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Dashti P, Thaler R, Hawse JR, Galvan ML, van der Eerden BJ, van Wijnen AJ, Dudakovic A. G-protein coupled receptor 5C (GPRC5C) is required for osteoblast differentiation and responds to EZH2 inhibition and multiple osteogenic signals. Bone 2023; 176:116866. [PMID: 37558192 PMCID: PMC10962865 DOI: 10.1016/j.bone.2023.116866] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/24/2023] [Accepted: 08/03/2023] [Indexed: 08/11/2023]
Abstract
Osteoblast differentiation is epigenetically suppressed by the H3K27 methyltransferase EZH2, and induced by the morphogen BMP2 and transcription factor RUNX2. These factors also regulate distinct G protein coupled receptors (GPRCs; e.g., PTH1R, GPR30/GPER1). Because GPRCs transduce many physiological stimuli, we examined whether BMP2 or EZH2 inhibition (i.e., GSK126) regulates other GPRC genes in osteoblasts. RNA-seq screening of >400 mouse GPRC-related genes showed that many GPRCs are downregulated during osteogenic differentiation. The orphan receptor GPRC5C, along with a small subset of other GPRCs, is induced by BMP2 or GSK126 during Vitamin C dependent osteoblast differentiation, but not by all-trans retinoic acid. ChIP-seq analysis revealed that GSK126 reduces H3K27me3 levels at the GPRC5C gene locus in differentiating MC3T3-E1 osteoblasts, consistent with enhanced GPRC5C mRNA expression. Loss of function analyses revealed that shRNA-mediated depletion of GPRC5C decreases expression of bone markers (e.g., BGLAP and IBSP) and mineral deposition in response to BMP2 or GSK126. GPRC5C mRNA was found to be reduced in the osteopenic bones of KLF10 null mice which have compromised BMP2 signaling. GPRC5C mRNA is induced by the bone-anabolic activity of 17β-estradiol in trabecular but not cortical bone following ovariectomy. Collectively, these findings suggest that GPRC5C protein is a key node in a pro-osteogenic axis that is normally suppressed by EZH2-mediated H3K27me3 marks and induced during osteoblast differentiation by GSK126, BMP2, and/or 17β-estradiol. Because GPRC5C protein is an understudied orphan receptor required for osteoblast differentiation, identification of ligands that induce GPRC5C signaling may support therapeutic strategies to mitigate bone-related disorders.
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Affiliation(s)
- Parisa Dashti
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Roman Thaler
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - John R Hawse
- Department of Biochemistry & Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - M Lizeth Galvan
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Bram J van der Eerden
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Andre J van Wijnen
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands; Department of Biochemistry, University of Vermont, Burlington, VT, USA.
| | - Amel Dudakovic
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Biochemistry & Molecular Biology, Mayo Clinic, Rochester, MN, USA.
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2
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Kawabata Y, Takai S, Sanematsu K, Iwata S, Kawabata F, Kanematsu T, Jimi E, Shigemura N. The G protein-coupled receptor GPRC5C is a saccharide sensor with a novel 'off' response. FEBS Lett 2023; 597:2006-2016. [PMID: 37418589 DOI: 10.1002/1873-3468.14695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 07/09/2023]
Abstract
GPRC5C is an orphan G protein-coupled receptor (GPCR) that belongs to the class C GPCR family. Although GPRC5C is expressed in various organs, its function and ligand are still undetermined. We found that GPRC5C is expressed in mouse taste cells, enterocytes, and pancreatic α-cells. In functional imaging assays, HEK293 cells heterologously expressing GPRC5C and the chimeric G protein α subunit Gα16-gust44 showed robust intracellular Ca2+ increases in response to monosaccharides, disaccharides, and a sugar alcohol, but not an artificial sweetener or sweet-tasting amino acid. Notably, Ca2+ increases occurred after washout, not during stimulation. Our findings suggest that GPRC5C has receptor properties which lead to novel 'off' responses to saccharide detachment and may work as an internal or external chemosensor specifically tuned to natural sugars.
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Affiliation(s)
- Yuko Kawabata
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
| | - Shingo Takai
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
- Dent-Craniofacial Development and Regeneration Center, Kyushu University, Fukuoka, Japan
| | - Keisuke Sanematsu
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
- Oral Health/Brain Health/Total Health Research Center, Kyushu University, Fukuoka, Japan
- Research and Development Center for Five-Sense Devices Taste and Odor Sensing, Kyushu University, Fukuoka, Japan
| | - Shusuke Iwata
- Department of Oral Physiology, Asahi University School of Dentistry, Mizuho, Japan
| | - Fuminori Kawabata
- Physiology of Domestic Animals, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Takashi Kanematsu
- Division of Oral Biological Sciences, Department of Cell Biology, Aging Science, and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Eijiro Jimi
- Oral Health/Brain Health/Total Health Research Center, Kyushu University, Fukuoka, Japan
- Laboratory of Molecular and Cellular Biochemistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
| | - Noriatsu Shigemura
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
- Research and Development Center for Five-Sense Devices Taste and Odor Sensing, Kyushu University, Fukuoka, Japan
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3
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Fu W, Franchini L, Orlandi C. Comprehensive Spatial Profile of the Orphan G Protein Coupled Receptor GPRC5B Expression in Mouse Brain. Front Neurosci 2022; 16:891544. [PMID: 35812210 PMCID: PMC9259939 DOI: 10.3389/fnins.2022.891544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Orphan G Protein Coupled Receptors (GPCRs) are GPCRs whose endogenous ligands are unknown or still debated. Due to the lack of pharmacological modulators, the physiological function of orphan GPCRs is understudied. However, relevant physiological roles associated with orphan GPCRs have been revealed by analysis of animal models and genome wide association studies illuminating an untapped potential for drug discovery. G Protein Coupled Receptor class C Group 5 Member B (GPRC5B) is among the most expressed GPCRs in the central nervous system. Thus, the expression profiling of GPRC5B is an essential step toward understanding GPRC5B function in health and disease. In this study, we generated new GPRC5B polyclonal antibodies and investigated the expression levels of GPRC5B across different organs and brain regions. We identified high levels of GPRC5B glycosylation both in transfected cells and in mouse brain. Moreover, in situ hybridization imaging analysis indicated that Gprc5b was expressed at the highest level in olfactory bulb, hippocampus, cerebellum, and pons. To dissect expression within various neuronal populations, we conducted a comprehensive spatial profiling of Gprc5b across excitatory and inhibitory neuronal types in medial prefrontal cortex, motor cortex, hippocampal regions, hypothalamus, and cerebellum. Overall, we discovered that GABAergic neurons displayed higher Gprc5b expression levels than glutamatergic neurons in most of the analyzed regions with the important exception of the hippocampal dentate gyrus. Overall, the expression analysis of GPRC5B in mouse brain will guide functional studies ultimately positioning GPRC5B in pathophysiological mechanisms and drug discovery.
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Xu W, Nelson-Maney NP, Bálint L, Kwon HB, Davis RB, Dy DCM, Dunleavey JM, St. Croix B, Caron KM. Orphan G-Protein Coupled Receptor GPRC5B Is Critical for Lymphatic Development. Int J Mol Sci 2022; 23:ijms23105712. [PMID: 35628521 PMCID: PMC9146384 DOI: 10.3390/ijms23105712] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 12/22/2022] Open
Abstract
Numerous studies have focused on the molecular signaling pathways that govern the development and growth of lymphatics in the hopes of elucidating promising druggable targets. G protein-coupled receptors (GPCRs) are currently the largest family of membrane receptors targeted by FDA-approved drugs, but there remain many unexplored receptors, including orphan GPCRs with no known biological ligand or physiological function. Thus, we sought to illuminate the cadre of GPCRs expressed at high levels in lymphatic endothelial cells and identified four orphan receptors: GPRC5B, AGDRF5/GPR116, FZD8 and GPR61. Compared to blood endothelial cells, GPRC5B is the most abundant GPCR expressed in cultured human lymphatic endothelial cells (LECs), and in situ RNAscope shows high mRNA levels in lymphatics of mice. Using genetic engineering approaches in both zebrafish and mice, we characterized the function of GPRC5B in lymphatic development. Morphant gprc5b zebrafish exhibited failure of thoracic duct formation, and Gprc5b-/- mice suffered from embryonic hydrops fetalis and hemorrhage associated with subcutaneous edema and blood-filled lymphatic vessels. Compared to Gprc5+/+ littermate controls, Gprc5b-/- embryos exhibited attenuated developmental lymphangiogenesis. During the postnatal period, ~30% of Gprc5b-/- mice were growth-restricted or died prior to weaning, with associated attenuation of postnatal cardiac lymphatic growth. In cultured human primary LECs, expression of GPRC5B is required to maintain cell proliferation and viability. Collectively, we identify a novel role for the lymphatic-enriched orphan GPRC5B receptor in lymphangiogenesis of fish, mice and human cells. Elucidating the roles of orphan GPCRs in lymphatics provides new avenues for discovery of druggable targets to treat lymphatic-related conditions such as lymphedema and cancer.
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Affiliation(s)
- Wenjing Xu
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - Nathan P. Nelson-Maney
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - László Bálint
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - Hyouk-Bum Kwon
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - Reema B. Davis
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - Danielle C. M. Dy
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
| | - James M. Dunleavey
- Tumor Angiogenesis Unit, Mouse Cancer Genetics Program, National Cancer Institute–Frederick, NIH, Frederick, MD 21702, USA; (J.M.D.); (B.S.C.)
| | - Brad St. Croix
- Tumor Angiogenesis Unit, Mouse Cancer Genetics Program, National Cancer Institute–Frederick, NIH, Frederick, MD 21702, USA; (J.M.D.); (B.S.C.)
| | - Kathleen M. Caron
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC 27599, USA; (W.X.); (N.P.N.-M.); (L.B.); (H.-B.K.); (R.B.D.); (D.C.M.D.)
- Correspondence:
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Takizawa N, Hironaka T, Mae K, Ueno T, Horii Y, Nagasaka A, Nakaya M. GPRC5B promotes collagen production in myofibroblasts. Biochem Biophys Res Commun 2021; 561:180-186. [PMID: 34023784 DOI: 10.1016/j.bbrc.2021.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 05/11/2021] [Indexed: 01/01/2023]
Abstract
Fibrosis is a condition characterized by the overproduction of extracellular matrix (ECM) components (e.g., collagen) in the myofibroblasts, causing tissue hardening and eventual organ dysfunction. Currently, the molecular mechanisms that regulate ECM production in the myofibroblasts are still obscure. In this study, we investigated the function of GPRC5B in the cardiac and lung myofibroblasts using real-time RT-PCR and siRNA-mediated knockdown. We discovered a significantly high expression of Gprc5b in the tissues of the fibrosis mice models and confirmed that Gprc5b was consistently expressed in the myofibroblasts of fibrotic hearts and lungs. We also found that Gprc5b expression was associated and may be dependent on the actin-MRTF-SRF signaling pathway. Notably, we observed that Gprc5b knockdown reduced the expression of collagen genes in the cardiac and lung myofibroblasts. Therefore, our findings reveal that GPRC5B enhances collagen production in the myofibroblasts, which directly promotes fibrosis in the tissues.
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Affiliation(s)
- Noburo Takizawa
- Department of Disease Control, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Takanori Hironaka
- Department of Disease Control, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Kyosuke Mae
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tomoyuki Ueno
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yuma Horii
- Department of Disease Control, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Akiomi Nagasaka
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Michio Nakaya
- Department of Disease Control, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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6
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Watkins LR, Orlandi C. Orphan G Protein Coupled Receptors in Affective Disorders. Genes (Basel) 2020; 11:E694. [PMID: 32599826 PMCID: PMC7349732 DOI: 10.3390/genes11060694] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022] Open
Abstract
G protein coupled receptors (GPCRs) are the main mediators of signal transduction in the central nervous system. Therefore, it is not surprising that many GPCRs have long been investigated for their role in the development of anxiety and mood disorders, as well as in the mechanism of action of antidepressant therapies. Importantly, the endogenous ligands for a large group of GPCRs have not yet been identified and are therefore known as orphan GPCRs (oGPCRs). Nonetheless, growing evidence from animal studies, together with genome wide association studies (GWAS) and post-mortem transcriptomic analysis in patients, pointed at many oGPCRs as potential pharmacological targets. Among these discoveries, we summarize in this review how emotional behaviors are modulated by the following oGPCRs: ADGRB2 (BAI2), ADGRG1 (GPR56), GPR3, GPR26, GPR37, GPR50, GPR52, GPR61, GPR62, GPR88, GPR135, GPR158, and GPRC5B.
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Affiliation(s)
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA;
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Rajkumar P, Cha B, Yin J, Arend LJ, Păunescu TG, Hirabayashi Y, Donowitz M, Pluznick JL. Identifying the localization and exploring a functional role for Gprc5c in the kidney. FASEB J 2018; 32:2046-2059. [PMID: 29196502 DOI: 10.1096/fj.201700610rr] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The investigation of orphan GPCRs (GPRs) has the potential to uncover novel insights into whole animal physiology. In this study, our goal was to determine the renal localization of Gprc5c, a receptor that we previously reported to be highly expressed in murine whole kidney, and to examine physiologic parameters in Gprc5c knockout (KO) mice to gain insight into function. Gprc5c localized to the apical membrane of renal proximal tubules (PTs) in mice, rats, and humans. With the comparison of Gprc5c wild-type (WT) and KO mice, we found that Gprc5c KO mice have altered acid-base homeostasis. Specifically, Gprc5c KO mice have lower blood pH and higher urine pH compared with WT mice, with a reduced level of titratable acids in their urine. In an in vitro GPCR internalization assay, we observed that Gprc5c internalization (an index of activation) was triggered by alkaline extracellular pH. Furthermore, with the use of an in vitro BCECF assay, we observed that Gprc5c increases Na+/H+ exchanger 3 (NHE3) activity at alkaline pH. We also find that the NHE3 activity is reduced in Gprc5c KO mice by 2 photon imaging in seminaphthorhodafluors (SNARF)-4F-loaded kidney sections. NHE3 is a primary contributor to apical transport of H+ in the renal PT. Together, these data imply that Gprc5c modulates the renal contribution to systemic pH homeostasis, at least in part, by taking part in the regulation of NHE3.-Rajkumar, P., Cha, B., Yin, J., Arend, L. J., Păunescu, T. G., Hirabayashi, Y., Donowitz, M., Pluznick, J. L. Identifying the localization and exploring a functional role for Gprc5c in the kidney.
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Affiliation(s)
- Premraj Rajkumar
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Boyoung Cha
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jianyi Yin
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lois J Arend
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Teodor G Păunescu
- Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Yoshio Hirabayashi
- Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, Saitama, Japan
| | - Mark Donowitz
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jennifer L Pluznick
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Chung HJ, Kim JD, Kim KH, Jeong NY. G protein-coupled receptor, family C, group 5 (GPRC5B) downregulation in spinal cord neurons is involved in neuropathic pain. Korean J Anesthesiol 2014; 66:230-6. [PMID: 24729846 PMCID: PMC3983420 DOI: 10.4097/kjae.2014.66.3.230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 10/02/2013] [Accepted: 10/22/2013] [Indexed: 01/10/2023] Open
Abstract
Background G protein-coupled receptor, family C, group 5 (GPRC5B), a retinoic acid-inducible orphan G-protein-coupled receptor (GPCR), is a member of the group C metabotropic glutamate receptor family proteins presumably related in non-canonical Wnt signaling. In this study, we investigated altered GPRC5B expression in the dorsal horn of the spinal cord after spinal nerve injury and its involvement in the development of neuropathic pain. Methods After induction of anesthesia by intraperitoneal injection of pentobarbital (35 mg /kg), the left L5 spinal nerve at the level of 2 mm distal to the L5 DRG was tightly ligated with silk and cut just distal to the ligature. Seven days after nerve injury, animals were perfused with 4% paraformaldehyde, and the spinal cords were extracted and post-fixed at 4℃ overnight. To identify the expression of GPRC5B and analyze the involvement of GPRC5B in neuropathic pain, immunofluorescence was performed using several markers for neurons and glial cells in spinal cord tissue. Results After L5 spinal nerve ligation (SNL), the expression of GPRC5B was decreased in the ipsilateral part, as compared to the contralateral part, of the spinal dorsal horn. SNL induced the downregulation of GPRC5B in NeuN-positive neurons in the spinal dorsal horn. However, CNPase-positive oligodendrocytes, OX42-positive microglia, and GFAP-positive astrocytes were not immunolabeled with GPRC5B antibody in the spinal dorsal horn. Conclusions These results imply that L5 SNL-induced GPRC5B downregulation may affect microglial activation in the spinal dorsal horn and be involved in neuropathic pain.
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Affiliation(s)
- Hyung-Joo Chung
- Department of Anesthesiology and Pain Medicine, Kosin University College of Medicine, Busan, Korea
| | - Ju Deok Kim
- Department of Anesthesiology and Pain Medicine, Kosin University College of Medicine, Busan, Korea
| | - Kyung Han Kim
- Department of Anesthesiology and Pain Medicine, Kosin University College of Medicine, Busan, Korea
| | - Na Young Jeong
- Department of Anatomy and Cell Biology and Mitochondria Hub Regulation Center, Dong-A University College of Medicine, Busan, Korea
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Tomita H, Ziegler ME, Kim HB, Evans SJ, Choudary PV, Li JZ, Meng F, Dai M, Myers RM, Neal CR, Speed TP, Barchas JD, Schatzberg AF, Watson SJ, Akil H, Jones EG, Bunney WE, Vawter MP. G protein-linked signaling pathways in bipolar and major depressive disorders. Front Genet 2013; 4:297. [PMID: 24391664 PMCID: PMC3870297 DOI: 10.3389/fgene.2013.00297] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 12/05/2013] [Indexed: 01/03/2023] Open
Abstract
The G-protein linked signaling system (GPLS) comprises a large number of G-proteins, G protein-coupled receptors (GPCRs), GPCR ligands, and downstream effector molecules. G-proteins interact with both GPCRs and downstream effectors such as cyclic adenosine monophosphate (cAMP), phosphatidylinositols, and ion channels. The GPLS is implicated in the pathophysiology and pharmacology of both major depressive disorder (MDD) and bipolar disorder (BPD). This study evaluated whether GPLS is altered at the transcript level. The gene expression in the dorsolateral prefrontal (DLPFC) and anterior cingulate (ACC) were compared from MDD, BPD, and control subjects using Affymetrix Gene Chips and real time quantitative PCR. High quality brain tissue was used in the study to control for confounding effects of agonal events, tissue pH, RNA integrity, gender, and age. GPLS signaling transcripts were altered especially in the ACC of BPD and MDD subjects. Transcript levels of molecules which repress cAMP activity were increased in BPD and decreased in MDD. Two orphan GPCRs, GPRC5B and GPR37, showed significantly decreased expression levels in MDD, and significantly increased expression levels in BPD. Our results suggest opposite changes in BPD and MDD in the GPLS, “activated” cAMP signaling activity in BPD and “blunted” cAMP signaling activity in MDD. GPRC5B and GPR37 both appear to have behavioral effects, and are also candidate genes for neurodegenerative disorders. In the context of the opposite changes observed in BPD and MDD, these GPCRs warrant further study of their brain effects.
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Affiliation(s)
- Hiroaki Tomita
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA ; Department of Biological Psychiatry, Tohoku University Sendai, Japan ; Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine CA, USA
| | - Mary E Ziegler
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA ; Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine CA, USA
| | - Helen B Kim
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA ; Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine CA, USA
| | - Simon J Evans
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | | | - Jun Z Li
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | - Fan Meng
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | - Manhong Dai
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | | | - Charles R Neal
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA ; John A. Burns School of Medicine, University of Hawaii Honolulu, HI, USA
| | - Terry P Speed
- Department of Statistics, University of California Berkeley CA, USA
| | - Jack D Barchas
- Department of Psychiatry, Weill Cornell Medical College New York, NY, USA
| | - Alan F Schatzberg
- Department of Psychiatry and Behavioral Sciences, Stanford University Palo Alto, CA, USA
| | - Stanley J Watson
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | - Huda Akil
- Molecular and Behavioral Neurosciences Institute, University of Michigan Ann Arbor, MI, USA
| | - Edward G Jones
- Center for Neuroscience, University of California Davis, CA, USA
| | - William E Bunney
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA
| | - Marquis P Vawter
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA ; Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine CA, USA
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10
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Wang L, Kamath A, Frye J, Iwamoto GA, Chun JL, Berry SE. Aorta-derived mesoangioblasts differentiate into the oligodendrocytes by inhibition of the Rho kinase signaling pathway. Stem Cells Dev 2011; 21:1069-89. [PMID: 21793703 DOI: 10.1089/scd.2011.0124] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mesoangioblasts are vessel-derived stem cells that differentiate into mesodermal derivatives. We have isolated postnatal aorta-derived mesoangioblasts (ADMs) that differentiate into smooth, skeletal, and cardiac muscle, and adipocytes, and regenerate damaged skeletal muscle in a murine model for Duchenne muscular dystrophy. We report that the marker profile of ADM is similar to that of mesoangioblasts isolated from embryonic dorsal aorta, postnatal bone marrow, and heart, but distinct from mesoangioblasts derived from skeletal muscle. We also demonstrate that ADM differentiate into myelinating glial cells. ADM localize to peripheral nerve bundles in regenerating muscles and exhibit morphology and marker expression of mature Schwann cells, and myelinate axons. In vitro, ADM spontaneously express markers of oligodendrocyte progenitors, including the chondroitin sulphate proteoglycan NG2, nestin, platelet-derived growth factor (PDGF) receptor α, the A2B5 antigen, thyroid hormone nuclear receptor α, and O4. Pharmacological inhibition of Rho kinase (ROCK) initiated process extension by ADM, and when combined with insulin-like growth factor 1, PDGF, and thyroid hormone, enhanced ADM expression of oligodendrocyte precursor markers and maturation into the oligodendrocyte lineage. ADM injected into the right lateral ventricle of the brain migrate to the corpus callosum, and cerebellar white matter, where they express components of myelin. Because ADM differentiate or mature into cell types of both mesodermal and ectodermal origin, they may be useful for treatment of a variety of degenerative diseases, or repair and regeneration of multiple cell types in severely damaged tissue.
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Affiliation(s)
- Lei Wang
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
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11
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Sano T, Kim YJ, Oshima E, Shimizu C, Kiyonari H, Abe T, Higashi H, Yamada K, Hirabayashi Y. Comparative characterization of GPRC5B and GPRC5C LacZ knockin mice; behavioral abnormalities in GPRC5B-deficient mice. Biochem Biophys Res Commun 2011; 412:460-5. [DOI: 10.1016/j.bbrc.2011.07.118] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 07/29/2011] [Indexed: 11/15/2022]
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12
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Kurtenbach S, Mayer C, Pelz T, Hatt H, Leese F, Neuhaus EM. Molecular evolution of a chordate specific family of G protein-coupled receptors. BMC Evol Biol 2011; 11:234. [PMID: 21827690 PMCID: PMC3238225 DOI: 10.1186/1471-2148-11-234] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 08/09/2011] [Indexed: 11/23/2022] Open
Abstract
Background Chordate evolution is a history of innovations that is marked by physical and behavioral specializations, which led to the development of a variety of forms from a single ancestral group. Among other important characteristics, vertebrates obtained a well developed brain, anterior sensory structures, a closed circulatory system and gills or lungs as blood oxygenation systems. The duplication of pre-existing genes had profound evolutionary implications for the developmental complexity in vertebrates, since mutations modifying the function of a duplicated protein can lead to novel functions, improving the evolutionary success. Results We analyzed here the evolution of the GPRC5 family of G protein-coupled receptors by comprehensive similarity searches and found that the receptors are only present in chordates and that the size of the receptor family expanded, likely due to genome duplication events in the early history of vertebrate evolution. We propose that a single GPRC5 receptor coding gene originated in a stem chordate ancestor and gave rise by duplication events to a gene family comprising three receptor types (GPRC5A-C) in vertebrates, and a fourth homologue present only in mammals (GPRC5D). Additional duplications of GPRC5B and GPRC5C sequences occurred in teleost fishes. The finding that the expression patterns of the receptors are evolutionarily conserved indicates an important biological function of these receptors. Moreover, we found that expression of GPRC5B is regulated by vitamin A in vivo, confirming previous findings that linked receptor expression to retinoic acid levels in tumor cell lines and strengthening the link between the receptor expression and the development of a complex nervous system in chordates, known to be dependent on retinoic acid signaling. Conclusions GPRC5 receptors, a class of G protein-coupled receptors with unique sequence characteristics, may represent a molecular novelty that helped non-chordates to become chordates.
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Affiliation(s)
- Stefan Kurtenbach
- 1Department of Cell Physiology, Ruhr University Bochum, Universitaetsstrasse150, 44801 Bochum, Germany
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A flanking gene problem leads to the discovery of a Gprc5b splice variant predominantly expressed in C57Bl/6J mouse brain and in maturing neurons. PLoS One 2010; 5:e10351. [PMID: 20436672 PMCID: PMC2859937 DOI: 10.1371/journal.pone.0010351] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 03/22/2010] [Indexed: 01/19/2023] Open
Abstract
Background Gprc5b, a retinoic acid-inducible orphan G protein–coupled receptor (GPCR), is a member of the group C metabotropic glutamate receptor family proteins possibly involved in non-canonical Wnt signaling. Many GPCR transcripts are alternatively spliced, which diversifies this class of proteins in their cell- and tissue-specific signaling, regulatory and/or pharmacological properties. We previously generated p97FE65 isoform-specific knockout mice that showed learning/memory deficits. In this study, we further characterized the 97FE65 null mice using cDNA microarray and RT-PCR analyses. Methodology/Principal Findings We discovered a novel brain-specific C-terminal splice variant of Gprc5b, Gprc5b_v2, which was differentially expressed in p97FE65 wild type and null mouse brains. The null mice were generated in 129/Sv ES cells, and backcrossed to C57Bl/6J for ten generations. We found that expression of Gprc5b_v2 mRNA in the brains of p97FE65 null mice was dramatically down-regulated (more than 20 fold) compared to their wild type littermates. However, expression profiles of Gprc5b variants and SNP analysis surrounding the FE65 locus suggest that the down-regulation is unlikely due to the altered FE65 function, but rather is caused by gene retention from the 129/Sv ES cells. Consistently, in contrast to ubiquitously expressed Gprc5b_v1, Gprc5b_v2 was predominantly expressed in the brain tissues of C57Bl/6J mice. The alternative splicing of the 3′ terminal exon also altered the protein coding sequences, giving rise to the characteristic C-termini. Levels of Gprc5b_v2 mRNA were increased during neuronal maturation, paralleling the expression of synaptic proteins. Overexpression of both Gprc5b variants stimulated neurite-like outgrowth in a neuroblastoma cell line. Conclusions/Significance Our results suggest that Gprc5b-v2 may play a role during brain maturation and in matured brain, possibly through the regulation of neuronal morphology and protein-protein interaction. This study also highlights the fact that unexpected gene retention following repeated backcrosses can lead to important biological consequences.
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Anatomical and histological profiling of orphan G-protein-coupled receptor expression in gastrointestinal tract of C57BL/6J mice. Cell Tissue Res 2009; 338:257-69. [DOI: 10.1007/s00441-009-0859-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 07/31/2009] [Indexed: 02/07/2023]
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15
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A novel method incorporating gene ontology information for unsupervised clustering and feature selection. PLoS One 2008; 3:e3860. [PMID: 19052637 PMCID: PMC2585795 DOI: 10.1371/journal.pone.0003860] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 11/08/2008] [Indexed: 01/22/2023] Open
Abstract
Background Among the primary goals of microarray analysis is the identification of genes that could distinguish between different phenotypes (feature selection). Previous studies indicate that incorporating prior information of the genes' function could help identify physiologically relevant features. However, current methods that incorporate prior functional information do not provide a relative estimate of the effect of different genes on the biological processes of interest. Results Here, we present a method that integrates gene ontology (GO) information and expression data using Bayesian regression mixture models to perform unsupervised clustering of the samples and identify physiologically relevant discriminating features. As a model application, the method was applied to identify the genes that play a role in the cytotoxic responses of human hepatoblastoma cell line (HepG2) to saturated fatty acid (SFA) and tumor necrosis factor (TNF)-α, as compared to the non-toxic response to the unsaturated FFAs (UFA) and TNF-α. Incorporation of prior knowledge led to a better discrimination of the toxic phenotypes from the others. The model identified roles of lysosomal ATPases and adenylate cyclase (AC9) in the toxicity of palmitate. To validate the role of AC in palmitate-treated cells, we measured the intracellular levels of cyclic AMP (cAMP). The cAMP levels were found to be significantly reduced by palmitate treatment and not by the other FFAs, in accordance with the model selection of AC9. Conclusions A framework is presented that incorporates prior ontology information, which helped to (a) perform unsupervised clustering of the phenotypes, and (b) identify the genes relevant to each cluster of phenotypes. We demonstrate the proposed framework by applying it to identify physiologically-relevant feature genes that conferred differential toxicity to saturated vs. unsaturated FFAs. The framework can be applied to other problems to efficiently integrate ontology information and expression data in order to identify feature genes.
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Acquaviva J, Wong R, Charest A. The multifaceted roles of the receptor tyrosine kinase ROS in development and cancer. Biochim Biophys Acta Rev Cancer 2008; 1795:37-52. [PMID: 18778756 DOI: 10.1016/j.bbcan.2008.07.006] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Accepted: 07/21/2008] [Indexed: 12/26/2022]
Abstract
The proto-oncogene receptor tyrosine kinase ROS was originally discovered through the identification of oncogenic variants isolated from tumors. These discoveries spearheaded a body of work aimed at elucidating the function of this evolutionarily conserved receptor in development and cancer. Through genetic and biochemical approaches, progress in the characterization of ROS points to distinctive roles in the program of epithelial cell differentiation during the development of a variety of organs. Although substantial, these advances remain hampered by the absence of an identified ligand, making ROS one of the last two remaining orphan receptor tyrosine kinases. Recent studies on the oncogenic activation of ROS as a result of different chromosomal rearrangements found in brain and lung cancers have shed light on the molecular mechanisms underlying ROS transforming activities. ROS and its oncogenic variants therefore constitute clinically relevant targets for cancer therapeutic intervention. This review highlights the various roles that this receptor plays in multiple system networks in normalcy and disease and points to future directions towards the elucidation of ROS function in the context of ligand identification, signaling pathways and clinical applications.
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Affiliation(s)
- Jaime Acquaviva
- Molecular Oncology Research Institute, Tufts University School of Medicine, Tufts Medical Center, Boston, MA 02111, USA
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17
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Li X, Liu H, Qin L, Tamasi J, Bergenstock M, Shapses S, Feyen JHM, Notterman DA, Partridge NC. Determination of dual effects of parathyroid hormone on skeletal gene expression in vivo by microarray and network analysis. J Biol Chem 2007; 282:33086-97. [PMID: 17690103 DOI: 10.1074/jbc.m705194200] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Parathyroid hormone (PTH) stimulates bone formation when injected daily but causes severe bone loss with continuous infusion. The mechanism of its paradoxical effects is still elusive. In this study, we compared changes in the gene expression profile in bone induced by intermittent or continuous treatment with three different PTH peptides, PTH-(1-34), -(1-31), and -(3-34), in Sprague-Dawley female rats. PTH-(1-34) regulated numerous genes (approximately 1,000), but differentially, in both regimes. PTH-(1-31) regulated a similar number of genes in the intermittent regimen but fewer in the continuous regimen, consistent with its less potent catabolic effect. PTH-(3-34) regulated very few genes in both regimes, which suggests the protein kinase C pathway plays a limited role in mediating the dual effects of PTH, whereas the cAMP-dependent protein kinase A pathway appears to predominate. In the intermittent treatment, many genes encoding signaling mediators, transcription factors, cytokines, and proteases/protease inhibitors are regulated rapidly and cyclically with each PTH injection; genes associated with skeletal development show a slowly accruing pattern of expression. With continuous treatment, some genes are regulated from 6 h, and the mRNA levels are sustained with a longer infusion, whereas others show a kinetic decrease and then increase later. Significant up-regulation of genes stimulating osteoclastogenesis in the anabolic regime suggests a provocative and paradoxical theme for the anabolic effect of PTH that a full anabolic response requires a transient up-regulation of genes classically associated with a resorptive response. Ingenuity pathway analysis was performed on the microarray data. A novel signaling network was established that is differentially regulated in the two PTH treatment regimes. Key regulators are suggested to be AREG, CCL2, WNT4, and cAMP-responsive element modulator.
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Affiliation(s)
- Xin Li
- Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA
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Lotem J, Sachs L. Epigenetics and the plasticity of differentiation in normal and cancer stem cells. Oncogene 2006; 25:7663-72. [PMID: 16847453 DOI: 10.1038/sj.onc.1209816] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Embryonic stem cells are characterized by their differentiation to all cell types during embryogenesis. In adult life, different tissues also have somatic stem cells, called adult stem cells, which in specific niches can undergo multipotent differentiation. The use of these adult stem cells has considerable therapeutic potential for the regeneration of damaged tissues. In both embryonic and adult stem cells, differentiation is controlled by epigenetic mechanisms, and the plasticity of differentiation in these cells is associated with transcription accessibility for genes expressed in different normal tissues. Abnormalities in genetic and/or epigenetic controls can lead to development of cancer, which is maintained by self-renewing cancer stem cells. Although the genetic abnormalities produce defects in growth and differentiation in cancer stem cells, these cells have not always lost the ability to undergo differentiation through epigenetic changes that by-pass the genomic abnormalities, thus creating the basis for differentiation therapy. Like normal stem cells, cancer stem cells can show plasticity for differentiation. This plasticity of cancer stem cells is also associated with transcription accessibility for genes that are normally expressed in different tissues, including tissues other than those from which the cancers originated. This broad transcription accessibility can also contribute to the behavior of cancer cells by overexpressing genes that promote cell viability, growth and metastasis.
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Affiliation(s)
- J Lotem
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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19
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Rickhag M, Wieloch T, Gidö G, Elmér E, Krogh M, Murray J, Lohr S, Bitter H, Chin DJ, von Schack D, Shamloo M, Nikolich K. Comprehensive regional and temporal gene expression profiling of the rat brain during the first 24 h after experimental stroke identifies dynamic ischemia-induced gene expression patterns, and reveals a biphasic activation of genes in surviving tissue. J Neurochem 2006; 96:14-29. [PMID: 16300643 DOI: 10.1111/j.1471-4159.2005.03508.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In order to identify biological processes relevant for cell death and survival in the brain following stroke, the postischemic brain transcriptome was studied by a large-scale cDNA array analysis of three peri-infarct brain regions at eight time points during the first 24 h of reperfusion following middle cerebral artery occlusion in the rat. K-means cluster analysis revealed two distinct biphasic gene expression patterns that contained 44 genes (including 18 immediate early genes), involved in cell signaling and plasticity (i.e. MAP2K7, Sprouty2, Irs-2, Homer1, GPRC5B, Grasp). The first gene induction phase occurred at 0-3 h of reperfusion, and the second at 9-15 h, and was validated by in situ hybridization. Four gene clusters displayed a progressive increase in expression over time and included 50 genes linked to cell motility, lipid synthesis and trafficking (i.e. ApoD, NPC1, G3P-dehydrogenase1, and Choline kinase) or cell death-regulating genes such as mitochondrial CLIC. We conclude that a biphasic transcriptional up-regulation of the brain-derived neurotrophic factor (BDNF)-G-protein coupled receptor (GPCR)-mitogen-activated protein (MAP) kinase signaling pathways occurs in surviving tissue, concomitant with a progressive and persistent activation of cell proliferation signifying tissue regeneration, which provide the means for cell survival and postischemic brain plasticity.
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Affiliation(s)
- Mattias Rickhag
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, University of Lund, Lund, Sweden
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20
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Xu J, Tian J, Shapiro SD. Normal Lung Development in RAIG1-Deficient Mice Despite Unique Lung Epithelium–Specific Expression. Am J Respir Cell Mol Biol 2005; 32:381-7. [PMID: 15677768 DOI: 10.1165/rcmb.2004-0343oc] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
RAIG1, 2, and 3 and GPCR5d represent a new subfamily of orphan G protein-coupled receptors. RAIG1 is expressed abundantly and specifically in the lung during development and in adult mice. During lung development, RAIG1 expression is initiated at E14.5 and gradually increases, reaching its highest levels at E18. High levels of expression are maintained in adult lungs. Given its abundant lung-specific expression and role in retinoic acid signaling, we hypothesized that RAIG1 plays a role in epithelial cell differentiation during lung development. To determine RAIG1 function and track endogenous RAIG1 spatial expression, a null allele of Raig1 was generated and the lacZ gene was "knocked-in." Although expression was detected in both proximal and distal epithelium during embryogenesis, it became restricted to type I and type II pneumocytes and the most distal bronchiolar cells in postnatal lungs. This is the first gene known to have this unique epithelial cell expression pattern. Despite this high level of expression, targeted inactivation of Raig1 did not cause significant developmental defects. Epithelial cell differentiation was normal and lung structure was intact. Analysis of other family members demonstrated some overlapping embryonic expression of RAIG3 mRNA that could have led to functional redundancy in the single RAIG1 null mutant mouse.
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Affiliation(s)
- Jingsong Xu
- Harvard Medical School, Brigham and Women's Hospital, 75 Francis St., Boston, MA 02115, USA.
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21
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Enna SJ, Bowery NG. GABA(B) receptor alterations as indicators of physiological and pharmacological function. Biochem Pharmacol 2005; 68:1541-8. [PMID: 15451397 DOI: 10.1016/j.bcp.2004.06.037] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 06/21/2004] [Indexed: 11/15/2022]
Abstract
Given the widespread distribution of GABA(B) receptors throughout the central nervous system, and within certain peripheral organs, it is likely their selective pharmacological manipulation could be of benefit in the treatment of a variety of disorders. Studies aimed at defining the clinical potential of GABA(B) receptor agonists and antagonists have included gene deletion experiments, examination of changes in receptor binding, subunit expression and function in diseased tissue, as well as after the chronic administration of drugs. The results indicate that a functional GABA(B) receptor requires the combination of GABA(B(1)) and GABA(B(2)) subunits, that receptor function does not always correlate with subunit expression and receptor binding, and that GABA(B) receptor modifications may be associated with the clinical response to antidepressants, mood stabilizers, and GABA(B) receptor agonists and antagonists. Moreover, changes in GABA(B) binding or expression suggest this receptor may be involved in mediating symptoms associated with chronic pain, epilepsy and schizophrenia. This, together with results from other types of studies, indicates the potential therapeutic value of developing drugs capable of selectively activating, inhibiting, or modulating GABA(B) receptor function.
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Affiliation(s)
- S J Enna
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical School, 3901 Rainbow Boulevard, Mail Stop 1018, Kansas City, Kansas 66160-0227, USA.
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Brendel C, Kuklick L, Hartmann O, Kim TD, Boudriot U, Schwell D, Neubauer A. Distinct gene expression profile of human mesenchymal stem cells in comparison to skin fibroblasts employing cDNA microarray analysis of 9600 genes. Gene Expr 2005; 12:245-57. [PMID: 16355723 PMCID: PMC6009126 DOI: 10.3727/000000005783992043] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Broad differentiation capacity has been described for mesenchymal stem cells (MSC) from human bone marrow. We sought to identify genes associated with the immature state and pluripotency of this cell type. To prove the pluripotent state of the MSC, differentiation into osteocytes, adipocytes, and chondrocytes was performed in vitro. In contrast, normal skin cells did not harbor these differentiation abilities. We compared the expression profile of human bone marrow MSC with cDNA from one primary human skin cell line as control, using a cDNA chip providing 9600 genes. The identity of all relevant genes was confirmed by direct sequencing. Data of gene array expression were corroborated employing quantitative PCR analysis. About 80 genes were differently expressed more than threefold in MSC compared to mature skin fibroblasts. Interestingly, primary human MSC were found to upregulate a number of genes important for embryogenesis such as distal-less homeo box 5, Eyes absent homolog 2, inhibitor of DNA binding 3, and LIM protein. In contrast, mesenchymal lineage genes were downregulated in MSC in comparison to skin cells. We also detected expression of some genes involved in neural development, indicating the broad differentiation capabilities of MSC. We conclude that human mesenchymal stem cells harbor an expression profile distinct from mature skin fibroblast, and genes associated with developmental processes and stem cell function are highly expressed in adult mesenchymal stem cells.
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Affiliation(s)
- Cornelia Brendel
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, Baldingerstrasse, Marburg, Germany
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Tagliafico E, Brunelli S, Bergamaschi A, De Angelis L, Scardigli R, Galli D, Battini R, Bianco P, Ferrari S, Cossu G, Ferrari S. TGFβ/BMP activate the smooth muscle/bone differentiation programs in mesoangioblasts. J Cell Sci 2004; 117:4377-88. [PMID: 15331661 DOI: 10.1242/jcs.01291] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Mesoangioblasts are vessel-derived stem cells that can be induced to differentiate into different cell types of the mesoderm such as muscle and bone. The gene expression profile of four clonal derived lines of mesoangioblasts was determined by DNA micro-array analysis: it was similar in the four lines but different from 10T1/2 embryonic fibroblasts, used as comparison. Many known genes expressed by mesoangioblasts belong to response pathways to developmental signalling molecules, such as Wnt or TGFβ/BMP. Interestingly, mesoangioblasts express receptors of the TGFβ/BMP family and several Smads and, accordingly, differentiate very efficiently into smooth muscle cells in response to TGFβ and into osteoblasts in response to BMP. In addition, insulin signalling promotes adipogenic differentiation, possibly through the activation of IGF-R. Several Wnts and Frizzled, Dishevelled and Tcfs are expressed, suggesting the existence of an autocrine loop for proliferation and indeed, forced expression of Frzb-1 inhibits cell division. Mesoangioblasts also express many neuro-ectodermal genes and yet undergo only abortive neurogenesis, even after forced expression of neurogenin 1 or 2, MASH or NeuroD. Finally, mesoangioblasts express several pro-inflammatory genes, cytokines and cytokine receptors, which may explain their ability to be recruited by tissue inflammation. Our data define a unique phenotype for mesoangioblasts, explain several of their biological features and set the basis for future functional studies on the role of these cells in tissue histogenesis and repair.
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Affiliation(s)
- Enrico Tagliafico
- Dipartimento di Scienze Biomediche, Università di Modena e Reggio Emilia, Via G. Campi 287, 41100 Modena, Italy
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Abstract
Arginine plays an important role in many physiologic and biologic processes beyond its role as a protein-incorporated amino acid. Dietary supplementation of arginine can enhance wound healing, regulate endocrine activity and potentiate immune activity. Under normal unstressed conditions the arginine requirement of adult humans is fulfilled by endogenous sources, however this is compromised during times of stress, especially in critical illness. These finding have led to use of arginine supplementation as part of an immune-enhancing dietary regimen to help combat the immune suppression seen in such patients. Though the results from studies examining the use of this type of immunonutrition in critically ill patients are far from definitive, they are promising that this mode of therapy may be of some advantage. A better understanding of the in vivo biology of arginine and its metabolism is necessary to truly define a benefit from arginine supplementation.
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Affiliation(s)
- D Efron
- Department of Surgery, Sinai Hospital of Baltimore, MD 21215, USA
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