Sirolimus stimulates vascular stem/progenitor cell migration and differentiation into smooth muscle cells via epidermal growth factor receptor/extracellular signal-regulated kinase/β-catenin signaling pathway.
OBJECTIVE
Sirolimus-eluting stent therapy has achieved considerable success in overcoming coronary artery restenosis. However, there remain a large number of patients presenting with restenosis after the treatment, and the source of its persistence remains unclarified. Although recent evidence supports the contribution of vascular stem/progenitor cells in restenosis formation, their functional and molecular responses to sirolimus are largely unknown.


RESULTS
Using an established technique, vascular progenitor cells were isolated from adventitial tissues of mouse vessel grafts and purified with microbeads specific for stem cell antigen-1. We provide evidence that vascular progenitor cells treated with sirolimus resulted in an induction of their migration in both transwell and wound healing models, clearly mediated by CXCR4 activation. We confirmed the sirolimus-mediated increase of migration from the adventitial into the intima side using an ex vivo decellularized vessel scaffold, where they form neointima-like lesions that expressed high levels of smooth muscle cell (SMC) markers (SM-22α and calponin). Subsequent in vitro studies confirmed that sirolimus can induce SMC but not endothelial cell differentiation of progenitor cells. Mechanistically, we showed that sirolimus-induced progenitor-SMC differentiation was mediated via epidermal growth factor receptor and extracellular signal-regulated kinase 1/2 activation that lead to β-catenin nuclear translocation. The ablation of epidermal growth factor receptor, extracellular signal-regulated kinase 1/2, or β-catenin attenuated sirolimus-induced SM-22α promoter activation and SMC differentiation.


CONCLUSIONS
These findings provide direct evidence of sirolimus-induced progenitor cell migration and differentiation into SMC via CXCR4 and epidermal growth factor receptor/extracellular signal-regulated kinase/β-catenin signal pathways, thus implicating a novel mechanism of restenosis formation after sirolimus-eluting stent treatment.
From the Cardiovascular Division, King's College London BHF Centre, London, United Kingdom.
Mei Mei
MM
Wong
Bernhard
B
Winkler
Eirini
E
Karamariti
Xiaocong
X
Wang
Baoqi
B
Yu
Russell
R
Simpson
Ting
T
Chen
Andriani
A
Margariti
Qingbo
Q
Xu
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D053687:Adult Stem Cells / Q000187:drug effects* / Q000201:enzymology; D063194:Adventitia / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects*; D003251:Constriction, Pathologic; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology; D034622:RNA Interference; D019718:Receptors, CXCR4 / Q000819:agonists / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020123:Sirolimus / Q000494:pharmacology*; D013997:Time Factors; D054457:Tissue Scaffolds; D014162:Transfection; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000096985:Calponins
D000950:Antigens, Ly; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D019718:Receptors, CXCR4; D020123:Sirolimus; D051176:beta Catenin; D000096985:Calponins; C495267:CTNNB1 protein, mouse; C514936:CXCR4 protein, mouse; C074650:Ly6a protein, mouse; C058992:Tagln protein, mouse; C541485:EGFR protein, mouse
progenitor cells; sirolimus; smooth muscle; stem cells; stents; vascular