• Journal of Animal Reproduction and Biotechnology
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• v.38 no.1
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• pp.2-9
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• 2023

Mammalian eyes have a limited ability to regenerate once neurons degenerate. This results in visual impairment that impacts the quality of life among adult populations as well as in young children leading to lifelong consequences. Various therapies are in development to restore vision, and these include gene therapy, stem cell therapy, in-vivo transdifferentiation, and transplantation of a patient's whole eye obtained from interspecies blastocyst complementation. This review discusses advances in the research as well as hurdles that need to be resolved to have a successful restoration of vision.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.426-439
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• 2021

It is already well known that castration improves marbling quality but exact timing of castration is still highly debated in beef cattle production industry. After castration, blood hormonal changes occur in steer and objective of this study was to investigate the effects of growth hormone (GH) levels on adipocyte differentiation in stromal vascular cells (SVCs) and transdifferentiation into adipocytes in C2C12 myoblasts. Total GH concentrations were measured via enzyme-linked immunosorbent assay (ELISA) in 24 male calves and 4 female calves. Cell proliferation, cellular triglyceride (TG) accumulation, and the cell's lipolytic capability were measured in C2C12 myoblasts and SVCs. Myogenic, adipogenic, and brown adipocyte-specific gene expression was measured via real-time polymerase chain reaction (PCR) using SYBR green. Serum GH levels were the highest in late-castrated calves. Treatment with 5 ng/mL GH resulted in greater TG accumulation as well as increased CCAAT-enhancer-binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ expression compared to that after treatment with 15 ng/mL GH. Treatment with 5 ng/mL GH also resulted in lower myogenin (myo)G and myoD expression compared to that after treatment with 15 ng/mL GH. The expression of bone morphogenetic protein (BMP) 7 after treatment with 5 ng/mL GH was higher than that after treatment with 15 ng/mL GH. But carcass characteristics data showed no significant difference between early and late castrated steers. Therefore, our results indicate that castration timing does not seem to be inevitable determinate of carcass qualities, particularly carcass weight and marbling score in Hanwoo beef cattle.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.249-255
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• 2015

Diabetes mellitus, the most common metabolic disorder, is divided into two types: type 1 and type 2. The essential treatment of type 1 diabetes, caused by immune-mediated destruction of ${\beta}-cells$, is transplantation of the pancreas; however, this treatment is limited by issues such as the lack of donors for islet transplantation and immune rejection. As an alternative approach, stem cell therapy has been used as a new tool. The present study revealed that bone marrowderived mesenchymal stromal cells (BM-MSCs) could be transdifferentiated into pancreatic cells by the insertion of a key gene for embryonic development of the pancreas, the pancreatic and duodenal homeobox factor 1 (PDX1). To avoid immune rejection associated with xenotransplantation and to develop a new cell-based treatment, BM-MSCs from ${\alpha}$-1,3-galactosyltransferase knockout (GalT KO) pigs were used as the source of the cells. Transfection of the EGFP-hPDX1 gene into GalT KO pig-derived BM-MSCs was performed by electroporation. Cells were evaluated for hPDX1 expression by immunofluorescence and RT-PCR. Transdifferentiation into pancreatic cells was confirmed by morphological transformation, immunofluorescence, and endogenous pPDX1 gene expression. At 3~4 weeks after transduction, cell morphology changed from spindle-like shape to round shape, similar to that observed in cuboidal epithelium expressing EGFP. Results of RT-PCR confirmed the expression of both exogenous hPDX1 and endogenous pPDX1. Therefore, GalT KO pig-derived BM-MSCs transdifferentiated into pancreatic cells by transfection of hPDX1. The present results are indicative of the therapeutic potential of PDX1-expressing GalT KO pig-derived BM-MSCs in ${\beta}-cell$ replacement. This potential needs to be explored further by using in vivo studies to confirm these findings.

• Biomedical Science Letters
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• v.8 no.3
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• pp.127-135
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• 2002

Anterior subcapsular cataract was developed by opacification with transdifferentiation and abnormal proliferation of lens epithelial cells (LECs) and pathological accumulation of extracellular matrix (ECM). After-cataract also be caused by a similar transdifferentiation of LECs remaining after surgery and the accompanying increase of ECM deposits. It is blown that prostaglandin E2 and cytokine, such as TGF-$\beta$, bFGF, and IL-1, were associated with abnormal proliferation and transdifferentiation of LECs. The aim of this study was to detect the expression of transforming growth factor-$\alpha$ (TGF-$\alpha$), transforming growth factor-$\beta_1$(TGF-$\beta_1$) and basic fibroblast growth factor (bFGF) in LECs of senile and diabetic cataract. The expressions of these growth factors in lens epithelial cells were determined. The sample for growth factor determination were collected in senile cataract patients without metabolic disorder, especially diabetes mellitus and diabetic cataract patients. The mRNA expression of growth factors was detected by semi-quantitative reverse transcription - polymerase chain reaction (RT-PCR) followed by Southern blot analysis. Statistics were analysed using Wilcoxon rank sum test. Semi-quantitative RT-PCR/southern analysis of RNA obtained from thirty surgical specimens demonstrated that the level of mRNA expression of TGF-$\alpha$, -$\beta_1$ and bFGF was increased in diabetic cataract lens tissues compared with senile cataract specimens but non-significant, bFGF and TGF-$\beta_1$ mRNA expression were detected in most patients, expression level of TGF-$\beta_1$ was most high on the basis of normal ocular concentration. Detection rate of TGF-$\alpha$ in diabetic cataract was 1.5 fold higher than in senile cataract (P=0.098). TGF-$\alpha$, TGF-$\beta_1$, and bFGF mRNA expression of LECs were detected in senile and diabetic cataract. In both patient groups, expression level of TGF-$\beta_1$, mRNA was high, so We suggest TGF-$\beta_1$ strong influence in development of senile cataract and of diabetic cataract also. TGF-$\alpha$ expression level was similar but more frequently detected in diabetic cataract than in senile cataract. In conclusion, TGF-$\alpha$ may be associated with early development of diabetic cataract.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.53-59
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• 2010

A specific deleted version of ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) lacking the signal receiver domain (1.152 amino acids)-coding sequence, referred to as $ARR1{\Delta}DDK$, was amplified using Arabidopsis thaliana cDNA prepared from adult leaves and transferred into the genome of Nicotiana tabacum cv. Samsun under the transcriptional control of a ${\beta}$-estradiol-inducible expression system. The ectopic expression of $ARR1{\Delta}DDK$ affected the morphology of transgenic seedlings and their segments in vitro. In the presence of an inducer, ${\beta}$-estradiol, ectopic expression of $ARR1{\Delta}DDK$ induced only the formation of soft, pseudo-bulbous tissue in the root tip region of intact seedlings, which appeared similar to callus generated on a hypocotyl segment in the presence of 2,4-D and 6-benzyladenine (BA), both at $1\;{\mu}M$. Those callus tissues on the root tip region could not generate shoots unless $1\;{\mu}M$ BA was supplied. In segment culture, ectopic expression of $ARR1{\Delta}DDK$ induced calluslike tissue around the cut-end of cotyledon and hypocotyl segments with occasional shoot formation, suggesting that the expression of $ARR1{\Delta}DDK$ could substitute for the effects of cytokinin on these segments. Additionally, treatment with only ${\beta}$-estradiol induced NtWUS, a WUS ortholog in tobacco, which was detected during the process of callus tissue formation in the root tip region and also in cotyledon or hypocotyl segments. These findings suggest that the NtWUS might be associated in the transdifferentiation process caused by the functional regulation of $ARR1{\Delta}DDK$ in transgenic tobacco seedlings.

• Journal of Korean Neurosurgical Society
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• v.42 no.2
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• pp.118-124
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• 2007

Objective : Adipose tissue is derived from the embryonic mesoderm and contains a heterogenous stromal cell population. Authors have tried to verify the characteristics of stem cell of adipose derived stromal cells (ADSCs) and to investigate immunohistochemical findings after transplantation of ADSC into rat brain to evaluate survival, migration and differentiation of transplanted stromal cells. Methods : First ADSCs were isolated from human adipose tissue and induced adipose, osseous and neuronal differentiation under appropriate culture condition in vitro and examined phenotypes profile of human ADSCs in undifferentiated states using flow cytometry and immunohistochemical study. Human ADSCs were transplanted into the healthy rat brain to investigate survival, migration and differentiation after 4 weeks. Results : From human adipose tissue, adipose stem cells were harvested and subcultured for several times. The cultured ADSCs were differentiated into adipocytes, osteoctye and neuron-like cell under conditioned media. Flow cytometric analysis of undifferentiated ADSCs revealed that ADSCs were positive for CD29, CD44 and negative for CD34, CD45, CD117 and HLA-DR. Transplanted human ADSCs were found mainly in cortex adjacent to injection site and migrated from injection site at a distance of at least 1 mm along the cortex and corpus callosum. A few transplanted cells have differentiated into neuron and astrocyte. Conclusion : ADSCs were differentiated into multilineage cell lines through transdifferentiation. ADSCs were survived and migrated in xenograft without immunosuppression. Based on this data, ADSCs may be potential source of stem cells for many human disease including neurologic disorder.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5063-5067
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• 2012

New molecular markers of cancer had emerged with novel applications in cancer prevention and therapeutics, including for breast cancer of unknown causes, which has a high impact on the health of women worldwide. The purpose of this research was to detemine protein and mRNA expression of synaptic vesicle 2 (SV2) isoforms A, B and C in breast cancer cell lines. Cultured cell lines MDA-MB-231, SKBR3, T47D were lysed and their protein and mRNA expression analyzed by real-time PCR and western blot technique, respectively. SV2A, B proteins were identified in non-tumor (MCF-10A) and tumor cell lines (MDA-MB-231 and T47D) while SV2C only was found in the T47D cell line. Furthermore, the genomic expression was consistent with protein expression for a such cell line, but in MDA-MB-231 there was no SV2B genomic expression, and the SV2C mRNA and protein were not found in the non tumoral cell line. These findings suggest a possible cellular transdifferentiation to neural character in breast cancer, of possible relevance to cancer development, and point to possible use of SV2 as molecular marker and a vehicle for cancer treatment with botulinum toxin.

• Toxicological Research
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• v.26 no.1
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• pp.15-19
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• 2010

Mesenchymal stem cells (MSCs) have greater potential for immediate clinical and toxicological applications, due to their ability to self-renew, proliferate, and differentiate into a variety of cell types. To identify novel candidate genes that were specifically expressed during transdifferentiation of human MSCs to neuronal cells, we performed a differential expression analysis with random priming approach using annealing control primer-based differential display reverse transcription-polymerase chain reaction approach. We identified genes for acyl-CoA thioesterase, tissue inhibitor of metalloproteinases-1, brain glycogen phosphorylase, ubiquitin C-terminal hydrolase and aldehyde reductase were up-regualted, whereas genes for transgelin and heparan sulfate proteoglycan were down-regulated in MSC-derived neurons. These differentially expressed genes may have potential role in regulation of neurogenesis. This study could be applied to environmental toxicology in the field of testing the toxicity of a chemical or a physical agent.

• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.264-275
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• 2023

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by tremors, bradykinesia, and rigidity. PD is caused by loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN) and therefore, replenishment of DA neurons via stem cell-based therapy is a potential treatment option. Astrocytes are the most abundant non-neuronal cells in the central nervous system and are promising candidates for reprogramming into neuronal cells because they share a common origin with neurons. The ability of neural progenitor cells (NPCs) to proliferate and differentiate may overcome the limitations of the reduced viability and function of transplanted cells after cell replacement therapy. Achaete-scute complex homolog-like 1 (Ascl1) is a well-known neuronal-specific factor that induces various cell types such as human and mouse astrocytes and fibroblasts to differentiate into neurons. Nurr1 is involved in the differentiation and maintenance of DA neurons, and decreased Nurr1 expression is known to be a major risk factor for PD. Previous studies have shown that direct conversion of astrocytes into DA neurons and NPCs can be induced by overexpression of Ascl1 and Nurr1 and additional transcription factors genes such as superoxide dismutase 1 and SRY-box 2. Here, we demonstrate that astrocytes isolated from the ventral midbrain, the origin of SN DA neurons, can be effectively converted into DA neurons and NPCs with enhanced viability. In addition, when these NPCs are inducted to differentiate, they exhibit key characteristics of DA neurons. Thus, direct conversion of midbrain astrocytes is a possible cell therapy strategy to treat neurodegenerative diseases.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.71-71
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• 2003

Human umbilical cord blood cells(HUCBC) are rich in mesenchymal progenitor cells, endothelial cell precursors and hematopoietic cells. HUCBC have been used as a source of transplantable stem and progenitor cells. However, little is known about survival and development of HUCBC transplantation in the CNS. Estrogen has a neuroprotective potential against oxidative stress-induced cell death so has an effect on reducing infarct size of ischemic brain. We investigated the potential use of HUCBC as donor cells and tested whether estrogen mediates intravenously infused HUCBC enter and survive in ischemic brain. PKH26 labeled mononuclear fraction of HUCBC were injected into the tail vein of ischemic OVX rat brain with or without $17\beta$-estradiol valerate(EV). Under fluorescence microscopy, labeled cells were observed in the brain section. Significantly more cells were found in the ischemic brain than in the non-ischemic brain. HUCBC transplanted into ischemic brain could migrate and survive. Some of cells have shown neuronal like cells in hippocampus, striatum and cortex tissues. These result suggest that estrogen reduces ischemic damage and increases the migration of human umbilical cord blood cells. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) though the Biohealth Products Research Center(BPRC), Inje University, Korea.