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Taoro-González L, Cabrera-Pastor A, Sancho-Alonso M, Felipo V. Intracellular and extracelluar cyclic GMP in the brain and the hippocampus. VITAMINS AND HORMONES 2022; 118:247-288. [PMID: 35180929 DOI: 10.1016/bs.vh.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cyclic Guanosine-Monophosphate (cGMP) is implicated as second messenger in a plethora of pathways and its effects are executed mainly by cGMP-dependent protein kinases (PKG). It is involved in both peripheral (cardiovascular regulation, intestinal secretion, phototransduction, etc.) and brain (hippocampal synaptic plasticity, neuroinflammation, cognitive function, etc.) processes. Stimulation of hippocampal cGMP signaling have been proved to be beneficial in animal models of aging, Alzheimer's disease or hepatic encephalopathy, restoring different cognitive functions such as passive avoidance, object recognition or spatial memory. However, even when some inhibitors of cGMP-degrading enzymes (PDEs) are already used against peripheral pathologies, their utility as neurological treatments is still under clinical investigation. Additionally, it has been demonstrated a list of cGMP roles as not second but first messenger. The role of extracellular cGMP has been specially studied in hippocampal function and cognitive impairment in animal models and it has emerged as an important modulator of neuroinflammation-mediated cognitive alterations and hippocampal synaptic plasticity malfunction. Specifically, it has been demonstrated that extracellular cGMP decreases hippocampal IL-1β levels restoring membrane expression of glutamate receptors in the hippocampus and cognitive function in hyperammonemic rats. The mechanisms implicated are still unclear and might involve complex interactions between hippocampal neurons, astrocytes and microglia. Membrane targets for extracellular cGMP are still poorly understood and must be addressed in future studies.
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Affiliation(s)
- Lucas Taoro-González
- Department of Clinical Psychology, Psychobiology and Methodology, Area of Psycobiology, University of La Laguna, Tenerife, Spain
| | - Andrea Cabrera-Pastor
- Fundación Investigación Hospital Clínico, Instituto de Investigación Sanitaria (INCLIVA), Valencia, Spain; Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - María Sancho-Alonso
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain.
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Peake N, Su N, Ramachandran M, Achan P, Salter DM, Bader DL, Moyes AJ, Hobbs AJ, Chowdhury TT. Natriuretic peptide receptors regulate cytoprotective effects in a human ex vivo 3D/bioreactor model. Arthritis Res Ther 2013; 15:R76. [PMID: 23883591 PMCID: PMC3978875 DOI: 10.1186/ar4253] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 07/24/2013] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION The present study examined the effect of C-type natriuretic peptide (CNP) and biomechanical signals on anabolic and catabolic activities in chondrocyte/agarose constructs. METHODS Natriuretic peptide (Npr) 2 and 3 expression were compared in non-diseased (grade 0/1) and diseased (grade IV) human cartilage by immunofluoresence microscopy and western blotting. In separate experiments, constructs were cultured under free-swelling conditions or subjected to dynamic compression with CNP, interleukin-1β (IL-1β), the Npr2 antagonist P19 or the Npr3 agonist cANF⁴⁻²³. Nitric oxide (NO) production, prostaglandin E₂ (PGE₂) release, glycosaminoglycan (GAG) synthesis and CNP concentration were quantified using biochemical assays. Gene expression of Npr2, Npr3, CNP, aggrecan and collagen type II were assessed by real-time qPCR. Two-way ANOVA and a post hoc Bonferroni-corrected t-test were used to analyse the data. RESULTS The present study demonstrates increased expression of natriuretic peptide receptors in diseased or older cartilage (age 70) when compared to non-diseased tissue (age 60) which showed minimal expression. There was strong parallelism in the actions of CNP on cGMP induction resulting in enhanced GAG synthesis and reduction of NO and PGE₂ release induced by IL-1β. Inhibition of Npr2 with P19 maintained catabolic activities whilst specific agonism of Npr3 with cANF⁴⁻²³ had the opposite effect and reduced NO and PGE₂ release. Co-stimulation with CNP and dynamic compression enhanced anabolic activities and inhibited catabolic effects induced by IL-1β. The presence of CNP and the Npr2 antagonist abolished the anabolic response to mechanical loading and prevented loading-induced inhibition of NO and PGE₂ release. In contrast, the presence of the Npr3 agonist had the opposite effect and increased GAG synthesis and cGMP levels in response to mechanical loading and reduced NO and PGE₂ release comparable to control samples. In addition, CNP concentration and natriuretic peptide receptor expression were increased with dynamic compression. CONCLUSIONS Mechanical loading mediates endogenous CNP release leading to increased natriuretic peptide signalling. The loading-induced CNP/Npr2/cGMP signalling route mediates anabolic events and prevents catabolic activities induced by IL-1β. The CNP pathway therefore represents a potentially chondroprotective intervention for patients with OA, particularly when combined with physiotherapeutic approaches to stimulate biomechanical signals.
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Hirrlinger J, Moeller H, Kirchhoff F, Dringen R. Expression of Multidrug Resistance Proteins (Mrps) in Astrocytes of the Mouse Brain: A Single Cell RT-PCR Study. Neurochem Res 2005; 30:1237-44. [PMID: 16341585 DOI: 10.1007/s11064-005-8795-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2005] [Indexed: 12/30/2022]
Abstract
Multidrug resistance proteins (Mrps) are ATP-driven export pumps which mediate the export of organic anions such as glutathione conjugates and glucuronides from eukaryotic cells. Within the central nervous system astrocytes have important functions in metabolism and detoxification. In such processes Mrps play essential roles. To identify the Mrp repertoire of mouse brain and of astrocytes in particular, the expression of six mouse Mrps was investigated by reverse-transcription polymerase-chain reaction (RT-PCR). Using mouse brain mRNA as source, amplification products were obtained for Mrp1, Mrp3, Mrp4, Mrp5 and Mrp6. In contrast, mRNA of Mrp2 could not be detected in mouse brain. To investigate whether individual astrocytes express different Mrps in brain, single-cell RT-PCRs were performed from the cytosol harvested from single astrocytes in acutely isolated brain slices from cortex and cerebellum of TgN(GFAP-EGFP) mice. In these mice astrocytes can readily be identified by glial fibrillary acidic protein promoter-controlled green fluorescent protein expression. Investigation of individual cortical astrocytes and Bergmann glial cells revealed that these cells express Mrp1, Mrp4 and Mrp5 and that individual astrocytes can contain mRNA of one, two or three of these Mrps simultaneously.
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Affiliation(s)
- Johannes Hirrlinger
- Max-Planck-Institut für Experimentelle Medizin, Hermann-Rein-Str. 3, D-37075, Göttingen, Germany
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Abstract
The biokinetics of guanosine 3',5'-cyclic monophosphate (cGMP) is characterized by three distinct processes: synthesis by guanylate cyclases (GCs), conversion of cGMP to GMP by cyclic nucleotide phosphodiesterases (PDEs) and the excretion of unchanged cGMP by transport proteins in the cell membrane. Efflux is observed in virtually all cell types including cells which originate from brain. Studies of intact cells, in which metabolic inhibitors and probenecid reduced extrusion of cGMP and wherein cGMP was extruded against concentration gradients, indicated the existence of ATP requiring organic anion transport system(s). Functional studies of inside-out vesicles have revealed cGMP transport systems wherein translocation is coupled to hydrolysis of ATP. The extrusion of cGMP is inhibited by a number of unrelated compounds and this indicates that cGMP is substrate for multispecific transporters. Recent transfection studies suggest that members of the MRP (multidrug resistance protein) family; MRP4, MRP5 and MRP8 translocate cGMP across the cell membrane. Many of the MRPs have been detected in brain. In addition tertiary active transport by the organic anion transporter family has also been identified. At least one member (OAT1) shows relative high affinity for cGMP and is also expressed in brain. The biological significance of cGMP transporters has to be clarified. Their role in cGMP biokinetics, being responsible for one of the cellular elimination pathways, is well established. However, there is growing evidence that extracellular cGMP has effects on cell physiology and pathophysiology by an auto- or paracrine mechanism.
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Affiliation(s)
- Georg Sager
- Department of Pharmacology, Faculty of Medicine, Institute of Medical Biology, University of Tromsø, NB 9037, Tromsø, Norway.
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Boadu E, Sager G. Reconstitution of ATP-dependent cGMP transport into proteoliposomes by membrane proteins from human erythrocytes. Scandinavian Journal of Clinical and Laboratory Investigation 2004; 64:41-8. [PMID: 15025427 DOI: 10.1080/00365510410003895] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The cellular efflux of cGMP from human erythrocytes has previously been characterized in functional studies. The purpose of the present study was to find membrane proteins with the ability to restore ATP-dependent uptake of cGMP into proteoliposomes. Human erythrocyte membranes were solubilized with CHAPS (3-([3-cholamidopropyl]dimethylammonio)-1-propanesulfonate) and gel filtration gave three protein fractions with the ability to restore active transport. Only two of these fractions were retained on a lentil lectin column. By using these two purification steps, active transport was 11 times higher in the first fraction compared to the original material and SDS-PAGE showed the presence of proteins with sizes of 145 kDa and 165 kDa. The second fraction gave 20 times higher active transport after purification and comprised proteins with sizes of 145 kDa and 180 kDa. At present three members of the MRP (multi-resistance associated protein) family have been detected in human erythrocytes: MRPI, MRP4 and MRP5. The last two proteins have been shown to transport cyclic nucleotides. The present findings are compatible with MRP4 as the 145 kDa protein, MRP5 as the 165 kDa protein and MRP1 as the 180 kDa protein. However, the 145 kDa protein could also be SMRP (short multi-resistance protein), the gene splice variant of MRP5. Immunoprecipitation of MRP5 from CHAPS-solubilized extract reduced active transport and specific binding by about 45% and 40%, respectively. This shows that MRP5 is an important cGMP-transporting protein in human erythrocytes.
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Affiliation(s)
- E Boadu
- Department of Pharmacology, Institute of Medical Biology, Medical Faculty, University of Tromsø, Norway
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Pedraza CE, Baltrons MA, Heneka MT, García A. Interleukin-1 beta and lipopolysaccharide decrease soluble guanylyl cyclase in brain cells: NO-independent destabilization of protein and NO-dependent decrease of mRNA. J Neuroimmunol 2004; 144:80-90. [PMID: 14597101 DOI: 10.1016/j.jneuroim.2003.08.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We previously showed that soluble guanylyl cyclase (sGC) is down-regulated in astroglial cells after exposure to LPS. Here, we show that this effect is not mediated by released IL-1beta but that this cytokine is also able to decrease NO-dependent cGMP accumulation in a time- and concentration-dependent manner. The effect of IL-1beta is receptor-mediated, mimicked by tumor necrosis factor-alpha and involves a decrease in sGC activity and protein. IL-1beta and LPS decrease the half-life of the sGC beta1 subunit by a NO-independent but transcription- and translation-dependent mechanism. Additionally, both agents induce a NO-dependent decrease of sGC subunit mRNA. Decreased sGC subunit protein and mRNA levels are also observed in adult rat brain after focal injection of IL-1beta or LPS.
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Affiliation(s)
- Carlos E Pedraza
- Institute of Biotechnology and Biomedicine V. Villar Palasi, and Department of Biochemistry and Molecular Biology, Autonomous University of Barcelona, 08193 Bellaterra, Spain
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Connor TJ, O'Sullivan J, Nolan Y, Kelly JP. Inhibition of constitutive nitric oxide production increases the severity of lipopolysaccharide-induced sickness behaviour: a role for TNF-alpha. Neuroimmunomodulation 2003; 10:367-78. [PMID: 12907844 DOI: 10.1159/000071478] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2003] [Accepted: 04/25/2003] [Indexed: 11/19/2022] Open
Abstract
Administration of bacterial lipopolysaccharide (LPS) to rodents induces hypophagia, body weight loss and hypolocomotion, a constellation of symptoms collectively referred to as 'sickness behaviour'. We examined the role of the gaseous transmitter nitric oxide (NO) in mediating LPS-induced sickness behaviour in rats. Treatment with the non-selective NO synthase (NOS) inhibitor N(G)-nitro-L-arginine (L-NA) (20 mg/kg; i.p.) increased the severity of LPS-induced sickness behaviour in rats, suggesting that endogenous NO does not act as a mediator of LPS-induced sickness behaviour, but may rather have a protective role, acting in an inhibitory feedback manner to limit LPS-induced sickness. To evaluate the role of the different NOS isoforms in this response, we examined the effect of the neuronal NOS inhibitor, 7-nitroindazole (7-NI; 25 and 50 mg/kg; i.p.), and the inducible NOS inhibitor, aminoguanidine (AGN; 50 and 100 mg/kg; i.p.). Neither 7-NI nor AGN significantly altered LPS-induced sickness behaviour. Therefore, it is likely that the endothelial isoform of NOS mediates the effect of L-NA on LPS-induced sickness behaviour. As pro-inflammatory cytokines are mediators of LPS-induced sickness behaviour, we examined the effect of L-NA (20 mg/kg; i.p.) on LPS-induced interleukin (IL)-1beta, IL-6 and tumour necrosis factor (TNF)-alpha production. L-NA increased LPS-induced TNF-alpha without significantly altering IL-1beta or IL-6 production. Moreover, pre-treatment with the TNF-alpha inhibitor pentoxyfilline (25 mg/kg; i.p.) largely reversed the augmenting effect of L-NA on LPS-induced sickness behaviour, suggesting that the ability of L-NA to increase TNF-alpha production underpinned its ability to increase the severity of sickness. In conclusion, L-NA increases the severity of LPS-induced sickness behaviour, most likely by blocking the tonic inhibitory action of constitutively produced NO on TNF-alpha production.
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Affiliation(s)
- Thomas J Connor
- Department of Pharmacology, National University of Ireland, Galway, Ireland.
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Wielinga PR, van der Heijden I, Reid G, Beijnen JH, Wijnholds J, Borst P. Characterization of the MRP4- and MRP5-mediated transport of cyclic nucleotides from intact cells. J Biol Chem 2003; 278:17664-71. [PMID: 12637526 DOI: 10.1074/jbc.m212723200] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclic nucleotides are known to be effluxed from cultured cells or isolated tissues. Two recently described members of the multidrug resistance protein family, MRP4 and MRP5, might be involved in this process, because they transport the 3',5'-cyclic nucleotides, cAMP and cGMP, into inside-out membrane vesicles. We have investigated cGMP and cAMP efflux from intact HEK293 cells overexpressing MRP4 or MRP5. The intracellular production of cGMP and cAMP was stimulated with the nitric oxide releasing compound sodium nitroprusside and the adenylate cyclase stimulator forskolin, respectively. MRP4- and MRP5-overexpressing cells effluxed more cGMP and cAMP than parental cells in an ATP-dependent manner. In contrast to a previous report we found no glutathione requirement for cyclic nucleotide transport. Transport increased proportionally with intracellular cyclic nucleotide concentrations over a calculated range of 20-600 microm, indicating low affinity transport. In addition to several classic inhibitors of organic anion transport, prostaglandins A(1) and E(1), the steroid progesterone and the anti-cancer drug estramustine all inhibited cyclic nucleotide efflux. The efflux mediated by MRP4 and MRP5 did not lead to a proportional decrease in the intracellular cGMP or cAMP levels but reduced cGMP by maximally 2-fold over the first hour. This was also the case when phosphodiesterase-mediated cyclic nucleotide hydrolysis was inhibited by 3-isobutyl-1-methylxanthine, conditions in which efflux was maximal. These data indicate that MRP4 and MRP5 are low affinity cyclic nucleotide transporters that may at best function as overflow pumps, decreasing steep increases in cGMP levels under conditions where cGMP synthesis is strongly induced and phosphodiesterase activity is limiting.
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Affiliation(s)
- Peter R Wielinga
- Division of Molecular Biology and Center for Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands
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Wellard J, Rapp M, Hamprecht B, Verleysdonk S. Atrial natriuretic peptides elevate cyclic GMP levels in primary cultures of rat ependymal cells. Neurochem Res 2003; 28:225-33. [PMID: 12608696 DOI: 10.1023/a:1022373032239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to examine the effect of atrial natriuretic peptides on primary cultures of ependymal cells, as measured by changes in intracellular levels of cyclic GMP. Incubation of ependymal cells with rat atrial natriuretic peptide-(1-28) (rANP) elicited a 30-fold increase in ependymal cGMP content within 1 min and more than a 100-fold increase within 10 min to a plateau value of approximately 30 pmol/mg protein. The C-type natriuretic peptide (CNP) elicited a similar increase in cGMP levels; however the maximal effect was observed within 1 min and the levels subsequently dropped by 90% to a low plateau within 10 min. A comparison of the concentration-response curves for rANP, human ANP-(1-28) (hANP) and CNP showed that rANP, hANP and CNP had similar effects, with regards to elevation of cGMP levels at high concentrations, but with differing EC50 values. These results demonstrate the presence of a heterogenous population of functional ANP receptors i n cultured ependymalcells suggesting that ANP may regulate specific ependymal cell activity.
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Affiliation(s)
- John Wellard
- Physiologisch-chemisches Institut der Universität, Hoppe-Seyler-Str. 4, D-72076 Tübingen, Germany
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Hirrlinger J, König J, Dringen R. Expression of mRNAs of multidrug resistance proteins (Mrps) in cultured rat astrocytes, oligodendrocytes, microglial cells and neurones. J Neurochem 2002; 82:716-9. [PMID: 12153495 DOI: 10.1046/j.1471-4159.2002.01082.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Multidrug resistance proteins (Mrps) are ATP-driven export pumps that mediate the export of organic anions from cells. So far only little information is available on expression and physiological functions of Mrps in brain. The expression of mRNAs of six Mrp paralogs in rat brain, as well as in rat cultures enriched for neurones, astrocytes, oligodendrocytes and microglial cells, was studied by qualitative and semiquantitative RT-PCR analysis. In adult rat brain as well as in neural cell cultures the mRNAs coding for Mrp1, Mrp3, Mrp4 and Mrp5 were detected. Semiquantitative analysis revealed that the mRNAs coding for Mrp1 and Mrp5 were more abundant in the four cell culture types than mRNAs of the other Mrps. mRNAs coding for Mrp3 and Mrp4 were found at significant levels in cultured astrocytes and microglial cells, whereas cultures of neurones and oligodendrocytes contained only marginal quantities of these mRNAs. Putative physiological functions of Mrps in brain cells are discussed.
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