The Effects Of Stromal Vascular Fraction From Adipose Tissue On Rat Acute Myocardial Infarction

Part1, Isolation and Culture of the Stromal Vascular Fraction from Rat Adipose TissueObjective:To establish a method for isolation and culture of stromal vascular fraction (SVF), which is of characteristics of stem cells from rat adipose tissue in vitro.Methods:The normal rat abdominal subcutaneous adipose tissue was digested with collagenaseⅠ. The lowest layer cells were suspended and cultured with DMEM-F12, SVF was isolated from adipose tissue of 12-week old SD rats and cultured in vitro. Cells were infected by lentivirous with GFP before transplantation. Immunofluorescence assay was used to determine the surface molecule marker CD31 and CD34. Result:Immunofluorescence assay showed that most of the cultured 2nd generation SVF cells were CD34 positive, but CD31 negative.Conclusion:A rapid reproductable method was set up for isolation and culture of SVF having characteristics of stem cells from rat adipose tissue, which is of significant in clinical and basic research of stem cells.Part2, The Effects of Green Fluorescent Protein labeled Stromal Vascular Fraction with from Adipose Tissue on Rat Acute Myocardial InfarctionObjective:To observe the effects of transplantation of cultured stromal vascular fraction, which was infected by lentiviral vector transfeted with green fluorescent protein(GFP),on infarcted myocardial tissue, cardiac function and underling mechanism.Methods:Acute myocardial infarction model was established by ligation of the coronary arteries. Rats were randomly divived into 3 groups: sham-operated group, AMI control group and SVF transplantation group. SVF labeled with GFP after three days or PBS was injected into infarcted tissue. 2 weeks after transplantation, cardiac function was evaluated with hemodynamic measurement. Fluorescence microscope was used to identify the survival of SVF cells in heart. CD31 were determined by immunohistochemitry and infarction value fraction of left ventricle was calculated by H-E straining.Results:1.Hemodynamic measurements showed that +dp/dtmax in sham-operation group was 4830.74±863.36 mmHg/, infarction contral group was 1952.94±635.13mmHg/s,SVF transplation group was 2742.65±659.50 mmHg/s;-dp/dtmax in sham-operation group was -4407.80±396.07 mmHg/s, infarction contral group was -1871.67±306.92 mmHg/s,SVF transplation group was -2448.14±532.27 mmHg/s,P<0.05; LVEDP in sham-operation group was -3.14±7.95 mmHg,infarction contral group was 38.86±17.79 mmHg,SVF transplation group was 7.17±15.58 mmHg. -dp/dtmax were significantly decreased and LVDP was increased in infarction contral group 2 weeks after SVF transplation compared with infarction contral group(P<0.05). LV+dp/dtmax, -dp/dtmax were higher but LVDP was lower in SVF transplation group compared with those in the infarction contral group(P<0.05); While the 2 groups compared with sham-operation group, LV+dp/dtmax, -dp/dtmax were lower but LVDP was higher(P<0.01).2.GFP labeled SVF were found in myocardial infarcted zone.3.Compared with those in the infarction control group, the construction of myocardial tissues in SVF transplation group recovered better, but both of the 2 groups were worse than sham-operation group.4.Computer quantitive analysis after H-E straining displayed that the myocardial infarcted size in sham-operation group was 1%,infarction contral group was 38.22%,SVF transplation group was 34.34%. It is significantly lower in the SVF transplantation group than that in infarction control group(P<0.05), while both of the 2 groups were higher than that in sham-operation group(P<0.01).5.Endothelial marker CD31-positive cells per eyeshot was accounted, sham-operation group had 14.5,infarction contral group had 6.43, SVF transplantation group had 9.43. It is higher in the SVF transplantation group than that in infarction contral group(P<0.05), but both lower than sham-operation group(P<0.01).Conclusions:1.The lentivirus vector with GFP may be used as a trace marker of the transplantation cells.2 . SVF transplantation may survive in infarcted heart and reduce myocardial infarction size.3.The SVF may meriarate heart function and the vascular genesis of infraction zone in AMI rat.