• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.479-488
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• 2007

In spite of the attention given to the study of mesenchymal stem cells derived periodontal ligament (PDL), there is a lack of information about canine PDL cells. In this study, we characterized canine PDL cells to clarify their stem cell properties, including self renewal, proliferate rate, stem cell markers and multipotency. PDL cells were obtained from extracted premolars of canines, following a colony forming assay and proliferation rate of sub-confluent cultures of cells for self-renewal, immunostaining for STRO-1 and CD146/MUC18 and a differentiation assay for multipotency. Canine PDL cells formed single-cells colonies and 25% of the PDL cells displayed positive staining for BrdU. The cells expressed the mesenchymal stem-cell markers, STRO-1 and CD146/MUC18. Under defined culture conditions, the cells differentiated into osteoblasts and adipocytes, but the cells didn't differentiated into chondrocytes. The findings of this study indicated that the canine PDL cells possess crucial stem cells properties, such as self-renewal and multipotency, and express the mesenchymal stem cell markers on their surface. The isolation and characterization of canine PDL cells makes it feasible to pursue preclinical models of periodontal regeneration in canine.

• Molecules and Cells
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• 제41권3호
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• pp.207-213
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• 2018

Hypoxic culture is widely recognized as a method to efficiently expand human mesenchymal stem cells (MSCs) without loss of stem cell properties. However, the molecular basis of how hypoxia priming benefits MSC expansion remains unclear. In this report, our systemic quantitative proteomic and RT-PCR analyses revealed the involvement of hypoxic conditioning activated genes in the signaling process of the mitotic cell cycle. Introduction of screened two mitotic cyclins, CCNA2 and CCNB1, significantly extended the proliferation lifespan of MSCs in normoxic condition. Our results provide important molecular evidence that multipotency of human MSCs by hypoxic conditioning is determined by the mitotic cell cycle duration. Thus, the activation of mitotic cyclins could be a potential strategy to the application of stem cell therapy.

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.339-347
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• 2011

Human eyelid adipose-derived stem cells (hEAs) and amniotic mesenchymal stem cells (hAMs) are very valuable sources for the cell therapeutics. Both types of cells have a great proliferating ability in vitro and a multipotency to differentiate into adipocytes, osteoblasts and chondrocytes. In the present study, we evaluated their stem cell characteristics after long-time cryopreservation for 6, 12 and 24 months. When frozen-thawed cells were cultivated in vitro, their cumulative cell number and doubling time were similar to freshly prepared cells. Also they expressed stem cell-related genes of SCF, NANOG, OCT4, and TERT, ectoderm-related genes of NCAM and FGF5, mesoderm/endoderm-related genes of CK18 and VIM, and immune-related genes of HLA-ABC and ${\beta}$2M. Following differentiation culture in appropriate culture media for 2-3 weeks, both types of cells exhibited well differentiation into adipocyte, osteoblast, and chondrocyte, as revealed by adipogenic, osteogenic or chondrogenic-specific staining and related genes, respectively. In conclusion, even after long-term storage hEAs and hAMs could maintain their stem cell characteristics, suggesting that they might be suitable for clinical application based on stem cell therapy.

• KSBB Journal
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• 제26권3호
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• pp.183-188
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• 2011

Adult stem cells, which have characteristic of self-renewal and multipotency, are specialized cell types, responsible for the tissue regeneration of the damaged tissue. Recent studies suggest that stem cells senescence (or stem cells' ageing) is closely associated with the variety of ageing-related phenotypes such as tissue atrophy, degenerative diseases and onset of cancers. During ageing, declining of stem cells function and subsequently occurring mal-differentiation of stem cells would be important to understand the biological process of development of ageing-related phenotypes such as tissue degenerations and cancers. This review focuses on the DNA damage stress as a cause of senescence of stem cells and their mal differentiation, which is closely link to defect of regeneration potentials and neoplastic transformation. Understanding of molecular mechanisms governingsuch events is likely to have important implications for developing novel avenues for balancing tissue homeostasis longer period of time, further leading to 'Healthy ageing'.

• 생명과학회지
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• 제25권6호
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• pp.724-731
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• 2015

중간엽줄기세포는 성체줄기세포의 한 종류로, 자기재생산능력(self-renwal)과 다분화능(multipotency)을 가지고 있고, 다양한 자양인자(trophic factors)들을 분비한다. 뿐만 아니라, 중간엽줄기세포는 골수, 지방, 탯줄과 같은 조직에서 쉽게 얻을 수 있기 때문에 줄기세포치료에 좋은 도구로 이용되고 있다. 하지만, 줄기세포치료의 효율성을 높이기 위해 추출한 세포의 개체 수를 늘리는 과정에서 중간엽줄기세포는 점차적인 노화를 겪게 되고, 이는 줄기세포 자체의 기능적인 감소를 야기한다. 인체 내에서, 노화된 줄기세포는 조직 내의 항상성 유지에 부정적인 영향 을 미치게 되고, 이러한 상태가 지속되면 대표적인 노인성 질환인 퇴행성 질환의 원인이 된다. 최근 연구들에 의하면 중간엽줄기세포가 노화를 겪을 때, 노화 관련된 DNA 메틸화 패턴의 변화와 히스톤의 변형이 일어남을 확인하였다. 또한, 중간엽줄기세포의 노화에 있어서 DNA 메틸화효소(DNA methyltransferase) 억제제와 히스톤 아세틸화효소(histone deacetylase) 억제제가 부분적으로 노화를 개선하는 효과를 관찰한 연구사례들이 있다. 본 총설에서는, 노화에 따른 후생유전학적인 변화에 의해, 조절되는 노화 관련 유전자들과 중간엽줄기세포의 노화에 대한 연구사례들을 분석하여 서술하고자 한다.

• International Journal of Oral Biology
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• 제41권2호
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• pp.69-74
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• 2016

Skin-derived precursors (SKPs) have potential to differentiate to various cell types including osteoblasts, adipocytes and neurons. SKPs are a candidate for cell-based therapy since they are easily accessible and have multipotency. Most mammalian cells are exposed to a low oxygen environment with 1 to 5% $O_2$ concentration in vivo, while 21% $O_2$ concentration is common in in vitro culture. The difference between in vitro and in vivo $O_2$ concentration may affect to the behavior of cultured cells. In this report, we investigated the effect of hypoxic condition on stemness and proliferation of SKPs. The results indicated that SKPs exposed to hypoxic condition for 5 days showed no change in proliferation. In terms of mRNA expression, hypoxia maintained expression of stemness markers; whereas, oncogenes, such as Klf4 and c-Myc, were downregulated, and the expression of Nestin, related to cancer migration, was also downregulated. Thus, SKPs cultured in hypoxia may reduce the risk of cancer in SKP cell-based therapy.

• BMB Reports
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• 제47권3호
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• pp.135-140
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• 2014

The mesenchymal stem cells (MSCs), which are derived from the mesoderm, are considered as a readily available source for tissue engineering. They have multipotent differentiation capacity and can be differentiated into various cell types. Many studies have demonstrated that the MSCs identified from amniotic membrane (AM-MSCs) and amniotic fluid (AF-MSCs) are shows advantages for many reasons, including the possibility of noninvasive isolation, multipotency, self-renewal, low immunogenicity, anti-inflammatory and nontumorigenicity properties, and minimal ethical problem. The AF-MSCs and AM-MSCs may be appropriate sources of mesenchymal stem cells for regenerative medicine, as an alternative to embryonic stem cells (ESCs). Recently, regenerative treatments such as tissue engineering and cell transplantation have shown potential in clinical applications for degenerative diseases. Therefore, amnion and MSCs derived from amnion can be applied to cell therapy in neuro-degeneration diseases. In this review, we will describe the potential of AM-MSCs and AF-MSCs, with particular focus on cures for neuronal degenerative diseases.

• Molecules and Cells
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• 제40권8호
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• pp.598-605
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• 2017

Human mesenchymal stem cells (MSCs) are currently being evaluated as a cell-based therapy for tissue injury and degenerative diseases. Recently, several methods have been suggested to further enhance the therapeutic functions of MSCs, including genetic modifications with tissue- and/or diseasespecific genes. The objective of this study was to examine the efficiency and stability of transduction using an adenoviral vector in human MSCs. Additionally, we aimed to assess the effects of transduction on the proliferation and multipotency of MSCs. The results indicate that MSCs can be transduced by adenoviruses in vitro, but high viral titers are necessary to achieve high efficiency. In addition, transduction at a higher multiplicity of infection (MOI) was associated with attenuated proliferation and senescence-like morphology. Furthermore, transduced MSCs showed a diminished capacity for adipogenic differentiation while retaining their potential to differentiate into osteocytes and chondrocytes. This work could contribute significantly to clinical trials of MSCs modified with therapeutic genes.

• International Journal of Stem Cells
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• 제17권1호
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• pp.80-90
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• 2024

Cellular senescence causes cell cycle arrest and promotes permanent cessation of proliferation. Since the senescence of mesenchymal stem cells (MSCs) reduces proliferation and multipotency and increases immunogenicity, aged MSCs are not suitable for cell therapy. Therefore, it is important to inhibit cellular senescence in MSCs. It has recently been reported that metabolites can control aging diseases. Therefore, we aimed to identify novel metabolites that regulate the replicative senescence in MSCs. Using a fecal metabolites library, we identified nervonic acid (NA) as a candidate metabolite for replicative senescence regulation. In replicative senescent MSCs, NA reduced senescence-associated 𝛽-galactosidase positive cells, the expression of senescence-related genes, as well as increased stemness and adipogenesis. Moreover, in non-senescent MSCs, NA treatment delayed senescence caused by sequential subculture and promoted proliferation. We confirmed, for the first time, that NA delayed and inhibited cellular senescence. Considering optimal concentration, duration, and timing of drug treatment, NA is a novel potential metabolite that can be used in the development of technologies that regulate cellular senescence.

• Molecules and Cells
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• 제27권6호
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• pp.635-640
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• 2009

Testis-derived germline stem (GS) cells can undergo reprogramming to acquire multipotency when cultured under appropriate culture conditions. These multipotent GS (mGS) cells have been known to differ from GS cells in their DNA methylation pattern. In this study, we examined the DNA methylation status of the H19 imprinting control region (ICR) in multipotent adult germline stem (maGS) cells to elucidate how epigenetic imprints are altered by culture conditions. DNA methylation was analyzed by bisulfite sequencing PCR of established maGS cells cultured in the presence of glial cell line-derived neurotrophic factor (GDNF) alone or both GDNF and leukemia inhibitory factor (LIF). The results showed that the H19 ICR in maGS cells of both groups was hypermethylated and had an androgenetic pattern similar to that of GS cells. In line with these data, the relative abundance of the Igf2 mRNA transcript was two-fold higher and that of H19 was three fold lower than in control embryonic stem cells. The androgenetic DNA methylation pattern of the H19 ICR was maintained even after 54 passages. Furthermore, differentiating maGS cells from retinoic acid-treated embryoid bodies maintained the androgenetic imprinting pattern of the H19 ICR. Taken together these data suggest that our maGS cells are epigenetically stable for the H19 gene during in vitro modifications. Further studies on the epigenetic regulation and chromatin structure of maGS cells are therefore necessary before their full potential can be utilized in regenerative medicine.