• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.379-387
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• 2009

We have previously reported that N-ethylmaleimide (NEM) induces apoptosis through activation of $K^+$, $Cl^-$-cotransport (KCC) in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of phospholipase $A_2$ ($PLA_2$)-arachidonic acid (AA) signals in the mechanism of the NEM-induced apoptosis. In these experiments we used arachidonyl trifluoromethylketone ($AACOCF_3$), bromoenol lactone (BEL) and p-bromophenacyl bromide (BPB) as inhibitors of the calcium-dependent cytosolic $PLA_2$ ($cPLA_2$), the calcium-independent $PLA_2$ ($iPLA_2$) and the secretory $PLA_2$ ($sPLA_2$), respectively. BEL significantly inhibited the NEM-induced apoptosis, whereas $AACOCF_3$ and BPB did not. NEM increased AA liberation in a dose-dependent manner, which was markedly prevented only by BEL. In addition AA by itself induced $K^+$ efflux, a hallmark of KCC activation, which was comparable to that of NEM. The NEM-induced apoptosis was not significantly altered by treatment with indomethacin (Indo) and nordihydroguaiaretic acid (NDGA), selective inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX), respectively. Treatment with AA or 5,8,11,14-eicosatetraynoic acid (ETYA), a non-metabolizable analogue of AA, significantly induced apoptosis. Collectively, these results suggest that AA liberated through activation of $iPLA_2$ may mediate the NEMinduced apoptosis in HepG2 cells.

• Applied Microscopy
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• v.25 no.2
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• pp.20-28
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• 1995

This study observes the change of small intestine mucosa paneth cell by changing the amount of radiation to rat. It uses the rat(Wistar) of 250-300g as the experimental animal and irradiation equipment is Gammacell 3000Elan System. and the irradiation is conducted for 500Rad group for 34sec., 1000rad for 68sec., and 1500Rad for 102sec. once on the whole body of each group, eachgroup is anesthetized with ether after 24hours. its small intestine is extrated and then it is observed by transmission electronic microscopy. The experimental results are as follows : 1. 500 Rad Group The Slightly elongated form of mitochondria and rough endoplasmic reticulum are observed in 500 Rad group. 2. 1000 Rad Group Golgi apparatus is appeared as the extended plasmodium, secretory granules exist only external membrane due to the self-fusion, the number of mitochondria that are changed as L-type are reduced, rough endoplasmic reticulum is distributed with the expanded form. 3. 1500 Rad Group The number of Golgi apparatus and granules is remarkably reduced, mitochondria is changed into C-type and free ribosomes can be observed instead of the reduction of rough endoplasmic reticulum.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.5
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• pp.289-293
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• 2004

To investigate whether VacA (vacuolating toxin) produced by Helicobacter pylori Korean stain 99 induces intestinal secretion, purified VacA was added to T84 cell monolayers mounted in Ussing chambers, and electrical parameters were monitored. Mucosal addition of low pH-pretreated VacA increased short circuit current (Isc). The effect was time- and dose-dependent and saturable. The time-to-peak Isc was concentration-dependent. Chloride channel inhibitors, niflumic acid or 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB), inhibited VacA-stimulated Isc. Carbachol (CCh)-induced increase of Isc was prolonged by the addition of VacA to the mucosal side only. The effect was unaltered by the addition of niflumic acid. VacA did not show cytopathic effects. These studies indicate that VacA is a nonlethal toxin that acts in a polar manner on T84 monolayers to potentiate $Cl^-$ secretion and the response to CCh secretion without decrease in monolayer resistance. VacA may contribute to diarrhea diseases in human intestinal epithelial cells.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.70-70
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• 2003

The uterus undergoes dynamic changes during the cycle and displays many features typical of developmental process. In order to be prepared for implantation, endometrium undergoes predictable, sequential phases of proliferation and secretory changes. The uterus during estrus cycle synthesize a complex of signaling molecules with specific spatial and temporal modes of expression and which are critical for cell proliferation and differentiation. The purpose of this investigation was to use cDNA microarrays to evaluate the expression of genes of rat uterus in estrus cycle. Animals were sacrificed on proestrus, estrus, metestrus, diestrus. Differential gene expression profiles were revealed(growth-related c-myc reponsive protein RCL, heat shock 47-kDa protein (HSP47), cytochrome c oxidase polypeptide Vlc2 (COX6C2), calreticulin (CALR)). Reverse transcription polymerase chain reaction (RT-PCR) was used to validate the relative expression pattern. Using this approach, we found several genes whose expression in rat uterus was altered with estrus cycle. Our long-term goal is to determine the role of these differentially expressed genes during estrus cycle. This study was supported by through the Biohealth Products Research Center(BPRC), Inje University.

• Parasites, Hosts and Diseases
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• v.40 no.3
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• pp.113-117
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• 2002

We investigated the sero-prevalence of toxocariasis among healthy Korean adults in 1999. A total of 314 sera from normal inhabitants in Whachon-gun, Gangwon do, Korea was examined for specific antibody levels against excretory-secretory products of second stage larvae of Toxocara (TES). The presence of cross-reactions with other helminthiases such as cysticercosis, paragonimiasis, sparganosis or clonorchiasis was also checked by specific IgG ELISA. Sera showing positive reaction against TES were also tested by IgG immunoblot and by IgE ELISA. Out of 314 subjects, 16 was found to be positive by TES IgG ELISA and immunoblot, among whom 12 were also positive by TES IgE ELISA. Among the 16 seropositive samples, two sera showed positive reaction against Paragonimus and sparganum antigen, respectively. These results inferred that cross-reactions were negligible between toxocariasis and other helminthiases. Toxocariasis seroprevalence among Korean rural adults was detected to be approximately 5%.

• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.1-7
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• 2010

Neutrophils play an important role in the human immune system for protection against such microorganisms as a protozoan parasite, Trichomonas vaginalis; however, the precise role of neutrophils in the pathogenesis of trichomoniasis is still unknown. Moreover, it is thought that trichomonal lysates and excretory-secretory products (ESP), as well as live T. vaginalis, could possibly interact with neutrophils in local tissues, including areas of inflammation induced by T. vaginalis in humans. The aim of this study was to investigate the influence of T. vaginalis lysate on the fate of neutrophils. We found that T. vaginalis lysate inhibits apoptosis of human neutrophils as revealed by Giemsa stain. Less altered mitochondrial membrane potential (MMP) and surface CD16 receptor expression also supported the idea that neutrophil apoptosis is delayed after T. vaginalis lysate stimulation. In contrast, ESP stimulated-neutrophils were similar in apoptotic features of untreated neutrophils. Maintained caspase-3 and myeloid cell leukemia-1 (Mcl-1) in neutrophils co-cultured with trichomonad lysate suggest that an intrinsic mitochondrial pathway of apoptosis was involved in T. vaginalis lysate-induced delayed neutrophil apoptosis; this phenomenon may contribute to local inflammation in trichomoniasis.

• Korean Journal of Veterinary Research
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• v.19 no.2
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• pp.99-105
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• 1979

In order to know the histological changes of rat preputial gland during normal sexual cycle and sex hormone treatment, matured Wistar rats (B.W.about 200g) were used for the experiment. Rats were subcutaneously given $2{\mu}g$ 17-${\beta}$-estradiol (Sigma) and 2.5g progesterone (Nakarai Chem., Japan) daily in 0.5ml propylen glycol for ten days respectively. The results obtained are as follow: At the stage of estrus and metestrus, the eosinophilic crystalloid granules and large vacuoles in the acinar cells appeared numerously, and the excretory ducts were severely extended. The developed connective tissue between the acinus were also found. At the stage of proestrus and diestrus, however, the small vacuoles and a few eosinophilic crystalloid granules appeared in the acinar cell. In the estradiol treatment, on the other hand, severely extended excretory ducts and a small number of the eosinophilic crystalloid granules compared with the progesterone treatment were found. The cyst-like structure was found, and in that the acinus disappeared completely. In the progesterone treatment, remarkably extended excretory ducts and nomerous appearance of oval formed eosinophilic granules in the acinar cells were found. As these findings, it could be suggested that the secretion of rat preputial gland was active at the estrus and metestrus stage, and estrogen may concerned in the secretion, land progesterone in the formation of secretory products.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.591-597
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• 2003

Human urokinase kringle domain, sharing homology with angiostatin kringles, has been shown to be an inhibitor of angiogenesis, which can be used for the treatment of cancer, rheumatoid arthritis, psoriasis, and retinopathy. Here, the expression of the kringle domain of urokinase (UK1) as a secreted protein in high levels is reported. UK1 was expressed in the methylotrophic yeast Pichia pastoris GS115 by fusion of the cDNA spanning from Ser47 to Lys135 to the secretion signal sequence of ${\alpha}-factor$ prepro-peptide. In a flask culture, the secreted UK1 reached about 1 g/l level after 120h of methanol induction and was purified to homogeneity by ion-exchange chromatography. Amino-terminal sequencing of the purified UK1 revealed that it was cleaved at the Ste13 signal cleavage site. The molecular mass of UK1 was determined to be 10,297.01 Da. It was also confirmed that the purified UK1 inhibited endothelial cell proliferation stimulated by basic fibroblast growth factor, vascular endothelial growth factor, or epidermal growth factor, in a dose-dependent manner. These results suggest that a P. pastoris sytem can be employed to obtain large amounts of soluble and active UK1.

• Nutritional Sciences
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• v.7 no.1
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• pp.31-34
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• 2004

This paper reviews the effects of Spirulina platensis and its extracts and phycocyanin, a blue photosynthetic pigment protein in Spirulina on the mucosal immune functions in humans and animals as follows: TEX>$\bullet$ IgA antibody response and other classes in mucosal immunity of mice treated with Spirulina platensis and its extract. $\bullet$ Effect of Spirulina phycocyanin ingestion on the mucosal antibody responses in mice. - Distinct effects of phycocyanin on secretory IgA and allergic IgE antibody responses in mice following oral immunization with antigen-entrapped biodegradable microparticles. $\bullet$ Influence of dietary Spirulina platensis on IgA level in human saliva. $\bullet$ A study on enhancement of bone-marrow cell-proliferation and differentiation by Spirulina platensis in mice: in vivo and in vitro study

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.42-48
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• 1998

In order to maximize the secretory expression of human serum albumin (HSA) in the yeast Saccharomyces cerevisiae, a series of HSA expression vectors were constructed with a combination of different promoters, 5' untranslated regions (5'UTR), and secretion signal sequences. The expression vector composed of the galactose-inducible promoter GALl0, the natural 5'UTR, and the natural signal sequence of HSA directed the most efficient expression and secretion of HSA among the constructed vectors when introduced into several S. cerevisiae strains. Although the major form of HSA expressed and secreted in the yeast transformants was the mature form of 66 kDa, the truncated form of 45 kDa was also detected both in the cell extract and in the culture supernatant. The level of the intact HSA protein in the culture supernatant reached up to 30 mg/l at 24 h of cultivation in a shake-flask culture but began to decrease afterwards, indicating that the secreted HSA protein was unstable in a prolonged culture of yeast.