Neuronal Cell Morphology Research Articles

Effect of aerobic exercise on BDNF/proBDNF expression in the ischemic hippocampus and depression recovery of rats after stroke

BDNF and proBDNF play an opposite role in hippocampal neurogenesis. What remains to be known is the effect of balance between BDNF and proBDNF in the ischemic hippocampus on pathogenesis of post-stroke depression (PSD) and the potential mechanisms of aerobic exercise (AE) on PSD. Wistar rats were randomly divided into control, Sham, Sedentary and AE groups. After PSD model was successful made, the blood lactate threshold corresponding speed (SLT) were measured. The behavioral tests (open field, forced swimming and sucrose preference tests) were performed before and after 4 weeks of aerobic treadmill training. HE staining and immunostaining for doublecortin (DCX)+ neurons were used to observe the changes of neuronal cell morphology and proliferation, migration of the neural progenitor cells (NPCs). The expression of mature brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), precursor BDNF (proBDNF), pan-neurotrophin receptor 75 (p75NTR) proteins, BDNF mRNA in the ischemic hippocampus and serum adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were detected by Western blotting, immunohistochemistry, RT-PCR and ELISA. Higher immobility time and levels of proBDNF, p75NTR, ACTH, CORT proteins and lower sucrose preference, total distance, climbing frequency and levels of BDNF, TrkB proteins, BDNF mRNA were observed in the Sedentary group. Neuronal cells in the ischemic hippocampus were loosely arranged and expression of DCX reduced in the Sedentary group. There were significant differences in above results between Sedentary and AE groups after 4 weeks of aerobic exercise. The balance between BDNF and proBDNF in the ischemic hippocampus are likely to play an important role in the pathogenesis of PSD. And AE could improve depression, hippocampal neurogenesis, and increase BDNF/proBDNF ratio in the ischemic hippocampus of the PSD rats.

The combination of <em>Acalypha indica</em>–<em>Centella asiatica</em> extracts decreases the neuronal damage in hypoxia-induced hippocampal injury animal model

Background: Approximately 80–85% of strokes are ischemic and lead to alterations in neuronal cell morphology and cell death. There is a lack of studies on the effect of the combination of Acalypha indica L. (AI) and Centella asiatica L. (CA) in terms of its neurotherapy property. This study was conducted to investigate the neurotherapeutic effect of the combination of AI–CA extracts in improving rat’s hippocampal neuron injury post-hypoxia.Methods: A total of 36 Sprague-Dawley rats were categorized into six groups and placed in a hypoxia chamber for 7 consecutive days. Then, they were moved to normoxia cages and treated for 7 consecutive days as follows: control group without treatment as a negative control; treatment groups were administered citicoline 50 mg/kgBW as a positive control; three different dose combinations of AI150–CA150, AI200–CA150, and AI250–CA150 mg/kgBW, respectively. Histological analyses were performed to assess the improvement in nerve cell damage in the hippocampus.Results: Treatment with citicoline significantly decreased the damage of nerve cells (30.8%); the combination of the AI–CA extracts of AI150–CA150, AI200–CA150, and AI250–CA150 also significantly decreased the damage of nerve cells (36%, 36.4%, and 30.4%, respectively) compared to the control rats (15.4%).Conclusion: The combination of AI–CA extracts decreased the neuronal damage in the hypoxia-induced hippocampal injury animal model. The improvement effect of the combination of AI–CA extracts was not significantly different to citicoline.

RETRACTED: Curcumin alleviates lipopolysaccharide-induced neuroinflammation in fetal mouse brain

Curcumin exerts multiple functions including antioxidant and anti-inflammation, and has been shown protective potential on neurological disorders. Maternal or intrauterine infection/inflammation is one of the major factors underlying perinatal brain damage. This study aimed to determine whether maternal administration of curcumin has attenuation on neuroinflammation in fetal brain caused by lipopolysaccharide (LPS) administration. LPS was used to establish mouse fetal brain injury model, and we investigated the effects of curcumin (40 mg/kg) on the fetal mouse brain by evaluating the morphological change of the neuronal cells and the expression of different pro-inflammatory cytokines and chemokines at protein and mRNA levels in the fetal brains, the maternal serum and amniotic fluid. Our results demonstrated that maternal administration of curcumin has attenuation on neuroinflammation in the fetal brain induced by LPS. Pretreatment of curcumin in the LPS-induced mice effectively reestablished the neuronal cell morphology, attenuated the expression of soluble intercellular adhesion molecule-1, sE-Selectin, macrophage chemoattractant protein-1 and cytokine-induced neutrophil chemoattractant-1 in the maternal serum, decreased the expression of cyclooxygenase-2, interleukin-1 beta and chemokine (C-C motif) ligand 2 in the brain, and suppressed interleukin-6 (IL-6) mRNA transcription in the amniotic fluid. In addition, curcumin suppressed the LPS-induced microglia activation. Our study in animal models indicates that maternal administration of curcumin alleviates neuroinflammation in the fetal brain caused by LPS. Long-term consumption of curcumin might improve the neurological outcomes of premature neonates delivered from dams suffering from infection/ inflammation.

Netrin-1/DCC-mediated PLCγ1 activation is required for axon guidance and brain structure development.

Coordinated expression of guidance molecules and their signal transduction are critical for correct brain wiring. Previous studies have shown that phospholipase C gamma1 (PLCγ1), a signal transducer of receptor tyrosine kinases, plays a specific role in the regulation of neuronal cell morphology and motility in vitro However, several questions remain regarding the extracellular stimulus that triggers PLCγ1 signaling and the exact role PLCγ1 plays in nervous system development. Here, we demonstrate that PLCγ1 mediates axonal guidance through a netrin-1/deleted in colorectal cancer (DCC) complex. Netrin-1/DCC activates PLCγ1 through Src kinase to induce actin cytoskeleton rearrangement. Neuronal progenitor-specific knockout of Plcg1 in mice causes axon guidance defects in the dorsal part of the mesencephalon during embryogenesis. Adult Plcg1-deficient mice exhibit structural alterations in the corpus callosum, substantia innominata, and olfactory tubercle. These results suggest that PLCγ1 plays an important role in the correct development of white matter structure by mediating netrin-1/DCC signaling.

Hippocampal amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid GluA1 (AMPA GluA1) receptor subunit involves in learning and memory improvement following treatment with Centella asiatica extract in adolescent rats.

Introduction Centella asiatica is an herbal plant that contains phytochemicals that are widely believed to have positive effects on cognitive function. The adolescent stage is a critical development period for the maturation of brain processes that encompass changes in physical and psychological systems. However, the effect of C. asiatica has not been extensively studied in adolescents. The aim of this study was therefore to investigate the effects of a C. asiatica extract on the enhancement of learning and memory in adolescent rats.MethodsThe locomotor activity, learning, and memory were assessed by using open field test and water T‐maze test. This study also examined changes in neuronal cell morphology using cresyl violet and apoptosis staining. We also performed immunohistochemical study to analyse the expression of the glutamate AMPA receptor (α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid) GluA1 subunit and the GABA receptor (γ‐Aminobutyric Acid) subtype GABAA α1 subunit in the hippocampus of the same animals.ResultsWe found no significant changes in locomotor activity (p > 0.05). The water T‐maze data showed that 30 mg/kg dose significantly (p < 0.05) improved learning, memory, and the memory consolidation phase but had no effect on reversal learning (p > 0.05). Histological data revealed no neuronal morphological changes. Immunohistochemical analysis revealed increased expression of the AMPA GluA1 receptor subunit but there was no effect on GABAA receptor α1 subunit expression in the CA1 and CA2 subregions of the hippocampus.ConclusionsThe C. asiatica extract therefore improved hippocampus‐dependent spatial learning and memory in a dose‐dependent manner in rats through the GluA1‐containing AMPA receptor in the CA1 and CA2 sub regions of the hippocampus.

Confocal micrographs: automated segmentation and quantitative shape analysis of neuronal cells treated with ostreolysin A/pleurotolysin B pore-forming complex.

Detailed shape analysis of cells is important to better understand the physiological mechanisms of toxins and determine their effects on cell morphology. This study aimed to develop a procedure for accurate morphological analysis of cell shape and use it as a tool to estimate toxin activity. With the aim of optimizing the method of cell morphology analysis, we determined the influence of ostreolysin A and pleurotolysin B complex (OlyA/PlyB) on the morphology of murine neuronal NG108-15 cells. A computational method was introduced and successfully applied to quantify morphological attributes of the NG108-15 cell line before and after 30 and 60min exposure to OlyA/PlyB using confocal microscopy. The modified circularity measure [Formula: see text] for shape analysis was applied, which defines the degree to which the shape of the neuron differs from a perfect circle. It enables better detection of small changes in the shape of cells, making the outcome easily detectable numerically. Additionally, we analyzed the influence of OlyA/PlyB on the cell area, allowing us to detect the cells with blebs. This is important because the formation of plasma membrane protrusions such as blebs often reflects cell injury that leads to necrotic cell death. In summary, we offer a novel analytical method of neuronal cell shape analysis and its correlation with the toxic effects of the pore-forming OlyA/PlyB toxin in situ.

Stochastic Modeling of Radiation-induced Dendritic Damage on in silico Mouse Hippocampal Neurons

Cognitive dysfunction associated with radiotherapy for cancer treatment has been correlated to several factors, one of which is changes to the dendritic morphology of neuronal cells. Alterations in dendritic geometry and branching patterns are often accompanied by deficits that impact learning and memory. The purpose of this study is to develop a novel predictive model of neuronal dendritic damages caused by exposure to low linear energy transfer (LET) radiation, such as X-rays, γ-rays and high-energy protons. We established in silico representations of mouse hippocampal dentate granule cell layer (GCL) and CA1 pyramidal neurons, which are frequently examined in radiation-induced cognitive decrements. The in silico representations are used in a stochastic model that describes time dependent dendritic damage induced by exposure to low LET radiation. Changes in morphometric parameters, such as total dendritic length, number of branch points and branch number, including the Sholl analysis for single neurons are described by the model. Our model based predictions for different patterns of morphological changes based on energy deposition in dendritic segments (EDDS) will serve as a useful basis to compare specific patterns of morphological alterations caused by EDDS mechanisms.

Chrysophanol Relieves Cognition Deficits and Neuronal Loss Through Inhibition of Inflammation in Diabetic Mice.

Patients with diabetes mellitus are easy to experience diabetic encephalopathy (DE) and other cognition dysfunction, whereas the neural alterations in developing this disease are unknown yet. Chrysophanol (CHR) is one of traditional Chinese medicine which was reported to show protective effects in cognition dysfunction and inflammatory in previously studies. In this current study, whether CHR protects learning and memory dysfunctions induced by diabetes disease or not and underlying mechanisms were studied. DE model was induced by streptozotocin (STZ, i.p.) in ICR mice. CHR was administrated 3days after STZ treated mice which was confirmed with diabetes for consecutive 6days. Learning and memory function was tested by Morris water maze after the CHR injection. The morphology of neuronal cells in hippocampus CA3 region was stained by HE-staining. ELISA and Western blot assay were used to determine the levels of pro-inflammation cytokines (IL-1β, IL-4, IL-6, TNF-α) in hippocampus. Here, we demonstrated that mice harboring diabetes mellitus induced by STZ exhibit high blood glucose, learning and memory deficits detected by Morris water maze behavior tests. Application with CHR right after developing diabetes disease rescues partial blood sugar increasing, learning and memory deficits. The data also indicated that the death rate of neurons and the number of astrocytes in hippocampus CA3 region was significantly improved in diabetic mice. Moreover, the underlying mechanisms of CHR's protective effect are likely associated with anti-inflammation by downregulating the expression of pro-inflammation cytokines (IL-1β, IL-4, IL-6, TNF-α) in hippocampus and inhibiting the over-activation of astrocytes in hippocampus CA3 region. Therefore, application with CHR contributes to the learning and memory deficits induced by diabetes disease via inhibitory expressions of inflammatory in hippocampus region.

Neuronal Cell Morphology in Primary Cerebellar Granule Cells Using High-Content Analysis.

Neurite outgrowth, one of the underlying cellular processes that defines the development and functionality of the mammalian nervous system, is also a sensitive indicator of neuronal cell health. From screening libraries of putative neurotherapeutic compounds to analyzing the millions of environmental pollutants for which we have inadequate neurotoxicity safety data, the large volume of chemical compounds that require evaluation is a major obstacle for manual imaging and analysis methods. In this context, high-content analysis (HCA) has emerged as a sensitive and accurate method for detecting changes in neuronal cell morphology within a format applicable to screening large chemical libraries. Advances in HCA technologies have enabled the automated imaging and quantitative analysis of neurite outgrowth morphology within a 96-well plate in less than 5 min. Traditionally, neurite outgrowth assessment has been conducted on immortalized cell lines such as pheochromocytoma (PC-12) cells that differentiate into neuron-like cells upon culture with nerve growth factor. Unfortunately, they do not retain all the in vivo characteristics of physiological neuronal tissue, including lack of synapse formation. As researchers refine neurite outgrowth quantitative analysis using HCA, an emerging question is how to quantify this biology in more complex models that more faithfully recapitulate in vivo environments. Primary neurons provide several benefits relative to neuronal cell lines, including the elaboration of axons from secondary dendrites and formation of both pre- and postsynaptic junctions. This chapter reviews techniques for evaluating neurite outgrowth using the ArrayScan HCA platform within a model system of primary cultures of rodent cerebellar granule cells.

The BET/BRD inhibitor JQ1 attenuates diabetes-induced cognitive impairment in rats by targeting Nox4-Nrf2 redox imbalance

Diabetes-induced oxidative damage is believed to play an important role in the development of cognitive dysfunction. In this study, the involvement of the Nox4-Nrf2 redox imbalance was investigated. STZ-induced diabetic rats exhibited obvious oxidative stress and apoptosis in the hippocampus assessed by augmentation of lipid peroxidation, positive TUNEL staining, elevated ratio of Bax/Bcl-2 and increased caspase 3 activity. Furthermore, hyperglycemia markedly increased Nox4 activity and reduced the activation of Nrf2 by suppressing its up-stream regulatory Akt as well as down-stream target HO-1. Significant improvement of cognitive performance was observed after treatment with the BET/BRD inhibitor JQ1, accompanied by decreased oxidative stress, neuroinflammation and apoptosis in the hippocampus. JQ1 treatment also improved changes in the neuronal cell morphology as well as increased the expression of p-AKT, Nrf2 and HO-1. Our results provide evidence indicating that JQ1 treatment could modulate Nox4-Nrf2 redox imbalance in the hippocampus and may be a promising agent for diabetes-associated cognitive dysfunction.

Quercetin ameliorates learning and memory via the Nrf2-ARE signaling pathway in d-galactose-induced neurotoxicity in mice

Aging is accompanied by deficits in cognitive function and neuronal degeneration or loss. Quercetin is a flavonoid that exhibits powerful antioxidant activity. This study evaluated the protective effects and mechanisms of quercetin in d-galactose-induced neurotoxicity in mice. Quercetin was administered daily at doses of 20 or 50 mg/kg in d-galactose-injected (50 mg/kg/subcutaneous (s.c.)) mice for eight weeks. Morris water maze tests demonstrated that quercetin significantly improved learning and memory compared to d-galactose-treated control mice. Quercetin also prevented changes in the neuronal cell morphology and apoptosis in the hippocampus as well as increased the expression of Nrf2, HO-1 and SOD in d-galactose-treated mice. Treatment with the Nrf2 inhibitor Brusatol reversed the effects of quercetin on HO-1 and SOD expression as well as neuronal cell protection. In conclusion, quercetin protected mice from d-galactose-induced cognitive functional impairment and neuronal cell apoptosis via activation of the Nrf2-ARE signaling pathway.

From the Cover: Evaluation of the Effects of Tanezumab, a Monoclonal Antibody Against Nerve Growth Factor, on the Sympathetic Nervous System in Adult Cynomolgus Monkeys (Macaca fascicularis): A Stereologic, Histomorphologic, and Cardiofunctional Assessment.

Tanezumab, a humanized monoclonal antibody against nerve growth factor is in development for treatment of chronic pain. Three nonclinical studies assessed effects of clinically relevant and supratherapeutic doses of tanezumab on the sympathetic nervous system (SNS) of adult nonhuman primates. Study 1 evaluated potential effects of subcutaneous (SC) tanezumab (1.2 mg/kg every 8 weeks [Q8W]) on SNS in cynomolgus monkeys for 3 or 6 months and reversibility or persistence of any effects through a nondosing/recovery period. Study 2 evaluated whether neuronal cell death occurs shortly after a single SC tanezumab injection (1.2 mg/kg). Assessments for these two studies included evaluations of superior cervical and cervicothoracic ganglia for neuronal cell death and morphology. Study 3 evaluated effects of SC tanezumab (1.2 mg/kg Q8W and 30 mg/kg/week) over 6 months on sympathetic control of cardiovascular function. Tanezumab exposure was associated with stereologic changes in sympathetic ganglia, including smaller ganglion volume, and smaller average neuron size/area beginning at 2 weeks and reaching maximal levels by 1 month with no further progression through 6 months. These changes were not associated with clinical signs, completely reversed upon tanezumab withdrawal, and were not considered adverse. Tanezumab had no adverse effects on sympathetic control of cardiovascular function. These data support the conclusion that tanezumab administration for up to 6 months has no adverse effects on SNS morphology or function and does not cause neuronal cell death in adult nonhuman primates.

Identification of NEK3 interacting proteins and functional characterization of its signaling mechanisms

NEKs ( N IMA-r e lated k inases) are a group of kinases that share high amino acid sequence identity to NIMA ( N ever i n m itosis gene A ), which exists as a single member in the fungi Aspergillus nidulans and is functionally involved in the initiation of mitosis. NEK3 is a 506 amino acid serine/threonine kinase, localizes both to the nucleus and cytoplasm, and its gene localizes to 13q14.2 chromosome. It has an N-terminal catalytic domain and a C-terminal regulatory domain, which contains Thr475 in its PEST domain, which gets phosphorylated upon activation. Expression of mutants without Thr475 or PEST domain causes changes in cellular morphology and polarity of neuronal cells. NEK3 is also involved in cell motility and invasiveness of breast cancer tumor cells through interaction with regulators of the Rho GTPases Rac1 and RhoA, mediated by prolactin induced association of NEK3 to the human Prolactin Receptor (PRLR). Using the Matchmaker Gold Yeast Two-Hybrid system, a screening for interaction partners wasperformed and 65 clones were obtained, which cDNAs encode 27 different proteins. The identified candidate interacting proteins are functionally involved in sumoylation, ubiquitinylation, transcriptional regulation, DNA repair, RNA processing, and the regulation of cell proliferation, invasiveness and metastasis.Some interaction partners for NEK3 are located in the nucleus and plasma membrane but most of them localize to the cytoplasm. One of the cytoplasmatic interactors for NEK3, RhoGDI2, is a regulator of RhoGTPases and inhibits Rac1 and RhoA activation levels. In our pull down assay, NEK3 overexpression increases Rac1-GTP while concomittant overexpression of RhoGDI2 reducesit to non-detectable levels. Our data suggests that NEK3 interaction with RhoGDI2 is a important new regulatory elements in Rac1 signaling pathways.

Early- versus Late-Onset Fetal Growth Restriction Differentially Affects the Development of the Fetal Sheep Brain

Fetal growth restriction (FGR) is a common complication of pregnancy, principally caused by suboptimal placental function, and is associated with high rates of perinatal mortality and morbidity. Clinical studies suggest that the time of onset of placental insufficiency is an important contributor towards the neurodevelopmental impairments that are evident in children who had FGR. It is however currently unknown how early-onset and late-onset FGR differentially affect brain development. The aim of this study was to examine neuropathology in early-onset and late-onset FGR fetal sheep and to determine whether they differentially alter brain development. We induced placental insufficiency and FGR via single umbilical artery ligation at either 88 days (early-onset) or 105 days (late-onset) of fetal sheep gestation (term is approx. 147 days), reflecting a period of rapid white matter brain development. Fetal blood samples were collected for the first 10 days after surgery, and all fetuses were sacrificed at 125 days' gestation for brain collection and subsequent histopathology. Our results show that early-onset FGR fetuses became progressively hypoxic over the first 10 days after onset of placental insufficiency, whereas late-onset FGR fetuses were significantly hypoxic compared to controls from day 1 after onset of placental insufficiency (Sa<smlcap>O</smlcap>₂ 46.7 ± 7.4 vs. 65.7 ± 3.9%, respectively, p = 0.03). Compared to control brains, early-onset FGR brains showed widespread white matter injury, with a reduction in both CNPase-positive and MBP-positive density of staining in the periventricular white matter (PVWM), subcortical white matter, intragyral white matter (IGWM), subventricular zone (SVZ), and external capsule (p < 0.05 for all). Total oligodendrocyte lineage cell counts (Olig-2-positive) did not differ across groups, but mature oligodendrocytes (MBP-positive) were reduced, and neuroinflammation was evident in early-onset FGR brains with reactive astrogliosis (GFAP-positive) in the IGWM and cortex (p < 0.05), together with an increased number of Iba-1-positive activated microglia in the PVWM, SVZ, and cortex (p < 0.05). Late-onset FGR was associated with a widespread reduction of CNPase-positive myelin expression (p < 0.05) and a reduced number of mature oligodendrocytes in all white matter regions examined (p < 0.05). NeuN-positive neuronal cell counts in the cortex were not different across groups; however, the morphology of neuronal cells was different in response to placental insufficiency, most notable in the early-onset FGR fetuses, but it was late-onset FGR that induced caspase-3-positive apoptosis within the cortex. This study demonstrates that early-onset FGR is associated with more widespread white matter injury and neuroinflammation; however, both early- and late-onset FGR are associated with complex patterns of white and grey matter injury. These results indicate that it is the timing of the onset of fetal compromise relative to brain development that principally mediates altered brain development associated with FGR.

Automated neuron tracing using probability hypothesis density filtering.

The functionality of neurons and their role in neuronal networks is tightly connected to the cell morphology. A fundamental problem in many neurobiological studies aiming to unravel this connection is the digital reconstruction of neuronal cell morphology from microscopic image data. Many methods have been developed for this, but they are far from perfect, and better methods are needed. Here we present a new method for tracing neuron centerlines needed for full reconstruction. The method uses a fundamentally different approach than previous methods by considering neuron tracing as a Bayesian multi-object tracking problem. The problem is solved using probability hypothesis density filtering. Results of experiments on 2D and 3D fluorescence microscopy image datasets of real neurons indicate the proposed method performs comparably or even better than the state of the art. Software implementing the proposed neuron tracing method was written in the Java programming language as a plugin for the ImageJ platform. Source code is freely available for non-commercial use at https://bitbucket.org/miroslavradojevic/phd . meijering@imagescience.org. Supplementary data are available at Bioinformatics online.

Protective Role of Hypothermia Against Heat Stress in Differentiated and Undifferentiated Human Neural Precursor Cells: A Differential Approach for the Treatment of Traumatic Brain Injury

Introduction:The present study aimed to explore protective mechanisms of hypothermia against mild cold and heat stress on highly proliferative homogeneous human Neural Precursor Cells (NPCs) derived from Subventricular Zone (SVZ) of human fetal brain.Methods:CD133+ve enriched undifferentiated and differentiated human NPCs were exposed to heat stress at 42°C. Then, Western-blot quantification was performed using Hsp-70 (70 kilodalton heat shock proteins) recombinant protein. Finally, changes in pluripotency and Hsp-70 expression were measured using immunofluorescence staining and RT-qPCR (Quantitative reverse transcription PCR) analysis, respectively.Results:Heat stress resulted in abnormal neurospheres development. The apoptosis rate was enhanced during long-term in vitro culture of neurospheres. Neurogenic differentiation reduced and showed aberrent phenotypes during heat stress. After hypothermia treatment significant improvement in neurospheres and neuronal cell morphology was observed.Conclusion:Mild-hypothermia treatment induces attenuated heat shock response against heat stress resulting in induced HSP-70 expression that significantly improves structure and function of both undifferentiated human NPCs and differentiated neurons.

Inhibition of the SOCS1-JAK2-STAT3 Signaling Pathway Confers Neuroprotection in Rats with Ischemic Stroke

The present study aims to investigate the protective effects of the SOCS1-JAK2-STAT3 signaling pathway on neurons in a rat model of ischemic stroke. Our study was conducted using an ischemic stroke rat model. After the microglia were extracted, 40 neonatal Sprague-Dawley (SD) rats were assigned into the blank, AG490, model and negative control (NC) groups. The neurological function of all the rats was evaluated. Histopathological changes were observed. qRT-PCR and western blotting were applied to measure the expression of genes and proteins in the SOCS1-JAK2-STAT3 signaling pathway and related to apoptosis. The TUNEL assay was conducted to calculate the cellular morphology and apoptosis of neuronal cells. Cell viability was detected using the MTT assay. In addition, immunoassays were used to measure the content of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) as well as the levels of oxidative stress. Compared with the blank group, the model and NC groups showed higher neurological function scores-the cytoplasm of the neurons were cavitated, the organelles were reduced with unclear margins, some of the neurons were necrotic, and apoptosis was increased. In addition, the NC and model groups exhibited decreased cell viability, lower mRNA and protein expression of SOCS1 SOCS3 and bcl-2 and reduced SOD and GSH levels but higher mRNA and protein expression levels of AK2, STAT3,Bax and caspase-3 as well as increased protein expression of P-JAK2, P-STAT3 and activated caspase-3 (c-caspase-3). Moreover, the MDA levels were up-regulated in the NC and model groups. In contrast, opposing trends were found in the AG490 group compared with the NC and model groups. These data demonstrate that inhibiting the SOCS1-JAK2-STAT3 signaling pathway can reduce the loss of nerve function and apoptosis of neuronal cells, which provides a new target for the clinical treatment of ischemic stroke.

Topographical impact of silver nanolines on the morphology of neuronal SH-SY5Y Cells.

An extracellular environment is critical in neuronal development and growth. Changes in neuronal morphology, neuron adhesion, and even the rate of neurite formation, can be modified by both the chemical and physical properties of interfacing substrates. Topography has a major impact on neuronal growth. Neuronal behavior and morphology are affected by the size, shape and pattern of the topographic elements. Combining topography with active materials may lead to enhanced influence. This paper demonstrates the effects of silver nanolines (AgNLs) on the growth pattern of SH-SY5Y cells. The morphology of the cells atop the nanotopographical substrates is measured, revealing a significant promoting effect. The number of neurites initiating from the soma is larger in SH-SY5Y cells plated on AgNLs than in control samples. The cells also exhibit an increase in neurite branching points towards more complex structures. These results indicate that substrates decorated with nanotopography affect cellular growth in a way that may be useful for enhanced regeneration, opening new possibilities for electrode and implant design.

Downregulation of Oxytocin Receptor Decreases the Length of Projections Stimulated by Retinoic Acid in the U-87MG Cells.

Oxytocin is a neuropeptide widely expressed in the brain. Oxytocin plays a role in both proliferation and differentiation of various cells. Previous studies have suggested that oxytocin could affect the morphology of neuronal cells, therefore the objective of the present study was to test whether (1) oxytocin receptor stimulation/inhibition by specific ligands may change cell morphology and gene expression of selected cytoskeletal proteins (2) oxytocin receptor silencing/knockdown may decrease the length of cell projections (3) oxytocin receptor knockdown may affect human glioblastoma U-87MG cell survival. We confirmed the stimulatory effect of retinoic acid (10µM) and oxytocin (1µM) on projection growth. The combination of retinoic acid (10µM) and oxytocin receptor antagonist (L-371,257, 1µM) decreased projections length. Contrary to our assumptions, oxytocin receptor silencing did not prevent stimulation of length of projection by retinoic acid. Retinoic acid's and oxytocin's stimulation of projections length was significantly blunted in U-87MG cells with oxytocin receptor knockdown. Cell viability was significantly decreased in U-87MG cells with oxytocin receptor knockdown. Significantly higher levels of mRNA for cytoskeletal proteins drebrin and vimentin were observed in response to oxytocin incubation for 48h. The data obtained in the present study clearly show that oxytocin induces formation and elongation of cell projections in astrocyte-like U-87MG cells. The effect is mediated by oxytocin receptors and it is accompanied by an increase in gene expression of drebrin and vimentin. Thus, oxytocin receptor signaling, particularly in the glial cells, may play an important role in native cell life, differentiation processes, and tumor progression, as well.

EphA5 and EphA6: regulation of neuronal and spine morphology.

BackgroundThe Eph family of receptor tyrosine kinases plays important roles in neural development. Previous studies have implicated Eph receptors and their ligands, the ephrins, in neuronal migration, axon bundling and guidance to specific targets, dendritic spine formation and neural plasticity. However, specific contributions of EphA5 and EphA6 receptors to the regulation of neuronal cell morphology have not been well studied.ResultsHere we show that deletion of EphA5 and EphA6 results in abnormal Golgi staining patterns of cells in the brain, and abnormal spine morphology.ConclusionThese observations suggest novel functions of these Eph receptors in the regulation of neuronal and spine structure in brain development and function.