Aging-related atherosclerosis is exacerbated by arterial expression of tumor necrosis factor receptor-1: evidence from mouse models and human association studies.

My research efforts involves studying the pathogenesis of vein graft neointimal hyperplasia and atherosclerosis.
The greatest amount of my time in the past years has been devoted to developing and characterizing our interposition vein graft model in mice. This model allows us to use IVC to carotid artery transplants between congenic mice. These transplants allow us to ask the questions about which gene products contribute to the pathogenesis of vein graft disease. In addition, I have used carotid artery to carotid artery transplants to study the role of TNF receptors in atherosclerosis. For these studies, we have used apolipoprotein E-deficient mice as graft recipients.
By using mouse vein graft model we demonstrate that most of the neointimal cells in vein grafts originate from cellular pools outside of the vein graft at the time of its implantation. The importance of this work relates to our persistent inability to treat vein graft disease in human beings. The second work demonstrates that expression of the tumor necrosis factor receptor-1, even in just in the vein graft cells themselves, contributes to the pathogenesis of vein graft neointimal hyperplasia. In this project, I surgically created chimeric mice to demonstrate molecular mechanisms by which the tumor necrosis factor receptor-1 aggravates neointimal hyperplasia, a process that is believed to lay the foundation for accelerated atherosclerosis in vein grafts.
I have also adapted my vein graft procedure in mice to ask questions about the arterial wall’s role in atherosclerosis. This atherosclerosis model involves making carotid interposition grafts not with veins, but with the carotid artery of congenic mice, and placing them into the carotid artery of spontaneously atherogenic mice that are deficient in apolipoprotein E.
I plan to continue our studies related to the role of inflammatory cytokine receptors in neointimal hyperplasia and atherosclerosis. In addition, I envision extending this work with the surgical models I have created in mice.

My research focuses on developing new statistical methods for identifying susceptibility loci involved in complex human disease.  It involves a mix of genetics, statistics, and computer science and is motivated by the complexities of real data encountered in collaborative disease-gene mapping projects.

Dr. Gregory is the Margaret Harris and David Silverman Distinguished Professor and Director of the Brain Tumor Omics Program in the Duke Department of Neurosurgery, the Vice Chair of Research in the Department of Neurology, and Director of the Molecular Genomics Core at the Duke Molecular Physiology Institute. 

As a neurogenomicist, Dr. Gregory applies the experience gained from leading the sequencing of chromosome 1 for the Human Genome Project to elucidating the mechanisms underlying multi-factorial diseases using genetic, genomic, and epigenetic approaches. Dr. Gregory’s primary areas of research involve understanding the molecular processes associated with disease development and progression in brain tumors and Alzheimer’s disease, drug induced white matter injury repair in multiple sclerosis, and the characterization of lesion microenvironmental changes in MS.

He is broadly regarded across Duke as a leader in the development of novel single cell and spatial molecular technologies towards understanding the pathogenic mechanisms of disease development. Dr. Gregory is also the Section Chair of Genomics and Epigenetics at the DMPI and Director of the Duke Center of Autoimmunity and MS in the Department of Neurology.

Our work focuses on atherosclerosis-related signal transduction and the genetic bases of atherosclerosis and vein graft failure, both in vitro and in vivo. We investigate the regulation of receptor protein tyrosine kinases by G protein-coupled receptor kinases (GRKs), and the role of GRKs and β-arrestins in atherosclerosis; molecular mechanisms of atherogenesis associated with the dual Rho-GEF kalirin, the F-actin-binding protein Drebrin, and small nucleolar RNAs (snoRNAs) of the Rpl13a locus. For in vivo modeling of atherosclerosis and neointimal hyperplasia, we use mouse carotid artery bypass grafting with either veins or arteries from gene-deleted or congenic wild type mice, as well as aortic atherosclerosis studies and bone marrow transplantation. To study receptor phosphorylation, signal transduction, and intracellular trafficking, we employ primary smooth muscle cells, endothelial cells, and macrophages derived from knockout mice, as well as cells treated with RNA interference.

Key Words: atherosclerosis, G protein-coupled receptor kinases, arrestins, desensitization, phosphorylation, receptor protein tyrosine kinases, smooth muscle cells, neointimal hyperplasia, Rho-GEF, Drebrin, snoRNAs.