Bacterial meningitis is a serious infection of the CNS that results when blood-borne bacteria are able to cross the blood-brain barrier (BBB). Group B
Brandon J. Kim, Bryan M. Hancock, Andres Bermudez, Natasha Del Cid, Efren Reyes, Nina M. van Sorge, Xavier Lauth, Cameron A. Smurthwaite, Brett J. Hilton, Aleksandr Stotland, Anirban Banerjee, John Buchanan, Roland Wolkowicz, David Traver, Kelly S. Doran
BACKGROUND. Individuals treated with the cholesteryl ester transfer protein (CETP) inhibitor anacetrapib exhibit a reduction in both LDL cholesterol and apolipoprotein B (ApoB) in response to monotherapy or combination therapy with a statin. It is not clear how anacetrapib exerts these effects; therefore, the goal of this study was to determine the kinetic mechanism responsible for the reduction in LDL and ApoB in response to anacetrapib.
METHODS. We performed a trial of the effects of anacetrapib on ApoB kinetics. Mildly hypercholesterolemic subjects were randomized to background treatment of either placebo (
RESULTS. Anacetrapib markedly reduced the LDL-ApoB-100 pool size (PS) in both the placebo and ATV groups. These changes in PS resulted from substantial increases in LDL-ApoB-100 FCRs in both groups. Anacetrapib had no effect on LDL-ApoB-100 PRs in either treatment group. Moreover, there were no changes in the PCSK9 PS, FCR, or PR in either group. Anacetrapib treatment was associated with considerable increases in the LDL triglyceride/cholesterol ratio and LDL size by NMR.
CONCLUSION. These data indicate that anacetrapib, given alone or in combination with a statin, reduces LDL-ApoB-100 levels by increasing the rate of ApoB-100 fractional clearance.
TRIAL REGISTRATION. ClinicalTrials.gov NCT00990808.
FUNDING. Merck & Co. Inc., Kenilworth, New Jersey, USA. Additional support for instrumentation was obtained from the National Center for Advancing Translational Sciences (UL1TR000003 and UL1TR000040).
John S. Millar, Gissette Reyes-Soffer, Patricia Jumes, Richard L. Dunbar, Emil M. deGoma, Amanda L. Baer, Wahida Karmally, Daniel S. Donovan, Hashmi Rafeek, Laura Pollan, Junichiro Tohyama, Amy O. Johnson-Levonas, John A. Wagner, Stephen Holleran, Joseph Obunike, Yang Liu, Rajasekhar Ramakrishnan, Michael E. Lassman, David E. Gutstein, Henry N. Ginsberg, Daniel J. Rader
Functional interactions between neurons, vasculature, and glia within neurovascular units are critical for maintenance of the retina and other CNS tissues. For example, the architecture of the neurosensory retina is a highly organized structure with alternating layers of neurons and blood vessels that match the metabolic demand of neuronal activity with an appropriate supply of oxygen within perfused blood. Here, using murine genetic models and cell ablation strategies, we have demonstrated that a subset of retinal interneurons, the amacrine and horizontal cells, form neurovascular units with capillaries in 2 of the 3 retinal vascular plexuses. Moreover, we determined that these cells are required for generating and maintaining the intraretinal vasculature through precise regulation of hypoxia-inducible and proangiogenic factors, and that amacrine and horizontal cell dysfunction induces alterations to the intraretinal vasculature and substantial visual deficits. These findings demonstrate that specific retinal interneurons and the intraretinal vasculature are highly interdependent, and loss of either or both elicits profound effects on photoreceptor survival and function.
Yoshihiko Usui, Peter D. Westenskow, Toshihide Kurihara, Edith Aguilar, Susumu Sakimoto, Liliana P. Paris, Carli Wittgrove, Daniel Feitelberg, Mollie S.H. Friedlander, Stacey K. Moreno, Michael I. Dorrell, Martin Friedlander
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a life-threatening disease in which intracranial hemorrhage (ICH) is the major risk. Although thrombocytopenia, which is caused by maternal antibodies against β3 integrin and occasionally by maternal antibodies against other platelet antigens, such as glycoprotein GPIbα, has long been assumed to be the cause of bleeding, the mechanism of ICH has not been adequately explored. Utilizing murine models of FNAIT and a high-frequency ultrasound imaging system, we found that ICH only occurred in fetuses and neonates with anti–β3 integrin–mediated, but not anti-GPIbα–mediated, FNAIT, despite similar thrombocytopenia in both groups. Only anti–β3 integrin–mediated FNAIT reduced brain and retina vessel density, impaired angiogenic signaling, and increased endothelial cell apoptosis, all of which were abrogated by maternal administration of intravenous immunoglobulin (IVIG). ICH and impairment of retinal angiogenesis were further reproduced in neonates by injection of anti–β3 integrin, but not anti-GPIbα antisera. Utilizing cultured human endothelial cells, we found that cell proliferation, network formation, and AKT phosphorylation were inhibited only by murine anti–β3 integrin antisera and human anti–HPA-1a IgG purified from mothers with FNAIT children. Our data suggest that fetal hemostasis is distinct and that impairment of angiogenesis rather than thrombocytopenia likely causes FNAIT-associated ICH. Additionally, our results indicate that maternal IVIG therapy can effectively prevent this devastating disorder.
Issaka Yougbaré, Sean Lang, Hong Yang, Pingguo Chen, Xu Zhao, Wei-She Tai, Darko Zdravic, Brian Vadasz, Conglei Li, Siavash Piran, Alexandra Marshall, Guangheng Zhu, Heidi Tiller, Mette Kjaer Killie, Shelley Boyd, Howard Leong-Poi, Xiao-Yan Wen, Bjorn Skogen, S. Lee Adamson, John Freedman, Heyu Ni
Disturbed blood flow (d-flow) causes endothelial cell (EC) dysfunction, leading to atherosclerotic plaque formation. We have previously shown that d-flow increases SUMOylation of p53 and ERK5 through downregulation of sentrin/SUMO-specific protease 2 (SENP2) function; however, it is not known how SENP2 itself is regulated by d-flow. Here, we determined that d-flow activated the serine/threonine kinase p90RSK, which subsequently phosphorylated threonine 368 (T368) of SENP2. T368 phosphorylation promoted nuclear export of SENP2, leading to downregulation of eNOS expression and upregulation of proinflammatory adhesion molecule expression and apoptosis. In an LDLR-deficient murine model of atherosclerosis, EC-specific overexpression of p90RSK increased EC dysfunction and lipid accumulation in the aorta compared with control animals; however, these pathologic changes were not observed in atherosclerotic mice overexpressing dominant negative p90RSK (DN-p90RSK). Moreover, depletion of SENP2 in these mice abolished the protective effect of DN-p90RSK overexpression. We propose that p90RSK-mediated SENP2-T368 phosphorylation is a master switch in d-flow–induced signaling, leading to EC dysfunction and atherosclerosis.
Kyung-Sun Heo, Nhat-Tu Le, Hannah J. Cushman, Carolyn J. Giancursio, Eugene Chang, Chang-Hoon Woo, Mark A. Sullivan, Jack Taunton, Edward T.H. Yeh, Keigi Fujiwara, Jun-ichi Abe
As the central pacemaker, the suprachiasmatic nucleus (SCN) has long been considered the primary regulator of blood pressure circadian rhythm; however, this dogma has been challenged by the discovery that each of the clock genes present in the SCN is also expressed and functions in peripheral tissues. The involvement and contribution of these peripheral clock genes in the circadian rhythm of blood pressure remains uncertain. Here, we demonstrate that selective deletion of the circadian clock transcriptional activator aryl hydrocarbon receptor nuclear translocator–like (
Zhongwen Xie, Wen Su, Shu Liu, Guogang Zhao, Karyn Esser, Elizabeth A. Schroder, Mellani Lefta, Harald M. Stauss, Zhenheng Guo, Ming Cui Gong
Genome-wide association studies have identified a link between genetic variation at the human chromosomal locus 1p13.3 and coronary artery disease. The gene encoding sortilin (
Martin B. Mortensen, Mads Kjolby, Stine Gunnersen, Jakob V. Larsen, Johan Palmfeldt, Erling Falk, Anders Nykjaer, Jacob F. Bentzon
The signal-responsive E3 ubiquitin ligase pellino 1 (PELI1) regulates TLR and T cell receptor (TCR) signaling and contributes to the maintenance of autoimmunity; however, little is known about the consequence of mutations that result in upregulation of PELI1. Here, we developed transgenic mice that constitutively express human
Hye-Young Park, Heounjeong Go, Ha Rim Song, Suhyeon Kim, Geun-Hyoung Ha, Yoon-Kyung Jeon, Ji-Eun Kim, Ho Lee, Hyeseong Cho, Ho Chul Kang, Hee-Young Chung, Chul-Woo Kim, Doo Hyun Chung, Chang-Woo Lee
Coronary arteries (CAs) stem from the aorta at 2 highly stereotyped locations, deviations from which can cause myocardial ischemia and death. CA stems form during embryogenesis when peritruncal blood vessels encircle the cardiac outflow tract and invade the aorta, but the underlying patterning mechanisms are poorly understood. Here, using murine models, we demonstrated that VEGF-C–deficient hearts have severely hypoplastic peritruncal vessels, resulting in delayed and abnormally positioned CA stems. We observed that VEGF-C is widely expressed in the outflow tract, while cardiomyocytes develop specifically within the aorta at stem sites where they surround maturing CAs in both mouse and human hearts. Mice heterozygous for islet 1 (
Heidi I. Chen, Aruna Poduri, Harri Numi, Riikka Kivela, Pipsa Saharinen, Andrew S. McKay, Brian Raftrey, Jared Churko, Xueying Tian, Bin Zhou, Joseph C. Wu, Kari Alitalo, Kristy Red-Horse
Patients with cerebral small-vessel disease (CSVD) exhibit perturbed end-artery function and have an increased risk for stroke and age-related cognitive decline. Here, we used targeted genome-wide association (GWA) analysis and defined a CSVD locus adjacent to the forkhead transcription factor
Curtis R. French, Sudha Seshadri, Anita L. Destefano, Myriam Fornage, Corey R. Arnold, Philip J. Gage, Jonathan M. Skarie, William B. Dobyns, Kathleen J. Millen, Ting Liu, William Dietz, Tsutomu Kume, Marten Hofker, Derek J. Emery, Sarah J. Childs, Andrew J. Waskiewicz, Ordan J. Lehmann