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Li Y, Yu S, Li Y, Liang X, Su M, Li R. Medical Significance of Uterine Corpus Endometrial Carcinoma Patients Infected With SARS-CoV-2 and Pharmacological Characteristics of Plumbagin. Front Endocrinol (Lausanne) 2021; 12:714909. [PMID: 34712201 PMCID: PMC8547653 DOI: 10.3389/fendo.2021.714909] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/08/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Clinically, evidence shows that uterine corpus endometrial carcinoma (UCEC) patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have a higher death-rate. However, current anti-UCEC/coronavirus disease 2019 (COVID-19) treatment is lacking. Plumbagin (PLB), a pharmacologically active alkaloid, is an emerging anti-cancer inhibitor. Accordingly, the current report was designed to identify and characterize the anti-UCEC function and mechanism of PLB in the treatment of patients infected with SARS-CoV-2 via integrated in silico analysis. METHODS The clinical analyses of UCEC and COVID-19 in patients were conducted using online-accessible tools. Meanwhile, in silico methods including network pharmacology and biological molecular docking aimed to screen and characterize the anti-UCEC/COVID-19 functions, bio targets, and mechanisms of the action of PLB. RESULTS The bioinformatics data uncovered the clinical characteristics of UCEC patients infected with SARS-CoV-2, including specific genes, health risk, survival rate, and prognostic index. Network pharmacology findings disclosed that PLB-exerted anti-UCEC/COVID-19 effects were achieved through anti-proliferation, inducing cytotoxicity and apoptosis, anti-inflammation, immunomodulation, and modulation of some of the key molecular pathways associated with anti-inflammatory and immunomodulating actions. Following molecular docking analysis, in silico investigation helped identify the anti-UCEC/COVID-19 pharmacological bio targets of PLB, including mitogen-activated protein kinase 3 (MAPK3), tumor necrosis factor (TNF), and urokinase-type plasminogen activator (PLAU). CONCLUSIONS Based on the present bioinformatic and in silico findings, the clinical characterization of UCEC/COVID-19 patients was revealed. The candidate, core bio targets, and molecular pathways of PLB action in the potential treatment of UCEC/COVID-19 were identified accordingly.
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Affiliation(s)
- Yongming Li
- Department of Gynecology, Guigang Maternal and Child Health Care Hospital, Guigang, China
| | - Songzuo Yu
- Department of Neurosurgery, Guigang City People’s Hospital, The Eighth Affiliated Hospital of Guangxi Medical University, Guigang, China
| | - Yu Li
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
| | - Xiao Liang
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
| | - Min Su
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
- Guangxi Key Laboratory of Tumor Immunology and Microenvironmental Regulation, Guilin Medical University, Guilin, China
- *Correspondence: Min Su, ; Rong Li, ;
| | - Rong Li
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
- Guangxi Key Laboratory of Tumor Immunology and Microenvironmental Regulation, Guilin Medical University, Guilin, China
- *Correspondence: Min Su, ; Rong Li, ;
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Abstract
Statins lower cholesterol and risk of cardiovascular disease. Statins can increase blood glucose and risk of new-onset diabetes. It is unclear why statins can have opposing effects on lipids versus glucose. Statins have cholesterol-independent pleiotropic effects that influence both insulin and glucose control. Statin lowering of isoprenoids required for protein prenylation promotes pancreatic β-cell dysfunction and adipose tissue insulin resistance. Protein prenylation influences immune function and statin-mediated adipose tissue insulin resistance involves the NLR family pyrin domain-containing 3 (NLRP3) inflammasome and IL-1β. However, the intracellular cues that statins engage to activate the NLRP3 inflammasome and those responsible for IL-1β-mediated insulin resistance in adipose tissue have not been identified. We hypothesized that stress kinases or components of the insulin signaling pathway mediated statin-induced insulin resistance. We tested the associations of p38, ERK, JNK, phosphatase, and tensin homolog (PTEN), and mTOR in statin-exposed adipose tissue from WT and IL-1β-/- mice. We found that statins increased phosphorylation of p38 in WT and IL-1β-/- mice. Statin activation of p38 upstream of IL-1β led to priming of this NLRP3 inflammasome effector in macrophages. We found that mTORC1 inhibition with low doses of rapamycin (2 or 20 nM) lowered macrophage priming of IL-1β mRNA and secretion of IL-1β caused by multiple statins. Rapamycin (20 nM) or the rapalog everolimus (20 nM) prevented atorvastatin-induced lowering of insulin-mediated phosphorylation of Akt in mouse adipose tissue. These results position p38 and mTOR as mediators of statin-induced insulin resistance in adipose tissue and highlight rapalogs as candidates to mitigate the insulin resistance and glycemic side effects of statins.
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Affiliation(s)
- Brandyn D Henriksbo
- Department of Biochemistry and Biomedical Sciences and Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton Ontario, Canada
| | - Akhilesh K Tamrakar
- Biochemistry Division, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Jobanjit S Phulka
- Department of Biochemistry and Biomedical Sciences and Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton Ontario, Canada
| | - Nicole G Barra
- Department of Biochemistry and Biomedical Sciences and Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton Ontario, Canada
| | - Jonathan D Schertzer
- Department of Biochemistry and Biomedical Sciences and Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton Ontario, Canada
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
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Chai W, Aylor K, Liu Z, Gan LM, Michaëlsson E, Barrett E. Inhibiting myeloperoxidase prevents onset and reverses established high-fat diet-induced microvascular insulin resistance. Am J Physiol Endocrinol Metab 2019; 317:E1063-E1069. [PMID: 31593502 DOI: 10.1152/ajpendo.00203.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A high-fat diet (HFD) can rapidly recruit neutrophils to insulin target tissues and within days induce microvascular insulin resistance (IR). Myeloperoxidase (MPO) is highly enriched in neutrophils, can inhibit nitric oxide-mediated vasorelaxation in vitro and is associated with increased cardiovascular disease risk. AZD5904 irreversibly inhibits MPO and in human clinical trials. MPO knockout, or chemical inhibition, blunts HFD-induced metabolic IR in mice. Whether MPO affects microvascular IR or muscle metabolic insulin sensitivity in vivo is unknown. We used contrast-enhanced ultrasound and the euglycemic insulin clamp to test whether inhibiting MPO could prevent the development or reverse established HFD-induced metabolic and/or microvascular IR in Sprague-Dawley rats. Two weeks of HFD feeding blocked insulin-mediated skeletal muscle capillary recruitment, inhibited glucose utilization, and insulin signaling to muscle. Continuous subcutaneous AZD5904 infusion during the 2 wk selectively blocked HFD's microvascular effect. Furthermore, AZD5904 infusion during the last 2 of 4 wk of HFD feeding restored microvascular insulin sensitivity but not metabolic IR. We conclude that inhibiting MPO selectively improves vascular IR. This selective microvascular effect may connote a therapeutic potential for MPO inhibition in the prevention of vascular disease/dysfunction seen in IR humans.
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Affiliation(s)
- Weidong Chai
- Division of Endocrinology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Kevin Aylor
- Division of Endocrinology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Zhenqi Liu
- Division of Endocrinology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Li-Ming Gan
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Erik Michaëlsson
- Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Eugene Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia
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Krieger CC, Perry JD, Morgan SJ, Kahaly GJ, Gershengorn MC. TSH/IGF-1 Receptor Cross-Talk Rapidly Activates Extracellular Signal-Regulated Kinases in Multiple Cell Types. Endocrinology 2017; 158:3676-3683. [PMID: 28938449 PMCID: PMC5659693 DOI: 10.1210/en.2017-00528] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/08/2017] [Indexed: 12/25/2022]
Abstract
We previously showed that thyrotropin (TSH)/insulinlike growth factor (IGF)-1 receptor cross-talk appears to be involved in Graves' orbitopathy (GO) pathogenesis and upregulation of thyroid-specific genes in human thyrocytes. In orbital fibroblasts from GO patients, coadministration of TSH and IGF-1 induces synergistic increases in hyaluronan secretion. In human thyrocytes, TSH plus IGF-1 synergistically increased expression of the sodium-iodide symporter that appeared to involve ERK1/2 activation. However, the details of ERK1/2 activation were not known, nor was whether ERK1/2 was involved in this synergism in other cell types. Using primary cultures of GO fibroblasts (GOFs) and human thyrocytes, as well as human embryonic kidney (HEK) 293 cells overexpressing TSH receptors (HEK-TSHRs), we show that simultaneous activation of TSHRs and IGF-1 receptors (IGF-1Rs) causes rapid, synergistic phosphorylation/activation of ERK1 and ERK2 in all three cell types. This effect is partially inhibited by pertussis toxin, an inhibitor of TSHR coupling to Gi/Go proteins. In support of a role for Gi/Go proteins in ERK1/2 phosphorylation, we found that knockdown of Gi(1-3) and Go in HEK-TSHRs inhibited ERK1/2 phosphorylation stimulated by TSH and TSH plus IGF-1. These data demonstrate that the synergistic effects of TSH plus IGF-1 occur early in the TSHR signaling cascade and further support the idea that TSHR/IGF-1R cross-talk is an important mechanism for regulation of human GOFs and thyrocytes.
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Affiliation(s)
- Christine C. Krieger
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Joseph D. Perry
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Sarah J. Morgan
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - George J. Kahaly
- Molecular Thyroid Research Laboratory, Department of Medicine I, Johannes Gutenberg University Medical Center, Langenbeckstreet 1, 55131 Mainz, Germany
| | - Marvin C. Gershengorn
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Szeto A, Sun-Suslow N, Mendez AJ, Hernandez RI, Wagner KV, McCabe PM. Regulation of the macrophage oxytocin receptor in response to inflammation. Am J Physiol Endocrinol Metab 2017; 312:E183-E189. [PMID: 28049625 PMCID: PMC5374296 DOI: 10.1152/ajpendo.00346.2016] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/16/2016] [Accepted: 12/27/2016] [Indexed: 12/17/2022]
Abstract
It has been demonstrated that the neuropeptide oxytocin (OT) attenuates oxidative stress and inflammation in macrophages. In the current study, we examined the role of inflammation on the expression of the oxytocin receptor (OXTR). We hypothesized that OXTR expression is increased during the inflammation through a nuclear factor-κB (NF-κB)-mediated pathway, thus responding as an acute-phase protein. Inflammation was induced by treating macrophages (human primary, THP-1, and murine) with lipopolysaccharide (LPS) and monitored by expression of IL-6. Expression of OXTR and vasopressin receptors was assessed by qPCR, and OXTR expression was confirmed by immunoblotting. Inflammation upregulated OXTR transcription 10- to 250-fold relative to control in THP-1 and human primary macrophages and increased OXTR protein expression. In contrast, vasopressin receptor-2 mRNA expression was reduced following LPS treatment. Blocking NF-κB activation prevented the increase in OXTR transcription. OT treatment of control cells and LPS-treated cells increased ERK1/2 phosphorylation, demonstrating activation of the OXTR/Gαq/11 signaling pathway. OT activation of OXTR reduced secretion of IL-6 in LPS-activated macrophages. Collectively, these findings suggest that OXTR is an acute-phase protein and that its increased expression is regulated by NF-κB and functions to attenuate cellular inflammatory responses in macrophages.
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Affiliation(s)
- Angela Szeto
- Department of Psychology, University of Miami, Coral Gables, Florida; and
| | - Ni Sun-Suslow
- Department of Psychology, University of Miami, Coral Gables, Florida; and
| | - Armando J Mendez
- Division of Endocrinology, Diabetes, and Metabolism and Diabetes Research Institute, Miller School of Medicine, University of Miami, Florida
| | - Rosa I Hernandez
- Division of Endocrinology, Diabetes, and Metabolism and Diabetes Research Institute, Miller School of Medicine, University of Miami, Florida
| | - Klaus V Wagner
- Department of Psychology, University of Miami, Coral Gables, Florida; and
| | - Philip M McCabe
- Department of Psychology, University of Miami, Coral Gables, Florida; and
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Harris RBS, Desai BN. Fourth-ventricle leptin infusions dose-dependently activate hypothalamic signal transducer and activator of transcription 3. Am J Physiol Endocrinol Metab 2016; 311:E939-E948. [PMID: 27802966 PMCID: PMC5183885 DOI: 10.1152/ajpendo.00343.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/18/2016] [Accepted: 10/25/2016] [Indexed: 12/16/2022]
Abstract
Previous studies have shown that very low-dose infusions of leptin into the third or the fourth ventricle alone have little effect on energy balance, but simultaneous low-dose infusions cause rapid weight loss and increased phosphorylation of STAT3 (p-STAT3) in hypothalamic sites that express leptin receptors. Other studies show that injecting high doses of leptin into the fourth ventricle inhibits food intake and weight gain. Therefore, we tested whether fourth-ventricle leptin infusions that cause weight loss are associated with increased leptin signaling in the hypothalamus. In a dose response study 14-day infusions of increasing doses of leptin showed significant hypophagia, weight loss, and increased hypothalamic p-STAT3 in rats receiving at least 0.9 μg leptin/day. In a second study 0.6 μg leptin/day transiently inhibited food intake and reduced carcass fat, but had no significant effect on energy expenditure. In a final study, we identified the localization of STAT3 activation in the hypothalamus of rats receiving 0, 0.3, or 1.2 μg leptin/day. The high dose of leptin, which caused weight loss in the first experiment, increased p-STAT3 in the ventromedial, dorsomedial, and arcuate nuclei of the hypothalamus. The low dose that increased brown fat UCP1 but did not affect body composition in the first experiment had little effect on hypothalamic p-STAT3. We propose that hindbrain leptin increases the precision of control of energy balance by lowering the threshold for leptin signaling in the forebrain. Further studies are needed to directly test this hypothesis.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Bhavna N Desai
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
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Li J, Wu S, Tang HT, Zhu GW. [Effects of Electroacupuncture at Neiguan (PC6) on Protein Expressions of Raf-1, ERK 1/2, and p-ERK 1/2 of Rats with Myocardial Hypertrophy]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2016; 36:1335-1339. [PMID: 30641627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Objective To observe the effects of electroacupuncture (EA) at Neiguan (PC6) on protein expressions of proto-oncogene serine/threonine-protein kinase-1 ( Raf-1 ) , phospho-extracellular signal-regulated kinase 1/2 (p-ERK 1/2), and extracellular signal-regulated kinase 1/2 (ERK 1/2) in rats with myocardial hypertrophy. Methods Totally 40 healthy Sprague-Dawley (SD) rats of clean grade were divided into 4 groups according to random digit table, i.e., the normal group, the model group, the electroa- cupuncture (EA) group, the sham-EA group, 10 in each group. Rats in the normal group were fed with reg- ular forage. Left ventricular myocardial hypertrophy model was established in rats of the rest 3 groups by subcutaneously injecting isoprinosine hydrochloride (ISO) (at the daily dose of 3 mg/kg) from the nape for a total of 14 days. Rats in the EA group were needed at Neiguan (PC6) using continuous wave (2 Hz, 1 mA, 20-min switching, once per day for 14 days). Rats in the sham-EA group were needled at non-acu- points [5 mm from Neiguan (PC6)] in the same intervention method as the EA group. After intervention ECG was observed and body weight weighed in all rats. Their hearts were removed by open heart surgery and weighed after anesthesia, and then left ventricle were separated and weighed. At last heart weight index (HWI) and left ventricular weight index (LVWI) were calculated. Protein contents of Raf-1 , p-ERK 1/2, and ERK 1/2 in left ventricular myocardial tissue were detected by Western blot. Results Compared with the normal group, elevated ST-segment amplitude, HWI, LVWI, protein expressions of Raf-1 and p-ERK 1/2 were significantly higher in the model group with statistical significance (P <0. 01). Compared with the model group and the sham-EA group, elevated ST-segment amplitude, HWI, LVWI, protein expressions of Raf-1 and p-ERK 1/2 were significantly lower in the EA group with statistical significance (P <0. 05). Conclusion EA could effectively regulate myocardial ischemia in myocardial hypertrophy rats, reduce heart index, and lower protein expressions of Raf-1 and p-ERK 1/2, which might be one of signal regulating mechanisms for EA improving myocardial hypertrophy through Raf/MEK/ERK pathways.
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Jamieson D, Griffin MJ, Sludden J, Drew Y, Cresti N, Swales K, Merriman M, Allen R, Bevan P, Buerkle M, Mala C, Coyle V, Rodgers L, Dean E, Greystoke A, Banerji U, Wilson RH, Evans TRJ, Anthoney A, Ranson M, Boddy AV, Plummer R. A phase I pharmacokinetic and pharmacodynamic study of the oral mitogen-activated protein kinase kinase (MEK) inhibitor, WX-554, in patients with advanced solid tumours. Eur J Cancer 2016; 68:1-10. [PMID: 27693888 DOI: 10.1016/j.ejca.2016.08.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/15/2016] [Accepted: 08/27/2016] [Indexed: 11/15/2022]
Abstract
PURPOSE We performed a multi-centre phase I study to assess the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of the orally available small molecule mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, WX-554, and to determine the optimal biological dose for subsequent trials. EXPERIMENTAL DESIGN Patients with treatment-refractory, advanced solid tumours, with adequate performance status and organ function were recruited to a dose-escalation study in a standard 3 + 3 design. The starting dose was 25 mg orally once weekly with toxicity, PK and PD guided dose-escalation with potential to explore alternative schedules. RESULTS Forty-one patients with advanced solid tumours refractory to standard therapies and with adequate organ function were recruited in eight cohorts up to doses of 150 mg once weekly and 75 mg twice weekly. No dose-limiting toxicities were observed during the study, and a maximum tolerated dose (MTD) was not established. The highest dose cohorts demonstrated sustained inhibition of extracellular signal-regulated kinase (ERK) phosphorylation in peripheral blood mononuclear cells following ex-vivo phorbol 12-myristate 13-acetate stimulation. There was a decrease of 70 ± 26% in mean phosphorylated (p)ERK in C1 day 8 tumour biopsies when compared with pre-treatment tumour levels in the 75 mg twice a week cohort. Prolonged stable disease (>6 months) was seen in two patients, one with cervical cancer and one with ampullary carcinoma. CONCLUSIONS WX-554 was well tolerated, and an optimal biological dose was established for further investigation in either a once or twice weekly regimens. The recommended phase 2 dose is 75 mg twice weekly.
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Affiliation(s)
- David Jamieson
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Melanie J Griffin
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Julieann Sludden
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Yvette Drew
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; Northern Centre for Cancer Care, Newcastle Freeman Hospital, Newcastle upon Tyne, NE7 7DN, UK
| | - Nicola Cresti
- Northern Centre for Cancer Care, Newcastle Freeman Hospital, Newcastle upon Tyne, NE7 7DN, UK
| | - Karen Swales
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, UK
| | | | | | - Paul Bevan
- WILEX AG, Grillparzerstr. 18, 81675, Munich, Germany
| | | | - Carola Mala
- WILEX AG, Grillparzerstr. 18, 81675, Munich, Germany
| | - Vicky Coyle
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK; Northern Ireland Cancer Center, Belfast City Hospital, Belfast, UK
| | - Lisa Rodgers
- Beatson West of Scotland Cancer Centre, University of Glasgow, Glasgow, G12 OYN, UK
| | - Emma Dean
- The Christie NHS Foundation Trust, The University of Manchester, Manchester, M20 4BX, UK
| | - Alastair Greystoke
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; Northern Centre for Cancer Care, Newcastle Freeman Hospital, Newcastle upon Tyne, NE7 7DN, UK
| | - Udai Banerji
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, UK
| | - Richard H Wilson
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK; Northern Ireland Cancer Center, Belfast City Hospital, Belfast, UK
| | - T R Jeffery Evans
- Beatson West of Scotland Cancer Centre, University of Glasgow, Glasgow, G12 OYN, UK
| | - Alan Anthoney
- St. James's Institute of Oncology, Beckett Street, Leeds, LS9 7TF, UK
| | - Malcolm Ranson
- The Christie NHS Foundation Trust, The University of Manchester, Manchester, M20 4BX, UK
| | - Alan V Boddy
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ruth Plummer
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; Northern Centre for Cancer Care, Newcastle Freeman Hospital, Newcastle upon Tyne, NE7 7DN, UK.
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Luo N, Zhao LC, Shi QQ, Feng ZQ, Chen DL, Li J. Induction of Apoptosis in Human Leukemic Cell Lines by Diallyl Disulfide via Modulation of EGFR/ERK/PKM2 Signaling Pathways. Asian Pac J Cancer Prev 2015; 16:3509-15. [PMID: 25921170 DOI: 10.7314/apjcp.2015.16.8.3509] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diallyl disulfide (DADS) may exert potent anticancer action both in vitro and in vivo. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between DADS and pyruvate kinase (PKM2). MATERIALS AND METHODS KG1α, a leukemia cell line highly expressing PKM2 was used with a cell counting kit (CCK)-8 and flow cytometry (FCM) to investigate the effects of DADS. Relationships between PKM2 and DADS associated with phosphorylation of EGFR, ERK1/2 and MEK, were assessed by western blot analysis. RESULTS In KG1α cells highly expressing PKM2, we found that DADS could affect proliferation, apoptosis and EGFR/ERK/PKM2 signaling pathways, abrogating EGF-induced nuclear accumulation of PKM2. CONCLUSIONS These results suggested that DADS suppressed the proliferation of KG1α cells, providing evidence that its proapoptotic effects are mediated through the inhibition of EGFR/ERK/PKM2 signaling pathways.
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Affiliation(s)
- Nian Luo
- Laboratory of Stem Cells and Tissue Engineering, Histology and Embryology, Chongqing Medical University, Chongqing, China E-mail :
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Barba-Espín G, Clemente-Moreno MJ, Alvarez S, García-Legaz MF, Hernández JA, Díaz-Vivancos P. Salicylic acid negatively affects the response to salt stress in pea plants. Plant Biol (Stuttg) 2011; 13:909-17. [PMID: 21973182 DOI: 10.1111/j.1438-8677.2011.00461.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We studied the effect of salicylic acid (SA) treatment on the response of pea plants to salinity. Sodium chloride (NaCl)-induced damage to leaves was increased by SA, which was correlated with a reduction in plant growth. The content of reduced ascorbate and glutathione in leaves of salt-treated plants increased in response to SA, although accumulation of the respective oxidised forms occurred. An increase in hydrogen peroxide also occurred in leaves of salt-exposed plants treated with SA. In the absence of NaCl, SA increased ascorbate peroxidase (APX; 100 μm) and glutathione-S transferase (GST; 50 μm) activities and increased catalase (CAT) activity in a concentration-dependent manner. Salinity decreased glutathione reductase (GR) activity, but increased GST and CAT activity. In salt-stressed plants, SA also produced changes in antioxidative enzymes: 100 μm SA decreased APX but increased GST. Finally, a concentration-dependent increase in superoxide dismutase (SOD) activity was induced by SA treatment in salt-stressed plants. Induction of PR-1b was observed in NaCl-stressed plants treated with SA. The treatment with SA, as well as the interaction between salinity and SA treatment, had a significant effect on PsMAPK3 expression. The expression of PsMAPK3 was not altered by 70 mm NaCl, but was statistically higher in the absence than in the presence of SA. Overall, the results show that SA treatment negatively affected the response of pea plants to NaCl, and this response correlated with an imbalance in antioxidant metabolism. The data also show that SA treatment could enhance the resistance of salt-stressed plants to possible opportunistic pathogen attack, as suggested by increased PR-1b gene expression.
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Affiliation(s)
- G Barba-Espín
- Grupo de Biotecnología de Frutales, Department of Mejora Vegetal, Campus Espinardo, Murcia, Spain
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Lu TH, Hsieh SY, Yen CC, Wu HC, Chen KL, Hung DZ, Chen CH, Wu CC, Su YC, Chen YW, Liu SH, Huang CF. Involvement of oxidative stress-mediated ERK1/2 and p38 activation regulated mitochondria-dependent apoptotic signals in methylmercury-induced neuronal cell injury. Toxicol Lett 2011; 204:71-80. [PMID: 21549813 DOI: 10.1016/j.toxlet.2011.04.013] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 04/16/2011] [Accepted: 04/18/2011] [Indexed: 11/18/2022]
Abstract
Methylmercury (MeHg) is well-known for causing irreversible damage in the central nervous system as well as a risk factor for inducing neuronal degeneration. However, the molecular mechanisms of MeHg-induced neurotoxicity remain unclear. Here, we investigated the effects and possible mechanisms of MeHg in the mouse cerebrum (in vivo) and in cultured Neuro-2a cells (in vitro). In vivo study showed that the levels of LPO in the plasma and cerebral cortex significantly increased after administration of MeHg (50μg/kg/day) for 7 consecutive weeks. MeHg could also decrease glutathione level and increase the expressions of caspase-3, -7, and -9, accompanied by Bcl-2 down-regulation and up-regulation of Bax, Bak, and p53. Moreover, treatment of Neuro-2a cells with MeHg significantly reduced cell viability, increased oxidative stress damage, and induced several features of mitochondria-dependent apoptotic signals, including increased sub-G1 hypodiploids, mitochondrial dysfunctions, and the activation of PARP, and caspase cascades. These MeHg-induced apoptotic-related signals could be remarkably reversed by antioxidant NAC. MeHg also increased the phosphorylation of ERK1/2 and p38, but not JNK. Pharmacological inhibitors NAC, PD98059, and SB203580 attenuated MeHg-induced cytotoxicity, ERK1/2 and p38 activation, MMP loss, and caspase-3 activation in Neuro-2a cells. Taken together, these results suggest that the signals of ROS-mediated ERK1/2 and p38 activation regulated mitochondria-dependent apoptotic pathways that are involved in MeHg-induced neurotoxicity.
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Affiliation(s)
- Tien-Hui Lu
- Graduate Institute of Drug Safety, College of Pharmacy, China Medical University, Taichung 404, Taiwan
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Feliu L, Oliveras G, Cirac AD, Besalú E, Rosés C, Colomer R, Bardají E, Planas M, Puig T. Antimicrobial cyclic decapeptides with anticancer activity. Peptides 2010; 31:2017-26. [PMID: 20708052 DOI: 10.1016/j.peptides.2010.07.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 07/30/2010] [Accepted: 07/30/2010] [Indexed: 11/27/2022]
Abstract
Antimicrobial peptides have been considered as potential candidates for cancer therapy. We report here the cytotoxicity of a library of 66 antibacterial cyclodecapeptides on human carcinoma cell lines, and their effects on apoptosis [as assessed by cleavage of poly(ADP-ribose) polymerase (PARP)] and cell signaling proteins (p53 and ERK1/2) in cultured human cervical carcinoma cells. A design of experiments approach permitted to analyze the results of a subset of 16 peptides and define rules for high anticancer activity against MDA-MB-231 breast carcinoma cells. Eight peptides were identified with IC(50) values ranging from 18.5 to 57.5 μM against the five cell lines tested, being HeLa cells the most sensitive. Among these sequences, BPC88, BPC96, BPC98, and BPC194 displayed specificity and high cytotoxicity against HeLa cells (IC(50) of 22.5-38.5 μM), showed low hemolytic activity and low cytotoxicity to non-malignant fibroblasts, and were stable to proteases in human serum. Induction of apoptosis by these peptides was observed and the apoptotic effect of BPC88 and BPC96 caused a marked decrease on the activated form of ERK1/2 kinase and an induction of p53. We further showed that BPC96 at low doses synergized the cytotoxic effect of cisplatin. These findings suggest that cyclic decapeptides may represent novel anticancer agents providing a new strategy in cancer therapy.
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Affiliation(s)
- Lidia Feliu
- LIPPSO, Department of Chemistry, University of Girona, Campus Montilivi, E-17071 Girona, Spain
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Feng L, Wang XH, Peng HB. [Effect of ERK1/2 signal pathway on the proliferation of lung fibroblast activated by SiO₂]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2010; 28:565-568. [PMID: 21126445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To observe the effect of ERK1/2 signal pathway activated by SiO₂ in the proliferation of human embryonic lung fibroblast mediated by silicotic alveolar macrophages. METHOD The alveolar macrophages (AM) harvested from silicotic sufferers by bronchoalveolar lavage (BAL) were interacted with SiO₂ suspension once more. HELF, pretreated with the inhibitor PD98059 (50 µmol/L) for 1 hour, were stimulated by conditional supernatant fluid of silicotic sufferers. The experimentation have been classificated four group: blank group, AM control group, SiO₂ treatment group, PD98059 intervention group. The proliferation activity and expressions of Phospho-ERK1/2 of lung fibroblast activated by AM supernatant fluids of silicotic are detected with the MTT assay, flow cytometry and Western blot method after being pretreatmented with PD98059. RESULT The A values of cell proliferation in SiO₂ treatment group and AM control group are 2.6 and 2.0 times that of blank group, in which the difference was statistically significant (P < 0.05). Comparing with SiO₂ treatment group, the A values of every concentrations of PD98059 intervention group decreased with a dose-response relationship, after 10, 25 and 50 µmol/L PD98059 intervention. The 25 and 50 µmol/L PD98059 intervention group were 72.1% and 48.5% of SiO₂ treatment group, which the difference is statistic (P < 0.05). The expression of phospho-ERK1/2 in SiO₂ treatment group was up, which appeared in 15 min and apparent activated in 30 min (A value is 0.4653 ± 0.0265), and then still in the higher state afterwards declined after 60 min. In addition to 15 min, the expression of phospho-ERK1/2 protein in SiO₂ treatment group at each time point are 1.25, 1.23, 1.25 times over the same period AM control group respectively, the differences were statistically significant (P < 0.05). CONCLUSION The silicotic supernatant of alveolar macrophages have promote proliferation of HELF and activation of ERK1/2, which may involve in the development of silicosis pathogenesis by ERK1/2 signal pathway.
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Affiliation(s)
- Li Feng
- Department of Pathology of North China Coal Medical College, Tangshan, Hebei Province, China
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Jager J, Grémeaux T, Gonzalez T, Bonnafous S, Debard C, Laville M, Vidal H, Tran A, Gual P, Le Marchand-Brustel Y, Cormont M, Tanti JF. Tpl2 kinase is upregulated in adipose tissue in obesity and may mediate interleukin-1beta and tumor necrosis factor-{alpha} effects on extracellular signal-regulated kinase activation and lipolysis. Diabetes 2010; 59:61-70. [PMID: 19808894 PMCID: PMC2797946 DOI: 10.2337/db09-0470] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Activation of extracellular signal-regulated kinase-(ERK)-1/2 by cytokines in adipocytes is involved in the alterations of adipose tissue functions participating in insulin resistance. This study aims at identifying proteins regulating ERK1/2 activity, specifically in response to inflammatory cytokines, to provide new insights into mechanisms leading to abnormal adipose tissue function. RESEARCH DESIGN AND METHODS Kinase activities were inhibited with pharmacological inhibitors or siRNA. Lipolysis was monitored through glycerol production. Gene expression in adipocytes and adipose tissue of obese mice and subjects was measured by real-time PCR. RESULTS IkappaB kinase-(IKK)-beta inhibition prevented mitogen-activated protein (MAP) kinase kinase (MEK)/ERK1/2 activation in response to interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha but not insulin in 3T3-L1 and human adipocytes, suggesting that IKKbeta regulated a MAP kinase kinase kinase (MAP3K) involved in ERK1/2 activation induced by inflammatory cytokines. We show that the MAP3K8 called Tpl2 was expressed in adipocytes and that IL-1beta and TNF-alpha activated Tpl2 and regulated its expression through an IKKbeta pathway. Pharmacological inhibition or silencing of Tpl2 prevented MEK/ERK1/2 activation by these cytokines but not by insulin, demonstrating its involvement in ERK1/2 activation specifically in response to inflammatory stimuli. Importantly, Tpl2 was implicated in cytokine-induced lipolysis and in insulin receptor substrate-1 serine phosphorylation. Tpl2 mRNA expression was upregulated in adipose tissue of obese mice and patients and correlated with TNF-alpha expression. CONCLUSIONS Tpl2 is selectively involved in inflammatory cytokine-induced ERK1/2 activation in adipocytes and is implicated in their deleterious effects on adipocyte functions. The deregulated expression of Tpl2 in adipose tissue suggests that Tpl2 may be a new actor in adipose tissue dysfunction in obesity.
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Affiliation(s)
- Jennifer Jager
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
| | - Thierry Grémeaux
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
| | - Teresa Gonzalez
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
| | - Stéphanie Bonnafous
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
- INSERM, U895, Team 8 “Hepatic Complications in Obesity,” Nice, France
- Centre Hospitalier Universitaire of Nice, Digestive Center, Nice, France
| | - Cyrille Debard
- INSERM, U870-INRA U1235, “Metabolic Regulations, Nutrition, and Diabetes,” Lyon, France
| | - Martine Laville
- INSERM, U870-INRA U1235, “Metabolic Regulations, Nutrition, and Diabetes,” Lyon, France
| | - Hubert Vidal
- INSERM, U870-INRA U1235, “Metabolic Regulations, Nutrition, and Diabetes,” Lyon, France
| | - Albert Tran
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
- INSERM, U895, Team 8 “Hepatic Complications in Obesity,” Nice, France
- Centre Hospitalier Universitaire of Nice, Digestive Center, Nice, France
| | - Philippe Gual
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
- INSERM, U895, Team 8 “Hepatic Complications in Obesity,” Nice, France
- Centre Hospitalier Universitaire of Nice, Digestive Center, Nice, France
| | - Yannick Le Marchand-Brustel
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
- Centre Hospitalier Universitaire of Nice, Digestive Center, Nice, France
| | - Mireille Cormont
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
| | - Jean-François Tanti
- Institut National de la Santé et de la Recherche Médicale (INSERM), U895, Mediterranean Center of Molecular Medicine, Team 7 “Molecular and Cellular Physiopathology of Obesity and Diabetes,” Nice, France
- University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France
- Corresponding author: Jean-François Tanti,
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George J, Headen KV, Ogunleye AO, Perry GA, Wilwerding TM, Parrish LC, McVaney TP, Mattson JS, Cerutis DR. Lysophosphatidic Acid signals through specific lysophosphatidic Acid receptor subtypes to control key regenerative responses of human gingival and periodontal ligament fibroblasts. J Periodontol 2009; 80:1338-47. [PMID: 19656035 PMCID: PMC11037860 DOI: 10.1902/jop.2009.080624] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND We showed that the pluripotent platelet growth factor and mediator lysophosphatidic acid (LPA) controls key regenerative responses of human gingival fibroblasts (GFs) and periodontal ligament fibroblasts (PDLFs) and positively modulates their responses to platelet-derived growth factor (PDGF). This study determined which LPA receptor (LPAR) subtype(s) LPA signals through to stimulate mitogenic extracellular signal-regulated kinase (ERK) 1/2 signaling and chemotaxis and to elicit intracellular Ca(2+) increases in GFs and PDLFs because many healing responses are calcium-dependent. METHODS Activation of mitogen-activated protein kinase was determined using Western blotting with an antibody to phosphorylated ERK1/2. Migration responses were measured using a microchemotaxis chamber. GF and PDLF intracellular Ca(2+) mobilization responses to multiple LPA species and LPAR subtype-specific agonists were measured by using a cell-permeable fluorescent Ca(2+) indicator dye. RESULTS LPA stimulated ERK1/2 phosphorylation via LPA(1)(-3). For GFs, LPA(1) preferentially elicited chemotaxis, and LPA(1-3) for PDLFs, as confirmed using subtype-specific agonists. Elevation of intracellular calcium seems to be mediated through LPA(1) and LPA(3), with little, if any, contribution from LPA(2). CONCLUSIONS To the best of our knowledge, this study provides the first evidence that LPA signals through specific LPAR subtypes to stimulate human oral fibroblast regenerative responses. These data, in conjunction with our previous findings showing that LPA modulates GF and PDLF responses to PDGF, suggest that LPA is a factor of emerging importance to oral wound healing.
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Affiliation(s)
- JoJu George
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE
| | - Karmel V. Headen
- Department of Oral Biology, Creighton University School of Dentistry, Omaha, NE
| | | | - Greg A. Perry
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine
| | | | | | | | - John S. Mattson
- Department of Periodontics, Creighton University School of Dentistry
| | - D. Roselyn Cerutis
- Department of Oral Biology, Creighton University School of Dentistry, Omaha, NE
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Kanemura M, Abe M, Ueda M, Ueki M, Awaya A, Sato Y. MS-818 Accelerates Mobilization of Endothelial Progenitor Cells and Differentiation to Endothelial Cells. ACTA ACUST UNITED AC 2009; 11:221-30. [PMID: 15763941 DOI: 10.1080/10623320490904089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
MS-818 that is a synthetic pyrimidine compound and shown to have neurotrophic actions, enhanced basic fibroblast growth factor (bFGF)-induced angiogenesis in vivo. However, the mechanism and whether MS-818 affects endothelial cells (ECs) directly is not known. Here, the authors investigated whether MS-818 alone could induce angiogenesis and tried to clarify the mechanism of neovascularization by MS-818 in terms of angiogenesis and vasculogenesis. The authors show that MS-818 affects ECs directly and induces migration of and tube formation by ECs in vitro (angiogenesis). Furthermore, the authors demonstrate that MS-818 mobilizes endothelial progenitor cells (EPCs) from the bone marrow and potentiates their differentiation to ECs (vasculogenesis). The effect of MS-818 on the endothelial differentiation was further confirmed with an in vitro differentiation system using mouse embryonic stem cells. MS-818 activates the mitogen-activated protein kinase (MAPK) pathway but not the phosphoinositol 3-kinase (PI3K)-Akt pathway in ECs. These results indicate that MS-818, a synthetic compound, promotes both angiogenesis and vasculogenesis.
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Affiliation(s)
- Masanori Kanemura
- Department of Vascular Biology, Institute of Development, Aging, and Cancer, Tohoku University, Seiryo-machi, Sendai, Japan
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Zeng XJ, Zhang LK, Wang HX, Lu LQ, Ma LQ, Tang CS. Apelin protects heart against ischemia/reperfusion injury in rat. Peptides 2009; 30:1144-52. [PMID: 19463748 DOI: 10.1016/j.peptides.2009.02.010] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 02/11/2009] [Accepted: 02/11/2009] [Indexed: 12/20/2022]
Abstract
Apelin, the endogenous ligand of the G protein-coupled APJ receptor, is a peptide mediator with emerging regulatory actions in the heart. We aimed to determine whether the endogenous apelin/APJ system is an intrinsic protective pathway in ischemic/reperfusion injury. A Langendorff model of perfused isolated rat hearts and primary cultured myocardial cells from neonatal rats were used. Cardiac function was monitored and apelin/APJ expression was determined by real-time PCR and Western blot analysis. In rats under I/R, cardiac function was significantly decreased as compared with controls, and APJ was over-expressed at both the mRNA and protein levels (by 7-fold and 35%, respectively, both p<0.01). However, pre-administration of apelin (30pmol/L) greatly ameliorated the reduced heart function. To gain mechanistic insight into the cardio-protective effects of apelin/APJ, cultured cardiomyocytes were treated with apelin (30 pmol/L), and those under hypoxia/re-oxygenation showed H/R-induced apoptosis and up-regulated apelin/APJ mRNA expression by 6-fold and 7-fold, respectively (both p<0.01). And lactate dehydrogenase leakage was greatly increased as well. Meanwhile, apoptosis, the generation of reactive oxygen species and malonaldehyde content as well as lactate dehydrogenase leakage were inhibited by apelin. Furthermore, apelin enhanced superoxide dismutase activity and phosphorylation of extracellular signal-regulated kinase 1/2 and Akt after hypoxia/re-oxygenation. In conclusion, apelin/APJ has protective effects in ischemic heart disease and might constitute an important therapy target.
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Affiliation(s)
- Xiang Jun Zeng
- Department of Pathophysiology, Capital Medical University, Beijing, China
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Abstract
Two cardiac hormones, vessel dilator and kaliuretic peptide, localize to fibroblasts with immunohistochemistry. Vessel dilator and kaliuretic peptide were investigated in dose-response and time-sequenced experiments for their cell signaling of extracellular signal-regulated kinases 1/2 in human fibroblasts to test the hypothesis that these two cardiovascular hormones contribute to fibroblast proliferation by activating extracellular signal-regulated kinases 1/2. Vessel dilator at 10 pM (physiological range) enhanced the phosphorylation of extracellular signal-regulated kinases 1/2 by 188+/-9% (p<0.001) in 10 min and, maximally, by 200+/-10% in 15 min (p<0.001). Vessel dilator at 10 nM enhanced the phosphorylation of extracellular signal-regulated kinases 1/2 by 107+/-5% (p<0.01) in 10 min. Kaliuretic peptide at 10 pM enhanced the activation of extracellular signal-regulated kinases 1/2 by 389+/-19% in 10 min (p<0.001). Kaliuretic peptide at 10 nM enhanced the phosphorylation of extracellular signal-regulated kinases 1/2 by 82+/-4% (p<0.01). Our results show that both cardiac hormones activate extracellular signal-regulated kinases 1/2 in human fibroblasts, suggesting that they may have a role in enhancing fibroblast proliferation.
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Affiliation(s)
- Y Sun
- Department of Internal Medicine, Molecular Pharmacology and Physiology, James A. Haley Veterans Medical Center and University of South Florida Cardiac Hormone Center, Tampa, Florida 33612, USA
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Carr KD, de Vaca SC, Sun Y, Chau LS, Pan Y, Dela Cruz J. Effects of the MEK inhibitor, SL-327, on rewarding, motor- and cellular-activating effects of D-amphetamine and SKF-82958, and their augmentation by food restriction in rat. Psychopharmacology (Berl) 2009; 201:495-506. [PMID: 18766328 PMCID: PMC2803695 DOI: 10.1007/s00213-008-1313-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 08/20/2008] [Indexed: 12/12/2022]
Abstract
RATIONALE Food restriction (FR) enhances learned and unlearned behavioral responses to drugs of abuse and increases D-1 dopamine (DA) receptor-mediated activation of extracellular signal-regulated kinases (ERK) 1/2 MAP kinase in nucleus accumbens (NAc). While a role has been established for ERK signaling in drug-mediated associative learning, it is not clear whether ERK regulates unconditioned behavioral effects of abused drugs. OBJECTIVES The purpose of this study was to determine whether blockade of ERK signaling, using the brain-penetrant MEK inhibitor, SL-327, decreases behavioral or NAc cellular responses to acute drug treatment and their augmentation by FR. MATERIALS AND METHODS Separate experiments assessed the effects of SL-327 (50 mg/kg, intraperitoneally) on (1) the reward-potentiating effect of D-amphetamine in an intracranial self-stimulation protocol, (2) the locomotor-activating effect of the D-1 agonist, SKF-82958, and (3) Fos-immunostaining induced in the NAc by SKF-82958. RESULTS FR rats displayed enhanced responses to drug treatment on all measures. SL-327 had no effect on sensitivity to rewarding brain stimulation or the reward-potentiating effect of D-amphetamine. The MEK inhibitor, U0126, microinjected into the NAc was also without effect. The locomotor-activating effect of SKF-82958 was unaffected by SL-327. In contrast, SL-327 decreased NAc Fos-immunostaining and abolished the difference between feeding groups. CONCLUSIONS These results support the conclusion that ERK signaling does not mediate unlearned behavioral responses to drug treatment. However, the upregulation of ERK and downstream transcriptional responses to acute drug treatment may underlie the reported enhancement of reward-related learning in FR subjects.
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Affiliation(s)
- Kenneth D Carr
- Department of Psychiatry, School of Medicine, New York University, 550 First Avenue, New York, NY 10016, USA.
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Cheng YW, Chang CY, Lin KL, Hu CM, Lin CH, Kang JJ. Shikonin derivatives inhibited LPS-induced NOS in RAW 264.7 cells via downregulation of MAPK/NF-kappaB signaling. J Ethnopharmacol 2008; 120:264-271. [PMID: 18835347 DOI: 10.1016/j.jep.2008.09.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 09/01/2008] [Accepted: 09/03/2008] [Indexed: 05/26/2023]
Abstract
AIM OF THE STUDY Shikonin/alkannin (SA) derivatives, analogs of naphthoquinone pigments, are the major components of root extracts of the Chinese medicinal herb (Lithospermum erythrorhizon; LE) and widely distributed in several folk medicines. In the present study, the effect and the underline molecular mechanism of shikonin derivatives isolated from root extracts of Lithospermum euchroma on lipopolysaccharide (LPS)-induced inflammatory response were investigated. MATERIALS AND METHODS Effects of five SA derivatives, including SA, acetylshikonin, beta,beta-dimethylacrylshikonin, 5,8-dihydroxy-1.4-naphthoquinone, and 1,4-naphthoquinone on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in mouse macrophage RAW264.7 cells were examined. RESULTS Data suggested that SA derivatives inhibited LPS-induced NO and PGE(2) production, and iNOS protein expression. RT-PCR analysis showed that SA derivatives diminished LPS-induced iNOS mRNA expression. Moreover, the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 in LPS-stimulated RAW 264.7 cells was concentration-dependently suppressed by SA derivatives. SA inhibited NF-kappaB activation by prevention of the degradation of inhibitory factor-kappaB and p65 level in nuclear fractions induced by LPS. CONCLUSIONS Taken together, these results suggest that the anti-inflammatory properties of SA derivatives might result from inhibition of iNOS protein expression through the downregulation of NF-kappaB activation via suppression of phosphorylation of ERK, in LPS-stimulated RAW 264.7 cells.
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Affiliation(s)
- Yu Wen Cheng
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan, Republic of China.
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Bonacasa B, Sanchez ML, Rodriguez F, Lopez B, Quesada T, Fenoy FJ, Hernández I. 2-Methoxyestradiol attenuates hypertension and coronary vascular remodeling in spontaneously hypertensive rats. Maturitas 2008; 61:310-6. [PMID: 19010616 DOI: 10.1016/j.maturitas.2008.09.028] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 09/24/2008] [Accepted: 09/26/2008] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Accumulating data provide evidence that some metabolites of 17beta-estradiol are biologically active and mediate multiple effects on the cardiovascular and renal systems. We investigated the effect of 2-methoxyestradiol (an active metabolite of estradiol with non-feminizing activity) on the development of hypertension and myocardial vascular remodeling in male and female ovarectomized SHR. METHODS Rats were divided into five groups: intact females, ovarectomized (OVX), OVX+ 2-methoxyestradiol (2ME), control males, and male+2ME. Systolic blood pressure was determined from 10 to 18 weeks. Structural changes in coronary vessels were quantified by an image analyzer. Immunoblotting of phosphorylated ERK1/2 and NADPH oxidase activity were performed on mesenteric arteries. RESULTS Treatment with 2ME reduced the increase in systolic blood pressure in male and ovarectomized rats to values not different from those obtained in intact females. Myocardial arterioles and small arteries showed significant increases in wall-to-lumen ratio and perivascular fibrosis in male and ovarectomized rats when compared with intact females. NADPH oxidase activity was increased in mesenteric arteries from males and ovarectomized females as compared with intact females. Finally, the expression of phosphorilated ERK1/2 were significantly higher in mesenteric arteries from male and ovariectomized animals than in those from intact females. Those effects of ovarectomy and gender differences were totally or partially prevented by treatment with 2-methoxyestradiol. CONCLUSIONS These data demonstrate that 2-methoxyestradiol protects the vasculature from hypertension-induced myocardial arterial remodeling in male and ovarectomized SHR, and that might be in part related to decreased superoxide generation and ERK1/2 activation.
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Affiliation(s)
- B Bonacasa
- Department of Physiology, Facultad de Medicina, Universidad de Murcia, Spain
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Tokuda H, Takai S, Matsushima-Nishiwaki R, Hanai Y, Adachi S, Minamitani C, Mizutani J, Otsuka T, Kozawa O. Function of Rho-kinase in prostaglandin D2-induced interleukin-6 synthesis in osteoblasts. Prostaglandins Leukot Essent Fatty Acids 2008; 79:41-6. [PMID: 18771907 DOI: 10.1016/j.plefa.2008.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 06/27/2008] [Accepted: 07/10/2008] [Indexed: 11/24/2022]
Abstract
We have previously reported that prostaglandin D2 (PGD2) stimulates interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells. In the present study, we investigated whether Rho-kinase is implicated in the PGD2-stimulated IL-6 synthesis in MC3T3-E1 cells. PGD2 time-dependently induced the phosphorylation of myosin phosphatase targeting subunit (MYPT-1), a Rho-kinase substrate. Y27632, a specific Rho-kinase inhibitor, significantly reduced the PGD2-stimulated IL-6 synthesis as well as the MYPT-1 phosphorylation. Fasudil, another inhibitor of Rho-kinase, suppressed the PGD2-stimulated IL-6 synthesis. The PGD2-stimulated IL-6 synthesis was reduced by PD98059, a MEK inhibitor, and SB203580, an inhibitor of p38 mitogen-activated protein (MAP) kinase, but not SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). However, Y27632 and fasudil failed to affect the PGD2-induced phosphorylation of p44/p42 MAP kinase. On the other hand, Y27632 as well as fasudil markedly attenuated the PGD2-induced phosphorylation of p38 MAP kinase. In addition, PGD2 additively induced IL-6 synthesis in combination with endothelin-1 which induces IL-6 synthesis through p38 MAP kinase regulated by Rho-kinase. These results strongly suggest that Rho-kinase regulates PGD2-stimulated IL-6 synthesis via p38 MAP kinase activation in osteoblasts.
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Affiliation(s)
- Haruhiko Tokuda
- Department of Clinical Laboratory, National Hospital for Geriatric Medicine, National Center for Geriatrics and Gerontology, 36-3 Gengo, Obu, Aichi 474-8511, Japan.
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Umannová L, Neča J, Andrysík Z, Vondráček J, Upham B, Trosko J, Hofmanová J, Kozubík A, Machala M. Non-dioxin-like polychlorinated biphenyls induce a release of arachidonic acid in liver epithelial cells: a partial role of cytosolic phospholipase A(2) and extracellular signal-regulated kinases 1/2 signalling. Toxicology 2008; 247:55-60. [PMID: 18367304 PMCID: PMC2577785 DOI: 10.1016/j.tox.2008.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 02/06/2008] [Accepted: 02/06/2008] [Indexed: 01/07/2023]
Abstract
Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) have been shown to act as tumor promoters in liver; however, the exact mechanisms of their action are still only partially understood. One of the interesting effects of NDL-PCBs is the acute inhibition of gap junctional intercellular communication (GJIC), an effect, which has been often found to be associated with tumor promotion. As previous studies have suggested that NDL-PCB-induced disruption of lipid signalling pathways might correspond with GJIC inhibition, we investigated effects of PCBs on the release of arachidonic acid (AA) in the rat liver epithelial WB-F344 cell line, a well-established model of liver progenitor cells. We found that both 2,2',4,4'-tetrachlorobiphenyl (PCB 47) and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), but not the dioxin-like, non-ortho-substituted, 3,3',4,4',5-pentachlorobiphenyl (PCB 126), induce a massive release of AA. The AA release, induced by PCB 153, was partially inhibited by extracellular signal-regulated kinases 1/2 (ERK1/2) signalling inhibitor, U0126, and by cytosolic phospholipase A(2) (cPLA(2)) inhibitor, AACOCF(3). Although PCB 153 induced both ERK1/2 and p38 activation, the specific p38 kinase inhibitor, SB203580, had no effect on AA release. Inhibitors of other phospholipases, including phosphatidylcholine-specific phospholipase C or phosphatidylinositol-specific phospholipase C, were also without effect. Taken together, our findings suggest that the AA release, induced by non-dioxin-like PCBs in liver progenitor cell line, is partially mediated by cytosolic PLA(2) and regulated by ERK1/2 kinases. Our results suggest that more attention should be paid to cell signalling pathways regulated by AA or eicosanoids after PCB exposure, which might be involved in their toxic effects.
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Affiliation(s)
- L. Umannová
- Department of Cytokinetics, Institute of Biophysics ASCR, 612 65 Brno, Czech Republic
- Department of Chemistry and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - J. Neča
- Department of Chemistry and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - Z. Andrysík
- Department of Cytokinetics, Institute of Biophysics ASCR, 612 65 Brno, Czech Republic
| | - J. Vondráček
- Department of Cytokinetics, Institute of Biophysics ASCR, 612 65 Brno, Czech Republic
- Department of Chemistry and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - B.L. Upham
- National Food Safety & Toxicology Center, Michigan State University, East Lansing MI 48824, USA
| | - J.E. Trosko
- National Food Safety & Toxicology Center, Michigan State University, East Lansing MI 48824, USA
| | - J. Hofmanová
- Department of Cytokinetics, Institute of Biophysics ASCR, 612 65 Brno, Czech Republic
- Institute of Experimental Biology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
| | - A. Kozubík
- Department of Cytokinetics, Institute of Biophysics ASCR, 612 65 Brno, Czech Republic
- Institute of Experimental Biology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
| | - M. Machala
- Department of Chemistry and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
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Guan X, Hu J, Li S. Involvement of extracellular signal-regulated protein kinase in acute cocaine-induced c-fos in nucleus accumbens. Neurosci Lett 2008; 438:155-8. [PMID: 18479823 DOI: 10.1016/j.neulet.2008.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 03/23/2008] [Accepted: 04/07/2008] [Indexed: 11/19/2022]
Abstract
It is well known that acute cocaine administration increases c-Fos expression that is involved in cocaine-induced persistent changes in the central nervous system. In the present study, we investigated a possible involvement of extracellular signal-regulated protein kinase (ERK) in induction of c-fos expression in response to acute cocaine treatment in nucleus accumbens (NAc). We found that inhibition of ERK activation significantly attenuated cocaine-induced c-fos expression at both protein and mRNA levels in the NAc. Furthermore, using an immunofluorescent staining approach, we found that inhibition of ERK activation completely abolished cocaine-induced increase in number of c-Fos-positive cells in the core region of NAc, whereas, in shell region of NAc, inhibition of ERK activation partially attenuated cocaine-induced c-Fos expression. Our findings suggest that ERK might participate in cocaine-induced c-fos expression in the NAc, particularly in the core region of NAc.
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Affiliation(s)
- Xiaowei Guan
- Department of Pharmacology, Nanjing Medical University, 140 HanZhong Road, Nanjing 210029, China
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25
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Nicola C, Chirpac A, Lala PK, Chakraborty C. Roles of Rho guanosine 5'-triphosphatase A, Rho kinases, and extracellular signal regulated kinase (1/2) in prostaglandin E2-mediated migration of first-trimester human extravillous trophoblast. Endocrinology 2008; 149:1243-51. [PMID: 18079197 DOI: 10.1210/en.2007-1136] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prostaglandin (PG) E(2) may regulate invasiveness of human placenta because we previously reported stimulation of migration of placental trophoblasts by PGE(2) acting through PGE receptor (EP)-1 and activating calpain. RhoA GTPase and its important effector Rho kinase (ROCK) have also been previously shown to regulate trophoblast migration. Using immortalized HTR-8/SVneo trophoblast cells and first-trimester human chorionic villus explant cultures on matrigel, we further examined the role of RhoA/ROCK and MAPK (ERK1/2) pathways on PGE(2)-mediated stimulation of trophoblast migration. Migration of cytotrophoblasts was shown to be inhibited by treatment of the trophoblast cell line and chorionic villus explants with either cell-permeable C3 transferase or selective RhoA small interfering RNA. These inhibitions were significantly mitigated by the addition of PGE(2), an EP1/EP3 agonist or an EP3/EP4 agonist, suggesting that RhoA plays an important role in trophoblast migration but may not be obligatory for PGE(2) action. Treatment of HTR-8/SVneo cells with nonselective ROCK inhibitor Y27632 or ROCK small interfering RNAs inhibited migration of these cells, which could not be rescued with PGE(2) or the other two EP agonists, suggesting the obligatory role of ROCK in PGE(2)-induced migratory response. Furthermore, U0126, an inhibitor of MAPK kinases MEK1 and MEK2, abrogated PGE(2)-induced migration of trophoblasts, and PGE(2) or the other two EP agonists stimulated ERK1/2 activation in trophoblasts, which was not abrogated by pretreatment with C3 transferase, indicating that ERK signaling pathway is an efficient alternate pathway for RhoA in PGE(2)-mediated migration of trophoblasts. These results suggest that ROCK and ERK1/2 play more important roles than RhoA in PGE(2)-mediated migration stimulation of first-trimester trophoblasts.
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Affiliation(s)
- Catalin Nicola
- Department of Anatomy, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada N6A 5C1
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Ryu M, Kim EH, Chun M, Kang S, Shim B, Yu YB, Jeong G, Lee JS. Astragali Radix elicits anti-inflammation via activation of MKP-1, concomitant with attenuation of p38 and Erk. J Ethnopharmacol 2008; 115:184-193. [PMID: 17996413 DOI: 10.1016/j.jep.2007.09.027] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 09/21/2007] [Accepted: 09/21/2007] [Indexed: 05/25/2023]
Abstract
Although Astragali Radix (Astragalus, AR), the root of Astragalus membranaceus (Fisch) Bunge, is widely used in oriental medicine for tonifying the immune response and improving circulation, the underlying mechanism(s) by which these effects are induced remains unclear. Here, we report that AR displays anti-inflammatory effects in zymosan air-pouch mice by reducing the expression of iNOS, COX-2, IL-6, IL-1beta and TNF-alpha and by decreasing the production of nitric oxide (NO). In a similar manner, AR reduces the expression of IL-6, iNOS, and COX-2 in lipopolysaccharide (LPS)-treated Raw 264.7 cells. We further demonstrate that AR attenuates the activity of p38 and Erk1/2 and stimulates mitogen-activated protein kinase phosphatase-1 (MKP-1) in LPS-treated Raw 264.7 cells. Additionally, AR interferes with the translocation of NFkappaB to the nucleus, subsequently resulting in NFkappaB-dependent transcriptional repression. Taken together, these data reveal that AR has an anti-inflammatory effect that is mediated by the MKP-1-dependent inactivation of p38 and Erk1/2 and inhibition of NFkappaB-mediated transcription. These results imply that the AR herb has a potential anti-inflammatory activity.
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Affiliation(s)
- Minsook Ryu
- Department of Biological Sciences, Ajou University, Republic of Korea
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27
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van Tol HTA, van Eerdenburg FJCM, Colenbrander B, Roelen BAJ. Enhancement of Bovine oocyte maturation by leptin is accompanied by an upregulation in mRNA expression of leptin receptor isoforms in cumulus cells. Mol Reprod Dev 2008; 75:578-87. [PMID: 17886271 DOI: 10.1002/mrd.20801] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this study, the mechanisms of supposed leptin action on oocyte maturation were examined. Expression of leptin mRNA, as determined with RT-PCR, was present in oocytes but not in cumulus cells. The long isoform of the leptin receptor (ObR-L) was expressed exclusively in cumulus cells after 7 and 23 hr of maturation. In oocytes the expression of the short receptor isoform (ObR-S) and all the receptor isoforms combined (ObR-T) did not change during maturation, as determined by quantitative RT-PCR, but in cumulus cells there was a significant increase in ObR-S transcripts after 7 hr of maturation. To determine if leptin plays a role in resumption of meiosis, oocytes meiotically arrested by the connection of the cumulus to a piece of granulosa layer were exposed to leptin. After 23 hr of culture, the proportion of oocytes that had resumed meiosis did not differ from the control. Exposure of COCs to leptin (1,000 ng/ml) resulted after 17 hr of maturation in a smaller proportion of oocytes that was still in metaphase-I stage (M-I) compared to the control group. Fertilization of oocytes after maturation in the presence of leptin resulted in a larger proportion of embryos that had developed to the 8-cell stage on Day 5 compared to the control group and in more blastocysts on Day 8 of culture. It is concluded that leptin enhances meiotic maturation of bovine oocytes, and that this effect is cumulus cell-mediated.
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Affiliation(s)
- Helena T A van Tol
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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Nguyen LN, Holdren MS, Nguyen AP, Furuya MH, Bianchini M, Levy E, Mordoh J, Liu A, Guncay GD, Campbell JS, Parks WT. Sorting nexin 1 down-regulation promotes colon tumorigenesis. Clin Cancer Res 2007; 12:6952-9. [PMID: 17145813 DOI: 10.1158/1078-0432.ccr-06-0317] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Colon cancer is one of the most common human malignancies, yet studies have only begun to identify the multiple mechanisms that underlie the development of this tumor. In this study, we have identified a novel mechanism, dysregulation of endocytic sorting, which promotes colon cancer development. EXPERIMENTAL DESIGN Immunohistochemical and microarray analyses were done on human colon cancer tissue specimens to determine the levels of one endocytic protein, sorting nexin 1 (SNX1). SW480 cells, a human colon cancer cell line that retains a relatively high level of SNX1 expression, were used to assess the effects of down-regulating this protein by small hairpin RNA. Activation of signal transduction cascades was evaluated in these cells using Western blotting, and multiple functional assays were done. RESULTS We determined by immunohistochemistry that the level of SNX1 was significantly down-regulated in 75% of human colon cancers. In corroborative studies using microarray analysis, SNX1 message was significantly decreased (log(2) ratio less than -1) for 8 of 19 colon carcinomas. Cell lines with reduced SNX1 levels showed increased proliferation, decreased apoptosis, and decreased susceptibility to anoikis. They also showed increased activation of epidermal growth factor receptor and extracellular signal-regulated kinase 1/2 in response to epidermal growth factor. This increased activation was abolished by inhibition of endocytosis. CONCLUSIONS These data suggest that loss of SNX1 may play a significant role in the development and aggressiveness of human colon cancer, at least partially through the mechanism of increased signaling from endosomes. Further, these findings suggest that dysregulation of endocytic proteins may represent a new paradigm in the process of carcinogenesis.
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Affiliation(s)
- Lananh N Nguyen
- Department of Pathology, University of Washington, Seattle, Washington 98195, USA
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29
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Georgakis GV, Li Y, Rassidakis GZ, Medeiros LJ, Younes A. The HSP90 inhibitor 17-AAG synergizes with doxorubicin and U0126 in anaplastic large cell lymphoma irrespective of ALK expression. Exp Hematol 2007; 34:1670-9. [PMID: 17157164 DOI: 10.1016/j.exphem.2006.07.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 07/08/2006] [Accepted: 07/10/2006] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Heat shock protein 90 (HSP90) chaperones and maintains the molecular integrity of a variety of signal transduction proteins, including the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) oncogenic protein, a genetic abnormality that is frequently observed in anaplastic large cell lymphoma (ALCL) cells. Here we demonstrate that HSP90 is overexpressed in primary and cultured ALK-positive and ALK-negative ALCL cells, and we evaluate the potential role of the small molecule inhibitor of HSP90, 17-allylamino-17-demethoxygeldanamycin (17-AAG) in treating ALCL. METHODS The antiproliferative effect of 17-AAG-cultured cells was determined by MTS assay. Apoptosis and cell-cycle arrest were determined by Annexin-V/propidium iodide and propidium iodide staining, respectively, and fluorescein-activated cell sorting analysis. Expression of HSP90 was evaluated by immunohistochemistry, and molecular changes were determined by Western blot. RESULTS Treatment of cultured ALCL cells with 17-AAG induced cell-cycle arrest and apoptosis, irrespective of ALK expression. At the molecular level, 17-AAG induced degradation of ALK and Akt proteins, dephosphorylated extracellular signal-regulated kinase, and degraded the cell-cycle regulatory protein cyclin D1 and its cyclin-dependent kinases, CDK4 and CDK6, but had a differential effect on p27 and p53 proteins. Inhibition of extracellular signal-regulated kinase phosphorylation by the mitogen activated protein kinase inhibitor U0126 induced cell death in all ALCL cell lines, and sublethal concentration 17-AAG showed synergistic antiproliferative effects when combined with U0126 or doxorubicin. CONCLUSION Our data demonstrate that targeting HSP90 function by 17-AAG may offer a novel therapeutic strategy for ALCL, either as single-agent activity or by combining 17-AAG with conventional or targeted therapeutic schemes.
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Affiliation(s)
- Georgios V Georgakis
- Departments of Lymphoma and Myeloma, The University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030, USA
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30
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Marin-Kuan M, Nestler S, Verguet C, Bezençon C, Piguet D, Delatour T, Mantle P, Cavin C, Schilter B. MAPK-ERK activation in kidney of male rats chronically fed ochratoxin A at a dose causing a significant incidence of renal carcinoma. Toxicol Appl Pharmacol 2007; 224:174-81. [PMID: 17651772 DOI: 10.1016/j.taap.2007.06.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 05/16/2007] [Accepted: 06/26/2007] [Indexed: 11/26/2022]
Abstract
Kidney samples of male Fischer 344 (F-344) rats fed a carcinogenic dose of OTA over 7 days, 21 days and 12 months were analysed for various cell signalling proteins known to be potentially involved in chemical carcinogenicity. OTA was found to increase the phosphorylation of atypical-PKC. This was correlated with a selective downstream activation of the MAP-kinase extracellular regulated kinases isoforms 1 and 2 (ERK1/2) and of their substrates ELK1/2 and p90RSK. Moreover, analysis of effectors acting upstream of PKC indicated a possible mobilisation of the insulin-like growth factor-1 receptor (lGFr) and phosphoinositide-dependent kinase-1 (PDK1) system. An increased histone deacetylase (HDAC) enzymatic activity associated with enhanced HDAC3 protein expression was also observed. These findings are potentially relevant with respect to the understanding of OTA nephrocarcinogenicity. HDAC-induced gene silencing has previously been shown to play a role in tumour development. Furthermore, PKC and the MEK-ERK MAP-kinase pathways are known to play important roles in cell proliferation, cell survival, anti-apoptotic activity and renal cancer development.
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Affiliation(s)
- M Marin-Kuan
- Nestlé Research Center, PO Box 44, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Switzerland.
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31
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Secker GA, Shortt AJ, Sampson E, Schwarz QP, Schultz GS, Daniels JT. TGFbeta stimulated re-epithelialisation is regulated by CTGF and Ras/MEK/ERK signalling. Exp Cell Res 2007; 314:131-42. [PMID: 17915216 DOI: 10.1016/j.yexcr.2007.09.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 08/31/2007] [Accepted: 09/04/2007] [Indexed: 12/13/2022]
Abstract
The complex mechanisms by which transforming growth factor beta (TGFbeta) regulate re-epithelialisation following injury of stratified epithelia are not fully understood. TGFbeta signals via binding to distinct receptors activating downstream effectors, including Smads which initiate transcription of target genes. However, studies have shown that TGFbeta can also signal independently of Smads through MAPK pathways, demonstrating the diversity of TGFbeta signalling. Connective tissue growth factor (CTGF) is strongly induced by and acts downstream of TGFbeta causing pathophysiology in tissues by inducing matrix deposition, conversion of fibroblasts into contractile myofibroblasts (e.g. dermis and corneal stroma) and stimulation of epithelial-to-mesenchymal transition (e.g. kidney and lung) all of which are known to cause fibrosis. However, a role for CTGF in epithelial cell function which does not involve direct contribution to fibrosis has not been demonstrated. We show for the first time that synthesis of CTGF in cultures of human corneal epithelial cells is induced by TGFbeta through the Ras/MEK/ERK MAPK signalling pathway and that this is required for re-epithelialisation to occur through cell migration. These data reveal a novel function for CTGF in the regulation of epithelial tissue repair beyond its established role in fibrosis, and further highlight the complexity of TGFbeta regulation of epithelial cell function.
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Affiliation(s)
- Genevieve A Secker
- Department of Pathology, Cells for Sight Transplantation and Research Programme, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
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Förster K, Kuno A, Solenkova N, Felix SB, Krieg T. The δ-opioid receptor agonist DADLE at reperfusion protects the heart through activation of pro-survival kinases via EGF receptor transactivation. Am J Physiol Heart Circ Physiol 2007; 293:H1604-8. [PMID: 17545478 DOI: 10.1152/ajpheart.00418.2007] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The specific δ-opioid receptor agonist [d-Ala2-d-Leu5]enkephalin (DADLE) protects against infarction in the heart when given before ischemia. In rabbit, this protection leads to phosphorylation of the pro-survival kinases Akt and extracellular signal-regulated kinase (ERK) and is dependent on transactivation of the epidermal growth factor receptor (EGFR). DADLE reportedly protects rat hearts at reperfusion. We therefore tested whether DADLE at reperfusion could protect isolated rabbit hearts subjected to 30 min of regional ischemia and 120 min of reperfusion and whether this protection is dependent on Akt, ERK, and EGFR. DADLE (40 nM) was infused for 1 h starting 5 min before reperfusion and reduced infarct size from 31.0 ± 2.3% in the control group to 14.6 ± 1.6% ( P = 0.01). This protection was abolished by cotreatment of the metalloproteinase inhibitor (MPI) and the EGFR inhibitor AG1478. In contrast, 20 nM DADLE, although known to be protective before ischemia, failed to protect. Western blotting revealed that DADLE's protection was correlated to increase in phosphorylation of the kinases Akt and ERK1 and -2 in reperfused hearts (2.5 ± 0.5, 1.6 ± 0.2, and 2.3 ± 0.7-fold of baseline levels, P < 0.05 vs. control). The DADLE-dependent increases in Akt and ERK1/2 phosphorylation were abolished by either MPI or AG1478, confirming a signaling through the EGFR pathway. Additionally, DADLE treatment increased phosphorylation of EGFR (1.4 ± 0.2-fold, P = 0.03 vs. control). Thus the δ-opioid agonist DADLE protects rabbit hearts at reperfusion through activation of the pro-survival kinases Akt and ERK and is dependent on the transactivation of the EGFR.
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Affiliation(s)
- Karina Förster
- Department of Cardiology, Ernst-Moritz-Arndt University, Loefflerstr. 23, 17487 Greifswald, Germany
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Swiatek-De Lange M, Stampfl A, Hauck SM, Zischka H, Gloeckner CJ, Deeg CA, Ueffing M. Membrane-initiated effects of progesterone on calcium dependent signaling and activation of VEGF gene expression in retinal glial cells. Glia 2007; 55:1061-73. [PMID: 17551930 DOI: 10.1002/glia.20523] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neurosteroids, such as progesterone, influence central nervous system development and function by regulating a broad spectrum of physiological processes. Here, we investigated membrane-initiated actions of progesterone in the retina and identified the membrane-associated progesterone receptor component 1 (PGRMC1). We found PGRMC1 expressed mainly in retinal Muller glia (RMG) and retinal pigment epithelium, and localized uniquely to microsomal and plasma membrane fractions. In RMG, membrane-impermeable progesterone conjugate induced calcium influx and subsequent phosphatidylinositol 3-kinase-mediated phosphorylation of PKC and ERK-1/2. Induction by progesterone also led to PKC-dependent activation of VEGF gene expression and protein synthesis, suggesting a contribution of membrane-initiated hormone effects to VEGF induced neovascularization within retina.
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Affiliation(s)
- Magdalena Swiatek-De Lange
- Institute of Human Genetics, GSF National-Research Center for Environment and Health, Neuherberg, Germany
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Fibuch EE, Wang JQ. Inhibition of the MAPK/ERK cascade: a potential transcription-dependent mechanism for the amnesic effect of anesthetic propofol. Neurosci Bull 2007; 23:119-24. [PMID: 17592535 PMCID: PMC5550596 DOI: 10.1007/s12264-007-0017-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Intravenous anesthetics are known to cause amnesia, but the underlying molecular mechanisms remain elusive. To identify a possible molecular mechanism, we recently turned our attention to a key intracellular signaling pathway organized by a family of mitogen-activated protein kinases (MAPKs). As a prominent synapse-to-nucleus superhighway, MAPKs couple surface glutamate receptors to nuclear transcriptional events essential for the development and/or maintenance of different forms of synaptic plasticity (long-term potentiation and long-term depression) and memory formation. To define the role of MAPK-dependent transcription in the amnesic property of anesthetics, we conducted a series of studies to examine the effect of a prototype intravenous anesthetic propofol on the MAPK response to N-methyl-D-aspartate receptor (NMDAR) stimulation in hippocampal neurons. Our results suggest that propofol possesses the ability to inhibit NMDAR-mediated activation of a classic subclass of MAPKs, extracellular signal-regulated protein kinase 1/2 (ERK1/2). Concurrent inhibition of transcriptional activity also occurs as a result of inhibited responses of ERK1/2 to NMDA. These findings provide first evidence for an inhibitory modulation of the NMDAR-MAPK pathway by an intravenous anesthetic and introduce a new avenue to elucidate a transcription-dependent mechanism processing the amnesic effect of anesthetics.
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Affiliation(s)
- Eugene E. Fibuch
- Department of Anesthesiology, University of Missouri-Kansas City School of Medicine, Saint Luke’s Hospital, Kansas City, Missouri 64108 USA
| | - John Q. Wang
- Department of Anesthesiology, University of Missouri-Kansas City School of Medicine, Saint Luke’s Hospital, Kansas City, Missouri 64108 USA
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Bourgin P, Fabre V, Huitrón-Reséndiz S, Henriksen SJ, Prospero-Garcia O, Criado JR, de Lecea L. Cortistatin promotes and negatively correlates with slow-wave sleep. Eur J Neurosci 2007; 26:729-38. [PMID: 17686045 DOI: 10.1111/j.1460-9568.2007.05696.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sleep need is characterized by the level of slow-wave activity (SWA) and increases with time spent awake. The molecular nature of this sleep homeostatic process is practically unknown. Here, we show that intracerebroventricular administration of the neuropeptide, cortistatin (CST-14), enhances EEG synchronization by selectively promoting deep slow-wave sleep (SWS) during both the light and dark period in rats. CST-14 also increases the level of slow-wave activity (SWA) within deep SWS during the first two hours following CST-14 administration. Steady-state levels of preprocortistatin mRNA oscillate during the light:dark cycle and are four-fold higher upon total 24-h sleep deprivation, returning progressively to normal levels after eight hours of sleep recovery. Preprocortistatin mRNA is expressed upon sleep deprivation in a particular subset of cortical interneurons that colocalize with c-fos. In contrast, the number of CST-positive cells coexpressing pERK1/2 decreases under sleep deprivation. The capacity of CST-14 to increase SWA, together with preprocortistatin's inverse correlation with time spent in SWS, suggests a potential role in sleep homeostatic processes.
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Affiliation(s)
- Patrice Bourgin
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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36
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Ryu JY, Whang J, Park H, Im JY, Kim J, Ahn MY, Lee J, Kim HS, Lee BM, Yoo SD, Kwack SJ, Oh JH, Park KL, Han SY, Kim SH. Di(2-ethylhexyl) phthalate induces apoptosis through peroxisome proliferators-activated receptor-gamma and ERK 1/2 activation in testis of Sprague-Dawley rats. J Toxicol Environ Health A 2007; 70:1296-303. [PMID: 17654247 DOI: 10.1080/15287390701432160] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is a well-known hepatic and reproductive toxicant whose toxicity may be mediated by peroxisome proliferators-activated receptor (PPAR). This study examined the effects of DEHP on the expression of PPAR-regulated genes involved in testicular cells apoptosis. Sprague-Dawley male rats were treated orally with 250, 500, or 750 mg/kg/d DEHP for 28 d, while control rats were given corn oil. The levels of cell cycle regulators (pRb, cyclins, CDKs, and p21) and apoptosis-related proteins were analyzed by Western blot analysis. The role of PPAR-gamma (PPAR-gamma), class B scavenger receptor type 1 (SR-B1), and ERK1/2 was further studied to examine the signaling pathway for DEHP-induced apoptosis. Results showed that the levels of pRB, cyclin D, CDK2, cyclin E, and CDK4 were significantly lower in rats given 500 and 750 mg/kg/d DEHP, while levels of p21 were significantly higher in rat testes. Dose-dependent increases in PPAR-gamma and RXRalpha proteins were observed in testes after DEHP exposure, while there was a significant decrease in RXRgamma protein levels. In addition to PPAR-gamma, DEHP also significantly increased SR-B1 mRNA and phosphorylated ERK1/2 protein levels. Furthermore, DEHP treatment induced pro-caspase-3 and cleavage of its substrate protein, poly(ADP-ribose) polymerase (PARP), in a dose-dependent manner. Data suggest that DEHP exposure may induce the expression of apoptosis-related genes in testes through induction of PPAR-gamma and activation of the ERK1/2 pathway.
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Affiliation(s)
- Ju Young Ryu
- College of Pharmacy, Pusan National University, Pusan, Republic of Korea
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Kang KA, Lee KH, Zhang R, Piao MJ, Kang MY, Kwak YS, Yoo BS, You HJ, Hyun JW. Protective effects of Castanopsis cuspidate through activation of ERK and NF-kappaB on oxidative cell death induced by hydrogen peroxide. J Toxicol Environ Health A 2007; 70:1319-28. [PMID: 17654250 DOI: 10.1080/15287390701429315] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The protective effect of Castanopsis cuspidate var. sieboldii was examined on H2O2-induced cell damage. The ethanol extract of Castanopsis cuspidate was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and reduce intracellular reactive oxygen species (ROS) generation, and thus prevent lipid peroxidation and cellular DNA damage induced by H2O2. As a result, Castanopsis extract reduced H2O2-induced cell death of V79-4 cells via inhibition of apoptosis. Castanopsis extract was also found to increase catalase activity and its protein expression. Further molecular mechanistic studies revealed that Castanopsis extract enhanced phosphorylation of extracellular signal regulated kinase (ERK) and activity of nuclear factor kappa B (NF-kappaB). Taken together, the results suggest that Castanopsis extract protects V79-4 cells against oxidative damage by enhancing catalase activity and modulating the ERK and NF-kappaB signal pathway.
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Affiliation(s)
- Kyoung Ah Kang
- Department of Biochemistry, College of Medicine and Applied Radiological Science Research Institute, Cheju National University, Jeju-si, Republic of Korea
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Riad A, Du J, Stiehl S, Westermann D, Mohr Z, Sobirey M, Doehner W, Adams V, Pauschinger M, Schultheiss HP, Tschöpe C. Low-dose treatment with atorvastatin leads to anti-oxidative and anti-inflammatory effects in diabetes mellitus. Eur J Pharmacol 2007; 569:204-11. [PMID: 17669395 DOI: 10.1016/j.ejphar.2007.04.065] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 04/24/2007] [Accepted: 04/25/2007] [Indexed: 11/17/2022]
Abstract
We investigated whether atorvastatin, given in a dose to low to influence the lipid profile, has any effect on oxidative stress, inflammation and endothelial function under streptozotocin-induced diabetic conditions. Diabetes mellitus was induced in male Sprague Dawley rats by a single injection of streptozotocin. Rats were treated chronically with atorvastatin (50 mg/kg/day; p.o.) or vehicle until day 48 and compared with controls. NAD(P)H activity, protein expression nuclear factor-kappaBp65 (NF-kappaBp65) and phosphorylation of the extracellular signal-regulated kinase (ERK1/2) were assessed in the quadriceps muscle. Protein and mRNA levels of intracellular and vascular adhesion molecules (ICAM-1, VCAM-1) and cytokines were measured by Taqman or immunohistochemistry staining, respectively. Endothelial function was investigated in vivo using the autoperfused hind limb model. Diabetic groups displayed similar severe hyperglycemia. Untreated diabetic rats showed enhanced NAD(P)H activity, activation of the ERK1/2/NF-kappaBp65-pathway, enhanced expression of cytokines and cellular adhesion molecules and impaired vascular function. Low-dose therapy by atorvastatin did not alter the lipid profile but led to a reduction of NAD(P)H activity (-28%, P<0.05) associated with reduced protein expression of NF-kappaBp65 (-53%, P<0.05) and phosphorylation of its regulator mitogen-activated protein kinase (MAPK) ERK1/2 in diabetic rats. Also inflammatory markers were reduced after atorvastatin treatment indexed by reduced mRNA expression of VCAM-1 (-24%), tumor necrosis factor alpha (-59%) and interleukin 1beta (-50%) and reduced ICAM-1 (-81%) and VCAM-1 (-74%) positive staining. These beneficial effects were associated with improved endothelium-dependent vasodilatation (maximal vasodilatation: +101%; P<0.05). Lipid-independent anti-oxidative and anti-inflammatory effects of low-dose atorvastatin involving the ERK1/2/NF-kappaB-pathway are sufficient to improve endothelial function under experimental diabetic conditions.
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Affiliation(s)
- Alexander Riad
- Department of Cardiology and Pneumology, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12206 Berlin, Germany
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Schnoke M, Midura RJ. Pulsed electromagnetic fields rapidly modulate intracellular signaling events in osteoblastic cells: comparison to parathyroid hormone and insulin. J Orthop Res 2007; 25:933-40. [PMID: 17427956 DOI: 10.1002/jor.20373] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pulsed electromagnetic field (PEMF) devices are approved for the healing of bone nonunions, but there is a lack of understanding as to their mechanism of action at the cell and molecular level. Intermittent parathyroid hormone (PTH) therapy is currently utilized for treatment of osteoporosis, and is also being investigated for the purpose of augmenting fracture healing. Insulin and IGF-1 are also thought to play important anabolic roles in osteogenesis. In this report, signaling pathways activated by acute PTH or insulin treatments were compared to those activated by PEMF treatment in osteoblast-like cells. Some signaling molecules like the extracellular response kinases 1/2 (Erk1/2) and the cAMP response element binding protein (CREB) were activated by insulin and PTH, respectively, but not by PEMF treatment. Other signaling molecules like the insulin receptor substrate-1 (IRS-1), the S6 ribosomal subunit kinase, and the endothelial nitric oxide synthase (eNOS) were phosphorylated by PTH, insulin, and PEMF to the same relative extent and within the same time frame. IRS-1, eNOS, and S6 have been implicated in bone anabolism, and our results suggest that the anabolic effects of PEMF may be mediated, in part, through the activation of these proteins.
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Affiliation(s)
- Matthew Schnoke
- Department of Biomedical Engineering and The Orthopaedic Research Center, Lerner Research Institute, ND20, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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Duguay D, deBlois D. Differential regulation of Akt, caspases and MAP kinases underlies smooth muscle cell apoptosis during aortic remodelling in SHR treated with amlodipine. Br J Pharmacol 2007; 151:1315-23. [PMID: 17592516 PMCID: PMC2189834 DOI: 10.1038/sj.bjp.0707334] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND AND PURPOSE The regression of aortic hypertrophy is initiated by a transient wave of smooth muscle cell (SMC) apoptosis in spontaneously hypertensive rats (SHR) treated with antihypertensive drugs, although the molecular pathways remain unclear. EXPERIMENTAL APPROACH Enzymes involved in apoptosis regulation were examined daily during onset aortic remodelling in SHR treated with amlodipine (20 mg kg(-1) day(-1)). KEY RESULTS Significant reduction of aortic SMC number occurred by day 3 of amlodipine, reaching -13% at 28 days, followed by a significant regression of medial hypertrophy by day 5, reaching -13% at 28 days. ISOL-positive (apoptotic) SMC nuclei increased by 4.6-fold between days 2 and 4, in temporal correlation with the activation of caspase-8 (2.7-fold) at day 2 only, caspase-3 at days 3 and 4 (1.7-fold) and caspase-9 at day 3 only (3.1-fold). Akt phosphorylation, a pro-survival pathway, was reduced prior to apoptosis at day 1 (-52%) and until day 3. During the first 6 days of amlodipine treatment, significant reduction in phosphorylation of mitogen-activated protein (MAP) kinases was transient for p38 (-46% at day 3 only) but continuous for ERK1/2 after 3 days (-40%), and for JNK after 4 days (>-50%). CONCLUSIONS AND IMPLICATIONS Amlodipine inhibition of Akt occurred prior to and during SMC apoptosis induction, a process mediated by the early activation of caspase-8 followed by caspase-9 and -3 and associated with MAP kinase inhibition. These findings provide insights about the molecular pathways underlying SMC apoptosis leading to vascular remodelling during amlodipine treatment of hypertension.
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Affiliation(s)
- D Duguay
- Department of Pharmacology, University of Montreal, 2900 Edouard-Montpetit Montreal, Quebec, Canada
| | - D deBlois
- Department of Pharmacology, University of Montreal, 2900 Edouard-Montpetit Montreal, Quebec, Canada
- Author for correspondence:
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Egea J, Rosa AO, Cuadrado A, García AG, López MG. Nicotinic receptor activation by epibatidine induces heme oxygenase-1 and protects chromaffin cells against oxidative stress. J Neurochem 2007; 102:1842-1852. [PMID: 17540012 DOI: 10.1111/j.1471-4159.2007.04665.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation of neuronal nicotinic acetylcholine receptors (nAChR) provides neuroprotection against different toxic stimuli that often lead to overproduction of reactive oxygen species (ROS) and cell death. ROS production has been related with disease progression in several neurodegenerative pathologies such as Alzheimer's or Parkinson's diseases. In this context, we investigated here if the exposure of bovine chromaffin cells to the potent nAChR agonist epibatidine protected against rotenone (30 micromol/L) plus oligomycin (10 micromol/L) (rot/oligo) toxicity, an in vitro model of mitochondrial ROS production. Epibatidine induced a concentration- and time-dependent protection, which was maximal at 3 mumol/L after 24 h. Pre-incubation with dantrolene (100 micromol/L) (a blocker of the ryanodine receptor channel), chelerythrine (1 micromol/L) (a protein kinase C inhibitor), or PD98059 (50 micromol/L) (a MEK inhibitor), aborted epibatidine-elicited cytoprotection. Mitochondrial depolarization, ROS, and caspase 3 active produced by rot/oligo were also prevented by epibatidine. Epibatidine doubled the amount of heme oxygenase-1 (HO-1), a critical cell defence enzyme against oxidative stress. Furthermore, the HO-1 inhibitor Sn(IV) protoporphyrin IX dichloride reversed the epibatidine protecting effects and HO-1 inducer Co (III) protoporphyrin IX dichloride exhibited neuroprotective effects by itself. The results of this study point to HO-1 as the cytoprotective target of nAChR activation through the following pathway: endoplasmic reticulum Ca(2+)-induced Ca(2+)-release activates the protein kinase C/extracellular regulated kinase/HO-1 axis to mitigate mitochondrial depolarization and ROS production. This study provides a mechanistic insight on how nAChR activation translates into an antioxidant and antiapoptotic signal through up-regulation of HO-1.
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Affiliation(s)
- Javier Egea
- Intituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, SpainDepartamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, SpainServicio de Farmacología Clínica and Instituto Universitario de Investigación Gerontológica y metabólica, Hospital Universitario de la Princesa, Madrid, Spain
| | - Angelo O Rosa
- Intituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, SpainDepartamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, SpainServicio de Farmacología Clínica and Instituto Universitario de Investigación Gerontológica y metabólica, Hospital Universitario de la Princesa, Madrid, Spain
| | - Antonio Cuadrado
- Intituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, SpainDepartamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, SpainServicio de Farmacología Clínica and Instituto Universitario de Investigación Gerontológica y metabólica, Hospital Universitario de la Princesa, Madrid, Spain
| | - Antonio G García
- Intituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, SpainDepartamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, SpainServicio de Farmacología Clínica and Instituto Universitario de Investigación Gerontológica y metabólica, Hospital Universitario de la Princesa, Madrid, Spain
| | - Manuela G López
- Intituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, SpainDepartamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, SpainServicio de Farmacología Clínica and Instituto Universitario de Investigación Gerontológica y metabólica, Hospital Universitario de la Princesa, Madrid, Spain
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Yeh TC, Marsh V, Bernat BA, Ballard J, Colwell H, Evans RJ, Parry J, Smith D, Brandhuber BJ, Gross S, Marlow A, Hurley B, Lyssikatos J, Lee PA, Winkler JD, Koch K, Wallace E. Biological characterization of ARRY-142886 (AZD6244), a potent, highly selective mitogen-activated protein kinase kinase 1/2 inhibitor. Clin Cancer Res 2007; 13:1576-83. [PMID: 17332304 DOI: 10.1158/1078-0432.ccr-06-1150] [Citation(s) in RCA: 439] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The Ras-Raf-mitogen-activated protein kinase kinase (MEK) pathway is overactive in many human cancers and is thus a target for novel therapeutics. We have developed a highly potent and selective inhibitor of MEK1/2. The purpose of these studies has been to show the biological efficacy of ARRY-142886 (AZD6244) in enzymatic, cellular, and animal models. EXPERIMENTAL DESIGN The ability of ARRY-142886 to inhibit purified MEK1 as well as other kinases was evaluated. Its effects on extracellular signal-regulated kinase (ERK) phosphorylation and proliferation in several cell lines were also determined. Finally, the inhibitor was tested in HT-29 (colorectal) and BxPC3 (pancreatic) xenograft tumor models. RESULTS The IC(50) of ARRY-142886 was determined to be 14 nmol/L against purified MEK1. This activity is not competitive with ATP, which is consistent with the high specificity of compound for MEK1/2. Basal and epidermal growth factor-induced ERK1/2 phosphorylation was inhibited in several cell lines as well as 12-O-tetradecanoylphorbol-13-acetate-induced ERK1/2 phosphorylation in isolated peripheral blood mononuclear cells. Treatment with ARRY-142886 resulted in the growth inhibition of several cell lines containing B-Raf and Ras mutations but had no effect on a normal fibroblast cell line. When dosed orally, ARRY-142886 was capable of inhibiting both ERK1/2 phosphorylation and growth of HT-29 xenograft tumors in nude mice. Tumor regressions were also seen in a BxPC3 xenograft model. In addition, tumors remained responsive to growth inhibition after a 7-day dosing holiday. CONCLUSIONS ARRY-142886 is a potent and selective MEK1/2 inhibitor that is highly active in both in vitro and in vivo tumor models. This compound is currently being investigated in clinical studies.
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Affiliation(s)
- Tammie C Yeh
- Array BioPharma, Inc., Boulder, Colorado 80301, USA.
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Abstract
Connective tissue growth factor (CTGF) level is elevated in eyes with proliferative vitreoretinal diseases, such as proliferative diabetic retinopathy and proliferative vitreoretinopathy (PVR), as we previously reported, but its functional characteristics on vitreoretinal cells are yet to be clarified. In this study, we demonstrated a growth-promoting effect of CTGF on cultured hyalocytes and bovine retinal pigment epithelial cells (BRPEs) with the induction of p44/p42 mitogen-activated protein kinase phosphorylation and [(3)H]thymidine incorporation. CTGF also stimulated the synthesis of fibronectin by hyalocytes and BRPEs without significant effect on collagen gel contraction by these cells. On the other hand, CTGF had no direct effects on the proliferation, migration, or in vitro tube formation by vascular endothelial cells. Nevertheless, CTGF promoted vascular endothelial growth factor (VEGF) gene expression by hyalocytes and BRPEs. Although the concentrations of both CTGF and VEGF in the human vitreous samples with proliferative vitreoretinal diseases were elevated, there was no significant correlation between these concentrations. These findings indicate that CTGF appears to be involved in the formation of proliferative membranes without direct regulation of their cicatricial contraction in the pathogenesis of proliferative vitreoretinal diseases. Whereas CTGF might have no direct effects or minimal effects, if any, on retinal neovascularization, it is possible that CTGF has indirect effects by modulating the expression of VEGF.
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Affiliation(s)
- Takeshi Kita
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-Ku, Fukuoka, Japan
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Kim TJ, Jeon J, Jin YR, Son DJ, Yoo HS, Hong JT, Ryu CK, Shin HS, Lee KH, Yun YP. Effects of KTJ740, a Novel Antithrombotic Agent, on Platelet-Derived Growth Factor-Induced Rat Aortic Smooth Muscle Cell Proliferation and Cell Cycle Progression. J Cardiovasc Pharmacol 2007; 49:280-6. [PMID: 17513946 DOI: 10.1097/fjc.0b013e3180399448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hyperproliferation of platelet-derived growth factor (PDGF)-BB-induced vascular smooth muscle cell (VSMC) is a hallmark of atherosclerosis and related vascular disorders. In the previous study, we reported that KTJ740 [2-chloro-3-(4-(ethylcarboxy)-phenyl)-amino-1,4-naphthoquinone], a newly synthesized vitamin K derivative, has potent antithrombotic effects in mice and antiplatelet activity in vitro and ex vivo. In the present study, we have tested that KTJ740 could inhibit PDGF-BB-stimulated VSMC proliferation. We have examined the potential inhibitory effect of this compound on rat aortic smooth muscle cells (RASMCs). Our results show that this compound significantly inhibits PDGF-BB-stimulated RASMC number and DNA synthesis in a concentration-dependent manner. Furthermore, we have examined its effect on cell cycle progression by flow cytometry. KTJ740 treatment resulted in a significant arrest in cell cycle progression of RASMCs induced by PDGF-BB, and this effect was achieved by suppressing activation of PDGF-beta receptor (PDGF-Rbeta) tyrosine kinase pathway. These results suggest that a possibility of KTJ740 can be a potential agent to control vascular disorders and its antiproliferative mechanism may be mediated through PDGF-Rbeta tyrosine kinase-dependent signaling pathway.
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Affiliation(s)
- Tack-Joong Kim
- College of Pharmacy, Research Center for Bioresource and Health, Chungbuk National University, Heungduk-Gu, Cheongju, Korea
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Hwang HJ, Kwon MJ, Nam TJ. Chemoprotective effect of insulin-like growth factor I against acetaminophen-induced cell death in Chang liver cells via ERK1/2 activation. Toxicology 2007; 230:76-82. [PMID: 17169476 DOI: 10.1016/j.tox.2006.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Revised: 10/21/2006] [Accepted: 11/01/2006] [Indexed: 10/23/2022]
Abstract
The insulin-like growth factor (IGF) system and type-I IGF receptor (IGF-IR) signaling are involved in protecting against chemotherapeutic drug-induced cell death in human hepatoma cells. Acetaminophen (AAP) hepatotoxicity is the leading cause of liver failure, and the prevention of AAP-induced cell death has been the focus of many studies. We determined whether IGF-I could protect against AAP-induced cell death in Chang liver cells and investigated the protective mechanism. Based on the results of MTS assays, LDH release assays, Hoechst 33342 cell staining, and DNA fragmentation experiments, AAP induced cell death in a dose-dependent manner. According to Western blot analysis, treatment with AAP increased the level of poly(ADP-ribose) polymerase (PARP) fragments in cells compared with that in control cells; however, caspase-3, a critical signaling molecule in apoptosis, was not activated after AAP overdose. Moreover, combined treatment with AAP and IGF-I inhibited PARP cleavage, which was consistent with the ability of IGF-I to restore the level of glutathione (GSH) and cell viability in GSH and MTS assays, respectively. We investigated whether the protective effect of IGF-I against AAP cytotoxicity is related to the extracellular signal-related kinase ERK1/2, which is generally activated by mitogenic and proliferative stimuli such as growth factors. Compared with AAP treatment alone, IGF-I and AAP co-treatment increased ERK1/2 phosphorylation but inhibited PARP cleavage. Thus ERK1/2 activation is instrumental in the protective effect of IGF-I against AAP-induced cell death in Chang liver cells.
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Affiliation(s)
- Hye-Jung Hwang
- Faculty of Food Science and Biotechnology, Pukyong National University, 599-1, Daeyeon 3-Dong, Nam-Gu, Busan, Republic of Korea
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Gao QT, Choi RCY, Cheung AWH, Zhu JTT, Li J, Chu GKY, Duan R, Cheung JKH, Jiang ZY, Dong XB, Zhao KJ, Dong TTX, Tsim KWK. Danggui Buxue Tang - A Chinese herbal decoction activates the phosphorylations of extracellular signal-regulated kinase and estrogen receptorαin cultured MCF-7 cells. FEBS Lett 2006; 581:233-40. [PMID: 17187784 DOI: 10.1016/j.febslet.2006.12.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 12/07/2006] [Accepted: 12/07/2006] [Indexed: 10/23/2022]
Abstract
Danggui buxue tang (DBT), a Chinese herbal decoction used to treat ailments in women, contains radix Astragali (Huangqi; RA) and radix Angelicae Sinensis (Danggui; RAS). The weight ratio of RA to RAS used in DBT must be 5:1 as stipulated as early as AD 1247; however, DBT's mechanism of action has never been described. Here, the estrogenic effects of DBT were investigated by determining the phosphorylations of estrogen receptor alpha (ER alpha) and extracellular signal-regulated kinase 1/2 (Erk1/2) in cultured MCF-7 cells. The application of DBT triggered the phosphorylation of ER alpha and Erk1/2 in a time-dependent manner. In contrast to the effect of estrogen, DBT triggered ER alpha phosphorylation at both S118 and S167. This DBT-specific phosphorylation was not triggered by an extract of one of the individual herbs, or by mixing the extracts of RA and RAS. DBT-induced downstream signals are described here. These signals suggest the uniqueness of this Chinese herbal decoction that requires a well-defined formulation.
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Affiliation(s)
- Qiu T Gao
- Department of Biology and Center for Chinese Medicine R&D, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
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Dai HY, Ge ZM, Li YH. [Effect of urotensin II on proliferative potential and phosphorylation of extracellular signal-regulated kinase 1/2 of adventitial fibroblasts from spontaneously hypertensive rat]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2006; 28:776-80. [PMID: 17260465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
OBJECTIVE To study the effect of urotensin II ( U II ) on the proliferative potential of adventitial fibroblasts (AFs) from spontaneously hypertensive rat (SHR) and to determine whether extracellular signal-regulated kinase 1/2 (ERK1/2) pathway is involved in this progress. METHODS 3H-thymidine incorporation test was used to estimate the U II -induced proliferative potential of AFs from SHR and the influence of Urantide (U II receptor antagonist) and PD98059 (ERK1/2 inhibitor). Western blotting was used to test the U II -induced ERK1/2 phosphorylation as well as the effect of Urantide and PD98059 on U II -induced ERKl/2 phosphorylation. RESULTS U 11 increased the proliferative potential of AFs from SHR in a dose-dependent way. Urantide and PD98059 wholly or partly inhibited U II -induced proliferation of SHR-AFs. In SHR-AFs, U II induced the phosphorylation of ERK1/2 in a time-dependent way, which was completely inhibited by Urantide and PD98059. CONCLUSION U II can increase the proliferative potential of AFs from SHR and ERK1/2 pathway is partly involved in this progress.
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Affiliation(s)
- Hong-yan Dai
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Shandong University, Jinan 250012, China
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Faustino RS, Stronger LNW, Richard MN, Czubryt MP, Ford DA, Prociuk MA, Dibrov E, Pierce GN. RanGAP-mediated nuclear protein import in vascular smooth muscle cells is augmented by lysophosphatidylcholine. Mol Pharmacol 2006; 71:438-45. [PMID: 17105874 DOI: 10.1124/mol.105.021667] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The intracellular mechanism responsible for the mitogenic effects of lysophosphatidylcholine (LPC) is unclear. Import of proteins from the cytoplasm into the cell nucleus is integral to the regulation of gene expression and cell growth. We hypothesized that LPC exerts its intracellular effects through alterations in nuclear protein import. Rabbit aortic smooth muscle cells incubated with LPC induced a significant increase in cell proliferation in both quiescent cells (63.2+/-6.48% of control) and cells grown in 1% fetal bovine serum (FBS) (28.3+/-7.35% of control). Vascular smooth muscle cells were preincubated with LPC then microinjected with a marker protein for nuclear import. A significant stimulation of nuclear protein transport was observed. Using a conventional nuclear protein import assay in permeabilized cells, a significant stimulation of import (72.3+/-5.2% of control) was again observed when the cytosolic nuclear import cocktail was treated with LPC. This effect was not observed with other lysophosphatidyl species. LPC also activated the extracellular signal-regulated kinase (ERK) 1/2 mitogen-activated protein kinase (MAPK) pathway, and this was blocked by 2'-amino-3'-methoxyflavone (PD98059), which inhibits the activation of ERK 1/2. The stimulation of nuclear import was also blocked by PD98059. LPC-induced MAPK activation augmented GTP hydrolysis by RanGAP, a RanGTPase activating protein and a critical regulatory component of nuclear protein import, and this stimulation was again blocked by PD98059. We conclude that LPC alters gene expression and cell proliferation through striking effects on nuclear protein import via a MAP kinase-induced activation of RanGAP. This may play an important role in cancer and atherosclerosis and other disorders involving accelerated cell growth/proliferation.
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Affiliation(s)
- Randolph S Faustino
- Cell Biology Laboratory, Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, and Department of Physiology, Faculty of Medicine, University of Manitoba, 351 Tache Avenue, Winnipeg, Manitoba, Canada
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Tanabe Y, Morikawa Y, Kato T, Kanai S, Watakabe T, Nishijima A, Iwata H, Isobe K, Ishizaki M, Nakayama K. Effects of olmesartan, an AT1 receptor antagonist, on hypoxia-induced activation of ERK1/2 and pro-inflammatory signals in the mouse lung. Naunyn Schmiedebergs Arch Pharmacol 2006; 374:235-48. [PMID: 17089097 DOI: 10.1007/s00210-006-0110-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Accepted: 09/29/2006] [Indexed: 12/01/2022]
Abstract
The present study aimed to investigate the effects of olmesartan, an antagonist for angiotensin II receptor type 1(AT1), on the activation of extracellular signal-regulated kinases (ERK)1/2, tissue remodeling, and pro-inflammatory signals in the right ventricle and lung of mice during the early phase of hypobaric hypoxia. Phosphorylation of ERK1/2 in both tissue types in response to hypoxia peaked at 1-3 days, and declined rapidly in the right ventricle, whereas in the lung it was sustained for at least 8 days. Upregulation of angiotensinogen mRNA was observed in the hypoxic lung at 4-9 days, but not in the hypoxic right ventricle and pulmonary artery. Olmesartan inhibited the hypoxia-induced phosphorylation of ERK1/2 in the lung, but not in the right ventricle. Neither right ventricular hypertrophy nor the thickening of the intrapulmonary arterial wall was ameliorated by olmesartan. However, this drug inhibited the expression of the mRNA for angiotensinogen and several pro-inflammatory factors, including interleukin-6 and inducible nitric oxide synthase in the hypoxic lung. These results suggest that olmesartan blocks a potential positive feedback loop of the angiotensin II-AT1 receptor system, which may lead to attenuate pro-inflammatory signals in the mouse lung, that are associated with hypoxic pulmonary hypertension, without inducing any appreciable effects on the compensatory cardiopulmonary hypertrophy at an early phase of exposure to a hypobaric hypoxic environment.
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Affiliation(s)
- Yoshiyuki Tanabe
- Department of Cellular and Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka-shi, Shizuoka, 422-8526, Japan
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Abstract
Oxidative stress is the main cause of neuronal death in pathological conditions. Hydrogen peroxide (H(2)O(2)), one of the reactive oxygen species, activates many intracellular signaling cascades including src family and mitogen-activated protein kinases (MAPKs), some of which are critically involved in the induction of cellular damage. We previously showed that H(2)O(2)-induced cell death in astrocytes and adenosine 5(')-triphosphate (ATP), acting on P2Y(1) receptors, had a protective effect. Here, we examined the H(2)O(2)-induced changes in intracellular signaling cascades that promote cell death in astrocytes, showing the molecular mechanisms by which the activation of P2Y(1) receptors counteracts such signals. Although H(2)O(2) activated three MAPKs including ERK1/2, p38, and JNK, only the activation of ERK1/2 participated in the H(2)O(2)-evoked cell death. H(2)O(2) induced a sustained activation of ERK1/2 mainly in the nucleus region, which was well in accordance with the H(2)O(2)-induced cell death. H(2)O(2) also activated the src tyrosine kinase family, which was an upstream signal for ERK1/2. Activation of P2Y(1) receptors by 2methylthio-ADP (2MeSADP) inhibited the H(2)O(2)-evoked activation of src tyrosine kinase, resulting in the inhibition of the phosphorylated-ERK1/2 accumulation in the nucleus. 2MeSADP enhanced the gene expression and activity of protein tyrosine phosphatase (PTP), which was responsible for the inhibition of src tyrosine kinase. Thioredoxin reductase, another cytoprotective gene we previously showed to be upregulated by 2MeSADP, also controlled the activity of PTP. Taken together, ATP, acting on P2Y(1) receptors, upregulates the PTP expression and its activity, which counteracts the H(2)O(2)-promoted death signaling cascades including ERK1/2 and its upstream signal src tyrosine kinase in astrocytes.
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Affiliation(s)
- Youichi Shinozaki
- Division of Pharmacology, National Institute of Health Sciences, Setagaya, Tokyo 158-8501, Japan
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