• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
• /
• pp.102-102
• /
• 2003

Embryonic stem (ES) cells proliferate extensively in the undifferentiated state and have the potential to differentiate into a variety of cell types in response to various environmental cues. The generation of functional dopaminergic neurons from ES cells is promising for cell replacement therapy to treat Parkinson's disease. We compared the in vitro differentiation potential of pluripotent human embryonic stem (hES, MB03) cells induced with basic fibroblast growth factor (bFGF) or retinoic acid (RA). Both types of treatment resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with brain derived neurotrophic factor (BDNF) or transforming growth factor (TGF)- $\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression, compared to control (P<0.05). In contrast, no effect was observed on the rate of mature or glutamic acid decarboxylase-positive neurons. Immunostaining and HPLC analyses revealed the higher levels of TH (20.3%) and dopamine in bFGF and TGF-$\alpha$ treated hES cells than in RA or BDNF treated hES cells. The results indicate that TGF-$\alpha$ may be successfully used in the bFGF induction protocol to yield higher numbers of functional dopaminergic neurons from hES cells.

• Journal of Microbiology and Biotechnology
• /
• 제27권10호
• /
• pp.1877-1884
• /
• 2017

Mesenchymal stem cells (MSCs) have been suggested as a primary candidate for cell therapy applications because they have self-renewal and differentiation capabilities. Although they can be expanded in ex vivo system, clinical application of these cells is still limited because they survive poorly and undergo senescence or apoptosis when transplanted and exposed to environmental factors such as oxidative stress. Thus, reducing oxidative stress is expected to improve the efficacy of MSC therapy. The milk protein lactoferrin is a multifunctional iron-binding glycoprotein that plays various roles, including reduction of oxidative stress. Thus, we explored the effect of lactoferrin on oxidative stress-induced senescence and apoptosis of human MSCs (hMSCs). Measurement of reactive oxygen species (ROS) revealed that lactoferrin inhibited the production of hydrogen peroxide-induced intracellular ROS, suggesting lactoferrin as a good candidate as an antioxidant in hMSCs. Pretreatment of lactoferrin suppressed hydrogen peroxide-induced senescence of hMSCs. In addition, lactoferrin reduced hydrogen peroxide-induced apoptosis via inhibition of caspase-3 and Akt activation. These results demonstrate that lactoferrin can be a promising factor to protect hMSCs from oxidative stress-induced senescence and apoptosis, thus increasing the efficacy of MSC therapy.

• Tuberculosis and Respiratory Diseases
• /
• 제78권3호
• /
• pp.239-245
• /
• 2015

Background: Chronic obstructive pulmonary disease is characterized by emphysema, chronic bronchitis, and small airway remodeling. The alveolar destruction associated with emphysema cannot be repaired by current clinical practices. Stem cell therapy has been successfully used in animal models of cigarette smoke- and elastase-induced emphysema. However, the optimal dose of mesenchymal stem cells (MSCs) for the most effective therapy has not yet been determined. It is vital to determine the optimal dose of MSCs for clinical application in emphysema cases. Methods: In the present study, we evaluated the therapeutic effects of various doses of MSCs on elastase-induced emphysema in mice. When 3 different doses of MSCs were intravenously injected into mice treated with elastase, only $5{\times}10^4$ MSCs showed a significant effect on the emphysematous mouse lung. We also identified action mechanisms of MSCs based on apoptosis, lung regeneration, and protease/antiprotease imbalance. Results: The MSCs were not related with caspase-3/7 dependent apoptosis. But activity of matrix metalloproteinase 9 increased by emphysematous lung was decreased by intravenously injected MSCs. Vascular endothelial growth factor were also increased in lung from MSC injected mice, as compared to un-injected mice. Conclusion: This is the first study on the optimal dose of MSCs as a therapeutic candidate. This data may provide important basic data for determining dosage in clinical application of MSCs in emphysema patients.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.130.1-130.1
• /
• 2003

As a potent antigen presenting cells and a powerful inducer of antigen specific immunity including cytotoxic T cell activity, dendritic cells(DCs) are being considered as a promising anti-tumor therapeutic module. Unlike solid tumors, leukemia is the hematologic malignancy involving immune effector cells. The expected usage of DCs in leukemia is the treatment of minimal residual disease(MRD) after the remission or stem cell transplantation. In this study, syngeneic leukemia cells were inoculated intra-venously into the mouse (WEHI-3 into the Balb/c), and the autologous tumor cell lysate pulsed DCs were injected as a therapeutic module twice in two weeks. (omitted)

• Archives of Plastic Surgery
• /
• 제47권3호
• /
• pp.217-222
• /
• 2020

Background Surgical reconstruction of chronic wounds is often infeasible due to infection, comorbidities, or poor viability of local tissues. The aim of this study was to describe the authors' technique for improving the regenerative and antimicrobial potential of a combination of modified nanofat and platelet-rich plasma (PRP) in nonhealing infected wounds. Methods Fourteen patients met the inclusion criteria. Fat tissue was harvested from the lower abdomen following infiltration of a solution of 1,000 mL of NaCl solution, 225 mg of ropivacaine, and 1 mg of epinephrine. Aspiration was performed using a 3-mm cannula with 1-mm holes. The obtained solution was decanted and mechanically emulsified, but was not filtered. Non-activated leukocyte-rich PRP (naLR-PRP) was added to the solution before injection. Patients underwent three sessions of injection of 8-mL naLR-PRP performed at 2-week intervals. Results Thirteen of 14 patients completed the follow-up. Complete healing was achieved in seven patients (53.8%). Four patients (30.8%) showed improvement, with a mean ulcer width reduction of 57.5%±13.8%. Clinical improvements in perilesional skin quality were reported in all patients, with reduced erythema, increased thickness, and increased pliability. An overall wound depth reduction of 76.6%±40.8% was found. Pain was fully alleviated in all patients who underwent re-epithelization. A mean pain reduction of 42%±33.3% (as indicated by visual analog scale score) was found in non-re-epithelized patients at a 3-month follow-up. Conclusions The discussed technique facilitated improvement of both the regenerative and the antimicrobial potential of fat grafting. It proved effective in surgically-untreatable infected chronic wounds unresponsive to conventional therapies.

• IMMUNE NETWORK
• /
• 제23권2호
• /
• pp.17.1-17.16
• /
• 2023

Latent membrane protein 2A (LMP2A), a latent Ag commonly expressed in Epstein-Barr virus (EBV)-infected host cells, is a target for adoptive T cell therapy in EBV-associated malignancies. To define whether individual human leukocyte antigen (HLA) allotypes are used preferentially in EBV-specific T lymphocyte responses, LMP2A-specific CD8⁺ and CD4⁺ T cell responses in 50 healthy donors were analyzed by ELISPOT assay using artificial Ag-presenting cells expressing a single allotype. CD8⁺ T cell responses were significantly higher than CD4⁺ T cell responses. CD8⁺ T cell responses were ranked from highest to lowest in the order HLA-A, HLA-B, and HLA-C loci, and CD4⁺ T cell responses were ranked in the order HLA-DR, HLA-DP, and HLA-DQ loci. Among the 32 HLA class I and 56 HLA class II allotypes, 6 HLA-A, 7 HLA-B, 5 HLA-C, 10 HLA-DR, 2 HLA-DQ, and 2 HLA-DP allotypes showed T cell responses higher than 50 spot-forming cells (SFCs)/5×105 CD8⁺ or CD4⁺ T cells. Twenty-nine donors (58%) showed a high T cell response to at least one allotype of HLA class I or class II, and 4 donors (8%) had a high response to both HLA class I and class II allotypes. Interestingly, we observed an inverse correlation between the proportion of LMP2A-specific T cell responses and the frequency of HLA class I and II allotypes. These data demonstrate the allele dominance of LMP2A-specific T cell responses among HLA allotypes and their intra-individual dominance in response to only a few allotypes in an individual, which may provide useful information for genetic, pathogenic, and immunotherapeutic approaches to EBV-associated diseases.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권16호
• /
• pp.6495-6497
• /
• 2014

Rapidly increasing number of outstanding developments in the field of TRAIL mediated signaling have revolutionized our current information about inducing and maximizing TRAIL mediated apoptosis in resistant cancer cells. Data obtained with high-throughput technologies have provided finer resolution of tumor biology and now it is known that a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constitutes the tumor stroma. Utility of mesenchymal stem cells (MSCs) as cellular vehicles has added new layers of information. There is sufficient experimental evidence substantiating efficient gene deliveries into MSCs by retroviral, lentiviral and adenoviral vectors. Moreover, there is a paradigm shift in molecular oncology and recent high impact research has shown controlled expression of TRAIL in cancer cells on insertion of complementary sequences for frequently downregulated miRNAs. In this review we have attempted to provide an overview of utility of TRAIL engineered MSCs for effective killing of tumor and potential of using miRNA response elements as rheostat like switch to control expression of TRAIL in cancer cells.

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
• /
• pp.98-98
• /
• 2003

Recently, human embryonic stem (hES) cells have become very important resources for ES cell basic research, cell replacement therapy, and other medical applications; thus, efficient cryopreservation methods for these cells are needed. This study examined whether a newly developed minimum volume cooling (MVC) vitrification method, which was tested through cryopreservation of sensitive bovine oocytes, can be used for freezing hES cells. Feeder-free cultured hES cell (MB03) colonies were mechanically dissected into several small clumps following enzymatic treatment. We compared the freezing efficiency of a slow-cooling method using a cryo-module (0.4-0.6C/min, 20-30 clumps/vial) and MVC vitrification using a modified 0.5-ml French mini-straw designated as a MVC straw (>$20,000{\circ}C$/min, 10 clumps/straw) After thawing, in vitro survival of hES cell clumps was higher for MVC-vitrified cells (80.8%, 97/120) than for slow-cooled cells (38.2%, 39/102). Further, the proliferation rate of surviving MVC-vitrified cells was similar to that of control hES cells from 2 weeks after thawing. In addition, vitrified-thawed hES cells demonstrated a normal karyotype, were positively immunostained for surface marker antibodies (AP, SSEA-4 and TRA-1-60) and the Oct-4 antibody, and could differentiate into all three embryonic germ layer cells in vitro. This result demonstrates that hES cell clumps can be successfully cryopreserved by a newly developed MVC vitrification method without loss of human cell characteristics.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.372-373
• /
• 2003

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.113-114
• /
• 2013

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging is a powerful technique for producing chemical images of small biomolecules (ex. metabolites, lipids, peptides) "as received" because of its high molecular specificity, high surface sensitivity, and submicron spatial resolution. In addition, matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) imaging is an essential technique for producing chemical images of large biomolecules (ex. genes and proteins). For this talk, we will show that label-free mass imaging technique can be a platform technology for biomedical studies such as early detection/diagnostics, accurate histologic diagnosis, prediction of clinical outcome, stem cell therapy, biosensors, nanomedicine and drug screening [1-7].