(A) Western blot analysis with total tissue lysate from WT and CRIF1 EKO mice hearts. α-Tubulin was used as the internal control. (B) The expression level of VCAM-1 was quantified by densitometric analysis using image J. (right panel,... more
(A) Western blot analysis with total tissue lysate from WT and CRIF1 EKO mice hearts. α-Tubulin was used as the internal control. (B) The expression level of VCAM-1 was quantified by densitometric analysis using image J. (right panel, values are means ± SEM, *p &lt; 0.05). (n=4 per group) <br>
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Triple-negative breast cancer (TNBC) represents a relatively small proportion of all BCs but a relatively large proportion of BC-related death. Thus more effective therapeutic strategies are needed for the management of TNBC. We... more
Triple-negative breast cancer (TNBC) represents a relatively small proportion of all BCs but a relatively large proportion of BC-related death. Thus more effective therapeutic strategies are needed for the management of TNBC. We previously demonstrated that the stimulation of apoptosis by the binding of secreted acetylated-apurinic apyrimidinic endonuclease 1/redox factor-1 (Ac-APE1/Ref-1) to the receptor for advanced glycation end products (RAGE) was essential for the TNBC cell death in response to hyperacetylation. The aim of the present study was to assess the potential therapeutic efficacy of secretory Ac-APE1/Ref-1 in orthotopic TNBC xenografts in vivo. We found that hyperacetylation in xenografts caused secretion of Ac-APE1/Ref-1 into the blood, where the factor bound directly to RAGE in hyperacetylated tumor tissues. Hyperacetylation in the TNBC xenografts induced strong inhibition of tumor growth and development. Hyperacetylation also caused cell death in tumors, accompanied...
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Tonic extrasynaptic GABAA receptor (GABAAR) activation is under the tight control of tonic GABA release from astrocytes to maintain the brain's excitation/inhibition (E/I) balance; any slight E/I balance disturbance can cause serious... more
Tonic extrasynaptic GABAA receptor (GABAAR) activation is under the tight control of tonic GABA release from astrocytes to maintain the brain's excitation/inhibition (E/I) balance; any slight E/I balance disturbance can cause serious pathological conditions including epileptic seizures. However, the pathophysiological role of tonic GABA release from astrocytes has not been tested in epileptic seizures. Here, we report that pharmacological or genetic intervention of the GABA‐permeable Bestrophin‐1 (Best1) channel prevented the generation of tonic GABA inhibition, disinhibiting CA1 pyramidal neuronal firing and augmenting seizure susceptibility in kainic acid (KA)‐induced epileptic mice. Astrocyte‐specific Best1 over‐expression in KA‐injected Best1 knockout mice fully restored the generation of tonic GABA inhibition and effectively suppressed seizure susceptibility. We demonstrate for the first time that tonic GABA from reactive astrocytes strongly contributes to the compensatory ...
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In persistent inflammatory state involving the chronic activation of the immune system, the interplay between breast cancer and stromal cells is closely associated. We have previously shown that APE1/Ref-1 which could inhibit inflammatory... more
In persistent inflammatory state involving the chronic activation of the immune system, the interplay between breast cancer and stromal cells is closely associated. We have previously shown that APE1/Ref-1 which could inhibit inflammatory signaling by reductive conformational change of cytokines receptors. In response to hyperacetylation, stimulation by secreted Ac-APE1/Ref-1 binding to RAGE initiated apoptotic cell death in TNBC models, in vitro and in vivo. In the present study, we used Ad-APE1/Ref-1 adenovirus, which can be overexpressed and be secreted into the blood of xenografts. We investigated how the Ad-APE1/Ref-1 influences growth retardation and apoptotic cell death of inflammation associated TNBC in vivo. The Ad-APE1/Ref-1-injection in MDA-MB 231 orthotopic xenografts caused a decrease in the volume and weight of tumors as shown in IVIS images. The treatment of Ad-APE1/Ref-1 also induced an inhibition of tumor growth and development, leading to apoptotic cell death, accompanied by generation of reactive oxygen species. Tumor tissues derived from Ad-APE1/Ref-1 exhibited apoptotic bodies compared with tumors of control or Adβ-galactosidase-injected mice. Moreover, level of inflammatory cytokines was evaluated in plasma of the xenografts; ratio of anti- to pro inflammatory cytokines was comparable with one of normal mice. The PAK1-STAT-3-NFkB axis in inflammatory signaling of tumor tissues derived from AdAPE1/Ref-1 injected mice was significantly inhibited compared to those of control or Adβ-galactosidase-injected mice. These results suggest that regulation of inflammatory signaling with adenoviral mediated APE1/Ref-1 in tumors of MDA-MB-231 xenografts modulates cytokine secretion, thereby inhibiting cancer cell growth. Note: This abstract was not presented at the meeting. Citation Format: Sunga Choi, Yu Ran Lee, Yeon Hyang Kim, Ki Mo Kim, Myoung Soo Park, Byeong Hwa Jeon. Anti-tumor effect of adenovirus encoding APE1/Ref-1 in breast cancer xenografts: anti-inflammation and apoptotic cell death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4777.
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Objectives: Apurinic apyrimidinic endonuclease 1/Redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a DNA repair and redox regulation with secretory activity. The aim of this study was to evaluate the biological role of... more
Objectives: Apurinic apyrimidinic endonuclease 1/Redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a DNA repair and redox regulation with secretory activity. The aim of this study was to evaluate the biological role of extracellular APE1/Ref-1 in human cultured endothelial cells. Methods: Intracellular acetylation is induced by the incubation of trichostatin A, secreted APE1/Ref-1 is quantified with sandwich ELISA. Results: During treatment of trichostatin A in culture, a time-dependent increase in secreted APE1/Ref-1 was confirmed. Trichostatin A significantly suppressed vascular cell adhesion molecule-1 expression in response to TNF-&agr;. The acetyl moiety of acetylated-APE1/Ref-1 was rapidly removed based on the removal kinetics. Additionally, recombinant human APE1/Ref-1 with reducing activity induced a conformational change in rhTNF-&agr; receptor 1 by thiol-disulfide exchange. Following treatment with the neutralizing anti-APE1/Ref-1 antibody, inflammatory signals via the binding of TNF-&agr; to TNFR1 were remarkably recovered, leading to up-regulation of reactive oxygen species generation and VCAM-1. Conclusion: Furthermore, rhAPE1/Ref-1 inhibited VCAM-1 expression in interleukin-1&bgr;-stimulated endothelial cells, and inhibited inducible nitric oxide synthase. These results strongly indicate that anti-inflammatory effects in TNF-&agr;-stimulated endothelial cells by acetylation are tightly linked to secreted APE1/Ref-1, which inhibits inflammatory cytokines binding to its receptors.
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The anticancer properties of acetylated secretory apurinic/apyrimidinic endonuclease-1 (Ape1/Ref-1) was suggested in triple-negative breast cancer (TNBC) cells; Posttranslational modification, hyperacetylation in MDA-MB-231 cells caused... more
The anticancer properties of acetylated secretory apurinic/apyrimidinic endonuclease-1 (Ape1/Ref-1) was suggested in triple-negative breast cancer (TNBC) cells; Posttranslational modification, hyperacetylation in MDA-MB-231 cells caused extracellular secretion of acetylated-APE1/Ref-1 (Ac-APE1/Ref-1) and initiated apoptotic cell death by auto-, paracrine binding to the receptor for advanced glycation end products (RAGE). In the present study, we observed potential therapeutic efficacy of Ac-APE1/Ref-1 in preclinical orthotopic models of TNBC in response to hyperacetylation. The extracellular Ac-APE1/Ref-1 was confirmed by proximity ligation assay in hyperacetylated tumor tissue, showing direct binding of Ac-APE1/Ref-1 and RAGE. Treatment of orthotopic TNBC xenografts with acetylating agents induced a strong growth inhibition in the tumor development as observed in computed tomography: it caused an increase of RAGE expression and activation of caspase-3 and PARP. The tumors also exhi...
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Acetylation is one of the dynamic post-translational modification of lysine residues on protein determining the structure, function and intracellular localization that plays an important role in the signal transduction pathways related to... more
Acetylation is one of the dynamic post-translational modification of lysine residues on protein determining the structure, function and intracellular localization that plays an important role in the signal transduction pathways related to diverse cell functions - proliferation, cell death, and differentiation as well as transcriptional regulation. Recently, it has been reported that acetylating agents including chemical histone deacetylase inhibitors and plant polyphenols lead to the increased acetylation of histone and non-histone proteins, which induces to rapid cancer cell death. In this present study, we are focused on molecular mechanism of cell death in two Aspirin-treated human breast cancer cells, MCF-7 and MDA-MB-231. Trichostatin A (TSA) treatment was combined for maintaining acetylation of intracellular proteins at 0.1 μM concentration, which was not caused cell death itself. It was observed that Aspirin/TSA treatment caused the significant inhibition of cell growth in a ...
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To investigate the effect of crude saponin and nonsaponin fraction of Korean red ginseng (KRG) on the blood pressure and nitric oxide (NO) production in the conscious rats and cultured endothelial cell line, ECV 304 cells. Systolic blood... more
To investigate the effect of crude saponin and nonsaponin fraction of Korean red ginseng (KRG) on the blood pressure and nitric oxide (NO) production in the conscious rats and cultured endothelial cell line, ECV 304 cells. Systolic blood pressure and heart rate were monitored in the conscious rats. Nitric oxide levels and the expression of nitric oxide synthase were measured by a spectrophotometric assay using Griess reagents and Western blotting, respectively. Nitric-oxide synthase activity was measured based on the conversion rate of [3H]arginine to [3H]citrulline. Systolic blood pressure was decreased by crude saponin (100 mg/kg, i.v.) of KRG in the conscious control and one-kidney, one-clip Goldblatt hypertensive (1K, 1C-GBH) rats. The hypotensive effect induced by crude saponin of KRG reached maximum at 2-4 min and slowly recovered after 20 min to the initial level in both groups. Crude saponin of KRG induced tachycardia in the conscious rats but induced bradycardia in the anes...
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In supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs), γ-GABA, via activation of GABAA receptors (GABAA Rs), mediates persistent tonic inhibitory currents (Itonic ), as well as conventional inhibitory postsynaptic currents... more
In supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs), γ-GABA, via activation of GABAA receptors (GABAA Rs), mediates persistent tonic inhibitory currents (Itonic ), as well as conventional inhibitory postsynaptic currents (IPSCs, Iphasic ). In the present study, we examined the functional significance of Itonic in SON MNCs challenged by 24-h water deprivation (24WD). Although the main characteristics of spontaneous IPSCs were similar in 24WD compared to euhydrated (EU) rats, Itonic , measured by bicuculline (BIC)-induced Iholding shifts, was significantly smaller in 24WD compared to EU rats (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Propofol and diazepam prolonged IPSC decay time to a similar extent in both groups but induced less Itonic in 24WD compared to EU rats, suggesting a selective decrease in GABAA receptors mediating Itonic over Iphasic in 24WD rats. THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), a preferential δ subunit agonist, and L-655,708, a GABAA receptor α5 subunit selective imidazobenzodiazepine, caused a significantly smaller inward and outward shift in Iholding , respectively, in 24WD compared to EU rats (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 in both cases), suggesting an overall decrease in the α5 subunit-containing GABAA Rs and the δ subunit-containing receptors mediating Itonic in 24WD animals. Consistent with a decrease in 24WD Itonic , bath application of GABA induced significantly less inhibition of the neuronal firing activity in 24WD compared to EU SON MNCs (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Taken together, the results of the present study indicate a selective decrease in GABAA Rs functions mediating Itonic as opposed to those mediating Iphasic in SON MNCs, demonstrating the functional significance of Itonic with respect to increasing neuronal excitability and hormone secretion in 24WD rats.
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Inflammation is considered to play an important role in the cancer pathophysiology as a result of chronic reaction in vivo. Chronic inflammation has been involved in carcinogenesis including cellular transformation, proliferation,... more
Inflammation is considered to play an important role in the cancer pathophysiology as a result of chronic reaction in vivo. Chronic inflammation has been involved in carcinogenesis including cellular transformation, proliferation, invasion, angiogenesis and metastasis as well as vascular diseases. During the carcinogenesis, several kinds of pro-inflammatory cytokines and chemokines which were produced by tumor-infiltrating inflammatory cells can activate NFκB transcriptional factor influencing proliferation, differentiation and movement of tumor cells. Therefore, the regulation of NFκB signaling pathway and might be a therapeutically impact diseases associated with cancer. Naematolma (=Hypholoma) is a basidiomycete of the fungus that is known to produce antitumor compound, clavaric acid. In this present study, we report for the first time that Naematoloma sublateritium butanol fraction (NSBF) dose-dependently inhibited TNF alpha-induced monocyte adhesion to endothelial cells. Anti-a...
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Research Interests: Materials Science, Biomedical Engineering, Biomaterials, Animal Studies, Fluorescence Microscopy, and 15 morePolymers, Medicine, Multidisciplinary, Porosity, Animals, Nerve Regeneration, Rats, Peripheral nerves, Peripheral Nerve, PLGA, Rat Model, Light microscopy, Lactic Acid, Poloxamer, and Mechanical strength
Research Interests: Chemistry, Kinetics, Oxidative Stress, Medicine, Gene expression, and 15 moreAntioxidants, Liver, Ischemia, Nitric oxide, Animals, Biochemical, Nitric Oxide Synthase, Enzyme activity, P, Biochemistry and cell biology, Dimerization, Medical biochemistry and metabolomics, acetylcysteine, Nitric oxide synthase type II, and mRNA expression
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Research Interests: Molecular Biology, Biology, Medicine, Humans, Lysine, and 10 moreAcetylation, Histone, Hydroxamic Acids, Site-directed Mutagenesis, Extracellular Space, Biochemistry and cell biology, Histone deacetylase inhibitors, Psychology and Cognitive Sciences, Medical and Health Sciences, and Medical biochemistry and metabolomics
Apurinic/apyrimidinic endonuclease1/ref-1(APE1/ref-1) is a key enzyme in the base excision repair and in transcriptional modulation against oxidative stress. We investigated the altered expression of APE1/ref-1 and antioxidant systems in... more
Apurinic/apyrimidinic endonuclease1/ref-1(APE1/ref-1) is a key enzyme in the base excision repair and in transcriptional modulation against oxidative stress. We investigated the altered expression of APE1/ref-1 and antioxidant systems in lung cancer. Tumor specimens from 48 patients with operable non-small cell lung cancer were obtained from 2004 to 2006. Immunohistochemistry, Western blot, lipid peroxidation and superoxide production were performed on the tumor samples and a cultured H460 cell line. APE1/ref-1 was mainly localized to the nucleus in the non-tumor regions of the lung cancer tissue specimens. However, nuclear and cytoplasmic expressions of APE1/ref-1 in the lung cancers were markedly up-regulated in the non-small cell lung cancer (NSCLC) specimens including squamous cell and adenocarcinoma specimens. Extracellular superoxide dismutase (ECSOD) and catalase were down-regulated and manganese superoxide dismutase (MnSOD) was up-regulated in the tumor regions of the NSCLC. Tumor regions of the NSCLC showed higher superoxide production and lipid peroxidation levels than non-tumor regions. In the lung adenocarcinoma cell line, H460, treatment with hydrogen peroxide in the presence of a catalase inhibitor, aminotriazole, increased APE1/ref-1 expression, suggesting oxidative stress might have contributed to the induction of APE1/ref-1. The results of this study suggest that APE1/ref-1 is up-regulated in the tumor regions of NSCLC. Altered expression of antioxidant systems lead to enhanced production of superoxide production and lipid peroxidation, which can induce APE1/ref-1 in the tumor regions of NSCLS.
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We investigated the role that endothelial nitric oxide synthase plays in post-exercise hypotension in spontaneously hypertensive rats. To accomplish this, rats were subjected to a single bout of dynamic exercise on a treadmill at 15 m/min... more
We investigated the role that endothelial nitric oxide synthase plays in post-exercise hypotension in spontaneously hypertensive rats. To accomplish this, rats were subjected to a single bout of dynamic exercise on a treadmill at 15 m/min for 20 min. L-nitroarginine methyl ester (L-NAME, 40 mg/kg, i.p.) significantly inhibited post-exercise hypotension (25+/-11 and 5+/-3 mm Hg, respectively; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). In addition, the superoxide anion generation was decreased, while the plasma nitrite production and serine phosphorylation of endothelial nitric oxide synthase were significantly elevated in spontaneously hypertensive rats at 30 min after the termination of exercise. Taken together, these data demonstrate that the increased phosphorylation of endothelial nitric oxide synthase plays a crucial role in the reduction of arterial pressure following a single bout of dynamic exercise in spontaneously hypertensive rats.
Research Interests: Endocrinology, Chemistry, Enzyme Inhibitors, Medicine, Internal Medicine, and 14 moreNitric oxide, Animals, Male, Nitrite, Phosphorylation, Rats, Nitric Oxide Synthase, Superoxide, Hypotension, Treadmill, Biochemistry and cell biology, Endothelial nitric oxide synthase, Medical biochemistry and metabolomics, and NG-nitroarginine methyl ester
Research Interests: Molecular Biology, Biology, Cell Adhesion, Cell Biology, Medicine, and 12 moreHumans, Endothelial Cells, Escherichia coli, Vasculitis, Green Fluorescent Protein, Amino Acid Sequence, Protein Transport, Nucleotides, Biochemistry and cell biology, Molecular Sequence Data, Monocyte, and Medical biochemistry and metabolomics
Research Interests: Cardiovascular, Biology, Cell Biology, Medicine, Signal Transduction, and 14 moreHumans, Endothelial Cells, Mice, Animals, Phosphorylation, Vasoconstriction, Rats, Time Factors, Transfection, Recombinant Proteins, Protein Kinase Inhibitors, Protein Transport, Protein Kinase C, and Cardiovascular medicine and haematology
Non-alcoholic fatty liver disease (NAFLD) is associated with hepatic metabolism dysfunction. However, the mechanistic role of miR204 in the development of NAFLD is unknown. We investigate the functional significance of miR204 in the... more
Non-alcoholic fatty liver disease (NAFLD) is associated with hepatic metabolism dysfunction. However, the mechanistic role of miR204 in the development of NAFLD is unknown. We investigate the functional significance of miR204 in the evolution of NAFLD. IDH2 KO mice feed a normal diet (ND) or HFD increased body weight, epididymal fat-pad weight, lipid droplet in liver, blood parameter and inflammation compared to WT mice fed a ND or HFD. Moreover, the expression of miR204 is increased in mice with IDH2 deficiency. Increased miR204 by IDH2 deficiency regulates carnitine palmitoyltransferase 1a (cpt1a) synthesis, which inhibits fatty acid β-oxidation. Inhibition of miR204 prevents the disassembly of two fatty acid-related genes by activating CPT1a expression, which decreases lipid droplet in liver, inflammatory cytokines, epididymal fat pad weight, blood parameters. Increased miR204 by IDH2 deficiency promotes the pathogenesis of HFD-induced NAFLD by regulating hepatic fatty acid metab...
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Background Arginase II activity contributes to reciprocal regulation of endothelial nitric oxide synthase ( eNOS ). We tested the hypotheses that arginase II activity participates in the regulation of Ca/Ca/calmodulin-dependent kinase II... more
Background Arginase II activity contributes to reciprocal regulation of endothelial nitric oxide synthase ( eNOS ). We tested the hypotheses that arginase II activity participates in the regulation of Ca/Ca/calmodulin-dependent kinase II / eNOS activation, and this process is dependent on mitochondrial p32. Methods and Results Downregulation of arginase II increased the concentration of cytosolic Ca ([Ca]c) and decreased mitochondrial Ca ([Ca]m) in microscopic and fluorescence-activated cell sorting analyses, resulting in augmented eNOS Ser1177 phosphorylation and decreased eNOS Thr495 phosphorylation through Ca/Ca/calmodulin-dependent kinase II . These changes were observed in human umbilical vein endothelial cells treated with small interfering RNA against p32 (sip32). Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, fluorescence immunoassay, and ion chromatography, inhibition of arginase II reduced the amount of spermine, a binding molecule, and...
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Angiotensin II (Ang II) is implicated in the development of cardiovascular disorders including hypertension and atherosclerosis. However, the role of Ang II in the interaction between apurinic/apyrimidinic endonuclease/redox factor-1... more
Angiotensin II (Ang II) is implicated in the development of cardiovascular disorders including hypertension and atherosclerosis. However, the role of Ang II in the interaction between apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1) and sphingosine-1-phosphate (S1P) signals in relation to vascular disorders remains to be clarified. This study aimed to determine whether APE/Ref-1 plays a role in epigenetic regulation of the S1P receptor (S1PR) in response to Ang II in vascular smooth muscle cell (VSMC) migration and vascular neointima formation. Ang II augmented the expression of S1PR1 in aortic smooth muscle cells of Sprague Dawley rats (RASMCs), which was attenuated by Ang II receptor (AT) 1 inhibitors, antioxidants, and APE/Ref-1 knockdown with small interference RNA. Ang II stimulation produced HO, and exogenous HO elevated S1PR1 expression in RASMCs. Moreover, Ang II caused translocation of cytoplasmic APE/Ref-1 into the nucleus in RASMCs. H3 histone acetylation and...
Research Interests: Endocrinology, Chemistry, Biology, Cell Biology, Medicine, and 14 moreSignal Transduction, Internal Medicine, Animals, Male, Histones, Time Factors, Acetylation, Angiotensin II, Oxidation-Reduction, CAROTID ARTERY INJURIES, Neointima, Vascular Smooth Muscle, binding sites, and Pharmacology and pharmaceutical sciences
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Mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2) plays an essential role protecting cells against oxidative stress-induced damage. A deficiency in IDH2 leads to mitochondrial dysfunction and the production of reactive... more
Mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2) plays an essential role protecting cells against oxidative stress-induced damage. A deficiency in IDH2 leads to mitochondrial dysfunction and the production of reactive oxygen species (ROS) in cardiomyocytes and cancer cells. However, the function of IDH2 in vascular endothelial cells is mostly unknown. In this study the effects of IDH2 deficiency on mitochondrial and vascular function were investigated in endothelial cells. IDH2 knockdown decreased the expression of mitochondrial oxidative phosphorylation (OXPHOS) complexes I, II and III, which lead to increased mitochondrial superoxide. In addition, the levels of fission and fusion proteins (Mfn-1, OPA-1, and Drp-1) were significantly altered and MnSOD expression also was decreased by IDH2 knockdown. Furthermore, knockdown of IDH2 decreased eNOS phosphorylation and nitric oxide (NO) concentration in endothelial cells. Interestingly, treatment with Mito-TEMPO, a mitochondrial-specific superoxide scavenger, recovered mitochondrial fission-fusion imbalance and blunted mitochondrial superoxide production, and reduced the IDH2 knockdown-induced decrease in MnSOD expression, eNOS phosphorylation and NO production in endothelial cells. Endothelium-dependent vasorelaxation was impaired, and the concentration of bioavailable NO decreased in the aortic ring in IDH2 knockout mice. These findings suggest that IDH2 deficiency induces endothelial dysfunction through the induction of dynamic mitochondrial changes and impairment in vascular function.
Research Interests: Chemistry, Oxidative Stress, Mitochondria, Medicine, Humans, and 15 moreEndothelial Cells, Reactive Oxygen Species, Mice, Nitric oxide, Animals, Organophosphorus Compounds, Superoxide Dismutase, Oxidative phosphorylation, ENDOTHELIUM, Knockout Mice, Oxidation-Reduction, Superoxides, Biochemistry and cell biology, Gene Expression Regulation, and Piperidines
The purpose of this study was to evaluate the overall rate and risk factors for the development of an incisional hernia and a parastomal hernia after colorectal surgery. The study cohort consisted of 795 consecutive patients who underwent... more
The purpose of this study was to evaluate the overall rate and risk factors for the development of an incisional hernia and a parastomal hernia after colorectal surgery. The study cohort consisted of 795 consecutive patients who underwent open colorectal surgery between 2005 and 2007 by a single surgeon. A retrospective analysis of prospectively collected data was performed. The overall incidence of incisional hernias was 2% (14/690). This study revealed that the cumulative incidences of incisional hernia were 1% at 12 months and 3% after 36 months. Eighty-six percent of all incisional hernias developed within 3 years after a colectomy. The overall rate of parastomal hernias in patients with a stoma was 6.7% (7/105). The incidence of parastomal hernias was significantly higher in the colostomy group than in the ileostomy group (11.9% vs. 0%; P = 0.007). Obesity, abdominal aortic aneurysm, American Society of Anesthesiologists score, serum albumin level, emergency surgery and postope...
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Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in DNA repair and redox regulation. The redox activity of APE1/Ref-1 is involved in inflammatory responses and regulation of DNA... more
Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in DNA repair and redox regulation. The redox activity of APE1/Ref-1 is involved in inflammatory responses and regulation of DNA binding of transcription factors related to cell survival pathways. However, the effect of APE1/Ref-1 on adipogenic transcription factor regulation remains unknown. In this study, we investigated the effect of APE1/Ref-1 on the regulation of adipocyte differentiation in 3T3-L1 cells. During adipocyte differentiation, APE1/Ref-1 expression significantly decreased with the increased expression of adipogenic transcription factors such as CCAAT/enhancer binding protein (C/EBP)-α and peroxisome proliferator-activated receptor (PPAR)-γ, and the adipocyte differentiation marker adipocyte protein 2 (aP2) in a time-dependent manner. However, APE1/Ref-1 overexpression inhibited C/EBP-α, PPAR-γ, and aP2 expression, which was upregulated during adipocyte differentiat...
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Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to... more
Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest tha...
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Protein kinase C (PKC) induces mitochondrial dysfunction, which is an important pathological factor in cardiovascular diseases. The role of apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE1/Ref-1) on PKC-induced mitochondrial... more
Protein kinase C (PKC) induces mitochondrial dysfunction, which is an important pathological factor in cardiovascular diseases. The role of apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE1/Ref-1) on PKC-induced mitochondrial dysfunction has not been variously investigated. In this study, phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, induced mitochondrial hyperpolarization and reactive oxygen species generation and also increased mitochondrial translocation of APE1/Ref-1. APE1/Ref-1 overexpression suppressed PMA-induced mitochondrial dysfunction. In contrast, gene silencing of APE1/Ref-1 increased the sensitivity of mitochondrial dysfunction. Moreover, mitochondrial targeting sequence (MTS)-fused APE1/Ref-1 more effectively suppressed PMA-induced mitochondrial dysfunctions. These results suggest that mitochondrial APE1/Ref-1 is contributed to the protective role to protein kinase C-induced mitochondrial dysfunction in endothelial cells.
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Activation of serotonin (5-hydroxytryptamine, 5-HT) receptors produces various autonomic and neuroendocrine responses in the hypothalamic paraventricular nucleus (PVN), including increased blood pressure and heart rate. However, the... more
Activation of serotonin (5-hydroxytryptamine, 5-HT) receptors produces various autonomic and neuroendocrine responses in the hypothalamic paraventricular nucleus (PVN), including increased blood pressure and heart rate. However, the role(s) of 5-HT on the local GABA synaptic circuit have not been well understood in the PVN, where the inhibitory neurotransmitter GABA plays a key role in the modulation of sympathoexcitatory outflow. In the present study, we examined the effects of 5-HT on GABA synaptic transmission in presympathetic PVN neurons projecting to spinal cord using patch-clamp electrophysiology combined with tract-tracing techniques. Bath application of 5-HT (0.01-100 microM) reversibly decreased the frequency of spontaneous GABAergic inhibitory postsynaptic currents (sIPSC) in a concentration dependent manner (IC50, 0.07 microM), with no significant changes in the amplitudes and decay kinetics of sIPSC. The sIPSC inhibition of 5-HT was mimicked by 5-HT1A agonist, 8-OH-DPAT (8-hydroxy-2(di-n-propylamino)tetralin, 10 microM), and blocked by 5-HT1A antagonist WAY-100635 but not by 5-HT1B antagonist SB224289. 5-HT also reduced the frequency of miniature IPSC (mIPSC) (2.59+/-0.51 Hz, control vs. 1.25+/-0.31 Hz, 5-HT, n=16) in similar extent with 5-HT induced reduction of sIPSC frequency (sIPSCs, 55.8+/-6.2%, n=11 vs. mIPSCs, 52.30+/-5.85%, n=16; p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.5). All together, our results indicate that 5-HT can inhibit presynaptic GABA release via presynaptic 5-HT1A receptors in presympathetic PVN neurons projecting to spinal cord.
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Using slice patch clamp recording, we examined the effects of general anesthetic propofol (2,6-diisoprophlphenol) on dual modality of GABA(A) inhibition in supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs): conventional... more
Using slice patch clamp recording, we examined the effects of general anesthetic propofol (2,6-diisoprophlphenol) on dual modality of GABA(A) inhibition in supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs): conventional quantal synaptic transmission (IPSCs, I(phasic)) and persistent tonic form of inhibitory current (I(tonic)). Propofol (10 μM) enhanced I(tonic) as shown by an inward shift in I(holding) (16.46±2.93 pA, n=27) and RMS increase (from 3.37±0.21 pA to 4.68±0.33 pA, n=27) in SON MNCs. Propofol also prolonged the decay time of IPSCs with decreased IPSCs frequency but no significant changes in IPSCs amplitude. Overall, propofol (1-10 μM) caused much smaller increase in mean I(phasic) than mean I(tonic) at all tested concentrations. In consistent with the enhancement of GABA(A) currents, propofol attenuated ongoing firing activities of SON MNCs by ∼65% of control. Selective inhibition of I(phasic) by a GABA(A) antagonist, gabazine (1 μM), failed to block the propofol suppression of the firing activities, while inhibition of I(tonic) and I(phasic) by bicuculline (20 μM) efficiently blocked the propofol-induced neurodepression in SON MNCs. Taken together, our results showed that propofol facilitated I(tonic) with marginal increase in mean I(phasic), and this could be a mechanism reducing the intrinsic SON MNCs excitability during propofol anesthesia.