• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1837-1841
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• 2003

In an attempt to isolate novel molecules that may play a regulatory role in adipocyte differentiation, we devised an experimental strategy to identify adipose tissue-specific genes by modifying cDNA microarray technique. We used genefilter membranes containing approximately 15,000 rat non-redundant EST clones of which 4,000 EST were representative clones of known genes and 11,000 ESTs were uncharacterized clones. A series of hybridization of genefilter membranes with cDNA probes prepared from various rat tissues and nucleic acids sequence analysis allowed us to identify two adipose-tissue specific genes, adipocyte-specific secretory factor (ADSF) and H-rev107. Verification of tissue-specific expression patterns of these two genes by Northern blot analysis showed that ADSF mRNA is exclusive expressed in adipose tissue and the H-rev107 mRNA is predominantly expressed in adipose tissue. Further analysis of gene expression of ADSF and H-rev107 during 3T3-L1 adipocyte differentiation revealed that the ADSF and H-rev107 gene expression patterns are closely associated with the adipocyte differentiation program, indicating their possible role in the regulation of adipose tissue development. Overall, we demonstrated an application of modified cDNA microarray technique in molecular cloning, resulting in identification of two novel adipose tissue-specific genes. This technique will also be used as a useful tool in identifying novel genes expressed in a tissue-specific manner.

• Toxicological Research
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• 제29권4호
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• pp.221-227
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• 2013

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.

• 한국환경성돌연변이발암원학회지
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• 제15권2호
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• pp.88-93
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• 1995

Effects of hyperthermia on the induction of DNA single strand breaks and replication inhibition were studied in bleomycin-treated CHO-K$_1$ cells by alkaline elution and alkaline sucrose gradient sedimentation. Bleomycin-induced DNA single strand breaks of DNA were dose-and time-dependently increased, and these strand breaks of DNA were gradually rejoined as post-incubation time passed. Treatment with hyperthermia alone did not affect the induction of DNA single strand breaks. However, pre-exposure of cells to hyperthermia followed by bleomycin treatment greatly increased the single strand breaks, and also reduced the rejoining processes of bleomycin-induced DNA single strand breaks. Bleomycin selectively inhibited the replicon initiation. The combined treatment with hyperthermia and bleomycin markedly potentiated the nonspecific inhibition of replication.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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• pp.117-132
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• 1987

Plants are inherited spatial and temporal coordination systems in their growth and differentiation processes which are precisely governed by the two interlocked control systems; autogenous and environmental. Looking into the overall course of plant development from molecular to organismal level, it can be comparable to a concerto for plant hormones, environmental stimuli and plant genomic orchestra conducted by an unidentified virtuoso. Some of the recent significant attempts to puzzle out the mystery of the life processes of plant development are briefly reviewed. The revolutionary advances in understanding the mystic processes are contemporarily achieved by the application of various molecular techniques. The characterization of plant genomes is now attained through recombinant DNA approaches, and the sensitive detection of specific gene products during the plant development is perimitted by the immunochemical procedures. However, along with the recognition of underlying molecular events such as developmental changes in gene expression and hormone-receptor interrelation associated with tissue sensitivity to hormones, more emphasis should be placed upon the physiological approaches of organismal level for the understanding the correlative systems of the developmental processes of plants as intact eukaryotic organisms.

• The Korean Journal of Physiology and Pharmacology
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• 제70권3호
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• pp.435-442
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• 2019

Endocrine-disrupting chemicals (EDCs) have structures similar to steroid hormones and can interfere with hormone synthesis and normal physiological functions of reproductive organs. For example, sex steroid hormones influence calcium signaling of the cardiac muscle in early embryo development. To confirm the effect of progesterone (P4), octyl-phenol (OP), and bisphenolA(BPA) on early differentiation of mouse embryonic stem cells(mESCs) into cardiomyocytes, mESCs were treated with P4, OP, and BPA two days after attachment and media were replaced every two days. In addition, cells were treated with mifepristone (RU486), a synthetic steroid that has an affinity for progesterone receptor (Pgr), for one day starting on day 11. Beating ratio was decreased with P4, OP, and BPA treatment. The Pgr mRNA level was significantly increased in the P4-, OP- and BPA-treated groups. However, the mRNA level of the calcium channel gene (Trpv2), contraction-related genes (Ryr2, Cam2, and Mylk3) and cardiac development and morphogenesis genes (Rbp4, Ly6e, and Gata4) were significantly decreased in the P4-, OP-, and BPA-treated groups. Interestingly, treatment with RU486 rescued the altered calcium channel gene, contraction-related genes, and cardiac development and morphogenesis genes. P4, OP, and BPA treatments reduced the intracellular calcium level. Taken together, these results indicate that EDCs (OP and BPA) has a structure similar to that of endogenous steroid hormones such as progesterone and estrogen, and OP and BPA act like progesterone to inhibit and disrupt cardiomyocyte differentiation of mESCs.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.306-312
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• 2020

Despite the importance of brown adipocytes as a therapeutic target for the prevention and treatment of obesity, the molecular mechanism underlying brown adipocyte differentiation is not fully understood. In particular, the role of post-translational modifications in brown adipocyte differentiation has not been extensively studied. Histidine phosphorylation is increasingly recognized an important process for protein post-translational modifications. In this study, we show that histidine phosphorylation patterns change during brown adipocyte differentiation. In addition, the expression level of protein histidine phosphatase 1 (PHPT1), a major mammalian phosphohistidine phosphatase, is reduced rapidly at the early phase of differentiation and recovers at the later phase. During white adipocyte differentiation of 3T3-L1 preadipocytes, however, the expression level of PHPT1 do not significantly change. Knockdown of PHPT1 promotes brown adipocyte differentiation, whereas ectopic expression of PHPT1 suppresses brown adipocyte differentiation. These results collectively suggest that histidine phosphorylation is closely linked to brown adipocyte differentiation and could be a therapeutic target for obesity and related metabolic diseases.

• Genomics & Informatics
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• 제5권1호
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• pp.1-5
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• 2007

Embryonic stem cells can be differentiated into various types of cells, requiring a tight regulation of transcription. Biomarkers related to each lineage of cells are used to guide the differentiation into neural or any other fates. In previous experiments, we reported the guided differentiation (GD)-specific genes by comparing profiles of random differentiation (RD). Interestingly 68% of differentially expressed genes in GD overlap with that of RD, which makes it difficult for us to separate the lineages by examining several markers. In this paper, we design a prediction model to identify the differentiation into neural fates from any other lineage. From the profiles of 11,376 genes, 203 differentially expressed genes between neural and random differentiation were selected by random variance T-test with 95% confidence and 5% false discovery rate. Based on support vector machine algorithm, we could select 79 marker genes from the 203 informative genes to construct the optimal prediction model. Here we propose a prediction model for the prediction of neural fates from random differentiation which is constructed with a perfect accuracy.

• International Journal of Oral Biology
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• 제43권2호
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• pp.77-82
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• 2018

The mesenchymal stem cells (MSCs) that reside in dental tissues hold a great potential for future applications in regenerative dentistry. In this study, we used human dental pulp cells, isolated from the molars (DPCs), in order to establish the organoid culture. DPCs were established after growing pulp cells in an MSC expansion media (MSC-EM). DPCs were subjected to organoid growth media (OGM) in comparison with human dental pulp stem cells (DPSCs). Inside the extracellular matrix in the OGM, the DPCs and DPSCs readily formed vessel-like structures, which were not observed in the MSC-EM. Immunocytochemistry analysis and flow cytometry analysis showed the elevated expression of CD31 in the DPCs and DPSCs cultured in the OGM. These results suggest endothelial cell-prone differentiation of the DPCs and DPSCs in organoid culture condition.

• Molecules and Cells
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• 제40권12호
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• pp.976-985
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• 2017

Iron is an essential divalent ion for aerobic life. Life has evolved to maintain iron homeostasis for normal cellular and physiological functions and therefore imbalances in iron levels exert a wide range of consequences. Responses to iron dysregulation in blood development, however, remain elusive. Here, we found that iron homeostasis is critical for differentiation of Drosophila blood cells in the larval hematopoietic organ, called the lymph gland. Supplementation of an iron chelator, bathophenanthroline disulfate (BPS) results in an excessive differentiation of the crystal cell in the lymph gland. This phenotype is recapitulated by loss of Fer1HCH in the intestine, indicating that reduced levels of systemic iron enhances crystal cell differentiation. Detailed analysis of Fer1HCH-tagged-GFP revealed that Fer1HCH is also expressed in the hematopoietic systems. Lastly, blocking Fer1HCH expression in the mature blood cells showed marked increase in the blood differentiation of both crystal cells and plasmatocytes. Thus, our work suggests a relevance of systemic and local iron homeostasis in blood differentiation, prompting further investigation of molecular mechanisms underlying iron regulation and cell fate determination in the hematopoietic system.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.885-894
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• 2000

Deer antler has been widely prescribed in Chinese and Korean pharmacology. Although there have been several reports concerning the effects of deer antler, such as anti-aging action, anti-inflammatory activity, antifungal action and regulatory activity of the level of glucose, the effect on bone has not determined yet. The purpose of this study was to examine the effect of deer antler on osteoblast differentiation. Hexane extract(CN-H) and chloroform extract(CN-C) were acquired from deer antler(Cervus nippon) and MC3T3-E1 pre-osteoblasts were cultured in the presence or absence of each extract. Osteoblast differentiation was estimated with the formation of mineralized nodules and the mRNA expression of alkaline phosphatase(ALP), osteocalcin(OC) and bone sialoprotein(BSP) which are markers of osteoblast differentiation. Non-treated group did not show mineralized nodule. CN-C or CN-H-treated group showed minerlaized nodules in 16 days. In northern blot analysis, CN-C or CN-H-treated group showed the elevated expression of ALP, BSP and OC in 16 days. These results suggest the possibility to develop deer antler as a bone regenerative agent in periodontal therapy by showing the stimulating activity of deer antler on differentiation of osteoblast.