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Abstract
In this contribution, we demonstrate the utility of the systems genetics-systems biology approach to the study of iron regulation while employing a comprehensive database. We describe our work in iron regulation in the brain and periphery under normal iron and iron-restricted dietary conditions in the BXD family of recombinant inbred mouse strains. Using multiple measures, we showed wide variation among the strains in the effect of being fed an iron-restricted diet for 100 days in every measure from brain and from the periphery. All data were entered into GeneNetwork ( www.genenetwork.org ), a database that contains genotypic, phenotypic, and gene expression data (Rosen et al., Methods Mol Biol 401:287-303, 2007). Using this resource, we were able to ask the following four questions concerning possible candidate genes underlying our measures: (1) what is the range of response for each of the measures? (2) Does the pattern of variability show continuous (additive genetic) or discrete (Mendelian) distribution across strains? (3) Are there genetic markers that are associated with the variability in the measures? (4) Are there genes in near the markers that contain associated allelic differences, and whose expression is related to the variability in the measures? Other questions that we could address include: (5) what is the association among the measures between the sexes? (6) What is the association among the measures, e.g., is liver iron status under the diets related to brain iron? (7) What is the relationship between our measures and other phenotypic parameters-i.e., is there an association between our brain iron measures and neurochemical phenotypes extant in the database? And finally, (8) are there gene networks that underlie single or combined measures?
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Blaeser A, Awano H, Lu P, Lu QL. Distinct expression of functionally glycosylated alpha-dystroglycan in muscle and non-muscle tissues of FKRP mutant mice. PLoS One 2018; 13:e0191016. [PMID: 29320543 PMCID: PMC5761899 DOI: 10.1371/journal.pone.0191016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 12/27/2017] [Indexed: 01/06/2023] Open
Abstract
The glycosylation of alpha-dystroglycan (α-DG) is crucial in maintaining muscle cell membrane integrity. Dystroglycanopathies are identified by the loss of this glycosylation leading to a breakdown of muscle cell membrane integrity and eventual degeneration. However, a small portion of fibers expressing functionally glycosylated α-DG (F-α-DG) (revertant fibers, RF) have been identified. These fibers are generally small in size, centrally nucleated and linked to regenerating fibers. Examination of different muscles have shown various levels of RFs but it is unclear the extent of which they are present. Here we do a body-wide examination of muscles from the FKRP-P448L mutant mouse for the prevalence of RFs. We have identified great variation in the distribution of RF in different muscles and tissues. Triceps shows a large increase in RFs and together with centrally nucleated fibers whereas the pectoralis shows a reduction in revertant but increase in centrally nucleated fibers from 6 weeks to 6 months of age. We have also identified that the sciatic nerve with near normal levels of F-α-DG in the P448Lneo- mouse with reduced levels in the P448Lneo+ and absent in LARGEmyd. The salivary gland of LARGEmyd mice expresses high levels of F-α-DG. Interestingly the same glands in the P448Lneo-and to a lesser degree in P448Lneo+ also maintain considerable amount of F-α-DG, indicating the non-proliferating epithelial cells have a molecular setting permitting glycosylation.
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Bakst RL, Xiong H, Chen CH, Deborde S, Lyubchik A, Zhou Y, He S, McNamara W, Lee SY, Olson OC, Leiner IM, Marcadis AR, Keith JW, Al-Ahmadie HA, Katabi N, Gil Z, Vakiani E, Joyce JA, Pamer E, Wong RJ. Inflammatory Monocytes Promote Perineural Invasion via CCL2-Mediated Recruitment and Cathepsin B Expression. Cancer Res 2017; 77:6400-6414. [PMID: 28951461 PMCID: PMC5831809 DOI: 10.1158/0008-5472.can-17-1612] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/21/2017] [Accepted: 09/18/2017] [Indexed: 12/14/2022]
Abstract
Perineural invasion (PNI) is an ominous event strongly linked to poor clinical outcome. Cells residing within peripheral nerves collaborate with cancer cells to enable PNI, but the contributing conditions within the tumor microenvironment are not well understood. Here, we show that CCR2-expressing inflammatory monocytes (IM) are preferentially recruited to sites of PNI, where they differentiate into macrophages and potentiate nerve invasion through a cathepsin B-mediated process. A series of adoptive transfer experiments with genetically engineered donors and recipients demonstrated that IM recruitment to nerves was driven by CCL2 released from Schwann cells at the site of PNI, but not CCL7, an alternate ligand for CCR2. Interruption of either CCL2-CCR2 signaling or cathepsin B function significantly impaired PNI in vivo Correlative studies in human specimens demonstrated that cathepsin B-producing macrophages were enriched in invaded nerves, which was associated with increased local tumor recurrence. These findings deepen our understanding of PNI pathogenesis and illuminate how PNI is driven in part by corruption of a nerve repair program. Further, they support the exploration of inhibiting IM recruitment and function as a targeted therapy for PNI. Cancer Res; 77(22); 6400-14. ©2017 AACR.
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MESH Headings
- Animals
- Cathepsin B/metabolism
- Cell Line
- Cell Line, Tumor
- Chemokine CCL2/genetics
- Chemokine CCL2/metabolism
- Humans
- Macrophages/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Nude
- Monocytes/metabolism
- Monocytes/pathology
- Neoplasm Invasiveness
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Peripheral Nerves/metabolism
- Peripheral Nerves/pathology
- Receptors, CCR2/genetics
- Receptors, CCR2/metabolism
- Schwann Cells/metabolism
- Transplantation, Heterologous
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Assis AD, de Assis Araújo F, Dos Santos RAS, Andrade SP, Zanon RG. Pattern of Mas expression in acute and post-acute stage of nerve injury in mice. Peptides 2017; 96:15-19. [PMID: 28870798 DOI: 10.1016/j.peptides.2017.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/12/2017] [Accepted: 08/28/2017] [Indexed: 12/24/2022]
Abstract
Angiotensin-(1-7) (Ang [1-7]) and its receptor Mas are involved in a number of physiological processes, including control of arterial pressure and modulation of nervous system actions. However, the involvement of the Ang-(1-7)/Mas axis in peripheral nerve injury has not been investigated. Using a model of sciatic nerve injury in mice, we demonstrated opposing changes in Mas receptor expression at days 2 and 14 post-injury. Mas receptor expression was more intense 2days after the nerve lesion, compared with the intensity of the intact nerve. At this time point, the sciatic nerve functional index was -20. At day 14 after the lesion, the intensity of the immunostaining labeling in longitudinal sections of the nerve was reduced (∼30%) and the functional index increased +36 (gait improvement). In the axotomized group treated with A779 (a Mas receptor antagonist), the functional recovery index decreased in relation to the untreated axotomized group. The Mas receptor inhibitor also altered the intensity of labeling of S-100, GAP43, and IBA-1 (morphological features compatible with delayed axon growth). This study demonstrated that Ang-(1-7)/Mas axis activity was differentially modulated in the acute and post-acute stages of nerve injury.
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Roberts SL, Dun XP, Doddrell RDS, Mindos T, Drake LK, Onaitis MW, Florio F, Quattrini A, Lloyd AC, D'Antonio M, Parkinson DB. Sox2 expression in Schwann cells inhibits myelination in vivo and induces influx of macrophages to the nerve. Development 2017; 144:3114-3125. [PMID: 28743796 PMCID: PMC5611958 DOI: 10.1242/dev.150656] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/13/2017] [Indexed: 12/25/2022]
Abstract
Correct myelination is crucial for the function of the peripheral nervous system. Both positive and negative regulators within the axon and Schwann cell function to ensure the correct onset and progression of myelination during both development and following peripheral nerve injury and repair. The Sox2 transcription factor is well known for its roles in the development and maintenance of progenitor and stem cell populations, but has also been proposed in vitro as a negative regulator of myelination in Schwann cells. We wished to test fully whether Sox2 regulates myelination in vivo and show here that, in mice, sustained Sox2 expression in vivo blocks myelination in the peripheral nerves and maintains Schwann cells in a proliferative non-differentiated state, which is also associated with increased inflammation within the nerve. The plasticity of Schwann cells allows them to re-myelinate regenerated axons following injury and we show that re-myelination is also blocked by Sox2 expression in Schwann cells. These findings identify Sox2 as a physiological regulator of Schwann cell myelination in vivo and its potential to play a role in disorders of myelination in the peripheral nervous system.
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Freundt-Revilla J, Kegler K, Baumgärtner W, Tipold A. Spatial distribution of cannabinoid receptor type 1 (CB1) in normal canine central and peripheral nervous system. PLoS One 2017; 12:e0181064. [PMID: 28700706 PMCID: PMC5507289 DOI: 10.1371/journal.pone.0181064] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 06/26/2017] [Indexed: 12/18/2022] Open
Abstract
The endocannabinoid system is a regulatory pathway consisting of two main types of cannabinoid receptors (CB1 and CB2) and their endogenous ligands, the endocannabinoids. The CB1 receptor is highly expressed in the central and peripheral nervous systems (PNS) in mammalians and is involved in neuromodulatory functions. Since endocannabinoids were shown to be elevated in cerebrospinal fluid of epileptic dogs, knowledge about the species specific CB receptor expression in the nervous system is required. Therefore, we assessed the spatial distribution of CB1 receptors in the normal canine CNS and PNS. Immunohistochemistry of several regions of the brain, spinal cord and peripheral nerves from a healthy four-week-old puppy, three six-month-old dogs, and one ten-year-old dog revealed strong dot-like immunoreactivity in the neuropil of the cerebral cortex, Cornu Ammonis (CA) and dentate gyrus of the hippocampus, midbrain, cerebellum, medulla oblongata and grey matter of the spinal cord. Dense CB1 expression was found in fibres of the globus pallidus and substantia nigra surrounding immunonegative neurons. Astrocytes were constantly positive in all examined regions. CB1 labelled neurons and satellite cells of the dorsal root ganglia, and myelinating Schwann cells in the PNS. These results demonstrate for the first time the spatial distribution of CB1 receptors in the healthy canine CNS and PNS. These results can be used as a basis for further studies aiming to elucidate the physiological consequences of this particular anatomical and cellular distribution.
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Li G, Xiao Q, McNaughton R, Han L, Zhang L, Wang Y, Yang Y. Nanoengineered porous chitosan/CaTiO 3 hybrid scaffolds for accelerating Schwann cells growth in peripheral nerve regeneration. Colloids Surf B Biointerfaces 2017; 158:57-67. [PMID: 28672204 DOI: 10.1016/j.colsurfb.2017.06.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 01/11/2023]
Abstract
To further improve the property of promoting peripheral nerve regeneration of chitosan materials, CaTiO3 nanoparticles with various concentrations were synthesized in chitosan (CS) solution and formed to porous CS/CaTiO3 hybrid scaffolds. The properties including morphology, wettability, porosity, crystallization intensity and surface charges were characterized, respectively. The influence of the porous CS/CaTiO3 hybrid scaffolds on Schwann cells growth was evaluated. The results showed that the CaTiO3 hybridized CS scaffolds possessed homogeneous nanoparticles distribution with concentration-dependent effect. The hybridization of CaTiO3 nanoparticles could increase the hydrophobicity while reduce the porosity and surface charge density of the porous CS/CaTiO3 hybrid scaffolds The crystal structure of the hybridized scaffolds was mainly the orthorhombic structure of the calcium titanate accompanied by the amorphous phase of chitosan. Culture of Schwann cells indicated that the CS/CaTiO3 hybrid scaffolds with a suitable concentration of CaTiO3 nanoparticles could obviously promote the attachment, proliferation and biological function maintenance of Schwann cells, thus showing potentially great significance towards application in peripheral nerve regeneration.
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Grässel S, Muschter D. Peripheral Nerve Fibers and Their Neurotransmitters in Osteoarthritis Pathology. Int J Mol Sci 2017; 18:ijms18050931. [PMID: 28452955 PMCID: PMC5454844 DOI: 10.3390/ijms18050931] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 12/21/2022] Open
Abstract
The importance of the nociceptive nervous system for maintaining tissue homeostasis has been known for some time, and it has also been suggested that organogenesis and tissue repair are under neuronal control. Changes in peripheral joint innervation are supposed to be partly responsible for degenerative alterations in joint tissues which contribute to development of osteoarthritis. Various resident cell types of the musculoskeletal system express receptors for sensory and sympathetic neurotransmitters, allowing response to peripheral neuronal stimuli. Among them are mesenchymal stem cells, synovial fibroblasts, bone cells and chondrocytes of different origin, which express distinct subtypes of adrenoceptors (AR), receptors for vasoactive intestinal peptide (VIP), substance P (SP) and calcitonin gene-related peptide (CGRP). Some of these cell types synthesize and secrete neuropeptides such as SP, and they are positive for tyrosine-hydroxylase (TH), the rate limiting enzyme for biosynthesis of catecholamines. Sensory and sympathetic neurotransmitters are involved in the pathology of inflammatory diseases such as rheumatoid arthritis (RA) which manifests mainly in the joints. In addition, they seem to play a role in pathogenesis of priori degenerative joint disorders such as osteoarthritis (OA). Altogether it is evident that sensory and sympathetic neurotransmitters have crucial trophic effects which are critical for joint tissue and bone homeostasis. They modulate articular cartilage, subchondral bone and synovial tissue properties in physiological and pathophysiological conditions, in addition to their classical neurological features.
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Zendedel A, Gharibi Z, Anbari K, Abbaszadeh A, Khayat ZK, Khorramabadi RM, Soleymaninejad M, Gholami M. Selenium Ameliorate Peripheral Nerve Ischemic-Reperfusion Injury via Decreased TNF-α. Biol Trace Elem Res 2017; 176:328-337. [PMID: 27600929 DOI: 10.1007/s12011-016-0836-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/22/2016] [Indexed: 10/21/2022]
Abstract
Selenium is considered as a trace element that plays antioxidant role in the body. So, the aim of this study was to evaluate the effect of selenium on ameliorating of sciatic nerve ischemia-reperfusion injury. Eighty (80) adult male Wistar rats weighing 250-300 g were used. They were divided into 10 groups (n = 8). Then, femoral vessels were obstructed by using 4/0 silk and splitknot techniques. After 3-h ischemia for all the groups, reperfusion was applied for different periods: 3, 7, 14, and 28 days. In half of each experimental group, 0.2 mg/kg selenium was injected intraperitoneally, coinciding with ischemia. After reperfusion, according to the grouping, rats were killed by using high dose of anesthetic drug and then sciatic nerve was removed and fixed. Then, tissue samples were processed and subsequently stained with hematoxylin-eosin, apoptosis, and immunohistochemistry stains. On the third day of reperfusion, the amount of TNF-α as an inflammatory marker of ischemia-reperfusion acute phase increased. On the seventh day of reperfusion, the amount of NF-кB as an apoptotic index and infiltration of mast cells increased in the tissue as a result of development of inflammation. But, on the 14th day of reperfusion, the amount of NF-кB as an apoptotic index decreased to the lowest amount. On the 28th day of reperfusion, the amount of TNF-α as an inflammatory marker decreased to its lowest level. Prescription of selenium concurrent with development of ischemia can reduce the damage caused by sciatic nerve ischemia-reperfusion.
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Areti A, Komirishetty P, Akuthota M, Malik RA, Kumar A. Melatonin prevents mitochondrial dysfunction and promotes neuroprotection by inducing autophagy during oxaliplatin-evoked peripheral neuropathy. J Pineal Res 2017; 62. [PMID: 28118492 DOI: 10.1111/jpi.12393] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/20/2017] [Indexed: 12/31/2022]
Abstract
Oxaliplatin, an organoplatinum compound, is used in the treatment of colorectal cancer, but its clinical use can be limited due to the development of peripheral neuropathy. Whilst mitochondrial dysfunction has been implicated as a major pathomechanism for oxaliplatin-induced neurotoxicity, the prevention of autophagy may also aggravate neuronal cell death. Melatonin, a well-known mitoprotectant and autophagy inducer, was used to examine its neuroprotective role in oxaliplatin-induced peripheral neuropathy (OIPN). Melatonin prevented the loss of mitochondrial membrane potential (Ψm) and promoted neuritogenesis in oxaliplatin-challenged neuro-2a cells. It did not interfere with the cytotoxic activity of oxaliplatin in human colon cancer cell line, HT-29. Melatonin treatment significantly alleviated oxaliplatin-induced pain behavior and neuropathic deficits in rats. It also ameliorated nitro-oxidative stress mediated by oxaliplatin, thus prevented nitrosylation of proteins and loss of antioxidant enzymes, and therefore, it improved mitochondrial electron transport chain function and maintained cellular bioenergetics by improving the ATP levels. The protective effects of melatonin were attributed to preventing oxaliplatin-induced neuronal apoptosis by increasing the autophagy pathway (via LC3A/3B) in peripheral nerves and dorsal root ganglion (DRG). Hence, it preserved the epidermal nerve fiber density in oxaliplatin-induced neuropathic rats. Taken together, we provide detailed molecular mechanisms for the neuroprotective effect of melatonin and suggest it has translational potential for oxaliplatin-induced neuropathy.
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Ino D, Iino M. Schwann cell mitochondria as key regulators in the development and maintenance of peripheral nerve axons. Cell Mol Life Sci 2017; 74:827-835. [PMID: 27638763 PMCID: PMC11107563 DOI: 10.1007/s00018-016-2364-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/09/2016] [Indexed: 01/13/2023]
Abstract
Formation of myelin sheaths by Schwann cells (SCs) enables rapid and efficient transmission of action potentials in peripheral axons, and disruption of myelination results in disorders that involve decreased sensory and motor functions. Given that construction of SC myelin requires high levels of lipid and protein synthesis, mitochondria, which are pivotal in cellular metabolism, may be potential regulators of the formation and maintenance of SC myelin. Supporting this notion, abnormal mitochondria are found in SCs of neuropathic peripheral nerves in both human patients and the relevant animal models. However, evidence for the importance of SC mitochondria in myelination has been limited, until recently. Several studies have recently used genetic approaches that allow SC-specific ablation of mitochondrial metabolic activity in living animals to show the critical roles of SC mitochondria in the development and maintenance of peripheral nerve axons. Here, we review current knowledge about the involvement of SC mitochondria in the formation and dysfunction of myelinated axons in the peripheral nervous system.
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Jasinski-Bergner S, Büttner M, Quandt D, Seliger B, Kielstein H. Adiponectin and Its Receptors Are Differentially Expressed in Human Tissues and Cell Lines of Distinct Origin. Obes Facts 2017; 10:569-583. [PMID: 29207395 PMCID: PMC5836243 DOI: 10.1159/000481732] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/21/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Adiponectin is secreted by adipose tissue and exerts high abundance and an anti-inflammatory potential. However, only little information exists about the expression profiles of adiponectin and its recently identified receptor CDH13 in non-tumorous human tissues and their association to clinical parameters. METHODS The expression levels of adiponectin and CDH13 were analyzed in heart, liver, kidney, spleen, skin, blood vessels, peripheral nerve and bone marrow of 21 human body donors, in 12 human cell lines, and in purified immune effector cell populations of healthy blood donors by immunohistochemistry, Western-blot, and semi-quantitative PCR. The obtained results were then correlated to clinical parameters, including age, sex and known diseases like cardiovascular and renal diseases. RESULTS Adiponectin expression in renal corpuscles was significantly higher in humans with known renal diseases. A coordinated expression of adiponectin and CDH13 was observed in the myocard. High levels of adiponectin could be detected in the bone marrow, in certain lymphoid tumor cell lines and in purified immune effector cell populations of healthy donors, in particular in cytotoxic T cells. CONCLUSION For the first time, the expression profiles of adiponectin and CDH13 are analyzed in many human tissues in correlation to each other and to clinical parameters.
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Graham JB, Muir D. Chondroitinase C Selectively Degrades Chondroitin Sulfate Glycosaminoglycans that Inhibit Axonal Growth within the Endoneurium of Peripheral Nerve. PLoS One 2016; 11:e0167682. [PMID: 27973564 PMCID: PMC5156433 DOI: 10.1371/journal.pone.0167682] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/19/2016] [Indexed: 11/19/2022] Open
Abstract
The success of peripheral nerve regeneration is highly dependent on the regrowth of axons within the endoneurial basal lamina tubes that promote target-oriented pathfinding and appropriate reinnervation. Restoration of nerve continuity at this structural level after nerve transection injury by direct repair and nerve grafting remains a major surgical challenge. Recently, biological approaches that alter the balance of growth inhibitors and promoters in nerve have shown promise to improve appropriate axonal regeneration and recovery of peripheral nerve function. Chondroitin sulfate proteoglycans (CSPGs) are known inhibitors of axonal growth. This growth inhibition is mainly associated with a CSPG's glycosaminoglycan chains. Enzymatic degradation of these chains with chondroitinase eliminates this inhibitory activity and, when applied in vivo, can improve the outcome of nerve repair. To date, these encouraging findings were obtained with chondroitinase ABC (a pan-specific chondroitinase). The aim of this study was to examine the distribution of CSPG subtypes in rodent, rabbit, and human peripheral nerve and to test more selective biological enzymatic approaches to improve appropriate axonal growth within the endoneurium and minimize aberrant growth. Here we provide evidence that the endoneurium, but not the surrounding epineurium, is rich in CSPGs that have glycosaminoglycan chains readily degraded by chondroitinase C. Biochemical studies indicate that chondroitinase C has degradation specificity for 6-sulfated glycosaminoglycans found in peripheral nerve. We found that chondroitinase C degrades and inactivates inhibitory CSPGs within the endoneurium but not so much in the surrounding nerve compartments. Cryoculture bioassays (neurons grown on tissue sections) show that chondroitinase C selectively and significantly enhanced neuritic growth associated with the endoneurial basal laminae without changing growth-inhibiting properties of the surrounding epineurium. Interestingly, chondroitinase ABC treatment increased greatly the growth-promoting properties of the epineurial tissue whereas chondroitinase C had little effect. Our evidence indicates that chondroitinase C effectively degrades and inactivates inhibitory CSPGs present in the endoneurial Schwann cell basal lamina and does so more specifically than chondroitinase ABC. These findings are discussed in the context of improving nerve repair and regeneration and the growth-promoting properties of processed nerve allografts.
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Solt Z, Zsombok A, Pollák E, Molnár L. NADPH-diaphorase histochemistry selectively stains peripheral and central sensory structures of lumbricid earhworms. ACTA BIOLOGICA HUNGARICA 2016; 67:364-372. [PMID: 28000510 DOI: 10.1556/018.67.2016.4.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
By means of whole mount NADPH-diaphorase histochemistry the distribution pattern of primary sensory cells (PSC) and the pathway of their central processes in the ventral nerve cord (VNC) ganglia were investigated in the lumbricid earthworms, Eisenia fetida and Lumbricus terrestris. The distribution pattern of the stained structures seemed to be the same in both species investigated. Strong labelling occurred in sensory fibre branches of segmental nerves and in each of the sensory longitudinal axon bundles of VNC ganglia. Based on their anatomical location some NADPH-d positive central sensory cells were identified from among which the putative tactile receptors were characterized by constant, strong staining.
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Nomura A, Majumder K, Giri B, Dauer P, Dudeja V, Roy S, Banerjee S, Saluja AK. Inhibition of NF-kappa B pathway leads to deregulation of epithelial-mesenchymal transition and neural invasion in pancreatic cancer. J Transl Med 2016; 96:1268-1278. [PMID: 27775688 PMCID: PMC5121017 DOI: 10.1038/labinvest.2016.109] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 01/04/2023] Open
Abstract
NF-κB has an essential role in the initiation and progression of pancreatic cancer and specifically mediates the induction of epithelial-mesenchymal transition and invasiveness. In this study, we demonstrate the importance of activated NF-κB signaling in EMT induction, lymphovascular metastasis, and neural invasion. Modulation of NF-κB activity was accomplished through the specific NF-κB inhibitor (BAY 11-7085), triptolide, and Minnelide treatment, as well as overexpression of IKBα repressor and IKK activator plasmids. In the classical lymphovascular metastatic cascade, inhibition of NF-κB decreased the expression of several EMT transcription factors (SNAI1, SNAI2, and ZEB1) and mesenchymal markers (VIM and CDH2) and decreased in vitro invasion, which was rescued by IKK activation. This was further demonstrated in vivo via BAY 11-7085 treatment in a orthotopic model of pancreatic cancer. In vivo NF-κB inhibition decreased tumor volume; decreased tumor EMT gene expression, while restoring cell-cell junctions; and decreasing overall metastasis. Furthermore, we demonstrate the importance of active NF-κB signaling in neural invasion. Triptolide treatment inhibits Nerve Growth Factor (NGF) mediated, neural-tumor co-culture in vitro invasion, and dorsal root ganglia (DRG) neural outgrowth through a disruption in tumor-neural cross talk. In vivo, Minnelide treatment decreased neurotrophin expression, nerve density, and sciatic nerve invasion. Taken together, this study demonstrates the importance of NF-κB signaling in the progression of pancreatic cancer through the modulation of EMT induction, lymphovascular invasion, and neural invasion.
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Bannerman P, Burns T, Xu J, Miers L, Pleasure D. Mice Hemizygous for a Pathogenic Mitofusin-2 Allele Exhibit Hind Limb/Foot Gait Deficits and Phenotypic Perturbations in Nerve and Muscle. PLoS One 2016; 11:e0167573. [PMID: 27907123 PMCID: PMC5132404 DOI: 10.1371/journal.pone.0167573] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 11/16/2016] [Indexed: 12/31/2022] Open
Abstract
Charcot-Marie-Tooth disease type 2A (CMT2A), the most common axonal form of hereditary sensory motor neuropathy, is caused by mutations of mitofusin-2 (MFN2). Mitofusin-2 is a GTPase required for fusion of mitochondrial outer membranes, repair of damaged mitochondria, efficient mitochondrial energetics, regulation of mitochondrial-endoplasmic reticulum calcium coupling and axonal transport of mitochondria. We knocked T105M MFN2 preceded by a loxP-flanked STOP sequence into the mouse Rosa26 locus to permit cell type-specific expression of this pathogenic allele. Crossing these mice with nestin-Cre transgenic mice elicited T105M MFN2 expression in neuroectoderm, and resulted in diminished numbers of mitochondria in peripheral nerve axons, an alteration in skeletal muscle fiber type distribution, and a gait abnormality.
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Mathis S, Franques J, Richard L, Vallat JM. Monoclonal gammopathy of undeterminated significance and endoneurial IgG deposition: A case report. Medicine (Baltimore) 2016; 95:e4807. [PMID: 27603395 PMCID: PMC5023918 DOI: 10.1097/md.0000000000004807] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Monoclonal gammopathy of undeterminated significance is the most common form of plasma cell dyscrasia, usually considered as benign. In rare cases it may have a malignant course, sometimes limited to an organ such as peripheral nerves. METHODS We describe clinical, electrophysiological and pathological findings in a patient presenting a immunoglobulin G (IgG) paraproteinemic polyneuropathy clinically mimicking a chronic inflammatory demyelinating polyneuropathy. RESULTS Immuno-electron microscopy (immune-EM) demonstrated that the widenings of the myelin lamellae resulted from the infiltration of IgG between a significant number of myelin lamellae (with absence of inflammatory cells in the epineurium, endoneurium, and perineurium, and the lack signs of vasculitis). This patient was finally treated successfully with lenalidomide then mycophenolate mofetil. CONCLUSIONS In polyneuropathies associated to a monoclonal gammopathy, a nerve biopsy may clinch the diagnosis. Immuno-EM may be required to determine the role of the pathological immunoglobulin in the destruction of the peripheral nerve parenchyma. Diagnosis of such a direct involvement of peripheral nerve can endorse more aggressive treatment of real efficiency.
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Stecker M, Stevenson M. Effects of insulin on peripheral nerves. J Diabetes Complications 2016; 30:770-7. [PMID: 27134033 DOI: 10.1016/j.jdiacomp.2016.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 03/08/2016] [Accepted: 03/14/2016] [Indexed: 12/14/2022]
Abstract
AIMS To assess the effects of insulin on peripheral nerve under normoglycemic and hyperglycemic conditions in the presence and absence of anoxia. METHODS This study uses the in-vitro sciatic nerve model to assess the effect of insulin on peripheral nerve with the nerve action potential (NAP) as an index of nerve function. RESULTS Under normoglycemic conditions, low concentrations of regular insulin (0.01nM) reduced the conduction velocity of oxygenated nerves. Hyperglycemia increased the duration of the NAP and this increase was nearly completely eliminated by insulin in the 0.1nM-100nM concentration range. Insulin (1nM) also had effects on normoglycemic nerves exposed to intermittent anoxia, producing a decrease in the paired-pulse response and NAP amplitude and an increase in peak duration. This was associated with a reduced time to anoxia-induced conduction block. Similar effects were seen when regular insulin was replaced by insulin detemir, but the latter required much higher concentrations. CONCLUSIONS Insulin has concentration dependent effects on the peripheral nerve that are dependent on glucose and anoxia. These effects may be important in modulating neuropathic consequences of diabetes.
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McDonagh B, Scullion SM, Vasilaki A, Pollock N, McArdle A, Jackson MJ. Ageing-induced changes in the redox status of peripheral motor nerves imply an effect on redox signalling rather than oxidative damage. Free Radic Biol Med 2016; 94:27-35. [PMID: 26876649 PMCID: PMC4851218 DOI: 10.1016/j.freeradbiomed.2016.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/02/2016] [Accepted: 02/05/2016] [Indexed: 01/17/2023]
Abstract
Ageing is associated with loss of skeletal muscle fibres, atrophy of the remaining fibres and weakness. These changes in muscle are accompanied by disruption of motor neurons and neuromuscular junctions although the direct relationship between the nerve and muscle degeneration is not understood. Oxidative changes have been implicated in the mechanisms leading to age-related loss of muscle mass and in degeneration of the central nervous system, but little is known about age-related changes in oxidation in specific peripheral nerves that supply muscles that are affected by ageing. We have therefore examined the sciatic nerve of old mice at an age when loss of tibialis anterior muscle mass and function is apparent. Sciatic nerve from old mice did not show a gross increase in oxidative damage, but electron paramagnetic resonance (EPR) studies indicated an increase in the activity of superoxide and/or peroxynitrite in the nerves of old mice at rest that was further exacerbated by electrical stimulation of the nerve to activate muscle contractions. Proteomic analyses indicated that specific redox-sensitive proteins are increased in content in the nerves of old mice that may reflect an adaptation to regulate the increased superoxide/peroxynitrite and maintain redox homoeostasis. Analysis of redox active cysteines showed some increase in reversible oxidation in specific proteins in nerves of old mice, but this was not universally seen across all redox-active cysteines. Detailed analysis of the redox-active cysteine in one protein in the nerve of old mice that is key to redox signalling (Peroxiredoxin 6, Cys 47) showed a minor increase in reversible oxidation that would be compatible with a change in its redox signalling function. In conclusion, the data presented indicate that sciatic nerve from old mice does not show a gross increase in oxidative damage similar to that seen in the TA and other muscles that it innervates. Our results indicate an adaptation to increased oxidation with minor changes in the oxidation of key cysteines that may contribute to defective redox signalling in the nerve.
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Key Words
- cp, 3-carboxy-proxyl
- cph, 1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine
- nav1.5, voltage gated sodium channel isoform
- ncam, neural cell adhesion molecule
- nem, n-ethylmaleimide
- nmj, neuromuscular junction
- nox2, nad(p)h oxidase 2
- prdx, peroxiredoxin
- sod1, cuzn superoxide dismutase
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Liu L, Fissel JA, Tasnim A, Borzan J, Gocke A, Calabresi PA, Farah MH. Increased TNFR1 expression and signaling in injured peripheral nerves of mice with reduced BACE1 activity. Neurobiol Dis 2016; 93:21-7. [PMID: 27080468 DOI: 10.1016/j.nbd.2016.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/01/2016] [Accepted: 04/06/2016] [Indexed: 11/19/2022] Open
Abstract
Hematogenous macrophages remove myelin debris from injured peripheral nerves to provide a micro-environment conducive to axonal regeneration. Previously, we observed that injured peripheral nerves from Beta-site APP Cleaving Enzyme 1 (BACE1) knockout (KO) mice displayed earlier influx of and enhanced phagocytosis by macrophages when compared to wild-type (WT) mice. These observations suggest that BACE1 might regulate macrophage influx into distal stumps of injured nerves. To determine through which pathway BACE1 influences macrophage influx, we used a mouse inflammation antibody array to assay the expression of inflammation-related proteins in injured nerves of BACE1 KO and WT mice. The most significant change was in expression of tumor necrosis factor receptor 1 (TNFR1) in the distal stump of injured BACE1 KO nerves. Western blotting of protein extracts confirmed increased expression of TNFR1 and its downstream transcriptional factor NFκB in the BACE1 KO distal stumps. Additionally, treatment of WT mice with a BACE1 inhibitor resulted in increased TNFR1 expression and signaling in the distal stump of injured nerves. Exogenous TNFα increased nuclear translocation of p65 NFκB in BACE1 KO tissue and cultured fibroblasts compared with control WT. BACE1 regulates TNFR1 expression at the level of gene expression and not through proteolytic processing. The accelerated macrophage influx in injured nerves of BACE1 KO mice correlates with increased expression and signaling via TNFR1, indicating a link between BACE1 activity and TNFR1 expression/signaling that might contribute to repair of the injured nervous system.
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KAJIGAYA H, ISHIBASHI T, HAYASHI A, YAMAGUCHI Y, BABA H. Concentration of neddylation-related molecules in paranodal myelin of the peripheral nervous system. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:56-68. [PMID: 26860454 PMCID: PMC4906812 DOI: 10.2183/pjab.92.56] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/09/2015] [Indexed: 06/05/2023]
Abstract
Neddylation is a reversible post-translational modification in which a small ubiquitin-like molecule called NEDD8 covalently binds to substrate proteins. Although a recent study suggests that neddylation is essential for formation and maintenance of dendritic spines in the brain, the role of this protein modification in the peripheral nerves is wholly unknown. In this study, we demonstrate that neddylation-related molecules, NEDD8 and DCUN1D2 (defective in cullin neddylation 1, domain containing 2), were concentrated at the paranode of peripheral myelin, in addition to the myelinated and unmyelinated Schwann cell bodies. These proteins were localized mainly within larger fibers, but not in fibers with small diameters. Developmental analyses showed that these molecules first appeared at the paranode during later stages of myelination, and this characteristic distribution disappeared in sulfatide-deficient mice in which paranodal axo-glial junctions were disrupted. These results suggest that the myelin paranode may be one of the regions where neddylation occurs within the peripheral nerves.
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Østergaard L, Finnerup NB, Terkelsen AJ, Olesen RA, Drasbek KR, Knudsen L, Jespersen SN, Frystyk J, Charles M, Thomsen RW, Christiansen JS, Beck-Nielsen H, Jensen TS, Andersen H. The effects of capillary dysfunction on oxygen and glucose extraction in diabetic neuropathy. Diabetologia 2015; 58:666-77. [PMID: 25512003 PMCID: PMC4351434 DOI: 10.1007/s00125-014-3461-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/06/2014] [Indexed: 12/14/2022]
Abstract
Diabetic neuropathy is associated with disturbances in endoneurial metabolism and microvascular morphology, but the roles of these factors in the aetiopathogenesis of diabetic neuropathy remain unclear. Changes in endoneurial capillary morphology and vascular reactivity apparently predate the development of diabetic neuropathy in humans, and in manifest neuropathy, reductions in nerve conduction velocity correlate with the level of endoneurial hypoxia. The idea that microvascular changes cause diabetic neuropathy is contradicted, however, by reports of elevated endoneurial blood flow in early experimental diabetes, and of unaffected blood flow when early histological signs of neuropathy first develop in humans. We recently showed that disturbances in capillary flow patterns, so-called capillary dysfunction, can reduce the amount of oxygen and glucose that can be extracted by the tissue for a given blood flow. In fact, tissue blood flow must be adjusted to ensure sufficient oxygen extraction as capillary dysfunction becomes more severe, thereby changing the normal relationship between tissue oxygenation and blood flow. This review examines the evidence of capillary dysfunction in diabetic neuropathy, and whether the observed relation between endoneurial blood flow and nerve function is consistent with increasingly disturbed capillary flow patterns. The analysis suggests testable relations between capillary dysfunction, tissue hypoxia, aldose reductase activity, oxidative stress, tissue inflammation and glucose clearance from blood. We discuss the implications of these predictions in relation to the prevention and management of diabetic complications in type 1 and type 2 diabetes, and suggest ways of testing these hypotheses in experimental and clinical settings.
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73
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Yang CQ, Duan LP, Qiao PT, Zhao L, Guo LL. Increased VGLUT3 involved in visceral hyperalgesia in a rat model of irritable bowel syndrome. World J Gastroenterol 2015; 21:2959-2966. [PMID: 25780293 PMCID: PMC4356915 DOI: 10.3748/wjg.v21.i10.2959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/10/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the activity of vesicular glutamate transporter-3 (VGLUT3) in a visceral hyperalgesia rat model of irritable bowel syndrome, and the role of mast cells (MCs).
METHODS: Transient intestinal infection was induced by oral administration of Trichinella spiralis larvae in rats. On the 100th day post-infection (PI), the rats were divided into an acute cold restraint stress (ACRS) group and a non-stressed group. Age-matched untreated rats served as controls. The abdominal withdrawal reflex was used to measure the visceromotor response to colorectal distension (CRD). The expression levels of VGLUT3 in peripheral and central neurons were analyzed by immunofluorescence and western blotting.
RESULTS: VGLUT3 expression in the L6S1 dorsal root ganglion cells was significantly higher in the PI group than in the control group (0.32 ± 0.009 vs 0.22 ± 0.008, P < 0.01), and there was no significant difference in the expression of VGLUT3 between MC-deficient rats and their normal wild-type littermates. Immunofluorescence showed that the expression levels of VGLUT3 in PI + ACRS rats were enhanced in the prefrontal cortex of the brain compared with the control group.
CONCLUSION: VGLUT3 is involved in the pathogenesis of visceral hyperalgesia. Coexpression of c-fos, 5-hydroxytryptamine and VGLUT3 after CRD was observed in associated neuronal pathways. Increased VGLUT3 induced by transient intestinal infection was found in peripheral nerves, and was independent of MCs. Moreover, the expression of VGLUT3 was enhanced in the prefrontal cortex in rats with induced infection and stress.
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Osman AAM, Dahlin LB, Thomsen NOB, Mohseni S. Autophagy in the posterior interosseous nerve of patients with type 1 and type 2 diabetes mellitus: an ultrastructural study. Diabetologia 2015; 58:625-32. [PMID: 25523623 DOI: 10.1007/s00125-014-3477-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/27/2014] [Indexed: 11/30/2022]
Abstract
AIMS/HYPOTHESIS We addressed the question of whether the autophagy pathway occurs in human peripheral nerves and whether this pathway is associated with peripheral neuropathy in diabetes mellitus. METHODS By using electron microscopy, we evaluated the presence of autophagy-related structures and neuropathy in the posterior interosseous nerve of patients who had undergone carpal tunnel release and had type 1 or type 2 diabetes mellitus, and in patients with no diabetes (controls). RESULTS Autophagy-related ultrastructures were observed in the samples taken from all patients of the three groups. The number of autophagy-associated structures was significantly higher (p < 0.05) in the nerves of patients with type 1 than type 2 diabetes. Qualitative and quantitative evaluations of fascicle area, diameter of myelinated and unmyelinated nerve fibres, the density of myelinated and unmyelinated fibres and the g-ratio of myelinated fibres were performed. We found degeneration and regeneration of a few myelinated axons in controls, and a well-developed neuropathy with the loss of large myelinated axons and the presence of many small ones in patients with diabetes. The pathology in type 1 diabetes was more extensive than in type 2 diabetes. CONCLUSIONS/INTERPRETATION The results of this study show that the human peripheral nerves have access to the autophagy machinery, and this pathway may be regulated differently in type 1 and type 2 diabetes; insulin, presence of extensive neuropathy, and/or other factors such as duration of diabetes and HbA1c level may underlie this differential regulation.
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Clarke JR, Lyra E Silva NM, Figueiredo CP, Frozza RL, Ledo JH, Beckman D, Katashima CK, Razolli D, Carvalho BM, Frazão R, Silveira MA, Ribeiro FC, Bomfim TR, Neves FS, Klein WL, Medeiros R, LaFerla FM, Carvalheira JB, Saad MJ, Munoz DP, Velloso LA, Ferreira ST, De Felice FG. Alzheimer-associated Aβ oligomers impact the central nervous system to induce peripheral metabolic deregulation. EMBO Mol Med 2015; 7:190-210. [PMID: 25617315 PMCID: PMC4328648 DOI: 10.15252/emmm.201404183] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is associated with peripheral metabolic disorders. Clinical/epidemiological data indicate increased risk of diabetes in AD patients. Here, we show that intracerebroventricular infusion of AD-associated Aβ oligomers (AβOs) in mice triggered peripheral glucose intolerance, a phenomenon further verified in two transgenic mouse models of AD. Systemically injected AβOs failed to induce glucose intolerance, suggesting AβOs target brain regions involved in peripheral metabolic control. Accordingly, we show that AβOs affected hypothalamic neurons in culture, inducing eukaryotic translation initiation factor 2α phosphorylation (eIF2α-P). AβOs further induced eIF2α-P and activated pro-inflammatory IKKβ/NF-κB signaling in the hypothalamus of mice and macaques. AβOs failed to trigger peripheral glucose intolerance in tumor necrosis factor-α (TNF-α) receptor 1 knockout mice. Pharmacological inhibition of brain inflammation and endoplasmic reticulum stress prevented glucose intolerance in mice, indicating that AβOs act via a central route to affect peripheral glucose homeostasis. While the hypothalamus has been largely ignored in the AD field, our findings indicate that AβOs affect this brain region and reveal novel shared molecular mechanisms between hypothalamic dysfunction in metabolic disorders and AD.
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76
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Drummond PD, Dawson LF, Finch PM, Drummond ES, Wood FM, Fear MW. Up-regulation of cutaneous α1-adrenoceptors after a burn. Burns 2015; 41:1227-34. [PMID: 25630693 DOI: 10.1016/j.burns.2014.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 12/22/2014] [Accepted: 12/26/2014] [Indexed: 01/02/2023]
Abstract
Stimulation of α1-adrenoceptors evokes inflammatory cytokine production, boosts neurogenic inflammation and pain, and influences cellular migration and proliferation. As expression of α1-adrenoceptors increases on dermal nerves and keratinocytes after peripheral nerve injury, the aim of this study was to determine whether another form of tissue injury (a cutaneous burn) triggered a similar response. In particular, changes in expression of α1-adrenoceptors were investigated on dermal nerve fibres, keratinocytes and fibroblast-like cells using immunohistochemistry 2-12 weeks after a full thickness burn in Wistar rats. Within two weeks of the burn, local increases in α1-adrenoceptor expression were seen in the re-forming epidermis, in dense bands of spindle-shaped cells in the upper dermis (putatively infiltrating immune cells and fibroblasts), and on nerve fibres in the deep dermis. In addition, nerve fibre density increased approximately three-fold in the deep dermis, and this response persisted for several more weeks. In contrast, α1-adrenoceptor labelled cells and staining intensity in the upper dermis decreased contralateral to the burn, as did nerve fibre density in the deep dermis. These findings suggest that inflammatory mediators and/or growth factors at the site of a burn trigger the synthesis of α1-adrenoceptors on resident epidermal cells and nerve fibres, and an influx of α1-adrenoceptor labelled cells. The heightened expression of α1-adrenoceptors in injured tissue could shape inflammatory and wound healing responses.
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Jang SY, Shin YK, Park SY, Park JY, Rha SH, Kim JK, Lee HJ, Park HT. Autophagy is involved in the reduction of myelinating Schwann cell cytoplasm during myelin maturation of the peripheral nerve. PLoS One 2015; 10:e0116624. [PMID: 25581066 PMCID: PMC4291222 DOI: 10.1371/journal.pone.0116624] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 12/11/2014] [Indexed: 12/21/2022] Open
Abstract
Peripheral nerve myelination involves dynamic changes in Schwann cell morphology and membrane structure. Recent studies have demonstrated that autophagy regulates organelle biogenesis and plasma membrane dynamics. In the present study, we investigated the role of autophagy in the development and differentiation of myelinating Schwann cells during sciatic nerve myelination. Electron microscopy and biochemical assays have shown that Schwann cells remove excess cytoplasmic organelles during myelination through macroautophagy. Inhibition of autophagy via Schwann cell-specific removal of ATG7, an essential molecule for macroautophagy, using a conditional knockout strategy, resulted in abnormally enlarged abaxonal cytoplasm in myelinating Schwann cells that contained a large number of ribosomes and an atypically expanded endoplasmic reticulum. Small fiber hypermyelination and minor anomalous peripheral nerve functions are observed in this mutant. Rapamycin-induced suppression of mTOR activity during the early postnatal period enhanced not only autophagy but also developmental reduction of myelinating Schwann cells cytoplasm in vivo. Together, our findings suggest that autophagy is a regulatory mechanism of Schwann cells structural plasticity during myelination.
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Manole E, Ceafalan LC, Oproiu AM, Popa-Wagner A, Popescu BO. Claudin-1 and occludin expression in demyelinating peripheral neuropathies. ROMANIAN JOURNAL OF MORPHOLOGY AND EMBRYOLOGY = REVUE ROUMAINE DE MORPHOLOGIE ET EMBRYOLOGIE 2015; 56:1097-1102. [PMID: 26662145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the last years, only few studies focused on the role of tight junctions in human peripheral nerve. This type of junction is found between apposed membranes of myelinating Schwann cells, between perineurial cells and between endothelial cells (of the epi-, peri- and endo-neurium vessels). We investigated the presence of claudin-1 and occludin in peripheral nerve biopsy of patients with demyelinating peripheral neuropathies by immunolabeling (immunohistochemistry and immunofluorescence) and Western blot. Immunolabeling highlighted claudin-1 expression mostly in the tight junctions of the perineurial cells and in the autotypic junctions of the Schwann cells of the patients with demyelinating peripheral neuropathies. Occludin was mostly expressed in the tight junctions of perineurial cells and endothelial cells and only faintly in autotypic junctions of Schwann cells. The Western blot data showed significant differences in claudin-1 and occludin expression levels in patients with demyelinating peripheral neuropathies versus normal unaffected control. Our results show that autotypic tight junctions molecular composition, like claudin-1 and occludin expression could influence the demyelinating process by altering the permeability of the blood-nerve barrier.
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Zhao Q, Liang X, Han H. [Cannabinoid receptor 1 controls nerve growth in ectopic cyst in a rat endometriosis model]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 2014; 43:827-830. [PMID: 25623980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To investigate whether cannabinoid receptor 1 (CB1R) is involved in nerve growth in endometriosis-associated ectopic cyst. METHODS The effect of CB1R agonist and antagonist on the expression of pan-neuronal marker protein gene product (PGP) 9.5 in ectopic cyst was examined by immunofluorescence and Western blot in endometriosis model of 18 rats. RESULTS Immunofluorescence revealed that PGP 9.5 was expressed in the nerve fibers and was mainly distributed in the cyst hilum. Western blot revealed that the protein density of either PGP 9.5 (2 week: 0.38 ± 0.05; 4 week: 0.63 ± 0.03; 8 week: 0.80 ± 0.07, P < 0.01) or CB1R (2 week: 0.48 ± 0.04; 4 week: 0.68 ± 0.01; 8 week: 0.80 ± 0.03, P < 0.01) in the ectopic cyst increased with cyst size. In addition, compared to control group (0.75 ± 0.01), PGP 9.5 expression in the ectopic cyst was promoted by CB1R agonist ACPA (0.81 ± 0.01, P < 0.05), and inhibited by CB1R antagonist AM251 (0.67 ± 0.03, P < 0.01). CONCLUSIONS CB1R was involved in the nerve growth of ectopic cyst associated with endometriosis.
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Schuelert N, Just S, Kuelzer R, Corradini L, Gorham LCJ, Doods H. The somatostatin receptor 4 agonist J-2156 reduces mechanosensitivity of peripheral nerve afferents and spinal neurons in an inflammatory pain model. Eur J Pharmacol 2014; 746:274-81. [PMID: 25445035 DOI: 10.1016/j.ejphar.2014.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/04/2014] [Accepted: 11/04/2014] [Indexed: 11/19/2022]
Abstract
Somatostatin (SST) is a peptide hormone that regulates the endocrine system and affects neurotransmission via interaction with G protein-coupled SST receptors and inhibition of the release of different hormones. The aim of this study was to investigate whether the analgesic properties of the selective SSTR4 agonist J-2156 are mediated via peripheral and/or spinal receptors. Effect on mechanical hyperalgesia in the Complete Freund׳s Adjuvant (CFA) model was measured after intraperitoneal application of J-2156. Electrophysiological neuronal recordings were conducted 24 h after injection of CFA or vehicle into the paw of Wistar rats. Mechanosensitivity of peripheral afferents of the saphenous nerve as well as of spinal wide dynamic range (WDR) and nociceptive-specific (NS) neurons were measured after systemic or spinal application of J-2156. In CFA animals J-2156 dose dependently reduced hyperalgesia in behavioral studies. The minimal effective dose was 0.1 mg/kg. Mechanosensitivity of peripheral afferents and spinal neurons was significantly reduced by J-2156. NS neurons were dose dependently inhibited by J-2156 while in WDR neurons only the highest concentration of 100 µM had an effect. In sham controls, J-2156 had no effect on neuronal activity. We demonstrated that J-2156 dose-dependently reduces peripheral and spinal neuronal excitability in the CFA rat model without affecting physiological pain transmission. Given the high concentration of the compound required to inhibit spinal neurons, it is unlikely that the behavioral effect seen in CFA model is mediated centrally. Overall these data demonstrated that the analgesic effect of J-2156 is mediated mainly via peripheral SST4 receptors.
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MESH Headings
- Administration, Cutaneous
- Analgesics, Non-Narcotic/administration & dosage
- Analgesics, Non-Narcotic/blood
- Analgesics, Non-Narcotic/pharmacokinetics
- Analgesics, Non-Narcotic/therapeutic use
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/administration & dosage
- Anti-Inflammatory Agents, Non-Steroidal/blood
- Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Behavior, Animal/drug effects
- Butanes/administration & dosage
- Butanes/blood
- Butanes/pharmacokinetics
- Butanes/therapeutic use
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Electrophysiological Phenomena/drug effects
- Hyperalgesia/blood
- Hyperalgesia/drug therapy
- Hyperalgesia/immunology
- Hyperalgesia/metabolism
- Injections, Intraperitoneal
- Injections, Intravenous
- Male
- Mechanoreceptors/drug effects
- Mechanoreceptors/immunology
- Mechanoreceptors/metabolism
- Naphthalenes/administration & dosage
- Naphthalenes/blood
- Naphthalenes/pharmacokinetics
- Naphthalenes/therapeutic use
- Neuritis/blood
- Neuritis/drug therapy
- Neuritis/immunology
- Neuritis/metabolism
- Neurons, Afferent/drug effects
- Neurons, Afferent/immunology
- Neurons, Afferent/metabolism
- Nociceptors/drug effects
- Nociceptors/immunology
- Nociceptors/metabolism
- Peripheral Nerves/drug effects
- Peripheral Nerves/immunology
- Peripheral Nerves/metabolism
- Rats, Wistar
- Receptors, Somatostatin/agonists
- Receptors, Somatostatin/metabolism
- Spinal Nerves/drug effects
- Spinal Nerves/immunology
- Spinal Nerves/metabolism
- Sulfones/administration & dosage
- Sulfones/blood
- Sulfones/pharmacokinetics
- Sulfones/therapeutic use
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KleinJan GH, Buckle T, van Willigen DM, van Oosterom MN, Spa SJ, Kloosterboer HE, van Leeuwen FWB. Fluorescent lectins for local in vivo visualization of peripheral nerves. Molecules 2014; 19:9876-92. [PMID: 25006792 PMCID: PMC6271788 DOI: 10.3390/molecules19079876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/19/2014] [Accepted: 07/01/2014] [Indexed: 01/26/2023] Open
Abstract
Damage to peripheral nerves caused during a surgical intervention often results in function loss. Fluorescence imaging has the potential to improve intraoperative identification and preservation of these structures. However, only very few nerve targeting agents are available. This study describes the in vivo nerve staining capabilities of locally administered fluorescent lectin-analogues. To this end WGA, PNA, PHA-L and LEL were functionalized with Cy5 (λex max 640 nm; λem max 680 nm). Transfer of these imaging agents along the sciatic nerve was evaluated in Thy1-YFP mice (n = 12) after intramuscular injection. Migration from the injection site was assessed in vivo using a laboratory fluorescence scanner and ex vivo via fluorescence confocal microscopy. All four lectins showed retrograde movement and staining of the epineurium with a signal-to-muscle ratio of around two. On average, the longest transfer distance was obtained with WGA-Cy5 (0.95 cm). Since WGA also gave minimal uptake in the lymphatic system, this lectin type revealed the highest potential as a migration imaging agent to visualize nerves.
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Liu F, Ma F, Kong G, Wu K, Deng Z, Wang H. Zinc supplementation alleviates diabetic peripheral neuropathy by inhibiting oxidative stress and upregulating metallothionein in peripheral nerves of diabetic rats. Biol Trace Elem Res 2014; 158:211-8. [PMID: 24615552 DOI: 10.1007/s12011-014-9923-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/18/2014] [Indexed: 02/05/2023]
Abstract
We investigated the effect of zinc supplementation on the expression of metallothionein, lipid peroxidation (malondialdehyde, MDA), and poly(ADP-ribose) polymerase-1 (PARP-1) in the sciatic nerve, motor nerve conduction velocity of the left sciatic posterior tibial nerve in streptozotocin (STZ)-induced diabetic rats. Twenty-four male rats were equally divided into four groups. The first group served as untreated controls although the second group received 5 mg/kg/day zinc chloride. The third group was treated with STZ to induce diabetes, and the fourth group was treated with STZ and supplemented with zinc. A gradual but insignificant decline in motor nerve conduction velocity was observed at 2 weeks of induction of diabetes. Zinc supplementation markedly attenuated the decrease in motor nerve conduction velocity at week 8 post-induction of diabetes. Furthermore, the tactile response threshold of diabetic rats receiving normal saline was lower than that of diabetic rats receiving zinc supplementation. Additionally, zinc supplementation accentuated the increase in the mRNA transcript levels of metallothionein but attenuated the increase in the mRNA transcript levels of PARP-1. At week 8 post-induction of diabetes, diabetic rats receiving normal saline had markedly higher MDA contents than diabetic rats receiving zinc supplementation. In conclusion, the present study shows that zinc has a protective effect against diabetes-induced peripheral nerve damage by stimulating metallothionein synthesis and downregulating oxidative stress.
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83
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Scanlon P, Tian J, Zhong J, Silva I, Shapiro R, Pavlick A, Berman R, Osman I, Darvishian F. Enhanced immunohistochemical detection of neural infiltration in primary melanoma: is there a clinical value? Hum Pathol 2014; 45:1656-63. [PMID: 24890944 DOI: 10.1016/j.humpath.2014.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/27/2014] [Accepted: 04/02/2014] [Indexed: 11/17/2022]
Abstract
Neural infiltration in primary melanoma is a histopathologic feature that has been associated with desmoplastic histopathologic subtype and local recurrence in the literature. We tested the hypothesis that improved detection and characterization of neural infiltration into peritumoral or intratumoral location and perineural or intraneural involvement could have a prognostic relevance. We studied 128 primary melanoma cases prospectively accrued and followed at New York University using immunohistochemical detection with antihuman neurofilament protein and routine histology with hematoxylin and eosin. Neural infiltration, defined as the presence of tumor cells involving or immediately surrounding nerve foci, was identified and characterized using both detection methods. Neural infiltration rate of detection was enhanced by immunohistochemistry for neurofilament in matched-pair design (47% by immunohistochemistry versus 25% by routine histology). Immunohistochemical detection of neural infiltration was significantly associated with ulceration (P = .021), desmoplastic and acral lentiginous histologic subtype (P = .008), and head/neck/hands/feet tumor location (P = .037). Routinely detected neural infiltration was significantly associated with local recurrence (P = .010). Immunohistochemistry detected more intratumoral neural infiltration cases compared with routine histology (30% versus 3%, respectively). Peritumoral and intratumoral nerve location had no impact on clinical outcomes. Using a multivariate model controlling for stage, neither routinely detected neural infiltration nor enhanced immunohistochemical characterization of neural infiltration was significantly associated with disease-free or overall survival. Our data demonstrate that routinely detected neural infiltration is associated with local recurrence in all histologic subtypes but that improved detection and characterization of neural infiltration with immunohistochemistry in primary melanoma does not add to prognostic relevance.
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84
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Yuan F, Yosef N, Lakshmana Reddy C, Huang A, Chiang SC, Tithi HR, Ubogu EE. CCR2 gene deletion and pharmacologic blockade ameliorate a severe murine experimental autoimmune neuritis model of Guillain-Barré syndrome. PLoS One 2014; 9:e90463. [PMID: 24632828 PMCID: PMC3954548 DOI: 10.1371/journal.pone.0090463] [Citation(s) in RCA: 26] [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: 11/07/2013] [Accepted: 02/03/2014] [Indexed: 01/13/2023] Open
Abstract
The molecular determinants and signaling pathways responsible for hematogenous leukocyte trafficking during peripheral neuroinflammation are incompletely elucidated. Chemokine ligand/receptor pair CCL2/CCR2 has been pathogenically implicated in the acute inflammatory demyelinating polyradiculoneuropathy variant of Guillain-Barré syndrome (GBS). We evaluated the role of CCR2 in peripheral neuroinflammation utilizing a severe murine experimental autoimmune neuritis (sm-EAN) model. Sm-EAN was induced in 8-12 week old female SJL CCR2 knockout (CCR2KO), heterozygote (CCR2HT) and wild type (CCR2WT) mice, and daily neuromuscular severity scores and weights recorded. In vitro and in vivo splenocyte proliferation and cytokine expression assays, and sciatic nerve Toll-like receptor (TLR) 2, TLR4 and CCL2 expression assays were performed to evaluate systemic and local innate immune activation at disease onset. Motor nerve electrophysiology and sciatic nerve histology were also performed to characterize the inflammatory neuropathy at expected peak severity. To further determine the functional relevance of CCR2 in sm-EAN, 20 mg/kg CCR2 antagonist, RS 102895 was administered daily for 5 days to a cohort of CCR2WT mice following sm-EAN disease onset, with efficacy compared to 400 mg/kg human intravenous immunoglobulin (IVIg). CCR2KO mice were relatively resistant to sm-EAN compared to CCR2WT and CCR2HT mice, associated with attenuated peripheral nerve demyelinating neuritis. Partial CCR2 gene deletion did not confer any protection against sm-EAN. CCR2KO mice demonstrated similar splenocyte activation or proliferation profiles, as well as TLR2, TLR4 and CCL2 expression to CCR2WT or CCR2HT mice, implying a direct role for CCR2 in sm-EAN pathogenesis. CCR2 signaling blockade resulted in rapid, near complete recovery from sm-EAN following disease onset. RS 102895 was significantly more efficacious than IVIg. CCR2 mediates pathogenic hematogenous monocyte trafficking into peripheral nerves, with consequential demyelination in sm-EAN. CCR2 is amenable to pharmacologic blockade, making it a plausible drug target for GBS.
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85
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Shul'ga AE, Norkin IA, Ninel' VG, Puchin'ian DM, Zaretskov VV, Korshunova GA, Ostrovskiĭ VV, Smol'kin AA. [Modern aspects of pathogenesis of the trauma of the spinal cord and trunks of peripheral nerves]. ROSSIISKII FIZIOLOGICHESKII ZHURNAL IMENI I.M. SECHENOVA 2014; 100:145-160. [PMID: 25470893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In pathogenesis of the traumatic disease of the spinal cord, two mechanisms of the injuries of its neuronal apparatus are defined: primary (necrosis) and secondary (apoptosis). In the work a participation of a number of internal causes in the progression of apoptosis in injury of the spinal cord and peripheral nerve trunks, the role of those remains little-studied up to date, is discussed.
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86
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Gusel'nikova VV, Sukhorukova EG, Fedorova EA, Polevshchikov AV, Korzhevskiĭ DÉ. [Method for simultaneous visualization of mast cells and nerve terminals in the rodent thymus]. MORFOLOGIIA (SAINT PETERSBURG, RUSSIA) 2014; 145:70-73. [PMID: 25282830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The purpose of this study was to develop the method for the simultaneous visualization of mast cells (MCs) and nerve terminals, based on generally accepted techniques of histochemical identification of MCs with alcian blue and immunohistochemical detection of synaptophysin. The protocol presented allows simultaneous identification of mast cells and nerve terminals in the sections of paraffin-embedded thymus of laboratory mammals with high selectivity and good reproducibility. The method can be used for both visualization of spatial relationship between MCs and nerve terminals and independent research of the innervation of mammalian internal organs. Zinc-ethanol-formaldehyde is recommended as an optimal fixative.
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87
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Ghosh A, Kling T, Snaidero N, Sampaio JL, Shevchenko A, Gras H, Geurten B, Göpfert MC, Schulz JB, Voigt A, Simons M. A global in vivo Drosophila RNAi screen identifies a key role of ceramide phosphoethanolamine for glial ensheathment of axons. PLoS Genet 2013; 9:e1003980. [PMID: 24348263 PMCID: PMC3861124 DOI: 10.1371/journal.pgen.1003980] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/12/2013] [Indexed: 01/08/2023] Open
Abstract
Glia are of vital importance for all complex nervous system. One of the many functions of glia is to insulate and provide trophic and metabolic support to axons. Here, using glial-specific RNAi knockdown in Drosophila, we silenced 6930 conserved genes in adult flies to identify essential genes and pathways. Among our screening hits, metabolic processes were highly represented, and genes involved in carbohydrate and lipid metabolic pathways appeared to be essential in glia. One critical pathway identified was de novo ceramide synthesis. Glial knockdown of lace, a subunit of the serine palmitoyltransferase associated with hereditary sensory and autonomic neuropathies in humans, resulted in ensheathment defects of peripheral nerves in Drosophila. A genetic dissection study combined with shotgun high-resolution mass spectrometry of lipids showed that levels of ceramide phosphoethanolamine are crucial for axonal ensheathment by glia. A detailed morphological and functional analysis demonstrated that the depletion of ceramide phosphoethanolamine resulted in axonal defasciculation, slowed spike propagation, and failure of wrapping glia to enwrap peripheral axons. Supplementing sphingosine into the diet rescued the neuropathy in flies. Thus, our RNAi study in Drosophila identifies a key role of ceramide phosphoethanolamine in wrapping of axons by glia.
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88
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Glenn TD, Talbot WS. Signals regulating myelination in peripheral nerves and the Schwann cell response to injury. Curr Opin Neurobiol 2013; 23:1041-8. [PMID: 23896313 PMCID: PMC3830599 DOI: 10.1016/j.conb.2013.06.010] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 06/20/2013] [Accepted: 06/27/2013] [Indexed: 11/23/2022]
Abstract
In peripheral nerves, Schwann cells form myelin, which facilitates the rapid conduction of action potentials along axons in the vertebrate nervous system. Myelinating Schwann cells are derived from neural crest progenitors in a step-wise process that is regulated by extracellular signals and transcription factors. In addition to forming the myelin sheath, Schwann cells orchestrate much of the regenerative response that occurs after injury to peripheral nerves. In response to injury, myelinating Schwann cells dedifferentiate into repair cells that are essential for axonal regeneration, and then redifferentiate into myelinating Schwann cells to restore nerve function. Although this remarkable plasticity has long been recognized, many questions remain unanswered regarding the signaling pathways regulating both myelination and the Schwann cell response to injury.
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89
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Gao X, Wang Y, Chen J, Peng J. The role of peripheral nerve ECM components in the tissue engineering nerve construction. Rev Neurosci 2013; 24:443-53. [PMID: 23907421 DOI: 10.1515/revneuro-2013-0022] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 07/05/2013] [Indexed: 11/15/2022]
Abstract
The extracellular matrix (ECM) is the naturally occurring substrate that provides a support structure and an attachment site for cells. It also produces a biological signal, which plays an important role in and has significant impact on cell adhesion, migration, proliferation, differentiation, and gene expression. Peripheral nerve repair is a complicated process involving Schwann cell proliferation and migration, 'bands of Büngner' formation, and newborn nerve extension. In the ECM of peripheral nerves, macromolecules are deposited among cells; these constitute the microenvironment of Schwann cell growth. Such macromolecules include collagen (I, III, IV, V), laminin, fibronectin, chondroitin sulfate proteoglycans (CSPGs), and other nerve factors. Collagen, the main component of ECM, provides structural support and guides newborn neurofilament extension. Laminin, fibronectin, CSPGs, and neurotrophic factors, are promoters or inhibitors, playing different roles in nerve repair after injury. By a chemical decellularization process, acellular nerve allografting eliminates the antigens responsible for allograft rejection and maintains most of the ECM components, which can effectively guide and enhance nerve regeneration. Thus, the composition and features of peripheral nerve ECM suggest its superiority as nerve repair material. This review focuses on the structure, function, and application in the tissue engineering nerve construction of the peripheral nerve ECM components.
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90
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Ortiz FC, Vergara C, Alcayaga J. Micromolar copper modifies electrical properties and spontaneous discharges of nodose ganglion neurons in vitro. Biometals 2013; 27:45-52. [PMID: 24213945 DOI: 10.1007/s10534-013-9685-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/04/2013] [Indexed: 11/25/2022]
Abstract
Copper plays a key role in aerobic cell physiology mainly related to mitochondrial metabolism. This element is also present at higher than basal levels in some central nuclei and indeed, current evidence support copper's role as a neuromodulator in the central nervous system. More recent data indicate that copper may also affect peripheral neuronal activity, but so far, there are not detailed descriptions of what peripheral neuronal characteristics are targeted by copper. Here, we studied the effect of physiological concentration of CuCl2 (μM range) on the activity of peripheral neurons using a preparation of nodose ganglion in vitro. By mean of conventional intracellular recordings passive and active electrical membrane properties were studied. Extracellular copper modified (in a redox-independent manner) the resting membrane potential and the input resistance of the nodose ganglion neurons, increasing the excitability in most of the tested neurons. These results suggest that Cu(2+) modulates the activity of nodose ganglion neurons and support nodose ganglion in vitro preparation as a simple model to study the subcellular mechanisms involved in the Cu(2+) effects on neuron electrical properties.
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91
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Cama A, Verginelli F, Lotti LV, Napolitano F, Morgano A, D’Orazio A, Vacca M, Perconti S, Pepe F, Romani F, Vitullo F, di Lella F, Visone R, Mannelli M, Neumann HPH, Raiconi G, Paties C, Moschetta A, Tagliaferri R, Veronese A, Sanna M, Mariani-Costantini R. Integrative genetic, epigenetic and pathological analysis of paraganglioma reveals complex dysregulation of NOTCH signaling. Acta Neuropathol 2013; 126:575-94. [PMID: 23955600 PMCID: PMC3789891 DOI: 10.1007/s00401-013-1165-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 08/02/2013] [Indexed: 02/06/2023]
Abstract
Head and neck paragangliomas, rare neoplasms of the paraganglia composed of nests of neurosecretory and glial cells embedded in vascular stroma, provide a remarkable example of organoid tumor architecture. To identify genes and pathways commonly deregulated in head and neck paraganglioma, we integrated high-density genome-wide copy number variation (CNV) analysis with microRNA and immunomorphological studies. Gene-centric CNV analysis of 24 cases identified a list of 104 genes most significantly targeted by tumor-associated alterations. The "NOTCH signaling pathway" was the most significantly enriched term in the list (P = 0.002 after Bonferroni or Benjamini correction). Expression of the relevant NOTCH pathway proteins in sustentacular (glial), chief (neuroendocrine) and endothelial cells was confirmed by immunohistochemistry in 47 head and neck paraganglioma cases. There were no relationships between level and pattern of NOTCH1/JAG2 protein expression and germline mutation status in the SDH genes, implicated in paraganglioma predisposition, or the presence/absence of immunostaining for SDHB, a surrogate marker of SDH mutations. Interestingly, NOTCH upregulation was observed also in cases with no evidence of CNVs at NOTCH signaling genes, suggesting altered epigenetic modulation of this pathway. To address this issue we performed microarray-based microRNA expression analyses. Notably 5 microRNAs (miR-200a,b,c and miR-34b,c), including those most downregulated in the tumors, correlated to NOTCH signaling and directly targeted NOTCH1 in in vitro experiments using SH-SY5Y neuroblastoma cells. Furthermore, lentiviral transduction of miR-200s and miR-34s in patient-derived primary tympano-jugular paraganglioma cell cultures was associated with NOTCH1 downregulation and increased levels of markers of cell toxicity and cell death. Taken together, our results provide an integrated view of common molecular alterations associated with head and neck paraganglioma and reveal an essential role of NOTCH pathway deregulation in this tumor type.
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92
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KRAJNAK KM, WAUGH S, JOHNSON C, MILLER GR, XU X, WARREN C, DONG RG. The effects of impact vibration on peripheral blood vessels and nerves. INDUSTRIAL HEALTH 2013; 51:572-80. [PMID: 24077447 PMCID: PMC4202742 DOI: 10.2486/indhealth.2012-0193] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Accepted: 07/30/2013] [Indexed: 05/03/2023]
Abstract
Research regarding the risk of developing hand-arm vibration syndrome after exposure to impact vibration has produced conflicting results. This study used an established animal model of vibration-induced dysfunction to determine how exposure to impact vibration affects peripheral blood vessels and nerves. The tails of male rats were exposed to a single bout of impact vibration (15 min exposure, at a dominant frequency of 30 Hz and an unweighted acceleration of approximately 345 m/s(2)) generated by a riveting hammer. Responsiveness of the ventral tail artery to adrenoreceptor-mediated vasoconstriction and acetylcholine-mediated re-dilation was measured ex vivo. Ventral tail nerves and nerve endings in the skin were assessed using morphological and immunohistochemical techniques. Impact vibration did not alter vascular responsiveness to any factors or affect trunk nerves. However, 4 days following exposure there was an increase in protein-gene product (PGP) 9.5 staining around hair follicles. A single exposure to impact vibration, with the exposure characteristics described above, affects peripheral nerves but not blood vessels.
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93
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Castañón MJ, Walko G, Winter L, Wiche G. Plectin-intermediate filament partnership in skin, skeletal muscle, and peripheral nerve. Histochem Cell Biol 2013; 140:33-53. [PMID: 23748243 PMCID: PMC3695321 DOI: 10.1007/s00418-013-1102-0] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2013] [Indexed: 01/13/2023]
Abstract
Plectin is a large, 500-kDa, intermediate filament (IF)-associated protein. It acts as a cytoskeletal crosslinker and signaling scaffold, affecting mechanical as well as dynamic properties of the cytoskeleton. As a member of the plakin family of cytolinker proteins, plectin has a multidomain structure that is responsible for its vast binding portfolio. It not only binds to all types of IFs, actin filaments and microtubules, but also to transmembrane receptors, proteins of the subplasma membrane protein skeleton, components of the nuclear envelope, and several kinases with known roles in migration, proliferation, and energy metabolism of cells. Due to alternative splicing, plectin is expressed as various isoforms with differing N-terminal heads that dictate their differential subcellular targeting. Through specific interactions with other proteins at their target sites and their ability to bind to all types of IFs, plectin molecules provide strategically located IF anchorage sites within the cytoplasm of cells. In this review, we will present an overview of the structural features and functional properties of plectin and discuss recent progress in defining the role of its isoforms in stress-prone tissues and the implicated diseases, with focus on skin, skeletal muscle, and Schwann cells of peripheral nerve.
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94
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Canclini L, Wallrabe H, Di Paolo A, Kun A, Calliari A, Sotelo-Silveira JR, Sotelo JR. Association of Myosin Va and Schwann cells-derived RNA in mammal myelinated axons, analyzed by immunocytochemistry and confocal FRET microscopy. Methods 2013; 66:153-61. [PMID: 23791767 DOI: 10.1016/j.ymeth.2013.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/06/2013] [Accepted: 06/10/2013] [Indexed: 11/19/2022] Open
Abstract
Evidence from multiple sources supports the hypothesis that Schwann cells in the peripheral nervous system transfer messenger RNA and ribosomes to the axons they ensheath. Several technical and methodological difficulties exist for investigators to unravel this process in myelinated axons - a complex two-cell unit. We present an experimental design to demonstrate that newly synthesized RNA is transferred from Schwann cells to axons in association with Myosin Va. The use of quantitative confocal FRET microscopy to track newly-synthesized RNA and determine the molecular association with Myosin Va, is described in detail.
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95
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Guerreiro LTA, Robottom-Ferreira AB, Ribeiro-Alves M, Toledo-Pinto TG, Rosa Brito T, Rosa PS, Sandoval FG, Jardim MR, Antunes SG, Shannon EJ, Sarno EN, Pessolani MCV, Williams DL, Moraes MO. Gene expression profiling specifies chemokine, mitochondrial and lipid metabolism signatures in leprosy. PLoS One 2013; 8:e64748. [PMID: 23798993 PMCID: PMC3683049 DOI: 10.1371/journal.pone.0064748] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 04/16/2013] [Indexed: 11/18/2022] Open
Abstract
Herein, we performed microarray experiments in Schwann cells infected with live M. leprae and identified novel differentially expressed genes (DEG) in M. leprae infected cells. Also, we selected candidate genes associated or implicated with leprosy in genetic studies and biological experiments. Forty-seven genes were selected for validation in two independent types of samples by multiplex qPCR. First, an in vitro model using THP-1 cells was infected with live Mycobacterium leprae and M. bovis bacillus Calmette-Guérin (BCG). In a second situation, mRNA obtained from nerve biopsies from patients with leprosy or other peripheral neuropathies was tested. We detected DEGs that discriminate M. bovis BCG from M. leprae infection. Specific signatures of susceptible responses after M. leprae infection when compared to BCG lead to repression of genes, including CCL2, CCL3, IL8 and SOD2. The same 47-gene set was screened in nerve biopsies, which corroborated the down-regulation of CCL2 and CCL3 in leprosy, but also evidenced the down-regulation of genes involved in mitochondrial metabolism, and the up-regulation of genes involved in lipid metabolism and ubiquitination. Finally, a gene expression signature from DEG was identified in patients confirmed of having leprosy. A classification tree was able to ascertain 80% of the cases as leprosy or non-leprous peripheral neuropathy based on the expression of only LDLR and CCL4. A general immune and mitochondrial hypo-responsive state occurs in response to M. leprae infection. Also, the most important genes and pathways have been highlighted providing new tools for early diagnosis and treatment of leprosy.
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96
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Stettner M, Wolffram K, Mausberg AK, Albrecht P, Derksen A, Methner A, Dehmel T, Hartung HP, Dietrich H, Kieseier BC. Promoting myelination in an in vitro mouse model of the peripheral nervous system: the effect of wine ingredients [corrected]. PLoS One 2013; 8:e66079. [PMID: 23762469 PMCID: PMC3676361 DOI: 10.1371/journal.pone.0066079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 05/01/2013] [Indexed: 12/11/2022] Open
Abstract
Protective properties of moderate wine consumption against cancers, cardiovascular, metabolic and degenerative diseases have been reported in various clinical studies. Here, we analysed the effect of red wine (RW) and white wine (WW) on myelination using an in vitro embryonic co-culture mouse model. The total amount of myelin was found to be significantly increased after RW and WW treatment, while only RW significantly increased the number of internodes. Both types of wine increased rat Schwann cell- (rSC) expression of the NAD+-dependent deacetylase sirtuin-two-homolog 2 (Sirt2), a protein known to be involved in myelination. Detailed chemical analysis of RW revealed a broad spectrum of anthocyanins, piceids, and phenolics, including resveratrol (RSV). In our assay system RSV in low concentrations induced myelination. Furthermore RSV raised intracellular glutathione concentrations in rSCs and in co-cultures and therefore augmented antioxidant capacity. We conclude that wine promotes myelination in a rodent in vitro model by controlling intracellular metabolism and SC plasticity. During this process, RSV exhibits protective properties; however, the fostering effect on myelinaton during exposure to wine appears to be a complex interaction of various compounds.
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97
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Zhang Z, Tublitz NJ. Expression of the SOFaRP2 gene in the central nervous system of the adult cuttlefish Sepia officinalis. Neuropeptides 2013; 47:149-55. [PMID: 23465584 DOI: 10.1016/j.npep.2013.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 01/19/2013] [Accepted: 01/29/2013] [Indexed: 11/28/2022]
Abstract
FMRFamide-related Peptides (FaRPs) are involved in a variety of physiological processes, including reproduction, feeding, development, body patterning and osmoregulation in vertebrates and invertebrates. Here we investigate the expression pattern of cuttlefish Sepia officinalis FaRP2 gene in the brain by in situ hybridization. The SOFaRP2 gene was found to be expressed most intensively in the posterior chromatophore lobe, vasomotor lobe and subvertical lobe. In addition, positive staining was also found in the fin lobe, brachial lobe, anterior chromatophore lobe, anterior, dorsal and lateral basal lobes, inferior and superior frontal lobes, and optic lobe. The expression pattern of SOFaRP2 suggests its involvement in chromatophore regulation, feeding behavior, and learning and memory.
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98
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King R, Ginsberg L. The nerve biopsy: indications, technical aspects, and contribution. HANDBOOK OF CLINICAL NEUROLOGY 2013; 115:155-170. [PMID: 23931779 DOI: 10.1016/b978-0-444-52902-2.00009-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This chapter discusses the indications for biopsying a peripheral nerve and the factors involved in justifying this decision and then deciding which nerve to take. There is a table summarizing some of the causes of neuropathy and attempting to relate these to the probability that nerve biopsy would be helpful in diagnosis. The surgical procedure for the nerve biopsy is described including aftercare and possible complications. The techniques involved in processing and staining the nerve are discussed. This section includes the possibilities of creating artefactual damage by mishandling or poor technique, and how to avoid these. Modification to the standard resin processing schedule to allow the teasing out of individual nerve fibers is briefly described, as are methods for measuring fiber density, fiber size and myelin thickness. There is also a brief discussion of the applications of immunohistochemistry. This is followed by a section on interpretation by light and electron microscopy in which some of the more important diagnostic features are described and illustrated, as are nonspecific morphological findings. Interpretation of teased fiber preparations is discussed. Finally, some common causes of incorrect interpretation are mentioned.
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Cao X, Liu XM, Zhou LH. Recent progress in research on the distribution and function of NUCB2/nesfatin-1 in peripheral tissues. Endocr J 2013; 60:1021-7. [PMID: 23955480 DOI: 10.1507/endocrj.ej13-0236] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nesfatin-1 is a polypeptide derived from the posttranslational processing of the N-terminal fragment of nucleobindin 2 (NUCB2), that was originally identified as an anorexigenic hypothalamic neuropeptide. A number of reports have recently shown that NUCB2/nesfatin-1 is widely expressed in various peripheral tissues, including those of the gastrointestinal tract where it may participate in various pathophysiological processes. One of its roles may be regulation of energy homeostasis. As a result, nesfatin-1 may be a novel target for exploring the underlying mechanisms and the treatment of metabolic syndromes.
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100
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Klimaschewski L, Hausott B, Angelov DN. The pros and cons of growth factors and cytokines in peripheral axon regeneration. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 108:137-71. [PMID: 24083434 DOI: 10.1016/b978-0-12-410499-0.00006-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Injury to a peripheral nerve induces a complex cellular and molecular response required for successful axon regeneration. Proliferating Schwann cells organize into chains of cells bridging the lesion site, which is invaded by macrophages. Approximately half of the injured neuron population sends out axons that enter the glial guidance channels in response to secreted neurotrophic factors and neuropoietic cytokines. These lesion-associated polypeptides create an environment that is highly supportive for axon regrowth, particularly after acute injury, and ensure that the vast majority of regenerating axons are directed toward the distal nerve stump. Unfortunately, most neurotrophic factors and neuropoietic cytokines are also strong stimulators of axonal sprouting. Although some of the axonal branches will withdraw at later stages, the sprouting effect contributes to the misdirection of reinnervation that results in the lack of functional recovery observed in many patients with peripheral nerve injuries. Here, we critically review the role of neuronal growth factors and cytokines during axon regeneration in the peripheral nervous system. Their differential effects on axon elongation and sprouting were elucidated in various studies on intraneuronal signaling mechanisms following nerve lesion. The present data define a goal for future therapeutic strategies, namely, to selectively stimulate a Ras/Raf/ERK-mediated axon elongation program over an intrinsic PI3K-dependent axonal sprouting program in lesioned motor and sensory neurons. Instead of modulating growth factor or cytokine levels at the lesion site, targeting specific intraneuronal molecules, such as the negative feedback inhibitors of ERK signaling, has been shown to promote long-distance regeneration while avoiding sprouting of regenerating axons until they have reached their target areas.
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