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Baum O. Expression of neuronal NO synthase α- and β-isoforms in skeletal muscle of mice. Biochem J 2024; 481:601-613. [PMID: 38592741 DOI: 10.1042/bcj20230458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 03/27/2024] [Accepted: 04/09/2024] [Indexed: 04/10/2024]
Abstract
Knowledge of the primary structure of neuronal NO synthase (nNOS) in skeletal muscle is still conflicting and needs further clarification. To elucidate the expression patterns of nNOS isoforms at both mRNA and protein level, systematic reverse transcription (RT)-PCR and epitope mapping by qualitative immunoblot analysis on skeletal muscle of C57/BL6 mice were performed. The ability of the nNOS isoforms to form aggregates was characterized by native low-temperature polyacrylamide electrophoresis (LT-PAGE). The molecular analysis was focused on the rectus femoris (RF) muscle, a skeletal muscle with a nearly balanced ratio of nNOS α- and β-isoforms. RT-PCR amplificates from RF muscles showed exclusive exon-1d mRNA expression, either with or without exon-μ. Epitope mapping demonstrated the simultaneous expression of the nNOS splice variants α/μ, α/non-μ, β/μ and β/non-μ. Furthermore, immunoblotting suggests that the transition between nNOS α- and β-isoforms lies within exon-3. In LT-PAGE, three protein nNOS associated aggregates were detected in homogenates of RF muscle and tibialis anterior muscle: a 320 kDa band containing nNOS α-isoforms, while 250 and 300 kDa bands consist of nNOS β-isoforms that form homodimers or heterodimers with non-nNOS proteins.
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Affiliation(s)
- Oliver Baum
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany
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2
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Hashitani H, Mitsui R, Hirai Y, Tanaka H, Miwa-Nishimura K. Nitrergic inhibition of sympathetic arteriolar constrictions in the female rodent urethra. J Physiol 2024; 602:2199-2226. [PMID: 38656747 DOI: 10.1113/jp285583] [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] [Received: 08/28/2023] [Accepted: 04/08/2024] [Indexed: 04/26/2024] Open
Abstract
During the urine storage phase, tonically contracting urethral musculature would have a higher energy consumption than bladder muscle that develops phasic contractions. However, ischaemic dysfunction is less prevalent in the urethra than in the bladder, suggesting that urethral vasculature has intrinsic properties ensuring an adequate blood supply. Diameter changes in rat or mouse urethral arterioles were measured using a video-tracking system. Intercellular Ca2+ dynamics in arteriolar smooth muscle (SMCs) and endothelial cells were visualised using NG2- and parvalbumin-GCaMP6 mice, respectively. Fluorescence immunohistochemistry was used to visualise the perivascular innervation. In rat urethral arterioles, sympathetic vasoconstrictions were predominantly suppressed by α,β-methylene ATP (10 μM) but not prazosin (1 μM). Tadalafil (100 nM), a PDE5 inhibitor, diminished the vasoconstrictions in a manner reversed by N-ω-propyl-l-arginine hydrochloride (l-NPA, 1 μM), a neuronal NO synthesis (nNOS) inhibitor. Vesicular acetylcholine transporter immunoreactive perivascular nerve fibres co-expressing nNOS were intertwined with tyrosine hydroxylase immunoreactive sympathetic nerve fibres. In phenylephrine (1 μM) pre-constricted rat or mouse urethral arterioles, nerve-evoked vasodilatations or transient SMC Ca2+ reductions were largely diminished by l-nitroarginine (l-NA, 10 μM), a broad-spectrum NOS inhibitor, but not by l-NPA. The CGRP receptor antagonist BIBN-4096 (1 μM) shortened the vasodilatory responses, while atropine (1 μM) abolished the l-NA-resistant transient vasodilatory responses. Nerve-evoked endothelial Ca2+ transients were abolished by atropine plus guanethidine (10 μM), indicating its neurotransmitter origin and absence of non-adrenergic non-cholinergic endothelial NO release. In urethral arterioles, NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions pre- and post-synaptically to restrict arteriolar contractility. KEY POINTS: Despite a higher energy consumption of the urethral musculature than the bladder detrusor muscle, ischaemic dysfunction of the urethra is less prevalent than that of the bladder. In the urethral arterioles, sympathetic vasoconstrictions are predominately mediated by ATP, not noradrenaline. NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions by its pre-synaptic inhibition of sympathetic transmission as well as post-synaptic arteriolar smooth muscle relaxation. Acetylcholine released from parasympathetic nerves contributes to endothelium-dependent, transient vasodilatations, while CGRP released from sensory nerves prolongs NO-mediated vasodilatations. PDE5 inhibitors could be beneficial to maintain and/or improve urethral blood supply and in turn the volume and contractility of urethral musculature.
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Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Retsu Mitsui
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuuna Hirai
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Hidekazu Tanaka
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Kyoko Miwa-Nishimura
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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3
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Tain YL, Hsu CN. The NOS/NO System in Renal Programming and Reprogramming. Antioxidants (Basel) 2023; 12:1629. [PMID: 37627624 PMCID: PMC10451971 DOI: 10.3390/antiox12081629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Nitric oxide (NO) is a gaseous signaling molecule with renoprotective properties. NO can be produced in NO synthase (NOS)-dependent or -independent manners. NO deficiency plays a decisive role in chronic kidney disease (CKD). Kidney development can be affected in response to adverse intrauterine conditions that induce renal programming, thereby raising the risk of developing CKD in adulthood. Conversely, detrimental programming processes could be postponed or halted prior to the onset of CKD by early treatments, namely reprogramming. The current review provides an overview of the NOS/NO research performed in the context of renal programming and reprogramming. NO deficiency has been increasingly found to interact with the different mechanisms behind renal programming, such as oxidative stress, aberrant function of the renin-angiotensin system, disturbed nutrient-sensing mechanisms, dysregulated hydrogen sulfide signaling, and gut microbiota dysbiosis. The supplementation of NOS substrates, the inhibition of asymmetric dimethylarginine (ADMA), the administration of NO donors, and the enhancement of NOS during gestation and lactation have shown beneficial effects against renal programming in preclinical studies. Although human data on maternal NO deficiency and offspring kidney disease are scarce, experimental data indicate that targeting NO could be a promising reprogramming strategy in the setting of renal programming.
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Affiliation(s)
- You-Lin Tain
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan;
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - Chien-Ning Hsu
- Department of Pharmacy, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
- School of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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4
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Solanki K, Rajpoot S, Bezsonov EE, Orekhov AN, Saluja R, Wary A, Axen C, Wary K, Baig MS. The expanding roles of neuronal nitric oxide synthase (NOS1). PeerJ 2022; 10:e13651. [PMID: 35821897 PMCID: PMC9271274 DOI: 10.7717/peerj.13651] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/07/2022] [Indexed: 01/17/2023] Open
Abstract
The nitric oxide synthases (NOS; EC 1.14.13.39) use L-arginine as a substrate to produce nitric oxide (NO) as a by-product in the tissue microenvironment. NOS1 represents the predominant NO-producing enzyme highly enriched in the brain and known to mediate multiple functions, ranging from learning and memory development to maintaining synaptic plasticity and neuronal development, Alzheimer's disease (AD), psychiatric disorders and behavioral deficits. However, accumulating evidence indicate both canonical and non-canonical roles of NOS1-derived NO in several other tissues and chronic diseases. A better understanding of NOS1-derived NO signaling, and identification and characterization of NO-metabolites in non-neuronal tissues could become useful in diagnosis and prognosis of diseases associated with NOS1 expression. Continued investigation on the roles of NOS1, therefore, will synthesize new knowledge and aid in the discovery of small molecules which could be used to titrate the activities of NOS1-derived NO signaling and NO-metabolites. Here, we address the significance of NOS1 and its byproduct NO in modifying pathophysiological events, which could be beneficial in understanding both the disease mechanisms and therapeutics.
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Affiliation(s)
- Kundan Solanki
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Simrol, Indore, India
| | - Sajjan Rajpoot
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Simrol, Indore, India
| | - Evgeny E Bezsonov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Federal State Budgetary Scientific Institution "Petrovsky National Research Centre of Surgery", Moscow, Russia.,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russia.,Department of Biology and General Genetics, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Federal State Budgetary Scientific Institution "Petrovsky National Research Centre of Surgery", Moscow, Russia.,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Rohit Saluja
- Department of Biochemistry, All India Institute of Medical Sciences, Bibinagar, Hyderabad, India
| | - Anita Wary
- Pharmacology and Regenerative Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Cassondra Axen
- Pharmacology and Regenerative Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Kishore Wary
- Pharmacology and Regenerative Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Mirza S Baig
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Simrol, Indore, India
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Smiley R, McCallum R, Showkat Ali M. Decreased Level of Neuropeptide Y Is Associated With Gastroparesis in Male Diabetic Rats. Gastroenterology Res 2021; 13:246-252. [PMID: 33447303 PMCID: PMC7781275 DOI: 10.14740/gr1322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/21/2020] [Indexed: 11/13/2022] Open
Abstract
Background Substance P (SP) and neuropeptide Y (NPY), excitatory and inhibitory neuropeptides, respectively, may impact gastric motility in patients with diabetic mellitus (DM). We investigated these neuropeptide levels, NPY receptors, total nitric oxide synthase (NOS) levels, and neuronal NOS alpha (nNOSα) activation status and levels in streptozotocin-induced type I diabetes in male rats. Methods Rats were grouped based on serum glucose and gastric emptying time: normal untreated control (CM), diabetic (DM) and diabetic gastroparesis (DM + GP). Neuropeptide serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting measured NPY receptors, Y1 and Y2, and nNOSα expression. Low-temperature SDS-PAGE followed by western blotting was used to measure the dimerization of nNOSα. An NOS colorimetric assay kit was used to measure total NOS activity. Results SP levels were significantly decreased (P < 0.05) in DM and DM + GP compared to CM. NPY levels were significantly decreased (P < 0.05) in DM compared to CM, and DM + GP had a more significantly decreased NPY when compared to both DM and CM. Protein levels of neuropeptide receptor Y1 (NPY-Y1) in the smooth muscle of pylorus were significantly increased in DM, but not in DM + GP when compared to CM. Neuropeptide receptor Y2 (NPY-Y2) was not detected. Changes in nNOSα activity and their protein levels, as well as total NOS activity, among the groups were insignificant. Conclusions Increased expression of pylorus NPY-1R and decreased serum NPY are present in diabetes. A more pronounced decreased serum NPY with no NPY-1R upregulation in pyloric smooth muscle is associated with gastroparesis. NPY levels show no relationship with nNOSα levels, their activation status, or total NOS activity in pyloric smooth muscle. These data suggest a pathophysiological role of severely depleted NPY and absence of NPY-Y1 upregulation for gastroparesis phenotype.
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Affiliation(s)
- Rebecca Smiley
- Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA
| | - Richard McCallum
- Department of Internal Medicine, Texas Tech Health Science Center, Paul L. Foster School of Medicine, 4800 Alberta Ave., El Paso, TX 79905-2709, USA
| | - Mohammed Showkat Ali
- Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA
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Abstract
The prevalence of cardiovascular and metabolic disease coupled with kidney dysfunction is increasing worldwide. This triad of disorders is associated with considerable morbidity and mortality as well as a substantial economic burden. Further understanding of the underlying pathophysiological mechanisms is important to develop novel preventive or therapeutic approaches. Among the proposed mechanisms, compromised nitric oxide (NO) bioactivity associated with oxidative stress is considered to be important. NO is a short-lived diatomic signalling molecule that exerts numerous effects on the kidneys, heart and vasculature as well as on peripheral metabolically active organs. The enzymatic L-arginine-dependent NO synthase (NOS) pathway is classically viewed as the main source of endogenous NO formation. However, the function of the NOS system is often compromised in various pathologies including kidney, cardiovascular and metabolic diseases. An alternative pathway, the nitrate-nitrite-NO pathway, enables endogenous or dietary-derived inorganic nitrate and nitrite to be recycled via serial reduction to form bioactive nitrogen species, including NO, independent of the NOS system. Signalling via these nitrogen species is linked with cGMP-dependent and independent mechanisms. Novel approaches to restoring NO homeostasis during NOS deficiency and oxidative stress have potential therapeutic applications in kidney, cardiovascular and metabolic disorders.
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7
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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: 74] [Impact Index Per Article: 14.8] [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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8
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Mosińska P, Jacenik D, Sałaga M, Wasilewski A, Cygankiewicz A, Sibaev A, Mokrowiecka A, Małecka-Panas E, Pintelon I, Storr M, Timmermans JP, Krajewska WM, Fichna J. FABP4 blocker attenuates colonic hypomotility and modulates white adipose tissue-derived hormone levels in mouse models mimicking constipation-predominant IBS. Neurogastroenterol Motil 2018; 30:e13272. [PMID: 29266569 DOI: 10.1111/nmo.13272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/28/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND The role of fatty acid binding protein 4 (FABP4) in lower gastrointestinal (GI) motility is unknown. We aimed to verify the effect of inhibition of FABP4 on GI transit in vivo, and to determine the expression of FABP4 in mouse and human tissues. METHODS Fatty acid binding protein 4 inhibitor, BMS309403, was administered acutely or chronically for 6 and 13 consecutive days and its effect on GI transit was assessed in physiological conditions and in loperamide-induced constipation. Intracellular recordings were made to examine the effects of BMS309403 on colonic excitatory and inhibitory junction potentials. Abdominal pain was evaluated using behavioral pain response. Localization and expression of selected adipokines were determined in the mouse colon and serum using immunohistochemistry and Enzyme-Linked ImmunoSorbent Assay respectively. mRNA expression of FABP4 and selected adipokines in colonic and serum samples from irritable bowel syndrome (IBS) patients and control group were assessed. KEY RESULTS Acute injection of BMS309403 significantly increased GI motility and reversed inhibitory effect of loperamide. BMS309403 did not change colonic membrane potentials. Chronic treatment with BMS309403 increased the number of pain-induced behaviors. In the mouse serum, level of resistin was significantly decreased after acute administration; no changes in adiponectin level were detected. In the human serum, level of adiponectin and resistin, but not of FABP4, were significantly elevated in patients with constipation-IBS (IBS-C). FABP4 mRNA expression was significantly downregulated in the human colon in IBS-C. CONCLUSIONS AND INFERENCES Fatty acid binding protein 4 may be involved in IBS pathogenesis and become a novel target in the treatment of constipation-related diseases.
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Affiliation(s)
- P Mosińska
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - D Jacenik
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - M Sałaga
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - A Wasilewski
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - A Cygankiewicz
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - A Sibaev
- Walter Brendel Center of Experimental Medicine, Ludwig Maximilians University of Munich, Munich, Germany
| | - A Mokrowiecka
- Department of Digestive Tract Disease, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - E Małecka-Panas
- Department of Digestive Tract Disease, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - I Pintelon
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - M Storr
- Walter Brendel Center of Experimental Medicine, Ludwig Maximilians University of Munich, Munich, Germany.,Center of Endoscopy, Stanberg, Germany
| | - J P Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - W M Krajewska
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - J Fichna
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
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Jang DE, Bae JH, Chang YJ, Lee YH, Nam KT, Kim IY, Seong JK, Lee YC, Yeom SC. Neuronal Nitric Oxide Synthase Is a Novel Biomarker for the Interstitial Cells of Cajal in Stress-Induced Diarrhea-Dominant Irritable Bowel Syndrome. Dig Dis Sci 2018; 63:619-627. [PMID: 29372479 DOI: 10.1007/s10620-018-4933-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 01/16/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder involving changes in normal bowel movements. The pathophysiology of IBS is not clearly understood owing to the lack of identifiable pathological abnormalities and reliable biomarkers. AIM The aim of this study was to discover the novel and reliable biomarker for IBS. METHOD In this study, neonatal maternal separation (NMS) stress model was used for the IBS mouse model. Further assessment was conducted with whole gastrointestinal transit test, quantitative RT-PCR, histological examination, and western blot. RESULTS Male pups developed symptoms similar to those of human IBS with diarrhea (IBS-D), such as low-grade inflammation, stool irregularity, and increased bowel motility. NMS stress influenced to the interstitial cells of Cajal (ICC) and induced altered bowel motility, resulting in IBS-D-like symptoms. In addition, we found neuronal nitric oxide synthase (nNOS) to be a novel biomarker for ICC under NMS stress. nNOS expression was only observed in the ICC of the submucosal plexus of IBS-D mice, and the inhibition of nNOS changed the phenotype from IBS-D to IBS with constipation. CONCLUSION Our study demonstrates that early-life stress can influence to ICC and modulate bowel activity and that nNOS might be used as a biomarker for ICC stimulation in IBS.
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Affiliation(s)
- Da Eun Jang
- Graduate School of International Agricultural Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea
| | - Ji Hyun Bae
- Designed Animal and Transplantation Research Institute, Institute of Greenbio Research and Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea
| | - Yoo Jin Chang
- Graduate School of International Agricultural Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea
| | - Yoon Hoo Lee
- Graduate School of International Agricultural Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea
| | - Ki Taek Nam
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 25354, Republic of Korea
| | - Il Yong Kim
- Department of Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
| | - Je Kyung Seong
- Department of Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
| | - Yong Chan Lee
- Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Su Cheong Yeom
- Graduate School of International Agricultural Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea.
- Designed Animal and Transplantation Research Institute, Institute of Greenbio Research and Technology, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Gangwon, 25354, Republic of Korea.
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NOS1 S-nitrosylates PTEN and inhibits autophagy in nasopharyngeal carcinoma cells. Cell Death Discov 2017; 3:17011. [PMID: 28243469 PMCID: PMC5317009 DOI: 10.1038/cddiscovery.2017.11] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/28/2016] [Accepted: 04/15/2016] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a cellular survival mechanism that involves the catabolic degradation of damaged proteins and organelles during periods of metabolic stress, and when overly stimulated, commonly contributes to cell death. Nitric oxide (NO), a potent cellular messenger, participates in a complex mechanism which assists in controlling autophagy. However, the mechanism by which endogenous NO formed by distinct isoforms of nitric oxide synthase (NOS) helps to regulate autophagy in cancer cells remains unclear. Here we report that NOS1 reduces excessive levels of autophagy and promotes the survival of nasopharyngeal carcinoma cells. We found that inhibition of NOS1 increased cell death resulting from siRNA or the use of pharmacologic agents; and this effect was reversed by the autophagy inhibitor, chloroquine. The role of NOS1 in the autophagy process depended on the activation of AKT/mTOR signaling by S-nitrosylation of phosphatase and tensin homolog (PTEN) proteins. The mechanism by which NOS1 modifies PTEN protein might involve a direct interaction between these two molecules. Moreover, in an in vivo study, the NOS1 inhibitor N(G)-nitro-L-arginine methyl ester activated AKT/mTOR signaling and promoted autophagy in xenograph tumors. Our studies demonstrated that NOS1 prevents excessive autophagy via S-nitrosylation of PTEN, and activation of the AKT/mTOR signaling pathway. PTEN and the AKT/mTOR signaling pathway are promising targets for improving the chemotherapeutic treatment of cancer.
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11
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Rosenfeld CR, Chen C, Roy T, Liu XT. Estrogen Selectively Up-Regulates eNOS and nNOS in Reproductive Arteries By Transcriptional Mechanisms. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/s1071-55760300049-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Charles R. Rosenfeld
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | | | | | - Xiao-Tie Liu
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
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12
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Halim MA, Gillberg L, Boghus S, Sundbom M, Karlbom U, Webb DL, Hellström PM. Nitric oxide regulation of migrating motor complex: randomized trial of N(G)-monomethyl-L-arginine effects in relation to muscarinic and serotonergic receptor blockade. Acta Physiol (Oxf) 2015; 215:105-18. [PMID: 26176347 DOI: 10.1111/apha.12554] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 05/28/2015] [Accepted: 07/08/2015] [Indexed: 12/13/2022]
Abstract
AIM The migrating motor complex (MMC) propels contents through the gastrointestinal tract during fasting. Nitric oxide (NO) is an inhibitory neurotransmitter in the gastrointestinal tract. Little is known about how NO regulates the MMC. In this study, the aim was to examine nitrergic inhibition of the MMC in man using N(G)-monomethyl-L-arginine (L-NMMA) in combination with muscarinic receptor antagonist atropine and 5-HT3 receptor antagonist ondansetron. METHODS Twenty-six healthy volunteers underwent antroduodenojejunal manometry for 8 h with saline or NO synthase (NOS) inhibitor L-NMMA randomly injected I.V. at 4 h with or without atropine or ondansetron. Plasma ghrelin, motilin and somatostatin were measured by ELISA. Intestinal muscle strip contractions were investigated for NO-dependent mechanisms using L-NMMA and tetrodotoxin. NOS expression was localized by immunohistochemistry. RESULTS L-NMMA elicited premature duodenojejunal phase III in all subjects but one, irrespective of atropine or ondansetron. L-NMMA shortened MMC cycle length, suppressed phase I and shifted motility towards phase II. Pre-treatment with atropine extended phase II, while ondansetron had no effect. L-NMMA did not change circulating ghrelin, motilin or somatostatin. Intestinal contractions were stimulated by L-NMMA, insensitive to tetrodotoxin. NOS immunoreactivity was detected in the myenteric plexus but not in smooth muscle cells. CONCLUSION Nitric oxide suppresses phase III of MMC independent of muscarinic and 5-HT3 receptors as shown by nitrergic blockade, and acts through a neurocrine disinhibition step resulting in stimulated phase III of MMC independent of cholinergic or 5-HT3 -ergic mechanisms. Furthermore, phase II of MMC is governed by inhibitory nitrergic and excitatory cholinergic, but not 5-HT3 -ergic mechanisms.
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Affiliation(s)
- M A Halim
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - L Gillberg
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - S Boghus
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - M Sundbom
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - U Karlbom
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - D-L Webb
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - P M Hellström
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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13
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Liu X, Liu S, Xu Y, Liu X, Sun D. Bone morphogenetic protein 2 regulates the differentiation of nitrergic enteric neurons by modulating Smad1 signaling in slow transit constipation. Mol Med Rep 2015; 12:6547-54. [PMID: 26352281 PMCID: PMC4626182 DOI: 10.3892/mmr.2015.4297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 08/17/2015] [Indexed: 01/30/2023] Open
Abstract
Bone morphogenetic proteins (BMPs) belong to the transforming growth factor superfamily and have been implicated in chondrogenesis and neuronal differentiation. In order to examine the function of bone morphogenetic protein 2 (BMP‑2) on the differentiation of nitrergic enteric neurons in slow transit constipation (STC), the expression of BMP‑2 and neuronal nitric oxide synthase (nNOS) was investigated in the myenteric nerve plexus in STC and control tissues by immunohistochemical assays. The present study demonstrated that BMP‑2 and nNOS were expressed in the myenteric nerve plexus and their levels were differentially altered in the STC group and control group. In addition, the effect of BMP‑2 on primary myenteric neurons was investigated by measuring the neurite length. The results demonstrated that BMP‑2 regulated the differentiation of primary enteric neurons and increased the length of neurites compared with the control group. In addition, the effect of BMP‑2 on the expression of nNOS was also investigated in primary enteric neurons and the Smad1 signal transduction pathway by western blot analysis, reverse transcription quantitative polymerase chain reaction and immunofluorescence assay. The results suggested that BMP‑2 promoted the expression of nNOS in primary myenteric neurons and induced phosphorylation of Smad1. These data indicate a new role for BMP‑2 as an important transcriptional cofactor that regulates the differentiation of nitrergic enteric neurons through the Smad1 pathway. Intervention of BMP‑2 may be useful for the treatment of STC.
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Affiliation(s)
- Xuliang Liu
- Department of General Surgery, The Second Hospital of Shandong University, Jinan, Shandong 250033, P.R. China
| | - Shangming Liu
- Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
| | - Yanan Xu
- Department of Health Care For Cadre, Qingdao Municipal Hospital, Qingdao, Shandong 266011, P.R. China
| | - Xiuqin Liu
- Department of Internal Pediatrics, Qingdao Municipal Hospital, Qingdao, Shandong 266011, P.R. China
| | - Daqing Sun
- Department of General Surgery, The Second Hospital of Shandong University, Jinan, Shandong 250033, P.R. China
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14
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Fichna J, Poole DP, Veldhuis N, MacEachern SJ, Saur D, Zakrzewski PK, Cygankiewicz AI, Mokrowiecka A, Małecka-Panas E, Krajewska WM, Liedtke W, Steinhoff MS, Timmermans JP, Bunnett NW, Sharkey KA, Storr MA. Transient receptor potential vanilloid 4 inhibits mouse colonic motility by activating NO-dependent enteric neurotransmission. J Mol Med (Berl) 2015; 93:1297-309. [PMID: 26330151 DOI: 10.1007/s00109-015-1336-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/12/2015] [Accepted: 08/17/2015] [Indexed: 01/15/2023]
Abstract
UNLABELLED Recent studies implicate TRPV4 receptors in visceral pain signaling and intestinal inflammation. Our aim was to evaluate the role of TRPV4 in the control of gastrointestinal (GI) motility and to establish the underlying mechanisms. We used immunohistochemistry and PCR to study TRPV4 expression in the GI tract. The effect of TRPV4 activation on GI motility was characterized using in vitro and in vivo motility assays. Calcium and nitric oxide (NO) imaging were performed to study the intracellular signaling pathways. Finally, TRPV4 expression was examined in the colon of healthy human subjects. We demonstrated that TRPV4 can be found on myenteric neurons of the colon and is co-localized with NO synthase (NOS-1). In vitro, the TRPV4 agonist GSK1016790A reduced colonic contractility and increased inhibitory neurotransmission. In vivo, TRPV4 activation slowed GI motility and reduced stool production in mouse models mimicking pathophysiological conditions. We also showed that TRPV4 activation inhibited GI motility by reducing NO-dependent Ca(2+) release from enteric neurons. In conclusion, TRPV4 is involved in the regulation of GI motility in health and disease. KEY MESSAGES • Recent studies implicate TRPV4 in pain signaling and intestinal inflammation. • Our aim was to characterize the role of TRPV4 in the control of GI motility. • We found that TRPV4 activation reduced colonic contractility. • Our studies also showed altered TRPV4 mRNA expression in IBS-C patients. • TRPV4 may be a novel pharmacological target in functional GI diseases.
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Affiliation(s)
- J Fichna
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.,Department of Medicine, Division of Gastroenterology, University of Calgary, Calgary, AB, Canada.,Department of Biochemistry, Medical University of Lodz, Lodz, Poland
| | - D P Poole
- Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - N Veldhuis
- Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
| | - S J MacEachern
- Department of Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - D Saur
- II Medizinische Klinik, Technische Universität München, Munich, Germany
| | - P K Zakrzewski
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - A I Cygankiewicz
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - A Mokrowiecka
- Department of Digestive Tract Diseases, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - E Małecka-Panas
- Department of Digestive Tract Diseases, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - W M Krajewska
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - W Liedtke
- Center for Translational Neuroscience, Duke University, Durham, NC, USA
| | - M S Steinhoff
- Department of Dermatology and Surgery, University of California San Francisco, San Francisco, CA, USA
| | - J-P Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - N W Bunnett
- Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia.,Department of Pharmacology, The University of Melbourne, Parkville, VIC, Australia
| | - K A Sharkey
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.,Department of Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - M A Storr
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Department of Medicine, Division of Gastroenterology, University of Calgary, Calgary, AB, Canada. .,Department of Medicine, Division of Gastroenterology, Ludwig Maximilians University of Munich, Marchioninistrasse 15, 81377, Munich, Germany.
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15
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Sibaev A, Fichna J, Saur D, Yuece B, Timmermans JP, Storr M. Nociceptin effect on intestinal motility depends on opioid-receptor like-1 receptors and nitric oxide synthase co-localization. World J Gastrointest Pharmacol Ther 2015; 6:73-83. [PMID: 26261735 PMCID: PMC4526842 DOI: 10.4292/wjgpt.v6.i3.73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/10/2015] [Accepted: 05/18/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the effect of the opioid-receptor like-1 (ORL1) agonist nociceptin on gastrointestinal (GI) myenteric neurotransmission and motility.
METHODS: Reverse transcriptase - polymerase chain reaction and immunohistochemistry were used to localize nociceptin and ORL1 in mouse tissues. Intracellular electrophysiological recordings of excitatory and inhibitory junction potentials (EJP, IJP) were made in a chambered organ bath. Intestinal motility was measured in vivo.
RESULTS: Nociceptin accelerated whole and upper GI transit, but slowed colonic expulsion in vivo in an ORL1-dependent manner, as shown using [Nphe1]NOC and AS ODN pretreatment. ORL1 and nociceptin immunoreactivity were found on enteric neurons. Nociceptin reduced the EJP and the nitric oxide-sensitive slow IJP in an ORL1-dependent manner, whereas the fast IJP was unchanged. Nociceptin further reduced the spatial spreading of the EJP up to 2 cm.
CONCLUSION: Compounds acting at ORL1 are good candidates for the future treatment of disorders associated with increased colonic transit, such as diarrhea or diarrhea-predominant irritable bowel syndrome.
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16
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Chaudhury A. A Hypothesis for Examining Skeletal Muscle Biopsy-Derived Sarcolemmal nNOSμ as Surrogate for Enteric nNOSα Function. Front Med (Lausanne) 2015; 2:48. [PMID: 26284245 PMCID: PMC4517061 DOI: 10.3389/fmed.2015.00048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/10/2015] [Indexed: 12/13/2022] Open
Abstract
The pathophysiology of gastrointestinal motility disorders is controversial and largely unresolved. This provokes empiric approaches to patient management of these so-called functional gastrointestinal disorders. Preliminary evidence demonstrates that defects in neuronal nitric oxide synthase (nNOS) expression and function, the enzyme that synthesizes nitric oxide (NO), the key inhibitory neurotransmitter mediating mechano-electrical smooth muscle relaxation, is the major pathophysiological basis for sluggishness of oro-aboral transit of luminal contents. This opinion is an ansatz of the potential of skeletal muscle biopsy and examining sarcolemmal nNOSμ to provide complementary insights regarding nNOSα expression, localization, and function within enteric nerve terminals, the site of stimulated de novo NO synthesis. The main basis of this thesis is twofold: (a) the molecular similarity of the structures of nNOS α and μ, similar mechanisms of localizations to “active zones” of nitrergic synthesis, and same mechanisms of electron transfers during NO synthesis and (b) pragmatic difficulty to routinely obtain full-thickness biopsies of gastrointestinal tract, even in patients presenting with the most recalcitrant manifestations of stasis and delayed transit of luminal contents. This opinion attempts to provoke dialog whether this approach is feasible as a surrogate to predict catalytic potential of nNOSα and defects in nitrergic neurotransmission. This discussion makes an assumption that similar molecular mechanisms of nNOS defects shall be operant in both the enteric nerve terminals and the skeletal muscles. These overlaps of skeletal and gastrointestinal dysfunction are largely unknown, thus meriting that the thesis be validated in future by proof-of-principle experiments.
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17
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Becker V, Drabner R, Graf S, Schlag C, Nennstiel S, Buchberger AM, Schmid RM, Saur D, Bajbouj M. New aspects in the pathomechanism and diagnosis of the laryngopharyngeal reflux-clinical impact of laryngeal proton pumps and pharyngeal pH metry in extraesophageal gastroesophageal reflux disease. World J Gastroenterol 2015; 21:982-987. [PMID: 25624734 PMCID: PMC4299353 DOI: 10.3748/wjg.v21.i3.982] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/22/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the laryngeal H+K+-ATPase and pharyngeal pH in patients with laryngopharyngeal reflux (LPR)-symptoms as well as to assess the symptom scores during PPI therapy.
METHODS: Endoscopy was performed to exclude neoplasia and to collect biopsies from the posterior cricoid area (immunohistochemistry and PCR analysis). Immunohistochemical staining was performed with monoclonal mouse antibodies against human H+K+-ATPase. Quantitative real-time RT-PCR for each of the H+K+-ATPase subunits was performed. The pH values were assessed in the aerosolized environment of the oropharynx (DxpH Catheter) and compared to a subsequently applied combined pH/MII measurement.
RESULTS: Twenty patients with LPR symptoms were included. In only one patient, the laryngeal H+K+-ATPase was verified by immunohistochemical staining. In another patient, real-time RT-PCR for each H+K+-ATPase subunit was positive. Fourteen out of twenty patients had pathological results in DxpH, and 6/20 patients had pathological results in pH/MII. Four patients had pathological results in both functional tests. Nine out of twenty patients responded to PPIs.
CONCLUSION: The laryngeal H+K+-ATPase can only be sporadically detected in patients with LPR symptoms and is unlikely to cause the LPR symptoms. Alternative hypotheses for the pathomechanism are needed. The role of pharyngeal pH-metry remains unclear and its use can only be recommended for patients in a research study setting.
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18
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Abstract
The cerebrovascular regulation involves highly complex mechanisms to assure that the brain is perfused at all times. These mechanisms depend on all components of the neurovascular units: neurons, glia, and vascular cells. All these cell types can produce nitric oxide (NO), a powerful vasodilator through different NO synthases. Many studies underlined the key role of NO in the maintenance of resting cerebral blood flow (CBF) as well as in the mechanisms that control cerebrovascular tone: autoregulation and neurovascular coupling. However, although the role of NO in the control of CBF has been largely investigated, the complexity of the NO system and the lack of specific NO synthase inhibitors led to still unresolved questions such as the origin of NO and the pathways by which it controls the vascular tone. In this chapter, the role of NO in the regulation of CBF is critically reviewed and discussed in the context of the neurovascular unit and the general principles of cerebrovascular regulation.
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19
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Aquilano K, Baldelli S, Ciriolo MR. Nuclear recruitment of neuronal nitric-oxide synthase by α-syntrophin is crucial for the induction of mitochondrial biogenesis. J Biol Chem 2013; 289:365-78. [PMID: 24235139 DOI: 10.1074/jbc.m113.506733] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuronal nitric-oxide synthase (nNOS) has various splicing variants and different subcellular localizations. nNOS can be found also in the nucleus; however, its exact role in this compartment is still not completely defined. In this report, we demonstrate that the PDZ domain allows the recruitment of nNOS to nuclei, thus favoring local NO production, nuclear protein S-nitrosylation, and induction of mitochondrial biogenesis. In particular, overexpression of PDZ-containing nNOS (nNOSα) increases S-nitrosylated CREB with consequent augmented binding on cAMP response element consensus sequence on peroxisome proliferator-activated receptor γ co-activator (PGC)-1α promoter. The resulting PGC-1α induction is accompanied by the expression of mitochondrial genes (e.g., TFAM, MtCO1) and increased mitochondrial mass. Importantly, full active nNOS lacking PDZ domain (nNOSβ) does not localize in nuclei and fails in inducing the expression of PGC-1α. Moreover, we substantiate that the mitochondrial biogenesis normally accompanying myogenesis is associated with nuclear translocation of nNOS. We demonstrate that α-Syntrophin, which resides in nuclei of myocytes, functions as the upstream mediator of nuclear nNOS translocation and nNOS-dependent mitochondrial biogenesis. Overall, our results indicate that altered nNOS splicing and nuclear localization could be contributing factors in human muscular diseases associated with mitochondrial impairment.
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Affiliation(s)
- Katia Aquilano
- From the Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy and
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20
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Traini C, Cipriani G, Evangelista S, Santicioli P, Faussone-Pellegrini MS, Vannucchi MG. Chronic treatment with otilonium bromide induces changes in L-type Ca²⁺ channel, tachykinins, and nitric oxide synthase expression in rat colon muscle coat. Neurogastroenterol Motil 2013; 25:e728-39. [PMID: 23901937 DOI: 10.1111/nmo.12197] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/03/2013] [Indexed: 12/20/2022]
Abstract
BACKGROUND Otilonium bromide (OB) is a quaternary ammonium derivative used for the treatment of intestinal hypermotility and is endowed with neurokinin2 receptor (NK2r) antagonist and Ca²⁺ channel blocker properties. Therefore, the possibility that OB might play a role in the neurokinin receptor/Substance-P/nitric oxide (NKr/SP/NO) circuit was investigated after chronic exposition to the drug. METHODS Rats were treated with OB 2-20 mg kg⁻¹ for 10 and 30 days. In the proximal colon, the expression and distribution of muscle NOsynthase 1 (NOS1), NK1r, NK2r, SP and Cav 1.2 subunit (for L-type Ca²⁺ channel) and the spontaneous activity and stimulated responses to NK1r and NK2r agonists were investigated. KEY RESULTS Immunohistochemistry showed a redistribution of NK1r and L-type Ca²⁺ channel in muscle cells with no change of NK2r at 30 days, a significant increase in muscle NOS1 expression at 10 days and a significant decrease in the SP content early in the ganglia and later in the intramuscular nerve fibers. Functional studies showed no change in spontaneous activity but a significant increase in maximal contraction induced by NK1r agonist. CONCLUSIONS & INFERENCES Chronic exposition to OB significantly affects the NKr/SP/NO circuit. The progressive decrease in SP-expression might be the consequence of the persistent presence of OB, the increase of NOS1 expression in muscle cells at 10 days in an attempt to guarantee an adequate NO production, and, at 30 days, the redistribution of the L-type Ca²⁺ channel and NK1r as a sign to compensate the drug channel block by re-cycling both of them. The physiological data suggest NK1r hypersensitivity.
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Affiliation(s)
- C Traini
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Florence, Italy
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21
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Hyndman KA, Boesen EI, Elmarakby AA, Brands MW, Huang P, Kohan DE, Pollock DM, Pollock JS. Renal collecting duct NOS1 maintains fluid-electrolyte homeostasis and blood pressure. Hypertension 2013; 62:91-8. [PMID: 23608660 DOI: 10.1161/hypertensionaha.113.01291] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nitric oxide is a pronatriuretic and prodiuretic factor. The highest renal NO synthase (NOS) activity is found in the inner medullary collecting duct. The collecting duct (CD) is the site of daily fine-tune regulation of sodium balance, and led us to hypothesize that a CD-specific deletion of NOS1 would result in an impaired ability to excrete a sodium load leading to a salt-sensitive blood pressure phenotype. We bred AQP2-CRE mice with NOS1 floxed mice to produce flox control and CD-specific NOS1 knockout (CDNOS1KO) littermates. CDs from CDNOS1KO mice produced 75% less nitrite, and urinary nitrite+nitrate (NOx) excretion was significantly blunted in the knockout genotype. When challenged with high dietary sodium, CDNOS1KO mice showed significantly reduced urine output, sodium, chloride, and NOx excretion, and increased mean arterial pressure relative to flox control mice. In humans, urinary NOx is a newly identified biomarker for the progression of hypertension. These findings reveal that NOS1 in the CD is critical in the regulation of fluid-electrolyte balance, and this new genetic model of CD NOS1 gene deletion will be a valuable tool to study salt-dependent blood pressure mechanisms.
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Affiliation(s)
- Kelly A Hyndman
- Section of Experimental Medicine, Department of Medicine, Georgia Regents University, Augusta, GA 30912, USA
| | | | - Ahmed A Elmarakby
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Mansoura University, Egypt
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22
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Hoshino M, Omura N, Yano F, Tsuboi K, Kashiwagi H, Yanaga K. Immunohistochemical study of the muscularis externa of the esophagus in achalasia patients. Dis Esophagus 2013; 26:14-21. [PMID: 22309323 DOI: 10.1111/j.1442-2050.2011.01318.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The etiology of achalasia is believed to be the neuropathy associated with chronic inflammation of the nerve plexus, but the cause of plexus inflammation is unknown. The purpose of this study was to evaluate the pathophysiology of achalasia by examining the muscularis externa of the esophagus. We used the muscularis externa of the esophagus of 62 patients with achalasia (median 44 years, male : female 32:30) who underwent surgical treatment (achalasia group) and of 10 patients (median 65.5 years, male : female 9:1) who underwent esophagectomy for thoracic esophageal cancer (control group) to perform immunohistochemical staining with S-100, CD43, c-kit (CD117), n-NOS, vasoactive intestinal polypeptide (VIP), and ubiquitin. The cell counts that were positive for S-100, n-NOS, VIP, and ubiquitin were significantly lower in the achalasia group compared with the control group (P < 0.001, P= 0.001, P < 0.001, and P= 0.001, respectively). There were no statistically significant differences with respect to CD43 and c-kit staining (P= 0.586 and P= 0.209, respectively). In conclusion, the pathophysiology of achalasia is therefore considered to be an impaired production of NO and VIP, which both affect interstitial cell of Cajal and smooth muscles, and this impairment is therefore considered to play a role in the pathophysiology of achalasia.
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Affiliation(s)
- M Hoshino
- Department of Surgery, Jikei University School of Medicine, 3-19-18 Nishishinbashi, Minato-ku, Tokyo, Japan.
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23
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Baccari MC, Traini C, Garella R, Cipriani G, Vannucchi MG. Relaxin exerts two opposite effects on mechanical activity and nitric oxide synthase expression in the mouse colon. Am J Physiol Endocrinol Metab 2012; 303:E1142-50. [PMID: 22932783 DOI: 10.1152/ajpendo.00260.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hormone relaxin exerts a variety of functions on the smooth muscle of reproductive and nonreproductive organs, most of which occur through a nitric oxide (NO)-mediated mechanism. In the stomach and ileum, relaxin causes muscle relaxation by modulating the activity and expression of different nitric oxide synthase (NOS) isoforms region-dependently. Nothing is known on the effects of relaxin in the colon, the gut region expressing the highest number of neuronal (n) NOSβ-immunoreactive neurons and mainly involved in motor symptoms of pregnancy and menstrual cycle. Therefore, we studied the effects of relaxin exposure in the mouse proximal colon in vitro evaluating muscle mechanical activity and NOS isoform expression. The functional experiments showed that relaxin decreases muscle tone and increases amplitude of spontaneous contractions; the immunohistochemical results showed that relaxin increases nNOSβ and endothelial (e) NOS expression in the neurons and decreases nNOSα and eNOS expression in the smooth muscle cells (SMC). We hypothesized that, in the colon, relaxin primarily increases the activity and expression of nNOSβ and eNOS in the neurons, causing a reduction of the muscle tone. The downregulation of nNOSα and eNOS expression in the SMC associated with increased muscle contractility could be the consequence of continuous exposue of these cells to the NO of neuronal origin. These findings may help to better understand the physiology of NO in the gastrointestinal tract and the role that the "relaxin-NO" system plays in motor disorders such as functional bowel disease.
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MESH Headings
- Anesthetics, Local/pharmacology
- Animals
- Colon/blood supply
- Colon/cytology
- Colon/innervation
- Colon/metabolism
- Colon, Ascending/cytology
- Colon, Ascending/drug effects
- Colon, Ascending/innervation
- Colon, Ascending/metabolism
- Colon, Transverse/cytology
- Colon, Transverse/drug effects
- Colon, Transverse/innervation
- Colon, Transverse/metabolism
- Enzyme Inhibitors/pharmacology
- Female
- Guanylate Cyclase/antagonists & inhibitors
- In Vitro Techniques
- Interstitial Cells of Cajal/cytology
- Interstitial Cells of Cajal/drug effects
- Interstitial Cells of Cajal/metabolism
- Mechanical Phenomena
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Muscle, Smooth/blood supply
- Muscle, Smooth/cytology
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Synthase Type I/antagonists & inhibitors
- Nitric Oxide Synthase Type I/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/metabolism
- Osmolar Concentration
- Relaxin/metabolism
- Submucous Plexus/cytology
- Submucous Plexus/drug effects
- Submucous Plexus/metabolism
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Affiliation(s)
- M C Baccari
- Department of Physiological Sciences, University of Florence, Florence, Italy
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24
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Gender and estradiol as major factors in the expression and dimerization of nNOSα in rats with experimental diabetic gastroparesis. Dig Dis Sci 2012; 57:2814-25. [PMID: 22684582 DOI: 10.1007/s10620-012-2230-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 05/01/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND The molecular mechanisms of cellular changes responsible for diabetic gastroparesis, primarily seen in middle-aged women, still remain incompletely defined. We hypothesized that a decrease in the expression, dimerization, and post-translational modification of neuronal nitric oxide synthase alpha (nNOSα) is estrogen mediated and responsible for the gender-specific prevalence of this malady. METHODS We induced diabetes by injecting male and female rats with streptozotocin. Male diabetic rats without gastroparesis were then injected with estrogen for 3 weeks and evaluated for gastroparesis development. Gastric tissues were analyzed for the elucidation of biochemical events associated with diabetes and gastroparetic dysfunction. RESULTS Although male diabetic, gastroparetic (either streptozotocin- or estrogen-induced) rats exhibited similarity in disease pathology to that of females, the molecular mechanisms of development were different. Our results indicate that slow gastric emptying in both male diabetic, gastroparetic rat groups was not associated with the level of expression of nNOSα in gastric tissues. However, nNOSα dimerization, which reflects nNOSα activation, did decline slightly in the antrum of diabetic males with estrogen-induced gastroparesis, suggesting a possible estrogen role. Females with diabetic gastroparesis, in contrast, demonstrated significantly impaired levels and dimerization of nNOSα in the antrum and pylorus. Although the precise mechanism remains unknown, nNOSα dimerization impairment in female antrum is apparently associated with reduced phosphorylation of Ser(1416) in the activation loop of nNOSα. CONCLUSION Taken together, these results demonstrate that gender and estrogens may be leading factors, through molecular changes involved in nitric oxide synthesis down-regulation, within the antrum and pylorus of female diabetic, gastroparetic rats.
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Duchemin S, Boily M, Sadekova N, Girouard H. The complex contribution of NOS interneurons in the physiology of cerebrovascular regulation. Front Neural Circuits 2012; 6:51. [PMID: 22907993 PMCID: PMC3414732 DOI: 10.3389/fncir.2012.00051] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/19/2012] [Indexed: 12/23/2022] Open
Abstract
Following the discovery of the vasorelaxant properties of nitric oxide (NO) by Furchgott and Ignarro, the finding by Bredt and coll. of a constitutively expressed NO synthase in neurons (nNOS) led to the presumption that neuronal NO may control cerebrovascular functions. Consequently, numerous studies have sought to determine whether neuraly-derived NO is involved in the regulation of cerebral blood flow (CBF). Anatomically, axons, dendrites, or somata of NO neurons have been found to contact the basement membrane of blood vessels or perivascular astrocytes in all segments of the cortical microcirculation. Functionally, various experimental approaches support a role of neuronal NO in the maintenance of resting CBF as well as in the vascular response to neuronal activity. Since decades, it has been assumed that neuronal NO simply diffuses to the local blood vessels and produce vasodilation through a cGMP-PKG dependent mechanism. However, NO is not the sole mediator of vasodilation in the cerebral microcirculation and is known to interact with a myriad of signaling pathways also involved in vascular control. In addition, cerebrovascular regulation is the result of a complex orchestration between all components of the neurovascular unit (i.e., neuronal, glial, and vascular cells) also known to produce NO. In this review article, the role of NO interneuron in the regulation of cortical microcirculation will be discussed in the context of the neurovascular unit.
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Affiliation(s)
- Sonia Duchemin
- Department of Pharmacology, Université de Montréal Montreal, QC, Canada
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Castro M, Muñoz JM, Arruebo MP, Murillo MD, Arnal C, Bonafonte JI, Plaza MA. Involvement of neuronal nitric oxide synthase (nNOS) in the regulation of migrating motor complex (MMC) in sheep. Vet J 2011; 192:352-8. [PMID: 21995890 DOI: 10.1016/j.tvjl.2011.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 08/29/2011] [Accepted: 09/07/2011] [Indexed: 01/17/2023]
Abstract
The objectives of this study were to evaluate the role of nitric oxide (NO) synthase isoforms (nNOS, eNOS, and iNOS) in the regulation of the migrating motor complex (MMC) in sheep using electromyography and their expression in the gastrointestinal (GI) tract by Western blot (WB) and immunohistochemistry. Intravenous administration of L-NAME or the nNOS inhibitor 7-nitroindazole (7-NI) decreased the MMC interval. Myoelectric activity of intestinal phase II was increased, whereas antral activity was reduced. These effects were blocked by L-arginine. Inhibitors of either iNOS (aminoguanidine and S-methylisothiourea) or eNOS (L-NIO) were ineffective. The NO donor sodium nitroprusside decreased GI myoelectric activity, inhibited the MMC pattern, and prevented the effects induced by L-NAME and 7-NI in the intestine. Intracerebroventricular administration of these agents did not modify GI motility. In the rumen, abomasal antrum, duodenum, and jejunum, WB showed three bands at about 155, 145, and 135kDa corresponding to nNOS, and a 140-kDa band (eNOS); however iNOS was not detected. Positive nNOS immunostaining was observed in neurons of the myenteric and submucous plexus of all GI tissues, while eNOS was found in the endothelial cells, ruminal and intestinal epithelium, as well as in some enteric neurons and in endocrine-like cells of the duodenal Brunner's glands. In contrast, only weak iNOS immunoreactivity was found in ruminal epithelium. Taken together, our results suggest that NO, synthesized at a peripheral level by nNOS, is tonically inhibiting the MMC pattern and intestinal motility in sheep.
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Affiliation(s)
- M Castro
- Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet, 177, 50013 Zaragoza, Spain
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The beta-isoform of neuronal nitric oxide synthase (nNOS) lacking the PDZ domain is localized at the sarcolemma. FEBS Lett 2011; 585:3219-23. [DOI: 10.1016/j.febslet.2011.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 09/09/2011] [Accepted: 09/12/2011] [Indexed: 11/21/2022]
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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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Schicho R, Bashashati M, Bawa M, McHugh D, Saur D, Hu HM, Zimmer A, Lutz B, Mackie K, Bradshaw HB, McCafferty DM, Sharkey KA, Storr M. The atypical cannabinoid O-1602 protects against experimental colitis and inhibits neutrophil recruitment. Inflamm Bowel Dis 2011; 17:1651-64. [PMID: 21744421 PMCID: PMC3116968 DOI: 10.1002/ibd.21538] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 09/24/2010] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cannabinoids are known to reduce intestinal inflammation. Atypical cannabinoids produce pharmacological effects via unidentified targets. We were interested in whether the atypical cannabinoid O-1602, reportedly an agonist of the putative cannabinoid receptor GPR55, reduces disease severity of dextran sulfate sodium (DSS) and trinitrobenzene sulfonic acid (TNBS)-induced colitis in C57BL/6N and CD1 mice. METHODS DSS (2.5% and 4%) was supplied in drinking water for 1 week while TNBS (4 mg) was applied as a single intrarectal bolus. RESULTS Both treatments caused severe colitis. Injection of O-1602 (5 mg/kg intraperitoneally) significantly reduced macroscopic and histological colitis scores, and myeloperoxidase activity. The protective effect was still present in cannabinoid receptor 1 (CB₁) and 2 (CB₂) double knockout mice and mice lacking the GPR55 gene. To investigate a potential mechanism underlying the protection by O-1602 we performed neutrophil chemotactic assays. O-1602 concentration-dependently inhibited migration of murine neutrophils to keratinocyte-derived chemokine (KC), N-formyl-methionyl-leucyl-phenylalanine (fMLP), and the N-formyl-peptide receptor ligand WKYMVm. The inhibitory effect of O-1602 was preserved in neutrophils from CB₁/CB₂ double knockout and GPR55 knockout mice. No differences were seen in locomotor activity between O-1602-treated and control mice, indicating lack of central sedation by this compound. CONCLUSIONS Our data demonstrate that O-1602 is protective against experimentally induced colitis and inhibits neutrophil recruitment independently of CB₁, CB₂, and GPR55 receptors. Thus, atypical cannabinoids represent a novel class of therapeutics that may be useful for the treatment of inflammatory bowel diseases.
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Affiliation(s)
- Rudolf Schicho
- Division of Gastroenterology, Department of Medicine, Snyder Institute of Infection, Immunity and Inflammation (III), Alberta, Canada,Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Austria
| | - Mohammad Bashashati
- Hotchkiss Brain Institute and III, Department of Physiology and Pharmacology, University of Calgary, Canada
| | - Misha Bawa
- Gastrointestinal Research Group, Department of Physiology and Pharmacology, University of Calgary, Canada
| | - Douglas McHugh
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, USA
| | - Dieter Saur
- Department of Internal Medicine II, Technical University, Munich, Germany
| | - Huang-Ming Hu
- Hotchkiss Brain Institute and III, Department of Physiology and Pharmacology, University of Calgary, Canada,Division of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Taiwan, China
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, USA
| | - Heather B. Bradshaw
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, USA
| | - Donna-Marie McCafferty
- Gastrointestinal Research Group, Department of Physiology and Pharmacology, University of Calgary, Canada
| | - Keith A. Sharkey
- Hotchkiss Brain Institute and III, Department of Physiology and Pharmacology, University of Calgary, Canada
| | - Martin Storr
- Division of Gastroenterology, Department of Medicine, Snyder Institute of Infection, Immunity and Inflammation (III), Alberta, Canada
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Savidge TC. S-nitrosothiol signals in the enteric nervous system: lessons learnt from big brother. Front Neurosci 2011; 5:31. [PMID: 21441985 PMCID: PMC3058138 DOI: 10.3389/fnins.2011.00031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/28/2011] [Indexed: 12/13/2022] Open
Abstract
Nitric oxide (NO) is a functionally important neurotransmitter signaling molecule generated by mammalian and bacterial nitric oxide synthases (NOS), and by chemical conversion of dietary nitrite in the gastrointestinal (GI) tract. Neuronal NOS (nNOS) is the most abundant isoenzyme in the enteric nervous system, and targeted deletion in transgenic mice has clearly demonstrated its importance in normal gut function. Enteric neuropathy is also often associated with abnormal NO production, for example in achalasia and diabetic gastroparesis. Not surprisingly therefore, aberrant nNOS activity is widely implicated in enteric disease, and represents a potential molecular target for therapeutic intervention. One physiological signaling mechanism of NO bioactivity is through chemical reaction with the heme center of guanylyl cyclase, resulting in the conversion of cGMP from GTP. This second messenger nucleotide signal activates cGMP-dependent protein kinases, phosphodiesterases, and ion channels, and is implicated in the neuronal control of GI function. However, few studies in the GI tract have fully related NO bioactivity with specific molecular targets of NO-derived signals. In the central nervous system (CNS), it is now increasingly appreciated that NO bioactivity is often actively transduced via S-nitrosothiol (SNO) signals rather than via activation of guanylyl cyclase. Moreover, aberrant S-nitrosylation of specific molecular targets is implicated in CNS pathology. S-nitrosylation refers to the post-translational modification of a protein cysteine thiol by NO, forming an endogenous SNO. Because cysteine residues are often key regulators of protein function, S-nitrosylation represents a physiologically important signaling mechanism analogous to other post-translational modifications, such as O-phosphorylation. This article provides an overview of how neurotransmitter NO is produced by nNOS as this represents the most prominent and well defined source of SNO production in the enteric nervous system. Further, it provides a perspective of how S-nitrosylation signals derived from multiple diverse sources may potentially transduce NO bioactivity in the GI tract. Possible lessons that might be learnt from the CNS, such as SNO mediated auto-inhibition of nNOS activity and modulation of neuronal cell death, are also explored as these may have pathophysiological relevance in enteric neuropathy. Thus, S-nitrosylation may mediate previously underappreciated NO-derived signals in the enteric nervous system that regulate homeostatic gut functions and disease susceptibility.
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Affiliation(s)
- Tor C Savidge
- Division of Gastroenterology and Hepatology, The University of Texas Medical Branch Galveston, TX, USA
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Neuronal nitric oxide synthase interacts with Sp1 through the PDZ domain inhibiting Sp1-mediated copper-zinc superoxide dismutase expression. Int J Biochem Cell Biol 2010; 43:163-9. [PMID: 21056687 DOI: 10.1016/j.biocel.2010.10.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 10/19/2010] [Accepted: 10/28/2010] [Indexed: 11/20/2022]
Abstract
In this report we demonstrate that neuronal nitric oxide synthase (nNOS) is able to interact with Sp1 both in vivo and in vitro. In particular, we show that such interaction is mediated by the N-terminal PDZ domain of full length nNOS (fl-nNOS). In fact nNOS mutant lacking the PDZ domain (ΔnNOS) displays an impaired ability to bind to Sp1, as demonstrated by co-immunoprecipitation experiments. The overexpression of fl-nNOS in SH-SY5Y cells leads to the formation of nNOS/Sp1 heterocomplex and inhibits the binding of Sp1 to DNA. Among the Sp1 target genes we looked at the possible alteration of binding to copper-zinc superoxide dismutase gene (sod1) promoter. We find that the interaction of nNOS with Sp1 leads to a significant decrease of SOD1 mRNA, protein level and activity. The overexpression of ΔnNOS results in an inability to sequester Sp1 and unaffected Sp1 DNA binding capacity, allowing sod1 to be expressed. The data reported give effort to the possible involvement of nNOS in regulating gene transcription in NO-independent manner giving an additional significance to the expression of specific nNOS splicing variants.
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Lagerstedt-Robinson K, Svenningsson A, Nordenskjöld A. No association between a promoter NOS1 polymorphism (rs41279104) and Infantile Hypertrophic Pyloric Stenosis. J Hum Genet 2009; 54:706-8. [DOI: 10.1038/jhg.2009.101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nagl F, Schönhofer K, Seidler B, Mages J, Allescher HD, Schmid RM, Schneider G, Saur D. Retinoic acid-induced nNOS expression depends on a novel PI3K/Akt/DAX1 pathway in human TGW-nu-I neuroblastoma cells. Am J Physiol Cell Physiol 2009; 297:C1146-56. [PMID: 19726747 DOI: 10.1152/ajpcell.00034.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) acts as a neurotransmitter and intracellular signaling molecule in the central and peripheral nervous system. NO regulates multiple processes like neuronal development, plasticity, and differentiation and is a mediator of neurotoxicity. The nNOS gene is highly complex with 12 alternative first exons, exon 1a-1l, transcribed from distinct promoters, leading to nNOS variants with different 5'-untranslated regions. Transcriptional control of the nNOS gene is not understood in detail. To investigate regulation of nNOS gene expression by retinoic acid (RA), we used the human neuroblastoma cell line TGW-nu-I as a model system. We show that RA induces nNOS transcription in a protein synthesis-dependent fashion. We identify the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway and the atypical orphan nuclear receptor DAX1 (NR0B1) as critical mediators involved in RA-induced nNOS gene transcription. RA treatment increases DAX1 expression via PI3K/Akt signaling. Upregulation of DAX1 expression in turn induces nNOS transcription in response to RA. These results identify nNOS as a target gene of a novel RA/PI3K/Akt/DAX1-dependent pathway in human neuroblastoma cells and stress the functional importance of the transcriptional regulator DAX1 for nNOS gene expression in response to RA treatment.
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Affiliation(s)
- Florian Nagl
- II. Medizinische Klinik, Technische Universität München, 81675 Munich, Germany
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von Burstin J, Eser S, Paul MC, Seidler B, Brandl M, Messer M, von Werder A, Schmidt A, Mages J, Pagel P, Schnieke A, Schmid RM, Schneider G, Saur D. E-cadherin regulates metastasis of pancreatic cancer in vivo and is suppressed by a SNAIL/HDAC1/HDAC2 repressor complex. Gastroenterology 2009; 137:361-71, 371.e1-5. [PMID: 19362090 DOI: 10.1053/j.gastro.2009.04.004] [Citation(s) in RCA: 279] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2008] [Revised: 03/16/2009] [Accepted: 04/02/2009] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Early metastasis is a hallmark of pancreatic ductal adenocarcinoma and responsible for >90% of pancreatic cancer death. Because little is known about the biology and genetics of the metastatic process, we desired to elucidate molecular pathways mediating pancreatic cancer metastasis in vivo by an unbiased forward genetic approach. METHODS Highly metastatic pancreatic cancer cell populations were selected by serial in vivo passaging of parental cells with low metastatic potential and characterized by global gene expression profiling, chromatin immunoprecipitation, and in vivo metastatic assay. RESULTS In vivo selection of highly metastatic pancreatic cancer cells induced epithelial-mesenchymal transition (EMT), loss of E-cadherin expression, and up-regulation of mesenchymal genes such as Snail. Genetic inactivation of E-cadherin in parental cells induced EMT and increased metastasis in vivo. Silencing of E-cadherin in highly metastatic cells is mediated by a transcriptional repressor complex containing Snail and histone deacetylase 1 (HDAC1) and HDAC2. In line, mesenchymal pancreatic cancer specimens and primary cell lines from genetically engineered Kras(G12D) mice showed HDAC-dependent down-regulation of E-cadherin and high metastatic potential. Finally, transforming growth factor beta-driven E-cadherin silencing and EMT of human pancreatic cancer cells depends on HDAC activity. CONCLUSIONS We provide the first in vivo evidence that HDACs and Snail play an essential role in silencing E-cadherin during the metastatic process of pancreatic cancer cells. These data link the epigenetic HDAC machinery to EMT and metastasis and provide preclinical evidence that HDACs are promising targets for antimetastatic therapy.
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Smith C, Merchant M, Fekete A, Nyugen HL, Oh P, Tain YL, Klein JB, Baylis C. Splice variants of neuronal nitric oxide synthase are present in the rat kidney. Nephrol Dial Transplant 2008; 24:1422-8. [PMID: 19073653 DOI: 10.1093/ndt/gfn676] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Decreased renal cortical neuronal NO synthase (nNOS) abundance/activity correlates with progression of chronic kidney disease (CKD) in a number of animal models. METHODS Western blotting with both N-terminal and C-terminal antibodies, immunoprecipitation, proteomics, RT-PCR and in situ hybridization were used to identify nNOS splice variants in the rat kidney. RESULTS We have identified two nNOS proteins and transcripts in the rat kidney; nNOSalpha (approximately 160 kDa) and nNOSbeta (approximately 140 kDa), a catalytically active exon-2 deletion variant, lacking both the PDZ and protein inhibitor of nNOS (PIN) domains. We also report that nNOSbeta protein abundance is increased in the kidney at 11 weeks following 5/6th nephrectomy (5/6NX)-induced CKD while nNOSalpha protein abundance is diminished. The transcript data parallel the protein data in 5/6NX. By in situ hybridization, there is abundant nNOSalpha mRNA widely distributed throughout the normal kidney cortex, with very sparse nNOSbeta mRNA confined to a few proximal tubules. In a second injury model (6 weeks after 5/6 renal mass reduction by combined right kidney ablation and infarction of approximately 2/3 of the left kidney; 5/6 A/I), nNOSalpha mRNA almost disappears from the kidney cortex while nNOSbeta mRNA abundance increases in tubules and tubulo-interstitium. CONCLUSION The renal cortical nNOSbeta protein is present in low abundance in the normal kidney and increases with injury, in an inverse pattern of change with the nNOSalpha.
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Affiliation(s)
- Cheryl Smith
- Department of Physiology and Functional Genomics, University of Florida, POB 100274, Gainesville, FL 36210, USA
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Freytag C, Seeger J, Siegemund T, Grosche J, Grosche A, Freeman DE, Schusser GF, Härtig W. Immunohistochemical characterization and quantitative analysis of neurons in the myenteric plexus of the equine intestine. Brain Res 2008; 1244:53-64. [PMID: 18930715 DOI: 10.1016/j.brainres.2008.09.070] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 09/18/2008] [Accepted: 09/19/2008] [Indexed: 01/16/2023]
Abstract
The present study was performed on whole-mount preparations to investigate the chemical neuroanatomy of the equine myenteric plexus throughout its distribution in the intestinal wall. The objective was to quantify neurons of the myenteric plexus, especially the predominant cholinergic and nitrergic subpopulations. Furthermore, we investigated the distribution of vasoactive intestinal polypeptide and the calcium-binding protein calretinin. Samples from different defined areas of the small intestine and the flexura pelvina were taken from 15 adult horses. After fixation and preparation of the tissue, immunofluorescence labeling was performed on free floating whole-mounts. Additionally, samples used for neuropeptide staining were incubated with colchicine to reveal the neuropeptide distribution within the neuronal soma. The evaluation was routinely accomplished using confocal laser-scanning microscopy. For quantitative and qualitative analysis, the pan-neuronal marker anti-HuC/D was applied in combination with the detection of the marker enzymes for cholinergic neurons and nitrergic nerve cells. Quantitative data revealed that the cholinergic subpopulation is larger than the nitrergic one in several different locations of the small intestine. On the contrary, the nitrergic neurons outnumber the cholinergic neurons in the flexura pelvina of the large colon. Furthermore, ganglia are more numerous in the small intestine compared with the large colon, but ganglion sizes are bigger in the large colon. However, comparison of the entire population of neurons in the different locations of the gut showed no difference. The present study adds further data on the chemoarchitecture of the myenteric plexus which might facilitate the understanding of several gastrointestinal disorders in the horse.
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Affiliation(s)
- Christiane Freytag
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, D-04109 Leipzig, Germany
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von Burstin J, Eser S, Seidler B, Meining A, Bajbouj M, Mages J, Lang R, Kind AJ, Schnieke AE, Schmid RM, Schneider G, Saur D. Highly sensitive detection of early-stage pancreatic cancer by multimodal near-infrared molecular imaging in living mice. Int J Cancer 2008; 123:2138-47. [PMID: 18709639 DOI: 10.1002/ijc.23780] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pancreatic cancer is a serious disease with poor patient outcome, often as a consequence of late diagnosis in advanced stages. This is in large part due to the lack of diagnostic tools for early detection. To address this deficiency, we have investigated novel molecular near-infrared fluorescent (NIRF) in vivo imaging techniques in clinically relevant mouse models of pancreatic cancer. Genome wide gene expression profiling was used to identify cathepsin cystein proteases and matrix metalloproteinases (MMP) as targets for NIRF imaging. Appropriate protease activatable probes were evaluated for detection of early-stage pancreatic cancer in mice with orthotopically implanted pancreatic cancer cell lines. Mice with pancreatitis served as controls. Whole body in vivo NIRF imaging using activatable cathepsin sensitive probes specifically detected pancreatic tumors as small as 1-2 mm diameter. Imaging of MMP activity demonstrated high specificity for MMP positive tumors. Intravital flexible confocal fluorescence lasermicroscopy of protease activity enabled specific detection of pancreatic tumors at the cellular level. Importantly, topical application of NIRF-probes markedly reduced background without altering signal intensity. Taken together, macroscopic and confocal lasermicroscopic molecular in vivo imaging of protease activity is highly sensitive, specific and allows discrimination between normal pancreatic tissue, inflammation and pancreatic cancer. Translation of this approach to the clinic could significantly improve endoscopic and laparoscopic detection of early-stage pancreatic cancer.
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Affiliation(s)
- Johannes von Burstin
- Department of Internal Medicine II, Technical University of Munich, Munich, Germany
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Chaudhury A, Rao YM, Goyal RK. PIN/LC8 is associated with cytosolic but not membrane-bound nNOS in the nitrergic varicosities of mice gut: implications for nitrergic neurotransmission. Am J Physiol Gastrointest Liver Physiol 2008; 295:G442-51. [PMID: 18635601 PMCID: PMC2536782 DOI: 10.1152/ajpgi.90280.2008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This investigation demonstrates the presence and binding of the protein LC8 (described as "protein inhibitor of nNOS" or PIN in some reports) to different components of neuronal nitric oxide synthase (nNOS) in nitrergic varicosities of mice gut. Whole varicosity extracts showed three (320-, 250-, and 155-kDa) nNOS bands with anti-nNOS(1422-1433) antibody and a 10-kDa band with anti-LC8 antibody. The LC8 immunoprecipitate (IP) showed three nNOS bands, suggesting that LC8 was bound with all three forms of nNOS but dissociated from them during SDS-PAGE. Studies using LC8 IP and supernatant and probed with anti-CaM showed that LC8 was not associated with CaM-bound 320-kDa nNOS but was present in the CaM-lacking fraction. Probing these fractions with anti-serine847-P-nNOS showed that 320-kDa serine847-phosphorylated-nNOS consisted of LC8-bound and LC8-lacking components. Subsequent studies with varicosity membrane and cytosolic fractions separately showed that membrane contained CaM-bound and CaM-lacking, serine847-phosphorylated 320-kDa nNOS; both these fractions lacked LC8. On the other hand, the cytosolic fraction contained CaM-lacking, serine847-phosphorylated 320-kDa, 250-kDa, and 155-kDa nNOS bands that were all associated with LC8. These studies, along with in vitro nitric oxide assays, show that in gut nitrergic nerve varicosities 1) all cytosolic serine847-phosphorylated nNOS was catalytically inactive and bound with LC8, and 2) membrane-associated nNOS consisted of catalytically active, CaM-bound and catalytically inactive, CaM-lacking, serine847-phosphorylated nNOSalpha dimers, both of which lacked LC8. These results suggest that LC8 may dissociate from the 320-kDa nNOSalpha dimer upon binding to membrane, thus supporting the view that LC8 may transport nNOSalpha dimer to the varicosity membrane for participation in nitrergic neurotransmission.
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Affiliation(s)
- Arun Chaudhury
- Center for Swallowing and Motility Disorders, Veterans Affairs Boston Healthcare System and Harvard Medical School, Boston, Massachusetts
| | - Y. Manjula Rao
- Center for Swallowing and Motility Disorders, Veterans Affairs Boston Healthcare System and Harvard Medical School, Boston, Massachusetts
| | - Raj K. Goyal
- Center for Swallowing and Motility Disorders, Veterans Affairs Boston Healthcare System and Harvard Medical School, Boston, Massachusetts
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Rao YM, Chaudhury A, Goyal RK. Active and inactive pools of nNOS in the nerve terminals in mouse gut: implications for nitrergic neurotransmission. Am J Physiol Gastrointest Liver Physiol 2008; 294:G627-34. [PMID: 18096606 PMCID: PMC2497337 DOI: 10.1152/ajpgi.00519.2007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nitric oxide (NO) is responsible for nitrergic neurotransmission in the gut, and its release is dependent on its de novo synthesis by neuronal nitric oxide synthase (nNOS). The magnitude of NO synthesis and release during neurotransmission may be related to the fraction of catalytically active nNOS out of a larger pool of inactive nNOS in the nerve terminals. The purpose of the present study was to identify catalytically active and inactive pools of nNOS in the varicosities from mouse gut. Enteric varicosities were confirmed as nitrergic by colocalization of nNOS with the nerve varicosity marker synaptophysin. Low-temperature SDS-PAGE of these varicosity extracts showed 320-, 250-, and 155-kDa bands when blotted with anti-nNOS(1422-1433) and 320- and 155-kDa bands when blotted with anti-nNOS(1-20) antibodies, respectively. The 320- and 155-kDa bands represent dimers and monomers of nNOSalpha; the 250- and 135-kDa bands represent dimers and monomers of nNOSbeta. Immunoprecipitation with calmodulin (CaM) showed that a portion of nNOSalpha dimer was bound with CaM. On the other hand, a portion of nNOSalpha dimer, nNOSbeta dimer, and all monomers lacked CaM binding. The CaM-lacking nNOS fractions reacted with anti-serine 847-phospho-nNOS. In vitro assays of NO production revealed that only the CaM-bound dimeric nNOSalpha was catalytically active; all other forms were inactive. We suggest that the amount of catalytically active nNOSalpha dimers may be regulated by serine 847 phosphorylation and equilibrium between dimers and monomers of nNOSalpha.
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Sullivan JC, Goodchild TT, Cai Z, Pollock DM, Pollock JS. Endothelin(A) (ET(A)) and ET(B) receptor-mediated regulation of nitric oxide synthase 1 (NOS1) and NOS3 isoforms in the renal inner medulla. Acta Physiol (Oxf) 2007; 191:329-36. [PMID: 17892518 DOI: 10.1111/j.1748-1716.2007.01754.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM Our laboratory and others have shown that endothelin (ET)-1 directly stimulates nitric oxide (NO) production in inner medullary collecting duct (IMCD) cells. The goal of this study was to determine which NO synthase (NOS) isoforms in IMCD are sensitive to ET-1, and the role of ET(A) and ET(B) receptor activation in vivo and in vitro. METHODS NOS enzymatic activity and NOS isoform protein expression were examined in cultured IMCD-3 cells and isolated renal inner medulla. ET(B) receptor-deficient homozygous rats (sl/sl) have elevated levels of circulating ET-1 and lack a functional ET(B) signalling pathway in kidneys, and furthermore provides a unique model to study ET(A) receptor signalling in the renal inner medulla in vivo. RESULTS Incubation of IMCD-3 cells with exogenous ET-1 (50 nm) resulted in ET(A)-dependent increased NOS1 protein expression in IMCD-3 cells with no effect on NOS2 or NOS3 expression. ET(B) receptor antagonism has no effect on NOS expression in IMCD-3 cells. Consistent with in vitro results, cytosolic NOS1 protein expression was significantly greater in the renal inner medulla of sl/sl rats compared with heterozygous (sl/+) controls, with no alteration in NOS3 expression. In contrast to protein expression data, NOS1- and NOS3-specific enzymatic activities decreased in the cytosolic fraction from the renal inner medulla of sl/sl compared with sl/+. CONCLUSION These results provide evidence that both ET(A) and ET(B) receptors regulate NOS isoform activity in the renal inner medulla and specifically support the hypothesis that ET(A) receptor activation increases NOS1 expression.
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Affiliation(s)
- J C Sullivan
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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Sullivan JC, Smart EJ, Pollock DM, Pollock JS. Influence of salt on subcellular localization of nitric oxide synthase activity and expression in the renal inner medulla. Clin Exp Pharmacol Physiol 2007; 35:120-5. [PMID: 17892502 DOI: 10.1111/j.1440-1681.2007.04802.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. The aims of this study were: (i) to characterize the subcellular localization of nitric oxide synthase (NOS) 1 and NOS3 activity and expression within the cytosolic, plasma membrane and intracellular membrane subcellular fractions of the renal inner medulla of rats; and (ii) to determine whether NOS1 and NOS3 activity and expression in subcellular fractions of the renal inner medulla are regulated by dietary salt intake. Although the NOS system is important in maintaining Na(+) and water homeostasis, the identity of the NOS isoform that is sensitive to dietary Na(+) remains unclear. In addition, subcellular localization of both NOS1 and NOS3 has been shown to regulate enzymatic activity and influence the ability of NOS to produce nitric oxide (NO). 2. Renal inner medullae were dissected from male Sprague-Dawley rats and separated into cytosolic, plasma membrane and intracellular membrane fractions for measurement of NOS activity and western blot analysis. 3. On a normal-salt diet, NOS activity and NOS1 and NOS3 protein expression were present in all three subcellular fractions, although total NOS activity was enriched in the intracellular membrane fraction. In response to a high-salt diet, urinary nitrate/nitrite (NO(x)) increased. Despite an increase in NO(x) excretion, total NOS activity in the renal inner medullary homogenate was decreased. There were no detectable differences in NOS activity in the subcellular fractions. Expression of NOS1 protein was decreased in the cytoplasmic and plasma membrane fractions, although maintained in the intracellular membrane fraction, in response to high salt. Expression of NOS3 protein was unaffected by high salt. 4. In conclusion, we hypothesize that NOS1 localization in the intracellular membrane is important in increasing NO production to aid Na(+) and water homeostasis.
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Affiliation(s)
- Jennifer C Sullivan
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912, USA
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Bros M, Boissel JP, Gödtel-Armbrust U, Förstermann U. The untranslated region of exon 2 of the human neuronal nitric oxide synthase (NOS1) gene exerts regulatory activity. Gene 2007; 405:36-46. [PMID: 17949925 DOI: 10.1016/j.gene.2007.08.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 08/27/2007] [Accepted: 08/29/2007] [Indexed: 11/19/2022]
Abstract
Expressional dysregulation of the human neuronal nitric oxide synthase (NOS1) gene represents an important mechanism in the pathogenesis of certain neuronal disease states. The structure and regulation of the human NOS1 gene is highly complex based on cell type- and stimulus-dependent usage of multiple exon 1 variants. Here we demonstrate that the untranslated region of exon 2 exerts promoter and enhancer functions as well, facilitated in large part by cooperative interaction of two conserved adjacent CREB/AP-1 binding sites. In human neuronal A673 cells, NOS1 expression is stimulated by several compounds which act through these sites, but also stimulate the combined promoter region of exons 1f and 1g. While stimulation of NOS1 expression by dibutyryl-cAMP is mediated by protein kinase A (blocked by H-89), the antiepileptic drug valproic acid is likely to activate phosphatidylinositol-3 kinase (inhibited by LY 294002).
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Affiliation(s)
- Matthias Bros
- Department of Dermatology, Johannes Gutenberg University, Mainz, Germany
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Yüce B, Sibaev A, Haaken A, Saur D, Allescher HD, Göke B, Timmermans JP, Storr M. ORL-1 receptor mediates the action of nociceptin on ascending myenteric reflex pathways in rats. Gastroenterology 2007; 133:574-86. [PMID: 17681177 DOI: 10.1053/j.gastro.2007.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 05/10/2007] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIMS Nociceptin is the endogenous agonist of the "orphan" opioid receptor-1 (ORL-1). We investigated whether activation of the ORL-1 receptor influences smooth muscle contractility and enteric neurotransmission within ascending myenteric reflex pathways of rats. METHODS Reverse transcriptase polymerase chain reaction was performed to evaluate the presence of ORL-1 receptors. The ascending part of the ascending myenteric reflex in rats was studied in ileal segments using a 3-chambered organ bath. Intracellular recordings were performed to evaluate pharmacologic effects on excitatory and inhibitory junction potentials (EJP; IJP). Single- and double-labeling immunohistochemistry was used to examine the distribution of ORL-1 within the intestinal wall. RESULTS ORL-1 expression and immunoreactivity was found in the large majority of myenteric neurons. In addition to the cholinergic myenteric neurons, all nitrergic myenteric neurons expressed the ORL-1 receptor. Nociceptin significantly reduced cholinergic twitch contractions, an effect that was reversed by the ORL-1 receptor antagonist [Nphe(1)]nociceptin(1-13)NH(2). Neither nociceptin nor [Nphe(1)]nociceptin(1-13)NH(2) had a direct influence on smooth muscle contractility. Nociceptin significantly reduced ascending myenteric reflex contractions and prolonged the latency from stimulation to contraction. Both effects were antagonized by [Nphe(1)]nociceptin(1-13)NH(2). Intracellular recordings demonstrated that nociceptin reduces the cholinergically mediated EJP and the nitrergic phase of IJP in a concentration-dependent manner, effects that were reversible in presence of [Nphe(1)]nociceptin(1-13)NH(2). CONCLUSIONS We conclude that activation of ORL-1 receptors on myenteric neurons reduce excitatory and inhibitory neurotransmission within the gastrointestinal tract. This is accompanied by a reduction of the small intestinal peristaltic reflex response. These effects might be used pharmacologically.
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Affiliation(s)
- Birol Yüce
- Department of Internal Medicine II, Ludwig Maximilians University Munich, Munich, Germany
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Gangula PRR, Maner WL, Micci MA, Garfield RE, Pasricha PJ. Diabetes induces sex-dependent changes in neuronal nitric oxide synthase dimerization and function in the rat gastric antrum. Am J Physiol Gastrointest Liver Physiol 2007; 292:G725-33. [PMID: 17347455 PMCID: PMC2786258 DOI: 10.1152/ajpgi.00406.2006] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Diabetic gastroparesis is a disorder that predominantly affects women. However, the biological basis of this sex bias remains completely unknown. In this study we tested the hypothesis that a component of this effect may be mediated by the nitrergic inhibitory system of the enteric nervous system. Age-matched male and female Sprague-Dawley rats were studied 8 or 12 wk after streptozotocin (55 mg/kg body wt ip)-induced sustained hyperglycemia and compared with controls. Solid gastric emptying (GE) studies were performed in all the groups. Changes in gastric antrum neuronal nitric oxide synthase (nNOS) mRNA and protein levels were analyzed by real-time PCR and Western immunoblotting, respectively. nNOS dimerization studies were performed using low-temperature SDS-PAGE. In vitro nitrergic relaxation (area under curve/mg tissue wt) was studied after the application of electric field stimulation in an organ bath. Changes in intragastric pressure (mmHg.s) in freely moving rats in the presence or absence of N(G)-nitro-l-arginine methyl ester (nitric oxide synthase inhibitor) were examined by an ambulatory telemetric method. After diabetes induction, GE is delayed in both male and female rats. However, diabetic females exhibited significant delayed GE than in diabetic males. Compared with male controls, gastric nNOS expression and nitrergic relaxation were substantially elevated in healthy female control rats, accompanied by significantly reduced intragastric pressure. The active dimeric form and dimer-to-monomer ratio of nNOSalpha were also higher in healthy females compared with male rats (P < 0.05). Diabetic females, but not males, showed significant (P < 0.05) impairment in both gastric nNOSalpha dimerization and nitrergic relaxation, accompanied by an increase in intragastric pressure. Our data provide evidence that females may have a greater dependency on the nitrergic mechanisms in health. Furthermore, diabetes seems to affect the nitrergic system to a greater extent in females than in males. Together, these changes may account for the greater vulnerability of females to diabetic gastric dysfunction.
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Affiliation(s)
- Pandu R R Gangula
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, The University of Texas Medical Branch, Galveston, Texas 77555, USA.
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Kwon SY, Groszmann RJ, Iwakiri Y. Increased neuronal nitric oxide synthase interaction with soluble guanylate cyclase contributes to the splanchnic arterial vasodilation in portal hypertensive rats. Hepatol Res 2007; 37:58-67. [PMID: 17300699 DOI: 10.1111/j.1872-034x.2007.00005.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Splanchnic arterial vasodilation represents the pathophysiological hallmark of the hemodynamic dysfunction observed in portal hypertensive states. The role of neuronal nitric oxide synthase (nNOS) in the splanchnic arterial vasodilation remains to be elucidated. We therefore investigated: (i) if nNOS is involved in the splanchnic arterial vasodilation; and (ii) the possible interaction of nNOS with soluble guanylate cyclase (sGC) in superior mesenteric arterial (SMA) beds in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation (PVL). To determine the role of nNOS, we removed endothelial layer and measured contractile response and nitric oxide (NO) release in the presence or absence of 7-nitroindazole (7-NI, 10 muM), an nNOS-specific inhibitor. In endothelium-removed vessels, nNOS inhibitor significantly increased the contractile response to methoxamine in SMA beds isolated from the portal hypertensive rats, compared to non-treated SMA beds (106.8 +/- 10.7 vs 86.8 +/- 7.2 mmHg, P = 0.003). This effect of nNOS inhibitor was accompanied with decreased NO production in SMA of portal hypertensive rats (321.3 +/- 18.6 vs 139.5 +/- 16.9 pmol/mL/min, P = 0.0001). Unlike endothelial NOS that is located in endothelial cells, nNOS protein is highly expressed in smooth muscle layers of SMA. Furthermore, there was a significant increase in ~90 kDa nNOS protein in the portal hypertensive group, compared to the sham-operated group (P < 0.01). Interestingly, this 90 kDa nNOS was coimmunoprecipitated with sGC. In conclusion, increased nNOS expression in smooth muscle layers of arteries in the splanchnic circulation may be an additional and more efficient pathway for the activation of sGC by NO, which sustains arterial vasodilation.
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Affiliation(s)
- So Young Kwon
- Hepatic Hemodynamic Laboratory, VA Connecticut Healthcare System, West Haven, CT
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Giulivi C, Kato K, Cooper CE. Nitric oxide regulation of mitochondrial oxygen consumption I: cellular physiology. Am J Physiol Cell Physiol 2006; 291:C1225-31. [PMID: 16885394 DOI: 10.1152/ajpcell.00307.2006] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial biochemistry is complex, expanding from oxygen consumption, oxidative phosphorylation, lipid catabolism, heme biosynthesis, to apoptosis, calcium homeostasis, and production of reactive oxygen species, including nitric oxide (NO). The latter molecule is produced by a mitochondrial NO synthase (mtNOS). The rates of consumption and production determine the steady-state concentration of NO at subcellular levels, leading to regulation of mitochondrial events. Temporospatial processes tightly regulate production of NO in mitochondria to maximize target effects and minimize deleterious reactions. Temporal regulatory mechanisms of mtNOS include activation by calcium signaling and transcriptional/translational regulations. Calcium-activated mtNOS inhibits mitochondrial respiration, resulting in a decrease of the oxygen consumption. This negative regulation antagonizes the effects of calcium on calcium-dependent dehydrogenases in the citric acid cycle, preventing the formation of anoxic foci. Temporal regulation of NO production by intracellular calcium signaling is a complex process, considering the heterogeneous intracellular calcium response and distribution. NO production in mitochondria is spatially regulated by mechanisms that determine subcellular localization of mtNOS, likely acylation and protein-protein interactions, in addition to transcriptional regulation as neuronal NOS. Because NO rapidly decays in mitochondria, subcellular localization of mtNOS is crucial for NO to function as a signal molecule. These temporospatial processes are biologically important to allow NO to act as an effective signal molecule to regulate mitochondrial events such as oxygen consumption and reactive oxygen species production.
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Affiliation(s)
- Cecilia Giulivi
- University of California, Department of Molecular Biosciences, Davis, California 95616.
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Cordelier P, Estève JP, Najib S, Moroder L, Vaysse N, Pradayrol L, Susini C, Buscail L. Regulation of Neuronal Nitric-oxide Synthase Activity by Somatostatin Analogs following SST5 Somatostatin Receptor Activation. J Biol Chem 2006; 281:19156-71. [PMID: 16690617 DOI: 10.1074/jbc.m602024200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Somatostatin receptor SST5 is an inhibitory G protein-coupled receptor that exerts a strong cytostatic effect on various cell types. We reported previously that the SST5 anti-proliferative effect results in the inhibition of mitogen-induced increases in intracellular cGMP levels and MAPK activity. This study was conducted to define the early molecular events accountable for the SST5-mediated anti-proliferative effect. Here, we demonstrate that, in Chinese hamster ovary cells expressing SST5 (CHO/SST5 cells), somatostatin inhibited cell proliferation induced by nitric oxide donors and overexpression of the neuronal nitric-oxide synthase (nNOS) protein isoform. Accordingly, nNOS activity and dimerization were strongly inhibited following SST5 activation by the somatostatin analog RC-160. In CHO/SST5 cells, nNOS was dynamically recruited by the SST5 receptor and phosphorylated at tyrosyl residues following RC-160 treatment. RC-160 induced SST5-p60(src) kinase complex formation and subsequent p60(src) kinase activation. Coexpression of an inactive p60(src) kinase mutant with SST5 blocked RC-160-induced nNOS phosphorylation and inactivation and prevented the SST5-mediated anti-proliferative effect. In CHO/SST5 cells, p60(src) kinase associated with nNOS to induce its inactivation by phosphorylation at tyrosyl residues following RC-160 treatment. Using recombinant proteins, we demonstrated that such phosphorylation prevented nNOS homodimerization. Next, surface plasmon resonance and mutation analysis revealed that p60(src) directly associated with nNOS phosphorylated Tyr604. SST5-mediated inhibition of nNOS activity was demonstrated to be essential to the RC-160 anti-proliferative effect on pancreatic endocrine tumor-derived cells. We therefore identified nNOS as a new p60(src) kinase substrate essential for SST5-mediated anti-proliferative action.
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Affiliation(s)
- Pierre Cordelier
- INSERM U531, IFR31, Centre Hospitalier Universitaire Rangueil, 31432 Toulouse Cedex 4, France.
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Ward ME, Toporsian M, Scott JA, Teoh H, Govindaraju V, Quan A, Wener AD, Wang G, Bevan SC, Newton DC, Marsden PA. Hypoxia induces a functionally significant and translationally efficient neuronal NO synthase mRNA variant. J Clin Invest 2006; 115:3128-39. [PMID: 16276418 PMCID: PMC1265848 DOI: 10.1172/jci20806] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Accepted: 08/30/2005] [Indexed: 11/17/2022] Open
Abstract
We tested the hypothesis that induction of neuronal NO synthase (nNOS) impairs vascular smooth muscle contractility after hypoxia. nNOS protein was increased in aorta, mesenteric arterioles, pulmonary arteries, brain, and diaphragm from rats exposed to 8% O2 for 48 hours and in human aortic SMCs after hypoxic incubation (1% O2). Ca-dependent NO synthase activity was increased in endothelium-denuded aortic segments from hypoxia-exposed rats. N-nitro-L-arginine methyl ester enhanced the contractile responses of endothelium-denuded aortic rings and mesenteric arterioles from hypoxia-exposed but not normoxic rats (P < 0.05). The hypoxia-inducible mRNA transcript expressed by human cells was found to contain a novel 5'-untranslated region, consistent with activation of transcription in the genomic region contiguous with exon 2. Translational efficiency of this transcript is markedly increased compared with previously described human nNOS mRNAs. Transgenic mice possessing a lacZ reporter construct under control of these genomic sequences demonstrated expression of the construct after exposure to hypoxia (8% O2, 48 hours) in the aorta, mesenteric arterioles, renal papilla, and brain. These results reveal a novel human nNOS promoter that confers the ability to rapidly upregulate nNOS expression in response to hypoxia with a functionally significant effect on vascular smooth muscle contraction.
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Affiliation(s)
- Michael E Ward
- Division of Respirology, University of Toronto, Toronto, Ontario, Canada.
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Micci MA, Kahrig KM, Simmons RS, Sarna SK, Espejo-Navarro MR, Pasricha PJ. Neural stem cell transplantation in the stomach rescues gastric function in neuronal nitric oxide synthase-deficient mice. Gastroenterology 2005; 129:1817-24. [PMID: 16344050 DOI: 10.1053/j.gastro.2005.08.055] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Accepted: 08/24/2005] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Nitric oxide is a major inhibitory neurotransmitter in the enteric nervous system. Loss or dysfunction of nitrinergic neurons is associated with serious disruptions of motility, intractable symptoms, and long-term suffering. The aim of this study was to evaluate the effect of intrapyloric transplantation of neural stem cells (NSCs) on gastric emptying and pyloric function in nNOS-/- mice, a well-established genetic model of gastroparesis. METHODS NSCs were isolated from embryonic mice transgenically engineered to express green fluorescent protein and transplanted into the pylorus of nNOS-/- mice. Grafted cells were visualized in pyloric sections and further characterized by immunofluorescence staining. One week posttransplantation, gastric emptying to a non-nutrient meal was measured using the phenol red method and pyloric function was assessed by measuring the relaxation of pyloric strips in an organ bath in response to electrical field stimulation (EFS) under nonadrenergic, noncholinergic conditions. RESULTS One week following implantation, grafted NSCs differentiated into neurons and expressed neuronal nitric oxide synthase. Gastric emptying was significantly increased in mice that received NSCs as compared with vehicle-injected controls (49.67% vs 35.09%; P < .01 by Student t test). EFS-induced relaxation of pyloric strips was also significantly increased (P < .01 by 2-way analysis of variance). The nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester and the neuronal blocker tetrodotoxin blocked the EFS-induced relaxation, indicating that the observed effect is NO mediated and neuronally derived. CONCLUSIONS Our results support the potential of NSC transplantation as a viable therapeutic option for neuroenteric disorders.
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Affiliation(s)
- Maria-Adelaide Micci
- Enteric Neuromuscular Disorders and Pain Laboratory, Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston, Texas 77555-0764, USA
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Saur D, Seidler B, Schneider G, Algül H, Beck R, Senekowitsch-Schmidtke R, Schwaiger M, Schmid RM. CXCR4 expression increases liver and lung metastasis in a mouse model of pancreatic cancer. Gastroenterology 2005; 129:1237-50. [PMID: 16230077 DOI: 10.1053/j.gastro.2005.06.056] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2005] [Accepted: 06/16/2005] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Expression of the Gi-protein-coupled chemokine receptor CXCR4 has recently been linked to increased proliferation, invasion, and migration of human pancreatic cancer cell lines. However, the relevance of CXCR4 for organ-specific pancreatic cancer metastasis in vivo remains unclear. Here, we have studied the role of CXCR4 in vivo using noninvasive imaging of targeted metastasis in a mouse model of pancreatic cancer. METHODS Functional expression of the chemokine receptors CXCR4 and CCR7 was achieved by stable transfection of murine TD-2 pancreatic cancer cells and analyzed by flow cytometry, calcium flux, migration, and proliferation assays. The metastatic potential of the different stable TD-2 cell clones was assessed by tail vein metastatic assays in nude mice using in vivo bioluminescent imaging. RESULTS Native TD-2 cells display very low abundant CXCR4 and CCR7 expression and show poor metastatic potential after tail vein injection. To study the role of CXCR4 in pancreatic cancer metastasis, we selected stable TD-2 cell clones with similar CXCR4 expression levels as human pancreatic cancer cell lines derived from metastatic lesions. CXCR4, but not CCR7, expression dramatically increased the in vivo metastatic potential of TD-2 cells, resulting in liver and lung metastasis in nude mice. Systemic administration of the selective CXCR4 inhibitor AMD 3100 effectively blocked the enhanced metastatic potential of CXCR4-expressing pancreatic cancer cells. CONCLUSIONS These results indicate that CXCR4 expression mediates organ-specific metastasis of pancreatic cancer cells and provide preclinical evidence that blockade of the CXCL12/CXCR4 axis is a target for antimetastatic therapy.
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Affiliation(s)
- Dieter Saur
- Department of Internal Medicine 2, Technical University of Munich, Germany.
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