The Cardeza Center pursues a broad range of basic research that can be divided into three focus areas: basic research, clinical/translational and core laboratories.
Paul Bray, MD
Dr. Bray’s laboratory studies the role of platelets in cardiovascular disease and disorders of bleeding and excessive blood clotting. He identifies and characterizes novel variations in platelet genes and in platelet gene expression that affect both clinical and platelet phenotypes. His laboratory utilizes genomic and transcriptomic approaches, and molecular and cell biology approaches to address these important areas of research. He is a clinician-scientist who has been continuously funded by the National Institutes of Health from 1986 to the present. He is a member of the Genomics and Cancer Biology graduate program. Current areas of investigation include:
Studies on demographic effects on platelet function and thrombosis
Studies on microRNA function in human megakaryocytes
Testing for interactions between genetic variations and medications for clinical outcomes of myocardial infarction, stroke or bleeding
Testing for interactions between genetic variations and medications for platelet functional responses
Visit Plateletomics.com for more information.
Paul Bray, MD
Leonard Edelstein, PhD
Research Assistant Professor
Xiango Kong, MD
Corey Lindsay, PhD
Seema Bhatlekar, PhD
Leonard Edelstein, PhD
Dr. Edelstein’s laboratory studies gene expression in megakaryocytes and platelets and their role in cardiovascular disease and thrombopoiesis. Current research includes:
Activated platelets release microparticles (MPs) which contain RNA and protein. These MPs have been shown to deliver miRNAs to endothelial cells in culture and alter the level of RNAs in these cells. We are studying this effect in a flow chamber in which the endothelial cells are cultured under shear stress and then analyzing the effect on genes regulated by inflammation or shear stress, two processes important to atherosclerotic plaque formation.
Genome wide association studies have identified ~50 loci in the human genome associated with heart attacks. However, neither the genetic variant responsible for the increased risk nor the cell type in which it functions has been identified. We are developing methods to identify which locus-linked genes are functional in platelets and the effect the common variants have on their expression and function.
The DLK1-DIO3 locus in an imprinted region of the genome containing 54 maternally-expressed miRNAs. Among hematopoietic cells, these miRNAs are platelet specific. We have generated data that expression of these miRNAs increases during megakaryopoiesis and that early overexpression inhibits megakaryopoiesis. We are investigating the role of these miRNAs in megakaryocyte development.
Arterial hypertension is associated with thrombotic events due to platelet activation. The exact mechanism by which hypertensive platelets become more sensitive to agonist stimulation is unknown. We have collected platelet miRNA from healthy and pre-hypertensive subjects and found association between miRNA level and blood pressure. We will use this data to identify differentially expressed genes responsible for the increased function in platelets.
Michael Holinstat, PhD
The Holinstat lab focuses on understanding complex platelet signaling mechanisms that regulate hemostasis and thrombosis. The work focuses on three primary areas of platelet research spanning from a basic science and drug discovery program to clinical and translational projects, including a clinical trial focused on platelet function in type 2 diabetes mellitus. This work is fully funded by three National Institutes of Health grants (NIH R01 grants), support from the American Heart Association (AHA), the Parenteral Drug Association Foundation (PDAF) and the Cardeza Foundation for Hematologic Research at Thomas Jefferson University.
One project in the lab focuses on identifying the inherent racial differences in platelet function between blacks and whites. This clinical project investigates some of the underlying genetic differences in blacks and whites that predispose some people to a higher risk for thrombosis and stroke while sparing others. Through this effort, we will be able to determine for the first time how to differentially treat patients based on their genetic/racial background. This area of research, often termed “individualized medicine,” has the potential to shift our mode of treatment from disease to patient by understanding that not all treatments will equally benefit every patient who presents with a thrombotic event, and more importantly prevention of thrombotic events may differ based on genetic or racial background. Early findings in this study have already shown that blacks express a higher level of the thrombin receptor PAR4 and have uncovered a novel protein in the human platelet (absent in the mouse platelet), phosphatidylcholine transfer protein (PCTP), which appears to play an important role in platelet activation and is highly expressed in platelets from blacks compared to whites.
A second area of focus in the lab is identifying how platelet activation is regulated by the enzyme 12-lipoxygenase (12-LOX). Similar to COX-1, 12-LOX oxidizes free fatty acids in order to form bioactive metabolites (called eicosanoids). Our lab has recently shown that the 12-LOX eicosanoids derived from arachidonic acid in the platelet are pro-thrombotic and we, along with our collaborators across the country, have developed the first selective inhibitor against human 12-LOX activity. This new class of inhibitors prevents agonist-mediated platelet activation and clot formation in human platelets. Subsequently, we also identified that 12-LOX oxidizes Omega-6 fatty acids to produce a novel eicosanoid, 12-HETrE, which is a potent inhibitor of platelet function. We are currently trying to identify the underlying mechanisms by which 12-HETrE protects against platelet activation, clot formation and stroke.
A third focus of the lab takes advantage of our basic scientific observations that altering the fatty acid content on the platelet may allow for formation of 12-LOX metabolites which would protect type 2 diabetics from suffering a thrombotic event. This translational project investigates in animal and patients the potential for omega-3 and omega-6 fatty acids and their 12-LOX eicosanoids to prevent platelet activation and unwanted thrombosis. This is an important area in diabetes research as 65% of deaths in type 2 diabetes mellitus are due to thrombosis and stroke.
Michael Holinstat, PhD
Benjamin Tourdot, PhD
Jin Ren, PhD
Katrin Niisuke, PhD
Jennifer Yeung, MS
Steven McKenzie, MD PhD
Dr. McKenzie is a Hematology physician-scientist with clinical expertise in adult and pediatric non-malignant hematologic disorders and a scientific expertise in translational research. He works in the Cardeza Hemophilia and Thrombosis Center and also in the Hereditary Anemias Center. He is a member of the Sidney Kimmel Cancer Center (SKCC), in the Molecular Biology and Genetics Program. He is a member of two Graduate Programs:
Genetics, Genomics and Cancer Biology
Immunology and Microbial Pathogenesis
He is a physician mentor for Thomas Jefferson University MD/PhD program.
Dr. McKenzie directs two major laboratory research projects. The first project has a focus on immune-mediated thrombocytopenia and thrombosis syndromes (see McKenzie and Sachais, Current Opinion in Hematology, September 2014). This work led to the first and only mouse model of heparin-induced thrombocytopenia and thrombosis (HIT). The current work explores Novel Therapeutics in HIT, in an NIH-supported Program Project grant with Drs. Poncz and Rauova at Children’s Hospital of Philadelphia, Drs. Cines, Sachais and Cuker at University of Pennsylvania, and Dr. Arepally at Duke. In another subproject, Dr. McKenzie is co-funded on an NIH R01 with Dr. Bergmeier at UNC Chapel Hill and Dr. Woulfe at University of Delaware to explore platelet signaling mechanisms.
The second major McKenzie lab project focuses on the Genomics and Molecular Genetics of inter-individual variation in human platelet activation via FcgammaRIIa. This molecule has dual functions, as a receptor for IgG immune complexes and as a transmembrane adapter in integrin “outside-in” signaling. In collaboration with Dr. Paul Bray, who led the PRAX1 study, our team has identified differentially expressed mRNAs and miRNAs as well as genomic variants that regulate platelet reactivity. Team members of our longstanding Platelet Interest Group are Drs. Bray, McKenzie, Holinstat, Edelstein and Naik at Thomas Jefferson University, Drs. Rigoutsos and Londin at Thomas Jefferson University Computational Medicine Center, Dr. Fortina of SKCC Genomics, Drs. Shaw and Simon at Baylor, and Dr. Kunapuli at Temple. Dr. McKenzie is also co-funded, with Dr. Holinstat as PI, on work that involves 12-LOX and diabetes vascular biology. Our foci in the McKenzie lab moving forward are novel molecular genetic pathways for determination of receptor levels, protein tyrosine phosphatase activity and oligo-ubiquitylation in platelet FcgammaRIIa functions.
Identification of a developmental gene expression signature, including hox genes, for the normal human colonic crypt stem cell niche: Overexpression of the signature parallels stem cell overpopulation during colon tumorigenesis
Steven E. McKenzie, MD PhD
Shaji Abraham, PhD
Ulhas P. Naik, PhD
The Naik laboratory is focused on developing therapeutic strategies to interrupt the progress of cardiovascular disease and cancer. In this regard, the team has identified several novel gene products that play key regulatory roles in the progression of these diseases. Using cell and molecular biological approaches, the team has characterized the potential role of calcium- and integrin-binding protein family and junctional adhesion molecule family members in physiological and pathological settings. Cutting edge technologies, such as the yeast two-hybrid system, siRNA, transgenic mouse models, systems biology, nanotechnology and fluid dynamics modeling are routinely employed in the laboratory.
Some specific projects involve:
Positive and negative regulatory mechanisms of platelet activation during thrombosis
Mechanism of new blood vessel formation (angiogenesis) during ischemia and cancer
Mechanism of breast and prostate cancer cell metastasis
Use of nanotechnology to deliver drugs to specifically targeted sites
Fraunhofer-UD Research Grant
Ulhas P. Naik, PhD
Brendan Bachman, M.S.
Randall Derstine, MS
Vilas Desai, PhD
Kalyan Golla, PhD
Meghna U. Naik, MSc
Pravin Patel, BS
All Seminars in Cardeza Library (Curtis Building Room 903) at 12:00 pm unless otherwise noted.
January 28 – Athan Kuliopulos (Tufts University)
February 11 – Rajanikanth Vadigepalli (Thomas Jefferson University)
February 25 – Khadija Rafiq (Thomas Jefferson University)
March 11 – Robert Flaumenhaft (Harvard University)
March 25 – Jean Pierre Issa (Temple University)
April 8 – Shawn Jobe (Milwaukee Blood Research Institute)
April 22 – Jerry Nadler (EVMS, Chair of Medicine)
May 13 – Ian Blair (University of Pennsylvania)
May 27 – TBA
September 3 – Caleb Kallen (Thomas Jefferson University)
September 17 – Shey-Shing Sheu (Thomas Jefferson University)
October 1 – Deepak Deshpande (Thomas Jefferson University)
October 15 – Domenico Pratico (Temple University)
October 29 – John Semple (University of Toronto; St. Michael’s Hospital)
November 12 – John Weisel (University of Pennsylvania)