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    15 February 2019, Volume 14 Issue 2 Previous Issue    Next Issue
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    Amyotrophic lateral sclerosis as a synaptopathy
    Matthew J. Fogarty
    2019, 14 (2):  189-192.  doi: 10.4103/1673-5374.244782
    Abstract ( 115 )   PDF (343KB) ( 729 )   Save

    The synapse is an incredibly specialized structure that allows for the coordinated communication of information from one neuron to another. When assembled into circuits, steady streams of excitatory and inhibitory synaptic activity shape neural outputs. At the organismal level, ensembles of neural networks underlie behavior, emotion and memory. Disorder or dysfunctions of synapses, a synaptopathy, may underlie a host of developmental and degenerative neurological conditions. There is a possibility that amyotrophic lateral sclerosis may be a result of a synaptopathy within the neuromotor system. To this end, particular attention has been trained on the excitatory glutamatergic synapses and their morphological proxy, the dendritic spine. The extensive detailing of these dysfunctions in vulnerable neuronal populations, including corticospinal neurons and motor neurons, has recently been the subject of original research in rodents and humans. If amyotrophic lateral sclerosis is indeed a synaptopathy, it is entirely consistent with other proposed pathogenic mechanisms – including glutamate excitotoxicity, accumulation of misfolded proteins and mitochondrial dysfunction at distal axon terminals (cortico-motor neuron and neuromuscular). Further, although the exact mechanism of disease spread from region to region is unknown, the synaptopathy hypothesis is consistent with emerging die-forward evidence and the prion-like propagation of misfolded protein aggregates to distant neuronal populations. Here in this mini-review, we focus on the timeline of synaptic observations in both cortical and spinal neurons from different rodent models, and provide a conceptual framework for assessing the synaptopathy hypothesis in amyotrophic lateral sclerosis.

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    Amyotrophic lateral sclerosis: a complex syndrome that needs an integrated research approach
    Javier Riancho,Francisco J. Gil-Bea, Ana Santurtun, Adolfo López de Munaín
    2019, 14 (2):  193-196.  doi: 10.4103/1673-5374.244783
    Abstract ( 107 )   PDF (447KB) ( 153 )   Save

    Amyotrophic lateral sclerosis, the most common neurodegenerative disease affecting motor neurons, lacks an effective treatment. A small fraction of amyotrophic lateral sclerosis cases have a familial origin, related to mutations in causative genes, while the vast majority of amyotrophic lateral sclerosis cases are considered to be sporadic, resulting from the interaction between genes and environmental factors in predisposed individuals. During the past few years, dozens of drugs have been postulated as promising strategies for the disease after showing some beneficial effects in preclinical cellular and murine models. However, the translation into clinical practice has been largely unsuccessful and the compounds failed when were tested in clinical trials. This might be explained, at least partially, by the enormous complexity of the disease both from clinico-epidemiological and a pathogenic points of view. In this review, we will briefly comment on the complexity of the disease focusing on some recent findings, and we will suggest how amyotrophic lateral sclerosis research might be reoriented to foster the advance in the diagnostic and therapeutic questions.

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    Evidences on neuroprotective properties of coenzyme Q10 in the treatment of glaucom
    Alessio Martucci, Carlo Nucci
    2019, 14 (2):  197-200.  doi: 10.4103/1673-5374.244781
    Abstract ( 266 )   PDF (328KB) ( 928 )   Save

    Glaucoma, the leading cause of visual impairment and irreversible blindness worldwide, is a multifactorial, progressive optic neuropathy characterized by loss of retinal ganglion cells, alterations of the optic nerve head, and specific visual field defects. Clinical evidence shows that intraocular pressure is the major risk factor of the treatable disease. However, in some patients, glaucoma develops and continues to progress despite normal intraocular pressure values, suggesting that other risk factors are involved in the disease. Consequently, neuroprotective treatments, focused on preventing retinal ganglion cells death by acting on different therapeutic strategies but not focused on intraocular pressure reduction, has therefore become of great interest. In this contest, coenzyme Q10, showing evidences in slowing or reversing pathological changes typical of the disease, has been proposed as a potential neuroprotective agent in glaucoma. In this review, we describe the possible mechanisms of action of coenzyme Q10 and the recent evidence in literature regarding the neuroprotective activity of the molecule.

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    Neural plasticity and adult neurogenesis: the deep biology perspective
    Anna Maria Colangelo, Giovanni Cirillo, Lilia Alberghina, Michele Papa, Hans V. Westerhoff
    2019, 14 (2):  201-205.  doi: 10.4103/1673-5374.244775
    Abstract ( 113 )   PDF (277KB) ( 238 )   Save

    The recognition that neurogenesis does not stop with adolescence has spun off research towards the reduction of brain disorders by enhancing brain regeneration. Adult neurogenesis is one of the tougher problems of developmental biology as it requires the generation of complex intracellular and pericellular anatomies, amidst the danger of neuroinflammation. We here review how a multitude of regulatory pathways optimized for early neurogenesis has to be revamped into a new choreography of time dependencies. Distinct pathways need to be regulated, ranging from neural growth factor induced differentiation to mitochondrial bioenergetics, reactive oxygen metabolism, and apoptosis. Requiring much Gibbs energy consumption, brain depends on aerobic energy metabolism, hence on mitochondrial activity. Mitochondrial fission and fusion, movement and perhaps even mitoptosis, thereby come into play. All these network processes are interlinked and involve a plethora of molecules. We recommend a deep thinking approach to adult neurobiology.

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    Contactins in the central nervous system: role in health and disease
    Madhurima Chatterjee, Detlev Schild, Charlotte E. Teunissen
    2019, 14 (2):  206-216.  doi: 10.4103/1673-5374.244776
    Abstract ( 132 )   PDF (627KB) ( 162 )   Save

    Contactins are a group of cell adhesion molecules that are mainly expressed in the brain and play pivotal roles in the organization of axonal domains, axonal guidance, neuritogenesis, neuronal development, synapse formation and plasticity, axo-glia interactions and neural regeneration. Contactins comprise a family of six members. Their absence leads to malformed axons and impaired nerve conduction. Contactin mediated protein complex formation is critical for the organization of the axon in early central nervous system development. Mutations and differential expression of contactins have been identified in neuro-developmental or neurological disorders. Taken together, contactins are extensively studied in the context of nervous system development. This review summarizes the physiological roles of all six members of the Contactin family in neurodevelopment as well as their involvement in neurological/neurodevelopmental disorders.

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    A paracrine role for white thermogenic adipocytes in innervation: an evidence-based hypothesis
    Aejin Lee, Ouliana Ziouzenkova
    2019, 14 (2):  217-221.  doi: 10.4103/1673-5374.244777
    Abstract ( 110 )   PDF (1191KB) ( 245 )   Save

    White adipose tissue (WAT) stores energy and also plays an important endocrine role in producing adipokines for communication with the peripheral and central nervous system. WAT consists of the major lipogenic unilocular adipocytes and the minor populations of beige and brite multilocular adipocytes. These multilocular adipocytes express thermogenic genes and have phenotypic similarity with thermogenic brown adipose tissue. According to a current paradigm, multilocular adipocytes have a thermogenic function in WAT. In this mini review, we discuss data revealing heterogeneity among multilocular cell subsets in WAT and their functions beyond thermogenesis. We propose a hypothetical neuroendocrine role for multilocular adipocytes subsets in the formation of adaptive sensory-sympathetic circuits between the central nervous system and adipose tissue, which activate lipolysis and thermogenesis in WAT in high energy demand situations.

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    Investigating neurogenic bowel in experimental spinal cord injury: where to begin?
    Amanda R. White,Gregory M. Holmes
    2019, 14 (2):  222-226.  doi: 10.4103/1673-5374.244779
    Abstract ( 102 )   PDF (475KB) ( 176 )   Save

    The devastating losses following traumatic spinal cord injury (SCI) encompass the motor, sensory and autonomic nervous systems. Neurogenic bowel is a slow transit colonic dysfunction marked by constipation, rectal evacuation difficulties, decreased anorectal sensation, fecal incontinence or some combination thereof. Furthermore, neurogenic bowel is one of the most prevalent comorbidities of SCI and is recognized by afflicted individuals and caregivers as a lifelong physical and psychological challenge that profoundly affects quality of life. The restoration of post-injury control of movement has received considerable scientific scrutiny yet the daily necessity of voiding the bowel and bladder remains critically under-investigated. Subsequently, physicians and caregivers are rarely presented with consistent, evidence-based strategies to successfully address the consequences of dysregulated voiding reflexes. Neurogenic bowel is commonly believed to result from the interruption of the supraspinal control of the spinal autonomic circuits regulating the colon. In this mini-review, we discuss the clinical challenges presented by neurogenic bowel and emerging pre-clinical evidence that is revealing that SCI also initiates functional remodeling of the colonic wall concurrent with a decrease in local enteric neurons. Since the enteric input to the colonic smooth muscle is the final common pathway for functional contractions of the colon, changes to the neuromuscular interface must first be understood in order to maximize the efficacy of therapeutic interventions targeting colonic dysfunction following SCI.

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    Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury
    Yana O. Mukhamedshina, Olga A. Gracheva, Dina M. Mukhutdinova, Yurii A. Chelyshev, Albert A. Rizvanov
    2019, 14 (2):  227-237.  doi: 10.4103/1673-5374.244778
    Abstract ( 127 )   PDF (598KB) ( 190 )   Save

    Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti-apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried (1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation; (2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI; (3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy.

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    Oxidative stress: the lowest common denominator of multiple diseases
    Veronika Matschke,Carsten Theiss 1,Johann Matschke
    2019, 14 (2):  238-241.  doi: 10.4103/1673-5374.244780
    Abstract ( 132 )   PDF (221KB) ( 228 )   Save

    Oxygen is essential to the human life and life of all aerobic organisms. The complete oxidation of nutrients for the biological energy supply is one of the most important prerequisites for the formation of higher life forms. However, cells that benefit from oxidative respiration also suffer from reactive oxygen species because they adapted to oxygen as an energy source. Healthy cells balance the formation and elimination of reactive oxygen species thereby creating and keeping reactive oxygen species-homeostasis. When the concentration of free radicals exceeds a critical level and homeostasis is disturbed, oxidative stress occurs leading to damage of multiple cellular molecules and compartments. Therefore, oxidative stress plays an important role in the physiology and pathology of various diseases. Often, the antioxidant protection system becomes pathologically unbalanced in the genesis of several diseases, leading to functional losses of the organism, as in the case of amyotrophic lateral sclerosis, or cells develop metabolic mechanisms to use this system as protection against external influences, such as in the case of glioblastoma cells. Either way, understanding the underlying deregulated mechanisms of the oxidative protection system would allow the development of novel treatment strategies for various diseases. Thus, regardless of the direction in which the reactive oxygen species-homeostasis disequilibrate, the focus should be on the oxidative protection system.

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    MicroRNAs as diagnostic and therapeutic tools for Alzheimer’s disease: advances and limitations
    Bridget Martinez,Philip V. Peplow
    2019, 14 (2):  242-255.  doi: 10.4103/1673-5374.244784
    Abstract ( 165 )   PDF (553KB) ( 242 )   Save

    Alzheimer’s disease (AD) is the most common age-related, progressive neurodegenerative disease. It is characterized by memory loss and cognitive decline and responsible for most cases of dementia in the elderly. Late-onset or sporadic AD accounts for > 95% of cases, with age at onset > 65 years. Currently there are no drugs or other therapeutic agents available to prevent or delay the progression of AD. The cellular and molecular changes occurring in the brains of individuals with AD include accumulation of β-amyloid peptide and hyperphosphorylated tau protein, decrease of acetylcholine neurotransmitter, inflammation, and oxidative stress. Aggregation of β-amyloid peptide in extracellular plaques and the hyperphosphorylated tau protein in intracellular neurofibrillary tangles are characteristic of AD. A major challenge is identifying molecular biomarkers of the early-stage AD in patients as most studies have been performed with blood or brain tissue samples (postmortem) at late-stage AD. Subjects with mild cognitive impairment almost always have the neuropathologic features of AD with about 50% of mild cognitive impairment patients progressing to AD. They could provide important information about AD pathomechanism and potentially also highlight minimally or noninvasive, easy-to-access biomarkers. MicroRNAs are dysregulated in AD, and may facilitate the early detection of the disease and potentially the continual monitoring of disease progression and allow therapeutic interventions to be evaluated. Four recent reviews have been published of microRNAs in AD, each of which identified areas of weakness or limitations in the reported studies. Importantly, studies in the last three years have shown considerable progress in overcoming some of these limitations and identifying specific microRNAs as biomarkers for AD and mild cognitive impairment. Further large-scale human studies are warranted with less disparity in the study populations, and using an appropriate method to validate the findings.

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    Adult neural stem cell plasticity
    Elizabeth J. Sandquist, Donald S. Sakaguchi
    2019, 14 (2):  256-257.  doi: 10.4103/1673-5374.244785
    Abstract ( 107 )   PDF (201KB) ( 210 )   Save

    Stem cells derived from adult tissues have long been considered multipotent, able to differentiate into a limited number of cell types found in their tissue of origin. Embryonic stem cells, in contrast, are pluripotent, which may differentiate into almost all cell types.With the ability to create induced pluripotent stem cells from somatic cells now available, the properties of multipotent stem cells are being re-evaluated. If adult cells may be reverted to pluripotent stem cells, can multipotent stem cells also be manipulated towards pluripotency? Advancements in biotechnology now allow for better methods to investigate stem cell plasticity, such as the relative influence of external versus intrinsic factors on cell fate. Recent studies indicate that adult neural stem cells (NSCs) demonstrate greater plasticity under certain conditions, resulting in the deriva-tion of a variety of cell types including muscle, hematopoietic, and epithelial cells. This suggests that NSCs may provide a potential source of rare cell types for clinical application as an alternative to embryonic stem cells. Producing rare cell types from NSCs rather than embryonic stem cells avoids the ethical issues surrounding the use of this cell type. Further, NSCs may be an advantageous source compared to induced pluripotent stem cells, which are difficult to create, expensive, and time-consuming to develop.

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    Emerging roles for insulin-like growth factor binding protein like protein 1
    Yingqian Li, Eric Zhao, Dong Feng Chen
    2019, 14 (2):  258-259.  doi: 10.4103/1673-5374.244787
    Abstract ( 111 )   PDF (230KB) ( 208 )   Save

    Insulin-like growth factors (IGFs) mediate diverse cellular processes in various tissues, including the central nervous system (CNS) and thus require robust and delicate regulatory mechanisms. It is now known that IGF signaling is regulated by a superfamily of IGF binding proteins (IGFBPs) which share significant sequence homology and are secreted to the extracellular environment to bind IGF. Currently, there are 6 known IGFBPs and 10 IGFBP related proteins. A new member of the IGFBP superfamily, IGFBP like protein 1 (IGFBPL1), was then identified and shown to have tumor suppressor like properties. Since then, little has been reported about the physiological roles of IGFBPL1. Recently, IGFBPL1 was found to be critically involved in mediating IGF-1 signaling to control CNS axon growth and regeneration. The study has uncovered a new signaling loop in the regulation of the pleiotropic functions of IGF-1 and presents a possible novel pharmacological manipulation for promoting nerve regeneration and repair.

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    Stem cell-based in utero therapies for spina bifida: implications for neural regeneration
    Connor Long, Lee Lankford, Aijun Wang
    2019, 14 (2):  260-261.  doi: 10.4103/1673-5374.244786
    Abstract ( 106 )   PDF (113KB) ( 1134 )   Save

    The history: Myelomeningocele – also known as spina bifida – is a devastating congenital anomaly of the central nervous system that is caused by the malformation of the spinal cord and vertebral column during embryogenesis. Depending on the location of the spina bifida lesion on the spine, patients suffer from neurological dysfunction ranging from paresis and incontinence to complete paralysis. The current standard of care for spina bifida is in utero surgical repair of the defect,which has been shown to minimize the secondary deficits associated with this disorder. Despite these successes, this approach does not reliably improve neurologic function of affected children. Several groups, including our own, have performed studies aimed at augmenting the in utero surgical repair of spina bifida by applying principles of stem cell and tissue engineering to provide an enhanced protection of the exposed neural elements. The ultimate goal of these studies is to improve the neurologic function in patients while maintaining the benefits of the existing fetal surgical treatment.

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    Lessons from tenascin-C knockout mice and potential clinical application to subarachnoid hemorrhage
    Masato Shiba, Hidenori Suzuki
    2019, 14 (2):  262-264.  doi: 10.4103/1673-5374.244789
    Abstract ( 99 )   PDF (178KB) ( 254 )   Save

    Subarachnoid hemorrhage by a ruptured cerebral aneurysm remains the most devastating cerebrovascular disorders with high morbidity and mortality, which are mainly caused by early brain injury and delayed cerebral ischemia. Despite many experimental and clinical research efforts, the mechanisms of early brain injury as well as delayed cerebral ischemia remain unclarified. However, recent works have suggested that tenascin-C, which is a special type of secreted extracellular matrix proteins, is promising as a novel therapeutic target against post-subarachnoid hemorrhage early brain injury and delayed cerebral ischemia.

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    Effect of sevoflurane preconditioning on astrocytic dynamics and neural network formation after cerebral ischemia and reperfusion in rats
    Qiong Yu,Li Li,Wei-Min Liang
    2019, 14 (2):  265-271.  doi: 10.4103/1673-5374.244790
    Abstract ( 119 )   PDF (2616KB) ( 306 )   Save

    Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning improved the integrity of blood-brain barriers after ischemia and reperfusion injury in rats. This led us to investigate the effects of sevoflurane preconditioning on the astrocytic dynamics in ischemia and reperfusion rats, in order to explore astrocytic cell-based mechanisms of sevoflurane preconditioning. In the present study, 2,3,5-triphenyltetrazolium chloride staining and Garcia behavioral scores were utilized to evaluate cerebral infarction and neurological outcome from day 1 to day 3 after transient middle cerebral artery occlusion surgery. Using immunofluorescent staining, we found that sevoflurane preconditioning substantially promoted the astrocytic activation and migration from the penumbra to the infarct with microglial activation from day 3 after middle cerebral artery occlusion. The formation of astrocytic scaffolds facilitated neuroblasts migrating from the subventricular zone to the lesion sites on day 14 after injury. Neural networks increased in the infarct of sevoflurane preconditioned rats, consistent with decreased infarct volume and improved neurological scores after ischemia and reperfusion injury. These findings demonstrate that sevoflurane preconditioning confers neuroprotection, not only by accelerating astrocytic spatial and temporal dynamics, but also providing astrocytic scaffolds for neuroblasts migration to ischemic regions, which facilitates neural reconstruction after brain ischemia.

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    Diffusion kurtosis imaging of microstructural changes in brain tissue affected by acute ischemic stroke in different locations
    Liu-Hong Zhu,Zhong-Ping Zhang,Fu-Nan Wang, Qi-Hua Cheng, Gang Guo
    2019, 14 (2):  272-279.  doi: 10.4103/1673-5374.244791
    Abstract ( 136 )   PDF (2227KB) ( 215 )   Save

    The location of an acute ischemic stroke is associated with its prognosis. The widely used Gaussian model-based parameter, apparent diffusion coefficient (ADC), cannot reveal microstructural changes in different locations or the degree of infarction. Diffusion kurtosis imaging (DKI) was used to detect 199 lesions in 156 patients with acute ischemic stroke (61 males and 95 females), mean age 63.15 ± 12.34 years. A total of 199 lesions were located in the periventricular white matter (n = 52), corpus callosum (n = 14), cerebellum (n = 29), basal ganglia and thalamus (n = 21), brainstem (n = 21) and gray-white matter junctions (n = 62). Percentage changes of apparent diffusion coefficient (ΔADC) and DKI-derived indices (fractional anisotropy [ΔFA], mean diffusivity [ΔMD], axial diffusivity [ΔDa], radial diffusivity ΔDr, mean kurtosis [ΔMK], axial kurtosis [ΔKa], and radial kurtosis [ΔKr]) of each lesion were computed relative to the normal contralateral region. The results showed that (1) there was no significant difference in ΔADC, ΔMD, ΔDa or ΔDr among almost all locations. (2) There was significant difference in ΔMK among almost all locations (except basal ganglia and thalamus vs. brain stem; basal ganglia and thalamus vs. gray-white matter junctions; and brainstem vs. gray-white matter junctions. (3) The degree of change in diffusional kurtosis in descending order was as follows: corpus callosum > periventricular white matter > brainstem > gray-white matter junctions > basal ganglia and thalamus > cerebellum. In conclusion, DKI could reveal the differences in microstructure changes among various locations affected by acute ischemic stroke, and performed better than diffusivity among all groups.

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    Neuronal autophagy aggravates microglial inflammatory injury by downregulating CX3CL1/fractalkine after ischemic stroke
    Hong-Yun He, Lu Ren, Tao Guo, Yi-Hao Deng
    2019, 14 (2):  280-288.  doi: 10.4103/1673-5374.244793
    Abstract ( 220 )   PDF (5589KB) ( 243 )   Save

    Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between neuronal autophagy and microglial inflammation following ischemic stroke are poorly understood. CX3CL1/fractalkine, a membrane-bound chemokine expressed on neurons, can suppress microglial inflammation by binding to its receptor CX3CR1 on microglia. In the present study, to investigate whether autophagy could alter CX3CL1 expression on neurons and consequently change microglial inflammatory activity, middle cerebral artery occlusion (MCAO) was established in Sprague-Dawley rats to model ischemic stroke, and tissues from the ischemic penumbra were obtained to evaluate autophagy level and microglial inflammatory activity. MCAO rats were administered 3-methyladenine (autophagy inhibitor) or Tat-Beclin 1 (autophagy inducer). Western blot assays were conducted to quantify expression of Beclin-1, nuclear factor kappa B p65 (NF-κB), light chain 3B (LC3B), and CX3CL1 in ischemic penumbra. Moreover, immunofluorescence staining was performed to quantify numbers of LC3B-, CX3CL1-, and Iba-1-positive cells in ischemic penumbra. In addition, enzyme linked immunosorbent assays were utilized to analyze concentrations of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1 beta (IL-1β), and prostaglandin E2 (PGE2). A dry/wet weight method was used to detect brain water content, while 2,3,5,-triphenyltetrazolium chloride staining was utilized to measure infarct volume. The results demonstrated that autophagy signaling (Beclin-1 and LC3B expression) in penumbra was prominently activated by MCAO, while CX3CL1 expression on autophagic neurons was significantly reduced and microglial inflammation was markedly activated. However, after inhibition of autophagy signaling with 3-methyladenine, CX3CL1 expression on neurons was obviously increased, whereas Iba-1 and NF-κB expression was downregulated; TNF-α, IL-6, IL-1β, and PGE2 levels were decreased; and cerebral edema was obviously mitigated. In contrast, after treatment with the autophagy inducer Tat-Beclin 1, CX3CL1 expression on neurons was further reduced; Iba-1 and NF-κB expression was increased; TNF-α, IL-6, IL-1β, and PGE2 levels were enhanced; and cerebral edema was aggravated. Our study suggests that ischemia-induced neuronal autophagy facilitates microglial inflammatory injury after ischemic stroke, and the efficacy of this process may be associated with downregulated CX3CL1 expression on autophagic neurons.

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    Structural and functional damage to the hippocampal neurovascular unit in diabetes-related depression
    Jian Liu,Yu-Hong Wang, Wei Li 1,Lin Liu, Hui Yang,Pan Meng, Yuan-Shan Han
    2019, 14 (2):  289-297.  doi: 10.4103/1673-5374.244794
    Abstract ( 154 )   PDF (1955KB) ( 231 )   Save

    Previous studies have shown that models of depression exhibit structural and functional changes to the neurovascular unit. Thus, we hypothesized that diabetes-related depression might be associated with damage to the hippocampal neurovascular unit. To test this hypothesis, neurons, astrocytes and endothelial cells were isolated from the brain tissues of rat embryos and newborn rats. Hippocampal neurovascular unit co-cultures were produced using the Transwell chamber co-culture system. A model of diabetes-related depression was generated by adding 150 mM glucose and 200 μM corticosterone to the culture system and compared with the neuron + astrocyte and astrocyte + endothelial cell co-culture systems. Western blot assay was used to measure levels of structural proteins in the hippocampal neurovascular unit co-culture system. Levels of basic fibroblast growth factor, angiogenic factor 1, glial cell line–derived neurotrophic factor, transforming growth factor β1, leukemia inhibitory factor and 5-hydroxytryptamine in the hippocampal neurovascular unit co-culture system were measured by enzyme-linked immunosorbent assay. Flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling staining was used to assess neuronal apoptosis in the hippocampal neurovascular unit. The neurovascular unit triple cell co-culture system had better barrier function and higher levels of structural and secretory proteins than the double cell co-culture systems. In comparison, in the model of diabetes-related depression, the neurovascular unit was damaged with decreased barrier function, poor structural integrity and impaired secretory function. Moreover, neuronal apoptosis was markedly increased, and 5-hydroxytryptamine levels were reduced. These results suggest that diabetes-related depression is associated with structural and functional damage to the neurovascular unit. Our findings provide a foundation for further studies on the pathogenesis of diabetes-related depression.

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     Predator stress-induced depression is associated with inhibition of hippocampal neurogenesis in adult male mice
    Yan-Ping Wu,Hua-Ying Gao, Shu-Hua Ouyang, Hiroshi Kurihara, Rong-Rong He, Yi-Fang Li
    2019, 14 (2):  298-305.  doi: 10.4103/1673-5374.244792
    Abstract ( 136 )   PDF (890KB) ( 477 )   Save

    Stress has been suggested to disturb the 5-hydroxytryptamine system and decrease neurogenesis, which contribute to the development of depression. Few studies have investigated the effect of predator stress, a type of psychological stress, on depression and hippocampal neurogenesis in adult mice; we therefore investigated this in the present study. A total of 35 adult male Kunming mice were allocated to a cat stress group, cat odor stress group, cat stress + fluoxetine group, cat odor stress + fluoxetine group, or a control group (no stress/treat¬ment). After 12 days of cat stress or cat odor stress, behavioral correlates of depression were measured using the open field test, elevated plus maze test, and dark-avoidance test. The concentrations of hippocampal 5-hydroxytryptamine and 5-hydroxyindoleacetic acid were measured using high-performance liquid chromatography-electrochemical detection. Neurogenesis was also analyzed using a bromode¬oxyuridine and doublecortin double-immunostaining method. Cat stress and cat odor stress induced depression-like behaviors; this effect was stronger in the cat stress model. Furthermore, compared with the control group, cat stress mice exhibited lower 5-hydroxytryptamine concentrations, higher 5-hydroxyindoleacetic acid concentrations, and significantly fewer bromodeoxyuridine+/doublecortin+-labeled cells in the dentate gyrus, which was indicative of less neurogenesis. The changes observed in the cat stress group were not seen in the cat stress + fluoxetine group, which suggests that the effects of predator stress on depression and neurogenesis were reversed by fluoxetine. Taken together, our results indicate that depression-like behaviors induced by predator stress are associated with the inhibition of hippocampal neurogenesis.

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    Endogenous automatic nerve discharge promotesnerve repair: an optimized animal model
    Jing Rui, Ying-Jie Zhou,Xin Zhao,Ji-Feng Li,Yu-Dong Gu, Jie Lao
    2019, 14 (2):  306-312.  doi: 10.4103/1673-5374.244802
    Abstract ( 115 )   PDF (1815KB) ( 173 )   Save

    Exogenous electrical nerve stimulation has been reported to promote nerve regeneration. Our previous study has suggested that en¬dogenous automatic nerve discharge of the phrenic nerve and intercostal nerve has a positive effect on nerve regeneration at 1 month postoperatively, but a negative effect at 2 months postoperatively, which may be caused by scar compression. In this study, we designed four different rat models to avoid the negative effect from scar compression. The control group received musculocutaneous nerve cut and repair. The other three groups were subjected to side-to-side transfer of either the phrenic (phrenic nerve group), intercostal (intercostal nerve group) or thoracodorsal nerves (thoracic dorsal nerve group), with sural nerve autograft distal to the anastomosis site. Muscu¬locutaneous nerve regeneration was assessed by electrophysiology of the musculocutaneous nerve, muscle tension, muscle wet weight, maximum cross-sectional area of biceps, and myelinated fiber numbers of the proximal and distal ends of the anastomosis site of the mus¬culocutaneous nerve and the middle of the nerve graft. At 1 month postoperatively, compound muscle action potential amplitude of the biceps in the phrenic nerve group and the intercostal nerve group was statistically higher than that in the control group. The myelinated nerve fiber numbers in the distal end of the musculocutaneous nerve and nerve graft anastomosis in the phrenic nerve and the intercos¬tal nerve groups were statistically higher than those in the control and thoracic dorsal nerve groups. The neural degeneration rate in the middle of the nerve graft in the thoracic dorsal nerve group was statistically higher than that in the phrenic nerve and the intercostal nerve groups. At 2 and 3 months postoperatively, no significant difference was detected between the groups in all the assessments. These findings confirm that the phrenic nerve and intercostal nerve have a positive effect on nerve regeneration at the early stage of recovery. This study established an optimized animal model in which suturing the nerve graft to the distal site of the musculocutaneous nerve anastomosis pre¬vented the inhibition of recovery from scar compression.

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    Safety of intrathecal injection of Wharton’s jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy
    Monika Barczewska, Mariusz Grudniak, Stanisław Maksymowicz, Tomasz Siwek, Tomasz Ołdak, Katarzyna Jezierska-Woźniak, Dominika Gładysz, Wojciech Maksymowicz
    2019, 14 (2):  313-318.  doi: 10.4103/1673-5374.243723
    Abstract ( 173 )   PDF (188KB) ( 232 )   Save

    Animal experiments have confirmed that mesenchymal stem cells can inhibit motor neuron apoptosis and inflammatory factor expression and increase neurotrophic factor expression. Therefore, mesenchymal stem cells have been shown to exhibit prospects in the treatment of amyotrophic lateral sclerosis. However, the safety of their clinical application needs to be validated. To investigate the safety of intrathecal injection of Wharton’s jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy, 43 patients (16 females and 27 males, mean age of 57.3 years) received an average dose of 0.42 × 106 cells/kg through intrathecal administration at the cervical, thoracic or lumbar region depending on the clinical symptoms. There was a 2 month interval between two injections. The adverse events occurring during a 6-month treatment period were evaluated. No adverse events occurred. Headache occurred in one case only after first injection of stem cells. This suggests that intrathecal injection of Wharton’s Jelly-derived mesenchymal stem cells is well tolerated in patients with amyotrophic lateral sclerosis. This study was approved by the Bioethical Committee of School of Medicine, University of Warmia and Mazury in Olsztyn, Poland (approval No. 36/2014 and approval No. 8/2016). This study was registered with the ClinicalTrials.gov (identifier: NCT02881476) on August 29, 2016.

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    Implications of alpha-synuclein nitration at tyrosine 39 in methamphetamine-induced neurotoxicity in vitro and in vivo
    Hong-Hua Qiao,Lin-Nan Zhu, Yue Wang,Jia-Liang Hui,Wei-Bing Xie, Chao Liu, Ling Chen, Ping-Ming Qiu
    2019, 14 (2):  319-327.  doi: 10.4103/1673-5374.244795
    Abstract ( 170 )   PDF (2402KB) ( 260 )   Save

    Methamphetamine is an amphetamine-type psychostimulant that can damage dopaminergic neurons and cause characteristic pathological changes similar to neurodegenerative diseases such as Parkinson’s disease. However, its specific mechanism of action is still unclear. In the present study, we established a Parkinson’s disease pathology model by exposing SH-SY5Y cells and C57BL/6J mice to methamphetamine.  In vitro experiments were performed with 0, 0.5, 1.0, 1.5, 2.0 or 2.5 mM methamphetamine for 24 hours or 2.0 mM methamphetamine for 0-, 2-, 4-, 8-, 16-, and 24-hour culture of SH-SY5Y cells. Additional experimental groups of SH-SY5Y cells were administered a nitric oxide inhibitor, 0.1 mM N-nitro-L-arginine, 1 hour before exposure to 2.0 mM methamphetamine for 24 hours. In vivo experiments: C57BL/6J mice were intraperitoneally injected with N-nitro-L-arginine (8 mg/kg), eight times, at intervals of 12 hours. Methamphetamine 15 mg/kg was intraperitoneally injected eight times, at intervals of 12 hours, but 0.5-hour after each N-nitro-L-arginine injection in the combined group. Western blot assay was used to determine the expression of nitric oxide synthase, α-synuclein (α-Syn), 5G4, nitrated α-synuclein at the residue Tyr39 (nT39 α-Syn), cleaved caspase-3, and cleaved poly ADP-ribose polymerase (PARP) in cells and mouse brain tissue. Immunofluorescence staining was conducted to measure the positive reaction of NeuN, nT39 α-Syn and 5G4. Enzyme linked immunosorbent assay was performed to determine the dopamine levels in the mouse brain. After methamphetamine exposure, α-Syn expression increased; the aggregation of α-Syn 5G4 increased; nT39 α-Syn, nitric oxide synthase, cleaved caspase-3, and cleaved PARP expression increased in the cultures of SH-SY5Y cells and in the brains of C57BL/6J mice; and dopamine levels were reduced in the mouse brain. These changes were markedly reduced when N-nitro-L-arginine was administered with methamphetamine in both SH-SY5Y cells and C57BL/6J mice. These results suggest that nT39 α-Syn aggregation is involved in methamphetamine neurotoxicity.

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    Melatonin combined with chondroitin sulfate ABC promotes nerve regeneration after root-avulsion brachial plexus injury
    Wen-Lai Guo, Zhi-Ping Qi, Li Yu, Tian-Wen Sun, Wen-Rui Qu,Qian-Qian Liu, Zhe Zhu,Rui Li
    2019, 14 (2):  328-338.  doi: 10.4103/1673-5374.244796
    Abstract ( 195 )   PDF (3673KB) ( 216 )   Save

    After nerve-root avulsion injury of the brachial plexus, oxidative damage, inflammatory reaction, and glial scar formation can affect nerve regeneration and functional recovery. Melatonin (MT) has been shown to have good anti-inflammatory, antioxidant, and neuroprotective effects. Chondroitin sulfate ABC (ChABC) has been shown to metabolize chondroitin sulfate proteoglycans and can reduce colloidal scar formation. However, the effect of any of these drugs alone in the recovery of nerve function after injury is not completely satisfactory. There¬fore, this experiment aimed to explore the effect and mechanism of combined application of melatonin and chondroitin sulfate ABC on nerve regeneration and functional recovery after nerve-root avulsion of the brachial plexus. Fifty-two Sprague-Dawley rats were selected and their C5–7 nerve roots were avulsed. Then, the C6 nerve roots were replanted to construct the brachial plexus nerve-root avulsion model. After successful modeling, the injured rats were randomly divided into four groups. The first group (injury) did not receive any drug treatment, but was treated with a pure gel-sponge carrier nerve-root implantation and an ethanol-saline solution via intraperitoneal (i.p.) injection. The second group (melatonin) was treated with melatonin via i.p. injection. The third group (chondroitin sulfate ABC) was treated with chondroi¬tin sulfate ABC through local administration. The fourth group (melatonin + chondroitin sulfate ABC) was treated with melatonin through i.p. injection and chondroitin sulfate ABC through local administration. The upper limb Terzis grooming test was used 2–6 weeks after injury to evaluate motor function. Inflammation and oxidative damage within 24 hours of injury were evaluated by spectrophotometry. Immunoflu¬orescence and neuroelectrophysiology were used to evaluate glial scar, neuronal protection, and nerve regeneration. The results showed that the Terzis grooming-test scores of the three groups that received treatment were better than those of the injury only group. Additionally, these three groups showed lower levels of C5–7 intramedullary peroxidase and malondialdehyde. Further, glial scar tissue in the C6 spinal segment was smaller and the number of motor neurons was greater. The endplate area of the biceps muscle was larger and the structure was clear. The latency of the compound potential of the myocutaneous nerve-biceps muscle was shorter. All these indexes were even greater in the melatonin + chondroitin sulfate ABC group than in the melatonin only or chondroitin sulfate ABC only groups. Thus, the results showed that melatonin combined with chondroitin sulfate ABC can promote nerve regeneration after nerve-root avulsion injury of the brachial plexus, which may be achieved by reducing oxidative damage and inflammatory reaction in the injury area and inhibiting glial scar formation.

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    A novel primary culture method for high-purity satellite glial cells derived from rat dorsal root ganglion
    Xian-Bin Wang, Wei Ma, Tao Luo,Jin-Wei Yang,Xiang-Peng Wang,Yun-Fei Dai,Jian-Hui Guo,Li-Yan Li
    2019, 14 (2):  339-345.  doi: 10.4103/1673-5374.244797
    Abstract ( 266 )   PDF (1402KB) ( 229 )   Save

    Satellite glial cells surround neurons within dorsal root ganglia. Previous studies have focused on single-cell suspensions of cultured neurons derived from rat dorsal root ganglia. At present, the primary culture method for satellite glial cells derived from rat dorsal root ganglia requires no digestion skill. Hence, the aim of the present study was to establish a novel primary culture method for satellite glial cells derived from dorsal root ganglia. Neonatal rat spine was collected and an incision made to expose the transverse protrusion and remove dorsal root ganglia. Dorsal root ganglia were freed from nerve fibers, connective tissue, and capsule membranes, then rinsed and transferred to 6-well plates, and cultured in a humidified 5% CO2 incubator at 37°C. After 3 days in culture, some cells had migrated from dorsal root ganglia. After subculture, cells were identified by immunofluorescence labeling for three satellite glial cell-specific markers: glutamine synthetase, glial fibrillary acidic protein, and S100β. Cultured cells expressed glutamine synthetase, glial fibrillary acidic protein, and S100β, suggesting they are satellite glial cells with a purity of > 95%. Thus, we have successfully established a novel primary culture method for obtaining high-purity satellite glial cells from rat dorsal root ganglia without digestion.

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    Association of GTF2IRD1–GTF2I polymorphisms with neuromyelitis optica spectrum disorders in Han Chinese patients
    Jing-Lu Xie, Ju Liu, Zhi-Yun Lian, Hong-Xi Chen, Zi-Yan Shi, Qin Zhang, Hui-Ru Feng, Qin Du, Xiao-Hui Miao, Hong-Yu Zhou
    2019, 14 (2):  346-353.  doi: 10.4103/1673-5374.244800
    Abstract ( 126 )   PDF (474KB) ( 162 )   Save

    Variants at the GTF2I repeat domain containing 1 (GTF2IRD1)–GTF2I locus are associated with primary Sjögren’s syndrome, systemic lupus erythematosus, and rheumatoid arthritis. Numerous studies have indicated that this susceptibility locus is shared by multiple autoimmune diseases. However, until now there were no studies of the correlation between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders (NMOSD). This case control study assessed this association by recruiting 305 participants with neuromyelitis optica spectrum disorders and 487 healthy controls at the Department of Neurology, from September 2014 to April 2017. Peripheral blood was collected, DNA extracteds and the genetic association between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders in the Chinese Han population was analyzed by genotyping. We found that the T allele of rs117026326 was associated with an increased risk of neuromyelitis optica spectrum disorders (odds ratio (OR) = 1.364, 95% confidence interval (CI) 1.019–1.828; P = 0.037). This association persisted after stratification analysis for aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) positivity (OR = 1.397, 95% CI 1.021–1.912; P = 0.036) and stratification according to coexisting autoimmune diseases (OR = 1.446, 95% CI 1.072–1.952; P = 0.015). Furthermore, the CC genotype of rs73366469 was frequent in AQP4-IgG-seropositive patients (OR = 3.15, 95% CI 1.183–8.393, P = 0.022). In conclusion, the T allele of rs117026326 was associated with susceptibility to neuromyelitis optica spectrum disorders, and the CC genotype of rs73366469 conferred susceptibility to AQP4-IgG-seropositivity in Han Chinese patients.

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    Comparison of walking quality variables between incomplete spinal cord injury patients and healthy subjects by using a footscan plantar pressure system
    Xiang-Nan Yuan,Wei-Di Liang,Feng-Hua Zhou, Han-Ting Li, Li-Xin Zhang, Zhi-Qiang Zhang,Jian-Jun Li
    2019, 14 (2):  354-360.  doi: 10.4103/1673-5374.244798
    Abstract ( 142 )   PDF (773KB) ( 257 )   Save

    The main goal of spinal cord rehabilitation is to restore walking ability and improve walking quality after spinal cord injury (SCI). The spatiotemporal parameters of walking and the parameters of plantar pressure can be obtained using a plantar pressure analysis system. Previous studies have reported step asymmetry in patients with bilateral SCI. However, the asymmetry of other parameters in patients with SCI has not been reported. This was a prospective, cross-sectional study, which included 23 patients with SCI, aged 48.1 ± 14.5 years, and 28 healthy subjects, aged 47.1 ± 9.8 years. All subjects underwent bare foot walking on a plantar pressure measurement device to measure walking speed and spatiotemporal parameters. Compared with healthy subjects, SCI patients had slower walking speed, longer stride time and stance time, larger stance phase percentage, and shorter stride length. The peak pressures under the metatarsal heads and toe were lower in SCI patients than in healthy subjects. In the heel, regional impulse and the contact area percentage in SCI patients were higher than those in healthy subjects. The symmetry indexes of stance time, step length, maximum force, impulse and contact area were increased in SCI patients, indicating a decline in symmetry. The results confirm that the gait quality, including spatiotemporal variables and plantar pressure parameters, and symmetry index were lower in SCI patients compared with healthy subjects. Plantar pressure parameters and symmetry index could be sensitive quantitative parameters to improve gait quality of SCI patients. The protocols were approved by the Clinical Research Ethics Committee of Shengjing Hospital of China Medical University (approval No. 2015PS54J) on August 13, 2015. This trial was registered in the ISRCTN Registry (ISRCTN42544587) on August 22, 2018. Protocol version: 1.0.

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    MGMT is down-regulated independently of promoter DNA methylation in rats with all-trans retinoic acid-induced spina bifida aperta
    He-Nan Zhang,Yi Guo,Wei Ma,Jia Xue,Wei-Lin Wang, Zheng-Wei Yuan
    2019, 14 (2):  361-368.  doi: 10.4103/1673-5374.244799
    Abstract ( 126 )   PDF (1142KB) ( 212 )   Save

    O6-methylguanine DNA methyltransferase (MGMT), a DNA repair enzyme, has been reported in some congenital malformations, but it is less frequently reported in neural tube defects. This study investigated MGMT mRNA expression and methylation levels in the early embryo and in different embryonic stages, as well as the relationship between MGMT and neural tube defects. Spina bifida aperta was induced in rats by a single intragastric administration of all-trans retinoic acid on embryonic day (E) 10, whereas normal control rats re¬ceived the same amount of olive oil on the same embryonic day. DNA damage was assessed by detecting γ-H2A.X in spina bifida aperta rats. Real time-polymerase chain reaction was used to examine mRNA expression of MGMT in normal control and spina bifida aperta rats. In normal controls, the MGMT mRNA expression decreased with increasing embryonic days, and was remarkably reduced from E11 to E14, reaching a minimum at E18. In the spina bifida aperta model, γ-H2A.X protein expression was increased, and mRNA expression of MGMT was markedly decreased on E14, E16, and E18. Bisulfite sequencing polymerase chain reaction for MGMT promoter methyla¬tion demonstrated that almost all CpG sites in the MGMT promoter remained unmethylated in both spina bifida aperta rats and normal controls, and there was no significant difference in methylation level between the two groups on either E14 or E18. Our results show that DNA damage occurs in spina bifida aperta rats. The mRNA expression of MGMT is downregulated, and this downregulation is indepen¬dent of promoter DNA methylation.

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