1
|
Xiao G, Chen Q, Zhang X. MicroRNA-455-5p/CPEB1 pathway mediates Aβ-related learning and memory deficits in a mouse model of Alzheimer's disease. Brain Res Bull 2021; 177:282-294. [PMID: 34678444 DOI: 10.1016/j.brainresbull.2021.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 09/12/2021] [Accepted: 10/12/2021] [Indexed: 12/01/2022]
Abstract
Alzheimer's disease (AD), a common neurodegenerative disease, is the main cause of dementia, with cognitive decline as the core symptom observed during diagnosis. Synaptic loss may be the main cause of early cognitive dysfunction in AD, but the detailed mechanism is still unclear. In this study, we investigated the role of abnormal miR-455-5p/CPEB1 pathway in AD mouse model. We found that miR-455-5p was upregulated, while its downstream target, cytoplasmic polyadenylation element-binding 1 (CPEB1), was downregulated in the hippocampus of APP/PS1 mice at the age of 9 m. Abnormal miR-455-5p/CPEB1 pathway mediated cognitive deficits in APP/PS1 mice through suppressing α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor expressions. And miR-455-5p suppression, CPEB1 overexpression or application of a peptide disrupting the miR-455-5p/CPEB1 interaction in CA1 of APP/PS1 mice rescued AD-like phenotypes in mice, including deficits in synaptic plasticity and memory. In conclusion, our results indicated that miRNA-455-5p/CPEB1 pathway mediated synaptic and memory deficits in Alzheimer's Disease through targeting on AMPARs, providing a potential therapeutic strategy for AD.
Collapse
Affiliation(s)
- Gelei Xiao
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China; Diagnosis and Treatment Center for Hydrocephalus, Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China
| | - Qianwei Chen
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, PR China
| | - Xuewei Zhang
- Department of Health Managent Center, Xiangya hospital, Central South University, Changsha, Hunan 410008, PR China; Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410008, PR China.
| |
Collapse
|
2
|
Jiang H, Liu JP, Xi K, Liu LY, Kong LY, Cai J, Cai SQ, Han XY, Song JG, Yang XM, Wan Y, Xing GG. Contribution of AMPA Receptor-Mediated LTD in LA/BLA-CeA Pathway to Comorbid Aversive and Depressive Symptoms in Neuropathic Pain. J Neurosci 2021; 41:7278-7299. [PMID: 34272314 PMCID: PMC8387122 DOI: 10.1523/jneurosci.2678-20.2021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 06/30/2021] [Accepted: 07/08/2021] [Indexed: 11/21/2022] Open
Abstract
Comorbid anxiety and depressive symptoms in chronic pain are a common health problem, but the underlying mechanisms remain unclear. Previously, we have demonstrated that sensitization of the CeA neurons via decreased GABAergic inhibition contributes to anxiety-like behaviors in neuropathic pain rats. In this study, by using male Sprague Dawley rats, we reported that the CeA plays a key role in processing both sensory and negative emotional-affective components of neuropathic pain. Bilateral electrolytic lesions of CeA, but not lateral/basolateral nucleus of the amygdala (LA/BLA), abrogated both pain hypersensitivity and aversive and depressive symptoms of neuropathic rats induced by spinal nerve ligation (SNL). Moreover, SNL rats showed structural and functional neuroplasticity manifested as reduced dendritic spines on the CeA neurons and enhanced LTD at the LA/BLA-CeA synapse. Disruption of GluA2-containing AMPAR trafficking and endocytosis from synapses using synthetic peptides, either pep2-EVKI or Tat-GluA2(3Y), restored the enhanced LTD at the LA/BLA-CeA synapse, and alleviated the mechanical allodynia and comorbid aversive and depressive symptoms in neuropathic rats, indicating that the endocytosis of GluA2-containing AMPARs from synapses is probably involved in the LTD at the LA/BLA-CeA synapse and the comorbid aversive and depressive symptoms in neuropathic pain in SNL-operated rats. These data provide a novel mechanism for elucidating comorbid aversive and depressive symptoms in neuropathic pain and highlight that structural and functional neuroplasticity in the amygdala may be important as a promising therapeutic target for comorbid negative emotional-affective disorders in chronic pain.SIGNIFICANCE STATEMENT Several studies have demonstrated the high comorbidity of negative affective disorders in patients with chronic pain. Understanding the affective aspects related to chronic pain may facilitate the development of novel therapies for more effective management. Here, we unravel that the CeA plays a key role in processing both sensory and negative emotional-affective components of neuropathic pain, and LTD at the amygdaloid LA/BLA-CeA synapse mediated by GluA2-containing AMPAR endocytosis underlies the comorbid aversive and depressive symptoms in neuropathic pain. This study provides a novel mechanism for elucidating comorbid aversive and depressive symptoms in neuropathic pain and highlights that structural and functional neuroplasticity in the amygdala may be important as a promising therapeutic target for comorbid negative emotional-affective disorders in chronic pain.
Collapse
Affiliation(s)
- Hong Jiang
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Jiang-Ping Liu
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Ke Xi
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Ling-Yu Liu
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Ling-Yu Kong
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Jie Cai
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Si-Qing Cai
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Xi-Yuan Han
- Second Affiliated Hospital of Xinxiang Medical University, Henan, Xinxiang 453002, China
| | - Jing-Gui Song
- Second Affiliated Hospital of Xinxiang Medical University, Henan, Xinxiang 453002, China
| | - Xiao-Mei Yang
- Department of Human anatomy and Embryology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - You Wan
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
| | - Guo-Gang Xing
- Neuroscience Research Institute, Peking University, Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, 100191, China
- Second Affiliated Hospital of Xinxiang Medical University, Henan, Xinxiang 453002, China
| |
Collapse
|
3
|
Fang YC, Hsieh JY, Vidyanti AN, Yang CH, Jan JS, Chang KW, Hu CJ, Tu YK. HDACi protects against vascular cognitive impairment from CCH injury via induction of BDNF-related AMPA receptor activation. J Cell Mol Med 2021; 25:7418-7425. [PMID: 34216182 PMCID: PMC8335662 DOI: 10.1111/jcmm.16770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 06/15/2021] [Accepted: 06/19/2021] [Indexed: 12/12/2022] Open
Abstract
We previously showed a hydroxamic acid‐based histone deacetylase inhibitor (HDACi), compound 13, provides neuroprotection against chronic cerebral hypoperfusion (CCH) both in vitro under oxygen‐glucose deprivation (OGD) conditions and in vivo under bilateral common carotid artery occlusion (BCCAO) conditions. Intriguingly, the protective effect of this HDACi is via H3K14 or H4K5 acetylation–mediated differential BDNF isoform activation. BDNF is involved in cell proliferation and differentiation in development, synaptic plasticity and in learning and memory related with receptors or synaptic proteins. B6 mice underwent BCCAO and were randomized into 4 groups; a sham without BCCAO (sham), BCCAO mice injected with DMSO (DMSO), mice injected with HDACi‐compound 13 (compound 13) and mice injected with suberoylanilide hydroxamic acid (SAHA). The cortex and hippocampus of mice were harvested at 3 months after BCCAO, and levels of BDNF, AMPA receptor and dopamine receptors (D1, D2 and D3) were studied using Western blotting analysis or immunohistochemistry. We found that the AMPA receptor plays a key role in the molecular mechanism of this process by modulating HDAC. This protective effect of HDACi may be through BDNF; therefore, activation of this downstream signalling molecule, for example by AMPA receptors, could be a therapeutic target or intervention applied under CCH conditions.
Collapse
Affiliation(s)
- Yao-Ching Fang
- Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan
| | - Jia-Yu Hsieh
- Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Amelia Nur Vidyanti
- Department of Neurology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Chih-Hao Yang
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jing-Shiun Jan
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Kang-Wei Chang
- Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan.,Laboratory Animal Center, Taipei Medical University, Taipei, Taiwan
| | - Chaur-Jong Hu
- Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan.,Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Yong-Kwang Tu
- Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan.,Department of Neurology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| |
Collapse
|
4
|
van Gelder CAGH, Altelaar M. Neuroproteomics of the Synapse: Subcellular Quantification of Protein Networks and Signaling Dynamics. Mol Cell Proteomics 2021; 20:100087. [PMID: 33933679 PMCID: PMC8167277 DOI: 10.1016/j.mcpro.2021.100087] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 01/21/2023] Open
Abstract
One of the most fascinating features of the brain is its ability to adapt to its surroundings. Synaptic plasticity, the dynamic mechanism of functional and structural alterations in synaptic strength, is essential for brain functioning and underlies a variety of processes such as learning and memory. Although the molecular mechanisms underlying such rapid plasticity are not fully understood, a consensus exists on the important role of proteins. The study of these neuronal proteins using neuroproteomics has increased rapidly in the last decades, and advancements in MS-based proteomics have broadened our understanding of neuroplasticity exponentially. In this review, we discuss the trends in MS-based neuroproteomics for the study of synaptic protein-protein interactions and protein signaling dynamics, with a focus on sample types, different labeling and enrichment approaches, and data analysis and interpretation. We highlight studies from the last 5 years, with a focus on synapse structure, composition, functioning, or signaling and finally discuss some recent developments that could further advance the field of neuroproteomics.
Collapse
Affiliation(s)
- Charlotte A G H van Gelder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands.
| |
Collapse
|
5
|
Khan R, Kulasiri D, Samarasinghe S. Functional repertoire of protein kinases and phosphatases in synaptic plasticity and associated neurological disorders. Neural Regen Res 2021; 16:1150-1157. [PMID: 33269764 PMCID: PMC8224123 DOI: 10.4103/1673-5374.300331] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Protein phosphorylation and dephosphorylation are two essential and vital cellular mechanisms that regulate many receptors and enzymes through kinases and phosphatases. Ca2+- dependent kinases and phosphatases are responsible for controlling neuronal processing; balance is achieved through opposition. During molecular mechanisms of learning and memory, kinases generally modulate positively while phosphatases modulate negatively. This review outlines some of the critical physiological and structural aspects of kinases and phosphatases involved in maintaining postsynaptic structural plasticity. It also explores the link between neuronal disorders and the deregulation of phosphatases and kinases.
Collapse
Affiliation(s)
- Raheel Khan
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand
| | - Sandhya Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
| |
Collapse
|
6
|
Williams KR, Nairn AC. Editorial for Special Issue: Neuroproteomics. Proteomes 2019; 7:24. [PMID: 31159207 PMCID: PMC6630506 DOI: 10.3390/proteomes7020024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 05/27/2019] [Indexed: 11/17/2022] Open
Abstract
Recent advances in mass spectrometry (MS) instrumentation [...].
Collapse
Affiliation(s)
- Kenneth R Williams
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Angus C Nairn
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- Department of Psychiatry, Yale School of Medicine, Connecticut Mental Health Center, New Haven, CT 06511, USA.
| |
Collapse
|
7
|
Sun J, Liu S, Ling Z, Wang F, Ling Y, Gong T, Fang N, Ye S, Si J, Liu J. Fructooligosaccharides Ameliorating Cognitive Deficits and Neurodegeneration in APP/PS1 Transgenic Mice through Modulating Gut Microbiota. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:3006-3017. [PMID: 30816709 DOI: 10.1021/acs.jafc.8b07313] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Alzheimer's disease (AD) is closely related to gut microbial alteration. Prebiotic fructooligosaccharides (FOS) play major roles by regulating gut microbiota. The present study aimed to explore the effect and mechanism of FOS protection against AD via regulating gut microbiota. Male Apse/PSEN 1dE9 (APP/PS1) transgenic (Tg) mice were administrated with FOS for 6 weeks. Cognitive deficits and amyloid deposition were evaluated. The levels of synaptic plasticity markers including postsynaptic density protein 95 (PSD-95) and synapsin I, as well as phosphorylation of c-Jun N-terminal kinase (JNK), were determined. The intestinal microbial constituent was detected by 16S rRNA sequencing. Moreover, the levels of glucagon-like peptide-1 (GLP-1) in the gut and GLP-1 receptor (GLP-1R) in the brain were measured. The results indicated that FOS treatment ameliorated cognitive deficits and pathological changes in the Tg mice. FOS significantly upregulated the expression levels of synapsin I and PSD-95, as well as decreased phosphorylated level of JNK. The sequencing results showed that FOS reversed the altered microbial composition. Furthermore, FOS increased the level of GLP-1 and decreased the level of GLP-1R in the Tg mice. These findings indicated that FOS exerted beneficial effects against AD via regulating the gut microbiota-GLP-1/GLP-1R pathway.
Collapse
Affiliation(s)
- Jing Sun
- Department of Neurology , the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , Zhejiang 325027 , China
| | - Suzhi Liu
- Department of Neurology, The Affiliated Taizhou Hospital , Wenzhou Medical University , 150# Ximen Road , Linhai District, Taizhou 317000 , Zhejiang China
| | - Zongxin Ling
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou , Zhejiang 310003 , China
| | - Fangyan Wang
- Departments of Pathophysiology, School of Basic Medicine Science , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| | - Yi Ling
- Department of Neurology , the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , Zhejiang 325027 , China
| | - Tianyu Gong
- Department of Preventive Medicine, School of Public Health and Management , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| | - Na Fang
- Department of Preventive Medicine, School of Public Health and Management , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| | - Shiqing Ye
- Department of Preventive Medicine, School of Public Health and Management , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| | - Jue Si
- Department of Preventive Medicine, School of Public Health and Management , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| | - Jiaming Liu
- Department of Neurology , the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , Zhejiang 325027 , China
- Department of Preventive Medicine, School of Public Health and Management , Wenzhou Medical University , Wenzhou , Zhejiang 325035 , China
| |
Collapse
|
8
|
The Reactive Plasticity of Hippocampal Ionotropic Glutamate Receptors in Animal Epilepsies. Int J Mol Sci 2019; 20:ijms20051030. [PMID: 30818767 PMCID: PMC6429472 DOI: 10.3390/ijms20051030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/18/2019] [Accepted: 02/22/2019] [Indexed: 12/21/2022] Open
Abstract
Ionotropic glutamate receptors (iGluRs) mediate the synaptic and metabolic actions of glutamate. These iGluRs are classified within the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type, kainate-type, and N-methyl-d-aspartate (NMDA)-type functional receptor families. The iGluR assemblies are regulated by transcription, alternative splicing, and cytoplasmic post-translational modifications. The iGluR subunit proteins are transported from the endoplasmic reticulum, inserted into the synaptic membranes, and anchored at their action site by different scaffolding and interacting proteins. The functional properties of iGluRs depend on their subunit composition, the amino acid sequence of the protein domains, and the scaffolding proteins in the synaptic membranes. The iGluRs are removed from the membranes by enzymatic action and endocytosis. Hippocampal iGluRs are rearranged through the upregulation and downregulation of the subunits following deafferentation and epileptic seizures. The rearrangement of iGluRs and the alteration of their subunit composition transform neurons into “pathological” cells, determining the further plasticity or pathology of the hippocampal formation. In the present review, we summarize the expression of AMPA, kainate, and NMDA receptor subunits following deafferentation, repeated mild seizures, and status epilepticus. We compare our results to literature descriptions, and draw conclusions as to the reactive plasticity of iGluRs in the hippocampus.
Collapse
|
9
|
From Synapse to Function: A Perspective on the Role of Neuroproteomics in Elucidating Mechanisms of Drug Addiction. Proteomes 2018; 6:proteomes6040050. [PMID: 30544849 PMCID: PMC6315754 DOI: 10.3390/proteomes6040050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/05/2018] [Accepted: 12/07/2018] [Indexed: 12/18/2022] Open
Abstract
Drug addiction is a complex disorder driven by dysregulation in molecular signaling across several different brain regions. Limited therapeutic options currently exist for treating drug addiction and related psychiatric disorders in clinical populations, largely due to our incomplete understanding of the molecular pathways that influence addiction pathology. Recent work provides strong evidence that addiction-related behaviors emerge from the convergence of many subtle changes in molecular signaling networks that include neuropeptides (neuropeptidome), protein-protein interactions (interactome) and post-translational modifications such as protein phosphorylation (phosphoproteome). Advancements in mass spectrometry methodology are well positioned to identify these novel molecular underpinnings of addiction and further translate these findings into druggable targets for therapeutic development. In this review, we provide a general perspective of the utility of novel mass spectrometry-based approaches for addressing critical questions in addiction neuroscience, highlighting recent innovative studies that exemplify how functional assessments of the neuroproteome can provide insight into the mechanisms of drug addiction.
Collapse
|