Objective: Given the important role of Ang II/Ang 1-7 in atherogenesis, we investigated the impact of ACE2 deficiency on the development of atherosclerosis. Methods and Results:C57Bl6, Ace2 knockout (KO), apolipoprotein E (ApoE) KO and ApoE/Ace2 double KO mice were followed until 30 weeks of age. Plaque accumulation was increased in ApoE/Ace2 double KO mice when compared to ApoE KO mice. This was associated with increased expression of adhesion molecules and inflammatory cytokines, including interleukin-6, monocyte chemoattractant protein-1, and vascular cell adhesion molecule-1, and an early increase in white cell adhesion across the whole aortae on dynamic flow assay. In the absence of a proatherosclerotic (ApoE KO) genotype, ACE2 deficiency was also associated with increased expression of these markers, suggesting that these differences were not an epiphenomenon. ACE inhibition prevented increases of these markers and atherogenesis in ApoE/ACE2 double KO mice. Bone marrow macrophages isolated from Ace2 KO mice showed increased proinflammatory responsiveness to lipopolysaccharide and Ang II when compared to macrophages isolated from C57Bl6 mice. Endothelial cells isolated from Ace2 KO mice also showed increased basal activation and elevated inflammatory responsiveness to TNF-␣. Similarly, selective inhibition of ACE2 with MLN-4760 also resulted in a proinflammatory phenotype with a physiological response similar to that observed with exogenous Ang II (10 ؊7 mol/L). Conclusions: Genetic

E ndothelial cells (ECs) play an essential role in the modulation of vascular homeostasis. During aging and specifically during the development of atherosclerosis, ECs are exposed to various damaging stimuli and are thereby prone to injury.1 Rapid endothelial recovery, or re-endothelialization, correlates with diminished plaque formation. 2 Likewise, coronary intervention-induced vascular injury requires an Background-ADAMTS-7, a member of the disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family, was recently identified to be significantly associated genomewide with coronary artery disease. However, the mechanisms that link ADAMTS-7 and coronary artery disease risk remain elusive. We have previously demonstrated that ADAMTS-7 promotes vascular smooth muscle cell migration and postinjury neointima formation via degradation of a matrix protein cartilage oligomeric matrix protein. Because delayed endothelium repair renders neointima and atherosclerosis plaque formation after vessel injury, we examined whether ADAMTS-7 also inhibits re-endothelialization. Methods and Results-Wire injury of the carotid artery and Evans blue staining were performed in Adamts7-/-and wild-type mice. Adamts-7 deficiency greatly promoted re-endothelialization at 3, 5, and 7 days after injury. Consequently, Adamts-7 deficiency substantially ameliorated neointima formation in mice at days 14 and 28 after injury in comparison with the wild type. In vitro studies further indicated that ADAMTS-7 inhibited both endothelial cell proliferation and migration. Surprisingly, cartilage oligomeric matrix protein deficiency did not affect endothelial cell proliferation/migration and re-endothelialization in mice. In a further examination of other potential vascular substrates of ADAMTS-7, a labelfree liquid chromatography-tandem mass spectrometry secretome analysis revealed thrombospondin-1 as a potential ADAMTS-7 target. The subsequent studies showed that ADAMTS-7 was directly associated with thrombospondin-1 by its C terminus and degraded thrombospondin-1 in vivo and in vitro. The inhibitory effect of ADAMTS-7 on postinjury endothelium recovery was circumvented in Tsp1 -/-mice. Conclusions-Our study revealed a novel mechanism by which ADAMTS-7 affects neointima formation. Thus, ADAMTS-7 is a promising treatment target for postinjury vascular intima hyperplasia. potentially because they inhibit not only vascular smooth muscle cell (VSMC) proliferation/migration, but also reendothelialization. 6,7 Therefore, new strategies that aim to promote endothelial recovery, and simultaneously inhibit VSMC activation, as well, are needed for the effective prevention and treatment of atherosclerosis and postinjury restenosis.Metalloproteinases are critical in vascular wall remodeling through matrix or nonmatrix degradation. 8 Recently, we described ADAMTS-7, a member of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family, in the mediation of VSMC migration and the promotion of neointima formation following ar...

endothelial cells ͉ arachidonic acid ͉ AP-1 ͉ promoter ͉ hypertension A rachidonic acid (AA) derived from membrane phospholipids plays a key role in vascular inflammatory and/or antiinflammatory responses. AA can be converted to eicosanoids by three major enzymatic pathways, namely, cyclooxygenase, lipoxygenase, and CYP 450 epoxygenase. Exerting autocrine effects on vascular endothelial cells (ECs), four epoxyeicosatrienoic acids (EETs) regioisomers 5,6-, 8,9-, 11,12-, and 14,15-EET are the major metabolites generated by CYP 450 epoxygenase (1). EETs can be released by ECs to act as paracrine mediators on neighboring cells such as vascular smooth muscle cells (VSMCs) (2). EETs exert membrane potential-independent effects and modulate several signaling cascades that affect EC proliferation and angiogenesis. EETs also function as endothelium-derived hyperpolarizing factors (3). By increasing intracellular Ca 2ϩ concentration, EETs activate large conductance Ca 2ϩ -activated K ϩ channel (BK Ca ) in the smooth muscle. The activation of BK Ca then causes hyperpolarization of VSMCs and subsequent vasodilation, which lowers the blood pressure (4). As well, EETs inhibit cytokine-induced inflammatory responses in ECs (5, 6). Treating ECs with 11,12-EET or overexpression of CYP2J2 attenuated the TNF␣-, IL-1␣-, and LPSinduced expression of adhesion molecules in ECs, thus decreasing leukocyte adhesion to the vascular wall (7).Epoxide hydrolases (EHs) convert epoxides to the corresponding diols. Under physiological conditions, EETs can be enzymatically hydrolysed to dihydroxyeicosatrienoic acids (DHETs) by EHs (1). Two major EHs in the ␣/␤ hydrolase family exist in mammalian cells: soluble EH (sEH), which primarily presents in the cytosol and peroxisomes, and microsomal EH, which binds to the intracellular membranes (8). Highly expressed in the liver, kidney, intestine, and vasculature, sEH is the main enzyme that converts 5,8,11,14,8,11,14, respectively. The mammalian sEH is a homodimer, and each subunit contains a C-and an N-terminal domain. The active site is located in the C-terminal domain in which the residues Asp-333, Asp-495, and His-523 form the catalytic triad (9). DHETs are much more polar than EETs and are generally considered as biologically inactive products of EETs. However, their roles are not fully understood.Angiotensin II (Ang II), a potent vessel constrictor, elevates blood pressure in various animal models. i.p. injection of sEHselective inhibitors to Ang II-infused hypertensive rats greatly increased the level of EETs and lowered systolic blood pressure (10). Thus, augmentation of EET levels with enhanced production by CYP450s or decreased hydrolysis by sEH seems to control blood pressure in vivo. In line with this hypothesis, recent studies demonstrated that the selective sEH inhibitor Ncyclohexyl-N-dodecyl urea reversed the hypertensive phenotype in the spontaneously hypertensive rat (SHR) (11).We have previously shown that laminar shear stress, an atheroprotective flow, decreased the expression of sE...

Three-dimensional (3D) chromatin architectural differences can influence the integrity of topologically associating domains (TADs) and rewire specific enhancer-promoter interactions, impacting gene expression and leading to human disease. Here, we investigate the 3D chromatin architecture in T cell acute lymphoblastic leukemia (T-ALL) using primary human leukemia specimens and its dynamic responses to pharmacological agents. Systematic integration of matched in situ Hi-C, RNA-seq and CTCF ChIP-seq datasets revealed widespread differences in intra-TAD chromatin interactions and TAD boundary insulation in T-ALL. Our studies identify and focus on a TAD “fusion” event associated with absence of CTCF-mediated insulation, enabling direct interactions between the MYC promoter and a distal super-enhancer. Moreover, our data also demonstrate that small molecule inhibitors targeting either oncogenic signal transduction or epigenetic regulation can alter specific 3D interactions found in leukemia. Overall, our study highlights the impact, complexity and dynamic nature of 3D chromatin architecture in human acute leukemia.

This paper documents the results of an experimental study conducted to demonstrate the capabilities of multiple magnetorheological (MR) devices for seismic control of civil engineering structures. A six-story test structure in the Washington University Structural Control and Earthquake Engineering Lab (http://www.seas.wustl.edu/research/quake/) is considered, and four parallel-plate, shear-mode MR dampers are used to control this test structure. Two control devices are installed in the test structure between the base and first floor, and two are installed between the first floor and second floor. The system identification method used to develop a model of the integrated structural system is discussed. This method is an extension of a method successfully used in a previous semi-active experiment. Two semi-active control algorithms including a Lyapunov algorithm and a clipped-optimal algorithm are considered. An El Centro earthquake is used to disturb the system and three amplitude levels. The results indicate that high performance levels can be achieved, and the responses of the semi-active system are significantly better than that of comparable passive systems.

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Compelling evidence indicates that epigenetic regulations orchestrate dynamic macrophage polarization. N6-methyladenosine (m6A) methylation is the most abundant epigenetic modification of mammalian mRNA, but its role in macrophage polarization is still completely unknown. Here, we show that the m6A-catalytic enzyme methyltransferase like 3 (METTL3) is specifically upregulated following the M1 polarization of mouse macrophages. Furthermore, METTL3 knockdown through siRNA transfection markedly inhibited M1, but enhanced M2, macrophage polarization. Conversely, its overexpression via plasmid transfection greatly facilitated M1, but attenuated M2, macrophage polarization. Further methylated RNA immunoprecipitation and in vitro m6A methylation assays suggested that METTL3 directly methylates mRNA encoding signal transducer and activator of transcription 1 (STAT1), a master transcription factor controlling M1 macrophage polarization, at its coding sequence and 3′-untranslated regions. In addition, METTL3-mediated STAT1 mRNA methylation significantly increased mRNA stability and subsequently upregulated STAT1 expression. In conclusion, METTL3 drives M1 macrophage polarization by directly methylating STAT1 mRNA, potentially serving as an anti-inflammatory target.

Tau protein—a member of the microtubule-associated protein family—is a key protein involved in many neurodegenerative diseases. Tau pathology in neurodegenerative diseases is characterized by pathological tau aggregation in neurofibrillary tangles (NFTs). Diseases with this typical pathological feature are called tauopathies. Parkinson's disease (PD) was not initially considered to be a typical tauopathy. However, recent studies have demonstrated increasing evidence of tau pathology in PD. A genome-wide association (GWA) study indicated a potential association between tauopathy and sporadic PD. The aggregation and deposition of tau were also observed in ~50% of PD brains, and it seems to be transported from neuron to neuron. The aggregation of NFTs, the abnormal hyperphosphorylation of tau protein, and the interaction between tau and alpha-synuclein may all contribute to the cell death and poor axonal transport observed in PD and Parkinsonism.