Generation of functional endothelial-like cells from adult mouse germline-derived pluripotent stem cells

Human gingival fibroblasts induced and differentiated into vascular endothelial-like cells

A novel method for repair of vascular disease, mechanical damage, and tissue rebuilding is urgently required. Vascular endothelial cells (VECs) play an essential role in vascular rebuilding and vasotransplantation. In the present study, human gingival fibroblasts (HGFs) were cultured and induced into endothelial-like cells in vitro in order to confirm that HGFs with stem cell properties possessed the potential for differentiation into endothelial-like cells. The epithelium was extracted from normal human gingiva consisting of epithelium and connective tissue, which was isolated from patients. The identification of HGFs and induced endothelial-like cells were confirmed by flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), immunocytochemical stain (ICS), and immunofluorescence stain (ISA). The morphology of human gingival fibroblasts with 8 ng/mL VEGF165 induced for different periods of days were observed by inverted microscope. Before induction, flow cytometry analysis showed that HGFs were positive for vimentin, but negative for CD31. RT-PCR, ICS, and ISA showed vimentin, S100A4, α-SMA, collagen III, and S100A4 were specifically expressed in these fibroblast cells. After induction, ICS showed induced vascular endothelial-like cells were positive for CD34 and CD31; ISA showed cells induced were positive for vWF and E-cadherin; RT-PCR results demonstrated that tie2 was specifically expressed in the cells induced. Flow cytometry analysis of the transformation efficiency from HGFs to endothelial-like cells. In conclusion, we found that HGFs possessed capacity for being induced and differentiated into vessel endothelial-like cells with typical and specific morphological, ultrastructural, and immunological characters of endothelial-like cells by induction with VEGF.

Protein kinases and associated pathways in pluripotent state and lineage differentiation

Protein kinases (PKs) mediate the reversible conversion of substrate proteins to phosphorylated forms, a key process in controlling intracellular signaling transduction cascades. Pluripotency is, among others, characterized by specifically expressed PKs forming a highly interconnected regulatory network that culminates in a finely-balanced molecular switch. Current high-throughput phosphoproteomic approaches have shed light on the specific regulatory PKs and their function in controlling pluripotent states. Pluripotent cell-derived endothelial and hematopoietic developments represent an example of the importance of pluripotency in cancer therapeutics and organ regeneration. This review attempts to provide the hitherto known kinome profile and the individual characterization of PK-related pathways that regulate pluripotency. Elucidating the underlying intrinsic and extrinsic signals may improve our understanding of the different pluripotent states, the maintenance or induction of pluripotency, and the ability to tailor lineage differentiation, with a particular focus on endothelial cell differentiation for anti-cancer treatment, cell-based tissue engineering, and regenerative medicine strategies.