• Title/Summary/Keyword: calmodulin 2

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Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures

  • Jung, Yeon Joo;Suh, Eun Cheng;Lee, Kyung Eun
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.6
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    • pp.423-429
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    • 2012
  • Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.

Identification and Characterization of a Putative Basic Helix-Loop-Helix (bHLH) Transcription Factor Interacting with Calcineurin in C. elegans

  • Lee, Soo-Ung;Song, Hyun-Ok;Lee, Wonhae;Singaravelu, Gunasekaran;Yu, Jae-Ran;Park, Woo-Yoon
    • Molecules and Cells
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    • v.28 no.5
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    • pp.455-461
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    • 2009
  • Calcineurin is a $Ca^{2+}$/Calmodulin activated Ser/Thr phosphatase that is well conserved from yeast to human. It is composed of catalytic subunit A (CnA) and regulatory subunit B (CnB). C. elegans homolog of CnA and CnB has been annotated to tax-6 and cnb-1, respectively and in vivo function of both genes has been intensively studied. In C. elegans, calcineurin play roles in various signaling pathways such as fertility, movement, body size regulation and serotonin-mediated egg laying. In order to understand additional signaling pathway(s) in which calcineurin functions, we screened for binding proteins of TAX-6 and found a novel binding protein, HLH-11. The HLH-11, a member of basic helix-loop-helix (bHLH) proteins, is a putative counterpart of human AP4 transcription factor. Previously bHLH transcription factors have been implicated to regulate many developmental processes such as cell proliferation and differentiation, sex determination and myogenesis. However, the in vivo function of hlh-11 is largely unknown. Here, we show that hlh-11 is expressed in pharynx, intestine, nerve cords, anal depressor and vuvla muscles where calcineurin is also expressed. Mutant analyses reveal that hlh-11 may have role(s) in regulating body size and reproduction. More interestingly, genetic epistasis suggests that hlh-11 may function to regulate serotoninmediated egg laying at the downstream of tax-6.

Undescribed Fungal Species of Eupenicillium, Mortierella, and Trichoderma Isolated in the Vicinity of Demilitarized Zone in Yeoncheon-gun, Gyeonggi-do, Korea (경기도 연천비무장지대 근역에서 분리한 국내 미기록 Eupenicillium, Mortierella, Trichoderma 진균 종 보고)

  • Ahn, Geum Ran;Kim, Ji Eun;Oh, Yun Seok;Lee, Kyoung Min;Jin, Hyeop;Kim, Min Uk;Kim, Jun Young;Kim, Seong Hwan
    • The Korean Journal of Mycology
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    • v.46 no.4
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    • pp.359-367
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    • 2018
  • As an effort to explore fungal diversity, fungal survey was undertaken in 2017 in the vicinity of demilitarized zone (DMZ) located in Yeoncheon-gun, Gyeonggi-do, Korea. For the survey, wild plants and soils were sampled and subjected to fungal isolation. A total of 18 genera and 23 species including five unrecorded fungal species, Mortierella sclerotiella, M. sossauensis, M. verticillate, Eupenicillium saturniforme, and Trichoderma hispanicum, were obtained from the survey. This study described their morphological characteristics including colony features formed on media, light microscopic images and molecular characteristics of nucleotide sequences of the internal transcribed spacer (ITS) region, 18S and 28S rDNA, ${\beta}-tubulin$ gene, calmodulin, and translation elongation factor $1{\alpha}$ ($tef1{\alpha}$) nDNA genes.

Panaxcerol D from Panax ginseng ameliorates the memory impairment induced by cholinergic blockade or Aβ25-35 peptide in mice

  • Keontae Park;Ranhee Kim;Kyungnam Cho;Chang Hyeon Kong;Mijin Jeon;Woo Chang Kang;Seo Yun Jung;Dae Sik Jang ;Jong Hoon Ryu
    • Journal of Ginseng Research
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    • v.48 no.1
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    • pp.59-67
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    • 2024
  • Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca2+/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

Effects of phenylephrine-induced PKC activation on Mg2+ release in guinea pig heart and isolated ventricular myocytes (기니픽 심장과 심근세포에서 Phenylephrine에 의한 PKC 활성화가 Mg2+ 유리에 미치는 영향)

  • Chang, Sung-eun;Kang, Hyung-sub;Kim, Jin-sang
    • Korean Journal of Veterinary Research
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    • v.38 no.1
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    • pp.29-42
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    • 1998
  • $Mg^{2+}$ is one of the most abundant divalent cations in mammalian body(0.2~1.0mM) and the important physiological roles are : first, the cofactor of many enzyme activities, second, the regulator of glycolysis and DNA synthesis, third, the important role of bioenergetics by regulating of phosphorylation, fourth, the influence of cardiac metabolism and function. In this work we have investigated the regulation of the $Mg^{2+}$ induced by ${\alpha}_1-adrenoceptor$ stimulation in perfused guinea pig hearts and isolated myocytes. The $Mg^{2+}$ content of the perfusate or the supernatant was measured by atomic absorbance spectrophotometry. The elimination of $Mg^{2+}$ in the medium increased the force of contraction of right ventricular papillary muscles, and the left ventricular pressure. Phenylephrine also enhanced the force of contraction in the presence of $Mg^{2+}-free$ medium. ${\alpha}_1-Agonists$ such as phenylephrine and methoxamine were found to induce $Mg^{2+}$ efflux in both perfused hearts and myocytes. These effects were blocked by prazosin, an ${\alpha}_1-adrenoceptor$ antagonist. The $Mg^{2+}$ influx could also be induced by phenylephrine and R59022, a diacylglycerol kinase inhibitor. In the presence of protein kinase C(PKC) inhibitors, phenylephrine produced an increase in $Mg^{2+}$ efflux from perfused hearts. Furthermore, $Mg^{2+}$ efflux by phenylephrine was amplified by phorbol 12-myristate 13-acetate(PMA). This enhancement of $Mg^{2+}$ efflux by PMA was blocked by prazosin in perfused hearts. By contrast, the $Mg^{2+}$ influx could be induced by verapamil, nifedipine, ryanodine in perfused hearts, but not in myocytes. $W^7$, a $Ca^{2+}$/calmodulin antagonist, completely blocked the phenylephrine-induced $Mg^{2+}$ efflux in perfused hearts. In conclusion, $Mg^{2+}$ is responsible for the cardiac activity associated with ${\alpha}_1-adrenoceptor$ stimulation. The mobilization of $Mg^{2+}$ is decreased or increased by ${\alpha}_1-adrenoceptor$ stimulation in guinea pig hearts. These responses may be related specifically to the respective pathways of signal transduction. A decrease in $Mg^{2+}$ efflux by ${\alpha}_1-adrenoceptor$ stimulation in hearts can be through PKC dependent and intracellular $Ca^{2+}$ levels.

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Effect of Neurogranin Phosphorylation on Oxidative Stress by Hydrogen Peroxide in Early Onset of Batten Disease (과산화수소에 의한 산화스트레스가 영아형 바텐병에서 neurogranin의 인산화에 미치는 영향)

  • Yoon, Dong-Ho;Kim, Han-Bok;Park, Joo-Hoon;Kim, Sung-Jo
    • Journal of Life Science
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    • v.19 no.4
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    • pp.520-525
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    • 2009
  • Early onset of Batten disease (EBD), one of the most lethal neurodegenerative storage disorders of childhood, is caused by inactivating mutations in the Ceroid Lipofuscinosis, Neuronal (CLN1) gene. Neurogranin, a calmodulin-binding protein, is expressed in the brain and participates in the protein kinase C (PKC) signaling pathway. While oxidative stress is the suggested cause of neurodegeneration in EBD, its molecular mechanism(s) remains obscure. In this research, we examined the levels of neurogranin in the brain mRNA of wild-type (WT) mice and EBD knockout (KO) mice, as well as the proteins. We also performed neuronal cultures to measure the expression levels of neurgranin and phosphorylated-neurogranin with or without oxidative stress inducers and anti-oxidants. Results showed that neurogranin in both EBD KO mice brain mRNA and protein extracts decreased in an age dependent manner. However, high amounts of phosphorylated-neurogranin were detected in the 6-month brain. This pattern was also confirmed by cultured neurospheres samples. Moreover, neurospheres treated with $H_2O_2$, an oxidative stress inducer, showed increased phosphorylated-neurogranin patterns. Interestingly, this pattern returned to normal status when treated with N-acetyl-L-cystein, an anti-oxidant, after $H_2O_2$ treatment was performed. Our results suggest that the phosphorylation of neurogranin is affected by oxidative stress status in EBD, and appropriate anti-oxidant treatment will relieve hyper-phosphorylation of neurogranin.

The Roles of Arachidonic Acid and Calcium in the Angiotensin II-induced Inhibition of $Na^+$ Uptake in Renal Proximal Tubule Cells

  • Park, Soo-Hyun;Koh, Hyun-Joo;Lee, Yeun-Hee;Son, Chang-Ho;Park, Min-Kyoung;Lee, Young-Jae;Han, Ho-Jae
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.1
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    • pp.83-91
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    • 1999
  • Angiotensin II (ANG II) has a biphasic effect on $Na^+$ transport in proximal tubule: low doses of ANG II increase the $Na^+$ transport, whereas high doses of ANG II inhibit it. However, the mechanisms of high dose ANG II-induced inhibition on $Na^+$ uptake are poorly understood. Thus the aim of the present study was to investigate signal transduction pathways involved in the ANG II-induced inhibition of $Na^+$ uptake in the primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined serum-free medium. ANG II $(10^{-9}\;M)-induced$ inhibition of $Na^+$ uptake was blocked by losartan $(10^{-8}\;M,\;AT_1\;antagonist),$ but not by PD123319 $(10^{-8}\;M,\;AT_2\;antagonist)$ (P<0.05). ANG II-induced inhibition of $Na^+$ uptake was also completely abolished by neomycin $(10^{-4}\;M,$ PLC inhibitor), W-7 $(10^{-4}\;M,$ calmodulin antagonist), and $AACOCF_3\;(10^{-6}\;M,\;PLA_2\;inhibitor)$ (P<0.05). ANG II significantly increased $[^3H]arachidonic$ acid (AA) release compared to control. The ANG II-induced $[^3H]AA$ release was blocked by losartan, $AACOCF_3,$ neomycin, and W-7, but not by PD123319. ANG II-induced $[^3H]AA$ release in the presence of extracellular $Ca^{2+}$ was greater than in $Ca^{2+}-free$ medium, and it was partially blocked by TMB-8 $(10^{-4}\;M,$ intracelluar $Ca^{2+}$ mobilization blocker). However, in the absence of extracellular $Ca^{2+},$ it was completely blocked by TMB-8. In addition, econazole $(10^{-6}\;M,$ cytochrome P-450 monooxygenase inhibitor) and indomethacin $(10^{-6}\;M,$ cyclooxygenase inhibitor) blocked ANG II-induced inhibition of $Na^+$ uptake, but NGDA $(10^{-6}\;M,$ lipoxygenase inhibitor) did not affect it. In conclusion, $PLA_2-mediated$ AA release is involved in ANG II-induced inhibition of $Na^+$ uptake and is modulated by $[Ca^{2+}]_i$ in the PTCs.

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Cell death phenotype of vacuole Ca2+-ATPase11 (ACA11) transgenic plant in Arabidopsis (애기장대에서 액포막 존재 Ca2+-ATPase11 (ACA11) 형질전환제의 세포사멸 표현형 분석)

  • Lee, Sang-Min;Hoang, My-HanhThi;Kim, Kyung-Eun;Chung, Woo-Sik
    • Journal of Plant Biotechnology
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    • v.36 no.1
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    • pp.59-63
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    • 2009
  • Calcium ion ($Ca^{2+}$) is thought to play the important role as a second messenger for signal transduction that results in various physiological responses to cope with developmental programs and environmental changes in plant. In plant cells, the central vacuole functions as a major calcium store, which is important for both signal transduction and preventing cytotoxicity. Although there is evidence for the biochemical characterizations of a calmodulin-regulated $Ca^{2+}$-ATPase (ACA11) localized to vacuole membrane, the biological function to ACA11 in plant has not been verified. In this study, we show that the cell death as the hypersensitive response (HR) in mature leaves is induced in transgenic plant of a vacuole ACA-type $Ca^{2+}$-ATPase, ACA11. Evidence that cell death phenotype is the result of ACA11 gene silencing is provided by Western blot assay using membrane fraction proteins extracted from transgenic plant. The 3, 3'-diaminobenzidine (DAB) staining study provides that the cell death is caused by the increase of reactive oxygen species (ROS) in mature leaves of transgenic plants.

Regulatory Mechanisms of Angiotensin II on the $Na^+/H^+$ Antiport System in Rabbit Renal Proximal Tubule Cells. II. Inhibitory Effects of ANG II on $Na^+$ Uptake

  • Han, Ho-Jae;Park, Soo-Hyun;Koh, Hyun-Ju
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.4
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    • pp.425-434
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    • 1997
  • Many reports represent that angiotensin II (ANG II) caused a dose dependent biphasic effects on fluid transport in the proximal tubule. However, respective roles of different signaling pathways in mediating these effects remain unsettled. The aim of the present study was to examine signaling pathways at high doses of ANG II on the $Na^+$ uptake of primary cultured rabbit renal proximal tubule cells(PTCs) in hormonally defined serum-free medium. High concentrations of ANG II $(>10^{-9}\;M)$ inhibited $Na^+$ uptake and increased $[Ca^{2+}]_i\;level$ in the PTCs. However, low concentrations of $(<10^{-11}\;ANG\;II)$ stimulated $Na^+$ uptake and did not affect $[Ca^{2+}]_i\;level$. 8-(N, N-diethylamino)-octyl-3,3,5- trimethoxybenzoate (TMB-8), ethylene glycol-bis$({/beta}-amino\;ethyl ether)-N,N,N'$, N'-tetra acetic acid (EGTA), and nifedifine partially blocked the inhibitory effects of ANG II on $Na^+$ uptake. When ANG II and bradykinin (BK) were treated together, $Na^+$ uptake was further reduced $(88.47{\pm}1.98%\;of\;that\;of\;ANG\;II,\;81.85{\pm}1.84%\;of\;that\;of\;BK)$. In addition, W-7 and KN-62 blocked the ANG II-induced inhibition of $Na^+$ uptake. Arachidonic acid reduced $Na^+$ uptake in a dose-dependent manner. When ANG II and arachidonic acid were treated together, inhibitory effects on $Na^+$ uptake significantly exhibited greater reduction than that of each group, respectively. When PTCs were treated by mepacrine $(10^{-6}\;M)$ and AACOCF3 $(10^{-5}\;M)$ for 1 hr before the addition of $(<10^{-9}\;ANG\;II)$, the inhibitory effect of ANG II was reversed. In addition, econazole $(>10^{-6}\;M)$ blocked ANG II-induced inhibition of $Na^+$ uptake. In conclusion, the $[Ca^{2+}]_i$ (calcium-calmodulin-dependent kinase) and phospholipase $A_2\;(PLA_2)$ metabolites are involved in the inhibitory effects of ANG II on $Na^+$ uptake in the PTCs.

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Integrative Study on PPARGC1A: Hypothalamic Expression of Ppargc1a in ob/ob Mice and Association between PPARGC1A and Obesity in Korean Population

  • Hong, Mee-Suk;Kim, Hye-Kyung;Shin, Dong-Hoon;Song, Dae-Kyu;Ban, Ju Yeon;Kim, Bum Shik;Chung, Joo-Ho
    • Molecular & Cellular Toxicology
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    • v.4 no.4
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    • pp.318-322
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    • 2008
  • Obesity is an increasing worldwide health problem that is strongly related to the imbalance of food intake and energy metabolism. It was well-known that several substances in the hypothalamus regulate food intake and energy metabolism. We planned an integrative study to elucidate the mechanism of the development of obesity. Firstly, to find candidate genes with the marvelous effect, the different expression in the hypothalamus between ob/ob and 48-h fasting mice was investigated by using DNA microarray technology. As a result, we found 3 genes [peroxisome proliferator activated receptor, gamma, coactivator 1 alpha (Ppargc1a), calmodulin 1 (Calm1), and complexin 2 (Cplx2)] showing the different hypothalamic expression between ob/ob and 48-h fasting mice. Secondly, a genetic approach on PPARGC1A gene was performed, because PPARGC1A acts as a transcriptional coactivator and a metabolic regulator. Two hundred forty three obese female patients with body mass index (BMI)${\geq}$25 and 285 control female subjects with BMI 18 to<23 were recruited according to the Classification of Korean Society for the Study of Obesity. Among the coding single nucleotide polymorphisms (cSNPs) of PPARGC1A, 2 missense SNPs (rs8192678, Gly482Ser; rs3736265, Thr612Met) and 1 synonymous SNP (rs3755863, Thr528Thr) were selected, and analyzed by PCR-RFLP and pyrosequencing. For the analysis of genetic data, chi-square ($X^2$) test and EH program were used. The rs8192678 was significantly associated with obese women (P<0.0006; odds ratio, 1.5327; 95% confidence interval, 1.2006-1.9568). Haplotypes also showed significant association with obese women ($X^2$=33.28, P<0.0008). These results suggest that PPARGC1A might be related to the development of obesity.