Publications by authors named "Yun-Gwi Park"
Article Synopsis
- The c.453delC mutation in the KCNH2 gene is linked to a higher risk of Long QT syndrome (LQTS) and potentially fatal heart arrhythmias, although its specific loss-of-function mechanism isn't fully understood.
- Researchers conducted experiments using patch-clamp and immunoblot techniques on both a lab expression system and patient-derived stem cell heart cells (iPSC-CMs) to explore how this mutation affects heart function.
- Their findings revealed that the mutation leads to a truncated version of the hERG channel that results in lower expression and ionic current, but can be partially corrected with a hERG activator, improving heart cell function in lab settings and in patient cells.
Cardiac radioablation is emerging as an alternative option for refractory ventricular arrhythmias. However, the immediate acute effect of high-dose irradiation on human cardiomyocytes remains poorly known. We measured the electrical activities of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) upon irradiation with 0, 20, 25, 30, 40, and 50 Gy using a multi-electrode array, and cardiomyocyte function gene levels were evaluated.
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- COVID-19, caused by the SARS-CoV-2 virus, is a major global health crisis, with remdesivir being the only drug currently authorized for emergency use against it.
- A study comparing remdesivir's antiviral activity and cardiotoxic effects found it to be significantly more effective in human stem cell-derived heart cells than in traditional Vero E6 cells, but it also showed moderate heart toxicity.
- The research highlighted a risk of QT interval prolongation with remdesivir, suggesting that patients taking this drug, especially those with existing heart conditions, should be monitored closely for heart rhythm issues.
Objective: If fertilization does not occur within a specific period, the quality of unfertilized oocytes in the oviduct (in vivo aging) or in culture (in vitro aging) will deteriorate over time. Icariin (ICA), found in all species of Epimedium herbs, has strong antioxidant activity, and is thought to exert anti-aging effects in vitro. We asked whether ICA protects oocytes against age-related changes in vitro.
View Article and Find Full Text PDFOptimization of culture conditions is important to improve oocyte maturation and subsequent embryo development. In particular, this study analyzed the effects of increasing concentrations of PIO in the maturation medium on spindle formation and chromosome alignment, glutathione, and intracellular ROS levels and expression of selected genes related to maternal markers, apoptosis, and lipid metabolism. The percentage of oocytes displaying normal spindle formation and chromosome alignment was higher in the 1 µM PIO (1 PIO)-treated group than in the control group.
View Article and Find Full Text PDFAllicin protects porcine oocytes against damage during aging in vitro.
Mol Reprod Dev
September 2019
Allicin, a chemical component of garlic, has strong antioxidant activity and is thought to exert antiaging effects in vitro. We investigated whether allicin treatment would protect porcine oocytes and embryos from postovulatory aging mediated by apoptosis and autophagy. The rates of oocyte survival and polar body extrusion in samples treated with 1 µM allicin (1 AL) were significantly higher than in untreated samples (0 AL).
View Article and Find Full Text PDFThe citrus flavonoid hesperetin has a variety of pharmacological actions, including antioxidant, antiinflammatory, and anticancer activities. This study investigated whether hesperetin prevents aging of oocytes in vitro in which it determined the maturation of nuclear and cytoplasm and the developmental capacity of embryo by modulating the reactive oxygen species (ROS) level. Porcine oocytes were matured in vitro for 44 hr (control) and for an additional 24 hr in the presence of 0, 1, 10, 100, and 250 μM hesperetin (aging, H-1, H-10, H-100, and H-250, respectively).
View Article and Find Full Text PDFSomatic cell nuclear transfer (SCNT) is required for the generation of transgenic animals as disease models. During the in vitro development of SCNT embryos, the quality of matured oocytes is one of the major factors regulating the developmental potential of embryos. Time-lapse monitoring systems are new tools that assess the developmental capacity of embryos for use in embryo transfer.
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- Oxidative stress negatively impacts the quality of porcine oocytes during in vitro maturation (IVM), prompting research on the antioxidant β-cryptoxanthin.
- A concentration of 1µM β-cryptoxanthin significantly improved key maturation indicators, reduced reactive oxygen species, and enhanced antioxidant gene expression in the oocytes compared to the control group.
- Following activation, embryos from the β-cryptoxanthin-treated group showed better blastocyst formation rates, higher cell counts, and increased expression levels of pluripotency and antioxidant genes, suggesting improved developmental potential.
Article Synopsis
- Modifying culture media with factors like lysophosphatidic acid (LPA) is crucial for developing oocytes and embryos in vitro.
- This study found that treating porcine embryos with LPA from Days 4 to 7 improved blastocyst formation and embryo size, compared to control embryos.
- LPA treatment also enhanced the expression of specific genes related to cell communication and adhesion, while reducing apoptosis in the embryos.
Article Synopsis
- The 0.1 μM AL-treated group showed a higher rate of polar body emission and significantly improved cleavage and blastocyst formation compared to the control group.
- Allicin treatment also altered the expression of certain genes and proteins, suggesting that it enhances oocyte maturation and developmental potential through cellular signaling changes.
Alzheimer's disease (AD) is a progressive neurodegenerative disease associated with memory loss and cognitive impairments. An AD transgenic (Tg) pig model would be useful for preclinical testing of therapeutic agents. We generated an AD Tg pig by somatic cell nuclear transfer (SCNT) using a multi-cistronic vector that harbored three AD-related genes with a total of six well-characterized mutations: hAPP (K670N/M671L, I716V, and V717I), hTau (P301L), and hPS1 (M146V and L286P).
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- Specific transcription factors can reprogram induced pluripotent stem cells and other cell types, prompting investigation into whether chemical molecules like BMP4 can achieve similar results.
- In the study, mouse skin fibroblasts were treated with BMP4, which led to changes in the cells' characteristics and increased their ability to proliferate, indicating a transition to stem-like cells.
- The reprogrammed cells were found to express key stem cell markers and successfully differentiated into cardiomyocytes, showing potential for BMP4 as an alternative method in cell therapy.
Article Synopsis
- The study examines how varying concentrations of Fibroblast Growth Factor 10 (FGF10) affect cumulus cell expansion, oocyte maturation, and embryo development in vitro.
- Results showed that the 10 ng/mL FGF10 treatment significantly improved cumulus cell expansion and resulted in a higher percentage of oocytes with normal spindles compared to controls.
- Additionally, various gene transcripts related to cell functions were upregulated in the FGF10-treated groups, leading to better embryo cleavage rates, blastocyst formation, and overall developmental outcomes.
Article Synopsis
- * Porcine fibroblasts treated with 1 μM rapamycin for 3 days showed a higher proportion of cells in the G0/G1 phase and maintained good viability, although their proliferation was decreased compared to control and serum-starved cells.
- * SCNT using rapamycin-treated cells led to increased rates of cleavage and blastocyst formation, improved embryo quality, and significant differences in the expression of developmental and proapoptotic genes, demonstrating the potential of rapamycin in enhancing SC
The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group.
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