Differing calcification processes in cultured vascular smooth muscle cells and osteoblasts

© 2019 Published by Elsevier Inc.Arterial medial calcification (AMC) is the deposition of calcium phosphate mineral, often as hydroxyapatite, inthe medial layer of the arteries. AMC shares some similarities to skeletal mineralisation and has been associatedwith the transdifferentiation of vascular smooth muscle cells (VSMCs) towards an osteoblast-like phenotype. Thisstudy used primary mouse VSMCs and calvarial osteoblasts to directly compare the established and widely usedin vitromodels of AMC and bone formation. Significant differences were identified between osteoblasts andcalcifying VSMCs. First, osteoblasts formed large mineralised bone nodules that were associated with widespreaddeposition of an extracellular collagenous matrix. In contrast, VSMCs formed small discrete regions of calcifi-cation that were not associated with collagen deposition and did not resemble bone. Second, calcifying VSMCsdisplayed a progressive reduction in cell viability over time (≤7-fold), with a 50% increase in apoptosis,whereas osteoblast and control VSMCs viability remained unchanged. Third, osteoblasts expressed high levels ofalkaline phosphatase (TNAP) activity and TNAP inhibition reduced bone formation by to 90%. TNAP activity incalcifying VSMCs was∼100-fold lower than that of bone-forming osteoblasts and cultures treated withβ-gly-cerophosphate, a TNAP substrate, did not calcify. Furthermore, TNAP inhibition had no effect on VSMC calci-fication. Although, VSMC calcification was associated with increased mRNA expression of osteoblast-relatedgenes (e.g. Runx2, osterix, osteocalcin, osteopontin), the relative expression of these genes was up to 40-foldlower in calcifying VSMCs versus bone-forming osteoblasts. In summary, calcifying VSMCsin vitrodisplay somelimited osteoblast-like characteristics but also differ in several key respects: 1) their inability to form collagen-containing bone; 2) their lack of reliance on TNAP to promote mineral deposition; and, 3) the deleterious effectof calcification on their viability.Peer reviewedFinal Published versio

Endothelial HO-1 induction by model TG-rich lipoproteins is regulated through a NOX4-Nrf2 pathway

Circulating levels of chylomicron remnants (CMRs) increase postprandially and their composition directly reflects dietary lipid intake. These TG-rich lipoproteins likely contribute to the development of endothelial dysfunction, albeit via unknown mechanisms. Here, we investigated how the FA composition of CMRs influences their actions on human aortic endothelial cells (HAECs) by comparing the effects of model CMRs—artificial TG-rich CMR-like particles (A-CRLPs)—containing TGs extracted from fish, DHA-rich algal, corn, or palm oils. HAECs responded with distinct transcriptional programs according to A-CRLP TG content and oxidation status, with genes involved in antioxidant defense and cytoprotection most prominently affected by n-3 PUFA-containing A-CRLPs. These particles were significantly more efficacious inducers of heme oxygenase-1 (HO-1) than n-6 PUFA corn or saturated FA-rich palm CRLPs. Mechanistically, HO-1 induction by all CRLPs requires NADPH oxidase 4, with PUFA-containing particles additionally dependent upon mitochondrial reactive oxygen species. Activation of both p38 MAPK and PPARβ/δ culminates in increased nuclear factor erythroid 2-related factor 2 (Nrf2) expression/nuclear translocation and HO-1 induction. These studies define new molecular pathways coupling endothelial cell activation by model CMRs with adaptive regulation of Nrf2-dependent HO-1 expression and may represent key mechanisms through which dietary FAs differentially impact progression of endothelial dysfunction

Vascular Endothelial Growth Factor Receptor-2 Couples Cyclo-Oxygenase-2 with Pro-Angiogenic Actions of Leptin on Human Endothelial Cells

The adipocyte-derived hormone leptin influences the behaviour of a wide range of cell types and is now recognised as a pro-angiogenic and pro-inflammatory factor. In the vasculature, these effects are mediated in part through its direct leptin receptor (ObRb)-driven actions on endothelial cells (ECs) but the mechanisms responsible for these activities have not been established. In this study we sought to more fully define the molecular links between inflammatory and angiogenic responses of leptin-stimulated human ECs../Akt/COX-2 signalling axis is required for leptin's pro-angiogenic actions and that this is regulated upstream by ObRb-dependent activation of VEGFR2. These studies identify a new function for VEGFR2 as a mediator of leptin-stimulated COX-2 expression and angiogenesis and have implications for understanding leptin's regulation of the vasculature in both non-obese and obese individuals

Suppression of nuclear factor-κB activity in macrophages by chylomicron remnants: modulation by the fatty acid composition of the particles

Current evidence indicates that chylomicron remnants (CMR) induce macrophage foam cell formation, an early event in atherosclerosis. Inflammation also plays a part in atherogenesis and the transcription factor nuclear factor-κB (NF-κB) has been implicated. In this study, the influence of CMR on the activity of NF-κB in macrophages and its modulation by the fatty acid composition of the particles were investigated using macrophages derived from the human monocyte cell line THP-1 and CMR-like particles (CRLPs). Incubation of THP-1 macrophages with CRLPs caused decreased NF-κB activation and downregulated the expression of phospho-p65–NF-κB and phospho-IκBα (pIκBα). Secretion of the inflammatory cytokines tumour necrosis factor α, interleukin-6 and monocyte chemoattractant protein-1, which are under NF-κB transcriptional control, was inhibited and mRNA expression for cyclooxygenase-2, an NF-κB target gene, was reduced. CRLPs enriched in polyunsaturated fatty acids compared with saturated or monounsaturated fatty acids had a markedly greater inhibitory effect on NF-κB binding to DNA and the expression of phospho-p65–NF-κB and pIκB. Lipid loading of macrophages with CRLPs enriched in polyunsaturated fatty acids compared with monounsaturated fatty acids or saturated fatty acids also increased the subsequent rate of cholesterol efflux, an effect which may be linked to the inhibition of NF-κB activity. These findings demonstrate that CMR suppress NF-κB activity in macrophages, and that this effect is modulated by their fatty acid composition. This downregulation of inflammatory processes in macrophages may represent a protective effect of CMR which is enhanced by dietary polyunsaturated fatty acids

The Johnsonian January 26, 1924

The Johnsonian is the weekly student newspaper of Winthrop University. It is published during fall and spring semesters with the exception of university holidays and exam periods. We have proudly served the Winthrop and Rock Hill community since 1923.https://digitalcommons.winthrop.edu/thejohnsonian/1006/thumbnail.jp

Foundations in Wisconsin: A Directory [23rd ed. 2004]

This 2004 edition of Foundations in Wisconsin marks the 23rd release of the print directory and the 4th year of the online version. The directory is designed as a research tool for grantseekers interested in locating information on private, corporate, and community foundations registered in Wisconsin. Each entry in this new edition has been updated or reviewed to provide the most current information available. Most of the data was extracted from IRS 990-PF tax returns filed by the foundations. However, additional information was obtained from surveys, annual reports, and foundation Web sites. Wisconsin foundations have shown small increases as compared to the 2003 edition. The number of active foundations has grown to an all-time high of 1184. Both total assets and grants for the state’s foundations increased from 2003, albeit not to the heights documented in the 2002 edition. Total assets grew by 1.53% and total grants by .23%. The following table details the financial pattern over the 10 years.https://epublications.marquette.edu/lib_fiw/1007/thumbnail.jp