• Journal of mucopolysaccharidosis and rare diseases
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• v.2 no.2
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• pp.43-45
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• 2016

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. Serotonin is among those traditional pharmacological targets for anti-obesity treatment because central 5-HT functions as an anorexigenic neurotransmitter in the brain. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Fat specific Tph1 knock-out (Tph1 FKO) mice exhibit similar phenotypes as mice with pharmacological inhibition of 5-HT synthesis, suggesting the localized effects of 5-HT in adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure in BAT and Htr2a KO mice exhibit the decreased lipid accumulation in WAT. These data suggest the clinical significance of the peripheral serotonergic system as a new therapeutic target for anti-obesity treatment.

• Journal of Life Science
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• v.20 no.4
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• pp.503-510
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• 2010

Most allergens have protease activities, suggesting that proteases may be a key link between Th2-type immune reactions in allergic responses. Protease activated receptor (PAR) 2 is activated via the proteolytic cleavage of its N-terminal domain by proteinases. To know the role of PAR2 in Aspergillus protease allergen activated Th2 immune responses in airway epithelial cells, we investigated and compared immune cell recruitment and level of chemokines and cytokines between PAR2 knock out (KO) mice and wild type (WT) mice. There were evident immune cell infiltrations into the bronchial alveolar lavage fluid (BALF) of WT mice, but the infiltrations in PAR2 KO mice were significantly lowered than those of WT mice. The IL-25, TSLP, and eotaxin gene expressions were profoundly increased after Aspergillus protease, but their expression was significantly lowered in PAR2 KO mice in this study. Compared to PAR2 KO mice, OVA specific IgE concentrations in serum of WT mice were quite increased; moreover, the IgE level of PAR2 KO mice was lower than in WT mice. The IL-25 expression by Aspergillus protease stimulation was significantly reduced by p38 specific inhibitor treatment. In this study, we determined that Th2 response was initiated with IL-25 and TSLP mRNA up-regulation in lung epithelial cells via PAR2 after Aspergillus protease allergen treatment.

• Journal of Life Science
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• v.20 no.4
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• pp.555-560
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• 2010

The objective of this study was to investigate levels of serum creatinine, CuSOD and MnSOD protein expression in the kidney after renal ischemic reperfusion with pre-exercise using heat shock protein 70.1 in knock-out mice (KO). The C57/BL6 strain (Wild type: WT) and KO were divided into 4 groups as follows: Sham control group (Sham), pre-exercise group (Ex), pre-exercise +ischemia group (Ex+IR), and ischemia group (IR). CuSOD and MnSOD expression were significantly decreased (p<0.01, p<0.05) and blood creatinine concentration was significantly increased (p<0.01) in the IR group of KO. In contrast, CuSOD and MnSOD expression in the Ex+IR group of KO were higher than the IR group, while creatinine concentration was significantly lower. These results suggest that Hsp70 is directly correlated to renal ischemic reperfusion injury. Pre-exercise in renal ischemia might prevent or inhibit positive oxidative stress inhibitory effects by increasing anti-oxidative enzymes (CuSOD, MnSOD) within the kidney and improve to prevent renal function. Thus, pre-exercise may have a protective role against renal injury after renal ischemia.

• BMB Reports
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• v.46 no.2
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• pp.103-106
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• 2013

Phosphoinositide 3-kinases (PI3Ks) play key roles in synaptic plasticity and cognitive functions in the brain. We recently found that genetic deletion of $PI3K{\gamma}$, the only known member of class IB PI3Ks, results in impaired N-methyl-D-aspartate receptor-dependent long-term depression (NMDAR-LTD) in the hippocampus. The activity of RalA, a small GTP-binding protein, increases following NMDAR-LTD inducing stimuli, and this increase in RalA activity is essential for inducing NMDAR-LTD. We found that RalA activity increased significantly in $PI3K{\gamma}$ knockout mice. Furthermore, NMDAR-LTD-inducing stimuli did not increase RalA activity in $PI3K{\gamma}$ knockout mice. These results suggest that constitutively increased RalA activity occludes further increases in RalA activity during induction of LTD, causing impaired NMDAR-LTD. We propose that $PI3K{\gamma}$ regulates the activity of RalA, which is one of the molecular mechanisms inducing NMDAR-dependent LTD.

• Animal cells and systems
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• v.16 no.4
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• pp.295-301
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• 2012

Interdigital tissue regression is one of the most well-known examples of embryonic programmed cell death, providing the mechanism behind separation of developing digits. Caspases have been shown to play a key part in this process, with activated caspase-3 localized between the developing digits. In caspase-3 knock-out adult mice, however, the digits are completely separated with no webbing. In other mutants with defects in the apoptotic machinery, such as Apaf1 deficient mice, interdigital tissue regression is initially inhibited but the webbing eventually disappears as alternative/additional cell death mechanisms step in. In order to investigate whether a similar temporal effect occurs after loss of caspase-3, we have used an in vitro approach to inhibit caspase-3 at specific times during digit separation. Previous limb explant culture approaches have encountered problems with proper limb development in culture, and thus a modified technique was used. The new approach enables detailed observation of the effects of caspase-3 inhibition on interdigital regression. Using these methods, we show that caspase-3 inhibition caused a delay in the loss of interdigital tissue compared with control explants, similar to that observed in Apaf1 mutant mice. Along with immunohistochemistry, active caspase-3 positive cells of the interdigital vs. digital regions were measured by flow cytometry. Notably, activated caspase-3 in vivo was found not only in the interdigital mesenchyme but also in the TUNEL negative digit region, supporting a role for caspase-3 in nonapoptotic events.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.248-253
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• 2007

This research investigated whether exposure of diesel exhaust particulate (DEP) and particulate matter (PM) effects on airway remodeling in asthma induced Balb/c and IL-10 knock out (KO) mouse. Mice were sensitized with intraperitoneal injection with ovalbumin, followed by challenges with intranasal ovalbumin. After that mice placed in inhalation chamber and exposed to DEP and $PM(10\;mg/m^3)$. The evidence of airway remodeling was assessed by masson's trichrome staining and PAS staining. The stainability of masson's trichrome and PAS reaction were increased in asthma-induced Baltic mice groups compared with control mice groups. More intensive stainability for masson's trichrome and PAS were appeared in the asthma-induced DEP and PM-exposed groups than asthama-induced groups. But, not significantly increased subepithelial fibrosis and the nember of goblet cell hyperplasia in asthma-induced IL-10 KO mice groups and asthma-induced+DEP and PM-exposed IL-10 KO mice than IL-10 KO mice groups. These results indirectly suggesting that exposure to DEP and PM in asthmatic patients might be aggravate clinical symptoms and IL-10 which seems to play a central role in allergic asthma. In conclusion, DEP and PM exposure might have additive effects on the ovalbumin- induced asthma in a murine model.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.3-4
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• 2000

The synthesis of acyl-CoA catalyzed by acyl-CoA synthetase (ACS, EC 6.2.1.3) from fatty acid, ATP, and CoA is a crucial reaction in mammalian fatty acid metabolism. In arachidonate metabolism, acyl-CoA synthetase(ACS) plays a key role in the esterification of free arachidonate into membrane phospholipids. Following its release by the action of calcium dependent phospholipase, free arachidonate is believed to be rapidly converted to arachidonoyl-CoA and reesterified into phospholipids in order to prevent excessive synthesis of eicosanoids. In previous studies, we have characterized five ACSs (designated as ACS1-5) with different tissue distribution. ACS1, ACS2, and ACS5 are similar in structure and fatty acid preference, and completely different from ACS3 and ACS4. The latter are arachidonate-preferring enzymes closely related in structure but expressed in different tissues: ACS3 mRNA is highly expressed in the brain and the mRNA for ACS4 is expressed in steroidogenic tissues including adrenal gland, ovary, and testis. To learn more about the potential function of ACS4 in arachidonate metabolism, we have produced knock-out mice for ACS4 gene. ACS4+/- females become pregnant less frequently and produce small litters with extremely low transmission of the disrupted alleles. Striking morphological changes including extremely enlarged uterine filled with numerous proliferative cysts of various size were detected in ACS4+/- females. Furthermore, marked accumulation of prostaglandins were seen in the uterus of heterozygous females. These results indicate that ACS4 is critical for the uterine arachidonate metabolism and heterozygous disruption of its gene lead to impaired pregnancy.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.219-240
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• 2009

Since NF-${\kappa}B$ has been identified as a transcription factor associated with immune cell activation, groups of researchers have dedicated to reveal detailed mechanisms of nuclear factor of ${\kappa}B$ (NF-${\kappa}B$) in inflammatory signaling for decades. The various molecular components of NF-${\kappa}B$ transcription factor pathway have been being evaluated as important therapeutic targets due to their roles in diverse human diseases including inflammation, cystic fibrosis, sepsis, rheumatoid arthritis, cancer, atherosclerosis, ischemic injury, myocardial infarction, osteoporosis, transplantation rejection, and neurodegeneration. With regards to new drugs directly or indirectly modulating the NF-${\kappa}B$ pathway, FDA recently approved a proteasome inhibitor bortezomib for the treatment of multiple myeloma. Many pharmaceutical companies have been trying to develop new drugs to inhibit various kinases in the NF-${\kappa}B$ signaling pathway for many therapeutic applications. However, a gene knock-out study for $IKK{\beta}$ in the NF-${\kappa}B$ pathway has given rise to controversies associated with efficacy as therapeutics. Mice lacking hepatocyte $IKK{\beta}$ accelerated cancer instead of preventing progress of cancer. However, it is clear that pharmacological inhibition of $IKK{\beta}$ appears to be beneficial to reduce HCC. This article will update issues of the NF-${\kappa}B$ pathway and inhibitors regulating this pathway.

• Molecules and Cells
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• v.22 no.1
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• pp.65-69
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• 2006

In murine gastrointestinal myocytes muscarinic stimulation activates nonselective cation channels via a G-protein and $Ca^{2+}$-dependent pathway. We recorded inward cationic currents following application of carbachol ($I_{CCh}$) to murine gastric myocytes held at -60 mV, using the whole-cell patch-clamp method. The properties of the inward cationic currents were similar to those of the nonselective cation channels activated by muscarinic stimulation in other gastrointestinal smooth muscle cells. CCh-induced $I_{CCh}$ and spontaneous decay of $I_{CCh}$ (desensitization of $I_{CCh}$) occurred. Unlike the situation in guinea pig gastric myocytes, desensitization was not affected by varying $[EGTA]_i$. Pretreatment with the PLC inhibitor (U73122) blocked the activation of $I_{CCh}$, and desensitization of $I_{CCh}$ was attenuated in PLC ${\beta}_1$ knock-out mice. These results suggest that the desensitization of $I_{CCh}$ in murine gastric myocytes is not due to a pathway dependent on intracellular $Ca^{2+}$ but to the PLC ${\beta}_1$ pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.511-519
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• 2001

Nimopidine, one of dihydropyridine derivatives, has been widely used to pharmacologically identify L-type Ca currents. In this study, it was tested if nimodipine is a selective blocker for L-type Ca currents in sensory neurons and heterologous system. In mouse dorsal root ganglion neurons (DRG), low concentrations of nimodipine $(<10\;{\mu}M),$ mainly targeting L-type Ca currents, blocked high-voltage-activated calcium channel currents by ${\sim}38%.$ Interestingly, high concentrations of nimodipine $(>10\;{\mu}M)$ further reduced the 'residual' currents in DRG neurons from ${\alpha}_{1E}$ knock-out mice, after blocking L-, N- and P/Q-type Ca currents with $10\;{\mu}M$ nimodipine, $1\;{\mu}M\;{\omega}-conotoxin$ GVIA and 200 nM ${\omega-agatoxin$ IVA, indicating inhibitory effects of nimodipine on R-type Ca currents. Nimodipine $(>10\;{\mu}M)$ also produced the inhibition of both low-voltage-activated calcium channel currents in DRG neurons and ${\alpha}_{1B}\;and\;{\alpha}_{1E}$ subunit based Ca channel currents in heterologous system. These results suggest that higher nimodipine $(>10\;{\mu}M)$ is not necessarily selective for L-type Ca currents. While care should be taken in using nimodipine for pharmacologically defining L-type Ca currents from native macroscopic Ca currents, nimodipine $(>10\;{\mu}M)$ could be a useful pharmacological tool for characterizing R-type Ca currents when combined with toxins blocking other types of Ca channels.