1
|
Sur A, Wang Y, Capar P, Margolin G, Prochaska MK, Farrell JA. Single-cell analysis of shared signatures and transcriptional diversity during zebrafish development. Dev Cell 2023; 58:3028-3047.e12. [PMID: 37995681 PMCID: PMC11181902 DOI: 10.1016/j.devcel.2023.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/24/2023] [Accepted: 11/01/2023] [Indexed: 11/25/2023]
Abstract
During development, animals generate distinct cell populations with specific identities, functions, and morphologies. We mapped transcriptionally distinct populations across 489,686 cells from 62 stages during wild-type zebrafish embryogenesis and early larval development (3-120 h post-fertilization). Using these data, we identified the limited catalog of gene expression programs reused across multiple tissues and their cell-type-specific adaptations. We also determined the duration each transcriptional state is present during development and identify unexpected long-term cycling populations. Focused clustering and transcriptional trajectory analyses of non-skeletal muscle and endoderm identified transcriptional profiles and candidate transcriptional regulators of understudied cell types and subpopulations, including the pneumatic duct, individual intestinal smooth muscle layers, spatially distinct pericyte subpopulations, and recently discovered best4+ cells. To enable additional discoveries, we make this comprehensive transcriptional atlas of early zebrafish development available through our website, Daniocell.
Collapse
Affiliation(s)
- Abhinav Sur
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA
| | - Yiqun Wang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Paulina Capar
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA
| | - Gennady Margolin
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA
| | - Morgan Kathleen Prochaska
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA
| | - Jeffrey A Farrell
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA.
| |
Collapse
|
2
|
Zannad F, Ferreira JP, Butler J, Filippatos G, Januzzi JL, Sumin M, Zwick M, Saadati M, Pocock SJ, Sattar N, Anker SD, Packer M. Effect of empagliflozin on circulating proteomics in heart failure: mechanistic insights into the EMPEROR programme. Eur Heart J 2022; 43:4991-5002. [PMID: 36017745 PMCID: PMC9769969 DOI: 10.1093/eurheartj/ehac495] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/15/2022] [Accepted: 08/25/2022] [Indexed: 01/12/2023] Open
Abstract
AIMS Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in diverse patient populations, but their mechanism of action requires further study. The aim is to explore the effect of empagliflozin on the circulating levels of intracellular proteins in patients with heart failure, using large-scale proteomics. METHODS AND RESULTS Over 1250 circulating proteins were measured at baseline, Week 12, and Week 52 in 1134 patients from EMPEROR-Reduced and EMPEROR-Preserved, using the Olink® Explore 1536 platform. Statistical and bioinformatical analyses identified differentially expressed proteins (empagliflozin vs. placebo), which were then linked to demonstrated biological actions in the heart and kidneys. At Week 12, 32 of 1283 proteins fulfilled our threshold for being differentially expressed, i.e. their levels were changed by ≥10% with a false discovery rate <1% (empagliflozin vs. placebo). Among these, nine proteins demonstrated the largest treatment effect of empagliflozin: insulin-like growth factor-binding protein 1, transferrin receptor protein 1, carbonic anhydrase 2, erythropoietin, protein-glutamine gamma-glutamyltransferase 2, thymosin beta-10, U-type mitochondrial creatine kinase, insulin-like growth factor-binding protein 4, and adipocyte fatty acid-binding protein 4. The changes of the proteins from baseline to Week 52 were generally concordant with the changes from the baseline to Week 12, except empagliflozin reduced levels of kidney injury molecule-1 by ≥10% at Week 52, but not at Week 12. The most common biological action of differentially expressed proteins appeared to be the promotion of autophagic flux in the heart, kidney or endothelium, a feature of 6 proteins. Other effects of differentially expressed proteins on the heart included the reduction of oxidative stress, inhibition of inflammation and fibrosis, and the enhancement of mitochondrial health and energy, repair, and regenerative capacity. The actions of differentially expressed proteins in the kidney involved promotion of autophagy, integrity and regeneration, suppression of renal inflammation and fibrosis, and modulation of renal tubular sodium reabsorption. CONCLUSIONS Changes in circulating protein levels in patients with heart failure are consistent with the findings of experimental studies that have shown that the effects of SGLT2 inhibitors are likely related to actions on the heart and kidney to promote autophagic flux, nutrient deprivation signalling and transmembrane sodium transport.
Collapse
Affiliation(s)
- Faiez Zannad
- Corresponding author. Tel: +33 3 83 15 73 15, Fax: +33 3 83 15 73 24, Emails: ;
| | - João Pedro Ferreira
- Corresponding author. Tel: +33 3 83 15 73 15, Fax: +33 3 83 15 73 24, Emails: ;
| | - Javed Butler
- Heart and Vascular Research, Baylor Scott and White Research Institute, 34 Live Oak St Ste 501, Dallas, TX 75204, USA,University of Mississippi Medical Center, 2500 North State Street Jackson, MS 39216, USA
| | - Gerasimos Filippatos
- Heart Failure Unit, National and Kapodistrian University of Athens School of Medicine, Mikras Asias 75, Athina 115 27 Athens, Greece
| | - James L Januzzi
- Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114USA,The Baim Institute for Clinical Research, 930 Commonwealth Ave #3, Boston, MA 02215USA
| | - Mikhail Sumin
- Boehringer Ingelheim International GmbH, Binger Str. 173, 55218 Ingelheim am RheinGermany
| | - Matthias Zwick
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der RissGermany
| | - Maral Saadati
- Elderbrook Solutions GmbH on behalf of Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riss, Germany
| | - Stuart J Pocock
- London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HTUK
| | - Naveed Sattar
- BHF, UK School of Cardiovascular and Metabolic Health, University of Glasgow, 126 University Place, Glasgow G12 8TAUK
| | - Stefan D Anker
- Department of Cardiology (CVK) Berlin Institute of Health Center for Regenerative Therapies (BCRT) German Centre for Cardiovascular Research (DZHK) partner site Berlin, Charité Universitätsmedizin Berlin, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany,Institute of Heart Diseases, Wroclaw Medical University, Borowska Street 213, 50-556 Warsaw, Poland
| | - Milton Packer
- Baylor Heart and Vascular Hospital, Baylor University Medical Center, 621 N Hall St, Dallas, TX 75226, USA,Imperial College, London, Exhibition Rd, South Kensington, London SW7 2BX, UK
| |
Collapse
|
3
|
Brierley SM, Grundy L, Castro J, Harrington AM, Hannig G, Camilleri M. Guanylate cyclase-C agonists as peripherally acting treatments of chronic visceral pain. Trends Pharmacol Sci 2022; 43:110-122. [PMID: 34865885 PMCID: PMC8760167 DOI: 10.1016/j.tips.2021.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/28/2021] [Accepted: 11/02/2021] [Indexed: 02/03/2023]
Abstract
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and altered bowel habit that affects ~11% of the global population. Over the past decade, preclinical and clinical studies have revealed a variety of novel mechanisms relating to the visceral analgesic effects of guanylate cyclase-C (GC-C) agonists. Here we discuss the mechanisms by which GC-C agonists target the GC-C/cyclic guanosine-3',5'-monophosphate (cGMP) pathway, resulting in visceral analgesia as well as clinically relevant relief of abdominal pain and other sensations in IBS patients. Due to the preponderance of evidence we focus on linaclotide, a 14-amino acid GC-C agonist with very low oral bioavailability that acts within the gut. Collectively, the weight of experimental and clinical evidence supports the concept that GC-C agonists act as peripherally acting visceral analgesics.
Collapse
Affiliation(s)
- Stuart M. Brierley
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, South Australia, 5042, AUSTRALIA.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, AUSTRALIA.,Discipline of Medicine, University of Adelaide, North Terrace, Adelaide, South Australia 5000, AUSTRALIA.,Corresponding Author: Prof. Stuart M. Brierley, Ph.D. Visceral Pain Research Group, Level 7, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, SA 5000, AUSTRALIA.
| | - Luke Grundy
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, South Australia, 5042, AUSTRALIA.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, AUSTRALIA
| | - Joel Castro
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, South Australia, 5042, AUSTRALIA.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, AUSTRALIA
| | - Andrea M. Harrington
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, South Australia, 5042, AUSTRALIA.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, AUSTRALIA
| | | | - Michael Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiologic Research Program, Mayo Clinic, Rochester, MN, USA
| |
Collapse
|
4
|
Takei Y. Evolution of the membrane/particulate guanylyl cyclase: From physicochemical sensors to hormone receptors. Gen Comp Endocrinol 2022; 315:113797. [PMID: 33957096 DOI: 10.1016/j.ygcen.2021.113797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 12/26/2022]
Abstract
Guanylyl cyclase (GC) is an enzyme that produces 3',5'-cyclic guanosine monophosphate (cGMP), one of the two canonical cyclic nucleotides used as a second messenger for intracellular signal transduction. The GCs are classified into two groups, particulate/membrane GCs (pGC) and soluble/cytosolic GCs (sGC). In relation to the endocrine system, pGCs include hormone receptors for natriuretic peptides (GC-A and GC-B) and guanylin peptides (GC-C), while sGC is a receptor for nitric oxide and carbon monoxide. Comparing the functions of pGCs in eukaryotes, it is apparent that pGCs perceive various environmental factors such as light, temperature, and various external chemical signals in addition to endocrine hormones, and transmit the information into the cell using the intracellular signaling cascade initiated by cGMP, e.g., cGMP-dependent protein kinases, cGMP-sensitive cyclic nucleotide-gated ion channels and cGMP-regulated phosphodiesterases. Among vertebrate pGCs, GC-E and GC-F are localized on retinal epithelia and are involved in modifying signal transduction from the photoreceptor, rhodopsin. GC-D and GC-G are localized in olfactory epithelia and serve as sensors at the extracellular domain for external chemical signals such as odorants and pheromones. GC-G also responds to guanylin peptides in the urine, which alters sensitivity to other chemicals. In addition, guanylin peptides that are secreted into the intestinal lumen, a pseudo-external environment, act on the GC-C on the apical membrane for regulation of epithelial transport. In this context, GC-C and GC-G appear to be in transition from exocrine pheromone receptor to endocrine hormone receptor. The pGCs also exist in various deuterostome and protostome invertebrates, and act as receptors for environmental, exocrine and endocrine factors including hormones. Tracing the evolutionary history of pGCs, it appears that pGCs first appeared as a sensor for physicochemical signals in the environment, and then evolved to function as hormone receptors. In this review, the author proposes an evolutionary history of pGCs that highlights the emerging role of the GC/cGMP system for signal transduction in hormone action.
Collapse
Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
| |
Collapse
|
5
|
Mazzawi T, Eikrem Ø, Lied GA, Hausken T. Abnormal Uroguanylin Immunoreactive Cells Density in the Duodenum of Patients with Diarrhea-Predominant Irritable Bowel Syndrome Changes following Fecal Microbiota Transplantation. Gastroenterol Res Pract 2020; 2020:3520686. [PMID: 32089675 PMCID: PMC7024100 DOI: 10.1155/2020/3520686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 12/17/2019] [Accepted: 01/07/2020] [Indexed: 12/18/2022] Open
Abstract
Altered densities of enteroendocrine cells play an important role in patients with irritable bowel syndrome (IBS). Uroguanylin activates guanylate cyclase-C to regulate intestinal electrolyte and water transport. Aim. To quantify uroguanylin immunoreactive cells density in the duodenum of diarrhea-predominant IBS (IBS-D) patients compared to controls and to investigate the effect of fecal microbiota transplantation (FMT) on these cell densities. Method. Twelve patients with IBS-D according to Rome III criteria were included. The cause was identified as post infectious (PI, n = 6) or idiopathic (n = 6). They completed the IBS-symptom questionnaire before and 3 weeks after FMT. Thirty grams of fresh feces donated from healthy relatives were diluted with 60 ml normal saline and instilled via endoscope into the duodenum. Biopsies were taken from the patients' duodenum before and 3 weeks after FMT. Duodenal biopsies taken from eight healthy controls were also included. The biopsies were immunostained for uroguanylin and quantified using computerized image analysis. Results. Uroguanylin immunoreactive cells were found both in duodenal villi and crypts in both controls and IBS-D patients. The densities of uroguanylin immunoreactive cells were significantly lower in the villi (P < 0.0001) and higher in the crypts (P < 0.0001) for the patients than the controls. Following FMT, the densities of uroguanylin immunoreactive cells for the total group and idiopathic subgroup decreased significantly in the duodenal crypts (P = 0.049 and 0.04, respectively) but not in the villi. No significant changes were shown in the PI-IBS subgroups. The cells density in only the crypts correlated with diarrhea (r = 0.97, P = 0.001) and bloating (r = -0.91, P = 0.01) in the PI-IBS subgroup before FMT and with abdominal pain (r = 0.63, P = 0.03) in the total group of IBS-D patients after FMT. Conclusion. Altered uroguanylin immunoreactive cells density was found in IBS-D patients compared to controls. Changes in these cells density following FMT correlated with IBS symptoms (diarrhea, bloating, and abdominal pain).
Collapse
Affiliation(s)
- Tarek Mazzawi
- Section of Gastroenterology, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Øystein Eikrem
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Gülen Arslan Lied
- Section of Gastroenterology, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Trygve Hausken
- Section of Gastroenterology, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| |
Collapse
|
6
|
Abstract
Introduction: As an analogue of uroguanylin plecanatide binds to the Guanylate Cyclase-C receptor activating fluid and ion secretion in the small intestine with the same pH-dependent binding kinetics as the natural ligand. Plecanatide has been FDA approved as safe and effective for the indications of Chronic Idiopathic Constipation (CIC) and Irritable Bowel Syndrome with Constipation (IBS-C).Areas covered: All clinical trial results supporting approval of plecanatide in IBS-C are reported, evaluated and interpreted in the context of the complex pathophysiology of functional diseases and the barriers that must be overcome for appropriate protocol design and conduct.Expert opinion: The Expert Opinion section discusses safety and efficacy of plecanatide for IBS-C. Broader consideration of some of the inherent challenges in understanding and treating functional gastrointestinal disorders includes: 1. the difficulty of understanding diseases with complex pathophysiology that clinically present with a few simple symptoms, 2. exploring the pathophysiology of functional diseases using pharmacophysiology, 3. value of 'Set Theory' in the evaluation of complex clinical data and 4. physiologic and pathophysiologic insight gained by evaluation 'physiologic redundancy' and 'conservation of function'.
Collapse
Affiliation(s)
- Philip B Miner
- Oklahoma Foundation for Digestive Research, Oklahoma City, OK, USA
| |
Collapse
|
7
|
Bassotti G, Usai Satta P, Bellini M. Plecanatide for the treatment of chronic idiopathic constipation in adult patients. Expert Rev Clin Pharmacol 2019; 12:1019-1026. [PMID: 31575291 DOI: 10.1080/17512433.2019.1670057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Introduction. Chronic idiopathic constipation (CIC) is a functional gastrointestinal disorder that is associated with an increased healthcare cost and an abnormally poor quality of life. Plecanatide is a natural analog to the peptide agonist of the guanylate cyclase-C (GC-C) receptor, uroguanylin. The conversion of guanosine 5-triphosphate to cyclic guanosine monophosphate results in an increased bowel fluid secretion. Plecanatide is a promising new agent for CIC unresponsive to current therapeutic regimes.Areas covered. A comprehensive online search of Medline and the Science Citation Index was made using the keywords 'plecanatide', 'guanylate cyclase-C agonists', and 'constipation', in various combinations. We reviewed the pharmacodynamics, pharmacokinetics, and metabolism of this agent, and the most significant studies regarding the clinical efficacy and safety of plecanatide in CIC therapy.Expert opinion. Experimental studies showed that plecanatide was significantly better than placebo in reducing CIC severity, straining, stool consistency, bowel movements and quality of life. Apart from limited cases of diarrhea, no serious adverse events were reported. However, few data are available on its long-term safety. Furthermore, patients' affordability of plecanatide can be limited by its costs. Finally, this new agent with a different way of action can be proposed in patients refractory to common therapy.
Collapse
Affiliation(s)
- Gabrio Bassotti
- Gastroenterology & Hepatology Section, Department of Medicine, University of Perugia Medical School, Perugia, Italy
| | | | - Massimo Bellini
- Gastrointestinal Unit, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| |
Collapse
|
8
|
Akieda-Asai S, Ma H, Date Y. Palmitic acid induces guanylin gene expression through the Toll-like receptor 4/nuclear factor-κB pathway in rat macrophages. Am J Physiol Cell Physiol 2019; 317:C1239-C1246. [PMID: 31553648 DOI: 10.1152/ajpcell.00081.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, we showed that double-transgenic rats overexpressing guanylin (Gn), a bioactive peptide, and its receptor, guanylyl cyclase-C (GC-C), specifically in macrophages demonstrate an antiobesity phenotype and low-expression levels of proinflammatory cytokines in the mesenteric fat even when fed a high-fat diet. Here, we examined the levels and mechanism of Gn and GC-C transcription following saturated fatty acid and lipopolysaccharide (LPS), an activator of Toll-like receptor 4 (TLR4), exposure by using the NR8383 macrophage cell line. In addition, the levels of guanylin and cGMP were increased by addition of either palmitic acid or LPS. Next, we investigated the interaction of the gene transcription and nuclear factor-κB (NF-κB) by using an NF-κB inhibitor and chromatin immunoprecipitation assay. We showed that palmitic acid induced Gn gene expression via TLR4 and NF-κB. Moreover, we demonstrated that NF-κB binding to the Gn promoter was responsible for the induction of gene transcription by palmitic acid or LPS. Our results indicate that saturated fatty acids such as palmitic acid activate Gn gene expression via the NF-κB pathway, raising the possibility that the activated Gn-GC-C system may contribute to the inhibition of high-fat diet-induced proinflammatory cytokines in macrophages.
Collapse
Affiliation(s)
- Sayaka Akieda-Asai
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Hao Ma
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Yukari Date
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| |
Collapse
|
9
|
Zegeye ED, Govasli ML, Sommerfelt H, Puntervoll P. Development of an enterotoxigenic Escherichia coli vaccine based on the heat-stable toxin. Hum Vaccin Immunother 2018; 15:1379-1388. [PMID: 30081709 PMCID: PMC6663125 DOI: 10.1080/21645515.2018.1496768] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Infection with enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea-related illness and death among children under 5 years of age in low– and middle-income countries (LMIC). Recent studies have found that it is the ETEC subtypes that produce the heat-stable enterotoxin (ST), irrespective of whether they also secrete the heat-labile enterotoxin (LT), which contribute most importantly to the disease burden in children from LMIC. Therefore, adding an ST toxoid would importantly complement ongoing ETEC vaccine development efforts. The ST’s potent toxicity, its structural similarity to the endogenous peptides guanylin and uroguanylin, and its poor immunogenicity have all complicated the advancement of ST-based vaccine development. Recent remarkable progress, however, including the unprecedented screening for optimal ST mutants, mapping of cross-reacting ST epitopes and improved ST-carrier coupling strategies (bioconjugation and genetic fusion), enables the rational design of safe, immunogenic, and well-defined ST-based vaccine candidates.
Collapse
Affiliation(s)
| | | | - Halvor Sommerfelt
- b Centre for Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care , University of Bergen , Bergen , Norway.,c Norwegian Institute of Public Health , Oslo , Norway
| | - Pål Puntervoll
- a Centre for Applied Biotechnology , Uni Research AS , Bergen , Norway
| |
Collapse
|
10
|
Akieda-Asai S, Ida T, Miyazato M, Kangawa K, Date Y. Interleukin-15 derived from Guanylin-GC-C-expressing macrophages inhibits fatty acid synthase in adipocytes. Peptides 2018; 99:14-19. [PMID: 29097254 DOI: 10.1016/j.peptides.2017.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 01/13/2023]
Abstract
Recently we found that guanylin (Gn) and its receptor, guanylyl cyclase C (GC-C), are uniquely expressed in the mesenteric macrophages of some diet-resistant rats and that double-transgenic (dTg) rats overexpressing Gn and GC-C in macrophages demonstrate reduced fatty acid synthase and fat accumulation in fat tissue even when fed a high-fat diet (HFD). Lipid accumulation and fatty acid synthase mRNA levels in cocultured dTg rat adipocytes and macrophages were reduced compared with those in adipocytes cultured with WT rat macrophages. Here, we investigated whether Interleukin-15 (IL-15) derived from Gn-GC-C-expressing macrophages regulates lipid accumulation in adipocytes. IL-15 inhibited fatty acid synthase and lipid accumulation via STAT5 in cultured adipocytes. IL-15 mRNA and protein levels in the mesenteric fat of HFD-fed dTg rats were significantly higher than those of HFD-fed WT rats. Phosphorylated STAT5 levels in the mesenteric fat of HFD-fed dTg rats were increased compared with those of HFD-fed WT rats. In addition, the mRNA level of fatty acid synthase in the mesenteric fat was lower in HFD-fed dTg rats than in HFD-fed WT rats. These results support the hypothesis that IL-15 secreted from Gn-GC-C-expressing macrophages contributes to the inhibition of fatty acid synthase and lipid accumulation in adipocytes, leading to obesity resistance.
Collapse
Affiliation(s)
- Sayaka Akieda-Asai
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Takanori Ida
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan
| | - Yukari Date
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan.
| |
Collapse
|
11
|
von Volkmann HL, Brønstad I, Gilja OH, R Tronstad R, Sangnes DA, Nortvedt R, Hausken T, Dimcevski G, Fiskerstrand T, Nylund K. Prolonged intestinal transit and diarrhea in patients with an activating GUCY2C mutation. PLoS One 2017; 12:e0185496. [PMID: 28957388 PMCID: PMC5619782 DOI: 10.1371/journal.pone.0185496] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 09/13/2017] [Indexed: 12/21/2022] Open
Abstract
Introduction Increased intestinal hydration by activation of the epithelial enzyme linked receptor guanylate cyclase C (GC-C) is a pharmacological principle for treating constipation. Activating mutations in the GUCY2C gene encoding GC-C cause Familial GUCY2C diarrhea syndrome (FGDS) which has been diagnosed with severe dysmotility. Aim To investigate gut motility and hormones before and after a meal in FGDS patients and compare with healthy controls (HC). Subjects and methods Bristol stool chart and stool frequency was assessed. Before and after a meal occlusive and non-occlusive contractions were obtained using ultrasound. A wireless motility capsule (WMC) recorded gut transit time, pH, contractions and pressure. Plasma levels of selected gut hormones were measured at different time points. Results The FGDS patients had 4 (range 1–10) loose stools/day and prolonged total gut transit time compared to HC, 55.5 h vs 28.5 h, respectively,with significantly increased colon transit time. In FGDS patients, pH in duodenum, small bowel and colon was increased and the number of contractions and the intraluminal pressure were significantly decreased, measured by WMC. Ultrasound showed in small bowel increased number of non-occlusive contractions in the FGDS patients. Serotonin (5-HT) plasma levels in the HC peaked 30 min after the meal, while the FGDS patients had no response. Conclusion Despite having diarrhea, the FGDS patients have prolonged transit time through the gut compared to HC, particularly in colon. The reduced number of intestinal contractions and lack of 5-HT release after a meal in FGDS patients surprisingly resemble colonic motility disturbances seen in patients with constipation.
Collapse
Affiliation(s)
- Hilde L von Volkmann
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Ingeborg Brønstad
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Odd Helge Gilja
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Rune R Tronstad
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Dag Andre Sangnes
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway
| | - Ragnar Nortvedt
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway
| | - Trygve Hausken
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Georg Dimcevski
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Torunn Fiskerstrand
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Centres for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Kim Nylund
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
12
|
A Randomized Phase III Clinical Trial of Plecanatide, a Uroguanylin Analog, in Patients With Chronic Idiopathic Constipation. Am J Gastroenterol 2017; 112:613-621. [PMID: 28169285 PMCID: PMC5415706 DOI: 10.1038/ajg.2016.611] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/02/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVES This study assessed the efficacy and safety of plecanatide, a guanylate cyclase-C (GC-C) agonist and the first uroguanylin analog approved for the treatment of chronic idiopathic constipation (CIC). METHODS This phase III, multicenter, double-blind, placebo-controlled study randomized 1,394 patients with CIC. Patients received either plecanatide (3 or 6 mg) or placebo, orally, once daily, for 12 weeks. The primary efficacy endpoint was the percentage of patients who were durable overall complete spontaneous bowel movement (CSBM) responders over the 12-week treatment period. Patients were instructed to record their daily bowel movements, stool consistency scores, and abdominal symptoms in an electronic diary. Treatment-emergent adverse events (AEs) were collected. RESULTS Each dose of plecanatide resulted in a significantly greater percentage of durable overall CSBM responders (21.0%, 3 mg; 19.5%, 6 mg) as compared with placebo (10.2%; P<0.001 for both). Plecanatide (3 and 6 mg) also significantly increased mean weekly CSBM frequency from baseline (increase of 2.5 and 2.2/week, respectively) vs. placebo (1.2/week; P<0.001 for both) and mean weekly spontaneous bowel movement frequency (increase of 3.2 and 3.1/week, respectively) vs. placebo (1.3/week; P<0.001, for both) over the 12-week treatment period. Both plecanatide doses significantly improved all secondary and additional efficacy endpoints. The most common AE, diarrhea, occurred in 1.3% (placebo), 5.9% (3 mg) and 5.7% (6 mg) of patients. CONCLUSIONS Plecanatide significantly improved constipation and its related symptoms with a low rate of adverse events. These results suggest that plecanatide will be a useful treatment option in the management of CIC. ClinicalTrials.gov: NCT01982240.
Collapse
|
13
|
Williams KR, Colangelo CM, Hou L, Chung L, Belcher JM, Abbott T, Hall IE, Zhao H, Cantley LG, Parikh CR. Use of a Targeted Urine Proteome Assay (TUPA) to identify protein biomarkers of delayed recovery after kidney transplant. Proteomics Clin Appl 2017; 11. [PMID: 28261998 DOI: 10.1002/prca.201600132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/17/2017] [Accepted: 03/01/2017] [Indexed: 11/07/2022]
Abstract
PURPOSE Development of delayed graft function (DGF) following kidney transplant is associated with poor outcomes. An ability to rapidly identify patients with DGF versus those with immediate graft function (IGF) may facilitate the treatment of DGF and the research needed to improve prognosis. The purpose of this study was to use a Targeted Urine Proteome Assay to identify protein biomarkers of delayed recovery from kidney transplant. EXPERIMENTAL DESIGN Potential biomarkers were identified using the Targeted Urine Proteome (MRM) Assay to interrogate the relative DGF/IGF levels of expression of 167 proteins in urine taken 12-18 h after kidney implantation from 21 DGF, 15 SGF (slow graft function), and 16 IGF patients. An iterative Random Forest analysis approach evaluated the relative importance of each biomarker, which was then used to identify an optimum biomarker panel that provided the maximum sensitivity and specificity with the least number of biomarkers. CONCLUSIONS AND CLINICAL RELEVANCE Four proteins were identified that together distinguished DGF with a sensitivity of 77.4%, specificity of 82.6%, and AUC of 0.891. This panel represents an important step toward identifying DGF at an early stage so that more effective treatments can be developed to improve long-term graft outcomes.
Collapse
Affiliation(s)
- Kenneth R Williams
- W.M. Keck Foundation Biotechnology Laboratory, Yale University School of Medicine, New Haven, USA
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, USA
| | | | - Lin Hou
- Center for Statistical Science, Tsinghua University, Beijing, China
| | - Lisa Chung
- W.M. Keck Foundation Biotechnology Laboratory, Yale University School of Medicine, New Haven, USA
| | - Justin M Belcher
- Internal Medicine, Yale University School of Medicine, New Haven, USA
| | - Thomas Abbott
- W.M. Keck Foundation Biotechnology Laboratory, Yale University School of Medicine, New Haven, USA
| | - Isaac E Hall
- Division of Nephrology, Hypertension & Renal Transplantation, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, USA
| | - Hongyu Zhao
- Epidemiology & Public Health, Yale University School of Medicine, New Haven, USA
| | - Lloyd G Cantley
- Internal Medicine, Yale University School of Medicine, New Haven, USA
| | - Chirag R Parikh
- Internal Medicine, Yale University School of Medicine, New Haven, USA
- Program of Applied Translational Research, Yale University School of Medicine, New Haven, USA
| |
Collapse
|
14
|
Møller MN, Kirkeby S, Vikeså J, Nielsen FC, Cayé-Thomasen P. The human endolymphatic sac expresses natriuretic peptides. Laryngoscope 2017; 127:E201-E208. [DOI: 10.1002/lary.26074] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/07/2016] [Accepted: 04/12/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Martin Nue Møller
- Department of Otorhinolaryngology, Head and Neck Surgery; Rigshospitalet; Copenhagen Denmark
| | - Svend Kirkeby
- Department of Oral Medicine, Dental School, Panum Institute; University of Copenhagen; Copenhagen Denmark
| | - Jonas Vikeså
- Center for Genomic Medicine; University of Copenhagen; Rigshospitalet Copenhagen Denmark
| | - Finn Cilius Nielsen
- Center for Genomic Medicine; University of Copenhagen; Rigshospitalet Copenhagen Denmark
| | - Per Cayé-Thomasen
- Department of Otorhinolaryngology, Head and Neck Surgery; Rigshospitalet; Copenhagen Denmark
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| |
Collapse
|
15
|
Pires ÁS, Porto WF, Castro PO, Franco OL, Alencar SA. Theoretical structural characterization of lymphoguanylin: A potential candidate for the development of drugs to treat gastrointestinal disorders. J Theor Biol 2017; 419:193-200. [PMID: 28214543 DOI: 10.1016/j.jtbi.2017.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/18/2017] [Accepted: 02/13/2017] [Indexed: 10/20/2022]
Abstract
Guanylin peptides (GPs) are small cysteine-rich peptide hormones involved in salt absorption, regulation of fluids and electrolyte homeostasis. This family presents four members: guanylin (GN), uroguanylin (UGN), lymphoguanylin (LGN) and renoguanylin (RGN). GPs have been used as templates for the development of drugs for the treatment of gastrointestinal disorders. Currently, LGN is the only GP with only one disulfide bridge, making it a remarkable member of this family and a potential drug template; however, there is no structural information about this peptide. In fact, LGN is predicted to be highly disordered and flexible, making it difficult to obtain structural information using in vitro methods. Therefore, this study applied a series of 1μs molecular dynamics simulations in order to understand the structural behavior of LGN, comparing it to the C115Y variant of GN, which shows the same Cys to Tyr modification. LGN showed to be more flexible than GN C115Y. While the negatively charged N-terminal, despite its repellent behavior, seems to be involved mainly in pH-dependent activity, the hydrophobic core showed to be the determinant factor in LGN's flexibility, which could be essential in its activity. These findings may be determinant in the development of new medicines to help in the treatment of gastrointestinal disorders. Moreover, our investigation of LGN structure clarified some issues in the structure-activity relationship of this peptide, providing new knowledge of guanylin peptides and clarifying the differences between GN C115Y and LGN.
Collapse
Affiliation(s)
- Állan S Pires
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil; Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil
| | - William F Porto
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil; Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil; Porto Reports, Brasília-DF, Brazil
| | - Pryscilla O Castro
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil
| | - Octavio L Franco
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil; Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil; S-Inova Biotech, Pós-graduação em Biotecnologia, Universidade Católica Dom Bosco,, Campo Grande, MS, Brazil
| | - Sérgio A Alencar
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF, Brazil.
| |
Collapse
|
16
|
von Volkmann HL, Nylund K, Tronstad RR, Hovdenak N, Hausken T, Fiskerstrand T, Gilja OH. An activating gucy2c mutation causes impaired contractility and fluid stagnation in the small bowel. Scand J Gastroenterol 2016; 51:1308-15. [PMID: 27338166 DOI: 10.1080/00365521.2016.1200139] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Familial GUCY2C diarrhoea syndrome (FGDS) is caused by an activating mutation in the GUCY2C gene encoding the receptor guanylate cyclase C in enterocytes. Activation leads to increased secretion of fluid into the intestinal lumen. Twenty percent of the patients have increased risk of Crohn's disease and intestinal obstruction (CD, 20%) and the condition resembles irritable bowel syndrome with diarrhoea. We aimed to describe fluid content, contractility, peristaltic activity and bowel wall thickness in the intestine in fasting FGDS patients, using ultrasound, with healthy volunteers serving as controls. METHODS Twenty-three patients with FGDS and 22 healthy controls (HC) were examined with a Logiq E9 scanner in a fasting state. Bowel wall thickness was measured and fluid-filled small bowel loops were counted using three-dimensional (3D) magnetic positioning navigation. The HC ingested 500 ml PEG solution, an electrolyte balanced, non-absorbable solution, in order to investigate the contractions of the small bowel. RESULTS The fasting 23 FGDS patients had significantly higher number of fluid-filled small bowel segments compared to 22 fasting HC, p < 0.001. A high number of non-occlusive contractions in the ileum was observed, which was significant when compared to HC after ingesting PEG solution, p < 0.016. An increase in intestinal wall thickness or other signs of CD were not observed. CONCLUSIONS FGDS is characterised by multiple, fluid-filled small bowel loops with incomplete contractions and fluid stagnation in fasting state. These findings may play a role in the increased risk of bowel obstruction as well as IBS-like symptoms observed in these patients.
Collapse
Affiliation(s)
- Hilde Løland von Volkmann
- a National Centre for Ultrasound in Gastroenterology , Haukeland University Hospital , Bergen , Norway ;,b Department of Clinical Medicine , University of Bergen , Bergen , Norway
| | - Kim Nylund
- a National Centre for Ultrasound in Gastroenterology , Haukeland University Hospital , Bergen , Norway ;,b Department of Clinical Medicine , University of Bergen , Bergen , Norway
| | - Rune Rose Tronstad
- c Department of Pediatrics , Haukeland University Hospital , Bergen , Norway ;,d Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Nils Hovdenak
- b Department of Clinical Medicine , University of Bergen , Bergen , Norway
| | - Trygve Hausken
- a National Centre for Ultrasound in Gastroenterology , Haukeland University Hospital , Bergen , Norway ;,b Department of Clinical Medicine , University of Bergen , Bergen , Norway
| | - Torunn Fiskerstrand
- d Department of Clinical Science , University of Bergen , Bergen , Norway ;,e Center for Medical Genetics and Molecular Medicine , Haukeland University Hospital , Bergen , Norway
| | - Odd Helge Gilja
- a National Centre for Ultrasound in Gastroenterology , Haukeland University Hospital , Bergen , Norway ;,b Department of Clinical Medicine , University of Bergen , Bergen , Norway
| |
Collapse
|
17
|
Sterl K, Wang S, Oestricker L, Wallendorf MJ, Patterson BW, Reeds DN, Wice BM. Metabolic responses to xenin-25 are altered in humans with Roux-en-Y gastric bypass surgery. Peptides 2016; 82:76-84. [PMID: 27288245 PMCID: PMC4958565 DOI: 10.1016/j.peptides.2016.06.001] [Citation(s) in RCA: 12] [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: 05/11/2016] [Revised: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 12/25/2022]
Abstract
Xenin-25 (Xen) is a neurotensin-related peptide secreted by a subset of enteroendocrine cells located in the proximal small intestine. Many effects of Xen are mediated by neurotensin receptor-1 on neurons. In healthy humans with normal glucose tolerance (NGT), Xen administration causes diarrhea and inhibits postprandial glucagon-like peptide-1 (GLP-1) release but not insulin secretion. This study determines (i) if Xen has similar effects in humans with Roux-en-Y gastric bypass (RYGB) and (ii) whether neural pathways potentially mediate effects of Xen on glucose homeostasis. Eight females with RYGB and no history of type 2 diabetes received infusions with 0, 4 or 12pmol Xen/kg/min with liquid meals on separate occasions. Plasma glucose and gastrointestinal hormone levels were measured and insulin secretion rates calculated. Pancreatic polypeptide and neuropeptide Y levels were surrogate markers for parasympathetic input to islets and sympathetic tone, respectively. Responses were compared to those in well-matched non-surgical participants with NGT from our earlier study. Xen similarly increased pancreatic polypeptide and neuropeptide Y responses in patients with and without RYGB. In contrast, the ability of Xen to inhibit GLP-1 release and cause diarrhea was severely blunted in patients with RYGB. With RYGB, Xen had no statistically significant effect on glucose, insulin secretory, GLP-1, glucose-dependent insulinotropic peptide, and glucagon responses. However, insulin and glucose-dependent insulinotropic peptide secretion preceded GLP-1 release suggesting circulating GLP-1 does not mediate exaggerated insulin release after RYGB. Thus, Xen has unmasked neural circuits to the distal gut that inhibit GLP-1 secretion, cause diarrhea, and are altered by RYGB.
Collapse
Affiliation(s)
- Karin Sterl
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO 63110
| | - Songyan Wang
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO 63110
| | - Lauren Oestricker
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO 63110
| | - Michael J Wallendorf
- Department of Internal Medicine, Divsion of Biostatistics, Washington University School of Medicine, Saint Louis, MO 63110
| | - Bruce W Patterson
- Department of Internal Medicine, Division of Nutritional Science, Washington University School of Medicine, Saint Louis, MO 63110
| | - Dominic N Reeds
- Department of Internal Medicine, Division of Nutritional Science, Washington University School of Medicine, Saint Louis, MO 63110
| | - Burton M Wice
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO 63110
| |
Collapse
|
18
|
Uroguanylin modulates (Na++K+)ATPase in a proximal tubule cell line: Interactions among the cGMP/protein kinase G, cAMP/protein kinase A, and mTOR pathways. Biochim Biophys Acta Gen Subj 2016; 1860:1431-8. [PMID: 27102282 DOI: 10.1016/j.bbagen.2016.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/31/2016] [Accepted: 04/15/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND The natriuretic effect of uroguanylin (UGN) involves reduction of proximal tubule (PT) sodium reabsorption. However, the target sodium transporters as well as the molecular mechanisms involved in these processes remain poorly understood. METHODS To address the effects of UGN on PT (Na(+)+K(+))ATPase and the signal transduction pathways involved in this effect, we used LLC-PK1 cells. The effects of UGN were determined through ouabain-sensitive ATP hydrolysis and immunoblotting assays during different experimental conditions. RESULTS We observed that UGN triggers cGMP/PKG and cAMP/PKA pathways in a sequential way. The activation of PKA leads to the inhibition of mTORC2 activity, PKB phosphorylation at S473, PKB activity and, consequently, a decrease in the mTORC1/S6K pathway. The final effects are decreased expression of the α1 subunit of (Na(+)+K(+))ATPase and inhibition of enzyme activity. CONCLUSIONS These results suggest that the molecular mechanism of action of UGN on sodium reabsorption in PT cells is more complex than previously thought. We propose that PKG-dependent activation of PKA leads to the inhibition of the mTORC2/PKB/mTORC1/S6K pathway, an important signaling pathway involved in the maintenance of the PT sodium pump expression and activity. GENERAL SIGNIFICANCE The current results expand our understanding of the signal transduction pathways involved in the overall effect of UGN on renal sodium excretion.
Collapse
|
19
|
Jarmuż A, Zielińska M, Storr M, Fichna J. Emerging treatments in Neurogastroenterology: Perspectives of guanylyl cyclase C agonists use in functional gastrointestinal disorders and inflammatory bowel diseases. Neurogastroenterol Motil 2015; 27:1057-68. [PMID: 25930667 DOI: 10.1111/nmo.12574] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/28/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Functional gastrointestinal disorders (FGID) and inflammatory bowel diseases (IBD) are the most frequent pathologic conditions affecting the gastrointestinal (GI) tract and both significantly reduce patients' quality of life. Recent studies suggest that guanylyl cyclase C (GC-C) expressed in the GI tract constitutes a novel pharmacological target in the treatment of FGID and IBD. Endogenous GC-C agonists - guanylin peptides: guanylin and uroguanylin, by the regulation of water and electrolyte transport, are involved in the maintenance of homeostasis in the intestines and integrity of the intestinal mucosa. Linaclotide, a synthetic agonist of GC-C was approved by Food and Drug Administration and European Medicines Agency as a therapeutic in constipation-predominant irritable bowel syndrome (IBS-C) and chronic idiopathic constipation (CIC). Lately, several preclinical and clinical trials focused on assessment of therapeutic properties of synthetic agonists of uroguanylin, plecanatide, and SP-333. Plecanatide is currently tested as a potential therapeutic in diseases related to constipation and SP-333 is a promising drug in ulcerative colitis treatment. PURPOSE Here, we discuss the most recent findings and future trends on the development of GC-C agonists and their use in clinical trials.
Collapse
Affiliation(s)
- A Jarmuż
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - M Zielińska
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - M Storr
- Walter Brendel Center of Experimental Medicine, Ludwig Maximilians University Munich, Munich, Germany.,Center of Endoscopy, Starnberg, Germany
| | - J Fichna
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| |
Collapse
|