Neuroprotective effect of Spilanthes acmella Murr. on pesticide-induced neuronal cells death

Objective: To investigate protective effects of Spilanthes acmella(S,acmella) Murr,extracts against pesticide-induced neuronal cells death and to elucidate the underlying molecular mechanism in dopaminergic(SH-SY5Y) cells lines,Methods: Cell viability of SH-SY5 Y cells was studied by treating the cells with various concentration of pirimicarb for 24 hr,Neuroprotective effect of S,acmella Murr,extracts was investigated by adding the plant extracts to the medium for 24 hr prior to the incubation with 100 μM H_2O_2 or with pirimicarb for 24 hr,Control-untreated cells were incubated with the culture medium,Cell viability was measured by MTT assay,calpain and calpastatin expressions were analyzed by Western blotting and immunocytochemistry,Results: Pretreatment of SH-SY5 Y cells with S,acmella Murr,extracts(1 μg/m L) for 24 hr significantly increased the dopaminergic neurons in pirimicarb-induced neurotoxicity,In addition,pretreatment with the S,acmella Murr,extracts led to decreased calpain but increased calpastatin protein levels,Conclusion: S,acmella Murr,extracts exerted neuroprotective effect,via an alteration of calcium homeostasis,against pirimicarb induced neurotoxicity,The S,acmella Murr,might be a potential natural candidate with neuroprotective activity.

Relevance and therapeutic potential of Cyp A targeting to block apoptosis inducing factor-mediated neuronal cell death

Programmed cell death （PCD） signaling pathways are import- ant contributors to acute neurological insults such as hypox- ic-ischemic brain damage, traumatic brain injury, stroke etc. The pathogenesis of all these diseases is closely linked with ab- erration of apoptotic cell death pathways. Mitochondria play a crucial role during PCD, acting as both sensors of death signals, and as initiators of biochemical path- ways, which cause cell death （Bras et al., 2005）. Cytochrome c was the firstly identified apoptogenic factor released from mitochondria into the cytosol, where it induces apoptosome formation through the activation of caspases. Other proteins, such as apoptosis inducing factor （AIF）, have been subsequently identified as mitochondrial released factors. AIF contributes to apoptotic nuclear DNA damage （Bras et al., 2005）. in a caspase-independent way

Caspase 3 siRNA decreases apoptosis in cultured neuronal cells

BACKGROUND： Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction. OBJECTIVE： To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid （shRNA） into Neuro 2a cells using a lentiviral vector.DESIGN： TiME-AND SETTING： An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008. MATERIALS： PLL3.7, PCMV-VSV-G, and PH＇8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.METHODS： Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.MAIN OUTCOME MEASURES： Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS： The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION： Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.

One-step cell biomanufacturing platform:porous gelatin microcarrier beads promote human embryonic stem cell-derived midbrain dopaminergic progenitor cell differentiation in vitro and survival after transplantation in vivo

Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.

APP and APLP1 are degraded through autophagy in response to proteasome inhibition in neuronal cells

Amyloid beta(Aβ)precursor protein(APP)is a key protein in the pathogenesis of Alzheimer’s disease(AD).Both APP and its paralogue APLP1(amyloid beta precursor-like protein 1)have multiple functions in cell adhesion and proliferation.Previously it was thought that autophagy is a novel beta-amyloid peptide(Aβ)-generating pathway activated in AD.However,the protein proteolysis of APLP1 is still largely unknown.The present study shows that APLP1 is rapidly degraded in neuronal cells in response to stresses,such as proteasome inhibition.Activation of the endoplasmic reticulum(ER)stress by proteasome inhibitors induces autophagy,causing reduction of mature APLP1/APP.Blocking autophagy or JNK stress kinase rescues the protein expression for both APP and APLP1.Therefore,our results suggest that APP/APLP1 is degraded through autophagy and the APLP1 proteolysis is mainly mediated by autophagy-lysosome pathway.

Anionic liposomes for small interfering ribonucleic acid （siRNA） delivery to primary neuronal cells： Evaluation of alpha-synuclein knockdown efficacy

Alpha-synuclein （a-syn） deposition in Lewy bodies （LB） is one of the main neuropathological hallmarks of Parkinson＇s disease （PD）. LB accumulation is considered a causative factor of PD, which suggests that strategies aimed at reducing a-syn levels could be relevant for its treatment. In the present study, we developed novel nanocarriers suitable for systemic delivery of small interfering ribonucleic acid （siRNA） that were specifically designed to reduce neuronal α-syn by RNA interference. Anionic liposomes loaded with an siRNA-protamine complex for α-syn gene silencing and decorated with a rabies virus glycoprotein （RVG）-derived peptide as a targeting agent were prepared. The nanoparticles were characterized for their ability to load, protect, and deliver the functional siRNA to mouse primary hippocampal and cortical neurons as well as their efficiency to induce gene silencing in these cells. Moreover, the nanocarriers were evaluated for their stability in serum. The RVG-decorated liposomes displayed suitable characteristics for future in vivo applications and successfully induced α-syn gene silencing in primary neurons without altering cell viability. Collectively, our results indicate that RVG-decorated liposomes may be an ideal tool for further studies aimed at achieving efficient in vivo α-syn gene silencing in mouse models of PD.

Induction of clusterin Expression by Neuronal Cell Death in Zebrafish

Clusterin, a protein associated with multiple functions, is expressed in a wide variety of mammalian tissues. Although clusterin is known to be involved in neurodegenerative diseases, ageing, and tumorigenesis, a detailed analysis of the consequences of gain- or loss-of- function approaches has yet to be performed to understand the underlying mechanisms of clusterin functions. Since clusterin levels change in neurological diseases, it is likely that clusterin contributes to cell death and degeneration in general. Zebrafish was investigated as a model system to study human diseases. During development, zebrafish clusterin was expressed in the notochord and nervous system. Embryonic overexpression of clusterin by mRNA microinjection did not affect axis formation, whereas its knock-down by anti-sense morpholino treatment resulted in neuronal cell death. To analyze the function of clusterin in neurodegeneration, a transgenic zebrafish was investigated, in which nitroreductase expression is regulated under the control of a neuron-specifc huC promoter which is active between the stages of early neuronal precursors and mature neurons. Nitroreductase turns metronidazole into a cytotoxic agent that induces cell death within 12 h. After metronidazole treatment, transgenic zebrafish showed neuron-specific cell death. Interestingly, we also observed a dramatic induction of clusterin expression in the brain and spinal cord in these fish, suggesting a direct or indirect role of clusterin in neuronal cell death and thus, more generally, in neurodegeneration.

Real-time effects of nicotine exposure and withdrawal on neurotransmitter metabolism of hippocampal neuronal cells by microfluidic chip-coupled LC-MS

Nicotine ingested from smoking exerts neuroprotection and developmental neurotoxicity in central nervous system.It can produce several changes of cognitive behaviors through regulating the release of different neurotransmitters in the brain.However,the effects of nicotine exposure or withdrawal on neurotransmitter metabolism of hippocampus are still unclear.In this study,we real-time evaluated the dynamic alterations in neurotransmitter metabolism of hippocampal neuronal(HT22)cells induced by nicotine exposure and withdrawal at relevant exposure levels of smoking and secondhand smoke by using a microfluidic chip-coupled with liquid chromatography-mass spectrometry(MC-LC-MS)system.We found HT22 cells mainly released related neurotransmitters of tryptophan and choline metabolism,both nicotine exposure and withdraw altered its neurotransmitters and their metabolites release.Exposure to nicotine mainly altered the secretion of serotonin,kynurenic acid,choline and acetylcholine of HT22 cells to improve hippocampal dependent cognition,and the change are closely related to the dose and duration of exposure.Moreover,the altered metabolites could rapidly recover after nicotine withdrawal,but picolinic acid was elevated.MC-LC-MS system used in present study showed a greater advantage to detect unstable metabolites than conventional method by using in vitro model,and the results of dynamic alterations of neurotransmitter metabolism induced by nicotine might provide a potential targets for drug development of neuroprotection or cognitive improvement.

c-Abl-MST1 Signaling Pathway Mediates Oxidative Stress Induced Neuronal Cell Death

Oxidative stress influences cell survival and homeostasis, but the mechanisms underlying the biological effects of oxidative stress remain to be elucidated. We have defined that the

Denervated hippocampus provides a favorable microenvironment for neuronal differentiation of endogenous neural stem cells

Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal differentiation of neural stem cells.However,the pathways and mechanisms in this process are still unclear.Seven days after fimbria fornix transection,our reverse transcription polymerase chain reaction,western blot assay,and enzyme linked immunosorbent assay results show a significant increase in ciliary neurotrophic factor m RNA and protein expression in the denervated hippocampus.Moreover,neural stem cells derived from hippocampi of fetal（embryonic day 17） Sprague-Dawley rats were treated with ciliary neurotrophic factor for 7 days,with an increased number of microtubule associated protein-2-positive cells and decreased number of glial fibrillary acidic protein-positive cells detected.Our results show that ciliary neurotrophic factor expression is up-regulated in the denervated hippocampus,which may promote neuronal differentiation of neural stem cells in the denervated hippocampus.

Cell cycle exit and neuronal differentiation 1-engineered embryonic neural stem cells enhance neuronal differentiation and neurobehavioral recovery after experimental traumatic brain injury

Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can improve the prognosis of traumatic brain injury remained unclear.In this study,we performed quantitative proteomic analysis and found that after traumatic brain injury,CEND1 expression was downregulated in mouse brain tissue.Three days after traumatic brain injury,we transplanted CEND1-transfected neural stem cells into the area surrounding the injury site.We found that at 5 weeks after traumatic brain injury,transplantation of CEND1-transfected neural stem cells markedly alleviated brain atrophy and greatly improved neurological function.In vivo and in vitro results indicate that CEND1 overexpression inhibited the proliferation of neural stem cells,but significantly promoted their neuronal differentiation.Additionally,CEND1 overexpression reduced protein levels of Notch1 and cyclin D1,but increased levels of p21 in CEND1-transfected neural stem cells.Treatment with CEND1-transfected neural stem cells was superior to similar treatment without CEND1 transfection.These findings suggest that transplantation of CEND1-transfected neural stem cells is a promising cell therapy for traumatic brain injury.This study was approved by the Animal Ethics Committee of the School of Biomedical Engineering of Shanghai Jiao Tong University,China(approval No.2016034)on November 25,2016.

Combination of mild therapeutic hypothermia and adipose-derived stem cells for ischemic brain injury

Mild therapeutic hypothermia has been shown to mitigate cerebral ischemia, reduce cerebral edema, and improve the prognosis of patients with cerebral ischemia. Adipose-derived stem cell-based therapy can decrease neuronal death and infiltration of inflammatory cells, exerting a neuroprotective effect. We hypothesized that the combination of mild therapeutic hypothermia and adipose-derived stem cells would be neuroprotective for treatment of stroke. A rat model of transient middle cerebral artery occlusion was established using the nylon monofilament method. Mild therapeutic hypothermia（33°C） was induced after 2 hours of ischemia. Adipose-derived stem cells were administered through the femoral vein during reperfusion. The severity of neurological dysfunction was measured by a modified Neurological Severity Score Scaling System. The area of the infarct lesion was determined by 2,3,5-triphenyltetrazolium chloride staining. Apoptotic neurons were detected by terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling（TUNEL） staining. The regeneration of microvessels and changes in the glial scar were detected by immunofluorescence staining. The inflammatory responses after ischemic brain injury were evaluated by in situ staining using markers of inflammatory cells. The expression of inflammatory cytokines was measured by reverse transcription-polymerase chain reaction. Compared with mild therapeutic hypothermia or adipose-derived stem cell treatment alone, their combination substantially improved neurological deficits and decreased infarct size. They synergistically reduced the number of TUNEL-positive cells and glial fibrillary acidic protein expression, increased vascular endothelial growth factor levels, effectively reduced inflammatory cell infiltration and down-regulated the m RNA expression of the proinflammatory cytokines interleukin-1β, tumor necrosis factor-α and interleukin-6. Our findings indicate that combined treatment is a better approach for treating stroke compared with mild therapeutic hypothermia or adipose-derived stem cells alone.

Differentiation of neuron-like cells from mouse parthenogenetic embryonic stem cells

Parthenogenetic embryonic stem cells have pluripotent differentiation potentials, akin to fertilized embryo-derived embryonic stem cells. The aim of this study was to compare the neuronal differentiation potential of parthenogenetic and fertilized embryo-derived embryonic stem cells. Before differentiation, karyotype analysis was performed, with normal karyotypes detected in both parthenogenetic and fertilized embryo-derived embryonic stem cells. Sex chromosomes were identified as XX. Immunocytochemistry and quantitative real-time PCR detected high expression of the pluripotent gene, Oct4, at both the mRNA and protein levels, indicating pluripotent differentiation potential of the two embryonic stem cell subtypes. Embryonic stern cells were induced with retinoic acid to form embryoid bodies, and then dispersed into single cells. Single cells were differentiated in N2 differentiation medium for 9 days. Immunocytochemistry showed parthenogenetic and fertilized embryo-derived embryonic stem cells both express the neuronal cell markers nestin, ~lll-tubulin and myelin basic protein. Quantitative real-time PCR found expression of neuregenesis related genes （Sox-1, Nestin, GABA, Pax6, Zic5 and Pitxl） in both types of embryonic stem cells, and Oct4 expression was significantly decreased. Nestin and Pax6 expression in parthenogenetic embryonic stem cells was significantly higher than that in fertilized embryo-derived embryonic stem cells. Thus, our experimental findings indicate that parthenogenetic embryonic stem cells have stronger neuronal differentiation potential than fertilized embryo-derived embryonic stem cells.

Bis(7)-Tacrine, a Promising Anti-Alzheimer's Agent,Attenuates Glutamate-Induced Cell Injury in Primary Cultured Cerebrocortical Neurons of Rats

The effects of bis(7) tacrine, a novel dimeric acetylcholinesterase (AChE) inhibitor, on glutamate induced cell injury were investigated in primary cerebral cortical neurons of rats. Exposure of cultured neurons (12 days after plating) to 0.5 mmol/L glutamate for 30 min resulted in significant cell damage. Pretreatment with bis(7) tacrine (0.03 1.0 μmol/L) reduced the glutamate induced neurotoxicity in a concentration dependent manner and the maximal response was seen at 1 μmol/L with approximately 30% protection. A receptor binding assay showed that bis(7) tacrine can completely displace MK 801 binding to rat cortical membrane with an IC 50 of 0.57 μmol/L. These findings suggest that bis(7) tacrine can directly interact with N methyl D aspartate receptor channel complex, which may contribute to the inhibitor's protective effects against glutamate induced excitotoxicity. Thus, it is possible that anti glutamate/anti AChE synergism is responsible for potentially better Alzheimer's therapy of bis(7) tacrine relative to tacrine.

Therapeutic effect of bone marrow mesenchymal stem cells on cold stress induced changes in the hippocampus of rats

The present study aims to evaluate the effect of bone marrow mesenchymal stem cells on cold stress induced neuronal changes in hippocampal CA1 region of Wistar rats. Bone marrow mes- enchymal stem cells were isolated from a 6-week-old Wistar rat. Bone marrow from adult femora and tibia was collected and mesenchymal stem cells were cultured in minimal essential medium containing 10% heat-inactivated fetal bovine serum and were sub-cultured. Passage 3 cells were analyzed by flow cytometry for positive expression of CD44 and CD90 and negative expression of CD45. Once CD44 and CD90 positive expression was achieved, the cells were cultured again to 90% confluence for later experiments. Twenty-four rats aged 8 weeks old were randomly and evenly divided into normal control, cold water swim stress （cold stress）, cold stress ＋ PBS （intra- venous infusion）, and cold stress ＋ bone marrow mesenchymal stem cells （1 x 106; intravenous infusion） groups. The total period of study was 60 days which included 1 month stress period followed by 1 month treatment. Behavioral functional test was performed during the entire study period. After treatment, rats were sacrificed for histological studies. Treatment with bone marrow mesenchymal stem cells significantly increased the number of neuronal cells in hippocampal CA 1 region. Adult bone marrow mesenchymal stem cells injected by intravenous administration show potential therapeutic effects in cognitive decline associated with stress-related lesions.

Direct reprogramming of somatic cells into neural stem cells or neurons for neurological disorders

Direct reprogramming of somatic cells into neurons or neural stem cells is one of the most important frontier fields in current neuroscience research. Without undergoing the pluripotency stage, induced neurons or induced neural stem cells are a safer and timelier manner resource in comparison to those derived from induced pluripotent stem cells. In this prospective, we review the recent advances in generation of induced neurons and induced neural stem cells in vitro and in vivo and their potential treatments of neurological disorders.

Deriving striatal projection neurons from human pluripotent stem cells with Activin A

The striatum is the main input structure of the basal ganglia and is involved in voluntary motor control,habit learning and reward processing.Medium spiny neurons（MSNs）comprise80%and 95%of striatal neurons in primates and rodents,respectively.

Using induced pluripotent stem cells derived neurons to model brain diseases

The ability to use induced pluripotent stem cells（i PSC）to model brain diseases is a powerful tool for unraveling mechanistic alterations in these disorders.Rodent models of brain diseases have spurred understanding of pathology but the concern arises that they may not recapitulate the full spectrum of neuron disruptions associated with human neuropathology.iPSC derived neurons,or other neural cell types,provide the ability to access pathology in cells derived directly from a patient＇s blood sample or skin biopsy where availability of brain tissue is limiting.Thus,utilization of iPSC to study brain diseases provides an unlimited resource for disease modelling but may also be used for drug screening for effective therapies and may potentially be used to regenerate aged or damaged cells in the future.Many brain diseases across the spectrum of neurodevelopment,neurodegenerative and neuropsychiatric are being approached by iPSC models.The goal of an iPSC based disease model is to identify a cellular phenotype that discriminates the disease-bearing cells from the control cells.In this mini-review,the importance of iPSC cell models validated for pluripotency,germline competency and function assessments is discussed.Selected examples for the variety of brain diseases that are being approached by iPSC technology to discover or establish the molecular basis of the neuropathology are discussed.

Live-cell imaging:new avenues to investigate retinal regeneration

Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish（Danio rerio） possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.