1
|
Bsteh G, Dal Bianco A, Zrzavy T, Berger T. Novel and Emerging Treatments to Target Pathophysiological Mechanisms in Various Phenotypes of Multiple Sclerosis. Pharmacol Rev 2024; 76:564-578. [PMID: 38719481 DOI: 10.1124/pharmrev.124.001073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/22/2024] [Accepted: 04/29/2024] [Indexed: 06/16/2024] Open
Abstract
The objective is to comprehensively review novel pharmacotherapies used in multiple sclerosis (MS) and the possibilities they may carry for therapeutic improvement. Specifically, we discuss pathophysiological mechanisms worth targeting in MS, ranging from well known targets, such as autoinflammation and demyelination, to more novel and advanced targets, such as neuroaxonal damage and repair. To set the stage, a brief overview of clinical MS phenotypes is provided, followed by a comprehensive recapitulation of both clinical and paraclinical outcomes available to assess the effectiveness of treatments in achieving these targets. Finally, we discuss various promising novel and emerging treatments, including their respective hypothesized modes of action and currently available evidence from clinical trials. SIGNIFICANCE STATEMENT: This comprehensive review discusses pathophysiological mechanisms worth targeting in multiple sclerosis. Various promising novel and emerging treatments, including their respective hypothesized modes of action and currently available evidence from clinical trials, are reviewed.
Collapse
Affiliation(s)
- Gabriel Bsteh
- Department of Neurology (G.B., A.D.B., T.Z., T.B.) and Comprehensive Center for Clinical Neurosciences & Mental Health (G.B., A.D.B., T.Z., T.B.), Medical University of Vienna, Vienna, Austria
| | - Assunta Dal Bianco
- Department of Neurology (G.B., A.D.B., T.Z., T.B.) and Comprehensive Center for Clinical Neurosciences & Mental Health (G.B., A.D.B., T.Z., T.B.), Medical University of Vienna, Vienna, Austria
| | - Tobias Zrzavy
- Department of Neurology (G.B., A.D.B., T.Z., T.B.) and Comprehensive Center for Clinical Neurosciences & Mental Health (G.B., A.D.B., T.Z., T.B.), Medical University of Vienna, Vienna, Austria
| | - Thomas Berger
- Department of Neurology (G.B., A.D.B., T.Z., T.B.) and Comprehensive Center for Clinical Neurosciences & Mental Health (G.B., A.D.B., T.Z., T.B.), Medical University of Vienna, Vienna, Austria
| |
Collapse
|
2
|
Matovina M, Tomašić Paić A, Tomić S, Brkić H, Horvat L, Barbarić L, Filić V, Pinterić M, Jurić S, Kussayeva A. Identification of SH2 Domain-Containing Protein 3C as a Novel, Putative Interactor of Dipeptidyl Peptidase 3. Int J Mol Sci 2023; 24:14178. [PMID: 37762480 PMCID: PMC10532290 DOI: 10.3390/ijms241814178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Dipeptidyl peptidase 3 (DPP3) is a zinc-dependent exopeptidase with broad specificity for four to eight amino acid residue substrates. It has a role in the regulation of oxidative stress response NRF2-KEAP1 pathway through the interaction with KEAP1. We have conducted stable isotope labeling by amino acids in a cell culture coupled to mass spectrometry (SILAC-MS) interactome analysis of TRex HEK293T cells using DPP3 as bait and identified SH2 Domain-Containing Protein 3C (SH2D3C) as prey. SH2D3C is one of three members of a family of proteins that contain both the SH2 domain and a domain similar to guanine nucleotide exchange factor domains of Ras family GTPases (Ras GEF-like domain), named novel SH2-containing proteins (NSP). NSPs, including SH2D3C (NSP3), are adaptor proteins involved in the regulation of adhesion, migration, tissue organization, and immune response. We have shown that SH2D3C binds to DPP3 through its C-terminal Ras GEF-like domain, detected the colocalization of the proteins in living cells, and confirmed direct interaction in the cytosol and membrane ruffles. Computational analysis also confirmed the binding of the C-terminal domain of SH2D3C to DPP3, but the exact model could not be discerned. This is the first indication that DPP3 and SH2D3C are interacting partners, and further studies to elucidate the physiological significance of this interaction are on the way.
Collapse
Affiliation(s)
- Mihaela Matovina
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| | - Ana Tomašić Paić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| | - Sanja Tomić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| | - Hrvoje Brkić
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia;
| | - Lucija Horvat
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (L.H.); (V.F.)
| | - Lea Barbarić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| | - Vedrana Filić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (L.H.); (V.F.)
| | - Marija Pinterić
- Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia;
| | - Snježana Jurić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| | - Akmaral Kussayeva
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (A.T.P.); (S.T.); (L.B.); (S.J.); (A.K.)
| |
Collapse
|
3
|
Li X, Jin DS, Eadara S, Caterina MJ, Meffert MK. Regulation by noncoding RNAs of local translation, injury responses, and pain in the peripheral nervous system. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2023; 13:100119. [PMID: 36798094 PMCID: PMC9926024 DOI: 10.1016/j.ynpai.2023.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/17/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
Neuropathic pain is a chronic condition arising from damage to somatosensory pathways that results in pathological hypersensitivity. Persistent pain can be viewed as a consequence of maladaptive plasticity which, like most enduring forms of cellular plasticity, requires altered expression of specific gene programs. Control of gene expression at the level of protein synthesis is broadly utilized to directly modulate changes in activity and responsiveness in nociceptive pathways and provides an effective mechanism for compartmentalized regulation of the proteome in peripheral nerves through local translation. Levels of noncoding RNAs (ncRNAs) are commonly impacted by peripheral nerve injury leading to persistent pain. NcRNAs exert spatiotemporal regulation of local proteomes and affect signaling cascades supporting altered sensory responses that contribute to hyperalgesia. This review discusses ncRNAs found in the peripheral nervous system (PNS) that are dysregulated following nerve injury and the current understanding of their roles in pathophysiological pain-related responses including neuroimmune interactions, neuronal survival and axon regeneration, Schwann cell dedifferentiation and proliferation, intercellular communication, and the generation of ectopic action potentials in primary afferents. We review progress in the field beyond cataloging, with a focus on the relevant target transcripts and mechanisms underlying pain modulation by ncRNAs.
Collapse
Affiliation(s)
- Xinbei Li
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, United States
| | - Daniel S. Jin
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, United States
| | - Sreenivas Eadara
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, United States
| | - Michael J. Caterina
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, United States
- Department of Neurosurgery and Neurosurgery Pain Research Institute, Johns Hopkins University School of Medicine, United States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, United States
| | - Mollie K. Meffert
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, United States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, United States
| |
Collapse
|
4
|
Role of nerves in neurofibromatosis type 1-related nervous system tumors. Cell Oncol (Dordr) 2022; 45:1137-1153. [PMID: 36327093 DOI: 10.1007/s13402-022-00723-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that affects nearly 1 in 3000 infants. Neurofibromin inactivation and NF1 gene mutations are involved in various aspects of neuronal function regulation, including neuronal development induction, electrophysiological activity elevation, growth factor expression, and neurotransmitter release. NF1 patients often exhibit a predisposition to tumor development, especially in the nervous system, resulting in the frequent occurrence of peripheral nerve sheath tumors and gliomas. Recent evidence suggests that nerves play a role in the development of multiple tumor types, prompting researchers to investigate the nerve as a vital component in and regulator of the initiation and progression of NF1-related nervous system tumors. CONCLUSION In this review, we summarize existing evidence about the specific effects of NF1 mutation on neurons and emerging research on the role of nerves in neurological tumor development, promising a new set of selective and targeted therapies for NF1-related tumors.
Collapse
|
5
|
Aberrant promoter hypermethylation inhibits RGMA expression and contributes to tumor progression in breast cancer. Oncogene 2021; 41:361-371. [PMID: 34754080 DOI: 10.1038/s41388-021-02083-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 12/09/2022]
Abstract
Breast cancer (BC) is the most common cancer in women worldwide, and the exploration of aberrantly expressed genes might clarify tumorigenesis and help uncover new therapeutic strategies for BC. Although RGMA was recently recognized as a tumor suppressor gene, its detailed biological function and regulation in BC remain unclear. Herein, we found that RGMA was downregulated in BC tissues compared with non-tumorous breast tissues, particularly in metastatic BC samples, and that patients with low RGMA expression manifested a poorer prognosis. Furthermore, DNMT1 and DNMT3A were found to be recruited to the RGMA promoter and induced aberrant hypermethylation, resulting in downregulation of RGMA expression in BC. In contrast, RGMA overexpression suppressed BC cell proliferation and colony-formation capabilities and increased BC cell apoptosis. Furthermore, RGMA knockdown accelerated BC cell proliferation and suppressed cellular apoptosis in vitro and in vivo. Reversal of RGMA promoter methylation with 5-Aza-CdR restored RGMA expression and blocked tumor growth. Overall, DNMT1- and DNMT3A-mediated RGMA promoter hypermethylation led to downregulation of RGMA expression, and low RGMA expression contributed to BC growth via activation of the FAK/Src/PI3K/AKT-signaling pathway. Our data thus suggested that RGMA might be a promising therapeutic target in BC.
Collapse
|
6
|
Song F, Yang Z, Li L, Wei Y, Tang X, Liu S, Yu M, Chen J, Wang S, Fu J, Zhang K, Yang P, Yang X, Chen Z, Zhang B, Wang H. MiR-552-3p promotes malignant progression of gallbladder carcinoma by reactivating the Akt/β-catenin signaling pathway due to inhibition of the tumor suppressor gene RGMA. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1374. [PMID: 34733926 PMCID: PMC8506546 DOI: 10.21037/atm-21-2013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/23/2021] [Indexed: 11/06/2022]
Abstract
Background Gallbladder carcinoma (GBC) remains a highly lethal disease worldwide. MiR-552 family members promote the malignant progression of a variety of digestive system tumors, but the role of miR-552-3p in GBC has not been elucidated. miR-552-3p was predicted to target the 3'-untranslated region (3'UTR) of the mRNA for the tumor suppressor gene "repulsive guidance molecule BMP co-receptor a" (RGMA). The aim of the present study was to clarify the roles and mechanisms of miR-552-3p targeting RGMA in the malignant progression of GBC. Methods In vitro: expression of miR-552-3p was detected by real-time quantitative PCR (qRT-PCR) in tumor and non-tumor adjacent tissues (NATs). Lentivirus-miR-552-3p was employed to knockdown this miRNA in GBC cell lines. Stem cell-related transcription factors and markers were assessed by qRT-PCR. Cell Counting Kit-8 (CCK-8), sphere formation and transwell assays were used to determine the malignant phenotypes of GBC cells. Targeting the 3'UTR of RGMA by miR-552-3p was verified by integrated analysis including bioinformatics prediction, luciferase assays, measures of changes of gene expression and rescue experiments. In vivo: mouse models of subcutaneous tumors and lung metastases were established to observe the effect of miR-552-3p on tumorigenesis and organ metastasis, respectively. Results MiR-552-3p was abnormally highly expressed in GBC tissues and cancer stem cells. Interference with miR-552-3p in SGC-996 and GBC-SD cells significantly inhibited GBC stem cell expansion. Reciprocally, miR-552-3p promoted GBC cell proliferation, migration and invasion both in vitro and in vivo; hence, interference with this miRNA impeded the malignant progression of GBC. Furthermore, the important tumor suppressor gene RGMA was identified as a target of miR-552-3p. The effects of miR-552-3p on cell proliferation and metastasis were abrogated or enhanced by gain or loss of RGMA function, respectively. Mechanistically, miR-552-3p promoted GBC progression by reactivating the Akt/β-catenin pathway and epithelial-mesenchymal transformation (EMT). Clinically, miR-552-3p correlated with multi-malignant characteristics of GBC and acted as a prognostic marker for GBC outcome. Conclusions MiR-552-3p promotes the malignant progression of GBC by inhibiting the mRNA of the tumor suppressor gene RGMA, resulting in reactivation of the Akt/β-catenin signaling pathway.
Collapse
Affiliation(s)
- Fengliang Song
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,Department of General Surgery, The Affiliated Hospital of Nantong University, Nantong, China
| | - Zhao Yang
- Department of Hepatic Surgery II, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Liang Li
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Yanping Wei
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Xuewu Tang
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Shuowu Liu
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Miao Yu
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Jin Chen
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Suyang Wang
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Jingbo Fu
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Kecheng Zhang
- Department of Biliary Tract Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Pinghua Yang
- Department of Biliary Tract Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xinwei Yang
- Department of Biliary Tract Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Zhong Chen
- Department of General Surgery, The Affiliated Hospital of Nantong University, Nantong, China
| | - Baohua Zhang
- Department of Biliary Tract Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Hongyang Wang
- International Co-operation Laboratory on Signal Transduction, Eastern Hepato-biliary Surgery Institute, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China.,National Laboratory for Oncogenes and Related Genes, Cancer Institute, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
7
|
The roles of GTPase-activating proteins in regulated cell death and tumor immunity. J Hematol Oncol 2021; 14:171. [PMID: 34663417 PMCID: PMC8524929 DOI: 10.1186/s13045-021-01184-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/27/2021] [Indexed: 12/22/2022] Open
Abstract
GTPase-activating protein (GAP) is a negative regulator of GTPase protein that is thought to promote the conversion of the active GTPase-GTP form to the GTPase-GDP form. Based on its ability to regulate GTPase proteins and other domains, GAPs are directly or indirectly involved in various cell requirement processes. We reviewed the existing evidence of GAPs regulating regulated cell death (RCD), mainly apoptosis and autophagy, as well as some novel RCDs, with particular attention to their association in diseases, especially cancer. We also considered that GAPs could affect tumor immunity and attempted to link GAPs, RCD and tumor immunity. A deeper understanding of the GAPs for regulating these processes could lead to the discovery of new therapeutic targets to avoid pathologic cell loss or to mediate cancer cell death.
Collapse
|
8
|
Oda W, Fujita Y, Baba K, Mochizuki H, Niwa H, Yamashita T. Inhibition of repulsive guidance molecule-a protects dopaminergic neurons in a mouse model of Parkinson's disease. Cell Death Dis 2021; 12:181. [PMID: 33589594 PMCID: PMC7884441 DOI: 10.1038/s41419-021-03469-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 11/26/2022]
Abstract
Repulsive guidance molecule-a (RGMa), a glycosylphosphatidylinositol-anchored membrane protein, has diverse functions in axon guidance, cell patterning, and cell survival. Inhibition of RGMa attenuates pathological dysfunction in animal models of central nervous system (CNS) diseases including spinal cord injury, multiple sclerosis, and neuromyelitis optica. Here, we examined whether antibody-based inhibition of RGMa had therapeutic effects in a mouse model of Parkinson's disease (PD). We treated mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and found increased RGMa expression in the substantia nigra (SN). Intraventricular, as well as intravenous, administration of anti-RGMa antibodies reduced the loss of tyrosine hydroxylase (TH)-positive neurons and accumulation of Iba1-positive microglia/macrophages in the SN of MPTP-treated mice. Selective expression of RGMa in TH-positive neurons in the SN-induced neuronal loss/degeneration and inflammation, resulting in a progressive movement disorder. The pathogenic effects of RGMa overexpression were attenuated by treatment with minocycline, which inhibits microglia and macrophage activation. Increased RGMa expression upregulated pro-inflammatory cytokine expression in microglia. Our observations suggest that the upregulation of RGMa is associated with the PD pathology; furthermore, inhibitory RGMa antibodies are a potential therapeutic option.
Collapse
Affiliation(s)
- Wakana Oda
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Suita, Osaka, 565-0871, Japan
| | - Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- World Premier International, Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kousuke Baba
- Department of Neurology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hideki Mochizuki
- Department of Neurology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hitoshi Niwa
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Suita, Osaka, 565-0871, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- World Premier International, Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
9
|
Bellazzo A, Collavin L. Cutting the Brakes on Ras-Cytoplasmic GAPs as Targets of Inactivation in Cancer. Cancers (Basel) 2020; 12:cancers12103066. [PMID: 33096593 PMCID: PMC7588890 DOI: 10.3390/cancers12103066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/11/2020] [Accepted: 10/15/2020] [Indexed: 12/16/2022] Open
Abstract
Simple Summary GTPase-Activating Proteins (RasGAPs) are a group of structurally related proteins with a fundamental role in controlling the activity of Ras in normal and cancer cells. In particular, loss of function of RasGAPs may contribute to aberrant Ras activation in cancer. Here we review the multiple molecular mechanisms and factors that are involved in downregulating RasGAPs expression and functions in cancer. Additionally, we discuss how extracellular stimuli from the tumor microenvironment can control RasGAPs expression and activity in cancer cells and stromal cells, indirectly affecting Ras activation, with implications for cancer development and progression. Abstract The Ras pathway is frequently deregulated in cancer, actively contributing to tumor development and progression. Oncogenic activation of the Ras pathway is commonly due to point mutation of one of the three Ras genes, which occurs in almost one third of human cancers. In the absence of Ras mutation, the pathway is frequently activated by alternative means, including the loss of function of Ras inhibitors. Among Ras inhibitors, the GTPase-Activating Proteins (RasGAPs) are major players, given their ability to modulate multiple cancer-related pathways. In fact, most RasGAPs also have a multi-domain structure that allows them to act as scaffold or adaptor proteins, affecting additional oncogenic cascades. In cancer cells, various mechanisms can cause the loss of function of Ras inhibitors; here, we review the available evidence of RasGAP inactivation in cancer, with a specific focus on the mechanisms. We also consider extracellular inputs that can affect RasGAP levels and functions, implicating that specific conditions in the tumor microenvironment can foster or counteract Ras signaling through negative or positive modulation of RasGAPs. A better understanding of these conditions might have relevant clinical repercussions, since treatments to restore or enhance the function of RasGAPs in cancer would help circumvent the intrinsic difficulty of directly targeting the Ras protein.
Collapse
|
10
|
Isaksen TJ, Fujita Y, Yamashita T. Repulsive Guidance Molecule A Suppresses Adult Neurogenesis. Stem Cell Reports 2020; 14:677-691. [PMID: 32243839 PMCID: PMC7160374 DOI: 10.1016/j.stemcr.2020.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 01/17/2023] Open
Abstract
Repulsive guidance molecule A (RGMa) is a glycosylphosphatidylinositol-anchored glycoprotein that exhibits repulsive neurite guidance and regulates neuronal differentiation and survival during brain development. However, the function of RGMa in the adult brain is unknown. Here, we show that RGMa is expressed in the adult hippocampus and provide evidence that RGMa signaling suppresses adult neurogenesis. Knockdown of RGMa in the dentate gyrus increased the number of surviving newborn neurons; however, these cells failed to properly migrate into the granular cell layer. In vitro, RGMa stimulation of adult neural stem cells suppressed neurite outgrowth of newborn neurons, which could be prevented by knockdown of the multifunctional receptor neogenin, as well as pharmacological inhibition of the downstream target Rho-associated protein kinase. These findings present a function for RGMa in the adult brain and add to the intricate molecular network that regulates adult brain plasticity. RGMa suppress survival and growth of newborn neurons in the adult dentate gyrus RGMa signaling depends on neogenin for the regulation of adult neurogenesis RGMa induces RhoA/ROCK activation in adult neuronal stem cells
Collapse
Affiliation(s)
- Toke Jost Isaksen
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Bioscience, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
11
|
Rigby MJ, Gomez TM, Puglielli L. Glial Cell-Axonal Growth Cone Interactions in Neurodevelopment and Regeneration. Front Neurosci 2020; 14:203. [PMID: 32210757 PMCID: PMC7076157 DOI: 10.3389/fnins.2020.00203] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 02/24/2020] [Indexed: 12/19/2022] Open
Abstract
The developing nervous system is a complex yet organized system of neurons, glial support cells, and extracellular matrix that arranges into an elegant, highly structured network. The extracellular and intracellular events that guide axons to their target locations have been well characterized in many regions of the developing nervous system. However, despite extensive work, we have a poor understanding of how axonal growth cones interact with surrounding glial cells to regulate network assembly. Glia-to-growth cone communication is either direct through cellular contacts or indirect through modulation of the local microenvironment via the secretion of factors or signaling molecules. Microglia, oligodendrocytes, astrocytes, Schwann cells, neural progenitor cells, and olfactory ensheathing cells have all been demonstrated to directly impact axon growth and guidance. Expanding our understanding of how different glial cell types directly interact with growing axons throughout neurodevelopment will inform basic and clinical neuroscientists. For example, identifying the key cellular players beyond the axonal growth cone itself may provide translational clues to develop therapeutic interventions to modulate neuron growth during development or regeneration following injury. This review will provide an overview of the current knowledge about glial involvement in development of the nervous system, specifically focusing on how glia directly interact with growing and maturing axons to influence neuronal connectivity. This focus will be applied to the clinically-relevant field of regeneration following spinal cord injury, highlighting how a better understanding of the roles of glia in neurodevelopment can inform strategies to improve axon regeneration after injury.
Collapse
Affiliation(s)
- Michael J Rigby
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States.,Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, United States.,Waisman Center, University of Wisconsin-Madison, Madison, WI, United States
| | - Timothy M Gomez
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, United States.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, United States
| | - Luigi Puglielli
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States.,Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, United States.,Waisman Center, University of Wisconsin-Madison, Madison, WI, United States.,Geriatric Research Education Clinical Center, Veterans Affairs Medical Center, Madison, WI, United States
| |
Collapse
|
12
|
Prieto-Dominguez N, Parnell C, Teng Y. Drugging the Small GTPase Pathways in Cancer Treatment: Promises and Challenges. Cells 2019; 8:E255. [PMID: 30884855 PMCID: PMC6468615 DOI: 10.3390/cells8030255] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/08/2019] [Accepted: 03/13/2019] [Indexed: 02/07/2023] Open
Abstract
Small GTPases are a family of low molecular weight GTP-hydrolyzing enzymes that cycle between an inactive state when bound to GDP and an active state when associated to GTP. Small GTPases regulate key cellular processes (e.g., cell differentiation, proliferation, and motility) as well as subcellular events (e.g., vesicle trafficking), making them key participants in a great array of pathophysiological processes. Indeed, the dysfunction and deregulation of certain small GTPases, such as the members of the Ras and Arf subfamilies, have been related with the promotion and progression of cancer. Therefore, the development of inhibitors that target dysfunctional small GTPases could represent a potential therapeutic strategy for cancer treatment. This review covers the basic biochemical mechanisms and the diverse functions of small GTPases in cancer. We also discuss the strategies and challenges of inhibiting the activity of these enzymes and delve into new approaches that offer opportunities to target them in cancer therapy.
Collapse
Affiliation(s)
- Néstor Prieto-Dominguez
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA.
- Institute of Biomedicine (IBIOMED), University of León, León 24010, Spain.
| | | | - Yong Teng
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA.
- Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
- Department of Medical laboratory, Imaging and Radiologic Sciences, College of Allied Health, Augusta University, Augusta, GA 30912, USA.
| |
Collapse
|
13
|
Song M, Tian F, Xia H, Xie Y. Repulsive guidance molecule a suppresses seizures and mossy fiber sprouting via the FAK‑p120RasGAP‑Ras signaling pathway. Mol Med Rep 2019; 19:3255-3262. [PMID: 30816469 DOI: 10.3892/mmr.2019.9951] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 01/21/2019] [Indexed: 11/05/2022] Open
Abstract
Repulsive guidance molecule a (RGMa) is a membrane‑associated glycoprotein that regulates axonal guidance and inhibits axon outgrowth. In our previous study, we hypothesized that RGMa may be involved in temporal lobe epilepsy (TLE) via the repulsive guidance molecule a (RGMa)‑focal adhesion kinase (FAK)‑Ras signaling pathway. To investigate the role of RGMa in epilepsy, recombinant RGMa protein and FAK inhibitor 14 was intracerebroventricularly injected into a pentylenetetrazol (PTZ) kindling model and Timm staining, co‑immunoprecipitation and western blotting analyses were subsequently performed. The results of the present study revealed that intracerebroventricular injection of recombinant RGMa protein reduced the phosphorylation of FAK (Tyr397) and intracerebroventricular injection of FAK inhibitor 14 reduced the interaction between FAK and p120GAP, as wells as Ras expression. Recombinant RGMa protein and FAK inhibitor 14 exerted seizure‑suppressant effects; however, recombinant RGMa protein but not FAK inhibitor 14 suppressed mossy fiber sprouting in the PTZ kindling model. Collectively, these results demonstrated that RGMa may be considered as a potential therapeutic agent for epilepsy, and that RGMa may exert the aforementioned biological effects partly via the FAK‑p120GAP‑Ras signaling pathway.
Collapse
Affiliation(s)
- Mingyu Song
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Fafa Tian
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Huang Xia
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yuanyuan Xie
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| |
Collapse
|
14
|
RGMa mediates reactive astrogliosis and glial scar formation through TGFβ1/Smad2/3 signaling after stroke. Cell Death Differ 2018; 25:1503-1516. [PMID: 29396549 PMCID: PMC6113216 DOI: 10.1038/s41418-018-0058-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 12/22/2017] [Accepted: 12/27/2017] [Indexed: 01/11/2023] Open
Abstract
In response to stroke, astrocytes become reactive astrogliosis and are a major component of a glial scar. This results in the formation of both a physical and chemical (production of chondroitin sulfate proteoglycans) barrier, which prevent neurite regeneration that, in turn, interferes with functional recovery. However, the mechanisms of reactive astrogliosis and glial scar formation are poorly understood. In this work, we hypothesized that repulsive guidance molecule a (RGMa) regulate reactive astrogliosis and glial scar formation. We first found that RGMa was strongly expressed by reactive astrocytes in the glial scar in a rat model of middle cerebral artery occlusion/reperfusion. Genetic or pharmacologic inhibition of RGMa in vivo resulted in a strong reduction of reactive astrogliosis and glial scarring as well as in a pronounced improvement in functional recovery. Furthermore, we showed that transforming growth factor β1 (TGFβ1) stimulated RGMa expression through TGFβ1 receptor activin-like kinase 5 (ALK5) in primary cultured astrocytes. Knockdown of RGMa abrogated key steps of reactive astrogliosis and glial scar formation induced by TGFβ1, including cellular hypertrophy, glial fibrillary acidic protein upregulation, cell migration, and CSPGs secretion. Finally, we demonstrated that RGMa co-immunoprecipitated with ALK5 and Smad2/3. TGFβ1-induced ALK5-Smad2/3 interaction and subsequent phosphorylation of Smad2/3 were impaired by RGMa knockdown. Taken together, we identified that after stroke, RGMa promotes reactive astrogliosis and glial scar formation by forming a complex with ALK5 and Smad2/3 to promote ALK5-Smad2/3 interaction to facilitate TGFβ1/Smad2/3 signaling, thereby inhibiting neurological functional recovery. RGMa may be a new therapeutic target for stroke.
Collapse
|
15
|
Repulsive Guidance Molecule a (RGMa) Induces Neuropathological and Behavioral Changes That Closely Resemble Parkinson's Disease. J Neurosci 2017; 37:9361-9379. [PMID: 28842419 DOI: 10.1523/jneurosci.0084-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 07/12/2017] [Accepted: 08/11/2017] [Indexed: 01/06/2023] Open
Abstract
Repulsive guidance molecule member a (RGMa) is a membrane-associated or released guidance molecule that is involved in axon guidance, cell patterning, and cell survival. In our previous work, we showed that RGMa is significantly upregulated in the substantia nigra of patients with Parkinson's disease. Here we demonstrate the expression of RGMa in midbrain human dopaminergic (DA) neurons. To investigate whether RGMa might model aspects of the neuropathology of Parkinson's disease in mouse, we targeted RGMa to adult midbrain dopaminergic neurons using adeno-associated viral vectors. Overexpression of RGMa resulted in a progressive movement disorder, including motor coordination and imbalance, which is typical for a loss of DA release in the striatum. In line with this, RGMa induced selective degeneration of dopaminergic neurons in the substantia nigra (SN) and affected the integrity of the nigrostriatal system. The degeneration of dopaminergic neurons was accompanied by a strong microglia and astrocyte activation. The behavioral, molecular, and anatomical changes induced by RGMa in mice are remarkably similar to the clinical and neuropathological hallmarks of Parkinson's disease. Our data indicate that dysregulation of RGMa plays an important role in the pathology of Parkinson's disease, and antibody-mediated functional interference with RGMa may be a disease modifying treatment option.SIGNIFICANCE STATEMENT Parkinson's disease (PD) is a neurodegenerative disease characterized by severe motor dysfunction due to progressive degeneration of mesencephalic dopaminergic (DA) neurons in the substantia nigra. To date, there is no regenerative treatment available. We previously showed that repulsive guidance molecule member a (RGMa) is upregulated in the substantia nigra of PD patients. Adeno-associated virus-mediated targeting of RGMa to mouse DA neurons showed that overexpression of this repulsive axon guidance and cell patterning cue models the behavioral and neuropathological characteristics of PD in a remarkable way. These findings have implications for therapy development as interfering with the function of this specific axon guidance cue may be beneficial to the survival of DA neurons.
Collapse
|
16
|
Siebold C, Yamashita T, Monnier PP, Mueller BK, Pasterkamp RJ. RGMs: Structural Insights, Molecular Regulation, and Downstream Signaling. Trends Cell Biol 2017; 27:365-378. [PMID: 28007423 PMCID: PMC5404723 DOI: 10.1016/j.tcb.2016.11.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 11/27/2016] [Accepted: 11/28/2016] [Indexed: 12/20/2022]
Abstract
Although originally discovered as neuronal growth cone-collapsing factors, repulsive guidance molecules (RGMs) are now known as key players in many fundamental processes, such as cell migration, differentiation, iron homeostasis, and apoptosis, during the development and homeostasis of many tissues and organs, including the nervous, skeletal, and immune systems. Furthermore, three RGMs (RGMa, RGMb/DRAGON, and RGMc/hemojuvelin) have been linked to the pathogenesis of various disorders ranging from multiple sclerosis (MS) to cancer and juvenile hemochromatosis (JHH). While the molecular details of these (patho)biological effects and signaling modes have long remained unknown, recent studies unveil several exciting and novel aspects of RGM processing, ligand-receptor interactions, and downstream signaling. In this review, we highlight recent advances in the mechanisms-of-action and function of RGM proteins.
Collapse
Affiliation(s)
- Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Philippe P Monnier
- Krembil Research Institute, 60 Leonard Street, M5T 2S8, Toronto, ONT, Canada
| | - Bernhard K Mueller
- Neuroscience Discovery Research, Abbvie, Knollstrasse 50, 67061 Ludwigshafen, Germany
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands.
| |
Collapse
|
17
|
Grewal T, Hoque M, Conway JRW, Reverter M, Wahba M, Beevi SS, Timpson P, Enrich C, Rentero C. Annexin A6-A multifunctional scaffold in cell motility. Cell Adh Migr 2017; 11:288-304. [PMID: 28060548 DOI: 10.1080/19336918.2016.1268318] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Annexin A6 (AnxA6) belongs to a highly conserved protein family characterized by their calcium (Ca2+)-dependent binding to phospholipids. Over the years, immunohistochemistry, subcellular fractionations, and live cell microscopy established that AnxA6 is predominantly found at the plasma membrane and endosomal compartments. In these locations, AnxA6 acts as a multifunctional scaffold protein, recruiting signaling proteins, modulating cholesterol and membrane transport and influencing actin dynamics. These activities enable AnxA6 to contribute to the formation of multifactorial protein complexes and membrane domains relevant in signal transduction, cholesterol homeostasis and endo-/exocytic membrane transport. Hence, AnxA6 has been implicated in many biological processes, including cell proliferation, survival, differentiation, inflammation, but also membrane repair and viral infection. More recently, we and others identified roles for AnxA6 in cancer cell migration and invasion. This review will discuss how the multiple scaffold functions may enable AnxA6 to modulate migratory cell behavior in health and disease.
Collapse
Affiliation(s)
- Thomas Grewal
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Monira Hoque
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - James R W Conway
- b The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Sydney , NSW , Australia
| | - Meritxell Reverter
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
| | - Mohamed Wahba
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Syed S Beevi
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Paul Timpson
- b The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Sydney , NSW , Australia
| | - Carlos Enrich
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
| | - Carles Rentero
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
| |
Collapse
|
18
|
Minocycline Promotes Neurite Outgrowth of PC12 Cells Exposed to Oxygen-Glucose Deprivation and Reoxygenation Through Regulation of MLCP/MLC Signaling Pathways. Cell Mol Neurobiol 2016; 37:417-426. [PMID: 27098315 DOI: 10.1007/s10571-016-0374-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/17/2015] [Indexed: 10/21/2022]
Abstract
Minocycline, a semi-synthetic second-generation derivative of tetracycline, has been reported to exert neuroprotective effects both in animal models and in clinic trials of neurological diseases. In the present study, we first investigated the protective effects of minocycline on oxygen-glucose deprivation and reoxygenation-induced impairment of neurite outgrowth and its potential mechanism in the neuronal cell line, PC12 cells. We found that minocycline significantly increased cell viability, promoted neurite outgrowth and enhanced the expression of growth-associated protein-43 (GAP-43) in PC12 cells exposed to oxygen-glucose deprivation/reoxygenation injury. In addition, immunoblots revealed that minocycline reversed the overexpression of phosphorylated myosin light chain (MLC) and the suppression of activated extracellular signal-regulated kinase 1/2 (ERK1/2) caused by oxygen-glucose deprivation/reoxygenation injury. Moreover, the minocycline-induced neurite outgrowth was significantly blocked by Calyculin A (1 nM), an inhibitor of myosin light chain phosphatase (MLCP), but not by an ERK1/2 inhibitor (U0126; 10 μM). These findings suggested that minocycline activated the MLCP/MLC signaling pathway in PC12 cells after oxygen-glucose deprivation/reoxygenation injury, which resulted in the promotion of neurite outgrowth.
Collapse
|
19
|
Antoine-Bertrand J, Duquette PM, Alchini R, Kennedy TE, Fournier AE, Lamarche-Vane N. p120RasGAP Protein Mediates Netrin-1 Protein-induced Cortical Axon Outgrowth and Guidance. J Biol Chem 2015; 291:4589-602. [PMID: 26710849 DOI: 10.1074/jbc.m115.674846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 12/23/2022] Open
Abstract
The receptor deleted in colorectal cancer (DCC) mediates the attraction of growing axons to netrin-1 during brain development. In response to netrin-1 stimulation, DCC becomes a signaling platform to recruit proteins that promote axon outgrowth and guidance. The Ras GTPase-activating protein (GAP) p120RasGAP inhibits Ras activity and mediates neurite retraction and growth cone collapse in response to repulsive guidance cues. Here we show an interaction between p120RasGAP and DCC that positively regulates netrin-1-mediated axon outgrowth and guidance in embryonic cortical neurons. In response to netrin-1, p120RasGAP is recruited to DCC in growth cones and forms a multiprotein complex with focal adhesion kinase and ERK. We found that Ras/ERK activities are elevated aberrantly in p120RasGAP-deficient neurons. Moreover, the expression of p120RasGAP Src homology 2 (SH2)-SH3-SH2 domains, which interact with the C-terminal tail of DCC, is sufficient to restore netrin-1-dependent axon outgrowth in p120RasGAP-deficient neurons. We provide a novel mechanism that exploits the scaffolding properties of the N terminus of p120RasGAP to tightly regulate netrin-1/DCC-dependent axon outgrowth and guidance.
Collapse
Affiliation(s)
- Judith Antoine-Bertrand
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Philippe M Duquette
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Ricardo Alchini
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Timothy E Kennedy
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Alyson E Fournier
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Nathalie Lamarche-Vane
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| |
Collapse
|
20
|
Repulsive guidance molecule A suppresses angiogenesis. Biochem Biophys Res Commun 2015; 469:993-9. [PMID: 26721439 DOI: 10.1016/j.bbrc.2015.12.073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 12/18/2015] [Indexed: 11/23/2022]
Abstract
The repulsive guidance molecule-a (RGMa) is a membrane-associated glycoprotein that has diverse functions in the developing and adult central nervous system. Here, we show that RGMa suppresses new blood vessel formation. Treatment of human umbilical artery endothelial cells (HUAEC) on Matrigel with recombinant RGMa inhibits vascular endothelial growth factor (VEGF)-induced and VEGF-independent tubular formation and migration. RGMa enhances adhesion presumably through dephosphorylation of focal adhesion kinase (FAK) at tyrosine-397. Neogenin, an RGMa receptor, in HUAEC is required for the effect of RGMa. In vivo Matrigel plug assay reveals that treatment with recombinant RGMa suppresses angiogenesis. Thus, we conclude that RGMa inhibits angiogenesis in vitro and in vivo suggesting that its manipulation would be an efficient therapeutic strategy for pro-angiogenic conditions.
Collapse
|
21
|
Song MY, Tian FF, Wang YZ, Huang X, Guo JL, Ding DX. Potential roles of the RGMa-FAK-Ras pathway in hippocampal mossy fiber sprouting in the pentylenetetrazole kindling model. Mol Med Rep 2014; 11:1738-44. [PMID: 25420768 PMCID: PMC4270322 DOI: 10.3892/mmr.2014.2993] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 08/01/2014] [Indexed: 11/23/2022] Open
Abstract
Mossy fiber sprouting (MFS) is a unique feature of chronic epilepsy. However, the molecular signals underlying MFS are still unclear. The repulsive guidance molecule A (RGMa) appears to contribute to axon growth and axonal guidance, and may exert its biological effects by dephosphorylating focal adhesion kinase (FAK) at Tyr397, then regulating the activation of Ras. The objective of this study was to explore the expression patterns of RGMa, FAK (Tyr397) and Ras in epileptogenesis, and their correlation with MFS. The epileptic models were established by intraperitoneal pentylenetetrazole (PTZ) injection of Sprague-Dawley rats. At 3 days and at 1, 2, 4 and 6 weeks after the first PTZ injection, Timm staining was scored at different time points in the CA3 region of the hippocampus and dentate gyrus. The protein levels of RGMa, FAK (Tyr397) and Ras were analyzed at different time points in the CA3 region of the hippocampus using immunofluorescence, immunohistochemistry and western blot analysis. Compared with the control (saline-injected) group, the expression of RGMa in the CA3 area was significantly downregulated (P<0.05) from 3 days and still maintained the low expression at 6 weeks in the PTZ group. The expression of FAK (Tyr397) and Ras was upregulated (P<0.05) in the PTZ groups. The Timm score in the CA3 region was significantly higher than that in the control group at different time points and reached a peak at 4 weeks. In the CA3 region, no obvious distinction was observed at the different time points in the control group. To the best of our knowledge, these are the first results to indicate that the RGMa-FAK-Ras pathway may be involved in MFS and the development of temporal lobe epilepsy.
Collapse
Affiliation(s)
- Ming-Yu Song
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Fa-Fa Tian
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yu-Zhong Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xia Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Jia-Ling Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Dong-Xue Ding
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| |
Collapse
|
22
|
Repulsive Guidance Molecule-a Is Involved in Th17-Cell-Induced Neurodegeneration in Autoimmune Encephalomyelitis. Cell Rep 2014; 9:1459-70. [DOI: 10.1016/j.celrep.2014.10.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 09/22/2014] [Accepted: 10/14/2014] [Indexed: 12/21/2022] Open
|
23
|
Armendáriz BG, Masdeu MDM, Soriano E, Ureña JM, Burgaya F. The diverse roles and multiple forms of focal adhesion kinase in brain. Eur J Neurosci 2014; 40:3573-90. [DOI: 10.1111/ejn.12737] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 08/25/2014] [Indexed: 02/04/2023]
Affiliation(s)
- Beatriz G. Armendáriz
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Maria del Mar Masdeu
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Eduardo Soriano
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Jesús M. Ureña
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Ferran Burgaya
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| |
Collapse
|
24
|
Focal adhesion kinase function in neuronal development. Curr Opin Neurobiol 2014; 27:89-95. [DOI: 10.1016/j.conb.2014.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/17/2014] [Accepted: 03/09/2014] [Indexed: 11/21/2022]
|
25
|
15q26.1 microdeletion encompassing only CHD2 and RGMA in two adults with moderate intellectual disability, epilepsy and truncal obesity. Eur J Med Genet 2014; 57:520-3. [PMID: 24932903 DOI: 10.1016/j.ejmg.2014.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/02/2014] [Indexed: 01/28/2023]
Abstract
We report two patients with microdeletions in chromosomal subdomain 15q26.1 encompassing only two genes, CHD2 and RGMA. Both patients present a distinct phenotype with intellectual disability, epilepsy, behavioral issues, truncal obesity, scoliosis and facial dysmorphism. CHD2 haploinsufficiency is known to cause intellectual disability and epilepsy, RGMA haploinsufficiency might explain truncal obesity with onset around puberty observed in our two patients.
Collapse
|
26
|
MicroRNA-132 is enriched in developing axons, locally regulates Rasa1 mRNA, and promotes axon extension. J Neurosci 2014; 34:66-78. [PMID: 24381269 DOI: 10.1523/jneurosci.3371-13.2014] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Developing axons can locally synthesize proteins, with roles in axon growth, guidance, and regeneration, but the mechanisms that regulate axonal mRNA translation are not well understood. MicroRNAs (miRNAs) are important regulators of translation but have still been little characterized in developing axons. Here we study mouse dorsal root ganglion (DRG) axons and show that their extension is impaired by conditional deficiency of the miRNA-processing enzyme Dicer in vitro and in vivo. A screen for axonal localization identifies a specific set of miRNAs preferentially enriched within the developing axon. High axonal expression and preferential localization were observed for miR-132, a miRNA previously known for roles in dendrites and dysregulation in major neurologic diseases. miR-132 knockdown reduced extension of cultured DRG axons, whereas overexpression increased extension. Mechanistically, miR-132 regulated the mRNA for the Ras GTPase activator Rasa1, a novel target in neuronal function. Moreover, miR-132 regulation of Rasa1 translation was seen in severed axons, demonstrating miRNA function locally within the axon. miR-132 expression in DRGs peaked in the period of maximum axon growth in vivo, consistent with its effect on axon growth, and suggesting a role as a developmental timer. Together, these findings identify miR-132 as a positive regulator of developing axon extension, acting through repression of Rasa1 mRNA, in a mechanism that operates locally within the axon.
Collapse
|
27
|
Barderas R, Mendes M, Torres S, Bartolomé RA, López-Lucendo M, Villar-Vázquez R, Peláez-García A, Fuente E, Bonilla F, Casal JI. In-depth characterization of the secretome of colorectal cancer metastatic cells identifies key proteins in cell adhesion, migration, and invasion. Mol Cell Proteomics 2013; 12:1602-20. [PMID: 23443137 DOI: 10.1074/mcp.m112.022848] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Liver metastasis in colorectal cancer is the major cause of cancer-related deaths. To identify and characterize proteins associated with colon cancer metastasis, we have compared the conditioned serum-free medium of highly metastatic KM12SM colorectal cancer cells with the parental, poorly metastatic KM12C cells using quantitative stable isotope labeling by amino acids in cell culture (SILAC) analyses on a linear ion trap-Orbitrap Velos mass spectrometer. In total, 1337 proteins were simultaneously identified in SILAC forward and reverse experiments. For quantification, 1098 proteins were selected in both experiments, with 155 proteins showing >1.5-fold change. About 52% of these proteins were secreted directly or using alternative secretion pathways. GDF15, S100A8/A9, and SERPINI1 showed capacity to discriminate cancer serum samples from healthy controls using ELISAs. In silico analyses of deregulated proteins in the secretome of metastatic cells showed a major abundance of proteins involved in cell adhesion, migration, and invasion. To characterize the tumorigenic and metastatic properties of some top up- and down-regulated proteins, we used siRNA silencing and antibody blocking. Knockdown expression of NEO1, SERPINI1, and PODXL showed a significant effect on cellular adhesion. Silencing or blocking experiments with SOSTDC1, CTSS, EFNA3, CD137L/TNFSF9, ZG16B, and Midkine caused a significant decrease in migration and invasion of highly metastatic cells. In addition, silencing of SOSTDC1, EFNA3, and CD137L/TNFSF9 reduced liver colonization capacity of KM12SM cells. Finally, the panel of six proteins involved in invasion showed association with poor prognosis and overall survival after dataset analysis of gene alterations. In summary, we have defined a collection of proteins that are relevant for understanding the mechanisms underlying adhesion, migration, invasion, and metastasis in colorectal cancer.
Collapse
Affiliation(s)
- Rodrigo Barderas
- Functional Proteomics Laboratory, Centro de Investigaciones Biológicas, 28040 Madrid, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Spatiotemporal expression of repulsive guidance molecules (RGMs) and their receptor neogenin in the mouse brain. PLoS One 2013; 8:e55828. [PMID: 23457482 PMCID: PMC3573027 DOI: 10.1371/journal.pone.0055828] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 01/02/2013] [Indexed: 02/07/2023] Open
Abstract
Neogenin has been implicated in a variety of developmental processes such as neurogenesis, neuronal differentiation, apoptosis, migration and axon guidance. Binding of repulsive guidance molecules (RGMs) to Neogenin inhibits axon outgrowth of different neuronal populations. This effect requires Neogenin to interact with co-receptors of the uncoordinated locomotion-5 (Unc5) family to activate downstream Rho signaling. Although previous studies have reported RGM, Neogenin, and/or Unc5 expression, a systematic comparison of RGM and Neogenin expression in the developing nervous system is lacking, especially at later developmental stages. Furthermore, information on RGM and Neogenin expression at the protein level is limited. To fill this void and to gain further insight into the role of RGM-Neogenin signaling during mouse neural development, we studied the expression of RGMa, RGMb, Neogenin and Unc5A-D using in situ hybridization, immunohistochemistry and RGMa section binding. Expression patterns in the primary olfactory system, cortex, hippocampus, habenula, and cerebellum were studied in more detail. Characteristic cell layer-specific expression patterns were detected for RGMa, RGMb, Neogenin and Unc5A-D. Furthermore, strong expression of RGMa, RGMb and Neogenin protein was found on several major axon tracts such as the primary olfactory projections, anterior commissure and fasciculus retroflexus. These data not only hint at a role for RGM-Neogenin signaling during the development of different neuronal systems, but also suggest that Neogenin partners with different Unc5 family members in different systems. Overall, the results presented here will serve as a framework for further dissection of the role of RGM-Neogenin signaling during neural development.
Collapse
|
29
|
Kong Y, Rogers MR, Qin X. Effective neuroprotection by ischemic postconditioning is associated with a decreased expression of RGMa and inflammation mediators in ischemic rats. Neurochem Res 2013; 38:815-25. [PMID: 23389659 DOI: 10.1007/s11064-013-0984-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Revised: 01/17/2013] [Accepted: 01/25/2013] [Indexed: 12/25/2022]
Abstract
Whether ischemic postconditioning (IPC) can significantly alleviate ischemic injury hinges on the appropriate measure. In this study, the expression RGMa and IL-1β, IL-6 are investigated to estimate the therapeutic benefits of various postconditioning strategies after cerebral ischemia/reperfusion. The study consists of the sham-operated group and five treatment groups: ischemia/reperfusion (I/R), two proximate ischemic postconditioning (IPC-S and IPC-M), remote postconditioning (RIPC) and delayed postconditioning (DIPC) groups. We find that rats in IPC and RIPC groups exhibit significantly less neural deficit and lower infarct volume than that in I/R and DIPC groups after ischemia/reperfusion. Moreover, in ischemic cortex and hippocampus, the mRNA level of RGMa is much lower in IPC and RIPC groups. Immunohistochemical analysis indicates that the expression of RGMa, IL-1β and IL-6 are reduced in IPC and RIPC groups (especially in IPC-S group). Furthermore, neurofilament staining reveals that the rats in IPC and RIPC groups have less axonal injury than that in I/R and DIPC groups. Our studies suggest that the optimal strategy to attenuate cerebral ischemia/reperfusion is achieved by early, short-term, and multiple cycles of proximal IPC. The cerebral protective effect of IPC may be associated with the decreased expression of RGMa and inflammation mediators.
Collapse
Affiliation(s)
- Yuhan Kong
- Department of Neurology and Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | | | | |
Collapse
|
30
|
Neurofibromin mediates FAK signaling in confining synapse growth at Drosophila neuromuscular junctions. J Neurosci 2013; 32:16971-81. [PMID: 23175848 DOI: 10.1523/jneurosci.1756-12.2012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neurofibromatosis type I (NF1), caused by the mutation in the NF1 gene, is characterized by multiple pathological symptoms. Importantly, ~50% of NF1 patients also suffer learning difficulty. Although downstream pathways are well studied, regulation of the NF1-encoded neurofibromin protein is less clear. Here, we focused on the pathophysiology of Drosophila NF1 mutants in synaptic growth at neuromuscular junctions. Our analysis suggests that the Drosophila neurofibromin protein NF1 is required to constrain synaptic growth and transmission. NF1 functions downstream of the Drosophila focal adhesion kinase (FAK) Fak56 and physically interacts with Fak56. The N-terminal region of NF1 mediates the interaction with Fak56 and is required for the signaling activity and presynaptic localization of NF1. In presynapses, NF1 acts via the cAMP pathway, but independent of its GAP activity, to restrain synaptic growth. Thus, presynaptic FAK signaling may be disrupted, causing abnormal synaptic growth and transmission in the NF1 genetic disorder.
Collapse
|
31
|
Pentassuglia L, Sawyer DB. ErbB/integrin signaling interactions in regulation of myocardial cell-cell and cell-matrix interactions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:909-16. [PMID: 23261977 DOI: 10.1016/j.bbamcr.2012.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 12/02/2012] [Accepted: 12/03/2012] [Indexed: 12/17/2022]
Abstract
Neuregulin (Nrg)/ErbB and integrin signaling pathways are critical for the normal function of the embryonic and adult heart. Both systems activate several downstream signaling pathways, with different physiological outputs: cell survival, fibrosis, excitation-contraction coupling, myofilament structure, cell-cell and cell-matrix interaction. Activation of ErbB2 by Nrg1β in cardiomycytes or its overexpression in cancer cells induces phosphorylation of FAK (Focal Adhesion Kinase) at specific sites with modulation of survival, invasion and cell-cell contacts. FAK is also a critical mediator of integrin receptors, converting extracellular matrix alterations into intracellular signaling. Systemic FAK deletion is lethal and is associated with left ventricular non-compaction whereas cardiac restriction in adult hearts is well tolerated. Nevertheless, these hearts are more susceptible to stress conditions like trans-aortic constriction, hypertrophy, and ischemic injury. As FAK is both downstream and specifically activated by integrins and Nrg-1β, here we will explore the role of FAK in the heart as a protective factor and as possible mediator of the crosstalk between the ErbB and Integrin receptors. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction.
Collapse
|
32
|
Myers JP, Robles E, Ducharme-Smith A, Gomez TM. Focal adhesion kinase modulates Cdc42 activity downstream of positive and negative axon guidance cues. J Cell Sci 2012; 125:2918-29. [PMID: 22393238 DOI: 10.1242/jcs.100107] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
There is biochemical, imaging and functional evidence that Rho GTPase signaling is a crucial regulator of actin-based structures such as lamellipodia and filopodia. However, although Rho GTPases are believed to serve similar functions in growth cones, the spatiotemporal dynamics of Rho GTPase signaling has not been examined in living growth cones in response to known axon guidance cues. Here we provide the first measurements of Cdc42 activity in living growth cones acutely stimulated with both growth-promoting and growth-inhibiting axon-guidance cues. Interestingly, we find that both permissive and repulsive factors can work by modulating Cdc42 activity, but in opposite directions. We find that the growth-promoting factors laminin and BDNF activate Cdc42, whereas the inhibitor Slit2 reduces Cdc42 activity in growth cones. Remarkably, we find that regulation of focal adhesion kinase (FAK) activity is a common upstream modulator of Cdc42 by BDNF, laminin and Slit. These findings suggest that rapid modulation of Cdc42 signaling through FAK by receptor activation underlies changes in growth cone motility in response to permissive and repulsive guidance cues.
Collapse
Affiliation(s)
- Jonathan P Myers
- Department of Neuroscience, Medical Scientist Training Program and Neuroscience Training Program, University of Wisconsin, Madison, WI 53706, USA
| | | | | | | |
Collapse
|
33
|
Identification of the neogenin-binding site on the repulsive guidance molecule A. PLoS One 2012; 7:e32791. [PMID: 22396795 PMCID: PMC3291610 DOI: 10.1371/journal.pone.0032791] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/31/2012] [Indexed: 11/25/2022] Open
Abstract
Repulsive guidance molecule (RGM) is a membrane-bound protein that was originally identified as an axon guidance molecule in the chick retinotectal system. RGMa, one of the 3 isoforms found in mammals, is involved in laminar patterning, cephalic neural tube closure, axon guidance, and inhibition of axonal regeneration. In addition to its roles in the nervous system, RGMa plays a role in enhancing helper T-cell activation. Binding of RGM to its receptor, neogenin, is considered necessary to transduce these signals; however, information on the binding of RGM to neogenin is limited. Using co-immunoprecipitation studies, we have identified that the RGMa region required for binding to neogenin contains amino acids (aa) 259–295. Synthesized peptide consisting of aa 284–293 directly binds to the extracellular domain (ECD) of recombinant neogenin, and addition of this peptide inhibits RGMa-induced growth cone collapse in mouse cortical neurons. Thus, we propose that this peptide is a promising lead in finding reagents capable of inhibiting RGMa signaling.
Collapse
|
34
|
Tassew N, Charish J, Seidah N, Monnier P. SKI-1 and Furin Generate Multiple RGMa Fragments that Regulate Axonal Growth. Dev Cell 2012; 22:391-402. [DOI: 10.1016/j.devcel.2011.11.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 09/19/2011] [Accepted: 11/21/2011] [Indexed: 11/26/2022]
|
35
|
Focal adhesion kinase promotes integrin adhesion dynamics necessary for chemotropic turning of nerve growth cones. J Neurosci 2011; 31:13585-95. [PMID: 21940449 DOI: 10.1523/jneurosci.2381-11.2011] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The ability of extending axons to navigate using combinations of extracellular cues is essential for proper neural network formation. One intracellular signaling molecule that integrates convergent signals from both extracellular matrix (ECM) proteins and growth factors is focal adhesion kinase (FAK). Analysis of FAK function shows that it influences a variety of cellular activities, including cell motility, proliferation, and differentiation. Recent work in developing neurons has shown that FAK and Src function downstream of both attractive and repulsive growth factors, but little is known about the effectors or cellular mechanisms that FAK controls in growth cones on ECM proteins. We report that FAK functions downstream of brain-derived neurotrophic factor (BDNF) and laminin in the modulation of point contact dynamics, phosphotyrosine signaling at filopodial tips, and lamellipodial protrusion. BDNF stimulation accelerates paxillin-containing point contact turnover and formation. Knockdown of FAK function either with a FAK antisense morpholino or by expression of FRNK, a dominant-negative FAK isoform, blocks all aspects of the response to BDNF, including the acceleration of point contact dynamics. On the other hand, expression of specific FAK point mutants can selectively disrupt distinct aspects of the response to BDNF. We also show that growth cone turning depends on both signaling cascades tested here. Finally, we provide the first evidence that growth cone point contacts are asymmetrically regulated during turning to an attractive guidance cue.
Collapse
|
36
|
Zhao H, Yao R, Cao X, Wu G. Neuroimmune modulation following traumatic stress in rats: evidence for an immunoregulatory cascade mediated by c-Src, miRNA222 and PAK1. J Neuroinflammation 2011; 8:159. [PMID: 22078298 PMCID: PMC3256122 DOI: 10.1186/1742-2094-8-159] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 11/14/2011] [Indexed: 11/10/2022] Open
Abstract
Background Neuroimmune modulation following traumatic stress is accompanied by cortical upregulation of c-Src expression, but the mechanistic details of the potential regulatory link between c-Src expression and immunosuppression have not been established. Methods We used a combination of techniques to measure temporal changes in: (i) the parallel expression of c-Src and microRNA222; (ii) levels of PAK1 (p21-activated kinase 1); and (iii) the association between PAK1 and interleukin 1β signaling, both in cortex of rats following traumatic stress and in primary cortical neurons. Techniques included real-time PCR, immunoprecipitation, western blotting and subcellular fractionation by discontinuous centrifugation. We also measured lymphocyte proliferation and natural killer (NK) cell activity. Results We confirm robust upregulation of c-Src expression following traumatic stress. c-Src upregulation was accompanied by marked increases in levels of miRNA222; other studied miRNAs were not affected by stress. We also established that PAK1 is a primary target for miRNA222, and that increased levels of miRNA222 following traumatic stress are accompanied by downregulation of PAK1 expression. PAK1 was shown to mediate the association of IL-1RI with lipid rafts and thereby enhance IL-1 signaling. Detailed analyses in cultured neurons and glial cells revealed that PAK1-mediated enhancement of IL-1RI activation is governed to a large extent by c-Src/miRNA222 signaling; this signaling played a central role in the modulation of lymphocyte proliferation and NK cell activity. Conclusions Our results suggest that neuroimmune modulation following traumatic stress is mediated by a cascade that involves c-Src-mediated enhancement of miRNA222 expression and downregulation of PAK1, which in turn impairs signaling via IL-1β/IL1-RI, leading to immunosuppression. The regulatory networks involving c-Src/miRNA222 and PAK1/IL-1RI signaling have significant potential for the development of therapeutic approaches designed to promote recovery following traumatic injury.
Collapse
Affiliation(s)
- Hui Zhao
- Department of Integrative Medicine and Neurobiology, State Key Lab of Medical Neurobiology, Shanghai Medical College, Brain Research Institute, Fudan University, Shanghai, P R China.
| | | | | | | |
Collapse
|
37
|
Abstract
Ever since their discovery as cellular counterparts of viral oncogenes more than 25 years ago, much progress has been made in understanding the complex networks of signal transduction pathways activated by oncogenic Ras mutations in human cancers. The activity of Ras is regulated by nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), and much emphasis has been put into the biochemical and structural analysis of the Ras/GAP complex. The mechanisms by which GAPs catalyze Ras-GTP hydrolysis have been clarified and revealed that oncogenic Ras mutations confer resistance to GAPs and remain constitutively active. However, it is yet unclear how cells coordinate the large and divergent GAP protein family to promote Ras inactivation and ensure a certain biological response. Different domain arrangements in GAPs to create differential protein-protein and protein-lipid interactions are probably key factors determining the inactivation of the 3 Ras isoforms H-, K-, and N-Ras and their effector pathways. In recent years, in vitro as well as cell- and animal-based studies examining GAP activity, localization, interaction partners, and expression profiles have provided further insights into Ras inactivation and revealed characteristics of several GAPs to exert specific and distinct functions. This review aims to summarize knowledge on the cell biology of RasGAP proteins that potentially contributes to differential regulation of spatiotemporal Ras signaling.
Collapse
Affiliation(s)
- Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia
| | | | | | | |
Collapse
|
38
|
Okamura Y, Kohmura E, Yamashita T. TACE cleaves neogenin to desensitize cortical neurons to the repulsive guidance molecule. Neurosci Res 2011; 71:63-70. [PMID: 21645559 DOI: 10.1016/j.neures.2011.05.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 05/16/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
Abstract
Neogenin is a receptor for netrins and proteins of the repulsive guidance molecule (RGM) family. It regulates several key developmental processes within the nervous system. The binding of RGMa to neogenin induces the inhibition of neurite outgrowth and the collapse of the growth cone of neurons. Here, we report that a disintegrin and metalloprotease (ADAM) transmembrane protein regulates the sensitivity of neurons to RGMa, by inducing the shedding of the ectodomain of neogenin. The extracellular domain of neogenin is directly associated with and cleaved off by the tumor necrosis factor-α converting enzyme (TACE), also called ADAM17. TACE is endogenously expressed in embryonic cortical neurons and regulates the cleavage of neogenin, and the inhibition of TACE in turn enhances RGMa-induced inhibition of neurite outgrowth and collapse of the growth cone. Conversely, exogenous expression of TACE abolishes the effect of RGMa. Therefore, TACE may play a role in modulating the RGM-induced repulsive behavior of neurons by regulating the expression of neogenin on the cell surface.
Collapse
Affiliation(s)
- Yusuke Okamura
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | | | |
Collapse
|
39
|
Chacón MR, Fazzari P. FAK: dynamic integration of guidance signals at the growth cone. Cell Adh Migr 2011; 5:52-5. [PMID: 20953136 DOI: 10.4161/cam.5.1.13681] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
During the formation of neural circuitry, axons are known to be guided to their specific targets by a relatively small arsenal of guidance signals. However, the molecular integration of this guidance information inside the axonal growth cone (GC) is still baffling. Focal adhesion kinase (FAK) is a cytosolic kinase which interacts with a complex molecular network via multiple phosphorylation sites. Paradoxically, FAK activation is required by both attractive and repulsive cues to control respectively axon outgrowth and disassembly of adhesive structures together with cytoskeletal dynamics. It was suggested that FAK might work as a versatile molecular integrator switching to different functions depending on its activation state. Two studies published recently by our group and Woo et al. shed light on this issue: for the first time, these works report a detailed molecular analysis of FAK activation and phosphorylation pattern in primary neuronal cultures in response to the repulsive cues Semaphorin3A and ephrinA1 respectively. Here we comment on the major novelties provided by these papers in the context of previous literature and we speculate on the future avenues of investigation opened by these works.
Collapse
Affiliation(s)
- Mariola R Chacón
- Instituto de Neurociencias de Alicante, CSIC, Sant Joan d'Alacant, Spain
| | | |
Collapse
|
40
|
Molecular biology, genetics and biochemistry of the repulsive guidance molecule family. Biochem J 2009; 422:393-403. [PMID: 19698085 DOI: 10.1042/bj20090978] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
RGMs (repulsive guidance molecules) comprise a recently discovered family of GPI (glycosylphosphatidylinositol)-linked cell-membrane-associated proteins found in most vertebrate species. The three proteins, RGMa, RGMb and RGMc, products of distinct single-copy genes that arose early in vertebrate evolution, are approximately 40-50% identical to each other in primary amino acid sequence, and share similarities in predicted protein domains and overall structure, as inferred by ab initio molecular modelling; yet the respective proteins appear to undergo distinct biosynthetic and processing steps, whose regulation has not been characterized to date. Each RGM also displays a discrete tissue-specific pattern of gene and protein expression, and each is proposed to have unique biological functions, ranging from axonal guidance during development (RGMa) to regulation of systemic iron metabolism (RGMc). All three RGM proteins appear capable of binding selected BMPs (bone morphogenetic proteins), and interactions with BMPs mediate at least some of the biological effects of RGMc on iron metabolism, but to date no role for BMPs has been defined in the actions of RGMa or RGMb. RGMa and RGMc have been shown to bind to the transmembrane protein neogenin, which acts as a critical receptor to mediate the biological effects of RGMa on repulsive axonal guidance and on neuronal survival, but its role in the actions of RGMc remains to be elucidated. Similarly, the full spectrum of biological functions of the three RGMs has not been completely characterized yet, and will remain an active topic of ongoing investigation.
Collapse
|