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Tsai NW, Lin CC, Yeh TY, Chiu YA, Chiu HH, Huang HP, Hsieh ST. An induced pluripotent stem cell-based model identifies molecular targets of vincristine neurotoxicity. Dis Model Mech 2022; 15:dmm049471. [PMID: 36518084 PMCID: PMC10655812 DOI: 10.1242/dmm.049471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2023] Open
Abstract
To model peripheral nerve degeneration and investigate molecular mechanisms of neurodegeneration, we established a cell system of induced pluripotent stem cell (iPSC)-derived sensory neurons exposed to vincristine, a drug that frequently causes chemotherapy-induced peripheral neuropathy. Sensory neurons differentiated from iPSCs exhibit distinct neurochemical patterns according to the immunocytochemical phenotypes, and gene expression of peripherin (PRPH, hereafter referred to as Peri) and neurofilament heavy chain (NEFH, hereafter referred to as NF). The majority of iPSC-derived sensory neurons were PRPH positive/NEFH negative, i.e. Peri(+)/NF(-) neurons, whose somata were smaller than those of Peri(+)/NF(+) neurons. On exposure to vincristine, projections from the cell body of a neuron, i.e. neurites, were degenerated quicker than somata, the lethal concentration to kill 50% (LC50) of neurites being below the LC50 for somata, consistent with the clinical pattern of length-dependent neuropathy. We then examined the molecular expression in the MAP kinase signaling pathways of, extracellular signal-regulated kinases 1/2 (MAPK1/3, hereafter referred to as ERK), p38 mitogen-activated protein kinases (MAPK11/12/13/14, hereafter referred to as p38) and c-Jun N-terminal kinases (MAPK8/9/10, hereafter referred to as JNK). Regarding these three cascades, only phosphorylation of JNK was upregulated but not that of p38 or ERK1/2. Furthermore, vincristine-treatment resulted in impaired autophagy and reduced autophagic flux. Rapamycin-treatment reversed the effect of impaired autophagy and JNK activation. These results not only established a platform to study peripheral degeneration of human neurons but also provide molecular mechanisms for neurodegeneration with the potential for therapeutic targets.
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Affiliation(s)
- Neng-Wei Tsai
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Cheng-Chen Lin
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Ti-Yen Yeh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Yu-An Chiu
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Hsin-Hui Chiu
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
| | - Hsiang-Po Huang
- Department of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Pediatrics, National Taiwan University Children's Hospital, Taipei 100, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Department of Neurology, National Taiwan University Hospital, Taipei 100, Taiwan
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Vakili O, Asili P, Babaei Z, Mirahmad M, Keshavarzmotamed A, Asemi Z, Mafi A. Circular RNAs in Alzheimer's Disease: A New Perspective of Diagnostic and Therapeutic Targets. CNS Neurol Disord Drug Targets 2022; 22:CNSNDDT-EPUB-125997. [PMID: 36043720 DOI: 10.2174/1871527321666220829164211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/06/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Circular RNAs (circRNAs), as covalently closed single-stranded noncoding RNA molecules, have been recently identified to involve in several biological processes, principally through targeting microRNAs. Among various neurodegenerative diseases (NDs), accumulating evidence has proposed key roles for circRNAs in the pathogenesis of Alzheimer's disease (AD); although the exact relationship between these RNA molecules and AD progression is not clear, they have been believed to mostly act as miRNA sponges or gene transcription modulators through correlating with multiple proteins, involved in the accumulation of Amyloid β (Aβ) peptides, as well as tau protein, as AD's pathological hallmark. More interestingly, circRNAs have also been reported to play diagnostic and therapeutic roles during AD progression. OBJECTIVE Literature review indicated that circRNAs could essentially contribute to the onset and development of AD. Thus, in the current review, the circRNAs' biogenesis and functions are addressed at first, and then the interplay between particular circRNAs and AD is comprehensively discussed. Eventually, the diagnostic and therapeutic significance of these noncoding RNAs is highlighted in brief. RESULTS A large number of circRNAs are expressed in the brain. Thereby, these RNA molecules are noticed as potential regulators of neural functions in healthy circumstances, as well as neurological disorders. Moreover, circRNAs have also been reported to have potential diagnostic and therapeutic capacities in relation to AD, the most prevalent ND. CONCLUSION CircRNAs have been shown to act as sponges for miRNAs, thereby regulating the function of related miRNAs, including oxidative stress, reduction of neuroinflammation, and the formation and metabolism of Aβ, all of which developed in AD. CircRNAs have also been proposed as biomarkers that have potential diagnostic capacities in AD. Despite these characteristics, the use of circRNAs as therapeutic targets and promising diagnostic biomarkers will require further investigation and characterization of the function of these RNA molecules in AD.
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Affiliation(s)
- Omid Vakili
- Department of Clinical Biochemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Pooria Asili
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Zeinab Babaei
- Department of Clinical Biochemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Mirahmad
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Alireza Mafi
- Department of Clinical Biochemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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Li S, Shi S, Luo B, Xia F, Ha Y, Merkley KH, Motamedi M, Zhang W, Liu H. Tauopathy induces degeneration and impairs regeneration of sensory nerves in the cornea. Exp Eye Res 2021; 215:108900. [PMID: 34929160 DOI: 10.1016/j.exer.2021.108900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/21/2021] [Accepted: 12/13/2021] [Indexed: 12/26/2022]
Abstract
The cornea is transparent and innervated by a dense collection of sensory nerves originating from the ocular branch of the trigeminal nerve. This study was designed to comprehensively analyze alterations of corneal sub-basal nerve plexus in a mouse model of tauopathy (P301L transgenic mice) to test the possibility of using corneal nerves as a biomarker for tauopathy. Corneal sensitivity, thickness and epithelial wound healing were measured non-invasively by aeshesiometer, optical coherence tomography and fluorescein staining, respectively. Tau, corneal nerves and immune cells were examined by immunohistochemistry or Western blot. At the early stage of tauopathy, although corneal sensitivity, thickness and nerve fiber density were not greatly altered, corneal nerve abnormalities were observed in the peripheral region of young P301L mice. With aging, the density of abnormal nerves increased, while corneal sensitivity, epithelial thickness, nerve fiber density and length decreased in middle-aged P301L mice compared with WT mice. After corneal epithelial injury in young mice, no difference in reepithelialization was observed between two groups of mice, however, the regeneration of corneal nerves in P301L mice lagged behind WT mice, which was reflected by delayed recovery of corneal sensitivity, decreased corneal nerve density and length and density of CD45+ dendriform cells in P301L mice. In conclusion, our data provide compelling evidence that corneal nerves were changed in a mouse model of tauopathy in an age-dependent manner. Moreover, tau overexpression impairs corneal nerve regeneration. These results suggest that cornea may serve as a promising ocular site for the early diagnosis of tauopathy.
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Affiliation(s)
- Shengguo Li
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China; Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Shuizhen Shi
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Ban Luo
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Fan Xia
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Yonju Ha
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Kevin H Merkley
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Massoud Motamedi
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Wenbo Zhang
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA; Departments of Neuroscience, Cell Biology & Anatomy, University of Texas Medical Branch, Galveston, TX, USA.
| | - Hua Liu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA.
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Khodabakhsh P, Bazrgar M, Dargahi L, Mohagheghi F, Asgari Taei A, Parvardeh S, Ahmadiani A. Does Alzheimer's disease stem in the gastrointestinal system? Life Sci 2021; 287:120088. [PMID: 34715145 DOI: 10.1016/j.lfs.2021.120088] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/13/2021] [Accepted: 10/21/2021] [Indexed: 02/07/2023]
Abstract
Over the last decades, our knowledge of the key pathogenic mechanisms of Alzheimer's disease (AD) has dramatically improved. Regarding the limitation of current therapeutic strategies for the treatment of multifactorial diseases, such as AD, to be translated into the clinic, there is a growing trend in research to identify risk factors associated with the onset and progression of AD. Here, we review the current literature with a focus on the relationship between gastrointestinal (GI)/liver diseases during the lifespan and the incidence of AD, and discuss the possible mechanisms underlying the link between the diseases. We also aim to review studies evaluating the possible link between the chronic use of the most common GI medications and the future risk of AD development.
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Affiliation(s)
- Pariya Khodabakhsh
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Bazrgar
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Dargahi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Mohagheghi
- Institute of Experimental Hematology, Center for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Afsaneh Asgari Taei
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Siavash Parvardeh
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Abolhassan Ahmadiani
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Rajič Bumber J, Pilipović K, Janković T, Dolenec P, Gržeta N, Križ J, Župan G. Repetitive Traumatic Brain Injury Is Associated With TDP-43 Alterations, Neurodegeneration, and Glial Activation in Mice. J Neuropathol Exp Neurol 2021; 80:2-14. [PMID: 33212475 DOI: 10.1093/jnen/nlaa130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence points to a relationship between repetitive mild traumatic brain injury (mTBI), the Tar DNA binding protein 43 (TDP-43) pathology and some neurodegenerative diseases, but the underlying pathophysiological mechanisms are still unknown. We examined TDP-43 regulation, neurodegeneration, and glial responses following repetitive mTBI in nontransgenic mice and in animals with overexpression of human mutant TDP-43 protein (TDP-43G348C). In the frontal cortices of the injured nontransgenic animals, early TDP-43 cytoplasmatic translocation and overexpression of the protein and its pathological forms were detected. In the injured animals of both genotypes, neurodegeneration and pronounced glial activity were detected in the optic tract. In TDP-43G348C mice, these changes were significantly higher at day 7 after the last mTBI compared with the values in the nontransgenic animals. Results of this study suggest that the changes in the TDP-43 regulation in the frontal cortices of the nontransgenic animals were a transient stress response to the brain injury. Repetitive mTBI did not produce additional TDP-43 dysregulation or neurodegeneration or pronounced gliosis in the frontal cortex of TDP-43G348C mice. Our research also suggests that overexpression of mutated human TDP-43 possibly predisposes the brain to more intense neurodegeneration and glial activation in the optic tract after repetitive mTBI.
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Affiliation(s)
- Jelena Rajič Bumber
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Kristina Pilipović
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Tamara Janković
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Petra Dolenec
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Nika Gržeta
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Jasna Križ
- Department of Psychiatry and Neuroscience, Faculty of Medicine, University of Laval, Quebec, QC, Canada
| | - Gordana Župan
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
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Kosaka Y, Yafuso T, Shimizu-Okabe C, Kim J, Kobayashi S, Okura N, Ando H, Okabe A, Takayama C. Development and persistence of neuropathic pain through microglial activation and KCC2 decreasing after mouse tibial nerve injury. Brain Res 2020; 1733:146718. [PMID: 32045595 DOI: 10.1016/j.brainres.2020.146718] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 01/27/2020] [Accepted: 02/07/2020] [Indexed: 12/20/2022]
Abstract
Gamma-amino butyric acid (GABA) is an inhibitory neurotransmitter in the mature brain, but is excitatory during development and after motor nerve injury. This difference in GABAergic action depends on the intracellular chloride ion concentration ([Cl-]i), primarily regulated by potassium chloride co-transporter 2 (KCC2). To reveal precise processes of the neuropathic pain through changes in GABAergic action, we prepared tibial nerve ligation and severance models using male mice, and examined temporal relationships amongst changes in (1) the mechanical withdrawal threshold in the sural nerve area, (2) localization of the molecules involved in GABAergic transmission and its upstream signaling in the dorsal horn, and (3) histology of the tibial nerve. In the ligation model, tibial nerve degeneration disappeared by day 56, but mechanical allodynia, reduced KCC2 localization, and increased microglia density remained until day 90. Microglia density was higher in the tibial zone than the sural zone before day 21, but this result was inverted after day 28. In contrast, in the severance model, all above changes were detected until day 28, but were simultaneously and significantly recovered by day 90. These results suggested that in male mice, allodynia may be caused by reduced GABAergic synaptic inhibition, resulting from elevated [Cl-]i after the reduction of KCC2 by activated microglia. Furthermore, our results suggested that factors from degenerating nerve terminals may diffuse into the sural zone, whereby they induced the development of allodynia in the sural nerve area, while other factors in the sural zone may mediate persistent allodynia through the same pathway.
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Affiliation(s)
- Yoshinori Kosaka
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Tsukasa Yafuso
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Chigusa Shimizu-Okabe
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Jeongtae Kim
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan; Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 63243, Republic of Korea
| | - Shiori Kobayashi
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Nobuhiko Okura
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Hironobu Ando
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Akihito Okabe
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan; Department of Nutritional Science, Faculty of Health and Welfare, Seinan Jo Gakuin University, Fukuoka 803-0835, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
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Abstract
The robust axonal growth and regenerative capacities of young neurons decrease substantially with age. This developmental downregulation of axonal growth may facilitate axonal pruning and neural circuit formation but limits functional recovery following nerve damage. While external factors influencing axonal growth have been extensively investigated, relatively little is known about the intrinsic molecular changes underlying the age-dependent reduction in regeneration capacity. We report that developmental downregulation of LIS1 is responsible for the decreased axonal extension capacity of mature dorsal root ganglion (DRG) neurons. In contrast, exogenous LIS1 expression or endogenous LIS1 augmentation by calpain inhibition restored axonal extension capacity in mature DRG neurons and facilitated regeneration of the damaged sciatic nerve. The insulator protein CTCF suppressed LIS1 expression in mature DRG neurons, and this reduction resulted in excessive accumulation of phosphoactivated GSK-3β at the axon tip, causing failure of the axonal extension. Conversely, sustained LIS1 expression inhibited developmental axon pruning in the mammillary body. Thus, LIS1 regulation may coordinate the balance between axonal growth and pruning during maturation of neuronal circuits. Summary: Developmental downregulation of LIS1 coordinates the balance between axonal elongation and pruning, which is essential for proper neuronal circuit formation but limits nerve regeneration.
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Affiliation(s)
- Kanako Kumamoto
- Department of Genetic Disease Research, Osaka City University, Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
| | - Tokuichi Iguchi
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Ryuichi Ishida
- Department of Genetic Disease Research, Osaka City University, Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
| | - Takuya Uemura
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
| | - Makoto Sato
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan.,Research Center for Child Mental Development, University of Fukui, Fukui 910-1193, Japan.,United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University, and University of Fukui, Osaka 565-0871, Japan
| | - Shinji Hirotsune
- Department of Genetic Disease Research, Osaka City University, Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
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Choi EJ, Choi YM, Jang EJ, Kim JY, Kim TK, Kim KH. Neural Ablation and Regeneration in Pain Practice. Korean J Pain 2016; 29:3-11. [PMID: 26839664 PMCID: PMC4731549 DOI: 10.3344/kjp.2016.29.1.3] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 11/26/2015] [Accepted: 12/22/2015] [Indexed: 11/18/2022] Open
Abstract
A nerve block is an effective tool for diagnostic and therapeutic methods. If a diagnostic nerve block is successful for pain relief and the subsequent therapeutic nerve block is effective for only a limited duration, the next step that should be considered is a nerve ablation or modulation. The nerve ablation causes iatrogenic neural degeneration aiming only for sensory or sympathetic denervation without motor deficits. Nerve ablation produces the interruption of axonal continuity, degeneration of nerve fibers distal to the lesion (Wallerian degeneration), and the eventual death of axotomized neurons. The nerve ablation methods currently available for resection/removal of innervation are performed by either chemical or thermal ablation. Meanwhile, the nerve modulation method for interruption of innervation is performed using an electromagnetic field of pulsed radiofrequency. According to Sunderland's classification, it is first and foremost suggested that current neural ablations produce third degree peripheral nerve injury (PNI) to the myelin, axon, and endoneurium without any disruption of the fascicular arrangement, perineurium, and epineurium. The merit of Sunderland's third degree PNI is to produce a reversible injury. However, its shortcoming is the recurrence of pain and the necessity of repeated ablative procedures. The molecular mechanisms related to axonal regeneration after injury include cross-talk between axons and glial cells, neurotrophic factors, extracellular matrix molecules, and their receptors. It is essential to establish a safe, long-standing denervation method without any complications in future practices based on the mechanisms of nerve degeneration as well as following regeneration.
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Affiliation(s)
- Eun Ji Choi
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
| | - Yun Mi Choi
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
| | - Eun Jung Jang
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
| | - Ju Yeon Kim
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
| | - Tae Kyun Kim
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
| | - Kyung Hoon Kim
- Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea
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Unlusoy Acar Z, Yalinay Dikmen P, Yayla V, Başaran K, Emekli U, Öge AE. Decline of compound muscle action potentials and statistical MUNEs during Wallerian degeneration. Neurophysiol Clin 2014; 44:257-65. [PMID: 25240559 DOI: 10.1016/j.neucli.2014.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 01/21/2014] [Accepted: 04/12/2014] [Indexed: 12/12/2022] Open
Abstract
AIM OF THE STUDY In two previous studies, we found that the compound muscle action potential (CMAP) amplitude loss was significantly higher than the loss of estimated motor unit numbers in the course of Wallerian degeneration (WD). In order to overcome some drawbacks of the method previously used, we performed a similar CMAP vs MUNE comparison by using the statistical motor unit number estimation (MUNE) method. PATIENTS AND METHODS Initial electrophysiological studies on 6 patients were performed between 22 and 98 hours after the injuries; it was possible to make repeated examinations, four times in 1 nerve, twice in 1 nerve and three times in 4 nerves, before the eventual complete disappearance of the CMAPs. RESULTS The transected/intact (T/I) side CMAP ratios declined steeply as WD evolved. They were significantly lower than the relatively stable MUNE ratios 48 hours after the injury. CONCLUSION This study, performed with the use of statistical MUNE, strengthens our previous observation by the incremental method that might have some relevance to the pathophysiology of early WD. CMAP amplitude loss that is more than expected from the amount of axonal degeneration may indicate a considerable amount of inactive muscle fibers in the motor units innervated by the nerve fibers, which are undergoing degeneration but still retain their excitability. Although technical sources of error cannot be totally excluded, our findings could more likely be explained by the failing of neuromuscular synapses in an asynchronous order before complete unresponsiveness of the motor unit ensues.
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Affiliation(s)
- Z Unlusoy Acar
- Department of Neurology, TDV 29 May Hospital, 34091 Istanbul, Turkey
| | - P Yalinay Dikmen
- Department of Neurology, Acıbadem University School of Medicine, 34140 Istanbul, Turkey.
| | - V Yayla
- Department of Neurology, Dr. Sadi Konuk Bakırköy Education and Research Hospital, 34147 Istanbul, Turkey
| | - K Başaran
- Department of Plastic and Reconstructive Surgery, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
| | - U Emekli
- Department of Plastic and Reconstructive Surgery, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
| | - A E Öge
- Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, 34390 Istanbul, Turkey
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Abstract
Objective To understand the neural generator of double-peak potentials and the change of latency and amplitude of double peaks with aging. Method In 50 healthy subjects made up of groups of 10 people per decade from the age of 20 to 60, orthodromic sensory nerve conduction studies were performed on the median nerves using submaximal stimulation. Various stimulus durations and interstimulation distances were used to obtain each double peak in the different age groups. The latency and amplitude of the second peak were measured. Statistical analyses included one-way ANOVA and correlation tests. p-values<0.05 were considered significant. Results When the cathode moved in a proximal direction, the interpeak intervals increased. Second peak amplitudes decreased, and second peak latencies were delayed with aging (p<0.05). In some older people, second peaks were not obtained. Conclusion Our experiments indicate that the double-peak response represented the two stimulation sites under the cathode and anode. The delayed latency and decreased amplitude of the second peak that occurs with aging represented peripheral nerve degeneration in aging, which starts at the distal nerve.
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Affiliation(s)
- Kyung Lim Joa
- Department of Physical & Rehabilitation Medicine, School of Medicine, Inha University, Incheon 400-711, Korea
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