Hematology Commons^™

Clinical Utility Of Lactate Dehydrogenase In Determining The Severity Of Hemolysis In Sickle Cell Anemia., Samir K. Ballas

Cardeza Foundation for Hematologic Research

No abstract provided.

Emerging Drugs For Sickle Cell Anemia., Priya C Singh, Samir K. Ballas

Cardeza Foundation for Hematologic Research

INTRODUCTION: The search for effective therapeutic interventions for sickle cell disease (SCD) has been an ongoing endeavor for over 50 years. During this period, only hydroxyurea (HU), which received US FDA approval in February 1998, was identified as an effective therapeutic agent in preventing or ameliorating the frequency of vaso-occlusive crises, acute chest syndrome and the need for blood transfusion. Approximately 25% of patients with sickle cell anemia (SCA), however, do not respond to HU and some patients experiencing serious side effects of this chemotherapeutic agent. Nevertheless, the success of HU opened the sluice gates to identify other effective drug …

Morphine For The Treatment Of Pain In Sickle Cell Disease., Mihir Gupta, Lilian Msambichaka, Samir K. Ballas, Kalpna Gupta

Cardeza Foundation for Hematologic Research

Pain is a hallmark of sickle cell disease (SCD) and its treatment remains challenging. Opioids are the major family of analgesics that are commonly used for treating severe pain. However, these are not always effective and are associated with the liabilities of their own. The pharmacology and multiorgan side effects of opioids are rapidly emerging areas of investigation, but there remains a scarcity of clinical studies. Due to opioid-induced endothelial-, mast cell-, renal mesangial-, and epithelial-cell-specific effects and proinflammatory as well as growth influencing signaling, it is likely that when used for analgesia, opioids may have organ specific pathological effects. …

Deferiprone Versus Deferoxamine In Sickle Cell Disease: Results From A 5-Year Long-Term Italian Multi-Center Randomized Clinical Trial., Giusi Calvaruso, Angela Vitrano, Rosario Di Maggio, Samir K. Ballas, Martin H Steinberg, Paolo Rigano, Massimiliano Sacco, Paul Telfer, Disma Renda, Rita Barone, Aurelio Maggio

Cardeza Foundation for Hematologic Research

Blood transfusion and iron chelation currently represent a supportive therapy to manage anemia, vasculopathy and vaso-occlusion crises in Sickle-Cell-Disease. Here we describe the first 5-year long-term randomized clinical trial comparing Deferiprone versus Deferoxamine in patients with Sickle-Cell-Disease. The results of this study show that Deferiprone has the same effectiveness as Deferoxamine in decreasing body iron burden, measured as repeated measurements of serum ferritin concentrations on the same patient over 5-years and analyzed according to the linear mixed-effects model (LMM) (p=0.822). Both chelators are able to decrease, significantly, serum ferritin concentrations, during 5-years, without any effect on safety (p=0.005). Moreover, although …

Racial Differences In Human Platelet Par4 Reactivity Reflect Expression Of Pctp And Mir-376c., Leonard Edelstein, Lukas M Simon, Raúl Teruel Montoya, Michael Holinstat, Edward S Chen, Angela Bergeron, Xianguo Kong, Srikanth Nagalla, Narla Mohandas, David E Cohen, Jing-Fei Dong, Chad Shaw, Paul Bray

Cardeza Foundation for Hematologic Research

Racial differences in the pathophysiology of atherothrombosis are poorly understood. We explored the function and transcriptome of platelets in healthy black (n = 70) and white (n = 84) subjects. Platelet aggregation and calcium mobilization induced by the PAR4 thrombin receptor were significantly greater in black subjects. Numerous differentially expressed RNAs were associated with both race and PAR4 reactivity, including PCTP (encoding phosphatidylcholine transfer protein), and platelets from black subjects expressed higher levels of PC-TP protein. PC-TP inhibition or depletion blocked PAR4- but not PAR1-mediated activation of platelets and megakaryocytic cell lines. miR-376c levels were differentially expressed by race and …

Neuropathy, Neuropathic Pain, And Sickle Cell Disease., Samir K. Ballas, Deepika S Darbari

Cardeza Foundation for Hematologic Research

No abstract provided.

Erosive Arthritis And Hepatic Granuloma Formation Induced By Peptidoglycan Polysaccharide In Rats Is Aggravated By Prasugrel Treatment., Analia E Garcia, Mario C Rico, Elisabetta Liverani, Raul A Dela Cadena, Paul F. Bray, Satya P Kunapuli

Cardeza Foundation for Hematologic Research

Administration of the thienopyridine P2Y12 receptor antagonist, clopidogrel, increased the erosive arthritis induced by peptidoglycan polysaccharide (PG-PS) in rats or by injection of the arthritogenic K/BxN serum in mice. To determine if the detrimental effects are caused exclusively by clopidogrel, we evaluated prasugrel, a third-generation thienopyridine pro-drug, that contrary to clopidogrel is mostly metabolized into its active metabolite in the intestine. Prasugrel effects were examined on the PG-PS-induced arthritis rat model. Erosive arthritis was induced in Lewis rats followed by treatment with prasugrel for 21 days. Prasugrel treated arthritic animals showed a significant increase in the inflammatory response, compared with …

A 2-Step Approach To Myeloablative Haploidentical Stem Cell Transplantation With Optimized T-Cell Dosing: Early Immune Reconstitution Leads To Better Outcomes, Sameh Gaballa, Onder Alpdogan, Matthew Carabasi, Joanne Filicko, Margaret Kasner, Ubaldo E. Martinez-Outshoorn, Md, John L Wagner, Mark Weiss, Neal Flomenberg, Delores Grosso

Department of Medical Oncology Faculty Papers

We developed a 2-step approach to myeloablative haploidentical HSCT in which patients receive a large fixed dose of cyclophosphamide (CY)-tolerized T cells separately frm the HSC infusion in the hopes of accelerating post HSCT immune reconstitution (IR). The uniformity of the T cell dosing facilitates comparison of patients without (low risk) and with (high risk) active malignancy at HSCT to ascertain the impact of disease status at HSCT on IR with fewer confounding effects from conditioning or T cell dosing.

The Complex Transcriptional Landscape Of The Anucleate Human Platelet., Paul F. Bray, Steven E. Mckenzie, Leonard Edelstein, Srikanth Nagalla, Kathleen Delgrosso, Adam Ertel, Joan Kupper, Yi Jing, Eric R. Londin, Phillipe Loher, Huang-Wen Chen, Paolo Fortina, Isidore Rigoutsos

Cardeza Foundation for Hematologic Research

BACKGROUND: Human blood platelets are essential to maintaining normal hemostasis, and platelet dysfunction often causes bleeding or thrombosis. Estimates of genome-wide platelet RNA expression using microarrays have provided insights to the platelet transcriptome but were limited by the number of known transcripts. The goal of this effort was to deep-sequence RNA from leukocyte-depleted platelets to capture the complex profile of all expressed transcripts.

RESULTS: From each of four healthy individuals we generated long RNA (≥40 nucleotides) profiles from total and ribosomal-RNA depleted RNA preparations, as well as short RNA (<40 >nucleotides) profiles. Analysis of ~1 billion reads revealed that coding …

The Use Of Infliximab To Control Recurrent Cytokine Storms In Ebv-Associated Angioimmunoblastic Lymphoma And Hemophagocytic Syndrome, Sameh Gaballa, Emmanuel Besa, Onder Alpdogan

Department of Medical Oncology Faculty Papers

Introduction: Chronic active Epstein-Barr virus infection (CAEBV) has been implicated in several diseases including hemophagocytic lymphohistiocytosis (EBV-HLH) and lymphomas including Angioimmunoblastic T cell lymphoma. The exact mechanism by which EBV infection causes these complications is currently not well understood. EBV-HLH is a syndrome in which T-cells, NK cells and macrophages are aberrantly activated. Cytokine storms play a major role in cellular damage and organ dysfunction. In the event that the body is unable to clear the EBV viremia, dysregulated T, NK cells and macrophages continue to release cytokines leading to the accumulation of lymphohistiocytic infiltrates into organs and organ damage. …

Sickle Cell Pain: A Critical Reappraisal., Samir K. Ballas, Kalpna Gupta, Patricia Adams-Graves

Department of Medicine Faculty Papers

Sickle cell pain includes 3 types: acute recurrent painful crises, chronic pain syndromes, and neuropathic pain. The acute painful crisis is the hallmark of the disease and the most common cause of hospitalization and treatment in the emergency department. It evolves through 4 phases: prodromal, initial, established, and resolving. Each acute painful episode is associated with inflammation that worsens with recurrent episodes, often culminating in serious complications and organ damage, such as acute chest syndrome, multiorgan failure, and sudden death. Three pathophysiologic events operate in unison during the prodromal phase of the crisis: vaso-occlusion, inflammation, and nociception. Aborting the acute …

Drugs For Preventing Red Blood Cell Dehydration In People With Sickle Cell Disease., Srikanth Nagalla, Samir K Ballas

Department of Medicine Faculty Papers

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs.

OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells.

SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials …

Newer Agents In Antiplatelet Therapy: A Review., Jennifer Yeung, Michael Holinstat

Cardeza Foundation for Hematologic Research

Antiplatelet therapy remains the mainstay in preventing aberrant platelet activation in pathophysiological conditions such as myocardial infarction, ischemia, and stroke. Although there has been significant advancement in antiplatelet therapeutic approaches, aspirin still remains the gold standard treatment in the clinical setting. Limitations in safety, efficacy, and tolerability have precluded many of the antiplatelet inhibitors from use in patients. Unforeseen incidences of increased bleeding risk and recurrent arterial thrombosis observed in patients have hampered the development of superior next generation antiplatelet therapies. The pharmacokinetic and pharmacodynamic profiles have also limited the effectiveness of a number of antiplatelet inhibitors currently in use …

Transfection Of Human Platelets With Short Interfering Rna., Wei Hong, Altaf A Kondkar, Srikanth Nagalla, Wolfgang Bergmeier, Ying Jin, Jay Herman, Paul Bray

Cardeza Foundation for Hematologic Research

Platelets contain mRNAs and are capable of translating mRNA into protein, and it has been previously demonstrated that platelets increase their levels of integrin β3 overtime while in blood bank storage conditions. We are unaware of prior attempts to introduce nucleic acids into platelets. Considering the potential clinical and research utility of manipulating platelet gene expression, we tested whether small interfering RNAs (siRNAs) could be transfected into normal human platelets. Multiple conditions were tested, including lipofectamine versus electroporation, different amounts of siRNA, the effect of different buffers and the presence of plasma during transfection, and the time for optimal siRNA …

Septic Shock: Current Management And New Therapeutic Frontiers, R. Phillip Dellinger, Md

Division of Pulmonary, Allergy, and Critical Care Medicine Presentations and Grand Rounds

No audio is available for this presentation.

Dr. R. Phillip Dellinger is a Professor of Medicine who holds a faculty appointment in the Division of Pulmonary and Critical Care Medicine at the Robert Wood Johnson School of Medicine, University of Medicine and Dentistry of New Jersey. He is also the Vice-Chair, Department of Medicine and the Director, Medical/Surgical/Cardiovascular Surgical Intensive Care Unit at the Cooper Medical Center in Camden New Jersey. In 2006-2007, he was selected as South Jersey Top Docs by South Jersey Magazine. Dr. Dellinger's interests are in the treatment and outcomes of septic shock.

Differences In Responses Of Platelets To Fluid Shear Stress In Patients With Peripheral Artery Disease (Pad) And Coronary Artery Disease (Cad)., Vijay Nambi, Kay T Kimball, Paul Bray, Angela L Bergeron, Shawna L Johnson, Joel D Morrisett, Changyi Chen, Peter H Lin, Alan B Lumsden, Christie M Ballantyne, Jing-Fei Dong

Cardeza Foundation for Hematologic Research

Information on differences in platelet function between patients with peripheral arterial disease (PAD) and patients with coronary artery disease (CAD) is limited. We sought to examine the differences in the platelets response to shear stress in patients with PAD compared to those with CAD. Men with symptomatic PAD (ankle brachial index [ABI] < 0.9; n = 29) were compared with similarly aged men with CAD (post coronary artery bypass grafting; n = 40) but without PAD. All participants were on aspirin, and none were on clopidogrel. We measured changes in shear-induced platelet aggregation (SIPA) and shear-induced P-selectin expression (SIPE) under fluid shear rates of 5000 and 10,000 s(-1)which are typically found in arterioles and stenosed arteries, respectively. Aggregation was also induced by a combined stimulation of collagen, fluid shear stress, and adenosine diphosphate (ADP) or epinephrine using a platelet function analyzer (PFA-100) as well as optical aggregometry (arachidonic acid, collagen and epinephrine). Analyses of covariance adjusted for age, aspirin dose, and statin use were used to estimate differences between the groups. Values of SIPA at fluid shear rates of 5000 and 10,000 s(-1) were significantly higher in the PAD group, while there were no differences between the PAD and CAD groups in SIPE at both fluid shear rates. However, baseline shear-induced P-selectin expression was higher in patients with PAD than CAD (mean fluorescence intensity [MFI] = 2.93 +/- 1.37 vs.1.94 +/- 0.67; p = 0.01), while the percentage increases in SIPA and SIPE at fluid shear rates of 5000 and 10,000 s(-1) were significantly higher in patients with CAD when compared to PAD (p < 0.001 for all comparisons). Although there were several similarities in platelet function between men with PAD and men with CAD, significant differences in platelet responses to shear stress were observed in men with PAD when compared to those with CAD. Although the mechanism for these observed differences are not clear, we hypothesize that in vivo platelet activation in PAD patients may contribute to the differences and will need to be further investigated.

Usefulness Of Baseline Lipids And C-Reactive Protein In Women Receiving Menopausal Hormone Therapy As Predictors Of Treatment-Related Coronary Events., Paul Bray, Joseph C Larson, Andrea Z Lacroix, Joann Manson, Marian C Limacher, Jacques E Rossouw, Norman L Lasser, William E Lawson, Marcia L Stefanick, Robert D Langer, Karen L Margolis

Cardeza Foundation for Hematologic Research

Blood lipids and high-sensitivity C-reactive protein (hs-CRP) are altered by hormone therapy. The goal of the present study was to determine whether lipids and hs-CRP have predictive value for hormone therapy benefit or risk for coronary heart disease events in postmenopausal women without previous cardiovascular disease. A nested case-control study was performed in the Women's Health Initiative hormone trials. Baseline lipids and hs-CRP were obtained from 271 incident patients with coronary heart disease (cases) and 707 controls. In a combined trial analysis, favorable lipid status at baseline tended to predict better coronary heart disease outcomes when using conjugated equine estrogen …

A New Model For Hemoglobin Ingestion And Transport By The Human Malaria Parasite Plasmodium Falciparum., Michelle D Lazarus, Timothy G Schneider, Theodore F Taraschi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The current model for hemoglobin ingestion and transport by intraerythrocytic Plasmodium falciparum malaria parasites shares similarities with endocytosis. However, the model is largely hypothetical, and the mechanisms responsible for the ingestion and transport of host cell hemoglobin to the lysosome-like food vacuole (FV) of the parasite are poorly understood. Because actin dynamics play key roles in vesicle formation and transport in endocytosis, we used the actin-perturbing agents jasplakinolide and cytochalasin D to investigate the role of parasite actin in hemoglobin ingestion and transport to the FV. In addition, we tested the current hemoglobin trafficking model through extensive analysis of serial …

Platelet Hyperreactivity: Predictive And Intrinsic Properties., Paul F. Bray

Cardeza Foundation for Hematologic Research

Platelet thrombi are central to the development of most vascular ischemic events. There is marked interindividual variation in platelet responsiveness, with some subjects displaying platelet hyperreactivity. An increasing number of reports indicate that there are laboratory measures of platelet function that predict clinical thrombotic events. Some, but not all, measures of platelet function are reproducible. Platelet hyperreactivity can be assessed with multiple stimuli in multiple assays and is more likely to be present in women and in subjects who have elevated fibrinogen levels.

Genome-Wide Analysis Of Neuroblastomas Using High-Density Single Nucleotide Polymorphism Arrays., Rani E George, Edward F Attiyeh, Shuli Li, Lisa A Moreau, Donna Neuberg, Cheng Li, Edward A Fox, Matthew Meyerson, Lisa Diller, Paolo Fortina, A Thomas Look, John M Maris

Cardeza Foundation for Hematologic Research

BACKGROUND: Neuroblastomas are characterized by chromosomal alterations with biological and clinical significance. We analyzed paired blood and primary tumor samples from 22 children with high-risk neuroblastoma for loss of heterozygosity (LOH) and DNA copy number change using the Affymetrix 10K single nucleotide polymorphism (SNP) array.

FINDINGS: Multiple areas of LOH and copy number gain were seen. The most commonly observed area of LOH was on chromosome arm 11q (15/22 samples; 68%). Chromosome 11q LOH was highly associated with occurrence of chromosome 3p LOH: 9 of the 15 samples with 11q LOH had concomitant 3p LOH (P = 0.016). Chromosome 1p …

Induction Of Beta3-Integrin Gene Expression By Sustained Activation Of The Ras-Regulated Raf-Mek-Extracellular Signal-Regulated Kinase Signaling Pathway., Douglas Woods, Holly Cherwinski, Eleni Venetsanakos, Arun Bhat, Stephan Gysin, Martine Humbert, Paul F. Bray, Vicki L. Saylor, Martin Mcmahon

Cardeza Foundation for Hematologic Research

Alterations in the expression of integrin receptors for extracellular matrix (ECM) proteins are strongly associated with the acquisition of invasive and/or metastatic properties by human cancer cells. Despite this, comparatively little is known of the biochemical mechanisms that regulate the expression of integrin genes in cells. Here we demonstrate that the Ras-activated Raf-MEK-extracellular signal-regulated kinase (ERK) signaling pathway can specifically control the expression of individual integrin subunits in a variety of human and mouse cell lines. Pharmacological inhibition of MEK1 in a number of human melanoma and pancreatic carcinoma cell lines led to reduced cell surface expression of alpha6- and …

The Pl(A2) Polymorphism Of Integrin Beta(3) Enhances Outside-In Signaling And Adhesive Functions., K Vinod Vijayan, Pascal J. Goldschmidt-Clermont, Christine Roos, Paul F. Bray

Cardeza Foundation for Hematologic Research

Genetic factors are believed to influence the development of arterial thromboses. Because integrin alpha(IIb)beta(3) plays a crucial role in thrombus formation, we analyzed receptor adhesive properties using Chinese hamster ovary and human kidney embryonal 293 cells overexpressing the Pl(A1) or Pl(A2) polymorphic forms of alpha(IIb)beta(3). Soluble fibrinogen binding was no different between Pl(A1) and Pl(A2) cells, either in a resting state or when alpha(IIb)beta(3) was activated with anti-LIBS6. Pl(A1) and Pl(A2) cells bound equivalently to immobilized fibronectin. In contrast, significantly more Pl(A2) cells bound to immobilized fibrinogen in an alpha(IIb)beta(3)-dependent manner than did Pl(A1) cells. Disruption of the actin cytoskeleton …

Integrin-Dependent Control Of Translation: Engagement Of Integrin Alphaiibbeta3 Regulates Synthesis Of Proteins In Activated Human Platelets., Ravinder Pabla, Andrew S. Weyrich, Dan A. Dixon, Paul F. Bray, Thomas M. Mcintyre, Stephen M. Prescott, Guy A. Zimmerman

Cardeza Foundation for Hematologic Research

Integrins are widely expressed plasma membrane adhesion molecules that tether cells to matrix proteins and to one another in cell-cell interactions. Integrins also transmit outside-in signals that regulate functional responses of cells, and are known to influence gene expression by regulating transcription. In previous studies we found that platelets, which are naturally occurring anucleate cytoplasts, translate preformed mRNA transcripts when they are activated by outside-in signals. Using strategies that interrupt engagement of integrin alphaIIbbeta3 by fibrinogen and platelets deficient in this integrin, we found that alphaIIbbeta3 regulates the synthesis of B cell lymphoma 3 (Bcl-3) when platelet aggregation is induced …

Clinical Problem-Solving. Through Thick And Thin., David R. Yu, Redonda Miller, Paul F. Bray

Cardeza Foundation for Hematologic Research

No abstract provided.

Glanzmann Thrombasthenia. Cooperation Between Sequence Variants In Cis During Splice Site Selection., Ying Jin, Harry C. Dietz, Robert A. Montgomery, William R. Bell, Iain Mcintosh, Barry Coller, Paul F. Bray

Cardeza Foundation for Hematologic Research

Glanzmann thrombasthenia (GT), an autosomal recessive bleeding disorder, results from abnormalities in the platelet fibrinogen receptor, GP(IIb)-IIIa (integrin alpha(IIb)beta3). A patient with GT was identified as homozygous for a G-->A mutation 6 bp upstream of the GP(IIIa) exon 9 splice donor site. Patient platelet GP(IIIa) transcripts lacked exon 9 despite normal DNA sequence in all of the cis-acting sequences known to regulate splice site selection. In vitro analysis of transcripts generated from mini-gene constructs demonstrated that exon skipping occurred only when the G-->A mutation was cis to a polymorphism 116 bp upstream, providing precedence that two sequence variations …

A Polymorphism Of A Platelet Glycoprotein Receptor As An Inherited Risk Factor For Coronary Thrombosis., Ethan J. Weiss, Paul F. Bray, Matthew Tayback, Steven P. Schulman, Thomas S. Kickler, Lewis C. Becker, James L. Weiss, Gary Gerstenblith, Pascal J. Goldschmidt-Clermont

Cardeza Foundation for Hematologic Research

BACKGROUND: Platelet glycoprotein IIb/IIIa is a membrane receptor for fibrinogen and von Willebrand factor, and it has an important role in platelet aggregation. It is known to be involved in the pathogenesis of acute coronary syndromes. Previously, we found a high frequency of a particular polymorphism, PlA2, of the gene encoding glycoprotein IIIa in kindreds with a high prevalence of premature myocardial infarction.

METHODS: To investigate the relation between the PlA2 polymorphism and acute coronary syndromes, we conducted a case-control study of 71 case patients with myocardial infarction or unstable angina and 68 inpatient controls without known heart disease. The …

Antibodies Against Epstein-Barr Nuclear Antigen (Ebna) In Multiple Sclerosis Csf, And Two Pentapeptide Sequence Identities Between Ebna And Myelin Basic Protein., Patrick F. Bray, J Luka, Paul F. Bray, K W. Culp, J P. Schlight

Cardeza Foundation for Hematologic Research

The Epstein-Barr virus (EBV) causes infectious mononucleosis and is linked to several disparate malignancies. Prior studies on patients with multiple sclerosis (MS) showed that 100% are EBV-seropositive and that their blood contains higher antibody titers than those of controls to both transformation and lytic cycle antigens. We performed three different assays for antibodies in CSF to three major EBV antigens from patients with MS and controls. Among 93 patients with MS, 79 (85%) had CSF that reacted with a 70 kD protein, shown to be the nuclear antigen, EBNA-1, whereas only 11 (13%) of 81 EBV-seropositive controls reacted, p less …

Physical Linkage Of The Genes For Platelet Membrane Glycoproteins Iib And Iiia., Paul F. Bray, Greg Barsh, Jean-Philippe Rosa, Xue Ya Luo, Ellen Magenis, Marc A. Shuman

Cardeza Foundation for Hematologic Research

The fibrinogen receptor on human platelets is a prototypic member of the integrin family and is composed of subunit glycoproteins IIb (gpIIb) and IIIa (gpIIIa) in a 1:1 stoichiometric ratio. We have isolated cDNA clones for gpIIb and gpIIIa and localized both genes to chromosome 17. In the current study, several approaches were used to localize and map the genes for gpIIb and gpIIIa. A preliminary evaluation of subchromosomal localization was performed by using a panel of mouse-human somatic cell hybrids that contain different amounts of the long arm of human chromosome 17. Southern hybridization to the DNA of these …

Platelet Glycoprotein Lib: Chromosomal Localization And Tissue Expression, Paul F. Bray, Jean-Philippe Rosa, Geoffrey I. Johnston, Donny T. Shiu, Richard G. Cook, Chris Lau, Yuet Wai Kan, Rodger P. Mcever, Marc A. Shuman

Cardeza Foundation for Hematologic Research

The GPIIb-IIIa complex functions as a receptor for cytoadhesive proteins on the platelet surface. Both GPIIb and GPIIIa are synthesized by a human erythroleukemia (HEL) cell line. We isolated several cDNA clones by screening a HEL cell cDNA library with an oligonucleotide derived from amino acid sequence of GPIIb. Nucleotide and amino acid sequences were determined from 703 bp of one of these clones. Amino acid sequence of purified platelet GPIIb peptides confirmed the identity of the clone. The cDNA encodes the carboxyl terminus of the large (a) subunit of GPIIb and all of the smaller (f6) subunit of GPIIb. …

Biogenesis Of The Platelet Receptor For Fibrinogen: Evidence For Separate Precursors For Glycoproteins Iib And Iiia., Paul F. Bray, Jean-Philippe Rosa, Vishwanath R. Lingappa, Yuet W. Kan, Rodger P. Mcever, Marc A. Shuman

Cardeza Foundation for Hematologic Research

Congenital absence of platelet glycoproteins IIb and IIIa (GPIIb and GPIIIa) results in a severe bleeding disorder characterized by defective platelet aggregation and failure of fibrinogen to bind to platelets. GPIIb is a two-chain protein containing disulfide-linked alpha and beta subunits. GPIIb and GPIIIa are present as a heterodimeric, noncovalent complex in the platelet plasma membrane and function as the fibrinogen receptor. To characterize synthesis of these two proteins, RNA isolated from a human leukemia cell line that contains GPIIb and GPIIIa was translated in a wheat germ cell-free system. Polyclonal antibodies specific for each protein immunoprecipitated distinct [35S]methionine-labeled precursors, …