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Peters CH, Singh RK, Langley AA, Nichols WG, Ferris HR, Jeffrey DA, Proenza C, Bankston JR. LRMP inhibits cAMP potentiation of HCN4 channels by disrupting intramolecular signal transduction. eLife 2024; 12:RP92411. [PMID: 38652113 PMCID: PMC11037915 DOI: 10.7554/elife.92411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024] Open
Abstract
Lymphoid restricted membrane protein (LRMP) is a specific regulator of the hyperpolarization-activated cyclic nucleotide-sensitive isoform 4 (HCN4) channel. LRMP prevents cAMP-dependent potentiation of HCN4, but the interaction domains, mechanisms of action, and basis for isoform-specificity remain unknown. Here, we identify the domains of LRMP essential for this regulation, show that LRMP acts by disrupting the intramolecular signal transduction between cyclic nucleotide binding and gating, and demonstrate that multiple unique regions in HCN4 are required for LRMP isoform-specificity. Using patch clamp electrophysiology and Förster resonance energy transfer (FRET), we identified the initial 227 residues of LRMP and the N-terminus of HCN4 as necessary for LRMP to associate with HCN4. We found that the HCN4 N-terminus and HCN4-specific residues in the C-linker are necessary for regulation of HCN4 by LRMP. Finally, we demonstrated that LRMP-regulation can be conferred to HCN2 by addition of the HCN4 N-terminus along with mutation of five residues in the S5 region and C-linker to the cognate HCN4 residues. Taken together, these results suggest that LRMP inhibits HCN4 through an isoform-specific interaction involving the N-terminals of both proteins that prevents the transduction of cAMP binding into a change in channel gating, most likely via an HCN4-specific orientation of the N-terminus, C-linker, and S4-S5 linker.
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Affiliation(s)
- Colin H Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Rohit K Singh
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
- Skaggs School of Pharmacy, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Avery A Langley
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - William G Nichols
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Hannah R Ferris
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Danielle A Jeffrey
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - John R Bankston
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
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Peters CH, Singh RK, Langley AA, Nichols WG, Ferris HR, Jeffrey DA, Proenza C, Bankston JR. LRMP inhibits cAMP potentiation of HCN4 channels by disrupting intramolecular signal transduction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.29.555242. [PMID: 37693562 PMCID: PMC10491135 DOI: 10.1101/2023.08.29.555242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Lymphoid restricted membrane protein (LRMP) is a specific regulator of the hyperpolarization-activated cyclic nucleotide-sensitive isoform 4 (HCN4) channel. LRMP prevents cAMP-dependent potentiation of HCN4 but the interaction domains, mechanisms of action, and basis for isoform-specificity remain unknown. Here we identify the domains of LRMP essential for regulation. We show that LRMP acts by disrupting the intramolecular signal transduction between cyclic nucleotide binding and gating. And we demonstrate that multiple unique regions in HCN4 are required for LRMP isoform-specificity. Using patch clamp electrophysiology and Förster resonance energy transfer (FRET), we showed that the initial 227 residues of LRMP and the N-terminus of HCN4 are necessary for LRMP to interact with HCN4. We found that the HCN4 N-terminus and HCN4-specific residues in the C-linker are necessary for regulation of HCN4 by LRMP. And we demonstrate that LRMP-regulation can be conferred to HCN2 by addition of the HCN4 N-terminus along with mutation of 5 residues in the S5 region and C-linker to the cognate HCN4 residues. Taken together, these results suggest that LRMP inhibits HCN4 through an isoform-specific interaction involving the N-terminals of both proteins that prevents the transduction of cAMP binding into a change in channel gating via an HCN4-specific orientation of the N-terminus, C-linker, and S4-S5 linker.
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Affiliation(s)
- Colin H Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
| | - Rohit K Singh
- Skaggs School of Pharmacy, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 E. Montview Boulevard, Aurora, CO 80045
| | - Avery A Langley
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
| | - William G Nichols
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
| | - Hannah R Ferris
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
| | - Danielle A Jeffrey
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, 12631 E. 17 Avenue, Aurora, CO 80045
| | - John R Bankston
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, 12800 E. 19 Avenue, Aurora, CO 80045
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Prüschenk S, Majer M, Schlossmann J. Novel Functional Features of cGMP Substrate Proteins IRAG1 and IRAG2. Int J Mol Sci 2023; 24:9837. [PMID: 37372987 DOI: 10.3390/ijms24129837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
The inositol triphosphate-associated proteins IRAG1 and IRAG2 are cGMP kinase substrate proteins that regulate intracellular Ca2+. Previously, IRAG1 was discovered as a 125 kDa membrane protein at the endoplasmic reticulum, which is associated with the intracellular Ca2+ channel IP3R-I and the PKGIβ and inhibits IP3R-I upon PKGIβ-mediated phosphorylation. IRAG2 is a 75 kDa membrane protein homolog of IRAG1 and was recently also determined as a PKGI substrate. Several (patho-)physiological functions of IRAG1 and IRAG2 were meanwhile elucidated in a variety of human and murine tissues, e.g., of IRAG1 in various smooth muscles, heart, platelets, and other blood cells, of IRAG2 in the pancreas, heart, platelets, and taste cells. Hence, lack of IRAG1 or IRAG2 leads to diverse phenotypes in these organs, e.g., smooth muscle and platelet disorders or secretory deficiency, respectively. This review aims to highlight the recent research regarding these two regulatory proteins to envision their molecular and (patho-)physiological tasks and to unravel their functional interplay as possible (patho-)physiological counterparts.
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Affiliation(s)
- Sally Prüschenk
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Michael Majer
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Jens Schlossmann
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany
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de Oliveira MG, Passos GR, de Gomes EDT, Leonardi GR, Zapparoli A, Antunes E, Mónica FZ. Inhibition of multidrug resistance proteins by MK571 restored the erectile function in obese mice through cGMP accumulation. Andrology 2023; 11:611-620. [PMID: 36375168 DOI: 10.1111/andr.13340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 09/09/2022] [Accepted: 11/06/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Intracellular levels of cyclic nucleotides can also be controlled by the action of multidrug resistance protein types 4 (MRP4) and 5 (MRP5). To date, no studies evaluated the role of their inhibition in an animal model of erectile dysfunction (ED). OBJECTIVES To evaluate the effect of a 2-week treatment with MK571, an inhibitor of the efflux of cyclic nucleotides in the ED of obese mice. MATERIALS AND METHODS Mice were divided in three groups: (i) lean, (ii) obese, and (iii) obese + MK571. The corpus cavernosum (CC) were isolated, and concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), and tadalafil in addition to electrical field stimulation (EFS) were carried out in phenylephrine pre-contracted tissues. Expression of ABCC4 and ABCC5, intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the protein levels for pVASPSer157 and pVASPSer239 , and the intracavernous pressure (ICP) were also determined. The intracellular and extracellular (supernatant) ratios in CC from obese and lean stimulated with a cGMP-increasing substance (BAY 58-2667) in the absence and presence of MK571 (20 μM, 30 min) were also assessed. RESULTS The treatment with MK571 completely reversed the lower relaxing responses induced by EFS, ACh, SNP, and tadalafil observed in obese mice CC in comparison with untreated obese mice. Cyclic GMP and p-VASPSer239 expression were significantly reduced in CC from obese groups. MK571 promoted a sixfold increase in cGMP without interfering in the protein expression of p-VASPSer239 . Neither the cAMP levels nor p-VASPSer157 were altered in MK571-treated animals. The ICP was ∼50% lower in obese than in the lean mice; however, the treatment with MK571 fully reversed this response. Expressions of ABCC4 and ABCC5 were not different between groups. The intra/extracellular ratio of cGMP was similar in CC from obese and lean mice stimulated with BAY 58-2667. CONCLUSIONS The MRPs inhibition by MK571 favored the accumulation of cGMP in the smooth muscle cells, thus improving the smooth muscle relaxation and the erectile function in obese mice.
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Affiliation(s)
- Mariana Gonçalves de Oliveira
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Gabriela Reolon Passos
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Erick de Toledo de Gomes
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Guilherme Ruiz Leonardi
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Adriana Zapparoli
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Edson Antunes
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Fabiola Zakia Mónica
- Department of Translation Medicine (Pharmacology area), Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Murali M, Turner SR, Belke DD, Cole WC, MacDonald JA. Smoothelin-like 1 knockout mice display sex-dependent alterations in blood flow and cardiac function. Can J Physiol Pharmacol 2023; 101:27-40. [PMID: 36342379 DOI: 10.1139/cjpp-2022-0172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Smoothelin-like 1 (SMTNL1) modulates the contractile performance of smooth muscle and thus has a key role in vascular homeostasis. Elevated vascular tone, recognized as a contributor to the development of progressive cardiac dysfunction, was previously found with SMTNL1 deletion. In this study, we assessed cardiac morphology and function of male and female, wild-type (Smtnl1+/+) and global SMTNL1 knockout (Smtnl1-/-) mice at 10 weeks of age. Gross dissection revealed distinct cardiac morphology only in males; Smtnl1-/- hearts were significantly smaller than Smtnl1+/+, but the left ventricle (LV) proportion of heart mass was greater. Male Smtnl1-/- mice also displayed increased ejection fraction and fractional shortening, as well as elevated aortic and pulmonary flow velocities. The impact of cardiac stress with pressure overload by transverse aortic constriction (TAC) was examined in male mice. With TAC banding, systolic function was preserved, but the LV filling pressure was selectively elevated due to relaxation impairment. Smtnl1-/- mice displayed higher early/passive filling velocity of LV/early mitral annulus velocity ratio (E/E' ratio) and myocardial performance index along with a prolonged isovolumetric relaxation time. Taken together, the findings support a novel, sex-dimorphic role for SMTNL1 in modulating cardiac structure and function of mice.
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Affiliation(s)
- Megha Murali
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine,University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Sara R Turner
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine,University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Darrell D Belke
- Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, 1403-29 Street NWCalgary, AB T2N 2T9, Canada
| | - William C Cole
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Justin A MacDonald
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine,University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
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Suvorava T, Metry S, Pick S, Kojda G. Alterations in endothelial nitric oxide synthase activity and their relevance to blood pressure. Biochem Pharmacol 2022; 205:115256. [DOI: 10.1016/j.bcp.2022.115256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 12/15/2022]
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Pereira da Silva EA, Martín-Aragón Baudel M, Navedo MF, Nieves-Cintrón M. Ion channel molecular complexes in vascular smooth muscle. Front Physiol 2022; 13:999369. [PMID: 36091375 PMCID: PMC9459047 DOI: 10.3389/fphys.2022.999369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 11/30/2022] Open
Abstract
Ion channels that influence membrane potential and intracellular calcium concentration control vascular smooth muscle excitability. Voltage-gated calcium channels (VGCC), transient receptor potential (TRP) channels, voltage (KV), and Ca2+-activated K+ (BK) channels are key regulators of vascular smooth muscle excitability and contractility. These channels are regulated by various signaling cues, including protein kinases and phosphatases. The effects of these ubiquitous signaling molecules often depend on the formation of macromolecular complexes that provide a platform for targeting and compartmentalizing signaling events to specific substrates. This manuscript summarizes our current understanding of specific molecular complexes involving VGCC, TRP, and KV and BK channels and their contribution to regulating vascular physiology.
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Foong D, Liyanage L, Zhou J, Zarrouk A, Ho V, O'Connor MD. Single-cell RNA sequencing predicts motility networks in purified human gastric interstitial cells of Cajal. Neurogastroenterol Motil 2022; 34:e14303. [PMID: 34913225 DOI: 10.1111/nmo.14303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/25/2021] [Accepted: 11/17/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Gastrointestinal (GI) motility disorders affect millions of people worldwide, yet they remain poorly treated in part due to insufficient knowledge of the molecular networks controlling GI motility. Interstitial cells of Cajal (ICC) are critical GI pacemaker cells, and abnormalities in ICC are implicated in GI motility disorders. Two cell surface proteins, KIT and ANO1, are used for identifying ICC. However, difficulties accessing human tissue and the low frequency of ICC in GI tissues have meant human ICC are insufficiently characterized. Here, a range of characterization assays including single-cell RNA sequencing (scRNA-seq) was performed using KIT+ CD45- CD11B- primary human gastric ICC to better understand networks controlling human ICC biology. METHODS Excess sleeve gastrectomy tissues were dissected; ICC were analyzed by immunofluorescence, fluorescence-activated cell sorting (FACSorting), real-time PCR, mass spectrometry, and scRNA-seq. KEY RESULTS Immunofluorescence identified ANO1+ /KIT+ cells throughout the gastric muscle. Compared to the FACSorted negative cells, PCR showed the KIT+ CD45- CD11B- ICC were enriched 28-fold in ANO1 expression (p < 0.01). scRNA-seq analysis of the KIT- CD45+ CD11B+ and KIT+ CD45- CD11B- ICC revealed separate clusters of immune cells and ICC (respectively); cells in the ICC cluster expressed critical GI motility genes (eg, CAV1 and PRKG1). The scRNA-seq data for these two cell clusters predicted protein interaction networks consistent with immune cell and ICC biology, respectively. CONCLUSIONS & INFERENCES The single-cell transcriptome of purified KIT+ CD45- CD11B- human gastric ICC presented here provides new molecular insights and hypotheses into evolving models of GI motility. This knowledge will provide an improved framework to investigate targeted therapies for GI motility disorders.
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Affiliation(s)
- Daphne Foong
- School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia
| | - Liwan Liyanage
- School of Computing, Data and Mathematical Sciences, Western Sydney University, Campbelltown, New South Wales, Australia
| | - Jerry Zhou
- School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia
| | - Ali Zarrouk
- Campbelltown Private Hospital, Campbelltown, New South Wales, Australia
| | - Vincent Ho
- School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia.,Campbelltown Private Hospital, Campbelltown, New South Wales, Australia
| | - Michael D O'Connor
- School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia
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Peters CH, Singh RK, Bankston JR, Proenza C. Regulation of HCN Channels by Protein Interactions. Front Physiol 2022; 13:928507. [PMID: 35795651 PMCID: PMC9251338 DOI: 10.3389/fphys.2022.928507] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022] Open
Abstract
Hyperpolarization-activated, cyclic nucleotide-sensitive (HCN) channels are key regulators of subthreshold membrane potentials in excitable cells. The four mammalian HCN channel isoforms, HCN1-HCN4, are expressed throughout the body, where they contribute to diverse physiological processes including cardiac pacemaking, sleep-wakefulness cycles, memory, and somatic sensation. While all HCN channel isoforms produce currents when expressed by themselves, an emerging list of interacting proteins shape HCN channel excitability to influence the physiologically relevant output. The best studied of these regulatory proteins is the auxiliary subunit, TRIP8b, which binds to multiple sites in the C-terminus of the HCN channels to regulate expression and disrupt cAMP binding to fine-tune neuronal HCN channel excitability. Less is known about the mechanisms of action of other HCN channel interaction partners like filamin A, Src tyrosine kinase, and MinK-related peptides, which have a range of effects on HCN channel gating and expression. More recently, the inositol trisphosphate receptor-associated cGMP-kinase substrates IRAG1 and LRMP (also known as IRAG2), were discovered as specific regulators of the HCN4 isoform. This review summarizes the known protein interaction partners of HCN channels and their mechanisms of action and identifies gaps in our knowledge.
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Affiliation(s)
- Colin H. Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Rohit K. Singh
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - John R. Bankston
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- *Correspondence: Catherine Proenza,
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Prüschenk S, Schlossmann J. Function of IRAG2 Is Modulated by NO/cGMP in Murine Platelets. Int J Mol Sci 2022; 23:ijms23126695. [PMID: 35743138 PMCID: PMC9223716 DOI: 10.3390/ijms23126695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/08/2022] [Accepted: 06/14/2022] [Indexed: 01/27/2023] Open
Abstract
Inositol 1,4,5-triphosphate receptor-associated 2 (IRAG2) is a type II membrane protein located at the endoplasmic reticulum. It is a homologue of inositol 1,4,5-triphosphate receptor-associated cGMP kinase substrate 1 (IRAG1), a substrate protein of cGMP-dependent protein kinase I (PKGI), and is among others expressed in platelets. Here, we studied if IRAG2 is also located in platelets and might be a substrate protein of PKGI. IRAG2 was detected in platelets of IRAG2-WT animals but not in those of IRAG2-KO animals. Next, we validated by co-immunoprecipitation studies that IRAG2 is associated with IP3R1-3. No direct stable interaction with PKGIβ or with IRAG1 was observed. Phosphorylation of IRAG2 in murine platelets using a Ser/Thr-specific phospho-antibody was found in vitro and ex vivo upon cGMP stimulation. To gain insight into the function of IRAG2, platelet aggregation studies were performed using thrombin and collagen as agonists for treatment of isolated IRAG2-WT or IRAG2-KO platelets. Interestingly, platelet aggregation was reduced in the absence of IRAG2. Pretreatment of wild type or IRAG2-KO platelets with sodium nitroprusside (SNP) or 8-pCPT-cGMP revealed a further reduction in platelet aggregation in the absence of IRAG2. These results show that IRAG2 is a substrate of PKGI in murine platelets. Furthermore, our results indicate that IRAG2 is involved in the induction of thrombin- or collagen-induced platelet aggregation and that this effect is enhanced by cGMP-dependent phosphorylation of IRAG2. As IRAG1 was previously shown to inhibit platelet aggregation in a cGMP-dependent manner, it can be speculated that IRAG2 exerts an opposing function and might be an IRAG1 counterpart in murine platelets.
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Islam BN, Sharman SK, Hou Y, Wang R, Ashby J, Li H, Liu K, Vega KJ, Browning DD. Type-2 cGMP-dependent protein kinase suppresses proliferation and carcinogenesis in the colon epithelium. Carcinogenesis 2022; 43:584-593. [PMID: 35188962 PMCID: PMC9234760 DOI: 10.1093/carcin/bgac022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 02/13/2022] [Accepted: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
A large body of evidence has demonstrated that cyclic-guanosine monophosphate (cGMP), signaling has anti-tumor effects that might be used for colon cancer prevention. The tumor-suppressive mechanism and the signaling components downstream of cGMP remain largely unknown. The present study has characterized the expression of cGMP-dependent protein kinases (PKG1, PKG2) in normal and cancerous tissue from human colon. PKG1 was detected in both normal and tumor tissue, where it localized exclusively to the lamina propria and stroma (respectively). In contrast, PKG2 localized specifically to the epithelium where its expression decreased markedly in tumors compared to matched normal tissue. Neither PKG isoform was detected at the RNA or protein level in established colon cancer cell lines. To test for a potential tumor-suppressor role of PKG2 in the colon epithelium, Prkg2 knockout (KO) mice were subjected to azoxymethane/dextran sulfate-sodium (AOM/DSS) treatment. PKG2 deficiency was associated with crypt hyperplasia (Ki67) and almost twice the number of polyps per mouse as wild-type (WT) siblings. In vitro culture of mouse colon epithelium as organoids confirmed that PKG2 was the only isoform expressed, and it was detected in both proliferating and differentiating epithelial compartments. Colon organoids derived from Prkg2 KO mice proliferated more rapidly and exhibited a reduced ability to differentiate compared to WT controls. Taken together our results highlight PKG2 as the central target of cGMP in the colon, where it suppresses carcinogenesis by controlling proliferation in an epithelial-cell intrinsic manner.
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Affiliation(s)
- Bianca N Islam
- Department of Internal Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah K Sharman
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yali Hou
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Rui Wang
- Department of Surgery, Case Western Reserve University, Cleveland, OH, USA
| | - Justin Ashby
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Honglin Li
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kebin Liu
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kenneth J Vega
- Department of Medicine, Section of Gastroenterology and Hepatology, Augusta University, Augusta, GA, USA
| | - Darren D Browning
- To whom correspondence should be addressed. Tel: +1 706 7219526; Fax: +1 706 7216608;
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Sanders KM, Baker SA, Drumm BT, Kurahashi M. Ca 2+ Signaling Is the Basis for Pacemaker Activity and Neurotransduction in Interstitial Cells of the GI Tract. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:229-241. [PMID: 36587162 DOI: 10.1007/978-3-031-05843-1_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Years ago gastrointestinal motility was thought to be due to interactions between enteric nerves and smooth muscle cells (SMCs) in the tunica muscularis. Thus, regulatory mechanisms controlling motility were either myogenic or neurogenic. Now we know that populations of interstitial cells, c-Kit+ (interstitial cells of Cajal or ICC), and PDGFRα+ cells (formerly "fibroblast-like" cells) are electrically coupled to SMCs, forming the SIP syncytium. Pacemaker and neurotransduction functions are provided by interstitial cells through Ca2+ release from the endoplasmic reticulum (ER) and activation of Ca2+-activated ion channels in the plasma membrane (PM). ICC express Ca2+-activated Cl- channels encoded by Ano1. When activated, Ano1 channels produce inward current and, therefore, depolarizing or excitatory effects in the SIP syncytium. PDGFRα+ cells express Ca2+-activated K+ channels encoded by Kcnn3. These channels generate outward current when activated and hyperpolarizing or membrane-stabilizing effects in the SIP syncytium. Inputs from enteric and sympathetic neurons regulate Ca2+ transients in ICC and PDGFRα+ cells, and currents activated in these cells conduct to SMCs and regulate contractile behaviors. ICC also serve as pacemakers, generating slow waves that are the electrophysiological basis for gastric peristalsis and intestinal segmentation. Pacemaker types of ICC express voltage-dependent Ca2+ conductances that organize Ca2+ transients, and therefore Ano1 channel openings, into clusters that define the amplitude and duration of slow waves. Ca2+ handling mechanisms are at the heart of interstitial cell function, yet little is known about what happens to Ca2+ dynamics in these cells in GI motility disorders.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA.
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
| | - Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
| | - Masaaki Kurahashi
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA.,Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Iowa, Iowa, Iowa City, USA
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PDE-Mediated Cyclic Nucleotide Compartmentation in Vascular Smooth Muscle Cells: From Basic to a Clinical Perspective. J Cardiovasc Dev Dis 2021; 9:jcdd9010004. [PMID: 35050214 PMCID: PMC8777754 DOI: 10.3390/jcdd9010004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular diseases are important causes of mortality and morbidity worldwide. Vascular smooth muscle cells (SMCs) are major components of blood vessels and are involved in physiologic and pathophysiologic conditions. In healthy vessels, vascular SMCs contribute to vasotone and regulate blood flow by cyclic nucleotide intracellular pathways. However, vascular SMCs lose their contractile phenotype under pathological conditions and alter contractility or signalling mechanisms, including cyclic nucleotide compartmentation. In the present review, we focus on compartmentalized signaling of cyclic nucleotides in vascular smooth muscle. A deeper understanding of these mechanisms clarifies the most relevant axes for the regulation of vascular tone. Furthermore, this allows the detection of possible changes associated with pathological processes, which may be of help for the discovery of novel drugs.
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Prüschenk S, Majer M, Schreiber R, Schlossmann J. IRAG2 Interacts with IP 3-Receptor Types 1, 2, and 3 and Regulates Intracellular Ca 2+ in Murine Pancreatic Acinar Cells. Int J Mol Sci 2021; 22:ijms222413409. [PMID: 34948204 PMCID: PMC8707672 DOI: 10.3390/ijms222413409] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 01/18/2023] Open
Abstract
The inositol 1,4,5-triphosphate receptor-associated 2 (IRAG2) is also known as Jaw1 or lymphoid-restricted membrane protein (LRMP) and shares homology with the inositol 1,4,5-triphosphate receptor-associated cGMP kinase substrate 1 (IRAG1). IRAG1 interacts with inositol trisphosphate receptors (IP3 receptors /IP3R) via its coiled-coil domain and modulates Ca2+ release from intracellular stores. Due to the homology of IRAG1 and IRAG2, especially in its coiled-coil domain, it is possible that IRAG2 has similar interaction partners like IRAG1 and that IRAG2 also modulates intracellular Ca2+ signaling. In our study, we localized IRAG2 in pancreatic acinar cells of the exocrine pancreas, and we investigated the interaction of IRAG2 with IP3 receptors and its impact on intracellular Ca2+ signaling and exocrine pancreatic function, like amylase secretion. We detected the interaction of IRAG2 with different subtypes of IP3R and altered Ca2+ release in pancreatic acinar cells from mice lacking IRAG2. IRAG2 deficiency decreased basal levels of intracellular Ca2+, suggesting that IRAG2 leads to activation of IP3R under unstimulated basal conditions. Moreover, we observed that loss of IRAG2 impacts the secretion of amylase. Our data, therefore, suggest that IRAG2 modulates intracellular Ca2+ signaling, which regulates exocrine pancreatic function.
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Affiliation(s)
- Sally Prüschenk
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (S.P.); (M.M.)
| | - Michael Majer
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (S.P.); (M.M.)
| | - Rainer Schreiber
- Institute of Physiology, University of Regensburg, 93040 Regensburg, Germany;
| | - Jens Schlossmann
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (S.P.); (M.M.)
- Correspondence: ; Tel.: +49-941-943-4770
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15
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Ali S, Solano AS, Gonzales AL, Thakore P, Krishnan V, Yamasaki E, Earley S. Nitric Oxide Signals Through IRAG to Inhibit TRPM4 Channels and Dilate Cerebral Arteries. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab051. [PMID: 34734188 PMCID: PMC8557268 DOI: 10.1093/function/zqab051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/12/2023]
Abstract
Nitric oxide (NO) relaxes vascular smooth muscle cells (SMCs) and dilates blood vessels by increasing intracellular levels of cyclic guanosine monophosphate (cGMP), which stimulates the activity of cGMP-dependent protein kinase (PKG). However, the vasodilator mechanisms downstream of PKG remain incompletely understood. Here, we found that transient receptor potential melastatin 4 (TRPM4) cation channels, which are activated by Ca2+ released from the sarcoplasmic reticulum (SR) through inositol triphosphate receptors (IP3Rs) under native conditions, are essential for SMC membrane depolarization and vasoconstriction. We hypothesized that signaling via the NO/cGMP/PKG pathway causes vasodilation by inhibiting TRPM4. We found that TRPM4 currents activated by stretching the plasma membrane or directly activating IP3Rs were suppressed by exogenous NO or a membrane-permeable cGMP analog, the latter of which also impaired IP3R-mediated release of Ca2+ from the SR. The effects of NO on TRPM4 activity were blocked by inhibition of soluble guanylyl cyclase or PKG. Notably, upon phosphorylation by PKG, IRAG (IP3R-associated PKG substrate) inhibited IP3R-mediated Ca2+ release, and knockdown of IRAG expression diminished NO-mediated inhibition of TRPM4 activity and vasodilation. Using superresolution microscopy, we found that IRAG, PKG, and IP3Rs form a nanoscale signaling complex on the SR of SMCs. We conclude that NO/cGMP/PKG signaling through IRAG inhibits IP3R-dependent activation of TRPM4 channels in SMCs to dilate arteries. SIGNIFICANCE STATEMENT Nitric oxide is a gaseous vasodilator produced by endothelial cells that is essential for cardiovascular function. Although NO-mediated signaling pathways have been intensively studied, the mechanisms by which they relax SMCs to dilate blood vessels remain incompletely understood. In this study, we show that NO causes vasodilation by inhibiting the activity of Ca2+-dependent TRPM4 cation channels. Probing further, we found that NO does not act directly on TRPM4 but instead initiates a signaling cascade that inhibits its activation by blocking the release of Ca2+ from the SR. Thus, our findings reveal the essential molecular pathways of NO-induced vasodilation-a fundamental unresolved concept in cardiovascular physiology.
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Affiliation(s)
| | | | - Albert L Gonzales
- Department of Physiology and Cell Biology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Vivek Krishnan
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
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16
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Nitric Oxide: From Gastric Motility to Gastric Dysmotility. Int J Mol Sci 2021; 22:ijms22189990. [PMID: 34576155 PMCID: PMC8470306 DOI: 10.3390/ijms22189990] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/27/2022] Open
Abstract
It is known that nitric oxide (NO) plays a key physiological role in the control of gastrointestinal (GI) motor phenomena. In this respect, NO is considered as the main non-adrenergic, non-cholinergic (NANC) inhibitory neurotransmitter responsible for smooth muscle relaxation. Moreover, many substances (including hormones) have been reported to modulate NO production leading to changes in motor responses, further underlying the importance of this molecule in the control of GI motility. An impaired NO production/release has indeed been reported to be implicated in some GI dysmotility. In this article we wanted to focus on the influence of NO on gastric motility by summarizing knowledge regarding its role in both physiological and pathological conditions. The main role of NO on regulating gastric smooth muscle motor responses, with particular reference to NO synthases expression and signaling pathways, is discussed. A deeper knowledge of nitrergic mechanisms is important for a better understanding of their involvement in gastric pathophysiological conditions of hypo- or hyper-motility states and for future therapeutic approaches. A possible role of substances which, by interfering with NO production, could prove useful in managing such motor disorders has been advanced.
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17
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Längst N, Adler J, Schweigert O, Kleusberg F, Cruz Santos M, Knauer A, Sausbier M, Zeller T, Ruth P, Lukowski R. Cyclic GMP-Dependent Regulation of Vascular Tone and Blood Pressure Involves Cysteine-Rich LIM-Only Protein 4 (CRP4). Int J Mol Sci 2021; 22:9925. [PMID: 34576086 PMCID: PMC8466836 DOI: 10.3390/ijms22189925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/09/2021] [Accepted: 08/25/2021] [Indexed: 01/14/2023] Open
Abstract
The cysteine-rich LIM-only protein 4 (CRP4), a LIM-domain and zinc finger containing adapter protein, has been implicated as a downstream effector of the second messenger 3',5'-cyclic guanosine monophosphate (cGMP) pathway in multiple cell types, including vascular smooth muscle cells (VSMCs). VSMCs and nitric oxide (NO)-induced cGMP signaling through cGMP-dependent protein kinase type I (cGKI) play fundamental roles in the physiological regulation of vascular tone and arterial blood pressure (BP). However, it remains unclear whether the vasorelaxant actions attributed to the NO/cGMP axis require CRP4. This study uses mice with a targeted deletion of the CRP4 gene (CRP4 KO) to elucidate whether cGMP-elevating agents, which are well known for their vasorelaxant properties, affect vessel tone, and thus, BP through CRP4. Cinaciguat, a NO- and heme-independent activator of the NO-sensitive (soluble) guanylyl cyclase (NO-GC) and NO-releasing agents, relaxed both CRP4-proficient and -deficient aortic ring segments pre-contracted with prostaglandin F2α. However, the magnitude of relaxation was slightly, but significantly, increased in vessels lacking CRP4. Accordingly, CRP4 KO mice presented with hypotonia at baseline, as well as a greater drop in systolic BP in response to the acute administration of cinaciguat, sodium nitroprusside, and carbachol. Mechanistically, loss of CRP4 in VSMCs reduced the Ca2+-sensitivity of the contractile apparatus, possibly involving regulatory proteins, such as myosin phosphatase targeting subunit 1 (MYPT1) and the regulatory light chain of myosin (RLC). In conclusion, the present findings confirm that the adapter protein CRP4 interacts with the NO-GC/cGMP/cGKI pathway in the vasculature. CRP4 seems to be part of a negative feedback loop that eventually fine-tunes the NO-GC/cGMP axis in VSMCs to increase myofilament Ca2+ desensitization and thereby the maximal vasorelaxant effects attained by (selected) cGMP-elevating agents.
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Affiliation(s)
- Natalie Längst
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Julia Adler
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Olga Schweigert
- Cardiovascular Systems Medicine and Molecular Translation, University Center of Cardiovascular Science, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; (O.S.); (T.Z.)
- DZHK, German Center for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany
| | - Felicia Kleusberg
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Melanie Cruz Santos
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Amelie Knauer
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Matthias Sausbier
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Tanja Zeller
- Cardiovascular Systems Medicine and Molecular Translation, University Center of Cardiovascular Science, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; (O.S.); (T.Z.)
- DZHK, German Center for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, 72076 Tuebingen, Germany; (N.L.); (J.A.); (F.K.); (M.C.S.); (A.K.); (M.S.)
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Loss of PKGIβ/IRAG1 Signaling Causes Anemia-Associated Splenomegaly. Int J Mol Sci 2021; 22:ijms22115458. [PMID: 34064290 PMCID: PMC8196906 DOI: 10.3390/ijms22115458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 01/24/2023] Open
Abstract
Inositol 1,4,5-triphosphate receptor-associated cGMP kinase substrate 1 (IRAG1) is a substrate protein of the NO/cGMP-signaling pathway and forms a ternary complex with the cGMP-dependent protein kinase Iβ (PKGIβ) and the inositol triphosphate receptor I (IP3R-I). Functional studies about IRAG1 exhibited that IRAG1 is specifically phosphorylated by the PKGIβ, regulating cGMP-mediated IP3-dependent Ca2+-release. IRAG1 is widely distributed in murine tissues, e.g., in large amounts in smooth muscle-containing tissues and platelets, but also in lower amounts, e.g., in the spleen. The NO/cGMP/PKGI signaling pathway is important in several organ systems. A loss of PKGI causes gastrointestinal disorders, anemia and splenomegaly. Due to the similar tissue distribution of the PKGIβ to IRAG1, we investigated the pathophysiological functions of IRAG1 in this context. Global IRAG1-KO mice developed gastrointestinal bleeding, anemia-associated splenomegaly and iron deficiency. Additionally, Irag1-deficiency altered the protein levels of some cGMP/PKGI signaling proteins—particularly a strong decrease in the PKGIβ—in the colon, spleen and stomach but did not change mRNA-expression of the corresponding genes. The present work showed that a loss of IRAG1 and the PKGIβ/IRAG1 signaling has a crucial function in the development of gastrointestinal disorders and anemia-associated splenomegaly. Furthermore, global Irag1-deficient mice are possible in vivo model to investigate PKGIβ protein functions.
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Mitri F, Bersano A, Hervé D, Kraemer M. Cutaneous manifestations in Moyamoya angiopathy: A review. Eur J Neurol 2021; 28:1784-1793. [PMID: 33486780 DOI: 10.1111/ene.14754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Moyamoya angiopathy (MA) is a progressive cerebrovascular disease with a poorly understood pathophysiology. It is mainly characterized by progressive bilateral stenosis of the terminal intracranial part of the supraclinoid internal carotid arteries and the proximal parts of the middle and anterior cerebral arteries. This results in early-onset ischemic or hemorrhagic strokes. The disease may be idiopathic (known as Moyamoya disease) or associated with other heritable or acquired conditions, including type 1 neurofibromatosis or other RASopathies, sickle cell disease, Down syndrome, or autoimmune disorders (known as Moyamoya syndrome). Apart from the brain, other organ manifestations including cutaneous ones have also been described in MA patients. MATERIALS AND METHODS A literature research on PubMed was performed for articles mentioning the cutaneous association in MA and published between 1994 and October 2020. CONCLUSION The present review summarizes the cutaneous associations as well as the coincidental dermatological findings seen in MA patients. Those include changes in the epidermis, dermis, or skin appendages for example café-au-lait spots, hypomelanosis of Ito, livedo racemosa, hemangiomas, premature graying of hair, chilblains etc.
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Affiliation(s)
- Fouad Mitri
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Anna Bersano
- Cerebrovascular Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Dominique Hervé
- CERVCO Centre de Référence des maladies Vasculaires rares du Cerveau et de l'Oeil, Hôpital Lariboisière, Paris, France
| | - Markus Kraemer
- Department of Neurology, Alfried Krupp von Bohlen und Halbach Hospital, Essen, Germany.,Department of Neurology, Heinrich Heine University Hospital, Düsseldorf, Germany
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20
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Koehler K, Hmida D, Schlossmann J, Landgraf D, Reisch N, Schuelke M, Huebner A. Homozygous mutation in murine retrovirus integration site 1 gene associated with a non-syndromic form of isolated familial achalasia. Neurogastroenterol Motil 2020; 32:e13923. [PMID: 32573102 DOI: 10.1111/nmo.13923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/18/2020] [Accepted: 05/25/2020] [Indexed: 01/23/2023]
Abstract
BACKGROUND Achalasia is a condition characterized by impaired function of esophageal motility and incomplete relaxation of the lower esophagus sphincter, causing dysphagia and regurgitation. Rare cases of early-onset achalasia appear often in combination with further symptoms in a syndromic form as an inherited disease. METHODS Whole genome sequencing was used to investigate the genetic basis of isolated achalasia in a family of Tunisian origin. We analyzed the function of the affected protein with immunofluorescence and affinity chromatography study. KEY RESULTS A homozygous nonsense mutation was detected in murine retrovirus integration site 1 (MRVI1) gene (Human Genome Organisation Gene Nomenclature Committee (HGNC) approved gene symbol: IRAG1) encoding the inositol 1,4,5-trisphosphate receptor 1 (IP3 R1)-associated cyclic guanosine monophosphate (cGMP) kinase substrate (IRAG). Sanger sequencing confirmed co-segregation of the mutation with the disease. Sequencing of the entire MRVI1 gene in 35 additional patients with a syndromic form of achalasia did not uncover further cases with MRVI1 mutations. Immunofluorescence analysis of transfected COS7 cells revealed GFP-IRAG with the truncating mutation p.Arg112* (transcript variant 1) or p.Arg121* (transcript variant 2) to be mislocalized in the cytoplasm and the nucleus. Co-transfection with cGMP-dependent protein kinase 1 isoform β (cGK1β) depicted a partial mislocalization of cGK1β due to mislocalized truncated IRAG. Isolation of protein complexes revealed that the truncation of this protein causes the loss of the interaction domain of IRAG with cGK1β. CONCLUSIONS & INFERENCES In individuals with an early onset of achalasia without further accompanying symptoms, MRVI1 mutations should be considered as the disease-causing defect.
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Affiliation(s)
- Katrin Koehler
- Medizinische Fakultät Carl Gustav Carus, Children's Hospital, Technische Universität Dresden, Dresden, Germany
| | - Dorra Hmida
- Department of Medical Genetics, Anatomy and Cytology, Farhat Hached Hospital, Sousse, Tunisia
| | - Jens Schlossmann
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Dana Landgraf
- Medizinische Fakultät Carl Gustav Carus, Children's Hospital, Technische Universität Dresden, Dresden, Germany
| | - Nicole Reisch
- Medizinische Klinik und Poliklinik IV, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Angela Huebner
- Medizinische Fakultät Carl Gustav Carus, Children's Hospital, Technische Universität Dresden, Dresden, Germany
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Reina-Torres E, De Ieso ML, Pasquale LR, Madekurozwa M, van Batenburg-Sherwood J, Overby DR, Stamer WD. The vital role for nitric oxide in intraocular pressure homeostasis. Prog Retin Eye Res 2020; 83:100922. [PMID: 33253900 DOI: 10.1016/j.preteyeres.2020.100922] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/13/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Catalyzed by endothelial nitric oxide (NO) synthase (eNOS) activity, NO is a gaseous signaling molecule maintaining endothelial and cardiovascular homeostasis. Principally, NO regulates the contractility of vascular smooth muscle cells and permeability of endothelial cells in response to either biochemical or biomechanical cues. In the conventional outflow pathway of the eye, the smooth muscle-like trabecular meshwork (TM) cells and Schlemm's canal (SC) endothelium control aqueous humor outflow resistance, and therefore intraocular pressure (IOP). The mechanisms by which outflow resistance is regulated are complicated, but NO appears to be a key player as enhancement or inhibition of NO signaling dramatically affects outflow function; and polymorphisms in NOS3, the gene that encodes eNOS modifies the relation between various environmental exposures and glaucoma. Based upon a comprehensive review of past foundational studies, we present a model whereby NO controls a feedback signaling loop in the conventional outflow pathway that is sensitive to changes in IOP and its oscillations. Thus, upon IOP elevation, the outflow pathway tissues distend, and the SC lumen narrows resulting in increased SC endothelial shear stress and stretch. In response, SC cells upregulate the production of NO, relaxing neighboring TM cells and increasing permeability of SC's inner wall. These IOP-dependent changes in the outflow pathway tissues reduce the resistance to aqueous humor drainage and lower IOP, which, in turn, diminishes the biomechanical signaling on SC. Similar to cardiovascular pathogenesis, dysregulation of the eNOS/NO system leads to dysfunctional outflow regulation and ocular hypertension, eventually resulting in primary open-angle glaucoma.
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Affiliation(s)
| | | | - Louis R Pasquale
- Eye and Vision Research Institute of New York Eye and Ear Infirmary at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London, UK.
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC, USA.
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22
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IRAG1 Deficient Mice Develop PKG1β Dependent Pulmonary Hypertension. Cells 2020; 9:cells9102280. [PMID: 33066124 PMCID: PMC7601978 DOI: 10.3390/cells9102280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 02/07/2023] Open
Abstract
PKGs are serine/threonine kinases. PKG1 has two isoforms-PKG1α and β. Inositol trisphosphate receptor (IP3R)-associated cGMP-kinase substrate 1 (IRAG1) is a substrate for PKG1β. IRAG1 is also known to further interact with IP3RI, which mediates intracellular Ca2+ release. However, the role of IRAG1 in PH is not known. Herein, WT and IRAG1 KO mice were kept under normoxic or hypoxic (10% O2) conditions for five weeks. Animals were evaluated for echocardiographic variables and went through right heart catheterization. Animals were further sacrificed to prepare lungs and right ventricular (RV) for immunostaining, western blotting, and pulmonary artery smooth muscle cell (PASMC) isolation. IRAG1 is expressed in PASMCs and downregulated under hypoxic conditions. Genetic deletion of IRAG1 leads to RV hypertrophy, increase in RV systolic pressure, and RV dysfunction in mice. Absence of IRAG1 in lung and RV have direct impacts on PKG1β expression. Attenuated PKG1β expression in IRAG1 KO mice further dysregulates other downstream candidates of PKG1β in RV. IRAG1 KO mice develop PH spontaneously. Our results indicate that PKG1β signaling via IRAG1 is essential for the homeostasis of PASMCs and RV. Disturbing this signaling complex by deleting IRAG1 can lead to RV dysfunction and development of PH in mice.
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Isoform-specific regulation of HCN4 channels by a family of endoplasmic reticulum proteins. Proc Natl Acad Sci U S A 2020; 117:18079-18090. [PMID: 32647060 DOI: 10.1073/pnas.2006238117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ion channels in excitable cells function in macromolecular complexes in which auxiliary proteins modulate the biophysical properties of the pore-forming subunits. Hyperpolarization-activated, cyclic nucleotide-sensitive HCN4 channels are critical determinants of membrane excitability in cells throughout the body, including thalamocortical neurons and cardiac pacemaker cells. We previously showed that the properties of HCN4 channels differ dramatically in different cell types, possibly due to the endogenous expression of auxiliary proteins. Here, we report the discovery of a family of endoplasmic reticulum (ER) transmembrane proteins that associate with and modulate HCN4. Lymphoid-restricted membrane protein (LRMP, Jaw1) and inositol trisphosphate receptor-associated guanylate kinase substrate (IRAG, Mrvi1, and Jaw1L) are homologous proteins with small ER luminal domains and large cytoplasmic domains. Despite their homology, LRMP and IRAG have distinct effects on HCN4. LRMP is a loss-of-function modulator that inhibits the canonical depolarizing shift in the voltage dependence of HCN4 in response to the binding of cAMP. In contrast, IRAG causes a gain of HCN4 function by depolarizing the basal voltage dependence in the absence of cAMP. The mechanisms of action of LRMP and IRAG are independent of trafficking and cAMP binding, and they are specific to the HCN4 isoform. We also found that IRAG is highly expressed in the mouse sinoatrial node where computer modeling predicts that its presence increases HCN4 current. Our results suggest important roles for LRMP and IRAG in the regulation of cellular excitability, as tools for advancing mechanistic understanding of HCN4 channel function, and as possible scaffolds for coordination of signaling pathways.
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Palmieri O, Mazza T, Bassotti G, Merla A, Tolone S, Biagini T, Cuttitta A, Bossa F, Martino G, Latiano T, Corritore G, Gioffreda D, Palumbo O, Carella M, Panza A, Andriulli A, Latiano A. microRNA-mRNA network model in patients with achalasia. Neurogastroenterol Motil 2020; 32:e13764. [PMID: 31773868 DOI: 10.1111/nmo.13764] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/07/2019] [Accepted: 10/28/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Achalasia is a rare idiopathic disease with a complex etio-pathogenesis still unknown. This study aimed to identify microRNA (miRNA)-mRNA regulatory networks underlying achalasia. METHODS The investigation was performed in tissue specimens from 11 patients and five controls using the microarray technology followed by an integrated bioinformatics analysis. KEY RESULTS One hundred and six miRNAs were significantly up-regulated and 64 were down-regulated in achalasia patients. The expression of the most 10 differential expressed miRNAs (miR-122-5p, miR-133a-3p, miR-504-5p, miR-187-3p, miR-133b, miR-200c-3p, miR-375, miR-200b-5p, miR-200b-3p, and miR203a) was confirmed by droplet digital PCR in an independent cohort. The interactions between the significant miRNAs and their targets uncovered 14 miRNA-mRNA interacting pairs with experimentally predicted genes (ie, FN1, ROCK2, DPYSL2), and 35 pairs with not experimentally target genes (ie, SULF1, MRVI1, PRKG1); all genes were involved in immune cell trafficking, skeletal and muscular system development, nervous system development macro-processes. CONCLUSION & INFERENCES The mRNA-miRNA regulatory networks described in this study provide new insights in the genetic background of the disease, suggesting further investigations in novel pathogenic mechanisms.
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Affiliation(s)
- Orazio Palmieri
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Tommaso Mazza
- Bioinformatics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Gabrio Bassotti
- Department of Medicine, Gastroenterology and Hepatology Section, Santa Maria della Misericordia Hospital, Perugia, Italy
| | - Antonio Merla
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Salvatore Tolone
- Department of Surgery, University of Campania 'Luigi Vanvitelli', Napoli, Italy
| | - Tommaso Biagini
- Bioinformatics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Antonello Cuttitta
- Unit of Thoracic Surgery, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Fabrizio Bossa
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Giuseppina Martino
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Tiziana Latiano
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Giuseppe Corritore
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Domenica Gioffreda
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Orazio Palumbo
- Medical Genetics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Massimo Carella
- Medical Genetics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Anna Panza
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Angelo Andriulli
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Anna Latiano
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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25
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Manoury B, Idres S, Leblais V, Fischmeister R. Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation. Pharmacol Ther 2020; 209:107499. [PMID: 32068004 DOI: 10.1016/j.pharmthera.2020.107499] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca2+ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K+ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.
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Affiliation(s)
- Boris Manoury
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Sarah Idres
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
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26
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Shvedova M, Litvak MM, Roberts JD, Fukumura D, Suzuki T, Şencan İ, Li G, Reventun P, Buys ES, Kim HH, Sakadžić S, Ayata C, Huang PL, Feil R, Atochin DN. cGMP-dependent protein kinase I in vascular smooth muscle cells improves ischemic stroke outcome in mice. J Cereb Blood Flow Metab 2019; 39:2379-2391. [PMID: 31423931 PMCID: PMC6893979 DOI: 10.1177/0271678x19870583] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/18/2019] [Indexed: 11/15/2022]
Abstract
Recent works highlight the therapeutic potential of targeting cyclic guanosine monophosphate (cGMP)-dependent pathways in the context of brain ischemia/reperfusion injury (IRI). Although cGMP-dependent protein kinase I (cGKI) has emerged as a key mediator of the protective effects of nitric oxide (NO) and cGMP, the mechanisms by which cGKI attenuates IRI remain poorly understood. We used a novel, conditional cGKI knockout mouse model to study its role in cerebral IRI. We assessed neurological deficit, infarct volume, and cerebral perfusion in tamoxifen-inducible vascular smooth muscle cell-specific cGKI knockout mice and control animals. Stroke experiments revealed greater cerebral infarct volume in smooth muscle cell specific cGKI knockout mice (males: 96 ± 16 mm3; females: 93 ± 12 mm3, mean±SD) than in all control groups: wild type (males: 66 ± 19; females: 64 ± 14), cGKI control (males: 65 ± 18; females: 62 ± 14), cGKI control with tamoxifen (males: 70 ± 8; females: 68 ± 10). Our results identify, for the first time, a protective role of cGKI in vascular smooth muscle cells during ischemic stroke injury. Moreover, this protective effect of cGKI was found to be independent of gender and was mediated via improved reperfusion. These results suggest that cGKI in vascular smooth muscle cells should be targeted by therapies designed to protect brain tissue against ischemic stroke.
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Affiliation(s)
- Maria Shvedova
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Maxim M Litvak
- Tomsk Polytechnic University, RASA Center, Tomsk, Russian Federation
| | - Jesse D Roberts
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Dai Fukumura
- Department of Radiation Oncology, Edwin L. Steele Laboratories, Massachusetts General Hospital, Boston, MA, USA
| | - Tomoaki Suzuki
- Department of Radiology, Neurovascular Research Laboratory, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - İkbal Şencan
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Ge Li
- Department of Radiology, Neurovascular Research Laboratory, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Paula Reventun
- Department of Biology Systems, School of Medicine, University of Alcalá, Madrid, Spain
| | - Emmanuel S Buys
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Hyung-Hwan Kim
- Department of Radiology, Neurovascular Research Laboratory, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Cenk Ayata
- Department of Radiology, Neurovascular Research Laboratory, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Paul L Huang
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Robert Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Dmitriy N Atochin
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
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Sanders KM, Ward SM. Nitric oxide and its role as a non-adrenergic, non-cholinergic inhibitory neurotransmitter in the gastrointestinal tract. Br J Pharmacol 2019; 176:212-227. [PMID: 30063800 PMCID: PMC6295421 DOI: 10.1111/bph.14459] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/06/2018] [Accepted: 07/12/2018] [Indexed: 12/19/2022] Open
Abstract
NO is a neurotransmitter released from enteric inhibitory neurons and responsible for modulating gastrointestinal (GI) motor behaviour. Enteric neurons express nNOS (NOS1) that associates with membranes of nerve varicosities. NO released from neurons binds to soluble guanylate cyclase in post-junctional cells to generate cGMP. cGMP-dependent protein kinase type 1 (PKG1) is a major mediator but perhaps not the only pathway involved in cGMP-mediated effects in GI muscles based on gene deletion studies. NOS1+ neurons form close contacts with smooth muscle cells (SMCs), interstitial cells of Cajal (ICC) and PDGFRα+ cells, and these cells are electrically coupled (SIP syncytium). Cell-specific gene deletion studies have shown that nitrergic responses are due to mechanisms in SMCs and ICC. Controversy exists about the ion channels and other post-junctional mechanisms that mediate nitrergic responses in GI muscles. Reduced nNOS expression in enteric inhibitory motor neurons and/or reduced connectivity between nNOS+ neurons and the SIP syncytium appear to be responsible for motor defects that develop in diabetes. An overproduction of NO in some inflammatory conditions also impairs normal GI motor activity. This review summarizes recent findings regarding the role of NO as an enteric inhibitory neurotransmitter. LINKED ARTICLES: This article is part of a themed section on Nitric Oxide 20 Years from the 1998 Nobel Prize. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.2/issuetoc.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell BiologyUniversity of Nevada, Reno, School of MedicineRenoNVUSA
| | - Sean M Ward
- Department of Physiology and Cell BiologyUniversity of Nevada, Reno, School of MedicineRenoNVUSA
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28
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Santoro C, Giugliano T, Kraemer M, Torella A, Schwitalla JC, Cirillo M, Melis D, Berlit P, Nigro V, Perrotta S, Piluso G. Whole exome sequencing identifies MRVI1 as a susceptibility gene for moyamoya syndrome in neurofibromatosis type 1. PLoS One 2018; 13:e0200446. [PMID: 30001348 PMCID: PMC6042724 DOI: 10.1371/journal.pone.0200446] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/26/2018] [Indexed: 12/30/2022] Open
Abstract
Background and purpose Moyamoya angiopathy is a progressive cerebral vasculopathy. The p.R4810K substitution in RNF213 has previously been linked to moyamoya disease in Asian populations. When associated with other medical conditions, such as neurofibromatosis type 1, this vasculopathy is frequently reported as moyamoya syndrome. Intriguingly, most cases of moyamoya-complicated neurofibromatosis type 1 have been described in Caucasians, inverting the population ratio observed in Asians, although prevalence of neurofibromatosis type 1 is constant worldwide. Our aim was to investigate whether, among Caucasians, additive genetic factors may contribute to the occurrence of moyamoya in neurofibromatosis type 1. Methods Whole exome sequencing was carried out on an Italian family with moyamoya-complicated neurofibromatosis type 1 to identify putative genetic modifiers independent of the NF1 locus and potentially involved in moyamoya pathogenesis. Results were validated in an unrelated family of German ancestry. Results We identified the p.P186S substitution (rs35857561) in MRVI1 that segregated with moyamoya syndrome in both the Italian and German family. Conclusions The rs35857561 polymorphism in MRVI1 may be a genetic susceptibility factor for moyamoya in European patients with neurofibromatosis type 1. MRVI1 is a functional partner of ITPR1, PRKG1 and GUCY1A3, which are involved in response to nitric oxide. Mutations in GUCY1A3 have been recently linked to a recessive syndromic form of moyamoya with esophageal achalasia.
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Affiliation(s)
- Claudia Santoro
- Dipartimento della Donna, del Bambino e di Chirurgia Generale e Specialistica, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
| | - Teresa Giugliano
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
| | - Markus Kraemer
- Department of Neurology, Alfried Krupp Hospital, Essen, Germany
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
| | - Annalaura Torella
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | | | - Mario Cirillo
- Dipartimento di Scienze Mediche, Chirurgiche, Neurologiche, Metaboliche e dell’Invecchiamento, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
| | - Daniela Melis
- Dipartimento di Pediatria, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Peter Berlit
- Department of Neurology, Alfried Krupp Hospital, Essen, Germany
| | - Vincenzo Nigro
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Silverio Perrotta
- Dipartimento della Donna, del Bambino e di Chirurgia Generale e Specialistica, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giulio Piluso
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy
- * E-mail:
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29
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Lei W, Ni J, Xia X, Jiang M, Bai G. Searching for synergistic calcium antagonists and novel therapeutic regimens for coronary heart disease therapy from a Traditional Chinese Medicine, Suxiao Jiuxin Pill. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1092:220-227. [PMID: 29908471 DOI: 10.1016/j.jchromb.2018.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 12/23/2022]
Abstract
Coronary heart disease is a vital cause of morbidity and mortality worldwide, and calcium channel blockers (CCBs) are important drugs that can be used to treat cardiovascular diseases. Suxiao Jiuxin Pill (SX), a traditional Chinese medicine, is widely used as an emergency drug for coronary heart disease therapy. However, understanding its potential mechanism in intracellular calcium concentration ([Ca2+]i) modulation remains a challenge. To identify the active pharmacological ingredients (APIs) and reveal a novel combination therapy for ameliorating cardiovascular diseases, the ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) combined with a dual-luciferase reporter [Ca2+]i assay system was applied. Ligustrazine, ferulic acid, senkyunolide I, senkyunolide A and ligustilide were identified as potential calcium antagonists in SX, and the combination of ligustrazine and senkyunolide A showed synergetic calcium antagonistic activity. Additionally, the synergetic mechanism was further investigated by live-imaging analysis with the Ca2+ indicator fluo-4/AM by monitoring fluorescence changes. Our results indicated that ligustrazine can block voltage-operated Ca2+ channels (VDCCs) effectively and senkyunolide A can exert an inhibition effect mostly on ryanodine receptors (RYRs) and partly on VDCCs. Finally, an arterial ring assay showed that the combination of ligustrazine and senkyunolide A exerted a better vasodilatation function than using any components alone. In this study, we first revealed that a pair of natural APIs in combination acting on VDCCs and RYRs was more effective on vasodilatation by regulating [Ca2+]i.
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Affiliation(s)
- Wei Lei
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, People's Republic of China
| | - Jianan Ni
- College of Traditional Chinese Medicine, Tianjing University of Traditional Chinese Medicine, Tianjin 300193, People's Republic of China
| | - Xueting Xia
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, People's Republic of China
| | - Min Jiang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, People's Republic of China.
| | - Gang Bai
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, People's Republic of China.
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30
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Wobst J, Schunkert H, Kessler T. Genetic alterations in the NO-cGMP pathway and cardiovascular risk. Nitric Oxide 2018; 76:105-112. [PMID: 29601927 DOI: 10.1016/j.niox.2018.03.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/18/2018] [Accepted: 03/26/2018] [Indexed: 12/18/2022]
Abstract
In the past ten years, several chromosomal loci have been identified by genome-wide association studies to influence the risk of coronary artery disease (CAD) and its risk factors. The GUCY1A3 gene encoding the α1 subunit of the soluble guanylyl cyclase (sGC) resides at one of these loci and has been strongly associated with blood pressure and CAD risk. More recently, further genes in the pathway encoding the endothelial nitric oxide synthase, the phosphodiesterases 3A and 5A, and the inositol 1,4,5-trisphosphate receptor I-associated protein (IRAG), i.e., NOS3, PDE3A, PDE5A, and MRVI1, respectively, were likewise identified as CAD risk genes. In this review, we highlight the genetic findings linking variants in NO-cGMP signaling and cardiovascular disease, discuss the potential underlying mechanisms which might propagate the development of atherosclerosis, and speculate about therapeutic implications.
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Affiliation(s)
- Jana Wobst
- Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Technische Universität München, Munich, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V., partner site Munich Heart Alliance, Munich, Germany
| | - Heribert Schunkert
- Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Technische Universität München, Munich, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V., partner site Munich Heart Alliance, Munich, Germany
| | - Thorsten Kessler
- Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Technische Universität München, Munich, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V., partner site Munich Heart Alliance, Munich, Germany.
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31
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Gheibi S, Jeddi S, Kashfi K, Ghasemi A. Regulation of vascular tone homeostasis by NO and H 2S: Implications in hypertension. Biochem Pharmacol 2018; 149:42-59. [PMID: 29330066 PMCID: PMC5866223 DOI: 10.1016/j.bcp.2018.01.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/05/2018] [Indexed: 02/09/2023]
Abstract
Nitric oxide (NO) and hydrogen sulfide (H2S) are two gasotransmitters that are produced in the vasculature and contribute to the regulation of vascular tone. NO and H2S are synthesized in both vascular smooth muscle and endothelial cells; NO functions primarily through the sGC/cGMP pathway, and H2S mainly through activation of the ATP-dependent potassium channels; both leading to relaxation of vascular smooth muscle cells. A deficit in the NO/H2S homeostasis is involved in the pathogenesis of various cardiovascular diseases, especially hypertension. It is now becoming increasingly clear that there are important interactions between NO and H2S and that have a profound impact on vascular tone and this may provide insights into the new therapeutic interventions. The aim of this review is to provide a better understanding of individual and interactive roles of NO and H2S in vascular biology. Overall, available data indicate that both NO and H2S contribute to vascular (patho)physiology and in regulating blood pressure. In addition, boosting NO and H2S using various dietary sources or donors could be a hopeful therapeutic strategy in the management of hypertension.
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Affiliation(s)
- Sevda Gheibi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center and Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sajad Jeddi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Khosrow Kashfi
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, NY, USA
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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32
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Liu Z, Qi H, Liu B, Liu K, Wu J, Cao H, Zhang J, Yan Y, He Y, Zhang L. Genetic susceptibility to salt-sensitive hypertension in a Han Chinese population: a validation study of candidate genes. Hypertens Res 2017; 40:876-884. [PMID: 28446801 DOI: 10.1038/hr.2017.57] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/01/2017] [Accepted: 03/23/2017] [Indexed: 12/20/2022]
Abstract
Salt-sensitive hypertension is a complex disease associated with genetic factors. This study aimed to identify the association between 29 candidate single-nucleotide polymorphisms and salt-sensitive hypertension in a Han Chinese population. Sixty-three participants with salt-sensitive hypertension and 279 controls with salt-resistant hypertension were recruited. A modified Sullivan's acute oral saline load and diuresis shrinkage test was used to detect blood pressure salt sensitivity. Lifestyle risk factors were obtained via a questionnaire. We used the Sequenom Mass ARRAY Platform to genotype the 29 candidate single-nucleotide polymorphisms, and the cumulative genetic risk score was used to evaluate the joint genetic effect. The frequencies of eight genotypes and five alleles in CYP11B2, PRKG1, ADRB2, FGF5, SLC8A1 and BCAT1 genes differed significantly between the salt-sensitive and salt-resistant hypertension groups. Multiple logistic regression adjusted for age and sex showed that subjects carrying rs7897633-A (PRKG1), rs434082-A (SLC8A1) and rs1042714-G (ADRB2) risk alleles had 1.83-, 2.84- and 2.40-fold increased risk for salt-sensitive hypertension, respectively. Combined risk allele analysis using the cumulative genetic risk score showed that subjects carrying one risk had 2.30-fold increased risk, and those carrying 2-4 risks had 3.32-fold increased risk for salt-sensitive hypertension. Among 29 candidate single-nucleotide polymorphisms, rs7897633-A in PRKG1, rs434082-A in SLC8A1 and rs1042714-G in ADRB2 were significantly associated with salt-sensitive hypertension. A joint effect of single-nucleotide polymorphisms from different pathways contributed to a high risk of salt-sensitive hypertension.
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Affiliation(s)
- Zheng Liu
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Han Qi
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Bin Liu
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Kuo Liu
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Jingjing Wu
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China
| | - Han Cao
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Jie Zhang
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Yuxiang Yan
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Yan He
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
| | - Ling Zhang
- Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China.,Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China
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33
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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Endothelium-Independent Hypoxic Contraction Is Prevented Specifically by Nitroglycerin via Inhibition of Akt Kinase in Porcine Coronary Artery. Stem Cells Int 2015; 2016:2916017. [PMID: 26839558 PMCID: PMC4709768 DOI: 10.1155/2016/2916017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 10/10/2015] [Accepted: 10/13/2015] [Indexed: 11/28/2022] Open
Abstract
Objective. Hypoxia-induced sustained contraction of porcine coronary artery is endothelium-independent and mediated by PI3K/Akt/Rho kinase. Nitroglycerin (NTG) is a vasodilator used to treat angina pectoris and acute heart failure. The present study was to determine the role of NTG in hypoxia-induced endothelium-independent contraction and the underlying mechanism. Methods and Results. Organ chamber technique was used to measure the isometric vessel tension of isolated porcine coronary arteries. Protein levels of phosphorylated and total Akt were determined by western blot. A sustained contraction of porcine coronary arteries induced by hypoxia was significantly reduced by NTG but not by isoproterenol. This contraction was also inhibited by DETA NONOate, 8-Br-cGMP, which can be reversed by ODQ, and Rp-8-Br-PET-cGMPS. The restored contraction was blocked by LY294002. The reduction of Akt-p at Ser-473 by NTG, DETA NONOate, and 8-Br-cGMP was significantly inhibited by ODQ, PKG-I. The decrease in Akt-p level by NTG and 8-Br-cGMP was prevented by calyculin A but not by okadaic acid. Conclusions. These results demonstrated that the endothelium-independent sustained hypoxic vasoconstriction can be prevented by NTG and that the inhibition of PI3K/Akt signaling pathway may be involved.
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Cross Regulation Between cGMP-dependent Protein Kinase and Akt in Vasodilatation of Porcine Pulmonary Artery. J Cardiovasc Pharmacol 2014; 64:452-9. [DOI: 10.1097/fjc.0000000000000137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lies B, Groneberg D, Friebe A. Toward a better understanding of gastrointestinal nitrergic neuromuscular transmission. Neurogastroenterol Motil 2014; 26:901-12. [PMID: 24827638 DOI: 10.1111/nmo.12367] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/21/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND Nitric oxide (NO) is an important inhibitory neurotransmitter in the gastrointestinal (GI) tract. The majority of nitrergic effects are transduced by NO-sensitive guanylyl cyclase (NO-GC) as the receptor for NO, and, thus, mediated by cGMP-dependent mechanisms. Work carried out during the past years has demonstrated NO to be largely involved in GI smooth muscle relaxation and motility. However, detailed investigation of nitrergic signaling has turned out to be complicated as NO-GC was identified in several different GI cell types such as smooth muscle cells, interstitial cells of Cajal and fibroblast-like cells. With regards to nitrergic neurotransmission, special focus has been placed on the role of interstitial cells of Cajal using mutant mice with reduced populations of ICC. Recently, global and cell-specific knockout mice for enzymes participating in nitrergic signaling have been generated providing a suitable approach to further examine the role of NO-mediated signaling in GI smooth muscle. PURPOSE This review discusses the current knowledge on nitrergic mechanisms in gastrointestinal neuromuscular transmission with a focus on genetic models and outlines possible further investigations to gain better understanding on NO-mediated effects in the GI tract.
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Affiliation(s)
- B Lies
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
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Gasheva OY, Gashev AA, Zawieja DC. Cyclic guanosine monophosphate and the dependent protein kinase regulate lymphatic contractility in rat thoracic duct. J Physiol 2013; 591:4549-65. [PMID: 23836689 DOI: 10.1113/jphysiol.2013.258681] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have previously demonstrated a principal role for nitric oxide (NO) in the endothelium/shear-dependent regulation of contractility in rat thoracic duct (TD). In this study we tested the hypothesis that cyclic guanosine monophosphate (cGMP) and the dependent protein kinase (PKG) are central to the intrinsic and extrinsic flow-dependent modulation of lymphatic contractility. Lymphatic diameters and indices of pumping in isolated, cannulated and pressurized segments of rat TD were measured. The influences of increased transmural pressure (1-5 cmH2O) and imposed flow (1-5 cm H2O transaxial pressure gradients) on lymphatic function were studied before and after: (1) inhibition of guanylate cyclase (GC) with and without a NO donor; (2) application of stable cGMP analogue; and (3) inhibition of the cGMP activation of PKG. Additionally, Western blotting and immunofluorescent tissue staining were used to analyse the PKG isoforms expressed in TD. We found that the GC inhibitor ODQ induced changes in TD contractility similar to NO synthase blockade and prevented the relaxation induced by the NO donor S-nitroso-N-acetylpenicillamine. The cGMP analogue, 8-(4-Chlorophenylthio)-guanosine 3,5-cyclic monophosphate sodium salt (8pCPTcGMP), mimicked the extrinsic flow-induced relaxation in a dose-dependent manner, whereas treatment with the cGMP/PKG inhibitor, guanosine 3,5-cyclic monophosphorothioate, 8-(4-chlorophenylthio)-, Rp-isomer, triethylammonium salt (Rp-8-Br-PETcGMPS), eliminated intrinsic flow-dependent relaxation, and largely inhibited extrinsic flow-dependent relaxation. Western blotting demonstrated that both PKG-Iα and -Iβ isoforms are found in TD, with ∼10 times greater expression of the PKG-Iα protein in TD compared with the aorta and vena cava. The PKG-Iβ isoform expressed equally in TD and vena cava, both being ∼2 times higher than that in the aorta. Immunofluorescent labelling of PKG-Iα protein in the wall of rat thoracic duct confirmed its localization inside TD muscle cells. These findings demonstrate that cGMP is critical to the flow-dependent regulation of TD contractility; they also indicate an important involvement of PKG, especially PKG-Iα in these processes and identifies PKG protein as a potential therapeutic target.
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Affiliation(s)
- Olga Yu Gasheva
- O. Y. Gasheva: Department of Medical Physiology, College of Medicine, Cardiovascular Research Institute Division of Lymphatic Biology, Texas A&M Health Science Center, 702 SW H.K. Dodgen Loop, Temple, TX 76504, USA.
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Groneberg D, Lies B, König P, Jäger R, Seidler B, Klein S, Saur D, Friebe A. Cell-specific deletion of nitric oxide-sensitive guanylyl cyclase reveals a dual pathway for nitrergic neuromuscular transmission in the murine fundus. Gastroenterology 2013; 145:188-196. [PMID: 23528627 DOI: 10.1053/j.gastro.2013.03.042] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 02/26/2013] [Accepted: 03/18/2013] [Indexed: 01/29/2023]
Abstract
BACKGROUND & AIMS It is not clear how nitric oxide (NO) released from enteric neurons relaxes gastrointestinal (GI) smooth muscle. In analogy to the vascular system, NO might directly induce relaxation of smooth muscle cells (SMCs) by acting on its receptor, NO-sensitive guanylyl cyclase (NO-GC). Alternatively, intermediate cells, such as the interstitial cells of Cajal (ICCs), might detect nitrergic signals to indirectly regulate smooth muscle tone, and thereby regulate the motor function of the GI tract. We investigated the role of ICCs and SMCs in nitrergic relaxation using mice with cell-specific disruption of the gene encoding the β1 subunit of NO-GC (GUCY1B3). METHODS We created mice that lack NO-GC specifically in SMCs (SM-guanylyl cyclase knockout [GCKO]), ICCs (ICC-GCKO), or both (SM/ICC-GCKO). We investigated the effects of exogenous and endogenous NO on murine fundus using isometric force studies. Total gut transit time was measured to monitor the functional consequences of NO-GC deletion on GI motility in vivo. RESULTS NO-GC is expressed in ICC and SMC. Deletion of the NO receptor from SMCs incompletely reduced NO-induced fundus relaxation, which was hardly affected after ICC-specific deletion. Gut transit time did not change in SM-GCKO or ICC-GCKO mice compared with control mice. However, nitrergic relaxation was not observed in SM/ICC-GCKO mice, which had increased gut transit time compared with controls. CONCLUSIONS In mice, NO-GC is the only NO receptor to relax the fundus; deletion of NO-GC from the combination of SMCs and ICCs blocks nitrergic signaling. Therefore, ICCs and SMCs jointly mediate the relaxant effect of enteric NO.
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Affiliation(s)
- Dieter Groneberg
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
| | - Barbara Lies
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
| | - Peter König
- Institut für Anatomie, Zentrum für medizinische Struktur- und Zellbiologie, Universität zu Lübeck, Lübeck, Germany
| | - Ronald Jäger
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
| | - Barbara Seidler
- II. Medizinische Klinik und Poliklinik, Technische Universität München, München, Germany
| | - Sabine Klein
- II. Medizinische Klinik und Poliklinik, Technische Universität München, München, Germany
| | - Dieter Saur
- II. Medizinische Klinik und Poliklinik, Technische Universität München, München, Germany
| | - Andreas Friebe
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany.
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Held KF, Dostmann WR. Real-time monitoring the spatiotemporal dynamics of intracellular cGMP in vascular smooth muscle cells. Methods Mol Biol 2013; 1020:131-145. [PMID: 23709030 PMCID: PMC4887092 DOI: 10.1007/978-1-62703-459-3_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Real-time and noninvasive imaging of intracellular second messengers in mammalian cells, while -preserving their in vivo phenotype, requires biosensors of exquisite constitution. Here we provide the methodology for utilizing the single wavelength cGMP-biosensor δ-FlincG in aortic vascular smooth muscle cells.
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Affiliation(s)
- Kara F Held
- Department of Pharmacology, Yale University, New Haven, USA
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Abstract
The cGMP-dependent protein kinases (cGK), which belong to the family of serine/threonine kinases, exhibit their diverse functions in cells through interaction with a variety of substrate proteins. Several substrates were identified and the interactions studied using different methods inter alia co-immunoprecipitation (Co-IP) and cGMP-agarose affinity purification. In the following chapter, we will describe the preparation of cell or tissue lysates, the procedures of cGMP-agarose affinity purification and co-immunoprecipitation, and finally the separation and analysis of the protein complexes by SDS-PAGE or mass spectrometry.
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Affiliation(s)
- Katharina Salb
- Pharmakologie und Toxikologie, Institut für Pharmazie, Universität Regensburg, Regensburg, Germany
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Abstract
cGMP-dependent protein kinases (cGK) are serine/threonine kinases that are widely distributed in eukaryotes. Two genes-prkg1 and prkg2-code for cGKs, namely, cGKI and cGKII. In mammals, two isozymes, cGKIα and cGKIβ, are generated from the prkg1 gene. The cGKI isozymes are prominent in all types of smooth muscle, platelets, and specific neuronal areas such as cerebellar Purkinje cells, hippocampal neurons, and the lateral amygdala. The cGKII prevails in the secretory epithelium of the small intestine, the juxtaglomerular cells, the adrenal cortex, the chondrocytes, and in the nucleus suprachiasmaticus. Both cGKs are major downstream effectors of many, but not all, signalling events of the NO/cGMP and the ANP/cGMP pathways. cGKI relaxes smooth muscle tone and prevents platelet aggregation, whereas cGKII inhibits renin secretion, chloride/water secretion in the small intestine, the resetting of the clock during early night, and endochondral bone growth. This chapter focuses on the involvement of cGKs in cardiovascular and non-cardiovascular processes including cell growth and metabolism.
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Affiliation(s)
- Franz Hofmann
- FOR 923, Institut für Pharmakologie und Toxikologie, der Technischen Universität München, Munich, Germany
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Kato M, Blanton R, Wang GR, Judson TJ, Abe Y, Myoishi M, Karas RH, Mendelsohn ME. Direct binding and regulation of RhoA protein by cyclic GMP-dependent protein kinase Iα. J Biol Chem 2012; 287:41342-51. [PMID: 23066013 DOI: 10.1074/jbc.m112.421040] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vascular smooth muscle cell (VSMC) tone is regulated by the state of myosin light chain (MLC) phosphorylation, which is in turn regulated by the balance between MLC kinase and MLC phosphatase (MLCP) activities. RhoA activates Rho kinase, which phosphorylates the regulatory subunit of MLC phosphatase, thereby inhibiting MLC phosphatase activity and increasing contraction and vascular tone. Nitric oxide is an important mediator of VSMC relaxation and vasodilation, which acts by increasing cyclic GMP (cGMP) levels in VSMC, thereby activating cGMP-dependent protein kinase Iα (PKGIα). PKGI is known to phosphorylate Rho kinase, preventing Rho-mediated inhibition of MLC phosphatase, promoting vasorelaxation, although the molecular mechanisms that mediate this are unclear. Here we identify RhoA as a target of activated PKGIα and show further that PKGIα binds directly to RhoA, inhibiting its activation and translocation. In protein pulldown and immunoprecipitation experiments, binding of RhoA and PKGIα was demonstrated via a direct interaction between the amino terminus of RhoA (residues 1-44), containing the switch I domain of RhoA, and the amino terminus of PKGIα (residues 1-59), which includes a leucine zipper heptad repeat motif. Affinity assays using cGMP-immobilized agarose showed that only activated PKGIα binds RhoA, and a leucine zipper mutant PKGIα was unable to bind RhoA even if activated. Furthermore, a catalytically inactive mutant of PKGIα bound RhoA but did not prevent RhoA activation and translocation. Collectively, these results support that RhoA is a PKGIα target and that direct binding of activated PKGIα to RhoA is central to cGMP-mediated inhibition of the VSMC Rho kinase contractile pathway.
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Affiliation(s)
- Mikio Kato
- Molecular Cardiology Research Institute, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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Inoue R, Shi J, Jian Z, Imai Y. Regulation of cardiovascular TRP channel functions along the NO-cGMP-PKG axis. Expert Rev Clin Pharmacol 2012; 3:347-60. [PMID: 22111615 DOI: 10.1586/ecp.10.15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
There is growing body of evidence that nitric oxide (NO)-cGMP-PKG signaling plays a central role in negative regulation of cardiovascular (CV) responses and its disorders through suppressed Ca(2+) dynamics. Other lines of evidence also reveal the stimulatory effects of this signaling on some CV functions. Recently, transient receptor potential (TRP) channels have received much attention as non-voltage-gated Ca(2+) channels involved in CV physiology and pathophysiology. Available information suggests that these channels undergo both inhibition and activation by NO via PKG-mediated phosphorylation and S-nitrosylation, respectively, and also act as upstream regulators to promote endothelial NO production. This review summarizes the roles of NO-cGMP-PKG signaling pathway, particularly in regulating TRP channel functions with their associated physiology and pathophysiology.
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Affiliation(s)
- Ryuji Inoue
- Department of Physiology, Graduate School of Medcial Sciences, Fukuoka University, Fukuoka, Japan.
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Morgado M, Cairrão E, Santos-Silva AJ, Verde I. Cyclic nucleotide-dependent relaxation pathways in vascular smooth muscle. Cell Mol Life Sci 2012; 69:247-66. [PMID: 21947498 PMCID: PMC11115151 DOI: 10.1007/s00018-011-0815-2] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 08/21/2011] [Accepted: 08/23/2011] [Indexed: 02/07/2023]
Abstract
Vascular smooth muscle tone is controlled by a balance between the cellular signaling pathways that mediate the generation of force (vasoconstriction) and release of force (vasodilation). The initiation of force is associated with increases in intracellular calcium concentrations, activation of myosin light-chain kinase, increases in the phosphorylation of the regulatory myosin light chains, and actin-myosin crossbridge cycling. There are, however, several signaling pathways modulating Ca(2+) mobilization and Ca(2+) sensitivity of the contractile machinery that secondarily regulate the contractile response of vascular smooth muscle to receptor agonists. Among these regulatory mechanisms involved in the physiological regulation of vascular tone are the cyclic nucleotides (cAMP and cGMP), which are considered the main messengers that mediate vasodilation under physiological conditions. At least four distinct mechanisms are currently thought to be involved in the vasodilator effect of cyclic nucleotides and their dependent protein kinases: (1) the decrease in cytosolic calcium concentration ([Ca(2+)]c), (2) the hyperpolarization of the smooth muscle cell membrane potential, (3) the reduction in the sensitivity of the contractile machinery by decreasing the [Ca(2+)]c sensitivity of myosin light-chain phosphorylation, and (4) the reduction in the sensitivity of the contractile machinery by uncoupling contraction from myosin light-chain phosphorylation. This review focuses on each of these mechanisms involved in cyclic nucleotide-dependent relaxation of vascular smooth muscle under physiological conditions.
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Affiliation(s)
- Manuel Morgado
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Elisa Cairrão
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - António José Santos-Silva
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Ignacio Verde
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
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Werder AV, Mayr M, Schneider G, Oesterle D, Fritsch RM, Seidler B, Schlossmann J, Hofmann F, Schemann M, Allescher HD, Schmid RM, Saur D. Truncated IRAG variants modulate cGMP-mediated inhibition of human colonic smooth muscle cell contraction. Am J Physiol Cell Physiol 2011; 301:C1445-57. [PMID: 21865585 DOI: 10.1152/ajpcell.00304.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) induces relaxation of colonic smooth muscle cells predominantly by cGMP/cGMP-dependent protein kinase I (cGKI)-induced phosphorylation of the inositol 1,4,5-trisphosphate receptor (IP(3)R)-associated cGMP kinase substrate (IRAG), to block store-dependent calcium signaling. In the present study we analyzed the structure and function of the human IRAG/MRVI1 gene. We describe four unique first exon variants transcribed from individual promoters in diverse human tissues. Tissue-specific alternative splicing with exon skipping and alternative splice donor and acceptor site usage further increases diversity of IRAG mRNA variants that encode for NH(2)- and COOH-terminally truncated proteins. At the functional level, COOH-terminally truncated IRAG variants lacking both the cGKI phosphorylation and the IP(3)RI interaction site counteract cGMP-mediated inhibition of calcium transients and relaxation of human colonic smooth muscle cells. Since COOH-terminally truncated IRAG mRNA isoforms are widely expressed in human tissues, our results point to an important role of IRAG variants as negative modulators of nitric oxide/cGKI-dependent signaling. The complexity of alternative splicing of the IRAG gene impressively demonstrates how posttranscriptional processing generates functionally distinct proteins from a single gene.
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Affiliation(s)
- Alexander von Werder
- II. Medizinische Klinik, Technische Universität München, Ismaninger Strasse 22, Munich, Germany
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Ertl C, Lukowski R, Sigl K, Schlossmann J, Hofmann F, Wegener JW. Kinetics of relaxation by cGMP/cGKI signaling in fundus smooth muscle. Eur J Pharmacol 2011; 670:266-71. [PMID: 21914444 DOI: 10.1016/j.ejphar.2011.07.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/14/2011] [Accepted: 07/30/2011] [Indexed: 01/17/2023]
Abstract
cGMP-dependent kinase I (cGKI) is a major mediator of smooth muscle relaxation and exists in two isoforms, α and β. Both isoforms are supposed to mediate their effects via different intracellular signaling pathways. To verify this concept, the kinetics of relaxation mediated by either isoform was analyzed in gastric fundus smooth muscle from mice. Muscles from mice that express selectively the Iα or Iβ isoform of cGKI in smooth muscle (sm-cGKIα or sm-cGKIβ mice) were compared to muscles from conventional cGKI(-/-) mice. Fundus muscles were contracted by carbachol and then relaxed by 8-Br-cGMP or by electrical field stimulation (EFS). The time course of relaxation by 8-Br-cGMP was not different between muscles from sm-cGKIα and sm-cGKIβ mice. EFS induced a fast transient relaxation in muscles from sm-cGKIα and sm-cGKIβ mice that was blocked by the NO synthase inhibitor L-NAME. Recovery from this relaxation was about 4-times slower in muscles from sm-cGKIα mice than in muscles from sm-cGKIβ mice. The different kinetic of recovery from relaxation after EFS in sm-cGKIα and sm-cGKIβ mice suggests that different signaling pathways exist for each cGKI isoform in vivo in fundus muscles.
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Affiliation(s)
- Claudia Ertl
- FOR923, Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
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cGMP-dependent protein kinases as potential targets for colon cancer prevention and treatment. Future Med Chem 2011; 2:65-80. [PMID: 21426046 DOI: 10.4155/fmc.09.142] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In recent years, several antitumor signaling pathways mediated by the cGMP-dependent protein kinases have been identified in colon cancer cells. This review aims to present the mounting evidence in favor of cGMP/protein kinase G (PKG) signaling as a therapeutic strategy in colon cancer. The homeostatic and tumor suppressive effects of cGMP in the intestine are uncontested, but the signaling details are not understood. PKG is the central cGMP effector, and can block proliferation and tumor angiogenesis by inhibiting β-catenin/TCF and SOX9 signaling. Therapeutic activation of cGMP/PKG offers a promising avenue for the prevention and treatment of colon cancer, but additional preclinical studies are needed to fully understand the potential of this system.
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Abstract
Signaling by nitric oxide (NO) determines several cardiovascular functions including blood pressure regulation, cardiac and smooth muscle hypertrophy, and platelet function. NO stimulates the synthesis of cGMP by soluble guanylyl cyclases and thereby activates cGMP-dependent protein kinases (PKGs), mediating most of the cGMP functions. Hence, an elucidation of the PKG signaling cascade is essential for the understanding of the (patho)physiological aspects of NO. Several PKG signaling pathways were identified, meanwhile regulating the intracellular calcium concentration, mediating calcium desensitization or cytoskeletal rearrangement. During the last decade it emerged that the inositol trisphosphate receptor-associated cGMP-kinase substrate (IRAG), an endoplasmic reticulum-anchored 125-kDa membrane protein, is a main signal transducer of PKG activity in the cardiovascular system. IRAG interacts specifically in a trimeric complex with the PKG1β isoform and the inositol 1,4,5-trisphosphate receptor I and, upon phosphorylation, reduces the intracellular calcium release from the intracellular stores. IRAG motifs for phosphorylation and for targeting to PKG1β and 1,4,5-trisphosphate receptor I were identified by several approaches. The (patho)physiological functions for the regulation of smooth muscle contractility and the inhibition of platelet activation were perceived. In this review, the IRAG recognition, targeting, and function are summarized compared with PKG and several PKG substrates in the cardiovascular system.
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Affiliation(s)
- Jens Schlossmann
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, Regensburg, Germany.
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Groneberg D, König P, Koesling D, Friebe A. Nitric oxide-sensitive guanylyl cyclase is dispensable for nitrergic signaling and gut motility in mouse intestinal smooth muscle. Gastroenterology 2011; 140:1608-17. [PMID: 21277853 DOI: 10.1053/j.gastro.2011.01.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 01/04/2011] [Accepted: 01/13/2011] [Indexed: 12/30/2022]
Abstract
BACKGROUND & AIMS The nitric oxide-guanosine 3',5'-cyclic monophosphate (cGMP) signaling pathway has an important role in the control of smooth muscle tone. NO is produced by NO synthases and acts as a major inhibitory neurotransmitter in the gastrointestinal (GI) tract. The main target, NO-sensitive guanylyl cyclase (NO-GC), is stimulated by NO to produce the intracellular messenger cGMP. We investigated the role of NO-GC in nitrergic relaxation and GI motility. METHODS We tested relaxation of GI smooth muscle in mice that do not express NO-GC or mice with disruption of NO-GC specifically in smooth muscle cells. Different segments of the GI tract (fundus, lower esophageal sphincter, pyloric sphincter, and duodenum) were used in isometric force studies. NO donors and electrical field stimulation were used to assess nitrergic signaling. Whole-gut transit time was measured as an indicator of GI motility. RESULTS Mice that lack NO-GC do not have NO-induced relaxation of GI smooth muscle. Gut transit time was increased, resulting in GI dysfunction. Surprisingly, in mice that lack NO-GC specifically in smooth muscle, NO-induced relaxation was reduced only slightly, and whole-gut transit time was unchanged compared with wild-type mice. CONCLUSIONS Lack of NO-GC in smooth muscle cells does not impair NO-induced relaxation of GI tissues or GI motility. The NO receptor guanylyl cyclase in GI smooth muscle is therefore dispensable for nitrergic signaling in mice.
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Affiliation(s)
- Dieter Groneberg
- Physiologisches Institut, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
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