| ObjectiveIschemic heart disease remains the major cause of mortality and morbidity worldwide, often along with systemic disease. Bone marrow resident and circulating progenitor cells play an important role in cell-based therapy and revasculization for ischemic heart disease. The aim of the study was to investigate, 1.Relationship between peri-operative risk factors and bone marrow mononuclear cells and bone marrow resident progenitor cells; 2.Relationship between peri-oprative risk factors and circulating progenitor cells; 3.Effects of cardiac surgery on bone marrow resident and circulating progenitor cells.Methods1. Bone marrow was aspirated from the 44 patient's sternum. BMMNCs were isolated by density centrifugation with ficoll Lymphoprep. The nucleated cells were counted and the viability was assesed by trypan blue exclusion. Morphology of the cells was observed. The CD34+, CD133+, and CD34+CD133+ progenitor cell counts were measured by flow cytometry. Progenitor cell functions were studied in vitro by clonogenic and migration assays.2.51 patients who were scheduled to undergo elective isolated coronary artery bypass graft surgery were prospectively enrolled in this study. Bone marrow aspirates were collected during surgery and blood samples were collected at baseline, in the morning on postoperative day 1, postoperative day 3, and postoperative day 5. The CD34+CD45dim cell, CD133+CD45dim cell, and CD34+CD133+ CD45dim cell counts were measured by flow cytometry. Bone marrow resident and circulating Progenitor cell functions were studied in vitro by clonogenic and migration assays. The plasma G-CSF, SDF-la, and VEGF levels were assesed by enzyme-linked immunosorbent assay.Results1.10 to 89×106 BMMNCs were obtained from 20 ml bone marrow, with viability> 95%. The cells were mononuclear without significant difference in size. A negative correlation was observed between the number of BMMNCs and the age(n=44, r=-0.788, p=0.001). Level of CD34+cells in BMMNCs was 0.94±0.39%, CD133+cells 0.46±0.28%, and CD34+CD133+cells 0.53±0.26%. Levels of CD34+cells and CD133+cells in patients with diabetes were significantly lower than those in patients without diabetes. Female, advanced age and poor heart function were related with reduced progenitor cell cologenic function, and Euroscore was a predictable variable for reduced CFU. A positive correlation was observed between level of CD34+cells and BMMNCs migration ability.2. Level of CD34+CD45dim cells in 10,000 leukocytes was 1.51±1.26, CD133+CD45dim cells 1.16±0.85, and CD34+CD133+CD45dim cells 1.86±1.59. Level of CD34+CD45dim cells in male patients was significantly higher than that in female patients(1.67±1.35(40) versus 0.92±0.55(11), p=0.008). Patients with poor heart function had lower level of CD133+CD45dim cells and CD34+CD133+CD45dim cells. With aging, colony forming function of circulating progenitor cells decreased (n=51, r=-0.786, p<0.001). Patients taking statins preoperatively had higher colony forming function than those who did not take statins preoperatively (7.48±3.04(33) versus 5.50±2.71(18), p=0.025). Male patients or patients with peripheral artery disease and left main stem coronary artery disease had higher migration ability in PBMNCs.3. All elective patients showed a significant post-operative increase of level of CD34+CD45dim and CD133+CD45dim cells, irrespective of on-pump CABG or off-pump CABG. The peri-opoerative change of circulating progenitor cells (CPC) in patients undergoing on-pump surgery was more significant than that in patients with off-pump surgery. The postoperative CPCs rise correlated with plasma G-CSF levels and SDF-la levels. Mobilized CPCs was positively related with BMMNCs migration ability.Conclusion1. Sufficient BMMNCs for ischemic heart disease cell therapy can be obtained from sternum by density centrifugation. Age, sex, diabetes, heart function and Euroscore correlated with the amounts and function of BMMNCs.2. Female patients or patients with poor heart function had a lower level of CPCs. The function of CPCs decreased with aging. Statins may increase the function of CPCs.3. Patients undergoing elective CABG surgery demonstrated an increase in CPC level postoperaively, which correlated with increased plasma G-CSF and SDF-1αlevel and migration ability of BMMNCs. Further studies are needed to verify whether mobilized progenitors participate in regeneration of injured tissues.
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