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Ahmad JN, Sebo P. cAMP signaling of Bordetella adenylate cyclase toxin blocks M-CSF triggered upregulation of iron acquisition receptors on differentiating CD14 + monocytes. mSphere 2024; 9:e0040724. [PMID: 39078132 PMCID: PMC11351043 DOI: 10.1128/msphere.00407-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 06/30/2024] [Indexed: 07/31/2024] Open
Abstract
Bordetella pertussis infects the upper airways of humans and disarms host defense by the potent immuno-subversive activities of its pertussis (PT) and adenylate cyclase (CyaA) toxins. CyaA action near-instantly ablates the bactericidal activities of sentinel CR3-expressing myeloid phagocytes by hijacking cellular signaling pathways through the unregulated production of cAMP. Moreover, CyaA-elicited cAMP signaling also inhibits the macrophage colony-stimulating factor (M-CSF)-induced differentiation of incoming inflammatory monocytes into bactericidal macrophages. We show that CyaA/cAMP signaling via protein kinase A (PKA) downregulates the M-CSF-elicited expression of monocyte receptors for transferrin (CD71) and hemoglobin-haptoglobin (CD163), as well as the expression of heme oxygenase-1 (HO-1) involved in iron liberation from internalized heme. The impact of CyaA action on CD71 and CD163 levels in differentiating monocytes is largely alleviated by the histone deacetylase inhibitor trichostatin A (TSA), indicating that CyaA/cAMP signaling triggers epigenetic silencing of genes for micronutrient acquisition receptors. These results suggest a new mechanism by which B. pertussis evades host sentinel phagocytes to achieve proliferation on airway mucosa.IMPORTANCETo establish a productive infection of the nasopharyngeal mucosa and proliferate to sufficiently high numbers that trigger rhinitis and aerosol-mediated transmission, the pertussis agent Bordetella pertussis deploys several immunosuppressive protein toxins that compromise the sentinel functions of mucosa patrolling phagocytes. We show that cAMP signaling elicited by very low concentrations (22 pM) of Bordetella adenylate cyclase toxin downregulates the iron acquisition systems of CD14+ monocytes. The resulting iron deprivation of iron, a key micronutrient, then represents an additional aspect of CyaA toxin action involved in the inhibition of differentiation of monocytes into the enlarged bactericidal macrophage cells. This corroborates the newly discovered paradigm of host defense evasion mechanisms employed by bacterial pathogens, where manipulation of cellular cAMP levels blocks monocyte to macrophage transition and replenishment of exhausted phagocytes, thereby contributing to the formation of a safe niche for pathogen proliferation and dissemination.
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Affiliation(s)
- Jawid Nazir Ahmad
- Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Peter Sebo
- Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
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2
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Kim YD, Park HG, Song S, Kim J, Lee BJ, Broadie K, Lee S. Presynaptic structural and functional plasticity are coupled by convergent Rap1 signaling. J Cell Biol 2024; 223:e202309095. [PMID: 38748250 PMCID: PMC11096849 DOI: 10.1083/jcb.202309095] [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] [Received: 09/19/2023] [Revised: 02/07/2024] [Accepted: 03/27/2024] [Indexed: 05/18/2024] Open
Abstract
Dynamic presynaptic actin remodeling drives structural and functional plasticity at synapses, but the underlying mechanisms remain largely unknown. Previous work has shown that actin regulation via Rac1 guanine exchange factor (GEF) Vav signaling restrains synaptic growth via bone morphogenetic protein (BMP)-induced receptor macropinocytosis and mediates synaptic potentiation via mobilization of reserve pool vesicles in presynaptic boutons. Here, we find that Gef26/PDZ-GEF and small GTPase Rap1 signaling couples the BMP-induced activation of Abelson kinase to this Vav-mediated macropinocytosis. Moreover, we find that adenylate cyclase Rutabaga (Rut) signaling via exchange protein activated by cAMP (Epac) drives the mobilization of reserve pool vesicles during post-tetanic potentiation (PTP). We discover that Rap1 couples activation of Rut-cAMP-Epac signaling to Vav-mediated synaptic potentiation. These findings indicate that Rap1 acts as an essential, convergent node for Abelson kinase and cAMP signaling to mediate BMP-induced structural plasticity and activity-induced functional plasticity via Vav-dependent regulation of the presynaptic actin cytoskeleton.
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Affiliation(s)
- Yeongjin David Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Hyun Gwan Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Seunghwan Song
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
| | - Joohyung Kim
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Byoung Ju Lee
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Kendal Broadie
- Departments of Cell and Developmental Biology, Pharmacology, and Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, USA
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
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3
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Li Z, Liu Q, Cai Y, Ye N, He Z, Yao Y, Ding Y, Wang P, Qi C, Zheng L, Wang L, Zhou J, Zhang QQ. EPAC inhibitor suppresses angiogenesis and tumor growth of triple-negative breast cancer. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167114. [PMID: 38447883 DOI: 10.1016/j.bbadis.2024.167114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 03/08/2024]
Abstract
AIMS Exchange protein directly activated by cAMP 1 (EPAC1), a major isoform of guanine nucleotide exchange factors, is highly expressed in vascular endothelia cells and regulates angiogenesis in the retina. High intratumor microvascular densities (MVD) resulting from angiogenesis is responsible for breast cancer development. Downregulation of EPAC1 in tumor cell reduces triple-negative breast cancer (TNBC)-induced angiogenesis. However, whether Epac1 expressed in vascular endothelial cells contributes to angiogenesis and tumor development of TNBC remains elusive. MAIN METHODS We employed NY0123, a previously identified potent EPAC inhibitor, to explore the anti-angiogenic biological role of EPAC1 in vitro and in vivo through vascular endothelial cells, rat aortic ring, Matrigel plug, and chick embryo chorioallantoic membrane (CAM) and yolk sac membrane (YSM) assays, as well as the in vivo xenograft tumor models of TNBC in both chick embryo and mice. KEY FINDINGS Inhibiting EPAC1 in vascular endothelial cells by NY0123 significantly suppresses angiogenesis and tumor growth of TNBC. In addition, NY0123 possesses a better inhibitory efficacy than ESI-09, a reported specific EPAC inhibitor tool compound. Importantly, inhibiting EPAC1 in vascular endothelia cells regulates the typical angiogenic signaling network, which is associated with not only vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor-2 (VEGFR2) signaling, but also PI3K/AKT, MEK/ERK and Notch pathway. CONCLUSIONS Our findings support that EPAC1 may serve as an effective anti-angiogenic therapeutic target of TNBC, and EPAC inhibitor NY0123 has the therapeutic potential to be developed for the treatment of TNBC.
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Affiliation(s)
- Zishuo Li
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Qiao Liu
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Yuhao Cai
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Zinan He
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Yuying Yao
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Yi Ding
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Cuiling Qi
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Lingyun Zheng
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Lijing Wang
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States.
| | - Qian-Qian Zhang
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou 510006, China.
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4
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Zhang T, Dolga AM, Eisel ULM, Schmidt M. Novel crosstalk mechanisms between GluA3 and Epac2 in synaptic plasticity and memory in Alzheimer's disease. Neurobiol Dis 2024; 191:106389. [PMID: 38142840 DOI: 10.1016/j.nbd.2023.106389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease which accounts for the most cases of dementia worldwide. Impaired memory, including acquisition, consolidation, and retrieval, is one of the hallmarks in AD. At the cellular level, dysregulated synaptic plasticity partly due to reduced long-term potentiation (LTP) and enhanced long-term depression (LTD) underlies the memory deficits in AD. GluA3 containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are one of key receptors involved in rapid neurotransmission and synaptic plasticity. Recent studies revealed a novel form of GluA3 involved in neuronal plasticity that is dependent on cyclic adenosine monophosphate (cAMP), rather than N-methyl-d-aspartate (NMDA). However, this cAMP-dependent GluA3 pathway is specifically and significantly impaired by amyloid beta (Aβ), a pathological marker of AD. cAMP is a key second messenger that plays an important role in modulating memory and synaptic plasticity. We previously reported that exchange protein directly activated by cAMP 2 (Epac2), acting as a main cAMP effector, plays a specific and time-limited role in memory retrieval. From electrophysiological perspective, Epac2 facilities the maintenance of LTP, a cellular event closely associated with memory retrieval. Additionally, Epac2 was found to be involved in the GluA3-mediated plasticity. In this review, we comprehensively summarize current knowledge regarding the specific roles of GluA3 and Epac2 in synaptic plasticity and memory, and their potential association with AD.
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Affiliation(s)
- Tong Zhang
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Amalia M Dolga
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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5
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Greiser M, Karbowski M, Kaplan AD, Coleman AK, Verhoeven N, Mannella CA, Lederer WJ, Boyman L. Calcium and bicarbonate signaling pathways have pivotal, resonating roles in matching ATP production to demand. eLife 2023; 12:e84204. [PMID: 37272417 PMCID: PMC10284600 DOI: 10.7554/elife.84204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 06/01/2023] [Indexed: 06/06/2023] Open
Abstract
Mitochondrial ATP production in ventricular cardiomyocytes must be continually adjusted to rapidly replenish the ATP consumed by the working heart. Two systems are known to be critical in this regulation: mitochondrial matrix Ca2+ ([Ca2+]m) and blood flow that is tuned by local cardiomyocyte metabolic signaling. However, these two regulatory systems do not fully account for the physiological range of ATP consumption observed. We report here on the identity, location, and signaling cascade of a third regulatory system -- CO2/bicarbonate. CO2 is generated in the mitochondrial matrix as a metabolic waste product of the oxidation of nutrients. It is a lipid soluble gas that rapidly permeates the inner mitochondrial membrane and produces bicarbonate in a reaction accelerated by carbonic anhydrase. The bicarbonate level is tracked physiologically by a bicarbonate-activated soluble adenylyl cyclase (sAC). Using structural Airyscan super-resolution imaging and functional measurements we find that sAC is primarily inside the mitochondria of ventricular cardiomyocytes where it generates cAMP when activated by bicarbonate. Our data strongly suggest that ATP production in these mitochondria is regulated by this cAMP signaling cascade operating within the inter-membrane space by activating local EPAC1 (Exchange Protein directly Activated by cAMP) which turns on Rap1 (Ras-related protein-1). Thus, mitochondrial ATP production is increased by bicarbonate-triggered sAC-signaling through Rap1. Additional evidence is presented indicating that the cAMP signaling itself does not occur directly in the matrix. We also show that this third signaling process involving bicarbonate and sAC activates the mitochondrial ATP production machinery by working independently of, yet in conjunction with, [Ca2+]m-dependent ATP production to meet the energy needs of cellular activity in both health and disease. We propose that the bicarbonate and calcium signaling arms function in a resonant or complementary manner to match mitochondrial ATP production to the full range of energy consumption in ventricular cardiomyocytes.
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Affiliation(s)
- Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Claude D. Pepper Older Americans Independence Center, University of Maryland School of MedicineBaltimoreUnited States
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Biochemistry and Molecular Biology, University of Maryland School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
| | - Aaron David Kaplan
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of MedicineBaltimoreUnited States
| | - Andrew Kyle Coleman
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
| | - Nicolas Verhoeven
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Biochemistry and Molecular Biology, University of Maryland School of MedicineBaltimoreUnited States
| | - Carmen A Mannella
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
| | - Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Physiology, University of Marylan School of MedicineBaltimoreUnited States
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore School of MedicineBaltimoreUnited States
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6
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Slika H, Mansour H, Nasser SA, Shaito A, Kobeissy F, Orekhov AN, Pintus G, Eid AH. Epac as a tractable therapeutic target. Eur J Pharmacol 2023; 945:175645. [PMID: 36894048 DOI: 10.1016/j.ejphar.2023.175645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/09/2023]
Abstract
In 1957, cyclic adenosine monophosphate (cAMP) was identified as the first secondary messenger, and the first signaling cascade discovered was the cAMP-protein kinase A (PKA) pathway. Since then, cAMP has received increasing attention given its multitude of actions. Not long ago, a new cAMP effector named exchange protein directly activated by cAMP (Epac) emerged as a critical mediator of cAMP's actions. Epac mediates a plethora of pathophysiologic processes and contributes to the pathogenesis of several diseases such as cancer, cardiovascular disease, diabetes, lung fibrosis, neurological disorders, and others. These findings strongly underscore the potential of Epac as a tractable therapeutic target. In this context, Epac modulators seem to possess unique characteristics and advantages and hold the promise of providing more efficacious treatments for a wide array of diseases. This paper provides an in-depth dissection and analysis of Epac structure, distribution, subcellular compartmentalization, and signaling mechanisms. We elaborate on how these characteristics can be utilized to design specific, efficient, and safe Epac agonists and antagonists that can be incorporated into future pharmacotherapeutics. In addition, we provide a detailed portfolio for specific Epac modulators highlighting their discovery, advantages, potential concerns, and utilization in the context of clinical disease entities.
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Affiliation(s)
- Hasan Slika
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | - Hadi Mansour
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, Doha, P.O. Box: 2713, Qatar.
| | - Firas Kobeissy
- Department of Neurobiology and Neuroscience, Morehouse School of Medicine, Atlanta, Georgia, USA.
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Institute of Human Morphology, 3 Tsyurupa Street, Moscow, 117418, Russia; Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow, 125315, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Osennyaya Street 4-1-207, Moscow, 121609, Russia.
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sassari, 07100, Sassari, Italy.
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
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7
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Protein interaction, cytotoxic, transcriptomic and proteomic responses to structurally distinct EPAC1 activators in HUVECs. Sci Rep 2022; 12:16505. [PMID: 36198739 PMCID: PMC9534843 DOI: 10.1038/s41598-022-20607-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/15/2022] [Indexed: 11/15/2022] Open
Abstract
The N-acylsulfonamide derivative, I942, represents the first non-cyclic nucleotide partial agonist of EPAC1. This was soon followed by the identification of the I942 analogues, PW0381, PW0521 and PWO577 and a series of benzofuran oxoacetic acid EPAC1 activators, SY006, SY007 and SY009. Protein interaction, cytotoxicity and EPAC1 activation assays applied here identify PWO577 and SY007 as being effective EPAC1 binders that are well tolerated in HUVECs at concentrations greater than 100 μM and up to 48 h incubation and are effective activators of transfected EPAC1 in U2OS cells. Using RNAseq in HUVECs we show that PWO577 and SY007 regulate approximately 11,000 shared genes, with only few differential gene changes being “off-target”. The genes significantly regulated by both PWO577 and SY007 included a subset of genes normally associated with endothelial activation, including ICAM1, MMP1 and CCL2. Of these, only the expression of MMP1 was markedly increased at the protein level, as determined by LC–MS-based proteomics. Both PWO577 and SY007 suppressed IL-6-induced STAT3 activation and associated downstream gene expression, including inhibition of SOCS3, STAT3, IL6ST and JAK3 genes. Together these results demonstrate the utility of structurally distinct, specific and non-toxic EPAC1 activators. Future modifications will be aimed at eliminating the few noted off-target effects.
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8
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Liu X, Vickstrom CR, Yu H, Liu S, Snarrenberg ST, Friedman V, Mu L, Chen B, Kelly TJ, Baker DA, Liu QS. Epac2 in midbrain dopamine neurons contributes to cocaine reinforcement via facilitation of dopamine release. eLife 2022; 11:80747. [PMID: 35993549 PMCID: PMC9436413 DOI: 10.7554/elife.80747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/21/2022] [Indexed: 11/21/2022] Open
Abstract
Repeated exposure to drugs of abuse results in an upregulation of cAMP signaling in the mesolimbic dopamine system, a molecular adaptation thought to be critically involved in the development of drug dependence. Exchange protein directly activated by cAMP (Epac2) is a major cAMP effector abundantly expressed in the brain. However, it remains unknown whether Epac2 contributes to cocaine reinforcement. Here, we report that Epac2 in the mesolimbic dopamine system promotes cocaine reinforcement via enhancement of dopamine release. Conditional knockout of Epac2 from midbrain dopamine neurons (Epac2-cKO) and the selective Epac2 inhibitor ESI-05 decreased cocaine self-administration in mice under both fixed-ratio and progressive-ratio reinforcement schedules and across a broad range of cocaine doses. In addition, Epac2-cKO led to reduced evoked dopamine release, whereas Epac2 agonism robustly enhanced dopamine release in the nucleus accumbens in vitro. This mechanism is central to the behavioral effects of Epac2 disruption, as chemogenetic stimulation of ventral tegmental area (VTA) dopamine neurons via deschloroclozapine (DCZ)-induced activation of Gs-DREADD increased dopamine release and reversed the impairment of cocaine self-administration in Epac2-cKO mice. Conversely, chemogenetic inhibition of VTA dopamine neurons with Gi-DREADD reduced dopamine release and cocaine self-administration in wild-type mice. Epac2-mediated enhancement of dopamine release may therefore represent a novel and powerful mechanism that contributes to cocaine reinforcement.
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Affiliation(s)
- Xiaojie Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Casey R Vickstrom
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Hao Yu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Shuai Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Shana Terai Snarrenberg
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Vladislav Friedman
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Lianwei Mu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Bixuan Chen
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - Thomas J Kelly
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
| | - David A Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Qing-Song Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
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Shen X, van den Brink J, Bergan-Dahl A, Kolstad TR, Norden ES, Hou Y, Laasmaa M, Aguilar-Sanchez Y, Quick AP, Espe EKS, Sjaastad I, Wehrens XHT, Edwards AG, Soeller C, Louch WE. Prolonged β-adrenergic stimulation disperses ryanodine receptor clusters in cardiomyocytes. eLife 2022; 11:77725. [PMID: 35913125 PMCID: PMC9410709 DOI: 10.7554/elife.77725] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/31/2022] [Indexed: 11/17/2022] Open
Abstract
Ryanodine receptors (RyRs) exhibit dynamic arrangements in cardiomyocytes, and we previously showed that ‘dispersion’ of RyR clusters disrupts Ca2+ homeostasis during heart failure (HF) (Kolstad et al., eLife, 2018). Here, we investigated whether prolonged β-adrenergic stimulation, a hallmark of HF, promotes RyR cluster dispersion and examined the underlying mechanisms. We observed that treatment of healthy rat cardiomyocytes with isoproterenol for 1 hr triggered progressive fragmentation of RyR clusters. Pharmacological inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) reversed these effects, while cluster dispersion was reproduced by specific activation of CaMKII, and in mice with constitutively active Ser2814-RyR. A similar role of protein kinase A (PKA) in promoting RyR cluster fragmentation was established by employing PKA activation or inhibition. Progressive cluster dispersion was linked to declining Ca2+ spark fidelity and magnitude, and slowed release kinetics from Ca2+ propagation between more numerous RyR clusters. In healthy cells, this served to dampen the stimulatory actions of β-adrenergic stimulation over the longer term and protect against pro-arrhythmic Ca2+ waves. However, during HF, RyR dispersion was linked to impaired Ca2+ release. Thus, RyR localization and function are intimately linked via channel phosphorylation by both CaMKII and PKA, which, while finely tuned in healthy cardiomyocytes, underlies impaired cardiac function during pathology.
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Affiliation(s)
- Xin Shen
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | | | - Anna Bergan-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Terje R Kolstad
- Insitute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | | | - Yufeng Hou
- KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Martin Laasmaa
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Yuriana Aguilar-Sanchez
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Ann Pepper Quick
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | | | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | | | | | - William Edward Louch
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
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10
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Rasmussen M, Zhou J, Schwede F, Ekström P. Enhanced cGMP Interactor Rap Guanine Exchange Factor 4 (EPAC2) Expression and Activity in Degenerating Photoreceptors: A Neuroprotective Response? Int J Mol Sci 2022; 23:ijms23094619. [PMID: 35563009 PMCID: PMC9103912 DOI: 10.3390/ijms23094619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/17/2022] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
The disease retinitis pigmentosa (RP) leads to photoreceptor degeneration by a yet undefined mechanism(s). In several RP mouse models (i.e., rd mice), a high cyclic GMP (cGMP) level within photoreceptors is detected, suggesting that cGMP plays a role in degeneration. The rap guanine exchange factor 4 (EPAC2) is activated by cyclic AMP (cAMP) and is an accepted cGMP-interacting protein. It is unclear whether and how cGMP interacts with EPAC2 in degenerating photoreceptors; we therefore investigated EPAC2 expression and interactions with cGMP and cAMP in retinas of the rd1 and rd10 models for retinal degeneration. EPAC2 expression in the photoreceptor layer increased significantly during rd1 and rd10 degeneration, and an increase in EPAC2 interactions with cGMP but not cAMP in the rd1 was also seen via a proximity ligation assay on histological sections. Retinal explant cultures revealed that pharmacological inhibition of the EPAC2 activity reduced the photoreceptor layer thickness in the rd10 retina, suggesting that EPAC2 inhibition promotes degeneration. Taken together, our results support the hypothesis that high degeneration-related cGMP leads to increased EPAC2 and cGMP interactions, inhibiting EPAC2. By inference, EPAC2 could have neuroprotective capacities that may be exploited in the future.
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Affiliation(s)
- Michel Rasmussen
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
- Correspondence:
| | - Jiaming Zhou
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co. KG, 28199 Bremen, Germany;
| | - Per Ekström
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
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11
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Glycine Release Is Potentiated by cAMP via EPAC2 and Ca 2+ Stores in a Retinal Interneuron. J Neurosci 2021; 41:9503-9520. [PMID: 34620721 PMCID: PMC8612479 DOI: 10.1523/jneurosci.0670-21.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022] Open
Abstract
Neuromodulation via the intracellular second messenger cAMP is ubiquitous at presynaptic nerve terminals. This modulation of synaptic transmission allows exocytosis to adapt to stimulus levels and reliably encode information. The AII amacrine cell (AII-AC) is a central hub for signal processing in the mammalian retina. The main apical dendrite of the AII-AC is connected to several lobular appendages that release glycine onto OFF cone bipolar cells and ganglion cells. However, the influence of cAMP on glycine release is not well understood. Using membrane capacitance measurements from mouse AII-ACs to directly measure exocytosis, we observe that intracellular dialysis of 1 mm cAMP enhances exocytosis without affecting the L-type Ca2+ current. Responses to depolarizing pulses of various durations show that the size of the readily releasable pool of vesicles nearly doubles with cAMP, while paired-pulse depression experiments suggest that release probability does not change. Specific agonists and antagonists for exchange protein activated by cAMP 2 (EPAC2) revealed that the cAMP-induced enhancement of exocytosis requires EPAC2 activation. Furthermore, intact Ca2+ stores were also necessary for the cAMP potentiation of exocytosis. Postsynaptic recordings from OFF cone bipolar cells showed that increasing cAMP with forskolin potentiated the frequency of glycinergic spontaneous IPSCs. We propose that cAMP elevations in the AII-AC lead to a robust enhancement of glycine release through an EPAC2 and Ca2+ store signaling pathway. Our results thus contribute to a better understanding of how AII-AC crossover inhibitory circuits adapt to changes in ambient luminance.SIGNIFICANCE STATEMENT The mammalian retina operates over a wide dynamic range of light intensities and contrast levels. To optimize the signal-to-noise ratio of processed visual information, both excitatory and inhibitory synapses within the retina must modulate their gain in synaptic transmission to adapt to different levels of ambient light. Here we show that increases of cAMP concentration within AII amacrine cells produce enhanced exocytosis from these glycinergic interneurons. Therefore, we propose that light-sensitive neuromodulators may change the output of glycine release from AII amacrine cells. This novel mechanism may fine-tune the amount of tonic and phasic synaptic inhibition received by bipolar cell terminals and, consequently, the spiking patterns that ganglion cells send to the upstream visual areas of the brain.
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12
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Camillo C, Facchinello N, Villari G, Mana G, Gioelli N, Sandri C, Astone M, Tortarolo D, Clapero F, Gays D, Oberkersch RE, Arese M, Tamagnone L, Valdembri D, Santoro MM, Serini G. LPHN2 inhibits vascular permeability by differential control of endothelial cell adhesion. J Cell Biol 2021; 220:212665. [PMID: 34581723 PMCID: PMC8480966 DOI: 10.1083/jcb.202006033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 03/22/2021] [Accepted: 09/02/2021] [Indexed: 01/20/2023] Open
Abstract
Dynamic modulation of endothelial cell-to-cell and cell–to–extracellular matrix (ECM) adhesion is essential for blood vessel patterning and functioning. Yet the molecular mechanisms involved in this process have not been completely deciphered. We identify the adhesion G protein–coupled receptor (ADGR) Latrophilin 2 (LPHN2) as a novel determinant of endothelial cell (EC) adhesion and barrier function. In cultured ECs, endogenous LPHN2 localizes at ECM contacts, signals through cAMP/Rap1, and inhibits focal adhesion (FA) formation and nuclear localization of YAP/TAZ transcriptional regulators, while promoting tight junction (TJ) assembly. ECs also express an endogenous LPHN2 ligand, fibronectin leucine-rich transmembrane 2 (FLRT2), that prevents ECM-elicited EC behaviors in an LPHN2-dependent manner. Vascular ECs of lphn2a knock-out zebrafish embryos become abnormally stretched, display a hyperactive YAP/TAZ pathway, and lack proper intercellular TJs. Consistently, blood vessels are hyperpermeable, and intravascularly injected cancer cells extravasate more easily in lphn2a null animals. Thus, LPHN2 ligands, such as FLRT2, may be therapeutically exploited to interfere with cancer metastatic dissemination.
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Affiliation(s)
- Chiara Camillo
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Nicola Facchinello
- Laboratory of Angiogenesis and Cancer Metabolism, Department of Biology, University of Padova, Padova, Italy
| | - Giulia Villari
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Giulia Mana
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Noemi Gioelli
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Chiara Sandri
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Matteo Astone
- Laboratory of Angiogenesis and Cancer Metabolism, Department of Biology, University of Padova, Padova, Italy
| | - Dora Tortarolo
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Fabiana Clapero
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Dafne Gays
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Roxana E Oberkersch
- Laboratory of Angiogenesis and Cancer Metabolism, Department of Biology, University of Padova, Padova, Italy
| | - Marco Arese
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Luca Tamagnone
- Institute of Histology and Embryology, School of Medicine, Catholic University of the Sacred Heart, Rome, Italy.,"Agostino Gemelli" University Polyclinic Foundation, Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy
| | - Donatella Valdembri
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Massimo M Santoro
- Laboratory of Angiogenesis and Cancer Metabolism, Department of Biology, University of Padova, Padova, Italy
| | - Guido Serini
- Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, Candiolo, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
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13
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Ramms DJ, Raimondi F, Arang N, Herberg FW, Taylor SS, Gutkind JS. G αs-Protein Kinase A (PKA) Pathway Signalopathies: The Emerging Genetic Landscape and Therapeutic Potential of Human Diseases Driven by Aberrant G αs-PKA Signaling. Pharmacol Rev 2021; 73:155-197. [PMID: 34663687 PMCID: PMC11060502 DOI: 10.1124/pharmrev.120.000269] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many of the fundamental concepts of signal transduction and kinase activity are attributed to the discovery and crystallization of cAMP-dependent protein kinase, or protein kinase A. PKA is one of the best-studied kinases in human biology, with emphasis in biochemistry and biophysics, all the way to metabolism, hormone action, and gene expression regulation. It is surprising, however, that our understanding of PKA's role in disease is largely underappreciated. Although genetic mutations in the PKA holoenzyme are known to cause diseases such as Carney complex, Cushing syndrome, and acrodysostosis, the story largely stops there. With the recent explosion of genomic medicine, we can finally appreciate the broader role of the Gαs-PKA pathway in disease, with contributions from aberrant functioning G proteins and G protein-coupled receptors, as well as multiple alterations in other pathway components and negative regulators. Together, these represent a broad family of diseases we term the Gαs-PKA pathway signalopathies. The Gαs-PKA pathway signalopathies encompass diseases caused by germline, postzygotic, and somatic mutations in the Gαs-PKA pathway, with largely endocrine and neoplastic phenotypes. Here, we present a signaling-centric review of Gαs-PKA-driven pathophysiology and integrate computational and structural analysis to identify mutational themes commonly exploited by the Gαs-PKA pathway signalopathies. Major mutational themes include hotspot activating mutations in Gαs, encoded by GNAS, and mutations that destabilize the PKA holoenzyme. With this review, we hope to incite further study and ultimately the development of new therapeutic strategies in the treatment of a wide range of human diseases. SIGNIFICANCE STATEMENT: Little recognition is given to the causative role of Gαs-PKA pathway dysregulation in disease, with effects ranging from infectious disease, endocrine syndromes, and many cancers, yet these disparate diseases can all be understood by common genetic themes and biochemical signaling connections. By highlighting these common pathogenic mechanisms and bridging multiple disciplines, important progress can be made toward therapeutic advances in treating Gαs-PKA pathway-driven disease.
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Affiliation(s)
- Dana J Ramms
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Francesco Raimondi
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Nadia Arang
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Friedrich W Herberg
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - Susan S Taylor
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
| | - J Silvio Gutkind
- Department of Pharmacology (D.J.R., N.A., J.S.G.), Department of Chemistry and Biochemistry (S.S.T.), and Moores Cancer Center (D.J.R., N.A., J.S.G.), University of California, San Diego, La Jolla, California; Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy (F.R.); and Department of Biochemistry, University of Kassel, Kassel, Germany (F.W.H.)
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14
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Chen W, McRoberts JA, Ennes HS, Marvizon JC. cAMP signaling through protein kinase A and Epac2 induces substance P release in the rat spinal cord. Neuropharmacology 2021; 189:108533. [PMID: 33744339 DOI: 10.1016/j.neuropharm.2021.108533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/18/2022]
Abstract
Using neurokinin 1 receptor (NK1R) internalization to measure of substance P release in rat spinal cord slices, we found that it was induced by the adenylyl cyclase (AC) activator forskolin, by the protein kinase A (PKA) activators 6-Bnz-cAMP and 8-Br-cAMP, and by the activator of exchange protein activated by cAMP (Epac) 8-pCPT-2-O-Me-cAMP (CPTOMe-cAMP). Conversely, AC and PKA inhibitors decreased substance P release induced by electrical stimulation of the dorsal root. Therefore, the cAMP signaling pathway mediates substance P release in the dorsal horn. The effects of forskolin and 6-Bnz-cAMP were not additive with NMDA-induced substance P release and were decreased by the NMDA receptor blocker MK-801. In cultured dorsal horn neurons, forskolin increased NMDA-induced Ca2+ entry and the phosphorylation of the NR1 and NR2B subunits of the NMDA receptor. Therefore, cAMP-induced substance P release is mediated by the activating phosphorylation by PKA of NMDA receptors. Voltage-gated Ca2+ channels, but not by TRPV1 or TRPA1, also contributed to cAMP-induced substance P release. Activation of PKA was required for the effects of forskolin and the three cAMP analogs. Epac2 contributed to the effects of forskolin and CPTOMe-cAMP, signaling through a Raf - mitogen-activated protein kinase pathway to activate Ca2+ channels. Epac1 inhibitors induced NK1R internalization independently of substance P release. In rats with latent sensitization to pain, the effect of 6-Bnz-cAMP was unchanged, whereas the effect of forskolin was decreased due to the loss of the stimulatory effect of Epac2. Hence, substance P release induced by cAMP decreases during pain hypersensitivity.
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Affiliation(s)
- Wenling Chen
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - James A McRoberts
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Helena S Ennes
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Juan Carlos Marvizon
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA.
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15
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Lv W, Liu S, Zhang Q, Hu W, Wu Y, Ren Y. Circular RNA CircCOL5A1 Sponges the MiR-7-5p/Epac1 Axis to Promote the Progression of Keloids Through Regulating PI3K/Akt Signaling Pathway. Front Cell Dev Biol 2021; 9:626027. [PMID: 33553184 PMCID: PMC7859531 DOI: 10.3389/fcell.2021.626027] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/04/2021] [Indexed: 01/25/2023] Open
Abstract
Keloids, as a result of abnormal wound healing in susceptible individuals, are characterized by the hyper-proliferation of fibroblasts and exaggerated deposition of extracellular matrix. Current surgical and therapeutic modalities provide limited satisfactory results. Growing evidence has highlighted the roles of circRNAs in acting as miRNA sponges. However, up to date, the regulatory mechanism of circRNAs in the pathological process of keloids has rarely been reported. In this study, cell proliferation, cell migration, flow cytometry, western blotting, fluorescence in situ hybridization, dual-luciferase activity, and immunohistochemistry assays were applied to explore the roles and mechanisms of the circCOL5A1/miR-7-5p/Epac1 axis in the keloid. The therapeutic potential of circCOL5A1 was investigated by establishing keloid implantation models. The RT-qPCR result revealed that circCOL5A1 expression was obviously higher in keloid tissues and keloid fibroblasts. Subsequent cellular experiments demonstrated that circCOL5A1 knockdown repressed the proliferation, migration, extracellular matrix (ECM) deposition, whereas promoted cell apoptosis, through the PI3K/Akt signaling pathway. Furthermore, RNA-fluorescence in situ hybridization (RNA-FISH) illustrated that both circCOL5A1 and miR-7-5p were located in the cytoplasm. The luciferase reporter gene assay confirmed that exact binding sites were present between circCOL5A1 and miR-7-5p, as well as between miR-7-5p and Epac1. Collectively, the present study revealed that circCOL5A1 functioned as competing endogenous RNA (ceRNA) by adsorbing miR-7-5p to release Epac1, which contributed to pathological hyperplasia of keloids through activating the PI3K/Akt signaling pathway. Our data indicated that circCOL5A1 might serve as a novel promising therapeutic target and represent a new avenue to understand underlying pathogenesis for keloids.
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Affiliation(s)
- Wenchang Lv
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Shengxuan Liu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Qi Zhang
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Weijie Hu
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Yiping Wu
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Yuping Ren
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
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16
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Wang P, Luchowska-Stańska U, van Basten B, Chen H, Liu Z, Wiejak J, Whelan P, Morgan D, Lochhead E, Barker G, Rehmann H, Yarwood SJ, Zhou J. Synthesis and Biochemical Evaluation of Noncyclic Nucleotide Exchange Proteins Directly Activated by cAMP 1 (EPAC1) Regulators. J Med Chem 2020; 63:5159-5184. [PMID: 32340447 DOI: 10.1021/acs.jmedchem.9b02094] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exchange proteins directly activated by cAMP (EPAC) play a central role in various biological functions, and activation of the EPAC1 protein has shown potential benefits for the treatment of various human diseases. Herein, we report the synthesis and biochemical evaluation of a series of noncyclic nucleotide EPAC1 activators. Several potent EPAC1 binders were identified including 25g, 25q, 25n, 25u, 25e, and 25f, which promote EPAC1 guanine nucleotide exchange factor activity in vitro. These agonists can also activate EPAC1 protein in cells, where they exhibit excellent selectivity toward EPAC over protein kinase A and G protein-coupled receptors. Moreover, 25e, 25f, 25n, and 25u exhibited improved selectivity toward activation of EPAC1 over EPAC2 in cells. Of these, 25u was found to robustly inhibit IL-6-activated signal transducer and activator of transcription 3 (STAT3) and subsequent induction of the pro-inflammatory vascular cell adhesion molecule 1 (VCAM1) cell-adhesion protein. These novel EPAC1 activators may therefore act as useful pharmacological tools for elucidation of EPAC function and promising drug leads for the treatment of relevant human diseases.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Boy van Basten
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jolanta Wiejak
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Padraic Whelan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Emma Lochhead
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Holger Rehmann
- Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Centre Utrecht, Utrecht 3584 CX, Netherlands
| | - Stephen J Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
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17
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Sivertsen Åsrud K, Bjørnstad R, Kopperud R, Pedersen L, Hoeven B, Karlsen TV, Brekke Rygh C, Curry F, Bakke M, Reed RK, Tenstad O, Døskeland SO. Epac1 null mice have nephrogenic diabetes insipidus with deficient corticopapillary osmotic gradient and weaker collecting duct tight junctions. Acta Physiol (Oxf) 2020; 229:e13442. [PMID: 31943825 DOI: 10.1111/apha.13442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 01/03/2023]
Abstract
AIM The cAMP-mediator Epac1 (RapGef3) has high renal expression. Preliminary observations revealed increased diuresis in Epac1-/- mice. We hypothesized that Epac1 could restrict diuresis by promoting transcellular collecting duct (CD) water and urea transport or by stabilizing CD paracellular junctions to reduce osmolyte loss from the renal papillary interstitium. METHODS In Epac1-/- and Wt C57BL/6J mice, renal papillae, dissected from snap-frozen kidneys, were assayed for the content of key osmolytes. Cell junctions were analysed by transmission electron microscopy. Urea transport integrity was evaluated by urea loading with 40% protein diet, endogenous vasopressin production was manipulated by intragastric water loading and moderate dehydration and vasopressin type 2 receptors were stimulated selectively by i.p.-injected desmopressin (dDAVP). Glomerular filtration rate (GFR) was estimated as [14 C]inulin clearance. The glomerular filtration barrier was evaluated by urinary albumin excretion and microvascular leakage by the renal content of time-spaced intravenously injected 125 I- and 131 I-labelled albumin. RESULTS Epac1-/- mice had increased diuresis and increased free water clearance under antidiuretic conditions. They had shorter and less dense CD tight junction (TJs) and attenuated corticomedullary osmotic gradient. Epac1-/- mice had no increased protein diet-induced urea-dependent osmotic diuresis, and expressed Wt levels of aquaporin-2 (AQP-2) and urea transporter A1/3 (UT-A1/3). Epac1-/- mice had no urinary albumin leakage and unaltered renal microvascular albumin extravasation. Their GFR was moderately increased, unless when treated with furosemide. CONCLUSION Our results conform to the hypothesis that Epac1-dependent mechanisms protect against diabetes insipidus by maintaining renal papillary osmolarity and the integrity of CD TJs.
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Affiliation(s)
| | - Ronja Bjørnstad
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Reidun Kopperud
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Line Pedersen
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Barbara Hoeven
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Tine V. Karlsen
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Cecilie Brekke Rygh
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
- Faculty of Health and Social Sciences Western Norway University of Applied Sciences Bergen Norway
| | - Fitz‐Roy Curry
- Department of Physiology and Membrane Biology School of Medicine University of California Davis CA USA
| | - Marit Bakke
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Rolf K. Reed
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
- Centre for Cancer Biomarkers University of Bergen Bergen Norway
| | - Olav Tenstad
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
| | - Stein O. Døskeland
- Department of Biomedicine Faculty of Medicine University of Bergen Bergen Norway
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18
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Shao H, Mohamed H, Boulton S, Huang J, Wang P, Chen H, Zhou J, Luchowska-Stańska U, Jentsch NG, Armstrong AL, Magolan J, Yarwood S, Melacini G. Mechanism of Action of an EPAC1-Selective Competitive Partial Agonist. J Med Chem 2020; 63:4762-4775. [PMID: 32297742 DOI: 10.1021/acs.jmedchem.9b02151] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The exchange protein activated by cAMP (EPAC) is a promising drug target for a wide disease range, from neurodegeneration and infections to cancer and cardiovascular conditions. A novel partial agonist of the EPAC isoform 1 (EPAC1), I942, was recently discovered, but its mechanism of action remains poorly understood. Here, we utilize NMR spectroscopy to map the I942-EPAC1 interactions at atomic resolution and propose a mechanism for I942 partial agonism. We found that I942 interacts with the phosphate binding cassette (PBC) and base binding region (BBR) of EPAC1, similar to cyclic adenosine monophosphate (cAMP). These results not only reveal the molecular basis for the I942 vs cAMP mimicry and competition, but also suggest that the partial agonism of I942 arises from its ability to stabilize an inhibition-incompetent activation intermediate distinct from both active and inactive EPAC1 states. The mechanism of action of I942 may facilitate drug design for EPAC-related diseases.
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Affiliation(s)
| | | | | | | | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
| | | | | | | | - Stephen Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
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Ranieri M, Di Mise A, Tamma G, Valenti G. Calcium sensing receptor exerts a negative regulatory action toward vasopressin-induced aquaporin-2 expression and trafficking in renal collecting duct. VITAMINS AND HORMONES 2020; 112:289-310. [PMID: 32061345 DOI: 10.1016/bs.vh.2019.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vasopressin (AVP) plays a major role in the regulation of water homeostasis by its antidiuretic action on the kidney, mediated by V2 receptors. An increase in plasma sodium concentration stimulates AVP release, which in turn promotes water reabsorption. Upon binding to the V2 receptors in the renal collecting duct, AVP induces the expression and apical membrane insertion of the aquaporin-2 (AQP2) water channels and subsequent water reabsorption. AVP regulates two independent mechanisms: the short-term regulation of AQP2 trafficking and long-term regulation of the total abundance of the AQP2 protein in the cells. On the other hand, several hormones, acting through specific receptors, have been reported to antagonize AVP-mediated water transport in kidney. In this respect, we previously described that high luminal Ca2+ in the renal collecting duct attenuates short-term AVP-induced AQP2 trafficking through activation of the Ca2+-sensing receptor (CaSR). This effect is due to reduction of AVP-dependent cAMP generation and possibly hydrolysis. Moreover, CaSR signaling reduces AQP2 abundance both via AQP2-targeting miRNA-137 and the proteasomal degradation pathway. This chapter summarizes recent data elucidating the molecular mechanisms underlying the physiological role of the CaSR-dependent regulation of AQP2 expression and trafficking.
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Affiliation(s)
- Marianna Ranieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Annarita Di Mise
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Grazia Tamma
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.
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20
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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.
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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:
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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.
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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
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22
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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.
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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
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Bordetella Adenylate Cyclase Toxin Inhibits Monocyte-to-Macrophage Transition and Dedifferentiates Human Alveolar Macrophages into Monocyte-like Cells. mBio 2019; 10:mBio.01743-19. [PMID: 31551332 PMCID: PMC6759761 DOI: 10.1128/mbio.01743-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Monocytes arriving at the site of infection differentiate into functional effector macrophages to replenish the resident sentinel cells. Bordetella pertussis, the pertussis agent, secretes an adenylate cyclase toxin-hemolysin (CyaA) that binds myeloid phagocytes through complement receptor 3 (CD11b/CD18) and swiftly delivers its adenylyl cyclase enzyme domain into phagocytes. This ablates the bactericidal capacities of phagocytes through massive and unregulated conversion of cytosolic ATP into the key signaling molecule cAMP. We show that exposure of primary human monocytes to as low a concentration as 22.5 pM CyaA, or a low (2:1) multiplicity of infection by CyaA-producing B. pertussis bacteria, blocks macrophage colony-stimulating factor (M-CSF)-driven differentiation of monocytes. CyaA-induced cAMP signaling mediated through the activity of protein kinase A (PKA) efficiently blocked expression of macrophage markers, and the monocytes exposed to 22.5 pM CyaA failed to acquire the characteristic intracellular complexity of mature macrophage cells. Neither M-CSF-induced endoplasmic reticulum (ER) expansion nor accumulation of Golgi bodies, mitochondria, or lysosomes was observed in toxin-exposed monocytes, which remained small and poorly phagocytic and lacked pseudopodia. Exposure to 22.5 pM CyaA toxin provoked loss of macrophage marker expression on in vitro differentiated macrophages, as well as on primary human alveolar macrophages, which appeared to dedifferentiate into monocyte-like cells with upregulated CD14 levels. This is the first report that terminally differentiated tissue-resident macrophage cells can be dedifferentiated in vitro The results suggest that blocking of monocyte-to-macrophage transition and/or dedifferentiation of the sentinel cells of innate immunity through cAMP-elevating toxin action may represent a novel immune evasion strategy of bacterial pathogens.IMPORTANCE Macrophages are key sentinel cells of the immune system, and, as such, they are targeted by the toxins produced by the pertussis agent Bordetella pertussis The adenylate cyclase toxin (CyaA) mediates immune evasion of B. pertussis by suspending the bactericidal activities of myeloid phagocytes. We reveal a novel mechanism of potential subversion of host immunity, where CyaA at very low (22 pM) concentrations could inhibit maturation of human monocyte precursors into the more phagocytic macrophage cells. Furthermore, exposure to low CyaA amounts has been shown to trigger dedifferentiation of mature primary human alveolar macrophages back into monocyte-like cells. This unprecedented capacity is likely to promote survival of the pathogen in the airways, both by preventing maturation of monocytes attracted to the site of infection into phagocytic macrophages and by dedifferentiation of the already airway-resident sentinel cells.
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Ng LCT, Zhuang M, Van Petegem F, Li YX, Accili EA. Binding and structural asymmetry governs ligand sensitivity in a cyclic nucleotide-gated ion channel. J Gen Physiol 2019; 151:1190-1212. [PMID: 31481514 PMCID: PMC6785730 DOI: 10.1085/jgp.201812162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 04/26/2019] [Accepted: 07/31/2019] [Indexed: 12/17/2022] Open
Abstract
HCN channel opening is facilitated by cyclic nucleotides, but what determines the sensitivity of these channels to cAMP or cGMP is unclear. Ng et al. propose that ligand sensitivity depends on negative cooperativity and the asymmetric effects of ligand binding on channel structure and pore opening. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels open more easily when cAMP or cGMP bind to a domain in the intracellular C-terminus in each of four identical subunits. How sensitivity of the channels to these ligands is determined is not well understood. Here, we apply a mathematical model, which incorporates negative cooperativity, to gating and mutagenesis data available in the literature and combine the results with binding data collected using isothermal titration calorimetry. This model recapitulates the concentration–response data for the effects of cAMP and cGMP on wild-type HCN2 channel opening and, remarkably, predicts the concentration–response data for a subset of mutants with single-point amino acid substitutions in the binding site. Our results suggest that ligand sensitivity is determined by negative cooperativity and asymmetric effects on structure and channel opening, which are tuned by ligand-specific interactions and residues within the binding site.
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Affiliation(s)
- Leo C T Ng
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Meiying Zhuang
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Yue Xian Li
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Eric A Accili
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
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Epac2 Elevation Reverses Inhibition by Chondroitin Sulfate Proteoglycans In Vitro and Transforms Postlesion Inhibitory Environment to Promote Axonal Outgrowth in an Ex Vivo Model of Spinal Cord Injury. J Neurosci 2019; 39:8330-8346. [PMID: 31409666 DOI: 10.1523/jneurosci.0374-19.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/05/2019] [Accepted: 08/08/2019] [Indexed: 02/07/2023] Open
Abstract
Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth are partly mediated by Epac, comprising Epac1 and Epac2; the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated, for the first time, that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulfate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated, for the first time, that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks after treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia after injury to facilitate axonal outgrowth.SIGNIFICANCE STATEMENT During development, neuronal cAMP levels decrease significantly compared with the embryonic stage when the nervous system is established. This has important consequences following spinal cord injury, as neurons fail to regrow. Elevating cAMP levels encourages injured CNS neurons to sprout and extend neurites. We have demonstrated that activating its downstream effector, Epac2, enhances neurite outgrowth in vitro, even in the presence of an inhibitory environment. Using a novel biomaterial-based drug delivery system in the form of a hydrogel to achieve local delivery of an Epac2 agonist, we further demonstrated that specific activation of Epac2 enhances axonal outgrowth and minimizes glial activation in an ex vivo model of spinal cord injury, suggesting a new strategy for spinal cord repair.
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26
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Rottlerin is a pan phosphodiesterase inhibitor and can induce neurodifferentiation in IMR-32 human neuroblastoma cells. Eur J Pharmacol 2019; 857:172448. [DOI: 10.1016/j.ejphar.2019.172448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 06/08/2019] [Accepted: 06/12/2019] [Indexed: 01/05/2023]
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27
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Fong Z, Griffin CS, Hollywood MA, Thornbury KD, Sergeant GP. β 3-Adrenoceptor agonists inhibit purinergic receptor-mediated contractions of the murine detrusor. Am J Physiol Cell Physiol 2019; 317:C131-C142. [PMID: 31042424 DOI: 10.1152/ajpcell.00488.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
β3-Adrenoceptor (β3-AR) agonists are used to treat overactive bladder syndrome; however, their mechanism of action has not been determined. The aims of this study were to compare the effects of β3-AR agonists on cholinergic versus purinergic receptor-mediated contractions of the detrusor and to examine the mechanisms underlying inhibition of the purinergic responses by β3-AR agonists. Isometric tension recordings were made from strips of murine detrusor and whole cell current recordings were made from freshly isolated detrusor myocytes using the patch-clamp technique. Transcriptional expression of exchange protein directly activated by cAMP (EPAC) subtypes in detrusor strips was assessed using RT-PCR and real-time quantitative PCR. The β3-AR agonists BRL37344 and CL316243 (100 nM) inhibited cholinergic nerve-mediated contractions of the detrusor by 19 and 23%, respectively, but did not reduce contractions induced by the cholinergic agonist carbachol (300 nM). In contrast, BRL37344 and CL316243 inhibited purinergic nerve-mediated responses by 55 and 56%, respectively, and decreased the amplitude of contractions induced by the P2X receptor agonist α,β-methylene ATP by 40 and 45%, respectively. The adenylate cyclase activator forskolin inhibited purinergic responses, and these effects were mimicked by a combination of the PKA activator N6-monobutyryl-cAMP and the EPAC activator 8-pCPT-2'-O-methyl-cAMP-AM (007-AM). Application of ATP (1 μM) evoked reproducible P2X currents in isolated detrusor myocytes voltage-clamped at -60 mV. These responses were reduced in amplitude in the presence of BRL37344 and also by 007-AM. This study demonstrates that β3-AR agonists reduce postjunctional purinergic responses in the detrusor via a pathway involving activation of the cAMP effector EPAC.
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Affiliation(s)
- Zhihui Fong
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Caoimhín S Griffin
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Keith D Thornbury
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Gerard P Sergeant
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
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28
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Lelle M, Otte M, Thon S, Bertinetti D, Herberg FW, Benndorf K. Chemical synthesis and biological activity of novel brominated 7-deazaadenosine-3',5'-cyclic monophosphate derivatives. Bioorg Med Chem 2019; 27:1704-1713. [PMID: 30879860 DOI: 10.1016/j.bmc.2019.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/09/2019] [Accepted: 03/11/2019] [Indexed: 11/19/2022]
Abstract
Synthetic derivatives of cyclic adenosine monophosphate, such as halogenated or other more hydrophobic analogs, are widely used compounds, to investigate diverse signal transduction pathways of eukaryotic cells. This inspired us to develop cyclic nucleotides, which exhibit chemical structures composed of brominated 7-deazaadenines and the phosphorylated ribosugar. The synthesized 8-bromo- and 7-bromo-7-deazaadenosine-3',5'-cyclic monophosphates rank among the most potent activators of cyclic nucleotide-regulated ion channels as well as cAMP-dependent protein kinase. Moreover, these substances bind tightly to exchange proteins directly activated by cAMP.
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Affiliation(s)
- Marco Lelle
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Maik Otte
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Susanne Thon
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany
| | - Daniela Bertinetti
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Friedrich W Herberg
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Klaus Benndorf
- Institute of Physiology II, University Hospital Jena, Kollegiengasse 9, 07743 Jena, Germany.
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29
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Matthews HR, Tan SRX, Shoesmith JA, Ahmad S, Valli H, Jeevaratnam K, Huang CLH. Sodium current inhibition following stimulation of exchange protein directly activated by cyclic-3',5'-adenosine monophosphate (Epac) in murine skeletal muscle. Sci Rep 2019; 9:1927. [PMID: 30760734 PMCID: PMC6374420 DOI: 10.1038/s41598-018-36386-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023] Open
Abstract
We investigated effects of pharmacological triggering of exchange protein directly activated by cyclic-3',5'-adenosine monophosphate (Epac) on Nav1.4 currents from intact murine (C67BL6) skeletal muscle fibres for the first time. This employed a loose patch clamp technique which examined ionic currents in response to superimposed 10-ms V1 steps to varying degrees of depolarisation, followed by V2 steps to a fixed, +100 mV depolarisation relative to resting membrane potential following 40 mV hyperpolarising prepulses of 50 ms duration. The activation and inactivation properties of the resulting Na+ membrane current densities revealed reduced maximum currents and steepnesses in their voltage dependences after addition of the Epac activator 8-(4-chlorophenylthio)adenosine-3',5'-cyclic monophosphate (1 µM) to the bathing Krebs-Henseleit solutions. Contrastingly, voltages at half-maximal current and timecourses of currents obtained in response to the V1 depolarising steps were unchanged. These effects were abolished by further addition of the RyR-inhibitor dantrolene (10 µM). In contrast, challenge by dantrolene alone left both currents and their parameters intact. These effects of Epac activation in inhibiting skeletal muscle, Nav1.4, currents, complement similar effects previously reported in the homologous Nav1.5 in murine cardiomyocytes. They are discussed in terms of a hypothesis implicating Epac actions in increasing RyR-mediated SR Ca2+ release resulting in a Ca2+-mediated inhibition of Nav1.4. The latter effect may form the basis for Ca2+-dependent Na+ channel dysregulation in SCN4A channelopathies associated with cold- and K+-aggravated myotonias.
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Affiliation(s)
- Hugh R Matthews
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Sapphire R X Tan
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Jonathan A Shoesmith
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, GU2 7AL, Guildford, Surrey, United Kingdom
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom.
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom.
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30
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Ramos-Alvarez I, Lee L, Jensen RT. Cyclic AMP-dependent protein kinase A and EPAC mediate VIP and secretin stimulation of PAK4 and activation of Na +,K +-ATPase in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2019; 316:G263-G277. [PMID: 30520694 PMCID: PMC6397337 DOI: 10.1152/ajpgi.00275.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rat pancreatic acinar cells possess only the p21-activated kinase (PAKs), PAK4 of the group II PAK, and it is activated by gastrointestinal hormones/neurotransmitters stimulating PLC and by a number of growth factors. However, little is known generally of cAMP agents causing PAK4 activation, and there are no studies with gastrointestinal hormones/neurotransmitters activating cAMP cascades. In the present study, we examined the ability of VIP and secretin, which stimulate cAMP generation in pancreatic acini, to stimulate PAK4 activation, the signaling cascades involved, and their possible role in activating sodium-potassium adenosine triphosphatase (Na+,K+-ATPase). PAK4 activation was compared with activation of the well-established cAMP target, cyclic AMP response element binding protein (CREB). Secretin-stimulated PAK4 activation was inhibited by KT-5720 and PKA Type II inhibitor (PKI), protein kinase A (PKA) inhibitors, whereas VIP activation was inhibited by ESI-09 and HJC0197, exchange protein directly activated by cAMP (EPAC) inhibitors. In contrast, both VIP/secretin-stimulated phosphorylation of CREB (pCREB) via EPAC activation; however, it was inhibited by the p44/42 inhibitor PD98059 and the p38 inhibitor SB202190. The specific EPAC agonist 8-CPT-2- O-Me-cAMP as well 8-Br-cAMP and forskolin stimulated PAK4 activation. Secretin/VIP activation of Na+,K+-ATPase, was inhibited by PAK4 inhibitors (PF-3758309, LCH-7749944). These results demonstrate PAK4 is activated in pancreatic acini by stimulation of both VIP-/secretin-preferring receptors, as is CREB. However, they differ in their signaling cascades. Furthermore, PAK4 activation is needed for Na+,K+ATPase activation, which mediates pancreatic fluid secretion. These results, coupled with recent studies reporting PAKs are involved in both pancreatitis/pancreatic cancer growth/enzyme secretion, show that PAK4, similar to PAK2, likely plays an important role in both pancreatic physiological/pathological responses. NEW & NOTEWORTHY Pancreatic acini possess only the group II p21-activated kinase, PAK4, which is activated by PLC-stimulating agents/growth factors and is important in enzyme-secretion/growth/pancreatitis. Little information exists on cAMP-activating agents stimulating group II PAKs. We studied ability/effect of cyclic AMP-stimulating agents [vasoactive intestinal polypeptide (VIP), secretin] on PAK4 activity in rat pancreatic-acini. Both VIP/secretin activated PAK4/CREB, but the cAMP signaling cascades differed for EPAC, MAPK, and PKA pathways. Both hormones require PAK4 activation to stimulate sodium-potassium adenosine triphosphatase activity. This study shows PAK4 plays an important role in VIP-/secretin-stimulated pancreatic fluid secretion and suggests it plays important roles in pancreatic acinar physiological/pathophysiological responses mediated by cAMP-activating agents.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - R. T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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31
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Chu KY, O'Reilly L, Mellet N, Meikle PJ, Bartley C, Biden TJ. Oleate disrupts cAMP signaling, contributing to potent stimulation of pancreatic β-cell autophagy. J Biol Chem 2018; 294:1218-1229. [PMID: 30518550 DOI: 10.1074/jbc.ra118.004833] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/19/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy is critical for maintaining cellular function via clearance of excess nutrients and damaged organelles. In pancreatic β-cells, it helps counter the endoplasmic reticulum (ER) stress that impairs insulin secretory capacity during Type 2 diabetes. Chronic exposure of β-cells to saturated fatty acids (FAs) such as palmitate stimulates ER stress and modulates autophagy, but the effects of unsaturated FAs such as oleate, which are also elevated during obesity, are less well understood. We therefore treated MIN6 cells and mouse islets for 8-48 h with either palmitate or oleate, and then monitored autophagic flux, signaling pathways, lysosomal biology, and phospholipid profiles. Compared with palmitate, oleate more effectively stimulated both autophagic flux and clearance of autophagosomes. The flux stimulation occurred independently of ER stress, nutrient-sensing (mTOR) and signaling pathways (protein kinases A, C, and D). Instead the mechanism involved the exchange factor directly activated by cAMP 2 (EPAC2). Oleate reduced cellular cAMP, and its effects on autophagic flux were reproduced or inhibited, respectively, by Epac2 knockdown or activation. Oleate also increased lysosomal acidity and increased phospholipid saturation, consistent with improved autophagosomal fusion with lysosomes. We conclude that a potent stimulation of autophagy might help explain the known benefits of unsaturated FAs in countering the toxicity of saturated FAs in β-cells during obesity and lipid loading.
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Affiliation(s)
- Kwan Yi Chu
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010; St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, NSW 2052
| | - Liam O'Reilly
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010
| | - Natalie Mellet
- Baker IDI Heart and Diabetes Institute, Prahran, Victoria 3004, Australia
| | - Peter J Meikle
- Baker IDI Heart and Diabetes Institute, Prahran, Victoria 3004, Australia
| | - Clarissa Bartley
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010
| | - Trevor J Biden
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010; St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, NSW 2052.
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32
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Zhou D, Ota K, Nardin C, Feldman M, Widman A, Wind O, Simon A, Reilly M, Levin LR, Buck J, Wakamatsu K, Ito S, Zippin JH. Mammalian pigmentation is regulated by a distinct cAMP-dependent mechanism that controls melanosome pH. Sci Signal 2018; 11:11/555/eaau7987. [PMID: 30401788 DOI: 10.1126/scisignal.aau7987] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The production of melanin increases skin pigmentation and reduces the risk of skin cancer. Melanin production depends on the pH of melanosomes, which are more acidic in lighter-skinned than in darker-skinned people. We showed that inhibition of soluble adenylyl cyclase (sAC) controlled pigmentation by increasing the pH of melanosomes both in cells and in vivo. Distinct from the canonical melanocortin 1 receptor (MC1R)-dependent cAMP pathway that controls pigmentation by altering gene expression, we found that inhibition of sAC increased pigmentation by increasing the activity of tyrosinase, the rate-limiting enzyme in melanin synthesis, which is more active at basic pH. We demonstrated that the effect of sAC activity on pH and melanin production in human melanocytes depended on the skin color of the donor. Last, we identified sAC inhibitors as a new class of drugs that increase melanosome pH and pigmentation in vivo, suggesting that pharmacologic inhibition of this pathway may affect skin cancer risk or pigmentation conditions.
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Affiliation(s)
- Dalee Zhou
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Koji Ota
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Charlee Nardin
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA.,Service de Dermatologie, Centre Hospitalier Universitaire, Besançon 25030, France
| | - Michelle Feldman
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Adam Widman
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Olivia Wind
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Amanda Simon
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Michael Reilly
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Kazumasa Wakamatsu
- Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake 470-1192, Japan
| | - Shosuke Ito
- Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake 470-1192, Japan
| | - Jonathan H Zippin
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA.
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33
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Lee JY, Matthias N, Pothiawala A, Ang BK, Lee M, Li J, Sun D, Pigeot S, Martin I, Huard J, Huang Y, Nakayama N. Pre-transplantational Control of the Post-transplantational Fate of Human Pluripotent Stem Cell-Derived Cartilage. Stem Cell Reports 2018; 11:440-453. [PMID: 30057264 PMCID: PMC6092881 DOI: 10.1016/j.stemcr.2018.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 01/24/2023] Open
Abstract
Cartilage pellets generated from ectomesenchymal progeny of human pluripotent stem cells (hPSCs) in vitro eventually show signs of commitment of chondrocytes to hypertrophic differentiation. When transplanted subcutaneously, most of the surviving pellets were fully mineralized by 8 weeks. In contrast, treatment with the adenylyl cyclase activator, forskolin, in vitro resulted in slightly enlarged cartilage pellets containing an increased proportion of proliferating immature chondrocytes that expressed very low levels of hypertrophic/terminally matured chondrocyte-specific genes. Forskolin treatment also enhanced hyaline cartilage formation by reducing type I collagen gene expression and increasing sulfated glycosaminoglycan accumulation in the developed cartilage. Chondrogenic mesoderm from hPSCs and dedifferentiated nasal chondrocytes responded similarly to forskolin. Furthermore, forskolin treatment in vitro increased the frequency at which the cartilage pellets maintained unmineralized chondrocytes after subcutaneous transplantation. Thus, the post-transplantational fate of chondrocytes originating from hPSC-derived chondroprogenitors can be controlled during their genesis in vitro. Forskolin/cAMP suppresses/delays BMP-induced chondrocyte maturation in vitro Forskolin supports chondrocyte proliferation and hyaline chondrogenesis in vitro Forskolin suppresses osteogenesis and BMP signaling gene expression in cartilage In vitro forskolin treatment improves in vivo maintenance of uncalcified cartilage
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Affiliation(s)
- John Y Lee
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston (UTHealth) Medical School, 1825 Pressler St., Houston, TX 77030, USA
| | - Nadine Matthias
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston (UTHealth) Medical School, 1825 Pressler St., Houston, TX 77030, USA
| | - Azim Pothiawala
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston (UTHealth) Medical School, 1825 Pressler St., Houston, TX 77030, USA
| | - Bryan K Ang
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston (UTHealth) Medical School, 1825 Pressler St., Houston, TX 77030, USA
| | - Minjung Lee
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Jia Li
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Deqiang Sun
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Sebastien Pigeot
- Department of Biomedicine, University Hospital Basel, Basel CH-4031, Switzerland
| | - Ivan Martin
- Department of Biomedicine, University Hospital Basel, Basel CH-4031, Switzerland
| | - Johnny Huard
- Department of Orthopaedic Surgery, UTHealth Medical School, Houston, TX 77030, USA
| | - Yun Huang
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Naoki Nakayama
- Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston (UTHealth) Medical School, 1825 Pressler St., Houston, TX 77030, USA; Department of Orthopaedic Surgery, UTHealth Medical School, Houston, TX 77030, USA.
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Deletion of exchange proteins directly activated by cAMP (Epac) causes defects in hippocampal signaling in female mice. PLoS One 2018; 13:e0200935. [PMID: 30048476 PMCID: PMC6062027 DOI: 10.1371/journal.pone.0200935] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 07/05/2018] [Indexed: 12/19/2022] Open
Abstract
Previous studies demonstrate essential roles for the exchange proteins directly activated by cAMP 1 and 2 (Epac1 and Epac2; here collectively referred to as Epac) in the brain. In the hippocampus, Epac contributes to the control of neuronal growth and differentiation and has been implicated in memory and learning as well as in anxiety and depression. In the present study we address the hypothesis that Epac affects hippocampal cellular responses to acute restraint stress. Stress causes activation of the hypothalamus-pituitary-adrenal (HPA)-axis, and glucocorticoid receptor (GR) signaling is essential for proper feedback regulation of the stress response, both in the brain and along the HPA axis. In the hippocampus, GR expression is regulated by cAMP and the brain enriched micro RNA miR-124. Epac has been associated with miR-124 expression in hippocampal neurons, but not in regulation of GR. We report that hippocampal expression of Epac1 and Epac2 increased in response to acute stress in female wild type mice. In female mice genetically deleted for Epac, nuclear translocation of GR in response to restraint stress was significantly delayed, and moreover, miR-124 expression was decreased in these mice. Male mice lacking Epac also showed abnormalities in miR-124 expression, but the phenotype was less profound than in females. Serum corticosterone levels were slightly altered immediately after stress in both male and female mice deleted for Epac. The presented data indicate that Epac1 and Epac2 are involved in controlling cellular responses to acute stress in the mouse hippocampus and provide novel insights into the underlying transcriptional and signaling networks. Interestingly, we observe sex specific differences when Epac is deleted. As the incidence and prevalence of stress-related diseases are higher in women than in men, the Epac knockout models might serve as genetic tools to further elucidate the cellular mechanisms underlying differences between male and female with regard to regulation of stress.
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35
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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.
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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
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36
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Li M, Hothi SS, Salvage SC, Jeevaratnam K, Grace AA, Huang CLH. Arrhythmic effects of Epac-mediated ryanodine receptor activation in Langendorff-perfused murine hearts are associated with reduced conduction velocity. Clin Exp Pharmacol Physiol 2018; 44:686-692. [PMID: 28316073 PMCID: PMC5488224 DOI: 10.1111/1440-1681.12751] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/05/2017] [Accepted: 03/07/2017] [Indexed: 12/19/2022]
Abstract
Recent papers have attributed arrhythmic substrate in murine RyR2‐P2328S hearts to reduced action potential (AP) conduction velocities (CV), reflecting acute functional inhibition and/or reduced expression of sodium channels. We explored for acute effects of direct exchange protein directly activated by cAMP (Epac)‐mediated ryanodine receptor‐2 (RyR2) activation on arrhythmic substrate and CV. Monophasic action potential (MAP) recordings demonstrated that initial steady (8 Hz) extrinsic pacing elicited ventricular tachycardia (VT) in 0 of 18 Langendorff‐perfused wild‐type mouse ventricles before pharmacological intervention. The Epac activator 8‐CPT (8‐(4‐chlorophenylthio)‐2′‐O‐methyladenosine‐3′,5′‐cyclic monophosphate) (VT in 1 of 7 hearts), and the RyR2 blocker dantrolene, either alone (0 of 11) or with 8‐CPT (0 of 9) did not then increase VT incidence (P>.05). Both progressively increased pacing rates and programmed extrasystolic (S2) stimuli similarly produced no VT in untreated hearts (n=20 and n=9 respectively). 8‐CPT challenge then increased VT incidences (5 of 7 and 4 of 8 hearts respectively; P<.05). However, dantrolene, whether alone (0 of 10 and 1 of 13) or combined with 8‐CPT (0 of 10 and 0 of 13) did not increase VT incidence relative to those observed in untreated hearts (P>.05). 8‐CPT but not dantrolene, whether alone or combined with 8‐CPT, correspondingly increased AP latencies (1.14±0.04 (n=7), 1.04±0.03 (n=10), 1.09±0.05 (n=8) relative to respective control values). In contrast, AP durations, conditions for 2:1 conduction block and ventricular effective refractory periods remained unchanged throughout. We thus demonstrate for the first time that acute RyR2 activation reversibly induces VT in specific association with reduced CV.
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Affiliation(s)
- Mengye Li
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Sandeep S Hothi
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Samantha C Salvage
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, VSM Building, University of Surrey, Guildford, United Kingdom
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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37
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Dale P, Head V, Dowling MR, Taylor CW. Selective inhibition of histamine-evoked Ca 2+ signals by compartmentalized cAMP in human bronchial airway smooth muscle cells. Cell Calcium 2017; 71:53-64. [PMID: 29604964 PMCID: PMC5893132 DOI: 10.1016/j.ceca.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 01/29/2023]
Abstract
β2-adrenoceptors, via cAMP and PKA, inhibit histamine-evoked Ca2+ signals in human bronchial airway smooth muscle cells. Responses to other Ca2+-mobilizing receptors are unaffected or minimally affected by cAMP. There is no consistent relationship between the amounts of cAMP produced by different stimuli and inhibition of histamine-evoked Ca2+ release. Local delivery of cAMP within hyperactive signaling junctions stimulates PKA. PKA inhibits an early step in the signaling pathway activated by H1 histamine receptors.
Intracellular Ca2+ and cAMP typically cause opposing effects on airway smooth muscle contraction. Receptors that stimulate these pathways are therapeutic targets in asthma and chronic obstructive pulmonary disease. However, the interactions between different G protein-coupled receptors (GPCRs) that evoke cAMP and Ca2+ signals in human bronchial airway smooth muscle cells (hBASMCs) are poorly understood. We measured Ca2+ signals in cultures of fluo-4-loaded hBASMCs alongside measurements of intracellular cAMP using mass spectrometry or [3H]-adenine labeling. Interactions between the signaling pathways were examined using selective ligands of GPCRs, and inhibitors of Ca2+ and cAMP signaling pathways. Histamine stimulated Ca2+ release through inositol 1,4,5-trisphosphate (IP3) receptors in hBASMCs. β2-adrenoceptors, through cAMP and protein kinase A (PKA), substantially inhibited histamine-evoked Ca2+ signals. Responses to other Ca2+-mobilizing stimuli were unaffected by cAMP (carbachol and bradykinin) or minimally affected (lysophosphatidic acid). Prostaglandin E2 (PGE2), through EP2 and EP4 receptors, stimulated formation of cAMP and inhibited histamine-evoked Ca2+ signals. There was no consistent relationship between the inhibition of Ca2+ signals and the amounts of intracellular cAMP produced by different stimuli. We conclude that β-adrenoceptors, EP2 and EP4 receptors, through cAMP and PKA, selectively inhibit Ca2+ signals evoked by histamine in hBASMCs, suggesting that PKA inhibits an early step in H1 receptor signaling. Local delivery of cAMP within hyperactive signaling junctions mediates the inhibition.
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Affiliation(s)
- Philippa Dale
- Department of Pharmacology,Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Victoria Head
- Novartis Institutes for BioMedical Research, Fabrikstrasse, CH-4056, Basel, Switzerland
| | - Mark R Dowling
- Novartis Institutes for BioMedical Research Inc., 250 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Colin W Taylor
- Department of Pharmacology,Tennis Court Road, Cambridge, CB2 1PD, UK.
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38
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Valli H, Ahmad S, Sriharan S, Dean LD, Grace AA, Jeevaratnam K, Matthews HR, Huang CLH. Epac-induced ryanodine receptor type 2 activation inhibits sodium currents in atrial and ventricular murine cardiomyocytes. Clin Exp Pharmacol Physiol 2017; 45:278-292. [PMID: 29027245 PMCID: PMC5814738 DOI: 10.1111/1440-1681.12870] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/23/2017] [Accepted: 09/27/2017] [Indexed: 12/16/2022]
Abstract
Acute RyR2 activation by exchange protein directly activated by cAMP (Epac) reversibly perturbs myocyte Ca2+ homeostasis, slows myocardial action potential conduction, and exerts pro‐arrhythmic effects. Loose patch‐clamp studies, preserving in vivo extracellular and intracellular conditions, investigated Na+ current in intact cardiomyocytes in murine atrial and ventricular preparations following Epac activation. Depolarising steps to varying test voltages activated typical voltage‐dependent Na+ currents. Plots of peak current against depolarisation from resting potential gave pretreatment maximum atrial and ventricular currents of −20.23 ± 1.48 (17) and −29.8 ± 2.4 (10) pA/μm2 (mean ± SEM [n]). Challenge by 8‐CPT (1 μmol/L) reduced these currents to −11.21 ± 0.91 (12) (P < .004) and −19.3 ± 1.6 (11) pA/μm2 (P < .04) respectively. Currents following further addition of the RyR2 inhibitor dantrolene (10 μmol/L) (−19.91 ± 2.84 (13) and −26.6 ± 1.7 (17)), and dantrolene whether alone (−19.53 ± 1.97 (8) and −27.6 ± 1.9 (14)) or combined with 8‐CPT (−19.93 ± 2.59 (12) and −29.9 ± 2.5(11)), were indistinguishable from pretreatment values (all P >> .05). Assessment of the inactivation that followed by applying subsequent steps to a fixed voltage 100 mV positive to resting potential gave concordant results. Half‐maximal inactivation voltages and steepness factors, and time constants for Na+ current recovery from inactivation in double‐pulse experiments, were similar through all the pharmacological conditions. Intracellular sharp microelectrode membrane potential recordings in intact Langendorff‐perfused preparations demonstrated concordant variations in maximum rates of atrial and ventricular action potential upstroke, (dV/dt)max. We thus demonstrate an acute, reversible, Na+ channel inhibition offering a possible mechanism for previously reported pro‐arrhythmic slowing of AP propagation following modifications of Ca2+ homeostasis, complementing earlier findings from chronic alterations in Ca2+ homeostasis in genetically‐modified RyR2‐P2328S hearts.
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Affiliation(s)
- Haseeb Valli
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Sujan Sriharan
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Lydia D Dean
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Kamalan Jeevaratnam
- Physiological Laboratory, University of Cambridge, Cambridge, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.,PU-RCSI School of Medicine, Perdana University, Serdang, Selangor Darul Ehsan, Malaysia
| | - Hugh R Matthews
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Cambridge, UK.,Department of Biochemistry, University of Cambridge, Cambridge, UK
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Wang X, Song S, Hu Z, Zhang Z, Li Y, Yan C, Li Z, Tang H. Activation of Epac alleviates inflammation and vascular leakage in LPS-induced acute murine lung injury. Biomed Pharmacother 2017; 96:1127-1136. [DOI: 10.1016/j.biopha.2017.11.110] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 11/04/2017] [Accepted: 11/20/2017] [Indexed: 12/14/2022] Open
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40
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Koinuma S, Takeuchi K, Wada N, Nakamura T. cAMP-induced activation of protein kinase A and p190B RhoGAP mediates down-regulation of TC10 activity at the plasma membrane and neurite outgrowth. Genes Cells 2017; 22:953-967. [PMID: 29072354 DOI: 10.1111/gtc.12538] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/08/2017] [Indexed: 12/14/2022]
Abstract
Cyclic AMP plays a pivotal role in neurite growth. During outgrowth, a trafficking system supplies membrane at growth cones. However, the cAMP-induced signaling leading to the regulation of membrane trafficking remains unknown. TC10 is a Rho family GTPase that is essential for specific types of vesicular trafficking. Recent studies have shown a role of TC10 in neurite growth in NGF-treated PC12 cells. Here, we investigated a mechanical linkage between cAMP and TC10 in neuritogenesis. Plasmalemmal TC10 activity decreased abruptly after cAMP addition in neuronal cells. TC10 was locally inactivated at extending neurite tips in cAMP-treated PC12 cells. TC10 depletion led to a decrease in cAMP-induced neurite outgrowth. Constitutively active TC10 could not rescue this growth reduction, supporting our model for a role of GTP hydrolysis of TC10 in neuritogenesis by accelerating vesicle fusion. The cAMP-induced TC10 inactivation was mediated by PKA. Considering cAMP-induced RhoA inactivation, we found that p190B, but not p190A, mediated inactivation of TC10 and RhoA. Upon cAMP treatment, p190B was recruited to the plasma membrane. STEF depletion and Rac1-N17 expression reduced cAMP-induced TC10 inactivation. Together, the PKA-STEF-Rac1-p190B pathway leading to inactivation of TC10 and RhoA at the plasma membrane plays an important role in cAMP-induced neurite outgrowth.
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Affiliation(s)
- Shingo Koinuma
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Kohei Takeuchi
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Naoyuki Wada
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba, Japan
| | - Takeshi Nakamura
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
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41
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Growth hormone-releasing hormone attenuates cardiac hypertrophy and improves heart function in pressure overload-induced heart failure. Proc Natl Acad Sci U S A 2017; 114:12033-12038. [PMID: 29078377 PMCID: PMC5692579 DOI: 10.1073/pnas.1712612114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pathological cardiac hypertrophy, characterized by heart growth in response to pressure or volume overload, such as in the setting of hypertension, is the main risk factor for heart failure (HF). The identification of therapeutic strategies to prevent or reverse cardiac hypertrophy is therefore a priority for curing HF. It is known that growth hormone-releasing hormone (GHRH) displays cardioprotective functions; however, its therapeutic potential in hypertrophy and HF is unknown. Here we show that GHRH reduces cardiomyocyte hypertrophy in vitro through inhibition of hypertrophic pathways. In vivo, the GHRH analog MR-409 attenuates cardiac hypertrophy in mice subjected to transverse aortic constriction and improves cardiac function. These findings suggest therapeutic use of GHRH analogs for treatment of pathological cardiac hypertrophy and HF. It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH2 attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Cε, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαs and cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy.
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Nygaard G, Herfindal L, Asrud KS, Bjørnstad R, Kopperud RK, Oveland E, Berven FS, Myhren L, Hoivik EA, Lunde THF, Bakke M, Døskeland SO, Selheim F. Epac1-deficient mice have bleeding phenotype and thrombocytes with decreased GPIbβ expression. Sci Rep 2017; 7:8725. [PMID: 28821815 PMCID: PMC5562764 DOI: 10.1038/s41598-017-08975-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/17/2017] [Indexed: 11/16/2022] Open
Abstract
Epac1 (Exchange protein directly activated by cAMP 1) limits fluid loss from the circulation by tightening the endothelial barrier. We show here that Epac1-/- mice, but not Epac2-/- mice, have prolonged bleeding time, suggesting that Epac1 may limit fluid loss also by restraining bleeding. The Epac1-/- mice had deficient in vitro secondary hemostasis. Quantitative comprehensive proteomics analysis revealed that Epac1-/- mouse platelets (thrombocytes) had unbalanced expression of key components of the glycoprotein Ib-IX-V (GPIb-IX-V) complex, with decrease of GP1bβ and no change of GP1bα. This complex is critical for platelet adhesion under arterial shear conditions. Furthermore, Epac1-/- mice have reduced levels of plasma coagulation factors and fibrinogen, increased size of circulating platelets, increased megakaryocytes (the GP1bβ level was decreased also in Epac1-/- bone marrow) and higher abundance of reticulated platelets. Viscoelastic measurement of clotting function revealed Epac1-/- mice with a dysfunction in the clotting process, which corresponds to reduced plasma levels of coagulation factors like factor XIII and fibrinogen. We propose that the observed platelet phenotype is due to deficient Epac1 activity during megakaryopoiesis and thrombopoiesis, and that the defects in blood clotting for Epac1-/- is connected to secondary hemostasis.
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Affiliation(s)
- Gyrid Nygaard
- Department of Biomedicine, University of Bergen, Bergen, Norway
- The Proteomics Unit at the University of Bergen, Bergen, Norway
| | - Lars Herfindal
- Centre for Pharmacy, Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Ronja Bjørnstad
- Centre for Pharmacy, Department of Clinical Science, University of Bergen, Bergen, Norway
- Hospital Pharmacies Enterprise, Western Norway, Bergen, Norway
| | | | - Eystein Oveland
- The Proteomics Unit at the University of Bergen, Bergen, Norway
| | - Frode S Berven
- Department of Biomedicine, University of Bergen, Bergen, Norway
- The Proteomics Unit at the University of Bergen, Bergen, Norway
| | - Lene Myhren
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Erling A Hoivik
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Turid Helen Felli Lunde
- Department of Immunology and Transfusion Medicine, Haukeland University Hospital, Bergen, Norway
| | - Marit Bakke
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Frode Selheim
- Department of Biomedicine, University of Bergen, Bergen, Norway.
- The Proteomics Unit at the University of Bergen, Bergen, Norway.
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Differential Pharmacophore Definition of the cAMP Binding Sites of Neuritogenic cAMP Sensor-Rapgef2, Protein Kinase A, and Exchange Protein Activated by cAMP in Neuroendocrine Cells Using an Adenine-Based Scaffold. ACS Chem Neurosci 2017; 8:1500-1509. [PMID: 28290664 DOI: 10.1021/acschemneuro.6b00462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We recently reported that the adenylate cyclase (AC) inhibitor SQ22,536 (9-tetrahydrofuranyl-adenine) also has inhibitory activity against the neuroendocrine-specific neuritogenic cAMP sensor-Rapgef2 (NCS-Rapgef2), a guanine nucleotide exchanger and activator for the small effector GTPase Rap1. Cell-based assays that distinguish signaling through the three intracellular cAMP sensors NCS-Rapgef2, exchange protein activated by cAMP (Epac), and protein kinase A (PKA), as well as AC, were used. These, collectively, assess the activities of adenine (6-amino-purine) derivatives modified at several positions to enhance selectivity for NCS-Rapgef2 by decreasing affinity for adenylate cyclase (AC), without increasing affinity for PKA or Epac. Testing of each adenine derivative in whole-cell assays incorporates features of cell permeability, target selectivity, and intrinsic potency into a single EC50 or IC50, making robust extrapolation to compound activity in vivo more likely. N6-MBC-cAMP is a selective PKA activator (EC50 = 265 μM) with low efficacy at NCS-Rapgef2. 8-CPT-2'-O-Me-cAMP and ESI-09 are confirmed as Epac-selective, for stimulation and inhibition, respectively, versus both PKA and NCS-Rapgef2. The compound N6-Phe-cAMP is a full agonist of NCS-Rapgef2 (EC50 = 256 μM). It has little or no activity against Epac or PKA. The compound N6-phenyl-9-tetrahydrofuranyladenine is a novel and potent NCS-Rapgef2 inhibitor without activity at PKA, Epac, or ACs, as assayed in the neuroendocrine NS-1 cell line. This line has been engineered to allow high-content screening for activation and inhibition of AC, PKA, Epac, and NCS-Rapgef2 and the cellular activities initiated by these signaling pathway protein components.
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Jorge-Finnigan A, Kleppe R, Jung-Kc K, Ying M, Marie M, Rios-Mondragon I, Salvatore MF, Saraste J, Martinez A. Phosphorylation at serine 31 targets tyrosine hydroxylase to vesicles for transport along microtubules. J Biol Chem 2017. [PMID: 28637871 DOI: 10.1074/jbc.m116.762344] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tyrosine hydroxylase (TH) catalyzes the conversion of l-tyrosine into l-DOPA, which is the rate-limiting step in the synthesis of catecholamines, such as dopamine, in dopaminergergic neurons. Low dopamine levels and death of the dopaminergic neurons are hallmarks of Parkinson's disease (PD), where α-synuclein is also a key player. TH is highly regulated, notably by phosphorylation of several Ser/Thr residues in the N-terminal tail. However, the functional role of TH phosphorylation at the Ser-31 site (THSer(P)-31) remains unclear. Here, we report that THSer(P)-31 co-distributes with the Golgi complex and synaptic-like vesicles in rat and human dopaminergic cells. We also found that the TH microsomal fraction content decreases after inhibition of cyclin-dependent kinase 5 (Cdk5) and ERK1/2. The cellular distribution of an overexpressed phospho-null mutant, TH1-S31A, was restricted to the soma of neuroblastoma cells, with decreased association with the microsomal fraction, whereas a phospho-mimic mutant, TH1-S31E, was distributed throughout the soma and neurites. TH1-S31E associated with vesicular monoamine transporter 2 (VMAT2) and α-synuclein in neuroblastoma cells, and endogenous THSer(P)-31 was detected in VMAT2- and α-synuclein-immunoprecipitated mouse brain samples. Microtubule disruption or co-transfection with α-synuclein A53T, a PD-associated mutation, caused TH1-S31E accumulation in the cell soma. Our results indicate that Ser-31 phosphorylation may regulate TH subcellular localization by enabling its transport along microtubules, notably toward the projection terminals. These findings disclose a new mechanism of TH regulation by phosphorylation and reveal its interaction with key players in PD, opening up new research avenues for better understanding dopamine synthesis in physiological and pathological states.
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Affiliation(s)
- Ana Jorge-Finnigan
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway.
| | - Rune Kleppe
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Kunwar Jung-Kc
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Ming Ying
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Michael Marie
- Department of Molecular Biology, University of Bergen, Thormøhlensgaten 55, 5020 Bergen Norway
| | - Ivan Rios-Mondragon
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Michael F Salvatore
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas 76107
| | - Jaakko Saraste
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Aurora Martinez
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
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45
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Mayati A, Moreau A, Denizot C, Stieger B, Parmentier Y, Fardel O. β2-adrenergic receptor-mediated in vitro regulation of human hepatic drug transporter expression by epinephrine. Eur J Pharm Sci 2017; 106:302-312. [PMID: 28603032 DOI: 10.1016/j.ejps.2017.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/25/2017] [Accepted: 06/07/2017] [Indexed: 11/26/2022]
Abstract
The catecholamine epinephrine is known to repress expression of hepatic drug metabolizing enzymes such as cytochromes P-450. The present study was designed to determine whether epinephrine may also target expression of main hepatic drug transporters, that play a major role in liver detoxification and are commonly coordinately regulated with drug detoxifying enzymes. Treatment of primary human hepatocytes with 10μM epinephrine for 24h repressed mRNA expression of various transporters, such as the sinusoidal influx transporters NTCP, OATP1B1, OATP2B1, OAT2, OAT7 and OCT1 and the efflux transporters MRP2, MRP3 and BSEP, whereas it induced that of MDR1, but failed to alter that of BCRP. Most of these changes in transporter mRNA levels were also found in epinephrine-exposed human highly-differentiated hepatoma HepaRG cells, which additionally exhibited reduced protein expression of OATP2B1 and MRP3, increased expression of P-glycoprotein and decreased transport activity of NTCP, OATPs and OCT1. Epinephrine effects towards transporter mRNA expression in human hepatocytes were next shown to be correlated to those of the selective β2-adrenoreceptor (ADR) agonist fenoterol, of the adenylate cyclase activator forskolin and of the cAMP analogue 8-bromo-cAMP. In addition, the non-selective β-ADR antagonist carazolol and the selective β2-ADR antagonist ICI-118,551, unlike the α-ADR antagonist phentolamine, suppressed epinephrine-mediated repressions of transporter mRNA expression. Taken together, these data indicate that epinephrine regulates in vitro expression of main hepatic drug transporters in a β2-ADR/adenylate cyclase/cAMP-dependent manner. Hepatic drug transport appears therefore as a target of the β2-adrenergic system, which may have to deserve attention for drugs interacting with β2-ADRs.
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Affiliation(s)
- Abdullah Mayati
- Institut de Recherches en Santé, Environnement et Travail (IRSET), UMR INSERM U1085, Faculté de Pharmacie, 2 Avenue du Pr Léon Bernard, 35043 Rennes, France
| | - Amélie Moreau
- Centre de Pharmacocinétique, Technologie Servier, 25-27 Rue Eugène Vignat, 45000 Orléans, France
| | - Claire Denizot
- Centre de Pharmacocinétique, Technologie Servier, 25-27 Rue Eugène Vignat, 45000 Orléans, France
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Yannick Parmentier
- Centre de Pharmacocinétique, Technologie Servier, 25-27 Rue Eugène Vignat, 45000 Orléans, France
| | - Olivier Fardel
- Institut de Recherches en Santé, Environnement et Travail (IRSET), UMR INSERM U1085, Faculté de Pharmacie, 2 Avenue du Pr Léon Bernard, 35043 Rennes, France; Pôle Biologie, Centre Hospitalier Universitaire, 2 Rue Henri Le Guilloux, 35033 Rennes, France.
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46
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Wang P, Liu Z, Chen H, Ye N, Cheng X, Zhou J. Exchange proteins directly activated by cAMP (EPACs): Emerging therapeutic targets. Bioorg Med Chem Lett 2017; 27:1633-1639. [PMID: 28283242 PMCID: PMC5397994 DOI: 10.1016/j.bmcl.2017.02.065] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/07/2017] [Accepted: 02/26/2017] [Indexed: 11/22/2022]
Abstract
Exchange proteins directly activated by cAMP (EPACs) are critical cAMP-dependent signaling pathway mediators. The discovery of EPAC proteins has significantly facilitated understanding on cAMP-dependent signaling pathway and efforts along this line open new avenues for developing novel therapeutics for cancer, diabetes, heart failure, inflammation, infections, neurological disorders and other human diseases. Over the past decade, important progress has been made in the identification of EPAC agonists, antagonists and their biological and pharmacological applications. In this review, we briefly summarize recently reported novel functions of EPACs and the discovery of their small molecule modulators. The challenges and future perspectives are also discussed.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX 77030, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States.
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47
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Knott EP, Assi M, Rao SNR, Ghosh M, Pearse DD. Phosphodiesterase Inhibitors as a Therapeutic Approach to Neuroprotection and Repair. Int J Mol Sci 2017; 18:E696. [PMID: 28338622 PMCID: PMC5412282 DOI: 10.3390/ijms18040696] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 12/21/2022] Open
Abstract
A wide diversity of perturbations of the central nervous system (CNS) result in structural damage to the neuroarchitecture and cellular defects, which in turn are accompanied by neurological dysfunction and abortive endogenous neurorepair. Altering intracellular signaling pathways involved in inflammation and immune regulation, neural cell death, axon plasticity and remyelination has shown therapeutic benefit in experimental models of neurological disease and trauma. The second messengers, cyclic adenosine monophosphate (cyclic AMP) and cyclic guanosine monophosphate (cyclic GMP), are two such intracellular signaling targets, the elevation of which has produced beneficial cellular effects within a range of CNS pathologies. The only known negative regulators of cyclic nucleotides are a family of enzymes called phosphodiesterases (PDEs) that hydrolyze cyclic nucleotides into adenosine monophosphate (AMP) or guanylate monophosphate (GMP). Herein, we discuss the structure and physiological function as well as the roles PDEs play in pathological processes of the diseased or injured CNS. Further we review the approaches that have been employed therapeutically in experimental paradigms to block PDE expression or activity and in turn elevate cyclic nucleotide levels to mediate neuroprotection or neurorepair as well as discuss both the translational pathway and current limitations in moving new PDE-targeted therapies to the clinic.
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Affiliation(s)
- Eric P Knott
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA.
| | - Mazen Assi
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Sudheendra N R Rao
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Mousumi Ghosh
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Department of Neurological Surgery, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Department of Neurological Surgery, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Neuroscience Program, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Interdisciplinary Stem Cell Institute, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- Bruce Wayne Carter Department of Veterans Affairs Medical Center, Miami, FL 33136, USA.
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48
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Yanguas-Casás N, Barreda-Manso MA, Nieto-Sampedro M, Romero-Ramírez L. TUDCA: An Agonist of the Bile Acid Receptor GPBAR1/TGR5 With Anti-Inflammatory Effects in Microglial Cells. J Cell Physiol 2017; 232:2231-2245. [DOI: 10.1002/jcp.25742] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/14/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Natalia Yanguas-Casás
- Departamento de Neurobiología Funcional y de Sistemas Instituto Cajal (CSIC); Madrid Spain
| | - M. Asunción Barreda-Manso
- Departamento de Neurobiología Funcional y de Sistemas Instituto Cajal (CSIC); Madrid Spain
- Unidad de Neurología Experimental; Hospital Nacional de Parapléjicos (SESCAM); Toledo Spain
| | - Manuel Nieto-Sampedro
- Departamento de Neurobiología Funcional y de Sistemas Instituto Cajal (CSIC); Madrid Spain
- Unidad de Neurología Experimental; Hospital Nacional de Parapléjicos (SESCAM); Toledo Spain
| | - Lorenzo Romero-Ramírez
- Unidad de Neurología Experimental; Hospital Nacional de Parapléjicos (SESCAM); Toledo Spain
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49
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Khaliulin I, Bond M, James AF, Dyar Z, Amini R, Johnson JL, Suleiman MS. Functional and cardioprotective effects of simultaneous and individual activation of protein kinase A and Epac. Br J Pharmacol 2017; 174:438-453. [PMID: 28071786 PMCID: PMC5323515 DOI: 10.1111/bph.13709] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 01/16/2023] Open
Abstract
Background and Purpose Myocardial cAMP elevation confers cardioprotection against ischaemia/reperfusion (I/R) injury. cAMP activates two independent signalling pathways, PKA and Epac. This study investigated the cardiac effects of activating PKA and/or Epac and their involvement in cardioprotection against I/R. Experimental Approach Hearts from male rats were used either for determination of PKA and PKC activation or perfused in the Langendorff mode for either cardiomyocyte isolation or used to monitor functional activity at basal levels and after 30 min global ischaemia and 2 h reperfusion. Functional recovery and myocardial injury during reperfusion (LDH release and infarct size) were evaluated. Activation of PKA and/or Epac in perfused hearts was induced using cell permeable cAMP analogues in the presence or absence of inhibitors of PKA, Epac and PKC. H9C2 cells and cardiomyocytes were used to assess activation of Epac and effect on Ca2+ transients. Key Results Selective activation of either PKA or Epac was found to trigger a positive inotropic effect, which was considerably enhanced when both pathways were simultaneously activated. Only combined activation of PKA and Epac induced marked cardioprotection against I/R injury. This was accompanied by PKCε activation and repressed by inhibitors of PKA, Epac or PKC. Conclusion and Implications Simultaneous activation of both PKA and Epac induces an additive inotropic effect and confers optimal and marked cardioprotection against I/R injury. The latter effect is mediated by PKCε activation. This work has introduced a new therapeutic approach and targets to protect the heart against cardiac insults.
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Affiliation(s)
- Igor Khaliulin
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - Mark Bond
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - Andrew F James
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - Zara Dyar
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - Raheleh Amini
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - Jason L Johnson
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
| | - M-Saadeh Suleiman
- School of Clinical Sciences and Bristol Cardiovascular, University of Bristol, Bristol, UK
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50
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Muñoz-Llancao P, de Gregorio C, Las Heras M, Meinohl C, Noorman K, Boddeke E, Cheng X, Lezoualc'h F, Schmidt M, Gonzalez-Billault C. Microtubule-regulating proteins and cAMP-dependent signaling in neuroblastoma differentiation. Cytoskeleton (Hoboken) 2017; 74:143-158. [PMID: 28164467 DOI: 10.1002/cm.21355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 01/15/2023]
Abstract
Neurons are highly differentiated cells responsible for the conduction and transmission of information in the nervous system. The proper function of a neuron relies on the compartmentalization of their intracellular domains. Differentiated neuroblastoma cells have been extensively used to study and understand the physiology and cell biology of neuronal cells. Here, we show that differentiation of N1E-115 neuroblastoma cells is more pronounced upon exposure of a chemical analog of cyclic AMP (cAMP), db-cAMP. We next analysed the expression of key microtubule-regulating proteins in differentiated cells and the expression and activation of key cAMP players such as EPAC, PKA and AKAP79/150. Most of the microtubule-promoting factors were up regulated during differentiation of N1E-115 cells, while microtubule-destabilizing proteins were down regulated. We observed an increase in tubulin post-translational modifications related to microtubule stability. As expected, db-cAMP increased PKA- and EPAC-dependent signalling. Consistently, pharmacological modulation of EPAC activity instructed cell differentiation, number of neurites, and neurite length in N1E-115 cells. Moreover, disruption of the PKA-AKAP interaction reduced these morphometric parameters. Interestingly, PKA and EPAC act synergistically to induce neuronal differentiation in N1E-115. Altogether these results show that the changes observed in the differentiation of N1E-115 cells proceed by regulating several microtubule-stabilizing factors, and the acquisition of a neuronal phenotype is a process involving concerted although independent functions of EPAC and PKA.
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Affiliation(s)
- Pablo Muñoz-Llancao
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Cristian de Gregorio
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Macarena Las Heras
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - Christopher Meinohl
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Kevin Noorman
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Erik Boddeke
- Department of Medical Physiology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, USA
| | - Frank Lezoualc'h
- Inserm UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France.,Université de Toulouse III, Paul Sabatier, Toulouse, France
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Christian Gonzalez-Billault
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, USA
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