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Lee JH, Park S, Perez-Flores MC, Chen Y, Kang M, Choi J, Levine L, Gratton MA, Zhao J, Notterpek L, Yamoah EN. Demyelination and Na + Channel Redistribution Underlie Auditory and Vestibular Dysfunction in PMP22-Null Mice. eNeuro 2024; 11:ENEURO.0462-23.2023. [PMID: 38378628 PMCID: PMC11059428 DOI: 10.1523/eneuro.0462-23.2023] [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: 11/05/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 02/22/2024] Open
Abstract
Altered expression of peripheral myelin protein 22 (PMP22) results in demyelinating peripheral neuropathy. PMP22 exhibits a highly restricted tissue distribution with marked expression in the myelinating Schwann cells of peripheral nerves. Auditory and vestibular Schwann cells and the afferent neurons also express PMP22, suggesting a unique role in hearing and balancing. Indeed, neuropathic patients diagnosed with PMP22-linked hereditary neuropathies often present with auditory and balance deficits, an understudied clinical complication. To investigate the mechanism by which abnormal expression of PMP22 may cause auditory and vestibular deficits, we studied gene-targeted PMP22-null mice. PMP22-null mice exhibit an unsteady gait, have difficulty maintaining balance, and live for only ∼3-5 weeks relative to unaffected littermates. Histological analysis of the inner ear revealed reduced auditory and vestibular afferent nerve myelination and profound Na+ channel redistribution without PMP22. Yet, Na+ current density was unaltered, in stark contrast to increased K+ current density. Atypical postsynaptic densities and a range of neuronal abnormalities in the organ of Corti were also identified. Analyses of auditory brainstem responses (ABRs) and vestibular sensory-evoked potential (VsEP) revealed that PMP22-null mice had auditory and vestibular hypofunction. These results demonstrate that PMP22 is required for hearing and balance, and the protein is indispensable for the formation and maintenance of myelin in the peripheral arm of the eighth nerve. Our findings indicate that myelin abnormalities and altered signal propagation in the peripheral arm of the auditory nerve are likely causes of auditory deficits in patients with PMP22-linked neuropathies.
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Affiliation(s)
- Jeong Han Lee
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Seojin Park
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
- Prestige BioPharma, Busan 67264, South Korea
| | - Maria C Perez-Flores
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Yingying Chen
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Mincheol Kang
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
- Prestige BioPharma, Busan 67264, South Korea
| | - Jinsil Choi
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Lauren Levine
- Program in Audiology and Communication Sciences, Washington University, St. Louis 63110, Missouri
| | | | - Jie Zhao
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Lucia Notterpek
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
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2
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Pashkova N, Peterson TA, Ptak CP, Winistorfer SC, Ahern CA, Shy ME, Piper RC. PMP22 associates with MPZ via their transmembrane domains and disrupting this interaction causes a loss-of-function phenotype similar to hereditary neuropathy associated with liability to pressure palsies (HNPP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.24.573255. [PMID: 38187781 PMCID: PMC10769442 DOI: 10.1101/2023.12.24.573255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
PMP22 and MPZ are major myelin proteins in the peripheral nervous system. MPZ is a single pass integral membrane protein with an extracellular immunoglobulin (Ig)-like domain and works as an adhesion protein to hold myelin wraps together across the intraperiod line. Loss of MPZ causes severe demyelinating Charcot-Marie-Tooth (CMT) peripheral neuropathy. PMP22 is an integral membrane tetraspan protein belonging to the Claudin superfamily. Homozygous loss of PMP22 also leads to severe demyelinating neuropathy, and duplication of wildtype PMP22 causes the most common form of CMT, CMT1A. Yet the molecular functions provided by PMP22 and how its alteration causes CMT are unknown. Here we find that these abundant myelin proteins form a strong and specific complex. Mutagenesis and domain swapping experiments reveal that these proteins interact through interfaces within their transmembrane domains. We also find that the PMP22 A67T patient variant that causes an HNPP (Hereditary neuropathy with pressure palsies) phenotype, reflecting a heterozygous loss-of-function, maps to this interface. The PMP22 A67T variant results in the specific loss of MPZ association with PMP22 without affecting PMP22 localization to the plasma membrane or its interactions with other proteins. These data define the molecular basis for the MPZ∼PMP22 interaction and indicate that the MPZ∼PMP22 complex fulfills an important function in myelinating cells.
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3
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Zhang N, Zhu HP, Huang W, Wen X, Xie X, Jiang X, Peng C, Han B, He G. Unraveling the structures, functions and mechanisms of epithelial membrane protein family in human cancers. Exp Hematol Oncol 2022; 11:69. [PMID: 36217151 PMCID: PMC9552464 DOI: 10.1186/s40164-022-00321-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/20/2022] [Indexed: 02/07/2023] Open
Abstract
Peripheral myelin protein 22 (PMP22) and epithelial membrane proteins (EMP-1, -2, and -3) belong to a small hydrophobic membrane protein subfamily, with four transmembrane structures. PMP22 and EMPs are widely expressed in various tissues and play important roles in cell growth, differentiation, programmed cell death, and metastasis. PMP22 presents its highest expression in the peripheral nerve and participates in normal physiological and pathological processes of the peripheral nervous system. The progress of molecular genetics has shown that the genetic changes of the PMP22 gene, including duplication, deletion, and point mutation, are behind various hereditary peripheral neuropathies. EMPs have different expression patterns in diverse tissues and are closely related to the risk of malignant tumor progression. In this review, we focus on the four members in this protein family which are related to disease pathogenesis and discuss gene mutations and post-translational modification of them. Further research into the interactions between structural alterations and function of PMP22 and EMPs will help understand their normal physiological function and role in diseases and might contribute to developing novel therapeutic tools.
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Affiliation(s)
- Nan Zhang
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Hong-Ping Zhu
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.,Antibiotics Research and Re‑Evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, 610106, China
| | - Wei Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xiang Wen
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xin Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xian Jiang
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.,Laboratory of Dermatology, Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-Related Molecular Network and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Bo Han
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Gu He
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China. .,Laboratory of Dermatology, Clinical Institute of Inflammation and Immunology (CIII), Frontiers Science Center for Disease-Related Molecular Network and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China.
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4
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Park SY, Jaiswal MS, Jang YS, Choi JH, Kim GC, Hong JW, Hwang DS. Effect of No-ozone Cold Plasma on Regeneration after Crushed Mental Nerve Injury in rats. Int J Med Sci 2022; 19:1732-1742. [PMID: 36313226 PMCID: PMC9608038 DOI: 10.7150/ijms.77484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/09/2022] [Indexed: 11/05/2022] Open
Abstract
Background: This experimental research aimed to determine whether No-ozone Cold Plasma (NCP) has regenerative effect on crushed injured sensory nerves in a rat model (Wistar A) and to evaluate whether NCP can be used as an alternative treatment method for sensory nerve injury in the oral-maxillofacial region. Methods: A total of 10 Wistar A rats were used for this experiment. They were divided into three groups according to whether the mental nerve of the left mandible was injured and NCP was applied or not: group 1 (n=3) (non-mental nerve damage, non-MD) - the left mental nerve was exposed and non-damaged; group 2 (n=3) (mental nerve damage, MD) - the left mental nerve was exposed and damaged, NCP was not applied; and group 3 (n=4) (mental nerve damage and NCP, MD-NCP) - the left mental nerve was exposed and damaged, NCP was applied with regular intervals (three times a week). Results: For the behavior analysis, von Frey test was used. Furthermore, the nerve tissues were examined with hematoxylin and eosin (H&E) staining, and the extent of neurorecovery was evaluated with the immunofluorescence staining of certain markers. The behavioral analysis showed that the function recovery sensory nerve was faster in group 3 (MD-NCP). In the histomorphologic and immunofluorescence analyses, the expression of the factors involved in neurorecovery was much higher in group 3 than in group 2 (MD). Conclusions: The expeditious recovery of sensory nerve function as well as the higher expression of the factors indicating nerve function recovery in the NCP-treated group suggest that NCP has a positive effect on regeneration after sensory nerve crushing injury. Therefore, in the case of sensory impairment of the oral-maxillofacial region, no-ozone cold plasma can be applied for therapeutic effect.
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Affiliation(s)
- Si-Yeon Park
- Department of Oral and Maxillofacial Surgery, Dental and Life Science Institute, Dental School, Pusan National University, Busan, South Korea
| | - M Shriya Jaiswal
- Department of Oral and Maxillofacial Surgery, Dental and Life Science Institute, Dental School, Pusan National University, Busan, South Korea
| | - Yoon-Seo Jang
- Department of Oral and Maxillofacial Surgery, Dental and Life Science Institute, Dental School, Pusan National University, Busan, South Korea
| | - Jeong-Hae Choi
- Department of Research and Development, FEAGLE Corporations, 70‑6, Jeungsan‑ro, Mulgeum‑eup, Yangsan‑si, Gyeongsangnam‑do 50614, South Korea
| | - Gyoo-Cheon Kim
- Department of Translational Dental Science, School of Dentistry, Pusan National University, Beomeo-ri, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, South Korea
| | - Jin-Woo Hong
- Department of Internal Medicine, School of Korean Medicine, Yangsan Campus of Pusan National University, Yangsan-si, Gyeongsangnam-do, 50612, South Korea
| | - Dae-Seok Hwang
- Department of Oral and Maxillofacial Surgery, Dental and Life Science Institute, Dental School, Pusan National University, Busan, South Korea.,Dental Research Institute, Pusan National University Dental Hospital, Yangsan, South Korea
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5
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Milon B, Shulman ED, So KS, Cederroth CR, Lipford EL, Sperber M, Sellon JB, Sarlus H, Pregernig G, Shuster B, Song Y, Mitra S, Orvis J, Margulies Z, Ogawa Y, Shults C, Depireux DA, Palermo AT, Canlon B, Burns J, Elkon R, Hertzano R. A cell-type-specific atlas of the inner ear transcriptional response to acoustic trauma. Cell Rep 2021; 36:109758. [PMID: 34592158 PMCID: PMC8709734 DOI: 10.1016/j.celrep.2021.109758] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/29/2021] [Accepted: 09/03/2021] [Indexed: 01/26/2023] Open
Abstract
Noise-induced hearing loss (NIHL) results from a complex interplay of damage to the sensory cells of the inner ear, dysfunction of its lateral wall, axonal retraction of type 1C spiral ganglion neurons, and activation of the immune response. We use RiboTag and single-cell RNA sequencing to survey the cell-type-specific molecular landscape of the mouse inner ear before and after noise trauma. We identify induction of the transcription factors STAT3 and IRF7 and immune-related genes across all cell-types. Yet, cell-type-specific transcriptomic changes dominate the response. The ATF3/ATF4 stress-response pathway is robustly induced in the type 1A noise-resilient neurons, potassium transport genes are downregulated in the lateral wall, mRNA metabolism genes are downregulated in outer hair cells, and deafness-associated genes are downregulated in most cell types. This transcriptomic resource is available via the Gene Expression Analysis Resource (gEAR; https://umgear.org/NIHL) and provides a blueprint for the rational development of drugs to prevent and treat NIHL.
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Affiliation(s)
- Beatrice Milon
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Eldad D Shulman
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kathy S So
- Decibel Therapeutics, Boston, MA 02215, USA
| | - Christopher R Cederroth
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK
| | - Erika L Lipford
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Michal Sperber
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Heela Sarlus
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; Applied Immunology & Immunotherapy, Neuroimmunology Unit, Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska University Hospital, 171 77 Stockholm, Sweden
| | | | - Benjamin Shuster
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sunayana Mitra
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joshua Orvis
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Zachary Margulies
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yoko Ogawa
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Christopher Shults
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | - Barbara Canlon
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Joe Burns
- Decibel Therapeutics, Boston, MA 02215, USA
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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6
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Pantera H, Hu B, Moiseev D, Dunham C, Rashid J, Moran JJ, Krentz K, Rubinstein CD, Won S, Li J, Svaren J. Pmp22 super-enhancer deletion causes tomacula formation and conduction block in peripheral nerves. Hum Mol Genet 2021; 29:1689-1699. [PMID: 32356557 DOI: 10.1093/hmg/ddaa082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/07/2020] [Accepted: 04/24/2020] [Indexed: 11/12/2022] Open
Abstract
Copy number variation of the peripheral nerve myelin gene Peripheral Myelin Protein 22 (PMP22) causes multiple forms of inherited peripheral neuropathy. The duplication of a 1.4 Mb segment surrounding this gene in chromosome 17p12 (c17p12) causes the most common form of Charcot-Marie-Tooth disease type 1A, whereas the reciprocal deletion of this gene causes a separate neuropathy termed hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is robustly induced in Schwann cells in early postnatal development, and several transcription factors and their cognate regulatory elements have been implicated in coordinating the gene's proper expression. We previously found that a distal super-enhancer domain was important for Pmp22 expression in vitro, with particular impact on a Schwann cell-specific alternative promoter. Here, we investigate the consequences of deleting this super-enhancer in vivo. We find that loss of the super-enhancer in mice reduces Pmp22 expression throughout development and into adulthood, with greater impact on the Schwann cell-specific promoter. Additionally, these mice display tomacula formed by excessive myelin folding, a pathological hallmark of HNPP, as have been previously observed in heterozygous Pmp22 mice as well as sural biopsies from patients with HNPP. Our findings demonstrate a mechanism by which smaller copy number variations, not including the Pmp22 gene, are sufficient to reduce gene expression and phenocopy a peripheral neuropathy caused by the HNPP-associated deletion encompassing PMP22.
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Affiliation(s)
- Harrison Pantera
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Bo Hu
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Daniel Moiseev
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Chris Dunham
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Jibraan Rashid
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - John J Moran
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Kathleen Krentz
- Biotechnology Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - C Dustin Rubinstein
- Biotechnology Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Seongsik Won
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Jun Li
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA.,Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53705, USA
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7
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Lee ST, Jang YS, Kim UK, Kim HJ, Ryu MH, Kim GC, Hwang DS. Non-thermal plasma application enhances the recovery of transected sciatic nerves in rats. Exp Biol Med (Maywood) 2021; 246:1287-1296. [PMID: 33653158 PMCID: PMC8371309 DOI: 10.1177/1535370221996655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/28/2021] [Indexed: 01/17/2023] Open
Abstract
This experimental research aimed to investigate the effects of non-thermal plasma on nerve regeneration after transected nerve damage using the sciatic nerve in Wistar albino (A) rats. The experiments were performed on 27 Wistar A rats. The rats underwent surgery for right sciatic nerve exposure and were divided into three groups (each group, n = 9) according to sciatic nerve transected injury (SNTI) and non-thermal plasma application: a non-nerve damage (non-ND) group, a only nerve damage without non-thermal plasma application (ND) group, and a nerve damage with non-thermal plasma application (ND + NTP) group. Subsequent to SNTI and immediate suture, non-thermal plasma was administered three times per week for eight weeks. Evaluation for functional recovery was performed using the static sciatic index measured over the full treatment period of eight weeks. The sciatic nerve specimens were obtained after euthanasia and third day from the last non-thermal plasma application. The sciatic nerve tissues were subjected to histological analysis. Behavior analysis presented that the ND + NTP group showed improved static sciatic index compared with the nerve damage group. Histopathological findings demonstrated that the ND + NTP group had more dense Schwann cells and well-established continuity of nerve fibers, greater than the nerve damage group. Immunohistochemistry showed that the ND + NTP group had increased levels of markers for microtubule-associated protein 2 (MAP2), tau, S100 calcium-binding protein B, and neurofilament-200 and regulated the overexpression of CD68 and MAP2. These results indicated that non-thermal plasma enhanced the motor function and restored the neuronal structure by accelerating myelination and axonal regeneration. Additionally, non-thermal plasma was confirmed to have a positive effect on the recovery of SNTI in rats.
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Affiliation(s)
- Sung-Tak Lee
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu 41940, Republic of Korea
| | - Yoon-Seo Jang
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
| | - Uk-Kyu Kim
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
| | - Hyung-Joon Kim
- Department of Oral Physiology, BK21 Plus Project and Institute of Translational Dental Sciences, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
| | - Mi-Heon Ryu
- Department of Oral Pathology, BK21 Plus Project, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
| | - Gyoo-Cheon Kim
- Department of Dental Anatomy, BK21 Plus Project, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
| | - Dae-Seok Hwang
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Gyeongnam 50612, Republic of Korea
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8
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Roberts O, Paraoan L. PERP-ing into diverse mechanisms of cancer pathogenesis: Regulation and role of the p53/p63 effector PERP. Biochim Biophys Acta Rev Cancer 2020; 1874:188393. [PMID: 32679166 DOI: 10.1016/j.bbcan.2020.188393] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 07/11/2020] [Accepted: 07/12/2020] [Indexed: 12/20/2022]
Abstract
The tetraspan plasma membrane protein PERP (p53 apoptosis effector related to PMP22) is a lesser-known transcriptional target of p53 and p63. A member of the PMP22/GAS3/EMP membrane protein family, PERP was originally identified as a p53 target specifically trans-activated during apoptosis, but not during cell-cycle arrest. Several studies have since shown downregulation of PERP expression in numerous cancers, suggesting that PERP is a tumour suppressor protein. This review focusses on the important advances made in elucidating the mechanisms regulating PERP expression and its function as a tumour suppressor in diverse human cancers, including breast cancer and squamous cell carcinoma. Investigating PERP's role in clinically-aggressive uveal melanoma has revealed that PERP engages a positive-feedback loop with p53 to regulate its own expression, and that p63 is required beside p53 to achieve pro-apoptotic levels of PERP in this cancer. Furthermore, the recent discovery of the apoptosis-mediating interaction of PERP with SERCA2b at the plasma membrane-endoplasmic reticulum interface demonstrates a novel mechanism of PERP stabilisation, and how PERP can mediate Ca2+ signalling to facilitate apoptosis. The multi-faceted role of PERP in cancer, involving well-documented functions in mediating apoptosis and cell-cell adhesion is discussed, alongside PERP's emerging roles in epithelial-mesenchymal transition, and PERP crosstalk with inflammation signalling pathways, and other signalling pathways. The potential for restoring PERP expression as a means of cancer therapy is also considered.
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Affiliation(s)
- Owain Roberts
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Luminita Paraoan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.
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9
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Zhou Y, Borchelt D, Bauson JC, Fazio S, Miles JR, Tavori H, Notterpek L. Subcellular diversion of cholesterol by gain- and loss-of-function mutations in PMP22. Glia 2020; 68:2300-2315. [PMID: 32511821 DOI: 10.1002/glia.23840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 03/22/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022]
Abstract
Abnormalities of the peripheral myelin protein 22 (PMP22) gene, including duplication, deletion and point mutations are a major culprit in Type 1 Charcot-Marie-Tooth (CMT) diseases. The complete absence of PMP22 alters cholesterol metabolism in Schwann cells, which likely contributes to myelination deficits. Here, we examined the subcellular trafficking of cholesterol in distinct models of PMP22-linked neuropathies. In Schwann cells from homozygous Trembler J (TrJ) mice carrying a Leu16Pro mutation, cholesterol was retained with TrJ-PMP22 in the Golgi, alongside a corresponding reduction in its plasma membrane level. PMP22 overexpression, which models CMT1A caused by gene duplication, triggered cholesterol sequestration to lysosomes, and reduced ATP-binding cassette transporter-dependent cholesterol efflux. Conversely, lysosomal targeting of cholesterol by U18666A treatment increased wild type (WT)-PMP22 levels in lysosomes. Mutagenesis of a cholesterol recognition motif, or CRAC domain, in human PMP22 lead to increased levels of PMP22 in the ER and Golgi compartments, along with higher cytosolic, and lower membrane-associated cholesterol. Importantly, cholesterol trafficking defects observed in PMP22-deficient Schwann cells were rescued by WT but not CRAC-mutant-PMP22. We also observed that myelination deficits in dorsal root ganglia explants from heterozygous PMP22-deficient mice were improved by cholesterol supplementation. Collectively, these findings indicate that PMP22 is critical in cholesterol metabolism, and this mechanism is likely a contributing factor in PMP22-linked hereditary neuropathies. Our results provide a basis for understanding how altered expression of PMP22 impacts cholesterol metabolism.
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Affiliation(s)
- Ye Zhou
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - David Borchelt
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Jodi C Bauson
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Sergio Fazio
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Joshua R Miles
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Hagai Tavori
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA.,Department of Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
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10
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Zhou Y, Bazick H, Miles JR, Fethiere AI, Salihi MOA, Fazio S, Tavori H, Notterpek L. A neutral lipid-enriched diet improves myelination and alleviates peripheral nerve pathology in neuropathic mice. Exp Neurol 2019; 321:113031. [DOI: 10.1016/j.expneurol.2019.113031] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 07/27/2019] [Accepted: 08/02/2019] [Indexed: 12/13/2022]
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11
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Chittoor-Vinod VG, Bazick H, Todd AG, Falk D, Morelli KH, Burgess RW, Foster TC, Notterpek L. HSP90 Inhibitor, NVP-AUY922, Improves Myelination in Vitro and Supports the Maintenance of Myelinated Axons in Neuropathic Mice. ACS Chem Neurosci 2019; 10:2890-2902. [PMID: 31017387 PMCID: PMC6588339 DOI: 10.1021/acschemneuro.9b00105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
![]()
Hereditary
demyelinating neuropathies linked to peripheral myelin
protein 22 (PMP22) involve the disruption of normal protein trafficking
and are therefore relevant targets for chaperone therapy. Using a
small molecule HSP90 inhibitor, EC137, in cell culture models, we
previously validated the chaperone pathway as a viable target for
therapy development. Here, we tested five commercially available inhibitors
of HSP90 and identified BIIB021 and AUY922 to support Schwann cell
viability and enhance chaperone expression. AUY922 showed higher efficacy,
compared to BIIB021, in enhancing myelin synthesis in dorsal root
ganglion explant cultures from neuropathic mice. For in vivo testing,
we randomly assigned 2–3 month old C22 and 6 week old Trembler
J (TrJ) mice to receive two weekly injections of either vehicle or
AUY922 (2 mg/kg). By the intraperitoneal (i.p.) route, the drug was
well-tolerated by all mice over the 5 month long study, without influence
on body weight or general grooming behavior. AUY922 improved the maintenance
of myelinated nerves of both neuropathic models and attenuated the
decline in rotarod performance and peak muscle force production in
C22 mice. These studies highlight the significance of proteostasis
in neuromuscular function and further validate the HSP90 pathway as
a therapeutic target for hereditary neuropathies.
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Affiliation(s)
- Vinita G. Chittoor-Vinod
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Hannah Bazick
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Adrian G. Todd
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Darin Falk
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Kathryn H. Morelli
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Robert W. Burgess
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Thomas C. Foster
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Lucia Notterpek
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
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12
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PMP22 Regulates Cholesterol Trafficking and ABCA1-Mediated Cholesterol Efflux. J Neurosci 2019; 39:5404-5418. [PMID: 31061090 DOI: 10.1523/jneurosci.2942-18.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/22/2019] [Accepted: 04/26/2019] [Indexed: 12/21/2022] Open
Abstract
The absence of functional peripheral myelin protein 22 (PMP22) is associated with shortened lifespan in rodents and severe peripheral nerve myelin abnormalities in several species including humans. Schwann cells and nerves from PMP22 knock-out (KO) mice show deranged cholesterol distribution and aberrant lipid raft morphology, supporting an unrecognized role for PMP22 in cellular lipid metabolism. To examine the mechanisms underlying these abnormalities, we studied Schwann cells and nerves from male and female PMP22 KO mice. Whole-cell current-clamp recordings in cultured Schwann cells revealed increased membrane capacitance and decreased membrane resistance in the absence of PMP22, which was consistent with a reduction in membrane cholesterol. Nerves from PMP22-deficient mice contained abnormal lipid droplets, with both mRNA and protein levels of apolipoprotein E (apoE) and ATP-binding cassette transporter A1 (ABCA1) being highly upregulated. Despite the upregulation of ABCA1 and apoE, the absence of PMP22 resulted in reduced localization of the transporter to the cell membrane and diminished secretion of apoE. The absence of PMP22 also impaired ABCA1-mediated cholesterol efflux capacity. In nerves from ABCA1 KO mice, the expression of PMP22 was significantly elevated and the subcellular processing of the overproduced protein was aberrant. In wild-type samples, double immunolabeling identified overlapping distribution of PMP22 and ABCA1 at the Schwann cell plasma membrane and the two proteins were coimmunoprecipitated from Schwann cell and nerve lysates. Together, these results reveal a novel role for PMP22 in regulating lipid metabolism and cholesterol trafficking through functional interaction with the cholesterol efflux regulatory protein ABCA1.SIGNIFICANCE STATEMENT Understanding the subcellular events that underlie abnormal myelin formation in hereditary neuropathies is critical for advancing therapy development. Peripheral myelin protein 22 (PMP22) is an essential peripheral myelin protein because its genetic abnormalities account for ∼80% of hereditary neuropathies. Here, we demonstrate that in the absence of PMP22, the cellular and electrophysiological properties of the Schwann cells' plasma membrane are altered and cholesterol trafficking and lipid homeostasis are perturbed. The molecular mechanisms for these abnormalities involve a functional interplay among PMP22, cholesterol, apolipoprotein E, and the major cholesterol-efflux transporter protein ATP-binding cassette transporter A1 (ABCA1). These findings establish a critical role for PMP22 in the maintenance of cholesterol homeostasis in Schwann cells.
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13
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Jouaud M, Mathis S, Richard L, Lia AS, Magy L, Vallat JM. Rodent models with expression of PMP22: Relevance to dysmyelinating CMT and HNPP. J Neurol Sci 2019; 398:79-90. [PMID: 30685714 DOI: 10.1016/j.jns.2019.01.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 12/26/2018] [Accepted: 01/16/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND Charcot-Marie-Tooth diseases (CMT) are due to abnormalities of many genes, the most frequent being linked to PMP22 (Peripheral Myelin Protein 22). In the past, only spontaneous genetic anomalies occurring in mouse mutants such as Trembler (Tr) mice were available; more recently, several rodent models have been generated for exploration of the pathophysiological mechanisms underlying these neuropathies. METHODS Based on the personal experience of our team, we describe here the pathological hallmarks of most of these animal models and compare them to the pathological features observed in some CMT patient nerves (CMT types 1A and E; hereditary neuropathy with liability to pressure palsies, HNPP). RESULTS We describe clinical data and detailed pathological analysis mainly by electron microscopy of the sciatic nerves of these animal models conducted in our laboratory; lesions of PMP22 deficient animals (KO and mutated PMP22) and PMP22 overexpressed models are described and compared to ultrastructural anomalies of nerve biopsies from CMT patients due to PMP22 gene anomalies. It is of note that while there are some similarities, there are also significant differences between the lesions in animal models and human cases. Such observations highlight the complex roles played by PMP22 in nerve development. CONCLUSION It should be borne in mind that we require additional correlations between animal models of hereditary neuropathies and CMT patients to rationalize the development of efficient drugs.
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Affiliation(s)
- Maxime Jouaud
- Equipe d'accueil 6309, Maintenance myélinique et Neuropathies périphériques, University of Limoges, 2 rue du Docteur Raymond Marcland, 87000 Limoges, France
| | - Stéphane Mathis
- Department of Neurology, Nerve-Muscle Unit, CHU Bordeaux (Pellegrin University Hospital), place Amélie Raba-Léon, 33000 Bordeaux, France; National Reference Center 'maladies neuromusculaires du Grand Sud-ouest', CHU Bordeaux (Pellegrin University Hospital), place Amélie Raba-Léon, 33000 Bordeaux, France
| | - Laurence Richard
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Anne-Sophie Lia
- Equipe d'accueil 6309, Maintenance myélinique et Neuropathies périphériques, University of Limoges, 2 rue du Docteur Raymond Marcland, 87000 Limoges, France; Department of Biochemistry and Molecular Genetics, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Laurent Magy
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Jean-Michel Vallat
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France.
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14
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Song W, Zhao Y, Wu Y, Li Z, Lv H, Li S, Jiang Y, Song C, Wang F, Huang Y. Fabrication, characterization and biocompatibility of collagen/oxidized regenerated cellulose-Ca composite scaffold for carrying Schwann cells. Int J Biol Macromol 2018; 119:1195-1203. [PMID: 30110602 DOI: 10.1016/j.ijbiomac.2018.08.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 01/14/2023]
Abstract
Schwann cell (SC) is the primary structural and functional part of the peripheral nervous system, and it plays a key role in the repair and regeneration of peripheral nerve. In order to develop a suitable scaffold for SC nerve tissue engineering, three kinds of scaffolds, including pristine collagen, pure oxidized regenerated cellulose-Ca (ORCCa) and collagen/ORC-Ca composite scaffolds, have been fabricated for carrying SC in this study. SC is then seeded on the scaffolds to form SC-scaffold nerve tissue engineering composites and evaluate their biocompatibility. The chemical and physical structure of the scaffolds are investigated by FTIR, NMR and SEM. The wettability of the collagen/ORC-Ca composite scaffold is close to that of pristine collagen, and the tensile strength of the composite scaffold (0.58 MPa) is better than that of pristine collagen (0.36 MPa). Cytotoxicity, cell proliferation, cell adhesion and western blotting assays are conducted to evaluate the biocompatibility and properties of different scaffolds. The results show that the three scaffolds exhibit no toxicity, and the proliferation rate of SC on the collagen/ORC-Ca composite scaffold is significantly higher than that of the other scaffolds (p < 0.05). The number of the adhesion cells on the composite scaffold (244.67 ± 13.02) is much more than that in the pure ORC-Ca group (p < 0.01). Furthermore, the expression of N-Cadheri and PMP22 proteins in the collagen/ORC-Ca composite scaffold is significantly superior to the other two scaffolds (both p < 0.01). Therefore, it could be concluded that the collagen/ORC-Ca composite is a promising candidate as a scaffold for carrying SC to form nerve tissue engineering composites in order to assist the peripheral nervous in the repair and regeneration.
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Affiliation(s)
- Wenli Song
- Harbin Sport University, Harbin 150008, China
| | - Yuhua Zhao
- Harbin Sport University, Harbin 150008, China
| | - Yadong Wu
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
| | - Zhipeng Li
- Harbin Sport University, Harbin 150008, China
| | - Hui Lv
- The First Affiliated Hospital of Harbin Medical University, Harbin 150007, China
| | - Siyu Li
- Harbin Medical University (Da Qing), Da Qing 163319, China
| | - Yue Jiang
- Harbin Medical University (Da Qing), Da Qing 163319, China
| | - Chun Song
- The First Affiliated Hospital of Harbin Medical University, Harbin 150007, China
| | - Fang Wang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Yudong Huang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
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15
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Masgutov R, Masgutova G, Mukhametova L, Garanina E, Arkhipova SS, Zakirova E, Mukhamedshina YO, Margarita Z, Gilazieva Z, Syromiatnikova V, Mullakhmetova A, Kadyrova G, Nigmetzyanova M, Mikhail S, Igor P, Yagudin R, Rizvanov A. Allogenic Adipose Derived Stem Cells Transplantation Improved Sciatic Nerve Regeneration in Rats: Autologous Nerve Graft Model. Front Pharmacol 2018; 9:86. [PMID: 29559908 PMCID: PMC5845725 DOI: 10.3389/fphar.2018.00086] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/25/2018] [Indexed: 01/19/2023] Open
Abstract
We examined the effect of transplantation of allogenic adipose-derived stem cells (ADSCs) with properties of mesenchymal stem cells (MSCs) on posttraumatic sciatic nerve regeneration in rats. We suggested an approach to rat sciatic nerve reconstruction using the nerve from the other leg as a graft. The comparison was that of a critical 10 mm nerve defect repaired by means of autologous nerve grafting versus an identical lesion on the contralateral side. In this experimental model, the same animal acts simultaneously as a test model, and control. Regeneration of the left nerve was enhanced by the use of ADSCs, whereas the right nerve healed under natural conditions. Thus the effects of individual differences were excluded and a result closer to clinical practice obtained. We observed significant destructive changes in the sciatic nerve tissue after surgery which resulted in the formation of combined contractures in knee and ankle joints of both limbs and neurotrophic ulcers only on the right limb. The stimulation of regeneration by ADSCs increased the survival of spinal L5 ganglia neurons by 26.4%, improved sciatic nerve vascularization by 35.68% and increased the number of myelin fibers in the distal nerve by 41.87%. Moreover, we have demonstrated that S100, PMP2, and PMP22 gene expression levels are suppressed in response to trauma as compared to intact animals. We have shown that ADSC-based therapy contributes to significant improvement in the regeneration.
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Affiliation(s)
- Ruslan Masgutov
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.,Republican Clinical Hospital, Kazan, Russia
| | - Galina Masgutova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Liliya Mukhametova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Ekaterina Garanina
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Svetlana S Arkhipova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Elena Zakirova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yana O Mukhamedshina
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.,Department of Histology, Cytology and Embryology, Kazan State Medical University, Kazan, Russia
| | - Zhuravleva Margarita
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Zarema Gilazieva
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Valeriia Syromiatnikova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Adelya Mullakhmetova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Gulnaz Kadyrova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Mariya Nigmetzyanova
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | | | - Pankov Igor
- Department of Traumatology and Orthopedics, Kazan State Medical Academy, Kazan, Russia
| | | | - Albert Rizvanov
- OpenLab "Gene and Cell Technologies", Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
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16
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Poitelon Y, Matafora V, Silvestri N, Zambroni D, McGarry C, Serghany N, Rush T, Vizzuso D, Court FA, Bachi A, Wrabetz L, Feltri ML. A dual role for Integrin α6β4 in modulating hereditary neuropathy with liability to pressure palsies. J Neurochem 2018; 145:245-257. [PMID: 29315582 DOI: 10.1111/jnc.14295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 12/14/2017] [Accepted: 12/21/2017] [Indexed: 12/23/2022]
Abstract
Peripheral myelin protein 22 (PMP22) is a component of compact myelin in the peripheral nervous system. The amount of PMP22 in myelin is tightly regulated, and PMP22 over or under-expression cause Charcot-Marie-Tooth 1A (CMT1A) and Hereditary Neuropathy with Pressure Palsies (HNPP). Despite the importance of PMP22, its function remains largely unknown. It was reported that PMP22 interacts with the β4 subunit of the laminin receptor α6β4 integrin, suggesting that α6β4 integrin and laminins may contribute to the pathogenesis of CMT1A or HNPP. Here we asked if the lack of α6β4 integrin in Schwann cells influences myelin stability in the HNPP mouse model. Our data indicate that PMP22 and β4 integrin may not interact directly in myelinating Schwann cells, however, ablating β4 integrin delays the formation of tomacula, a characteristic feature of HNPP. In contrast, ablation of integrin β4 worsens nerve conduction velocities and non-compact myelin organization in HNPP animals. This study demonstrates that indirect interactions between an extracellular matrix receptor and a myelin protein influence the stability and function of myelinated fibers.
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Affiliation(s)
- Yannick Poitelon
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, New York, USA.,Department of Biochemistry, University at Buffalo, Buffalo, New York, USA
| | - Vittoria Matafora
- Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy
| | | | - Desirée Zambroni
- Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy
| | - Claire McGarry
- Department of Biochemistry, University at Buffalo, Buffalo, New York, USA
| | - Nora Serghany
- Department of Biochemistry, University at Buffalo, Buffalo, New York, USA
| | - Thomas Rush
- Department of Biochemistry, University at Buffalo, Buffalo, New York, USA
| | - Domenica Vizzuso
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, New York, USA.,Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy
| | - Felipe A Court
- Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy.,Center for Integrative Biology, Universidad Mayor de Chile, Santiago, Chile
| | - Angela Bachi
- Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy
| | - Lawrence Wrabetz
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, New York, USA.,Department of Biochemistry, University at Buffalo, Buffalo, New York, USA.,Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy.,Department of Neurology, University at Buffalo, Buffalo, New York, USA
| | - Maria Laura Feltri
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, New York, USA.,Department of Biochemistry, University at Buffalo, Buffalo, New York, USA.,Division of Genetics and Cell Biology, San Raffaele Hospital, Milan, Italy.,Department of Neurology, University at Buffalo, Buffalo, New York, USA
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17
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Lee S, Bazick H, Chittoor-Vinod V, Al Salihi MO, Xia G, Notterpek L. Elevated Peripheral Myelin Protein 22, Reduced Mitotic Potential, and Proteasome Impairment in Dermal Fibroblasts from Charcot-Marie-Tooth Disease Type 1A Patients. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:728-738. [PMID: 29246495 PMCID: PMC5842032 DOI: 10.1016/j.ajpath.2017.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 10/05/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022]
Abstract
A common form of hereditary autosomal dominant demyelinating neuropathy known as Charcot-Marie-Tooth disease type 1A (CMT1A) is linked with duplication of the peripheral myelin protein 22 (PMP22) gene. Although studies from animal models have led to better understanding of the pathobiology of these neuropathies, there continues to be a gap in the translation of findings from rodents to humans. Because PMP22 was originally identified in fibroblasts as growth arrest specific gene 3 (gas3) and is expressed broadly in the body, it was tested whether skin cells from neuropathic patients would display the cellular pathology observed in Schwann cells from rodent models. Dermal fibroblasts from two CMT1A pedigrees with confirmed PMP22 gene duplication were studied. Samples from age-matched non-neuropathic individuals were used as controls. CMT1A patient–derived cultures contain approximately 1.5-fold elevated levels of PMP22 mRNA, exhibit reduced mitotic potential, and display intracellular protein aggregates as compared to cells from unaffected individuals. The presence of cytosolic PMP22 coincides with a decrease in proteasome activity and an increase in autophagy-lysosomal proteins, including LC3-II and LAMP1. These results indicate that the abnormalities in the subcellular processing of excess PMP22 elicit a detectable response in human CMT1A fibroblasts, a phenotype that resembles Schwann cells from neuropathic mice. These findings support the use of human CMT1A fibroblasts as a platform for therapy testing.
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Affiliation(s)
- Sooyeon Lee
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Hannah Bazick
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Vinita Chittoor-Vinod
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Mohammed Omar Al Salihi
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Guangbin Xia
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida.
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18
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Rosso G, Young P, Shahin V. Implications of Schwann Cells Biomechanics and Mechanosensitivity for Peripheral Nervous System Physiology and Pathophysiology. Front Mol Neurosci 2017; 10:345. [PMID: 29118694 PMCID: PMC5660964 DOI: 10.3389/fnmol.2017.00345] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/11/2017] [Indexed: 12/21/2022] Open
Abstract
The presence of bones around the central nervous system (CNS) provides it with highly effective physiologically crucial mechanical protection. The peripheral nervous system (PNS), in contrast, lacks this barrier. Consequently, the long held belief is that the PNS is mechanically vulnerable. On the other hand, the PNS is exposed to a variety of physiological mechanical stresses during regular daily activities. This fact prompts us to question the dogma of PNS mechanical vulnerability. As a matter of fact, impaired mechanics of PNS nerves is associated with neuropathies with the liability to mechanical stresses paralleled by significant impairment of PNS physiological functions. Our recent biomechanical integrity investigations on nerve fibers from wild-type and neuropathic mice lend strong support in favor of natural mechanical protection of the PNS and demonstrate a key role of Schwann cells (SCs) therein. Moreover, recent works point out that SCs can sense mechanical properties of their microenvironment and the evidence is growing that SCs mechanosensitivity is important for PNS development and myelination. Hence, SCs exhibit mechanical strength necessary for PNS mechanoprotection as well as mechanosensitivity necessary for PNS development and myelination. This mini review reflects on the intriguing dual ability of SCs and implications for PNS physiology and pathophysiology.
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Affiliation(s)
- Gonzalo Rosso
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Peter Young
- Department of Sleep Medicine and Neuromuscular Disorders, University of Münster, Münster, Germany
| | - Victor Shahin
- Institute of Physiology II, University of Münster, Münster, Germany
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19
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Rosso G, Liashkovich I, Young P, Shahin V. Nano-scale Biophysical and Structural Investigations on Intact and Neuropathic Nerve Fibers by Simultaneous Combination of Atomic Force and Confocal Microscopy. Front Mol Neurosci 2017; 10:277. [PMID: 28912683 PMCID: PMC5582161 DOI: 10.3389/fnmol.2017.00277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/17/2017] [Indexed: 11/14/2022] Open
Abstract
The links between neuropathies of the peripheral nervous system (PNS), including Charcot-Marie-Tooth1A and hereditary neuropathy with liability to pressure palsies, and impaired biomechanical and structural integrity of PNS nerves remain poorly understood despite the medical urgency. Here, we present a protocol describing simultaneous structural and biomechanical integrity investigations on isolated nerve fibers, the building blocks of nerves. Nerve fibers are prepared from nerves harvested from wild-type and exemplary PNS neuropathy mouse models. The basic principle of the designed experimental approach is based on the simultaneous combination of atomic force microscopy (AFM) and confocal microscopy. AFM is used to visualize the surface structure of nerve fibers at nano-scale resolution. The simultaneous combination of AFM and confocal microscopy is used to perform biomechanical, structural, and functional integrity measurements at nano- to micro-scale. Isolation of sciatic nerves and subsequent teasing of nerve fibers take ~45 min. Teased fibers can be maintained at 37°C in a culture medium and kept viable for up to 6 h allowing considerable time for all measurements which require 3–4 h. The approach is designed to be widely applicable for nerve fibers from mice of any PNS neuropathy. It can be extended to human nerve biopsies.
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Affiliation(s)
- Gonzalo Rosso
- Institute of Physiology II, WWU MünsterMünster, Germany
| | | | - Peter Young
- Department of Sleep Medicine and Neuromuscular DisordersMünster, Germany
| | - Victor Shahin
- Institute of Physiology II, WWU MünsterMünster, Germany
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20
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Lyu C, Mulder J, Barde S, Sahlholm K, Zeberg H, Nilsson J, Århem P, Hökfelt T, Fried K, Shi TJS. G protein-gated inwardly rectifying potassium channel subunits 1 and 2 are down-regulated in rat dorsal root ganglion neurons and spinal cord after peripheral axotomy. Mol Pain 2015. [PMID: 26199148 PMCID: PMC4511542 DOI: 10.1186/s12990-015-0044-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Background Increased nociceptive neuronal excitability underlies chronic pain conditions. Various ion channels, including sodium, calcium and potassium channels have pivotal roles in the control of neuronal excitability. The members of the family of G protein-gated inwardly rectifying potassium (GIRK) channels, GIRK1–4, have been implicated in modulating excitability. Here, we investigated the expression and distribution of GIRK1 and GIRK2 in normal and injured dorsal root ganglia (DRGs) and spinal cord of rats. Results We found that ~70% of the DRG neurons expressed GIRK1, while only <10% expressed GIRK2. The neurochemical profiles of GIRK1- and GIRK2-immunoreactive neurons were characterized using the neuronal markers calcitonin gene-related peptide, isolectin-B4 and neurofilament-200, and the calcium-binding proteins calbindin D28k, calretinin, parvalbumin and secretagogin. Both GIRK subunits were expressed in DRG neurons with nociceptive characteristics. However, while GIRK1 was widely expressed in several sensory neuronal subtypes, GIRK2 was detected mainly in a group of small C-fiber neurons. In the spinal dorsal horn, GIRK1- and -2-positive cell bodies and processes were mainly observed in lamina II, but also in superficial and deeper layers. Abundant GIRK1-, but not GIRK2-like immunoreactivity, was found in the ventral horn (laminae VI–X). Fourteen days after axotomy, GIRK1 and GIRK2 were down-regulated in DRG neurons at the mRNA and protein levels. Both after axotomy and rhizotomy there was a reduction of GIRK1- and -2-positive processes in the dorsal horn, suggesting a presynaptic localization of these potassium channels. Furthermore, nerve ligation caused accumulation of both subunits on both sides of the lesion, providing evidence for anterograde and retrograde fast axonal transport. Conclusions Our data support the hypothesis that reduced GIRK function is associated with increased neuronal excitability and causes sensory disturbances in post-injury conditions, including neuropathic pain. Electronic supplementary material The online version of this article (doi:10.1186/s12990-015-0044-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chuang Lyu
- School of Life Science and Technology, Harbin Institute of Technology, 150001, Harbin, China. .,Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Jan Mulder
- Department of Neuroscience, Science for Life Laboratory, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Kristoffer Sahlholm
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Hugo Zeberg
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Johanna Nilsson
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Peter Århem
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Kaj Fried
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Tie-Jun Sten Shi
- School of Life Science and Technology, Harbin Institute of Technology, 150001, Harbin, China. .,Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
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Abstract
Haploinsufficiency of peripheral myelin protein 22 (PMP22) causes hereditary neuropathy with liability to pressure palsies, a peripheral nerve lesion induced by minimal trauma or compression. As PMP22 is localized to cholesterol-enriched membrane domains that are closely linked with the underlying actin network, we asked whether the myelin instability associated with PMP22 deficiency could be mediated by involvement of the protein in actin-dependent cellular functions and/or lipid raft integrity. In peripheral nerves and cells from mice with PMP22 deletion, we assessed the organization of filamentous actin (F-actin), and actin-dependent cellular functions. Using in vitro models, we discovered that, in the absence of PMP22, the migration and adhesion capacity of Schwann cells and fibroblasts are similarly impaired. Furthermore, PMP22-deficient Schwann cells produce shortened myelin internodes, and display compressed axial cell length and collapsed lamellipodia. During early postnatal development, F-actin-enriched Schmidt-Lanterman incisures do not form properly in nerves from PMP22(-/-) mice, and the expression and localization of molecules associated with uncompacted myelin domains and lipid rafts, including flotillin-1, cholesterol, and GM1 ganglioside, are altered. In addition, we identified changes in the levels and distribution of cholesterol and ApoE when PMP22 is absent. Significantly, cholesterol supplementation of the culture medium corrects the elongation and migration deficits of PMP22(-/-) Schwann cells, suggesting that the observed functional impairments are directly linked with cholesterol deficiency of the plasma membrane. Our findings support a novel role for PMP22 in the linkage of the actin cytoskeleton with the plasma membrane, likely through regulating the cholesterol content of lipid rafts.
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Rosso G, Liashkovich I, Gess B, Young P, Kun A, Shahin V. Unravelling crucial biomechanical resilience of myelinated peripheral nerve fibres provided by the Schwann cell basal lamina and PMP22. Sci Rep 2014; 4:7286. [PMID: 25446378 PMCID: PMC4250911 DOI: 10.1038/srep07286] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/14/2014] [Indexed: 11/09/2022] Open
Abstract
There is an urgent need for the research of the close and enigmatic relationship between nerve biomechanics and the development of neuropathies. Here we present a research strategy based on the application atomic force and confocal microscopy for simultaneous nerve biomechanics and integrity investigations. Using wild-type and hereditary neuropathy mouse models, we reveal surprising mechanical protection of peripheral nerves. Myelinated peripheral wild-type fibres promptly and fully recover from acute enormous local mechanical compression while maintaining functional and structural integrity. The basal lamina which enwraps each myelinated fibre separately is identified as the major contributor to the striking fibre's resilience and integrity. In contrast, neuropathic fibres lacking the peripheral myelin protein 22 (PMP22), which is closely connected with several hereditary human neuropathies, fail to recover from light compression. Interestingly, the structural arrangement of the basal lamina of Pmp22−/− fibres is significantly altered compared to wild-type fibres. In conclusion, the basal lamina and PMP22 act in concert to contribute to a resilience and integrity of peripheral nerves at the single fibre level. Our findings and the presented technology set the stage for a comprehensive research of the links between nerve biomechanics and neuropathies.
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Affiliation(s)
- Gonzalo Rosso
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
| | - Burkhard Gess
- Department of Sleep Medicine and Neuromuscular Disorders, Albert-Schweitzer Campus 1, Geb. A1, 48149 Münster, Germany
| | - Peter Young
- Department of Sleep Medicine and Neuromuscular Disorders, Albert-Schweitzer Campus 1, Geb. A1, 48149 Münster, Germany
| | - Alejandra Kun
- Department of Proteins and Nucleic Acids, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Victor Shahin
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
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Guarneri C, Russo M, Mazzeo A, Cannavò SP. Etanercept for Psoriasis and Psoriatic Arthritis in a Patient with Charcot-Marie-Tooth Disease. Ann Pharmacother 2014; 48:550-1. [DOI: 10.1177/1060028013513226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Han H, Myllykoski M, Ruskamo S, Wang C, Kursula P. Myelin-specific proteins: a structurally diverse group of membrane-interacting molecules. Biofactors 2013; 39:233-41. [PMID: 23780694 DOI: 10.1002/biof.1076] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 11/15/2012] [Indexed: 12/15/2022]
Abstract
The myelin sheath is a multilayered membrane in the nervous system, which has unique biochemical properties. Myelin carries a set of specific high-abundance proteins, the structure and function of which are still poorly understood. The proteins of the myelin sheath are involved in a number of neurological diseases, including autoimmune diseases and inherited neuropathies. In this review, we briefly discuss the structural properties and functions of selected myelin-specific proteins (P0, myelin oligodendrocyte glycoprotein, myelin-associated glycoprotein, myelin basic protein, myelin-associated oligodendrocytic basic protein, P2, proteolipid protein, peripheral myelin protein of 22 kDa, 2',3'-cyclic nucleotide 3'-phosphodiesterase, and periaxin); such properties include, for example, interactions with lipid bilayers and the presence of large intrinsically disordered regions in some myelin proteins. A detailed understanding of myelin protein structure and function at the molecular level will be required to fully grasp their physiological roles in the myelin sheath.
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Affiliation(s)
- Huijong Han
- Department of Biochemistry and Biocenter Oulu, University of Oulu, Oulu, Finland
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Abstract
The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate.
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Affiliation(s)
- Grahame J Kidd
- Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
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26
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Li J, Parker B, Martyn C, Natarajan C, Guo J. The PMP22 gene and its related diseases. Mol Neurobiol 2012; 47:673-98. [PMID: 23224996 DOI: 10.1007/s12035-012-8370-x] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
Peripheral myelin protein-22 (PMP22) is primarily expressed in the compact myelin of the peripheral nervous system. Levels of PMP22 have to be tightly regulated since alterations of PMP22 levels by mutations of the PMP22 gene are responsible for >50 % of all patients with inherited peripheral neuropathies, including Charcot-Marie-Tooth type-1A (CMT1A) with trisomy of PMP22, hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of PMP22, and CMT1E with point mutations of PMP22. While overexpression and point-mutations of the PMP22 gene may produce gain-of-function phenotypes, deletion of PMP22 results in a loss-of-function phenotype that reveals the normal physiological functions of the PMP22 protein. In this article, we will review the basic genetics, biochemistry and molecular structure of PMP22, followed by discussion of the current understanding of pathogenic mechanisms involving in the inherited neuropathies with mutations in PMP22 gene.
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Affiliation(s)
- Jun Li
- VA Tennessee Valley Healthcare System, 1310 24th Avenue South, Nashville, TN 37212, USA.
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27
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Rosso G, Negreira C, Sotelo JR, Kun A. Myelinating and demyelinating phenotype of Trembler-J mouse (a model of Charcot-Marie-Tooth human disease) analyzed by atomic force microscopy and confocal microscopy. J Mol Recognit 2012; 25:247-55. [PMID: 22528185 DOI: 10.1002/jmr.2176] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The accumulation of misfolded proteins is associated with various neurodegenerative conditions. Mutations in PMP-22 are associated with the human peripheral neuropathy, Charcot-Marie-Tooth Type 1A (CMT1A). PMP-22 is a short-lived 22 kDa glycoprotein, which plays a key role in the maintenance of myelin structure and compaction, highly expressed by Schwann cells. It forms aggregates when the proteasome is inhibited or the protein is mutated. This study reports the application of atomic force microscopy (AFM) as a detector of profound topographical and mechanical changes in Trembler-J mouse (CMT1A animal model). AFM images showed topographical differences in the extracellular matrix and basal lamina organization of Tr-J/+ nerve fibers. The immunocytochemical analysis indicated that PMP-22 protein is associated with type IV collagen (a basal lamina ubiquitous component) in the Tr-J/+ Schwann cell perinuclear region. Changes in mechanical properties of single myelinating Tr-J/+ nerve fibers were investigated, and alterations in cellular stiffness were found. These results might be associated with F-actin cytoskeleton organization in Tr-J/+ nerve fibers. AFM nanoscale imaging focused on topography and mechanical properties of peripheral nerve fibers might provide new insights into the study of peripheral nervous system diseases.
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Affiliation(s)
- Gonzalo Rosso
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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28
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Pereira JA, Lebrun-Julien F, Suter U. Molecular mechanisms regulating myelination in the peripheral nervous system. Trends Neurosci 2011; 35:123-34. [PMID: 22192173 DOI: 10.1016/j.tins.2011.11.006] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 12/21/2022]
Abstract
Glial cells and neurons are engaged in a continuous and highly regulated bidirectional dialog. A remarkable example is the control of myelination. Oligodendrocytes in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS) wrap their plasma membranes around axons to organize myelinated nerve fibers that allow rapid saltatory conduction. The functionality of this system is critical, as revealed by numerous neurological diseases that result from deregulation of the system, including multiple sclerosis and peripheral neuropathies. In this review we focus on PNS myelination and present a conceptual framework that integrates crucial signaling mechanisms with basic SC biology. We will highlight signaling hubs and overarching molecular mechanisms, including genetic, epigenetic, and post-translational controls, which together regulate the interplay between SCs and axons, extracellular signals, and the transcriptional network.
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Affiliation(s)
- Jorge A Pereira
- Institute of Cell Biology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
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Naik AK, Latham JR, Obradovic A, Jevtovic-Todorovic V. Dorsal root ganglion application of muscimol prevents hyperalgesia and stimulates myelin protein expression after sciatic nerve injury in rats. Anesth Analg 2011; 114:674-82. [PMID: 22190549 DOI: 10.1213/ane.0b013e31823fad7e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Peripheral nerve injuries may result in debilitating pain that is poorly responsive to conventional treatment. Neuropathic pain induced by peripheral nerve injury is caused, in part, by ectopic discharges from the injury site or the dorsal root ganglia (DRG) resulting in enhanced central input and central hyperexcitability. A heterogeneous family of γ-aminobutyric acid (GABA)(A) channels is important in quieting neuronal excitability. We have recently reported that in vivo modulation of GABAergic neurons in DRG can alter the course of neuropathic pain development after peripheral nerve injury. It seems that direct application of a potent GABA(A) agonist, muscimol, to the ipsilateral DRG prevents the development of hyperalgesia in rats subjected to a sciatic nerve crush injury. In addition to potentially curtailing hyperexcitability, GABAergic stimulation upregulated expression of peripheral myelin protein 22 (PMP22), a key component of the basal lamina. PMP22 expression correlates with peripheral myelin formation and nerve regeneration. METHODS Because of the importance of PMP22 for the formation and stability of myelin, and the fact that PMP22 expression could be GABAergically modulated, we examined whether direct DRG application of muscimol can restore PMP22 protein expression and the integrity of nerve fibers after crush injury of a sciatic nerve. RESULTS Using adult female rats and a crush injury model, we found that GABAergic modulation in the ipsilateral DRG restores PMP22 protein expression in the distal segment of the sciatic nerve and improves myelin stability in the basal membrane of nerve fibers, thus giving the morphological appearance of lessened nerve injury or faster nerve fiber regeneration. Both the enhanced PMP22 protein expression and morphological improvements coincide with the abolishment of thermal and mechanical hypersensitivity. CONCLUSIONS The DRG could be a promising therapeutic target in nerve regeneration and pain alleviation after crush injury of a myelinated peripheral nerve.
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Affiliation(s)
- Ajit K Naik
- Department of Anesthesiology, University of Virginia Health System, PO Box 800710, Charlottesville, VA 22980, USA
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Saporta MA, Katona I, Zhang X, Roper HP, McClelland L, Macdonald F, Brueton L, Blake J, Suter U, Reilly MM, Shy ME, Li J. Neuropathy in a human without the PMP22 gene. ACTA ACUST UNITED AC 2011; 68:814-21. [PMID: 21670407 DOI: 10.1001/archneurol.2011.110] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Haploinsufficiency of PMP22 causes hereditary neuropathy with liability to pressure palsies. However, the biological functions of the PMP22 protein in humans have largely been unexplored owing to the absence of patients with PMP22-null mutations. OBJECTIVE To investigate the function of PMP22 in the peripheral nervous system by studying a boy without the PMP22 gene and mice without the Pmp22 gene. DESIGN The clinical and pathological features of a patient with a PMP22 homozygous deletion are compared with those of Pmp22-null mice. SETTING Clinical evaluation was performed at tertiary hospitals in the United Kingdom. Molecular diagnosis was performed at the West Midlands Regional Genetics Laboratory. Immunohistochemistry and electron microscopy analyses were conducted at Wayne State University, Detroit, Michigan. Analysis of the Pmp22 +/- and null mice was performed at Vanderbilt University, Nashville, Tennessee. PARTICIPANT A 7-year-old boy without the PMP22 gene. RESULTS Motor and sensory deficits in the proband were nonlength-dependent. Weakness was found in cranial muscles but not in the limbs. Large fiber sensory modalities were profoundly abnormal, which started prior to the maturation of myelin. This is in line with the temporal pattern of PMP22 expression predominantly in cranial motor neurons and dorsal root ganglia during embryonic development, becoming undetectable in adulthood. Moreover, there were conspicuous maturation defects of myelinating Schwann cells; these defects were more significant in motor nerve fibers than in sensory nerve fibers. CONCLUSIONS Taken together, the data suggest that PMP22 is important for the normal function of neurons that express PMP22 during early development, such as cranial motor neurons and spinal sensory neurons. Moreover, PMP22 deficiency differentially affects myelination between motor and sensory nerves, which may have contributed to the unique clinical phenotype in the patient with an absence of PMP22.
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Morales SA, Telander D, Notterpek L, Wadehra M, Braun J, Gordon LK. Rewiring integrin-mediated signaling and cellular response with the peripheral myelin protein 22 and epithelial membrane protein 2 components of the tetraspan web. Invest Ophthalmol Vis Sci 2011; 52:5465-72. [PMID: 21421883 DOI: 10.1167/iovs.10-6139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Integrin-mediated collagen gel contraction by ARPE-19 is an in vitro model for proliferative vitreoretinopathy (PVR), an aberrant wound healing response after retinal detachment or ocular trauma. Expression of the tetraspan protein epithelial membrane protein 2 (EMP2) controls gel contraction through FAK activation. Peripheral myelin protein 22 (PMP22), another member of the tetraspan web, is closely related to EMP2. The purpose of this study was to determine whether PMP22 also controls the contractile phase associated with PVR. METHODS Integrin expression, adhesion, and protein expression were assessed, respectively, through flow cytometry, binding to collagen types I and IV, and Western blot analysis. Collagen gel contraction was assessed using an in vitro assay. RESULTS Overexpression of PMP22 in ARPE-19 cells (ARPE-19/PMP22) resulted in increased collagen adhesion. Gel contraction, however, was reduced by greater than 50% in ARPE-19/PMP22 cells (P < 0.001). In contrast to the FAK activation observed by increasing EMP2 expression, PMP22 overexpression led to increased AKT activation. The decrease in gel contraction by the ARPE-19/PMP22 cells was partially reversed through either PMP22 siRNA or by blockade of AKT. CONCLUSIONS Relative expression of EMP2 or PMP22 within the tetraspan web drives a cellular response toward a FAK- or AKT-dependent pathway, respectively. EMP2 and PMP22 differentially regulate collagen gel contraction in the ARPE-19 cell line. The implication of this finding adds a new dimension to the concept of the tetraspan web, in which the abundance of individual tetraspan family members differentially regulates signal transduction and the downstream cellular response.
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Affiliation(s)
- Shawn A Morales
- Department of Ophthalmology, University of California at Los Angeles, Los Angeles, California, USA
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Myelin and axon pathology in a long-term study of PMP22-overexpressing mice. J Neuropathol Exp Neurol 2011; 70:386-98. [PMID: 21487305 DOI: 10.1097/nen.0b013e318217eba0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We analyzed clinical and pathological disease in 2 peripheral myelin protein-22 (PMP22) overexpressing mouse models for 1.5 years. C22 mice have 7 and C3-PMP mice have 3 to 4 copies of the human PMP22 gene. C3-PMP mice showed no overt clinical signs at 3 weeks and developed mild neuromuscular impairment; C22 mice showed signs at 3 weeks that progressed to severe impairment. Adult C3-PMP mice had very similar, stable, low nerve conduction velocities similar to adults with human Charcot-Marie-Tooth disease type 1A (CMT1A); velocities were much lower in C22 mice. Myelination was delayed, and normal myelination was not reached in either model but the degree of dysmyelination in C3-PMP mice was considerably less than that in C22 mice; myelination was stable in the adult mice. Numbers of myelinated, fibers were reduced at 3 weeks in both models, suggesting that normal numbers of myelinated fibers are not reached during development in the models. In adult C3-PMP and wild-type mice, there was no detectable loss of myelinated fibers,whereas there was clear loss of myelinated fibers in C22 mice.In C3-PMP mice, there is a balance between myelination status and axonal function early in life, whereas in C22 mice, early reduction of axons is more severe and there is major loss of axons in adulthood. We conclude that C3-PMP mice may be an appropriate model for most CMT1A patients, whereas C22 mice may be more relevant to severely affected patients in the CMT1 spectrum.
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Saher G, Quintes S, Nave KA. Cholesterol: a novel regulatory role in myelin formation. Neuroscientist 2011; 17:79-93. [PMID: 21343408 DOI: 10.1177/1073858410373835] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Myelin consists of tightly compacted membranes that form an insulating sheath around axons. The function of myelin for rapid saltatory nerve conduction is dependent on its unique composition, highly enriched in glycosphingolipids and cholesterol. Cholesterol emerged as the only integral myelin component that is essential and rate limiting for the development of CNS and PNS myelin. Experiments with conditional mouse mutants that lack cholesterol biosynthesis in oligodendrocytes revealed that only minimal changes of the CNS myelin lipid composition are tolerated. In Schwann cells of the PNS, protein trafficking and myelin compaction depend on cholesterol. In this review, the authors summarize the role of cholesterol in myelin biogenesis and myelin disease.
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Affiliation(s)
- Gesine Saher
- Max Planck Institute of Experimental Medicine, Neurogenetics, Göttingen, Germany.
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Rao RG, Sudhakar D, Hogue CP, Amici S, Gordon LK, Braun J, Notterpek L, Goodglick L, Wadehra M. Peripheral myelin protein-22 (PMP22) modulates alpha 6 integrin expression in the human endometrium. Reprod Biol Endocrinol 2011; 9:56. [PMID: 21518455 PMCID: PMC3110552 DOI: 10.1186/1477-7827-9-56] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 04/25/2011] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND PMP22, a member of the GAS3 family of tetraspan proteins, is associated with a variety of neurological diseases. Previous studies have shown that PMP22 is expressed in proliferative endometrium, but its function within this tissue is poorly understood. In this study, we first characterized the expression of PMP22 in the human menstrual cycle and began to characterize its function in the endometrium. METHODS Using a combination of immunohistochemistry and quantitative PCR, we characterized the expression of PMP22 in both proliferative and secretory endometrium. Differences in PMP22 expression between proliferative and secretory endometrium were determined using a Mann-Whitney U test. In order to investigate the influence of PMP22 on α6 integrin expression, cells were created that ectopically overexpressed PMP22 or expressed a siRNA to inhibit its expression. These cells were analyzed for changes in integrins and binding to extracellular matrices. RESULTS In this study, we show that PMP22 expression is higher in proliferative phase than secretory phase. Functionally, we have begun to characterize the functional significance of this expression. Previous studies have suggested a link between PMP22 and α6 integrin, and therefore we asked whether PMP22 could associate or potentially modulate the expression of α6 integrin. Expression of both PMP22 and α6 integrin were detectable in endometrial epithelial and stromal cells, and we show that both proteins can associate and colocalize with each other. To understand if PMP22 directly altered the expression of a6 integrin, we examined cell lines with modulated levels of the protein. Overexpression of PMP22 was sufficient to increase α6 integrin surface expression with a concominant increase in binding to the extracellular matrix laminin, while a reduction in PMP22 suppressed α6 integrin surface expression. CONCLUSION These findings suggest a physiologic role for PMP22 on the expression of α6 integrin. We predict that this may be important for the maintainence of endometrial integrity and to the disease biology associated with altered levels of α6 integrin expression in the endometrium.
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Affiliation(s)
- Rajiv G Rao
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
| | - Deepthi Sudhakar
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
| | - Claire P Hogue
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
| | - Stephanie Amici
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Lynn K Gordon
- Department of Ophthalmology, University of California, Los Angeles, California 90095, USA
| | - Jonathan Braun
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California 90095, USA
| | - Lucia Notterpek
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Lee Goodglick
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California 90095, USA
| | - Madhuri Wadehra
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California 90095, USA
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Ito T, Ikeda K, Tomita K, Yokoyama S. Interleukin-6 upregulates the expression of PMP22 in cultured rat Schwann cells via a JAK2-dependent pathway. Neurosci Lett 2010; 472:104-8. [DOI: 10.1016/j.neulet.2010.01.061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 01/26/2010] [Accepted: 01/26/2010] [Indexed: 02/04/2023]
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Saporta MA, Katona I, Lewis RA, Masse S, Shy ME, Li J. Shortened internodal length of dermal myelinated nerve fibres in Charcot-Marie-Tooth disease type 1A. Brain 2010; 132:3263-73. [PMID: 19923170 DOI: 10.1093/brain/awp274] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Charcot-Marie-Tooth disease type 1A is the most common inherited neuropathy and is caused by duplication of chromosome 17p11.2 containing the peripheral myelin protein-22 gene. This disease is characterized by uniform slowing of conduction velocities and secondary axonal loss, which are in contrast with non-uniform slowing of conduction velocities in acquired demyelinating disorders, such as chronic inflammatory demyelinating polyradiculoneuropathy. Mechanisms responsible for the slowed conduction velocities and axonal loss in Charcot-Marie-Tooth disease type 1A are poorly understood, in part because of the difficulty in obtaining nerve samples from patients, due to the invasive nature of nerve biopsies. We have utilized glabrous skin biopsies, a minimally invasive procedure, to evaluate these issues systematically in patients with Charcot-Marie-Tooth disease type 1A (n = 32), chronic inflammatory demyelinating polyradiculoneuropathy (n = 4) and healthy controls (n = 12). Morphology and molecular architecture of dermal myelinated nerve fibres were examined using immunohistochemistry and electron microscopy. Internodal length was uniformly shortened in patients with Charcot-Marie-Tooth disease type 1A, compared with those in normal controls (P < 0.0001). Segmental demyelination was absent in the Charcot-Marie-Tooth disease type 1A group, but identifiable in all patients with chronic inflammatory demyelinating polyradiculoneuropathy. Axonal loss was measurable using the density of Meissner corpuscles and associated with an accumulation of intra-axonal mitochondria. Our study demonstrates that skin biopsy can reveal pathological and molecular architectural changes that distinguish inherited from acquired demyelinating neuropathies. Uniformly shortened internodal length in Charcot-Marie-Tooth disease type 1A suggests a potential developmental defect of internodal lengthening. Intra-axonal accumulation of mitochondria provides new insights into the pathogenesis of axonal degeneration in Charcot-Marie-Tooth disease type 1A.
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Affiliation(s)
- Mario A Saporta
- Department of Neurology, Wayne State University, Detroit 48201, USA
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Abstract
Myelin abnormalities exist in schizophrenia leading to the hypothesis that oligodendrocyte dysfunction plays a role in the pathophysiology of the disease. The expression of the mRNA for the peripheral myelin protein-22 (PMP-22) is decreased in schizophrenia and recent genetic evidence suggests a link between PMP-22 and schizophrenia. While PMP-22 mRNA is found in both rodent and human brain it has been generally thought that no protein expression occurs. Here we show that PMP-22 protein is present in myelin isolated from adult mouse and human brain. These results suggest that PMP-22 protein likely plays a role in the maintenance and function of central nervous system (CNS) myelin and provide an explanation for why altered PMP-22 expression may be pathophysiologically relevant in a CNS disorder such as schizophrenia.
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Abstract
Myelin consists of several layers of tightly compacted membranes wrapped around axons in the nervous system. The main function of myelin is to provide electrical insulation around the axon to ensure the rapid propagation of nerve conduction. As the myelinating glia terminally differentiates, they begin to produce myelin membranes on a remarkable scale. This membrane is unique in its composition being highly enriched in lipids, in particular galactosylceramide and cholesterol. In this review we will summarize the role of cholesterol in myelin biogenesis in the central and peripheral nervous system.
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Affiliation(s)
- Gesine Saher
- Department of Neurogenetics, Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany
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Verrier JD, Lau P, Hudson L, Murashov AK, Renne R, Notterpek L. Peripheral myelin protein 22 is regulated post-transcriptionally by miRNA-29a. Glia 2009; 57:1265-79. [PMID: 19170179 DOI: 10.1002/glia.20846] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Peripheral myelin protein 22 (PMP22) is a dose-sensitive, disease-associated protein primarily expressed in myelinating Schwann cells. Either reduction or overproduction of PMP22 can result in hereditary neuropathy, suggesting a requirement for correct protein expression for peripheral nerve biology. PMP22 is post-transcriptionally regulated and the 3'untranslated region (3'UTR) of the gene exerts a negative effect on translation. MicroRNAs (miRNAs) are small regulatory molecules that function at a post-transcriptional level by targeting the 3'UTR in a reverse complementary manner. We used cultured Schwann cells to demonstrate that alterations in the miRNA biogenesis pathway affect PMP22 levels, and endogenous PMP22 is subjected to miRNA regulation. GW-body formation, the proposed cytoplasmic site for miRNA-mediated repression, and Dicer expression, an RNase III family ribonuclease involved in miRNA biogenesis, are co-regulated with the differentiation state of Schwann cells. Furthermore, the levels of Dicer inversely correlate with PMP22, while the inhibition of Dicer leads to elevated PMP22. Microarray analysis of actively proliferating and differentiated Schwann cells, in conjunction with bioinformatics programs, identified several candidate PMP22-targeting miRNAs. Here we demonstrate that miR-29a binds and inhibits PMP22 reporter expression through a specific miRNA seed binding region. Over-expression of miR-29a enhances the association of PMP22 RNA with Argonaute 2, a protein involved in miRNA function, and reduces the steady-state levels of PMP22. In contrast, inhibition of endogenous miR-29a relieves the miRNA-mediated repression of PMP22. Correlation analyses of miR-29 and PMP22 in sciatic nerves reveal an inverse relationship, both developmentally and in post-crush injury. These results identify PMP22 as a target of miRNAs and suggest that myelin gene expression by Schwann cells is regulated by miRNAs.
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Affiliation(s)
- Jonathan D Verrier
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA
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Verhamme C, van Schaik IN, Koelman JHTM, de Haan RJ, de Visser M. The natural history of Charcot-Marie-Tooth type 1A in adults: a 5-year follow-up study. Brain 2009; 132:3252-62. [DOI: 10.1093/brain/awp251] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Webber C, Hehir-Kwa JY, Nguyen DQ, de Vries BBA, Veltman JA, Ponting CP. Forging links between human mental retardation-associated CNVs and mouse gene knockout models. PLoS Genet 2009; 5:e1000531. [PMID: 19557186 PMCID: PMC2694283 DOI: 10.1371/journal.pgen.1000531] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 05/22/2009] [Indexed: 12/20/2022] Open
Abstract
Rare copy number variants (CNVs) are frequently associated with common neurological disorders such as mental retardation (MR; learning disability), autism, and schizophrenia. CNV screening in clinical practice is limited because pathological CNVs cannot be distinguished routinely from benign CNVs, and because genes underlying patients' phenotypes remain largely unknown. Here, we present a novel, statistically robust approach that forges links between 148 MR–associated CNVs and phenotypes from ∼5,000 mouse gene knockout experiments. These CNVs were found to be significantly enriched in two classes of genes, those whose mouse orthologues, when disrupted, result in either abnormal axon or dopaminergic neuron morphologies. Additional enrichments highlighted correspondences between relevant mouse phenotypes and secondary presentations such as brain abnormality, cleft palate, and seizures. The strength of these phenotype enrichments (>100% increases) greatly exceeded molecular annotations (<30% increases) and allowed the identification of 78 genes that may contribute to MR and associated phenotypes. This study is the first to demonstrate how the power of mouse knockout data can be systematically exploited to better understand genetically heterogeneous neurological disorders. Mental retardation (MR; also known as learning disability) affects 1%–3% of people and is often associated with the presence of genomic copy number variations (CNVs) such as deletions and duplications. Most of these CNVs are rare and they often involve tens, sometimes hundreds, of genes. Pinpointing exactly which particular gene or genes are responsible for MR in an individual patient is therefore challenging and limits diagnostic applications. In this study, the functions of genes present within a large collection of MR–associated CNVs were investigated by comparing them to data from large-scale mouse knock-out experiments. We found that MR–associated CNVs contain greater than expected numbers of genes that give specific nervous system phenotypes when disrupted in the mouse. Not only does this study confirm that CNVs frequently cause MR, but it narrows down the list of genes whose changes lead to this disorder from thousands to several dozen. This reduced list of genes brings wide-spread genetic testing for MR one step closer. It also provides a better understanding of the biology behind MR that could, eventually, yield medical treatments.
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Affiliation(s)
- Caleb Webber
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Jayne Y. Hehir-Kwa
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Duc-Quang Nguyen
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Bert B. A. de Vries
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Joris A. Veltman
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (JV); (CPP)
| | - Chris P. Ponting
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- * E-mail: (JV); (CPP)
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Itou J, Suyama M, Imamura Y, Deguchi T, Fujimori K, Yuba S, Kawarabayasi Y, Kawasaki T. Functional and comparative genomics analyses of pmp22 in medaka fish. BMC Neurosci 2009; 10:60. [PMID: 19534778 PMCID: PMC2714311 DOI: 10.1186/1471-2202-10-60] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 06/17/2009] [Indexed: 01/23/2023] Open
Abstract
Background Pmp22, a member of the junction protein family Claudin/EMP/PMP22, plays an important role in myelin formation. Increase of pmp22 transcription causes peripheral neuropathy, Charcot-Marie-Tooth disease type1A (CMT1A). The pathophysiological phenotype of CMT1A is aberrant axonal myelination which induces a reduction in nerve conduction velocity (NCV). Several CMT1A model rodents have been established by overexpressing pmp22. Thus, it is thought that pmp22 expression must be tightly regulated for correct myelin formation in mammals. Interestingly, the myelin sheath is also present in other jawed vertebrates. The purpose of this study is to analyze the evolutionary conservation of the association between pmp22 transcription level and vertebrate myelin formation, and to find the conserved non-coding sequences for pmp22 regulation by comparative genomics analyses between jawed fishes and mammals. Results A transgenic pmp22 over-expression medaka fish line was established. The transgenic fish had approximately one fifth the peripheral NCV values of controls, and aberrant myelination of transgenic fish in the peripheral nerve system (PNS) was observed. We successfully confirmed that medaka fish pmp22 has the same exon-intron structure as mammals, and identified some known conserved regulatory motifs. Furthermore, we found novel conserved sequences in the first intron and 3'UTR. Conclusion Medaka fish undergo abnormalities in the PNS when pmp22 transcription increases. This result indicates that an adequate pmp22 transcription level is necessary for correct myelination of jawed vertebrates. Comparison of pmp22 orthologs between distantly related species identifies evolutionary conserved sequences that contribute to precise regulation of pmp22 expression.
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Affiliation(s)
- Junji Itou
- Department of Radiation Biomedical Science IV, Radiation Biology Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
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Madorsky I, Opalach K, Waber A, Verrier JD, Solmo C, Foster T, Dunn WA, Notterpek L. Intermittent fasting alleviates the neuropathic phenotype in a mouse model of Charcot-Marie-Tooth disease. Neurobiol Dis 2009; 34:146-54. [PMID: 19320048 DOI: 10.1016/j.nbd.2009.01.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Charcot-Marie-Tooth type 1A (CMT1A) neuropathies linked to the misexpression of peripheral myelin protein 22 (PMP22) are progressive demyelinating disorders of the peripheral nervous system. In this study we asked whether dietary restriction by intermittent fasting (IF) could alleviate the neuropathic phenotype in the Trembler J (TrJ) mouse model of CMT1A. Our results show that neuropathic mice kept on a five month long IF regimen had improved locomotor performance compared to ad libitum (AL) fed littermates. The functional benefits of this dietary intervention are associated with an increased expression of myelin proteins combined with a thicker myelin sheath, less redundant basal lamina, and a reduction in aberrant Schwann cell proliferation. These morphological improvements are accompanied by a decrease in PMP22 protein aggregates, and enhanced expression of cytosolic chaperones and constituents of the autophagy-lysosomal pathway. These results indicate that dietary restriction is beneficial for peripheral nerve function in TrJ neuropathic mice, as it promotes the maintenance of locomotor performance.
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Affiliation(s)
- Irina Madorsky
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
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Krause S, Stendel C, Senderek J, Relvas JB, Suter U. Small Rho GTPases are key regulators of peripheral nerve biology in health and disease. J Peripher Nerv Syst 2009; 13:188-99. [PMID: 18844785 DOI: 10.1111/j.1529-8027.2008.00177.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A thorough knowledge of the cellular and molecular basis of the structure and function of peripheral nerves is of paramount importance not only for a better understanding of the fascinating biology of the peripheral nervous system but also for providing critical insights into the various diseases affecting peripheral nerves as the firm foundation of potential treatments. Genetic approaches in model organisms, in combination with research on hereditary forms of neuropathies, have contributed significantly to our progress in this field. In this review, we will focus on recent advances using these synergistic approaches that led to the identification of small Rho GTPases and their regulators as crucial functional players in proper development and function of myelinated peripheral nerves, with a particular emphasis on the cell biology of Schwann cells in health and disease.
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Affiliation(s)
- Sven Krause
- Institute of Cell Biology, Department of Biology, ETH Zürich, Zürich, Switzerland
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Hong S, Kang JK, Park JJ, Ryu ES, Choi SS, Lee SH, Lee JH, Seo JS. Association of matrix metalloproteinase-3 with cardiogenic activity during Noggin-induced differentiation of mouse embryonic stem cells. Int J Cardiol 2009; 141:49-60. [PMID: 19138802 DOI: 10.1016/j.ijcard.2008.11.156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 10/06/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Despite the pluripotency of embryonic stem (ES) cells, their clinical applications have been hindered due to the lack of reliable differentiation methods. Recently, it was shown that Noggin could effectively induce cardiomyocyte differentiation by transient treatment of ES cells. METHODS To determine how Noggin may induce cardiac differentiation, we compared differentially expressed genes during Noggin-induced differentiation of ES cells using microarray analysis. We found Matrix metalloproteinase-3 (Mmp-3) expression was highly up-regulated by Noggin treatment. To understand the role of Mmp-3 in the cardiac differentiation of ES cells, we inhibited Mmp-3 activity by treating with a specific Mmp-3 inhibitor during Noggin-induced cardiac differentiation of ES cells. We also analyzed the expression levels of cardiac markers and the ratio of spontaneously beating embryoid bodies (EBs) in the presence of the Mmp-3 inhibitor. RESULTS We analyzed EB samples from zero, two, and four days with or without Noggin treatment, and found that the expression levels of 2 (0 day), 56 (2 days), and 805 (4 days) genes were altered with Noggin treatment. Up-regulation of Mmp-3 was closely associated with relative increases of cardiogenic, vasculogenic, and hematopoietic genes in EB treated with Noggin. By inhibiting Mmp-3 activity, we verified that Mmp-3 activation is partly responsible for both the expression of cardiac markers and the elevated ratio of spontaneously beating to non-beating EBs. CONCLUSIONS The concurrent expression of Mmp-3 with many cardiogenic genes and the specific inhibition of Mmp-3 revealed a critical role for Mmp-3 in Noggin-induced cardiac differentiation of ES cells.
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Affiliation(s)
- Su Hong
- Macrogen Inc, World Meridian Venture Center, 60-24 Gasan-dong, Seoul 153-023, Republic of Korea
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Identification of dynamically regulated microRNA and mRNA networks in developing oligodendrocytes. J Neurosci 2008; 28:11720-30. [PMID: 18987208 DOI: 10.1523/jneurosci.1932-08.2008] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
MicroRNAs (miRNAs) play important roles in modulating gene expression at the posttranscriptional level. In postnatal oligodendrocyte lineage cells, the miRNA expression profile ("microRNAome") contains 43 miRNAs whose expression dynamically changes during the transition from A2B5(+) oligodendrocyte progenitor cells to premyelinating GalC(+) cells. The combination of microRNAome profiling with analyses of the oligodendrocyte transcriptome reveals a target bias for a class of miRNAs which includes miR-9. We show that miR-9 is downregulated during oligodendrocyte differentiation. In addition, miR-9 expression level inversely correlates with the expression of its predicted targets, among which is the peripheral myelin protein PMP22. We found that PMP22 mRNA but not protein is detectable in oligodendrocytes, whereas Schwann cells producing PMP22 protein lack miR-9. We demonstrate that miR-9 interacts with the 3' untranslated region of PMP22 and downregulates its expression. Our results support models in which miRNAs can act as guardians of the transcriptome.
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Conditional deletion of the Itgb4 integrin gene in Schwann cells leads to delayed peripheral nerve regeneration. J Neurosci 2008; 28:11292-303. [PMID: 18971471 DOI: 10.1523/jneurosci.3068-08.2008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Several different integrins participate in the complex interactions that promote repair of the peripheral nervous system. The role of the integrin alpha6beta4 in peripheral nerve regeneration was investigated in mice by cre-mediated deletion of the Itgb4 (beta4) gene in Schwann cells. After a crush lesion of the sciatic nerve, the recovery of motor, but not that of sensory, nerve function in beta4(-/-) mice was delayed. Immunostaining of neurofilament-200 showed that there also is a significant reduction in the number of newly outgrowing nerve sprouts in beta4(-/-) mice. Morphometric quantitative measurements revealed that fewer axons are myelinated in the nonlesioned beta4(-/-) nerves. After a sciatic nerve crush lesion, beta4(-/-) mice did not only have fewer myelinated axons compared with lesioned wild-type nerve, but their axons also showed a higher g-ratio and a thinner myelin sheath, pointing at reduced myelination. This study revealed that the beta4 protein remains expressed in the early stages of peripheral regeneration, albeit at levels lower than those before the lesion was inflicted, and showed that laminin deposition is not altered in the absence of beta4. These results together demonstrate that integrin alpha6beta4 plays an essential role in axonal regeneration and subsequent myelination.
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Analysis of peripheral nerve expression profiles identifies a novel myelin glycoprotein, MP11. J Neurosci 2008; 28:7563-73. [PMID: 18650334 DOI: 10.1523/jneurosci.1659-08.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The myelin sheath insulates axons and allows for rapid salutatory conduction in the nervous system of all vertebrates. The formation of peripheral myelin requires expression of the transcription factor Egr2, which is responsible for inducing such essential myelin-associated genes as Mpz, Mbp, Pmp22, and Mag. Using microarray analysis to compare gene expression patterns in peripheral nerve during development, during remyelination after nerve injury, and in a congenital hypomyelinating mouse model, we identified an evolutionarily conserved novel component of myelin called Mp11 (myelin protein of 11 kDa). The Mp11 genomic locus contains multiple conserved Egr binding sites, and Mp11 induction is regulated by the expression of Egr2. Similar to other Egr2-dependent genes, it is induced during developmental myelination and remyelination after nerve injury. Mp11 is a glycoprotein expressed preferentially in the myelin of the peripheral nervous system versus CNS and is specifically localized to the Schmidt-Lanterman incisures and paranodes of peripheral nerve. The Mp11 protein contains no identifiable similarity to other known protein domains or motifs. However, like other myelin genes, strict Mp11 expression levels are a requirement for the in vitro myelination of DRG neurons, indicating that this previously uncharacterized gene product is a critical component of peripheral nervous system myelin.
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Abstract
Schwann cells integrate signals deriving from the axon and the basal lamina to myelinate peripheral nerves. Integrin alpha6beta4 is a laminin receptor synthesized by Schwann cells and displayed apposed to the basal lamina. alpha6beta4 integrin expression in Schwann cells is induced by axons at the onset of myelination, and rises in adulthood. The beta4 chain has a uniquely long cytoplasmic domain that interacts with intermediate filaments such as dystonin, important in peripheral myelination. Furthermore, alpha6beta4 integrin binds peripheral myelin protein 22, whose alteration causes the most common demyelinating hereditary neuropathy. All these data suggest a role for alpha6beta4 integrin in peripheral nerve myelination. Here we show that ablating alpha6beta4 integrin specifically in Schwann cells of transgenic mice does not affect peripheral nerve development, myelin formation, maturation, or regeneration. However, consistent with maximal expression in adult nerves, alpha6beta4 integrin-null myelin is more prone to abnormal folding with aging. When the laminin receptor dystroglycan is also ablated, major folding abnormalities occur, associated with acute demyelination in some peripheral nervous system districts. These data indicate that, similar to its role in skin, alpha6beta4 integrin confers stability to myelin in peripheral nerves.
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Abstract
Integrin beta 4, one of the heterodimeric receptors, is expressed predominantly on epithelial cells. It is concentrated at the basement membrane zone, where it localizes to specialized adhesion structures called hemidesmosomes. In addition to its adhesive functions, novel insights have emerged regarding the specific roles of integrin beta 4 in their attachment to extracellular matrix and in their signal transduction pathways within the central nervous system (CNS) and peripheral nervous system in the past few years. It has been reported that integrin beta 4 is expressed in several kinds of neural cells including astrocyte, Schwann cells, neurons, and neural stem cells. In the mean while, it is expressed by some Schwann cells in the peripheral nervous system and mediated the Mycobacterium leprae invade the peripheral nervous system to reach the Schwann cells. This review highlights recent progress in the function and regulation of integrin beta 4 in neural cells.
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