• BMB Reports
• /
• 제56권1호
• /
• pp.32-42
• /
• 2023

Heart disease is one of the major life-threatening diseases with high mortality and incidence worldwide. Several model systems, such as primary cells and animals, have been used to understand heart diseases and establish appropriate treatments. However, they have limitations in accuracy and reproducibility in recapitulating disease pathophysiology and evaluating drug responses. In recent years, three-dimensional (3D) cardiac tissue models produced using tissue engineering technology and human cells have outperformed conventional models. In particular, the integration of cell reprogramming techniques with bioengineering platforms (e.g., microfluidics, scaffolds, bioprinting, and biophysical stimuli) has facilitated the development of heart-on-a-chip, cardiac spheroid/organoid, and engineered heart tissue (EHT) to recapitulate the structural and functional features of the native human heart. These cardiac models have improved heart disease modeling and toxicological evaluation. In this review, we summarize the cell types for the fabrication of cardiac tissue models, introduce diverse 3D human cardiac tissue models, and discuss the strategies to enhance their complexity and maturity. Finally, recent studies in the modeling of various heart diseases are reviewed.

• Interdisciplinary Bio Central
• /
• 제2권2호
• /
• pp.1.1-1.8
• /
• 2010

Microdevices have been used as effective experimental tools for the rapid and multiplexed analysis of individual cells in single-cell assays. Technological advances for miniaturizing such systems and the optimization of delicate controls in micron-sized space homing cells have motivated many researchers from diverse fields (e.g., cancer research, stem cell research, therapeutic agent development, etc.) to employ microtools in their scientific research. Microtools allow high-throughput, multiplexed analysis of single cells, and they are not limited by the lack of large samples. These characteristics may significantly benefit the study of immune cells, where the number of cells available for testing is usually limited. In this review, I present an overview of several microtools that are currently available for single-cell analyses in two popular formats: microarrays and microfluidic microdevices. Then, I discuss the potential to study human immunology on the single-cell level, and I highlight several recent examples of immunoassays performed with single-cell microdevice assays. Finally, I discuss the outlook for the development of optimized assay platforms to study human immune cells. The development and application of microdevices for studies on single immune cells presents novel opportunities for the qualitative and quantitative characterization of immune cells and may lead to a comprehensive understanding of fundamental aspects of human immunology.

• 한국응용과학기술학회지
• /
• 제36권2호
• /
• pp.394-406
• /
• 2019

본 연구는 사람의 다양한 세포주를 이용하여 활성산소종(과산화수소수)이 세포의 노화에 미치는 영향을 비교 조사하였다. 여러 농도의 과산화수소수에 세포주를 일주일 동안 배양하여 MTT 방법으로 과산화수소수에 대한 세포 성장의 반억제농도를 구하였다. 그 결과, 50대에서 유래하는 피부 섬유아세포와 10대의 노화 유도 피부 섬유아세포와 비교하여 10대에서 유래하는 피부 섬유아세포에서 과산화수소수에 대한 반억제농도의 값이 유의적으로 더 높았고, 10대의 피부 섬유아세포보다는 10대의 여러 조직 기원하는 성체줄기세포에서 반억제농도의 값이 유의적으로 더 높게 관찰되었다. 또한, 50 ppm 과산화수소수를 1주일 동안 처리한 후, 50대의 피부 섬유아세포에서 다른 세포주에 비해 세포 성장이 현저히 억제되었고, 노화 관련 베타-갈락토시다아제의 활성이 증가되는 것을 관찰하였다. 또한, 활성산소의 세포 독성을 중화시키는 두 유전자, 글루타티온 과산화효소(GPX)와 카탈라아제(CAT)의 발현을 각 세포주에서 조사하였을 때, CAT의 발현은 모든 세포주에서 대체로 낮았지만, GPX 유전자의 발현이 50대의 피부 섬유아세포보다 10대의 피부 섬유아세포와 성체줄기세포에서 현저히 높게 발현되는 것을 관찰하였다. 이상의 결과에서 활성산소는 세포 노화를 유도하고, GPX의 발현이 높은 10대의 피부 섬유아세포와 줄기세포보다는 50대의 피부 섬유아세포와 노화된 피부 섬유아세포에서 활성산소종에 대해 더 큰 민감성을 가지고 있는 것을 알 수 있었다.

• 한국발생생물학회지:발생과생식
• /
• 제9권2호
• /
• pp.105-114
• /
• 2005

배아 줄기세포는 세포 치료 목적을 위한 재료로써 매우 큰 잠재력을 가지고 있으며, 이러한 잠재력의 실현을 위해서 세포의 운명에 결정적인 역할을 하는 요소들을 확인하고 특정 세포의 대량 생산을 위한 방법을 개발하여야 한다. 조혈과정은 폭넓게 연구되어 왔으며, 배아 줄기세포로부터 조혈세포의 분화는 lineage commitment에 관한 연구에 좋은 모델이 된다. 본 연구에서는, 두 종류의 마우스 배아 줄기세포주 TC-1과 B6-1를 이용하여 그 특성과 조혈세포 분화능을 비교하여 보았다. 두 세포주는 작은 차이는 있으나 줄기세포로서의 특성을 공통적으로 가지고 있었다. 그러나 methylcellulose 배양 system을 사용하여 embryonic body 형성능을 확인한 결과 TC-1이 B6-1에 비해 월등함을 확인하였다. 조혈세포 분화의 추적을 위해 blast colony의 형성, progenitor assay, RT-PCR을 통한 조혈세포 분화 관련 marker의 발현 분석을 수행한 결과, TC-1은 정상적으로 조혈세포를 생성해 내지만, B6-1은 제대로 분화되지 못함을 확인할 수 있었다. 이러한 결과들은 in vitro에서 배아 줄기세포로부터 조혈세포로 분화를 유도할 때, 보다 적합한 세포주의 탐색이 요구됨을 제시하며 이는 향후 인간 배아 줄기세포주에서도 마찬가지로 적용될 수 있음을 암시한다고 사료된다.

• International Journal of Stem Cells
• /
• 제16권1호
• /
• pp.66-77
• /
• 2023

Background and Objectives: We compared the efficacy and safety of human bone marrow-derived mesenchymal stem cells (hBMSC), delivered at different doses and via different injection routes in an animal model of chronic kidney disease. Methods and Results: A total of ninety 12-week-old rats underwent 5/6 nephrectomy and randomized among nine groups: sham, renal artery control (RA-C), tail vein control (TV-C), renal artery low dose (RA-LD) (0.5×10⁶ cells), renal artery moderate dose (RA-MD) (1.0×10⁶ cells), renal artery high dose (RA-HD) (2.0×10⁶ cells), tail vein low dose (TV-LD) (0.5×10⁶ cells), tail vein moderate dose (TV-MD) (1.0×10⁶ cells), and tail vein high dose (TV-HD) (2.0×10⁶ cells). Renal function and mortality of rats were evaluated after hBMSC injection. Serum blood urea nitrogen was significantly lower in the TV-HD group at 2 weeks (p<0.01), 16 weeks (p<0.05), and 24 weeks (p<0.01) than in the TV-C group, as determined by one-way ANOVA. Serum creatinine was significantly lower in the TV-HD group at 24 weeks (p<0.05). At 8 weeks, creatinine clearance was significantly higher in the TV-MD and TV-HD groups (p<0.01, p<0.05) than in the TV-C group. In the safety evaluation, we observed no significant difference among the groups. Conclusions: Our findings confirm the efficacy and safety of high dose (2×10⁶ cells) injection of hBMSC via the tail vein.

• International Journal of Stem Cells
• /
• 제15권1호
• /
• pp.3-13
• /
• 2022

The current COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has completely changed human life for more than two years. Upon the emergence of this new lethal virus, multiple approaches were utilized to gain basic knowledge about its biology. Moreover, modern technologies, such as the organoid model system and next-generation sequencing, enabled us to rapidly establish strategies to tackle the disease, including vaccines and therapeutics. The recently developed organoid technology reflects human physiology more closely than other model systems. Coupled with its rapidness, high efficiency, and outstanding reliability, it has provided an opportunity to develop new drugs and understand the impact of the viral pathogen on the host. Recent findings using organoids have successfully revealed the cellular tropism of the virus in different organs and identified potential drug candidates that impact the disease. This review will summarize current achievements made with organoids in the fight against COVID-19.

• Clinical and Experimental Reproductive Medicine
• /
• 제50권4호
• /
• pp.213-222
• /
• 2023

Cryopreservation is an option for the preservation of pre- or post-pubertal female or male fertility. This technique not only is beneficial for human clinical applications, but also plays a crucial role in the breeding of livestock and endangered species. Unfortunately, frozen germ cells, including oocytes, sperm, embryos, and spermatogonial stem cells, are subject to cryoinjury. As a result, various cryoprotective agents and freezing techniques have been developed to mitigate this damage. Despite extensive research aimed at reducing apoptotic cell death during freezing, a low survival rate and impaired cell function are still observed after freeze-thawing. In recent decades, several cell death pathways other than apoptosis have been identified. However, the relationship between these pathways and cryoinjury is not yet fully understood, although necroptosis and autophagy appear to be linked to cryoinjury. Therefore, gaining a deeper understanding of the molecular mechanisms of cryoinjury could aid in the development of new strategies to enhance the effectiveness of the freezing of reproductive tissues. In this review, we focus on the pathways through which cryoinjury leads to cell death and propose novel approaches to enhance freezing efficacy based on signaling molecules.

• Biomolecules & Therapeutics
• /
• 제20권2호
• /
• pp.158-164
• /
• 2012

Inhibiting the bioactivities of circulating endothelial progenitor cells (EPCs) results in significant inhibition of neovessel formation during tumor angiogenesis. To investigate the potential effect of phloroglucinol as an EPC inhibitor, we performed several in vitro functional assays using $CD34^+$ cells isolated from human umbilical cord blood (HUCB). Although a high treatment dose of phloroglucinol did not show any cell toxicity, it specifically induced the cell death of EPCs under serum free conditions through apoptosis. In the EPC colony-forming assay (EPC-CFA), we observed a significant decreased in the small EPC-CFUs for the phloroglucinol group, implying that phloroglucinol inhibited the early stage of EPC commitment. In addition, in the in vitro expansion assay using $CD34^+$ cells, treatment with phloroglucinol was shown to inhibit endothelial lineage commitment, as demonstrated by the decrease in endothelial surface markers of EPCs including $CD34^+$, $CD34^+/CD133^+$, $CD34^+/CD31^+$ and $CD34^+/CXCR4^+$. This is the first report to demonstrate that phloroglucinol can inhibit the functional bioactivities of EPCs, indicating that phloroglucinol may be used as an EPC inhibitor in the development of biosafe anti-tumor drugs that target tumor angiogenesis.

• Molecules and Cells
• /
• 제26권5호
• /
• pp.454-458
• /
• 2008

Sex steroid hormone receptors play a central role in modulating telomerase activity, especially in cancer cells. However, information on the regulation of steroid hormone receptors and their distinct functions on telomerase activity within the mesenchymal stem cell are largely unavailable due to low telomerase activity in the cell. In this study, the effects of estrogen ($E_2$) treatment and function of estrogen receptor alpha ($ER{\alpha}$) and estrogen receptor beta ($ER{\beta}$) on telomerase activity were investigated in human mesenchymal stem cells (hMSCs). Telomerase activity and mRNA expression of the catalytic subunit of telomerase (hTERT) were upregulated by treatment of the cells with $E_2$. The protein concentration of $ER{\alpha}$ was also increased by $E_2$ treatment, and enhancement of $ER{\alpha}$ accumulation in the nucleus was clearly detected with immunocytochemistry. When $ER{\alpha}$ expression was reduced by siRNA transfection into hMSCs, the effect of $E_2$ on the induction of hTERT expression and telomerase activity was diminished. In contrast, the transient overexpression of $ER{\alpha}$ increased the effect of $E_2$ on the expression of hTERT mRNA. These findings indicate that the activation of hTERT expression and telomerase activity by $E_2$ in hMSCs depends on $ER{\alpha}$, but not on $ER{\beta}$.

• BMB Reports
• /
• 제53권10호
• /
• 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.