Tissue-engineered blood vessels (TEBVs) hold great promise for replacement of damaged or defective vascular tissues in vascular disease therapies, such as coronary and peripheral bypass graft surgeries. However, it remains a great challenge to obtain sufficient numbers of functional smooth muscle cells (SMCs) in the practice of constructing patient-specific TEBVs. This study aimed to develop an efficient method to generate a large number of functional SMCs in a short term for constructing tissue-engineered vascular tissues. Human induced pluripotent stem cells (iPSCs) were established by integration-free episomal vector-based reprogramming of donor peripheral blood mononuclear cells (PBMCs). These established iPSCs expressed pluripotency markers and were demonstrated to be able to differentiate into all three germ layer cells. Cardiovascular progenitor cell (CVPC) intermediates were then promptly and efficiently induced and expanded in chemically defined medium. Vascular smooth muscle cells (SMCs) were further induced under differentiation condition, which expressed typical SMCs markers including smooth muscle α-actin (α-SMA), calponin and SM22α validated by quantitative real-time PCR and immunocytochemistry stain. Importantly, the derived SMCs showed functional properties, validated by contraction responsiveness to carbachol treatment, up-regulation of specific collagens gene expression under transforming growth factor β1 treatment and up-regulation of specific matrix metalloproteinases gene expression under cytokine stimuli. Future studies will be focused on using these functional SMCs to construct functional TEBVs on biomimetic scaffolds. Taken together, our study established a facile procedure to generate large amount of functional and safe SMCs for vascular regeneration, via establishment of donor-specific integration-free human iPSCs and directed differentiation through CVPC intermediates.
Differentiation of human induced-pluripotent stem cells into smooth muscle cells
