Integrin beta 3-overexpressing mesenchymal stromal cells display enhanced homing and can reduce atherosclerotic plaque.

Background: Umbilical cord (UC) mesenchymal stem cell (MSC) transplantation is a potential therapeutic intervention for atherosclerotic vascular disease. Integrin beta 3 (ITGB3) promotes cell migration in several cell types. However, whether ITGB-modified MSCs can migrate to plaque sites in vivo and play an anti-atherosclerotic role remains unclear.

Aim: To investigate whether ITGB3-overexpressing MSCs (MSCs^ITGB3) would exhibit improved homing efficacy in atherosclerosis.

Methods: UC MSCs were isolated and expanded. Lentiviral vectors encoding ITGB3 or green fluorescent protein (GFP) as control were transfected into MSCs. Sixty male apolipoprotein E^-/- mice were acquired from Beijing Vital River Lab Animal Technology Co., Ltd and fed with a high-fat diet (HFD) for 12 wk to induce the formation of atherosclerotic lesions. These HFD-fed mice were randomly separated into three clusters. GFP-labeled MSCs (MSCs^GFP) or MSCs^ITGB3 were transplanted into the mice intravenously via the tail vein. Immunofluorescence staining, Oil red O staining, histological analyses, western blotting, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction were used for the analyses.

Results: ITGB3 modified MSCs successfully differentiated into the "osteocyte" and "adipocyte" phenotypes and were characterized by positive expression (> 91.3%) of CD29, CD73, and CD105 and negative expression (< 1.35%) of CD34 and Human Leukocyte Antigen-DR. In a transwell assay, MSCs^ITGB3 showed significantly faster migration than MSCs^GFP. ITGB3 overexpression had no effects on MSC viability, differentiation, and secretion. Immunofluorescence staining revealed that ITGB3 overexpression substantially enhanced the homing of MSCs to plaque sites. Oil red O staining and histological analyses further confirmed the therapeutic effects of MSCs^ITGB3, significantly reducing the plaque area. Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction revealed that MSC^ITGB3 transplantation considerably decreased the inflammatory response in pathological tissues by improving the dynamic equilibrium of pro- and anti-inflammatory cytokines.

Conclusion: These results showed that ITGB3 overexpression enhanced the MSC homing ability, providing a potential approach for MSC delivery to plaque sites, thereby optimizing their therapeutic effects.