Displaying publications 1 - 20 of 22 in total

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  1. Different pathological processes for acute white matter lesions in multiple sclerosis
    Alturkustani M, Bahakeem B, Zhang Q, Ang LC
    Malays J Pathol, 2020 Aug;42(2):187-194.
    PMID: 32860370
    INTRODUCTION: Multiple sclerosis (MS) has variable clinical presentations, prognoses, pathogeneses, and pathological patterns. We conducted a pathological review of acute MS-associated lesions that focused on the degree of axonal injury, myelin loss, and glial reaction to determine whether the observed demyelination was of the primary or secondary type.

    MATERIALS AND METHODS: After searching the records for a 15-year period at the London Health Sciences Centre Pathology Department, we identified 8 cases of surgical acute lesion biopsies in which clinical MS diagnoses were made before or after the biopsy.

    RESULTS: The white matter pathologies in these cases could be sorted into 3 morphological patterns. The first pattern, which represents typical demyelinated plaques, was observed in 4 cases and was characterised by nearly complete demyelination accompanied by variable degrees of axon preservation and axonal swelling. The second pattern was observed in 3 cases and was characterised by demyelinating lesions containing variable numbers of myelinated axons mixed with a few demyelinated axons and variable numbers of axonal swellings. The myelinated axons ranged from scattered fibres to bands of variable thickness, and the demyelination was a mixture of primary and secondary demyelination. The third pattern was observed in 1 case and was characterised by well-demarcated areas of reduced myelin staining and numerous apoptotic nuclei. Axonal staining revealed many fragmented axons with reduced myelin staining but no definitely demyelinated axons.

    CONCLUSIONS: This report shows that the predominant pathology underlying acute MS-related lesions is not limited to demyelination but can include axonal degeneration alone or in combination with primary demyelination which reflect different pathogenesis for these acute lesions.

    Matched MeSH terms: Axons/pathology
  2. Drug trapping and delivery for Alzheimer's diagnosis
    Jalil MA, Kamoldilok S, Saktioto T, Ong CT, Yupapin PP
    Artif Cells Blood Substit Immobil Biotechnol, 2012 Oct;40(5):303-8.
    PMID: 22384850 DOI: 10.3109/10731199.2012.657203
    In this investigation, a new design based on a PANDA ring resonator as an optical trapping tool for tangle protein, molecular motor storage, and delivery is proposed. The optical vortices are generated and the trapping mechanism is controlled in the same way as the conventional optical tweezers. The trapping force is produced by a combination of the gradient field and scattering photons. The required molecular volume is trapped and moved dynamically within the molecular network. The tangle protein and molecular motor can be transported and delivered to the required destinations for Alzheimer's diagnosis by molecular buffer and bus network.
    Matched MeSH terms: Axons/metabolism*; Axons/chemistry
  3. Fulltext Ancient Schwannoma Of The Facial Nerve: An Unusual Histological Variant Of A Rare Disease
    Baharudin, A., Din Suhaimi, S., Omar, E.
    International Medical Journal Malaysia, 2006;5(2):1-4.
    MyJurnal
    Schwannomas are benign slow growing lesions arising from the Schwann cells that ensheath the axons of the peripheral, cranial and autonomic nervous systems. Intracranial schwannomas develop from the facial nerve much more rarely than from the vestibular or trigeminal nerves. Ancient schwannoma is an unusual histological variant of this rare disease. A 48 years old man who had recurrent facial nerve paralysis and right external auditory mass is presented in this case report.
    Matched MeSH terms: Axons
  4. Association between apoptotic neural tissue and cell proliferation in the adult teleost brain
    Lim FT, Ogawa S, Parhar IS
    Brain Res, 2016 11 01;1650:60-72.
    PMID: 27568467 DOI: 10.1016/j.brainres.2016.08.033
    Injury to neuronal tissues in the central nervous system (CNS) of mammals results in neural degeneration and sometime leads to loss of function, whereas fish retain a remarkable potential for neuro-regeneration throughout life. Thus, understanding the mechanism of neuro-regeneration in fish CNS would be useful to improve the poor neuro-regenerative capability in mammals. In the present study, we characterized a neuro-regenerative process in the brain of a cichlid, tilapia, Oreochromis niloticus. Morphological observations showed that the damaged brain region (habenula) successfully regrew and reinnervated axonal projections by 60 days post-damage. A fluorescent carbocyanine tracer, DiI tracing revealed a recovery of the major neuronal projection from the regenerated habenula to the interpenduncular nucleus by 60 days post-damage. TUNEL assay showed a significant increase of apoptotic cells (~234%, P<0.01) at one day post-damage, while the number of bromodeoxyuridine (BrdU)-positive proliferative cells were significantly increased (~92%, P<0.05) at 7 days post-damage compared with sham-control fish. To demonstrate a potential role of apoptotic activity in the neuro-regeneration, effects of degenerative neural tissue on cell proliferation were examined in vivo. Implantation of detached neural but not non-neural tissues into the cranial cavity significantly (P<0.01) increased the number of BrdU-positive cells nearby the implantation regions at 3 days after the implantation. Furthermore, local injection of the protein extract and cerebrospinal fluid collected from injured fish brain significantly induced cell proliferation in the brain. These results suggest that factor(s) derived from apoptotic neural cells may play a critical role in the neuro-regeneration in teleost brain.
    Matched MeSH terms: Axons/metabolism
  5. Direction of commissural axon projections in different regions of the spinal cord during chicken embryonic development
    Li H, Yang C, Yusoff NM, Yahaya BH, Lin J
    Neuroscience, 2017 09 01;358:269-276.
    PMID: 28687312 DOI: 10.1016/j.neuroscience.2017.06.053
    Few researchers have investigated the direction of commissural axon projections on the contralateral side of the vertebrate embryonic spinal cord, especially for comparison between its different regions. In this study, pCAGGS-GFP plasmid expression was limited to different regions of the chicken embryonic spinal cord (cervical, anterior limb, anterior thorax, posterior thorax and posterior limb) at E3 using in ovo electroporation with modified electrodes and optimal electroporation conditions. Then open-book technique was performed at E6 to analyze the direction of axon projections in different spinal cord regions. The results show that in the five investigated regions, most axons projected rostrally after crossing the floor plate while a minority projected caudally. And there was a significant difference between the rostral and caudal projection quantities (P<0.01). The ratio of rostral and caudal projections was significantly different between the five investigated regions (P<0.05), except between the cervical region and the anterior limb (P>0.05). The projections were most likely to be rostral for the posterior limb followed by the posterior thorax, cervical region, anterior limb and anterior thorax. Our data for the direction of the commissural axon projections will be helpful in the future analyses of axon projection mechanisms and spinal cord-brain circuit formation.
    Matched MeSH terms: Axons/physiology*
  6. N-cadherin regulates beta-catenin signal and its misexpression perturbs commissural axon projection in the developing chicken spinal cord
    Yang C, Li X, Wang C, Fu S, Li H, Guo Z, et al.
    J Mol Histol, 2016 Dec;47(6):541-554.
    PMID: 27650519
    N-cadherin is a calcium-sensitive cell adhesion molecule that plays an important role in the formation of the neural circuit and the development of the nervous system. In the present study, we investigated the function of N-cadherin in cell-cell connection in vitro with HEK293T cells, and in commissural axon projections in the developing chicken spinal cord using in ovo electroporation. Cell-cell connections increased with N-cadherin overexpression in HEK293T cells, while cell contacts disappeared after co-transfection with an N-cadherin-shRNA plasmid. The knockdown of N-cadherin caused the accumulation of β-catenin in the nucleus, supporting the notion that N-cadherin regulates β-catenin signaling in vitro. Furthermore, N-cadherin misexpression perturbed commissural axon projections in the spinal cord. The overexpression of N-cadherin reduced the number of axons that projected alongside the contralateral margin of the floor plate, and formed intermediate longitudinal commissural axons. In contrast, the knockdown of N-cadherin perturbed commissural axon projections significantly, affecting the projections alongside the contralateral margin of the floor plate, but did not affect intermediate longitudinal commissural axons. Taken together, these findings suggest that N-cadherin regulates commissural axon projections in the developing chicken spinal cord.
    Matched MeSH terms: Axons/metabolism*
  7. Fulltext Curve interpolation model for visualising disjointed neural elements
    Rahim MS, Razzali N, Sunar MS, Altameem A, Rehman A
    Neural Regen Res, 2012 Jul 25;7(21):1637-44.
    PMID: 25657704 DOI: 10.3969/j.issn.1673-5374.2012.21.006
    Neuron cell are built from a myriad of axon and dendrite structures. It transmits electrochemical signals between the brain and the nervous system. Three-dimensional visualization of neuron structure could help to facilitate deeper understanding of neuron and its models. An accurate neuron model could aid understanding of brain's functionalities, diagnosis and knowledge of entire nervous system. Existing neuron models have been found to be defective in the aspect of realism. Whereas in the actual biological neuron, there is continuous growth as the soma extending to the axon and the dendrite; but, the current neuron visualization models present it as disjointed segments that has greatly mediated effective realism. In this research, a new reconstruction model comprising of the Bounding Cylinder, Curve Interpolation and Gouraud Shading is proposed to visualize neuron model in order to improve realism. The reconstructed model is used to design algorithms for generating neuron branching from neuron SWC data. The Bounding Cylinder and Curve Interpolation methods are used to improve the connected segments of the neuron model using a series of cascaded cylinders along the neuron's connection path. Three control points are proposed between two adjacent neuron segments. Finally, the model is rendered with Gouraud Shading for smoothening of the model surface. This produce a near-perfection model of the natural neurons with attended realism. The model is validated by a group of bioinformatics analysts' responses to a predefined survey. The result shows about 82% acceptance and satisfaction rate.
    Matched MeSH terms: Axons
  8. Fulltext Major cellular events in peripheral nerve regeneration: A brief overview
    Naidu, M., David, P.
    International Medical Journal Malaysia, 2009;8(1):61-64.
    MyJurnal
    Injury to a peripheral nerve leads to degeneration of the segment distal to the site of lesion, a process referred to as Wallerian degeneration. During Wallerian degeneration, axons and myelin sheaths undergo degeneration and are phagocytosed by macrophages and Schwann cells. The Schwann cells proliferate and the endoneurial tubes persist, together the whole structure is known as the band of Büngner. Within few hours, the damaged axons in the proximal stump initiate a regeneration response, with formation of new growth cones. During Wallerian degeneration, neurotrophins, neural cell adhesion molecules, cytokines and other soluble factors are upregulated to facilitate regeneration. The recovery of the target in mammals is often variable, but almost never complete. In humans, scar tissue forms at the site of lesion and this often results in poor recovery of the target. The major events underlying this regenerative process is highlighted and discussed in this review.
    Matched MeSH terms: Axons
  9. Fulltext Sodium phenylbutyrate inhibits Schwann cell inflammation via HDAC and NFκB to promote axonal regeneration and remyelination
    Yadav A, Huang TC, Chen SH, Ramasamy TS, Hsueh YY, Lin SP, et al.
    J Neuroinflammation, 2021 Oct 16;18(1):238.
    PMID: 34656124 DOI: 10.1186/s12974-021-02273-1
    BACKGROUND: Epigenetic regulation by histone deacetylases (HDACs) in Schwann cells (SCs) after injury facilitates them to undergo de- and redifferentiation processes necessary to support various stages of nerve repair. Although de-differentiation activates the synthesis and secretion of inflammatory cytokines by SCs to initiate an immune response during nerve repair, changes in either the timing or duration of prolonged inflammation mediated by SCs can affect later processes associated with repair and regeneration. Limited studies have investigated the regulatory processes through which HDACs in SCs control inflammatory cytokines to provide a favorable environment for peripheral nerve regeneration.

    METHODS: We employed the HDAC inhibitor (HDACi) sodium phenylbutyrate (PBA) to address this question in an in vitro RT4 SC inflammation model and an in vivo sciatic nerve transection injury model to examine the effects of HDAC inhibition on the expression of pro-inflammatory cytokines. Furthermore, we assessed the outcomes of suppression of extended inflammation on the regenerative potential of nerves by assessing axonal regeneration, remyelination, and reinnervation.

    RESULTS: Significant reductions in lipopolysaccharide (LPS)-induced pro-inflammatory cytokine (tumor necrosis factor-α [TNFα]) expression and secretion were observed in vitro following PBA treatment. PBA treatment also affected the transient changes in nuclear factor κB (NFκB)-p65 phosphorylation and translocation in response to LPS induction in RT4 SCs. Similarly, PBA mediated long-term suppressive effects on HDAC3 expression and activity. PBA administration resulted in marked inhibition of pro-inflammatory cytokine secretion at the site of transection injury when compared with that in the hydrogel control group at 6-week post-injury. A conducive microenvironment for axonal regrowth and remyelination was generated by increasing expression levels of protein gene product 9.5 (PGP9.5) and myelin basic protein (MBP) in regenerating nerve tissues. PBA administration increased the relative gastrocnemius muscle weight percentage and maintained the intactness of muscle bundles when compared with those in the hydrogel control group.

    CONCLUSIONS: Suppressing the lengthened state of inflammation using PBA treatment favors axonal regrowth and remyelination following nerve transection injury. PBA treatment also regulates pro-inflammatory cytokine expression by inhibiting the transcriptional activation of NFκB-p65 and HDAC3 in SCs in vitro.

    Matched MeSH terms: Axons/drug effects; Axons/metabolism*; Axons/pathology
  10. Fulltext The role of cells, neurotrophins, extracellular matrix and cell surface molecules in peripheral nerve regeneration
    Naidu M
    Malays J Med Sci, 2009 Apr;16(2):10-4.
    PMID: 22589652 MyJurnal
    Wallerian degeneration is a complicated process whereby axons and myelin sheaths undergo degeneration, and eventually are phagocytosed by macrophages and Schwann cells following nerve damage. Schwann cells proliferate and the endoneural tubes persist. In addition, neurotrophins, neural cell adhesion molecules, cytokines and other soluble factors are upregulated to facilitate regeneration. The important role of cellular components, neurotrophins, and extracellular matrix components, including cell surface molecules involved in this regenerative process, is highlighted and discussed in this review.
    Matched MeSH terms: Axons
  11. Neurogenic plasticity of mesenchymal stem cell, an alluring cellular replacement for traumatic brain injury
    Pati S, Muthuraju S, Hadi RA, Huat TJ, Singh S, Maletic-Savatic M, et al.
    Curr Stem Cell Res Ther, 2016;11(2):149-57.
    PMID: 26763886
    Traumatic brain injury (TBI) imposes horrendous neurophysiological alterations leading to most devastating forms of neuro-disability. Which includes impaired cognition, distorted locomotors activity and psychosomatic disability in both youths and adults. Emerging evidence from recent studies has identified mesenchymal stem cells (MSCs) as one of the promising category of stem cells having excellent neuroregenerative capability in TBI victims. Some of the clinical and animal studies reported that MSCs transplantation could cure neuronal damage as well as improve cognitive and locomotors behaviors in TBI. However, mechanism behind their broad spectrum neuroregenerative potential in TBI has not been reviewed yet. Therefore, in the present article, we present a comprehensive data on the important attributes of MSCs, such as neurotransdifferentiation, neuroprotection, axonal repair and plasticity, maintenance of blood-brain integrity, reduction of reactive oxygen species (ROS) and immunomodulation. We have reviewed in detail the crucial neurogenic capabilities of MSCs in vivo and provided consolidated knowledge regarding their cellular remodeling in TBI for future therapeutic implications.
    Matched MeSH terms: Axons/pathology
  12. Evaluation of peripapillary retinal nerve fiber layer thickness in myopic eyes by spectral-domain optical coherence tomography
    Mohammad Salih PA
    J Glaucoma, 2012 Jan;21(1):41-4.
    PMID: 21173707 DOI: 10.1097/IJG.0b013e3181fc8053
    To investigate the influence of myopia on peripapillary retinal nerve fiber layer (RNFL) thickness using Cirrus optical coherence tomography (OCT) in normal eyes.
    Matched MeSH terms: Axons/pathology*
  13. Ischemic optic neuropathy as a model of neurodegenerative disorder: A review of pathogenic mechanism of axonal degeneration and the role of neuroprotection
    Khalilpour S, Latifi S, Behnammanesh G, Majid AM, Majid AS, Tamayol A
    J Neurol Sci, 2017 Apr 15;375:430-441.
    PMID: 28320183 DOI: 10.1016/j.jns.2016.12.044
    Optic neuropathy is a neurodegenerative disease which involves optic nerve injury. It is caused by acute or intermittent insults leading to visual dysfunction. There are number of factors, responsible for optic neuropathy, and the optic nerve axon is affected in all type which causes the loss of retinal ganglion cells. In this review we will highlight various mechanisms involved in the cell loss cascades during axonal degeneration as well as ischemic optic neuropathy. These mechanisms include oxidative stress, excitotoxicity, angiogenesis, neuroinflammation and apoptosis following retinal ischemia. We will also discuss the effect of neuroprotective agents in attenuation of the negative effect of factors involve in the disease occurrence and progression.
    Matched MeSH terms: Axons/pathology
  14. Fulltext Effect of sonic hedgehog on motor neuron positioning in the spinal cord during chicken embryonic development
    Yang C, Li S, Li X, Li H, Li Y, Zhang C, et al.
    J Cell Mol Med, 2019 05;23(5):3549-3562.
    PMID: 30834718 DOI: 10.1111/jcmm.14254
    Sonic hedgehog (SHH) is a vertebrate homologue of the secreted Drosophila protein hedgehog and is expressed by the notochord and floor plate in the developing spinal cord. Sonic hedgehog provides signals relevant for positional information, cell proliferation and possibly cell survival, depending on the time and location of expression. Although the role of SHH in providing positional information in the neural tube has been experimentally proven, the underlying mechanism remains unclear. In this study, in ovo electroporation was employed in the chicken spinal cord during chicken embryo development. Electroporation was conducted at stage 17 (E2.5), after electroporation the embryos were continued incubating to stage 28 (E6) for sampling, tissue fixation with 4% paraformaldehyde and frozen sectioning. Sonic hedgehog and related protein expressions were detected by in situ hybridization and fluorescence immunohistochemistry and the results were analysed after microphotography. Our results indicate that the ectopic expression of SHH leads to ventralization in the spinal cord during chicken embryonic development by inducing abnormalities in the structure of the motor column and motor neuron integration. In addition, ectopic SHH expression inhibits the expression of dorsal transcription factors and commissural axon projections. The correct location of SHH expression is vital to the formation of the motor column. Ectopic expression of SHH in the spinal cord not only affects the positioning of motor neurons, but also induces abnormalities in the structure of the motor column. It leads to ventralization in the spinal cord, resulting in the formation of more ventral neurons forming during neuronal formation.
    Matched MeSH terms: Axons/metabolism
  15. Bickerstaff brainstem encephalitis and Fisher syndrome: anti-GQ1b antibody syndrome
    Shahrizaila N, Yuki N
    J Neurol Neurosurg Psychiatry, 2013 May;84(5):576-83.
    PMID: 22984203 DOI: 10.1136/jnnp-2012-302824
    In the 1950s, Bickerstaff and Fisher independently described cases with a unique presentation of ophthalmoplegia and ataxia. The neurological features were typically preceded by an antecedent infection and the majority of patients made a spontaneous recovery. In the cases with Bickerstaff brainstem encephalitis, there was associated altered consciousness and in some, hyperreflexia, in support of a central pathology whereas in Fisher syndrome, patients were areflexic in keeping with a peripheral aetiology. However, both authors recognised certain similarities to Guillain-Barré syndrome such as the presence of peripheral neuropathy and cerebrospinal fluid albuminocytological dissociation. The discovery of immunoglobulin G anti-GQ1b antibodies in patients with Fisher syndrome and later in Bickerstaff brainstem encephalitis was crucial in providing the necessary evidence to conclude that both conditions were in fact part of the same spectrum of disease by virtue of their common clinical and immunological profiles. Following this, other neurological presentations that share anti-GQ1b antibodies emerged in the literature. These include acute ophthalmoparesis and acute ataxic neuropathy, which represent the less extensive spectrum of the disease whereas pharyngeal-cervical-brachial weakness and Fisher syndrome overlap with Guillain-Barré syndrome represent the more extensive end of the spectrum. The conditions can be referred to as the 'anti-GQ1b antibody syndrome'. In this review, we look back at the historical descriptions and describe how our understanding of Fisher syndrome and Bickerstaff brainstem encephalitis has evolved from their initial descriptions more than half a century ago.
    Matched MeSH terms: Axons/pathology
  16. Efficacy of Human Cell-Seeded Muscle-Stuffed Vein Conduit in Rat Sciatic Nerve Repair
    Ramli K, Gasim AI, Ahmad AA, Htwe O, Mohamed Haflah NH, Law ZK, et al.
    Tissue Eng Part A, 2019 10;25(19-20):1438-1455.
    PMID: 30848172 DOI: 10.1089/ten.TEA.2018.0279
    We investigated the efficacy of a muscle-stuffed vein (MSV) seeded with neural-transdifferentiated human mesenchymal stem cells as an alternative nerve conduit to repair a 15-mm sciatic nerve defect in athymic rats. Other rats received MSV conduit alone, commercial polyglycolic acid conduit (Neurotube®), reverse autograft, or were left untreated. Motor and sensory functions as well as nerve conductivity were evaluated for 12 weeks, after which the grafts were harvested for histological analyses. All rats in the treatment groups demonstrated a progressive increase in the mean Sciatic Functional Index (motor function) and nerve conduction amplitude (electrophysiological function) and showed positive withdrawal reflex (sensory function) by the 10th week of postimplantation. Autotomy, which is associated with neuropathic pain, was severe in rats treated with conduit without cells; there was mild or no autotomy in the rats of other groups. Histologically, harvested grafts from all except the untreated groups exhibited axonal regeneration with the presence of mature myelinated axons. In conclusion, treatment with MSV conduit is comparable to that of other treatment groups in supporting functional recovery following sciatic nerve injury; and the addition of cells in the conduit alleviates neuropathic pain. Impact Statement It is shown that pretreated muscle-stuffed vein conduit is comparable to that of commercial nerve conduit and autograft in supporting functional recovery following peripheral nerve injury. The addition of neural-differentiated mesenchymal stem cells in the conduit is shown to alleviate neuropathic pain.
    Matched MeSH terms: Axons/metabolism
  17. The Two-Brains Hypothesis: Towards a guide for brain-brain and brain-machine interfaces
    Goodman G, Poznanski RR, Cacha L, Bercovich D
    J Integr Neurosci, 2015 Sep;14(3):281-93.
    PMID: 26477360 DOI: 10.1142/S0219635215500235
    Great advances have been made in signaling information on brain activity in individuals, or passing between an individual and a computer or robot. These include recording of natural activity using implants under the scalp or by external means or the reverse feeding of such data into the brain. In one recent example, noninvasive transcranial magnetic stimulation (TMS) allowed feeding of digitalized information into the central nervous system (CNS). Thus, noninvasive electroencephalography (EEG) recordings of motor signals at the scalp, representing specific motor intention of hand moving in individual humans, were fed as repetitive transcranial magnetic stimulation (rTMS) at a maximum intensity of 2.0[Formula: see text]T through a circular magnetic coil placed flush on each of the heads of subjects present at a different location. The TMS was said to induce an electric current influencing axons of the motor cortex causing the intended hand movement: the first example of the transfer of motor intention and its expression, between the brains of two remote humans. However, to date the mechanisms involved, not least that relating to the participation of magnetic induction, remain unclear. In general, in animal biology, magnetic fields are usually the poor relation of neuronal current: generally "unseen" and if apparent, disregarded or just given a nod. Niels Bohr searched for a biological parallel to complementary phenomena of physics. Pertinently, the two-brains hypothesis (TBH) proposed recently that advanced animals, especially man, have two brains i.e., the animal CNS evolved as two fundamentally different though interdependent, complementary organs: one electro-ionic (tangible, known and accessible), and the other, electromagnetic (intangible and difficult to access) - a stable, structured and functional 3D compendium of variously induced interacting electro-magnetic (EM) fields. Research on the CNS in health and disease progresses including that on brain-brain, brain-computer and brain-robot engineering. As they grow even closer, these disciplines involve their own unique complexities, including direction by the laws of inductive physics. So the novel TBH hypothesis has wide fundamental implications, including those related to TMS. These require rethinking and renewed research engaging the fully complementary equivalence of mutual magnetic and electric field induction in the CNS and, within this context, a new mathematics of the brain to decipher higher cognitive operations not possible with current brain-brain and brain-machine interfaces. Bohr may now rest.
    Matched MeSH terms: Axons
  18. Fulltext Centella asiatica (L.)-Neurodifferentiated Mesenchymal Stem Cells Promote the Regeneration of Peripheral Nerve
    Hussin HM, Lawi MM, Haflah NHM, Kassim AYM, Idrus RBH, Lokanathan Y
    Tissue Eng Regen Med, 2020 04;17(2):237-251.
    PMID: 32036567 DOI: 10.1007/s13770-019-00235-6
    BACKGROUND: Centella asiatica (L.) is a plant with neuroprotective and neuroregenerative properties; however, its effects on the neurodifferentiation of mesenchymal stem cells (MSCs) and on peripheral nerve injury are poorly explored. This study aimed to investigate the effects of C. asiatica (L.)-neurodifferentiated MSCs on the regeneration of peripheral nerve in a critical-size defect animal model.

    METHODS: Nerve conduit was developed using decellularised artery seeded with C. asiatica-neurodifferentiated MSCs (ndMSCs). A 1.5 cm sciatic nerve injury in Sprague-Dawley rat was bridged with reversed autograft (RA) (n = 3, the gold standard treatment), MSC-seeded conduit (MC) (n = 4) or ndMSC-seeded conduit (NC) (n = 4). Pinch test and nerve conduction study were performed every 2 weeks for a total of 12 weeks. At the 12th week, the conduits were examined by histology and transmission electron microscopy.

    RESULTS: NC implantation improved the rats' sensory sensitivity in a similar manner to RA. At the 12th week, nerve conduction velocity was the highest in NC compared with that of RA and MC. Axonal regeneration was enhanced in NC and RA as shown by the expression of myelin basic protein (MBP). The average number of myelinated axons was significantly higher in NC than in MC but significantly lower than in RA. The myelin sheath thickness was higher in NC than in MC but lower than in RA.

    CONCLUSION: NC showed promising effects on nerve regeneration and functional restoration similar to those of RA. These findings revealed the neuroregenerative properties of C. asiatica and its potential as an alternative strategy for the treatment of critical size nerve defect.

    Matched MeSH terms: Axons
  19. Fulltext Melatonin promotes Schwann cell dedifferentiation and proliferation through the Ras/Raf/ERK and MAPK pathways, and glial cell-derived neurotrophic factor expression
    Tiong YL, Ng KY, Koh RY, Ponnudurai G, Chye SM
    Exp Ther Med, 2020 Nov;20(5):16.
    PMID: 32934681 DOI: 10.3892/etm.2020.9143
    Upon peripheral nerve injury (PNI), continuous proliferation of Schwann cells is critical for axon regeneration and tubular reconstruction for nerve regeneration. Melatonin is a hormone that is able to induce proliferation in various cell types. In the present study, the effects of melatonin on promoting Schwann cell proliferation and the molecular mechanism involved were investigated. The present results showed that melatonin enhanced the melatonin receptors (MT1 and MT2) expression in Schwann cells. Melatonin induced Schwann cell dedifferentiation into progenitor-like Schwann cells, as observed by immunofluorescence staining, which showed Sox2 marker expression. In addition, melatonin enhanced Schwann cell proliferation, mediated by the upregulation of glial cell-derived neurotropic factor (GNDF) and protein kinase C (PKC). Furthermore, the Ras/Raf/ERK and MAPK signaling pathways were also involved in Schwann cell dedifferentiation and proliferation. In conclusion, melatonin induced Schwann cell dedifferentiation and proliferation via the Ras/Raf/ERK, MAPK and GDNF/PKC pathways. The present results suggested that melatonin could be used to enhance the recovery of PNI.
    Matched MeSH terms: Axons
  20. Fulltext The Changes in Rats with Sciatic Nerve Crush Injury Supplemented with Evening Primrose Oil: Behavioural, Morphologic, and Morphometric Analysis
    Ramli D, Aziz I, Mohamad M, Abdulahi D, Sanusi J
    Evid Based Complement Alternat Med, 2017;2017:3476407.
    PMID: 28620418 DOI: 10.1155/2017/3476407
    Nerve crush injuries are commonly used models for axonotmesis to examine peripheral nerve regeneration. As evening primrose oil (EPO) is rich in omega-6 essential fatty acid component and gamma-linolenic acid, studies have shown the potential role of EPO in myelination. Seventy-two healthy adult Sprague-Dawley rats were classified into three groups: normal group, control group, and experimental group. The result indicates that there was significant difference in toe-spreading reflex between the normal and the control groups (1.9 ± 0.031, p < 0.05) and the normal and the EPO groups (0.4 ± 0.031, p < 0.05) and significant difference between EPO and the control groups (1.5 ± 0.031, p < 0.05). Regeneration of axons and myelin in nerve fibre in the EPO-treated group developed better and faster than in the control group. In the control group, the shape of the axon was irregular with a thinner myelin sheath. In the experimental group, the shape of the axons, the thickness of the myelin sheath, and the diameter of the axons were almost the same as in the normal group. In conclusion, EPO supplementation may be beneficial as a therapeutic option for disturbances of nerve interaction.
    Matched MeSH terms: Axons
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