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Principal Investigator: Jason Knight
Organization: UNIVERSITY OF MICHIGAN AT ANN ARBOR
Fiscal Year: 2024
Award: $396,640
Funding agency: National Heart Lung and Blood Institute
PROJECT SUMMARY/ABSTRACT
This proposed renewal of “Purinergic modulation of the autoimmune vascular phenotype” builds upon 4 years
of discovery by an early stage investigator in the areas of lupus, COVID-19, and antiphospholipid syndrome
(APS). Despite the routine use of traditional anticoagulants in the latter disease, 1 in 5 APS patients is still
expected to experience a breakthrough thrombotic event. Furthermore, anticoagulants do little to mitigate the
chronic occlusive microangiopathy that damages APS organs over time. How to combat anticoagulant-
resistant manifestations of APS is unknown. This project now endeavors to use a deeply-phenotyped patient
cohort, selected in vitro systems, and the most relevant animal models to identify adjuvant therapeutic
approaches for the APS clinic. Its successful completion will shed additional light on neutrophil phenotypes in
APS and will provide a new understanding of the role that purinergic signaling, neutrophil-platelet interactions,
and neutrophil metabolism play in thrombotic events. The goal is that by the next cycle of this grant, we will
have identified the 1-2 most promising drug candidates for repurposing in our APS clinic.
APS is a leading acquired cause of both thrombosis and late-term pregnancy loss. In pursuit of a mechanistic
understanding of immunothrombosis in APS, our group was the first to show that neutrophil extracellular traps
(NETs, tangles of chromatin and microbicidal proteins expelled from activated neutrophils via “NETosis”) are
required for APS-associated thrombosis. Since our last competitive submission, we have found that
extracellular adenosine generated by the ectonucleotidase CD73 restrains NET release by activating surface
adenosine A2A receptors (A2AR) and thereby boosting intracellular cAMP. Key preliminary data that inform this
renewal demonstrate (i) restraint of platelet-mediated neutrophil activation by the CD73-A2AR axis; (ii)
exaggerated thrombosis in myeloid lineage-specific A2AR knockout mice; (iii) hyperactive glucose metabolism
in APS neutrophils that normalizes with A2AR agonists; and (iv) mitigation of thrombosis in APS mice by
metabolism-focused interventions. The hypothesis is that manipulation of the CD73-A2AR-cAMP axis will
restore neutrophil homeostasis in APS. Specific Aim 1 will define mechanisms by which purinergic signaling
influences neutrophil and platelet function in APS. This Aim will define for the first time the purinergic
landscape of a thrombophilic disorder, elucidate mechanisms by which purinergic signaling regulates
neutrophil-platelet communication, and potentially identify the subset of APS patients most likely to benefit from
antiplatelet and/or adenosine receptor-modulating therapies. Specific Aim 2 will determine the extent to which
purinergic signaling can be leveraged to normalize neutrophil metabolism in APS. This Aim is expected to
provide a new understanding of the metabolic requirements of NETosis, elucidate strategies for manipulating
neutrophil metabolism, and identify the subset of APS patients most likely to benefit from those strategies.
Terms: <3'5'-cyclic ester of AMP><A2AR><ADORA2><ADORA2A gene><Adenosine><Adenosine A(2A) Receptor><Adenosine A2A Receptor><Adenosine Cyclic 3',5'-Monophosphate><Adenosine Cyclic Monophosphate><Adenosine Cyclic Monophosphate-Dependent Protein Kinases><Adenosine Receptors><Adenosine, cyclic 3',5'-(hydrogen phosphate)><Adjuvant><Agonist><Animal Model><Animal Models and Related Studies><Anti-Inflammatories><Anti-Inflammatory Agents><Anti-Phospholipid Antibody Syndrome><Anti-inflammatory><Anti-phospholipid Syndrome><Antibodies><Anticoagulant Agents><Anticoagulant Drugs><Anticoagulants><Anticoagulation><Antiphospholipid Antibodies><Area><Autoimmune><Autoregulation><Bioenergetics><Blood Clotting><Blood Neutrophil><Blood Platelets><Blood Polymorphonuclear Neutrophil><Blood Vessels><Blood coagulation><COVID-19><CV-19><Cell Body><Cell Communication and Signaling><Cell Respiration><Cell Signaling><Cell Surface Receptors><Cells><Cellular Respiration><Chromatin><Chronic><Clinic><Clinical><Clotting><Coagulation><Coagulation Process><Communication><Coronavirus Infectious Disease 2019><Cyclic AMP><Cyclic AMP Receptors><Cyclic AMP-Dependent Protein Kinases><D-Glucose><Data><Deterioration><Dextrose><Disease><Disorder><Dysfunction><Enzyme Gene><Enzymes><Event><Familial antiphospholipid syndrome><Functional disorder><Glucose><Glycogen><Goals><Grant><Hexose Monophosphate Shunt><Homeostasis><Hughes syndrome><Hyperactivity><Immune><Immunes><In Vitro><Inflammation><Intermediary Metabolism><Intervention><Intervention Strategies><Intracellular Communication and Signaling><Investigators><KO mice><Knock-out Mice><Knockout Mice><Lupus><Marrow Neutrophil><Marrow platelet><Mass Photometry/Spectrum Analysis><Mass Spectrometry><Mass Spectroscopy><Mass Spectrum><Mass Spectrum Analyses><Mass Spectrum Analysis><Measurement><Mediating><Metabolic><Metabolic Processes><Metabolism><Mice><Mice Mammals><Modeling><Murine><Mus><Myelogenous><Myeloid><Neurofibrillary Tangles><Neutrophil Activation><Neutrophilic Granulocyte><Neutrophilic Leukocyte><Null Mouse><Organ><P1 Purinoceptors><PKA><Patients><Pentose Phosphate Pathway><Pentose Phosphate Shunt><Pentose Shunt><Pentosephosphate Pathway><Pentosephosphate Shunt><Phenotype><Phosphorylation><Physiological Homeostasis><Physiopathology><Platelets><Play><Polymorphonuclear Cell><Polymorphonuclear Leukocytes><Polymorphonuclear Neutrophils><Pregnancy loss><Protein Kinase A><Protein Phosphorylation><Proteins><Purine Nucleotides><Purinergic P1 Receptors><RDC8><Receptor Protein><Research Personnel><Researchers><Resistance><Role><Signal Transduction><Signal Transduction Systems><Signaling><Surface><System><Therapeutic><Thrombocytes><Thrombosis><Time><Work><adenosine 3'5' monophosphate><aerobic metabolism><aerobic respiration><biological signal transduction><blood damage><blood thinner><cAMP><cAMP Receptors><cAMP-Dependent Protein Kinases><cohort><combat><coronavirus disease 2019><coronavirus disease-19><coronavirus infectious disease-19><dietary><dietary manipulation><disease phenotype><drug candidate><ecto-nucleotidase><experience><experiment><experimental research><experimental study><experiments><extracellular><glucose metabolism><immune cell-mediated thrombosis><immune-mediated thrombosis><immunothrombosis><immunothrombotic><interventional strategy><microbicidal><microbicide><model of animal><neurofibrillary degeneration><neurofibrillary lesion><neurofibrillary pathology><neutrophil><oxidative metabolism><pathophysiology><platelet function><protection pathway><protective pathway><receptor><resistant><restraint><social role><tangle><thrombopoiesis inhibitor><thrombotic><thrombotic disease><thrombotic disorder><vascular>