Cardiology Commons^™

Measuring Adherence To Evidence-Based Practice Guidelines For The Management Of Hypertension In Women, Cristina M. Jorgensen

DNP Projects

Approximately 1 in 3 adults In the United States (U. S.) with approximately half being women have hypertension, a significant risk factor for cardiovascular disease (CVD) and stroke (Nwankwo, Yoon, Burt, & Gu, 2013). Nearly 70% of people who had a first heart attack, 80% of those who had a first stroke, and 75% of those who had congestive heart failure (CHF) have hypertension (Mozaffarian et al., 2013). Hypertension was the underlying or contributing cause of more than 375,000 deaths in 2011. Despite multiple publications of national hypertension guidelines, only 50% of adults with hypertension have their blood pressure under …

Left Ventricular Assist Device As Destination Therapy, Maya Guglin, Leslie W. Miller

The VAD Journal

Mechanical circulatory support is the most rapidly evolving strategy in heart failure management. The growing number of patients who need better results than medical therapy can offer, the limited pool of donors for cardiac transplantation, and several technological breakthroughs have all made the option of implanting a left ventricular assist device (LVAD) as destination therapy more important.

In this review, we outline the indications and decision making process of considering a patient for a destination therapy LVAD, as well as outcomes, complications, and issues related to management of patients on currently approved devices. The future direction of the field will …

The Bubbling Aorta, Hesham R. Omar, Maya Guglin

The VAD Journal

We are presenting the image of the bubbles in the descending aorta in a patient on VA ECMO.

Simplified Post Processing Of Cine Dense Cardiovascular Magnetic Resonance For Quantification Of Cardiac Mechanics, Jonathan D. Suever, Gregory J. Wehner, Christopher M. Haggerty, Linyuan Jing, Sean M. Hamlet, Cassi M. Binkley, Sage P. Kramer, Andrea C. Mattingly, David K. Powell, Kenneth C. Bilchick, Frederick H. Epstein, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Cardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30-40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis.

METHODS …

Dear Colleagues, Readers And Authors, Maya Guglin

The VAD Journal

No abstract provided.

Biomarkers Of Acute Myocardial Infarction In The Elderly: Troponin And Beyond, Martin G. Rains, Charles A. Laney, Alison L. Bailey, Charles L. Campbell

Gill Heart & Vascular Institute Faculty Publications

In the broadest context, biological markers, or biomarkers, are molecules that characterize a biological system or process. In the setting of cardiovascular disease, a number of biomarkers have become an integral part of diagnostic and risk stratification strategies. In this review, we will discuss classic and emerging biomarkers of cardiovascular disease and the role of these biomarkers in the diagnosis and prognosis of elderly patients presenting with acute myocardial infarction.

Osteopontin: A Novel Regulator At The Cross Roads Of Inflammation, Obesity And Diabetes, Florian Kahles, Hannes M. Findeisen, Dennis Bruemmer

Gill Heart & Vascular Institute Faculty Publications

Since its first description more than 20 years ago osteopontin has emerged as an active player in many physiological and pathological processes, including biomineralization, tissue remodeling and inflammation. As an extracellular matrix protein and proinflammatory cytokine osteopontin is thought to facilitate the recruitment of monocytes/macrophages and to mediate cytokine secretion in leukocytes. Modulation of immune cell response by osteopontin has been associated with various inflammatory diseases and may play a pivotal role in the development of adipose tissue inflammation and insulin resistance. Here we summarize recent findings on the role of osteopontin in metabolic disorders, particularly focusing on diabetes and …

Acute Sterol O-Acyltransferase 2 (Soat2) Knockdown Rapidly Mobilizes Hepatic Cholesterol For Fecal Excretion, Stephanie M. Marshall, Anthony D Gromovsky, Kathryn L. Kelley, Matthew A. Davis, Martha D. Wilson, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Lawrence L. Rudel, J. Mark Brown, Ryan E. Temel

Saha Cardiovascular Research Center Faculty Publications

The primary risk factor for atherosclerotic cardiovascular disease is LDL cholesterol, which can be reduced by increasing cholesterol excretion from the body. Fecal cholesterol excretion can be driven by a hepatobiliary as well as a non-biliary pathway known as transintestinal cholesterol efflux (TICE). We previously showed that chronic knockdown of the hepatic cholesterol esterifying enzyme sterol O-acyltransferase 2 (SOAT2) increased fecal cholesterol loss via TICE. To elucidate the initial events that stimulate TICE, C57Bl/6 mice were fed a high cholesterol diet to induce hepatic cholesterol accumulation and were then treated for 1 or 2 weeks with an antisense oligonucleotide targeting …

Limited Association Between Perceived Control And Health-Related Quality Of Life In Patients With Heart Failure, Teesta Banerjee, Kyoung Suk Lee, Steven R. Browning, Claudia Hopenhayn, Susan C. Westneat, Martha J. Biddle, Cynthia Arslanian-Angoren, Jo-Ann Eastwood, Gia Mudd, Debra K. Moser

Epidemiology and Environmental Health Faculty Publications

Background: Perceived control has been suggested as a modifiable factor associated with health-related quality of life (HRQOL). However, the relationship between perceived control and HRQOL has not been evaluated in patients with heart failure (HF). The purpose of this study was to determine whether perceived control independently predicts HRQOL in HF patients. Methods: A total of 423 HF patients were included. Hierarchical linear regression was performed to determine the independent association of perceived control to HRQOL after controlling for covariates. Results: Higher levels of perceived control were associated with better HRQOL in univariate analysis. However, this relationship was strongly attenuated …

Bisphenol A Increases Atherosclerosis In Pregnane X Receptor-Humanized Apoe Deficient Mice, Yipeng Sui, Se-Hyung Park, Robert N. Helsley, Manjula Sunkara, Frank J. Gonzalez, Andrew J. Morris, Changcheng Zhou

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Bisphenol A (BPA) is a base chemical used extensively in many consumer products. BPA has recently been associated with increased risk of cardiovascular disease (CVD) in multiple large-scale human population studies, but the underlying mechanisms remain elusive. We previously reported that BPA activates the pregnane X receptor (PXR), which acts as a xenobiotic sensor to regulate xenobiotic metabolism and has pro-atherogenic effects in animal models upon activation. Interestingly, BPA is a potent agonist of human PXR but does not activate mouse or rat PXR signaling, which confounds the use of rodent models to evaluate mechanisms of BPA-mediated CVD risk. …

The Role Of Bioactive Lipids In Stem Cell Mobilization And Homing: Novel Therapeutics For Myocardial Ischemia, Yuri M. Klyachkin, Anush V. Karapetyan, Mariusz Z. Ratajczak, Ahmed Abdel-Latif

Saha Cardiovascular Research Center Faculty Publications

Despite significant advances in medical therapy and interventional strategies, the prognosis of millions of patients with acute myocardial infarction (AMI) and ischemic heart disease (IHD) remains poor. Currently, short of heart transplantation with all of its inherit limitations, there are no available treatment strategies that replace the infarcted myocardium. It is now well established that cardiomyocytes undergo continuous renewal, with contribution from bone marrow (BM)-derived stem/progenitor cells (SPCs). This phenomenon is upregulated during AMI by initiating multiple innate reparatory mechanisms through which BMSPCs are mobilized towards the ischemic myocardium and contribute to myocardial regeneration. While a role for the SDF-1/CXCR4 …

Reduction Of Vldl Secretion Decreases Cholesterol Excretion In Niemann-Pick C1-Like 1 Hepatic Transgenic Mice, Stephanie M. Marshall, Kathryn L. Kelley, Matthew A. Davis, Martha D. Wilson, Allison L. Mcdaniel, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Lawrence L. Rudel, J. Mark Brown, Ryan E. Temel

Saha Cardiovascular Research Center Faculty Publications

An effective way to reduce LDL cholesterol, the primary risk factor of atherosclerotic cardiovascular disease, is to increase cholesterol excretion from the body. Our group and others have recently found that cholesterol excretion can be facilitated by both hepatobiliary and transintestinal pathways. However, the lipoprotein that moves cholesterol through the plasma to the small intestine for transintestinal cholesterol efflux (TICE) is unknown. To test the hypothesis that hepatic very low-density lipoproteins (VLDL) support TICE, antisense oligonucleotides (ASO) were used to knockdown hepatic expression of microsomal triglyceride transfer protein (MTP), which is necessary for VLDL assembly. While maintained on a high …

Aortic Aneurysms In Loeys-Dietz Syndrome - A Tale Of Two Pathways?, Frank Davis, Debra L. Rateri, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that is characterized by skeletal abnormalities, craniofacial malformations, and a high predisposition for aortic aneurysm. In this issue of the JCI, Gallo et al. developed transgenic mouse strains harboring missense mutations in the genes encoding type I or II TGF-β receptors. These mice exhibited several LDS-associated phenotypes. Despite being functionally defective, the mutated receptors enhanced TGF-β signaling in vivo, inferred by detection of increased levels of phosphorylated Smad2. Aortic aneurysms in these LDS mice were ablated by treatment with the Ang II type 1 (AT1) receptor antagonist losartan. The results from this …

Assessing Prevalence Of Known Risk Factors In A Regional Central Kentucky Medical Center Heart Failure Population As An Approach To Assessment Of Needs For Development Of A Program To Provide Targeted Services To Reduce 30 Day Readmissions, Christeen Ivy Broaddus

DNP Projects

Abstract

Objectives:

1. Determine demographic, physiologic, and laboratory characteristics at time of admission of the heart failure (HF) population in a regional acute care facility in Central Kentucky through review of patient electronic medical records.
2. Determine which HF population characteristics are significantly associated with readmissions to the hospital.
3. Provide identification of the statistically significant common characteristics of the HF population to this facility so that they may work towards development of an electronic risk for readmission predictive instrument.

Design: Retrospective chart review.

Setting: Regional acute care facility in Central Kentucky.

Participants: All patients (n = 175) with a diagnosis or history …

Sphingosine-1-Phosphate-Mediated Mobilization Of Hematopoietic Stem/Progenitor Cells During Intravascular Hemolysis Requires Attenuation Of Sdf-1-Cxcr4 Retention Signaling In Bone Marrow, Kasia Mierzejewska, Yuri M. Klyachkin, Janina Ratajczak, Ahmed Abdel-Latif, Magda Kucia, Mariusz Z. Ratajczak

Saha Cardiovascular Research Center Faculty Publications

Sphingosine-1-phosphate (S1P) is a crucial chemotactic factor in peripheral blood (PB) involved in the mobilization process and egress of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM). Since S1P is present at high levels in erythrocytes, one might assume that, by increasing the plasma S1P level, the hemolysis of red blood cells would induce mobilization of HSPCs. To test this assumption, we induced hemolysis in mice by employing phenylhydrazine (PHZ). We observed that doubling the S1P level in PB from damaged erythrocytes induced only a marginally increased level of mobilization. However, if mice were exposed to PHZ together with the …

Amlodipine Reduces Angii-Induced Aortic Aneurysms And Atherosclerosis In Hypercholesterolemic Mice, Xiaofeng Chen, Debra L. Rateri, Deborah A. Howatt, Anju Balakrishnan, Jessica J. Moorleghen, Andrew J. Morris, Richard Charnigo, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: The purpose of this study was to determine effects of amlodipine, a dihydropyridine calcium channel blocker, on development of angiotensin II (AngII)-induced vascular pathologies.

METHODS AND RESULTS: Male LDL receptor -/- mice were infused with vehicle, amlodipine (5 mg/kg/d), AngII (1,000 ng/kg/min), or AngII + amlodipine for 4 weeks through osmotic pumps (n=10/group). Mice were fed a saturated fat-enriched diet for 1 week prior to pump implantation and during 4 weeks of infusion. Infusion of amlodipine resulted in plasma concentrations of 32 ± 2 ng/ml and 27 ± 2 ng/ml for mice in saline + amlodipine and AngII + …

New Oral Anticoagulants Are Not Superior To Warfarin In Secondary Prevention Of Stroke Or Transient Ischemic Attacks, But Lower The Risk Of Intracranial Bleeding: Insights From A Meta-Analysis And Indirect Treatment Comparisons, Partha Sardar, Saurav Chatterjee, Wen-Chih Wu, Edgar Lichstein, Joydeep Ghosh, Shamik Aikat, Debabrata Mukherjee

Internal Medicine Faculty Publications

PURPOSE: Patients with Atrial Fibrillation (AF) and prior stroke are classified as high risk in all risk stratification schemes. A systematic review and meta-analysis was performed to compare the efficacy and safety of New Oral Anticoagulants (NOACs) to warfarin in patients with AF and previous stroke or transient ischemic attack (TIA).

METHODS: Three randomized controlled trials (RCTs), including total 14527 patients, comparing NOACs (apixaban, dabigatran and rivaroxaban) with warfarin were included in the analysis. Primary efficacy endpoint was ischemic stroke, and primary safety endpoint was intracranial bleeding. Random-effects models were used to pool efficacy and safety data across RCTs. RevMan …

Calpain-2 Compensation Promotes Angiotensin Ii-Induced Ascending And Abdominal Aortic Aneurysms In Calpain-1 Deficient Mice, Venkateswaran Subramanian, Jessica J. Moorleghen, Anju Balakrishnan, Deborah A. Howatt, Athar H. Chishti, Haruhito A. Uchida

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND AND OBJECTIVE: Recently, we demonstrated that angiotensin II (AngII)-infusion profoundly increased both aortic protein and activity of calpains, calcium-activated cysteine proteases, in mice. In addition, pharmacological inhibition of calpain attenuated AngII-induced abdominal aortic aneurysm (AA) in mice. Recent studies have shown that AngII infusion into mice leads to aneurysmal formation localized to the ascending aorta. However, the precise functional contribution of calpain isoforms (-1 or -2) in AngII-induced abdominal AA formation is not known. Similarly, a functional role of calpain in AngII-induced ascending AA remains to be defined. Using BDA-410, an inhibitor of calpains, and calpain-1 genetic deficient mice, …

Targeting Platelet Thrombin Receptor Signaling To Prevent Thrombosis, Eric L. Wallace, Susan S. Smyth

Gill Heart & Vascular Institute Faculty Publications

Platelets contribute fundamentally to ischemic heart disease, and antiplatelet therapy has been critical to reducing acute thrombotic complications of atherosclerotic disease. Thrombin, by acting on protease activated receptors (PAR), is one of the most potent platelet activators. PAR-1 antagonists may therefore provide more comprehensive antithrombotic effects. We review the pathophysiology of atherothrombosis, platelet activation by thrombin, the role of platelet protease activated receptors (PAR), and the clinical data supporting their use.

Nutrition Intervention To Decrease Symptoms In Patients With Advanced Heart Failure, Terry A. Lennie, Debra K. Moser, Martha J. Biddle, Darlene Welsh, Geza G. Bruckner, D. Travis Thomas, Mary Kay Rayens, Alison L. Bailey

Nursing Faculty Publications

For a majority of patients with advanced heart failure, there is a need for complementary, non-pharmacologic interventions that could be easily implemented by health care providers to provide palliative care. Three major pathologic pathways underlying heart failure symptoms have been identified: fluid overload, inflammation, and oxidative stress. Prior research has demonstrated that three nutrients-sodium, omega-3 fatty acids, and lycopene-can alter these pathologic pathways. Therefore, the purposes of this study are to test the effects of a 6-month nutrition intervention of dietary sodium reduction combined with supplementation of lycopene and omega-3 fatty acids on heart failure symptoms, health-related quality of life, …

The Impairment Of Macrophage-To-Feces Reverse Cholesterol Transport During Inflammation Does Not Depend On Serum Amyloid A, Maria C. De Beer, Joanne M. Wroblewski, Victoria P. Noffsinger, Ailing Ji, Jason M. Meyer, Deneys R. Van Der Westhuyzen, Frederick C. De Beer, Nancy R. Webb

Saha Cardiovascular Research Center Faculty Publications

Studies suggest that inflammation impairs reverse cholesterol transport (RCT). We investigated whether serum amyloid A (SAA) contributes to this impairment using an established macrophage-to-feces RCT model. Wild-type (WT) mice and mice deficient in SAA1.1 and SAA2.1 (SAAKO) were injected intraperitoneally with ³H-cholesterol-labeled J774 macrophages 4 hr after administration of LPS or buffered saline. ³H-cholesterol in plasma 4 hr after macrophage injection was significantly reduced in both WT and SAAKO mice injected with LPS, but this was not associated with a reduced capacity of serum from LPS-injected mice to promote macrophage cholesterol efflux in vitro. Hepatic accumulation of ^{3 …}

Depletion Of Endothelial Or Smooth Muscle Cell-Specific Angiotensin Ii Type 1a Receptors Does Not Influence Aortic Aneurysms Or Atherosclerosis In Ldl Receptor Deficient Mice, Debra L. Rateri, Jessica J. Moorleghen, Victoria Knight, Anju Balakrishnan, Deborah A. Howatt, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Whole body genetic deletion of AT1a receptors in mice uniformly reduces hypercholesterolemia and angiotensin II-(AngII) induced atherosclerosis and abdominal aortic aneurysms (AAAs). However, the role of AT1a receptor stimulation of principal cell types resident in the arterial wall remains undefined. Therefore, the aim of this study was to determine whether deletion of AT1a receptors in either endothelial cells or smooth muscle cells influences the development of atherosclerosis and AAAs.

METHODOLOGY/PRINCIPAL FINDINGS: AT1a receptor floxed mice were developed in an LDL receptor -/- background. To generate endothelial or smooth muscle cell specific deficiency, AT1a receptor floxed mice were bred with …

The P2y(12) Antagonists, 2mesamp And Cangrelor, Inhibit Platelet Activation Through P2y(12)/G(I)-Dependent Mechanism, Binggang Xiang, Guoying Zhang, Hongmei Ren, Manjula Sunkara, Andrew J. Morris, T. Kent Gartner, Susan S. Smyth, Zhenyu Li

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: ADP is an important physiological agonist that induces integrin activation and platelet aggregation through its receptors P2Y(1) (Gα(q)-coupled) and P2Y(12) (Gα(i)-coupled). P2Y(12) plays a critical role in platelet activation and thrombosis. Adenosine-based P2Y(12) antagonists, 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (2MeSAMP) and Cangrelor (AR-C69931MX) have been widely used to demonstrate the role of P2Y(12) in platelet function. Cangrelor is being evaluated in clinical trials of thrombotic diseases. However, a recent study reported that both 2MeSAMP and Cangrelor raise intra-platelet cAMP levels and inhibit platelet aggregation through a P2Y(12)-independent mechanism.

METHODOLOGY/PRINCIPAL FINDINGS: The present work, using P2Y(12) deficient mice, sought to …

Regional Variation In Aortic At1b Receptor Mrna Abundance Is Associated With Contractility But Unrelated To Atherosclerosis And Aortic Aneurysms, Aruna Poduri, A. Phillip Owens, Deborah A. Howatt, Jessica J. Moorleghen, Anju Balakrishnan, Lisa A. Cassis, Alan Daugherty

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Angiotensin II (AngII), the main bioactive peptide of the renin angiotensin system, exerts most of its biological actions through stimulation of AngII type 1 (AT1) receptors. This receptor is expressed as 2 structurally similar subtypes in rodents, termed AT1a and AT1b. Although AT1a receptors have been studied comprehensively, roles of AT1b receptors in the aorta have not been defined.

METHODOLOGY/RESULTS: We initially compared the regional distribution of AT1b receptor mRNA with AT1a receptor mRNA in the aorta. mRNA abundance of both subtypes increased from the proximal to the distal aorta, with the greatest abundance in the infra-renal region. Corresponding …

Characterization Of Secretory Sphingomyelinase Activity, Lipoprotein Sphingolipid Content And Ldl Aggregation In Ldlr-/- Mice Fed On A High-Fat Diet, Gergana M. Deevska, Manjula Sunkara, Andrew J. Morris, Mariana N. Nikolova‑Karakashian

Physiology Faculty Publications

The propensity of LDLs (low-density lipoproteins) for aggregation and/or oxidation has been linked to their sphingolipid content, specifically the levels of SM (sphingomyelin) and ceramide. To investigate this association in vivo, ldlr (LDL receptor)-null mice (ldlr-/-) were fed on a modified (atherogenic) diet containing saturated fats and cholesterol. The diet led to significantly elevated SM content in all serum lipoproteins. In contrast, ceramide increased only in the LDL particles. MS-based analyses of the lipid acyl chain composition revealed a marked elevation in C16:0 fatty acid in SM and ceramide, consistent with the prevalence of palmitic acid in the modified diet. …

Doxycycline Does Not Influence Established Abdominal Aortic Aneurysms In Angiotensin Ii-Infused Mice, Xiaojie Xie, Hong Lu, Jessica J. Moorleghen, Deborah A. Howatt, Debra L. Rateri, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

Background: There is no proven medical approach to attenuating expansion and rupture of abdominal aortic aneurysms (AAAs). One approach that is currently being investigated is the use of doxycycline. Despite being primarily used as an antimicrobial drug, doxycycline has been proposed to function in reducing AAA expansion. Doxycycline is effective in reducing the formation in the most commonly used mouse models of AAAs when administered prior to the initiation of the disease. The purpose of the current study was to determine the effects of doxycycline on established AAAs when it was administered at a dose that produces therapeutic serum …

Role Of The Immune System And Bioactive Lipids In Trafficking Bone Marrow-Derived Stem Cells In Patients With Ischemic Heart Disease, Ahmed Abdel-Latif

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Acute myocardial infarction (AMI) triggers the mobilization of stem/progenitor cells from bone marrow (BMSPCs) into peripheral blood (PB). The underlying mechanisms orchestrating this mobilization and subsequent homing of BMSPCs to the myocardium are poorly understood. While the role of traditional chemokines in the mobilization and homing of hematopoietic stem cell (HSCs) to BM niches is undisputed, their role in directing BMSPCs to the highly proteolytic environment of the ischemic myocardium is debatable and other redundant mechanism may exist. Based on our observation that bioactive lipids, such as sphingosine-1 phosphate (S1P) and ceramide-1 phosphate (C1P), play an important role in regulating …

Diurnal Variations Of Genes Contributing To Sodium And Potassium Cardiac Currents, Parvathi Nataraj

Kaleidoscope

No abstract provided.

Ghrelin Receptor Deficiency Does Not Affect Diet-Induced Atherosclerosis In Low-Density Lipoprotein Receptor-Null Mice, Kirk M. Habegger, Erin Grant, Paul Thomas Pfluger, Diego Perez-Tilve, Alan Daugherty, Dennis Bruemmer, Matthias H. Tschöp, Susanna M. Hofmann

Saha Cardiovascular Research Center Faculty Publications

OBJECTIVE: Ghrelin, a stomach-derived, secreted peptide, and its receptor (growth hormone secretagogue receptor, GHSR) are known to modulate food intake and energy homeostasis. The ghrelin system is also expressed broadly in cardiovascular tissues. Since ghrelin has been associated with anti-inflammatory and anti-atherogenic properties, but is also well known to promote obesity and impair glucose metabolism, we investigated whether ghrelin has any impact on the development of atherosclerosis. The hypothesis that endogenous ghrelin signaling may be involved in atherosclerosis has not been tested previously.

METHODS AND RESULTS: We crossed ghrelin receptor knockout mice (GHSr^-/-) into a low-density lipoprotein receptor-null …

Lipid Phosphate Phosphatase 3 Enables Efficient Thymic Egress, Béatrice Bréart, Willy D. Ramos-Perez, Alejandra Mendoza, Abdelghaffar K. Salous, Michael Gobert, Yong Huang, Ralf H. Adams, Juan J. Lafaille, Diana Escalante-Alcalde, Andrew J. Morris, Susan R. Schwab

Gill Heart & Vascular Institute Faculty Publications

The signaling lipid sphingosine-1-phosphate (S1P) stabilizes the vasculature, directs lymphocyte egress from lymphoid organs, and shapes inflammatory responses. However, little is known about how S1P distribution is controlled in vivo, and it is not clear how a ubiquitously made lipid functions as a signal that requires precise spatial and temporal control. We have found that lipid phosphate phosphatase 3 (LPP3) enables efficient export of mature T cells from the thymus into circulation, and several lines of evidence suggest that LPP3 promotes exit by destroying thymic S1P. Although five additional S1P-degrading enzymes are expressed in the thymus, they cannot compensate for …