Publications by authors named "Seungmi Ryu"

Lysosomal free sialic acid storage disorder (FSASD) is a rare neurodegenerative disease caused by biallelic mutations in SLC17A5, encoding the lysosomal sialic acid exporter, SLC17A5 (sialin). While the involvement of oligodendroglia in FSASD pathogenesis is established, the roles of other neural cell types remain elusive. In this study, we utilized radial glial cells (iRGCs), immature and mature astrocytes (iIAs and iMAs, respectively), and cortical neurons (iCNs) differentiated from induced pluripotent stem cells (iPSCs) derived from two individuals with FSASD, alongside two independent healthy donors for comparison.

View Article and Find Full Text PDF

The human cerebellum is a specialized brain region that is involved in various neurological and psychiatric diseases but has been challenging to study due its complex neurodevelopment and cellular diversity. Despite the progress in generating neural tissues from human induced pluripotent stem cells (iPSCs), an organoid model that recapitulates the key features of cerebellar development has not been widely established. Here, we report the generation of a 60-day method for human cerebellar organoids (hCBOs) that is characterized by induction of rhombomere 1 (R1) cellular identity followed by derivation of neuronal and glial cell types of the cerebellum.

View Article and Find Full Text PDF
Article Synopsis
  • Human pluripotent stem cells (hPSCs) are vital for understanding early development, but their differentiation into placental cells remains unclear.
  • This study introduces new methods for effectively turning hPSCs into cytotrophoblasts (CTB) and syncytiotrophoblasts (STB), as well as establishing trophoblast stem cells (TSCs) that can develop into other placental cell types.
  • The research outlines a clear pathway from hPSCs to identified placental cells, enhancing opportunities for investigating topics like human development, infertility, and pregnancy-related diseases.
View Article and Find Full Text PDF
Article Synopsis
  • The hypothalamus plays a critical role in maintaining homeostasis and is central to energy, glucose regulation, and reproduction through its arcuate nucleus (ARC).
  • Researchers developed a robotic cell culture platform to convert human pluripotent stem cells into specific neuronal types with ARC-like characteristics, showing potential for studying metabolic disorders.
  • This new model demonstrates responsiveness to hormones and neuropeptides, indicating its usefulness for disease research and understanding the dynamic regulation of related pathways, such as those involved in obesity and type 2 diabetes.
View Article and Find Full Text PDF

Embryoid bodies (EBs) and self-organizing organoids derived from human pluripotent stem cells (hPSCs) recapitulate tissue development in a dish and hold great promise for disease modeling and drug development. However, current protocols are hampered by cellular stress and apoptosis during cell aggregation, resulting in variability and impaired cell differentiation. Here, we demonstrate that EBs and various organoid models (e.

View Article and Find Full Text PDF

Human gliogenesis remains poorly understood, and derivation of astrocytes from human pluripotent stem cells (hPSCs) is inefficient and cumbersome. Here, we report controlled glial differentiation from hPSCs that bypasses neurogenesis, which otherwise precedes astrogliogenesis during brain development and in vitro differentiation. hPSCs were first differentiated into radial glial cells (RGCs) resembling resident RGCs of the fetal telencephalon, and modulation of specific cell signaling pathways resulted in direct and stepwise induction of key astroglial markers (NFIA, NFIB, SOX9, CD44, S100B, glial fibrillary acidic protein [GFAP]).

View Article and Find Full Text PDF

Development of new non-addictive analgesics requires advanced strategies to differentiate human pluripotent stem cells (hPSCs) into relevant cell types. Following principles of developmental biology and translational applicability, here we developed an efficient stepwise differentiation method for peptidergic and non-peptidergic nociceptors. By modulating specific cell signaling pathways, hPSCs were first converted into SOX10 neural crest, followed by differentiation into sensory neurons.

View Article and Find Full Text PDF

Human pluripotent stem cells (hPSCs) are inherently sensitive cells. Single-cell dissociation and the establishment of clonal cell lines have been long-standing challenges. This inefficiency of cell cloning represents a major obstacle for the standardization and streamlining of gene editing in induced pluripotent stem cells for basic and translational research.

View Article and Find Full Text PDF

Human pluripotent stem cells (hPSCs), such as induced pluripotent stem cells (iPSCs), hold great promise for drug discovery, toxicology studies, and regenerative medicine. Here, we describe standardized protocols and experimental procedures that combine automated cell culture for scalable production of hPSCs with quantitative high-throughput screening (qHTS) in miniaturized 384-well plates. As a proof of principle, we established dose-response assessments and determined optimal concentrations of 12 small molecule compounds that are commonly used in the stem cell field.

View Article and Find Full Text PDF
Article Synopsis
  • Human pluripotent stem cells (hPSCs) can grow a lot and turn into different cell types, but they are very sensitive to their surroundings, which makes them hard to use for treatments.
  • Scientists found a mix of special chemicals (called CEPT) that helps these cells survive better by stopping stress that harms them.
  • This mix can help with many important tasks in stem cell research, like freezing cells and editing genes, making it safer and easier to use hPSCs for different applications.
View Article and Find Full Text PDF

Brillouin light scattering offers a unique label-free approach to measure biomechanical properties non-invasively. While this technique is used in biomechanical analysis of cells and tissues, its potential for visualizing structural features of tissues based on the biomechanical contrast has not been much exploited. Here, we present high-resolution Brillouin microscopy images of four basic tissue types: muscular, connective, epithelial, and nervous tissues.

View Article and Find Full Text PDF

Cardiovascular diseases often cause substantial heart damage and even heart failure due to the limited regenerative capacity of adult cardiomyocytes. The direct cardiac reprogramming of fibroblasts could be a promising therapeutic option for these patients. Although exogenous transcriptional factors can induce direct cardiac reprogramming, the reprogramming efficiency is too low to be used clinically.

View Article and Find Full Text PDF

Prevention of biofouling and microbial contamination of implanted biomedical devices is essential to maintain their functionality and biocompatibility. For this purpose, polypept(o)ide block copolymers have been developed, in which a protein-resistant polysarcosine (pSar) block is combined with a dopamine-modified poly(glutamic acid) block for surface coating and silver nanoparticles (Ag NPs) formation. In the development of a novel, versatile, and biocompatible antibacterial surface coating, block lengths pSar were varied to derive structure-property relationships.

View Article and Find Full Text PDF

Development of localized inflammatory environments by M1 macrophages in the cardiac infarction region exacerbates heart failure after myocardial infarction (MI). Therefore, the regulation of inflammation by M1 macrophages and their timely polarization toward regenerative M2 macrophages suggest an immunotherapy. Particularly, controlling cellular generation of reactive oxygen species (ROS), which cause M1 differentiation, and developing M2 macrophage phenotypes in macrophages propose a therapeutic approach.

View Article and Find Full Text PDF

Purpose: The purpose of the study was to test a structural equation model in which social support, health beliefs, and stage of change predict the health behaviors of patients with cardiovascular disease.

Method: A cross-sectional correlational design was used. Using convenience sampling, a survey about social support, health belief, stage of change, and health behavior was completed by 314 adults with cardiovascular disease from outpatient clinics in 2 university hospitals in Korea.

View Article and Find Full Text PDF

Coculturing stem cells with the desired cell type is an effective method to promote the differentiation of stem cells. The features of the membrane used for coculturing are crucial to achieving the best outcome. Not only should the membrane act as a physical barrier that prevents the mixing of the cocultured cell populations, but it should also allow effective interactions between the cells.

View Article and Find Full Text PDF

Regulating stem cell microenvironment is one of the essential elements in stem cell culture. Recently, carbon nanotube (CNT) has come into the spotlight as a biomaterial that retains unique properties. Based on its high chemical stability, elasticity, mechanical strength, and electrical conductivity, CNT shows great potential as an application for biomedical substrate.

View Article and Find Full Text PDF

Carbon nanotubes (CNTs) have shown great potential in biomedical fields. However, in vivo applications of CNTs for regenerative medicine have been hampered by difficulties associated with the fabrication of three-dimensional (3D) scaffolds of CNTs due to CNTs' nano-scale nature. In this study, we devised a new method for biosynthesis of CNT-based 3D scaffold by in situ hybridizing CNTs with bacterial cellulose (BC), which has a structure ideal for tissue-engineering scaffolds.

View Article and Find Full Text PDF

Mesenchymal stem cell (MSC) implantation has emerged as a potential therapy for myocardial infarction (MI). However, the poor survival of MSCs implanted to treat MI has significantly limited the therapeutic efficacy of this approach. This poor survival is primarily due to reactive oxygen species (ROS) generated in the ischemic myocardium after the restoration of blood flow.

View Article and Find Full Text PDF

Electrophysiological phenotype development and paracrine action of mesenchymal stem cells (MSCs) are the critical factors that determine the therapeutic efficacy of MSCs for myocardial infarction (MI). In such respect, coculture of MSCs with cardiac cells has windowed a platform for cardiac priming of MSCs. Particularly, active gap junctional crosstalk of MSCs with cardiac cells in coculture has been known to play a major role in the MSC modification through coculture.

View Article and Find Full Text PDF

Carbon-based materials have been extensively studied for stem cell culture. However, difficulties associated with engineering pure carbon materials into 3D scaffolds have hampered applications in tissue engineering and regenerative medicine. Carbonized polyacrylonitrile (cPAN) could be a promising alternative, as cPAN is a highly ordered carbon isomorph that resembles the graphitic structure and can be easily processed into 3D scaffolds.

View Article and Find Full Text PDF

The potential of graphene as a mesenchymal stem cell (MSC) culture substrate to promote cardiomyogenic differentiation is demonstrated. Graphene exhibits no sign of cytotoxicity for stem cell culture. MSCs are committed toward cardiomyogenic lineage by simply culturing them on graphene.

View Article and Find Full Text PDF