• Journal of Life Science
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• v.13 no.5
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• pp.596-603
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• 2003

Cells respond to an accumulation of unfolded proteins in the endoplasmic reticulum (ER) by increasing transcription of genes encoding molecular chaperones and folding enzymes. The information is transmitted from the ER lumen to the nucleus by intracellular signaling pathway, called the unfolded protein response (UPR). To obtain genes related to UPR from B. mori, the cDNA library was constructed with mRNA isolated from Bm5 cell lines in which N-glycosylation was inhibited by tunicamycin treatment. From the cDNA library, we selected 40 clones that differentially expressed when cells were treated with tunicamycin. Among these clones, we have isolated ATFC gene showing similarity with Hac1p, encoding a bZIP transcription factor of 5. cerevisiae. Basic-leucine zipper (bZIP) domain in amino acid sequences of ATFC shared homology with yeast Hac1p. Also, ATFC is up-regulated by accumulation of unfolded proteins in the ER through the treatment of ER stress drugs. Therefore we suggest that ATFC represents a major component of the putative transcription factor responsible for the UPR leading to the induction of ER-localized stress proteins.

• Journal of fish pathology
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• v.18 no.1
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• pp.39-48
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• 2005

Pathogenicity of Vibrio tapetis, the causative bacterium of 'brown ring disease (BRD)' was evaluated in Manila clams (Ruditapes philippinarumi by artificially 0.1 $m\ell$ infection of $1.0\times10^5$cells and $1.0\times10^8$ cells at 20 $^{\circ}C$. A PCR assay based on 16S rRNA to detect the bacteria in clam tissues was established. Accumulative mortality of clams infected with $1.0\times10^7$cells and $1.0\times10^4$ cells per an individual of the bacteria was 67.5% and 7.5%, respectively. However, the deposit of brown pigment in the inner shells by accumulation of chonchiolin was not found. The bacteria were not be able to re-isolate from the infected clams by the conventional agar plate method but were easily detected by PCR assay established in this experiment. In clams artificially infected with 10 species of Vibrio, a 414bp for V. tapetis was detected in PCR assay. The specific band in the clams infected with $1.0\times10^4$cells per an individual of V. tapetis was detected only in gills one day after the infection but never be found in any tissues including gills three days after the infection. In the case of clams infected with $1.0\times10^8$cells per an individual of V. tapetis the specific band was detected in gills and intestine one day after the infection, in all tissues three days after the infection, and then in gills and adductor muscle nine days after the infection. The PCR assay was applied to detect V. tapetis in manila clam, surf clam (Mactra veneriformis), oyster (Crassostrea gigas) and Thomas' rapa whelk (Rapana venosa) taken from Taean and Gochang from April to July 2004. The infection rates were detected to 23.1% and 9.4% in the oyster and surf clam, while manila clam and Thomas' rapa whelk were not found.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.528-533
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• 2009

In the current study, the mesenchymal stem cells (MSCs) isolated and propagated from the human umbilical cord blood (UCB) were tested for their capabilities of differentiation into chondrocytes in vitro. The mesenchymal progenitor cells (MPCs) collected from UCB were cultured in a low glucose DMEM medium with 10% FBS, L-glutamine and antibiotics. The human MSC colonies were positively stained by PAS reaction. When the immunophenotypes of surface antigens on the MSCs were analyzed by fluorescence-activated cell sorter (FACS) analysis, these cells expressed positively MSC-related antigens of CD 29, CD44, CD 90 and CD105, whereas they did not express antigens of CD14, CD31, CD34, CD45, CD133 and HLA-DR. Following induction these MSCs into chondrocytes in the chondrogenic differentiation medium for 3 weeks or more, the cells were stained positively with safranin O. We clearly confirmed that human MSCs were successfully differentiated into chondrocytes by RT-PCR and immunofluorescent stain of type-II collagen protein. These data also indicate that the isolation, proliferation and differentiation of the hUCB-derived MSCs in vitro can be used for elucidating the mechanisms involved in chondrogenesis. Moreover this differentiation technique can be applied to developing cell-based tissue regeneration or repair damaged tissues.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.450-461
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• 2001

Background : The underlying pathogenesis of radiation-induced lung fibrosis (RTLF) has not been very well defined. However, the role of TGF-$\beta$ in the generation of RTLF has been a major focus because there is an increase in the expression of both the TGF-${\beta}m$-RNA and its protein preceding RTLF lesions. The down stream signal after a TGF-$\beta$ stimulated lung fibrosis includes the activation of many mediators such as Smad and c-Jun N-terminal kinase (JNK) through TAK1. It is we hypothesized that JNK activation may play a pivotal role in RTLF pathogenesis through increased transcription of the fibrogenic cytokines. The present study evaluates JNK activity in alveolar macrophages after irradiation and the relationship between JNK activity and the amount of collagen in the lung tissues. Methods : C57BL/6 mice(20-25 gr, males) received chlorotetracycline(2g/L) in their drinking water 1 week prior to irradiation and continuously there after. The mice were irradiated once with 1400 cGy of $60CO{\gamma}$-ray over the whole chest. The cellular composition of the whole lung bronchoalveoalr lavage fluids(BALF), elastin expression in the lung tissues, the level of hydroxyproline in lung tissues, and an in vitro JNK assay was measured before irradiation and one, four, and eight weeks after irradiation (RT). Results : The volumes of BALF retrieved from instilled 4 mL of saline with 2% heparin were 3.7-3.8 mL for each group. The cell numbers were similar before($4.1{\times}10^4{\pm}0.5{\times}10^4/mL$) and 1 week($3.1{\times}10^4{\pm}0.5{\times}10^4/mL$) after RT. At four and eight weeks after RT, the cell number reached to $14.0{\times}10^4{\pm}1.5{\times}10^4mL$ and $10.0{\times}10^4{\pm}1.3{\times}10^4/mL$, respectively. There we no changes in the lymphocytes and neutrophils population observed in the BALF after RT. The H-E stain of the lung tissues did not show any structural and fibrotic change in the lung tissues at 4 and 8 weeks after RT. In addition, the amount of elastin and collagen were not different on Verhoeff staining of the lung tissues before RT to eight weeks after RT. The hydroxyproine content was measured with the left lung dissected from the left main bronchus. The lung were homogenized and hydrolyzed with 6 N Hel for 12 hours at $110^{\circ}C$ then measured as previously described. The content of hydroxyproline, standardized with a lung protein concentration, reached a peak 4 weeks after RT, and thereafter showed a plateau. AnIn vitro JNK assay using c-$Jun_{1-79}$-GST sepharose beads were performed with the alveolar macrophages obtained from the BAL. JNK activity was not detected prior to RT, However, the JNK activity increased from one week after RT and reached a peak four weeks after RT. Conclusion : JNK may be involved in the pathogenesis because the JNK activity showed similar pattern observed with the hydroxyproine content. However, it is necessary to clarify that the JNK increases the transcription of fibrogenic cyiokines through the transcription factor.