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"Park, Y-K"
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TMPRSS4 promotes invasion, migration and metastasis of human tumor cells by facilitating an epithelial–mesenchymal transition
TMPRSS4 is a novel type II transmembrane serine protease found at the cell surface that is highly expressed in pancreatic, colon and gastric cancer tissues. However, the biological functions of TMPRSS4 in cancer are unknown. Here we show, using reverse transcription–PCR, that TMPRSS4 is highly elevated in lung cancer tissues compared with normal tissues and is also broadly expressed in a variety of human cancer cell lines. Knockdown of TMPRSS4 by small interfering RNA treatment in lung and colon cancer cell lines was associated with reduction of cell invasion and cell-matrix adhesion as well as modulation of cell proliferation. Conversely, the invasiveness, motility and adhesiveness of SW480 colon carcinoma cells were significantly enhanced by TMPRSS4 overexpression. Furthermore, overexpression of TMPRSS4 induced loss of E-cadherin-mediated cell–cell adhesion, concomitant with the induction of SIP1/ZEB2, an E-cadherin transcriptional repressor, and led to epithelial–mesenchymal transition events, including morphological changes, actin reorganization and upregulation of mesenchymal markers. TMPRSS4-overexpressing cells also displayed markedly increased metastasis to the liver in nude mice upon intrasplenic injection. Taken together, these studies suggest that TMPRSS4 controls the invasive and metastatic potential of human cancer cells by facilitating an epithelial–mesenchymal transition; TMPRSS4 may be a potential therapeutic target for cancer treatment.
Journal Article
Apigenin and tt-Farnesol with Fluoride Effects on S. mutans Biofilms and Dental Caries
by
BOWEN W. H.
,
KOO H.
,
SCHOBEL B.
in
Animals
,
Anti-Infective Agents, Local - administration & dosage
,
Anti-Infective Agents, Local - pharmacology
2005
Apigenin (Api) and tt-farnesol (Far) are two naturally occurring agents that affect the development of cariogenic biofilms. Fluoride (F) interferes physicochemically with caries development and also exhibits antibacterial activity. We examined whether the association of Api and Far enhance the anti-caries properties of F by acting cooperatively on the expression of virulence of Streptococcus mutans. The biological effects of each of the agents were greatly enhanced when used in combination with F. In general, biofilms treated with Api and/or Far in combination with F displayed less biomass and fewer insoluble glucans and iodophilic polysaccharides than did those treated with the test agents alone (P < 0.05). The combination of the test agents with F was highly effective in preventing caries development in rats, especially Api+Far+F, and results were comparable with those observed with chlorhexidine + F (positive control). Results from these studies showed that apigenin and tt-farnesol may enhance the cariostatic effectiveness of fluoride.
Journal Article
Abrogation of Disease Development in Plants Expressing Animal Antiapoptotic Genes
by
Clemente, T.
,
French, R.
,
Park, Y. K.
in
animal proteins
,
Apoptosis
,
Apoptosis Regulatory Proteins
2001
An emerging topic in plant biology is whether plants display analogous elements of mammalian programmed cell death during development and defense against pathogen attack. In many plant-pathogen interactions, plant cell death occurs in both susceptible and resistant host responses. For example, specific recognition responses in plants trigger formation of the hypersensitive response and activation of host defense mechanisms, resulting in restriction of pathogen growth and disease development. Several studies indicate that cell death during hypersensitive response involves activation of a plant-encoded pathway for cell death. Many susceptible interactions also result in host cell death, although it is not clear how or if the host participates in this response. We have generated transgenic tobacco plants to express animal genes that negatively regulate apoptosis. Plants expressing human Bcl-2 and Bcl-xl, nematode CED-9, or baculovirus Op-IAP transgenes conferred heritable resistance to several necrotrophic fungal pathogens, suggesting that disease development required host-cell death pathways. In addition, the transgenic tobacco plants displayed resistance to a necrogenic virus. Transgenic tobacco harboring Bcl-xl with a loss-of-function mutation did not protect against pathogen challenge. We also show that discrete DNA fragmentation (laddering) occurred in susceptible tobacco during fungal infection, but does not occur in transgenic-resistant plants. Our data indicate that in compatible plant-pathogen interactions apoptosis-like programmed cell death occurs. Further, these animal antiapoptotic genes function in plants and should be useful to delineate resistance pathways. These genes also have the potential to generate effective disease resistance in economically important crops.
Journal Article
Desmin Myopathy, a Skeletal Myopathy with Cardiomyopathy Caused by Mutations in the Desmin Gene
by
Dalakas, Marinos C
,
Lee, Hee Suk
,
Sivakumar, Kumaraswamy
in
Adult
,
Base Sequence
,
Biological and medical sciences
2000
Myofibrillar or desmin-related myopathies are a heterogeneous group of severe, dominantly inherited, skeletal myopathies, often accompanied by cardiomyopathy, that result in syncopal episodes or sudden death due to conduction defects.
1
–
5
They can be difficult to recognize because of the heterogeneity of the clinical characteristics among families and within families and the lack of diagnostic specificity of the findings on muscle biopsy. Various myofibrillar proteins, including desmin, dystrophin, vimentin, β-spectrin, and gelsolin, accumulate in the muscle fibers of affected patients,
1
–
3
but the role of these proteins in the degeneration of muscle fibers is unknown. Among these proteins, desmin, a . . .
Journal Article
Conversion of Isoflavone Glucosides to Aglycones by Partially Purified β-Glucosidases from Microbial and Vegetable Sources
by
Alencar, S. M
,
Park, Y. K
,
Fujita, A
in
Aspergillus niger
,
Aspergillus niger - enzymology
,
beta-glucosidase
2015
Isoflavone aglycones have been shown to be more rapidly and efficiently absorbed into intestines than isoflavone glucosides. Helpfully, β-glucosidases can be used to convert isoflavone glucosides to aglycones. In this study, β-glucosidases from microbial (Aspergillus niger) and vegetable lima bean (Phaseolus lunatus) sources were characterized, purified, and then employed to convert isoflavone glycosides to aglycones. The microbial crude extract showed maximum activity at 60 °C and pH 5.0. It was highly stable between 40 and 60 °C and between pH 4.0 and 9.0. Optimum activity for the vegetable crude extract was achieved also at 60 °C and pH 5.5. Similarly, it presented great stability at high temperatures and a wide pH range. The microbial enzyme was purified by a factor of 14-fold to a yield of 2.2 % and a specific activity of 17 IU/mg. The vegetable enzyme was purified by a factor of fourfold to a yield of 77 % and a specific activity of 0.18 IU/mg protein. Both β-glucosidases produced satisfactory conversion rates of daidzin and genistin into daidzein and genistein; however, the microbial enzyme performed better than the vegetable enzyme. Our results suggest a potential use of these enzymes to enhance the bioavailability of isoflavones in food products.
Journal Article
Arm balancing experiments in the deadweight torque standard machine with adjustable lever-arm lengths
2018
KRISS (Korea Research Institute of Standards and Science) has developed the 20 kN m-capacity deadweight torque standard machine that incorporates a double-arm design for the lever. Such a double-arm structure allows to separate two functions; supporting deadweight loads and determining effective lengths. One arm made of stainless steel supports the loads and the other made of INVAR determines the lever-arm length. Since the INVAR arm bears little loads, we could implement a translation mechanism in the INVAR torque arm to change its length in the range of approximately 6 mm. Using this unique feature of our machine, arm-balancing experiments have been conducted to investigate lever-arm length dependence on applied loads and determine the sensitivity of the air-bearing by intentionally unbalancing lengths on both sides to generate micro-torques under various loading conditions. In this paper, we present our plans of the experiments and discuss them.
Journal Article
Octanal-induced inflammatory responses in cells relevant for lung toxicity
by
Kim, Y-J
,
Choi, H-S
,
Park, Y-K
in
Air Pollutants - toxicity
,
Aldehydes - toxicity
,
Biological and medical sciences
2014
Inhalation is an important route of aldehyde exposure, and lung is one of the main targets of aldehyde toxicity. Octanal is distributed ubiquitously in the environment and is a component of indoor air pollutants. We investigated whether octanal exposure enhances the inflammatory response in the human respiratory system by increasing the expression and release of cytokines and chemokines. The effect of octanal in transcriptomic modulation was assessed in the human alveolar epithelial cell line A549 using oligonucleotide arrays. We identified a set of genes differentially expressed upon octanal exposure that may be useful for monitoring octanal pulmonary toxicity. These genes were classified according to the Gene Ontology functional category and Kyoto Encyclopedia of Genes and Genomes analysis to explore the biological processes related to octanal-induced pulmonary toxicity. The results show that octanal affects the expression of several chemokines and inflammatory cytokines and increases the levels of interleukin 6 (IL-6) and IL-8 released. In conclusion, octanal exposure modulates the expression of cytokines and chemokines important in the development of lung injury and disease. This suggests that inflammation contributes to octanal-induced lung damage and that the inflammatory genes expressed should be studied in detail, thereby laying the groundwork for future biomonitoring studies.
Journal Article
High removal of phosphate from wastewater using silica sulfate
2012
This report shows that silica sulfate is removing phosphate from wastewater very efficiently. Phosphorus removal and recovery from wastewater is a worldwide issue due to pollution of natural waters by phosphate and depletion of phosphate ores. Adsorption is a process that can remove phosphate at low concentrations. Adsorption also allows the recovery of phosphate for possible re-use. Here, we studied the adsorption of phosphate from wastewater using commercial Zr ferrite, Zr-MCM 41 and silica sulfate. We calculated equilibrium isotherms, kinetic models and thermodynamic effects under conditions similar to real wastewaters. We found that the equilibrium data for the adsorption of phosphate were best fitted to the Freundlich model. The results show that the maximum uptake of phosphate was 3.36 mg g
−1
for Zr-MCM, 27.73 mg g
−1
for Zr ferrite and 46.32 mg g
−1
for silica sulfate. The kinetic results of the three adsorbents were satisfactorily predicted using a pseudo-second-order model. We found that silica sulfate provided excellent characteristics in terms of the maximum adsorption and rate constant for the adsorption of phosphate. The thermodynamic data showed that increasing the temperature enhanced the adsorption of phosphate onto silica sulfate. Our findings will help to define efficient methods to remove phosphate from wastewater.
Journal Article
Electrophysiological study for comparing the effect of biological activity between type A botulinum toxins in rat gastrocnemius muscle
2013
Background:
New cosmetic applications and products based on the effects of botulinum toxin (BTX) treatment have stimulated demand for this class of natural compounds. This demand generates the need for appropriate standardized protocols to test and compare the effectiveness of new BTX preparations.
Objectives:
Based on the previously described electrophysiological methods, we measured and compared the inhibitory effects of two BTX type A (BTX-A) preparations on neuromuscular transmission through split-body test.
Methods:
The effectiveness was evaluated in terms of the compound muscle action potential (CMAP) and conduction velocity after BTX-A injection. We used a split-body method to compare two different BTX-As in the rat.
Results:
Based on the changes in the CMAP, the two different BTX-As induced paralytic effect on the rat tibialis anterior muscle. However, the two different BTX-A preparations did not differ significantly in effectiveness and did not induce a delay in conduction velocity.
Conclusions:
The new BTX-A preparation used in this electrophysiological study had similar effect compared with the previously marketed BTX-A.[AQ: Please approve the edits made to the sentence “The new BTX-A preparation…”) We propose that a split-body electrophysiological protocol will be useful in establishing the comparative effectiveness of new BTX products.
Journal Article
The Analysis of Milk Components and Pathogenic Bacteria Isolated from Bovine Raw Milk in Korea
2007
Bovine mastitis can be diagnosed by abnormalities in milk components and somatic cell count (SCC), as well as by clinical signs. We examined raw milk in Korea by analyzing SCC, milk urea nitrogen (MUN), and the percentages of milk components (milk fat, protein, and lactose). The associations between SCC or MUN and other milk components were investigated, as well as the relationships between the bacterial species isolated from milk. Somatic cell counts, MUN, and the percentages of milk fat, protein, and lactose were analyzed in 30,019 raw milk samples collected from 2003 to 2006. The regression coefficients of natural logarithmic-transformed SCC (SCCt) on milk fat (−0.0149), lactose (−0.8910), and MUN (−0.0096), and those of MUN on milk fat (−0.3125), protein (−0.8012), and SCCt (−0.0671) were negative, whereas the regression coefficient of SCCt on protein was positive (0.3023). When the data were categorized by the presence or absence of bacterial infection in raw milk, SCCt was negatively associated with milk fat (−0.0172), protein (−0.2693), and lactose (−0.4108). The SCCt values were significantly affected by bacterial species. In particular, 104 milk samples infected with Staphylococcus aureus had the highest SCCt (1.67) compared with milk containing other mastitis-causing bacteria: coagulase-negative staphylococci (n = 755, 1.50), coagulase-positive staphylococci (except Staphylococcus aureus; n = 77, 1.59), Streptococcus spp. (Streptococcus dysgalactiae, n = 37; Streptococcus uberis, n = 12, 0.83), Enterococcus spp. (n = 46, 1.04), Escherichia coli (n = 705, 1.56), Pseudomonas spp. (n = 456, 1.59), and yeast (n = 189, 1.52). These results show that high SCC and MUN negatively affect milk components and that a statistical approach associating SCC, MUN, and milk components by bacterial infection can explain the patterns among them. Bacterial species present in raw milk are an important influence on SCC in Korea.
Journal Article