Inhibition of CD34+ cell migration by matrix metalloproteinase-2 during acute myocardial ischemia, counteracted by ischemic preconditioning.
Background.Mobilization of bone marrow-origin CD34+ cells was investigated 3 days (3d) after acute myocardial infarction (AMI) with/without ischemic preconditioning (IP) in relation to stromal-derived factor-1 (SDF-1α)/ chemokine receptor type 4 (CXCR4) axis, to search for possible mechanisms behind insufficient cardiac repair in the first days post-AMI.Methods.Closed-chest reperfused AMI was performed by percutaneous balloon occlusion of the mid-left anterior descending (LAD) coronary artery for 90min, followed by reperfusion in pigs. Animals were randomized to receive either IP initiated by 3x5min cycles of re-occlusion/re-flow prior to AMI (n=6) or control AMI (n=12). Blood samples were collected at baseline, 3d post-AMI, and at 1-month follow-up to analyse chemokines and mobilized CD34+ cells. To investigate the effect of acute hypoxia, SDF-1α and matrix metalloproteinase (MMP)-2in vitrowere assessed, and a migration assay of CD34+ cells toward cardiomyocytes was performed.Results.Reperfused AMI induced significant mobilisation of CD34+ cells (baseline: 260±75 vs. 3d: 668±180; P<0.001) and secretion of MMP-2 (baseline: 291.83±53.40 vs. 3d: 369.64±72.89; P=0.011) into plasma, without affecting the SDF-1α concentration. IP led to the inhibition of MMP-2 (IP: 165.67±47.99 vs. AMI: 369.64±72.89; P=0.004) 3d post-AMI, accompanied by increased release of SDF-1α (baseline: 23.80±12.36 vs. 3d: 45.29±11.31; P=0.05) and CXCR4 (baseline: 0.59±0.16 vs. 3d: 2.06±1.42; P=0.034), with a parallel higher level of mobilisation of CD34+ cells (IP: 881±126 vs. AMI: 668±180; P=0.026), compared to non-conditioned AMI.In vitro, CD34+ cell migration toward cardiomyocytes was enhanced by SDF-1α, which was completely abolished by 90min hypoxia and co-incubation with MMP-2.Conclusions. Non-conditioned AMI induces MMP-2 release, hampering the ischemia-induced increase in SDF-1α and CXCR4 by cleaving the SDF-1α/CXCR4 axis, with diminished mobilization of the angiogenic CD34+ cells. IP might influence CD34+ cell mobilization via inhibition of MMP-2.
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Dominika
D
Lukovic
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Katrin
K
Zlabinger
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Alfred
A
Gugerell
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Andreas
A
Spannbauer
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Noemi
N
Pavo
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Ljubica
L
Mandic
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Denise T
DT
Weidenauer
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Stefan
S
Kastl
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Christoph
0000-0003-3873-7246
C
Kaun
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Aniko
A
Posa
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Inna
I
Sabdyusheva Litschauer
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Johannes
J
Winkler
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Mariann
M
Gyöngyösi
MMP-2  ; SDF-1/CXCR4 axis; acute myocardial infarction; preconditioning; stem cell mobilization