Project description:Vascular calcification is the ectopic deposition of calcium hydroxyapatite minerals in arterial wall. However, the underlying molecular mechanisms regulating vascular calcification remain incompletely understood. In this study, we applied RNA sequencing to explore the mechanism of vascular calcificaiton in both medial and atherosclerotic vascular calcification models.
Project description:IntroductionVascular calcification (VC) is a major risk factor for cardiovascular morbidity and mortality. Depending on the location of mineral deposition within the arterial wall, VC is classified as intimal and medial calcification. Using in vitro mineralization assays, we developed protocols triggering both types of calcification in vascular smooth muscle cells (SMCs) following diverging molecular pathways.Materials and methods and resultsHuman coronary artery SMCs were cultured in osteogenic medium (OM) or high calcium phosphate medium (CaP) to induce a mineralized extracellular matrix. OM induces osteoblast-like differentiation of SMCs-a key process in intimal calcification during atherosclerotic plaque remodeling. CaP mimics hyperphosphatemia, associated with chronic kidney disease-a risk factor for medial calcification. Transcriptomic analysis revealed distinct gene expression profiles of OM and CaP-calcifying SMCs. OM and CaP-treated SMCs shared 107 differentially regulated genes related to SMC contraction and metabolism. Real-time extracellular efflux analysis demonstrated decreased mitochondrial respiration and glycolysis in CaP-treated SMCs compared to increased mitochondrial respiration without altered glycolysis in OM-treated SMCs. Subsequent kinome and in silico drug repurposing analysis (Connectivity Map) suggested a distinct role of protein kinase C (PKC). In vitro validation experiments demonstrated that the PKC activators prostratin and ingenol reduced calcification triggered by OM and promoted calcification triggered by CaP.ConclusionOur direct comparison results of two in vitro calcification models strengthen previous observations of distinct intracellular mechanisms that trigger OM and CaP-induced SMC calcification in vitro. We found a differential role of PKC in OM and CaP-calcified SMCs providing new potential cellular and molecular targets for pharmacological intervention in VC. Our data suggest that the field should limit the generalization of results found in in vitro studies using different calcification protocols.
Project description:Medial arterial calcification is a chronic systemic vascular disorder distinct from atherosclerosis and is commonly observed in patients with chronic kidney disease (CKD), diabetes mellitus, and aging individuals. We previously showed that orphan nuclear receptor NR4A3 is a key regulator in the progression of apolipoprotein (apo) A-IV-induced atherosclerosis; however, little is known about its role in vascular calcification. NR4A3 expression was upregulated in calcified aortic tissues from CKD mice or 1,25(OH)2VitD3 overload-induced mice, and in human calcified aorta. NR4A3 deficiency preserved VSMCs contractile phenotype, inhibited the expression of osteoblast differentiation-related genes, and reduced calcium deposition in the vasculature.
Project description:Medial arterial calcification is a chronic systemic vascular disorder distinct from atherosclerosis and is commonly observed in patients with chronic kidney disease (CKD), diabetes mellitus, and aging individuals. We previously showed that orphan nuclear receptor NR4A3 is a key regulator in the progression of apolipoprotein (apo) A-IV-induced atherosclerosis; however, little is known about its role in vascular calcification. NR4A3 expression was upregulated in calcified aortic tissues from CKD mice or 1,25(OH)2VitD3 overload-induced mice, and in human calcified aorta. NR4A3 deficiency preserved VSMCs contractile phenotype, inhibited the expression of osteoblast differentiation-related genes, and reduced calcium deposition in the vasculature.
Project description:Medial arterial calcification is a chronic systemic vascular disorder distinct from atherosclerosis and is commonly observed in patients with chronic kidney disease (CKD), diabetes mellitus, and aging individuals. We previously showed that orphan nuclear receptor NR4A3 is a key regulator in the progression of apolipoprotein (apo) A-IV-induced atherosclerosis; however, little is known about its role in vascular calcification. NR4A3 expression was upregulated in calcified aortic tissues from CKD mice or 1,25(OH)2VitD3 overload-induced mice, and in human calcified aorta. NR4A3 deficiency preserved VSMCs contractile phenotype, inhibited the expression of osteoblast differentiation-related genes, and reduced calcium deposition in the vasculature.
Project description:Ectopic calcification in synovial tissues is devastating to diarthrodial joints. While some forms of synovial ectopic calcification have genetically simple basis, most cases manifest as complex traits with environmental and multigenic components. The location of causal loci or the physiological processes affected by allelic variants is poorly understood. Here, we report on genetic susceptibility to ectopic calcification in the LG/J and SM/J advanced intercross mice. Using 347 mice in 98 full-sibships, destabilization of medial meniscus was performed to induce joint injury. We performed quantitative trait locus (QTL) analysis to map calcification phenotypes to discrete genomic locations. To validate the functional significance of the selected QTL candidate genes, we compared mRNA expression between parental LG/J and SM/J inbred strains. Our findings showed that joint destabilization instigated ectopic calcifications as detected and quantified by micro-CT. Overall, we detected 20 QTLs affecting synovial and meniscus calcification phenotypes with 11 QTLs linked to synovial calcification. Functional and bioinformatic analyses of single nucleotide polymorphism identified functional classifications relevant to angiogenesis (Myo1e, Kif26b, Nprl3, Stab2, Fam105b), bone metabolism/calcification (Tle3, Tgfb2, Lipc, Nfe2l1, Ank, Fam105b), arthritis (Stab2, Tbx21, Map4k4, Hoxb9, Larp6, Col1a2, Adam10, Timp3, Nfe2l1, Trpm3), and ankylosing-spondylitis (Ank, Pon1, Il1r2, Tbkbp1) indicating that ectopic calcification involves multiple mechanisms. Furthermore, the expression of 11 candidate genes was significantly different between LG/J and SM/J. Correlation analysis showed that Aff3, Fam81a, Syn3, and Ank were correlated with synovial calcification. Our findings of multiple genetic loci affecting the phenotype suggest the involvement of multiple genes contributing to its pathogenesis. We collected tissue lysates from the formalin-fixed paraffin-embedded sections from mouse knee joints and analyzed the expression of several genes by Affymetrix QuantiGene Plex assay.