• Animal cells and systems
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• v.8 no.1
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• pp.65-70
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• 2004

Rbm is a male infertility gene located in the AZFb region of the Y chromosome. Expression pattern of Rbm indicates that Rbm is critical for early phase of male germ cell development. It shares strong structural homology with hnRNP G, suggesting a function as an RNA processing factor. In order to gain a clue on the molecular mechanisms of Rbm on male germ cell development, we examined interactions of Rbm with selected proteins in yeast. The results revealed specific interactions between Rbm, hnRNP K and Tra2${\alpha}$. These results suggest that hnRNP K and Tra2${\alpha}$ may be functional partners of Rbm in male germ cells. We propose a model in which hnRNP K may playa role as a platform for Rbm and Tra2${\alpha}$.

• 대한생식의학회:학술대회논문집
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• 2001.11a
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• pp.116.2-116.2
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• 2001

• Development and Reproduction
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• v.11 no.2
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• pp.85-96
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• 2007

Mesenchymal stem cells (MSC) are promising candidates for cell-based therapies. One major obstacle for their clinical use is the unsafety of fetal bovine serum (FBS), which is a crucial part of all media currently used for the culture of MSC. We investigated the effect of human cord serum (HCS) on the growth response, mRNA and protein expressions of human amnion-derived stem cells (HAM). HAM were isolated from the amnion after a Caesarean section and cultured in DMEM supplemented with 10% FBS, 5% HCS or 10% HCS. During culture, their biological characteristics at earlier and later passages were analyzed using RT-PCR and immunocytochemistry. Regardless of serum sources, HAM showed the prominent expression of Oct-4, Rex-1, SCF, FGF-5, BMP-4, nestin, GATA-4, NCAM and HLA ABC genes. The expression profile was observed even at later passages. Similarly, HAM cultured in either FBS or HCS exhibited the distinct protein expression of collagen I, II, III and XII, fibronectin, $\alpha$-smooth muscle actin, vimentin, CK18, CD54, FSP, TRA-1-60, SSEA-3, -4 and HLA ABC. However, desmin expression was only observed in HAM cultured in medium supplemented with FBS and vWF expression was only found in HAM cultured in medium supplemented with HCS. Overall pattern of gene and protein expression of HAM was typical of known adult stem cells such as bone marrow-derived MSC. In conclusion, HCS could be as effective as FBS for the culture of HAM.

• KSBB Journal
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• v.10 no.5
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• pp.589-597
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• 1995

Protein-bound polysaccahrides(PBP) were isolated, purified, and characterized from the sawdust media after harvesting the fruit body of Flammulina velutipes. The yield of the crude PBP(Fr.CA) extracted from the sawdust media, was 0.367% relative to the original sawdust media. The total sugar and protein contents of Fr.CA were 19.8% and 23.8% respectively. Using the membrane filtration, the fraction of which the molecular weight is over 300 kDa(Fr.A) was isolated from the Fr.CA and the yield was 44.6% relative to the Fr.CA. This result indicates that high molecular PBP is the dominant components of the Fr.CA. The Fr.A was separated into three fractions (Fr.A-1, Fr.A-2 and Fr.A-3) whose yields are 5.8%, 8.5% and 13.2% respectively. These fractions were further purified using gel filtration, obtaining a single peak in each fraction that considered as pure PBP Among them, the yield of Fr.A-1-${\alpha}$ was 20.9% relative to the Fr.A-1, and the molecular weight was 800 kDa. Monosaccharide components such as glucose, galactose, mannose, xylose and fucose could be detected all fractions by a HPLC analysis. Especially in the Fr.A-1-${\alpha}$ fraction, the content of glucose and galactose appeared to be high.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.23-34
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• 2009

Objectives: Mesenchymal stem cells (MSC) comprise a promising tool for cellular therapy. It is known that long-term in vitro culture of human bone marrow and adipose tissue derived-MSCs lead to a reduction of life span and a change of stem-like characters. The aim of our study was to examine whether stem cell properties of human umbilical cord-derived stem cells (HUC) could be affected by in vitro expansion. Methods: HUC were isolated from human umbilical cord and cultured for 10 passages in vitro. Morphology and population doubling time (PDT) were investigated, and changes of stem cell properties were examined using RT-PCR and immunocytochemistry during serial subcultures. Results: Morphology and PDT of HUC began to change slightly from the 7th passage (p7). Expression level of nestin and vimentin mRNAs increased along with the culture period from p4 until p10. In contrast, expression level of SCF mRNA decreased during the same culture period. Expression level of Oct-4 and HNF-4${\alpha}$ mRNAs was not significantly changed throughout the culture period until p10. Expression level of BMP-4, FGF-5, NCAM and HLA-ABC mRNAs appeared to increase as the culture continued, however, the difference was not significant. Immunocytochemical studies showed that HUC at p3, p6 and p9 positively were stained with antibodies against SSEA-3 and SSEA-4 proteins. Interestingly, staining intensity of HUC for ICAM-1 and HLA-ABC gradually increased throughout the culture period. Intensity against thy-1 and fibronectin antibodies increased at p9 while that against TRA-1-60 and VCAM-1 antibodies began to decrease at p6 until p9. Conclusions: These results suggest that HUC change some of their stem cell characteristics during in vitro culture. Development of culture system might be needed for the maintenance of characteristics.