipidemia and inflammation regarding atherosclerotic disease, much is still unknown about the role of endogenous vascular cells in atherosclerosis. More importantly, as targeting dyslipidemia and inflammation has yielded successful therapies, can therapeutically targeting vascular dysfunction enhance existing therapies for treating cardiovascular disease? In this thesis, I sought to investigate the role of the matrix metalloproteinase, ADAMTS7, a gene implicated in atherosclerosis by genome-wide association studies (GWAS). Subsequent to the human genetic studies associating ADAMTS7 with atherosclerotic cardiovascular disease, in vivo investigations demonstrated that ADAMTS7 is proatherogenic and induced in response to vascular injury. However, the mechanisms governing ADAMTS7's function and the causal cell type responsible for producing ADAMTS7 remain unclear. To determine where ADAMTS7 expression occurs in atherosclerosis, we interrogated the largest single-cell RNA sequencing dataset of human carotid atherosclerosis. We found ADAMTS7 expression in endothelial cells, smooth muscle cells (SMCs), fibroblasts, and mast cells. We subsequently created both endothelial and SMC-specific Adamts7 conditional knockout and transgenic mice. The conditional knockout of Adamts7 in either cell type is insufficient to reduce atherosclerosis, but transgenic induction in either cell type increases peripheral atherosclerosis. In SMC transgenic mice, this increase coincides with decreased plaque stability and an expansion of lipid-laden SMC foam cells. RNA sequencing in SMCs revealed an upregulation of lipid uptake genes typically assigned to macrophages. Subsequent experiments demonstrated that Adamts7 increases SMC oxLDL uptake through Cd36. Furthermore, Cd36 expression is increased due to an Adamts7-mediated increase in Spi1, a known myeloid cell fate transcription factor. In summary, Adamts7 is expressed by multiple vascular cell types during atherosclerosis, and in SMCs, Adamts7 promotes oxLDL uptake, thereby increasing SMC foam cell and atherosclerosis. While investigating ADAMTS7, we sought to identify a cell surface persistent marker of SMCs to aid investigations into ADAMTS7. SMCs play a central role in the development of atherosclerosis due in part to their capability to phenotypically transition into either a protective or harmful state. However, the ability to identify and trace SMCs and their progeny in vivo is limited due to the lack of well-defined SMC cell surface markers. Therefore, investigations into SMC fate must utilize lineage-tracing mouse models, which are time-consuming and challenging to generate and not feasible in humans. We, thus, employed CITE-seq to phenotypically characterize the expression of 119 cell surface proteins in mouse atherosclerosis. We found that CD200 is a highly expressed and specific marker of SMCs, which persists even with phenotypic modulation. We validated our findings using a combination of flow cytometry, qPCR, and immunohistochemistry, all confirming that CD200 can identify and mark SMCs and their derived cells in early to advanced mouse atherosclerotic lesions. Additionally, we describe a similar expression pattern of CD200 in human coronary and carotid atherosclerosis. Thus, CD200 is a lineage marker for SMCs and SMC-derived cells in mouse and human atherosclerosis. In conclusion, this body of work investigated the role of vascular cells in atherosclerosis. We have identified a new marker of SMCs, adding an additional tool that can be broadly employed to investigate the vasculature. In addition, we have mechanistically unraveled how one vascular GWAS hit, ADAMTS7, can perpetuate atherosclerosis. Our findings demonstrate that ADAMTS7 can promote foam cell expansion in atherosclerosis. While more work is needed to understand the role of these SMC foam cells in atherosclerosis, our investigations thus far have demonstrated that ADAMTS7 can greatly expand these cells. As such, our work supports the development of a drug to inhibit ADAMTS7 for treating atherosclerotic cardiovascular disease.