Bone marrow molecular alterations after myocardial infarction: Impact on endothelial progenitor cells.
OBJECTIVE
Standard drugs post-myocardial infarction (MI) such as angiotensin converting enzyme (ACE) and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) increase levels of endothelial progenitor cells (EPC). However, potential underlying mechanisms have not yet been investigated.


RESULTS
We studied the effects of ACE inhibition or statin treatment on EPC levels and on bone marrow molecular pathways involved in EPC mobilization after MI in rats. Three days post-infarction, acetylated LDL (acLDL)+/Ulex europeus-1 (UEA-1)+/VEGF receptor-2+/eNOS+ EPC levels and formation of endothelial colony forming units (CFU) were reduced to 60+/-12% (p < 0.05) and 68+/-7% (p < 0.05). In bone marrow, extracellular signal-regulated kinase (ERK) phosphorylation and matrix metalloproteinase (MMP)-9 activity were repressed. Endothelial nitric oxide synthase (eNOS) activity was unchanged, whereas reactive oxygen species (ROS) were increased two-fold in bone marrow. ACE or HMG-CoA reductase inhibition resulted in significant increases in EPC levels. ACE inhibition increased bone marrow ERK phosphorylation and MMP-9 activity. Statin therapy enhanced bone marrow VEGF protein levels, Akt phosphorylation, eNOS activity and normalized increased ROS levels. Augmented EPC levels in the early post-infarction phase by ACE inhibition or statin treatment were associated with improved cardiac function and increased capillary density in the peri-infarct area 7 days after MI. Moreover, increased EPC levels in response to ACE inhibition or statin treatment were sustained 10 weeks post-infarction.


CONCLUSIONS
Increased ROS and impaired MMP-9 activity in bone marrow likely contribute to reduced EPC mobilization in the early post-infarction phase. ACE inhibition or statin treatment increased EPC levels with distinct drug-specific effects on bone marrow molecular alterations.
Medizinische Klinik I, Kardiologie, Universitätsklinikum Würzburg, Julius-Maximilians-Universität, Josef-Schneider Str. 2, 97080 Würzburg, Germany. thum_t@klinik.uni-wuerzburg.de
Thomas
T
Thum
Daniela
D
Fraccarollo
Paolo
P
Galuppo
Dimitrios
D
Tsikas
Stefan
S
Frantz
Georg
G
Ertl
Johann
J
Bauersachs
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism*; D002452:Cell Count; D002465:Cell Movement; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D007150:Immunohistochemistry / Q000379:methods; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000032:analysis / Q000378:metabolism; D009203:Myocardial Infarction / Q000378:metabolism* / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D000806:Angiotensin-Converting Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D017382:Reactive Oxygen Species; D042461:Vascular Endothelial Growth Factor A; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D020780:Matrix Metalloproteinase 9