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BackgroundThe cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)‐42, total‐tau (T‐tau), and phosphorylated‐tau (P‐tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch‐to‐batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.MethodsThe program is open for laboratories using commercially available kits for Aβ, T‐tau, or P‐tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.ResultsForty laboratories participated. Twenty‐six used INNOTEST enzyme‐linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO‐BIA AlzBio3 kit (both measure Aβ‐(1‐42), P‐tau(181P), and T‐tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN‐42, AβN‐40, and AβN‐38) or T‐tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within‐laboratory precisions differed considerably between biomarkers within individual laboratories.ConclusionsMeasurements of CSF AD biomarkers show large between‐laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

Background— Atherosclerosis is a systemic inflammatory disease characterized by the formation of atherosclerotic plaques. Both innate immunity and adaptive immunity contribute to atherogenesis, but the mode of interaction is poorly understood. Chemokine receptor 7 (CCR7) is critically involved in the transition from innate to adaptive immune activation by coordinating the migration to and positioning of antigen-presenting dendritic cells and T cells in secondary lymphoid organs. More recently, it was shown that CCR7 is also responsible for T-cell migration into inflamed tissues and T-cell egress from these tissues via the afferent lymph. Thus, we investigated the influence of a systemic CCR7 deficiency on atherogenesis in atherosclerosis-prone low-density lipoprotein receptor ( ldlr ) knockout mice. Methods and Results— CCR7 deficiency resulted in reduced atherosclerotic plaque development. CCR7 −/− T cells showed impaired entry and exit behavior from atherosclerotic lesions. Oxidized low-density lipoprotein, a key molecule for atherogenesis with antigenic features, was used to pulse dendritic cells and to expand T cells ex vivo. Adoptive transfer of C57BL/6 wild-type T cells but not ccr7 −/− -derived T cells primed with oxidized low-density lipoprotein–pulsed dendritic cells resulted in a reconstitution of atherogenesis in ccr7 −/− / ldlr −/− mice. Conclusion— These results demonstrate that both CCR7-dependent T-cell priming in secondary lymphoid organs and CCR7-dependent recirculation of T cells between secondary lymphoid organs and inflamed tissue are crucially involved in atherosclerotic plaque development.

Background— Reductions in numbers of circulating progenitor cells (CD34+ cell subsets) have been demonstrated in patients at risk for, or in the presence of, cardiovascular disease. The mediators of these reductions remain undefined. To determine whether neurohumoral factors might regulate circulating CD34+ cell subsets in vivo, we studied complementary canine models of left ventricular (LV) dysfunction. Methods and Results— A pacing model of severe LV dysfunction and a hypertensive renal wrap model in which dogs were randomized to receive deoxycorticosterone acetate (DOCA) were studied. Circulating CD34+ cell subsets including hematopoietic precursor cells (HPCs: CD34+/CD45 dim /VEGFR2−) and endothelial progenitor cells (EPCs: CD34+/CD45−/VEGFR2+) were quantified. Additionally, the effect of mineralocorticoid excess on circulating progenitor cells in normal dogs was studied. The majority of circulating CD34+ cells expressed CD45dimly and did not express VEGFR2, consistent with an HPC phenotype. HPCs were decreased in response to pacing, and this decrease correlated with plasma aldosterone levels (Spearman rank correlation=−0.67, P =0.03). In the hypertensive renal wrap model, administration of DOCA resulted in decreased HPCs. No changes were seen in EPCs in either model. Normal dogs treated with DOCA exhibited a decrease in HPCs in peripheral blood but not bone marrow associated with decreased telomerase activity. Conclusions— This is the first study to demonstrate that mineralocorticoid excess, either endogenous or exogenous, results in reduction in HPCs. These data suggest that mineralocorticoids may induce accelerated senescence of progenitor cells, leading to their reduced survival and decline in numbers.

Background Different cerebrospinal fluid (CSF) amyloid-beta 1–42 (A β 1–42 ), total Tau (Tau) and Tau phosphorylated at threonine 181 (P-Tau) levels are reported, but currently there is a lack of quality control programmes. The aim of this study was to compare the measurements of these CSF biomarkers, between and within centres. Methods Three CSF-pool samples were distributed to 13 laboratories in 2004 and the same samples were again distributed to 18 laboratories in 2008. In 2004 six laboratories measured A β 1–42 , Tau and P-Tau and seven laboratories measured one or two of these marker(s) by enzyme-linked immunosorbent assays (ELISAs). In 2008, 12 laboratories measured all three markers, three laboratories measured one or two marker(s) by ELISAs and three laboratories measured the markers by Luminex. Results In 2004, the ELISA intercentre coefficients of variance (interCV) were 31%, 21% and 13% for A β 1–42 , Tau and P-Tau, respectively. These were 37%, 16% and 15%, respectively, in 2008. When we restricted the analysis to the Innotest ® ( N = 13) for A β 1–42 , lower interCV were calculated (22%). The centres that participated in both years ( N = 9) showed interCVs of 21%, 15% and 9% and intra-centre coefficients (intraCV) of variance of 25%,18% and 7% in 2008. Conclusions The highest variability was found for A β 1–42 . The variabilities for Tau and P-Tau were lower in both years. The centres that participated in both years showed a high intraCV comparable to their interCV, indicating that there is not only a high variation between but also within centres. Besides a uniform standardization of (pre)analytical procedures, the same assay should be used to decrease the inter/intracentre variation.

3-Deazaadenosine (c3Ado) is a potent inhibitor ofS-adenosylhomocysteine hydrolase, which regulates cellular methyltransferase activity. In the present study, we sought to determine the effect of c3Ado on vascular smooth muscle cell (VSMC) function and neointima formation in vivo. c3Ado dose-dependently prevented the proliferation and migration of human coronary VSMCs in vitro. This was accompanied by an increased expression of the cyclin-dependent kinase inhibitors p21WAF1/Cip1, p27Kip1, a decreased expression of G1/S phase cyclins, and a lack of retinoblastoma protein hyperphosphorylation. In accordance with these findings, fluorescence-activated cell-sorting analysis of propidium iodide–stained cells indicated a cell cycle arrest in the G0/G1phase. Importantly, c3Ado did not affect the number of viable (trypan blue exclusion) or apoptotic cells (TUNEL). Mechanistically, c3Ado prevented FCS-induced Ras carboxyl methylation and membrane translocation and activity by inhibiting isoprenylcysteine carboxyl methyltransferase and reduced FCS-induced extracellular signal-regulated kinase (ERK)1/2 and Akt phosphorylation in a dose-dependent manner. Conversely, rescuing signal transduction by overexpression of a constitutive active Ras mutant abrogated c3Ado’s effect on proliferation. For in vivo studies, the femoral artery of C57BL/6 mice was dilated and mice were fed a diet containing 150 μg of c3Ado per day. c3Ado prevented dilation-induced Ras activation, as well as ERK1/2 and Akt phosphorylation in vivo. At day 21, VSMC proliferation (proliferating-cell nuclear antigen [PCNA]-positive cells), as well as the neointima/media ratio (0.7±0.2 versus 1.6±0.4;P<0.05) were significantly reduced, without any changes in the number of apoptotic cells. Our data indicate that c3Ado interferes with Ras methylation and function and thereby with mitogenic activation of ERK1/2 and Akt, preventing VSMC cell cycle entry and proliferation and neointima formation in vivo. Thus, therapeutic inhibition ofS-adenosylhomocysteine hydrolase by c3Ado may represent a save and effective novel approach to prevent vascular proliferative disease.

Background and Purpose— Adipose tissue is an abundant source of endothelial cells as well as stem and progenitor cells which can develop an endothelial phenotype. It has been demonstrated that these cells have distinct angiogenic properties in vitro and in vivo. However, whether these cells have the capacity to directly improve large vessel form and function after vascular injury remains unknown. To define whether delivery of adipose-derived endothelial cells (ADECs) would improve healing of injured carotid arteries, a rabbit model of acute arterial injury was used. Methods— Autologous rabbit ADECs were generated using defined culture conditions. To test the ability of ADECs to enhance carotid artery repair, cells were delivered intraarterially after acute balloon injury. Additional delivery studies were performed after functional selection of cells before delivery. Results— After rabbit omental fat harvest and digestion, a proliferative, homogenous, and distinctly endothelial population of ADECs was identified. Direct delivery of autologous ADECs resulted in marked reendothelialization 48 hours after acute vascular injury as compared to saline controls (82.2±26.9% versus 4.2±3.0% P <0.001). Delivery of ADECs that were selected for their ability to take up acetylated LDL significantly improved vasoreactivity and decreased intimal formation after vascular injury. Conclusions— Taken together, these data suggest that ADECs represent an autologous source of proliferative endothelial cells, which demonstrate the capacity to rapidly improve reendothelialization, improve vascular reactivity, and decrease intimal formation in a carotid artery injury model.

Soluble guanylate cyclase is a heterodimeric enzyme with a prosthetic heme group that, on binding of its main ligand, NO, generates the second messenger cGMP. Unlike conventional nitrovasodilators, the novel direct NO- and heme-independent soluble guanylate cyclase activator BAY 58-2667 is devoid of non-cGMP actions, lacks tolerance development, and preferentially activates NO-insensitive heme-free or oxidized soluble guanylate cyclase. BAY 58-2667, therefore, represents a novel therapeutic advance in mediating vasodilation. To date, its cardiorenal actions in congestive heart failure (CHF) are undefined. We, therefore, hypothesized that BAY 58-2667 would have beneficial preload- and afterload-reducing actions in experimental severe CHF together with renal vasodilating properties. We assessed the cardiorenal actions of intravenous administration of 2 doses of BAY 58-2667 (0.1 and 0.3 μg/kg per minute, respectively) in a model of tachypacing-induced severe CHF. In CHF, BAY 58-2667 dose-dependently reduced mean arterial, right atrial, pulmonary artery, and pulmonary capillary wedge pressure (from baseline 19±1 to 12±2 mm Hg). Cardiac output (2.4±0.3 to 3.2±0.4 L/min) and renal blood flow increased. Glomerular filtration rate and sodium and water excretion were maintained. Consistent with cardiac unloading, atrial and B-type natriuretic peptide decreased. Plasma renin activity ( P =0.31) and aldosterone remained unchanged ( P =0.19). In summary, BAY 58-2667 in experimental CHF potently unloaded the heart, increased cardiac output and renal blood flow, and preserved glomerular filtration rate and sodium and water excretion without further neurohumoral activation. These beneficial properties make direct soluble guanylate cyclase stimulation with BAY 58-2667 a promising new therapeutic strategy for cardiovascular diseases, such as heart failure.

AbstractLong‐chain N‐acylethanolamines (NAE), including the endocannabinoid, anandamide, accumulate in mammalian tissues under a variety of pathological conditions. They have also been shown to inhibit the growth of various cancer cell lines in vitro. Here, we report the presence, in widely differing amounts (3.88–254.46 pmol/μmol lipid P), of NAE and their precursor phospholipids in various human tumors and some adjacent unaffected tissue. Anandamide ranged from 1.5 to 48% of total NAE, and incubation of tissue homogenates suggested possible NAE biosynthesis by both the established transacylation‐phosphodiesterase pathway via N‐acyl PE and by direct N‐acylation of ethanolamine.