Myocardial infarction

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Erin Ramsey
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NEW CARDIAC MARKERS AND CARDIAC REGENERATION Päivi Lakkisto, MD, PhD Specialist in Clinical Chemistry

infarction Myocardial infarction (MI) is one of major causes of morbidity and mortality worldwide

and regeneration mechanisms are activated in the infarcted heart Cytokines Growth factors Stem cells

1 NEW CARDIAC MARKERS AND CARDIAC REGENERATION Päivi Lakkisto, MD, PhD Specialist in Clinical Chemistry Clinical lecturer University of Helsinki and HUSLAB Minerva Institute for Medical Research Myocardial infarction Myocardial infarction (MI) is one of major causes of morbidity and mortality worldwide Treatment: early restoration of blood flow to limit infarct size and preserve cardiac function Repair and regeneration mechanisms are activated in the infarcted heart Cytokines Growth factors Stem cells are activated Despite the body s attempt to repair cardiac injury, infarct scar develops c-kit MHC DAPI 1

AMI left ventricular remodeling Structural changes in the non-infarcted myocardium Hypertrophy of cardiomyocytes (a) Interstitial (b) and perivascular (c) fibrosis Cardiomyocyte apoptosis

treatment in some patients Normalization of cardiac function after acute cardiac injury or acute decompensation of chronic heart failure in some patients possible activation of protective mechanisms

a c b Old and new cardiac markers Traditional cardiac markers: Cardiac troponins (ctn) and NTproBNP Diagnosis, cardiovascular risk assessment and outcome prediction Both associate with future

2 AMI left ventricular remodeling Structural changes in the non-infarcted myocardium Hypertrophy of cardiomyocytes (a) Interstitial (b) and perivascular (c) fibrosis Cardiomyocyte apoptosis Pharmacological treatment: renin-angiotensin-aldosterone (RAA) blockers and beta blockers prevent the progression of structural changes Development of terminal heart failure in spite of efficient treatment in some patients Normalization of cardiac function after acute cardiac injury or acute decompensation of chronic heart failure in some patients possible activation of protective mechanisms or enhanced repair of the injured myocardium? a c b Old and new cardiac markers Traditional cardiac markers: Cardiac troponins (ctn) and NTproBNP Diagnosis, cardiovascular risk assessment and outcome prediction Both associate with future cardiovascular events, mortality and progression of the disease Reflect the magnitude of cardiac injury or cardiac overload Underlying pathophysiological mechanisms of cardiac injury remain unknown Possible new cardiac markers (pathway-specific) Ischemia markers, FABP, IMA, PAPP-A Proinflammatory cytokines, hs-crp Matrix metalloproteinases, collagen synthesis and turnover markers mirnas Clinical usefulness unclear Multimarker approaches Clinical usefulness? 2

3 Classification of biomarkers Table 1 Traditional risk factors and biomarkers in CVD. Traditional risk factors Known and Novel Biomarkers Modi ables Non In ammation Neurohormonal modi ables and activation Endothelial Dysfunction Ischemia Necrosis Dyslipemia Hypertension Diabetes Smoking Obesity Physical Inactivity Age Gender Family History ICAM-1 VCAM-1 E-selectin CRP scd40l IL-18 MCP-1 Fibrinogen MPO ROS OPN FFA BNP NT-proBNP ADM MR-proADM Copeptin FFA IMA ApoJ ctnt ctni Badimon et al Heart-type fatty acid-binding protein, H-FABP Small 15 kda protein, transports intracellular long-chain fatty acids Released into plasma within 2 h after onset of ischemia, peaks at 6h and returns to normal levels within 24-36h Elisa methods, POC available Potential early marker of AMI 3

4 Ischemia modified albumin, IMA FDA-approved biomarker in US Detects myocardial ischemia within minutes, continues to increase 6 12h Cobalt-binding test, ischemia reduces the ability of albumin to bind cobalt Potential marker for early ruling out of acute coronary syndrome (good NPV, but low PPV) Problems: stability, not cardiospecific Pregnancy-associated plasma protein A, PAPP-A Metalloproteinase enzyme, activates IGF-1 Marker of ischemia Found in ruptures plaques, but not in stable plaques Clinical usefulness? 4

5 mirnas Additional reading (not required for exam) Cardiac marker reviews: Dekker et al. Heart 2010;96:1001e1010. doi: /hrt Tijsen et al. Am J Physiol Heart Circ Physiol 303:H1085- H1095, 2012 Lin et al. Resuscitation 83 (2012) Fiedler & Thum Arterioscler Thromb Vasc Biol. 2013;33:

Cardiac regeneration Adult mammalian heart is a regenerating organ Proliferation of cardiomyocytes Resident cardiac stem/ progenitor cells Limited capacity to regenerate Additional reading (not

6 Cardiac regeneration Adult mammalian heart is a regenerating organ Proliferation of cardiomyocytes Resident cardiac stem/ progenitor cells Limited capacity to regenerate Additional reading (not required in exam) Leri et al. Circ. Res. 2011, DOI: /CIRCRESAHA Hansson et al. Cell Stem Cell 5, October 2, 2009 Cardiac regeneration Anversa P et al., Circulation 2006,113: CSCs: c-kit+ MPC (myogenic progenitor cells), c-kit/kdr+ VPC (vascular progenitor cells (PNAS 2009;106: ) 6

7 Anversa P et al., Circulation 2006, 113: Cardiac progenitor cell classes - c-kit+ cells - Sca-1+ cells - Isl-1+ cells - Musashi-1+ - Nestin+ cells - Side population - Cardiospheres - EDPCs The origin of CSCs? Leri, A. Circulation 2009;120: Copyright 2009 American Heart Association 7

Cardiomyocyte renewal H3P MHC DAPI Estimation of cardiomyocyte annual renewal rate varies from 0.45-1% to 22% (Bergmann et al. 2009, Kajstura et al.

2011 Proliferation of cardiomyocytes Proliferating cardiomyocytes usually small mononucleated cells Proliferation increased in the infarct border

8 Cardiomyocyte renewal H3P MHC DAPI Estimation of cardiomyocyte annual renewal rate varies from % to 22% (Bergmann et al. 2009, Kajstura et al. 2010) Lakkisto et al Proliferation of cardiomyocytes Proliferating cardiomyocytes usually small mononucleated cells Proliferation increased in the infarct border area Kajstura et al How to enhance cardiac regeneration? Cell therapy bone marrow cells, CSCs, etc. Gene therapy Important role of paracrine factors (growth factors/ cytokines) activation of cardiac stem cells VEGF family, HGF, IGF-1, SDF-1 etc. Combination therapy 8

9 Cell therapy Many different cell types have been studied in experimental models - CSC/CPC - EDPC - HSC - ESC - MSC - adipose tissue derived cells - myoblasts - ipsc Clinical studies - Bone marrow mononuclear cells - CSC/CPC - cardiospheres Cell delivery options i.v. Intracoronary Intramyocardial Cell sheets 9

10 Challenges of cell therapy Survival of implanted cells (~5%) - Ischemia - Inflammation - Fibrosis Timing of the treatment? Preconditioning of cells or combination therapy Differentiation into desired cell type/ cell types Survival of cells or paracrine effects more important? - similar results with cell culture medium Growth factors, cytokines etc. Local or systemic administration or gene therapy Promote - CSC/CPC survival, proliferation and differentiation - cardiomyocyte proliferation IGF-1 (+ HGF) - CSC proliferation and differentiation - cardiomyocyte proliferation - cardioprotection SDF-1 CXCR4 - homing of stem cells into the ischemic area 10

Rebuilding the heart, is it possible? - Doris A.

skeleton of the heart - Perfusion in Langendorff system with SDS buffer - Decellularized

would avoid rejection and the need of antirejection medication Rat bioengineered heart: -

11 Rebuilding the heart, is it possible? - Doris A. Taylor - Bioengineered hearts - Decellularization of the whole heart to create the 3D skeleton of the heart - Perfusion in Langendorff system with SDS buffer - Decellularized heart can be recellularized by stem or progenitor cells - Use of patients own stem cells would avoid rejection and the need of antirejection medication Rat bioengineered heart: - endothelial cells, smooth muscle cells, cardiomyocytes and fibroblasts of neonatal rat hearts - Cells start contracting at day 4 - Pump function at day 8 11

Minerva - Unit of cardiovascular research Ilkka Tikkanen, MD, PhD, docent, head The group studies mechanisms and repair of end-organ damage in cardiovascular and renal diseases The role of HO-1 and

12 Minerva - Unit of cardiovascular research Ilkka Tikkanen, MD, PhD, docent, head The group studies mechanisms and repair of end-organ damage in cardiovascular and renal diseases The role of HO-1 and CO in post-mi cardiac repair Rat MI model Zebrafish cardiac injury model (cryoinjury) Collaboration with Ari Harjula s group (cell sheet transplantation) Collaboration with Regea, Tampere (ips cells) Role of HO-1 and CO in cardiac regeneration? Rat MI experiment to study HO-1 and CO in cardiac regeneration and remodeling after MI Lakkisto et al. Eur J Pharmacol 2010;635: Lakkisto et al. Exp Biol Med (Maywood) 2011;236: Experimental design: 12

13 c-kit+ progenitor cells c-kit MHC DAPI HO-1 and CO promote neovascularization Intermediate m Large >65 m 13

Cryoinjury-induced myocardial infarction.

zebrafish ventricle 14 days post injury showing

(B) Immunohistochemistry showing myosin heavy

14 Zebrafish model Figure. (A) Zebrafish larva at 9 days post fertilization. (B) Adult zebrafish. Zebrafish Figures by Jere Paavola Figure. Cryoinjury-induced myocardial infarction. (A) AFOG-stained sagittal section of an adult zebrafish ventricle 14 days post injury showing myocardium (orange), collagen (blue), and fibrin (red). Infarct area indicated by the broken yellow line. (B) Immunohistochemistry showing myosin heavy chain (myocardium, red), DAPI (nuclei, blue), and BRDU pos cells (green arrowheads), which indicate cells that are newly formed after the cryoinjury. Thank you 14

Paracrine Mechanisms in Adult Stem Cell Signaling and Therapy

Paracrine Mechanisms in Adult Stem Cell Signaling and Therapy Massimiliano Gnecchi, Zhiping Zhang, Aiguo Ni, Victor J. Dzau Circulation Research 2008 Nov 21;103(11):1204-19 Introduction(1) After AMI all