• The Korean Journal of Physiology and Pharmacology
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• v.18 no.6
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• pp.525-530
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• 2014

Transient receptor potential vanilloid subtype 1 (TRPV1) was originally found in sensory neurons. Recently, it has been reported that TRPV1 is expressed in salivary gland epithelial cells (SGEC). However, the physiological role of TRPV1 in salivary secretion remains to be elucidated. We found that TRPV1 is expressed in mouse and human submandibular glands (SMG) and HSG cells, originated from human submandibular gland ducts at both mRNA and protein levels. However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ($[Ca^{2+}]_i$) in these cells, although carbachol consistently increased $[Ca^{2+}]_i$. Exposure of cells to high temperature (> $43^{\circ}C$) or acidic bath solution (pH5.4) did not increase $[Ca^{2+}]_i$, either. We further examined the role of TRPV1 in salivary secretion using TRPV1 knock-out mice. There was no significant difference in the pilocarpine (PILO)-induced salivary flow rate between wild-type and TRPV1 knock-out mice. Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone. Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.148-156
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• 2019

The Transgenic livestock can be useful for the production of disease-resistant animals, pigs for xenotranplantation, animal bioreactor for therapeutic recombinant proteins and disease model animals. Previously, conventional methods without using artificial nuclease-dependent DNA cleavage system were used to produce such transgenic livestock, but their efficiency is known to be low. In the last decade, the development of artificial nucleases such as zinc-finger necleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regulatory interspaced short palindromic repeat (CRISPR)/Cas has led to more efficient production of knock-out and knock-in transgenic livestock. However, production of knock-in livestock is poor. In mouse, genetically modified mice are produced by coinjecting a pair of knock-in vector, which is a donor DNA, with a artificial nuclease in a pronuclear fertilized egg, but not in livestock. Gene targeting efficiency has been increased with the use of artificial nucleases, but the knock-in efficiency is still low in livestock. In many research now, somatic cell nuclear transfer (SCNT) methods used after selection of cell transfected with artificial nuclease for production of transgenic livestock. In particular, it is necessary to develop a system capable of producing transgenic livestock more efficiently by co-injection of artificial nuclease and knock-in vectors into fertilized eggs.

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.52-57
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• 2021

Fumonisin B1 (FB1) structurally resembles sphingolipids and interferes with their metabolism leading to sphingolipid dysregulation. We questioned if FB1 could exacerbate liver or kidney toxicities in glutathione peroxidase 1 (Gpx1) and catalase (Cat) knockout mice. While higher serum levels of thiobarbituric acid reactive substances (TBARS) and sphinganine (Sa) were measured in Gpx1/Cat knockout mice (Gpx1/Cat KO) than wild type mice after 5 days of FB1 treatment, serum levels of alanine aminotransferase (ALT), sphingosine-1 phosphate (So-1-P), and sphinganine-1 phosphate (Sa-1-P) were found to be relatively low. Although Sa was highly elevated in Gpx1/Cat KO mice and wild mice, lower levels of So and Sa were found in both the kidney and liver tissues of Gpx/Cat KO mice than wild type mice after FB1 treatment. Paradoxically, FB1-induced cellular apoptosis and necrosis were hastened under oxidative stress in Gpx1/Cat KO mice.

• Journal of Life Science
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• v.28 no.5
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• pp.597-604
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• 2018

Although the core mechanisms of Attention Deficit/Hyperactivity Disorder (ADHD) are unknown, several ADHD-associated proteins have been studied. G-protein - coupled receptor kinase interacting protein-1 (GIT1) is a multifunctional adapter protein that affects neuron growth and dendrite formation. GIT1-deficient mice have shown ADHD-like behavior and also recovered through amphetamine treatment. In this study, gliotransmitters were investigated in both intracellular and extracellular space from GIT1-deficient mice. To measure the amount of gliotransmitters, primary astrocyte cultures were taken from the cerebral and cerebellar cortices of wild (WT), hetero (HE), and knock-out (KO) mice. Major gliotransmitters were analyzed using high-performance liquid chromatography. It was observed that the amount of excitatory and inhibitory gliotransmitters were dependent on genotype and showed a change in excitation/inhibition ratios. Interestingly, the major excitatory gliotransmitter, glutamate, existed at the lowest level in WT mice, but the amount of inhibitory gliotransmitters, gamma-aminobutyric acid (GABA) and glycine, varied depending on brain region. Remarkably, an increased amount of GABA was measured at the intracellular cerebrum in WT mice compared with KO mice. It was presumed that KO mice would secrete more inhibitory gliotransmitters to compensate for GIT1 depletion or else acquire a defect to reuptake-secreted GABA. This may be a possible mechanism for ADHD pathology.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.605-616
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• 2006

A wide variety of drugs and endogenous bioactive amines are organic cations (OCs). Approximately 40% of all conventional drugs on the market are OCs. Thus, the transport of xenobiotics or endogenous OCs in the body has been a subject of considerable interest, since the discovery and cloning of a family of OC transporters, referred to as organic cation transporter (OCTs), and a new subfamily of OCTs, OCTNs, leading to the functional characterization of these transporters in various systems including oocytes and some cell lines. Organic cation transporters are critical in drug absorption, targeting, and disposition of a drug. In this review, the recent advances in the characterization of organic cation transporters and their distribution in the small intestine are discussed. The results of the in vitro transport studies of various OCs in the small intestine using techniques such as isolated brush-border membrane vesicles, Ussing chamber systems and Caco-2 cells are discussed, and in vivo knock-out animal studies are summarized. Such information is essential for predicting pharmacokinetics and pharmacodynamics and in the design and development of new cationic drugs. An understanding of the mechanisms that control the intestinal transport of OCs will clearly aid achieving desirable clinical outcomes.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.19-24
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• 2005

The low density lipoprotein receptor-related protein 5 (LRP5) highly expressed in many tissues, including hepatocytes and pancreatic beta cells, can bind to apolipoprotein E. To evaluate in vivo roles of LRP5, we generated LRP5-deficient mice. LRP5 genomic DNA was isolated from TT2 embryonic stem (ES) cells. Targeting vector was constructed to disrupt an exon 18 of the mouse LRP5 gene and transfected into ES cells. Three homologous recombinants at LRP5 locus were identified from 178 G418-resistant clones. Chimeric males generated by morula aggregation technique were mated to C57BL/6 female mice. After achieving germ-line transmission, LRP5+/- females were crossed with LRP5+/- males to obtain LRP5-deficient mice. One line of mice lacking LRP5 gene was confirmed by Southern blotting. Such knock-out mice may serve as an effective animal model to study in vivo function of LRP5 gene.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.145-153
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• 2018

The subgranular zone (SGZ) of hippocampal dentate gyrus (HDG) is a primary site of adult neurogenesis. Toll-like receptors (TLRs), are involved in neural system development of Drosophila and innate immune response of mammals. TLR2 is expressed abundantly in neurogenic niches such as adult mammalian hippocampus. It regulates adult hippocampal neurogenesis. However, the role of TLR2 in adult neurogenesis is not well studied in global or focal cerebral ischemia. Therefore, this study aimed to investigate the role of TLR2 in adult neurogenesis after photochemically induced cerebral ischemia. At 7 days after photothrombotic ischemic injury, the number of bromodeoxyuridine (BrdU)-positive cells was increased in both TLR2 knock-out (KO) mice and wild-type (WT) mice. However, the increment rate of BrdU-positive cells was lower in TLR2 KO mice compared to that in WT mice. The number of doublecortin (DCX) and neuronal nuclei (NeuN)-positive cells in HDG was decreased after photothrombotic ischemia in TLR2 KO mice compared to that in WT mice. The survival rate of cells in HDG was decreased in TLR2 KO mice compared to that in WT mice. In contrast, the number of cleaved-caspase 3 (apoptotic marker) and the number of GFAP (glia marker)/BrdU double-positive cells in TLR2 KO mice were higher than that in WT mice. These results suggest that TLR2 can promote adult neurogenesis from neural stem cell of hippocampal dentate gyrus through increasing proliferation, differentiation, and survival from neural stem cells after ischemic injury of the brain.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.59-59
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• 2001

Interleukin-10 (IL-10) is known as a regulator of inflammation and pathogenesis in mammalian organs, but its precise role is little known in the mammary gland. Our initial experiment showed that IL-10 expression levels in mice decreased at the lactation stage otherwise increased at the involution stage. To reveal the effects of IL-10 on the involution of mammary gland, expression profiles of the apoptosis-related genes were examined in transgenic mice expressing human IL-10 as well as in knock-out mice (IL-10-/-). Mild inflammatory legions by lymphocytes were observed in the mammary glands of transgenic lines at the lactation stage. The expression of TRAIL (Tumor necrosis factor-Related Apoptosis-Inducing Ligand) among the apoptosis-related genes was highly elevated in the transgenic mice while others were not significantly changed. Furthermore, TRAIL was down regulated by four fold in the IL-10-/- mice at the involution stage. The expression of DR4 was elevated at the involution stage of normal mice. DR4 was detected in the milk of transgenic mice but absent in that of normal mice. Our results proposed that the elevated IL-10 at the involution stage recruit lymphocytes and induce TRAIL and DR4 genes, therefore, lead to enter involution stage of mammary glands.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.265-270
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• 2004

Coronary heart disease (CHD) has been the number one killer in western society for a long time, and CHD in most instances is due to atherosclerosis. One of the earliest events in atherogenesis is the intracellular accumulation of lipids, particularly cholesterol esters, in the aortic intima. The lipids presumably came from the uptake of plasma lipoproteins, particularly from LDL. These foam cells were identified as being predominantly as macrophages. Currently, it is believed that oxidation of low density lipoprotein (LDL) might contribute to the generation of foam cells. An outcome of the oxidation hypothesis is that the consumption of antioxidants would be beneficial. In this study, Boldine, an alkaloid of Peumus boldus was tested for their antioxidant potency both in, in vitro oxidation system and in mouse models. Boldine decreased the ex-vivo oxidation of Low-density lipoprotein (LDL). In vivo studies were performed to study the effect of these compounds on the atherosclerotic lesion formation in LDL r-/- mice. Three groups of LDL r-/- mice (N=12 each) were fed an atherogenic diet. Group 1 was given vehicle and group 2 and 3 were given 1 and 5 mg of Boldine/day in addition to the atherogenic diet. The results indicated that there was a decrease in lesion formation reaching a 40% reduction due to Boldine compared to controls. The in vivo tolerance of Boldine in humans (has been used as an herbal medicine in other diseases) should make it an attractive alternative to vitamin E.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.3
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• pp.317-325
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• 2017

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in parallel with worldwide epidemic of obesity. Reactive oxygen species (ROS) contributes to the development and progression of NAFLD. Peroxisomes play an important role in fatty acid oxidation and ROS homeostasis, and catalase is an antioxidant exclusively expressed in peroxisome. The present study examined the role of endogenous catalase in early stage of NAFLD. 8-week-old male catalase knock-out (CKO) and age-matched C57BL/6J wild type (WT) mice were fed either a normal diet (ND: 18% of total calories from fat) or a high fat diet (HFD: 60% of total calories from fat) for 2 weeks. CKO mice gained body weight faster than WT mice at early period of HFD feeding. Plasma triglyceride and ALT, fasting plasma insulin, as well as liver lipid accumulation, inflammation (F4/80 staining), and oxidative stress (8-oxo-dG staining and nitrotyrosine level) were significantly increased in CKO but not in WT mice at 2 weeks of HFD feeding. While phosphorylation of Akt (Ser473) and $PGC1{\alpha}$ mRNA expression were decreased in both CKO and WT mice at HFD feeding, $GSK3{\beta}$ phosphorylation and Cox4-il mRNA expression in the liver were decreased only in CKO-HF mice. Taken together, the present data demonstrated that endogenous catalase exerted beneficial effects in protecting liver injury including lipid accumulation and inflammation through maintaining liver redox balance from the early stage of HFD-induced metabolic stress.