| 1. |
- Skenteris, Nikolaos T, et al.
(författare)
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Osteomodulin attenuates smooth muscle cell osteogenic transition in vascular calcification
- 2022
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Ingår i: Clinical and Translational Medicine. - : Wiley. - 2001-1326. ; 12:2, s. 1-22
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Vascular calcification is a prominent feature of late-stage diabetes, renal and cardiovascular disease (CVD), and has been linked to adverse events. Recent studies in patients reported that plasma levels of osteomodulin (OMD), a proteoglycan involved in bone mineralisation, associate with diabetes and CVD. We hypothesised that OMD could be implicated in these diseases via vascular calcification as a common underlying factor and aimed to investigate its role in this context.METHODS AND RESULTS: In patients with chronic kidney disease, plasma OMD levels correlated with markers of inflammation and bone turnover, with the protein present in calcified arterial media. Plasma OMD also associated with cardiac calcification and the protein was detected in calcified valve leaflets by immunohistochemistry. In patients with carotid atherosclerosis, circulating OMD was increased in association with plaque calcification as assessed by computed tomography. Transcriptomic and proteomic data showed that OMD was upregulated in atherosclerotic compared to control arteries, particularly in calcified plaques, where OMD expression correlated positively with markers of smooth muscle cells (SMCs), osteoblasts and glycoproteins. Immunostaining confirmed that OMD was abundantly present in calcified plaques, localised to extracellular matrix and regions rich in α-SMA+ cells. In vivo, OMD was enriched in SMCs around calcified nodules in aortic media of nephrectomised rats and in plaques from ApoE-/- mice on warfarin. In vitro experiments revealed that OMD mRNA was upregulated in SMCs stimulated with IFNγ, BMP2, TGFβ1, phosphate and β-glycerophosphate, and by administration of recombinant human OMD protein (rhOMD). Mechanistically, addition of rhOMD repressed the calcification process of SMCs treated with phosphate by maintaining their contractile phenotype along with enriched matrix organisation, thereby attenuating SMC osteoblastic transformation. Mechanistically, the role of OMD is exerted likely through its link with SMAD3 and TGFB1 signalling, and interplay with BMP2 in vascular tissues.CONCLUSION: We report a consistent association of both circulating and tissue OMD levels with cardiovascular calcification, highlighting the potential of OMD as a clinical biomarker. OMD was localised in medial and intimal α-SMA+ regions of calcified cardiovascular tissues, induced by pro-inflammatory and pro-osteogenic stimuli, while the presence of OMD in extracellular environment attenuated SMC calcification.
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| 2. |
- Karlöf, Eva, et al.
(författare)
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Correlation of computed tomography with carotid plaque transcriptomes associates calcification with lesion-stabilization
- 2019
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Ingår i: Atherosclerosis. - Stockholm : ELSEVIER IRELAND LTD. - 0021-9150 .- 1879-1484. ; 288, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Unstable carotid atherosclerosis causes stroke, but methods to identify patients and lesions at risk are lacking. We recently found enrichment of genes associated with calcification in carotid plaques from asymptomatic patients. Here, we hypothesized that calcification represents a stabilising feature of plaques and investigated how macro-calcification, as estimated by computed tomography (CT), correlates with gene expression profiles in lesions. Methods: Plaque calcification was measured in pre-operative CT angiographies. Plaques were sorted into high- and low-calcified, profiled with microarrays, followed by bioinformatic analyses. Immunohistochemistry and qPCR were performed to evaluate the findings in plaques and arteries with medial calcification from chronic kidney disease patients. Results: Smooth muscle cell (SMC) markers were upregulated in high-calcified plaques and calcified plaques from symptomatic patients, whereas macrophage markers were downregulated. The most enriched processes in high-calcified plaques were related to SMCs and extracellular matrix (ECM) organization, while inflammation, lipid transport and chemokine signaling were repressed. These findings were confirmed in arteries with high medial calcification. Proteoglycan 4 (PRG4) was identified as the most upregulated gene in association with plaque calcification and found in the ECM, SMA+ and CD68+/TRAP + cells. Conclusions: Macro-calcification in carotid lesions correlated with a transcriptional profile typical for stable plaques, with altered SMC phenotype and ECM composition and repressed inflammation. PRG4, previously not described in atherosclerosis, was enriched in the calcified ECM and localized to activated macrophages and smooth muscle-like cells. This study strengthens the notion that assessment of calcification may aid evaluation of plaque phenotype and stroke risk.
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| 3. |
- Karlöf, Eva
(författare)
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Improving stroke risk prediction and individualised treatment in carotid atherosclerosis
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Unstable carotid atherosclerosis causes stroke, but methods to identify patients and lesions at risk are lacking. Currently, this risk estimation is based on measurements of stenosis and neurological symptoms, which determines the therapy of either medical treatment with or without carotid endarterectomy. The efficacy of this therapy is low and higher accuracy of diagnosis and therapy is warranted. Imaging of carotid plaque morphology using software for visualisation of plaque components may improve assessment of plaque phenotype and stroke risk. These studies aimed firstly to investigate if, and if yes, how, the carotid plaque morphology with image analysis of CTA associated with on-going biology in the corresponding specimen. Secondly, if risk stratification in clinical risk scores can be linked to the aforementioned associations. Finally, if the on-going biological processes can be specifically predicted out of the CTA imaging analysis. Methods: Plaque features were analysed in pre-operative CTA with dedicated software. In study I and II, the plaques were stratified according to quantified high and low of each feature, profiled with microarrays, followed by bioinformatic analyses. Immunohistochemistry was performed to evaluate the findings in plaques. In study III, patient phenotype, according to clinical stroke risk scores of CAR and ABCD2 stratified the cohorts of high vs low scores which were subsequently profiled with microarrays, followed by bioinformatic analyses and correlation analyses of plaque morphology in CTA. In study IV, the microarray transcriptomes were individually coupled to morphological data from the CTA analysis, developing models with machine intelligence to predict the gene expression from a CTA image. The models were then tested in unseen patients. Results: In study I, stabilising markers and processes related to SMCs and ECM organisation were associated with highly calcified plaques, while inflammatory and lipid related processes were repressed. PRG4, a novel marker for atherosclerosis, was identified as the most up-regulated gene in highly calcified plaques. Study II showed that carotid lesions with large lipid rich necrotic core, intraplaque haemorrhage or plaque burden were characterized by molecular signatures coupled with inflammation and extracellular matrix degradation, typically linked with instability. Symptomatology associated with large lipid rich necrotic core and plaque burden. Cross-validated prediction model for symptoms, showed that plaque morphology by CTA alone was superior to stenosis degree. Study III revealed that a high clinical risk score in CAR and ABCD2, reflect a plaque phenotype linked to immune response and coagulation, where the novel ABCB5, was one of the most up-regulated genes. The high risk scores correlated with the plaque components matrix and calcification but no positive association with stenosis degree. Study IV resulted in 414 robustly predicted transcripts from the CTA image analysis, of which pathway analysis showed biological processes associated with typical pathophysiology of atherosclerosis and plaque instability. The model testing demonstrated a good correlation between predicted and observed transcript expression levels and pathway analysis revealed a unique dominant mechanism for each individual. Conclusions: Biological processes in carotid plaques associated to vulnerability, can be linked to plaque morphology analysed with CTA image analysis. Patient phenotype classified with clinical risk scores associates to plaque phenotype and morphology in CTA. The biological processes in the atherosclerotic plaque can be predicted with plaque morphology CTA analysis in this small pilot study, providing a possibility to precision medicine after validation in larger scale studies
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