Publications by authors named "Kyounghwan Roh"

Mesenchymal stem cells (MSCs) are a promising tool for treating immune disorders. However, the immunomodulatory effects of canine MSCs compared with other commercialized biologics for treating immune disorders have not been well studied. In this study we investigated the characteristics and immunomodulatory effects of canine amnion membrane (cAM)-MSCs.

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BACKGROUNDRecessive dystrophic epidermolysis bullosa (RDEB) is an incurable disease that causes severe mucocutaneous fragility due to mutations in COL7A1 (encoding type VII collagen [C7]). In this phase I/IIa trial, we evaluated the safety and possible clinical efficacy of intravenous infusion of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in patients with RDEB.METHODSFour adult and two pediatric patients with RDEB were treated with 3 intravenous injections of hUCB-MSCs (1 × 106 to 3 × 106 cells/kg) every 2 weeks and followed up for 8-24 months after treatment.

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Based on immunomodulatory actions of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), in vitro or preclinical studies of hUCB-MSCs have been conducted extensively in rheumatoid arthritis (RA). However, few human trials have investigated the outcomes of hUCB-MSC infusions. The CURE-iv trial was a phase I, uncontrolled, open label trial for RA patients with moderate disease activity despite treatment with methotrexate.

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Mesenchymal stem cells (MSCs) have been proven to be therapeutically effective against atopic dermatitis (AD) in preclinical studies. However, the safety and efficacy of MSCs against AD have not yet been investigated in a clinical study. To establish the safety and efficacy of human umbilical cord blood-derived MSCs (hUCB-MSCs) in AD, 34 adult patients with moderate-to-severe AD were enrolled in two phase trials with a follow-up for 1 month and 3 months, respectively.

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DNA methyltransferase (DNMT) inhibitors regulate target gene expression through epigenetic modifications, and these compounds have primarily been studied for cancer therapy or reprogramming. However, the effect of DNMT inhibitors on the immunomodulatory capacity of human mesenchymal stem cells (hMSCs) has not been investigated. In the present study, we treated hMSCs with 5-azacytidine (5-aza), a DNMT inhibitor, and confirmed that the inhibitory effects on mononuclear cell proliferation and cell migration toward activated T cells were increased.

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Background And Objectives: Half of patients with critical limb ischemia (CLI) are ineligible for revascularization at diagnosis. The aim of this study was to assess the safety and feasibility of intramuscular human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) therapy in patients with CLI due to atherosclerosis obliterans (ASO) or thromboangiitis obliterans (TAO).

Methods And Results: A total of eight patients (all male, median age 52 years, range 31∼77) with CLI were enrolled in this phase I trial.

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ZNF281 is one of the core transcription factors in embryonic stem cells (ESCs) and has activation and repression roles in the transcription of ESC genes. A known target molecule of Zfp281 (the mouse homologue of ZNF281) is Nanog. However, NANOG is not expressed in most human multipotent stem cells (hMSCs).

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Cellular senescence involves a reduction in adult stem cell self-renewal, and epigenetic regulation of gene expression is one of the main underlying mechanisms. Here, we observed that the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) caused by inhibition of histone deacetylase (HDAC) activity leads to down-regulation of high mobility group A2 (HMGA2) and, on the contrary, to up-regulation of p16(INK)⁴(A), p21(CIP)¹(/WAF)¹ and p27(KIP)¹. We found that let-7a1, let-7d, let-7f1, miR-23a, miR-26a and miR-30a were increased during replicative and HDAC inhibitor-mediated senescence of hUCB-MSCs by microRNA microarray and real-time quantitative PCR.

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Background: REX1/ZFP42 is a well-known embryonic stem cell (ESC) marker. However, the role of REX1, itself, is relatively unknown because the function of REX1 has only been reported in the differentiation of ESCs via STAT signaling pathways. Human mesenchymal stem cells (hMSCs) isolated from young tissues and cancer cells express REX1.

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It has widely been reported that basic fibroblast growth factor (bFGF) promotes proliferation of human stem cells and contributes to the maintenance of their self-renewal capability through repeated replications. In contrast to embryonic stem cells (ESCs), the effects of growth factors on adult stem cells are poorly understood. In human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs), bFGF is associated with an increased number of proliferating cells.

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The OCT4A gene, a POU homeodomain transcription factor, has been shown to be expressed in embryonic stem cells (ESC) as well as hUCB-MSCs. In this study, the roles played by OCT4A in hUCB-MSCs were determined by stably inhibiting OCT4A with lenti-viral vector-based small hairpin RNA (shRNA). A decreased rate of cell proliferation was observed in OCT4-inhibited hUCB-MSCs.

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Background Aims: Mesenchymal stromal cells (MSC) have been studied intensively in regenerative medicine. However, their therapeutic potential against tumor formation and cancer metastasis is still unclear. The effects of transplantation of MSCs in early-stage of carcinogenesis, should be evaluated.

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