1
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Zhang K, Xu XH, Wu J, Wang N, Li G, Hao GM, Cao JF. Decreased AKAP4/ PKA signaling pathway in high DFI sperm affects sperm capacitation. Asian J Androl 2023; 26:00129336-990000000-00114. [PMID: 37695244 PMCID: PMC10846834 DOI: 10.4103/aja202329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/12/2023] [Indexed: 09/12/2023] Open
Abstract
The sperm DNA fragmentation index (DFI) is a metric used to assess DNA fragmentation within sperm. During in vitro fertilization-embryo transfer (IVF-ET), high sperm DFI can lead to a low fertilization rate, poor embryo development, early miscarriage, etc. A kinase anchoring protein (AKAP) is a scaffold protein that can bind protein kinase A (PKA) to subcellular sites of specific substrates and protects the biophosphorylation reaction. Sperm protein antigen 17 (SPA17) can also bind to AKAP. This study intends to explore the reason for the decreased fertilization rate observed in high sperm DFI (H-DFI) patients during IVF-ET. In addition, the study investigates the expression of AKAP, protein kinase A regulatory subunit (PKARII), and SPA17 between H-DFI and low sperm DFI (L-DFI) patients. SPA17 at the transcriptional level is abnormal, the translational level increases in H-DFI patients, and the expression of AKAP4/PKARII protein decreases. H2O2 has been used to simulate oxidative stress damage to spermatozoa during the formation of sperm DFI. It indicates that H2O2 increases the expression of sperm SPA17 protein and suppresses AKAP4/PKARII protein expression. These processes inhibit sperm capacitation and reduce acrosomal reactions. Embryo culture data and IVF outcomes have been documented. The H-DFI group has a lower fertilization rate. Therefore, the results indicate that the possible causes for the decreased fertilization rate in the H-DFI patients have included loss of sperm AKAP4/PKARII proteins, blocked sperm capacitation, and reduced occurrence of acrosome reaction.
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Affiliation(s)
- Kun Zhang
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
- Department of Reproductive Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221000, China
| | - Xiu-Hua Xu
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Jian Wu
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Ning Wang
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Gang Li
- Department of Neurology, The 980 Hospital of the People’s Liberation Army Joint Logistics Support Force (Bethune International Peace Hospital), Shijiazhuang 050000, China
| | - Gui-Min Hao
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Jin-Feng Cao
- Hebei Key Laboratory of Infertility and Genetics, Department of Reproductive Medicine, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
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2
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Wilson BAP, Li N, Martinez Fiesco JA, Dalilian M, Wang D, Smith EA, Wamiru A, Shah R, Goncharova EI, Beutler JA, Grkovic T, Zhang P, O’Keefe BR. Biochemical Discovery, Intracellular Evaluation, and Crystallographic Characterization of Synthetic and Natural Product Adenosine 3',5'-Cyclic Monophosphate-Dependent Protein Kinase A ( PKA) Inhibitors. ACS Pharmacol Transl Sci 2023; 6:633-650. [PMID: 37082750 PMCID: PMC10111623 DOI: 10.1021/acsptsci.3c00010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Indexed: 04/22/2023]
Abstract
The recent demonstration that adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) plays an oncogenic role in a number of important cancers has led to a renaissance in drug development interest targeting this kinase. We therefore have established a suite of biochemical, cell-based, and structural biology assays for identifying and evaluating new pharmacophores for PKA inhibition. This discovery process started with a 384-well high-throughput screen of more than 200,000 substances, including fractionated natural product extracts. Identified active compounds were further prioritized in biochemical, biophysical, and cell-based assays. Priority lead compounds were assessed in detail to fully characterize several previously unrecognized PKA pharmacophores including the generation of new X-ray crystallography structures demonstrating unique interactions between PKA and bound inhibitor molecules.
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Affiliation(s)
- Brice A. P. Wilson
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ning Li
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Juliana A. Martinez Fiesco
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Masoumeh Dalilian
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Dongdong Wang
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Emily A. Smith
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Antony Wamiru
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Rohan Shah
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ekaterina I. Goncharova
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Advanced
Biomedical Computational Science, Frederick
National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - John A. Beutler
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Tanja Grkovic
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Natural
Products Branch, Developmental Therapeutics Program, Division of Cancer
Treatment and Diagnosis, National Cancer
Institute, Frederick, Maryland 21702, United States
| | - Ping Zhang
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Barry R. O’Keefe
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Natural
Products Branch, Developmental Therapeutics Program, Division of Cancer
Treatment and Diagnosis, National Cancer
Institute, Frederick, Maryland 21702, United States
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3
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Bahn MS, Ko YG. PROM1-mediated cell signal transduction in cancer stem cells and hepatocytes. BMB Rep 2023; 56:65-70. [PMID: 36617467 PMCID: PMC9978360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Indexed: 01/10/2023] Open
Abstract
Prominin-1 (PROM1), also called CD133, is a penta-span transmembrane protein that is localized in membrane protrusions, such as microvilli and filopodia. It is known to be expressed in cancer stem cells and various progenitor cells of bone marrow, liver, kidney, and intestine. Accumulating evidence has revealed that PROM1 has multiple functions in various organs, such as eye, tooth, peripheral nerve, and liver, associating with various molecular protein partners. PROM1 regulates PKA-induced gluconeogenesis, TGFβ-induced fibrosis, and IL-6-induced regeneration in the liver, associating with Radixin, SMAD7, and GP130, respectively. In addition, PROM1 is necessary to maintain cancer stem cell properties by activating PI3K and β-Catenin. PROM1-deficienct mice also show distinct phenotypes in eyes, brain, peripheral nerves, and tooth. Here, we discuss recent findings of PROM1-mediated signal transduction. [BMB Reports 2023; 56(2): 65-70].
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Affiliation(s)
- Myeong-Suk Bahn
- Division of Life Sciences, Korea University, Seoul 02841, Korea
| | - Young-Gyu Ko
- Division of Life Sciences, Korea University, Seoul 02841, Korea
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4
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Kóňa J, Šesták S, Wilson IBH, Poláková M. 1,4-Dideoxy-1,4-imino-D- and L-lyxitol-based inhibitors bind to Golgi α-mannosidase II in different protonation forms. Org Biomol Chem 2022; 20:8932-8943. [PMID: 36322142 PMCID: PMC7614232 DOI: 10.1039/d2ob01545e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 11/24/2022]
Abstract
The development of effective inhibitors of Golgi α-mannosidase II (GMII, E.C.3.2.1.114) with minimal off-target effects on phylogenetically-related lysosomal α-mannosidase (LMan, E.C.3.2.1.24) is a complex task due to the complicated structural and chemical properties of their active sites. The pKa values (and also protonation forms in some cases) of several ionizable amino acids, such as Asp, Glu, His or Arg of enzymes, can be changed upon the binding of the inhibitor. Moreover, GMII and LMan work under different pH conditions. The pKa calculations on large enzyme-inhibitor complexes and FMO-PIEDA energy decomposition analysis were performed on the structures of selected inhibitors obtained from docking and hybrid QM/MM calculations. Based on the calculations, the roles of the amino group incorporated in the ring of the imino-D-lyxitol inhibitors and some ionizable amino acids of Golgi-type (Asp270-Asp340-Asp341 of Drosophila melanogaster α-mannosidase dGMII) and lysosomal-type enzymes (His209-Asp267-Asp268 of Canavalia ensiformis α-mannosidase, JBMan) were explained in connection with the observed inhibitory properties. The pyrrolidine ring of the imino-D-lyxitols prefers at the active site of dGMII the neutral form while in JBMan the protonated form, whereas that of imino-L-lyxitols prefers the protonation form in both enzymes. The calculations indicate that the binding mechanism of inhibitors to the active-site of α-mannosidases is dependent on the inhibitor structure and could be used to design new selective inhibitors of GMII. A series of novel synthetic N-substituted imino-D-lyxitols were evaluated with four enzymes from the glycoside hydrolase GH38 family (two of Golgi-type, Drosophila melanogaster GMIIb and Caenorhabditis elegans AMAN-2, and two of lysosomal-type, Drosophila melanogaster LManII and Canavalia ensiformis JBMan, enzymes). The most potent structures [N-9-amidinononyl and N-2-(1-naphthyl)ethyl derivatives] inhibited GMIIb (Ki = 40 nM) and AMAN-2 (Ki = 150 nM) with a weak selectivity index (SI) toward Golgi-type enzymes of IC50(LManII)/IC50(GMIIb) = 35 or IC50(JBMan)/IC50(AMAN-2) = 86. On the other hand, weaker micromolar inhibitors, such as N-2-naphthylmethyl or 4-iodobenzyl derivatives [IC50(GMIIb) = 2.4 μM and IC50 (AMAN-2) = 7.6 μM], showed a significant SI in the range from 111 to 812.
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Affiliation(s)
- Juraj Kóňa
- Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dúbravska cesta 9, 845 38 Bratislava, Slovakia.
- Medical Vision, Civic Research Association, Záhradnícka 4837/55, 82108 Bratislava, Slovakia
| | - Sergej Šesták
- Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dúbravska cesta 9, 845 38 Bratislava, Slovakia.
| | - Iain B H Wilson
- Department of Chemistry, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Monika Poláková
- Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dúbravska cesta 9, 845 38 Bratislava, Slovakia.
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5
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Yamamoto T, Mulpuri Y, Izraylev M, Li Q, Simonian M, Kramme C, Schmidt BL, Seltzman HH, Spigelman I. Selective targeting of peripheral cannabinoid receptors prevents behavioral symptoms and sensitization of trigeminal neurons in mouse models of migraine and medication overuse headache. Pain 2021; 162:2246-2262. [PMID: 33534356 PMCID: PMC8277668 DOI: 10.1097/j.pain.0000000000002214] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/19/2021] [Indexed: 01/03/2023]
Abstract
ABSTRACT Migraine affects ∼15% of the world's population greatly diminishing their quality of life. Current preventative treatments are effective in only a subset of migraine patients, and although cannabinoids seem beneficial in alleviating migraine symptoms, central nervous system side effects limit their widespread use. We developed peripherally restricted cannabinoids (PRCBs) that relieve chronic pain symptoms of cancer and neuropathies, without appreciable central nervous system side effects or tolerance development. Here, we determined PRCB effectiveness in alleviating hypersensitivity symptoms in mouse models of migraine and medication overuse headache. Long-term glyceryl trinitrate (GTN, 10 mg/kg) administration led to increased sensitivity to mechanical stimuli and increased expression of phosphorylated protein kinase A, neuronal nitric oxide synthase, and transient receptor potential ankyrin 1 proteins in trigeminal ganglia. Peripherally restricted cannabinoid pretreatment, but not posttreatment, prevented behavioral and biochemical correlates of GTN-induced sensitization. Low pH-activated and allyl isothiocyanate-activated currents in acutely isolated trigeminal neurons were reversibly attenuated by PRCB application. Long-term GTN treatment significantly enhanced these currents. Long-term sumatriptan treatment also led to the development of allodynia to mechanical and cold stimuli that was slowly reversible after sumatriptan discontinuation. Subsequent challenge with a previously ineffective low-dose GTN (0.1-0.3 mg/kg) revealed latent behavioral sensitization and increased expression of phosphorylated protein kinase A, neuronal nitric oxide synthase, and transient receptor potential ankyrin 1 proteins in trigeminal ganglia. Peripherally restricted cannabinoid pretreatment prevented all behavioral and biochemical correlates of allodynia and latent sensitization. Importantly, long-term PRCB treatment alone did not produce any behavioral or biochemical signs of sensitization. These data validate peripheral cannabinoid receptors as potential therapeutic targets in migraine and medication overuse headache.
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Affiliation(s)
- Toru Yamamoto
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Yatendra Mulpuri
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Mikhail Izraylev
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Qianyi Li
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Menooa Simonian
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Christian Kramme
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
| | - Brian L. Schmidt
- Department of Oral & Maxillofacial Surgery and Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY
| | - Herbert H. Seltzman
- Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC
| | - Igor Spigelman
- Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA
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6
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Hossain M, Imran KM, Rahman MS, Yoon D, Marimuthu V, Kim YS. Sinapic acid induces the expression of thermogenic signature genes and lipolysis through activation of PKA/CREB signaling in brown adipocytes. BMB Rep 2020; 53:142-147. [PMID: 31401979 PMCID: PMC7118353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/03/2019] [Accepted: 06/14/2019] [Indexed: 03/29/2024] Open
Abstract
Lipid accumulation in white adipose tissue is the key contributor to the obesity and orchestrates numerous metabolic health problems such as type 2 diabetes, hypertension, atherosclerosis, and cancer. Nonetheless, the prevention and treatment of obesity are still inadequate. Recently, scientists found that brown adipose tissue (BAT) in adult humans has functions that are diametrically opposite to those of white adipose tissue and that BAT holds promise for a new strategy to counteract obesity. In this study, we evaluated the potential of sinapic acid (SA) to promote the thermogenic program and lipolysis in BAT. SA treatment of brown adipocytes induced the expression of brown-adipocyte activation-related genes such as Ucp1, Pgc-1α, and Prdm16. Furthermore, structural analysis and western blot revealed that SA upregulates protein kinase A (PKA) phosphorylation with competitive inhibition by a pan-PKA inhibitor, H89. SA binds to the adenosine triphosphate (ATP) site on the PKA catalytic subunit where H89 binds specifically. PKA-cat-α1 gene-silencing experiments confirmed that SA activates the thermogenic program via a mechanism involving PKA and cyclic AMP response element-binding protein (CREB) signaling. Moreover, SA treatment promoted lipolysis via a PKA/p38-mediated pathway. Our findings may allow us to open a new avenue of strategies against obesity and need further investigation. [BMB Reports 2020; 53(3): 142-147].
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Affiliation(s)
- Monir Hossain
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Khan Mohammad Imran
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Md. Shamim Rahman
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Dahyeon Yoon
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Vignesh Marimuthu
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Yong-Sik Kim
- Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Chenan 31151, Korea
- Department of Microbiology, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
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7
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Patra KC, Kato Y, Mizukami Y, Widholz S, Boukhali M, Revenco I, Grossman EA, Ji F, Sadreyev RI, Liss AS, Screaton RA, Sakamoto K, Ryan DP, Mino-Kenudson M, Castillo CFD, Nomura DK, Haas W, Bardeesy N. Mutant GNAS drives pancreatic tumourigenesis by inducing PKA-mediated SIK suppression and reprogramming lipid metabolism. Nat Cell Biol 2018; 20:811-822. [PMID: 29941929 PMCID: PMC6044476 DOI: 10.1038/s41556-018-0122-3] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 05/15/2018] [Indexed: 12/13/2022]
Abstract
G protein αs (GNAS) mediates receptor-stimulated cAMP signalling, which integrates diverse environmental cues with intracellular responses. GNAS is mutationally activated in multiple tumour types, although its oncogenic mechanisms remain elusive. We explored this question in pancreatic tumourigenesis where concurrent GNAS and KRAS mutations characterize pancreatic ductal adenocarcinomas (PDAs) arising from intraductal papillary mucinous neoplasms (IPMNs). By developing genetically engineered mouse models, we show that GnasR201C cooperates with KrasG12D to promote initiation of IPMN, which progress to invasive PDA following Tp53 loss. Mutant Gnas remains critical for tumour maintenance in vivo. This is driven by protein-kinase-A-mediated suppression of salt-inducible kinases (Sik1-3), associated with induction of lipid remodelling and fatty acid oxidation. Comparison of Kras-mutant pancreatic cancer cells with and without Gnas mutations reveals striking differences in the functions of this network. Thus, we uncover Gnas-driven oncogenic mechanisms, identify Siks as potent tumour suppressors, and demonstrate unanticipated metabolic heterogeneity among Kras-mutant pancreatic neoplasms.
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MESH Headings
- Animals
- Carcinoma, Pancreatic Ductal/enzymology
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/pathology
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cellular Reprogramming/genetics
- Chromogranins/genetics
- Chromogranins/metabolism
- Cyclic AMP-Dependent Protein Kinases/genetics
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Enzyme Repression
- Fatty Acids/metabolism
- Female
- GTP-Binding Protein alpha Subunits, Gs/genetics
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Gene Expression Regulation, Neoplastic
- Genes, ras
- Genetic Predisposition to Disease
- Humans
- Lipid Metabolism/genetics
- Male
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Mutant Strains
- Mice, Transgenic
- Mutation
- Oxidation-Reduction
- Pancreatic Neoplasms/enzymology
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/pathology
- Phenotype
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Signal Transduction
- Time Factors
- Tumor Cells, Cultured
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
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Affiliation(s)
- Krushna C Patra
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Departments of Medicine, Harvard Medical School, Boston, MA, USA
| | - Yasutaka Kato
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Yusuke Mizukami
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Institute of Biomedical Research, Sapporo Higashi Tokushukai Hospital, Sapporo, Hokkaido, Japan
- Asahikawa Medical University, Hokkaido, Japan
| | - Sebastian Widholz
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Myriam Boukhali
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Iulia Revenco
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Elizabeth A Grossman
- Departments of Nutritional Sciences and Toxicology, Chemistry, and Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Fei Ji
- Departments of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Ruslan I Sadreyev
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Departments of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Andrew S Liss
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Robert A Screaton
- Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Kei Sakamoto
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Scotland, UK
- Nestlé Institute of Health Sciences SA, Lausanne, Switzerland
| | - David P Ryan
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Departments of Medicine, Harvard Medical School, Boston, MA, USA
| | - Mari Mino-Kenudson
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Departments of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Carlos Fernandez-Del Castillo
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
- Departments of Surgery, Massachusetts General Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Daniel K Nomura
- Departments of Nutritional Sciences and Toxicology, Chemistry, and Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Wilhelm Haas
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA
| | - Nabeel Bardeesy
- Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA.
- Departments of Medicine, Harvard Medical School, Boston, MA, USA.
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8
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Hirakis SP, Malmstrom RD, Amaro RE. Molecular Simulations Reveal an Unresolved Conformation of the Type IA Protein Kinase A Regulatory Subunit and Suggest Its Role in the cAMP Regulatory Mechanism. Biochemistry 2017; 56:3885-3888. [PMID: 28661131 PMCID: PMC5751417 DOI: 10.1021/acs.biochem.7b00461] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We identify a previously unresolved, unrecognized, and highly stable conformation of the protein kinase A (PKA) regulatory subunit RIα. This conformation, which we term the "Flipback" structure, bridges conflicting characteristics in crystallographic structures and solution experiments of the PKA RIα heterotetramer. Our simulations reveal a hinge residue, G235, in the B/C helix that is conserved through all isoforms of RI. Brownian dynamics simulations suggest that the Flipback conformation plays a role in cAMP association to the A domain of the R subunit.
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Affiliation(s)
- Sophia P. Hirakis
- Department of Chemistry and Biochemistry and National Biomedical Computational Resource, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0304
| | - Robert D. Malmstrom
- Department of Chemistry and Biochemistry and National Biomedical Computational Resource, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0304
| | - Rommie E. Amaro
- Department of Chemistry and Biochemistry and National Biomedical Computational Resource, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0304
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9
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Blain M, Yau H, Jean-Gérard L, Auvergne R, Benazet D, Schreiner PR, Caillol S, Andrioletti B. Urea- and Thiourea-Catalyzed Aminolysis of Carbonates. ChemSusChem 2016; 9:2269-72. [PMID: 27467779 DOI: 10.1002/cssc.201600778] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Indexed: 05/28/2023]
Abstract
The aminolysis of (poly)carbonates by (poly)amines provides access to non-isocyanate polyurethanes (NIPUs) that are toxic-reagent-free analogues of polyurethanes (PUs). Owing to their low reactivity, the ring opening of cyclic carbonates requires the use of a catalyst. Herein, we report that the more available and cheaper ureas could advantageously be used for catalyzing the formation of NIPUs at the expense of the thiourea analogues. In addition, we demonstrate a medium-range pKa of the (thio)urea and an unqeual substitution pattern is critical for controlling the efficiency of the carbonate opening.
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Affiliation(s)
- Marine Blain
- Université de Lyon, Université Claude Bernard-Lyon 1, ICBMS-UMR CNRS 5246 Campus LyonTech la Doua - Bât. Curien/CPE, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne Cedex, France
- Ingénierie Architecture Macromoléculaire, Institut Charles Gerhardt UMR 5253 - CNRS, UM, ENSCM, 8, Rue Ecole Normale, 34296, Montpellier, France
| | - Honman Yau
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
| | - Ludivine Jean-Gérard
- Université de Lyon, Université Claude Bernard-Lyon 1, ICBMS-UMR CNRS 5246 Campus LyonTech la Doua - Bât. Curien/CPE, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne Cedex, France
| | - Rémi Auvergne
- Ingénierie Architecture Macromoléculaire, Institut Charles Gerhardt UMR 5253 - CNRS, UM, ENSCM, 8, Rue Ecole Normale, 34296, Montpellier, France
| | - Dominique Benazet
- Juxta, 5 rue de la Jalesie, BP 71039, 25401, Audincourt cedex, France
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
| | - Sylvain Caillol
- Ingénierie Architecture Macromoléculaire, Institut Charles Gerhardt UMR 5253 - CNRS, UM, ENSCM, 8, Rue Ecole Normale, 34296, Montpellier, France.
| | - Bruno Andrioletti
- Université de Lyon, Université Claude Bernard-Lyon 1, ICBMS-UMR CNRS 5246 Campus LyonTech la Doua - Bât. Curien/CPE, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne Cedex, France.
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10
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Kozorovitskiy Y, Peixoto R, Wang W, Saunders A, Sabatini BL. Neuromodulation of excitatory synaptogenesis in striatal development. eLife 2015; 4. [PMID: 26551563 PMCID: PMC4716836 DOI: 10.7554/elife.10111] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/08/2015] [Indexed: 11/30/2022] Open
Abstract
Dopamine is released in the striatum during development and impacts the activity of Protein Kinase A (PKA) in striatal spiny projection neurons (SPNs). We examined whether dopaminergic neuromodulation regulates activity-dependent glutamatergic synapse formation in the developing striatum. Systemic in vivo treatment with Gαs-coupled G-protein receptors (GPCRs) agonists enhanced excitatory synapses on direct pathway striatal spiny projection neurons (dSPNs), whereas rapid production of excitatory synapses on indirect pathway neurons (iSPNs) required the activation of Gαs GPCRs in SPNs of both pathways. Nevertheless, in vitro Gαs activation was sufficient to enhance spinogenesis induced by glutamate photolysis in both dSPNs and iSPNs, suggesting that iSPNs in intact neural circuits have additional requirements for rapid synaptic development. We evaluated the in vivo effects of enhanced glutamate release from corticostriatal axons and postsynaptic PKA and discovered a mechanism of developmental plasticity wherein rapid synaptogenesis is promoted by the coordinated actions of glutamate and postsynaptic Gαs-coupled receptors. DOI:http://dx.doi.org/10.7554/eLife.10111.001 The brain is composed of intricate circuits of connected neurons that communicate via a combination of electrical and chemical signals. Some signals (referred to as excitatory signals) increase the probability that the neuron receiving the chemical message will produce an electrical impulse. On the other hand, inhibitory messages decrease the likelihood of this activity. Both of these kinds of signals are fast, and act over milliseconds. There is also a diverse set of slower signals, referred to as neuromodulation, which regulates the faster signals. A signaling chemical called dopamine is involved in neuromodulation and is essential for rewarding behavior and complex motor actions. The importance of dopamine is clear from the profound lack of movement seen in individuals with Parkinson’s disease, which is caused by the death of dopamine producing brain cells. Many nerve endings from dopamine-releasing neurons connect to a part of the brain’s reward system called the striatum. The neurons in this region are organized into two pathways that have opposing impacts on behavior. Dopamine activates different kinds of receptors called “G protein-coupled dopamine receptors” on neurons from each pathway. This allows dopamine to alter the activity of a protein called Protein Kinase A (or PKA) and alter the signaling state of these neurons. The impact of dopamine on neural circuits in adults has been extensively studied. However it was unknown whether dopamine might influence how neural circuits are wired during brain development. Because the nerve endings from dopamine-releasing neurons reach the striatum before most excitatory connections between the neurons are formed, dopamine stands to influence the development of connections in the striatum. Kozorovitskiy et al. have now investigated the role of neuromodulation in brain development in young mice. This involved measuring the formation of excitatory connections or synapses and the electrical activity of different striatal neurons during the maturation of brain circuits that occurs after birth. This analysis revealed that turning on dopamine receptors that increase PKA activity rapidly enhances the number of excitatory synapses on the neurons that express this receptor. Kozorovitskiy et al. then used a variety of approaches to investigate whether there is cooperation between G protein-coupled receptors, PKA activity and a signaling molecule called glutamate in striatal development. This revealed a more general mechanism by which the activation of G-protein-coupled receptors interacts with glutamate (the primary excitatory signal sent between neurons) in order to produce new synapses. These results reveal a previously unknown role for neuromodulation in “wiring up” the brain and open the possibility of new therapies to treat neurodevelopmental and neurodegenerative disorders. DOI:http://dx.doi.org/10.7554/eLife.10111.002
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Affiliation(s)
- Yevgenia Kozorovitskiy
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States.,Department of Neurobiology, Northwestern University, Evanston, United States
| | - Rui Peixoto
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Wengang Wang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Arpiar Saunders
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Bernardo L Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
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11
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Geddes JMH, Croll D, Caza M, Stoynov N, Foster LJ, Kronstad JW. Secretome profiling of Cryptococcus neoformans reveals regulation of a subset of virulence-associated proteins and potential biomarkers by protein kinase A. BMC Microbiol 2015; 15:206. [PMID: 26453029 PMCID: PMC4600298 DOI: 10.1186/s12866-015-0532-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [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] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 09/25/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The pathogenic yeast Cryptococcus neoformans causes life-threatening meningoencephalitis in individuals suffering from HIV/AIDS. The cyclic-AMP/protein kinase A (PKA) signal transduction pathway regulates the production of extracellular virulence factors in C. neoformans, but the influence of the pathway on the secretome has not been investigated. In this study, we performed quantitative proteomics using galactose-inducible and glucose-repressible expression of the PKA1 gene encoding the catalytic subunit of PKA to identify regulated proteins in the secretome. METHODS The proteins in the supernatants of cultures of C. neoformans were precipitated and identified using liquid chromatography-coupled tandem mass spectrometry. We also employed multiple reaction monitoring in a targeted approach to identify fungal proteins in samples from macrophages after phagocytosis of C. neoformans cells, as well as from the blood and bronchoalveolar fluid of infected mice. RESULTS We identified 61 secreted proteins and found that changes in PKA1 expression influenced the extracellular abundance of five proteins, including the Cig1 and Aph1 proteins with known roles in virulence. We also observed a change in the secretome profile upon induction of Pka1 from proteins primarily involved in catabolic and metabolic processes to an expanded set that included proteins for translational regulation and the response to stress. We further characterized the secretome data using enrichment analysis and by predicting conventional versus non-conventional secretion. Targeted proteomics of the Pka1-regulated proteins allowed us to identify the secreted proteins in lysates of phagocytic cells containing C. neoformans, and in samples from infected mice. This analysis also revealed that modulation of PKA1 expression influences the intracellular survival of cryptococcal cells upon phagocytosis. CONCLUSIONS Overall, we found that the cAMP/PKA pathway regulates specific components of the secretome including proteins that affect the virulence of C. neoformans. The detection of secreted cryptococcal proteins from infected phagocytic cells and tissue samples suggests their potential utility as biomarkers of infection. The proteomics data are available via ProteomeXchange with identifiers PXD002731 and PASS00736.
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Affiliation(s)
- Jennifer M H Geddes
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Daniel Croll
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Mélissa Caza
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Nikolay Stoynov
- Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Leonard J Foster
- Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - James W Kronstad
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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Goto K, Kawahara I, Kuniyasu H, Takaki M. A protein tyrosine kinase receptor, c-RET signaling pathway contributes to the enteric neurogenesis induced by a 5-HT4 receptor agonist at an anastomosis after transection of the gut in rodents. J Physiol Sci 2015; 65:377-83. [PMID: 25850922 PMCID: PMC10717718 DOI: 10.1007/s12576-015-0377-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 03/19/2015] [Indexed: 02/07/2023]
Abstract
We previously reported that a serotonin 4 (5-HT4) receptor agonist, mosapride citrate (MOS), increased the number of c-RET-positive cells and levels of c-RET mRNA in gel sponge implanted in the necks of rats. The 5-HT4 receptor is a G protein coupled receptor (GPCR) coupled to G protein Gs-cAMP cascades. We investigated the possibility that 5-HT4 receptor activation induced c-RET activation and/or PKA activation by elevating cAMP levels. Rodents were orally administered MOS by adding it to drinking water for 2 weeks after enteric nerve circuit insult via gut transection and anastomosis, together with the RET inhibitors withaferin A (WA) and RPI-1 or the PKA inhibitor H89. We then examined PGP9.5-positive cells in the newly formed granulation tissue at the anastomotic site. MOS significantly increased the number of new neurons, but not when co-administered with WA or RPI-1. Co-administration of H89 failed to alter MOS-induced increases in neurogenesis. In conclusion, the c-RET signaling pathway contributes to enteric neurogenesis facilitated by MOS, though the contribution of PKA activation seems unlikely.
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Affiliation(s)
- Kei Goto
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 Japan
| | - Isao Kawahara
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 Japan
| | - Hiroki Kuniyasu
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 Japan
| | - Miyako Takaki
- Department of Molecular Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 Japan
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Abstract
PURPOSE OF REVIEW Cushing syndrome caused by cortisol-producing adrenal adenomas is a rare condition, associated with high morbidity due to weight gain, diabetes mellitus, osteoporosis, hypertension, muscle weakness, mood disturbance and others. The first gene to be identified as causative of Cushing syndrome was PRKAR1A. We present an update on protein kinase A (PKA) defects and Cushing syndrome. RECENT FINDINGS The cyclic AMP-dependent PKA catalytic subunit alpha (PRKACA) hotspot point mutation (c.617A > C [p.Leu206Arg]), leading to an increase of basal PKA activity, and formation of cortisol-producing adenoma has been frequently shown to cause the most common form of adrenocorticotropic hormone-independent Cushing syndrome. SUMMARY Somatic PRKACA mutations have been found in up to 50% of patients with adrenal adenomas. Germline PRKACA amplification was also seen in bilateral adrenal hyperplasias. PRKACA activation was associated with higher cortisol levels, smaller tumor size and overt Cushing syndrome. This breakthrough is expected to improve our understanding of how PKA defects lead to Cushing syndrome and may spearhead the development of new, molecularly designed therapies.
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Affiliation(s)
- Mihail Zilbermint
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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Abstract
The large conductance voltage- and Ca-activated K(BK) channel is a critical regulator of urinary bladder smooth muscle (UBSM) excitability and contractility in many species. BK channel activation can hyperpolarize the cell resting membrane potential (RMP), decrease the intracellular Ca level, and attenuate UBSM cell excitability, therefore cause UBSM relaxation. Elevation of cellular cAMP levels by β-adrenergic receptor activation or phosphodiesterase (PDE) inhibition suppresses guinea pig UBSM excitability and contractility via BK channel activation. The current study aimed at determining the mechanism by which basal PKA, without elevation of cellular cAMP levels, controls UBSM excitability, and contractility via BK channel activation. UBSM strips (—2-4 mm wide and —5-8 mm long) were harvested from guinea pig bladder following removing urothelium. We used perforated patch-clamp and line-scanning confocal techniques on freshly-isolated guinea pig UBSM cells, and isometric tension recordings of UBSM isolated strips. Our data show that PKA inhibitors, H-89, PKI 14-22, or KT-5720: (I) reduced Ca spark frequency, eliminated spontaneous transient BK channel currents, abolished the transient hyperpolarizations, and depolarized the cell RMP; (II) increased the spontaneous phasic contraction amplitude, force, duration, and decreased the phasic contraction frequency; (III) in the presence of PKA inhibitor, H-89, PDE1 inhibition with 8MM-IBMX did not affect BK channel activity or DSM contractility. Using a selective PKG inhibitor, DT-2, we provided direct evidence at cellular level that basal PKG does not play a role in the regulation of BK channel activity in UBSM cells. In conclusion, basal PKA plays an essential role in maintaining BK channel activity, and thereby controlling UBSM excitability and contractility.
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Kämpfer N, Lamyel F, Schütz I, Warnken M, Hoffmann K, von Kügelgen I, Racké K. Dual regulation of β2-adrenoceptor messenger RNA expression in human lung fibroblasts by β2-cAMP signaling; delayed upregulated inhibitors oppose a rapid in onset, direct stimulation of gene expression. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:649-57. [PMID: 24705868 PMCID: PMC4065340 DOI: 10.1007/s00210-014-0971-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 03/04/2014] [Indexed: 11/26/2022]
Abstract
Based on their bronchodilatory effect, β2-adrenoceptor agonists constitute essential elements in the treatment of bronchial asthma and COPD. As treatment with β2-adrenoceptor agonists has been associated with worsening of airway hyper-reactivity, possibly because of loss of β-adrenoceptor function, molecular mechanism of the regulation of β2-adrenoceptor expression were studied. MRC-5 human lung fibroblasts were cultured in absence or presence of test substances followed by β2-adrenoceptor messenger RNA (mRNA) determination by qPCR. After inhibition of mRNA synthesis by actinomycin D, β2-adrenoceptor mRNA decreased with a half-life of 23 min, whereas inhibition of protein synthesis by cycloheximide caused an about 5- and 6-fold increase within 1.5 and 4 h, respectively. β2-Adrenoceptor mRNA was increased by about 100 % after 1 h exposure to formoterol or olodaterol but decreased by about 60 % after 4 h agonist exposure. Both effects of β2-adrenoceptor agonists were mimicked by forskolin, a direct activator of adenylyl cyclase and cholera toxin, which stimulates adenylyl cyclase by permanent activation of Gs. β2-Adrenoceptor agonist-induced upregulation of β2-adrenoceptor mRNA was blocked by the β2-adrenoceptor antagonist ICI 118551 and prevented by actinomycin D, but not by cycloheximide. Moreover, in presence of cycloheximide, β2-adrenoceptor agonist-induced reduction in β2-adrenoceptor mRNA was converted into stimulation, resulting in a more than 10-fold increase. In conclusion, expression of β2-adrenoceptors in human lung fibroblasts is highly regulated at transcriptional level. The β2-adrenoceptor gene is under strong inhibitory control of short-living suppressor proteins. β2-Adrenoceptor activation induces via adenylyl cyclase - cyclic adenosine monophosphate (cAMP) signaling a rapid in onset direct stimulation of the β2-adrenoceptor gene transcription, an effect opposed by a delayed upregulation of inhibitory factors.
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Affiliation(s)
- N. Kämpfer
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - F. Lamyel
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - I. Schütz
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - M. Warnken
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - K. Hoffmann
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - I. von Kügelgen
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - Kurt Racké
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
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Fanti M, Singh S, Ledda-Columbano GM, Columbano A, Monga SP. Tri-iodothyronine induces hepatocyte proliferation by protein kinase A-dependent β-catenin activation in rodents. Hepatology 2014; 59:2309-20. [PMID: 24122933 PMCID: PMC3979513 DOI: 10.1002/hep.26775] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/25/2013] [Indexed: 12/31/2022]
Abstract
UNLABELLED Thyroid hormone (T3), like many other ligands of the steroid/thyroid hormone nuclear receptor superfamily, is a strong inducer of liver cell proliferation in rats and mice. However, the molecular basis of its mitogenic activity, which is currently unknown, must be elucidated if its use in hepatic regenerative medicine is to be considered. F-344 rats or C57BL/6 mice were fed a diet containing T3 for 2-7 days. In rats, administration of T3 led to an increased cytoplasmic stabilization and nuclear translocation of β-catenin in pericentral hepatocytes with a concomitant increase in cyclin-D1 expression. T3 administration to wild-type (WT) mice resulted in increased hepatocyte proliferation; however, no mitogenic response in hepatocytes to T3 was evident in the hepatocyte-specific β-catenin knockout mice (KO). In fact, T3 induced β-catenin-TCF4 reporter activity both in vitro and in vivo. Livers from T3-treated mice demonstrated no changes in Ctnnb1 expression, activity of glycogen synthase kinase-3β, known to phosphorylate and eventually promote β-catenin degradation, or E-cadherin-β-catenin association. However, T3 treatment increased β-catenin phosphorylation at Ser675, an event downstream of protein kinase A (PKA). Administration of PKA inhibitor during T3 treatment of mice and rats as well as in cell culture abrogated Ser675-β-catenin and simultaneously decreased cyclin-D1 expression to block hepatocyte proliferation. CONCLUSION We have identified T3-induced hepatocyte mitogenic response to be mediated by PKA-dependent β-catenin activation. Thus, T3 may be of therapeutic relevance to stimulate β-catenin signaling to in turn induce regeneration in selected cases of hepatic insufficiency.
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Affiliation(s)
- Maura Fanti
- Department of Pathology, University of Pittsburgh, School of Medicine, USA,Department of Biomedical Sciences, University of Cagliari, Italy
| | - Sucha Singh
- Department of Pathology, University of Pittsburgh, School of Medicine, USA
| | | | - Amedeo Columbano
- Department of Biomedical Sciences, University of Cagliari, Italy,Address correspondence to: Satdarshan Pal Singh Monga, MD, Endowed Chair, Vice Chair and Division Director of Experimental Pathology (EP), Professor of Pathology (EP) & Medicine (GI, Hepatology & Nutrition), University of Pittsburgh School of Medicine, 200 Lothrop Street S-422 BST, Pittsburgh, PA 15261; Tel: (412) 648-9966; Fax: (412) 648-1916; ; Amedeo Columbano, PhD, Department of Biomedical Sciences, Unit of Oncology and Molecular Pathology, University of Cagliari, Via Porcell 4, 09124 Cagliari, Italy, Tel: +39-070-6758345; Fax: +39-070-666062;
| | - Satdarshan P Monga
- Department of Pathology, University of Pittsburgh, School of Medicine, USA,Address correspondence to: Satdarshan Pal Singh Monga, MD, Endowed Chair, Vice Chair and Division Director of Experimental Pathology (EP), Professor of Pathology (EP) & Medicine (GI, Hepatology & Nutrition), University of Pittsburgh School of Medicine, 200 Lothrop Street S-422 BST, Pittsburgh, PA 15261; Tel: (412) 648-9966; Fax: (412) 648-1916; ; Amedeo Columbano, PhD, Department of Biomedical Sciences, Unit of Oncology and Molecular Pathology, University of Cagliari, Via Porcell 4, 09124 Cagliari, Italy, Tel: +39-070-6758345; Fax: +39-070-666062;
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17
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Abstract
RATIONALE Hypersignaling of corticotropin releasing factor (CRF) has been implicated in stress disorders; however, many of its downstream mechanisms of action remain unclear. In vitro, CRF1 receptor activation initiates multiple cell signaling cascades, including protein kinase A (PKA), protein kinase C (PKC), and mitogen-activated protein kinase kinase MEK1/2 signaling. It is unclear, however, which of these signaling cascades mediate CRF-induced behaviors during stress. OBJECTIVES We examined the role of PKA, PKC, and MEK1/2 signaling pathways in CRF-induced anxiety as measured by startle hyperreactivity. METHODS Mice treated with intracerbroventricular (ICV) ovine CRF (oCRF) were pretreated with the PKA inhibitor Rp-cAMPS, PKC inhibitor bisindolylmaleimide (BIM), or MEK1/2 inhibitor PD98059 (ICV) and assessed for acoustic startle reactivity. RESULTS The PKC inhibitor BIM significantly attenuated CRF-induced increases in startle. BIM was also able to block startle increases induced by oCRF when both compounds were infused directly into the bed nucleus of stria terminalis (BNST). PKA and MEK1/2 inhibition had no significant effects on CRF-induced changes in startle at the dose ranges tested. CRF-induced disruption of prepulse inhibition was not significantly reversed by any of the three pretreatments at the dose ranges tested. CONCLUSIONS PKC signaling is required for CRF-induced increases in startle, and this effect is mediated at least in part at the BNST. These findings suggest that PKC signaling cascades (1) may be important for the acute effects of CRF to induce startle hyperreactivity and (2) support further research of the role of PKC signaling in startle abnormalities relevant to disorders such as posttraumatic stress disorder.
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Affiliation(s)
- Toth M
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Gresack JE
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA,Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York NY USA
| | - Hauger RL
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Halberstadt AL
- Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Risbrough VB
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA,Corresponding author: Victoria Risbrough, Ph.D., University of California San Diego, 9500 Gilman Dr. MC0804, La Jolla CA 92093-0804, Tel: 16195433582; Fax: 16195432475:
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Pale T, Frisch EB, McClellan AD. Cyclic AMP stimulates neurite outgrowth of lamprey reticulospinal neurons without substantially altering their biophysical properties. Neuroscience 2013; 245:74-89. [PMID: 23603516 PMCID: PMC3672336 DOI: 10.1016/j.neuroscience.2013.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [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: 12/18/2012] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 01/03/2023]
Abstract
Reticulospinal (RS) neurons are critical for initiation of locomotor behavior, and following spinal cord injury (SCI) in the lamprey, the axons of these neurons regenerate and restore locomotor behavior within a few weeks. For lamprey RS neurons in culture, experimental induction of calcium influx, either in the growth cone or cell body, is inhibitory for neurite outgrowth. Following SCI, these neurons partially downregulate calcium channel expression, which would be expected to reduce calcium influx and possibly provide supportive conditions for axonal regeneration. In the present study, it was tested whether activation of second messenger signaling pathways stimulates neurite outgrowth of lamprey RS neurons without altering their electrical properties (e.g. spike broadening) so as to possibly increase calcium influx and compromise axonal growth. First, activation of cAMP pathways with forskolin or dbcAMP stimulated neurite outgrowth of RS neurons in culture in a PKA-dependent manner, while activation of cGMP signaling pathways with dbcGMP inhibited outgrowth. Second, neurophysiological recordings from uninjured RS neurons in isolated lamprey brain-spinal cord preparations indicated that dbcAMP or dbcGMP did not significantly affect any of the measured electrical properties. In contrast, for uninjured RS neurons, forskolin increased action potential duration, which might have increased calcium influx, but did not significantly affect most other electrical properties. Importantly, for injured RS neurons during the period of axonal regeneration, forskolin did not significantly alter their electrical properties. Taken together, these results suggest that activation of cAMP signaling by dbcAMP stimulates neurite outgrowth, but does not alter the electrical properties of lamprey RS neurons in such a way that would be expected to induce calcium influx. In conclusion, our results suggest that activation of cAMP pathways alone, without compensation for possible deleterious effects on electrical properties, is an effective approach for stimulating axonal regeneration of RS neuron following SCI.
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Affiliation(s)
- Timothée Pale
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-6190
| | - Emily B. Frisch
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-6190
| | - Andrew D. McClellan
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-6190
- Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO 65211-6190
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Soda T, Frank C, Ishizuka K, Baccarella A, Park YU, Flood Z, Park SK, Sawa A, Tsai LH. DISC1-ATF4 transcriptional repression complex: dual regulation of the cAMP-PDE4 cascade by DISC1. Mol Psychiatry 2013; 18:898-908. [PMID: 23587879 PMCID: PMC3730299 DOI: 10.1038/mp.2013.38] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 01/12/2013] [Accepted: 01/31/2013] [Indexed: 02/08/2023]
Abstract
Disrupted-In-Schizophrenia 1 (DISC1), a risk factor for major mental illnesses, has been studied extensively in the context of neurodevelopment. However, the role of DISC1 in neuronal signaling, particularly in conjunction with intracellular cascades that occur in response to dopamine, a neurotransmitter implicated in numerous psychiatric disorders, remains elusive. Previous data suggest that DISC1 interacts with numerous proteins that impact neuronal function, including activating transcription factor 4 (ATF4). In this study, we identify a novel DISC1 and ATF4 binding region in the genomic locus of phosphodiesterase 4D (PDE4D), a gene implicated in psychiatric disorders. We found that the loss of function of either DISC1 or ATF4 increases PDE4D9 transcription, and that the association of DISC1 with the PDE4D9 locus requires ATF4. We also show that PDE4D9 is increased by D1-type dopamine receptor dopaminergic stimulation. We demonstrate that the mechanism for this increase is due to DISC1 dissociation from the PDE4D locus in mouse brain. We further characterize the interaction of DISC1 with ATF4 to show that it is regulated via protein kinase A-mediated phosphorylation of DISC1 serine-58. Our results suggest that the release of DISC1-mediated transcriptional repression of PDE4D9 acts as feedback inhibition to regulate dopaminergic signaling. Furthermore, as DISC1 loss-of-function leads to a specific increase in PDE4D9, PDE4D9 itself may represent an attractive target for therapeutic approaches in psychiatric disorders.
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Affiliation(s)
- T Soda
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA,Howard Hughes Medical Institute, Cambridge, MA, USA,Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA,Daniel Tosteson Medical Education Center, Boston, MA, USA
| | - C Frank
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA,Howard Hughes Medical Institute, Cambridge, MA, USA,Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA
| | - K Ishizuka
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - A Baccarella
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Y-U Park
- Division of Molecular and Life Science, Department of Life Science, Biotechnology Research Center, Pohang University of Science and Technology, Pohang, Korea
| | - Z Flood
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA,Howard Hughes Medical Institute, Cambridge, MA, USA,Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA
| | - S K Park
- Division of Molecular and Life Science, Department of Life Science, Biotechnology Research Center, Pohang University of Science and Technology, Pohang, Korea
| | - A Sawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - L-H Tsai
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA,Howard Hughes Medical Institute, Cambridge, MA, USA,Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA,Howard Hughes Medical Institute, 77 Massachusetts Avenue, Room 46-4235, Cambridge, MA 02139, USA. E-mail:
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20
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Abstract
Prion diseases are a class of fatal neurodegenerative disorders that can be sporadic, genetic or iatrogenic. They are characterized by the unique nature of their etiologic agent: prions (PrP(Sc)). A prion is an infectious protein with the ability to convert the host-encoded cellular prion protein (PrP(C)) into new prion molecules by acting as a template. Since Stanley B. Prusiner proposed the "protein-only" hypothesis for the first time, considerable effort has been put into defining the role played by PrP(C) in neurons. However, its physiological function remains unclear. This review summarizes the major findings that support the involvement of PrP(C) in signal transduction.
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Affiliation(s)
- Alessandro Didonna
- Davee Department of Neurology, Feinberg School of Medicine Northwestern University, Chicago, IL 60611, USA.
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21
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Molosh AI, Sajdyk TJ, Truitt WA, Zhu W, Oxford GS, Shekhar A. NPY Y1 receptors differentially modulate GABAA and NMDA receptors via divergent signal-transduction pathways to reduce excitability of amygdala neurons. Neuropsychopharmacology 2013; 38:1352-64. [PMID: 23358240 DOI: 10.1038/npp.2013.33] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neuropeptide Y (NPY) administration into the basolateral amygdala (BLA) decreases anxiety-like behavior, mediated in part through the Y1 receptor (Y1R) isoform. Activation of Y1Rs results in G-protein-mediated reduction of cAMP levels, which results in reduced excitability of amygdala projection neurons. Understanding the mechanisms linking decreased cAMP levels to reduced excitability in amygdala neurons is important for identifying novel anxiolytic targets. We studied the intracellular mechanisms of activation of Y1Rs on synaptic transmission in the BLA. Activating Y1Rs by [Leu(31),Pro(34)]-NPY (L-P NPY) reduced the amplitude of evoked NMDA-mediated excitatory postsynaptic currents (eEPSCs), without affecting AMPA-mediated eEPSCs, but conversely increased the amplitude of GABAA-mediated evoked inhibitory postsynaptic currents (eIPSCs). Both effects were abolished by the Y1R antagonist, PD160170. Intracellular GDP-β-S, or pre-treatment with either forskolin or 8Br-cAMP, eliminated the effects of L-P NPY on both NMDA- and GABAA-mediated currents. Thus, both the NMDA and GABAA effects of Y1R activation in the BLA are G-protein-mediated and cAMP-dependent. Pipette inclusion of protein kinase A (PKA) catalytic subunit blocked the effect of L-P NPY on GABAA-mediated eIPSCs, but not on NMDA-mediated eEPSCs. Conversely, activating the exchange protein activated by cAMP (Epac) with 8CPT-2Me-cAMP blocked the effect of L-P NPY on NMDA-mediated eEPSCs, but not on GABAA-mediated eIPSCs. Thus, NPY regulates amygdala excitability via two signal-transduction events, with reduced PKA activity enhancing GABAA-mediated eIPSCs and Epac deactivation reducing NMDA-mediated eEPSCs. This multipathway regulation of NMDA- and GABAA-mediated currents may be important for NPY plasticity and stress resilience in the amygdala.
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22
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Washburn N, Borgquist A, Wang K, Jeffery GS, Kelly MJ, Wagner EJ. Receptor subtypes and signal transduction mechanisms contributing to the estrogenic attenuation of cannabinoid-induced changes in energy homeostasis. Neuroendocrinology 2013; 97:160-75. [PMID: 22538462 PMCID: PMC3702272 DOI: 10.1159/000338669] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [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: 12/05/2011] [Accepted: 04/02/2012] [Indexed: 01/21/2023]
Abstract
We examined the receptor subtypes and signal transduction mechanisms contributing to the estrogenic modulation of cannabinoid-induced changes in energy balance. Food intake and, in some cases, O2 consumption, CO2 production and the respiratory exchange ratio were evaluated in ovariectomized female guinea pigs treated s.c. with the cannabinoid receptor agonist WIN 55,212-2 or its cremephor/ethanol/0.9% saline vehicle, and either with estradiol benzoate (EB), the estrogen receptor (ER) α agonist PPT, the ERβ agonist DPN, the Gq-coupled membrane ER agonist STX, the GPR30 agonist G-1 or their respective vehicles. Patch-clamp recordings were performed in hypothalamic slices. EB, STX, PPT and G-1 decreased daily food intake. Of these, EB, STX and PPT blocked the WIN 55,212-2-induced increase in food intake within 1-4 h. The estrogenic diminution of cannabinoid-induced hyperphagia correlated with a rapid (within 15 min) attenuation of cannabinoid-mediated decreases in glutamatergic synaptic input onto arcuate neurons, which was completely blocked by inhibition of protein kinase C (PKC) and attenuated by inhibition of protein kinase A (PKA). STX, but not PPT, mimicked this rapid estrogenic effect. However, PPT abolished the cannabinoid-induced inhibition of glutamatergic neurotransmission in cells from animals treated 24 h prior. The estrogenic antagonism of this presynaptic inhibition was observed in anorexigenic proopiomelanocortin neurons. These data reveal that estrogens negatively modulate cannabinoid-induced changes in energy balance via Gq-coupled membrane ER- and ERα-mediated mechanisms involving activation of PKC and PKA. As such, they further our understanding of the pathways through which estrogens act to temper cannabinoid sensitivity in regulating energy homeostasis in females.
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Affiliation(s)
- Neal Washburn
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Amanda Borgquist
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Kate Wang
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Garrett S. Jeffery
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Martin J. Kelly
- Department of Physiology & Pharmacology, Oregon Health & Science University, Portland OR, USA
| | - Edward J. Wagner
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA, USA
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23
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Spirli C, Morell CM, Locatelli L, Okolicsanyi S, Ferrero C, Kim AK, Fabris L, Fiorotto R, Strazzabosco M. Cyclic AMP/ PKA-dependent paradoxical activation of Raf/MEK/ERK signaling in polycystin-2 defective mice treated with sorafenib. Hepatology 2012; 56:2363-74. [PMID: 22653837 PMCID: PMC3460040 DOI: 10.1002/hep.25872] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 05/25/2012] [Indexed: 12/22/2022]
Abstract
UNLABELLED Mutations in polycystins are a cause of polycystic liver disease. In polycystin-2 (PC2)-defective mice, cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)-dependent activation of the Rat Sarcoma (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen signal-regulated kinase-extracellular signal-regulated kinase (ERK) 1/2 pathway stimulates the growth of liver cysts. To test the hypothesis that sorafenib, a Raf inhibitor used for the treatment of liver and kidney cancers, inhibits liver cyst growth in PC2-defective mice, we treated PC2 (i.e., Pkd2(flox/-) :pCxCreER(TM) [Pkd2cKO]) mice with sorafenib-tosylate for 8 weeks (20-60 mg/kg/day). Sorafenib caused an unexpected increase in liver cyst area, cell proliferation (Ki67), and expression of phosphorylated ERK (pERK) compared with Pkd2cKO mice treated with vehicle. When given to epithelial cells isolated from liver cysts of Pkd2cKO mice (Pkd2cKO-cells), sorafenib progressively stimulated pERK1/2 and cell proliferation [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and bromodeoxyuridine assay (MTS)] at doses between 0.001 and 1 μM; however, both pERK1/2 and cell proliferation significantly decreased at the dose of 10 μM. Raf kinase activity assay showed that whereas B-Raf is inhibited by sorafenib in both wild-type (WT) and Pkd2cKO cells, Raf-1 is inhibited in WT cells but is significantly stimulated in Pkd2cKO cells. In Pkd2cKO cells pretreated with the PKA inhibitor 14-22 amide, myristolated (1 μM) and in mice treated with octreotide in combination with sorafenib, the paradoxical activation of Raf/ERK1/2 was abolished, and cyst growth was inhibited. CONCLUSION In PC2-defective cells, sorafenib inhibits B-Raf but paradoxically activates Raf-1, resulting in increased ERK1/2 phosphorylation, cell proliferation, and cyst growth in vivo. These effects are consistent with the ability of Raf inhibitors to transactivate Raf-1 when a PKA-activated Ras promotes Raf-1/B-Raf heterodimerization, and are inhibited by interfering with cAMP/PKA signaling both in vitro and in vivo, as shown by the reduction of liver cysts in mice treated with combined octreotide and sorafenib.
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Affiliation(s)
- Carlo Spirli
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Carola M. Morell
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA.,Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Luigi Locatelli
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA.,Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Stefano Okolicsanyi
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA.,Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Cecilia Ferrero
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Amy K. Kim
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Luca Fabris
- Department of Surgical, Oncological, and Gastroenterological Sciences, University of Padova, Padova, Italy
| | - Romina Fiorotto
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Mario Strazzabosco
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA.,Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
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24
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Ickowicz D, Finkelstein M, Breitbart H. Mechanism of sperm capacitation and the acrosome reaction: role of protein kinases. Asian J Androl 2012; 14:816-21. [PMID: 23001443 PMCID: PMC3720105 DOI: 10.1038/aja.2012.81] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/30/2012] [Accepted: 07/08/2012] [Indexed: 12/19/2022] Open
Abstract
Mammalian sperm must undergo a series of biochemical and physiological modifications, collectively called capacitation, in the female reproductive tract prior to the acrosome reaction (AR). The mechanisms of these modifications are not well characterized though protein kinases were shown to be involved in the regulation of intracellular Ca(2+) during both capacitation and the AR. In the present review, we summarize some of the signaling events that are involved in capacitation. During the capacitation process, phosphatidyl-inositol-3-kinase (PI3K) is phosphorylated/activated via a protein kinase A (PKA)-dependent cascade, and downregulated by protein kinase C α (PKCα). PKCα is active at the beginning of capacitation, resulting in PI3K inactivation. During capacitation, PKCα as well as PP1γ2 is degraded by a PKA-dependent mechanism, allowing the activation of PI3K. The activation of PKA during capacitation depends mainly on cyclic adenosine monophosphate (cAMP) produced by the bicarbonate-dependent soluble adenylyl cyclase. This activation of PKA leads to an increase in actin polymerization, an essential process for the development of hyperactivated motility, which is necessary for successful fertilization. Actin polymerization is mediated by PIP(2) in two ways: first, PIP(2) acts as a cofactor for phospholipase D (PLD) activation, and second, as a molecule that binds and inhibits actin-severing proteins such as gelsolin. Tyrosine phosphorylation of gelsolin during capacitation by Src family kinase (SFK) is also important for its inactivation. Prior to the AR, gelsolin is released from PIP(2) and undergoes dephosphorylation/activation, resulting in fast F-actin depolymerization, leading to the AR.
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Affiliation(s)
- Debby Ickowicz
- The Mina & Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52100, Israel
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25
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Kelly MJ, Rønnekleiv OK. Membrane-initiated actions of estradiol that regulate reproduction, energy balance and body temperature. Front Neuroendocrinol 2012; 33:376-87. [PMID: 22871514 PMCID: PMC3618441 DOI: 10.1016/j.yfrne.2012.07.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [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: 05/02/2012] [Revised: 07/07/2012] [Accepted: 07/11/2012] [Indexed: 12/21/2022]
Abstract
It is well known that many of the actions of estrogens in the central nervous system are mediated via intracellular receptor/transcription factors that interact with steroid response elements on target genes. However, there now exists compelling evidence for membrane estrogen receptors in hypothalamic and other brain neurons. But, it is not well understood how estrogens signal via membrane receptors, and how these signals impact not only membrane excitability but also gene transcription in neurons. Indeed, it has been known for sometime that estrogens can rapidly alter neuronal activity within seconds, indicating that some cellular effects can occur via membrane delimited events. In addition, estrogens can affect second messenger systems including calcium mobilization and a plethora of kinases to alter cell signaling. Therefore, this review will consider our current knowledge of rapid membrane-initiated and intracellular signaling by estrogens in the hypothalamus, the nature of receptors involved and how they contribute to homeostatic functions.
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Affiliation(s)
- Martin J. Kelly
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239
- Division of Neuroscience, Oregon Regional Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006
| | - Oline K. Rønnekleiv
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239
- Division of Neuroscience, Oregon Regional Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239
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26
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Pringle DR, Yin Z, Lee AA, Manchanda PK, Yu L, Parlow AF, Jarjoura D, La Perle KMD, Kirschner LS. Thyroid-specific ablation of the Carney complex gene, PRKAR1A, results in hyperthyroidism and follicular thyroid cancer. Endocr Relat Cancer 2012; 19:435-46. [PMID: 22514108 PMCID: PMC3667702 DOI: 10.1530/erc-11-0306] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [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] [Indexed: 11/08/2022]
Abstract
Thyroid cancer is the most common endocrine malignancy in the population, and the incidence of this cancer is increasing at a rapid rate. Although genetic analysis of papillary thyroid cancer (PTC) has identified mutations in a large percentage of patients, the genetic basis of follicular thyroid cancer (FTC) is less certain. Thyroid cancer, including both PTC and FTC, has been observed in patients with the inherited tumor predisposition Carney complex, caused by mutations in PRKAR1A. In order to investigate the role of loss of PRKAR1A in thyroid cancer, we generated a tissue-specific knockout of Prkar1a in the thyroid. We report that the resulting mice are hyperthyroid and developed follicular thyroid neoplasms by 1 year of age, including FTC in over 40% of animals. These thyroid tumors showed a signature of pathway activation different from that observed in other models of thyroid cancer. In vitro cultures of the tumor cells indicated that Prkar1a-null thyrocytes exhibited growth factor independence and suggested possible new therapeutic targets. Overall, this work represents the first report of a genetic mutation known to cause human FTC that exhibits a similar phenotype when modeled in the mouse. In addition to our knowledge of the mechanisms of human follicular thyroid tumorigenesis, this model is highly reproducible and may provide a viable mechanism for the further clinical development of therapies aimed at FTC.
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Affiliation(s)
- Daphne R. Pringle
- Department of Molecular, Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, 43210
| | - Zhirong Yin
- Department of Molecular, Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, 43210
| | - Audrey A. Lee
- Department of Molecular, Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, 43210
| | - Parmeet K. Manchanda
- Department of Molecular, Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, 43210
| | - Lianbo Yu
- Center for Biostatistics, The Ohio State University, Columbus, OH, 43210
| | - Alfred F. Parlow
- National Hormone and Peptide Program, Harbor-UCLA Medical Center, Torrance, California 90509
| | - David Jarjoura
- Center for Biostatistics, The Ohio State University, Columbus, OH, 43210
| | - Krista M. D. La Perle
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, 43210
| | - Lawrence S. Kirschner
- Department of Molecular, Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH, 43210
- Division of Endocrinology, Diabetes and Metabolism, The Ohio State University, Columbus, OH, 43210
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27
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Zimmerman NP, Kumar SN, Turner JR, Dwinell MB. Cyclic AMP dysregulates intestinal epithelial cell restitution through PKA and RhoA. Inflamm Bowel Dis 2012; 18:1081-91. [PMID: 21993975 PMCID: PMC3258471 DOI: 10.1002/ibd.21898] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [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: 08/12/2011] [Accepted: 08/22/2011] [Indexed: 01/17/2023]
Abstract
BACKGROUND Mucosal homeostasis is dependent on the establishment and maintenance of the cell-cell contacts that comprise the physiological barrier. Breaks in the barrier are linked to multiple diseases such as inflammatory bowel disease. While increased cyclic adenosine monophosphate (cAMP) levels limit inflammation by decreasing leukocyte infiltration, the effects of elevated cAMP on intestinal epithelial repair are unknown. METHODS Restitution in animals administered rolipram was monitored by microscopic examination after laser wounding of the intestinal epithelium or in mice treated with dextran sodium sulfate (DSS). In vitro analysis was conducted using IEC6 and T84 cells to determine the role of elevated cAMP in altering Rho-dependent cellular migration signaling pathways. RESULTS We show that treatment with rolipram, forskolin, and cAMP analogs decrease intestinal epithelial cell migration in vitro. In vivo cell imaging revealed that increased cAMP resulted in a decreased cellular migration rate, with cells at the edge displaying the highest activity. As expected, elevated cAMP elicited increased protein kinase A (PKA) activity, in turn resulting in the inactivation and sequestration of RhoA and decreased actin reorganization. The ablation of restitution by cAMP was not restricted to cell culture, as forskolin and rolipram treatment significantly decreased epithelial microwound closure induced by the two photon confocal injury model. CONCLUSIONS Together, these data suggest that administration of cAMP-elevating agents paradoxically decrease infiltration of damage-causing leukocytes while also preventing epithelial repair and barrier maintenance. We propose that treatment with cAMP-elevating agents severely limits mucosal reepithelialization and should be contraindicated for use in chronic inflammatory bowel disorders.
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Affiliation(s)
- Noah P. Zimmerman
- Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226
| | - Suresh N. Kumar
- Department of Pathology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226
| | | | - Michael B. Dwinell
- Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226
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28
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Zimmerman R, Peng DJ, Lanz H, Zhang YH, Danen-Van Oorschot A, Qu S, Backendorf C, Noteborn M. PP2A inactivation is a crucial step in triggering apoptin-induced tumor-selective cell killing. Cell Death Dis 2012; 3:e291. [PMID: 22476099 PMCID: PMC3358009 DOI: 10.1038/cddis.2012.31] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [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] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/20/2012] [Accepted: 02/21/2012] [Indexed: 01/08/2023]
Abstract
Apoptin (apoptosis-inducing protein) harbors tumor-selective characteristics making it a potential safe and effective anticancer agent. Apoptin becomes phosphorylated and induces apoptosis in a large panel of human tumor but not normal cells. Here, we used an in vitro oncogenic transformation assay to explore minimal cellular factors required for the activation of apoptin. Flag-apoptin was introduced into normal fibroblasts together with the transforming SV40 large T antigen (SV40 LT) and SV40 small t antigen (SV40 ST) antigens. We found that nuclear expression of SV40 ST in normal cells was sufficient to induce phosphorylation of apoptin. Mutational analysis showed that mutations disrupting the binding of ST to protein phosphatase 2A (PP2A) counteracted this effect. Knockdown of the ST-interacting PP2A-B56γ subunit in normal fibroblasts mimicked the effect of nuclear ST expression, resulting in induction of apoptin phosphorylation. The same effect was observed upon downregulation of the PP2A-B56δ subunit, which is targeted by protein kinase A (PKA). Apoptin interacts with the PKA-associating protein BCA3/AKIP1, and inhibition of PKA in tumor cells by treatment with H89 increased the phosphorylation of apoptin, whereas the PKA activator cAMP partially reduced it. We infer that inactivation of PP2A, in particular, of the B56γ and B56δ subunits is a crucial step in triggering apoptin-induced tumor-selective cell death.
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Affiliation(s)
- R Zimmerman
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
| | - D-J Peng
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - H Lanz
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
| | - Y-H Zhang
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
| | - A Danen-Van Oorschot
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
| | - S Qu
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - C Backendorf
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
| | - M Noteborn
- Department of Molecular Genetics, Leiden Institute for Chemistry, Leiden University, Leiden, The Netherlands
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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29
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de Joussineau C, Sahut-Barnola I, Levy I, Saloustros E, Val P, Stratakis CA, Martinez A. The cAMP pathway and the control of adrenocortical development and growth. Mol Cell Endocrinol 2012; 351:28-36. [PMID: 22019902 PMCID: PMC3678347 DOI: 10.1016/j.mce.2011.10.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [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: 06/01/2011] [Revised: 10/04/2011] [Accepted: 10/07/2011] [Indexed: 12/27/2022]
Abstract
In the last 10 years, extensive studies showed that the cAMP pathway is deregulated in patients suffering from adrenocortical tumours, and particularly in primary pigmented nodular adrenocortical disease (PPNAD). Here we describe how evidence arising from the analysis of patients' data, mouse models and in vitro experiments, have shed light on the cAMP pathway as a central player in adrenal physiopathology. We also show how novel data generated from mouse models may point to new targets for potential therapies.
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Affiliation(s)
- Cyrille de Joussineau
- CNRS UMR6247, INSERM U931, Génétique Reproduction et Développement (GReD), Clermont Université, Aubière, France
| | - Isabelle Sahut-Barnola
- CNRS UMR6247, INSERM U931, Génétique Reproduction et Développement (GReD), Clermont Université, Aubière, France
| | - Isaac Levy
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Emmanouil Saloustros
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Pierre Val
- CNRS UMR6247, INSERM U931, Génétique Reproduction et Développement (GReD), Clermont Université, Aubière, France
| | - Constantine A. Stratakis
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Antoine Martinez
- CNRS UMR6247, INSERM U931, Génétique Reproduction et Développement (GReD), Clermont Université, Aubière, France
- Corresponding author. Address: CNRS UMR6247, INSERM U931, Génétique Reproduction et Développement (GReD), Clermont Université, BP 80026, 24 avenue des Landais, 63171 Aubière, France. Tel.: +33 4 73 40 74 09; fax: +33 4 73 40 70 42. (A. Martinez)
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Kuroiwa M, Snyder GL, Shuto T, Fukuda A, Yanagawa Y, Benavides DR, Nairn AC, Bibb JA, Greengard P, Nishi A. Phosphodiesterase 4 inhibition enhances the dopamine D1 receptor/ PKA/DARPP-32 signaling cascade in frontal cortex. Psychopharmacology (Berl) 2012; 219:1065-79. [PMID: 21833500 DOI: 10.1007/s00213-011-2436-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/01/2011] [Indexed: 10/17/2022]
Abstract
RATIONALE Alteration of dopamine neurotransmission in the prefrontal cortex, especially hypofunction of dopamine D1 receptors, contributes to psychotic symptoms and cognitive deficit in schizophrenia. D1 receptors signal through the cAMP/PKA second messenger cascade, which is modulated by phosphodiesterase (PDE) enzymes that hydrolyze and inactivate cyclic nucleotides. Though several PDEs are expressed in cortical neurons, the PDE4 enzyme family (PDE4A-D) has been implicated in the control of cognitive function. The best studied isoform, PDE4B, interacts with a schizophrenia susceptibility factor, disrupted in schizophrenia 1 (DISC1). OBJECTIVES We explore the control of mouse frontal cortex dopamine D1 receptor signaling and associated behavior by PDE4. RESULTS Inhibition of PDE4 by rolipram induced activation of cAMP/PKA signaling in cortical slices and in vivo, leading to the phosphorylation of DARPP-32 and other postsynaptic and presynaptic PKA-substrates. Rolipram also enhanced DARPP-32 phosphorylation invoked by D1 receptor activation. Immunohistochemical studies demonstrated PDE4A, PDE4B, and PDE4D expression in DARPP-32-positive neurons in layer VI of frontal cortex, most likely in D1 receptor-positive, glutamatergic corticothalamic pyramidal neurons. Furthermore, the ability of rolipram treatment to improve the performance of mice in a sensorimotor gating test was DARPP-32-dependent. CONCLUSIONS PDE4, which is co-expressed with DARPP-32 in D1 receptor-positive cortical pyramidal neurons in layer VI, modulates the level of D1 receptor signaling and DARPP-32 phosphorylation in the frontal cortex, likely influencing cognitive function. These biochemical and behavioral actions of PDE4 inhibitors may contribute to the hypothesized antipsychotic actions of this class of compounds.
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Brandao KE, Dell'Acqua ML, Levinson SR. A-kinase anchoring protein 150 expression in a specific subset of TRPV1- and CaV 1.2-positive nociceptive rat dorsal root ganglion neurons. J Comp Neurol 2012; 520:81-99. [PMID: 21674494 PMCID: PMC4807902 DOI: 10.1002/cne.22692] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [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: 11/11/2022]
Abstract
Modulation of phosphorylation states of ion channels is a critical step in the development of hyperalgesia during inflammation. Modulatory enhancement of channel activity may increase neuronal excitability and affect downstream targets such as gene transcription. The specificity required for such regulation of ion channels quickly occurs via targeting of protein kinases and phosphatases by the scaffolding A-kinase anchoring protein 79/150 (AKAP79/150). AKAP79/150 has been implicated in inflammatory pain by targeting protein kinase A (PKA) and protein kinase C (PKC) to the transient receptor potential vanilloid 1 (TRPV1) channel in peripheral sensory neurons, thus lowering threshold for activation of the channel by multiple inflammatory reagents. However, the expression pattern of AKAP150 in peripheral sensory neurons is unknown. Here we identify the peripheral neuron subtypes that express AKAP150, the subcellular distribution of AKAP150, and the potential target ion channels in rat dorsal root ganglion (DRG) slices. We found that AKAP150 is expressed predominantly in a subset of small DRG sensory neurons, where it is localized at the plasma membrane of the soma, axon initial segment, and small fibers. Most of these neurons are peripherin positive and produce C fibers, although a small portion produce Aδ fibers. Furthermore, we demonstrate that AKAP79/150 colocalizes with TRPV1 and Ca(V) 1.2 in the soma and axon initial segment. Thus AKAP150 is expressed in small, nociceptive DRG neurons, where it is targeted to membrane regions and where it may play a role in the modulation of ion channel phosphorylation states required for hyperalgesia.
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Affiliation(s)
- Katherine E Brandao
- Program in Neuroscience, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
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Affiliation(s)
- Shoji Osawa
- Department of Cell and Developmental Biology, The University of North Carolina at Chapel Hill, CB# 7090, 108 Taylor Hall, Chapel Hill, NC 27599, USA
| | - Ellen R. Weiss
- Department of Cell and Developmental Biology, The University of North Carolina at Chapel Hill, CB# 7090, 108 Taylor Hall, Chapel Hill, NC 27599, USA. Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, USA
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Alexov E, Mehler EL, Baker N, Baptista AM, Huang Y, Milletti F, Nielsen JE, Farrell D, Carstensen T, Olsson MHM, Shen JK, Warwicker J, Williams S, Word JM. Progress in the prediction of pKa values in proteins. Proteins 2011; 79:3260-75. [PMID: 22002859 PMCID: PMC3243943 DOI: 10.1002/prot.23189] [Citation(s) in RCA: 198] [Impact Index Per Article: 15.2] [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: 09/10/2011] [Accepted: 09/12/2011] [Indexed: 01/18/2023]
Abstract
The pK(a) -cooperative aims to provide a forum for experimental and theoretical researchers interested in protein pK(a) values and protein electrostatics in general. The first round of the pK(a) -cooperative, which challenged computational labs to carry out blind predictions against pK(a) s experimentally determined in the laboratory of Bertrand Garcia-Moreno, was completed and results discussed at the Telluride meeting (July 6-10, 2009). This article serves as an introduction to the reports submitted by the blind prediction participants that will be published in a special issue of PROTEINS: Structure, Function and Bioinformatics. Here, we briefly outline existing approaches for pK(a) calculations, emphasizing methods that were used by the participants in calculating the blind pK(a) values in the first round of the cooperative. We then point out some of the difficulties encountered by the participating groups in making their blind predictions, and finally try to provide some insights for future developments aimed at improving the accuracy of pK(a) calculations.
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Affiliation(s)
- Emil Alexov
- Department of Physics, Clemson University, Clemson, SC, USA.
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Pace TW, Hu F, Miller AH. Activation of cAMP-protein kinase A abrogates STAT5-mediated inhibition of glucocorticoid receptor signaling by interferon-alpha. Brain Behav Immun 2011; 25:1716-24. [PMID: 21798341 PMCID: PMC3608107 DOI: 10.1016/j.bbi.2011.07.227] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 07/05/2011] [Accepted: 07/06/2011] [Indexed: 10/17/2022] Open
Abstract
IFN-alpha has been found to inhibit glucocorticoid receptor (GR) function by activating janus kinase-signal transducer and activator of transcription (JAK-STAT) inflammatory signaling pathways. In contrast, through stimulation of protein kinase A (PKA), cAMP has been shown to enhance GR function and can inhibit inflammatory signaling. We therefore examined whether increased cAMP-PKA pathway activation could reverse IFN-alpha-induced inhibition of GR function and whether decreased cAMP-PKA activity might exacerbate IFN-alpha effects on the GR. Activation of cAMP by forskolin (10 μM) reversed the inhibitory effects of mIFN-alpha (1000 U/ml) on dexamethasone (DEX)-induced MMTV-luciferase activity in hippocampal HT22 cells. Forskolin treatment also blocked both IFN-alpha-induced activation of phosphorylated STAT5 (pSTAT5) and inhibitory protein-protein interactions between pSTAT5 and GR in the nucleus of HT22 cells treated with IFN-alpha and DEX. These effects of forskolin were reversed by co-administration of the PKA inhibitor, H89. Conversely, the combination of IFN-alpha and treatment with either H89 or siRNA directed against the alpha and beta catalytic subunit isoforms of PKA led to an additive inhibitory effect on DEX-induced GR activity in HT22 cells. Taken together, these findings suggest that inhibition of GR signaling by mIFN-alpha and STAT5 can be reversed by activation of cAMP-PKA pathways, whereas decreased PKA activity increases the inhibitory effect of IFN-alpha on GR function. Given decreased PKA activity found in patients with major depression, these data suggest that depressed patients may be vulnerable to cytokine effects on GR, and cAMP-PKA agonists may serve to reverse glucocorticoid resistance in patients with depression and increased inflammation.
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Affiliation(s)
- Thaddeus W.W. Pace
- Corresponding author: Thaddeus Pace, Ph.D., +1 404.778.5564 (phone), + 1 404.778.3965 (fax),
| | - Fang Hu
- Corresponding author: Thaddeus Pace, Ph.D., +1 404.778.5564 (phone), + 1 404.778.3965 (fax),
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Renzi A, Glaser S, DeMorrow S, Mancinelli R, Meng F, Franchitto A, Venter J, White M, Francis H, Han Y, Alvaro D, Gaudio E, Carpino G, Ueno Y, Onori P, Alpini G. Melatonin inhibits cholangiocyte hyperplasia in cholestatic rats by interaction with MT1 but not MT2 melatonin receptors. Am J Physiol Gastrointest Liver Physiol 2011; 301:G634-43. [PMID: 21757639 PMCID: PMC3191552 DOI: 10.1152/ajpgi.00206.2011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In bile duct-ligated (BDL) rats, large cholangiocytes proliferate by activation of cAMP-dependent signaling. Melatonin, which is secreted from pineal gland as well as extrapineal tissues, regulates cell mitosis by interacting with melatonin receptors (MT1 and MT2) modulating cAMP and clock genes. In the liver, melatonin suppresses oxidative damage and ameliorates fibrosis. No information exists regarding the role of melatonin in the regulation of biliary hyperplasia. We evaluated the mechanisms of action by which melatonin regulates the growth of cholangiocytes. In normal and BDL rats, we determined the hepatic distribution of MT1, MT2, and the clock genes, CLOCK, BMAL1, CRY1, and PER1. Normal and BDL (immediately after BDL) rats were treated in vivo with melatonin before evaluating 1) serum levels of melatonin, bilirubin, and transaminases; 2) intrahepatic bile duct mass (IBDM) in liver sections; and 3) the expression of MT1 and MT2, clock genes, and PKA phosphorylation. In vitro, large cholangiocytes were stimulated with melatonin in the absence/presence of luzindole (MT1/MT2 antagonist) and 4-phenyl-2-propionamidotetralin (MT2 antagonist) before evaluating cell proliferation, cAMP levels, and PKA phosphorylation. Cholangiocytes express MT1 and MT2, CLOCK, BMAL1, CRY1, and PER1 that were all upregulated following BDL. Administration of melatonin to BDL rats decreased IBDM, serum bilirubin and transaminases levels, the expression of all clock genes, cAMP levels, and PKA phosphorylation in cholangiocytes. In vitro, melatonin decreased the proliferation, cAMP levels, and PKA phosphorylation, decreases that were blocked by luzindole. Melatonin may be important in the management of biliary hyperplasia in human cholangiopathies.
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Affiliation(s)
| | - Shannon Glaser
- 2Department of Medicine, ,3Scott & White Digestive Disease Research Center,
| | - Sharon DeMorrow
- 2Department of Medicine, ,3Scott & White Digestive Disease Research Center,
| | - Romina Mancinelli
- Departments of 5Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, and
| | - Fanyin Meng
- 2Department of Medicine, ,3Scott & White Digestive Disease Research Center, ,4Division of Research and Education, Scott & White and Texas A&M Health Science Center College of Medicine, Temple, Texas;
| | - Antonio Franchitto
- Departments of 5Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, and
| | | | | | - Heather Francis
- 2Department of Medicine, ,3Scott & White Digestive Disease Research Center, ,4Division of Research and Education, Scott & White and Texas A&M Health Science Center College of Medicine, Temple, Texas;
| | | | - Domenico Alvaro
- 6Science and Medical-Surgical Biotechnology, Fondazione Eleonora Lorillard Spencer Cenci, Polo Pontino, University of Rome “Sapienza”, Rome;
| | - Eugenio Gaudio
- Departments of 5Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, and
| | - Guido Carpino
- 7Department of Health Science, University of Rome “Foro Italico”, Rome;
| | - Yoshiyuki Ueno
- 8Rohoku University Graduate School of Medicine Sendai, Japan;
| | - Paolo Onori
- 9Department of Experimental Medicine, University of L'Aquila, L'Aquila, Italy
| | - Gianfranco Alpini
- 1Division of Research, Central Texas Veterans Health Care System, ,2Department of Medicine, ,3Scott & White Digestive Disease Research Center,
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Roscioni SS, Prins AG, Elzinga CRS, Menzen MH, Dekkers BGJ, Halayko AJ, Meurs H, Maarsingh H, Schmidt M. Protein kinase A and the exchange protein directly activated by cAMP (Epac) modulate phenotype plasticity in human airway smooth muscle. Br J Pharmacol 2011; 164:958-69. [PMID: 21426315 PMCID: PMC3195918 DOI: 10.1111/j.1476-5381.2011.01354.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [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: 11/11/2010] [Revised: 02/21/2011] [Accepted: 03/02/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Platelet-derived growth factor (PDGF) modulates the airway smooth muscle (ASM) 'contractile' phenotype to a more 'proliferative' phenotype, resulting in increased proliferation and reduced contractility. Such phenotypic modulation may contribute to airway remodelling in asthma. We have previously shown that the cAMP effector molecules, protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac) inhibited PDGF-induced phenotypic modulation in bovine ASM. Here, we investigated these mechanisms in human ASM strips and cells. EXPERIMENTAL APPROACH ASM strips were incubated with PDGF in the absence or presence of the activators of Epac (8-pCPT-2'-O-Me-cAMP) or of PKA (6-Bnz-cAMP) for 4 days. Strips were mounted for isometric contraction experiments or analysed for the expression of contractile markers. Cell proliferation was measured and proliferative markers were analysed under similar conditions. KEY RESULTS Activation of Epac and PKA prevented PDGF-induced ASM strip hypocontractility, and restored the expression of smooth muscle actin, myosin and calponin, which had been markedly diminished by PDGF. Epac and PKA activation inhibited the PDGF-induced ASM cell proliferation and G(1)/S phase transition and the expression and phosphorylation of cell cycle regulators. CONCLUSIONS AND IMPLICATIONS Epac and PKA maintain a normally contractile ASM phenotype in a mitogenic environment, suggesting that specific activators of Epac and PKA may be beneficial in the treatment of airway remodelling in asthma.
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Affiliation(s)
- Sara S Roscioni
- Department of Molecular Pharmacology, University of Groningen, The Netherlands.
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37
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Zhang L, Yun H, Murray F, Lu R, Wang L, Hook V, Insel PA. Cytotoxic T lymphocyte antigen-2 alpha induces apoptosis of murine T-lymphoma cells and cardiac fibroblasts and is regulated by cAMP/ PKA. Cell Signal 2011; 23:1611-6. [PMID: 21620962 PMCID: PMC3148345 DOI: 10.1016/j.cellsig.2011.05.014] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 05/12/2011] [Accepted: 05/13/2011] [Indexed: 11/23/2022]
Abstract
The mechanism of cAMP-promoted apoptosis is not well defined. In wild-type (WT) murine S49 lymphoma cells, cAMP promotes apoptosis in a protein kinase A (PKA)-dependent manner. We find that treatment of WT S49 cells with 8-CPT-cAMP prominently increases the expression (as determined by DNA microarray analysis, real-time PCR and immunblotting) of cytotoxic T lymphocyte antigen-2α (CTLA-2α), a cathepsin L-like cysteine protease inhibitor. By contrast, CTLA-2α expression is only slightly increased by 8-CPT-cAMP treatment of D-S49 cells, which lack cAMP/PKA-promoted apoptosis. Raising endogenous cAMP (by use of forskolin or inhibition of phosphodiesterase [PDE] 4) or a PKA-selective, but not an Epac-selective, cAMP analogue, increases CTLA-2α mRNA expression; PKA, and not Epac, thus mediates the increase in CTLA-2α expression. An adenoviral CLTA-2α (Ad-CTLA-2α) construct induces apoptosis and enhances cAMP-promoted apoptosis in WT S49 cells but such cells do not have an increase in cathepsin L activity nor does a cathepsin L inhibitor alter cAMP-promoted apoptosis. 8-CPT-cAMP also increases CTLA-2α expression and induces apoptosis in murine cardiac fibroblasts; knockdown of CTLA-2α expression by siRNA blocks 8-CPT-cAMP-promoted apoptosis. Thus, cAMP increases CTLA-2α expression in murine lymphoma and cardiac fibroblasts and this increase in CTLA-2α contributes to cAMP/PKA-promoted apoptosis by mechanisms that are independent of the ability of CTLA-2α to inhibit cathepsin L.
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Affiliation(s)
- Lingzhi Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Hongruo Yun
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Fiona Murray
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Ruilin Lu
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Lin Wang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Vivian Hook
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
- Skaggs School of Pharmacy, University of California San Diego, La Jolla, CA 92093
| | - Paul A. Insel
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
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Acin-Perez R, Gatti DL, Bai Y, Manfredi G. Protein phosphorylation and prevention of cytochrome oxidase inhibition by ATP: coupled mechanisms of energy metabolism regulation. Cell Metab 2011; 13:712-9. [PMID: 21641552 PMCID: PMC3118639 DOI: 10.1016/j.cmet.2011.03.024] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 01/31/2011] [Accepted: 03/25/2011] [Indexed: 10/18/2022]
Abstract
Rapid regulation of oxidative phosphorylation is crucial for mitochondrial adaptation to swift changes in fuels availability and energy demands. An intramitochondrial signaling pathway regulates cytochrome oxidase (COX), the terminal enzyme of the respiratory chain, through reversible phosphorylation. We find that PKA-mediated phosphorylation of a COX subunit dictates mammalian mitochondrial energy fluxes and identify the specific residue (S58) of COX subunit IV-1 (COXIV-1) that is involved in this mechanism of metabolic regulation. Using protein mutagenesis, molecular dynamics simulations, and induced fit docking, we show that mitochondrial energy metabolism regulation by phosphorylation of COXIV-1 is coupled with prevention of COX allosteric inhibition by ATP. This regulatory mechanism is essential for efficient oxidative metabolism and cell survival. We propose that S58 COXIV-1 phosphorylation has evolved as a metabolic switch that allows mammalian mitochondria to rapidly toggle between energy utilization and energy storage.
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Affiliation(s)
- Rebeca Acin-Perez
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10065, USA
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Nurminsky D, Shanmugasundaram S, Deasey S, Michaud C, Allen S, Hendig D, Dastjerdi A, Francis-West P, Nurminskaya M. Transglutaminase 2 regulates early chondrogenesis and glycosaminoglycan synthesis. Mech Dev 2011; 128:234-45. [PMID: 21129482 PMCID: PMC3140913 DOI: 10.1016/j.mod.2010.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [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: 05/20/2010] [Revised: 11/24/2010] [Accepted: 11/25/2010] [Indexed: 11/20/2022]
Abstract
The expression pattern for tissue transglutaminase (TG2) suggests that it regulates cartilage formation. We analyzed the role of TG2 in early stages of chondrogenesis using differentiating high-density cultures of mesenchymal cells from chicken limb bud as a model. We demonstrate that TG2 promotes cell differentiation towards a pre-hypertrophic stage without inducing precocious hypertrophic maturation. This finding, combined with distinctive up-regulation of extracellular TG2 in the pre-hypertrophic cartilage of the growth plate, indicates that TG2 is an autocrine regulator of chondrocyte differentiation. We also show that TG2 regulates synthesis of the cartilaginous glycosaminoglycan (GAG)-rich extracellular matrix. Elevated levels of TG2 down-regulate xylosyltransferase activity which mediates the key steps in chondroitin sulfate synthesis. On the contrary, inhibition of endogenous transglutaminase activity in differentiating chondrogenic micromasses results in increased GAG deposition and enhancement of early chondrogenic markers. Regulation of GAG synthesis by TG2 appears independent of TGF-β activity, which is a downstream mediator of the TG2 functions in some biological systems. Instead, our data suggest a major role for cAMP/PKA signaling in transmitting TG2 signals in early chondrogenic differentiation. In summary, we demonstrate that matrix synthesis and early stages of chondrogenic differentiation are regulated through a novel mechanism involving TG2-dependent inhibition of PKA. These findings further advance understanding of cartilage formation and disease, and contribute to cartilage bioengineering.
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Affiliation(s)
- Dmitry Nurminsky
- Dept. Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Shobana Shanmugasundaram
- Dept. Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Stephanie Deasey
- Dept. Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Claire Michaud
- Dept. Anatomy and Cell Biology, Tufts University School of Medicine, Boston, MA 02111
| | | | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin Herz- und Diabeteszentrum, Universität Bochum Bad Oeynhausen, Germany
| | - Akbar Dastjerdi
- Dept. of Craniofacial Development, King's College London, London, UK
| | | | - Maria Nurminskaya
- Dept. Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
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Harmati G, Bányász T, Bárándi L, Szentandrássy N, Horváth B, Szabó G, Szentmiklósi JA, Szénási G, Nánási PP, Magyar J. Effects of β-adrenoceptor stimulation on delayed rectifier K(+) currents in canine ventricular cardiomyocytes. Br J Pharmacol 2011; 162:890-6. [PMID: 20973780 PMCID: PMC3042199 DOI: 10.1111/j.1476-5381.2010.01092.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 09/08/2010] [Accepted: 10/09/2010] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE While the slow delayed rectifier K(+) current (I(Ks)) is known to be enhanced by the stimulation of β-adrenoceptors in several mammalian species, phosphorylation-dependent regulation of the rapid delayed rectifier K(+) current (I(Kr)) is controversial. EXPERIMENTAL APPROACH In the present study, therefore, the effect of isoprenaline (ISO), activators and inhibitors of the protein kinase A (PKA) pathway on I(Kr) and I(Ks) was studied in canine ventricular myocytes using the whole cell patch clamp technique. KEY RESULTS I (Kr) was significantly increased (by 30-50%) following superfusion with ISO, forskolin or intracellular application of PKA activator cAMP analogues (cAMP, 8-Br-cAMP, 6-Bnz-cAMP). Inhibition of PKA by Rp-8-Br-cAMP had no effect on baseline I(Kr). The stimulating effect of ISO on I(Kr) was completely inhibited by selective β₁-adrenoceptor antagonists (metoprolol and CGP-20712A), by the PKA inhibitor Rp-8-Br-cAMP and by the PKA activator cAMP analogues, but not by the EPAC activator 8-pCPT-2'-O-Me-cAMP. In comparison, I(Ks) was increased threefold by the activation of PKA (by ISO or 8-Br-cAMP), and strongly reduced by the PKA inhibitor Rp-8-Br-cAMP. The ISO-induced enhancement of I(Ks) was decreased by Rp-8-Br-cAMP and completely inhibited by 8-Br-cAMP. CONCLUSIONS AND IMPLICATIONS The results indicate that the stimulation of β₁-adrenoceptors increases I(Kr), similar to I(Ks), via the activation of PKA in canine ventricular cells.
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Affiliation(s)
- G Harmati
- Department of Physiology, University of Debrecen, Debrecen, Hungary
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41
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Liu Y, Lehmler HJ, Robertson LW, Duffel MW. Physicochemical properties of hydroxylated polychlorinated biphenyls aid in predicting their interactions with rat sulfotransferase 1A1 (rSULT1A1). Chem Biol Interact 2011; 189:153-60. [PMID: 21130751 PMCID: PMC3032042 DOI: 10.1016/j.cbi.2010.11.009] [Citation(s) in RCA: 11] [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: 09/29/2010] [Revised: 11/24/2010] [Accepted: 11/25/2010] [Indexed: 10/18/2022]
Abstract
Hydroxylated metabolites of polychlorinated biphenyls (OHPCBs) interact with rat sulfotransferase 1A1 (rSULT1A1) as substrates and inhibitors. Previous studies have shown that there are complex and incompletely understood structure-activity relationships governing the interaction of rSULT1A1 with these molecules. Furthermore, modification of the enzyme with glutathione disulfide (GSSG) results in the conversion of some OHPCBs from inhibitors to substrates. We have now examined estimated values for the acid-dissociation constant (K(a)) and the octanol-water distribution coefficient (D), as well as experimentally determined dissociation constants for enzyme complexes, to assist in the prediction of interactions of OHPCBs with rSULT1A1. Under reducing conditions, initial velocities for rSULT1A1-catalyzed sulfation exhibited a positive correlation with pK(a) and a negative correlation with logD of the OHPCBs. IC(50) values of inhibitory OHPCBs decreased with decreasing pK(a) values for both the glutathione (GSH)-pretreated and GSSG-pretreated forms of rSULT1A1. Comparison of GSH- and GSSG-pretreated forms of rSULT1A1 with respect to binding of OHPCB in the presence and absence of adenosine 3',5'-diphosphate (PAP) revealed that the dissociation constants with the two redox states of the enzyme were similar for each OHPCB. Thus, pK(a) and logD values are useful in predicting the binding of OHPCBs to the two redox forms of rSULT1A1 as well as the rates of sulfation of those OHPCBs that are substrates. However, the differences in substrate specificity for OHPCBs that are seen with changes in redox status of the enzyme are not directly related to specific structural effects of individual OHPCBs within inhibitory enzyme-PAP-OHPCB complexes.
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Affiliation(s)
- Yungang Liu
- Division of Medicinal and Natural Products Chemistry, College of Pharmacy University of Iowa, Iowa City, IA 52242
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guandong, China 510515
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242
| | - Michael W. Duffel
- Division of Medicinal and Natural Products Chemistry, College of Pharmacy University of Iowa, Iowa City, IA 52242
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Shen W, Ahmad F, Hockman S, Ma J, Omi H, Raghavachari N, Manganiello V. Female infertility in PDE3A(-/-) mice: polo-like kinase 1 (Plk1) may be a target of protein kinase A ( PKA) and involved in meiotic arrest of oocytes from PDE3A(-/-) mice. Cell Cycle 2010; 9:4720-34. [PMID: 21099356 PMCID: PMC3048038 DOI: 10.4161/cc.9.23.14090] [Citation(s) in RCA: 11] [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: 07/07/2010] [Revised: 10/29/2010] [Accepted: 11/02/2010] [Indexed: 01/01/2023] Open
Abstract
Mechanisms of cAMP/PKA-induced meiotic arrest in oocytes are not completely identified. In cultured, G2/M-arrested PDE3A(-/-) murine oocytes, elevated PKA activity was associated with inactivation of Cdc2 and Plk1, and inhibition of phosphorylation of histone H3 (S10) and of dephosphorylation of Cdc25B (S323) and Cdc2 (Thr14/Tyr15). In cultured WT oocytes, PKA activity was transiently reduced and then increased to that observed in PDE3A(-/-) oocytes; Cdc2 and Plk1 were activated, phosphorylation of histone H3 (S10) and dephosphorylation of Cdc25B (S323) and Cdc2 (Thr14/Tyr15) were observed. In WT oocytes, PKAc were rapidly translocated into nucleus, and then to the spindle apparatus, but in PDE3A(-/-) oocytes, PKAc remained in the cytosol. Plk1 was reactivated by incubation of PDE3A(-/-) oocytes with PKA inhibitor, Rp-cAMPS. PDE3A was co-localized with Plk1 in WT oocytes, and co-immunoprecipitated with Plk1 in WT ovary and Hela cells. PKAc phosphorylated rPlk1 and Hela cell Plk1 and inhibited Plk1 activity in vitro. Our results suggest that PKA-induced inhibition of Plk1 may be critical in oocyte meiotic arrest and female infertility in PDE3A(-/-) mice.
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Affiliation(s)
- Weixing Shen
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - Faiyaz Ahmad
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - Steven Hockman
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - John Ma
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - Hitoshi Omi
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - Nalini Raghavachari
- Genomics Core Facility; Pulmonary and Vascular Medicine Branch (PVMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
| | - Vincent Manganiello
- Translational Medicine Branch (TMB); National Heart, Lung and Blood Institute (NHLBI); National Institutes of Health; Bethesda, MD USA
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El-Zaatari M, Zavros Y, Tessier A, Waghray M, Lentz S, Gumucio D, Todisco A, Merchant JL. Intracellular calcium release and protein kinase C activation stimulate sonic hedgehog gene expression during gastric acid secretion. Gastroenterology 2010; 139:2061-2071.e2. [PMID: 20816837 PMCID: PMC2997213 DOI: 10.1053/j.gastro.2010.08.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 08/21/2010] [Accepted: 08/26/2010] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Hypochlorhydria during Helicobacter pylori infection inhibits gastric Sonic Hedgehog (Shh) expression. We investigated whether acid-secretory mechanisms regulate Shh gene expression through intracellular calcium (Ca2(+)(i))-dependent protein kinase C (PKC) or cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) activation. METHODS We blocked Hedgehog signaling by transgenically overexpressing a secreted form of the Hedgehog interacting protein-1, a natural inhibitor of hedgehog ligands, which induced hypochlorhydria. Gadolinium, ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) + 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), PKC-overexpressing adenoviruses, and PKC inhibitors were used to modulate Ca(2+)(i)-release, PKC activity, and Shh gene expression in primary gastric cell, organ, and AGS cell line cultures. PKA hyperactivity was induced in the H(+)/K(+)-β-cholera-toxin-overexpressing mice. RESULTS Mice that expressed secreted hedgehog-interacting protein-1 had lower levels of gastric acid (hypochlorhydria), reduced production of somatostatin, and increased gastrin gene expression. Hypochlorhydria in these mice repressed Shh gene expression, similar to the levels obtained with omeprazole treatment of wild-type mice. However, Shh expression also was repressed in the hyperchlorhydric H(+)/K(+)-β-cholera-toxin model with increased cAMP, suggesting that the regulation of Shh was not solely acid-dependent, but pertained to specific acid-stimulatory signaling pathways. Based on previous reports that Ca(2+)(i) release also stimulates acid secretion in parietal cells, we showed that gadolinium-, thapsigargin-, and carbachol-mediated release of Ca(2+)(i) induced Shh expression. Ca(2+)-chelation with BAPTA + EGTA reduced Shh expression. Overexpression of PKC-α, -β, and -δ (but not PKC-ϵ) induced an Shh gene expression. In addition, phorbol esters induced a Shh-regulated reporter gene. CONCLUSIONS Secretagogues that stimulate gastric acid secretion induce Shh gene expression through increased Ca(2+)(i)-release and PKC activation. Shh might be the ligand transducing changes in gastric acidity to the regulation of G-cell secretion of gastrin.
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Affiliation(s)
- Mohamad El-Zaatari
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Yana Zavros
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH
| | - Art Tessier
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Meghna Waghray
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Steve Lentz
- Michigan Diabetes Research and Training Center, University of Michigan, Ann Arbor, MI
| | - Deborah Gumucio
- Cell and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Andrea Todisco
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Juanita L. Merchant
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI,Correspondence: Juanita L. Merchant, M.D., Ph.D., 109 Zina Pitcher Place, BSRB, Rm. 2051, Ann Arbor, MI 48109-2200, Phone: (734) 647-2944, Fax: (734) 736-4686,
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Zhang S, Liu Y, Guo S, Zhang J, Chu X, Jiang C, Zhu D. Vasoactive intestinal polypeptide relaxes isolated rat pulmonary artery rings through two distinct mechanisms. J Physiol Sci 2010; 60:389-97. [PMID: 20694540 PMCID: PMC10717274 DOI: 10.1007/s12576-010-0107-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 07/20/2010] [Indexed: 11/26/2022]
Abstract
Vasoactive intestinal polypeptide (VIP), an endogenous neuropeptide normally present in lungs and other organs, relaxes pulmonary arteries (PAs) in different species, whereas the underlying mechanisms are still not fully understood. The aim of this study, therefore, is to investigate the signal transduction of VIP in the relaxation of isolated rat PA rings. The isometric tension of the rings was studied in vitro with force-electricity transducers. In endothelium-intact (EI) rings, VIP elicited concentration-dependent relaxation after the rings were pre-contracted by phenylephrine. A similar effect, though smaller, was observed in endothelium-denuded (ED) rings. Inhibition of the endothelial nitric oxide synthase (eNOS) by NG-nitro-L-arginine methyl ester diminished the VIP-induced vasodilatation of PA rings. The VIP-induced vasorelaxation was markedly reduced by the inhibition of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway with wortmannin and LY294002, respectively, which was seen in EI rings, but not in ED rings. Western blot analysis revealed that VIP increased the phosphorylation of eNOS at Ser 1177, but did not affect the overall expression of eNOS. In ED rings, the PKA inhibitor H-89 and K(ATP) channel inhibitor glibenclamide almost totally abolished the vasodilatation effect of VIP. The results suggested that the vasodilatation effect of VIP on rat PAs is mediated by both vascular endothelium and smooth muscle, involving respectively the PI3K/Akt-eNOS pathway and the PKA-K(ATP) channel pathway.
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Affiliation(s)
- Shuang Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
| | - Yun Liu
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
| | - Shouli Guo
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
| | - Jianing Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
| | - Xiaojie Chu
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
| | - Chun Jiang
- Department of Biology, Georgia State University, 24 Peachtree Center Avenue, Atlanta, GA 30302-4010 USA
| | - Daling Zhu
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, 150081 Heilongjiang People’s Republic of China
- Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin, 150081 China
- Biopharmaceutical Key Laboratory of Ministry of Education, Harbin, China
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Abstract
Pain is a frequent complaint of people living with sickle cell disease (SCD); however, the neurobiology of pain in SCD remains poorly understood. Whereas this pain has been thought to be primarily related to visceral and somatic tissue injury subsequent to vaso-occlusion events, emerging evidence from human and animal studies has suggested that a component of SCD pain may be related to neuropathic processes. Significant knowledge has been obtained from studies of molecular and neurobiological mechanisms leading to and maintaining neuropathic pain. Some of the most promising evidence has implicated major roles of protein kinase C and Ca2+/calmodulin-dependent protein kinase II, and their interaction with the N-methyl-D-aspartate receptors and the transient receptor potential vanilloid 1 receptor in the development of neuropathic pain. The latest evidence from our studies suggests that these pathways are important for SCD pain as well. Coupled with emerging animal models of SCD pain, we can now start to elucidate neurobiological mechanisms underlying pain in SCD, which may lead to better understanding and effective therapies.
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Affiliation(s)
- Zaijie J Wang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Marin MT, Berkow A, Golden SA, Koya E, Planeta CS, Hope BT. Context-specific modulation of cocaine-induced locomotor sensitization and ERK and CREB phosphorylation in the rat nucleus accumbens. Eur J Neurosci 2009; 30:1931-40. [PMID: 19912338 PMCID: PMC2810354 DOI: 10.1111/j.1460-9568.2009.06982.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [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: 11/29/2022]
Abstract
Learned associations are hypothesized to develop between drug effects and contextual stimuli during repeated drug administration to produce context-specific sensitization that is expressed only in the drug-associated environment and not in a non-drug-paired environment. The neuroadaptations that mediate such context-specific behavior are largely unknown. We investigated context-specific modulation of cAMP-response element-binding protein (CREB) phosphorylation and that of four upstream kinases in the nucleus accumbens that phosphorylate CREB, including extracellular signal-regulated kinase (ERK), cAMP-dependent protein kinase, calcium/calmodulin-dependent kinase (CaMK) II and CaMKIV. Rats received seven once-daily injections of cocaine or saline in one of two distinct environments outside their home cages. Seven days later, test injections of cocaine or saline were administered in either the paired or the non-paired environment. CREB and ERK phosphorylation were assessed with immunohistochemistry, and phosphorylation of the remaining kinases, as well as of CREB and ERK, was assessed by western blotting. Repeated cocaine administration produced context-specific sensitized locomotor responses accompanied by context-specific enhancement of the number of cocaine-induced phosphoCREB-immunoreactive and phosphoERK-immunoreactive nuclei in a minority of neurons. In contrast, CREB and CaMKIV phosphorylation in nucleus accumbens homogenates were decreased by cocaine test injections. We have recently shown that a small number of cocaine-activated accumbens neurons mediate the learned association between cocaine effects and the drug administration environment to produce context-specific sensitization. Context-specific phosphorylation of ERK and CREB in the present study suggests that this signal transduction pathway is selectively activated in the same set of cocaine-activated accumbens neurons that mediate this learned association.
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Affiliation(s)
- Marcelo T. Marin
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Rod. Araraquara-Jaú km 1, 14801-902, Araraquara-SP, Brazil
| | - Alexander Berkow
- Behavioral Neuroscience Branch, IRP/NIDA/NIH/DHHS, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Sam A. Golden
- Behavioral Neuroscience Branch, IRP/NIDA/NIH/DHHS, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Eisuke Koya
- Behavioral Neuroscience Branch, IRP/NIDA/NIH/DHHS, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Cleopatra S. Planeta
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Rod. Araraquara-Jaú km 1, 14801-902, Araraquara-SP, Brazil
| | - Bruce T. Hope
- Behavioral Neuroscience Branch, IRP/NIDA/NIH/DHHS, 251 Bayview Blvd, Baltimore, MD 21224, USA
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Datta S, Siwek DF, Huang MP. Improvement of two-way active avoidance memory requires protein kinase a activation and brain-derived neurotrophic factor expression in the dorsal hippocampus. J Mol Neurosci 2009; 38:257-64. [PMID: 19418263 PMCID: PMC2716211 DOI: 10.1007/s12031-009-9206-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [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: 03/26/2009] [Accepted: 04/16/2009] [Indexed: 11/24/2022]
Abstract
Previous studies have shown that two-way active avoidance (TWAA) memory processing involves a functional interaction between the pontine wave (P wave) generator and the CA3 region of the dorsal hippocampus (DH-CA3). The present experiments examined whether the interaction between P wave generator activity and the DH-CA3 involves the intracellular protein kinase A (PKA) signaling system. In the first series of experiments, rats were subjected to a session of TWAA training followed immediately by bilateral microinjection of either the PKA activation inhibitor (KT-5720) or vehicle control into the DH-CA3 and tested for TWAA memory 24 h later. The results indicated that immediate KT-5720 infusion impaired improvement of TWAA performance. Additional experiments showed that KT-5720 infusion also blocked TWAA training-induced BDNF expression in the DH-CA3. Together, these findings suggest that the PKA activation and BDNF expression in the DH-CA3 is essential for the improvement of TWAA memory.
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Affiliation(s)
- Subimal Datta
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, MA, 02118, USA.
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Abstract
Drugs of abuse usurp the mechanisms underlying synaptic plasticity in areas of the brain, a process that may contribute to the development of addiction. We previously reported that GABAergic synapses onto dopaminergic neurons in the ventral tegmental area (VTA) exhibit long-term potentiation (LTP(GABA)) blocked by in vivo exposure to morphine. The presynaptically maintained LTP requires the retrogradely released nitric oxide (NO) to activate a presynaptic cGMP signaling cascade. Previous work reported that inhibitory GABA(A) receptor synapses in the VTA are also potentiated by cAMP. Here, we explored the interactions between cGMP-dependent (PKG) and cAMP-dependent (PKA) protein kinases in the regulation of these GABAergic synapses and LTP(GABA). Activation of PKG was required for NO-cGMP signaling and was also essential for the induction of synaptically elicited LTP(GABA), but not for its maintenance. Synapses containing GABA(A) receptors were potentiated by NO-cGMP signaling, whereas synapses containing GABA(B) receptors on the same cells were not potentiated. Moreover, although the cAMP-PKA system potentiated GABA(A) synapses, synaptically induced LTP(GABA) was independent of PKA activation. Surprisingly, however, raising cGMP levels saturated potentiation of these synapses, precluding further potentiation by cAMP and suggesting a convergent end point for both signaling pathways in the regulation of GABAergic release. We further found that persistent GABAergic synaptic modifications observed with in vivo morphine did not involve the presynaptic cAMP-PKA cascade. Taken together, our data suggest a synapse-specific role for NO-cGMP-PKG signaling pathway in opioid-induced plasticity of VTA GABA(A) synapses.
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Abstract
Although it has long been recognized that multiple water molecules strongly associate with an extra proton in bulk water, some models and conceptual frameworks continue to utilize the classical hydronium ion (H(3)O(+)) as a fundamental building block. In this work, the nature of the hydronium ion in aqueous systems is examined using an ab initio energy decomposition analysis (EDA) that evaluates both the magnitude of and energetic stabilization due to charge transfer among H(3)O(+) and the surrounding water molecules. The EDA is performed on structures extracted from dynamical bulk-phase simulations and used to determine how frequently the pure hydronium ion, where the excess charge is primarily localized on H(3)O(+), occurs under dynamic conditions. The answer is essentially never. The energetic stabilization of H(3)O(+) due to charge delocalization to neighboring water molecules is found to be much larger (16-49 kcal/mol) than for other ions (even Li(+)) and to constitute a substantial portion (20-52%) of the complex's binding energy. The charge defect is also shown to have intrinsic dynamical asymmetry and to display dynamical signatures that can be related to features appearing in IR spectra.
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Affiliation(s)
- Jessica M J Swanson
- Henry Eyring Center for Theoretical Chemistry, University of Utah, Department of Chemistry, 315 South 1400 East Room 2020, Salt Lake City, Utah 84112-0850, USA.
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50
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Abraham SJ, Kobayashi T, Solaro RJ, Gaponenko V. Differences in lysine pKa values may be used to improve NMR signal dispersion in reductively methylated proteins. J Biomol NMR 2009; 43:239-46. [PMID: 19280122 PMCID: PMC2736131 DOI: 10.1007/s10858-009-9306-2] [Citation(s) in RCA: 15] [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] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 02/18/2009] [Indexed: 05/03/2023]
Abstract
Reductive methylation of lysine residues in proteins offers a way to introduce 13C methyl groups into otherwise unlabeled molecules. The 13C methyl groups on lysines possess favorable relaxation properties that allow highly sensitive NMR signal detection. One of the major limitations in the use of reductive methylation in NMR is the signal overlap of 13C methyl groups in NMR spectra. Here we show that the uniform influence of the solvent on chemical shifts of exposed lysine methyl groups could be overcome by adjusting the pH of the buffering solution closer to the pKa of lysine side chains. Under these conditions, due to variable pKa values of individual lysine side chains in the protein of interest different levels of lysine protonation are observed. These differences are reflected in the chemical shift differences of methyl groups in reductively methylated lysines. We show that this approach is successful in four different proteins including Ca2+-bound Calmodulin, Lysozyme, Ca2+-bound Troponin C, and Glutathione S-Transferase. In all cases significant improvement in NMR spectral resolution of methyl signals in reductively methylated proteins was obtained. The increased spectral resolution helps with more precise characterization of protein structural rearrangements caused by ligand binding as shown by studying binding of Calmodulin antagonist trifluoperazine to Calmodulin. Thus, this approach may be used to increase resolution in NMR spectra of 13C methyl groups on lysine residues in reductively methylated proteins that enhances the accuracy of protein structural assessment.
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Affiliation(s)
- Sherwin J. Abraham
- Department of Biochemistry and Molecular Genetics University of Illinois at Chicago Chicago, IL 60607
| | - Tomoyoshi Kobayashi
- Department of Physiology and Biophysics Center for Cardiovascular Research University of Illinois at Chicago Chicago, IL 60612
| | - R. John Solaro
- Department of Physiology and Biophysics Center for Cardiovascular Research University of Illinois at Chicago Chicago, IL 60612
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics University of Illinois at Chicago Chicago, IL 60607
- Address correspondence to: Vadim Gaponenko, Phone: (312) 355-4965; Fax: (312) 413-0353;
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