Understanding Vascular Endothelium: A Pilgrim s Progress

Transcription

1 Society for Cardiovascular Pathology Distinguished Achievement Award Presentation USCAP Meeting, Baltimore March 3, 2013 Understanding Vascular Endothelium: A Pilgrim s Progress Michael A. Gimbrone, Jr., M.D. Elsie T. Friedman Professor of Pathology Harvard Medical School Director, Center for Excellence in Vascular Biology Brigham and Women s Hospital Boston, MA

2 Keys to a Successful (& Rewarding) Career in the Biomedical Sciences Picking the Right Question Being Persistent Choosing Good Mentor(s) Using Interdisciplinary Approaches Learning from Patho-biology

3 Endothelium: Its Development, Morphology, Function, and Pathology by Rudolf Altschul, M.U.Dr. (Macmillan, New York, 1954) The largest number of natural deaths from a single cause in North America is ascribed to cardiovascular diseases. Because the great majority of [fatal] heart disease is caused by coronary [artery] thrombosis, we may as well cancel the first word in cardiovascular and conclude that most people succumb to a vascular disease. Blood vessels are primarily endothelial [lined] tubes and therefore,..the endothelium has a great importance in our life and its failure will cause the death of many of us.

4 The Challenge: We probably know only a few of the numerous functions of endothelium, and not all of them are unanimously agreed upon. Altschul, 1954

5 An Experimental Strategy: Endothelial Culture? But the rather common belief [is] that endothelial cells in tissue culture will turn into fibroblasts or fibroblast-like cells. Altschul, 1954

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9 J. Cell Biol. 60: (1974)

10 Michael A. Gimbrone, Jr. and R. Wayne Alexander Science 189: (1975).

11 Interleukin-1 acts on Cultured Human Vascular Endothelium to increase the Adhesion of Polymorphonuclear Leukocytes, Monocytes, and related Leukocyte Lines M. P. Bevilacqua et al (Gimbrone, MA) J. Clin. Invest Control Interleukin-1b

12 Monoclonal Antibody Screening (IHC) Control HUVEC Interleukin-1b

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14 Immunoprecipitation of E-LAM-1 from 35 S-Cys/Met labeled HEC

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21 While working on the problem of arteriosclerosis, I have realized not only how little I knew about endothelium -- but also how much I ought to know for the proper understanding of arteriosclerosis. Altschul, 1954

22 ORIGINAL RESPONSE TO INJURY HYPOTHESIS Central role of endothelial denudation * Ross & Glomset,1976

23 Courtesy of P. Davies

24 Cybulsky & Gimbrone, Science 1991

25 Pathophysiological Stimuli of Endothelial Dysfunction CYTOKINES BACTERIAL PRODUCTS VIRAL INFECTION/TRANSFORMATION ADVANCED GLYCOSYLATION ENDPRODUCTS OXIDIZED LIPOPROTEINS HOMOCYSTEINE HEMODYNAMIC FORCES

26 Non-random Distribution of Early Lesions of Atherosclerosis in Rabbit and Mouse Models WHHL Rabbit Cybulsky & Gimbrone LDLR-/- Mouse Cybulsky et al.

27 Bussolari, Dewey, Gimbrone Rev.Sci.Instrum

28 Endothelial Genes Modulated by Fluid Shear Stress tpa ICAM-1 VCAM-1 ACE Hsp70 Thrombomodulin c-fos c-myc Egr-1 NF-kB Smad 6 Smad 7 TGF-b PDGF-A PDGF-B bfgf enos COX-2 SOD

29 Dynamic Flow System Blackman BR, Garcia-Cardena G, Gimbrone MA Jr. A new in vitro model to evaluate differential responses of endothelial cells to simulated arterial shear stress waveforms. J. Biomech. Eng. 2002

30 Prototypical Arterial Waveforms derived from Regions of the Human Carotid Artery Bifurcation that are Relatively Resistant or Susceptible to Atherosclerosis Athero-protective Waveform Athero-prone Waveform Dai G, Kaazempur-Mofrad MR,Natarajan S, Zhang Y, Vaugh S, Blackman B, Kamm R, Garcia-Cardena G, Gimbrone MA.Jr. PNAS 101:14871, 2004).

31 Genome-wide Analysis of Gene Expression in HUVEC Exposed to Atheroprotective vs. Atheroprone Waveforms 160 genes Athero-protective 113 genes Total: ~35,000 genes Celera Arrays Athero-prone (n=3 experiments) Garcia-Cardena & Gimbrone, unpublished

32 Differential Expression of Biomechanically Induced Endothelial Transcriptional Regulators

33 Expression of KLF2 in the Mouse Aorta Athero-susceptible 1mm Athero-resistant Garcia-Cardena (Unpublished) In situ Hybridization

34 Atheroprotective Flow KLF2 Statins (Other drugs?) Endothelial Cell Vasoprotective Phenotype Inflammation VCAM-1 E-Selectin Multiple chemokines/ Chemokine receptors Elafin IL-11 Vasomotor Reactivity enos CNP Adrenomedullin Endothelin Thrombosis Thrombomodulin Tissue Factor PAI-1 Parmar K et al. J.Clin.Invest. 116: 49 (2006)

35 One is as old as one s endothelium. Altschul, 1954

36 Endothelial Activation and the Vascular Pathobiology of Progeria Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare, monogenic, autosomal dominant disorder, characterized by premature aging, affecting multiple organ systems, and resulting in early death. Severely accelerated arteriosclerosis typically results in fatal heart attacks and strokes in teen-aged subjects. Progerin, a mutant form of the nuclear lamin A/C protein, accumulates in various cell types, in particular endothelium. Progerin also accumulates in vessels with physiological aging.

37 Cardiovascular Pathology in Hutchinson-Gilford Progeria: Correlation With the Vascular Pathology of Aging Michelle Olive, Ingrid Harten, Richard Mitchell, Jeanette K. Beers, Karima Djabali, Kan Cao, Michael R. Erdos, Cecilia Blair, Birgit Funke, Leslie Smoot, Marie Gerhard-Herman, Jason T. Machan, Robert Kutys, Renu Virmani, Francis S. Collins, Thomas N. Wight, Elizabeth G. Nabel, Leslie B. Gordon Arteriosclerosis, Thrombosis, and Vascular Biology 11: (2010)

38 VCAM-1 expression is initiated in the endothelium and progresses into the smooth muscle in the aortas of HGPS mice VCAM-1

39 Increased expression of pro-inflammatory cytokines in the aortas of HGPS mice MCP-1 IL-1b

40 In vitro model of adenovirus-transduced progerin-expressing human endothelial cells (EC) Site of HGPS mutation G608G (GGC GGT) (B) Lamin A Pre-mRNA Exon 11 (A) Exon 12 Wild type splice (A) 50aa Mutant splice (B)

41 Progerin expression in EC induces a multi-faceted pro-inflammatory activation ( Ad-Progerin / Ad-Null )

42 Conditioned medium from progerin-expressing EC triggers the expression of pro-inflammatory genes in quiescent EC 4h Conditioned medium transfer Adenovirus-infected EC Acceptor EC (Quiescent) Acceptor EC

43 Conditioned medium from progerin-expressing EC triggers the expression of pro-inflammatory genes in neighboring quiescent SMC Adenovirus-infected EC

44 Silencing IL-1 expression suppresses progerin-induced EC pro-inflammatory genes Control shrna + Ad-Progerin IL-1 +b shrna + Ad-Progerin b

45 Summary The aortas of HGPS mice exhibit pro-inflammatory, pro-atherogenic activation as evidenced by: a) Progressive expression of VCAM-1 ( athero-elam ) in EC and SMC. b) Expression of pro-inflammatory cytokines (IL-1, MCP-1) in the aortic wall with increasing age. Progerin accumulation in human endothelial cells provokes a program of multifaceted endothelial activation resulting in a pro-inflammatory, pro-atherogenic phenotype. Progerin-expressing EC can mediate paracrine activation of neighboring cells (quiescent EC and SMC) potentially contributing to amplification and chronicity of vascular changes. IL-1 induction appears to play a key role in this process.

46 These results reveal a previously unappreciated role for progerin-induced endothelial activation in the vascular pathobiology of HGPS, and potentially that of physiological, multi-organ aging.

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51 CENTER FOR EXCELLENCE IN VASCULAR BIOLOGY BRIGHAM AND WOMEN S HOSPITAL Gimbrone Lab Belinda Yap Guohao Dai Brett Blackman Jason Comander Yvonne Ou Ivy Ku Noriaki Kume Masayuki Yoshida Nitzan Resnick Tobi Nagel James Topper Keith Anderson Jeanne Kiely Kay Case Bill Atkinson Garcia-Cardena Lab Kush Parmar Vinod Nambudiri Eric Wang Yuzhi Zhang Yao Liu Jessica Yu Johannes Kratz Sripriya Natarajan Stephanie Kwei Bioengineering Department MIT Forbes Dewey et al. Roger Kamm et al. Collaborators Myron Cybulsky Tucker Collins Ramzi Cotran Fred Schoen Peter Libby Mukesh Jain