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Ullo MF, Case LB. How cells sense and integrate information from different sources. WIREs Mech Dis 2023:e1604. [PMID: 36781396 DOI: 10.1002/wsbm.1604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/06/2023] [Accepted: 01/24/2023] [Indexed: 02/15/2023]
Abstract
Cell signaling is a fundamental cellular process that enables cells to sense and respond to information in their surroundings. At the molecular level, signaling is primarily carried out by transmembrane protein receptors that can initiate complex downstream signal transduction cascades to alter cellular behavior. In the human body, different cells can be exposed to a wide variety of environmental conditions, and cells express diverse classes of receptors capable of sensing and integrating different signals. Furthermore, different receptors and signaling pathways can crosstalk with each other to calibrate the cellular response. Crosstalk occurs through multiple mechanisms at different levels of signaling pathways. In this review, we discuss how cells sense and integrate different chemical, mechanical, and spatial signals as well as the mechanisms of crosstalk between pathways. To illustrate these concepts, we use a few well-studied signaling pathways, including receptor tyrosine kinases and integrin receptors. Finally, we discuss the implications of dysregulated cellular sensing on driving diseases such as cancer. This article is categorized under: Cancer > Molecular and Cellular Physiology Metabolic Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Maria F Ullo
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lindsay B Case
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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2
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Cryo-EM structures of human bradykinin receptor-G q proteins complexes. Nat Commun 2022; 13:714. [PMID: 35132089 PMCID: PMC8821558 DOI: 10.1038/s41467-022-28399-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/18/2022] [Indexed: 12/23/2022] Open
Abstract
The type 2 bradykinin receptor (B2R) is a G protein-coupled receptor (GPCR) in the cardiovascular system, and the dysfunction of B2R leads to inflammation, hereditary angioedema, and pain. Bradykinin and kallidin are both endogenous peptide agonists of B2R, acting as vasodilators to protect the cardiovascular system. Here we determine two cryo-electron microscopy (cryo-EM) structures of human B2R-Gq in complex with bradykinin and kallidin at 3.0 Å and 2.9 Å resolution, respectively. The ligand-binding pocket accommodates S-shaped peptides, with aspartic acids and glutamates as an anion trap. The phenylalanines at the tail of the peptides induce significant conformational changes in the toggle switch W2836.48, the conserved PIF, DRY, and NPxxY motifs, for the B2R activation. This further induces the extensive interactions of the intracellular loops ICL2/3 and helix 8 with Gq proteins. Our structures elucidate the molecular mechanisms for the ligand binding, receptor activation, and Gq proteins coupling of B2R.
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Nassour H, Hoang TA, Martin RD, Dallagnol JCC, Billard É, Létourneau M, Novellino E, Carotenuto A, Allen BG, Tanny JC, Fournier A, Hébert TE, Chatenet D. Lipidated peptides derived from intracellular loops 2 and 3 of the urotensin II receptor act as biased allosteric ligands. J Biol Chem 2021; 297:101057. [PMID: 34389356 PMCID: PMC8424217 DOI: 10.1016/j.jbc.2021.101057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 07/23/2021] [Accepted: 08/05/2021] [Indexed: 01/14/2023] Open
Abstract
Over the last decade, the urotensinergic system, composed of one G protein-coupled receptor and two endogenous ligands, has garnered significant attention as a promising new target for the treatment of various cardiovascular diseases. Indeed, this system is associated with various biomarkers of cardiovascular dysfunctions and is involved in changes in cardiac contractility, fibrosis and hypertrophy contributing, like the angiotensinergic system, to the pathogenesis and progression of heart failure. Significant investment has been made toward the development of clinically relevant UT ligands for therapeutic intervention, but with little or no success to date. This system therefore remains to be therapeutically exploited. Pepducins and other lipidated peptides have been used as both mechanistic probes and potential therapeutics; therefore, pepducins derived from the human urotensin II receptor might represent unique tools to generate signaling bias and study hUT signaling networks. Two hUT-derived pepducins, derived from the second and the third intracellular loop of the receptor (hUT-Pep2 and [Trp1, Leu2]hUT-Pep3, respectively) were synthesized and pharmacologically characterized. Our results demonstrated that hUT-Pep2 and [Trp1, Leu2]hUT-Pep3 acted as biased ago-allosteric modulators, triggered ERK1/2 phosphorylation and to a lesser extent, IP1 production and stimulated cell proliferation yet were devoid of contractile activity. Interestingly, both hUT-derived pepducins were able to modulate human urotensin II (hUII)- and urotensin II-related peptide (URP)-mediated contraction albeit to different extents. These new derivatives represent unique tools to reveal the intricacies of hUT signaling and also a novel avenue for the design of allosteric ligands selectively targeting hUT signaling potentially.
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Affiliation(s)
- Hassan Nassour
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Tuan Anh Hoang
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Juliana C C Dallagnol
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada; Department of Medicine, Université de Montreal, Montreal Heart Institute, Montreal, Québec, Canada
| | - Étienne Billard
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Myriam Létourneau
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Ettore Novellino
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Bruce G Allen
- Department of Medicine, Université de Montreal, Montreal Heart Institute, Montreal, Québec, Canada
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - Alain Fournier
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada
| | - David Chatenet
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Ville de Laval, Québec, Canada.
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4
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Ma Q, Cao Z, Li H, Wang W, Tian Y, Yan L, Liao Y, Chen X, Chen Y, Shi Y, Tang S, Zhou N. Two naturally occurring mutations of human GPR103 define distinct G protein selection bias. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119046. [PMID: 33872671 DOI: 10.1016/j.bbamcr.2021.119046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 11/18/2022]
Abstract
The neuropeptide 26RFa plays important roles in the regulation of many physiological functions. 26RFa has been recognized as an endogenous ligand for receptor GPR103. In the present study, we demonstrate that GPR103 dually couples to Gαq and Gαi/o proteins. However, two naturally occurring missense mutations were identified from a young male patient. In the first, Y68H, induction of Ca2+ mobilization was noted without detection of ERK1/2 activation. In the second, R371W, the potential to activate ERK1/2 signaling was retained but with failure to evoke Ca2+ mobilization. Further analysis provides evidence that Gαq, L-type Ca2+ channel and PKCβI and βII are involved in the Y68H-mediated signaling pathway, whereas Gαi/o, Gβγ, and PKCζ are implicated in the R371W-induced signaling. Our results demonstrate that two point mutations, Y68H and R371W, affect the equilibrium between the different receptor conformations, leading to alteration of G protein-coupling preferences. Importantly, these findings provide a foundation for future elucidation of GPCR-mediated biased signaling and the physiological implications of their bias.
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Affiliation(s)
- Qiang Ma
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China; Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brian Medicine, MOE Frontier Center of Brain Science and Brain-machine Integration, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zheng Cao
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Huanzheng Li
- Wenzhou Key Laboratory of Birth Defects, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000, China
| | - Weiwei Wang
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yanan Tian
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Lili Yan
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yuan Liao
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiangnan Chen
- Wenzhou Key Laboratory of Birth Defects, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000, China
| | - Yu Chen
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ying Shi
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shaohua Tang
- Wenzhou Key Laboratory of Birth Defects, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000, China; School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 32500, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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5
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Naguib YW, Givens BE, Ho G, Yu Y, Wei SG, Weiss RM, Felder RB, Salem AK. An injectable microparticle formulation for the sustained release of the specific MEK inhibitor PD98059: in vitro evaluation and pharmacokinetics. Drug Deliv Transl Res 2020; 11:182-191. [PMID: 32378175 DOI: 10.1007/s13346-020-00758-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PD98059 is a reversible MEK inhibitor that we are investigating as a potential treatment for neurochemical changes in the brain that drive neurohumoral excitation in heart failure. In a rat model that closely resembles human heart failure, we found that central administration of PD98059 inhibits phosphorylation of ERK1/2 in the paraventricular nucleus of the hypothalamus, ultimately reducing sympathetic excitation which is a major contributor to clinical deterioration. Studies revealed that the pharmacokinetics and biodistribution of PD98059 match a two-compartment model, with drug found in brain as well as other body tissues, but with a short elimination half-life in plasma (approximately 73 min) that would severely limit its potential clinical usefulness in heart failure. To increase its availability to tissues, we prepared a sustained release PD98059-loaded PLGA microparticle formulation, using an emulsion solvent evaporation technique. The average particle size, yield percent, and encapsulation percent were found to be 16.73 μm, 76.6%, and 43%, respectively. In vitro drug release occurred over 4 weeks, with no noticeable burst release. Following subcutaneous injection of the microparticles in rats, steady plasma levels of PD98059 were detected by HPLC for up to 2 weeks. Furthermore, plasma and brain levels of PD98059 in rats with heart failure were detectable by LC/MS, despite expected erratic absorption. These findings suggest that PD98059-loaded microparticles hold promise as a novel therapeutic intervention countering sympathetic excitation in heart failure, and perhaps in other disease processes, including cancers, in which activated MAPK signaling is a significant contributing factor. Graphical abstract.
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Affiliation(s)
- Youssef W Naguib
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA.,Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia, 61519, Egypt
| | - Brittany E Givens
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA.,Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, 40506, USA
| | - Giang Ho
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA
| | - Yang Yu
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Shun-Guang Wei
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Francois M. Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Robert M Weiss
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Robert B Felder
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Veterans Affairs Medical Center, Iowa City, IA, 52242, USA.,Francois M. Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Aliasger K Salem
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA. .,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, 52242, USA.
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6
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Chen M, Cecon E, Karamitri A, Gao W, Gerbier R, Ahmad R, Jockers R. Melatonin MT 1 and MT 2 receptor ERK signaling is differentially dependent on G i/o and G q/11 proteins. J Pineal Res 2020; 68:e12641. [PMID: 32080899 DOI: 10.1111/jpi.12641] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/15/2020] [Accepted: 02/17/2020] [Indexed: 12/14/2022]
Abstract
G protein-coupled receptors (GPCRs) transmit extracellular signals into cells by activating G protein- and β-arrestin-dependent pathways. Extracellular signal-regulated kinases (ERKs) play a central role in integrating these different linear inputs coming from a variety of GPCRs to regulate cellular functions. Here, we investigated human melatonin MT1 and MT2 receptors signaling through the ERK1/2 cascade by employing different biochemical techniques together with pharmacological inhibitors and siRNA molecules. We show that ERK1/2 activation by both receptors is exclusively G protein-dependent, without any participation of β-arrestin1/2 in HEK293 cells. ERK1/2 activation by MT1 is only mediated though Gi/o proteins, while MT2 is dependent on the cooperative activation of Gi/o and Gq/11 proteins. In the absence of Gq/11 proteins, however, MT2 -induced ERK1/2 activation switches to a β-arrestin1/2-dependent mode. The signaling cascade downstream of G proteins is the same for both receptors and involves activation of the PI3K/PKCζ/c-Raf/MEK/ERK cascade. The differential G protein dependency of MT1 - and MT2 -mediated ERK activation was confirmed at the level of EGR1 and FOS gene expression, two ERK1/2 target genes. Gi/o /Gq/11 cooperativity was also observed in Neuroscreen-1 cells expressing endogenous MT2 , whereas in the mouse retina, where MT2 is engaged into MT1 /MT2 heterodimers, ERK1/2 signaling is exclusively Gi/o -dependent. Collectively, our data reveal differential signaling modes of MT1 and MT2 in terms of ERK1/2 activation, with an unexpected Gi/o /Gq/11 cooperativity exclusively for MT2 . The plasticity of ERK activation by MT2 is highlighted by the switch to a β-arrestin1/2-dependent mode in the absence of Gq/11 proteins and by the switch to a Gi/o mode when engaged into MT1 /MT2 heterodimers, revealing a new mechanism underlying tissue-specific responses to melatonin.
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Affiliation(s)
- Min Chen
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | - Erika Cecon
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | | | - Wenwen Gao
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | - Romain Gerbier
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | - Raise Ahmad
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | - Ralf Jockers
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
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Santhosh D, Sherman J, Chowdhury S, Huang Z. Harnessing region-specific neurovascular signaling to promote germinal matrix vessel maturation and hemorrhage prevention. Dis Model Mech 2019; 12:dmm.041228. [PMID: 31601549 PMCID: PMC6899033 DOI: 10.1242/dmm.041228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/06/2019] [Indexed: 12/13/2022] Open
Abstract
Germinal matrix hemorrhage (GMH), affecting about 1 in 300 births, is a major perinatal disease with lifelong neurological consequences. Yet despite advances in neonatal medicine, there is no effective intervention. GMH is characterized by localized bleeding in the germinal matrix (GM), due to inherent vessel fragility unique to this developing brain region. Studies have shown that reduced TGFβ signaling contributes to this vascular immaturity. We have previously shown that a region-specific G-protein-coupled receptor pathway in GM neural progenitor cells regulates integrin β8, a limiting activator of pro-TGFβ. In this study, we use mice to test whether this regional pathway can be harnessed for GMH intervention. We first examined the endogenous dynamics of this pathway and found that it displays specific patterns of activation. We then investigated the functional effects of altering these dynamics by chemogenetics and found that there is a narrow developmental window during which this pathway is amenable to manipulation. Although high-level activity in this time window interferes with vessel growth, moderate enhancement promotes vessel maturation without compromising growth. Furthermore, we found that enhancing the activity of this pathway in a mouse model rescues all GMH phenotypes. Altogether, these results demonstrate that enhancing neurovascular signaling through pharmacological targeting of this pathway may be a viable approach for tissue-specific GMH intervention. They also demonstrate that timing and level are likely two major factors crucial for success. These findings thus provide critical new insights into both brain neurovascular biology and the intervention of GMH.
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Affiliation(s)
- Devi Santhosh
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA.,Program in Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Joe Sherman
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Shafi Chowdhury
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA .,Program in Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53705, USA
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8
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Wang Z, Huang J. Apela Promotes Cardiomyocyte Differentiation from Transgenic Human Embryonic Stem Cell Lines. Appl Biochem Biotechnol 2019; 189:396-410. [PMID: 31025171 DOI: 10.1007/s12010-019-03012-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/27/2019] [Indexed: 12/22/2022]
Abstract
Although embryonic stem (ES) cells (ESCs) may be a promising donor source for the repair of infarcted or ischemic heart tissues, their successful application in regenerative medicine has been hampered by difficulties in enriching, identifying, and selecting cardiomyocytes from the differentiating cells. We established transgenic human ES cell lines by transcriptional control of the α-cardiac myosin heavy chain (α-MHC) promoter driving green fluorescent protein (GFP) expression. Differentiated GFP-expressing cells display the characteristics of cardiomyocytes (CMs). Apela, a recently identified short peptide, up-regulated the expression of the cardiac-restricted transcription factors Tbx5 and GATA4 as well as differentiated the cardiomyocyte markers α-MHC and β-MHC. Flow cytometric analysis showed that apela increased the percentage of GFP-expressing cells in the beating foci of the embryoid bodies. The percentage of cardiac troponin T (TNT)-positive cells and the protein expression of TNT were increased in the ES cell-derived CMs with apela treatment. Functionally, the contractile frequency of the ES-derived CMs responded appropriately to the vasoactive drugs isoprenaline and carbachol. Our work presented a protocol for specially labelling and enriching CMs by combining transgenic human ES cell lines and exogenous growth factor treatment.
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Affiliation(s)
- Zhi Wang
- Department of Cardiovascular Medicine, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, People's Republic of China. .,Department of Cardiovascular Medicine, Nanjing Chest Hospital, Nanjing, People's Republic of China. .,Department of Cardiology, Nanjing Brain Hospital, Nanjing Medical University, No. 264 Guangzhou Road, Nanjing, 210029, People's Republic of China.
| | - Jin Huang
- Department of Cardiovascular Medicine, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, People's Republic of China. .,Department of Cardiovascular Medicine, Nanjing Chest Hospital, Nanjing, People's Republic of China.
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Li Z, Liu T, Gilmore A, Gómez NM, Mitchell CH, Li YP, Oursler MJ, Yang S. Regulator of G Protein Signaling Protein 12 (Rgs12) Controls Mouse Osteoblast Differentiation via Calcium Channel/Oscillation and Gαi-ERK Signaling. J Bone Miner Res 2019; 34:752-764. [PMID: 30489658 PMCID: PMC7675783 DOI: 10.1002/jbmr.3645] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 11/13/2018] [Accepted: 11/17/2018] [Indexed: 12/11/2022]
Abstract
Bone homeostasis intimately relies on the balance between osteoblasts (OBs) and osteoclasts (OCs). Our previous studies have revealed that regulator of G protein signaling protein 12 (Rgs12), the largest protein in the Rgs super family, is essential for osteoclastogenesis from hematopoietic cells and OC precursors. However, how Rgs12 regulates OB differentiation and function is still unknown. To understand that, we generated an OB-targeted Rgs12 conditional knockout (CKO) mice model by crossing Rgs12fl/fl mice with Osterix (Osx)-Cre transgenic mice. We found that Rgs12 was highly expressed in both OB precursor cells (OPCs) and OBs of wild-type (WT) mice, and gradually increased during OB differentiation, whereas Rgs12-CKO mice (OsxCre/+ ; Rgs12fl/fl ) exhibited a dramatic decrease in both trabecular and cortical bone mass, with reduced numbers of OBs and increased apoptotic cell population. Loss of Rgs12 in OPCs in vitro significantly inhibited OB differentiation and the expression of OB marker genes, resulting in suppression of OB maturation and mineralization. Further mechanism study showed that deletion of Rgs12 in OPCs significantly inhibited guanosine triphosphatase (GTPase) activity and cyclic adenosine monophosphate (cAMP) level, and impaired Calcium (Ca2+ ) oscillations via restraints of major Ca2+ entry sources (extracellular Ca2+ influx and intracellular Ca2+ release from endoplasmic reticulum), partially contributed by the blockage of L-type Ca2+ channel mediated Ca2+ influx. Downstream mediator extracellular signal-related protein kinase (ERK) was found inactive in OBs of OsxCre/+ ; Rgs12fl/fl mice and in OPCs after Rgs12 deletion, whereas application of pertussis toxin (PTX) or overexpression of Rgs12 could rescue the defective OB differentiation via restoration of ERK phosphorylation. Our findings reveal that Rgs12 is an important regulator during osteogenesis and highlight Rgs12 as a potential therapeutic target for bone disorders. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Ziqing Li
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA 19104, USA
| | - Tongjun Liu
- Department of Oral Biology, School of Dental Medicine, University of Buffalo, State University of New York, Buffalo, NY 14215, USA
- Department of Implantology, Shandong Provincial Key Laboratory of Oral Biomedicine, School of Stomatology, Shandong University
- Department of Stomatology, the Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong province 250000, China
| | - Alyssa Gilmore
- Department of Oral Biology, School of Dental Medicine, University of Buffalo, State University of New York, Buffalo, NY 14215, USA
| | - Néstor Más Gómez
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA 19104, USA
| | - Claire H Mitchell
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA 19104, USA
- Department of Physiology, School of Medicine, University of Pennsylvania Philadelphia, PA 19104, USA
| | - Yi-ping Li
- Department of Pathology, University of Alabama in Birmingham, Birmingham, AL 35294, USA
| | - Merry J Oursler
- Department of Medicine, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905, USA
| | - Shuying Yang
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA 19104, USA
- The Penn Center for Musculoskeletal Disorders, University of Pennsylvania Philadelphia, PA 19104, USA
- Department of Oral Biology, School of Dental Medicine, University of Buffalo, State University of New York, Buffalo, NY 14215, USA
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10
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Labed SA, Wani KA, Jagadeesan S, Hakkim A, Najibi M, Irazoqui JE. Intestinal Epithelial Wnt Signaling Mediates Acetylcholine-Triggered Host Defense against Infection. Immunity 2019; 48:963-978.e3. [PMID: 29768179 DOI: 10.1016/j.immuni.2018.04.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 02/02/2018] [Accepted: 04/17/2018] [Indexed: 12/21/2022]
Abstract
Regulated antimicrobial peptide expression in the intestinal epithelium is key to defense against infection and to microbiota homeostasis. Understanding the mechanisms that regulate such expression is necessary for understanding immune homeostasis and inflammatory disease and for developing safe and effective therapies. We used Caenorhabditis elegans in a preclinical approach to discover mechanisms of antimicrobial gene expression control in the intestinal epithelium. We found an unexpected role for the cholinergic nervous system. Infection-induced acetylcholine release from neurons stimulated muscarinic signaling in the epithelium, driving downstream induction of Wnt expression in the same tissue. Wnt induction activated the epithelial canonical Wnt pathway, resulting in the expression of C-type lectin and lysozyme genes that enhanced host defense. Furthermore, the muscarinic and Wnt pathways are linked by conserved transcription factors. These results reveal a tight connection between the nervous system and the intestinal epithelium, with important implications for host defense, immune homeostasis, and cancer.
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Affiliation(s)
- Sid Ahmed Labed
- Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Khursheed A Wani
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sakthimala Jagadeesan
- Department of Molecular Biology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA
| | - Abdul Hakkim
- Department of Molecular Biology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA
| | - Mehran Najibi
- Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Javier Elbio Irazoqui
- Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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11
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Choi C, Thi Thao Tran N, Van Ngu T, Park SW, Song MS, Kim SH, Bae YU, Ayudthaya PDN, Munir J, Kim E, Baek MJ, Song S, Ryu S, Nam KH. Promotion of tumor progression and cancer stemness by MUC15 in thyroid cancer via the GPCR/ERK and integrin-FAK signaling pathways. Oncogenesis 2018; 7:85. [PMID: 30420637 PMCID: PMC6232104 DOI: 10.1038/s41389-018-0094-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/10/2018] [Accepted: 10/03/2018] [Indexed: 12/21/2022] Open
Abstract
Thyroid cancer is the fifth most common cancer diagnosed in women worldwide. Notwithstanding advancements in the prognosis and treatment of thyroid cancer, 10–20% of thyroid cancer patients develops chemotherapeutic resistance and experience relapse. According to previous reports and TCGA database, MUC15 (MUCIN 15) upregulation is highly correlated with thyroid cancer progression. However, the role of MUC15 in tumor progression and metastasis is unclear. This study aimed to investigate factors mediating cancer stemness in thyroid cancer. MUC15 plays an important role in sphere formation, as an evident from the expression of stemness markers including SOX2, KLF4, ALDH1A3, and IL6. Furthermore, ectopic expression of MUC15 activated extracellular signal-regulated kinase (ERK) signaling via G-protein–coupled receptor (GPCR)/cyclic AMP (cAMP) and integrin/focal adhesion kinase pathways. Interestingly, ectopic expression of MUC15 did not affect RAF/mitogen-activated protein kinase kinase (MEK)-mediated ERK activation. The present findings may provide novel insights into the development of diagnostic, prognostic, and therapeutic applications of MUC15 in thyroid cancer.
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Affiliation(s)
- Cheolwon Choi
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Nguyen Thi Thao Tran
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Trinh Van Ngu
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Sae Woong Park
- Department of Microbiology & Immunology, Weill Cornell Medical College, New York, USA
| | - Min Suk Song
- Department of Life Sciences, Yeungnam University, Gyeongsan, Korea
| | - Sung Hyun Kim
- Department of Physiology, Kyung Hee University, School of Medicine, Seoul, Korea
| | - Yun-Ui Bae
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | | | - Javaria Munir
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Eunbit Kim
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Moo-Jun Baek
- Department of Surgery, College of Medicine, Soonchunhyang University, Chonan, Korea
| | - Sujung Song
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Seongho Ryu
- Soonchunhyang Institute of Med-bioscience (SIMS), Soonchunhyang University, Cheonan, Korea.
| | - Kee-Hyun Nam
- Department of Surgery, College of Medicine, Yonsei University, Seoul, Korea.
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12
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Renz BW, Tanaka T, Sunagawa M, Takahashi R, Jiang Z, Macchini M, Dantes Z, Valenti G, White RA, Middelhoff MA, Ilmer M, Oberstein PE, Angele MK, Deng H, Hayakawa Y, Westphalen CB, Werner J, Remotti H, Reichert M, Tailor YH, Nagar K, Friedman RA, Iuga AC, Olive KP, Wang TC. Cholinergic Signaling via Muscarinic Receptors Directly and Indirectly Suppresses Pancreatic Tumorigenesis and Cancer Stemness. Cancer Discov 2018; 8:1458-1473. [PMID: 30185628 PMCID: PMC6214763 DOI: 10.1158/2159-8290.cd-18-0046] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 07/15/2018] [Accepted: 08/30/2018] [Indexed: 12/18/2022]
Abstract
In many solid tumors, parasympathetic input is provided by the vagus nerve, which has been shown to modulate tumor growth. However, whether cholinergic signaling directly regulates progression of pancreatic ductal adenocarcinoma (PDAC) has not been defined. Here, we found that subdiaphragmatic vagotomy in LSL-Kras +/G12D;Pdx1-Cre (KC) mice accelerated PDAC development, whereas treatment with the systemic muscarinic agonist bethanechol restored the normal KC phenotype, thereby suppressing the accelerated tumorigenesis caused by vagotomy. In LSL-Kras +/G12D;LSL-Trp53 +/R172H;Pdx1-Cre mice with established PDAC, bethanechol significantly extended survival. These effects were mediated in part through CHRM1, which inhibited downstream MAPK/EGFR and PI3K/AKT pathways in PDAC cells. Enhanced cholinergic signaling led to a suppression of the cancer stem cell (CSC) compartment, CD11b+ myeloid cells, TNFα levels, and metastatic growth in the liver. Therefore, these data suggest that cholinergic signaling directly and indirectly suppresses growth of PDAC cells, and therapies that stimulate muscarinic receptors may be useful in the treatment of PDAC.Significance: Subdiaphragmatic vagotomy or Chrm1 knockout accelerates pancreatic tumorigenesis, in part via expansion of the CSC compartment. Systemic administration of a muscarinic agonist suppresses tumorigenesis through MAPK and PI3K/AKT signaling, in early stages of tumor growth and in more advanced, metastatic disease. Therefore, CHRM1 may represent a potentially attractive therapeutic target. Cancer Discov; 8(11); 1458-73. ©2018 AACR. This article is highlighted in the In This Issue feature, p. 1333.
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MESH Headings
- Animals
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/pathology
- Carcinoma, Pancreatic Ductal/prevention & control
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cholinergic Agents/pharmacology
- Genes, ras
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Neoplastic Stem Cells/drug effects
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Pancreatic Neoplasms/prevention & control
- Receptor, Muscarinic M1/physiology
- Signal Transduction
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Affiliation(s)
- Bernhard W Renz
- Department of General, Visceral and Transplantation Surgery, Hospital of the University of Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Takayuki Tanaka
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
| | - Masaki Sunagawa
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Ryota Takahashi
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Zhengyu Jiang
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Marina Macchini
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Zahra Dantes
- Department of Medicine II, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Giovanni Valenti
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Ruth A White
- Division of Oncology, Department of Medicine and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Moritz A Middelhoff
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Matthias Ilmer
- Department of General, Visceral and Transplantation Surgery, Hospital of the University of Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Paul E Oberstein
- Perlmutter Cancer Center, New York University Langone Medical Center, New York, New York
| | - Martin K Angele
- Department of General, Visceral and Transplantation Surgery, Hospital of the University of Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Huan Deng
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Pathology, and Molecular Medicine and Genetics Center, The Fourth Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Yoku Hayakawa
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Gastroenterology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - C Benedikt Westphalen
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Internal Medicine III, Hospital of the University of Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jens Werner
- Department of General, Visceral and Transplantation Surgery, Hospital of the University of Munich, Munich, Germany; German Cancer Consortium (DKTK), Partner Site Munich; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Helen Remotti
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Maximilian Reichert
- Department of Medicine II, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Yagnesh H Tailor
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Karan Nagar
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Richard A Friedman
- Biomedical Informatics Shared Resource of the Herbert Irving Comprehensive Cancer Center and Department of Biomedical Informatics, Columbia University Medical Center, New York, New York
| | - Alina C Iuga
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Kenneth P Olive
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
- Department of Pathology and Cell Biology and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Timothy C Wang
- Division of Digestive and Liver Diseases and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York.
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13
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Leist M, Rinné S, Datunashvili M, Aissaoui A, Pape HC, Decher N, Meuth SG, Budde T. Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway. J Physiol 2017; 595:5875-5893. [PMID: 28714121 DOI: 10.1113/jp274527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K+ currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K+ channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. ABSTRACT The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K+ channel (TWIK)-related acid-sensitive K+ (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons.
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Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
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14
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Resveratrol inhibits BK-induced COX-2 transcription by suppressing acetylation of AP-1 and NF-κB in human rheumatoid arthritis synovial fibroblasts. Biochem Pharmacol 2017; 132:77-91. [DOI: 10.1016/j.bcp.2017.03.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/07/2017] [Indexed: 01/27/2023]
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15
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Unveiling the participation of avian kinin ornithokinin and its receptors in the chicken inflammatory response. Vet Immunol Immunopathol 2017; 188:34-47. [PMID: 28615126 DOI: 10.1016/j.vetimm.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/28/2017] [Accepted: 04/11/2017] [Indexed: 01/06/2023]
Abstract
Vasoactive peptides are key early mediators of inflammation released through activation of different enzymatic systems. The mammalian kinin-kallikrein (K-KLK) system produces bradykinin (BK) through proteolytic cleavage of a kininogen precursor by enzymes named kallikreins. BK acts through specific ubiquitous G-protein coupled receptors (B1R and B2R) to participate in physiological processes and inflammatory responses, such as activation of mononuclear phagocytes. In chickens, the BK-like nonapeptide ornithokinin (OK) has been shown to promote intracellular calcium increase in embryonic fibroblasts and to be vasodilatory in vivo. Also, one of its receptors (B2R) was already cloned. However, the participation of chicken K-KLK system components in the inflammatory response remains unknown and was therefore investigated. We first showed that B1R, B2R and kininogen 1 (KNG1) are expressed in unstimulated chicken tissues and macrophages. We next showed that chicken B1R and B2R are expressed at transcript and protein levels in chicken macrophages and are upregulated by E. coli LPS or avian pathogenic E. coli (APEC) infection. Interestingly, exogenous OK induced internalization and degradation of OK receptors protein, notably B2R. Also, OK induced intracellular calcium increase and potentiated zymosan-induced ROS production and Dextran-FITC endocytosis by chicken macrophages. Exogenous OK itself did not promote APEC killing and had no pro-inflammatory effect. However, when combined with LPS or APEC, OK upregulated cytokine/chemokine gene expression and NO production by chicken macrophages. This effect was not blocked by canonical non-peptide B1R or B2R receptor antagonists but was GPCR- and PI3K/Akt-dependent. In vivo, pulmonary colibacillosis led to upregulation of OK receptors expression in chicken lungs and liver. Also, colibacillosis led to significant upregulation of OK precursor KNG1 expression in liver and in cultured hepatocytes (LMH). We therefore provide hitherto unknown information on how OK and its receptors are involved in inflammation and infection in chickens.
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16
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Pillat MM, Lameu C, Trujillo CA, Glaser T, Cappellari AR, Negraes PD, Battastini AMO, Schwindt TT, Muotri AR, Ulrich H. Bradykinin promotes neuron-generating division of neural progenitor cells through ERK activation. J Cell Sci 2016; 129:3437-48. [PMID: 27528403 DOI: 10.1242/jcs.192534] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/27/2016] [Indexed: 12/26/2022] Open
Abstract
During brain development, cells proliferate, migrate and differentiate in highly accurate patterns. In this context, published results indicate that bradykinin functions in neural fate determination, favoring neurogenesis and migration. However, mechanisms underlying bradykinin function are yet to be explored. Our findings indicate a previously unidentified role for bradykinin action in inducing neuron-generating division in vitro and in vivo, given that bradykinin lengthened the G1-phase of the neural progenitor cells (NPC) cycle and increased TIS21 (also known as PC3 and BTG2) expression in hippocampus from newborn mice. This role, triggered by activation of the kinin-B2 receptor, was conditioned by ERK1/2 activation. Moreover, immunohistochemistry analysis of hippocampal dentate gyrus showed that the percentage of Ki67(+) cells markedly increased in bradykinin-treated mice, and ERK1/2 inhibition affected this neurogenic response. The progress of neurogenesis depended on sustained ERK phosphorylation and resulted in ERK1/2 translocation to the nucleus in NPCs and PC12 cells, changing expression of genes such as Hes1 and Ngn2 (also known as Neurog2). In agreement with the function of ERK in integrating signaling pathways, effects of bradykinin in stimulating neurogenesis were reversed following removal of protein kinase C (PKC)-mediated sustained phosphorylation.
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Affiliation(s)
- Micheli M Pillat
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Claudiana Lameu
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Cleber A Trujillo
- Departments of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, San Diego, CA 92093-0695, USA
| | - Talita Glaser
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Angélica R Cappellari
- Departamento de Bioquímica, Instituto de Ciências Básicas e da Saúde, UFRGS, Porto Alegre 90035 000, Brazil
| | - Priscilla D Negraes
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil Departments of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, San Diego, CA 92093-0695, USA
| | - Ana M O Battastini
- Departamento de Bioquímica, Instituto de Ciências Básicas e da Saúde, UFRGS, Porto Alegre 90035 000, Brazil
| | - Telma T Schwindt
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Alysson R Muotri
- Departments of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, San Diego, CA 92093-0695, USA
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05508-900, Brazil
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17
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Kis Z, Rodin T, Zafar A, Lai Z, Freke G, Fleck O, Del Rio Hernandez A, Towhidi L, Pedrigi RM, Homma T, Krams R. Development of a synthetic gene network to modulate gene expression by mechanical forces. Sci Rep 2016; 6:29643. [PMID: 27404994 PMCID: PMC4940741 DOI: 10.1038/srep29643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/24/2016] [Indexed: 12/14/2022] Open
Abstract
The majority of (mammalian) cells in our body are sensitive to mechanical forces, but little work has been done to develop assays to monitor mechanosensor activity. Furthermore, it is currently impossible to use mechanosensor activity to drive gene expression. To address these needs, we developed the first mammalian mechanosensitive synthetic gene network to monitor endothelial cell shear stress levels and directly modulate expression of an atheroprotective transcription factor by shear stress. The technique is highly modular, easily scalable and allows graded control of gene expression by mechanical stimuli in hard-to-transfect mammalian cells. We call this new approach mechanosyngenetics. To insert the gene network into a high proportion of cells, a hybrid transfection procedure was developed that involves electroporation, plasmids replication in mammalian cells, mammalian antibiotic selection, a second electroporation and gene network activation. This procedure takes 1 week and yielded over 60% of cells with a functional gene network. To test gene network functionality, we developed a flow setup that exposes cells to linearly increasing shear stress along the length of the flow channel floor. Activation of the gene network varied logarithmically as a function of shear stress magnitude.
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Affiliation(s)
- Zoltán Kis
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Tania Rodin
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Asma Zafar
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Government College University, GC University, Katchery Road, Lahore, 54000, Pakistan
| | - Zhangxing Lai
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
- Department of Biomedical Engineering, National University of Singapore, 4 Engineering Drive 3, 117583, Singapore
| | - Grace Freke
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, United Kingdom
| | - Oliver Fleck
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, United Kingdom
| | - Armando Del Rio Hernandez
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Leila Towhidi
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Ryan M. Pedrigi
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Takayuki Homma
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Rob Krams
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
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18
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van Unen J, Stumpf AD, Schmid B, Reinhard NR, Hordijk PL, Hoffmann C, Gadella TWJ, Goedhart J. A New Generation of FRET Sensors for Robust Measurement of Gαi1, Gαi2 and Gαi3 Activation Kinetics in Single Cells. PLoS One 2016; 11:e0146789. [PMID: 26799488 PMCID: PMC4723041 DOI: 10.1371/journal.pone.0146789] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/22/2015] [Indexed: 01/14/2023] Open
Abstract
G-protein coupled receptors (GPCRs) can activate a heterotrimeric G-protein complex with subsecond kinetics. Genetically encoded biosensors based on Förster resonance energy transfer (FRET) are ideally suited for the study of such fast signaling events in single living cells. Here we report on the construction and characterization of three FRET biosensors for the measurement of Gαi1, Gαi2 and Gαi3 activation. To enable quantitative long-term imaging of FRET biosensors with high dynamic range, fluorescent proteins with enhanced photophysical properties are required. Therefore, we use the currently brightest and most photostable CFP variant, mTurquoise2, as donor fused to Gαi subunit, and cp173Venus fused to the Gγ2 subunit as acceptor. The Gαi FRET biosensors constructs are expressed together with Gβ1 from a single plasmid, providing preferred relative expression levels with reduced variation in mammalian cells. The Gαi FRET sensors showed a robust response to activation of endogenous or over-expressed alpha-2A-adrenergic receptors, which was inhibited by pertussis toxin. Moreover, we observed activation of the Gαi FRET sensor in single cells upon stimulation of several GPCRs, including the LPA2, M3 and BK2 receptor. Furthermore, we show that the sensors are well suited to extract kinetic parameters from fast measurements in the millisecond time range. This new generation of FRET biosensors for Gαi1, Gαi2 and Gαi3 activation will be valuable for live-cell measurements that probe Gαi activation.
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Affiliation(s)
- Jakobus van Unen
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Anette D Stumpf
- Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Department of Pharmacology and Toxicology, University of Wuerzburg, Versbacher Strasse 9, 97078, Wuerzburg, Germany
| | - Benedikt Schmid
- Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Department of Pharmacology and Toxicology, University of Wuerzburg, Versbacher Strasse 9, 97078, Wuerzburg, Germany
| | - Nathalie R Reinhard
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands.,Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, NL-1066 CX, Amsterdam, the Netherlands
| | - Peter L Hordijk
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands.,Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, NL-1066 CX, Amsterdam, the Netherlands
| | - Carsten Hoffmann
- Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Department of Pharmacology and Toxicology, University of Wuerzburg, Versbacher Strasse 9, 97078, Wuerzburg, Germany
| | - Theodorus W J Gadella
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Joachim Goedhart
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
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Weise M, Vettel C, Spiger K, Gilsbach R, Hein L, Lorenz K, Wieland T, Aktories K, Orth JHC. A systemic Pasteurella multocida toxin aggravates cardiac hypertrophy and fibrosis in mice. Cell Microbiol 2015; 17:1320-31. [PMID: 25759205 DOI: 10.1111/cmi.12436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 02/20/2015] [Accepted: 03/06/2015] [Indexed: 11/30/2022]
Abstract
Pasteurella multocida toxin (PMT) persistently activates heterotrimeric G proteins of the Gαq/11 , Gα12/13 and Gαi family without interaction with G protein-coupled receptors (GPCRs). We show that PMT acts on heart tissue in vivo and on cardiomyocytes and cardiac fibroblasts in vitro by deamidation of heterotrimeric G proteins. Increased normalized ventricle weights and fibrosis were detected after intraperitoneal administration of PMT in combination with the GPCR agonist phenylephrine. In neonatal rat cardiomyocytes, PMT stimulated the mitogen-activated protein kinase pathway, which is crucial for the development of cellular hypertrophy. The toxin induced phosphorylation of the canonical phosphorylation sites of the extracellular-regulated kinase 1/2 and, additionally, caused phosphorylation of the recently recognized autophosphorylation site, which appears to be important for the development of cellular hypertrophy. Moreover, PMT stimulated the small GTPases Rac1 and RhoA. Both switch proteins are involved in cardiomyocyte hypertrophy. In addition, PMT stimulated RhoA and Rac1 in neonatal rat cardiac fibroblasts. RhoA and Rac1 have been implicated in the regulation of connective tissue growth factor (CTGF) secretion and expression. Accordingly, we show that PMT treatment increased secretion and expression of CTGF in cardiac fibroblasts. Altogether, the data indicate that PMT is an inducer of pathological remodelling of cardiac cells and identifies the toxin as a promising tool for studying heterotrimeric G protein-dependent signalling in cardiac cells.
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Affiliation(s)
- Markus Weise
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany
| | - Christiane Vettel
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Katharina Spiger
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Ralf Gilsbach
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Lutz Hein
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany.,BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg, Germany
| | - Joachim H C Orth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany
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20
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Kamato D, Thach L, Bernard R, Chan V, Zheng W, Kaur H, Brimble M, Osman N, Little PJ. Structure, Function, Pharmacology, and Therapeutic Potential of the G Protein, Gα/q,11. Front Cardiovasc Med 2015; 2:14. [PMID: 26664886 PMCID: PMC4671355 DOI: 10.3389/fcvm.2015.00014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/11/2015] [Indexed: 11/19/2022] Open
Abstract
G protein coupled receptors (GPCRs) are one of the major classes of cell surface receptors and are associated with a group of G proteins consisting of three subunits termed alpha, beta, and gamma. G proteins are classified into four families according to their α subunit; Gαi, Gαs, Gα12/13, and Gαq. There are several downstream pathways of Gαq of which the best known is upon activation via guanosine triphosphate (GTP), Gαq activates phospholipase Cβ, hydrolyzing phosphatidylinositol 4,5-biphosphate into diacylglycerol and inositol triphosphate and activating protein kinase C and increasing calcium efflux from the endoplasmic reticulum. Although G proteins, in particular, the Gαq/11 are central elements in GPCR signaling, their actual roles have not yet been thoroughly investigated. The lack of research of the role on Gαq/11 in cell biology is partially due to the obscure nature of the available pharmacological agents. YM-254890 is the most useful Gαq-selective inhibitor with antiplatelet, antithrombotic, and thrombolytic effects. YM-254890 inhibits Gαq signaling pathways by preventing the exchange of guanosine diphosphate for GTP. UBO-QIC is a structurally similar compound to YM-254890, which can inhibit platelet aggregation and cause vasorelaxation in rats. Many agents are available for the study of signaling downstream of Gαq/11. The role of G proteins could potentially represent a novel therapeutic target. This review will explore the range of pharmacological and molecular tools available for the study of the role of Gαq/11 in GPCR signaling.
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Affiliation(s)
- Danielle Kamato
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Lyna Thach
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Rebekah Bernard
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Vincent Chan
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Wenhua Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre , Guangzhou , China ; Faculty of Health Sciences, University of Macau , Macau , China
| | - Harveen Kaur
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Margaret Brimble
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Narin Osman
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Peter J Little
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
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21
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Vakalopoulos C. The effect of deficient muscarinic signaling on commonly reported biochemical effects in schizophrenia and convergence with genetic susceptibility loci in explaining symptom dimensions of psychosis. Front Pharmacol 2014; 5:277. [PMID: 25566074 PMCID: PMC4266038 DOI: 10.3389/fphar.2014.00277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/27/2014] [Indexed: 11/13/2022] Open
Abstract
With the advent of DSM 5 criticism has generally centered on a lack of biological validity of the diagnostic criteria. Part of the problem in describing a nosology of psychosis is the tacit assumption of multiple genetic causes each with an incremental loading on the clinical picture that fails to differentiate a clear underlying pathophysiology of high impact. The aim of this paper is to consolidate a primary theory of deficient muscarinic signaling underlying key clinical features of schizophrenia and its regulation by several important genetic associations including neuregulin, DISC and dysbindin. Secondary reductions in markers for GABAergic function and changes in the levels of interneuron calcium binding proteins parvalbumin and calbindin can be attributed to dysfunctional muscarinic transduction. A parallel association exists for cytokine production. The convergent pathway hypothesis is likewise used to model dopaminergic and glutamatergic theories of schizophrenia. The negative symptom dimension is correlated with dysfunction of Akt and ERK transduction, a major point of convergence. The present paradigm predicts the importance of a recent finding of a deletion in a copy number variant of PLCB1 and its potential use if replicated, as one of the first testable biological markers differentiating schizophrenia from bipolar disorder and further subtyping of schizophrenia into deficit and non-deficit. Potential limitations of PLCB1 as a prospective marker are also discussed.
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22
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Srivastava S, Sharma K, Kumar N, Roy P. Bradykinin regulates osteoblast differentiation by Akt/ERK/NFκB signaling axis. J Cell Physiol 2014; 229:2088-105. [PMID: 24825463 DOI: 10.1002/jcp.24668] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 05/09/2014] [Indexed: 12/11/2022]
Abstract
Bradykinin (BK), a well known mediator of pain and inflammation, is also known to be involved in the process of bone resorption. The present study therefore evaluated the role of BK in osteoblast lineage commitment. Our data showed that BK inhibits the migration of bone marrow mesenchymal stem cells, but does not affect their viability. Moreover, BK also inhibits osteoblastic differentiation by significantly downregulating the levels of mRNAs for osteopontin, runX2, col24, osterix, osteocalcin genes and bone mineralization (P < 0.05). Further, BK was found to elicit the BK receptors (BDKR1 and BDKR2) mediated activation of ERK1/2 and Akt pathways, which finally led to the activation of NFκB. BK also promoted the osteoclast differentiation of bone marrow derived preosteoclast cells by upregulating the expression of c-fos, NFATC1, TRAP, clcn7, cathK, and OSCAR genes and increasing TRAP activity through NFκB pathway. In conclusion, our data suggest that BK decreases the differentiation of osteoblasts with concomitant increase in osteoclast formation and thus provides new insight into the mechanism of action of BK in modulating bone resorption.
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Affiliation(s)
- Swati Srivastava
- Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
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23
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Chapman NA, Dupré DJ, Rainey JK. The apelin receptor: physiology, pathology, cell signalling, and ligand modulation of a peptide-activated class A GPCR. Biochem Cell Biol 2014; 92:431-40. [PMID: 25275559 DOI: 10.1139/bcb-2014-0072] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The apelin receptor (AR or APJ) is a class A (rhodopsin-like) G-protein-coupled receptor with wide distribution throughout the human body. Activation of the AR by its cognate peptide ligand, apelin, induces diverse physiological effects including vasoconstriction and dilation, strengthening of heart muscle contractility, angiogenesis, and regulation of energy metabolism and fluid homeostasis. Recently, another endogenous peptidic activator of the AR, Toddler/ELABELA, was identified as having a crucial role in zebrafish (Danio rerio) embryonic development. The AR is also implicated in pathologies including cardiovascular disease, diabetes, obesity, and cancer, making it a promising therapeutic target. Despite its established importance, the precise roles of AR signalling remain poorly understood. Moreover, little is known about the mechanisms of peptide-AR activation. Additional complexity arises from modulation of the AR by 2 endogenous peptide ligands, both with multiple bioactive isoforms of variable length and distribution. The various apelin and Toddler/ELABELA isoforms may also produce distinct cellular effects. Further complexity arises through formation of functionally distinct heterodimers between the AR and other G-protein-coupled receptors. This minireview outlines key (patho)physiological actions of the AR, addresses what is known about signal transduction downstream of AR activation, and concludes by discussing unique properties of the endogenous peptidic ligands of the AR.
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Affiliation(s)
- Nigel A Chapman
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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24
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Sailler S, Schmitz K, Jäger E, Ferreiros N, Wicker S, Zschiebsch K, Pickert G, Geisslinger G, Walter C, Tegeder I, Lötsch J. Regulation of circulating endocannabinoids associated with cancer and metastases in mice and humans. Oncoscience 2014; 1:272-282. [PMID: 25594019 PMCID: PMC4278301 DOI: 10.18632/oncoscience.33] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/30/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND AIMS Endocannabinoids may modify cancer development, progression and associated pain. We determined whether cancer-evoked dysregulations in this system become manifest in altered tissue and plasma endocannabinoids. METHODS Endocannabinoid changes due to cancer were explored in a local and metastatic syngeneic mouse melanoma model. Endocannabinoid stratification in human cancer was cross-sectionally assessed in the plasma of 304 patients (147 men, 157 women, aged 32 - 87 years) suffering from several types of cancer at Roman Numeral Staging between I and IVc, mostly IV (n = 220), and compared with endocannabinoids of healthy controls. RESULTS In mice with local tumor growth, ethanolamide endocannabinoids, i.e., anandamide (AEA), palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) were downregulated, whereas 2-arachidonoylglycerol (2-AG) was increased. Upon spreading of the cancer cells particularly 2-AG steadily increased in parallel to disease progression while OEA modulated cell migration. Results translated into humans, in whom cancer was associated with a decreased AEA, increased 2-AG and increased OEA correlating with the number of metastases. CONCLUSIONS The endocannabinoid system was subject to cancer-associated regulations to an extent that led to measurable changes in circulating endocannabinoid levels, emphasizing the importance of the endocannabinoid system in the pathophysiology of cancer.
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Affiliation(s)
- Sebastian Sailler
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Katja Schmitz
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Elke Jäger
- Department of Hematology and Oncology, Krankenhaus Nordwest, Frankfurt am Main, Germany
| | - Nerea Ferreiros
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Sabine Wicker
- Occupational Health Service, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Katja Zschiebsch
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Geethanjali Pickert
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Gerd Geisslinger
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Carmen Walter
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Irmgard Tegeder
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
| | - Jörn Lötsch
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt am Main, Germany
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Dobrivojević M, Špiranec K, Sinđić A. Involvement of bradykinin in brain edema development after ischemic stroke. Pflugers Arch 2014; 467:201-12. [DOI: 10.1007/s00424-014-1519-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 04/07/2014] [Accepted: 04/09/2014] [Indexed: 01/04/2023]
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26
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Signalling mechanisms involved in renal pathological changes during cisplatin-induced nephropathy. Eur J Clin Pharmacol 2013; 69:1863-74. [PMID: 23929259 DOI: 10.1007/s00228-013-1568-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/24/2013] [Indexed: 12/20/2022]
Abstract
CONTEXT Cisplatin, a coordination platinum complex, is used as a potential anti-neoplastic agent, having well recognized DNA-damaging property that triggers cell-cycle arrest and cell death in cancer therapy. Beneficial chemotherapeutic actions of cisplatin can be detrimental for kidneys. BACKGROUND Unbound cisplatin gets accumulated in renal tubular cells, leading to cell injury and death. This liable action of cisplatin on kidneys is mediated by altered intracellular signalling pathways such as mitogen-activated protein kinase (MAPK), extracellular regulated kinase (ERK), or C- Jun N terminal kinase/stress-activated protein kinase (JNK/SAPK). Further, these signalling alterations are responsible for release and activation of tumour necrosis factor (TNF-α), mitochondrial dysfunction, and apoptosis, which ultimately cause the renal pathogenic process. Cisplatin itself enhances the generation of reactive oxygen species (ROS) and activation of nuclear factor-κB (NF-κB), inflammation, and mitochondrial dysfunction, which further leads to renal apoptosis. Cisplatin-induced nephropathy is also mediated through the p53 and protein kinase-Cδ (PKCδ) signalling pathways. OBJECTIVE This review explores these signalling alterations and their possible role in the pathogenesis of cisplatin-induced renal injury.
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27
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Batista WL, Ogata FT, Curcio MF, Miguel RB, Arai RJ, Matsuo AL, Moraes MS, Stern A, Monteiro HP. S-nitrosoglutathione and endothelial nitric oxide synthase-derived nitric oxide regulate compartmentalized ras S-nitrosylation and stimulate cell proliferation. Antioxid Redox Signal 2013; 18:221-38. [PMID: 22894707 DOI: 10.1089/ars.2011.4455] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS S-nitrosylation of Cys118 is a redox-based mechanism for Ras activation mediated by nitric oxide (NO) at the plasma membrane. RESULTS Ras signaling pathway stimulation by 50 and/or 100 μM of S-nitrosoglutathione (GSNO) causes proliferation of HeLa cells. Proliferation was not observed in HeLa cells overexpressing non-nitrosatable H-Ras(C118S). HeLa cells overexpressing H-Ras(wt) containing the spatiotemporal probe green fluorescent protein (GFP) fused to the Ras-binding domain of Raf-1 (GFP-RBD) incubated with 100 μM GSNO stimulated a rapid and transient redistribution of GFP-RBD to the plasma membrane, followed by a delayed and sustained recruitment to the Golgi. No activation of H-Ras at the plasma membrane occurred in cells overexpressing H-Ras(C118S), contrasting with a robust and sustained activation of the GTPase at the Golgi. Inhibition of Src kinase prevented cell proliferation and activation of H-Ras by GSNO at the Golgi. Human umbilical vein endothelial cells (HUVECs) stimulated with bradykinin to generate NO were used to differentiate cell proliferation and Ras activation at the plasma membrane versus Golgi. In this model, Src kinase was not involved in cell proliferation, whereas Ras activation proceeded only at the plasma membrane, indicating that HUVEC proliferation induced by NO resulted only from stimulation of Ras. INNOVATION The present work is the first to demonstrate that NO-mediated activation of Ras in different subcellular compartments regulates different downstream signaling pathways. CONCLUSION S-nitrosylation of H-Ras at Cys(118) and the activation of Src kinase are spatiotemporally linked events of the S-nitrosothiol-mediated signaling pathway that occurs at the plasma membrane and at the Golgi. The nonparticipation of Src kinase and the localized production of NO by endothelial NO synthase at the plasma membrane limited NO-mediated Ras activation to the plasma membrane.
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Affiliation(s)
- Wagner L Batista
- Department of Biological Sciences, Universidade Federal de São Paulo/Campus Diadema, São Paulo, Brazil
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28
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Bernardini L, Moretti-Rojas I, Brush M, Rojas FJ, Balmaceda JP. Failure of hCG/LH receptors to stimulate the transmembrane effector adenylyl cyclase in human endometrium. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/abb.2013.410126] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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29
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Lowry JL, Brovkovych V, Zhang Y, Skidgel RA. Endothelial nitric-oxide synthase activation generates an inducible nitric-oxide synthase-like output of nitric oxide in inflamed endothelium. J Biol Chem 2012; 288:4174-93. [PMID: 23255592 DOI: 10.1074/jbc.m112.436022] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
High levels of NO generated in the vasculature under inflammatory conditions are usually attributed to inducible nitric-oxide synthase (iNOS), but the role of the constitutively expressed endothelial NOS (eNOS) is unclear. In normal human lung microvascular endothelial cells (HLMVEC), bradykinin (BK) activates kinin B2 receptor (B2R) signaling that results in Ca(2+)-dependent activation of eNOS and transient NO. In inflamed HLMVEC (pretreated with interleukin-1β and interferon-γ), we found enhanced binding of eNOS to calcium-calmodulin at basal Ca(2+) levels, thereby increasing its basal activity that was dependent on extracellular l-Arg. Furthermore, B2R stimulation generated prolonged high output eNOS-derived NO that is independent of increased intracellular Ca(2+) and is mediated by a novel Gα(i)-, MEK1/2-, and JNK1/2-dependent pathway. This high output NO stimulated with BK was blocked with a B2R antagonist, eNOS siRNA, or eNOS inhibitor but not iNOS inhibitor. Moreover, B2R-mediated NO production and JNK phosphorylation were inhibited with MEK1/2 and JNK inhibitors or MEK1/2 and JNK1/2 siRNA but not with ERK1/2 inhibitor. BK induced Ca(2+)-dependent eNOS phosphorylation at Ser(1177), Thr(495), and Ser(114) in cytokine-treated HLMVEC, but these modifications were not dependent on JNK1/2 activation and were not responsible for prolonged NO output. Cytokine treatment did not alter the expression of B2R, Gα(q/11), Gα(i1,2), JNK, or eNOS. B2R activation in control endothelial cells enhanced migration, but in cytokine-treated HLMVEC it reduced migration. Both responses were NO-dependent. Understanding how JNK regulates prolonged eNOS-derived NO may provide new therapeutic targets for the treatment of disorders involving vascular inflammation.
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Affiliation(s)
- Jessica L Lowry
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, Illinois 60612, USA
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30
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Leschner J, Wennerberg G, Feierler J, Bermudez M, Welte B, Kalatskaya I, Wolber G, Faussner A. Interruption of the Ionic Lock in the Bradykinin B2 Receptor Results in Constitutive Internalization and Turns Several Antagonists into Strong Agonists. J Pharmacol Exp Ther 2012; 344:85-95. [DOI: 10.1124/jpet.112.199190] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Soliman MM, Ahmed MM, Salah-Eldin AE, Abdel-Aal AAA. Butyrate regulates leptin expression through different signaling pathways in adipocytes. J Vet Sci 2012; 12:319-23. [PMID: 22122897 PMCID: PMC3232390 DOI: 10.4142/jvs.2011.12.4.319] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leptin is an adipocytokine that regulates body weight, and maintains energy homeostasis by promoting reduced food intake and increasing energy expenditure. Leptin expression and secretion is regulated by various factors including hormones and fatty acids. Butyrate is a short-chain fatty acid that acts as source of energy in humans. We determined whether this fatty acid can play a role in leptin expression in fully differentiated human adipocytes. Mature differentiated adipocytes were incubated with or without increasing concentrations of butyrate. RNA was extracted and leptin mRNA expression was examined by Northern blot analysis. Moreover, the cells were incubated with regulators that may affect signals which may alter leptin expression and analyzed with Northern blotting. Butyrate stimulated leptin expression, and stimulated mitogen activated protein kinase (MAPK) and phospho-CREB signaling in a time-dependent manner. Prior treatment of the cells with signal transduction inhibitors as pertusis toxin, G(i) protein antagonist, PD98059 (a MAPK inhibitor), and wortmannin (a PI3K inhibitor) abolished leptin mRNA expression. These results suggest that butyrate can regulate leptin expression in humans at the transcriptional level. This is accomplished by: 1) G(i) protein-coupled receptors specific for short-chain fatty acids, and 2) MAPK and phosphatidylinositol-3-kinase (PI3K) signaling pathways.
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Affiliation(s)
- Mohamed Mohamed Soliman
- Department of Biochemistry, Faculty of Veterinary Medicine, Benha Universities, P.O 13736, Egypt.
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A novel player in cellular hypertrophy: Giβγ/PI3K-dependent activation of the RacGEF TIAM-1 is required for α₁-adrenoceptor induced hypertrophy in neonatal rat cardiomyocytes. J Mol Cell Cardiol 2012; 53:165-75. [PMID: 22564263 DOI: 10.1016/j.yjmcc.2012.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 04/25/2012] [Accepted: 04/26/2012] [Indexed: 01/08/2023]
Abstract
Activation of α(1)-adrenoceptors (α(1)-AR) by high catecholamine levels, e.g. in heart failure, is thought to be a driving force of cardiac hypertrophy. In this context several downstream mediators and cascades have been identified to potentially play a role in cardiomyocyte hypertrophy. One of these proteins is the monomeric G protein Rac1. However, until now it is unclear how this essential G protein is activated by α(1)-AR agonists and what are the downstream targets inducing cellular growth. By using protein-based as well as pharmacological inhibitors and the shRNA technique, we demonstrate that in neonatal rat cardiomyocytes (NRCM) Rac1 is activated via a cascade involving the α(1A)-AR subtype, G(i)βγ, the phosphoinositide-3'-kinase and the guanine nucleotide exchange factor Tiam1. We further demonstrate that this signaling induces an increase in protein synthesis, cell size and atrial natriuretic peptide expression. We identified the p21-activated kinase 2 (PAK2) as a downstream effector of Rac1 and were able to link this cascade to the activation of the pro-hypertrophic kinases ERK1/2 and p90RSK. Our data thus reveal a prominent role of the α(1A)-AR/G(i)βγ/Tiam1-mediated activation of Rac1 and its effector PAK2 in the induction of hypertrophy in NRCM.
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33
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Cheng CY, Tseng HC, Yang CM. Bradykinin-mediated cell proliferation depends on transactivation of EGF receptor in corneal fibroblasts. J Cell Physiol 2012; 227:1367-81. [PMID: 21604274 DOI: 10.1002/jcp.22849] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In previous studies, bradykinin (BK) has been shown to induce cell proliferation through BK B2 receptor (B2R) via p42/p44 MAPK in Statens Seruminstitut Rabbit Corneal Cells (SIRCs). In addition to this pathway, EGFR transactivation pathway has been implicated in linking a variety of G-protein coupled receptors to MAPK cascades. Here, we further investigate whether these transactivation mechanisms participating in BK-induced cell proliferation in SIRCs. Using an immunofluorescence staining and RT-PCR, we initially characterize that SIRCs were corneal fibroblasts and predominantly expressed B2R by BK. Inhibition of p42/p44 MAPK by the inhibitors of Src, EGFR, and Akt or transfection with respective siRNAs prevents BK-induced DNA synthesis in SIRCs. The mechanisms underlying these responses were mediated through phosphorylation of Src and EGFR via the formation of Src/EGFR complex which was attenuated by PP1 and AG1478. Moreover, BK-induced p42/p44 MAPK and Akt activation was mediated through EGFR transactivation, which was diminished by the inhibitors of MMP-2/9 and heparin-binding EGF-like factor (HB-EGF). Finally, increased nuclear translocation of Akt and p42/p44 MAPK turns on early gene expression leading to cell proliferation. These results suggest that BK-induced cell proliferation is mediated through c-Src-dependent transactivation of EGFR via MMP2/9-dependent pro-HB-EGF shedding linking to activation of Akt and p42/p44 MAPK in corneal fibroblasts.
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Affiliation(s)
- Ching-Yi Cheng
- Department of Biomedical Engineering, Chung Yuan Christian University, Tao-Yuan, Taiwan
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Leschner J, Ring L, Feierler J, Dinkel K, Jochum M, Faussner A. Fever-like temperature modification differentially affects in vitro signaling of bradykinin B(1) and B(2) receptors. Biol Chem 2011; 392:1021-9. [PMID: 21871009 DOI: 10.1515/bc.2011.095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The bradykinin (BK) B(2) and B(1) receptors (B(2)R, B(1)R) belong to the rhodopsin-like G protein-coupled receptors (GPCRs) and are involved in (patho)physiological processes such as blood pressure regulation or inflammation. They mediate the effects of the pro-inflammatory peptides bradykinin/kallidin and desArg(9)-BK/desArg(10)-kallidin, respectively. Whereas the B(2)R is constitutively expressed and gets internalized upon activation, the B(1)R is especially induced by inflammatory mediators and responds to stimulation with increased surface receptor numbers. Stimulation of both receptors activates phospholipase Cβ (PLCβ) and mitogen activated protein kinase (MAPK) signaling. Because inflammatory processes are characterized by heat (fever), we analyzed the effect of increased temperature (41°C vs. 37°C) on B(1)R and B(2)R signaling in HEK 293 and IMR 90 cells. Our results show that signaling of both receptors is temperature-sensitive, however to a different extent and with regard to the investigated pathways. Comparing PLCβ activity and Ca(2+)-regulated signals, a temperature-dependent increase was only observed for B(1)R but not for B(2)R activation, whereas MAPK activities were doubled at 41°C for both receptors. Taken together, our findings suggest that the observed temperature sensitivity of B(1)R-induced PLCβ activation is B(1)R-specific. In contrast, the enhanced stimulation of MAPK activity under hyperthermic conditions appears to be a common phenomenon for GPCRs.
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Affiliation(s)
- Jasmin Leschner
- Abteilung für Klinische Chemie und Klinische Biochemie, Ludwig-Maximilians-Universität, Nussbaumstrasse 20, D-80336 München, Germany
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Altered expression and function of regulator of G-protein signaling-17 (RGS17) in hepatocellular carcinoma. Cell Signal 2011; 23:1603-10. [PMID: 21620966 DOI: 10.1016/j.cellsig.2011.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 05/10/2011] [Accepted: 05/12/2011] [Indexed: 11/22/2022]
Abstract
Guanine nucleotide regulatory proteins (G-proteins) are central to normal hepatocyte function and are implicated in hepatic disease initiation and progression. Regulators of G-protein signaling (RGS) are critical to defining G-protein-dependent signal fidelity, yet the role of RGS proteins in the liver is poorly defined. The aims of this study were to determine RGS17 expression in normal and transformed hepatic tissue and cells, and address the function of RGS17 in hepatic tumorgenicity. RGS17 expression was determined in human and rat HCC tissue and cell lines. Molecular approaches were used to alter RGS17 expression in HCC cells, effects on cell function measured, and RGS17 association with specific Gα-subunits determined. Using these approaches RGS17 mRNA, but not protein, was detectable in human and rat HCC tissue and cells. Conversely, RGS17 mRNA was not detected in normal tissue, isolated hepatocytes, or non-tumorigenic hepatic cells. Subsequent studies using transfected cells demonstrated that RGS17 proteins were not post-translationally modified in HCC cells, and RGS17 expression is governed by protein degradation and not via miRNAs. Notwithstanding inherently low RGS17 protein levels, altering RGS17 expression profoundly affected HCC cell mitogenesis and migration. Analysis of RGS17-G-protein interaction demonstrated RGS17 associates with both Giα- and Gqα-subunits in HCC cells of human and rat origin. In conclusion, these data demonstrate that, despite difficulties in measuring endogenous RGS protein expression, RGS17 is differentially expressed in HCC and plays a central role in regulating transformed hepatocyte tumorgenicity.
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Liebmann C. EGF receptor activation by GPCRs: an universal pathway reveals different versions. Mol Cell Endocrinol 2011; 331:222-31. [PMID: 20398727 DOI: 10.1016/j.mce.2010.04.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 04/01/2010] [Indexed: 11/20/2022]
Abstract
About one decade ago has been demonstrated that G protein-coupled receptors (GPCRs) are able to utilize the epidermal growth factor (EGF) receptor (EGFR) as signalling intermediate. Thereby GPCRs are enabled to regulate cell growth, differentiation, and migration. A molecular mechanism for this process has been proposed that involves the activation of a distinct set of metalloproteases and the subsequent generation and release of particular members of the EGF peptide family which in turn activate the EGFR in an autocrine/paracrine manner. This model that allows GPCRs direct access to the signalling network of the EGFR family has emerged as a valid concept in a variety of cell types including cancer cells. The present review briefly summarizes the current knowledge but will be focussed on the ligand-dependency of EGFR transactivation. Several alternative mechanisms and novel aspects will be introduced. Using the example of head and neck squamous carcinoma, the potency of EGFR transactivation as a therapeutical target will be discussed.
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Affiliation(s)
- Claus Liebmann
- Center of Molecular Biomedicine (CMB), Institute of Biochemistry and Biophysics, Friedrich-Schiller-University Jena, Hans-Knöll-Str. 2, D-07745 Jena, Germany.
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Zimmerman B, Simaan M, Akoume MY, Houri N, Chevallier S, Séguéla P, Laporte SA. Role of ßarrestins in bradykinin B2 receptor-mediated signalling. Cell Signal 2010; 23:648-59. [PMID: 21145390 DOI: 10.1016/j.cellsig.2010.11.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/22/2010] [Accepted: 11/25/2010] [Indexed: 10/18/2022]
Abstract
G protein-coupled receptors (GPCRs) can engage multiple pathways to activate ERK1/2 via both G proteins and/or ßarrestin. Receptor recruitment of ßarrestin is also important for GPCR desensitization, internalization and resensitization. Modulation of the receptor/ßarrestin interaction through modification of either component would presumably alter the output generated by receptor activation. Here we examined how ßarrestins regulate bradykinin (BK) B2 receptor (B2R) signalling and desensitization by either truncating ßarrestin1 or ßarrestin2 or by alanine substitution of a serine/threonine cluster in the C-terminal tail of B2R (B2R-4A), conditions which all affect the avidity of the B2R/ßarrestin complex. We first demonstrate that BK-mediated ERK1/2 activation is biphasic containing an early peak (between 2-5min) followed by sustained activation for at least 60min. The early but not the sustained phase was predictably affected by inhibition of either Gαq/11 or Gαi/o, whereas loss of ßarrestin2 but not ßarrestin1 resulted in diminished prolonged ERK1/2 activation. ßarrestin2's role was further examined using a truncation mutant with augmented avidity for the agonist-occupied receptor, revealing an increase in both immediate and extended ERK1/2 signalling. We also show that ERK1/2 is recruited to the B2R/ßarrestin complex on endosomes as well as the plasma membrane. Moreover, we investigated ßarrestin's role using the B2R-4A, which is deficient in ßarrestin binding and does not internalize. We show that ERK1/2 signalling downstream of the receptor is entirely G protein-dependent and receptor-mediated intracellular calcium mobilization studies revealed a lack of desensitization. Functionally, the lack of desensitization resulted in increased cell growth and migration compared to the wild-type receptor, which was sensitive to MEK inhibition. These results highlight ßarrestin's crucial role in the maintenance of proper B2R signalling.
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Affiliation(s)
- Brandon Zimmerman
- McGill University Health Center Research Institute, Department of Medicine, Royal Victoria Hospital, 687 Pine Avenue West, Montreal, Quebec, Canada
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Szereszewski JM, Pampillo M, Ahow MR, Offermanns S, Bhattacharya M, Babwah AV. GPR54 regulates ERK1/2 activity and hypothalamic gene expression in a Gα(q/11) and β-arrestin-dependent manner. PLoS One 2010; 5:e12964. [PMID: 20886089 PMCID: PMC2944883 DOI: 10.1371/journal.pone.0012964] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 09/03/2010] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptor 54 (GPR54) is a Gq/11-coupled 7 transmembrane-spanning receptor (7TMR). Activation of GPR54 by kisspeptin (Kp) stimulates PIP2 hydrolysis, Ca2+ mobilization and ERK1/2 MAPK phosphorylation. Kp and GPR54 are established regulators of the hypothalamic-pituitary-gonadal (HPG) axis and loss-of-function mutations in GPR54 are associated with an absence of puberty and hypogonadotropic hypogonadism, thus defining an important role of the Kp/GPR54 signaling system in reproductive function. Given the tremendous physiological and clinical importance of the Kp/GPR54 signaling system, we explored the contributions of the GPR54-coupled Gq/11 and β-arrestin pathways on the activation of a major downstream signaling molecule, ERK, using Gq/11 and β-arrestin knockout mouse embryonic fibroblasts. Our study revealed that GPR54 employs the Gq/11 and β-arrestin-2 pathways in a co-dependent and temporally overlapping manner to positively regulate ERK activity and pERK nuclear localization. We also show that while β-arrestin-2 potentiates GPR54 signaling to ERK, β-arrestin-1 inhibits it. Our data also revealed that diminished β-arrestin-1 and -2 expression in the GT1-7 GnRH hypothalamic neuronal cell line triggered distinct patterns of gene expression following Kp-10 treatment. Thus, β-arrestin-1 and -2 also regulate distinct downstream responses in gene expression. Finally, we showed that GPR54, when uncoupled from the Gq/11 pathway, as is the case for several naturally occurring GPR54 mutants associated with hypogonadotropic hypogonadism, continues to regulate gene expression in a G protein-independent manner. These new and exciting findings add significantly to our mechanistic understanding of how this important receptor signals intracellularly in response to kisspeptin stimulation.
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Affiliation(s)
- Jacob M. Szereszewski
- The Children's Health Research Institute, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Macarena Pampillo
- The Children's Health Research Institute, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Ontario, Canada
| | - Maryse R. Ahow
- The Children's Health Research Institute, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Stefan Offermanns
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Moshmi Bhattacharya
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Andy V. Babwah
- The Children's Health Research Institute, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
- * E-mail:
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Bell RM, Yellon DM. There is More to Life than Revascularization: Therapeutic Targeting of Myocardial Ischemia/Reperfusion Injury. Cardiovasc Ther 2010; 29:e67-79. [DOI: 10.1111/j.1755-5922.2010.00190.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Kuhr F, Lowry J, Zhang Y, Brovkovych V, Skidgel RA. Differential regulation of inducible and endothelial nitric oxide synthase by kinin B1 and B2 receptors. Neuropeptides 2010; 44:145-54. [PMID: 20045558 PMCID: PMC2830320 DOI: 10.1016/j.npep.2009.12.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 12/01/2009] [Accepted: 12/04/2009] [Indexed: 02/07/2023]
Abstract
Kinins are vasoactive peptides that play important roles in cardiovascular homeostasis, pain and inflammation. After release from their precursor kininogens, kinins or their C-terminal des-Arg metabolites activate two distinct G protein-coupled receptors (GPCR), called B2 (B2R) or B1 (B1R). The B2R is expressed constitutively with a wide tissue distribution. In contrast, the B1R is not expressed under normal conditions but is upregulated by tissue insult or inflammatory mediators. The B2R is considered to mediate many of the acute effects of kinins while the B1R is more responsible for chronic responses in inflammation. Both receptors can couple to Galphai and Galphaq families of G proteins to release mediators such as nitric oxide (NO), arachidonic acid, prostaglandins, leukotrienes and endothelium-derived hyperpolarizing factor and can induce the release of other inflammatory agents. The focus of this review is on the different transduction events that take place upon B2R and B1R activation in human endothelial cells that leads to generation of NO via activation of different NOS isoforms. Importantly, B2R-mediated eNOS activation leads to a transient ( approximately 5min) output of NO in control endothelial cells whereas in cytokine-treated endothelial cells, B1R activation leads to very high and prolonged ( approximately 90min) NO production that is mediated by a novel signal transduction pathway leading to post-translational activation of iNOS.
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Affiliation(s)
- F Kuhr
- Department of Pharmacology, University of Illinois at Chicago, College of Medicine, 835 South Wolcott, (M/C 868), Chicago, IL 60612, United States
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Resende RR, Adhikari A. Cholinergic receptor pathways involved in apoptosis, cell proliferation and neuronal differentiation. Cell Commun Signal 2009; 7:20. [PMID: 19712465 PMCID: PMC2744676 DOI: 10.1186/1478-811x-7-20] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 08/27/2009] [Indexed: 11/14/2022] Open
Abstract
Acetylcholine (ACh) has been shown to modulate neuronal differentiation during early development. Both muscarinic and nicotinic acetylcholine receptors (AChRs) regulate a wide variety of physiological responses, including apoptosis, cellular proliferation and neuronal differentiation. However, the intracellular mechanisms underlying these effects of AChR signaling are not fully understood. It is known that activation of AChRs increase cellular proliferation and neurogenesis and that regulation of intracellular calcium through AChRs may underlie the many functions of ACh. Intriguingly, activation of diverse signaling molecules such as Ras-mitogen-activated protein kinase, phosphatidylinositol 3-kinase-Akt, protein kinase C and c-Src is modulated by AChRs. Here we discuss the roles of ACh in neuronal differentiation, cell proliferation and apoptosis. We also discuss the pathways involved in these processes, as well as the effects of novel endogenous AChRs agonists and strategies to enhance neuronal-differentiation of stem and neural progenitor cells. Further understanding of the intracellular mechanisms underlying AChR signaling may provide insights for novel therapeutic strategies, as abnormal AChR activity is present in many diseases.
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Affiliation(s)
- Rodrigo R Resende
- Department of Physics, Institute of Exact Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
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Chee MJS, Mörl K, Lindner D, Merten N, Zamponi GW, Light PE, Beck-Sickinger AG, Colmers WF. The third intracellular loop stabilizes the inactive state of the neuropeptide Y1 receptor. J Biol Chem 2008; 283:33337-46. [PMID: 18812316 PMCID: PMC2662261 DOI: 10.1074/jbc.m804671200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 09/15/2008] [Indexed: 11/06/2022] Open
Abstract
Constitutively active G-protein-coupled receptors (GPCRs) can signal even in the absence of ligand binding. Most Class I GPCRs are stabilized in the resting conformation by intramolecular interactions involving transmembrane domain (TM) 3 and TM6, particularly at loci 6.30 and 6.34 of TM6. Signaling by Gi/Go-coupled receptors such as the Neuropeptide Y1 receptor decreases already low basal metabolite levels. Thus, we examined constitutive activity using a biochemical assay mediated by a Gi/Gq chimeric protein and a more direct electrophysiological assay. Wild-type (WT-Y1) receptors express no measurable, agonist-independent activation, while mu-opioid receptors (MOR) and P2Y12 purinoceptors showed clear evidence of constitutive activation, especially in the electrophysiological assay. Neither point mutations at TM6 (T6.30A or N6.34A) nor substitution of the entire TM3 and TM6 regions from the MOR into the Y1 receptor increased basal WT-Y1 activation. By contrast, chimeric substitution of the third intracellular loop (ICL3) generated a constitutively active, Y1-ICL3-MOR chimera. Furthermore, the loss of stabilizing interactions from the native ICL3 enhanced the role of surrounding residues to permit basal receptor activation; because constitutive activity of the Y1-ICL3-MOR chimera was further increased by point mutation at locus 6.34, which did not alter WT-Y1 receptor activity. Our results indicate that the ICL3 stabilizes the Y1 receptor in the inactive state and confers structural properties critical for regulating Y receptor activation and signal transduction. These studies reveal the active participation of the ICL3 in the stabilization and activation of Class I GPCRs.
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MESH Headings
- Animals
- COS Cells
- Chlorocebus aethiops
- GTP-Binding Protein alpha Subunits, Gi-Go/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Humans
- Point Mutation
- Protein Structure, Secondary/physiology
- Protein Structure, Tertiary/physiology
- Receptors, Neuropeptide Y/genetics
- Receptors, Neuropeptide Y/metabolism
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Receptors, Purinergic P2/genetics
- Receptors, Purinergic P2/metabolism
- Receptors, Purinergic P2Y12
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Signal Transduction/physiology
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Affiliation(s)
- Melissa J S Chee
- Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Hsieh HL, Wu CY, Yang CM. Bradykinin induces matrix metalloproteinase-9 expression and cell migration through a PKC-delta-dependent ERK/Elk-1 pathway in astrocytes. Glia 2008; 56:619-32. [PMID: 18240315 DOI: 10.1002/glia.20637] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Many reports have shown that matrix metalloproteinase (MMP)-9 plays an important role in brain inflammation and diseases. In our previous study, bradykinin (BK) has been shown to induce proMMP-9 expression via MAPKs and NF-kappaB in rat brain astrocytes (RBA-1). However, the molecular mechanisms and physiological roles underlying BK-induced MMP-9 expression in RBA-1 remain unclear. Here we reported that BK induced proMMP-9 expression and promoted RBA-1 cell migration, via a B(2) BK receptor-activated protein kinase C-delta (PKC-delta)-dependent signaling pathway. Activation of PKC-delta led to phosphorylation and translocation of extracellular signal-regulated kinase 1/2 (ERK1/2) and then activated a transcription factor Elk-1. Phospho-Elk-1 bound to MMP-9 promoter and thereby induced transcription of MMP-9. The rat MMP-9 promoter containing an Elk-1 cis-binding site (Ets domain), that located at nucleotides -511 to -506 was identified as a crucial domain linking to BK action. Moreover, BK induced recruitment of p300 (as a transcriptional co-activator) to the MMP-9 promoter, leading to the acetylation of histone H4 in chromatin and facilitating MMP-9 gene transcription. Taken together, these results suggested that in RBA-1 cells, activation of ERK1/2 by a PKC-delta-dependent event mediated through Elk-1 pathway is essential for MMP-9 gene up-regulation and cell migration induced by BK.
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Affiliation(s)
- Hsi-Lung Hsieh
- Department of Pharmacology, Chang Gung University, Tao-Yuan, Taiwan
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Soliman M, Kimura K, Ahmed M, Yamaji D, Matsushita Y, Okamatsu-Ogura Y, Makondo K, Saito M. Inverse regulation of leptin mRNA expression by short- and long-chain fatty acids in cultured bovine adipocytes. Domest Anim Endocrinol 2007; 33:400-9. [PMID: 17011156 DOI: 10.1016/j.domaniend.2006.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 08/02/2006] [Accepted: 08/09/2006] [Indexed: 11/22/2022]
Abstract
Leptin is an adipose tissue-derived cytokine plays key roles in the regulation of food intake and energy expenditure. However, regulatory mechanisms of leptin gene expression are not fully elucidated in ruminants that utilize short-chain fatty acids (SCFA), known as volatile fatty acids, as principal energy sources. In this study, we determined effects of SCFA and long-chain fatty acids (LCFA) on leptin expression in bovine adipocytes. Bovine stromal vascular cells isolated from subcutaneous adipose tissue of Holstein cows were cultured to confluence and treated sequentially with dexamethasone and isobutylmethylxanthine for 2 days and insulin and troglitazone for 12 days to achieve full differentiation to adipocytes. The cells started to accumulate lipids 4 days after the onset of treatment, with increased mRNA expression of leptin, as well as aP2, adiponectin, and PPAR-gamma. Removal of fetal calf serum and reduction of glucose in the culture medium of differentiated adipocytes decreased leptin mRNA expression. Subsequent addition of acetate, butyrate, or propionate dose-dependently restored and rather increased leptin expression, while addition of LCFA suppressed it. The stimulatory effect of acetate was abolished by prior treatment of the cells with pertussis toxin and by addition of LCFA. Furthermore, cows fasted for 48h and fed thereafter, elaborate reduced and increased plasma leptin levels, respectively. Thus, these results suggest that plasma leptin levels in cows are inversely controlled at the transcription level by VFA and LCFA, and that the effects of SCFA possibly act through a G protein-coupled receptor for SCFA.
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Affiliation(s)
- Mohamed Soliman
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
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Abstract
G proteins provide signal-coupling mechanisms to heptahelical cell surface receptors and are critically involved in the regulation of different mitogen-activated protein kinase (MAPK) networks. The four classes of G proteins, defined by the G(s), G(i), G(q) and G(12) families, regulate ERK1/2, JNK, p38MAPK, ERK5 and ERK6 modules by different mechanisms. The alpha- as well as betagamma-subunits are involved in the regulation of these MAPK modules in a context-specific manner. While the alpha- and betagamma-subunits primarily regulate the MAPK pathways via their respective effector-mediated signaling pathways, recent studies have unraveled several novel signaling intermediates including receptor tyrosine kinases and small GTPases through which these G-protein subunits positively as well as negatively regulate specific MAPK modules. Multiple mechanisms together with specific scaffold proteins that can link G-protein-coupled receptors or G proteins to distinct MAPK modules contribute to the context-specific and spatio-temporal regulation of mitogen-activated protein signaling networks by G proteins.
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Affiliation(s)
- Z G Goldsmith
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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46
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Philip F, Sengupta P, Scarlata S. Signaling through a G Protein-coupled receptor and its corresponding G protein follows a stoichiometrically limited model. J Biol Chem 2007; 282:19203-16. [PMID: 17420253 DOI: 10.1074/jbc.m701558200] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The bradykinin receptor is a G protein-coupled receptor (GPCR) that is coupled to the Galpha(q) family of heterotrimeric G proteins. In general, a GPCR can exert intracellular signals either by transiently associating with multiple diffusing G protein subunits or by activating a G protein that is stably bound to the receptor, thus generating a signal that is limited by the stoichiometry of the complex. Here we have distinguished between these models by monitoring the association of type 2 bradykinin receptor (B(2)R) and the Galpha(q)/Gbetagamma heterotrimer in living human embryonic kidney 293 cells expressing fluorescent-tagged proteins. Stable B(2)R-Galpha(q) x Gbetagamma complexes are observed in resting cells by fluorescence resonance energy transfer from either Galpha(q)-eCFP or eCFP-Gbetagamma to B(2)R-eYFP. Stimulating the cells with bradykinin causes detachment of B(2)R from the G protein subunits as the receptor internalizes into early endosomes, with a corresponding elimination of B(2)R-G protein fluorescence resonance energy transfer because Galpha(q) and its associated Gbetagamma remain on the plasma membrane. Single point and scanning fluorescence correlation spectroscopy measurements show that a portion of B(2)R molecules diffuses with a mobility corresponding to dimers or small oligomers, whereas a second fraction diffuses in higher order molecular assemblies. Our studies support a model in which receptors are pre-coupled with their corresponding G proteins in the basal state of cells thereby limiting the response to an external signal to a defined stoichiometry that allows for a rapid and directed cellular response.
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Affiliation(s)
- Finly Philip
- Department of Physiology and Biophysics, Stony Brook University Medical Center, Stony Brook, New York 11794-8661, USA
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Pissios P, Bradley RL, Maratos-Flier E. Expanding the scales: The multiple roles of MCH in regulating energy balance and other biological functions. Endocr Rev 2006; 27:606-20. [PMID: 16788162 DOI: 10.1210/er.2006-0021] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Melanin-concentrating hormone (MCH) is a cyclic peptide originally identified as a 17-amino-acid circulating hormone in teleost fish, where it is secreted by the pituitary in response to stress and environmental stimuli. In fish, MCH lightens skin color by stimulating aggregation of melanosomes, pigment-containing granules in melanophores, cells of neuroectodermal origin found in fish scales. Although the peptide structure between fish and mammals is highly conserved, in mammals, MCH has no demonstrable effects on pigmentation; instead, based on a series of pharmacological and genetic experiments, MCH has emerged as a critical hypothalamic regulator of energy homeostasis, having effects on both feeding behavior and energy expenditure.
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Affiliation(s)
- Pavlos Pissios
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
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Ravasi S, Citro S, Viviani B, Capra V, Rovati GE. CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation. Respir Res 2006; 7:42. [PMID: 16553950 PMCID: PMC1488842 DOI: 10.1186/1465-9921-7-42] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Accepted: 03/22/2006] [Indexed: 01/02/2023] Open
Abstract
Background Cysteine-containing leukotrienes (cysteinyl-LTs) are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC) proliferation. We used human ASMC (HASMC) to identify the signal transduction pathway(s) of the leukotriene D4 (LTD4)-induced DNA synthesis. Methods Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R) and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS) was estimated by measuring dichlorodihydrofluorescein (DCF) oxidation. Results We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX) and phosphoinositide 3-kinase (PI3K) inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC) abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Conclusion Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF-R through the intervention of PI3K and ROS. While PI3K and ROS involvement is an early event, the activation of Src occurs downstream of EGF-R activation and is followed by the classical Ras-ERK1/2 signaling pathway to control G1 progression and cell proliferation.
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Affiliation(s)
- Saula Ravasi
- Laboratory of Molecular Pharmacology, Section of Eicosanoid Pharmacology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
| | - Simona Citro
- Laboratory of Molecular Pharmacology, Section of Eicosanoid Pharmacology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
| | - Barbara Viviani
- Laboratory of Toxicology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
| | - Valérie Capra
- Laboratory of Molecular Pharmacology, Section of Eicosanoid Pharmacology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
| | - G Enrico Rovati
- Laboratory of Molecular Pharmacology, Section of Eicosanoid Pharmacology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
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Scharfstein J. Parasite cysteine proteinase interactions with α2-macroglobulin or kininogens: differential pathways modulating inflammation and innate immunity in infection by pathogenic trypanosomatids. Immunobiology 2006; 211:117-25. [PMID: 16446176 DOI: 10.1016/j.imbio.2005.10.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Accepted: 10/05/2005] [Indexed: 11/29/2022]
Abstract
Plasma extravasation is a common endothelium response to tissue injury provoked by pathogens. Herein I will review studies showing that host proteinase inhibitors (e.g., alpha2-macroglobulin (alpha2M) or kininogens) interact with protozoan cysteine proteinases (CPs) in extravascular infection sites, linking inflammation to innate immunity by different mechanisms. Using human monocytes as antigen presenting cells, we first demonstrated that alpha2M entrapment of cruzipain, a Trypanosoma cruzi CP, reduced the activation threshold of cruzipain-specific CD4 T cells due to facilitated uptake of alpha2M-cruzipain complexes by the multiscavenger receptor (CD91). More recently, studies of the mechanisms underlying inflammation elicited by T. cruzi revealed that kininogens, once bound to glycosaminoglycans, are not able to efficiently inactivate cruzipain via their inhibitory cystatin-like domains. Instead, we found that cruzipain readily processes surface-bound kininogens, liberating bioactive kinins. Acting as paracrine hormones, kinins vigorously activate host cells through bradykinin (BK) receptors, thus stimulating endocytic uptake of the pathogen. Rather than unilaterally enhancing parasite infectivity, the liberated kinins activate innate immunity by potently stimulating dendritic cell maturation via the BK B2 receptor. The discovery of chagasin, a novel family of endogenous inhibitors expressed by trypanosomatids, is likely another regulatory player involved in the dynamics of the inflammatory response.
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Affiliation(s)
- Julio Scharfstein
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, C.C.S., Ilha do Fundão, Rio de Janeiro 21949-900, RJ, Brazil.
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Hanke S, Valkova C, Stirnweiss J, Drube S, Liebmann C. Activated EGF receptor may balance ERK-inhibitory network signalling pathways. Cell Signal 2005; 18:1031-40. [PMID: 16226010 DOI: 10.1016/j.cellsig.2005.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 07/20/2005] [Accepted: 08/31/2005] [Indexed: 11/25/2022]
Abstract
In the COS-7 cell signalling network high levels of cAMP produced, for example, by co-stimulation of beta2-adrenergic receptor (beta2-AR) and bradykinin B2 receptor (BKR) may affect epidermal growth factor receptor (EGFR)-mediated activation of extracellular signal-stimulated kinase (ERK). In contrast, co-stimulation of either beta2-AR or B2R with EGFR leads to synergistic activation of ERK. Due to triple stimulation of these receptors the synergistic effects on ERK activation as well as cAMP accumulation are diminished. Here we demonstrate that EGF is capable of inducing Src-mediated phosphorylation of the tyrosine residues 177 and 347 of BKR. Their replacement by phenylalanine led to BKR mutants which are unable to activate the cAMP pathway. Using these mutants we can show that EGF attenuates but does not completely inhibit the BKR/cAMP pathway which is counteracting the EGFR signalling to ERK. Our findings suggest that the EGFR may control the cellular network rather by balancing mechanisms then by switch on/off reactions.
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Affiliation(s)
- Sabine Hanke
- Institute of Biochemistry and Biophysics, Biological and Pharmaceutical Faculty, Friedrich-Schiller-University, Philosophenweg 12, D-07743 Jena, Germany
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