A genetic polymorphism in the human gene encoding connexin37 (CX37, encoded by GJA4, also known as CX37) has been reported as a potential prognostic marker for atherosclerosis. The expression of this gap-junction protein is altered in mouse and human atherosclerotic lesions: it disappears from the endothelium of advanced plaques but is detected in macrophages recruited to the lesions. The role of CX37 in atherogenesis, however, remains unknown. Here we have investigated the effect of deleting the mouse connexin37 (Cx37) gene (Gja4, also known as Cx37) on atherosclerosis in apolipoprotein E-deficient (Apoe(-/-)) mice, an animal model of this disease. We find that Gja4(-/-)Apoe(-/-) mice develop more aortic lesions than Gja4(+/+)Apoe(-/-) mice that express Cx37. Using in vivo adoptive transfer, we show that monocyte and macrophage recruitment is enhanced by eliminating expression of Cx37 in these leukocytes but not by eliminating its expression in the endothelium. We further show that Cx37 hemichannel activity in primary monocytes, macrophages and a macrophage cell line (H36.12j) inhibits leukocyte adhesion. This antiadhesive effect is mediated by release of ATP into the extracellular space. Thus, Cx37 hemichannels may control initiation of the development of atherosclerotic plaques by regulating monocyte adhesion. H36.12j macrophages expressing either of the two CX37 proteins encoded by a polymorphism in the human GJA4 gene show differential ATP-dependent adhesion. These results provide a potential mechanism by which a polymorphism in CX37 protects against atherosclerosis.

Glucose uptake and, probably, FdG uptake signals in atheroma may reflect hypoxia-stimulated macrophages rather than mere inflammatory burden. Cytokine-activated smooth-muscle cells also may contribute to the FdG signal.

Blood oxygen saturation (SO(2)) is a promising parameter for the assessment of brain tissue viability in numerous pathologies. Quantitative blood oxygenation level-dependent (qBOLD)-like approaches allow the estimation of SO(2) by modelling the contribution of deoxyhaemoglobin to the MR signal decay. These methods require a high signal-to-noise ratio to obtain accurate maps through fitting procedures. In this article, we present a version of the qBOLD method at long TE taking into account separate estimates of T(2), total blood volume fraction (BV(f)) and magnetic field inhomogeneities. Our approach was applied to the brains of 13 healthy rats under normoxia, hyperoxia and hypoxia. MR estimates of local SO(2) (MR_LSO(2)) were compared with measurements obtained from blood gas analysis. A very good correlation (R(2) = 0.89) was found between brain MR_LSO(2) and sagittal sinus SO(2).

Background-Drug eluting stents with durable polymers may be associated with hypersensitivity, delayed healing, and incomplete endothelialization, which may contribute to late/very late stent thrombosis and the need for prolonged dual antiplatelet therapy. Bioabsorbable polymers may facilitate stent healing, thus enhancing clinical safety. The SYNERGY stent is a thin-strut, platinum chromium metal alloy platform with an ultrathin bioabsorbable Poly(D,L-lactide-co-glycolide) abluminal everolimus-eluting polymer. We performed a multicenter, randomized controlled trial for regulatory approval to determine noninferiority of the SYNERGY stent to the durable polymer PROMUS Element Plus everolimus-eluting stent. Methods and Results-Patients (n=1684) scheduled to undergo percutaneous coronary intervention for non-ST-segmentelevation acute coronary syndrome or stable coronary artery disease were randomized to receive either the SYNERGY stent or the PROMUS Element Plus stent. The primary end point of 12-month target lesion failure was observed in 6.7% of SYNERGY and 6.5% PROMUS Element Plus treated subjects by intention-to-treat (P=0.83 for difference; P=0.0005 for noninferiority), and 6.4% in both the groups by per-protocol analysis (P=0.0003 for noninferiority). Clinically indicated revascularization of the target lesion or definite/probable stent thrombosis were observed in 2.6% versus 1.7% (P=0.21) and 0.4% versus 0.6% (P=0.50) of SYNERGY versus PROMUS Element Plus-treated subjects, respectively. Conclusions-In this randomized trial, the SYNERGY bioabsorbable polymer everolimus-eluting stent was noninferior to the PROMUS Element Plus everolimus-eluting stent with respect to 1-year target lesion failure. These data support the relative safety and efficacy of SYNERGY in a broad range of patients undergoing percutaneous coronary intervention. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01665053.(Circ Cardiovasc Interv. 2015;8:e002372.

Abstract-Arterial intimal thickening after endothelial injury induced in rodents has proven to be a relatively unreliable model of restenosis for testing clinically useful compounds. The same has been found for cultured rat or rabbit vascular smooth muscle cells (SMCs). To test alternative possibilities, we have studied several differentiation features of porcine coronary artery SMCs, cultured up to the 5th passage after enzymatic digestion of the media. The effects of heparin, transforming growth factor (TGF)-␤ 1 or TGF-␤ 2 , and all-trans-retinoic acid (tRA) on proliferation, migration, and differentiation of these cells also were examined. Porcine arterial SMCs in culture not only express high levels of ␣-smooth muscle (SM) actin but, contrary to rodent SMCs, also maintain an appreciable expression of SM myosin heavy chain isoforms 1 and 2, desmin, and smoothelin, a recently described late differentiation marker of vascular SMCs. We demonstrate for the first time that smoothelin is colocalized with ␣-SM actin in these cells. Finally, we show that in the porcine model, heparin is more potent than TGF-␤ 1 or TGF-␤ 2 and tRA in terms of inhibition of proliferation and migration and of increasing the expression of differentiation markers. This model should be a useful complement to in vivo studies of SMC differentiation and of pathological situations such as restenosis and atheromatosis. (Circ Res. 1999;85:99-107.)Key Words: atheromatosis Ⅲ restenosis Ⅲ actin Ⅲ smoothelin Ⅲ myosin T he arterial intimal thickenings (IT) induced in the rat or rabbit after endothelial lesion are presently the moststudied models for atheroma formation and/or restenosis and have been useful for defining several biological features of smooth muscle cells (SMCs). However, these models have many important limitations (for review, see Reference 1), which could explain the clinical failure of substances that proved to be efficient inhibitors of IT formation in these animal models.The biological features of SMCs in culture also have been systematically studied using cells derived from rat or rabbit arteries, 2-7 but these, too, have shown limitations similar to those observed in in vivo experiments. Among the models in large animals, the pig coronary artery IT has been used more and more. 8,9 Pigs may develop spontaneously coronary atheromatosis with age, and the induction of typical plaques is easily achieved by a cholesterol-rich diet. 10,11 Furthermore, angioplasty and other interventions can be performed in porcine coronary arteries with the same instruments as in humans. Although pig aortic and coronary SMCs have already been studied in vitro, no systematic description of their differentiation features during culture has been published.The present study describes the characterization of differentiation features and several biological properties of cultured porcine left anterior descending (LAD) coronary artery SMCs. We show that, contrary to rat or rabbit arterial SMCs, 2-7 porcine SMCs maintain in culture a high level of differentiati...

Purpose To investigate if delays in resting-state spontaneous fluctuations of the BOLD (sfBOLD) signal can be used to create maps similar to time-to-maximum of the residue function (Tmax) in Moyamoya patients and to determine whether sfBOLD delays affect the results of brain connectivity mapping. Methods Ten patients were scanned at 3T using a gradient-echo EPI sequence for sfBOLD imaging. Cross correlation analysis was performed between each brain voxel signal and a reference signal comprised of either the superior sagittal sinus (SSS) or whole brain (WB) average time course. sfBOLD delay maps were created based on the time shift necessary to maximize the correlation coefficient, and compared to dynamic susceptibility contrast Tmax maps. Standard and time-shifted resting-state BOLD connectivity analyses of the default mode network were compared. Results Good linear correlations were found between sfBOLD delays and Tmax using the SSS as reference (r2=0.8, slope=1.4, intercept=-4.6) or WB (r2=0.7, slope=0.8, intercept=-3.2). New nodes of connectivity were found in delayed regions when accounting for delays in the analysis. Conclusions Resting-state sfBOLD imaging can create delay maps similar to Tmax maps without the use of contrast agents in Moyamoya patients. Accounting for these delays may affect the results of functional connectivity maps.

Objective The current study tested the hypothesis that glucose utilization differs between VAT and SAT and investigated potential mechanisms for such a finding. Background Visceral adipose tissue (VAT) burden correlates better with cardiovascular risk than does subcutaneous adipose tissue (SAT) burden. Beyond volumetric measurement, glucose uptake in adipose tissue (AT) might reflect metabolic activity and provide pathophysiologic insight and aid risk stratification. Methods We retrospectively studied tissue-specific glucose uptake in vivo in clinically obtained whole-body fluorodeoxyglucose positron emission tomography (FdG-PET) scans. We also assessed glucose uptake in vitro, using stromal vascular cells isolated from SAT and VAT of diet-induced obese C57BL/6 mice. Quantitative PCR evaluated the expression of multiple genes involved in cellular glucose metabolism, including glucose transporters (GLUT 1, 3 and 4) and hexokinases (HK-1 and 2) in SAT and VAT of obese C57BL/6 mice. Results We analyzed whole-body FdG-PET scans from 31 obese and 26 lean patients. VAT exhibited higher FdG uptake compared to SAT (p<0.0001) independent of age, gender, body-mass index, comorbidities, and medications. To investigate mechanisms underlying this observation, we studied glucose uptake in the stromal vascular cell fraction of AT, rich in inflammatory cells. Stromal vascular cells from VAT of diet-induced obese C57BL/6 mice exhibited higher glucose uptake than those from SAT (p=0.01). Evaluation of expression of glucose transporters (GLUT 1, 3 and 4) and hexokinases (HK-1 and 2), revealed increased expression of HK-1 in VAT- compared to SAT-derived stromal vascular cells, and also in visceral versus subcutaneous unfractionated AT. Conclusions In humans in vivo, VAT has increased glucose uptake compared with SAT, as determined non-invasively with FdG PET imaging. Differential stromal metabolic activity may be one mechanism underlying differences in metabolic activity of visceral and subcutaneous AT.

In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre and post injection of an iron based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameters inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4µm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies.