Human Decidual Mesenchymal Stem Cells Obtained From Early Pregnancy Improve Cardiac Revascularization Postinfarction by Activating Ornithine Metabolism

Abstract

Background: Compared with bone marrow mesenchymal stem cells (BMSCs), decidual mesenchymal stem cells (DMSCs) are easy to obtain and exhibit excellent angiogenic effects, but their role in cell transplantation after myocardial infarction (MI) remains unclear.

Methods: BMSCs and DMSCs were harvested from healthy donors. The effects of both cell types on angiogenesis were observed in vitro. Metabonomics analysis was performed to compare different metabolites and screen critical metabolic pathways. A murine model of acute myocardial infarction (AMI) was established, which was randomized into five groups (control, BMSC, DMSC, DMSC + ODCshRNA and BMSC + ODC consisting of 50 animals, equally divided into each group). The therapeutic effect of DMSCs on MI in rats was assessed based on neovascularization and cardiac remodeling.

Results: DMSCs exhibited a better angiogenic effect on human umbilical vein endothelial cells (HUVECs) than BMSCs in vitro. In addition, ornithine metabolism, which is associated with vascularization, was significantly increased in DMSCs. The transplantation of DMSCs in the rat MI model significantly enhanced angiogenesis of the infarct border area and improved cardiac remodeling and dysfunction postinfarction compared with BMSCs. Furthermore, inhibition of ornithine metabolism by silencing ornithine decarboxylase (ODC) in DMSCs partly abolished the benefits of DMSC transplantation.

Conclusion: Compared with BMSCs, DMSCs exhibited better efficacy in improving revascularization and heart remodeling post-MI via the activation of ODC-associated ornithine metabolism.

Keywords: bone marrow mesenchymal stem cells; decidual mesenchymal stem cells; heart remodeling; ischemic heart disease; ornithine decarboxylase; revascularization.

Graphical Abstract

Silencing ODC in DMSCs inhibited spermine secretion, weakened endothelial cell proliferation and the expression of VEGF and bFGF, resulting in decreased angiogenesis. Overexpression of ODC in BMSCs promoted spermine secretion, enhanced endothelial cell proliferation and the expression of VEGF and bFGF, resulting in increased angiogenesis. Transplantation of DMSCs can better improve angiogenesis after myocardial infarction by activating ornithine metabolism.

Figure 1

Identification of DMSCs and BMSCs and comparison of their ability to promote proliferation and vascularization in vitro. (A) Flow cytometric analysis of cell surface markers on BMSCs and DMSCs. (B) Morphological observation of BMSCs and DMSCs. (C) Cell viability of BMSCs and DMSCs. (D,E) Morphological and quantitative analysis of representative colonies derived from BMSCs and DMSCs. (F) The proliferation ability of HUVECs in response to different treatments in vitro as assessed by EdU staining. (G) Quantitative analysis of EdU-positive cells. (H) Representative images of tube formation of HUVECs with different treatments in vitro. (I) Quantitative analysis of tube formation. (J,K) Detection of VEGF and bFGF secretion levels from HUVECs under different treatment conditions in vitro. *P < 0.05, **P < 0.01, ***P < 0.001. ^#P < 0.05, ^##P < 0.01, ^###P < 0.001.

Figure 2

Metabolic profiles of BMSCs and DMSCs. (A,B) Principal component analysis score plots for discriminating BMSCs and DMSCs in ESI + and ESI- modes. (C,D) PLS-DA plots and validation plots for discriminating BMSCs and DMSCs in ESI + and ESI- modes. (E) Column chart and bubble chart of KEGG enrichment analysis of all differential metabolites. (F–I) Metabolite profiles of different biomarkers between epithelial BMSCs and DMSCs. Each P-value was < 0.01.

Figure 3

ODC inhibition partly abolished the effects of DMSCs on angiogenesis in vitro. (A) Transfection of plasmid containing GFP gene in stem cells GFP Fluorescence in DMSCs (upper row) and in BMSCs (lower row), transfection efficiency of hMSCs was detected by fluorescence-activated cell sorting. (B,C) ODC protein expression in DMSCs after ODC inhibition and BMSCs after ODC overexpression. (D,E) Representative images of DAPI/EdU staining in DMSCs or BMSCs treated with ODC shRNA or overexpression plasma for 72 h, respectively. (F) Representative images of tube formation in HUVECs under different treatment conditions in vitro. (G) Quantitative analysis of tube formation. (H,I) Detection of VEGF and bFGF secretion levels from HUVECs after different treatments in vitro. *P < 0.05, **P < 0.01, ***P < 0.001, Scale bar, 100 μm. ^#P < 0.05, ^##P < 0.01, ^###P < 0.001.

Figure 4

ODC inhibition partly abolished the effects of DMSCs on angiogenesis in vivo. (A,B) Anti-human mitochondrial staining showed the survival of transplanted cells for 1 and 4 weeks in vivo. (C–F) Blood vessel density determined by a-SMA and VWF staining for 4 weeks in vivo. ***P < 0.001, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001.

Figure 5

DMSC transplantation improves cardiac remodeling and dysfunction partly via the ornithine decarboxylase-dependent pathway. (A,B) Masson's trichrome staining to assess the infarct size 4 weeks after cell transplantation (blue = collagen; red = myocardium). Serial sections were cut at 500-μm intervals from the site of the ligature toward the apex. (C) Representative echocardiography images before and after MI (high lines: LVEDd; low lines: LVESd). (D,E) LVEF and LVFS. (ANOVA; *P < 0.01, **P < 0.01, ***P < 0.001; n = 5). ^#P < 0.05, ^##P < 0.01, ^###P < 0.001.