1
|
Paradiž Leitgeb E, Kerčmar J, Križančić Bombek L, Pohorec V, Skelin Klemen M, Slak Rupnik M, Gosak M, Dolenšek J, Stožer A. Exendin-4 affects calcium signalling predominantly during activation and activity of beta cell networks in acute mouse pancreas tissue slices. Front Endocrinol (Lausanne) 2024; 14:1315520. [PMID: 38292770 PMCID: PMC10826511 DOI: 10.3389/fendo.2023.1315520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Tight control of beta cell stimulus-secretion coupling is crucial for maintaining homeostasis of energy-rich nutrients. While glucose serves as a primary regulator of this process, incretins augment beta cell function, partly by enhancing cytosolic [Ca2+] dynamics. However, the details of how precisely they affect beta cell recruitment during activation, their active time, and functional connectivity during plateau activity, and how they influence beta cell deactivation remain to be described. Performing functional multicellular Ca2+ imaging in acute mouse pancreas tissue slices enabled us to systematically assess the effects of the GLP-1 receptor agonist exendin-4 (Ex-4) simultaneously in many coupled beta cells with high resolution. In otherwise substimulatory glucose, Ex-4 was able to recruit approximately a quarter of beta cells into an active state. Costimulation with Ex-4 and stimulatory glucose shortened the activation delays and accelerated beta cell activation dynamics. More specifically, active time increased faster, and the time required to reach half-maximal activation was effectively halved in the presence of Ex-4. Moreover, the active time and regularity of [Ca2+]IC oscillations increased, especially during the first part of beta cell response. In contrast, subsequent addition of Ex-4 to already active cells did not significantly enhance beta cell activity. Network analyses further confirmed increased connectivity during activation and activity in the presence of Ex-4, with hub cell roles remaining rather stable in both control experiments and experiments with Ex-4. Interestingly, Ex-4 demonstrated a biphasic effect on deactivation, slightly prolonging beta cell activity at physiological concentrations and shortening deactivation delays at supraphysiological concentrations. In sum, costimulation by Ex-4 and glucose increases [Ca2+]IC during beta cell activation and activity, indicating that the effect of incretins may, to an important extent, be explained by enhanced [Ca2+]IC signals. During deactivation, previous incretin stimulation does not critically prolong cellular activity, which corroborates their low risk of hypoglycemia.
Collapse
Affiliation(s)
- Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jasmina Kerčmar
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | | | - Vilijem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| |
Collapse
|
2
|
Skelin Klemen M, Dolenšek J, Križančić Bombek L, Pohorec V, Gosak M, Slak Rupnik M, Stožer A. The effect of forskolin and the role of Epac2A during activation, activity, and deactivation of beta cell networks. Front Endocrinol (Lausanne) 2023; 14:1225486. [PMID: 37701894 PMCID: PMC10494243 DOI: 10.3389/fendo.2023.1225486] [Citation(s) in RCA: 1] [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: 05/19/2023] [Accepted: 08/08/2023] [Indexed: 09/14/2023] Open
Abstract
Beta cells couple stimulation by glucose with insulin secretion and impairments in this coupling play a central role in diabetes mellitus. Cyclic adenosine monophosphate (cAMP) amplifies stimulus-secretion coupling via protein kinase A and guanine nucleotide exchange protein 2 (Epac2A). With the present research, we aimed to clarify the influence of cAMP-elevating diterpene forskolin on cytoplasmic calcium dynamics and intercellular network activity, which are two of the crucial elements of normal beta cell stimulus-secretion coupling, and the role of Epac2A under normal and stimulated conditions. To this end, we performed functional multicellular calcium imaging of beta cells in mouse pancreas tissue slices after stimulation with glucose and forskolin in wild-type and Epac2A knock-out mice. Forskolin evoked calcium signals in otherwise substimulatory glucose and beta cells from Epac2A knock-out mice displayed a faster activation. During the plateau phase, beta cells from Epac2A knock-out mice displayed a slightly higher active time in response to glucose compared with wild-type littermates, and stimulation with forskolin increased the active time via an increase in oscillation frequency and a decrease in oscillation duration in both Epac2A knock-out and wild-type mice. Functional network properties during stimulation with glucose did not differ in Epac2A knock-out mice, but the presence of Epac2A was crucial for the protective effect of stimulation with forskolin in preventing a decline in beta cell functional connectivity with time. Finally, stimulation with forskolin prolonged beta cell activity during deactivation, especially in Epac2A knock-out mice.
Collapse
Affiliation(s)
- Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | | | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| |
Collapse
|
3
|
Ramanadham S, Turk J, Bhatnagar S. Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes. Compr Physiol 2023; 13:5023-5049. [PMID: 37358504 PMCID: PMC10809800 DOI: 10.1002/cphy.c220031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.
Collapse
Affiliation(s)
- Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
| | - John Turk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sushant Bhatnagar
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
| |
Collapse
|
4
|
Utilizing the Off-Target Effects of T1R3 Antagonist Lactisole to Enhance Nitric Oxide Production in Basal Airway Epithelial Cells. Nutrients 2023; 15:nu15030517. [PMID: 36771227 PMCID: PMC9919013 DOI: 10.3390/nu15030517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Human airway sweet (T1R2 + T1R3), umami (T1R1 + T1R3), and bitter taste receptors (T2Rs) are critical components of the innate immune system, acting as sensors to monitor pathogenic growth. T2Rs detect bacterial products or bitter compounds to drive nitric oxide (NO) production in both healthy and diseased epithelial cell models. The NO enhances ciliary beating and also directly kills pathogens. Both sweet and umami receptors have been characterized to repress bitter taste receptor signaling in healthy and disease models. We hypothesized that the sweet/umami T1R3 antagonist lactisole may be used to alleviate bitter taste receptor repression in airway basal epithelial cells and enhance NO production. Here, we show that lactisole activates cAMP generation, though this occurs through a pathway independent of T1R3. This cAMP most likely signals through EPAC to increase ER Ca2+ efflux. Stimulation with denatonium benzoate, a bitter taste receptor agonist which activates largely nuclear and mitochondrial Ca2+ responses, resulted in a dramatically increased cytosolic Ca2+ response in cells treated with lactisole. This cytosolic Ca2+ signaling activated NO production in the presence of lactisole. Thus, lactisole may be useful coupled with bitter compounds as a therapeutic nasal rinse or spray to enhance beneficial antibacterial NO production in patients suffering from chronic inflammatory diseases such as chronic rhinosinusitis.
Collapse
|
5
|
Savory Signaling: T1R Umami Receptor Modulates Endoplasmic Reticulum Calcium Store Content and Release Dynamics in Airway Epithelial Cells. Nutrients 2023; 15:nu15030493. [PMID: 36771200 PMCID: PMC9919336 DOI: 10.3390/nu15030493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/19/2023] Open
Abstract
T1Rs are expressed in solitary chemosensory cells of the upper airway where they detect apical glucose levels and repress bitter taste receptor Ca2+ signaling pathways. Microbial growth leads to a decrease in apical glucose levels. T1Rs detect this change and liberate bitter taste receptor signaling, initiating an innate immune response to both kill and expel pathogens through releasing antimicrobial peptides and increasing nitric oxide production and ciliary beat frequency. However, chronic inflammation due to disease, smoking, or viral infections causes a remodeling of the epithelial airway. The resulting squamous metaplasia causes a loss of multi-ciliated cells and solitary chemosensory cells, replaced by basal epithelial cells. To understand how T1R function is altered during disease, we used basal epithelial cells as a model to study the function of T1R3 on Ca2+ signaling dynamics. We found that both T1R1 and T1R3 detect amino acids and signal via cAMP, increasing the responsiveness of the cells to Ca2+ signaling stimuli. Either knocking down T1R1/3 or treating wild-type cells with MEM amino acids caused a reduction in ER Ca2+ content through a non-cAMP signaled pathway. Treatment with amino acids led to a reduction in downstream denatonium-induced Ca2+-signaled caspase activity. Thus, amino acids may be used to reduce unwanted apoptosis signaling in treatments containing bitter compounds.
Collapse
|
6
|
Harvey KE, Tang S, LaVigne EK, Pratt EPS, Hockerman GH. RyR2 regulates store-operated Ca2+ entry, phospholipase C activity, and electrical excitability in the insulinoma cell line INS-1. PLoS One 2023; 18:e0285316. [PMID: 37141277 PMCID: PMC10159205 DOI: 10.1371/journal.pone.0285316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
The ER Ca2+ channel ryanodine receptor 2 (RyR2) is required for maintenance of insulin content and glucose-stimulated insulin secretion, in part, via regulation of the protein IRBIT in the insulinoma cell line INS-1. Here, we examined store-operated and depolarization-dependent Ca2+entry using INS-1 cells in which either RyR2 or IRBIT were deleted. Store-operated Ca2+ entry (SOCE) stimulated with thapsigargin was reduced in RyR2KO cells compared to controls, but was unchanged in IRBITKO cells. STIM1 protein levels were not different between the three cell lines. Basal and stimulated (500 μM carbachol) phospholipase C (PLC) activity was also reduced specifically in RyR2KO cells. Insulin secretion stimulated by tolbutamide was reduced in RyR2KO and IRBITKO cells compared to controls, but was potentiated by an EPAC-selective cAMP analog in all three cell lines. Cellular PIP2 levels were increased and cortical f-actin levels were reduced in RyR2KO cells compared to controls. Whole-cell Cav channel current density was increased in RyR2KO cells compared to controls, and barium current was reduced by acute activation of the lipid phosphatase pseudojanin preferentially in RyR2KO cells over control INS-1 cells. Action potentials stimulated by 18 mM glucose were more frequent in RyR2KO cells compared to controls, and insensitive to the SK channel inhibitor apamin. Taken together, these results suggest that RyR2 plays a critical role in regulating PLC activity and PIP2 levels via regulation of SOCE. RyR2 also regulates β-cell electrical activity by controlling Cav current density and SK channel activation.
Collapse
Affiliation(s)
- Kyle E Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Shiqi Tang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Emily K LaVigne
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Evan P S Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| |
Collapse
|
7
|
Calcium-dependent cAMP mediates the mechanoresponsive behaviour of endothelial cells to high-frequency nanomechanostimulation. Biomaterials 2023; 292:121866. [PMID: 36526351 DOI: 10.1016/j.biomaterials.2022.121866] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/10/2022] [Accepted: 10/18/2022] [Indexed: 12/15/2022]
Abstract
The endothelial junction plays a central role in regulating intravascular and interstitial tissue permeability. The ability to manipulate its integrity therefore not only facilitates an improved understanding of its underlying molecular mechanisms but also provides insight into potential therapeutic solutions. Herein, we explore the effects of short-duration nanometer-amplitude MHz-order mechanostimulation on interendothelial junction stability and hence the barrier capacity of endothelial monolayers. Following an initial transient in which the endothelial barrier is permeabilised due to Rho-ROCK-activated actin stress fibre formation and junction disruption typical of a cell's response to insults, we observe, quite uniquely, the integrity of the endothelial barrier to not only spontaneously recover but also to be enhanced considerably-without the need for additional stimuli or intervention. Central to this peculiar biphasic response, which has not been observed with other stimuli to date, is the role of second messenger calcium and cyclic adenosine monophosphate (cAMP) signalling. We show that intracellular Ca2+, modulated by the high frequency excitation, is responsible for activating reorganisation of the actin cytoskeleton in the barrier recovery phase, in which circumferential actin bundles are formed to stabilise the adherens junctions via a cAMP-mediated Epac1-Rap1 pathway. Despite the short-duration stimulation (8 min), the approximate 4-fold enhancement in the transendothelial electrical resistance (TEER) of endothelial cells from different tissue sources, and the corresponding reduction in paracellular permeability, was found to persist over hours. The effect can further be extended through multiple treatments without resulting in hyperpermeabilisation of the barrier, as found with prolonged use of chemical stimuli, through which only 1.1- to 1.2-fold improvement in TEER has been reported. Such an ability to regulate and enhance endothelial barrier capacity is particularly useful in the development of in vitro barrier models that more closely resemble their in vivo counterparts.
Collapse
|
8
|
El Eid L, Reynolds CA, Tomas A, Ben Jones. Biased Agonism and Polymorphic Variation at the GLP-1 Receptor: Implications for the Development of Personalised Therapeutics. Pharmacol Res 2022; 184:106411. [PMID: 36007775 DOI: 10.1016/j.phrs.2022.106411] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 10/15/2022]
Abstract
Glucagon-like peptide-1 receptor (GLP-1R) is a well-studied incretin hormone receptor and target of several therapeutic drugs for type 2 diabetes (T2D), obesity and, more recently, cardiovascular disease. Some signalling pathways downstream of GLP-1R may be responsible for drug adverse effects such as nausea, while others mediate therapeutic outcomes of incretin-based T2D therapeutics. Understanding the interplay between different factors that alter signalling, trafficking, and receptor activity, including biased agonism, single nucleotide polymorphisms and structural modifications is key to develop the next-generation of personalised GLP-1R agonists. However, these interactions remain poorly described, especially for novel therapeutics such as dual and tri-agonists that target more than one incretin receptor. Comparison of GLP-1R structures in complex with G proteins and different peptide and non-peptide agonists has revealed novel insights into important agonist-residue interactions and networks crucial for receptor activation, recruitment of G proteins and engagement of specific signalling pathways. Here, we review the latest knowledge on GLP-1R structure and activation, providing structural evidence for biased agonism and delineating important networks associated with this phenomenon. We survey current biased agonists and multi-agonists at different stages of development, highlighting possible challenges in their translational potential. Lastly, we discuss findings related to non-synonymous genomic variants of GLP1R and the functional importance of specific residues involved in GLP-1R function. We propose that studies of GLP-1R polymorphisms, and specifically their effect on receptor dynamics and pharmacology in response to biased agonists, could have a significant impact in delineating precision medicine approaches and development of novel therapeutics.
Collapse
Affiliation(s)
- Liliane El Eid
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Christopher A Reynolds
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Alison Gingell Building, United Kingdom; School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom.
| | - Ben Jones
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom.
| |
Collapse
|
9
|
Abdul-Maksoud RS, Elsayed WSH, Rashad NM, Elsayed RS, Elshorbagy S, Hamed MG. GLP-1R polymorphism (rs1042044) and expression are associated with the risk of papillary thyroid cancer among the Egyptian population. Gene X 2022; 834:146597. [PMID: 35598685 DOI: 10.1016/j.gene.2022.146597] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/26/2022] [Accepted: 05/16/2022] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Glucagon like peptide-1 receptor (GLP-1R) agonist usage has previously been linked to an elevated incidence of thyroid cell adenomas and carcinomas in animals. AIM The goal of this study was to determine if there was an association between GLP-1R gene polymorphism and expression with the risk of papillary thyroid carcinoma (PTC) and its clinical characteristics among the Egyptian population. MATERIAL AND METHODS A total of eighty PTC patients and eighty healthy controls were included in the study. Real-time polymerase chain reaction (real-time PCR) and immunohistochemistry were used to determine GLP-1R expression in tumor tissue. The polymorphisms rs1042044 and rs6923761 in the GLP-1R gene were determined using PCR -restriction fragment length polymorphism (PCR-RFLP). RESULTS PTC patients exhibited considerably greater frequencies of rs1042044 AA genotypes and A allele than controls (OR (95% CI) = 4.5 (1.75-11.8), P < 0.001; OR (95% CI) = 2.032 (1.301-3.17), P < 0.001 respectively). GLP-1R mRNA and protein expressions were higher in tumor samples than normal thyroid tissues among PTC patients. In addition, high GLP-1R expressions were more common in rs1042044 AA genotype carriers than CC carriers (P < 0.001). GLP-1R mRNA expression showed 95 % sensitivity and 97% specificity for PTC diagnosis. Moreover, GLP-1R expression was closely associated with LN metastasis, tumor size, tumor stage, and multifocality in PTC patients. CONCLUSION This research provides new evidence linking the GLP-1R genetic polymorphism and tissue expression to PTC risk and invasiveness among the Egyptian population.
Collapse
Affiliation(s)
- Rehab S Abdul-Maksoud
- Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt.
| | - Walid S H Elsayed
- Pathology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Nearmeen M Rashad
- Internal Medicine Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Rasha S Elsayed
- General Surgery Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Shereen Elshorbagy
- Medical Oncology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Mohamed G Hamed
- Internal Medicine Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| |
Collapse
|
10
|
Emerging molecular technologies for light-mediated modulation of pancreatic beta-cell function. Mol Metab 2022; 64:101552. [PMID: 35863638 PMCID: PMC9352964 DOI: 10.1016/j.molmet.2022.101552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/22/2022] Open
Abstract
Background Optogenetic modalities as well as optochemical and photopharmacological strategies, collectively termed optical methods, have revolutionized the control of cellular functions via light with great spatiotemporal precision. In comparison to the major advances in the photomodulation of signaling activities noted in neuroscience, similar applications to endocrine cells of the pancreas, particularly insulin-producing β-cells, have been limited. The availability of tools allowing light-mediated changes in the trafficking of ions such as K+ and Ca2+ and signaling intermediates such as cyclic adenosine monophosphate (cAMP), renders β-cells and their glucose-stimulated insulin secretion (GSIS) amenable to optoengineering for drug-free control of blood sugar. Scope of review The molecular circuit of the GSIS in β-cells is described with emphasis on intermediates which are targetable for optical intervention. Various pharmacological agents modifying the release of insulin are reviewed along with their documented side effects. These are contrasted with optical approaches, which have already been employed for engineering β-cell function or are considered for future such applications. Principal obstacles are also discussed as the implementation of optogenetics is pondered for tissue engineering and biology applications of the pancreas. Major Conclusions Notable advances in optogenetic, optochemical and photopharmacological tools are rendering feasible the smart engineering of pancreatic cells and tissues with light-regulated function paving the way for novel solutions for addressing pancreatic pathologies including diabetes.
Collapse
|
11
|
Ježek P, Holendová B, Jabůrek M, Dlasková A, Plecitá-Hlavatá L. Contribution of Mitochondria to Insulin Secretion by Various Secretagogues. Antioxid Redox Signal 2022; 36:920-952. [PMID: 34180254 PMCID: PMC9125579 DOI: 10.1089/ars.2021.0113] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Significance: Mitochondria determine glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells by elevating ATP synthesis. As the metabolic and redox hub, mitochondria provide numerous links to the plasma membrane channels, insulin granule vesicles (IGVs), cell redox, NADH, NADPH, and Ca2+ homeostasis, all affecting insulin secretion. Recent Advances: Mitochondrial redox signaling was implicated in several modes of insulin secretion (branched-chain ketoacid [BCKA]-, fatty acid [FA]-stimulated). Mitochondrial Ca2+ influx was found to enhance GSIS, reflecting cytosolic Ca2+ oscillations induced by action potential spikes (intermittent opening of voltage-dependent Ca2+ and K+ channels) or the superimposed Ca2+ release from the endoplasmic reticulum (ER). The ATPase inhibitory factor 1 (IF1) was reported to tune the glucose sensitivity range for GSIS. Mitochondrial protein kinase A was implicated in preventing the IF1-mediated inhibition of the ATP synthase. Critical Issues: It is unknown how the redox signal spreads up to the plasma membrane and what its targets are, what the differences in metabolic, redox, NADH/NADPH, and Ca2+ signaling, and homeostasis are between the first and second GSIS phase, and whether mitochondria can replace ER in the amplification of IGV exocytosis. Future Directions: Metabolomics studies performed to distinguish between the mitochondrial matrix and cytosolic metabolites will elucidate further details. Identifying the targets of cell signaling into mitochondria and of mitochondrial retrograde metabolic and redox signals to the cell will uncover further molecular mechanisms for insulin secretion stimulated by glucose, BCKAs, and FAs, and the amplification of secretion by glucagon-like peptide (GLP-1) and metabotropic receptors. They will identify the distinction between the hub β-cells and their followers in intact and diabetic states. Antioxid. Redox Signal. 36, 920-952.
Collapse
Affiliation(s)
- Petr Ježek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Holendová
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jabůrek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Dlasková
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Lydie Plecitá-Hlavatá
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| |
Collapse
|
12
|
Mayendraraj A, Rosenkilde MM, Gasbjerg LS. GLP-1 and GIP receptor signaling in beta cells - A review of receptor interactions and co-stimulation. Peptides 2022; 151:170749. [PMID: 35065096 DOI: 10.1016/j.peptides.2022.170749] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 02/07/2023]
Abstract
Glucagon-like peptide 1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are two class B1 G protein-coupled receptors, which are stimulated by the gastrointestinal hormones GLP-1 and GIP, respectively. In the pancreatic beta cells, activation of both receptors lead to increased cyclic adenosine monophosphate (cAMP) and glucose-dependent insulin secretion. Marketed GLP-1R agonists such as dulaglutide, liraglutide, exenatide and semaglutide constitute an expanding drug class with beneficial effects for persons suffering from type 2 diabetes and/or obesity. In recent years another drug class, the GLP-1R-GIPR co-agonists, has emerged. Especially the peptide-based, co-agonist tirzepatide is a promising candidate for a better treatment of type 2 diabetes by improving glycemic control and weight reduction. The mechanism of action for tirzepatide include biased signaling of the GLP-1R as well as potent GIPR signaling. Since the implications of co-targeting these closely related receptors concomitantly are challenging to study in vivo, the pharmacodynamic mechanisms and downstream signaling pathways of the GLP-1R-GIPR co-agonists in general, are not fully elucidated. In this review, we present the individual signaling pathways for GLP-1R and GIPR in the pancreatic beta cell with a focus on the shared signaling pathways of the two receptors and interpret the implications of GLP-1R-GIPR co-activation in the light of recent co-activating therapeutic compounds.
Collapse
Affiliation(s)
- Ashok Mayendraraj
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lærke S Gasbjerg
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
13
|
Newsholme P, Rowlands J, Rose’Meyer R, Cruzat V. Metabolic Adaptions/Reprogramming in Islet Beta-Cells in Response to Physiological Stimulators—What Are the Consequences. Antioxidants (Basel) 2022; 11:antiox11010108. [PMID: 35052612 PMCID: PMC8773416 DOI: 10.3390/antiox11010108] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/25/2022] Open
Abstract
Irreversible pancreatic β-cell damage may be a result of chronic exposure to supraphysiological glucose or lipid concentrations or chronic exposure to therapeutic anti-diabetic drugs. The β-cells are able to respond to blood glucose in a narrow concentration range and release insulin in response, following activation of metabolic pathways such as glycolysis and the TCA cycle. The β-cell cannot protect itself from glucose toxicity by blocking glucose uptake, but indeed relies on alternative metabolic protection mechanisms to avoid dysfunction and death. Alteration of normal metabolic pathway function occurs as a counter regulatory response to high nutrient, inflammatory factor, hormone or therapeutic drug concentrations. Metabolic reprogramming is a term widely used to describe a change in regulation of various metabolic enzymes and transporters, usually associated with cell growth and proliferation and may involve reshaping epigenetic responses, in particular the acetylation and methylation of histone proteins and DNA. Other metabolic modifications such as Malonylation, Succinylation, Hydroxybutyrylation, ADP-ribosylation, and Lactylation, may impact regulatory processes, many of which need to be investigated in detail to contribute to current advances in metabolism. By describing multiple mechanisms of metabolic adaption that are available to the β-cell across its lifespan, we hope to identify sites for metabolic reprogramming mechanisms, most of which are incompletely described or understood. Many of these mechanisms are related to prominent antioxidant responses. Here, we have attempted to describe the key β-cell metabolic adaptions and changes which are required for survival and function in various physiological, pathological and pharmacological conditions.
Collapse
Affiliation(s)
- Philip Newsholme
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Jordan Rowlands
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Roselyn Rose’Meyer
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia;
| | - Vinicius Cruzat
- Faculty of Health, Torrens University Australia, Brisbane, QLD 4006, Australia;
| |
Collapse
|
14
|
Cyclic Nucleotide (cNMP) Analogues: Past, Present and Future. Int J Mol Sci 2021; 22:ijms222312879. [PMID: 34884683 PMCID: PMC8657615 DOI: 10.3390/ijms222312879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
Cyclic nucleotides are important second messengers involved in cellular events, and analogues of this type of molecules are promising drug candidates. Some cyclic nucleotide analogues have become standard tools for the investigation of biochemical and physiological signal transduction pathways, such as the Rp-diastereomers of adenosine and guanosine 3′,5′-cyclic monophosphorothioate, which are competitive inhibitors of cAMP- and cGMP-dependent protein kinases. Next generation analogues exhibit a higher membrane permeability, increased resistance against degradation, and improved target specificity, or are caged or photoactivatable for fast and/or targeted cellular imaging. Novel specific nucleotide analogues activating or inhibiting cyclic nucleotide-dependent ion channels, EPAC/GEF proteins, and bacterial target molecules have been developed, opening new avenues for basic and applied research. This review provides an overview of the current state of the field, what can be expected in the future and some practical considerations for the use of cyclic nucleotide analogues in biological systems.
Collapse
|
15
|
Mora FAA, Musheshe N, Arroyave Ospina JC, Geng Y, Soto JM, Rodrigo JA, Alieva T, Buist-Homan M, Lezoualc'h F, Cheng X, Schmidt M, Moshage H. Metformin protects against diclofenac-induced toxicity in primary rat hepatocytes by preserving mitochondrial integrity via a pathway involving EPAC. Biomed Pharmacother 2021; 143:112072. [PMID: 34464747 DOI: 10.1016/j.biopha.2021.112072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/23/2021] [Accepted: 08/17/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE It has been shown that the antidiabetic drug metformin protects hepatocytes against toxicity by various stressors. Chronic or excessive consumption of diclofenac (DF) - a pain-relieving drug, leads to drug-induced liver injury via a mechanism involving mitochondrial damage and ultimately apoptotic death of hepatocytes. However, whether metformin protects against DF-induced toxicity is unknown. Recently, it was also shown that cAMP elevation is protective against DF-induced apoptotic death in hepatocytes, a protective effect primarily involving the downstream cAMP effector EPAC and preservation of mitochondrial function. This study therefore aimed at investigating whether metformin protects against DF-induced toxicity via cAMP-EPACs. EXPERIMENTAL APPROACH Primary rat hepatocytes were exposed to 400 µmol/L DF. CE3F4 or ESI-O5 were used as EPAC-1 or 2 inhibitors respectively. Apoptosis was measured by caspase-3 activity and necrosis by Sytox green staining. Seahorse X96 assay was used to determine mitochondrial function. Mitochondrial reactive oxygen species (ROS) production was measured using MitoSox, mitochondrial MnSOD expression was determined by immunostaining and mitochondrial morphology (fusion and fission ratio) by 3D refractive index imaging. KEY RESULTS Metformin (1 mmol/L) was protective against DF-induced apoptosis in hepatocytes. This protective effect was EPAC-dependent (mainly EPAC-2). Metformin restored mitochondrial morphology in an EPAC-independent manner. DF-induced mitochondrial dysfunction which was demonstrated by decreased oxygen consumption rate, an increased ROS production and a reduced MnSOD level, were all reversed by metformin in an EPAC-dependent manner. CONCLUSION AND IMPLICATIONS Metformin protects hepatocytes against DF-induced toxicity via cAMP-dependent EPAC-2.
Collapse
Affiliation(s)
- Fabio Alejandro Aguilar Mora
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Nshunge Musheshe
- Deptartment Molecular Pharmacology, Groningen Research Institute of Pharmacy, Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
| | - Johanna C Arroyave Ospina
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Yana Geng
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Juan M Soto
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - José A Rodrigo
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - Tatiana Alieva
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - Manon Buist-Homan
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Frank Lezoualc'h
- Inserm UMR-1048, Institut des Maladies Metaboliques et Cardiovasculaires, Univ Toulouse Paul Sabatier, Toulouse, France.
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Martina Schmidt
- Deptartment Molecular Pharmacology, Groningen Research Institute of Pharmacy, Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
| | - Han Moshage
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| |
Collapse
|
16
|
Stožer A, Paradiž Leitgeb E, Pohorec V, Dolenšek J, Križančić Bombek L, Gosak M, Skelin Klemen M. The Role of cAMP in Beta Cell Stimulus-Secretion and Intercellular Coupling. Cells 2021; 10:1658. [PMID: 34359828 PMCID: PMC8304079 DOI: 10.3390/cells10071658] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 12/22/2022] Open
Abstract
Pancreatic beta cells secrete insulin in response to stimulation with glucose and other nutrients, and impaired insulin secretion plays a central role in development of diabetes mellitus. Pharmacological management of diabetes includes various antidiabetic drugs, including incretins. The incretin hormones, glucagon-like peptide-1 and gastric inhibitory polypeptide, potentiate glucose-stimulated insulin secretion by binding to G protein-coupled receptors, resulting in stimulation of adenylate cyclase and production of the secondary messenger cAMP, which exerts its intracellular effects through activation of protein kinase A or the guanine nucleotide exchange protein 2A. The molecular mechanisms behind these two downstream signaling arms are still not fully elucidated and involve many steps in the stimulus-secretion coupling cascade, ranging from the proximal regulation of ion channel activity to the central Ca2+ signal and the most distal exocytosis. In addition to modifying intracellular coupling, the effect of cAMP on insulin secretion could also be at least partly explained by the impact on intercellular coupling. In this review, we systematically describe the possible roles of cAMP at these intra- and inter-cellular signaling nodes, keeping in mind the relevance for the whole organism and translation to humans.
Collapse
Affiliation(s)
- Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Lidija Križančić Bombek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| |
Collapse
|
17
|
Xu W, Dahlke SP, Emery AC, Sung M, Chepurny OG, Holz GG, Eiden LE. Cyclic AMP-dependent activation of ERK via GLP-1 receptor signalling requires the neuroendocrine cell-specific guanine nucleotide exchanger NCS-RapGEF2. J Neuroendocrinol 2021; 33:e12974. [PMID: 33960038 PMCID: PMC8571116 DOI: 10.1111/jne.12974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 01/27/2023]
Abstract
Cyclic AMP activation of the Rap-Braf-MEK-ERK pathway after signalling initiated by the neuropeptide pituitary adenylate cyclase-activating peptide (PACAP), via the Gs -protein coupled receptor (Gs PCR) PAC1, occurs uniquely through the neuritogenic cAMP sensor Rap guanine nucleotide exchange factor 2 (NCS-RapGEF2) in Neuroscreen-1 (NS-1) neuroendocrine cells. We examined the expression of other Family B Gs PCRs in this cell line and assessed cAMP elevation and neuritogenesis after treatment with their cognate peptide ligands. Exposure of NS-1 cells to the VIPR1/2 agonist vasoactive intestinal polypeptide, or the GLP1R agonist exendin-4, did not induce neuritogenesis, or elevation of cAMP, presumably as a result of insufficient receptor protein expression. Vasoactive intestinal polypeptide and exendin-4 did induce neuritogenesis after transduction of human VIPR1, VIPR2 and GLP1R into NS-1 cells. Exendin-4/GLP1R-stimulated neuritogenesis was MEK-ERK-dependent (blocked by U0126), indicating its use of the cAMP→RapGEF2→ERK neuritogenic signalling pathway previously identified for PACAP/PAC1 signalling in NS-1 cells. NCS-RapGEF2 is expressed in the rodent insulinoma cell lines MIN6 and INS-1, as well as in human pancreatic islets. As in NS-1 cells, exendin-4 caused ERK phosphorylation in INS-1 cells. Reduction in RapGEF2 expression after RapGEF2-shRNA treatment reduced exendin-4-induced ERK phosphorylation. Transcriptome analysis of INS-1 cells after 1 hour of exposure to exendin-4 revealed an immediate early-gene response that was composed of both ERK-dependent and ERK-independent signalling targets. We propose that cAMP signalling initiated by glucagon-like peptide 1 (GLP-1) in pancreatic beta cells causes parallel activation of multiple cAMP effectors, including NCS-RapGEF2, Epac and protein kinase A, to separately control various facets of GLP-1 action, including insulin secretion and transcriptional modulation.
Collapse
Affiliation(s)
- Wenqin Xu
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Sam P. Dahlke
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Andrew C. Emery
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Michelle Sung
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Oleg G. Chepurny
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | - George G. Holz
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | - Lee E. Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| |
Collapse
|
18
|
A role for PAK1 mediated phosphorylation of β-catenin Ser552 in the regulation of insulin secretion. Biochem J 2021; 478:1605-1615. [PMID: 33605402 DOI: 10.1042/bcj20200862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022]
Abstract
The presence of adherens junctions and the associated protein β-catenin are requirements for the development of glucose-stimulated insulin secretion (GSIS) in β-cells. Evidence indicates that modulation of β-catenin function in response to changes in glucose levels can modulate the levels of insulin secretion from β-cells but the role of β-catenin phosphorylation in this process has not been established. We find that a Ser552Ala version of β-catenin attenuates glucose-stimulated insulin secretion indicating a functional role for Ser552 phosphorylation of β-catenin in insulin secretion. This is associated with alterations F/G actin ratio but not the transcriptional activity of β-catenin. Both glucose and GLP-1 stimulated phosphorylation of the serine 552 residue on β-catenin. We investigated the possibility that an EPAC-PAK1 pathway might be involved in this phosphorylation event. We find that reduction in PAK1 levels using siRNA attenuates both glucose and GLP-1 stimulated phosphorylation of β-catenin Ser552 and the effects of these on insulin secretion in β-cell models. Furthermore, both the EPAC inhibitor ESI-09 and the PAK1 inhibitor IPA3 do the same in both β-cell models and mouse islets. Together this identifies phosphorylation of β-catenin at Ser552 as part of a cell signalling mechanism linking nutrient and hormonal regulation of β-catenin to modulation of insulin secretory capacity of β-cells and indicates this phosphorylation event is regulated downstream of EPAC and PAK1 in β-cells.
Collapse
|
19
|
Ježek P, Holendová B, Jabůrek M, Tauber J, Dlasková A, Plecitá-Hlavatá L. The Pancreatic β-Cell: The Perfect Redox System. Antioxidants (Basel) 2021; 10:antiox10020197. [PMID: 33572903 PMCID: PMC7912581 DOI: 10.3390/antiox10020197] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Pancreatic β-cell insulin secretion, which responds to various secretagogues and hormonal regulations, is reviewed here, emphasizing the fundamental redox signaling by NADPH oxidase 4- (NOX4-) mediated H2O2 production for glucose-stimulated insulin secretion (GSIS). There is a logical summation that integrates both metabolic plus redox homeostasis because the ATP-sensitive K+ channel (KATP) can only be closed when both ATP and H2O2 are elevated. Otherwise ATP would block KATP, while H2O2 would activate any of the redox-sensitive nonspecific calcium channels (NSCCs), such as TRPM2. Notably, a 100%-closed KATP ensemble is insufficient to reach the -50 mV threshold plasma membrane depolarization required for the activation of voltage-dependent Ca2+ channels. Open synergic NSCCs or Cl- channels have to act simultaneously to reach this threshold. The resulting intermittent cytosolic Ca2+-increases lead to the pulsatile exocytosis of insulin granule vesicles (IGVs). The incretin (e.g., GLP-1) amplification of GSIS stems from receptor signaling leading to activating the phosphorylation of TRPM channels and effects on other channels to intensify integral Ca2+-influx (fortified by endoplasmic reticulum Ca2+). ATP plus H2O2 are also required for branched-chain ketoacids (BCKAs); and partly for fatty acids (FAs) to secrete insulin, while BCKA or FA β-oxidation provide redox signaling from mitochondria, which proceeds by H2O2 diffusion or hypothetical SH relay via peroxiredoxin "redox kiss" to target proteins.
Collapse
|
20
|
Diz-Chaves Y, Herrera-Pérez S, González-Matías LC, Lamas JA, Mallo F. Glucagon-Like Peptide-1 (GLP-1) in the Integration of Neural and Endocrine Responses to Stress. Nutrients 2020; 12:nu12113304. [PMID: 33126672 PMCID: PMC7692797 DOI: 10.3390/nu12113304] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/14/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Glucagon like-peptide 1 (GLP-1) within the brain is produced by a population of preproglucagon neurons located in the caudal nucleus of the solitary tract. These neurons project to the hypothalamus and another forebrain, hindbrain, and mesolimbic brain areas control the autonomic function, feeding, and the motivation to feed or regulate the stress response and the hypothalamic-pituitary-adrenal axis. GLP-1 receptor (GLP-1R) controls both food intake and feeding behavior (hunger-driven feeding, the hedonic value of food, and food motivation). The activation of GLP-1 receptors involves second messenger pathways and ionic events in the autonomic nervous system, which are very relevant to explain the essential central actions of GLP-1 as neuromodulator coordinating food intake in response to a physiological and stress-related stimulus to maintain homeostasis. Alterations in GLP-1 signaling associated with obesity or chronic stress induce the dysregulation of eating behavior. This review summarized the experimental shreds of evidence from studies using GLP-1R agonists to describe the neural and endocrine integration of stress responses and feeding behavior.
Collapse
Affiliation(s)
- Yolanda Diz-Chaves
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
| | - Salvador Herrera-Pérez
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | | | - José Antonio Lamas
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | - Federico Mallo
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
| |
Collapse
|
21
|
Rago V, De Rose D, Santoro M, Panza S, Malivindi R, Andò S, D'Agata R, Aquila S. Human Sperm Express the Receptor for Glucagon-like Peptide-1 (GLP-1), Which Affects Sperm Function and Metabolism. Endocrinology 2020; 161:5802751. [PMID: 32157297 DOI: 10.1210/endocr/bqaa031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022]
Abstract
AIM Glucagon-like peptide-1 (GLP-1) produces pleiotropic effects binding to the GLP-1 receptor (GLP1-R), potentiating insulin secretion in the pancreas. GLP1-R is expressed in peripheral tissues and evidence for its role in reproduction has come from knockout mice, although the relationship between GLP-1 and male fertility needs to be clarified. Given that human sperm is an insulin-sensitive and insulin-secreting cell, we hypothesized that the GLP-1/GLP1-R axis may be expressed and functional in these cells. RESULTS AND DISCUSSION We revealed the presence of GLP1-R by Western blotting and immunofluorescence analyses. Because Exendin-4 (Ex-4) displays similar functional properties to native GLP-1, we used this agonist to perform a dose-response study on progressive motility and cholesterol efflux, showing that 300 pM Ex-4 was the most effective treatment. These actions are mediated by GLP1-R and independent from sperm-secreted insulin. The exposure to Ex-4 fueled phosphatidylinositol-3-kinase (PI3K)/AKT signaling and was reversed by H89, indicating a protein kinase A (PKA)-dependence of GLP-1/GLP1-R signaling. It emerged that in sperm, insulin secretion regulated by Ex-4 did not occur in a strictly glucose-dependent manner. A stimulatory action of Ex-4/GLP1-R on lactate dehydrogenase and glucose-6-phosphate dehydrogenase (G6PDH) activities was observed. Ex-4/GLP1-R decreased triglycerides content concomitantly to enhanced lipase and acyl-coenzyme A (acyl-CoA) dehydrogenase activities, addressing a lipolytic effect. CONCLUSION Collectively, we discovered that human sperm is a new GLP1 incretin target, broadening our knowledge about the effects of the GLP1-R agonist in the male reproductive field. Further findings in humans should be conducted in the future to confirm it and to improve the translational aspect of this study.
Collapse
Affiliation(s)
- Vittoria Rago
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
| | - Daniela De Rose
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
- Centro Sanitario, University of Calabria Cosenza, Italy
| | - Marta Santoro
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
- Centro Sanitario, University of Calabria Cosenza, Italy
| | - Salvatore Panza
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
- Centro Sanitario, University of Calabria Cosenza, Italy
| | - Rocco Malivindi
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
| | - Sebastiano Andò
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
- Centro Sanitario, University of Calabria Cosenza, Italy
| | - Rosario D'Agata
- Department of Experimental and Clinical Medicine, University of Catania, Catania, Italy
| | - Saveria Aquila
- Department of Pharmacy and Sciences of Health and Nutrition, University of Calabria Cosenza, Italy
- Centro Sanitario, University of Calabria Cosenza, Italy
| |
Collapse
|
22
|
Integration of Rap1 and Calcium Signaling. Int J Mol Sci 2020; 21:ijms21051616. [PMID: 32120817 PMCID: PMC7084553 DOI: 10.3390/ijms21051616] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023] Open
Abstract
Ca2+ is a universal intracellular signal. The modulation of cytoplasmic Ca2+ concentration regulates a plethora of cellular processes, such as: synaptic plasticity, neuronal survival, chemotaxis of immune cells, platelet aggregation, vasodilation, and cardiac excitation–contraction coupling. Rap1 GTPases are ubiquitously expressed binary switches that alternate between active and inactive states and are regulated by diverse families of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Active Rap1 couples extracellular stimulation with intracellular signaling through secondary messengers—cyclic adenosine monophosphate (cAMP), Ca2+, and diacylglycerol (DAG). Much evidence indicates that Rap1 signaling intersects with Ca2+ signaling pathways to control the important cellular functions of platelet activation or neuronal plasticity. Rap1 acts as an effector of Ca2+ signaling when activated by mechanisms involving Ca2+ and DAG-activated (CalDAG-) GEFs. Conversely, activated by other GEFs, such as cAMP-dependent GEF Epac, Rap1 controls cytoplasmic Ca2+ levels. It does so by regulating the activity of Ca2+ signaling proteins such as sarcoendoplasmic reticulum Ca2+-ATPase (SERCA). In this review, we focus on the physiological significance of the links between Rap1 and Ca2+ signaling and emphasize the molecular interactions that may offer new targets for the therapy of Alzheimer’s disease, hypertension, and atherosclerosis, among other diseases.
Collapse
|
23
|
Islam MS. Stimulus-Secretion Coupling in Beta-Cells: From Basic to Bedside. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:943-963. [PMID: 31646540 DOI: 10.1007/978-3-030-12457-1_37] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Insulin secretion in humans is usually induced by mixed meals, which upon ingestion, increase the plasma concentration of glucose, fatty acids, amino acids, and incretins like glucagon-like peptide 1. Beta-cells can stay in the off-mode, ready-mode or on-mode; the mode-switching being determined by the open state probability of the ATP-sensitive potassium channels, and the activity of enzymes like glucokinase, and glutamate dehydrogenase. Mitochondrial metabolism is critical for insulin secretion. A sound understanding of the intermediary metabolism, electrophysiology, and cell signaling is essential for comprehension of the entire spectrum of the stimulus-secretion coupling. Depolarization brought about by inhibition of the ATP sensitive potassium channel, together with the inward depolarizing currents through the transient receptor potential (TRP) channels, leads to electrical activities, opening of the voltage-gated calcium channels, and exocytosis of insulin. Calcium- and cAMP-signaling elicited by depolarization, and activation of G-protein-coupled receptors, including the free fatty acid receptors, are intricately connected in the form of networks at different levels. Activation of the glucagon-like peptide 1 receptor augments insulin secretion by amplifying calcium signals by calcium induced calcium release (CICR). In the treatment of type 2 diabetes, use of the sulfonylureas that act on the ATP sensitive potassium channel, damages the beta cells, which eventually fail; these drugs do not improve the cardiovascular outcomes. In contrast, drugs acting through the glucagon-like peptide-1 receptor protect the beta-cells, and improve cardiovascular outcomes. The use of the glucagon-like peptide 1 receptor agonists is increasing and that of sulfonylurea is decreasing. A better understanding of the stimulus-secretion coupling may lead to the discovery of other molecular targets for development of drugs for the prevention and treatment of type 2 diabetes.
Collapse
Affiliation(s)
- Md Shahidul Islam
- Department of Clinical Science and Education, Södersjukhuset, Research Center, Karolinska Institutet, Stockholm, Sweden. .,Department of Emergency Care and Internal Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
24
|
Xu Y, Schwede F, Wienk H, Tengholm A, Rehmann H. A Membrane Permeable Prodrug of S223 for Selective Epac2 Activation in Living Cells. Cells 2019; 8:cells8121589. [PMID: 31817822 PMCID: PMC6952820 DOI: 10.3390/cells8121589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Signalling by cyclic adenosine monophosphate (cAMP) occurs via various effector proteins, notably protein kinase A and the guanine nucleotide exchange factors Epac1 and Epac2. These proteins are activated by cAMP binding to conserved cyclic nucleotide binding domains. The specific roles of the effector proteins in various processes in different types of cells are still not well defined, but investigations have been facilitated by the development of cyclic nucleotide analogues with distinct selectivity profiles towards a single effector protein. A remaining challenge in the development of such analogues is the poor membrane permeability of nucleotides, which limits their applicability in intact living cells. Here, we report the synthesis and characterisation of S223-AM, a cAMP analogue designed as an acetoxymethyl ester prodrug to overcome limitations of permeability. Using total internal reflection imaging with various fluorescent reporters, we show that S223-AM selectively activates Epac2, but not Epac1 or protein kinase A, in intact insulin-secreting β-cells, and that this effect was associated with pronounced activation of the small G-protein Rap. A comparison of the effects of different cAMP analogues in pancreatic islet cells deficient in Epac1 and Epac2 demonstrates that cAMP-dependent Rap activity at the β-cell plasma membrane is exclusively dependent on Epac2. With its excellent selectivity and permeability properties, S223-AM should get broad utility in investigations of cAMP effector involvement in many different types of cells.
Collapse
Affiliation(s)
- Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9a, 28199 Bremen, Germany;
| | - Hans Wienk
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Correspondence:
| |
Collapse
|
25
|
Luchowska-Stańska U, Morgan D, Yarwood SJ, Barker G. Selective small-molecule EPAC activators. Biochem Soc Trans 2019; 47:1415-1427. [PMID: 31671184 PMCID: PMC6824682 DOI: 10.1042/bst20190254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023]
Abstract
The cellular signalling enzymes, EPAC1 and EPAC2, have emerged as key intracellular sensors of the secondary messenger cyclic 3',5'-adenosine monophosphate (cyclic adenosine monophosphate) alongside protein kinase A. Interest has been galvanised in recent years thanks to the emergence of these species as potential targets for new cardiovascular disease therapies, including vascular inflammation and insulin resistance in vascular endothelial cells. We herein summarise the current state-of-the-art in small-molecule EPAC activity modulators, including cyclic nucleotides, sulphonylureas, and N-acylsulphonamides.
Collapse
Affiliation(s)
- Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Stephen J. Yarwood
- Institute of Biological Chemistry, Biophysics, and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| |
Collapse
|
26
|
Leypold T, Bonus M, Spiegelhalter F, Schwede F, Schwabe T, Gohlke H, Kusch J. N 6-modified cAMP derivatives that activate protein kinase A also act as full agonists of murine HCN2 channels. J Biol Chem 2019; 294:17978-17987. [PMID: 31615893 DOI: 10.1074/jbc.ra119.010246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/15/2019] [Indexed: 11/06/2022] Open
Abstract
cAMP acts as a second messenger in many cellular processes. Three protein types mainly mediate cAMP-induced effects: PKA, exchange protein directly activated by cAMP (Epac), and cyclic nucleotide-modulated channels (cyclic nucleotide-gated or hyperpolarization-activated and cyclic nucleotide-modulated (HCN) channels). Discrimination among these cAMP signaling pathways requires specific targeting of only one protein. Previously, cAMP modifications at position N 6 of the adenine ring (PKA) and position 2'-OH of the ribose (Epac) have been used to produce target-selective compounds. However, cyclic nucleotide-modulated ion channels were usually outside of the scope of these previous studies. These channels are widely distributed, so possible channel cross-activation by PKA- or Epac-selective agonists warrants serious consideration. Here we demonstrate the agonistic effects of three PKA-selective cAMP derivatives, N 6-phenyladenosine-3',5'-cyclic monophosphate (N 6-Phe-cAMP), N 6-benzyladenosine-3',5'-cyclic monophosphate (N 6-Bn-cAMP), and N 6-benzoyl-adenosine-3',5'-cyclic monophosphate (N 6-Bnz-cAMP), on murine HCN2 pacemaker channels. Electrophysiological characterization in Xenopus oocytes revealed that these derivatives differ in apparent affinities depending on the modification type but that their efficacy and effects on HCN2 activation kinetics are similar to those of cAMP. Docking experiments suggested a pivotal role of Arg-635 at the entrance of the binding pocket in HCN2, either causing stabilizing cation-π interactions with the aromatic ring in N 6-Phe-cAMP or N 6-Bn-cAMP or a steric clash with the aromatic ring in N 6-Bnz-cAMP. A reduced apparent affinity of N 6-Phe-cAMP toward the variants R635A and R635E strengthened that notion. We conclude that some PKA activators also effectively activate HCN2 channels. Hence, when studying PKA-mediated cAMP signaling with cAMP derivatives in a native environment, activation of HCN channels should be considered.
Collapse
Affiliation(s)
- Tim Leypold
- Friedrich Schiller University, University Hospital Jena, Institute of Physiology II, Kollegiengasse 9, 07743 Jena, Germany
| | - Michele Bonus
- Institute for Pharmaceutical and Medical Chemistry, Heinrich Heine University, Universitätsstraβe 1, 40225 Düsseldorf, Germany
| | - Felix Spiegelhalter
- Friedrich Schiller University, University Hospital Jena, Institute of Physiology II, Kollegiengasse 9, 07743 Jena, Germany
| | | | - Tina Schwabe
- Friedrich Schiller University, University Hospital Jena, Institute of Physiology II, Kollegiengasse 9, 07743 Jena, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medical Chemistry, Heinrich Heine University, Universitätsstraβe 1, 40225 Düsseldorf, Germany.,John von Neumann Institute for Computing, Jülich Supercomputing Centre and Institute for Complex Systems - Structural Biochemistry (ICS 6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Jana Kusch
- Friedrich Schiller University, University Hospital Jena, Institute of Physiology II, Kollegiengasse 9, 07743 Jena, Germany
| |
Collapse
|
27
|
Chung YT, Pasquinelli V, Jurado JO, Wang X, Yi N, Barnes PF, Garcia VE, Samten B. Elevated Cyclic AMP Inhibits Mycobacterium tuberculosis-Stimulated T-cell IFN-γ Secretion Through Type I Protein Kinase A. J Infect Dis 2019; 217:1821-1831. [PMID: 29438524 DOI: 10.1093/infdis/jiy079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 02/06/2018] [Indexed: 12/31/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is critical in immune regulation, and its role in tuberculosis infection remains unclear. We determined the levels of cAMP in peripheral blood mononuclear cells (PBMC) from tuberculosis patients and the mechanisms for cAMP suppression of IFN-γ production. PBMC from tuberculosis patients contained significantly elevated cAMP than latent tuberculosis infected subjects (LTBI), with an inverse correlation with IFN-γ production. Consistent with this, the expression of cAMP response element binding protein (CREB), activating transcription factor (ATF)-2 and c-Jun were reduced in tuberculosis patients compared with LTBI. PKA type I specific cAMP analogs inhibited Mtb-stimulated IFN-g production by PBMC through suppression of Mtb-induced IFN-γ promoter binding activities of CREB, ATF-2, and c-Jun and also miR155, the target miRNA of these transcription factors. Neutralizing both IL-10 and TGF-β1 or supplementation of IL-12 restored cAMP-suppressed IFN-g production. We conclude that increased cAMP inhibits IFN-g production through PKA type I pathway in tuberculosis infection.
Collapse
Affiliation(s)
- Yoon-Tae Chung
- Department of Pulmonary Immunology, University of Texas Health Science Center, Tyler
| | - Virginia Pasquinelli
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires, Universidad Nacional del Noroeste de la Provincia de Buenos Aires- Consejo Nacional de Investigaciones Científicas y Técnicas, Junín, Argentina
| | - Javier O Jurado
- Departamento de Química Biológica, and Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | - Xisheng Wang
- Department of Pulmonary Immunology, University of Texas Health Science Center, Tyler
| | - Na Yi
- Department of Pulmonary Immunology, University of Texas Health Science Center, Tyler
| | - Peter F Barnes
- Department of Pulmonary Immunology, University of Texas Health Science Center, Tyler
| | - Veronica E Garcia
- Departamento de Química Biológica, and Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | - Buka Samten
- Department of Pulmonary Immunology, University of Texas Health Science Center, Tyler
| |
Collapse
|
28
|
Pratt EPS, Harvey KE, Salyer AE, Hockerman GH. Regulation of cAMP accumulation and activity by distinct phosphodiesterase subtypes in INS-1 cells and human pancreatic β-cells. PLoS One 2019; 14:e0215188. [PMID: 31442224 PMCID: PMC6707593 DOI: 10.1371/journal.pone.0215188] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 08/11/2019] [Indexed: 01/09/2023] Open
Abstract
Pancreatic β-cells express multiple phosphodiesterase (PDE) subtypes, but the specific roles for each in β-cell function, particularly in humans, is not clear. We evaluated the cellular role of PDE1, PDE3, and PDE4 activity in the rat insulinoma cell line INS-1 and in primary human β-cells using subtype-selective PDE inhibitors. Using a genetically encoded, FRET-based cAMP sensor, we found that the PDE1 inhibitor 8MM-IBMX, elevated cAMP levels in the absence of glucose to a greater extent than either the PDE3 inhibitor cilostamide or the PDE4 inhibitor rolipram. In 18 mM glucose, PDE1 inhibition elevated cAMP levels to a greater extent than PDE3 inhibition in INS-1 cells, while PDE4 inhibition was without effect. Inhibition of PDE1 or PDE4, but not PDE3, potentiated glucose-stimulated insulin secretion in INS-1 cells. PDE1 inhibition, but not PDE3 or PDE4 inhibition, reduced palmitate-induced caspase-3/7 activation, and enhanced CREB phosphorylation in INS-1 cells. In human β-cells, only PDE3 or PDE4 inhibition increased cAMP levels in 1.7 mM glucose, but PDE1, PDE3, or PDE4 inhibition potentiated cAMP levels in 16.7 mM glucose. Inhibition of PDE1 or PDE4 increased cAMP levels to a greater extent in 16.7 mM glucose than in 1.7 mM glucose in human β-cells. In contrast, elevation of cAMP levels by PDE3 inhibition was not different at these glucose concentrations. PDE1 inhibition also potentiated insulin secretion from human islets, suggesting that the role of PDE1 may be conserved between INS-1 cells and human pancreatic β-cells. Our results suggest that inhibition of PDE1 may be a useful strategy to potentiate glucose-stimulated insulin secretion, and to protect β-cells from the toxic effects of excess fatty acids.
Collapse
Affiliation(s)
- Evan P. S. Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
- Purdue University Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, United States of America
| | - Kyle E. Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
| | - Amy E. Salyer
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
| | - Gregory H. Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
- * E-mail:
| |
Collapse
|
29
|
Cherezova A, Tomilin V, Buncha V, Zaika O, Ortiz PA, Mei F, Cheng X, Mamenko M, Pochynyuk O. Urinary concentrating defect in mice lacking Epac1 or Epac2. FASEB J 2019; 33:2156-2170. [PMID: 30252533 PMCID: PMC6338637 DOI: 10.1096/fj.201800435r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/27/2018] [Indexed: 11/11/2022]
Abstract
cAMP is a universal second messenger regulating a plethora of processes in the kidney. Two downstream effectors of cAMP are PKA and exchange protein directly activated by cAMP (Epac), which, unlike PKA, is often linked to elevation of [Ca2+]i. While both Epac isoforms (Epac1 and Epac2) are expressed along the nephron, their relevance in the kidney remains obscure. We combined ratiometric calcium imaging with quantitative immunoblotting, immunofluorescent confocal microscopy, and balance studies in mice lacking Epac1 or Epac2 to determine the role of Epac in renal water-solute handling. Epac1-/- and Epac2-/- mice developed polyuria despite elevated arginine vasopressin levels. We did not detect major deficiencies in arginine vasopressin [Ca2+]i signaling in split-opened collecting ducts or decreases in aquaporin water channel type 2 levels. Instead, sodium-hydrogen exchanger type 3 levels in the proximal tubule were dramatically reduced in Epac1-/- and Epac2-/- mice. Water deprivation revealed persisting polyuria, impaired urinary concentration ability, and augmented urinary excretion of Na+ and urea in both mutant mice. In summary, we report a nonredundant contribution of Epac isoforms to renal function. Deletion of Epac1 and Epac2 decreases sodium-hydrogen exchanger type 3 expression in the proximal tubule, leading to polyuria and osmotic diuresis.-Cherezova, A., Tomilin, V., Buncha, V., Zaika, O., Ortiz, P. A., Mei, F., Cheng, X., Mamenko, M., Pochynyuk, O. Urinary concentrating defect in mice lacking Epac1 or Epac2.
Collapse
Affiliation(s)
- Alena Cherezova
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Vadym Buncha
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleg Zaika
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Pablo A. Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Fang Mei
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Mykola Mamenko
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| |
Collapse
|
30
|
Rowlands J, Heng J, Newsholme P, Carlessi R. Pleiotropic Effects of GLP-1 and Analogs on Cell Signaling, Metabolism, and Function. Front Endocrinol (Lausanne) 2018; 9:672. [PMID: 30532733 PMCID: PMC6266510 DOI: 10.3389/fendo.2018.00672] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022] Open
Abstract
The incretin hormone Glucagon-Like Peptide-1 (GLP-1) is best known for its "incretin effect" in restoring glucose homeostasis in diabetics, however, it is now apparent that it has a broader range of physiological effects in the body. Both in vitro and in vivo studies have demonstrated that GLP-1 mimetics alleviate endoplasmic reticulum stress, regulate autophagy, promote metabolic reprogramming, stimulate anti-inflammatory signaling, alter gene expression, and influence neuroprotective pathways. A substantial body of evidence has accumulated with respect to how GLP-1 and its analogs act to restore and maintain normal cellular functions. These findings have prompted several clinical trials which have reported GLP-1 analogs improve cardiac function, restore lung function and reduce mortality in patients with obstructive lung disease, influence blood pressure and lipid storage, and even prevent synaptic loss and neurodegeneration. Mechanistically, GLP-1 elicits its effects via acute elevation in cAMP levels, and subsequent protein kinase(s) activation, pathways well-defined in pancreatic β-cells which stimulate insulin secretion in conjunction with elevated Ca2+ and ATP. More recently, new studies have shed light on additional downstream pathways stimulated by chronic GLP-1 exposure, findings which have direct relevance to our understanding of the potential therapeutic effects of longer lasting analogs recently developed for clinical use. In this review, we provide a comprehensive description of the diverse roles for GLP-1 across multiple tissues, describe downstream pathways stimulated by acute and chronic exposure, and discuss novel pleiotropic applications of GLP-1 mimetics in the treatment of human disease.
Collapse
Affiliation(s)
| | | | - Philip Newsholme
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Perth, WA, Australia
| | - Rodrigo Carlessi
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Perth, WA, Australia
| |
Collapse
|
31
|
Jahan I, Corbin KL, Bogart AM, Whitticar NB, Waters CD, Schildmeyer C, Vann NW, West HL, Law NC, Wiseman JS, Nunemaker CS. Reducing Glucokinase Activity Restores Endogenous Pulsatility and Enhances Insulin Secretion in Islets From db/db Mice. Endocrinology 2018; 159:3747-3760. [PMID: 30239634 PMCID: PMC6202857 DOI: 10.1210/en.2018-00589] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/12/2018] [Indexed: 12/22/2022]
Abstract
An early sign of islet failure in type 2 diabetes (T2D) is the loss of normal patterns of pulsatile insulin release. Disruptions in pulsatility are associated with a left shift in glucose sensing that can cause excessive insulin release in low glucose (relative hyperinsulinemia, a hallmark of early T2D) and β-cell exhaustion, leading to inadequate insulin release during hyperglycemia. Our hypothesis was that reducing excessive glucokinase activity in diabetic islets would improve their function. Isolated mouse islets were exposed to glucose and varying concentrations of the glucokinase inhibitor d-mannoheptulose (MH) to examine changes in intracellular calcium ([Ca2+]i) and insulin secretion. Acutely exposing islets from control CD-1 mice to MH in high glucose (20 mM) dose dependently reduced the size of [Ca2+]i oscillations detected by fura-2 acetoxymethyl. Glucokinase activation in low glucose (3 mM) had the opposite effect. We then treated islets from male and female db/db mice (age, 4 to 8 weeks) and heterozygous controls overnight with 0 to 10 mM MH to determine that 1 mM MH produced optimal oscillations. We then used 1 mM MH overnight to measure [Ca2+]i and insulin simultaneously in db/db islets. MH restored oscillations and increased insulin secretion. Insulin secretion rates correlated with MH-induced increases in amplitude of [Ca2+]i oscillations (R2 = 0.57, P < 0.01, n = 10) but not with mean [Ca2+]i levels in islets (R2 = 0.05, not significant). Our findings show that correcting glucose sensing can restore proper pulsatility to diabetic islets and improved pulsatility correlates with enhanced insulin secretion.
Collapse
Affiliation(s)
- Ishrat Jahan
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | - Kathryn L Corbin
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | - Avery M Bogart
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Honors Tutorial College, Ohio University, Athens, Ohio
| | - Nicholas B Whitticar
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | - Christopher D Waters
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Cara Schildmeyer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Honors Tutorial College, Ohio University, Athens, Ohio
| | - Nicholas W Vann
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Hannah L West
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Honors Tutorial College, Ohio University, Athens, Ohio
| | - Nathan C Law
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | | | - Craig S Nunemaker
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
- Correspondence: Craig S. Nunemaker, PhD, Department of Biomedical Sciences, 228 Irvine Hall, Ohio University Heritage College of Osteopathic Medicine, Athens, Ohio 45701. E-mail:
| |
Collapse
|
32
|
Deussing JM, Chen A. The Corticotropin-Releasing Factor Family: Physiology of the Stress Response. Physiol Rev 2018; 98:2225-2286. [DOI: 10.1152/physrev.00042.2017] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The physiological stress response is responsible for the maintenance of homeostasis in the presence of real or perceived challenges. In this function, the brain activates adaptive responses that involve numerous neural circuits and effector molecules to adapt to the current and future demands. A maladaptive stress response has been linked to the etiology of a variety of disorders, such as anxiety and mood disorders, eating disorders, and the metabolic syndrome. The neuropeptide corticotropin-releasing factor (CRF) and its relatives, the urocortins 1–3, in concert with their receptors (CRFR1, CRFR2), have emerged as central components of the physiological stress response. This central peptidergic system impinges on a broad spectrum of physiological processes that are the basis for successful adaptation and concomitantly integrate autonomic, neuroendocrine, and behavioral stress responses. This review focuses on the physiology of CRF-related peptides and their cognate receptors with the aim of providing a comprehensive up-to-date overview of the field. We describe the major molecular features covering aspects of gene expression and regulation, structural properties, and molecular interactions, as well as mechanisms of signal transduction and their surveillance. In addition, we discuss the large body of published experimental studies focusing on state-of-the-art genetic approaches with high temporal and spatial precision, which collectively aimed to dissect the contribution of CRF-related ligands and receptors to different levels of the stress response. We discuss the controversies in the field and unravel knowledge gaps that might pave the way for future research directions and open up novel opportunities for therapeutic intervention.
Collapse
Affiliation(s)
- Jan M. Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
33
|
Ng PY, McIntosh KA, Hargrave G, Ho KH, Paul A, Plevin R. Inhibition of cytokine-mediated JNK signalling by purinergic P2Y 11 receptors, a novel protective mechanism in endothelial cells. Cell Signal 2018; 51:59-71. [PMID: 30076967 DOI: 10.1016/j.cellsig.2018.07.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/23/2018] [Accepted: 07/31/2018] [Indexed: 10/28/2022]
Abstract
Previous research from our laboratory has demonstrated a novel phenomenon whereby GPCRs play a role in inhibiting cytokine-mediated c-Jun N-terminal kinase (JNK) signalling. So far this novel phenomenon seems to have been vastly overlooked, with little research in the area. Therefore, in this study we explored this further; by assessing the potential of P2YRs to mediate inhibition of cytokine-mediated JNK signalling and related functional outcomes in human endothelial cells. We utilised primary endothelial cells, and employed the use of endogenous activators of P2YRs and well characterised pharmacological inhibitors, to assess signalling parameters mediated by P2YRs, Interleukin-1β (IL-1β), TNFα and JNK. Activation of P2YRs with adenosine tri-phosphate (ATP) resulted in a time- and concentration-dependent inhibition of IL-1β-mediated phosphorylation of JNK and associated kinase activity. The effect was specific for cytokine-mediated JNK signalling, as ATP was without effect on JNK induced by other non-specific activators (e.g. sorbitol, anisomycin), nor effective against other MAPK pathways such as p38 and the canonical NFκB cascade. Pharmacological studies demonstrated a role for the P2Y11 receptor in mediating this effect, but not the P2Y1 nor the adenosine receptors (A1, A2A, A2B & A3). The novel Gαq/11 inhibitor YM254890 and a protein kinase A (PKA) inhibitor H89 both partially reversed ATP-mediated inhibition of IL-1β-stimulated JNK indicating involvement of both Gαq/11 and Gαs mediated pathways. ATP also partially reversed IL-1β-mediated induction of cyclo‑oxygenase-2 (COX-2) and E-selectin. Collectively, these studies indicate the potential for activation of purinergic receptors to protect the endothelium from inflammatory driven JNK activation and may be a new target for inflammatory disease therapy.
Collapse
Affiliation(s)
- Pei Y Ng
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - Kathryn A McIntosh
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK.
| | - Gillian Hargrave
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - Ka H Ho
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - Andrew Paul
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - Robin Plevin
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, UK
| |
Collapse
|
34
|
Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
Collapse
Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| |
Collapse
|
35
|
Rowlands J, Cruzat V, Carlessi R, Newsholme P. Insulin and IGF-1 receptor autocrine loops are not required for Exendin-4 induced changes to pancreatic β-cell bioenergetic parameters and metabolism in BRIN-BD11 cells. Peptides 2018; 100:140-149. [PMID: 29412813 DOI: 10.1016/j.peptides.2017.11.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/23/2017] [Accepted: 11/23/2017] [Indexed: 01/13/2023]
Abstract
Pharmacological long lasting Glucagon-like peptide-1 (GLP-1) analogues, such as Exendin-4, have become widely used diabetes therapies. Chronic GLP-1R stimulation has been linked to β-cell protection and these pro-survival actions of GLP-1 are dependent on the activation of the mammalian target of rapamycin (mTOR) leading to accumulation of Hypoxia inducible factor 1 alpha (HIF-1α). Recent studies from our lab indicate that prolonged GLP-1R stimulation promotes metabolic reprograming of β-cells towards a highly glycolytic phenotype and activation of the mTOR/HIF-1α pathway was required for this action. We hypothesised that GLP-1 induced metabolic changes depend on the activation of mTOR and HIF-1α, in a cascade that occurs after triggering of a potential Insulin-like growth factor 1 receptor (IGF-1R) or the Insulin receptor (IR) autocrine loops. Loss of function of these receptors, through the use of small interfering RNA, or neutralizing antibodies directed towards their products, was undertaken in conjunction with functional assays. Neither of these strategies mitigated the effect of GLP-1 on glucose uptake, protein expression or bioenergetic flux. Our data indicates that activation of IGF-1R and/or the IR autocrine loops resulting in β-cell protection and function, involve mechanisms independent to the enhanced metabolic effects resulting from sustained GLP-1R activation.
Collapse
Affiliation(s)
- Jordan Rowlands
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Bldg 305, Rm 135 - CHIRI, Kent St, Bentley, WA, 6102, Australia.
| | - Vinicius Cruzat
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Bldg 305, Rm 135 - CHIRI, Kent St, Bentley, WA, 6102, Australia.
| | - Rodrigo Carlessi
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Bldg 305, Rm 135 - CHIRI, Kent St, Bentley, WA, 6102, Australia.
| | - Philip Newsholme
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Bldg 305, Rm 135 - CHIRI, Kent St, Bentley, WA, 6102, Australia.
| |
Collapse
|
36
|
Hameed A, Hafizur RM, Hussain N, Raza SA, Rehman M, Ashraf S, Ul-Haq Z, Khan F, Abbas G, Choudhary MI. Eriodictyol stimulates insulin secretion through cAMP/PKA signaling pathway in mice islets. Eur J Pharmacol 2017; 820:245-255. [PMID: 29229531 DOI: 10.1016/j.ejphar.2017.12.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/21/2022]
Abstract
Eriodictyol, a flavonoid isolated from Lyonia ovalifolia, was found to be the most potent insulin secretagogue in our preliminary studies. Here, we explored mechanism(s) of insulin secretory activity of eriodictyol in vitro and in vivo. Mice islets and MIN6 cells were incubated in basal and stimulatory glucose containing eriodictyol with or without agonist/antagonist. Secreted insulin and cAMP contents were measured using ELISA kits. K+- and Ca2+-channels currents were recorded with patch-clamp technique. Oral glucose tolerance test and plasma insulin was evaluated in non-diabetic and diabetic rats. Eriodictyol stimulated insulin secretion from mice islets and MIN6 cells only at stimulatory glucose concentrations with maximum effect at 200μM. Eriodictyol showed no pronounced effect on inward rectifying K+ and Ca2+ currents. Furthermore, in KCl depolarized islets, in the presence of diazoxide, insulin secretory ability of eriodictyol was enhanced. IBMX, a phosphodiesterase inhibitor, significantly (P<0.001) enhanced eriodictyol-induced insulin secretion at 16.7mM glucose in comparison to eriodictyol or IBMX alone. The cAMP content after eriodictyol exposure was also increased. Eriodictyol-induced insulin secretion was partially inhibited by adenylate cyclase inhibitor (SQ22536) and completely inhibited by PKA inhibitor (H-89), suggesting that the eriodictyol effect is more on PKA. Molecular docking studies showed the best binding affinities of eriodictyol with PKA. Eriodictyol improved glucose tolerance and enhanced plasma insulin in non-diabetic and diabetic rats. Eriodictyol also lowered blood glucose in diabetic rats upon chronic treatment. Taken together, it can be concluded that eriodictyol, a novel insulin secretagogue, exerts an exclusive glucose-dependent insulinotropic effect through cAMP/PKA pathway.
Collapse
Affiliation(s)
- Abdul Hameed
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Rahman M Hafizur
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
| | - Nusrat Hussain
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi-75270, Pakistan
| | - Sayed Ali Raza
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Mujeeb Rehman
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi-75270, Pakistan
| | - Sajda Ashraf
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Zaheer Ul-Haq
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Faisal Khan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Ghulam Abbas
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi-75270, Pakistan
| | - M Iqbal Choudhary
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan; H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi-75270, Pakistan; Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah-21412, Saudi Arabia
| |
Collapse
|
37
|
Rehmann H. Interaction of Epac with Non-canonical Cyclic Nucleotides. Handb Exp Pharmacol 2017; 238:135-147. [PMID: 27900608 DOI: 10.1007/164_2015_37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epac1 and Epac2 are cyclic nucleotide-binding (CNB) domain containing proteins, which were originally identified as cAMP-regulated guanine nucleotide exchange factors (GEFs) for the small G-protein Rap. Therefore, Epac proteins founded next to protein kinase A (PKA) and cyclic nucleotide-regulated ion channels the third group of cAMP-responsive proteins in higher organisms. Epac proteins are involved in the regulation of several physiological processes. In particular Epac1 mediates the regulation of molecular processes underlying cell adhesion and mobility. In the pancreas activation of Epac2 potentiates the release of glucose-induced insulin secretion and received attention as a putative target for antidiabetic treatment. While the regulation of Epac by cAMP has been analysed in structural and biochemical detail, less is known on the interaction of Epac with non-canonical cyclic nucleotides. This chapter will discuss to what extent other cyclic purines than cAMP or cyclic pyrimidine could act as Epac agonists or antagonists. The focus will be on the biophysical analysis of the interaction between Epac and these cyclic nucleotides.
Collapse
Affiliation(s)
- Holger Rehmann
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
38
|
Pang B, Kim S, Li D, Ma Z, Sun B, Zhang X, Wu Z, Chen L. Glucagon-like peptide-1 potentiates glucose-stimulated insulin secretion via the transient receptor potential melastatin 2 channel. Exp Ther Med 2017; 14:5219-5227. [PMID: 29201240 DOI: 10.3892/etm.2017.5136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 06/22/2017] [Indexed: 12/22/2022] Open
Abstract
The transient receptor potential melastatin 2 (TRPM2) channel, a Ca2+ permeable channel activated by cAMP, is expressed on pancreatic β-cells and is responsible for the regulation of insulin secretion. It is known that glucose-stimulated insulin secretion (GSIS) can be potentiated by glucagon like peptide-1 (GLP-1), and that the changes in the extracellular glucose concentration alter the levels of intracellular adenosine ATP and cAMP. The present study hypothesized that TRPM2 mediates the modulatory effect of GLP-1 on insulin secretion. The results demonstrated that silencing of TRPM2 eliminated GLP-1-enhanced insulin secretion, indicating the involvement of TRPM2 in this process. In addition, the results of current recordings of TRPM2 and measurement of the resulting insulin secretion in β-cells in the presence of GLP-1 and various concentrations of glucose suggest that GLP-1 regulates GSIS via the TRPM2 channel. Furthermore, inhibiting the activity or expression of TRPM2 attenuated GLP-1-induced GSIS. By using specific activators or inhibitors, the present study demonstrated that the two primary downstream effectors of the GLP-1 receptor, exchange protein directly activated by cAMP and protein kinase A, differentially influence GSIS and GLP-1-potentiated GSIS. In conclusion, the present study revealed the role of TRPM2 in GLP-1-regulated insulin secretion. The results of the present study provide a novel avenue for the prevention and treatment of diabetes and its complications.
Collapse
Affiliation(s)
- Bo Pang
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Sungjoon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Daiqing Li
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Zejun Ma
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Bei Sun
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Xiaona Zhang
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Zhongming Wu
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Liming Chen
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| |
Collapse
|
39
|
Seino S, Sugawara K, Yokoi N, Takahashi H. β-Cell signalling and insulin secretagogues: A path for improved diabetes therapy. Diabetes Obes Metab 2017; 19 Suppl 1:22-29. [PMID: 28880474 DOI: 10.1111/dom.12995] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 04/24/2017] [Accepted: 04/27/2017] [Indexed: 12/26/2022]
Abstract
Insulin secretagogues including sulfonylureas, glinides and incretin-related drugs such as dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists are widely used for treatment of type 2 diabetes. In addition, glucokinase activators and G-protein-coupled receptor 40 (GPR40) agonists also have been developed, although the drugs are not clinically usable. These different drugs exert their effects on insulin secretion by different mechanisms. Recent advances in β-cell signalling studies have not only deepened our understanding of insulin secretion but also revealed novel mechanisms of insulin secretagogues. Clarification of the signalling mechanisms of the insulin secretagogues will contribute to improved drug therapy for diabetes.
Collapse
Affiliation(s)
- Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenji Sugawara
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Norihide Yokoi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| |
Collapse
|
40
|
Mondal P, Prasad A, Girdhar K. Interventions to improve β-cell mass and function. ANNALES D'ENDOCRINOLOGIE 2017; 78:469-477. [PMID: 28870707 DOI: 10.1016/j.ando.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/18/2016] [Accepted: 11/09/2016] [Indexed: 01/09/2023]
Abstract
Diabetes mellitus (T2DM) has become an epidemiologically important disease worldwide and is also becoming a great matter of concern due to the effects associated with it like: high morbidity, elevated health care cost and shortened life span. T2DM is a chronic metabolic disease characterized by insulin resistance as well as β-cell dysfunction. It is widely accepted that in the face of insulin resistance, euglycemia can be maintained by increase in pancreatic β-cell mass and insulin secretion. This compensation is largely due to enhanced secretion of insulin by the β-cell mass, which is present initially, and thereby subsequent increases in β-cell mass provide additional insulin secretion. However, the mechanism by which β-cell anatomical plasticity and functional plasticity for insulin secretion is coordinated and executed in different physiological and pathophysiological states is complex and has been poorly understood. As the incidence of T2DM continues to increase at an alarming rate, it is becoming imperative to shift the research focus towards the β-cell physiology where identification of novel pathways that influence the β-cell proliferation and/or contribute to increase insulin secretion has the potential to lead to new therapies for preventing or delaying onset of disease.
Collapse
Affiliation(s)
- Prosenjit Mondal
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India.
| | - Amit Prasad
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India
| | - Khyati Girdhar
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India
| |
Collapse
|
41
|
Hauge M, Ekberg JP, Engelstoft MS, Timshel P, Madsen AN, Schwartz TW. Gq and Gs signaling acting in synergy to control GLP-1 secretion. Mol Cell Endocrinol 2017; 449:64-73. [PMID: 27908836 DOI: 10.1016/j.mce.2016.11.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 10/24/2016] [Accepted: 11/24/2016] [Indexed: 01/07/2023]
Abstract
GPR40 is generally known to signal through Gq. However, in transfected cells, certain synthetic agonists can make the receptor signal also through Gs and cAMP (Hauge et al., 2015). Here we find that, in colonic crypt cultures, the GLP-1 secretion induced by such Gq + Gs GPR40 agonists is indeed inhibited by blockers of both Gq and Gs and is eliminated by combining these. This in contrast to Gq-only GPR40 agonists which only are affected by the Gq inhibitor. Importantly, Gq-only GPR40 agonists in combination with low doses of selective synthetic agonists for Gs coupled receptors, e.g. GPR119 and TGR5 provide more than additive GLP-1 secretion both ex vivo and in vivo in mice. It is concluded that under physiological circumstances triglyceride metabolites, i.e. long chain fatty acids and 2-monoacyl glycerol plus bile acids, act synergistically through their respective receptors, GPR40, GPR119 and TGR5 to stimulate GLP-1 secretion robustly by combining Gq and Gs signaling pathways.
Collapse
Affiliation(s)
- Maria Hauge
- NNF Center for Basic Metabolic Research, Section for Metabolic Receptology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
| | - Jeppe Pio Ekberg
- NNF Center for Basic Metabolic Research, Section for Metabolic Receptology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
| | - Maja Storm Engelstoft
- NNF Center for Basic Metabolic Research, Section for Metabolic Receptology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
| | - Pascal Timshel
- NNF Center for Basic Metabolic Research, Section of Metabolic Genomics, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
| | - Andreas N Madsen
- NNF Center for Basic Metabolic Research, Section for Metabolic Receptology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
| | - Thue W Schwartz
- NNF Center for Basic Metabolic Research, Section for Metabolic Receptology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
| |
Collapse
|
42
|
Molecular regulation of insulin granule biogenesis and exocytosis. Biochem J 2017; 473:2737-56. [PMID: 27621482 DOI: 10.1042/bcj20160291] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/19/2016] [Indexed: 12/15/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by hyperglycemia, insulin resistance and hyperinsulinemia in early disease stages but a relative insulin insufficiency in later stages. Insulin, a peptide hormone, is produced in and secreted from pancreatic β-cells following elevated blood glucose levels. Upon its release, insulin induces the removal of excessive exogenous glucose from the bloodstream primarily by stimulating glucose uptake into insulin-dependent tissues as well as promoting hepatic glycogenesis. Given the increasing prevalence of T2DM worldwide, elucidating the underlying mechanisms and identifying the various players involved in the synthesis and exocytosis of insulin from β-cells is of utmost importance. This review summarizes our current understanding of the route insulin takes through the cell after its synthesis in the endoplasmic reticulum as well as our knowledge of the highly elaborate network that controls insulin release from the β-cell. This network harbors potential targets for anti-diabetic drugs and is regulated by signaling cascades from several endocrine systems.
Collapse
|
43
|
Graaf CD, Donnelly D, Wootten D, Lau J, Sexton PM, Miller LJ, Ahn JM, Liao J, Fletcher MM, Yang D, Brown AJH, Zhou C, Deng J, Wang MW. Glucagon-Like Peptide-1 and Its Class B G Protein-Coupled Receptors: A Long March to Therapeutic Successes. Pharmacol Rev 2017; 68:954-1013. [PMID: 27630114 PMCID: PMC5050443 DOI: 10.1124/pr.115.011395] [Citation(s) in RCA: 219] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The glucagon-like peptide (GLP)-1 receptor (GLP-1R) is a class B G protein-coupled receptor (GPCR) that mediates the action of GLP-1, a peptide hormone secreted from three major tissues in humans, enteroendocrine L cells in the distal intestine, α cells in the pancreas, and the central nervous system, which exerts important actions useful in the management of type 2 diabetes mellitus and obesity, including glucose homeostasis and regulation of gastric motility and food intake. Peptidic analogs of GLP-1 have been successfully developed with enhanced bioavailability and pharmacological activity. Physiologic and biochemical studies with truncated, chimeric, and mutated peptides and GLP-1R variants, together with ligand-bound crystal structures of the extracellular domain and the first three-dimensional structures of the 7-helical transmembrane domain of class B GPCRs, have provided the basis for a two-domain-binding mechanism of GLP-1 with its cognate receptor. Although efforts in discovering therapeutically viable nonpeptidic GLP-1R agonists have been hampered, small-molecule modulators offer complementary chemical tools to peptide analogs to investigate ligand-directed biased cellular signaling of GLP-1R. The integrated pharmacological and structural information of different GLP-1 analogs and homologous receptors give new insights into the molecular determinants of GLP-1R ligand selectivity and functional activity, thereby providing novel opportunities in the design and development of more efficacious agents to treat metabolic disorders.
Collapse
Affiliation(s)
- Chris de Graaf
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Dan Donnelly
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Denise Wootten
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Jesper Lau
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Patrick M Sexton
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Laurence J Miller
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Jung-Mo Ahn
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Jiayu Liao
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Madeleine M Fletcher
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Dehua Yang
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Alastair J H Brown
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Caihong Zhou
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Jiejie Deng
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| | - Ming-Wei Wang
- Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands (C.d.G.); School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom (D.D.); Drug Discovery Biology Theme and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (D.W., P.M.S., M.M.F.); Protein and Peptide Chemistry, Global Research, Novo Nordisk A/S, Måløv, Denmark (J.La.); Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona (L.J.M.); Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas (J.-M.A.); Department of Bioengineering, Bourns College of Engineering, University of California at Riverside, Riverside, California (J.Li.); National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China (D.Y., C.Z., J.D., M.-W.W.); Heptares Therapeutics, BioPark, Welwyn Garden City, United Kingdom (A.J.H.B.); and School of Pharmacy, Fudan University, Zhangjiang High-Tech Park, Shanghai, China (M.-W.W.)
| |
Collapse
|
44
|
Roussel M, Mathieu J, Dalle S. Molecular mechanisms redirecting the GLP-1 receptor signalling profile in pancreatic β-cells during type 2 diabetes. Horm Mol Biol Clin Investig 2017; 26:87-95. [PMID: 26953712 DOI: 10.1515/hmbci-2015-0071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 01/24/2016] [Indexed: 02/06/2023]
Abstract
Treatments with β-cell preserving properties are essential for the management of type 2 diabetes (T2D), and the new therapeutic avenues, developed over the last years, rely on the physiological role of glucagon-like peptide-1 (GLP-1). Sustained pharmacological levels of GLP-1 are achieved by subcutaneous administration of GLP-1 analogues, while transient and lower physiological levels of GLP-1 are attained following treatment with inhibitors of dipeptidylpeptidase 4 (DPP4), an endoprotease which degrades the peptide. Both therapeutic classes display a sustained and durable hypoglycaemic action in patients with T2D. However, the GLP-1 incretin effect is known to be reduced in patients with T2D, and GLP-1 analogues and DPP4 inhibitors were shown to lose their effectiveness over time in some patients. The pathological mechanisms behind these observations can be either a decrease in GLP-1 secretion from intestinal L-cells and, as a consequence, a reduction in GLP-1 plasma concentrations, combined or not with a reduced action of GLP-1 in the β-cell, the so-called GLP-1 resistance. Much evidence for a GLP-1 resistance of the β-cell in subjects with T2D have emerged. Here, we review the potential roles of the genetic background, the hyperglycaemia, the hyperlipidaemia, the prostaglandin E receptor 3, the nuclear glucocorticoid receptor, the GLP-1R desensitization and internalisation processes, and the β-arrestin-1 expression levels on GLP-1 resistance in β-cells during T2D.
Collapse
|
45
|
Jin H, Fujita T, Jin M, Kurotani R, Hidaka Y, Cai W, Suita K, Prajapati R, Liang C, Ohnuki Y, Mototani Y, Umemura M, Yokoyama U, Sato M, Okumura S, Ishikawa Y. Epac activation inhibits IL-6-induced cardiac myocyte dysfunction. J Physiol Sci 2016; 68:77-87. [PMID: 27995459 PMCID: PMC6353818 DOI: 10.1007/s12576-016-0509-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 11/25/2016] [Indexed: 11/30/2022]
Abstract
Pro-inflammatory cytokines are released in septic shock and impair cardiac function via the Jak-STAT pathway. It is well known that sympathetic and thus catecholamine signaling is activated thereafter to compensate for cardiac dysfunction. The mechanism of such compensation by catecholamine signaling has been traditionally understood to be cyclic AMP-dependent protein kinase (PKA)-mediated enforcement of cardiac contractility. We hypothesized that the exchange protein activated by cAMP (Epac), a newly identified target of cAMP signaling that functions independently of PKA, also plays a key role in this mechanism. In cultured cardiac myocytes, activation of Epac attenuated the inhibitory effect of interleukin-6 on the increase of intracellular Ca2+ concentration and contractility in response to isoproterenol, most likely through inhibition of the Jak-STAT pathway via SOCS3, with subsequent changes in inducible nitric oxide synthase expression. These findings suggest a new role of catecholamine signaling in compensating for cardiac dysfunction in heart failure. Epac and its downstream pathway may be a novel target for treating cardiac dysfunction in endotoxemia.
Collapse
Affiliation(s)
- Huiling Jin
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Takayuki Fujita
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Meihua Jin
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita-shi, Osaka, 565-8565, Japan
| | - Reiko Kurotani
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Biochemical Engineering, Faculty of Engineering, Yamagata University, 4-3-16, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Yuko Hidaka
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Wenqian Cai
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Kenji Suita
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Rajesh Prajapati
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Chen Liang
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Yoshiki Ohnuki
- Department of Physiology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan
| | - Yasumasa Mototani
- Department of Physiology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan
| | - Masanari Umemura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Utako Yokoyama
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Motohiko Sato
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Department of Physiology, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Satoshi Okumura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan. .,Department of Physiology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan.
| | - Yoshihiro Ishikawa
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
| |
Collapse
|
46
|
Gao M, Ma Y, Bast RC, Li Y, Wan L, Liu Y, Sun Y, Fang Z, Zhang L, Wang X, Wei Z. Epac1 knockdown inhibits the proliferation of ovarian cancer cells by inactivating AKT/Cyclin D1/CDK4 pathway in vitro and in vivo. Med Oncol 2016; 33:73. [PMID: 27277757 DOI: 10.1007/s12032-016-0786-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 05/27/2016] [Indexed: 12/14/2022]
Abstract
Ovarian cancer is the leading cause of death among gynecological malignancies, and high grade serous ovarian carcinoma is the most common and most aggressive subtype. Recently, it was demonstrated that cAMP mediates protein kinase A-independent effects through Epac (exchange protein directly activated by cAMP) proteins. Epac proteins, including Epac1 and Epac2, are implicated in several diverse cellular responses, such as insulin secretion, exocytosis, cellular calcium handling and formation of cell-cell junctions. Several reports document that Epac1 could play vital roles in promoting proliferation, invasion and migration of some cancer cells. However, the expression levels and roles of Epac1 in ovarian cancer have not been investigated. In the present study, we detected the expression levels of Epac1 mRNA and protein in three kinds of ovarian cancer cells SKOV3, OVCAR3 and CAOV3. Furthermore, the effect of Epac1 knockdown on the proliferation and apoptosis of SKOV3 and OVCAR3 cells was evaluated in vitro and in vivo. The results showed that there was higher expression of Epac1 mRNA and protein in SKOV3 and OVCAR3 cells. Epac1 knockdown inhibited the proliferation of SKOV3 and OVCAR3 cells in vitro and in vivo. Decreased proliferation may be due to downregulation of Epac1-induced G1 phase arrest by inactivating the AKT/Cyclin D1/CDK4 pathway, but not to alterations in the MAPK pathway or to apoptosis. Taken together, our data provide new insight into the essential role of Epac1 in regulating growth of ovarian cancer cells and suggest that Epac1 might represent an attractive therapeutic target for treatment of ovarian cancer.
Collapse
Affiliation(s)
- Meng Gao
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Yanyan Ma
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Robert C Bast
- Department of Experimental Therapeutics, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yue Li
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Lu Wan
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Yanping Liu
- Department of Gynecology and Obstetrics, Jinan Central Hospital Affiliated to Shandong University, 105# Jiefang Road, Jinan, 250013, Shandong, People's Republic of China.,Department of Gynecology and Obstetrics, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Yingshuo Sun
- Department of Gynecology and Obstetrics, Jinan Central Hospital Affiliated to Shandong University, 105# Jiefang Road, Jinan, 250013, Shandong, People's Republic of China.,Department of Gynecology and Obstetrics, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Zhenghui Fang
- Department of Gynecology and Obstetrics, Jinan Central Hospital Affiliated to Shandong University, 105# Jiefang Road, Jinan, 250013, Shandong, People's Republic of China
| | - Lining Zhang
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Xiaoyan Wang
- Department of Immunology, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.
| | - Zengtao Wei
- Department of Gynecology and Obstetrics, Jinan Central Hospital Affiliated to Shandong University, 105# Jiefang Road, Jinan, 250013, Shandong, People's Republic of China. .,Department of Gynecology and Obstetrics, Shandong University School of Medicine, 44# Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.
| |
Collapse
|
47
|
Abstract
Glucagon-like peptide-1 (GLP-1) is a peptide hormone, released from intestinal L-cells in response to hormonal, neural and nutrient stimuli. In addition to potentiation of meal-stimulated insulin secretion, GLP-1 signalling exerts numerous pleiotropic effects on various tissues, regulating energy absorption and disposal, as well as cell proliferation and survival. In Type 2 Diabetes (T2D) reduced plasma levels of GLP-1 have been observed, and plasma levels of GLP-1, as well as reduced numbers of GLP-1 producing cells, have been correlated to obesity and insulin resistance. Increasing endogenous secretion of GLP-1 by selective targeting of the molecular mechanisms regulating secretion from the L-cell has been the focus of much recent research. An additional and promising strategy for enhancing endogenous secretion may be to increase the L-cell mass in the intestinal epithelium, but the mechanisms that regulate the growth, survival and function of these cells are largely unknown. We recently showed that prolonged exposure to high concentrations of the fatty acid palmitate induced lipotoxic effects, similar to those operative in insulin-producing cells, in an in vitro model of GLP-1-producing cells. The mechanisms inducing this lipototoxicity involved increased production of reactive oxygen species (ROS). In this review, regulation of GLP-1-secreting cells is discussed, with a focus on the mechanisms underlying GLP-1 secretion, long-term regulation of growth, differentiation and survival under normal as well as diabetic conditions of hypernutrition.
Collapse
|
48
|
The complexity of signalling mediated by the glucagon-like peptide-1 receptor. Biochem Soc Trans 2016; 44:582-8. [DOI: 10.1042/bst20150244] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Indexed: 01/14/2023]
Abstract
The glucagon-like peptide-1 receptor (GLP-1R) is a class B GPCR that is a major therapeutic target for the treatment of type 2 diabetes. The receptor is activated by the incretin peptide GLP-1 promoting a broad range of physiological effects including glucose-dependent insulin secretion and biosynthesis, improved insulin sensitivity of peripheral tissues, preservation of β-cell mass and weight loss, all of which are beneficial in the treatment of type 2 diabetes. Despite this, existing knowledge surrounding the underlying signalling mechanisms responsible for the physiological actions downstream of GLP-1R activation is limited. Here, we review the current understanding around GLP-1R-mediated signalling, in particular highlighting recent contributions to the field on biased agonism, the spatial and temporal aspects for the control of signalling and how these concepts may influence future drug development.
Collapse
|
49
|
Röder PV, Wu B, Liu Y, Han W. Pancreatic regulation of glucose homeostasis. Exp Mol Med 2016; 48:e219. [PMID: 26964835 PMCID: PMC4892884 DOI: 10.1038/emm.2016.6] [Citation(s) in RCA: 454] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/03/2015] [Accepted: 12/06/2015] [Indexed: 12/11/2022] Open
Abstract
In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed.
Collapse
Affiliation(s)
- Pia V Röder
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
| | - Bingbing Wu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Yixian Liu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Weiping Han
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
| |
Collapse
|
50
|
Takeda Y, Shimayoshi T, Holz GG, Noma A. Modeling analysis of inositol 1,4,5-trisphosphate receptor-mediated Ca2+ mobilization under the control of glucagon-like peptide-1 in mouse pancreatic β-cells. Am J Physiol Cell Physiol 2016; 310:C337-47. [PMID: 26741144 PMCID: PMC4888524 DOI: 10.1152/ajpcell.00234.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/19/2015] [Indexed: 01/22/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is an intestinally derived blood glucose-lowering hormone that potentiates glucose-stimulated insulin secretion from pancreatic β-cells. The secretagogue action of GLP-1 is explained, at least in part, by its ability to stimulate cAMP production so that cAMP may facilitate the release of Ca(2+) from inositol trisphosphate receptor (IP3R)-regulated Ca(2+) stores. However, a quantitative model has yet to be provided that explains the molecular mechanisms and dynamic processes linking GLP-1-stimulated cAMP production to Ca(2+) mobilization. Here, we performed simulation studies to investigate how GLP-1 alters the abilities of Ca(2+) and IP3 to act as coagonists at IP3R Ca(2+) release channels. A new dynamic model was constructed based on the Kaftan model, which demonstrates dual steady-state allosteric regulation of the IP3R by Ca(2+) and IP3. Data obtained from β-cells were then analyzed to understand how GLP-1 facilitates IP3R-mediated Ca(2+) mobilization when UV flash photolysis is used to uncage Ca(2+) and IP3 intracellularly. When the dynamic model for IP3R activation was incorporated into a minimal cell model, the Ca(2+) transients and oscillations induced by GLP-1 were successfully reconstructed. Simulation studies indicated that transient and oscillatory responses to GLP-1 were produced by sequential positive and negative feedback regulation due to fast activation and slow inhibition of the IP3R by Ca(2+). The slow rate of Ca(2+)-dependent inhibition was revealed to provide a remarkable contribution to the time course of the decay of cytosolic Ca(2+) transients. It also served to drive and pace Ca(2+) oscillations that are significant when evaluating how GLP-1 stimulates insulin secretion.
Collapse
Affiliation(s)
- Yukari Takeda
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu City, Japan;
| | - Takao Shimayoshi
- Department of Systems Science, Kyoto University, Kyoto, Japan; and
| | - George G Holz
- Departments of Medicine and Pharmacology, SUNY Upstate Medical University, Syracuse, New York
| | - Akinori Noma
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu City, Japan
| |
Collapse
|