Articles by Ha-Rim Seo in JoVE
Fabrication of Gradient Nanopattern by Thermal Nanoimprinting Technique and Screening of the Response of Human Endothelial Colony-forming Cells Dae Hwan Kim*1, Long-Hui Cui*2, Ha-Rim Seo2, Hyung Joon Joo2, Seung-Cheol Choi2, Do-Sun Lim2, Kyu Back Lee1 1School of Biomedical Engineering, Korea University, 2Department of Cardiology, Korea University Anam Hospital Here, we present a protocol for the fabrication of gradient nanopattern plates via thermal nanoimprinting and the method of screening responses of human endothelial progenitor cells to the nanostructures. By using the described technology, it is possible to produce a scaffold that can manipulate cell behavior by physical stimuli.
Other articles by Ha-Rim Seo on PubMed
Mixl1 and Flk1 Are Key Players of Wnt/TGF-β Signaling During DMSO-Induced Mesodermal Specification in P19 Cells Journal of Cellular Physiology. | Pubmed ID: 25521758 Dimethyl sulfoxide (DMSO) is widely used to induce multilineage differentiation of embryonic and adult progenitor cells. To date, little is known about the mechanisms underlying DMSO-induced mesodermal specification. In this study, we investigated the signaling pathways and lineage-determining genes involved in DMSO-induced mesodermal specification in P19 cells. Wnt/β-catenin and TGF-β superfamily signaling pathways such as BMP, TGF-β and GDF1 signaling were significantly activated during DMSO-induced mesodermal specification. In contrast, Nodal/Cripto signaling pathway molecules, required for endoderm specification, were severely downregulated. DMSO significantly upregulated the expression of cardiac mesoderm markers but inhibited the expression of endodermal and hematopoietic lineage markers. Among the DMSO-activated cell lineage markers, the expression of Mixl1 and Flk1 was dramatically upregulated at both the transcript and protein levels, and the populations of Mixl1+, Flk1+ and Mixl1+/Flk1+ cells also increased significantly. DMSO modulated cell cycle molecules and induced cell apoptosis, resulting in significant cell death during EB formation of P19 cells. An inhibitor of Flk1, SU5416 significantly blocked expressions of TGF-β superfamily members, mesodermal cell lineage markers and cell cycle molecules but it did not affect Wnt molecules. These results demonstrate that Mixl1 and Flk1 play roles as key downstream or interacting effectors of Wnt/TGF-β signaling pathway during DMSO-induced mesodermal specification in P19 cells.
Human Endothelial Colony Forming Cells from Adult Peripheral Blood Have Enhanced Sprouting Angiogenic Potential Through Up-regulating VEGFR2 Signaling International Journal of Cardiology. | Pubmed ID: 26113473 Endothelial colony forming cells (ECFCs), a subtype of endothelial progenitor cells, have been studied as a promising cellular source for therapeutic angiogenesis. Although ECFCs are very similar to mature endothelial cells, details regarding the role of ECFCs during angiogenesis are not known. We compared the cellular and angiogenic properties of ECFCs and mature endothelial cells (HUVECs).
Manipulation of the Response of Human Endothelial Colony-forming Cells by Focal Adhesion Assembly Using Gradient Nanopattern Plates Acta Biomaterialia. | Pubmed ID: 29037896 Nanotopography plays a pivotal role in the regulation of cellular responses. Nonetheless, little is known about how the gradient size of nanostructural stimuli alters the responses of endothelial progenitor cells without chemical factors. Herein, the fabrication of gradient nanopattern plates intended to mimic microenvironment nanotopography is described. The gradient nanopattern plates consist of nanopillars of increasing diameter ranges [120-200 nm (GP 120/200), 200-280 nm (GP 200/280), and 280-360 nm (GP 280/360)] that were used to screen the responses of human endothelial colony-forming cells (hECFCs). Nanopillars with a smaller nanopillar diameter caused the cell area and perimeter of hECFCs to decrease and their filopodial outgrowth to increase. The structure of vinculin (a focal adhesion marker in hECFCs) was also modulated by nanostructural stimuli of the gradient nanopattern plates. Moreover, Rho-associated protein kinase (ROCK) gene expression was significantly higher in hECFCs cultured on GP 120/200 than in those on flat plates (no nanopillars), and ROCK suppression impaired the nanostructural-stimuli-induced vinculin assembly. These results suggest that the gradient nanopattern plates generate size-specific nanostructural stimuli suitable for manipulation of the response of hECFCs, in a process dependent on ROCK signaling. This is the first evidence of size-specific nanostructure-sensing behavior of hECFCs.