Stromal vascular fraction transplantation as an alternative therapy for ischemic heart failure: anti-inflammatory role

Abstract

Background: The aims of this study were: (1) to show the feasibility of using adipose-derived stromal vascular fraction (SVF) as an alternative to bone marrow mono nuclear cell (BM-MNC) for cell transplantation into chronic ischemic myocardium; and (2) to explore underlying mechanisms with focus on anti-inflammation role of engrafted SVF and BM-MNC post chronic myocardial infarction (MI) against left ventricular (LV) remodelling and cardiac dysfunction.

Methods: Four weeks after left anterior descending coronary artery ligation, 32 Male Lewis rats with moderate MI were divided into 3 groups. SVF group (n = 12) had SVF cell transplantation (6 × 10(6) cells). BM-MNC group (n = 12) received BM-MNCs (6 × 10(6)) and the control (n = 10) had culture medium. At 4 weeks, after the final echocardiography, histological sections were stained with Styrus red and immunohistochemical staining was performed for α-smooth muscle actin, von Willebrand factor, CD3, CD8 and CD20.

Results: At 4 weeks, in SVF and BM-MNC groups, LV diastolic dimension and LV systolic dimension were smaller and fractional shortening was increased in echocardiography, compared to control group. Histology revealed highest vascular density, CD3+ and CD20+ cells in SVF transplanted group. SVF transplantation decreased myocardial mRNA expression of inflammatory cytokines TNF-α, IL-6, MMP-1, TIMP-1 and inhibited collagen deposition.

Conclusions: Transplantation of adipose derived SVF cells might be a useful therapeutic option for angiogenesis in chronic ischemic heart disease. Anti-inflammation role for SVF and BM transplantation might partly benefit for the cardioprotective effect for chronic ischemic myocardium.

Figure 1

Transplanted cells. PKH26 labeled donor cells (red fluorescence, x200) in SVF and BM-MNC transplanted groups. Bars represent a distance of 50 μm.

Figure 2

Vascular density. 2a (A-C) Immunohistochemistry for von Willebrand factor (brown, x100). Representative pictures in the peri-MI area from SVF, BM-MNC and Control groups, respectively. (D-F) Immunohistochemistry with α-smooth muscle actin antibody (brown, x100). Representative pictures in the peri-MI area from SVF, BM-MNC and Control groups, respectively. Scale bars indicate distances of 100 μm. 2b Graphs: the number of vessels (number/mm²) in the peri-MI area, micro-vessel density (density of vessels <30 μm in diameter) (A), and large-vessel density (density of vessels >30 μm in diameter) (B). Data are given as the mean ± SEM. *p < 0.05 vs. Control group, **p < 0.05 vs. BM-MNC group, ^†p < 0.001 vs. Control group.

Figure 3

Fibrotic area. Representative pictures from groups SVF, BM-MNC and Control, respectively. Bars represent a distance of 100 μm. Graphs: Percentage of fibrotic area inside the infarct (A) and peri-infarct area (B). Data are given as the mean ± SEM. *p < 0.05 vs. Control group, ^†p < 0.01 vs. Control group.

Figure 4

Expression of mRNA. Expression of mRNA levels of tumor necrosis factor α (A, TNFα); interleukin 6 (B, IL-6); matrix metalloproteinase 1 (C, MMP-1); tissue inhibitor of metalloproteinase 1 (D, TIMP-1), brain natriuretic peptide (E, BNP) and vascular endothelial growth factor (F, VEGF) in the left ventricular myocardium as measured by reverse transcription polymerase chain reaction in the rat left ventricular myocardium, 4 weeks after treatment. mRNA expressions were calculated via a standard curve and normalized to an endogen control. Data are given as the mean ± SEM. *p < 0.05 vs. Control group, **p < 0.01 vs. BM-MNC group, †p < 0.001 vs. Control group.

Figure 5

Immunohistochemistry for CD3+ (T lymphocytes), (brown, × 100). Representative pictures in the infarct area from SVF, BM-MNC and Control groups, respectively. Bars represent a distance of 100μm. Graph: the number of CD3+ (number/mm²) in the infarct area. Data are given as the mean ± SEM. *p < 0.05 vs. Control group.

Figure 6

Immunohistochemistry for CD20+ (B lymphocytes), (brown, × 100). Representative pictures in the infarct area from SVF, BM-MNC and Control groups, respectively. Bars represent a distance of 50μm. Graph: the number of CD20+ (number/mm²) in the infarct area. Data are given as the mean ± SEM. ^†p < 0.001 vs. Control group, **p < 0.01 vs. Control group.

Figure 7

Localization of IL-6 (brown) by immunohistochemical analysis in cell transplanted and control hearts. Magnification × 100. Representative pictures in the infarct area from SVF, BM-MNC and Control groups, respectively. Bars represent a distance of 100μm. Graph: Percentage of IL-6 positive area inside the infarct. Data are given as the mean ± SEM. ^†p < 0.001 vs. Control group.