The endothelium plays a pivotal role in vascular inflammation. Here we study bone morphogenetic protein (BMP) signaling in endothelial inflammation and in particular the role of BMPER, an extracellular BMP modulator that is important in vascular development and angiogenesis. Using the BMP antagonist dorsomorphin or BMP2 as an agonist we show that BMP signaling is essential for the inflammatory response of vascular endothelial cells as demonstrated by intravital microscopy. We found that BMPER is decreased in inflammation similar to vascular protective genes like KLF2 and eNOS. Using in vitro and in vivo models we show that BMPER is down-regulated through the TNF␣-NFB-KLF2 signaling pathway. Functionally, lack of BMPER induced by siRNA or in BMPER ؉/؊ mice confers a proinflammatory endothelial phenotype with reduced eNOS levels and enhanced expression of adhesion molecules leading to increased leukocyte adhesion and extravasation in ex vivo and in vivo experiments. Vice versa, addition of BMPER exerts endothelium protective functions and antagonizes TNF␣ induced inflammation. Mechanistically, we demonstrate that these effects of BMPER are dependent on BMP signaling because of enhanced NFB activity. In conclusion, the BMP modulator BMPER is a new protective regulator of vascular inflammation that modulates leukocyte adhesion and migration in vitro and in vivo. (Blood. 2011;118(18):5040-5049) IntroductionThe endothelium plays a pivotal role in the response to vascular inflammation. Inflammatory stimuli such as TNF␣ induce endothelial dysfunction and confer a proadhesive endothelial phenotype. 1 These events are important under physiologic conditions in wound healing as well as in inflammatory diseases like sepsis or atherosclerosis. Endothelial dysfunction initiates a cascade of events with leukocyte adhesion in a central position. It is of outstanding importance to understand the underlying molecular mechanisms of this process and to identify new mediators of a proadhesive endothelial phenotype.In endothelial dysfunction hundreds of genes are induced but inhibition of genes is a relatively rare event. 1 Among these few genes Kruepple like factor 2 (KLF2) and endothelial NO synthase (eNOS) are well characterized examples. 2 Consistent with downregulation in endothelial dysfunction KLF2 is up-regulated by laminar (physiologic) flow conditions or statin therapy. 3,4 KLF2 then up-regulates the expression of protective endothelial factors, such as eNOS. 5 ENOS and NO attenuated inflammatory response via inhibition of endothelial adhesion molecules VCAM-1 and ICAM-1 in vitro and in vivo. 6,7 Vice versa reduction of eNOS and endothelial NO caused endothelial dysfunction at the vascular wall reflected by proinflammatory endothelial phenotype with increasing leukocyte endothelial interaction. [7][8][9] Bone morphogenetic proteins (BMPs) are important regulators in blood vessel formation and vascular disease. 10 BMPs are expressed in atheroprone regions of blood vessels and are down-regulated in the endothelium under protec...

Objective-In addition to lowering cholesterol, statins exert pleiotropic effects on endothelial cells. Bone morphogenetic proteins (BMPs) have recently been implicated in vascular inflammation and disease. We set out to investigate the effect of statins on BMP endothelial cell precursor-derived regulator (BMPER), a novel member of the BMP pathway. Methods and Results-Mevastatin enhanced BMPER expression in cultured endothelial cells in a time-and concentrationdependent manner as determined by immunocytochemistry, RT-PCR, and Western blotting. Similar effects were observed in vitro and in vivo using simvastatin. Actinomycin D chase analysis and BMPER promoter reporter assays revealed that this is mostly a posttranscriptional event resulting in prolonged BMPER RNA half-life. We confirmed that the RhoA/Rho-associated coiled-coil containing protein kinase Rho kinase (Rock)/actin pathway is involved using the specific pathway activator cytotoxic necrotizing factor of Yersinia pseudotuberculosis, which prevented upregulation of BMPER expression by mevastatin and pathway inhibitors (C3-toxin, RhoAN19 mutant, fasudil, and cytochalasin D) that enhanced BMPER expression. Increasing concentrations of BMPER exert antiinflammatory features in endothelial cells as reflected by intercellular adhesion molecule-1 downregulation. Accordingly, silencing of BMPER enhances intercellular adhesion molecule-1 expression. Furthermore, mevastatin reduced the expression of proinflammatory BMP4, a well-known direct interaction partner of BMPER. Key Words: statins Ⅲ ICAM-1 Ⅲ bone morphogenetic proteins Ⅲ vascular biology B one morphogenetic proteins (BMPs) are members of the transforming growth factor-␤ superfamily. BMPs are important regulators in blood vessel formation and vascular disease. 1 BMP2 and BMP4 are upregulated in athero-prone regions in blood vessels, induce 2,3 a proinflammatory endothelial phenotype, and may contribute to the development of atherosclerotic plaques and vascular calcification. 4,5 Infusion of BMP4 in vivo leads to endothelial dysfunction and arterial hypertension. 6,7 Important insights have also come from the discovery of mutations of the BMP receptors in patients with familial pulmonary artery hypertension or teleangiectasia. 8 BMP endothelial cell precursor-derived regulator (BMPER) is a secreted glycoprotein that binds directly to BMPs and modulates their function in a dose-dependent fashion. In gain-offunction assays, BMPER behaves as a BMP antagonist, 9,10 whereas in loss-of-function models, BMPER may also exert pro-BMP functions. 11-14 BMPER was originally identified in a screen for differentially expressed proteins in embryonic endothelial precursor cells. 9 In mouse and zebrafish, it is expressed at sites and at the time of vasculogenesis, consistent with a regulatory role for BMPER in vascular events. When BMPER is inactivated in zebrafish embryos, intersomitic angiogenesis is severely perturbed. 11 Consistent with this vascular phenotype, BMPER may confer proangiogenic activity in endothelial cells ...

Purpose:The study aim is a comparative proteome-based analysis of different autologous bone entities (alveolar bone [AB], iliac cortical [IC] bone, and iliac spongiosa [IS]) used for alveolar onlay grafting.Experimental Design: Site-matched bone samples of AB, IC, and IS were harvested during alveolar onlay grafting. Proteins were extracted using a detergent-based (sodium dodecyl sulfate) strategy and trypsinized. Proteome analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). MaxQuant was used for peptide-to-spectrum matching, peak detection, and quantitation. Linear models for microarray analysis (LIMMA) were used to detect differentially abundant peptides and proteins.Results: A total of 1730 different proteins were identified across the 15 samples at a false discovery rate of 1%. Partial least-squares discriminant analysis approved segregation of AB, IC, and IS protein profiles. LIMMA statistics highlighted 66 proteins that were more abundant in AB then in IC (vs. 92 proteins were enriched in IC over AB).

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