• 대한생식의학회:학술대회논문집
• /
• 2004.11a
• /
• pp.69-70
• /
• 2004

• BMB Reports
• /
• v.53 no.10
• /
• pp.545-550
• /
• 2020

Combination therapy using chloroquine (CQ) and azithromycin (AZM) has drawn great attention due to its potential anti-viral activity against SARS-CoV-2. However, clinical trials have revealed that the co-administration of CQ and AZM resulted in severe side effects, including cardiac arrhythmia, in patients with COVID-19. To elucidate the cardiotoxicity induced by CQ and AZM, we examined the effects of these drugs based on the electrophysiological properties of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using multi-electrode arrays. CQ treatment significantly increased the field potential duration, which corresponds to prolongation of the QT interval, and decreased the spike amplitude, spike slope, and conduction velocity of hESC-CMs. AZM had no significant effect on the field potentials of hESC-CMs. However, CQ in combination with AZM greatly increased the field potential duration and decreased the beat period and spike slope of hESC-CMs when compared with CQ monotherapy. In support of the clinical data suggesting the cardiovascular side effects of the combination therapy of CQ and AZM, our results suggest that AZM reinforces the cardiotoxicity induced by CQ in hESC-CMs.

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2006.10a
• /
• pp.97-97
• /
• 2006

• Clinical and Experimental Reproductive Medicine
• /
• v.31 no.4
• /
• pp.261-271
• /
• 2004

Objective: This study was performed to evaluate the possibility of prolonged culture of human embryonic stem cells (hESC; SNUhES2) on human amniotic fluid cells (hAFC), which had been storaged after karyotyping. Method: The hAFC was prepared for feeder layer in the presence of Chang's medium and STO medium (90% DMEM, 10% FBS) at $37^{circ}C$ in a 5% $CO_2$ in air atmosphere. Prior to use as a feeder layer, hAFC was mitotically inactivated by mitomycin C. The hESCs on hAFC were passaged mechanically every seven days with ES culture medium (80% DMEM/F12, 20% SR, bFGF). Results: The hAFC feeder layer support the growth of undifferentiated state of SNUhES2 for at least 59 passages thus far. SNUhES2 colonies on hAFC feeder appeared slightly angular and flatter shape as compared with circular and thicker colonies observed with STO feeder layer and showed higher level with complete undifferentiation in seven days. Like hESC cultured on STO feeders, SNUhES2 grown on hAFC expressed normal karyotype, positive for alkaline phosphatase activity, high telomerase activity, Oct-4, SSEA-3, SSEA-4, Tra-1-60 and Tra-1-81 and formed embryoid bodies (EBs). Conclusion: The hAFC supports undifferentiated growth of hESC. Therefore, these results may help to provide a clinically practicable method for expansion of hESC for cell therapies.

• Clinical and Experimental Reproductive Medicine
• /
• v.31 no.4
• /
• pp.209-215
• /
• 2004

Objective: Embryonic stem (ES) cells could be differentiated into the specific cell types by alternation of culture condition and modification of gene expression. This study was performed to evaluate the differentiation protocol for mouse and human ES cells to insulin secreting cells. Methods: Undifferentiated mouse (JH-I) and human (Miz-hESI) ES cells were cultured on STO feeder layer, and embryoid bodies (EBs) were formed by suspension culture. For the differentiation, EBs were cultured by sequential system with three stage protocol. The differentiating ES cells were collected and marker gene expressions were analyzed by seIni-quantitative RT-PCR in each stage. Amount of secreted insulin levels in culture media of human ES cells were measured by human insulin specific RIA kit. Results: During the differentiation process of human ES cells, GATA-4, a-fetoprotein, glucose transporter-2 and Ngn-3 expression were increased whereas OctA was decreased progressively. Insulin and albuInin mRNAs were expressed from stage IT in mouse ES cells and from stage III in human ES cells. We detected 3.0~7.9 IlU/rnl secretion of insulin from differentiated human ES cells by in vitro culture for 36 days. Conclusion: The sequential culture system could induce the differentiation of mouse and human ES cells into insulin secreting cells. This is the fIrst report of differentiation of human ES cells into insulin secreting cells by in vitro culture with serum and insulin free medium.

• Reproductive and Developmental Biology
• /
• v.32 no.2
• /
• pp.105-110
• /
• 2008

The endogenous retrovirus-like elements (HERVs) found on several human chromosomes are somehow involved in gene regulation, especially during the transcription level. HERV-H, located on chromosome Xp22, may regulate gastrin-releasing peptide receptor (GRPR) in connection with diverse diseases. By suppression subtractive hybridization screen on SV40-immortalized lung fibroblast (WI-38 VA-13), we discovered that expression of HERV-HX2, a clustered HERV-H sequence on chromosome X, was upregulated in immortalized lung cells, compared to that of normal cells. Expression of HERV-HX2 was then analyzed in various cell lines, including normal somatic cells, cancer cells, SV40-immortalized cells, and undifferentiated and differentiated human embryonic stem cells. Expression of HERV-HX2 was specifically upregulated in continuously-dividing cells, such as cancer cells and SV40-immortalized cells. Especially, HERV-HX2 in HeLa cells was highly upregulated during the S phase of the cell cycle. Similar results were obtained in hES cells, in which undifferentiated cells expressed more HERV-HX2 mRNA than differentiated hES cells, including neural precursor and endothelial progenitor cells. Taken together, our results suggest that HERV-HX2 is upregulated in cancer cells and undifferentiated hES cells, whereas downregulated as differentiation progress. Therefore, we assume that HERV-HX2 may playa role on proliferation of cancer cells as well as differentiation of hES cells in the transcriptional level.

• 대한생식의학회:학술대회논문집
• /
• 2004.11a
• /
• pp.72.2-73
• /
• 2004

• 대한생식의학회:학술대회논문집
• /
• 2004.11a
• /
• pp.79-80
• /
• 2004

• Development and Reproduction
• /
• v.9 no.2
• /
• pp.105-114
• /
• 2005

Embryonic stem(ES) cells have tremendous potential as a cell source for cell-based therapies. Realization of that potential will depend on our ability to understand and manipulate the factors that influence cell fate decision and to develop methods for getting enough cell numbers for clinical applications. Hematopoiesis has been widely studied, and hematopoietic differentiation from ES cells is a good model to study lineage commitment. In this study, we investigated stemness and compared the efficiency of hematopoietic differentiation using two different mouse embryonic stem cell lines TC-1 and B6-1. Although the two cell lines showed known stem cell properties with minor differences, the embryoid body formation efficiency in methylcellulose was much higher in TC-1 than B6-1. When measured potentials of hematopoietic differentiation using functional(colony-forming cell) and phenotypic(specific marker expression) assays, we found that TC-1 can differentiate into hematopoietic cells in methylcellulose culture but B6-1 cannot. These results imply that we can improve the efficiency of hematopoietic cell differentiation by selection of proper cell lines and this may be also applied in the differentiation of human embryonic stem cells.

• Korean Journal of Agricultural Science
• /
• v.44 no.3
• /
• pp.309-317
• /
• 2017

Melatonin (N-acetyl-5-methoxytryptamine) is an indole synthesized from tryptophan by the pineal gland in animal. The major function of melatonin is to modulate circadian and circannual rhythms in photoperiodic mammals. Importantly, however, melatonin is also a free radical scavenger, anti-oxidant, and anti-apoptotic agent. Recently, the beneficial effects of melatonin on oocyte maturation and embryonic development in vitro have been reported in many species such as pig, cattle, sheep, mouse, and human. In this review, we will discuss recent studies about the role of melatonin in the production of porcine and bovine oocytes and embryos in vitro in order to provide useful information of melatonin in oocyte maturation and embryo culture in vitro.