• Toxicological Research
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• 제17권
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• pp.305-307
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• 2001

Toluene diisocyanate (TDI) is widely used in the manufacture of polyurethanes and is a recognized cause of occupational asthma. Although extensive investigations have been undertaken, the molecular mechanism(s) of the disease is still unclear. We hypothesized that inflammatory cytokines are required during both the sensitization and elicitation phases of the disease and have utilized TNF-R knock-out (KO) mice to address the hypothesis. Black C57 TNFR knock-out mice were exposed to TDI by sc injection and challenged by inhalation of 100 ppb TDI vapor. Control animals included: wild type C57 animals, sham-exposed animals that were challenged with TDI, and animals that were injected with anti-TNF antibodies prior to sensitization and again prior to challenge. Total IgE was increased in the knock-out animals compared with the wild type sensitized and challenged animals whereas TDI-specific IgG antibodies did not differ significantly in KO and wild type animals. There was less inflammation in the nares and trachea in KO animals compared with the wild type animals exposed to TD1 as well as less goblet cell hyperplasia and epithelial damage. Airway reactivity was assessed in animals treated with anti-TNF$\alpha$ antibody and found to be substantially reduced compared with that in sensitized and challenged animals. These results indicate that TNF$\alpha$ plays a role in the immunologic and physiologic responses and in airways inflammation in this animal model and suggests a role for TNF in occupational asthma due to TDI.

• Toxicological Research
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• 제31권4호
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• pp.347-354
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• 2015

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout ($Hfe^{-/-}$) and their control wild-type ($Hfe^{+/+}$) mice to $MnCl_2$ in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed $Hfe^{+/+}$ compared with water-drinking $Hfe^{+/+}$ mice. However, Mn-exposed $Hfe^{-/-}$ mice spent more time to find the target hole than Mn-drinking $Hfe^{+/+}$ mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.

• The Plant Pathology Journal
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• 제24권2호
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• pp.131-142
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• 2008

Magnaporthe oryzae, the causal agent of the rice blast disease, poses a worldwide threat to stable rice production. The large-scale functional characterization of genes controlling the pathogenicity of M. oryzae is currently under way, but little is known about heat shock protein 40 (Hsp40) function in the rice blast fungus or any other filamentous plant pathogen. We identified 25 genes encoding putative Hsp40s in the genome of M. oryzae using a bioinformatic approach, which we designated M. oryzae heat shock protein forty (MHF 1-25). To elucidate the roles of these genes, we characterized the functions of MHF16 and MHF21, which encode type ill and type n Hsp40 proteins, respectively. MHF16 and MHF21 expression was not significantly induced by heat shock, but it was down-regulated by cold shock. Knockout mutants of these genes $({\Delta}$mhf16 and ${\Delta}$mhf21) were viable, but conidiation was severely reduced. Moreover, sectoring was observed in the ${\Delta}mhf16$ mutant when it was grown on oatmeal agar medium. Conidial germination, appressorium formation, and pathogenicity in rice were not significantly affected in the mutants. The defects in conidiation and colony morphology were fully complemented by reintroduction of wild type MHF16 and MHF21 alleles, respectively. These data indicate that MHF16 and MHF21 play important roles in conidiation in the rice blast fungus.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1133-1140
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• 2012

Ribonucleic acid interference (RNAi) inhibits the expression of target genes in a sequence-specific manner, and shows potential for gene knockdown in filamentous fungi, in which the locus-specific gene knockout occurs in low frequency. In this study, the function of the repressor of cellulase expression I (ACEI) was verified in Trichoderma koningii (T. koningii) YC01 through RNAi, and ace1-silenced strains with improved cellulase productivity were obtained. An expression cassette that transcribed the interfering double-stranded RNA (dsRNA) of ace1 was constructed and transformed into T. koningii, and the transformants, in which the expression of ace1 was successfully silenced, were selected. As a result of the ace1 gene silencing, the expression levels of the main cellulase and xylanase genes were elevated, and the enhanced production of total proteins, cellulase, and xylanase was observed in the cultivation. In addition, the down-regulation of ace1 resulted in an increasing expression of xyr1, but no clear variation in the expression of cre1, which suggested that ACEI acted as a repressor of the xyr1 transcription, but was not involved in the regulation of the cre1 expression. The results of this work indicate that ace1 is a valid target gene for enhancing enzyme production in T. koningii, and RNAi is an appropriate tool for improving the properties of industrial fungi.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.207-212
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• 2012

The shortage of human organs for transplantation has induced the research on the possibility of using animal as porcine. However, pig to human transplantation as known as xeno-transplantation has major problem as immunorejection. Recently, the solutions of pig to human xenotransplantation are commonly mentioned as having a genetically modification which include alpha 1, 3 galatosyl transferase knockout (GTKO) and immune-suppressing gene transgenic model. Unfortunately, the expression level of transgenic gene is very low activity. Therefore, development of gene overexpression system is the most urgent issue. Also, the tissue specific overexpression system is very important. Because most blood vessels are endothelial cells, establishment of the endothelial-specific promoter is attractive candidates for the introduction of suppressing immunorejection. In this study, we focus the ICAM2 promoter which has endothelial-specific regulatory region. To detect the regulatory region of ICAM2 promoter, we cloned 3.7 kb size mini-pig ICAM2 promoter. We conduct serial deletion of 5' flanking region of mini-pig ICAM2 promoter then selected promoter size as 1 kb, 1.5 kb, 2 kb, 2.5 kb, and 3 kb. To analyze promoter activity, luciferase assay system was conducted among these vectors and compare endothelial activity with epithelial cells. The reporter gene assay revealed that ICAM2 promoter has critical activity in endothelial cells (CPAE) and 1 kb size of ICAM2 promoter activity was significantly increased. Taken together, our studies suggest that mini-pig ICMA2 promoter is endothelial cell specific overexpression promoter and among above all size of promoters, 1 kb size promoter is optimal candidate to overcome the vascular immunorejection in pig to human xenotransplantation.

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.265-271
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• 2009

Nitric oxide (NO) has both neuroprotective and neurotoxic effects depending on its concentration and the experimental model. We tested the effects of NG-nitro-L-arginine methyl ester (L-NAME), a nonselective nitric oxide synthase (NOS) inhibitor, and aminoguanidine, a selective inducible NOS (iNOS) inhibitor, on kainic acid (KA)-induced seizures and hippocampal CA3 neuronal death. L-NAME (50 mg/kg, i.p.) and/or aminoguanidine (200 mg/kg, i.p.) were administered 1 h prior to the intracerebroventricular (i.c.v.) injection of KA. Pretreatment with L-NAME significantly increased KA-induced CA3 neuronal death, iNOS expression, and activation of microglia. However, pretreatment with aminoguanidine significantly suppressed both the KA-induced and L-NAME-aggravated hippocampal CA3 neuronal death with concomitant decreases in iNOS expression and microglial activation. The protective effect of aminoguanidine was maintained for up to 2 weeks. Furthermore, iNOS knockout mice ($iNOS^{-1-}$) were resistant to KA-induced neuronal death. The present study demonstrates that aminoguanidine attenuates KA-induced neuronal death, whereas L-NAME aggravates neuronal death, in the CA3 region of the hippocampus, suggesting that NOS isoforms play different roles in KA-induced excitotoxicity.

• The Korean Journal of Pain
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• 제31권2호
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• pp.73-79
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• 2018

All drugs have both favorable therapeutic and untoward adverse effects. Conventional opioid analgesics possess both analgesia and adverse reactions, such as nausea, vomiting, and respiratory depression. The opioid ligand binds to ${\mu}$ opioid receptor and non-selectively activates two intracellular signaling pathways: the G protein pathway induce analgesia, while the ${\beta}$-arrestin pathway is responsible for the opioid-related adverse reactions. An ideal opioid should activate the G protein pathway while deactivating the ${\beta}$-arrestin pathway. Oliceridine (TRV130) has a novel characteristic mechanism on the action of the ${\mu}$ receptor G protein pathway selective (${\mu}$-GPS) modulation. Even though adverse reactions (ADRs) are significantly attenuated, while the analgesic effect is augmented, the some residual ADRs persist. Consequently, a G protein biased ${\mu}$ opioid ligand, oliceridine, improves the therapeutic index owing to increased analgesia with decreased adverse events. This review article provides a brief history, mechanism of action, pharmacokinetics, pharmacodynamics, and ADRs of oliceridine.

• The Korean Journal of Physiology and Pharmacology
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• 제14권3호
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• pp.157-161
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• 2010

Heat shock proteins (HSPs) are specifically induced by various forms of stress. Hsp70.1, a member of the hsp70 family is known to play an important role in cytoprotection from stressful insults. However, the functional role of Hsp70 in motor function after spinal cord injury (SCI) is still unclear. To study the role of hsp70.1 in motor recovery following SCI, we assessed locomotor function in hsp70.1 knockout (KO) mice and their wild-type (WT) mice via the Basso, Beattie and Bresnahan (BBB) locomotor rating scale, before and after spinal hemisection at T13 level. We also examined lesion size in the spinal cord using Luxol fast blue/cresyl violet staining. One day after injury, KO and WT mice showed no significant difference in the motor function due to complete paralysis following spinal hemisection. However, when it compared to WT mice, KO mice had significantly delayed and decreased functional outcomes from 4 days up to 21 days after SCI. KO mice also showed significantly greater lesion size in the spinal cord than WT mice showed at 21 days after spinal hemisection. These results suggest that Hsp70 has a protective effect against traumatic SCI and the manipulation of the hsp70.1 gene may help improve the recovery of motor function, thereby enhancing neuroprotection after SCI.

• The Korean Journal of Physiology and Pharmacology
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• 제13권3호
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• pp.153-159
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• 2009

We investigated whether deficiency of inducible nitric oxide synthase (iNOS) could prevent isoproterenol-induced cardiac hypertrophy in iNOS knockout (KO) mice. Isoproterenol was continuously infused subcutaneously (15 mg/kg/day) using an osmotic minipump. Isoproterenol reduced body weight and fat mass in both iNOS KO and wild-type mice compared with saline-infused wild-type mice. Isoproterenol increased the heart weight in both iNOS KO and wild-type mice but there was no difference between iNOS KO and wild-type mice. Posterior wall thickness of left ventricle showed the same tendency with heart weight. Protein level of iNOS in the left ventricle was increased in isoproterenol-infused wild-type mice. The gene expression of interleukin-6 (IL-6) and transforming growth factor-${\beta}$ (TGF-${\beta}$) in isoproterenol-infused wild-type was measured at 2, 4, 24, and 48-hour and isoproterenol increased both IL-6 (2, 4, 24, and 48-hour) and TGF-${\beta}$ (4 and 24-hour). Isoproterenol infusion for 7 days increased the mRNA level of IL-6 and TGF-${\beta}$ in iNOS KO mice, whereas the gene expression in wild-type mice was not increased. Phosphorylated form of extracellular signal-regulated kinases (pERK) was also increased by isoproterenol at 2 and 4-hour but was not increased at 7 days after infusion in wild-type mice. However, the increased pERK level in iNOS KO mice was maintained even at 7 days after isoproterenol infusion. These results suggest that deficiency of iNOS does not prevent isoproterenol-induced cardiac hypertrophy and may have potentially harmful effects on cardiac hypertrophy.

• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.353-360
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• 2017

Several human diseases have been associated with mitochondrial voltage-dependent anion channel-1 (VDAC1) due to its role in calcium ion transportation and apoptosis. Recent studies suggest that VDAC1 may interact with endothelium-dependent nitric oxide synthase (eNOS). Decreased VDAC1 expression may limit the physical interaction between VDAC1 and eNOS and thus impair nitric oxide production, leading to cardiovascular diseases, including pulmonary arterial hypertension (PAH). In this report, we conducted meta-analysis of genome-wide expression data to identify VDAC1 influenced genes implicated in PAH pathobiology. First, we identified the genes differentially expressed between wild-type and Vdac1 knockout mouse embryonic fibroblasts in hypoxic conditions. These genes were deemed to be influenced by VDAC1 deficiency. Gene ontology analysis indicates that the VDAC1 influenced genes are significantly associated with PAH pathobiology. Second, a molecular signature derived from the VDAC1 influenced genes was developed. We suggest that, VDAC1 has a protective role in PAH and the gene expression signature of VDAC1 influenced genes can be used to i) predict severity of pulmonary hypertension secondary to pulmonary diseases, ii) differentiate idiopathic pulmonary artery hypertension (IPAH) patients from controls, and iii) differentiate IPAH from connective tissue disease associated PAH.