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Thrombin Induces COX-2 and PGE2 Expression via PAR1/PKCalpha/MAPK-Dependent NF-kappaB Activation in Human Tracheal Smooth Muscle Cells. Mediators Inflamm 2022; 2022:4600029. [PMID: 35497094 PMCID: PMC9042634 DOI: 10.1155/2022/4600029] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 03/03/2022] [Indexed: 12/21/2022] Open
Abstract
The inflammation of the airway and lung could be triggered by upregulation cyclooxygenase (COX)-2 and prostaglandin E2 (PGE2) induced by various proinflammatory factors. COX-2 induction by thrombin has been shown to play a vital role in various inflammatory diseases. However, in human tracheal smooth muscle cells (HTSMCs), how thrombin enhanced the levels of COX-2/PGE2 is not completely characterized. Thus, in this study, the levels of COX-2 expression and PGE2 synthesis induced by thrombin were determined by Western blot, promoter-reporter assay, real-time PCR, and ELISA kit. The various signaling components involved in the thrombin-mediated responses were differentiated by transfection with siRNAs and selective pharmacological inhibitors. The role of NF-κB was assessed by a chromatin immunoprecipitation (ChIP) assay, immunofluorescent staining, as well as Western blot. Our results verified that thrombin markedly triggered PGE2 secretion via COX-2 upregulation which were diminished by the inhibitor of thrombin (PPACK), PAR1 (SCH79797), Gi/o protein (GPA2), Gq protein (GPA2A), PKCα (Gö6976), p38 MAPK (SB202190), JNK1/2 (SP600125), MEK1/2 (U0126), or NF-κB (helenalin) and transfection with siRNA of PAR1, Gqα, Giα, PKCα, JNK2, p38, p42, or p65. Moreover, thrombin induced PAR1-dependent PKCα phosphorylation in HTSMCs. We also observed that thrombin induced p38 MAPK, JNK1/2, and p42/p44 MAPK activation through a PAR1/PKCα pathway. Thrombin promoted phosphorylation of NF-κB p65, leading to nuclear translocation and binding to the COX-2 promoter element to enhance promoter activity, which was reduced by Gö6976, SP600125, SB202190, or U0126. These findings supported that COX-2/PGE2 expression triggered by thrombin was engaged in PAR1/Gq or Gi/o/PKCα/MAPK-dependent NF-κB activation in HTSMCs.
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Ryu J, Kwon DH, Choe N, Shin S, Jeong G, Lim YH, Kim J, Park WJ, Kook H, Kim YK. Characterization of Circular RNAs in Vascular Smooth Muscle Cells with Vascular Calcification. MOLECULAR THERAPY-NUCLEIC ACIDS 2019; 19:31-41. [PMID: 31790973 PMCID: PMC6909180 DOI: 10.1016/j.omtn.2019.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 10/09/2019] [Accepted: 11/05/2019] [Indexed: 02/06/2023]
Abstract
Circular RNAs (circRNAs) are generally formed by back splicing and are expressed in various cells. Vascular calcification (VC), a common complication of chronic kidney disease (CKD), is often associated with cardiovascular disease. The relationship between circRNAs and VC has not yet been studied. Inorganic phosphate (Pi) was used to treat rat vascular smooth muscle cells to induce VC. circRNAs were identified by analyzing RNA sequencing (RNA-seq) data, and their expression change during VC was validated. The selected circRNAs, including circSamd4a, circSmoc1-1, circMettl9, and circUxs1, were resistant to RNase R digestion and mostly localized in the cytoplasm. While silencing circSamd4a promoted VC, overexpressing it reduced VC in calcium assay and Alizarin red S (ARS) staining. In addition, microRNA (miRNA) microarray, luciferase reporter assay, and calcium assay suggested that circSamd4a could act as a miRNA suppressor. Our data show that circSamd4a has an anti-calcification role by functioning as a miRNA sponge. Moreover, mRNAs that can interact with miRNAs were predicted from RNA-seq and bioinformatics analysis, and the circSamd4a-miRNA-mRNA axis involved in VC was verified by luciferase reporter assay and calcium assay. Since circSamd4a is conserved in humans, it can serve as a novel therapeutic target in resolving VC.
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Affiliation(s)
- Juhee Ryu
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Biochemistry, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Duk-Hwa Kwon
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Nakwon Choe
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Sera Shin
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Geon Jeong
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Biochemistry, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Yeong-Hwan Lim
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Biochemistry, Chonnam National University Medical School, Jeollanam-do, Republic of Korea
| | - Jaetaek Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Woo Jin Park
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; College of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Hyun Kook
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Pharmacology, Chonnam National University Medical School, Jeollanam-do, Republic of Korea.
| | - Young-Kook Kim
- Basic Research Laboratory for Vascular Remodeling, Chonnam National University Medical School, Jeollanam-do, Republic of Korea; Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University, Jeollanam-do, Republic of Korea; Department of Biochemistry, Chonnam National University Medical School, Jeollanam-do, Republic of Korea.
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Al-Bayati A, Lukka D, Brown AE, Walker M. Effects of thrombin on insulin signalling and glucose uptake in cultured human myotubes. J Diabetes Complications 2016; 30:1209-16. [PMID: 27396242 DOI: 10.1016/j.jdiacomp.2016.06.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/19/2016] [Accepted: 06/14/2016] [Indexed: 01/22/2023]
Abstract
BACKGROUND Hyper-coagulability (elevated thrombin) is a feature of type 2 diabetes and contributes to an increased risk of thrombotic and vascular events. Skeletal muscle is the key peripheral tissue site of insulin resistance in type 2 diabetes. Cultured human skeletal muscle cells were used to explore the effects of thrombin on insulin signalling and glucose uptake. We hypothesized that thrombin affects insulin activity in human skeletal muscle cells which could link the hypercoagulability and insulin resistance in type 2 diabetes. METHODS Human skeletal muscle cell cultures (myotubes) were treated with +/-5 units/ml thrombin for 6h. Insulin signalling pathway components and AMPK were examined by Western blotting. Real time PCR and glucose uptake assays were performed. RESULTS There was a significant decrease (p<0.01) in insulin mediated IRS-1 and Akt phosphorylation in response to thrombin in cultured myotubes. Diminished Akt phosphorylation was alleviated by treatment with a PKC inhibitor. Thrombin directly increased basal glucose uptake (p<0.05) that involved AMPK phosphorylation (p<0.01) and this was partly repressed by compound C (AMPK inhibitor). Thrombin also significantly increased the gene expression level of both GLUT1 and GLUT4 in cultured human skeletal muscle cells. CONCLUSION Thrombin decreased insulin signalling in skeletal muscle cells through a PKC mediated mechanism, but did not affect the net action of insulin on glucose uptake. The direct stimulatory effect of thrombin on glucose uptake was mediated, at least in part, via an AMPK dependent mechanism. We conclude that thrombin activation results in multiple metabolic effects beyond increased thrombogenicity but does not include a decrease in insulin sensitivity (glucose uptake) in cultured human skeletal muscle cells.
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Affiliation(s)
- Ali Al-Bayati
- Diabetes Research Group, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - Dhanisha Lukka
- Diabetes Research Group, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Audrey E Brown
- Diabetes Research Group, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mark Walker
- Diabetes Research Group, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
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Pentassuglia L, Heim P, Lebboukh S, Morandi C, Xu L, Brink M. Neuregulin-1β promotes glucose uptake via PI3K/Akt in neonatal rat cardiomyocytes. Am J Physiol Endocrinol Metab 2016; 310:E782-94. [PMID: 26979522 DOI: 10.1152/ajpendo.00259.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 03/02/2016] [Indexed: 12/21/2022]
Abstract
Nrg1β is critically involved in cardiac development and also maintains function of the adult heart. Studies conducted in animal models showed that it improves cardiac performance under a range of pathological conditions, which led to its introduction in clinical trials to treat heart failure. Recent work also implicated Nrg1β in the regenerative potential of neonatal and adult hearts. The molecular mechanisms whereby Nrg1β acts in cardiac cells are still poorly understood. In the present study, we analyzed the effects of Nrg1β on glucose uptake in neonatal rat ventricular myocytes and investigated to what extent mTOR/Akt signaling pathways are implicated. We show that Nrg1β enhances glucose uptake in cardiomyocytes as efficiently as IGF-I and insulin. Nrg1β causes phosphorylation of ErbB2 and ErbB4 and rapidly induces the phosphorylation of FAK (Tyr(861)), Akt (Thr(308) and Ser(473)), and its effector AS160 (Thr(642)). Knockdown of ErbB2 or ErbB4 reduces Akt phosphorylation and blocks the glucose uptake. The Akt inhibitor VIII and the PI3K inhibitors LY-294002 and Byl-719 abolish Nrg1β-induced phosphorylation and glucose uptake. Finally, specific mTORC2 inactivation after knockdown of rictor blocks the Nrg1β-induced increases in Akt-p-Ser(473) but does not modify AS160-p-Thr(642) or the glucose uptake responses to Nrg1β. In conclusion, our study demonstrates that Nrg1β enhances glucose uptake in cardiomyocytes via ErbB2/ErbB4 heterodimers, PI3Kα, and Akt. Furthermore, although Nrg1β activates mTORC2, the resulting Akt-Ser(473) phosphorylation is not essential for glucose uptake induction. These new insights into pathways whereby Nrg1β regulates glucose uptake in cardiomyocytes may contribute to the understanding of its regenerative capacity and protective function in heart failure.
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MESH Headings
- Animals
- Animals, Newborn
- Blotting, Western
- Gene Knockdown Techniques
- Glucose/metabolism
- Heart Ventricles/cytology
- Hypoglycemic Agents/pharmacology
- Immunoprecipitation
- Insulin/pharmacology
- Insulin-Like Growth Factor I/pharmacology
- Mechanistic Target of Rapamycin Complex 2
- Mice
- Mice, Inbred C57BL
- Multiprotein Complexes/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Neuregulin-1/pharmacology
- Phosphatidylinositol 3-Kinases/drug effects
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphorylation/drug effects
- Protein Biosynthesis/drug effects
- Proto-Oncogene Proteins c-akt/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Small Interfering
- Rats
- Receptor, ErbB-2/drug effects
- Receptor, ErbB-2/genetics
- Receptor, ErbB-2/metabolism
- Receptor, ErbB-4/drug effects
- Receptor, ErbB-4/genetics
- Receptor, ErbB-4/metabolism
- TOR Serine-Threonine Kinases/metabolism
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Affiliation(s)
- Laura Pentassuglia
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Philippe Heim
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Sonia Lebboukh
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Christian Morandi
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Lifen Xu
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Marijke Brink
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland
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5
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Jose C, Melser S, Benard G, Rossignol R. Mitoplasticity: adaptation biology of the mitochondrion to the cellular redox state in physiology and carcinogenesis. Antioxid Redox Signal 2013; 18:808-49. [PMID: 22989324 DOI: 10.1089/ars.2011.4357] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Adaptation and transformation biology of the mitochondrion to redox status is an emerging domain of physiology and pathophysiology. Mitochondrial adaptations occur in response to accidental changes in cellular energy demand or supply while mitochondrial transformations are a part of greater program of cell metamorphosis. The possible role of mitochondrial adaptations and transformations in pathogenesis remains unexplored, and it has become critical to decipher the stimuli and the underlying molecular pathways. Immediate activation of mitochondrial function was described during acute exercise, respiratory chain injury, Endoplasmic Reticulum stress, genotoxic stress, or environmental toxic insults. Delayed adaptations of mitochondrial form, composition, and functions were evidenced for persistent changes in redox status as observed in endurance training, in fibroblasts grown in presence of respiratory chain inhibitors or in absence of glucose, in the smooth muscle of patients with severe asthma, or in the skeletal muscle of patients with a mitochondrial disease. Besides, mitochondrial transformations were observed in the course of human cell differentiation, during immune response activation, or in cells undergoing carcinogenesis. Little is known on the signals and downstream pathways that govern mitochondrial adaptations and transformations. Few adaptative loops, including redox sensors, kinases, and transcription factors were deciphered, but their implication in physiology and pathology remains elusive. Mitoplasticity could play a protective role against aging, diabetes, cancer, or neurodegenerative diseases. Research on adaptation and transformation could allow the design of innovative therapies, notably in cancer.
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Affiliation(s)
- Caroline Jose
- University Bordeaux, Maladies Rares: Génétique et Métabolisme, France
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Yamada S, Kotake Y, Sekino Y, Kanda Y. AMP-activated protein kinase-mediated glucose transport as a novel target of tributyltin in human embryonic carcinoma cells. Metallomics 2013; 5:484-91. [DOI: 10.1039/c3mt20268b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Siller-Matula JM, Schwameis M, Blann A, Mannhalter C, Jilma B. Thrombin as a multi-functional enzyme. Focus on in vitro and in vivo effects. Thromb Haemost 2011; 106:1020-33. [PMID: 21979864 DOI: 10.1160/th10-11-0711] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Accepted: 09/11/2011] [Indexed: 12/16/2022]
Abstract
Thrombin is the central protease in the coagulation cascade and one of the most extensively studied of all enzymes. In addition to its recognised role in the coagulation cascade and haemostasis, thrombin is known to have multiple pleiotropic effects, which mostly have been shown only in in vitro studies: it plays a role in inflammation and cellular proliferation and displays a mitogen activity on smooth muscle cells and endothelial cells, predominantly by activation of angiogenesis. In vivo , thrombin effects were examined in animal models of intravenous or intraarterial thrombin infusion. An extensive literature search regarding in vivo data showed that i) thrombin administered as a bolus causes microembolism, ii) thrombin infused slowly at steady-state conditions (up to 1.6 U/kg/min) leads to bleeds but not to intravascular clotting, iii) large quantity of thrombin infused at low rates (0.05 U/kg/min) does not have any measurable effect, and iv) thrombin increases vascular permeability leading to tissue damage. Although several decades of research on thrombin functions have provided a framework for understanding the biology of thrombin, animal and human studies with use of newer laboratory techniques are still needed to confirm the pleiotropic thrombin functions shown in in vitro studies.
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Affiliation(s)
- Jolanta M Siller-Matula
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
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8
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Reactive oxygen species mediate adipocyte differentiation in mesenchymal stem cells. Life Sci 2011; 89:250-8. [PMID: 21722651 DOI: 10.1016/j.lfs.2011.06.007] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 05/23/2011] [Accepted: 06/06/2011] [Indexed: 11/22/2022]
Abstract
AIMS Mesenchymal stem cells (MSC) have the potential to differentiate into various cell lineages, including adipocytes and osteoblasts. The formation of adipose tissue involves the commitment of MSC to the preadipocyte lineage and the differentiation of preadipocytes into mature adipocytes. In the present study, we investigated the involvement of reactive oxygen species (ROS) in adipocyte differentiation from MSC. MAIN METHODS ROS signaling was evaluated by the effects of antioxidant N-acetyl-l-cysteine (NAC) or shRNA against NAD(P)H oxidase in the multipotent mesenchymal stem cell line 10T1/2 cells. Intracellular ROS was measured using an H(2)DCF dye. KEY FINDINGS We found that NAC blocked adipocyte differentiation in MSC. An H(2)DCF assay revealed that differentiation-inducing agents induced ROS generation. These data suggest that ROS is involved in adipocyte differentiation in MSC. Next, we examined the source of ROS. Knockdown of NAD(P)H oxidase 4 (Nox4) by RNA interference inhibited ROS production and adipocyte differentiation by differentiation-inducing agents. Furthermore, treatment with NAC blocked the transcriptional activation of CREB, and the expression of dominant-negative mutants of CREB inhibited adipocyte differentiation. SIGNIFICANCE The findings suggest that the increase in the intracellular ROS level via Nox4 mediates adipocyte differentiation through CREB in MSC. This data will provide new insight into the drug development for obesity.
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9
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Abstract
Tyrosine kinases play significant roles in tumor progression and therapy resistance. Inhibitors of tyrosine kinases are on the forefront of targeted therapy. For prostate cancer, tyrosine kinases play an additional role in the development of castration-resistant disease state, the most troubling aspect of prostate cancinogenesis which presently defies any effective treatment. Among the 30 or so tyrosine kinases expressed in a typical prostate cancer cell, nearly one third of them have been implicated in prostate carcinogenesis. Interestingly, most of them channel signals through a trio of non-receptor tyrosine kinases, Src/Etk/FAK, referred here as Src tyrosine kinase complex. This complex has been shown to play a significant role in the aberrant activation of androgen receptor (AR) mediated by growth factors (e.g., epidermal growth factor (EGF)), cytokines (interleukin (IL)-6), chemokines (IL-8), and neurokines (gastrin-releasing peptide). These factors are induced and released from the prostate cancer to the stromal cells upon androgen withdrawal. The Src kinase complex has the ability to phosphorylate androgen receptor, resulting in the nuclear translocation and stabilization of un-liganded androgen receptor. Indeed, tyrosine kinase inhibitors targeting Src can inhibit androgen-independent growth of prostate cancer cells in vitro and in preclinical xenograft model. While effective in inducing growth arrest and inhibiting metastasis of castration-resistant tumors, Src inhibitors rarely induce a significant level of apoptosis. This is also reflected by the general ineffectiveness of tyrosine kinase inhibitors as monotherapy in clinical trials. One of the underlying causes of apoptosis resistance is "autophagy," which is induced by tyrosine kinase inhibitors and by androgen withdrawal. Autophagy is a self-digesting process to regenerate energy by removal of long-lived proteins and retired organelles to provide a survival mechanism to cells encountering stresses. Excessive autophagy, sometimes, could lead to type II programmed cell death. We demonstrated that autophagy blockade sensitizes prostate cancer cells toward Src tyrosine kinase inhibitor. Thus, a combination therapy based on Src tyrosine kinase inhibitor and autophagy modulator deserves further attention as a potential treatment for relapsed prostate cancer.
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Affiliation(s)
- Hsing-Jien Kung
- UC Davis Cancer Center, UCDMC, Res III, Rm. 2400, 4645 2nd Avenue, Sacramento, CA 95817, USA.
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Transient receptor potential canonical 3 (TRPC3) mediates thrombin-induced astrocyte activation and upregulates its own expression in cortical astrocytes. J Neurosci 2010; 30:13116-29. [PMID: 20881130 DOI: 10.1523/jneurosci.1890-10.2010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Reactive astrogliosis, defined by abnormal morphology and excessive cell proliferation, is a characteristic response of astrocytes to CNS injuries, including intracerebral hemorrhage. Thrombin, a major blood-derived serine protease, leaks into the brain parenchyma upon blood-brain barrier disruption and can induce brain injury and astrogliosis. Transient receptor potential canonical (TRPC) channels, Ca(2+)-permeable, nonselective cation channels, are expressed in astrocytes and involved in Ca(2+) influx after receptor stimulation; however, their pathophysiological functions in reactive astrocytes remain unknown. We investigated the pathophysiological roles of TRPC in thrombin-activated cortical astrocytes. Application of thrombin (1 U/ml, 20 h) upregulated TRPC3 protein, which was associated with increased Ca(2+) influx after thapsigargin treatment. Pharmacological manipulations revealed that the TRPC3 upregulation was mediated by protease-activated receptor 1 (PAR-1), extracellular signal-regulated protein kinase, c-Jun NH(2)-terminal kinase, and nuclear factor-κB signaling and required de novo protein synthesis. The Ca(2+) signaling blockers BAPTA-AM, cyclopiazonic acid, and 2-aminoethoxydiphenyl borate and a selective TRPC3 inhibitor, pyrazole-3, attenuated TRPC3 upregulation, suggesting that Ca(2+) signaling through TRPC3 contributes to its increased expression. Thrombin-induced morphological changes at 3 h upregulated S100B, a marker of reactive astrocytes, at 20 h and increased astrocytic proliferation by 72 h, all of which were inhibited by Ca(2+)-signaling blockers and specific knockdown of TRPC3 using small interfering RNA. Intracortical injection of SFLLR-NH(2), a PAR-1 agonist peptide, induced proliferation of astrocytes, most of which were TRPC3 immunopositive. These results suggest that thrombin dynamically upregulates TRPC3 and that TRPC3 contributes to the pathological activation of astrocytes in part through a feedforward upregulation of its own expression.
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11
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Riera MF, Galardo MN, Pellizzari EH, Meroni SB, Cigorraga SB. Molecular mechanisms involved in Sertoli cell adaptation to glucose deprivation. Am J Physiol Endocrinol Metab 2009; 297:E907-14. [PMID: 19638510 DOI: 10.1152/ajpendo.00235.2009] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sertoli cells provide the physical support and the necessary environment for germ cell development. Among the products secreted by Sertoli cells, lactate, the preferred energy substrate for spermatocytes and spermatids, is present. Considering the essential role of lactate on germ cell metabolism, it is supposed that Sertoli cells must ensure its production even in adverse conditions, such as those that would result from a decrease in glucose levels in the extracellular milieu. The aim of the present study was to investigate 1) a possible effect of glucose deprivation on glucose uptake and on the expression of glucose transporters in rat Sertoli cells and 2) the participation of different signal transduction pathways in the above-mentioned regulation. Results obtained show that decreasing glucose levels in Sertoli cell culture medium provokes 1) an increase in glucose uptake accompanied by only a slight decrease in lactate production, 2) an increase in GLUT1 and a decrease in GLUT3 expression, and 3) an activation of AMP-activated protein kinase (AMPK)-, phosphatidylinositol 3-kinase (PI3K)/PKB-, and p38 MAPK-dependent pathways. Additionally, by using specific inhibitors of these pathways, a possible participation of AMPK- and p38MAPK-dependent pathways in the regulation of glucose uptake and GLUT1 expression is shown. These results suggest that Sertoli cells adapt to conditions of glucose deprivation to ensure an adequate lactate concentration in the microenvironment where germ cell development occurs.
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Affiliation(s)
- María F Riera
- Centro de Investigaciones Endocrinológicas, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
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12
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Kim MS, Kewalramani G, Puthanveetil P, Lee V, Kumar U, An D, Abrahani A, Rodrigues B. Acute diabetes moderates trafficking of cardiac lipoprotein lipase through p38 mitogen-activated protein kinase-dependent actin cytoskeleton organization. Diabetes 2008; 57:64-76. [PMID: 17942824 DOI: 10.2337/db07-0832] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Heart disease is a leading cause of death in diabetes and could occur because of excessive use of fatty acid for energy generation. Our objective was to determine the mechanisms by which AMP-activated protein kinase (AMPK) augments cardiac lipoprotein lipase (LPL), the enzyme that provides the heart with the majority of its fatty acid. RESEARCH DESIGN AND METHODS We used diazoxide in rats to induce hyperglycemia or used 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) and thrombin to directly stimulate AMPK and p38 mitogen-activated protein kinase (MAPK), respectively, in cardiomyocytes. RESULTS There was a substantial increase in LPL at the coronary lumen following 4 h of diazoxide. In these diabetic animals, phosphorylation of AMPK, p38 MAPK, and heat shock protein (Hsp)25 produced actin cytoskeleton rearrangement to facilitate LPL translocation to the myocyte surface and, eventually, the vascular lumen. AICAR activated AMPK, p38 MAPK, and Hsp25 in a pattern similar to that seen with diabetes. AICAR also appreciably enhanced LPL, an effect reduced by preincubation with the p38 MAPK inhibitor SB202190 or by cytochalasin D, which inhibits actin polymerization. Thrombin activated p38 MAPK in the absence of AMPK phosphorylation. Comparable with diabetes, activation of p38 MAPK and, subsequently, Hsp25 phosphorylation and F-actin polymerization corresponded with an enhanced LPL activity. SB202190 and silencing of p38 MAPK also prevented these effects induced by thrombin and AICAR, respectively. CONCLUSIONS We propose that AMPK recruitment of LPL to the cardiomyocyte surface (which embraces p38 MAPK activation and actin cytoskeleton polymerization) represents an immediate compensatory response by the heart to guarantee fatty acid supply when glucose utilization is compromised.
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Affiliation(s)
- Min Suk Kim
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, Canada
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13
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Toi S, Shibata N, Sawada T, Kobayashi M, Uchiyama S. Activation of the non-receptor tyrosine kinase cSrc in macrophage-rich atherosclerotic plaques of human carotid arteries. Acta Histochem Cytochem 2007; 40:153-61. [PMID: 18224247 PMCID: PMC2156080 DOI: 10.1267/ahc.07026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 11/26/2007] [Indexed: 11/22/2022] Open
Abstract
To determine the involvement of the non-receptor tyrosine kinase cSrc in plaque destabilization in carotid atherosclerosis (CAS), which is responsible for cerebral infarction, we performed quantitative and morphological detection of phosphorylated active cSrc (p-cSrc) and histopathological examination in CAS lesions. We examined carotid endarterectomy specimens obtained from 32 CAS patients. Each specimen was used for immunoblot and immunohistochemical analyses of p-cSrc, histopathological analysis, and image analysis of macrophage content. There was a strong positive correlation between cSrc activation on blots and macrophage content on sections. When we defined the macrophage-rich plaque (MRP) and the macrophage-poor plaque (MPP) as having macrophage content more and less than 5%, respectively, the p-cSrc density and the occurrence of plaque hemorrhage and thrombus formation were significantly increased in the MRP group (n=18) compared to the MPP group (n=14). p-cSrc immunoreactivity was localized in lesional endothelial cells, macrophages, and smooth muscle cells, which contained proinflammatory substances: the upstream oxidized low density lipoprotein, tissue factor and osteopontin, and the downstream active forms of extracellular signal-activated kinase and p38 and nuclear factor-kappaB. Our results suggest that cSrc activation in lesional cells contributes to plaque destabilization in CAS via persistent inflammation.
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Affiliation(s)
- Sono Toi
- Department of Neurology, Tokyo Women’s Medical University, 8–1 Kawada-cho, Shinjuku-ku, Tokyo 162–8666, Japan
| | - Noriyuki Shibata
- Department of Pathology, Tokyo Women’s Medical University, 8–1 Kawada-cho, Shinjuku-ku, Tokyo 162–8666, Japan
| | - Tatsuo Sawada
- Department of Pathology, Tokyo Women’s Medical University, 8–1 Kawada-cho, Shinjuku-ku, Tokyo 162–8666, Japan
| | - Makio Kobayashi
- Department of Pathology, Tokyo Women’s Medical University, 8–1 Kawada-cho, Shinjuku-ku, Tokyo 162–8666, Japan
| | - Shinichiro Uchiyama
- Department of Neurology, Tokyo Women’s Medical University, 8–1 Kawada-cho, Shinjuku-ku, Tokyo 162–8666, Japan
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14
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Masori M, Hamamoto A, Mawatari K, Harada N, Takahasi A, Nakaya Y. Angiotensin II Decreases Glucose Uptake by Downregulation of GLUT1 in the Cell Membrane of the Vascular Smooth Muscle Cell Line A10. J Cardiovasc Pharmacol 2007; 50:267-73. [PMID: 17878754 DOI: 10.1097/fjc.0b013e318093ec74] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recent evidence suggests a crosstalk between angiotensin II (Ang II) and insulin. However, whether this crosstalk affects glucose uptake, particularly in terms of actin filament involvement, has not yet been studied in vascular smooth muscle cells. Pretreatment of cells with either Ang II or cytochalasin D disarranged actin filaments in a time-dependent manner and inhibited glucose uptake. However, insulin increased actin reorganization and glucose uptake. Membrane fractionation studies showed that Ang II decreased GLUT-1 at the cell membrane, whereas it increased GLUT-1 in the cytoplasm, indicating that Ang II may cause internalization of GLUT-1 via actin disorganization, consequently decreasing glucose uptake. The effects of Ang II on glucose uptake and actin reorganization were blocked by AT1 receptor antagonist, but not by AT2 antagonist. Either P38 or ERK1/2 inhibitors partially reversed the Ang II-inhibited actin reorganization and glucose uptake, suggesting that MAPK signaling pathways could be involved as downstream events in Ang II signaling, and this signaling may interfere with insulin-induced actin reorganization and glucose uptake. These data imply that Ang II induces insulin resistance by decreasing glucose uptake via disarrangement of actin filaments, which provides a novel insight into understanding of insulin resistance by Ang II at the molecular level.
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Affiliation(s)
- Maria Masori
- Department of Nutrition, Division of Nutrition and Metabolism, Graduate School of Medicine, University of Tokushima, Tokushima, Japan
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15
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Miller EJ, Li J, Sinusas KM, Holman GD, Young LH. Infusion of a biotinylated bis-glucose photolabel: a new method to quantify cell surface GLUT4 in the intact mouse heart. Am J Physiol Endocrinol Metab 2007; 292:E1922-8. [PMID: 17341550 DOI: 10.1152/ajpendo.00170.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose uptake in the heart is mediated by specific glucose transporters (GLUTs) present on cardiomyocyte cell surface membranes. Metabolic stress and insulin both increase glucose transport by stimulating the translocation of glucose transporters from intracellular storage vesicles to the cell surface. Isolated perfused transgenic mouse hearts are commonly used to investigate the molecular regulation of heart metabolism; however, current methods to quantify cell surface glucose transporter content in intact mouse hearts are limited. Therefore, we developed a novel technique to directly assess the cell surface content of the cardiomyocyte glucose transporter GLUT4 in perfused mouse hearts, using a cell surface impermeant biotinylated bis-glucose photolabeling reagent (bio-LC-ATB-BGPA). Bio-LC-ATB-BGPA was infused through the aorta and cross-linked to cell surface GLUTs. Bio-LC-ATB-BGPA-labeled GLUT4 was recovered from cardiac membranes by streptavidin isolation and quantified by immunoblotting. Bio-LC-ATB-BGPA-labeling of GLUT4 was saturable and competitively inhibited by d-glucose. Stimulation of glucose uptake by insulin in the perfused heart was associated with parallel increases in bio-LC-ATB-BGPA-labeling of cell surface GLUT4. Bio-LC-ATB-BGPA also labeled cell surface GLUT1 in the perfused heart. Thus, photolabeling provides a novel approach to assess cell surface glucose transporter content in the isolated perfused mouse heart and may prove useful to investigate the mechanisms through which insulin, ischemia, and other stimuli regulate glucose metabolism in the heart and other perfused organs.
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Affiliation(s)
- Edward J Miller
- Department of Internal Medicine, Yale University School of Medicine, FMP 3, 333 Cedar St., New Haven, CT 06520, USA
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16
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Inafuku M, Toda T, Okabe T, Shinjo A, Iwasaki H, Oku H. Expression of Cell-Cycle-Regulating Genes in the Development of Atherosclerosis in Japanese Quail (Coturnix japonica). Poult Sci 2007; 86:1166-73. [PMID: 17495088 DOI: 10.1093/ps/86.6.1166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The levels of mRNA expression in regulatory genes that are involved in the pathological changes of aortic atherosclerotic and fibroblastic intimal thickening was investigated in Japanese quail. The quail were divided into a control diet group and an atherogenic diet group. The quail were euthanized at 2, 4, 8, and 12 wk after consuming either a control diet or an atherogenic diet. Thereafter, both histological and immunohistochemical studies and mRNA expression analysis of the cell-cycle-regulating genes in aortic atherosclerotic lesions were performed on selected ascending aortas and their large branches. In the atherogenic diet group, aortic lipid-containing intimal and atheromatous lesions were seen mainly at 8 and 12 wk, respectively. Semiquantitative reverse-transcription PCR was used to analyze the alterations of mRNA expression on the development of atherosclerotic lesions. Messenger RNA expression of the c-fos and c-src genes showed peak levels at 8 wk in the atherogenic diet group. However, no significant alteration of c-jun mRNA expression was noted during the entire experimental period. According to the progression of aortic atherosclerotic lesions, c-myc mRNA expression in the atherogenic diet group increased chronologically, and the highest level was observed at 12 wk. Alterations in mRNA expression of proliferating cell nuclear antigen and the p27 gene were similar to that of c-myc. The levels of c-myc, proliferating cell nuclear antigen, and p27 mRNA expression was significantly correlated with the degree of aortic atherosclerotic lesion development at 12 wk in our experiment.
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Affiliation(s)
- M Inafuku
- United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, 890-0065, Japan
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17
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Kanda Y, Watanabe Y. Adrenaline increases glucose transport via a Rap1-p38MAPK pathway in rat vascular smooth muscle cells. Br J Pharmacol 2007; 151:476-82. [PMID: 17450172 PMCID: PMC2013965 DOI: 10.1038/sj.bjp.0707247] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Adrenaline has been implicated in the pathogenesis of atherosclerosis. However, little is known regarding the role of adrenaline in glucose transport in VSMC. EXPERIMENTAL APPROACH In this study, we examined the effects of adrenaline on glucose uptake in rat VSMC. We also examined the downstream signaling pathway from the beta-adrenoceptor to glucose uptake, using a pharmacological approach. To investigate the downstream action of adenylate cyclase, we studied the effects of GGTI-298, an inhibitor of geranylgeranylation of GTPases, including Rap1. To confirm the involvement of Rap1, we silenced Rap1 by siRNA. KEY RESULTS Adrenaline induced glucose uptake in a dose-dependent manner. The adrenaline-induced glucose uptake was inhibited by L-propranolol, (a selective beta-adrenoceptor antagonist), but not by prazosin (a selective alpha(1)-adrenoceptor antagonist) or UK14304 (a selective alpha(2)-adrenoceptor antagonist), suggesting the involvement of beta-adrenoceptors in glucose transport. Long-term treatment with cholera toxin, which resulted in sequestration of G(s) proteins, prevented the adrenaline-induced glucose uptake. Forskolin, a direct activator of adenylate cyclase, was found to mimic the effects of adrenaline. Adrenaline-induced glucose uptake was inhibited by GGTI-298, not by H89 (a selective inhibitor of PKA). Silencing of Rap1 by siRNA attenuated the adrenaline-induced glucose uptake. Adrenaline-induced glucose uptake was inhibited by SB203580 (a selective inhibitor of p38MAPK) and adrenaline-induced p38MAPK activation was inhibited by GGTI-298 and siRNA against Rap1. CONCLUSIONS AND IMPLICATIONS These findings suggest that adrenaline-induced glucose transport is mediated by beta-adrenoceptors, G(s), adenylate cyclase, Rap1, and p38MAPK in vascular smooth muscle cells.
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Affiliation(s)
- Y Kanda
- Department of Pharmacology, National Defense Medical College, Tokorozawa, Saitama, Japan.
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18
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Kanda Y, Watanabe Y. Nicotine-induced vascular endothelial growth factor release via the EGFR-ERK pathway in rat vascular smooth muscle cells. Life Sci 2007; 80:1409-14. [PMID: 17286987 DOI: 10.1016/j.lfs.2006.12.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 11/29/2006] [Accepted: 12/26/2006] [Indexed: 11/28/2022]
Abstract
Cigarette smoke has been firmly established as an independent risk factor for atherosclerosis and other vascular diseases. The proliferation and migration of vascular smooth muscle cells (VSMC) induced by growth factors have been proposed to play an important role in the progression of atherosclerosis. In the present study, we investigated the effects of nicotine, which is one of the important constituents of cigarette smoke, on vascular endothelial growth factor (VEGF) release, in rat VSMC. The stimulation of cells with nicotine resulted in a time- and concentration-dependent release of VEGF. Hexamethonium, an antagonist of nicotinic acetylcholine receptor (nAChR), inhibited nicotine-induced VEGF release. We next investigated the mechanisms by which nicotine induces VEGF release in the cells. The nicotine-induced VEGF release was inhibited by treatment with U0126, a selective inhibitor of MEK, which attenuated the nicotine-induced ERK phosphorylation. Nicotine induced a transient phosphorylation of ERK. Furthermore, AG1478, a selective inhibitor of epidermal growth factor receptor (EGFR) kinase, inhibited nicotine-induced ERK phosphorylation and VEGF release. These data suggest that nicotine releases VEGF through nAChR in VSMC. Moreover, VEGF release induced by nicotine is mediated by an EGFR-ERK pathway in VSMC. VEGF may contribute to the risk of cardiovascular diseases in cigarette smokers.
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MESH Headings
- Animals
- Blotting, Western
- Butadienes/pharmacology
- Enzyme Inhibitors/pharmacology
- ErbB Receptors/drug effects
- ErbB Receptors/metabolism
- Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors
- Extracellular Signal-Regulated MAP Kinases/physiology
- Hexamethonium/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nicotine/pharmacology
- Nicotinic Agonists/pharmacology
- Nicotinic Antagonists/pharmacology
- Nitriles/pharmacology
- Phosphorylation
- Quinazolines
- Rats
- Rats, Sprague-Dawley
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/metabolism
- Tyrphostins/pharmacology
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Yasunari Kanda
- Department of Pharmacology, National Defense Medical College, 3-2, Namiki, Tokorozawa, Saitama 359-8513, Japan.
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