• Animal cells and systems
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• 제5권2호
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• pp.91-99
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• 2001

Vertebrates regenerate tissues in three ways: proliferation of cells that maintain some or all of their differentiated structure and function, redifferentiation of mature cells followed by proliferation and redifferentiation into the same cell type or transdetermination to another cell type, and activation of restricted lineage stem cells, which have the ability to transdetermine to different lineages under the appropriate conditions. The behavior of the cells during regeneration is regulated by growth factors and extracellular matrix molecules. Some non-regenerating tissues are now known to harbor stem cells which, though they form scar tissue in vivo, are capable of producing new tissue-specific cells in vitro, suggesting that the injury environment inhibits latent regenerative capacity. Regenerative medicine seeks to restore tissues via transplantation of stem cell derivatives, implantation of bioartificial tissues, or stimulation of regeneration in vivo. These approaches have been partly successful, but several research issues must be addressed before regenerative medicine becomes a clinical reality.

• Archives of Plastic Surgery
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• 제45권2호
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• pp.111-117
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• 2018

Background Fat grafting, or lipofilling, represent frequent clinically used entities. The fate of these transplants is still not predictable, whereas only few animal models are available for further research. Quantum dots (QDs) are semiconductor nanocrystals which can be conveniently tracked in vivo due to photoluminescence. Methods Fat grafts in cluster form were labeled with cadmium-telluride (CdTe)-QD 770 and transplanted subcutaneously in a murine in vivo model. Photoluminescence levels were serially followed in vivo. Results Tracing of fat grafts was possible for 50 days with CdTe-QD 770. The remaining photoluminescence was $4.9%{\pm}2.5%$ for the QDs marked fat grafts after 30 days and $4.2%{\pm}1.7%$ after 50 days. There was no significant correlation in the relative course of the tracking signal, when vital fat transplants were compared to non-vital graft controls. Conclusions For the first-time fat grafts were tracked in vivo with CdTe-QDs. CdTe-QDs could offer a new option for in vivo tracking of fat grafts for at least 50 days, but do not document vitality of the grafts.

• Molecules and Cells
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• 제41권6호
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• pp.515-522
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• 2018

Patients with head and neck cancer are treated with therapeutic irradiation, which can result in irreversible salivary gland dysfunction. Because there is no complete cure for such patients, stem cell therapy is an emerging alternative for functional restoration of salivary glands. In this study, we investigated in vitro characteristics of primarily isolated epithelial cells from human salivary gland (Epi-SGs) and in vivo formation of acini-like structures by Epi-SGs. Primarily isolated Epi-SGs showed typical epithelial cell-like morphology and expressed E-cadherin but not N-cadherin. Epi-SGs expressed epithelial stem cell (EpiSC) and embryonic stem cell (ESC) markers. During long-term culture, the expression of EpiSC and ESC markers was highly detected and maintained within the core population with small size and low cytoplasmic complexity. The core population expressed cytokeratin 7 and cytokeratin 14, known as duct markers indicating that Epi-SGs might be originated from the duct. When Epi-SGs were transplanted in vivo with Matrigel, acini-like structures were readily formed at 4 days after transplantation and they were maintained at 7 days after transplantation. Taken together, our data suggested that Epi-SGs might contain stem cells which were positive for EpiSC and ESC markers, and Epi-SGs might contribute to the regeneration of acini-like structures in vivo. We expect that Epi-SGs will be useful source for the functional restoration of damaged salivary gland.

• KSBB Journal
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• 제19권3호
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• pp.210-214
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• 2004

본 연구에서는 생분해성 고분자 담체인 PGA 담체에 부착된 간세포의 이식을 통해서 이식된 간세포가 괴사하지 않고 남아 있으며 간 조직 구조의 일종인 담세관 유사구조를 확인하였다. 조직공학적인 간세포 이식 방법의 개발은 간 질환에 새로운 치료방법 개발의 가능성을 열어줄 수 있다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.259-264
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• 2005

Transplantation of cultured chondrocytes can regenerate cartilage tissues in cartilage defects in humans. However, this method requires a long culture period to expand chondrocytes to a large number of cells for transplantation. In addition, chondrocytes may dedifferentiate during long-term culture. These problems can potentially be overcome by the use of undifferentiated or partially developed cartilage precursor cells derived from neonatal cartilage, which, unlike chondrocytes from adult cartilage, have the capacity for rapid in vitro cell expansion and may retain their differentiated phenotype during long-term culture. The purpose of this study was to compare the cell growth rate and phenotypic modulation during in vitro culture between adult chondrocytes and neonatal chondrocytes, and to demonstrate the feasibility of regenerating cartilage tissues in vivo by transplantation of neonatal chondrocytes expanded in vitro and seeded onto polymer scaffolds. When cultured in vitro, chondrocytes isolated from neonatal (immediately postpartum, 2 h of age) rats exhibited much higher growth rate than chondrocytes isolated from adult rats. After 5 days of culture, more neonatal chondrocytes were in the differentiated state than adult chondrocytes. Cultured neonatal chondrocytes were seeded onto biodegradable polymer scaffolds and transplanted into athymic mice's subcutaneous sites. Four weeks after implantation, neonatal chondrocyte-seeded scaffolds formed white cartilaginous tissues. Histological analysis of the implants with hematoxylin and eosin showed mature and well-formed cartilage. Alcian blue/ safranin-O staining and Masson's trichrome staining indicated the presence of highly sulfated glycosarninoglycans and collagen, respectively, both of which are the major extracellular matrices of cartilage. Immunohistochemical analysis showed that the collagen was mainly type II, the major collagen type in cartilage. These results showed that neonatal chondrocytes have potential to be a cell source for cartilage tissue engineering.

• The Korean Journal of Physiology and Pharmacology
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• 제21권2호
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• pp.153-160
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• 2017

In this study, we aim to determine the in vivo effect of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) on neuropathic pain, using three, principal peripheral neuropathic pain models. Four weeks after hUCB-MSC transplantation, we observed significant antinociceptive effect in hUCB-MSC-transplanted rats compared to that in the vehicle-treated control. Spinal cord cells positive for c-fos, CGRP, p-ERK, p-p 38, MMP-9 and MMP 2 were significantly decreased in only CCI model of hUCB-MSCs-grafted rats, while spinal cord cells positive for CGRP, p-ERK and MMP-2 significantly decreased in SNL model of hUCB-MSCs-grafted rats and spinal cord cells positive for CGRP and MMP-2 significantly decreased in SNI model of hUCB-MSCs-grafted rats, compared to the control 4 weeks or 8weeks after transplantation (p<0.05). However, cells positive for TIMP-2, an endogenous tissue inhibitor of MMP-2, were significantly increased in SNL and SNI models of hUCB-MSCs-grafted rats. Taken together, subcutaneous injection of hUCB-MSCs may have an antinociceptive effect via modulation of pain signaling during pain signal processing within the nervous system, especially for CCI model. Thus, subcutaneous administration of hUCB-MSCs might be beneficial for improving those patients suffering from neuropathic pain by decreasing neuropathic pain activation factors, while increasing neuropathic pain inhibition factor.

• 한국임상수의학회지
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• 제28권4호
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• pp.399-402
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• 2011

In recent years, the mesenchymal stem cells (MSC) derived from various tissues have been widely tested for developing cell therapies, tissue repair and transplantation. Although there has been much interest in the immunomodulatory properties of MSC and their immunologic reactions following autologous, allogeneic and xenogenic transplantation of MSC in vivo, up to date, the expression of immunogenic markers, such as class I and II human leukocyte antigens (HLA), after differentiation of human umbilical cord blood (hUCB)-derived MSC has been poorly investigated and require extensive in vitro and in vivo testing. In this experiment, the expression of the HLA-ABC and HLA-DR on hUCB-derived MSC have been tested by immunocytochemical staining. The undifferentiated MSC were moderately stained for HLA-ABC but very weakly for HLA-DR. In order to investigate the inhibitory effect of allogeneic lymphocytes on proliferation of MSC, the MSC were cultured in the presence or absence of peripheral allogeneic lymphocytes stimulated with concanavalin A. The allogeneic lymphocytes did not significantly inhibit MSC proliferation. We conclude that hUCB-MSC expressed moderately class I HLA antigen while almost negatively class II HLA antigen. The MSC have an immunomodulatory effect which can suppress the allogeneic response of lymphocytes. These in vitro data suggest that allogeneic MSC derived from cord blood can be useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.105-111
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• 2005

End-stage renal disease is a fatal and devastating disease that is caused by progressive and irreversible loss of functioning nephrons in the kidney. Dialysis and renal transplantation are the common treatments at present, but these treatments have severe limitations. The present study investigated the possibility of reconstructing renal tissues by transplantation of renal precursor cells to replace the current treatments for end-stage renal disease. Embryonic renal precursor cells, freshly isolated from metanephroi of rat fetus at day 15 post-gestation, were seeded on biodegradable polymer scaffolds and transplanted into peritoneal cavities of athymic mice for three weeks. Histologic sections stained with hematoxylin & eosin and periodic acid-Schiff revealed the formation of primitive glomeruli, tubules, and blood vessels, suggesting the potential of embryonic renal precursor cells to reconstitute renal tissues. Immunohistochemical staining for proliferating cell nuclear antigen, a marker of proliferating cells, showed intensive nuclear expression in the regenerated renal structures, suggesting renal tissue reconstitution by transplanted embryonic renal precursor cells. This study demonstrates the reconstitution of renal tissue in vivo by transplanting renal precursor cells with biodegradable polymer scaffolds, which could be utilized as a new method for partial or full restoration of renal structure and function in the treatment of end-stage renal disease.

• The Korean Journal of Physiology and Pharmacology
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• 제28권3호
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• pp.209-217
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• 2024

In addition to cellular damage, ischemia-reperfusion (IR) injury induces substantial damage to the mitochondria and endoplasmic reticulum. In this study, we sought to determine whether impaired mitochondrial function owing to IR could be restored by transplanting mitochondria into the heart under ex vivo IR states. Additionally, we aimed to provide preliminary results to inform therapeutic options for ischemic heart disease (IHD). Healthy mitochondria isolated from autologous gluteus maximus muscle were transplanted into the hearts of Sprague-Dawley rats damaged by IR using the Langendorff system, and the heart rate and oxygen consumption capacity of the mitochondria were measured to confirm whether heart function was restored. In addition, relative expression levels were measured to identify the genes related to IR injury. Mitochondrial oxygen consumption capacity was found to be lower in the IR group than in the group that underwent mitochondrial transplantation after IR injury (p < 0.05), and the control group showed a tendency toward increased oxygen consumption capacity compared with the IR group. Among the genes related to fatty acid metabolism, Cpt1b (p < 0.05) and Fads1 (p < 0.01) showed significant expression in the following order: IR group, IR + transplantation group, and control group. These results suggest that mitochondrial transplantation protects the heart from IR damage and may be feasible as a therapeutic option for IHD.

• Molecules and Cells
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• 제23권2호
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• pp.132-137
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• 2007

With the advance of stem cell transplantation research, in vivo cell tracking techniques have become increasingly important in recent years. Magnetic resonance imaging (MRI) may provide a unique tool for non-invasive tracking of transplanted cells. Since the initial findings on the stem cell migration by MRI several years ago, there have been numerous studies using various animal models, notably in heart or brain disease models. In order to develop more reliable and clinically applicable methodologies, multiple aspects should be taken into consideration. In this review, we will summarize the current status and future perspectives of in vivo cell tracking technologies using MRI. In particular, use of different MR contrast agents and their detection methods using MRI will be described in much detail. In addition, various cell labeling methods to increase the sensitivity of signals will be extensively discussed. We will also review several key experiments, in which MRI techniques were utilized to detect the presence and/or migration of transplanted stem cells in various animal models. Finally, we will discuss the current problems and future directions of cell tracking methods using MRI.