Endothelial Injury and Repair as a Working Paradigm

Transcription

1 Endothelial Injury and Repair as a Working Paradigm A. Linke ESC Meeting 2010 UNIVERSITÄTLEIPZIG H ERZZEN TRUM

2 Physiology of Endothelial Function: Regulation of Vascular Tone L-Arg. L-Arg. Agonists Shear Stress Vascular Lumen Gefäßlumen L-Arg. L-Arg. + enos + Citrullin L-Citrulline Endothelial Endothelzelle Cell L-Arg. NO Extrazellularraum Extracellular Space NO GTP cgmp Ca 2+ Glatte Gefäßmuskelzelle Vascular Smooths Muscle Peroxynitrite

3 Pathophysiology Endothelial Dysfunction The conditio sine qua non for atherogenesis J. Ross, Nature 1993;362:

4 Pathophysiology of Endothelial Dysfunction in Cardiovascular Disease L-Arg. L-Arg. Vascular Lumen Gefäßlumen L-Arg. L-Arg. enos enos Citrullin L-Citrulline Endothelial Endothelzelle Cell L-Arg. NO ROS Extrazellularraum Extracellular Space NO GTP cgmp Ca 2+ Glatte Gefäßmuskelzelle Vascular Smooths Muscle Peroxynitrite

5 Therapeutic options in CAD: Exercise Training

6 Assessment of Endothelial Function Infusion Catheter Doppler Guide Wire, 12 MHz Coronary Artery ( target vessel ) 1 cm Distal Diameter

7 Shear Stress, Physical Activity and Endothelial Function Inclusion Criteria Coronary 1/2 Vessel Disease Preserved LV Function Stenosis Requiring Intervention Endothelial Dysfunction in Another Coronary Artery = Target Vessel Study Design Stable CAD (19 Pat.) Assessment of Endothelial Function Ergometer-Training 6x/d for 4 Weeks Control 4 Wo. Acetylcholine Assessment of Endothelial Function Hambrecht R, N Engl J Med 2000(342):454-60

8 Shear Stress, Physical Activity and Endothelial Function Training Group Control Group D Coronary Blood FLow [%] Begin 4 Weeks Begin 4 Weeks p<0.05 vs.kontrolle Hambrecht R, N Engl J Med 2000(342):454-60

9 Molecular Mechanisms: Exercise Training

10 Activation of enos by shear stress Shear stress Vessel PDK PI3K Akt P P S 1177 HSP90 Endothelium P enos P

11 LIMA-Study: Design Patients with stable CAD and indication for CABG (n=35) In-vivo-Assessment of Endothelial Function (LIMA) Control (n=18) Usual care 4 weeks Training (n=17) Daily Raw- / Bicycle ergometer training (4-6/d), 4 weeks In-vivo-Assessment of Endothelial Function (LIMA) In-vitro-Assessment of Endothelial Function (LIMA-Ring), Molecular Analysis of RNA- and Protein Expression Hambrecht R. et al., Circulation 2003

12 D APV vs. Baseline [%] Relaxation [%] Impact of exercise training on average peak blood flow velocity (APV) and Vasorelaxation of the LIMA ACH-induced APV after 4 weeks: - in vivo - Acetylcholine-induced Relaxation - in vitro p < 0.05 vs. Control Training Control p< Control Training Acetylcholine [µmol/l] Acetylcholine [µmol/l] Hambrecht R. et al., Circulation 2003

13 enos-expression [rel. Units] Protein expression [rel. units] Impact of Exercise Training on enos-expression and -Phosphorylation enos-expression C T C T enos-phosphorylation (Ser1177) K K T T 1.5 p< p< Control Training 0.0 Control Training Circulation 2003 (107):3452

14 D APV [rel. Units] Association between enos Ser1177 and DAPV 20 r=0.59 p< 0.02 Exercise Training Group p-enos Ser1177 [rel. Units] Hambrecht et al., Circulation 2003

15 NAD(P)H Oxidase - Subunits O 2 - O2 Rac Rap1A p47 gp91 p67 p22 Aktivation Phosphorylation NADPH NADP + Rap1A Rac gp91 p47 P p22 p67 Different Isoforms of gp91 phox described: Nox1 to Nox5, Nox2 = gp91 phox (Cheng et al., Gene 2001) In vessels: Nox-1, Nox-2 und Nox-4 mit relevanter Aktivität In endothelial cells: Nox-2 In vascular smooth muscle cells: Nox-1 und Nox-4

16 Gp91 phox / 18S-rRNA [x100] Nox4 / 18S-rRNA [x100] p22 phox / 18S-rRNA [x100] Expression of NAD(P)H Oxidase Subunits gp91 phox Nox4 p22 phox Control Training 0.0 Control Training 0 Control Training Adams V et al., Circulation 2005

17 NAD(P)H Oxidase-Activity and ROS-Production: Impact of Exercise Training NAD(P)H-Oxidase-Aktivity ROS-Generation NAD(P)H-Oxidase-Activity [mu/mg] Control p<0.05 Training ROS-Generation [DOD 550 / min] Control p<0.05 Training Adams V et al., Circulation 2005

18 Correction of Endothelial Dysfunktion by Exercise Training Endotheliale Dysfunktion O 2 - NO Exercise Training O 2 - NO enos Expression p-ecnos and p-akt NAD(P)H subunits p22 phox and gp91 phox Ang II-Receptor 1 Prognostic Implication?

19 Molecular Mechanisms: Importance of endogenous progenitor and stem cells

20 Function of EPCs Bone marrow Proliferation EPC Blood vessel Endothelium Recruitment Differentiation Mobilization Target organ Vasculogenesis in-situ EPC differentiation and proliferation

21 Application of ex vivo cultivated EPCs - Results from animal models - human human Medium mature EC EPCs Immediately after ischemia MNCs 7 days in culture 28 days after EPC application Animal model of Hind limb ischemia Kalka C et al., PNAS 2000; 97:3422

22 Progenitor Cells Regenerate Damaged Endothelium - Results from animal experiments - Friedrich E et al., Circ Res 2006; 98:e20

23 Apoptotic index Apopt. Endothelial Cells [%] Endothelial Integrity: Turnover of Endothelial Cells Oxidant stress oxldl Rössig L, J Am Coll Cardiol 2000(36):2081 Di-LDL/FITC-Lectin positive Cells Angiotensine II Catecholamine Cytokines Endotoxin Growth factor deficiency Control CHF Bone marrow Proapoptotic factors Endothelial progenitor cells Apoptosis

24 Molecular Mechanisms: Impact of ischemia on EPC release

25 Impact of an acute bout of exercise on EPC release Myocardial Ischemia (I) Pts with CAD and exercise induced ischema Control (C) Pts with CAD having no evidence of exercise-induced ischemia Healthy Subjects (HS) maximal symptom-limited bicycle ergometry Blood samples at 2, 4, 6, 8, 24, 48, 72, 96, 120 and 144h after the exercise test FACS-Analysis: Detection of CD34+/KDR+ cells in the blood Cell culture: Measurement of Di-acLDL/FITC-lectin positive cells after 4 days in culture Adams et al., Arterioscler Thromb Vasc Biol 2004

26 x-fold increase in CD34 + /KDR + cells vs. begin Impact of an acute bout of exercise on EPC mobilization 4 $ # Healthy subjects (HS) CAD without Ischemia (C) 3 2 $ # CAD with ischemia (I) $: p<0.05 vs. Beginn; #: p<0.05 vs. C and HS Time after exercise [h] Adams et al., Arterioscler Thromb Vasc Biol 2004

27 EPC-Mobilisation by Exercise Training: Results of 2 randomized studies Patients with PAOD Fontaine II b (n=18) Maximal Exercise Test on the Treadmill Blood sampling Patients CAD with patients PAOD after PTA (n=31) (n=18) Maximal max. exercise Exercise test Test on a on treadmill the Treadmill blood Blood samples sampling Ischemic Training (n=9) Inactive Control (n=9) Non-ischemic ET ET below at the AP-Threshold 75% of peak HR (n=15) (n=9) Inactive Inactive control Control (n=16) (n=9) Blood sampling (every week) blood Blood samples sampling (every (weekly) week) Maximal Exercise Test after 4 weeks Sandri M, et al; Circulation 2005

28 EPC Mobilization by Exercise Training Begin Circulating CD34 + /KDR + Cells Begin acldl + /Lectin + Zellen After 4 weeks After 4 weeks Sandri M, et al; Circulation 2005

29 x-facher x-fold increase Anstieg in CD34 CD34 + /KDR + /KDR + Zellen + cells vs. Beginn x-fold increase in CD34 + /KDR + cells vs. Begin EPC Mobilization by Exercise Training Ischemic Training Non-ischemic Training p<0.05 vs. Kontrolle Control Training Training PAOD-Patients CAD after patients PTA Kontrolle Control Training Control Control Training Time Zeit [d] [d] Time time [d] Sandri M, et al; Circulation 2005

30 Impact of Exercise Training on the Expression of Homing Factors Non-ischemia Training (n=9) Ischemic Training (n=9) mrna-expression [arb. units] mrna-expression [arb. units] CXCR4 and CPC-Homing in ischemic tissues Migration following An SDF1- Gradient CPC CXCR4 SDF-1 Ischemia CXCR4-Expression in patients with PAOD Begin 4 Wo Begin 4 Wo Training Control Begin 4 Wo Begin 4 Wo Training Control Sandri M, et al; Circulation 2005 p<0.05 vs. Begin and Control

31 Nicht-ischäm. Training % integrated CPCs Ischäm. Training % integrated CPCs Impact of Exercise Training on EPC function Matrigel-Assay Patients with PAOD Begin 4 Wo Begin 4 Wo Training (n=9) Control (n=9) blue = nucleus red = endothelial cells green = EPCs Beginn 4 Wo Begin 4 Wo Training (n=9) Control (n=9) Sandri M, et al; Circulation 2005 p<0.05 vs. Control

32 Impact of Exercise Training on the Mobilization of EPCs Improvement of myocardial Perfusion Endothelial Regeneration?? Arterio-/ Vasculogenesis Ischemia (HIF1a ) PI3K pakt NO circulating EPCs VEGF

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34 Thank you!