1
|
Pizzella A, Penna E, Abate N, Frenna E, Canafoglia L, Ragona F, Russo R, Chambery A, Perrone-Capano C, Cappello S, Crispino M, Di Giaimo R. Pathological Deficit of Cystatin B Impairs Synaptic Plasticity in EPM1 Human Cerebral Organoids. Mol Neurobiol 2024; 61:4318-4334. [PMID: 38087165 PMCID: PMC11236866 DOI: 10.1007/s12035-023-03812-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/17/2023] [Indexed: 07/11/2024]
Abstract
Cystatin B (CSTB) is a small protease inhibitor protein being involved in cell proliferation and neuronal differentiation. Loss-of-function mutations in CSTB gene cause progressive myoclonic epilepsy 1 (EPM1). We previously demonstrated that CSTB is locally synthesized in synaptic nerve terminals from rat brain and secreted into the media, indicating its role in synaptic plasticity. In this work, we have further investigated the involvement of CSTB in synaptic plasticity, using synaptosomes from human cerebral organoids (hCOs) as well as from rodents' brain. Our data demonstrate that CSTB is released from synaptosomes in two ways: (i) as a soluble protein and (ii) in extracellular vesicles-mediated pathway. Synaptosomes isolated from hCOs are enriched in pre-synaptic proteins and contain CSTB at all developmental stages analyzed. CSTB presence in the synaptic territories was also confirmed by immunostaining on human neurons in vitro. To investigate if the depletion of CSTB affects synaptic plasticity, we characterized the synaptosomes from EPM1 hCOs. We found that the levels of presynaptic proteins and of an initiation factor linked to local protein synthesis were both reduced in EPM1 hCOs and that the extracellular vesicles trafficking pathway was impaired. Moreover, EPM1 neurons displayed anomalous morphology with longer and more branched neurites bearing higher number of intersections and nodes, suggesting connectivity alterations. In conclusion, our data strengthen the idea that CSTB plays a critical role in the synapse physiology and reveal that pathologically low levels of CSTB may affect synaptic plasticity, leading to synaptopathy and altered neuronal morphology.
Collapse
Affiliation(s)
- Amelia Pizzella
- Department of Biology, University of Naples Federico II, Naples, Italy
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
| | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Natalia Abate
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Elisa Frenna
- Department of Biology, University of Naples Federico II, Naples, Italy
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
| | - Laura Canafoglia
- Integrated Diagnostics for Epilepsy, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rosita Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli, Caserta, Italy
| | - Angela Chambery
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli, Caserta, Italy
| | | | - Silvia Cappello
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
- Biomedical Center, Ludwig Maximilian University of Munich, Munich, Germany
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
| | - Rossella Di Giaimo
- Department of Biology, University of Naples Federico II, Naples, Italy.
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany.
| |
Collapse
|
2
|
Hu Y, Lopez VA, Xu H, Pfister JP, Song B, Servage KA, Sakurai M, Jones BT, Mendell JT, Wang T, Wu J, Lambowitz AM, Tomchick DR, Pawłowski K, Tagliabracci VS. Biochemical and structural insights into a 5' to 3' RNA ligase reveal a potential role in tRNA ligation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590974. [PMID: 38712170 PMCID: PMC11071452 DOI: 10.1101/2024.04.24.590974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
ATP-grasp superfamily enzymes contain a hand-like ATP-binding fold and catalyze a variety of reactions using a similar catalytic mechanism. More than 30 protein families are categorized in this superfamily, and they are involved in a plethora of cellular processes and human diseases. Here we identify C12orf29 as an atypical ATP-grasp enzyme that ligates RNA. Human C12orf29 and its homologs auto-adenylate on an active site Lys residue as part of a reaction intermediate that specifically ligates RNA halves containing a 5'-phosphate and a 3'-hydroxyl. C12orf29 binds tRNA in cells and can ligate tRNA within the anticodon loop in vitro. Genetic depletion of c12orf29 in female mice alters global tRNA levels in brain. Furthermore, crystal structures of a C12orf29 homolog from Yasminevirus bound to nucleotides reveal a minimal and atypical RNA ligase fold with a unique active site architecture that participates in catalysis. Collectively, our results identify C12orf29 as an RNA ligase and suggest its involvement in tRNA biology.
Collapse
Affiliation(s)
- Yingjie Hu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Victor A. Lopez
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Hengyi Xu
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, Texas 78712, USA
| | - James P. Pfister
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Bing Song
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kelly A. Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Masahiro Sakurai
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Benjamin T. Jones
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Joshua T. Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Tao Wang
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Jun Wu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, Children’s Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Alan M. Lambowitz
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, Texas 78712, USA
| | - Diana R. Tomchick
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Krzysztof Pawłowski
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Vincent S. Tagliabracci
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| |
Collapse
|
3
|
Jia F, Zhang B, Yu W, Chen Z, Xu W, Zhao W, Wang Z. Exploring the cuproptosis-related molecular clusters in the peripheral blood of patients with amyotrophic lateral sclerosis. Comput Biol Med 2024; 168:107776. [PMID: 38056214 DOI: 10.1016/j.compbiomed.2023.107776] [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: 07/18/2023] [Revised: 11/08/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a progressive and lethal neurodegenerative disease. Several studies have suggested the involvement of cuproptosis in its pathogenesis. In this research, we intend to explore the cuproptosis-related molecular clusters in ALS and develop a novel cuproptosis-related genes prediction model. METHODS The peripheral blood gene expression data was downloaded from the Gene Expression Omnibus (GEO) online database. Based on the GSE112681 dataset, we investigated the critical cuproptosis-related genes (CuRGs) and pathological clustering of ALS. The immune microenvironment features of the peripheral blood in ALS patients were also examined using the CIBERSORT algorithm. Cluster-specific hub genes were determined by the WGCNA. The most accurate prediction model was selected by comparing the performance of four machine learning techniques. ROC curves and two independent datasets were applied to validate the prediction accuracy. The available compounds targeting these hub genes were filtered to investigate their efficacy in treating ALS. RESULTS We successfully determined four critical cuproptosis-related genes and two pathological clusters with various immune profiles and biological characteristics in ALS. Functional analysis showed that genes in Cluster1 were primarily enriched in pathways closely associated with immunity. The Support Vector Machine (SVM) model exhibited the best discrimination properties with a large area under the curve (AUC = 0.862). Five hub prediction genes (BAP1, SMG1, BCLAF1, DHX15, EIF4G2) were selected to establish a nomogram model, suggesting significant risk prediction potential for ALS. The accuracy of this model in predicting ALS incidence was also demonstrated through calibration curves, nomograms, and decision curve analysis. Finally, three drugs targeting BAP1 were determined through drug-gene interactions. CONCLUSION This study elucidated the complex associations between cuproptosis and ALS and constructed a satisfactory predictive model to explore the pathological characteristics of different clusters in ALS patients.
Collapse
Affiliation(s)
- Fang Jia
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Bingchang Zhang
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Weijie Yu
- The School of Clinical Medicine, Fujian Medical University, Fuzhou, China
| | - Zheng Chen
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Wenbin Xu
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Wenpeng Zhao
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Zhanxiang Wang
- Department of Neurosurgery, Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
| |
Collapse
|
4
|
Dong L, Shang L, Liu C, Mao C, Huang X, Chu S, Peng B, Cui L, Gao J. Genotypic and phenotypic heterogeneity among Chinese pediatric genetic white matter disorders. Ital J Pediatr 2023; 49:155. [PMID: 37981684 PMCID: PMC10658925 DOI: 10.1186/s13052-023-01555-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 10/29/2023] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND The pediatric genetic white matter disorders are characterized by a broad disease spectrum. Genetic testing is valuable in the diagnosis. However, there are few studies on the clinical and genetic spectrum of Chinese pediatric genetic white matter disorders. METHODS The participants were enrolled from the cohort of Peking Union Medical College Hospital. They all received history collection, brain MRI and gene sequencing. Their neurologic complaints which were related to white matter disorders occurred before 18. Brain MRI indicated periventricular and/or deep white matter lesions, fazekas grade 2-3. RESULTS Among the 13 subjects, there were 11 males and two females. The average age of onset was 10.0 ± 5.5 years old. The potential genetic variants were found in 84.6% (11/13) subjects. The ABCD1 showed the greatest mutation frequency (30.8%, 4/13). The EIF2B3 A151fs, EIF2B4 c.885 + 2T > G, EIF2B5 R129X and MPV17 Q142X were novel pathogenic/likely pathogenic variants. 100% (4/4) ABCD1 carriers were accompanied by visual impairment, whereas 100% (3/3) EIF2B carriers developed dysuria. 100% (4/4) ABCD1 carriers exhibited diffuse white matter hyperintensities mainly in the posterior cortical regions, while the EIF2B4 and EIF2B5 carriers were accompanied by cystic degeneration. CONCLUSION There is genotypic and phenotypic heterogeneity among Chinese subjects with pediatric genetic white matter disorders. The knowledge of these clinical and genetic characteristics facilitates an accurate diagnosis of these diseases.
Collapse
Affiliation(s)
- Liling Dong
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Li Shang
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Caiyan Liu
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Chenhui Mao
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Xinying Huang
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Shanshan Chu
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Bin Peng
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Liying Cui
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China
| | - Jing Gao
- Neurology department, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shuaifuyuan No. 1, Dongcheng district, Beijing, 100005, China.
| |
Collapse
|
5
|
Luisier R, Andreassi C, Fournier L, Riccio A. The predicted RNA-binding protein regulome of axonal mRNAs. Genome Res 2023; 33:1497-1512. [PMID: 37582635 PMCID: PMC10620043 DOI: 10.1101/gr.277804.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 08/10/2023] [Indexed: 08/17/2023]
Abstract
Neurons are morphologically complex cells that rely on the compartmentalization of protein expression to develop and maintain their cytoarchitecture. The targeting of RNA transcripts to axons is one of the mechanisms that allows rapid local translation of proteins in response to extracellular signals. 3' Untranslated regions (UTRs) of mRNA are noncoding sequences that play a critical role in determining transcript localization and translation by interacting with specific RNA-binding proteins (RBPs). However, how 3' UTRs contribute to mRNA metabolism and the nature of RBP complexes responsible for these functions remains elusive. We performed 3' end sequencing of RNA isolated from cell bodies and axons of sympathetic neurons exposed to either nerve growth factor (NGF) or neurotrophin 3 (NTF3, also known as NT-3). NGF and NTF3 are growth factors essential for sympathetic neuron development through distinct signaling mechanisms. Whereas NTF3 acts mostly locally, NGF signal is retrogradely transported from axons to cell bodies. We discovered that both NGF and NTF3 affect transcription and alternative polyadenylation in the nucleus and induce the localization of specific 3' UTR isoforms to axons, including short 3' UTR isoforms found exclusively in axons. The integration of our data with CLIP sequencing data supports a model whereby long 3' UTR isoforms associate with RBP complexes in the nucleus and, upon reaching the axons, are remodeled locally into shorter isoforms. Our findings shed new light into the complex relationship between nuclear polyadenylation, mRNA localization, and local 3' UTR remodeling in developing neurons.
Collapse
Affiliation(s)
- Raphaëlle Luisier
- Idiap Research Institute, Martigny 1920, Switzerland;
- SIB Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Catia Andreassi
- UCL Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
| | - Lisa Fournier
- Idiap Research Institute, Martigny 1920, Switzerland
- SIB Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Antonella Riccio
- UCL Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
| |
Collapse
|
6
|
Shestakova ED, Smirnova VV, Shatsky IN, Terenin IM. Specific mechanisms of translation initiation in higher eukaryotes: the eIF4G2 story. RNA (NEW YORK, N.Y.) 2023; 29:282-299. [PMID: 36517212 PMCID: PMC9945437 DOI: 10.1261/rna.079462.122] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The eukaryotic initiation factor 4G2 (eIF4G2, DAP5, Nat1, p97) was discovered in 1997. Over the past two decades, dozens of papers have presented contradictory data on eIF4G2 function. Since its identification, eIF4G2 has been assumed to participate in noncanonical translation initiation mechanisms, but recent results indicate that it can be involved in scanning as well. In particular, eIF4G2 provides leaky scanning through some upstream open reading frames (uORFs), which are typical for long 5' UTRs of mRNAs from higher eukaryotes. It is likely the protein can also help the ribosome overcome other impediments during scanning of the 5' UTRs of animal mRNAs. This may explain the need for eIF4G2 in higher eukaryotes, as many mRNAs that encode regulatory proteins have rather long and highly structured 5' UTRs. Additionally, they often bind to various proteins, which also hamper the movement of scanning ribosomes. This review discusses the suggested mechanisms of eIF4G2 action, denotes obscure or inconsistent results, and proposes ways to uncover other fundamental mechanisms in which this important protein factor may be involved in higher eukaryotes.
Collapse
Affiliation(s)
- Ekaterina D Shestakova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Victoria V Smirnova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ilya M Terenin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
- Sirius University of Science and Technology, Sochi 354349, Russia
| |
Collapse
|
7
|
Sahoo PK, Twiss JL. Profiling Locally Translated mRNAs in Regenerating Axons. Methods Mol Biol 2023; 2636:145-161. [PMID: 36881299 DOI: 10.1007/978-1-0716-3012-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Spatial and temporal regulation of protein expression plays important roles in many cellular functions, particularly for highly polarized cell types. While the subcellular proteome can be altered by relocalizing proteins from other domains of the cell, transporting mRNAs to subcellular domains provides a means to locally synthesize new proteins in response to different stimuli. Localized protein synthesis is a critical mechanism in neurons that extend dendrites and axons long distances from their cell bodies. Here, we discuss methodologies that have been developed to study localized protein synthesis using axonal protein synthesis as an example. We provide an in-depth method using dual fluorescence recovery after photobleaching to visualize sites of protein synthesis using reporter cDNAs that encode two different localizing mRNAs along with diffusion-limited fluorescent reporter proteins. We show how this method can be used to determine how extracellular stimuli and different physiological states can alter the specificity of local mRNA translation in real time.
Collapse
Affiliation(s)
- Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| |
Collapse
|
8
|
Gale JR, Gedeon JY, Donnelly CJ, Gold MS. Local translation in primary afferents and its contribution to pain. Pain 2022; 163:2302-2314. [PMID: 35438669 PMCID: PMC9579217 DOI: 10.1097/j.pain.0000000000002658] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 04/08/2022] [Indexed: 02/06/2023]
Abstract
ABSTRACT Chronic pain remains a significant problem due to its prevalence, impact, and limited therapeutic options. Progress in addressing chronic pain is dependent on a better understanding of underlying mechanisms. Although the available evidence suggests that changes within the central nervous system contribute to the initiation and maintenance of chronic pain, it also suggests that the primary afferent plays a critical role in all phases of the manifestation of chronic pain in most of those who suffer. Most notable among the changes in primary afferents is an increase in excitability or sensitization. A number of mechanisms have been identified that contribute to primary afferent sensitization with evidence for both increases in pronociceptive signaling molecules, such as voltage-gated sodium channels, and decreases in antinociceptive signaling molecules, such as voltage-dependent or calcium-dependent potassium channels. Furthermore, these changes in signaling molecules seem to reflect changes in gene expression as well as posttranslational processing. A mechanism of sensitization that has received far less attention, however, is the local or axonal translation of these signaling molecules. A growing body of evidence indicates that this process not only is dynamically regulated but also contributes to the initiation and maintenance of chronic pain. Here, we review the biology of local translation in primary afferents and its relevance to pain pathobiology.
Collapse
Affiliation(s)
- Jenna R Gale
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - Jeremy Y Gedeon
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | | | - Michael S Gold
- Corresponding author: Michael S Gold, PhD, Department of Neurobiology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, P: 412-383-5367,
| |
Collapse
|
9
|
Tibolone Pre-Treatment Ameliorates the Dysregulation of Protein Translation and Transport Generated by Palmitic Acid-Induced Lipotoxicity in Human Astrocytes: A Label-Free MS-Based Proteomics and Network Analysis. Int J Mol Sci 2022; 23:ijms23126454. [PMID: 35742897 PMCID: PMC9223656 DOI: 10.3390/ijms23126454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 01/27/2023] Open
Abstract
Excessive accumulation and release of fatty acids (FAs) in adipose and non-adipose tissue are characteristic of obesity and are associated with the leading causes of death worldwide. Chronic exposure to high concentrations of FAs such as palmitic acid (pal) is a risk factor for developing different neurodegenerative diseases (NDs) through several mechanisms. In the brain, astrocytic dysregulation plays an essential role in detrimental processes like metabolic inflammatory state, oxidative stress, endoplasmic reticulum stress, and autophagy impairment. Evidence shows that tibolone, a synthetic steroid, induces neuroprotective effects, but its molecular mechanisms upon exposure to pal remain largely unknown. Due to the capacity of identifying changes in the whole data-set of proteins and their interaction allowing a deeper understanding, we used a proteomic approach on normal human astrocytes under supraphysiological levels of pal as a model to induce cytotoxicity, finding changes of expression in proteins related to translation, transport, autophagy, and apoptosis. Additionally, tibolone pre-treatment showed protective effects by restoring those same pal-altered processes and increasing the expression of proteins from cell survival processes. Interestingly, ARF3 and IPO7 were identified as relevant proteins, presenting a high weight in the protein-protein interaction network and significant differences in expression levels. These proteins are related to transport and translation processes, and their expression was restored by tibolone. This work suggests that the damage caused by pal in astrocytes simultaneously involves different mechanisms that the tibolone can partially revert, making tibolone interesting for further research to understand how to modulate these damages.
Collapse
|
10
|
Stavast CJ, van Zuijen I, Erkeland SJ. MicroRNA-139, an Emerging Gate-Keeper in Various Types of Cancer. Cells 2022; 11:cells11050769. [PMID: 35269391 PMCID: PMC8909004 DOI: 10.3390/cells11050769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 11/25/2022] Open
Abstract
Mounting data show that MIR139 is commonly silenced in solid cancer and hematological malignancies. MIR139 acts as a critical tumor suppressor by tuning the cellular response to different types of stress, including DNA damage, and by repressing oncogenic signaling pathways. Recently, novel insights into the mechanism of MIR139 silencing in tumor cells have been described. These include epigenetic silencing, inhibition of POL-II transcriptional activity on gene regulatory elements, enhanced expression of competing RNAs and post-transcriptional regulation by the microprocessor complex. Some of these MIR139-silencing mechanisms have been demonstrated in different types of cancer, suggesting that these are more general oncogenic events. Reactivation of MIR139 expression in tumor cells causes inhibition of tumor cell expansion and induction of cell death by the repression of oncogenic mRNA targets. In this review, we discuss the different aspects of MIR139 as a tumor suppressor gene and give an overview on different transcriptional mechanisms regulating MIR139 in oncogenic stress and across different types of cancer. The novel insights into the expression regulation and the tumor-suppressing activities of MIR139 may pave the way to new treatment options for cancer.
Collapse
|
11
|
Li L, Yu J, Ji SJ. Axonal mRNA localization and translation: local events with broad roles. Cell Mol Life Sci 2021; 78:7379-7395. [PMID: 34698881 PMCID: PMC11072051 DOI: 10.1007/s00018-021-03995-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/17/2021] [Accepted: 10/14/2021] [Indexed: 12/19/2022]
Abstract
Messenger RNA (mRNA) can be transported and targeted to different subcellular compartments and locally translated. Local translation is an evolutionally conserved mechanism that in mammals, provides an important tool to exquisitely regulate the subcellular proteome in different cell types, including neurons. Local translation in axons is involved in processes such as neuronal development, function, plasticity, and diseases. Here, we summarize the current progress on axonal mRNA transport and translation. We focus on the regulatory mechanisms governing how mRNAs are transported to axons and how they are locally translated in axons. We discuss the roles of axonally synthesized proteins, which either function locally in axons, or are retrogradely trafficked back to soma to achieve neuron-wide gene regulation. We also examine local translation in neurological diseases. Finally, we give a critical perspective on the remaining questions that could be answered to uncover the fundamental rules governing local translation, and discuss how this could lead to new therapeutic targets for neurological diseases.
Collapse
Affiliation(s)
- Lichao Li
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Jun Yu
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Sheng-Jian Ji
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
| |
Collapse
|
12
|
Mesquita-Ribeiro R, Fort RS, Rathbone A, Farias J, Lucci C, James V, Sotelo-Silveira J, Duhagon MA, Dajas-Bailador F. Distinct small non-coding RNA landscape in the axons and released extracellular vesicles of developing primary cortical neurons and the axoplasm of adult nerves. RNA Biol 2021; 18:832-855. [PMID: 34882524 PMCID: PMC8782166 DOI: 10.1080/15476286.2021.2000792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neurons have highlighted the needs for decentralized gene expression and specific RNA function in somato-dendritic and axonal compartments, as well as in intercellular communication via extracellular vesicles (EVs). Despite advances in miRNA biology, the identity and regulatory capacity of other small non-coding RNAs (sncRNAs) in neuronal models and local subdomains has been largely unexplored.We identified a highly complex and differentially localized content of sncRNAs in axons and EVs during early neuronal development of cortical primary neurons and in adult axons in vivo. This content goes far beyond miRNAs and includes most known sncRNAs and precisely processed fragments from tRNAs, sno/snRNAs, Y RNAs and vtRNAs. Although miRNAs are the major sncRNA biotype in whole-cell samples, their relative abundance is significantly decreased in axons and neuronal EVs, where specific tRNA fragments (tRFs and tRHs/tiRNAs) mainly derived from tRNAs Gly-GCC, Val-CAC and Val-AAC predominate. Notably, although 5'-tRHs compose the great majority of tRNA-derived fragments observed in vitro, a shift to 3'-tRNAs is observed in mature axons in vivo.The existence of these complex sncRNA populations that are specific to distinct neuronal subdomains and selectively incorporated into EVs, equip neurons with key molecular tools for spatiotemporal functional control and cell-to-cell communication.
Collapse
Affiliation(s)
| | - Rafael Sebastián Fort
- Laboratorio de Interacciones Moleculares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.,Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Alex Rathbone
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Joaquina Farias
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.,Polo de Desarrollo Universitario "Espacio de Biología Vegetal del Noreste", Centro Universitario Regional Noreste, UdelaR, Uruguay
| | - Cristiano Lucci
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Victoria James
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Jose Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Maria Ana Duhagon
- Laboratorio de Interacciones Moleculares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | | |
Collapse
|
13
|
Agrawal M, Welshhans K. Local Translation Across Neural Development: A Focus on Radial Glial Cells, Axons, and Synaptogenesis. Front Mol Neurosci 2021; 14:717170. [PMID: 34434089 PMCID: PMC8380849 DOI: 10.3389/fnmol.2021.717170] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
In the past two decades, significant progress has been made in our understanding of mRNA localization and translation at distal sites in axons and dendrites. The existing literature shows that local translation is regulated in a temporally and spatially restricted manner and is critical throughout embryonic and post-embryonic life. Here, recent key findings about mRNA localization and local translation across the various stages of neural development, including neurogenesis, axon development, and synaptogenesis, are reviewed. In the early stages of development, mRNAs are localized and locally translated in the endfeet of radial glial cells, but much is still unexplored about their functional significance. Recent in vitro and in vivo studies have provided new information about the specific mechanisms regulating local translation during axon development, including growth cone guidance and axon branching. Later in development, localization and translation of mRNAs help mediate the major structural and functional changes that occur in the axon during synaptogenesis. Clinically, changes in local translation across all stages of neural development have important implications for understanding the etiology of several neurological disorders. Herein, local translation and mechanisms regulating this process across developmental stages are compared and discussed in the context of function and dysfunction.
Collapse
Affiliation(s)
- Manasi Agrawal
- School of Biomedical Sciences, Kent State University, Kent, OH, United States
| | - Kristy Welshhans
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
| |
Collapse
|
14
|
Nagano S, Araki T. Axonal Transport and Local Translation of mRNA in Neurodegenerative Diseases. Front Mol Neurosci 2021; 14:697973. [PMID: 34194300 PMCID: PMC8236635 DOI: 10.3389/fnmol.2021.697973] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/25/2021] [Indexed: 12/13/2022] Open
Abstract
Since neurons have long neurites including axons, it is crucial for the axons to transport many intracellular substances such as proteins and mitochondria in order to maintain their morphology and function. In addition, mRNAs have also been shown to be transported within axons. RNA-binding proteins form complexes with mRNAs, and regulate transport of the mRNAs to axons, as well as locally translate them into proteins. Local translation of mRNAs actively occurs during the development and damage of neurons, and plays an important role in axon elongation, regeneration, and synapse formation. In recent years, it has been reported that impaired axonal transport and local translation of mRNAs may be involved in the pathogenesis of some neurodegenerative diseases. In this review, we discuss the significance of mRNA axonal transport and their local translation in amyotrophic lateral sclerosis/frontotemporal dementia, spinal muscular atrophy, Alzheimer’s disease, and fragile X syndrome.
Collapse
Affiliation(s)
- Seiichi Nagano
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Osaka, Japan.,Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| |
Collapse
|
15
|
Zhang Z, Zheng B, Du S, Han G, Zhao H, Wu S, Jia S, Bachmann T, Bekker A, Tao YX. Eukaryotic initiation factor 4 gamma 2 contributes to neuropathic pain through down-regulation of Kv1.2 and the mu opioid receptor in mouse primary sensory neurones. Br J Anaesth 2021; 126:706-719. [PMID: 33303185 PMCID: PMC8014947 DOI: 10.1016/j.bja.2020.10.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/02/2020] [Accepted: 10/19/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Nerve injury-induced changes in gene expression in the dorsal root ganglion (DRG) contribute to neuropathic pain genesis. Eukaryotic initiation factor 4 gamma 2 (eIF4G2) is a general repressor of cap-dependent mRNA translation. Whether DRG eIF4G2 participates in nerve injury-induced alternations in gene expression and nociceptive hypersensitivity is unknown. METHODS The expression and distribution of eIF4G2 mRNA and protein in mouse DRG after spinal nerve ligation (SNL) were assessed. Effects of eIF4G2 siRNA microinjected through a glass micropipette into the injured DRG on the SNL-induced DRG mu opioid receptor (MOR) and Kv1.2 downregulation and nociceptive hypersensitivity were examined. In addition, effects of DRG microinjection of adeno-associated virus 5-expressing eIF4G2 (AAV5-eIF4G2) on basal DRG MOR and Kv1.2 expression and nociceptive thresholds were analysed. RESULTS eIF4G2 protein co-expressed with Kv1.2 and MOR in DRG neurones. Levels of eIF4G2 mRNA (1.7 [0.24] to 2.3 [0.14]-fold of sham, P<0.01) and protein (1.6 [0.14] to 2.5 [0.22]-fold of sham, P<0.01) in injured DRG were time-dependently increased on days 3-14 after SNL. Blocking increased eIF4G2 through microinjection of eIF4G2 siRNA into the injured DRG attenuated SNL-induced downregulation of DRG MOR and Kv1.2 and development and maintenance of nociceptive hypersensitivities. DRG microinjection of AAV5-eIF4G2 reduced DRG MOR and Kv1.2 expression and elicited hypersensitivities to mechanical, heat and cold stimuli in naïve mice. CONCLUSIONS eIF4G2 contributes to neuropathic pain through participation in downregulation of Kv1.2 and MOR in injured DRG and is a potential target for treatment of this disorder.
Collapse
Affiliation(s)
- Zhen Zhang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Bixin Zheng
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Shibin Du
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Guang Han
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Hui Zhao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Shaogen Wu
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Shushan Jia
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Thomas Bachmann
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA; Departments of Cell Biology & Molecular Medicine and Physiology, Pharmacology & Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA.
| |
Collapse
|
16
|
Dalla Costa I, Buchanan CN, Zdradzinski MD, Sahoo PK, Smith TP, Thames E, Kar AN, Twiss JL. The functional organization of axonal mRNA transport and translation. Nat Rev Neurosci 2021; 22:77-91. [PMID: 33288912 PMCID: PMC8161363 DOI: 10.1038/s41583-020-00407-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2020] [Indexed: 12/13/2022]
Abstract
Axons extend for tremendously long distances from the neuronal soma and make use of localized mRNA translation to rapidly respond to different extracellular stimuli and physiological states. The locally synthesized proteins support many different functions in both developing and mature axons, raising questions about the mechanisms by which local translation is organized to ensure the appropriate responses to specific stimuli. Publications over the past few years have uncovered new mechanisms for regulating the axonal transport and localized translation of mRNAs, with several of these pathways converging on the regulation of cohorts of functionally related mRNAs - known as RNA regulons - that drive axon growth, axon guidance, injury responses, axon survival and even axonal mitochondrial function. Recent advances point to these different regulatory pathways as organizing platforms that allow the axon's proteome to be modulated to meet its physiological needs.
Collapse
Affiliation(s)
- Irene Dalla Costa
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Courtney N Buchanan
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | | | - Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Terika P Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Elizabeth Thames
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
| |
Collapse
|
17
|
Corradi E, Baudet ML. In the Right Place at the Right Time: miRNAs as Key Regulators in Developing Axons. Int J Mol Sci 2020; 21:ijms21228726. [PMID: 33218218 PMCID: PMC7699167 DOI: 10.3390/ijms21228726] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 01/02/2023] Open
Abstract
During neuronal circuit formation, axons progressively develop into a presynaptic compartment aided by extracellular signals. Axons display a remarkably high degree of autonomy supported in part by a local translation machinery that permits the subcellular production of proteins required for their development. Here, we review the latest findings showing that microRNAs (miRNAs) are critical regulators of this machinery, orchestrating the spatiotemporal regulation of local translation in response to cues. We first survey the current efforts toward unraveling the axonal miRNA repertoire through miRNA profiling, and we reveal the presence of a putative axonal miRNA signature. We also provide an overview of the molecular underpinnings of miRNA action. Our review of the available experimental evidence delineates two broad paradigms: cue-induced relief of miRNA-mediated inhibition, leading to bursts of protein translation, and cue-induced miRNA activation, which results in reduced protein production. Overall, this review highlights how a decade of intense investigation has led to a new appreciation of miRNAs as key elements of the local translation regulatory network controlling axon development.
Collapse
|
18
|
Di Paolo A, Eastman G, Mesquita-Ribeiro R, Farias J, Macklin A, Kislinger T, Colburn N, Munroe D, Sotelo Sosa JR, Dajas-Bailador F, Sotelo-Silveira JR. PDCD4 regulates axonal growth by translational repression of neurite growth-related genes and is modulated during nerve injury responses. RNA (NEW YORK, N.Y.) 2020; 26:1637-1653. [PMID: 32747606 PMCID: PMC7566564 DOI: 10.1261/rna.075424.120] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/20/2020] [Indexed: 05/07/2023]
Abstract
Programmed cell death 4 (PDCD4) protein is a tumor suppressor that inhibits translation through the mTOR-dependent initiation factor EIF4A, but its functional role and mRNA targets in neurons remain largely unknown. Our work identified that PDCD4 is highly expressed in axons and dendrites of CNS and PNS neurons. Using loss- and gain-of-function experiments in cortical and dorsal root ganglia primary neurons, we demonstrated the capacity of PDCD4 to negatively control axonal growth. To explore PDCD4 transcriptome and translatome targets, we used Ribo-seq and uncovered a list of potential targets with known functions as axon/neurite outgrowth regulators. In addition, we observed that PDCD4 can be locally synthesized in adult axons in vivo, and its levels decrease at the site of peripheral nerve injury and before nerve regeneration. Overall, our findings demonstrate that PDCD4 can act as a new regulator of axonal growth via the selective control of translation, providing a target mechanism for axon regeneration and neuronal plasticity processes in neurons.
Collapse
Affiliation(s)
- Andrés Di Paolo
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Guillermo Eastman
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | | | - Joaquina Farias
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Andrew Macklin
- Princess Margaret Cancer Centre, University Health Network, Toronto M5G 1L7, Canada
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto M5G 1L7, Canada
- University of Toronto, Department of Medical Biophysics, Toronto M5S 1A1, Canada
| | - Nancy Colburn
- Former Chief of Laboratory of Cancer Prevention at the National Cancer Institute-NIH at Frederick, Maryland 21702, USA
| | - David Munroe
- Former Laboratory of Molecular Technologies, LEIDOS at Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - José R Sotelo Sosa
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | | | - José R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
- Departamento de Biología Celular y Molecular, Facultad de Ciencias UdelaR, Montevideo 11400, Uruguay
| |
Collapse
|
19
|
Smith TP, Sahoo PK, Kar AN, Twiss JL. Intra-axonal mechanisms driving axon regeneration. Brain Res 2020; 1740:146864. [PMID: 32360100 DOI: 10.1016/j.brainres.2020.146864] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022]
Abstract
Traumatic injury to the peripheral and central nervous systems very often causes axotomy, where an axon loses connections with its target resulting in loss of function. The axon segments distal to the injury site lose connection with the cell body and degenerate. Axotomized neurons in the periphery can spontaneously mount a regenerative response and reconnect to their denervated target tissues, though this is rarely complete in humans. In contrast, spontaneous regeneration rarely occurs after axotomy in the spinal cord and brain. Here, we concentrate on the mechanisms underlying this spontaneous regeneration in the peripheral nervous system, focusing on events initiated from the axon that support regenerative growth. We contrast this with what is known for axonal injury responses in the central nervous system. Considering the neuropathy focus of this special issue, we further draw parallels and distinctions between the injury-response mechanisms that initiate regenerative gene expression programs and those that are known to trigger axon degeneration.
Collapse
Affiliation(s)
- Terika P Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
| |
Collapse
|
20
|
Lucci C, Mesquita-Ribeiro R, Rathbone A, Dajas-Bailador F. Spatiotemporal regulation of GSK3β levels by miRNA-26a controls axon development in cortical neurons. Development 2020; 147:dev.180232. [PMID: 31964775 PMCID: PMC7033742 DOI: 10.1242/dev.180232] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 12/19/2019] [Indexed: 12/17/2022]
Abstract
Both the establishment of neuronal polarity and axonal growth are crucial steps in the development of the nervous system. The local translation of mRNAs in the axon provides precise regulation of protein expression, and is now known to participate in axon development, pathfinding and synaptic formation and function. We have investigated the role of miR-26a in early stage mouse primary cortical neuron development. We show that micro-RNA-26a-5p (miR-26a) is highly expressed in neuronal cultures, and regulates both neuronal polarity and axon growth. Using compartmentalised microfluidic neuronal cultures, we identified a local role for miR-26a in the axon, where the repression of local synthesis of GSK3β controls axon development and growth. Removal of this repression in the axon triggers local translation of GSK3β protein and subsequent transport to the soma, where it can impact axonal growth. These results demonstrate how the axonal miR-26a can regulate local protein translation in the axon to facilitate retrograde communication to the soma and amplify neuronal responses, in a mechanism that influences axon development. Highlighted Article: Axonal miR-26a can regulate GSK3β translation in the axon to promote retrograde communication to the soma in a mechanism that modulates axon development.
Collapse
Affiliation(s)
- Cristiano Lucci
- School of Life Sciences, Medical School Building, University of Nottingham, NG7 2UH Nottingham, UK
| | - Raquel Mesquita-Ribeiro
- School of Life Sciences, Medical School Building, University of Nottingham, NG7 2UH Nottingham, UK
| | - Alex Rathbone
- School of Life Sciences, Medical School Building, University of Nottingham, NG7 2UH Nottingham, UK
| | - Federico Dajas-Bailador
- School of Life Sciences, Medical School Building, University of Nottingham, NG7 2UH Nottingham, UK
| |
Collapse
|
21
|
Cefaliello C, Penna E, Barbato C, Di Ruberto G, Mollica MP, Trinchese G, Cigliano L, Borsello T, Chun JT, Giuditta A, Perrone-Capano C, Miniaci MC, Crispino M. Deregulated Local Protein Synthesis in the Brain Synaptosomes of a Mouse Model for Alzheimer's Disease. Mol Neurobiol 2019; 57:1529-1541. [PMID: 31784883 DOI: 10.1007/s12035-019-01835-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/12/2019] [Indexed: 12/27/2022]
Abstract
While protein synthesis in neurons is largely attributed to cell body and dendrites, the capability of synaptic regions to synthesize new proteins independently of the cell body has been widely demonstrated as an advantageous mechanism subserving synaptic plasticity. Thus, the contribution that local protein synthesis at synapses makes to physiology and pathology of brain plasticity may be more prevalent than initially thought. In this study, we tested if local protein synthesis at synapses is deregulated in the brains of TgCRND8 mice, an animal model for Alzheimer's disease (AD) overexpressing mutant human amyloid precursor protein (APP). To this end, we used synaptosomes as a model system to study the functionality of the synaptic regions in mouse brains. Our results showed that, while TgCRND8 mice exhibit early signs of brain inflammation and deficits in learning, the electrophoretic profile of newly synthesized proteins in their synaptosomes was subtly different from that of the control mice. Interestingly, APP itself was, in part, locally synthesized in the synaptosomes, underscoring the potential importance of local translation at synapses. More importantly, after the contextual fear conditioning, de novo synthesis of some individual proteins was significantly enhanced in the synaptosomes of control animals, but the TgCRND8 mice failed to display such synaptic modulation by training. Taken together, our results demonstrate that synaptic synthesis of proteins is impaired in the brain of a mouse model for AD, and raise the possibility that this deregulation may contribute to the early progression of the pathology.
Collapse
Affiliation(s)
- Carolina Cefaliello
- Department of Biology, University of Naples Federico II, Naples, Italy.,current address: Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Carmela Barbato
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | | | | | - Luisa Cigliano
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Tiziana Borsello
- Department of Pharmacological and Biomolecular Sciences, Milan University, Milan, Italy.,Department of Neuroscience, Mario Negri Institute for Pharmacological Research-IRCCS, Milan, Italy
| | | | - Antonio Giuditta
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Carla Perrone-Capano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy.,Institute of Genetics and Biophysics "Adriano Buzzati Traverso," CNR, Naples, Italy
| | - Maria Concetta Miniaci
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy.
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
| |
Collapse
|
22
|
Guo S, Perets N, Betzer O, Ben-Shaul S, Sheinin A, Michaelevski I, Popovtzer R, Offen D, Levenberg S. Intranasal Delivery of Mesenchymal Stem Cell Derived Exosomes Loaded with Phosphatase and Tensin Homolog siRNA Repairs Complete Spinal Cord Injury. ACS NANO 2019; 13:10015-10028. [PMID: 31454225 DOI: 10.1021/acsnano.9b01892] [Citation(s) in RCA: 229] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Individuals with spinal cord injury (SCI) usually suffer from permanent neurological deficits, while spontaneous recovery and therapeutic efficacy are limited. Here, we demonstrate that when given intranasally, exosomes derived from mesenchymal stem cells (MSC-Exo) could pass the blood brain barrier and migrate to the injured spinal cord area. Furthermore, MSC-Exo loaded with phosphatase and tensin homolog small interfering RNA (ExoPTEN) could attenuate the expression of PTEN in the injured spinal cord region following intranasal administrations. In addition, the loaded MSC-Exo considerably enhanced axonal growth and neovascularization, while reducing microgliosis and astrogliosis. The intranasal ExoPTEN therapy could also partly improve structural and electrophysiological function and, most importantly, significantly elicited functional recovery in rats with complete SCI. The results imply that intranasal ExoPTEN may be used clinically to promote recovery for SCI individuals.
Collapse
Affiliation(s)
- Shaowei Guo
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
- The First Affiliated Hospital , Shantou University Medical College , Shantou 515041 , China
| | | | - Oshra Betzer
- Faculty of Engineering and the Institute of Nanotechnology & Advanced Materials , Bar-Ilan University , Ramat Gan 5290002 , Israel
| | - Shahar Ben-Shaul
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
| | | | - Izhak Michaelevski
- Department of Molecular Biology , Ariel University , Ariel 40700 , Israel
| | - Rachela Popovtzer
- Faculty of Engineering and the Institute of Nanotechnology & Advanced Materials , Bar-Ilan University , Ramat Gan 5290002 , Israel
| | | | - Shulamit Levenberg
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
| |
Collapse
|
23
|
Kats IR, Klann E. Translating from cancer to the brain: regulation of protein synthesis by eIF4F. ACTA ACUST UNITED AC 2019; 26:332-342. [PMID: 31416906 PMCID: PMC6699409 DOI: 10.1101/lm.050047.119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/03/2019] [Indexed: 12/27/2022]
Abstract
Formation of eukaryotic initiation factor 4F (eIF4F) is widely considered to be the rate-limiting step in cap-dependent translation initiation. Components of eIF4F are often up-regulated in various cancers, and much work has been done to elucidate the role of each of the translation initiation factors in cancer cell growth and survival. In fact, many of the basic mechanisms describing how eIF4F is assembled and how it functions to regulate translation initiation were first investigated in cancer cell lines. These same eIF4F translational control pathways also are relevant for neuronal signaling that underlies long-lasting synaptic plasticity and memory, and in neurological diseases where eIF4F and its upstream regulators are dysregulated. Although eIF4F is important in cancer and for brain function, there is not always a clear path to use the results of studies performed in cancer models to inform one of the roles that the same translation factors have in neuronal signaling. Issues arise when extrapolating from cell lines to tissue, and differences are likely to exist in how eIF4F and its upstream regulatory pathways are expressed in the diverse neuronal subtypes found in the brain. This review focuses on summarizing the role of eIF4F and its accessory proteins in cancer, and how this information has been utilized to investigate neuronal signaling, synaptic function, and animal behavior. Certain aspects of eIF4F regulation are consistent across cancer and neuroscience, whereas some results are more complicated to interpret, likely due to differences in the complexity of the brain, its billions of neurons and synapses, and its diverse cell types.
Collapse
Affiliation(s)
- Ilona R Kats
- Sackler Graduate Program, New York University School of Medicine, New York, New York 10016, USA.,Center for Neural Science, New York University, New York, New York 10003, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York 10003, USA.,NYU Neuroscience Institute, New York University School of Medicine, New York, New York 10016, USA
| |
Collapse
|
24
|
Farias J, Sotelo JR, Sotelo‐Silveira J. Toward Axonal System Biology: Genome Wide Views of Local mRNA Translation. Proteomics 2019; 19:e1900054. [DOI: 10.1002/pmic.201900054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/12/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Joaquina Farias
- Departamento de Proteínas y Ácidos NucleicosInstituto de Investigaciones Biológicas Clemente Estable Montevideo CP 11600 Uruguay
- Departamento de GenómicaInstituto de Investigaciones Biológicas Clemente Estable Montevideo CP 11600 Uruguay
| | - José Roberto Sotelo
- Departamento de Proteínas y Ácidos NucleicosInstituto de Investigaciones Biológicas Clemente Estable Montevideo CP 11600 Uruguay
| | - José Sotelo‐Silveira
- Departamento de GenómicaInstituto de Investigaciones Biológicas Clemente Estable Montevideo CP 11600 Uruguay
- Sección Biología CelularFacultad de Ciencias, Universidad de la República Montevideo CP 11400 Uruguay
| |
Collapse
|
25
|
Ding D, Enriquez-Algeciras M, Valdivia AO, Torres J, Pole C, Thompson JW, Chou TH, Perez-Pinzon M, Porciatti V, Udin S, Nestler E, Bhattacharya SK. The Role of Deimination in Regenerative Reprogramming of Neurons. Mol Neurobiol 2019; 56:2618-2639. [PMID: 30051351 PMCID: PMC6348056 DOI: 10.1007/s12035-018-1262-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Neurons from the adult central nervous system (CNS) demonstrate limited mRNA transport and localized protein synthesis versus developing neurons, correlating with lower regenerative capacity. We found that deimination (posttranslational conversion of protein-bound arginine into citrulline) undergoes upregulation during early neuronal development while declining to a low basal level in adults. This modification is associated with neuronal arborization from amphibians to mammals. The mRNA-binding proteins (ANP32a, REF), deiminated in neurons, have been implicated in local protein synthesis. Overexpression of the deiminating cytosolic enzyme peptidyl arginine deiminase 2 in nervous systems results in increased neuronal transport and neurite outgrowth. We further demonstrate that enriching deiminated proteins rescues transport deficiencies both in primary neurons and mouse optic nerve even in the presence of pharmacological transport blockers. We conclude that deimination promotes neuronal outgrowth via enhanced transport and local protein synthesis and represents a new avenue for neuronal regeneration in the adult CNS.
Collapse
Affiliation(s)
- Di Ding
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Mabel Enriquez-Algeciras
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Anddre Osmar Valdivia
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Juan Torres
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Cameron Pole
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - John W Thompson
- Neurological Surgery, University of Miami, Miami, FL, 33136, USA
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Miguel Perez-Pinzon
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
- Department of Neurology, University of Miami, Miami, FL, 33136, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Susan Udin
- Department of Physiology and Biophysics, State University of New York, Buffalo, 553 Biomedical Res. Building, Buffalo, NY, 14214, USA
| | - Eric Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1065, New York, NY, 10029, USA
| | - Sanjoy K Bhattacharya
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA.
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
| |
Collapse
|
26
|
Magnesium-sensitive upstream ORF controls PRL phosphatase expression to mediate energy metabolism. Proc Natl Acad Sci U S A 2019; 116:2925-2934. [PMID: 30718434 DOI: 10.1073/pnas.1815361116] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Phosphatases of regenerating liver (PRL-1, PRL-2, and PRL-3, also known as PTP4A1, PTP4A2, and PTP4A3) control magnesium homeostasis through an association with the CNNM magnesium transport regulators. Although high PRL levels have been linked to cancer progression, regulation of their expression is poorly understood. Here we show that modulating intracellular magnesium levels correlates with a rapid change of PRL expression by a mechanism involving its 5'UTR mRNA region. Mutations or CRISPR-Cas9 targeting of the conserved upstream ORF present in the mRNA leader derepress PRL protein synthesis and attenuate the translational response to magnesium levels. Mechanistically, magnesium depletion reduces intracellular ATP but up-regulates PRL protein expression via activation of the AMPK/mTORC2 pathway, which controls cellular energy status. Hence, altered PRL-2 expression leads to metabolic reprogramming of the cells. These findings uncover a magnesium-sensitive mechanism controlling PRL expression, which plays a role in cellular bioenergetics.
Collapse
|
27
|
Seo JY, Jung Y, Kim DY, Ryu HG, Lee J, Kim SW, Kim KT. DAP5 increases axonal outgrowth of hippocampal neurons by enhancing the cap-independent translation of DSCR1.4 mRNA. Cell Death Dis 2019; 10:49. [PMID: 30718468 PMCID: PMC6362140 DOI: 10.1038/s41419-018-1299-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/30/2018] [Accepted: 12/19/2018] [Indexed: 12/18/2022]
Abstract
Proper wiring between neurons is indispensable for proper brain function. From the early developmental stage, axons grow and navigate to connect to targets according to specific guidance cues. The accuracy of axonal outgrowth and navigation are controlled by a variety of genes, and mutations and/or deficiencies in these genes are closely related to several brain disorders, such as autism. DSCR1 is one of these genes and regulates actin filament formation in axons. Thus, identifying the detailed regulatory mechanisms of DSCR1 expression is crucial for the understanding of the axon development of neurons; however, these regulatory mechanisms of DSCR1 remain unknown. Here, we discovered that mRNA encoding the DSCR1 isoform DSCR1.4 is present and mainly translated by the cap-independent initiation mechanisms in both the soma and axons of hippocampal neurons. We found that translation of DSCR1.4 mRNA is enhanced by death-associated protein 5 (DAP5), which can bind to DSCR1.4 5'UTR. BDNF-stimulus induced an increase in DAP5 expression and the cap-independent translation efficiency of DSCR1.4 mRNA in axon as well as soma. Furthermore, we showed the importance of the cap-independent translation of DSCR1.4 on enhancement of DSCR1.4 expression by BDNF-stimulus and axonal outgrowth of hippocampal neurons. Our findings suggest a new translational regulatory mechanism for DSCR1.4 expressions and a novel function of DAP5 as a positive regulator of DSCR1.4 mRNA translation induced in soma and axon of hippocampal neurons.
Collapse
Affiliation(s)
- Ji-Young Seo
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Youngseob Jung
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University (KNU), Daegu, Republic of Korea
| | - Hye Guk Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Juhyun Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Sung Wook Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Kyong-Tai Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea. .,Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea.
| |
Collapse
|
28
|
Parvin S, Takeda R, Sugiura Y, Neyazaki M, Nogi T, Sasaki Y. Fragile X mental retardation protein regulates accumulation of the active zone protein Munc18-1 in presynapses via local translation in axons during synaptogenesis. Neurosci Res 2018; 146:36-47. [PMID: 30240639 DOI: 10.1016/j.neures.2018.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/27/2018] [Accepted: 09/14/2018] [Indexed: 11/26/2022]
Abstract
Fragile X mental retardation protein (FMRP), a causative gene (FMR1) product of Fragile X syndrome (FXS), is an RNA-binding protein to regulate local protein synthesis in dendrites for postsynaptic functions. However, involvement of FMRP in local protein synthesis in axons for presynaptic functions remains unclear. Here we investigated role of FMRP in local translation of the active zone protein Munc18-1 during presynapse formation. We found that leucine-rich repeat transmembrane neuronal 2 (LRRTM2)-conjugated beads, which promotes synchronized presynapse formation, induced simultaneous accumulation of FMRP and Munc18-1 in presynapses of axons of mouse cortical neurons in neuronal cell aggregate culture. The LRRTM2-induced accumulation of Munc18-1 in presynapses was observed in axons protein-synthesis-dependently, even physically separated from cell bodies. The accumulation of Munc18-1 was enhanced in Fmr1-knockout (KO) axons as compared to wild type (WT), suggesting FMRP-regulated suppression for local translation of Munc18-1 in axons during presynapse formation. Using naturally formed synapses of dissociated culture, structured illumination microscope revealed that accumulation of Munc18-1 puncta in Fmr1-KO neurons increased significantly at 19 days in vitro, as compared to WT. Our findings lead the possibility that excessive accumulation of Munc18-1 in presynapses at early stage of synaptic development in Fmr1-KO neurons may have a critical role in impaired presynaptic functions in FXS.
Collapse
Affiliation(s)
- Shumaia Parvin
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Renoma Takeda
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Yu Sugiura
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Makiko Neyazaki
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Terukazu Nogi
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Yukio Sasaki
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan.
| |
Collapse
|
29
|
Khalil B, Morderer D, Price PL, Liu F, Rossoll W. mRNP assembly, axonal transport, and local translation in neurodegenerative diseases. Brain Res 2018; 1693:75-91. [PMID: 29462608 PMCID: PMC5997521 DOI: 10.1016/j.brainres.2018.02.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/31/2018] [Accepted: 02/13/2018] [Indexed: 12/12/2022]
Abstract
The development, maturation, and maintenance of the mammalian nervous system rely on complex spatiotemporal patterns of gene expression. In neurons, this is achieved by the expression of differentially localized isoforms and specific sets of mRNA-binding proteins (mRBPs) that regulate RNA processing, mRNA trafficking, and local protein synthesis at remote sites within dendrites and axons. There is growing evidence that axons contain a specialized transcriptome and are endowed with the machinery that allows them to rapidly alter their local proteome via local translation and protein degradation. This enables axons to quickly respond to changes in their environment during development, and to facilitate axon regeneration and maintenance in adult organisms. Aside from providing autonomy to neuronal processes, local translation allows axons to send retrograde injury signals to the cell soma. In this review, we discuss evidence that disturbances in mRNP transport, granule assembly, axonal localization, and local translation contribute to pathology in various neurodegenerative diseases, including spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's disease (AD).
Collapse
Affiliation(s)
- Bilal Khalil
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Dmytro Morderer
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Phillip L Price
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA; Department of Cell Biology, Emory University, Atlanta, GA 30322 USA
| | - Feilin Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA; Eye Center, The Second Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Wilfried Rossoll
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA.
| |
Collapse
|
30
|
Sahoo PK, Smith DS, Perrone-Bizzozero N, Twiss JL. Axonal mRNA transport and translation at a glance. J Cell Sci 2018; 131:jcs196808. [PMID: 29654160 PMCID: PMC6518334 DOI: 10.1242/jcs.196808] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Localization and translation of mRNAs within different subcellular domains provides an important mechanism to spatially and temporally introduce new proteins in polarized cells. Neurons make use of this localized protein synthesis during initial growth, regeneration and functional maintenance of their axons. Although the first evidence for protein synthesis in axons dates back to 1960s, improved methodologies, including the ability to isolate axons to purity, highly sensitive RNA detection methods and imaging approaches, have shed new light on the complexity of the transcriptome of the axon and how it is regulated. Moreover, these efforts are now uncovering new roles for locally synthesized proteins in neurological diseases and injury responses. In this Cell Science at a Glance article and the accompanying poster, we provide an overview of how axonal mRNA transport and translation are regulated, and discuss their emerging links to neurological disorders and neural repair.
Collapse
Affiliation(s)
- Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., CLS 401, Columbia, SC 29208, USA
| | - Deanna S Smith
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., CLS 401, Columbia, SC 29208, USA
| | - Nora Perrone-Bizzozero
- Department of Neurosciences, University of New Mexico School of Medicine, 1 University of New Mexico, MSC08 4740, Albuquerque, NM 87131, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., CLS 401, Columbia, SC 29208, USA
| |
Collapse
|
31
|
Bellon A, Iyer A, Bridi S, Lee FCY, Ovando-Vázquez C, Corradi E, Longhi S, Roccuzzo M, Strohbuecker S, Naik S, Sarkies P, Miska E, Abreu-Goodger C, Holt CE, Baudet ML. miR-182 Regulates Slit2-Mediated Axon Guidance by Modulating the Local Translation of a Specific mRNA. Cell Rep 2017; 18:1171-1186. [PMID: 28147273 PMCID: PMC5300892 DOI: 10.1016/j.celrep.2016.12.093] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 12/07/2016] [Accepted: 12/27/2016] [Indexed: 11/15/2022] Open
Abstract
During brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mRNA translation. Different guidance cues elicit translation of subsets of mRNAs that differentially regulate the cytoskeleton, yet little is understood about how specific mRNAs are selected for translation. MicroRNAs (miRNAs) are critical translational regulators that act through a sequence-specific mechanism. Here, we investigate the local role of miRNAs in mRNA-specific translation during pathfinding of Xenopus laevis retinal ganglion cell (RGC) axons. Among a rich repertoire of axonal miRNAs, miR-182 is identified as the most abundant. Loss of miR-182 causes RGC axon targeting defects in vivo and impairs Slit2-induced growth cone (GC) repulsion. We find that miR-182 targets cofilin-1 mRNA, silencing its translation, and Slit2 rapidly relieves the repression without causing miR-182 degradation. Our data support a model whereby miR-182 reversibly gates the selection of transcripts for fast translation depending on the extrinsic cue. Small RNA-seq analysis reveals that miR-182 is the most abundant miRNA in RGC axons miR-182 regulates Slit2-mediated axon guidance of RGCs in vitro and in vivo miR-182 silences cofilin-1 local protein synthesis in growth cones Slit2 rapidly lifts miR-182-mediated repression of cofilin-1 without degrading it
Collapse
Affiliation(s)
- Anaïs Bellon
- PDN Department, University of Cambridge, Cambridge CB23DY, UK
| | - Archana Iyer
- CIBIO, University of Trento, Trento 38123, Italy
| | - Simone Bridi
- CIBIO, University of Trento, Trento 38123, Italy
| | - Flora C Y Lee
- PDN Department, University of Cambridge, Cambridge CB23DY, UK
| | | | | | - Sara Longhi
- CIBIO, University of Trento, Trento 38123, Italy
| | | | | | - Sindhu Naik
- CIBIO, University of Trento, Trento 38123, Italy
| | - Peter Sarkies
- Gurdon Institute, University of Cambridge, Cambridge CB21QN, UK
| | - Eric Miska
- Gurdon Institute, University of Cambridge, Cambridge CB21QN, UK
| | - Cei Abreu-Goodger
- Unidad de Genómica Avanzada (Langebio), Cinvestav, Irapuato 36821, Mexico
| | | | | |
Collapse
|
32
|
Gale JR, Aschrafi A, Gioio AE, Kaplan BB. Nuclear-Encoded Mitochondrial mRNAs: A Powerful Force in Axonal Growth and Development. Neuroscientist 2017; 24:142-155. [PMID: 28614981 DOI: 10.1177/1073858417714225] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Axons, their growth cones, and synaptic nerve terminals are neuronal subcompartments that have high energetic needs. As such, they are enriched in mitochondria, which supply the ATP necessary to meet these demands. To date, a heterogeneous population of nuclear-encoded mitochondrial mRNAs has been identified in distal axons and growth cones. Accumulating evidence suggests that the local translation of these mRNAs is required for mitochondrial maintenance and axonal viability. Here, we review evidence that suggests a critical role for axonal translation of nuclear-encoded mitochondrial mRNAs in axonal growth and development. Additionally, we explore the role that site-specific translation at the mitochondria itself may play in this process. Finally, we briefly review the clinical implications of dysregulation of local translation of mitochondrial-related mRNAs in neurodevelopmental disorders.
Collapse
Affiliation(s)
- Jenna R Gale
- 1 Laboratory of Molecular Biology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Armaz Aschrafi
- 1 Laboratory of Molecular Biology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Anthony E Gioio
- 1 Laboratory of Molecular Biology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Barry B Kaplan
- 1 Laboratory of Molecular Biology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
33
|
Kar AN, Lee SJ, Twiss JL. Expanding Axonal Transcriptome Brings New Functions for Axonally Synthesized Proteins in Health and Disease. Neuroscientist 2017; 24:111-129. [PMID: 28593814 DOI: 10.1177/1073858417712668] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intra-axonal protein synthesis has been shown to play critical roles in both development and repair of axons. Axons provide long-range connectivity in the nervous system, and disruption of their function and/or structure is seen in several neurological diseases and disorders. Axonally synthesized proteins or losses in axonally synthesized proteins contribute to neurodegenerative diseases, neuropathic pain, viral transport, and survival of axons. Increasing sensitivity of RNA detection and quantitation coupled with methods to isolate axons to purity has shown that a surprisingly complex transcriptome exists in axons. This extends across different species, neuronal populations, and physiological conditions. These studies have helped define the repertoire of neuronal mRNAs that can localize into axons and imply previously unrecognized functions for local translation in neurons. Here, we review the current state of transcriptomics studies of isolated axons, contrast axonal mRNA profiles between different neuronal types and growth states, and discuss how mRNA transport into and translation within axons contribute to neurological disorders.
Collapse
Affiliation(s)
- Amar N Kar
- 1 Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Seung Joon Lee
- 1 Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- 1 Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.,2 Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| |
Collapse
|
34
|
Wang B, Bao L. Axonal microRNAs: localization, function and regulatory mechanism during axon development. J Mol Cell Biol 2017; 9:82-90. [PMID: 27932485 PMCID: PMC5439374 DOI: 10.1093/jmcb/mjw050] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/25/2016] [Indexed: 11/30/2022] Open
Abstract
Subcellular localization and translation of messenger RNAs are essential for the regulation of neuronal development and synaptic function. As post-transcriptional regulators, microRNAs (miRNAs) have been emerging as central players in the development and maturation of the nervous system. Recent discoveries reveal the critical functions of miRNAs in the axon of neurons via multiple pathways of molecular regulation. Here, we introduce methods for isolating axonal miRNAs and review recent findings on the localization and function as well as regulatory mechanism of axonal miRNAs during axon development.
Collapse
Affiliation(s)
- Bin Wang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Lan Bao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| |
Collapse
|
35
|
Hirayama-Kurogi M, Takizawa Y, Kunii Y, Matsumoto J, Wada A, Hino M, Akatsu H, Hashizume Y, Yamamoto S, Kondo T, Ito S, Tachikawa M, Niwa SI, Yabe H, Terasaki T, Setou M, Ohtsuki S. Downregulation of GNA13-ERK network in prefrontal cortex of schizophrenia brain identified by combined focused and targeted quantitative proteomics. J Proteomics 2017; 158:31-42. [DOI: 10.1016/j.jprot.2017.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 02/10/2017] [Accepted: 02/13/2017] [Indexed: 01/06/2023]
|
36
|
Tu WY, Simpson JE, Highley JR, Heath PR. Spinal muscular atrophy: Factors that modulate motor neurone vulnerability. Neurobiol Dis 2017; 102:11-20. [PMID: 28161391 DOI: 10.1016/j.nbd.2017.01.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/10/2017] [Accepted: 01/31/2017] [Indexed: 01/07/2023] Open
Abstract
Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is a neurodegenerative disease characterised by the selective loss of particular groups of motor neurones in the anterior horn of the spinal cord with concomitant muscle weakness. To date, no effective treatment is available, however, there are ongoing clinical trials are in place which promise much for the future. However, there remains an ongoing problem in trying to link a single gene loss to motor neurone degeneration. Fortunately, given successful disease models that have been established and intensive studies on SMN functions in the past ten years, we are fast approaching the stage of identifying the underlying mechanisms of SMA pathogenesis Here we discuss potential disease modifying factors on motor neurone vulnerability, in the belief that these factors give insight into the pathological mechanisms of SMA and therefore possible therapeutic targets.
Collapse
Affiliation(s)
- Wen-Yo Tu
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - J Robin Highley
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK.
| |
Collapse
|
37
|
Tang K, Pasqua T, Biswas A, Mahata S, Tang J, Tang A, Bandyopadhyay GK, Sinha-Hikim AP, Chi NW, Webster NJG, Corti A, Mahata SK. Muscle injury, impaired muscle function and insulin resistance in Chromogranin A-knockout mice. J Endocrinol 2017; 232:137-153. [PMID: 27799464 PMCID: PMC5287349 DOI: 10.1530/joe-16-0370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 10/31/2016] [Indexed: 12/22/2022]
Abstract
Chromogranin A (CgA) is widely expressed in endocrine and neuroendocrine tissues as well as in the central nervous system. We observed CgA expression (mRNA and protein) in the gastrocnemius (GAS) muscle and found that performance of CgA-deficient Chga-KO mice in treadmill exercise was impaired. Supplementation with CgA in Chga-KO mice restored exercise ability suggesting a novel role for endogenous CgA in skeletal muscle function. Chga-KO mice display (i) lack of exercise-induced stimulation of pAKT, pTBC1D1 and phospho-p38 kinase signaling, (ii) loss of GAS muscle mass, (iii) extensive formation of tubular aggregates (TA), (iv) disorganized cristae architecture in mitochondria, (v) increased expression of the inflammatory cytokines Tnfα, Il6 and Ifnγ, and fibrosis. The impaired maximum running speed and endurance in the treadmill exercise in Chga-KO mice correlated with decreased glucose uptake and glycolysis, defects in glucose oxidation and decreased mitochondrial cytochrome C oxidase activity. The lack of adaptation to endurance training correlated with the lack of stimulation of p38MAPK that is known to mediate the response to tissue damage. As CgA sorts proteins to the regulated secretory pathway, we speculate that lack of CgA could cause misfolding of membrane proteins inducing aggregation of sarcoplasmic reticulum (SR) membranes and formation of tubular aggregates that is observed in Chga-KO mice. In conclusion, CgA deficiency renders the muscle energy deficient, impairs performance in treadmill exercise and prevents regeneration after exercise-induced tissue damage.
Collapse
Affiliation(s)
- Kechun Tang
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Teresa Pasqua
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Angshuman Biswas
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Sumana Mahata
- Division of Biology & Biological EngineeringCalifornia Institute of Technology, Pasadena, California, USA
| | - Jennifer Tang
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | - Alisa Tang
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
| | | | - Amiya P Sinha-Hikim
- Charles Drew University of Medicine and ScienceLos Angeles, California, USA
- David Geffen School of MedicineUniversity of California-Los Angeles, Los Angeles, California, USA
| | - Nai-Wen Chi
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
- VA San Diego Healthcare SystemSan Diego, California, USA
| | - Nicholas J G Webster
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
- VA San Diego Healthcare SystemSan Diego, California, USA
| | - Angelo Corti
- IRCCS San Raffaele Scientific InstituteSan Raffaele Vita-Salute University, Milan, Italy
| | - Sushil K Mahata
- Department of MedicineUniversity of California, San Diego, La Jolla, California, USA
- VA San Diego Healthcare SystemSan Diego, California, USA
| |
Collapse
|
38
|
Phay M, Kim HH, Yoo S. Analysis of piRNA-Like Small Non-coding RNAs Present in Axons of Adult Sensory Neurons. Mol Neurobiol 2016; 55:483-494. [PMID: 27966078 DOI: 10.1007/s12035-016-0340-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/02/2016] [Indexed: 10/20/2022]
Abstract
Small non-coding RNAs (sncRNAs) have been shown to play pivotal roles in spatiotemporal-specific gene regulation that is linked to many different biological functions. PIWI-interacting RNAs (piRNAs), typically 25-34-nucleotide long, are originally identified and thought to be restricted in germline cells. However, recent studies suggest that piRNAs associate with neuronal PIWI proteins, contributing to neuronal development and function. Here, we identify a cohort of piRNA-like sncRNAs (piLRNAs) in rat sciatic nerve axoplasm and directly contrast temporal changes of piLRNA levels in the nerve following injury, as compared with those in an uninjured nerve using deep sequencing. We find that 32 of a total of 53 annotated piLRNAs show significant changes in their levels in the regenerating nerve, suggesting that individual axonal piLRNAs may play important regulatory roles in local messenger RNA (mRNA) translation during regeneration. Bioinformatics and biochemical analyses show that these piLRNAs carry characteristic features of mammalian piRNAs, including sizes, a sequence bias for uracil at the 5'-end and a 2'-O-methylation at the 3'-end. Their axonal expression is directly visualized by fluorescence in situ hybridization in cultured dorsal root ganglion neurons as well as immunoprecipitation with MIWI. Further, depletion of MIWI protein using RNAi from cultured sensory neurons increases axon growth rates, decreases axon retraction after injury, and increases axon regrowth after injury. All these data suggest more general roles for MIWI/piLRNA pathway that could confer a unique advantage for coordinately altering the population of proteins generated in growth cones and axons of neurons by targeting mRNA cohorts.
Collapse
Affiliation(s)
- Monichan Phay
- Nemours Biomedical Research, Alfred I duPont Hospital for Children, Wilmington, DE, 19803, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Hak Hee Kim
- Nemours Biomedical Research, Alfred I duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Soonmoon Yoo
- Nemours Biomedical Research, Alfred I duPont Hospital for Children, Wilmington, DE, 19803, USA. .,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
| |
Collapse
|
39
|
López-Leal R, Alvarez J, Court FA. Origin of axonal proteins: Is the axon-schwann cell unit a functional syncytium? Cytoskeleton (Hoboken) 2016; 73:629-639. [DOI: 10.1002/cm.21319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 07/28/2016] [Accepted: 08/02/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Rodrigo López-Leal
- Faculty of Sciences, Center for Integrative Biology; Universidad Mayor; Santiago Chile
- Geroscience Center for Brain Health and Metabolism; Santiago Chile
- Millenium Nucleus for Regenerative Biology; Santiago Chile
| | - Jaime Alvarez
- Faculty of Sciences, Center for Integrative Biology; Universidad Mayor; Santiago Chile
- Millenium Nucleus for Regenerative Biology; Santiago Chile
| | - Felipe A. Court
- Faculty of Sciences, Center for Integrative Biology; Universidad Mayor; Santiago Chile
- Geroscience Center for Brain Health and Metabolism; Santiago Chile
- Millenium Nucleus for Regenerative Biology; Santiago Chile
| |
Collapse
|
40
|
Squid Giant Axon Contains Neurofilament Protein mRNA but does not Synthesize Neurofilament Proteins. Cell Mol Neurobiol 2016; 37:475-486. [PMID: 27207029 DOI: 10.1007/s10571-016-0382-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/06/2016] [Indexed: 12/16/2022]
Abstract
When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred into the giant axon. The question as to whether any de novo protein synthesis occurs in the giant axon itself is difficult to resolve because the small contribution of the proteins possibly synthesized intra-axonally is not easily distinguished from the large amounts of the proteins being supplied from the Schwann cells. In this paper, we reexamine this issue by studying the synthesis of endogenous neurofilament (NF) proteins in the axon. Our laboratory previously showed that NF mRNA and protein are present in the squid giant axon, but not in the surrounding adaxonal glia. Therefore, if the isolated squid axon could be shown to contain newly synthesized NF protein de novo, it could not arise from the adaxonal glia. The results of experiments in this paper show that abundant 3H-labeled NF protein is synthesized in the squid giant fiber lobe containing the giant axon's neuronal cell bodies, but despite the presence of NF mRNA in the giant axon no labeled NF protein is detected in the giant axon. This lends support to the glia-axon protein transfer hypothesis which posits that the squid giant axon obtains newly synthesized protein by Schwann cell transfer and not through intra-axonal protein synthesis, and further suggests that the NF mRNA in the axon is in a translationally repressed state.
Collapse
|
41
|
Kos A, Wanke KA, Gioio A, Martens GJ, Kaplan BB, Aschrafi A. Monitoring mRNA Translation in Neuronal Processes Using Fluorescent Non-Canonical Amino Acid Tagging. J Histochem Cytochem 2016; 64:323-33. [PMID: 27026294 DOI: 10.1369/0022155416641604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/29/2016] [Indexed: 11/22/2022] Open
Abstract
A steady accumulation of experimental data argues that protein synthesis in neurons is not merely restricted to the somatic compartment, but also occurs in several discrete cellular micro-domains. Local protein synthesis is critical for the establishment of synaptic plasticity in mature dendrites and in directing the growth cones of immature axons, and has been associated with cognitive impairment in mice and humans. Although in recent years a number of important mechanisms governing this process have been described, it remains technically challenging to precisely monitor local protein synthesis in individual neuronal cell parts independent from the soma. This report presents the utility of employing microfluidic chambers for the isolation and treatment of single neuronal cellular compartments. Furthermore, it is demonstrated that a protein synthesis assay, based on fluorescent non-canonical amino acid tagging (FUNCAT), can be combined with this cell culture system to label nascent proteins within a discrete structural and functional domain of the neuron. Together, these techniques could be employed for the detection of protein synthesis within developing and mature neurites, offering an effective approach to elucidate novel mechanisms controlling synaptic maintenance and plasticity.
Collapse
Affiliation(s)
- Aron Kos
- Department of Cognitive Neuroscience, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands (AK),Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, 6525 AJ Nijmegen, The Netherlands (AK, KAW)
| | - Kai A Wanke
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, 6525 AJ Nijmegen, The Netherlands (AK, KAW),Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands (KAW)
| | - Anthony Gioio
- Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland (AG, BBK, AA)
| | - Gerard J Martens
- Department of Cognitive Neuroscience, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands (AK),Department of Molecular Animal Physiology, Radboud University, Nijmegen, The Netherlands (GJM)
| | - Barry B Kaplan
- Department of Cognitive Neuroscience, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands (AK),Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland (AG, BBK, AA)
| | - Armaz Aschrafi
- Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland (AG, BBK, AA)
| |
Collapse
|
42
|
miR-139-5p controls translation in myeloid leukemia through EIF4G2. Oncogene 2015; 35:1822-31. [PMID: 26165837 DOI: 10.1038/onc.2015.247] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 05/21/2015] [Accepted: 05/22/2015] [Indexed: 12/15/2022]
Abstract
MicroRNAs (miRNAs) are crucial components of homeostatic and developmental gene regulation. In turn, dysregulation of miRNA expression is a common feature of different types of cancer, which can be harnessed therapeutically. Here we identify miR-139-5p suppression across several cytogenetically defined acute myeloid leukemia (AML) subgroups. The promoter of mir-139 was transcriptionally silenced and could be reactivated by histone deacetylase inhibitors in a dose-dependent manner. Restoration of mir-139 expression in cell lines representing the major AML subgroups (t[8;21], inv[16], mixed lineage leukemia-rearranged and complex karyotype AML) caused cell cycle arrest and apoptosis in vitro and in xenograft mouse models in vivo. During normal hematopoiesis, mir-139 is exclusively expressed in terminally differentiated neutrophils and macrophages. Ectopic expression of mir-139 repressed proliferation of normal CD34(+)-hematopoietic stem and progenitor cells and perturbed myelomonocytic in vitro differentiation. Mechanistically, mir-139 exerts its effects by repressing the translation initiation factor EIF4G2, thereby reducing overall protein synthesis while specifically inducing the translation of cell cycle inhibitor p27(Kip1). Knockdown of EIF4G2 recapitulated the effects of mir-139, whereas restoring EIF4G2 expression rescued the mir-139 phenotype. Moreover, elevated miR-139-5p expression is associated with a favorable outcome in a cohort of 165 pediatric patients with AML. Thus, mir-139 acts as a global tumor suppressor-miR in AML by controlling protein translation. As AML cells are dependent on high protein synthesis rates controlling the expression of mir-139 constitutes a novel path for the treatment of AML.
Collapse
|
43
|
Zhang Y, Chopp M, Liu XS, Kassis H, Wang X, Li C, An G, Zhang ZG. MicroRNAs in the axon locally mediate the effects of chondroitin sulfate proteoglycans and cGMP on axonal growth. Dev Neurobiol 2015; 75:1402-19. [PMID: 25788427 DOI: 10.1002/dneu.22292] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 02/25/2015] [Accepted: 03/16/2015] [Indexed: 01/08/2023]
Abstract
Axonal miRNAs locally regulate axonal growth by modulating local protein composition. Whether localized miRNAs in the axon mediate the inhibitory effect of Chondroitin sulfate proteoglycans (CSPGs) on the axon remains unknown. We showed that in cultured cortical neurons, axonal application of CSPGs inhibited axonal growth and altered axonal miRNA profiles, whereas elevation of axonal cyclic guanosine monophosphate (cGMP) levels by axonal application of sildenafil reversed the effect of CSPGs on inhibition of axonal growth and on miRNA profiles. Specifically, CSPGs elevated and reduced axonal levels of miR-29c and integrin β1 (ITGB1) proteins, respectively, while elevation of cGMP levels overcame these CSPG effects. Gain-of- and loss-of-function experiments demonstrated that miR-29c in the distal axon mediates axonal growth downstream of CSPGs and cGMP by regulating axonal protein levels of ITGB1, FAK, and RhoA. Together, our data demonstrate that axonal miRNAs play an important role in mediating the inhibitory action of CSPGs on axonal growth and that miR-29c at least partially mediates this process.
Collapse
Affiliation(s)
- Yi Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202.,Department of Physics, Oakland University, Rochester, Michigan, 48309
| | - Xian Shuang Liu
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Haifa Kassis
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Xinli Wang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Chao Li
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | | | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| |
Collapse
|
44
|
Kye MJ, Niederst ED, Wertz MH, Gonçalves IDCG, Akten B, Dover KZ, Peters M, Riessland M, Neveu P, Wirth B, Kosik KS, Sardi SP, Monani UR, Passini MA, Sahin M. SMN regulates axonal local translation via miR-183/mTOR pathway. Hum Mol Genet 2014; 23:6318-31. [PMID: 25055867 DOI: 10.1093/hmg/ddu350] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Reduced expression of SMN protein causes spinal muscular atrophy (SMA), a neurodegenerative disorder leading to motor neuron dysfunction and loss. However, the molecular mechanisms by which SMN regulates neuronal dysfunction are not fully understood. Here, we report that reduced SMN protein level alters miRNA expression and distribution in neurons. In particular, miR-183 levels are increased in neurites of SMN-deficient neurons. We demonstrate that miR-183 regulates translation of mTor via direct binding to its 3' UTR. Interestingly, local axonal translation of mTor is reduced in SMN-deficient neurons, and this can be recovered by miR-183 inhibition. Finally, inhibition of miR-183 expression in the spinal cord of an SMA mouse model prolongs survival and improves motor function of Smn-mutant mice. Together, these observations suggest that axonal miRNAs and the mTOR pathway are previously unidentified molecular mechanisms contributing to SMA pathology.
Collapse
Affiliation(s)
- Min Jeong Kye
- Department of Neurology, The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA, Institute of Human Genetics, Institute for Genetics and
| | - Emily D Niederst
- Department of Neurology, The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mary H Wertz
- Department of Neurology, The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Bikem Akten
- Department of Neurology, The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Katarzyna Z Dover
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology and
| | - Miriam Peters
- Institute of Human Genetics, Institute for Genetics and, Center of Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Markus Riessland
- Institute of Human Genetics, Institute for Genetics and, Center of Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Pierre Neveu
- Kavli Institute for Theoretical Physics and, Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106, USA, Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany and
| | - Brunhilde Wirth
- Institute of Human Genetics, Institute for Genetics and, Center of Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Kenneth S Kosik
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106, USA
| | - S Pablo Sardi
- Genzyme, a Sanofi Company, Framingham, MA 01701, USA
| | - Umrao R Monani
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology and, Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | | | - Mustafa Sahin
- Department of Neurology, The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA,
| |
Collapse
|
45
|
In vitro growth conditions and development affect differential distributions of RNA in axonal growth cones and shafts of cultured rat hippocampal neurons. Mol Cell Neurosci 2014; 61:141-51. [PMID: 24983517 DOI: 10.1016/j.mcn.2014.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/20/2014] [Accepted: 06/27/2014] [Indexed: 12/31/2022] Open
Abstract
Local synthesis of proteins in the axons participates in axonogenesis and axon guidance to establish appropriate synaptic connections and confer plasticity. To study the transcripts present in the growth cones and axonal shafts of cultured rat hippocampal neurons, two chip devices, differing in their abilities to support axonal growth and branching, are designed and employed here to isolate large quantities of axonal materials. Cone-, shaft- and axon-residing transcripts with amounts higher than that of a somatodendritic transcript, Actg1 (γ-actin), are selected and classified. Since the chips are optically transparent, distribution of transcripts over axons can be studied by fluorescence in situ hybridization. Three transcripts, Cadm1 (cell adhesion molecule 1), Nefl (neurofilament light polypeptide), and Cfl1 (non-muscle cofilin) are confirmed to be preferentially localized to the growth cones, while Pfn2 (profilin2) is preferentially localized to the shafts of those axons growing on the chip that restricts axonal growth. The different growing conditions of axons on chips and on conventional coverslips do not affect the cone-preferred localization of Cadm1 and shaft-preferred localization of Pfn2, but affect the distributions of Nefl and Cfl1 over the axons at 14th day in vitro. Furthermore, the distributions of Cadm1 and Nefl over the axons growing on conventional coverslips undergo changes during in vitro development. Our results suggest a dynamic nature of the mechanisms regulating the distributions of transcripts in axonal substructures in a manner dependent upon both growth conditions and neuronal maturation.
Collapse
|
46
|
Iyer AN, Bellon A, Baudet ML. microRNAs in axon guidance. Front Cell Neurosci 2014; 8:78. [PMID: 24672429 PMCID: PMC3953822 DOI: 10.3389/fncel.2014.00078] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 02/23/2014] [Indexed: 01/01/2023] Open
Abstract
Brain wiring is a highly intricate process in which trillions of neuronal connections are established. Its initial phase is particularly crucial in establishing the general framework of neuronal circuits. During this early step, differentiating neurons extend axons, which reach their target by navigating through a complex environment with extreme precision. Research in the past 20 years has unraveled a vast and complex array of chemotropic cues that guide the leading tip of axons, the growth cone, throughout its journey. Tight regulation of these cues, and of their receptors and signaling pathways, is necessary for the high degree of accuracy required during circuit formation. However, little is known about the nature of regulatory molecules or mechanisms fine-tuning axonal cue response. Here we review recent, and somewhat fragmented, research on the possibility that microRNAs (miRNAs) could be key fine-tuning regulatory molecules in axon guidance. miRNAs appear to shape long-range axon guidance, fasciculation and targeting. We also present several lines of evidence suggesting that miRNAs could have a compartmentalized and differential action at the cell soma, and within axons and growth cones.
Collapse
Affiliation(s)
- Archana N Iyer
- Center for Integrative Biology, University of Trento Trento, Italy
| | - Anaïs Bellon
- Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
| | | |
Collapse
|
47
|
Gomes C, Merianda TT, Lee SJ, Yoo S, Twiss JL. Molecular determinants of the axonal mRNA transcriptome. Dev Neurobiol 2014; 74:218-32. [PMID: 23959706 PMCID: PMC3933445 DOI: 10.1002/dneu.22123] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/05/2013] [Accepted: 08/13/2013] [Indexed: 12/12/2022]
Abstract
Axonal protein synthesis has been shown to play a role in developmental and regenerative growth, as well as in cell body responses to axotomy. Recent studies have begun to identify the protein products that contribute to these autonomous responses of axons. In the peripheral nervous system, intra-axonal protein synthesis has been implicated in the localized in vivo responses to neuropathic stimuli, and there is emerging evidence for protein synthesis in CNS axons in vivo. Despite that hundreds of mRNAs have now been shown to localize into the axonal compartment, knowledge of what RNA binding proteins are responsible for this is quite limited. Here, we review the current state of knowledge of RNA transport mechanisms and highlight recently uncovered mechanisms for dynamically altering the axonal transcriptome. Both changes in the levels or activities of components of the RNA transport apparatus and alterations in transcription of transported mRNAs can effectively shift the axonal mRNA population. Consistent with this, the axonal RNA population shifts with development, with changes in growth state, and in response to extracellular stimulation. Each of these events must impact the transcriptional and transport apparatuses of the neuron, thus directly and indirectly modifying the axonal transcriptome.
Collapse
Affiliation(s)
- Cynthia Gomes
- Department of Biology, Drexel University, Philadelphia, Pennsylvania 19104 USA
| | - Tanuja T. Merianda
- Department of Biology, Drexel University, Philadelphia, Pennsylvania 19104 USA
| | - Seung Joon Lee
- Department of Biology, Drexel University, Philadelphia, Pennsylvania 19104 USA
| | - Soonmoon Yoo
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware 19803 USA
| | - Jeffery L. Twiss
- Department of Biology, Drexel University, Philadelphia, Pennsylvania 19104 USA
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29201
| |
Collapse
|
48
|
Kar AN, Sun CY, Reichard K, Gervasi NM, Pickel J, Nakazawa K, Gioio AE, Kaplan BB. Dysregulation of the axonal trafficking of nuclear-encoded mitochondrial mRNA alters neuronal mitochondrial activity and mouse behavior. Dev Neurobiol 2013; 74:333-50. [PMID: 24151253 DOI: 10.1002/dneu.22141] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/03/2013] [Accepted: 10/16/2013] [Indexed: 01/22/2023]
Abstract
Local translation of nuclear-encoded mitochondrial mRNAs is essential for mitochondrial activity, yet there is little insight into the role that axonal trafficking of these transcripts play in neuronal function and behavior. Previously, we identified a 38 nucleotide stem-loop structure (zipcode) in the 3' untranslated region of the Cytochrome C oxidase IV (COXIV) mRNA that directs the transport of a reporter mRNA to the axon of superior cervical ganglion neurons (SCG). Overexpression of a chimeric reporter mRNA with the COXIV zipcode competed with the axonal trafficking of endogenous COXIV mRNA, and led to attenuated axon growth in SCG neurons. Here, we show that exogenous expression of the COXIV zipcode in cultured SCG neurons also results in the reduction of local ATP levels and increases levels of reactive oxygen species (ROS) in the axon. We took advantage of this "competition" phenotype to investigate the in vivo significance of axonal transport of COXIV mRNA. Toward this end, we generated transgenic mice expressing a fluorescent reporter fused to COXIV zipcode under a forebrain-specific promoter. Immunohistological analyses and RT-PCR analyses of RNA from the transgenic mouse brain showed expression of the reporter in the deep layer neurons in the pre-frontal and frontal cortex. Consistent with the in vitro studies, we observed increased ROS levels in neurons of these transgenic animals. A battery of behavioral tests on transgenic mice expressing the COXIV zipcode revealed an "anxiety-like" behavioral phenotype, suggesting an important role for axonal trafficking of nuclear-encoded mitochondrial mRNAs in neuronal physiology and animal behavior.
Collapse
Affiliation(s)
- Amar N Kar
- Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Obara I, Hunt SP. Axonal protein synthesis and the regulation of primary afferent function. Dev Neurobiol 2013; 74:269-78. [PMID: 24085547 PMCID: PMC4237183 DOI: 10.1002/dneu.22133] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/27/2013] [Accepted: 09/15/2013] [Indexed: 11/09/2022]
Abstract
Local protein synthesis has been demonstrated in the peripheral processes of sensory primary afferents and is thought to contribute to the maintenance of the neuron, to neuronal plasticity following injury and also to regeneration of the axon after damage to the nerve. The mammalian target of rapamycin (mTOR), a master regulator of protein synthesis, integrates a variety of cues that regulate cellular homeostasis and is thought to play a key role in coordinating the neuronal response to environmental challenges. Evidence suggests that activated mTOR is expressed by peripheral nerve fibers, principally by A-nociceptors that rapidly signal noxious stimulation to the central nervous system, but also by a subset of fibers that respond to cold and itch. Inhibition of mTOR complex 1 (mTORC1) has shown that while the acute response to noxious stimulation is unaffected, more complex aspects of pain processing including the setting up and maintenance of chronic pain states can be disrupted suggesting a route for the generation of new drugs for the control of chronic pain. Given the role of mTORC1 in cellular homeostasis, it seems that systemic changes in the physiological state of the body such as occur during illness are likely to modulate the sensitivity of peripheral sensory afferents through mTORC1 signaling pathways.
Collapse
Affiliation(s)
- Ilona Obara
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom; School of Medicine, Pharmacy and Health, Durham University, Stockton-on-Tees TS17 6BH, United Kingdom
| | | |
Collapse
|
50
|
Crispino M, Chun JT, Cefaliello C, Perrone Capano C, Giuditta A. Local gene expression in nerve endings. Dev Neurobiol 2013; 74:279-91. [PMID: 23853157 DOI: 10.1002/dneu.22109] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 06/28/2013] [Accepted: 07/05/2013] [Indexed: 12/11/2022]
Abstract
At the Nobel lecture for physiology in 1906, Ramón y Cajal famously stated that "the nerve elements possess reciprocal relationships in contiguity but not in continuity," summing up the neuron doctrine. Sixty years later, by the time the central dogma of molecular biology formulated the axis of genetic information flow from DNA to mRNA, and then to protein, it became obvious that neurons with extensive ramifications and long axons inevitably incur an innate problem: how can the effect of gene expression be extended from the nucleus to the remote and specific sites of the cell periphery? The most straightforward solution would be to deliver soma-produced proteins to the target sites. The influential discovery of axoplasmic flow has supported this scheme of protein supply. Alternatively, mRNAs can be dispatched instead of protein, and translated locally at the strategic target sites. Over the past decades, such a local system of protein synthesis has been demonstrated in dendrites, axons, and presynaptic terminals. Moreover, the local protein synthesis in neurons might even involve intercellular trafficking of molecules. The innovative concept of glia-neuron unit suggests that the local protein synthesis in the axonal and presynaptic domain of mature neurons is sustained by a local supply of RNAs synthesized in the surrounding glial cells and transferred to these domains. Here, we have reviewed some of the evidence indicating the presence of a local system of protein synthesis in axon terminals, and have examined its regulation in various model systems.
Collapse
Affiliation(s)
- Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | | | | | | |
Collapse
|