Granulocyte colony-stimulating factor and stem cell factor improve endogenous repair after myocardial infarction.
OBJECTIVE
The aims of this study were, first, to determine if granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) improved left ventricular function in the setting of a reperfusion model of myocardial infarction (MI) and, second, to evaluate the effects of G-CSF/SCF on cellular repair and, in particular, the fate of bone marrow cells homing to the site of tissue injury.


METHODS
MI was induced in mice by transient ligation of the left descending coronary artery. G-CSF/SCF were administered for 5 days after MI. Cardiac function was assessed 28 days after MI. The effect of G-CSF/SCF on the cellular composition of the infarct region was assessed by immunohistochemistry. MI was performed in mice reconstituted with bone marrow cells expressing DsRed to track the fate of bone marrow-derived cells within the infarct region.


RESULTS
G-CSF/SCF-treated mice had significantly improved left ventricular (LV) function as determined by LV developed pressure, LV+/-dp/dt(max/min), and LV end-diastolic pressure. G-CSF alone produced similar improvements in cardiac function. These improvements in LV function were associated with 70% more blood vessels and a doubling of cells expressing cardiomyocyte-specific transcription factors GATA-4, Nkx2.5 and alpha-actinin cells within the infarct zone. Cells within the infarct expressing stromal-derived factor also increased by 200%. To elucidate the origin of these cells, bone marrow chimeras, where hematopoietic cells expressed the fluorescent marker DsRed, were treated with G-CSF/SCF after MI. Bone marrow-derived, DsRed-expressing cells in the infarct region of G-CSF/SCF-treated chimeras increased by an average of 12-fold; however, the vast majority of DsRed cells expressed the hematopoietic-specific marker CD45 but not blood vessel or cardiomyocyte markers.


CONCLUSIONS
G-CSF/SCF therapy improved cardiac function when delivered after MI, increasing the number of blood vessels and cells of cardiomyogenic lineage. However, these cells were of myocardial rather than bone marrow origin.
Kanellakis
Peter
P
Cell Biology Laboratory, Baker Heart Research Institute, Melbourne, Australia.
Slater
Nicholas J
NJ
Du
Xiao-Jun
XJ
Bobik
Alex
A
Curtis
David J
DJ
D000185:Actinin / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D016026:Bone Marrow Transplantation; D019070:Cell Lineage; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000032:analysis; D004359:Drug Therapy, Combination; D005456:Fluorescent Dyes; D050991:GATA4 Transcription Factor / Q000032:analysis; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D007150:Immunohistochemistry / Q000379:methods; D008164:Luminescent Proteins; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000737:chemistry / Q000473:pathology; D016188:Receptors, Granulocyte Colony-Stimulating Factor / Q000378:metabolism; D011994:Recombinant Proteins; D019089:Stem Cell Factor / Q000627:therapeutic use*; D013234:Stem Cells / Q000502:physiology; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
D015415:Biomarkers; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D005456:Fluorescent Dyes; D050991:GATA4 Transcription Factor; D008164:Luminescent Proteins; D016188:Receptors, Granulocyte Colony-Stimulating Factor; D011994:Recombinant Proteins; D019089:Stem Cell Factor; C413663:fluorescent protein 583; D000185:Actinin; D016179:Granulocyte Colony-Stimulating Factor