Publications by authors named "Techuan Chan"

The injection of endothelial progenitor cells and mononuclear cells derived from bone marrow at the ischemic region of peripheral artery disease patients is reported to be effective for therapeutic angiogenesis; however, these cell therapies require large amounts of bone marrow to obtain sufficient numbers of cells. To solve this problem, we attempted to culture bone-marrow-derived mesenchymal stem cells (BM-MSC), which are supposed to secrete several cytokines that promote angiogenesis. We also focused on using platelet-rich plasma (PRP) as a supplement for cell culture instead of fetal bovine serum.

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Article Synopsis
  • Enzymes traditionally used for passaging human pluripotent stem cells can harm the cells by digesting surface proteins, and alternative methods that lack divalent cations may cause cell death.
  • The study finds that magnesium (Mg²⁺) and calcium (Ca²⁺) ions can effectively manage cell adhesion and detachment in hPSCs without using enzymes, allowing for healthier cell handling.
  • This new enzyme-free method preserves more cell integrity and facilitates the collection of undifferentiated cells in larger clumps, making the culture process safer and easier.
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Background: Cilostazol, an inhibitor of phosphodiesterase type III, is an antiplatelet agent and vasodilator. Some clinical reports have suggested that this drug can improve progressive and refractory lymphedema.

Objective: In this study, we investigated whether cilostazol has the potential to proliferate lymphatic vessels and to improve lymphatic function using human lymphatic endothelial cells (LECs) and mouse lymphedema models.

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Renal lineages including kidney are derived from intermediate mesoderm, which are differentiated from a subset of caudal undifferentiated mesoderm. The inductive mechanisms of mammalian intermediate mesoderm and renal lineages are still poorly understood. Mouse embryonic stem cells (mESCs) can be a good in vitro model to reconstitute the developmental pathway of renal lineages and to analyze the mechanisms of the sequential differentiation.

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In comprehensive glycome analysis with a high-density lectin microarray, we have previously shown that the recombinant N-terminal domain of the lectin BC2L-C from Burkholderia cenocepacia (rBC2LCN) binds exclusively to undifferentiated human induced pluripotent stem (iPS) cells and embryonic stem (ES) cells but not to differentiated somatic cells. Here we demonstrate that podocalyxin, a heavily glycosylated type 1 transmembrane protein, is a glycoprotein ligand of rBC2LCN on human iPS cells and ES cells. When analyzed by DNA microarray, podocalyxin was found to be highly expressed in both iPS cells and ES cells.

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Background: The successful establishment of human induced pluripotent stem cells (hiPSCs) has increased the possible applications of stem cell research in biology and medicine. In particular, hiPSCs are a promising source of cells for regenerative medicine and pharmacology. However, one of the major obstacles to such uses for hiPSCs is the risk of contamination from undefined pathogens in conventional culture conditions that use serum replacement and mouse embryonic fibroblasts as feeder cells.

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Amphibians have been used for over a century as experimental animals. In the field of developmental biology in particular, much knowledge has been accumulated from studies on amphibians, mainly because they are easy to observe and handle. Xenopus laevis is one of the most intensely investigated amphibians in developmental biology at the molecular level.

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Article Synopsis
  • Xenopus serves as a model organism for studying early vertebrate development, particularly organogenesis and inductive events, due to its abundance and size.
  • The animal cap in Xenopus embryos can turn into various tissue types (neural, mesodermal, endodermal) when exposed to specific inducers, similar to the functions of mammalian embryonic stem cells.
  • This text outlines methods for isolating and differentiating animal cap cells, including the animal cap assay, and discusses techniques for analyzing the molecular mechanisms involved in this differentiation process.
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  • Ripply1 and Ripply2 are thought to be transcriptional corepressors that are expressed in overlapping regions during somitogenesis in mice and zebrafish.
  • Ripply1 is known to be essential for somite segmentation in zebrafish, but the role of Ripply2 was unclear until the study involved creating Ripply2 knock-out mice.
  • The knock-out mice showed defects in axial skeleton segmentation, disrupted somite segmentation, and altered expression of Notch2 and Uncx4.1, indicating that Ripply2 plays a key role in somite segmentation and the development of rostrocaudal polarity.
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Bone morphogenetic proteins (BMPs) regulate multiple biological processes, including cellular proliferation, adhesion, differentiation, and early development. In Xenopus development, inhibition of the BMP pathway is essential for neural induction. Here, we report that dullard, a gene involved in neural development, functions as a negative regulator of BMP signaling.

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Segmentation of the vertebrate body via the sequential formation of somites is an important process in embryogenesis. This sequential process is governed by the activation and regulation of Notch-related molecular oscillators by fibroblast growth factor and retinoic acid (RA) signaling. In this study, we identified ledgerline, a novel gene of Xenopus laevis expressed specifically in the presomitic mesoderm.

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An understanding of the regulation of kidney development has increased dramatically in the past decade. The pronephros, mesonephros, and metanephros represent three distinct renal organs that function, in succession, as the vertebrate excretory system during development of the kidney. These three organ systems are derived from the intermediate mesoderm and develop in a well-defined temporal and spatial sequence.

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We isolated and characterized the Xenopus translocon-associated protein XTRAP-gamma, one of four subunits of the translocon-associated protein complex. TRAP has been proposed to aid the translocation of nascent polypeptides into the lumen of the endoplasmic reticulum, but this has not been demonstrated until now. XTRAP-gamma was specifically expressed in the pronephros tubules of Xenopus laevis from stage 25 during kidney development.

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Vertebrates use two or three forms of kidney successively during development and the nephric duct is essential for this succession of kidney induction. While transcripts of many Wnt ligands and Wnt receptor Frizzled genes have been localized in developing kidney, the relationship between Wnt signaling and nephric duct development remains unknown. This study investigated the role of Xenopus frizzled-8 (Xfz8) in pronephros development.

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We describe the isolation and characterization of the RNA-binding protein XC3H-3b that is expressed during pronephros development. XC3H-3b is a member of the TTP/TIS family of CCCH tandem zinc-finger proteins, which are physiological stimulators of instability for the mRNA encoding tumor necrosis factor-alpha in certain cell types. XC3H-3b is localized primarily to the mesodermal tissues around the pronephros.

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Article Synopsis
  • Researchers identified a new gene called "dullard," which is linked to neural tissue development.
  • The protein produced by dullard shares a conserved domain with a protein called NLI-IF, but its specific functions are not yet understood.
  • Inhibiting dullard expression led to issues in neural tube and head development in embryos, indicating that this gene is crucial for proper neural development.
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