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SH-SY5Y

RRID:CVCL_0019

Organism

Homo sapiens

Comments

Problematic cell line: Partially contaminated. Some laboratories that are redistributing this cell line are in fact redistributing a contaminated cell line of mouse origin (PubMed=25182563). Part of: Cancer Cell Line Encyclopedia (CCLE) project. Part of: ENCODE project common cell types; tier 3. From: Memorial Sloan Kettering Cancer Center; New York; USA. Registration: Memorial Sloan Kettering Cancer Center Office of Technology Development; SK 810. Characteristics: Neuroblastic type (N-type) (PubMed=15720811). Doubling time: >55 hours (DSMZ). Sequence variation: ALK p.Phe1174Leu (c.3522C>A) (PubMed=28350380). Omics: Deep antibody staining analysis. Omics: Deep exome analysis. Omics: Deep tyrosine phosphoproteome analysis. Omics: Deep RNAseq analysis. Omics: GPI-anchored proteins analysis by proteomics. Omics: Mitochondrial proteome analysis by 2D-DE/MS. Omics: N-glycan profiling. Omics: SNP array analysis. Omics: Transcriptome analysis. Genome ancestry: African=0%; Native American=1.17%; East Asian, North=0.35%; East Asian, South=0.1%; South Asian=0.08%; European, North=69.09%; European, South=29.2% (PubMed=30894373). Misspelling: SH-SY5; Occasionally. Derived from metastatic site: Bone marrow. DT Created: 04-04-12; Last updated: 05-07-19; Version: 29

Proper Citation

ECACC Cat# 94030304, RRID:CVCL_0019

Category

Cancer cell line DT Created: 04-04-12; Last updated: 05-07-19; Version: 29

Sex

DT Created: 04-04-12; Last updated: 05-07-19; Version: 29

Synonyms

SHSY5Y, SHSY-5Y, SH-Sy5y, SK-SH-SY5Y, SY5Y, SH-SY5Y Parental DT Created: 04-04-12, Last updated: 05-07-19, Version: 29

Vendor

ECACC

Cat Num

94030304

Cross References

BTO; BTO:0000793 CLO; CLO_0009015 EFO; EFO_0002717 MCCL; MCC:0000421 CLDB; cl4287 CLDB; cl4288 CLDB; cl4289 CLDB; cl4290 AddexBio; C0005004/63 ATCC; CRL-2266 BCRJ; 0223 BioSample; SAMN10987717 CCLE; SHSY5Y_AUTONOMIC_GANGLIA CCRID; 3111C0001CCC000026 CCRID; 3131C0001000700097 CCRID; 3142C0001000000486 CCTCC; GDC0210 Cell_Model_Passport; SIDM01236 CGH-DB; 63-1 ChEMBL-Cells; CHEMBL3307740 ChEMBL-Targets; CHEMBL614910 CLS; 300154/p822_SH-SY5Y Cosmic; 688084 Cosmic; 1019933 Cosmic; 1167410 Cosmic; 1212536 Cosmic; 2058109 Cosmic; 2239470 Cosmic; 2393641 DepMap; ACH-001188 DSMZ; ACC-209 ECACC; 94030304 ENCODE; ENCBS264AAA GEO; GSM692874 GEO; GSM887570 GEO; GSM888653 GEO; GSM1622294 GEO; GSM2371253 GEO; GSM2394368 ICLC; HTL95013 IZSLER; BS TCL 232 KCB; KCB 2006107YJ KCLB; 22266 LINCS_LDP; LCL-2000 Lonza; 132 MetaboLights; MTBLS455 NCBI_Iran; C611 PRIDE; PXD003105 PRIDE; PXD003914 TOKU-E; 3118 Wikidata; Q7390126 DT Created: 04-04-12; Last updated: 05-07-19; Version: 29

Arctic Aβ40 blocks the nicotine-induced neuroprotective effect of CHRNA7 by inhibiting the ERK1/2 pathway in human neuroblastoma cells.

  • Ju Y
  • Neurochem. Int.
  • 2018 Jun 6

Literature context:


Abstract:

Amyloid β protein (Aβ) plays a central role in Alzheimer's disease (AD) pathogenesis. Point mutations in the Aβ sequence, which cluster around the central hydrophobic core of the peptide, are associated with familial AD (FAD). Several mutations have been identified, with the Arctic mutation exhibiting a purely cognitive phenotype that is typical of AD. Our previous findings suggest that Arctic Aβ40 binds to and aggregates with CHRNA7, thereby inhibiting the calcium response and signaling pathways downstream of the receptor. Activation of CHRNA7 is neuroprotective both in vitro and in vivo. Therefore, in the present study, we investigated whether Arctic Aβ40 affects neuronal survival and/or death via CHRNA7. Using human neuroblastoma SH-SY5Y cells, we found that the neuroprotective function of CHRNA7 is blocked by CHRNA7 knockdown using RNA interference. Furthermore, Arctic Aβ40 blocked the neuroprotective effect of nicotine by inhibiting the ERK1/2 pathway downstream of CHRNA7. Moreover, we show that ERK1/2 activation mediates the neuroprotective effect of nicotine against oxidative stress. Collectively, our findings further our understanding of the molecular pathogenesis of Arctic FAD.

Funding information:
  • Medical Research Council - G0801983(United Kingdom)

Co-optation of Tandem DNA Repeats for the Maintenance of Mesenchymal Identity.

  • Balestrieri C
  • Cell
  • 2018 May 17

Literature context:


Abstract:

Tandem repeats (TRs) are generated by DNA replication errors and retain a high level of instability, which in principle would make them unsuitable for integration into gene regulatory networks. However, the appearance of DNA sequence motifs recognized by transcription factors may turn TRs into functional cis-regulatory elements, thus favoring their stabilization in genomes. Here, we show that, in human cells, the transcriptional repressor ZEB1, which promotes the maintenance of mesenchymal features largely by suppressing epithelial genes and microRNAs, occupies TRs harboring dozens of copies of its DNA-binding motif within genomic loci relevant for maintenance of epithelial identity. The deletion of one such TR caused quasi-mesenchymal cancer cells to reacquire epithelial features, partially recapitulating the effects of ZEB1 gene deletion. These data demonstrate that the high density of identical motifs in TRs can make them suitable platforms for recruitment of transcriptional repressors, thus promoting their exaptation into pre-existing cis-regulatory networks.

Funding information:
  • Wellcome Trust - 061858(United Kingdom)

Intracellular Proteolysis of Progranulin Generates Stable, Lysosomal Granulins that Are Haploinsufficient in Patients with Frontotemporal Dementia Caused by GRN Mutations.

  • Holler CJ
  • eNeuro
  • 2018 May 3

Literature context:


Abstract:

Homozygous or heterozygous mutations in the GRN gene, encoding progranulin (PGRN), cause neuronal ceroid lipofuscinosis (NCL) or frontotemporal dementia (FTD), respectively. NCL and FTD are characterized by lysosome dysfunction and neurodegeneration, indicating PGRN is important for lysosome homeostasis in the brain. PGRN is trafficked to the lysosome where its functional role is unknown. PGRN can be cleaved into seven 6-kDa proteins called granulins (GRNs); however, little is known about how GRNs are produced or if levels of GRNs are altered in FTD-GRN mutation carriers. Here, we report the identification and characterization of antibodies that reliably detect several human GRNs by immunoblot and immunocytochemistry. Using these tools, we find that endogenous GRNs are present within multiple cell lines and are constitutively produced. Further, extracellular PGRN is endocytosed and rapidly processed into stable GRNs within lysosomes. Processing of PGRN into GRNs is conserved between humans and mice and is modulated by sortilin expression and mediated by cysteine proteases (i.e. cathpesin L). Induced lysosome dysfunction caused by alkalizing agents or increased expression of transmembrane protein 106B (TMEM106B) inhibit processing of PGRN into GRNs. Finally, we find that multiple GRNs are haploinsufficient in primary fibroblasts and cortical brain tissue from FTD-GRN patients. Taken together, our findings raise the interesting possibility that GRNs carry out critical lysosomal functions and that loss of GRNs should be explored as an initiating factor in lysosomal dysfunction and neurodegeneration caused by GRN mutations.

Stress Granule Assembly Disrupts Nucleocytoplasmic Transport.

  • Zhang K
  • Cell
  • 2018 May 3

Literature context:


Abstract:

Defects in nucleocytoplasmic transport have been identified as a key pathogenic event in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) mediated by a GGGGCC hexanucleotide repeat expansion in C9ORF72, the most common genetic cause of ALS/FTD. Furthermore, nucleocytoplasmic transport disruption has also been implicated in other neurodegenerative diseases with protein aggregation, suggesting a shared mechanism by which protein stress disrupts nucleocytoplasmic transport. Here, we show that cellular stress disrupts nucleocytoplasmic transport by localizing critical nucleocytoplasmic transport factors into stress granules, RNA/protein complexes that play a crucial role in ALS pathogenesis. Importantly, inhibiting stress granule assembly, such as by knocking down Ataxin-2, suppresses nucleocytoplasmic transport defects as well as neurodegeneration in C9ORF72-mediated ALS/FTD. Our findings identify a link between stress granule assembly and nucleocytoplasmic transport, two fundamental cellular processes implicated in the pathogenesis of C9ORF72-mediated ALS/FTD and other neurodegenerative diseases.

Funding information:
  • Canadian Institutes of Health Research - (Canada)

Copper-Binding Small Molecule Induces Oxidative Stress and Cell-Cycle Arrest in Glioblastoma-Patient-Derived Cells.

  • Shimada K
  • Cell Chem Biol
  • 2018 May 17

Literature context:


Abstract:

Transition metals are essential, but deregulation of their metabolism causes toxicity. Here, we report that the compound NSC319726 binds copper to induce oxidative stress and arrest glioblastoma-patient-derived cells at picomolar concentrations. Pharmacogenomic analysis suggested that NSC319726 and 65 other structural analogs exhibit lethality through metal binding. Although NSC319726 has been reported to function as a zinc ionophore, we report here that this compound binds to copper to arrest cell growth. We generated and validated pharmacogenomic predictions: copper toxicity was substantially inhibited by hypoxia, through an hypoxia-inducible-factor-1α-dependent pathway; copper-bound NSC319726 induced the generation of reactive oxygen species and depletion of deoxyribosyl purines, resulting in cell-cycle arrest. These results suggest that metal-induced DNA damage may be a consequence of exposure to some xenobiotics, therapeutic agents, as well as other causes of copper dysregulation, and reveal a potent mechanism for targeting glioblastomas.

Funding information:
  • NCI NIH HHS - P01 CA087497()
  • NCI NIH HHS - R35 CA209896()
  • NIAID NIH HHS - R01 AI62261(United States)

The Orphan G Protein-coupled Receptor 75 Signaling is Activated by the Chemokine CCL5.

  • Dedoni S
  • J. Neurochem.
  • 2018 May 17

Literature context:


Abstract:

The chemokine CCL5 prevents neuronal cell death mediated both by amyloid β, as well as the human immunodeficiency virus (HIV) viral proteins gp120 and Tat. Because CCL5 binds to CCR5, CCR3 and/or CCR1 receptors, it is unclear which of these receptors plays a role in neuroprotection. Indeed, CCL5 also has neuroprotective activity in cells lacking these receptors. CCL5 may bind to a G protein-coupled receptor 75 (GPR75), which encodes for a 540 amino-acid orphan receptor of the Gqα family. In this study, we have used SH-SY5Y human neuroblastoma cells to characterize whether CCL5 could activate a Gq signaling through GPR75. Both qPCR and flow cytometry show that these cells express GPR75 but do not express CCR5, CCR3 or CCR1 receptors. SY-SY5Y cells were then used to examine CCL5-mediated signaling. We report that CCL5 promotes a time- and concentration-dependent phosphorylation of protein kinase B (AKT), glycogen synthase kinase 3β and extracellular signal-regulated kinase (ERK) 1/2. Specific antagonists of CCR5, CCR3 and CCR1 did not prevent CCL5 from increasing phosphorylated AKT or ERK. Moreover, CCL5 promotes a time-dependent internalization of GPR75. Lastly, knocking down GPR75 expression by a CRISPR-Cas9 approach inhibited the ability of CCL5 to activate pERK in SH-SY5Y cells. Therefore, we propose that GPR75 is a novel receptor for CCL5 that could explain some of the pharmacological action of this chemokine. These findings may help in the development of small molecule GPR75 agonists that mimic CCL5. This article is protected by copyright. All rights reserved.

Funding information:
  • NIGMS NIH HHS - R15GM055885(United States)
  • NINDS NIH HHS - R21 NS089446()

Small molecule induced oligomerization, clustering and clathrin-independent endocytosis of the dopamine transporter.

  • Sorkina T
  • Elife
  • 2018 Apr 9

Literature context:


Abstract:

Clathrin-independent endocytosis (CIE) mediates internalization of many transmembrane proteins but the mechanisms of cargo recruitment during CIE are poorly understood. We found that the cell-permeable furopyrimidine AIM-100 promotes dramatic oligomerization, clustering and CIE of human and mouse dopamine transporters (DAT), but not of their close homologues, norepinephrine and serotonin transporters. All effects of AIM-100 on DAT and the occupancy of substrate binding sites in the transporter were mutually exclusive, suggesting that AIM-100 may act by binding to DAT. Surprisingly, AIM-100-induced DAT endocytosis was independent of dynamin, cholesterol-rich microdomains and actin cytoskeleton, implying that a novel endocytic mechanism is involved. AIM-100 stimulated trafficking of internalized DAT was also unusual: DAT accumulated in early endosomes without significant recycling or degradation. We propose that AIM-100 augments DAT oligomerization through an allosteric mechanism associated with the DAT conformational state, and that oligomerization-triggered clustering leads to a coat-independent endocytosis and subsequent endosomal retention of DAT.

Funding information:
  • National Institutes of Health - DA014204()
  • NIAID NIH HHS - U01 AI101981(United States)

Dissecting the Functional Consequences of De Novo DNA Methylation Dynamics in Human Motor Neuron Differentiation and Physiology.

  • Ziller MJ
  • Cell Stem Cell
  • 2018 Apr 5

Literature context:


Abstract:

The somatic DNA methylation (DNAme) landscape is established early in development but remains highly dynamic within focal regions that overlap with gene regulatory elements. The significance of these dynamic changes, particularly in the central nervous system, remains unresolved. Here, we utilize a powerful human embryonic stem cell differentiation model for the generation of motor neurons (MNs) in combination with genetic mutations in the de novo DNAme machinery. We quantitatively dissect the role of DNAme in directing somatic cell fate with high-resolution genome-wide bisulfite-, bulk-, and single-cell-RNA sequencing. We find defects in neuralization and MN differentiation in DNMT3A knockouts (KO) that can be rescued by the targeting of DNAme to key developmental loci using catalytically inactive dCas9. We also find decreased dendritic arborization and altered electrophysiological properties in DNMT3A KO MNs. Our work provides a list of DNMT3A-regulated targets and a mechanistic link between de novo DNAme, cellular differentiation, and human MN function.

Funding information:
  • NCATS NIH HHS - UL1 TR000457(United States)

GPR68 Senses Flow and Is Essential for Vascular Physiology.

  • Xu J
  • Cell
  • 2018 Apr 19

Literature context:


Abstract:

Mechanotransduction plays a crucial role in vascular biology. One example of this is the local regulation of vascular resistance via flow-mediated dilation (FMD). Impairment of this process is a hallmark of endothelial dysfunction and a precursor to a wide array of vascular diseases, such as hypertension and atherosclerosis. Yet the molecules responsible for sensing flow (shear stress) within endothelial cells remain largely unknown. We designed a 384-well screening system that applies shear stress on cultured cells. We identified a mechanosensitive cell line that exhibits shear stress-activated calcium transients, screened a focused RNAi library, and identified GPR68 as necessary and sufficient for shear stress responses. GPR68 is expressed in endothelial cells of small-diameter (resistance) arteries. Importantly, Gpr68-deficient mice display markedly impaired acute FMD and chronic flow-mediated outward remodeling in mesenteric arterioles. Therefore, GPR68 is an essential flow sensor in arteriolar endothelium and is a critical signaling component in cardiovascular pathophysiology.

Funding information:
  • NCI NIH HHS - U24 CA126543(United States)

The Neuroprotective Effect of Thalidomide against Ischemia through the Cereblon-mediated Repression of AMPK Activity.

  • Sawamura N
  • Sci Rep
  • 2018 Feb 6

Literature context:


Abstract:

Thalidomide was originally used as a sedative and found to be a teratogen, but now thalidomide and its derivatives are widely used to treat haematologic malignancies. Accumulated evidence suggests that thalidomide suppresses nerve cell death in neurologic model mice. However, detailed molecular mechanisms are unknown. Here we examined the molecular mechanism of thalidomide's neuroprotective effects, focusing on its target protein, cereblon (CRBN), and its binding protein, AMP-activated protein kinase (AMPK), which plays an important role in maintaining intracellular energy homeostasis in the brain. We used a cerebral ischemia rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). Thalidomide treatment significantly decreased the infarct volume and neurological deficits of MCAO/R rats. AMPK was the key signalling protein in this mechanism. Furthermore, we considered that the AMPK-CRBN interaction was altered when neuroprotective action by thalidomide occurred in cells under ischemic conditions. Binding was strong between AMPK and CRBN in normal SH-SY5Y cells, but was weakened by the addition of H2O2. However, when thalidomide was administered at the same time as H2O2, the binding of AMPK and CRBN was partly restored. These results suggest that thalidomide inhibits the activity of AMPK via CRBN under oxidative stress and suppresses nerve cell death.

Funding information:
  • NCI NIH HHS - HHSN261200800001E(United States)

Palmitate-induced C/EBP homologous protein activation leads to NF-κB-mediated increase in BACE1 activity and amyloid beta genesis.

  • Marwarha G
  • J. Neurochem.
  • 2018 Jan 10

Literature context:


Abstract:

The etiology of Alzheimer's disease (AD) is egregiously comprehended, but epidemiological studies have posited that diets rich in the saturated fatty acid palmitic acid (palmitate) are a significant risk factor. The production and accumulation of amyloid beta peptide (Aβ) is considered the core pathological molecular event in the pathogenesis of AD. The rate-limiting step in Aβ genesis from amyloid-β precursor protein (AβPP) is catalyzed by the enzyme β-site amyloid precursor protein cleaving enzyme 1 (BACE1), the expression and enzymatic activity of which is significantly up-regulated in the AD brain. In this study, we determined the molecular mechanisms that potentially underlie the palmitate-induced up-regulation in BACE1 expression and augmented Aβ production. We demonstrate that a palmitate-enriched diet and exogenous palmitate treatment evoke an increase in BACE1 expression and activity leading to enhanced Aβ genesis in the mouse brain and SH-SY5Y-APPSwe cells, respectively, through the activation of the transcription factor NF-κB. Chromatin immunoprecipitation (ChIP) assays and luciferase reporter assays revealed that palmitate enhances BACE1 expression by increasing the binding of NF-κB in the BACE1 promoter followed by an enhancement in the transactivation of the BACE1 promoter. Elucidation and delineation of upstream molecular events unveiled a critical role of the endoplasmic reticulum stress-associated transcription factor, C/EBP homologous protein (CHOP) in the palmitate-induced NF-κB activation, as CHOP knock-down cells and Chop-/- mice do not exhibit the same degree of NF-κB activation in response to the palmitate challenge. Our study delineates a novel CHOP-NF-κB signaling pathway that mediates palmitate-induced up-regulation of BACE1 expression and Aβ genesis.

Funding information:
  • NIA NIH HHS - R01AG044420(United States)

The Histone Deacetylase Inhibitor Valproic Acid Exerts a Synergistic Cytotoxicity with the DNA-Damaging Drug Ellipticine in Neuroblastoma Cells.

  • Cerna T
  • Int J Mol Sci
  • 2018 Jan 5

Literature context:


Abstract:

Neuroblastoma (NBL) originates from undifferentiated cells of the sympathetic nervous system. Chemotherapy is judged to be suitable for successful treatment of this disease. Here, the influence of histone deacetylase (HDAC) inhibitor valproate (VPA) combined with DNA-damaging chemotherapeutic, ellipticine, on UKF-NB-4 and SH-SY5Y neuroblastoma cells was investigated. Treatment of these cells with ellipticine in combination with VPA led to the synergism of their anticancer efficacy. The effect is more pronounced in the UKF-NB-4 cell line, the line with N-myc amplification, than in SH-SY5Y cells. This was associated with caspase-3-dependent induction of apoptosis in UKF-NB-4 cells. The increase in cytotoxicity of ellipticine in UKF-NB-4 by VPA is dictated by the sequence of drug administration; the increased cytotoxicity was seen only after either simultaneous exposure to these drugs or after pretreatment of cells with ellipticine before their treatment with VPA. The synergism of treatment of cells with VPA and ellipticine seems to be connected with increased acetylation of histones H3 and H4. Further, co-treatment of cells with ellipticine and VPA increased the formation of ellipticine-derived DNA adducts, which indicates an easier accessibility of ellipticine to DNA in cells by its co-treatment with VPA and also resulted in higher ellipticine cytotoxicity. The results are promising for in vivo studies and perhaps later for clinical studies of combined treatment of children suffering from high-risk NBL.

Funding information:
  • NIA NIH HHS - R01 AG037868(United States)

An Image-Based miRNA Screen Identifies miRNA-135s As Regulators of CNS Axon Growth and Regeneration by Targeting Krüppel-like Factor 4.

  • van Battum EY
  • J. Neurosci.
  • 2018 Jan 17

Literature context:


Abstract:

During embryonic development, axons extend over long distances to establish functional connections. In contrast, axon regeneration in the adult mammalian CNS is limited in part by a reduced intrinsic capacity for axon growth. Therefore, insight into the intrinsic control of axon growth may provide new avenues for enhancing CNS regeneration. Here, we performed one of the first miRNome-wide functional miRNA screens to identify miRNAs with robust effects on axon growth. High-content screening identified miR-135a and miR-135b as potent stimulators of axon growth and cortical neuron migration in vitro and in vivo in male and female mice. Intriguingly, both of these developmental effects of miR-135s relied in part on silencing of Krüppel-like factor 4 (KLF4), a well known intrinsic inhibitor of axon growth and regeneration. These results prompted us to test the effect of miR-135s on axon regeneration after injury. Our results show that intravitreal application of miR-135s facilitates retinal ganglion cell (RGC) axon regeneration after optic nerve injury in adult mice in part by repressing KLF4. In contrast, depletion of miR-135s further reduced RGC axon regeneration. Together, these data identify a novel neuronal role for miR-135s and the miR-135-KLF4 pathway and highlight the potential of miRNAs as tools for enhancing CNS axon regeneration.SIGNIFICANCE STATEMENT Axon regeneration in the adult mammalian CNS is limited in part by a reduced intrinsic capacity for axon growth. Therefore, insight into the intrinsic control of axon growth may provide new avenues for enhancing regeneration. By performing an miRNome-wide functional screen, our studies identify miR-135s as stimulators of axon growth and neuron migration and show that intravitreal application of these miRNAs facilitates CNS axon regeneration after nerve injury in adult mice. Intriguingly, these developmental and regeneration-promoting effects rely in part on silencing of Krüppel-like factor 4 (KLF4), a well known intrinsic inhibitor of axon regeneration. Our data identify a novel neuronal role for the miR-135-KLF4 pathway and support the idea that miRNAs can be used for enhancing CNS axon regeneration.

Funding information:
  • NCI NIH HHS - R01 CA112054(United States)

Cilostazol Suppresses Aβ-induced Neurotoxicity in SH-SY5Y Cells through Inhibition of Oxidative Stress and MAPK Signaling Pathway.

  • Oguchi T
  • Front Aging Neurosci
  • 2017 Nov 2

Literature context:


Abstract:

Alzheimer's disease (AD) is a slowly progressive form of dementia, characterized by memory impairment and cognitive dysfunction. AD is mainly characterized by the deposition of amyloid β (Aβ) plaques and intracellular neurofibrillary tangles in the brain, along with neuronal degeneration and high levels of oxidative stress. Cilostazol (CSZ) was recently found to suppress the progression of cognitive decline in patients with stable AD receiving acetylcholinesterase inhibitors. This present study aimed to clarify the mechanism by which CSZ protects neurons from degeneration associated with Aβ(1-42). We used Aβ(1-42) to induce neurotoxicity in human neuroblastoma SH-SY5Y cells. Cells were pretreated with CSZ before co-treatment with Aβ. To evaluate the effect of CSZ on oxidative stress, we examined levels of reactive oxygen species (ROS), nicotinamide adenine dinucleotide phosphate oxidase (Nox) activity, mRNA expression of NOX4, and Cu/Zn-Superoxide Dismutase (SOD), as well as apoptosis biomarkers [MTT, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), caspase-3 and -9 activities and staining of annexin V]. We also assayed the activity of mitogen-activated protein kinases (MAPK): p38 MAPK and extracellular signal-regulated kinase1/2 (ERK1/2), and biomarkers of mitochondrial function (Bcl-2 and Bax), and cyclic adenosine monophosphate response element-binding protein (CREB). Aβ-induced oxidative stress (ROS, NOX4 activity, and expression of NOX mRNA), caspase activation (caspase-3 and -9), and p38 MAPK phosphorylation were suppressed by co-treatment with CSZ, but not by ERK1/2 activation. In addition, pretreatment with CSZ suppressed Aβ-induced apoptosis and increased cell viability via suppression of Bax (a proapoptotic protein), upregulation of Bcl-2 (an antiapoptotic protein) and Cu/Zn-SOD (a superoxide scavenging enzyme), and phosphorylation of CREB. These findings suggested that CSZ could counteract neurotoxicity through multiple mechanisms, one mechanism involving the attenuation of oxidative stress by suppressing NOX activity and Nox mRNA expression in Aβ-induced neurotoxicity and another involving the anti-neurotoxic effect via the ERK1/2/phosphorylated CREB pathway.

Funding information:
  • NIMHD NIH HHS - G12 MD007592(United States)

Mitochondrial Calcium Dysregulation Contributes to Dendrite Degeneration Mediated by PD/LBD-Associated LRRK2 Mutants.

  • Verma M
  • J. Neurosci.
  • 2017 Nov 15

Literature context:


Abstract:

Mutations in leucine-rich repeat kinase 2 (LRRK2) contribute to development of late-onset familial Parkinson's disease (PD), with clinical features of motor and cognitive dysfunction indistinguishable from sporadic PD. Calcium dysregulation plays an important role in PD pathogenesis, but the mechanisms of neurodegeneration remain unclear. Recent reports indicate enhanced excitatory neurotransmission in cortical neurons expressing mutant LRRK2, which occurs before the well-characterized phenotype of dendritic shortening. As mitochondria play a major role in the rapid buffering of cytosolic calcium, we hypothesized that altered mitochondrial calcium handling contributes to dendritic retraction elicited by the LRRK2-G2019S and -R1441C mutations. In primary mouse cortical neurons, we observed increased depolarization-induced mitochondrial calcium uptake. We found that expression of mutant LRRK2 elicited transcriptional upregulation of the mitochondrial calcium uniporter (MCU) and the mitochondrial calcium uptake 1 protein (MICU1) with no change in levels of the mitochondrial calcium antiporter NCLX. Elevated MCU and MICU1 were also observed in LRRK2-mutated patient fibroblasts, along with increased mitochondrial calcium uptake, and in postmortem brains of sporadic PD/PDD patients of both sexes. Transcriptional upregulation of MCU and MICU1 was caused by activation of the ERK1/2 (MAPK3/1) pathway. Inhibiting ERK1/2 conferred protection against mutant LRRK2-induced neurite shortening. Pharmacological inhibitors or RNAi knockdown of MCU attenuated mitochondrial calcium uptake and dendritic/neuritic shortening elicited by mutant LRRK2, whereas expression of a constitutively active mutant of NCLX that enhances calcium export from mitochondria was neuroprotective. These data suggest that an increased susceptibility to mitochondrial calcium dysregulation contributes to dendritic injury in mutant LRRK2 pathogenesis.SIGNIFICANCE STATEMENT Cognitive dysfunction and dementia are common features of Parkinson's disease (PD), causing significant disability. Mutations in LRRK2 represent the most common known genetic cause of PD. We found that PD-linked LRRK2 mutations increased dendritic and mitochondrial calcium uptake in cortical neurons and familial PD patient fibroblasts, accompanied by increased expression of the mitochondrial calcium transporter MCU. Blocking the ERK1/2-dependent upregulation of MCU conferred protection against mutant LRRK2-elicited dendrite shortening, as did inhibiting MCU-mediated calcium import. Conversely, stimulating the export of calcium from mitochondria was also neuroprotective. These results implicate increased susceptibility to mitochondrial calcium overload in LRRK2-driven neurodegeneration, and suggest possible interventions that may slow the progression of cognitive dysfunction in PD.

Funding information:
  • NIA NIH HHS - P50 AG005133()
  • NIA NIH HHS - R01 AG026389()
  • NIMH NIH HHS - R21 MH107966()
  • NINDS NIH HHS - P01 NS059806()
  • NINDS NIH HHS - P50 NS040256()
  • NINDS NIH HHS - R01 NS065789()
  • NINDS NIH HHS - R01 NS101628()
  • NINDS NIH HHS - R56 NS065789()
  • Wellcome Trust - 081277(United Kingdom)

Microenvironment-Driven Shift of Cohesion/Detachment Balance within Tumors Induces a Switch toward Metastasis in Neuroblastoma.

  • Delloye-Bourgeois C
  • Cancer Cell
  • 2017 Oct 9

Literature context:


Abstract:

Neuroblastoma (NB) is a childhood cancer arising from sympatho-adrenal neural crest cells. Disseminated forms have high frequency of multiple tumoral foci whose etiology remains unknown; NB embryonic origin limits investigations in patients and current models. We developed an avian embryonic model driving human NB tumorigenesis in tissues homologous to patients. We found that aggressive NBs display a metastatic mode, secondary dissemination via peripheral nerves and aorta. Through tumor transcriptional profiling, we found that NB dissemination is induced by the shutdown of a pro-cohesion autocrine signal, SEMA3C, which constrains the tumoral mass. Lowering SEMA3C levels shifts the balance toward detachment, triggering NB cells to collectively evade the tumor. Together with patient cohort analysis, this identifies a microenvironment-driven pro-metastatic switch for NB.

Split GFP technologies to structurally characterize and quantify functional biomolecular interactions of FTD-related proteins.

  • Foglieni C
  • Sci Rep
  • 2017 Oct 25

Literature context:


Abstract:

Protein multimerization in physiological and pathological conditions constitutes an intrinsic trait of proteins related to neurodegeneration. Recent evidence shows that TDP-43, a RNA-binding protein associated with frontotemporal dementia and amyotrophic lateral sclerosis, exists in a physiological and functional nuclear oligomeric form, whose destabilization may represent a prerequisite for misfolding, toxicity and subsequent pathological deposition. Here we show the parallel implementation of two split GFP technologies, the GFP bimolecular and trimolecular fluorescence complementation (biFC and triFC) in the context of TDP-43 self-assembly. These techniques coupled to a variety of assays based on orthogonal readouts allowed us to define the structural determinants of TDP-43 oligomerization in a qualitative and quantitative manner. We highlight the versatility of the GFP biFC and triFC technologies for studying the localization and mechanisms of protein multimerization in the context of neurodegeneration.

Apolipoprotein E4 Impairs Neuronal Insulin Signaling by Trapping Insulin Receptor in the Endosomes.

  • Zhao N
  • Neuron
  • 2017 Sep 27

Literature context:


Abstract:

Diabetes and impaired brain insulin signaling are linked to the pathogenesis of Alzheimer's disease (AD). The association between diabetes and AD-associated amyloid pathology is stronger among carriers of the apolipoprotein E (APOE) ε4 gene allele, the strongest genetic risk factor for late-onset AD. Here we report that apoE4 impairs neuronal insulin signaling in human apoE-targeted replacement (TR) mice in an age-dependent manner. High-fat diet (HFD) accelerates these effects in apoE4-TR mice at middle age. In primary neurons, apoE4 interacts with insulin receptor and impairs its trafficking by trapping it in the endosomes, leading to impaired insulin signaling and insulin-stimulated mitochondrial respiration and glycolysis. In aging brains, the increased apoE4 aggregation and compromised endosomal function further exacerbate the inhibitory effects of apoE4 on insulin signaling and related functions. Together, our study provides novel mechanistic insights into the pathogenic mechanisms of apoE4 and insulin resistance in AD.

Funding information:
  • NIA NIH HHS - P50 AG016574()
  • NIA NIH HHS - R01 AG027924()
  • NIA NIH HHS - R01 AG035355()
  • NIA NIH HHS - R01 AG046205()
  • NIA NIH HHS - R37 AG027924()
  • NIA NIH HHS - RF1 AG051504()

Identification of GPC2 as an Oncoprotein and Candidate Immunotherapeutic Target in High-Risk Neuroblastoma.

  • Bosse KR
  • Cancer Cell
  • 2017 Sep 11

Literature context:


Abstract:

We developed an RNA-sequencing-based pipeline to discover differentially expressed cell-surface molecules in neuroblastoma that meet criteria for optimal immunotherapeutic target safety and efficacy. Here, we show that GPC2 is a strong candidate immunotherapeutic target in this childhood cancer. We demonstrate high GPC2 expression in neuroblastoma due to MYCN transcriptional activation and/or somatic gain of the GPC2 locus. We confirm GPC2 to be highly expressed on most neuroblastomas, but not detectable at appreciable levels in normal childhood tissues. In addition, we demonstrate that GPC2 is required for neuroblastoma proliferation. Finally, we develop a GPC2-directed antibody-drug conjugate that is potently cytotoxic to GPC2-expressing neuroblastoma cells. Collectively, these findings validate GPC2 as a non-mutated neuroblastoma oncoprotein and candidate immunotherapeutic target.

Funding information:
  • NCI NIH HHS - T32 CA009615()
  • NIGMS NIH HHS - T32 GM008638()

Pimozide reduces toxic forms of tau in TauC3 mice via 5' adenosine monophosphate-activated protein kinase-mediated autophagy.

  • Kim YD
  • J. Neurochem.
  • 2017 Sep 20

Literature context:


Abstract:

In neurodegenerative diseases like Alzheimer's disease (AD), tau is hyperphosphorylated and forms aggregates and neurofibrillary tangles in affected neurons. Autophagy is critical to clear the aggregates of disease-associated proteins and is often altered in patients and animal models of AD. Because mechanistic target of rapamycin (mTOR) negatively regulates autophagy and is hyperactive in the brains of patients with AD, mTOR is an attractive therapeutic target for AD. However, pharmacological strategies to increase autophagy by targeting mTOR inhibition cause various side effects. Therefore, autophagy activation mediated by non-mTOR pathways is a new option for autophagy-based AD therapy. Here, we report that pimozide activates autophagy to rescue tau pathology in an AD model. Pimozide increased autophagic flux through the activation of the AMPK-Unc-51 like autophagy activating kinase 1 (ULK1) axis, but not of mTOR, in neuronal cells, and this function was independent of dopamine D2 receptor inhibition. Pimozide reduced levels of abnormally phosphorylated tau aggregates in neuronal cells. Further, daily intraperitoneal (i.p.) treatment of pimozide led to a recovery from memory deficits of TauC3 mice expressing a caspase-cleaved form of tau. In the brains of these mice, we found increased phosphorylation of AMPK1 and ULK1, and reduced levels of the soluble oligomers and NP40-insoluble aggregates of abnormally phosphorylated tau. Together, these results suggest that pimozide rescues memory impairments in TauC3 mice and reduces tau aggregates by increasing autophagic flux through the mTOR-independent AMPK-ULK1 axis.

Delta-Secretase Phosphorylation by SRPK2 Enhances Its Enzymatic Activity, Provoking Pathogenesis in Alzheimer's Disease.

  • Wang ZH
  • Mol. Cell
  • 2017 Sep 7

Literature context:


Abstract:

Delta-secretase, a lysosomal asparagine endopeptidase (AEP), simultaneously cleaves both APP and tau, controlling the onset of pathogenesis of Alzheimer's disease (AD). However, how this protease is post-translationally regulated remains unclear. Here we report that serine-arginine protein kinase 2 (SRPK2) phosphorylates delta-secretase and enhances its enzymatic activity. SRPK2 phosphorylates serine 226 on delta-secretase and accelerates its autocatalytic cleavage, leading to its cytoplasmic translocation and escalated enzymatic activities. Delta-secretase is highly phosphorylated in human AD brains, tightly correlated with SRPK2 activity. Overexpression of a phosphorylation mimetic (S226D) in young 3xTg mice strongly promotes APP and tau fragmentation and facilitates amyloid plaque deposits and neurofibrillary tangle (NFT) formation, resulting in cognitive impairment. Conversely, viral injection of the non-phosphorylatable mutant (S226A) into 5XFAD mice decreases APP and tau proteolytic cleavage, attenuates AD pathologies, and reverses cognitive defects. Our findings support that delta-secretase phosphorylation by SRPK2 plays a critical role in aggravating AD pathogenesis.

The Atypical MAP Kinase SWIP-13/ERK8 Regulates Dopamine Transporters through a Rho-Dependent Mechanism.

  • Bermingham DP
  • J. Neurosci.
  • 2017 Sep 20

Literature context:


Abstract:

The neurotransmitter dopamine (DA) regulates multiple behaviors across phylogeny, with disrupted DA signaling in humans associated with addiction, attention-deficit/ hyperactivity disorder, schizophrenia, and Parkinson's disease. The DA transporter (DAT) imposes spatial and temporal limits on DA action, and provides for presynaptic DA recycling to replenish neurotransmitter pools. Molecular mechanisms that regulate DAT expression, trafficking, and function, particularly in vivo, remain poorly understood, though recent studies have implicated rho-linked pathways in psychostimulant action. To identify genes that dictate the ability of DAT to sustain normal levels of DA clearance, we pursued a forward genetic screen in Caenorhabditis elegans based on the phenotype swimming-induced paralysis (Swip), a paralytic behavior observed in hermaphrodite worms with loss-of-function dat-1 mutations. Here, we report the identity of swip-13, which encodes a highly conserved ortholog of the human atypical MAP kinase ERK8. We present evidence that SWIP-13 acts presynaptically to insure adequate levels of surface DAT expression and DA clearance. Moreover, we provide in vitro and in vivo evidence supporting a conserved pathway involving SWIP-13/ERK8 activation of Rho GTPases that dictates DAT surface expression and function.SIGNIFICANCE STATEMENT Signaling by the neurotransmitter dopamine (DA) is tightly regulated by the DA transporter (DAT), insuring efficient DA clearance after release. Molecular networks that regulate DAT are poorly understood, particularly in vivo Using a forward genetic screen in the nematode Caenorhabditis elegans, we implicate the atypical mitogen activated protein kinase, SWIP-13, in DAT regulation. Moreover, we provide in vitro and in vivo evidence that SWIP-13, as well as its human counterpart ERK8, regulate DAT surface availability via the activation of Rho proteins. Our findings implicate a novel pathway that regulates DA synaptic availability and that may contribute to risk for disorders linked to perturbed DA signaling. Targeting this pathway may be of value in the development of therapeutics in such disorders.

Production of an anti-Aβ antibody fragment in Pichia pastoris and in vitro and in vivo validation of its therapeutic effect.

  • Montoliu-Gaya L
  • PLoS ONE
  • 2017 Aug 3

Literature context:


Abstract:

ScFv-h3D6 has been shown as an efficient therapy in the 3xTg-AD mouse model of Alzheimer's Disease. Because one of the major bottlenecks for the therapeutic uses of proteins produced in Escherichia coli is their potential contamination with endotoxins, LPS were extensively removed by a rather low-efficient, expensive, and time-consuming purification step. In addition, disulfide scrambling is favored in the reducing bacterial cytoplasm albeit the use of reductase deficient strains. To overcome these hurdles, as well as to improve the yield, the yeast Pichia pastoris, an endotoxin-free host system for recombinant protein production, has been used to produce scFv-h3D6, both in flask and in a fed-batch bioreactor. Comparison of the thermal stability of the obtained protein with that from E. coli showed no differences. Opposite to the case of the protein obtained from E. coli, no disulfide scrambled conformations or LPS traces were detected in that produced in P. pastoris. Cytotoxicity assays in SH-SY5Y neuroblastoma cell-cultures demonstrated that proteins from both expression systems were similarly efficient in precluding Aβ-induced toxicity. Finally, the 3xTg-AD mouse model was used to test the therapeutic effect of both proteins. Quantification of Aβ levels from cortex and hippocampus protein extracts by ELISA, and Aβ-immunohistochemistry, showed that both proteins reduced Aβ burden. This work demonstrates that scFv-h3D6 obtained from P. pastoris shows the same benefits as those already known for that obtained from E. coli, with multiple advantages in terms of recombinant production and safety.

Inhibition of Drp1 Ameliorates Synaptic Depression, Aβ Deposition, and Cognitive Impairment in an Alzheimer's Disease Model.

  • Baek SH
  • J. Neurosci.
  • 2017 May 17

Literature context:


Abstract:

Excessive mitochondrial fission is a prominent early event and contributes to mitochondrial dysfunction, synaptic failure, and neuronal cell death in the progression of Alzheimer's disease (AD). However, it remains to be determined whether inhibition of excessive mitochondrial fission is beneficial in mammal models of AD. To determine whether dynamin-related protein 1 (Drp1), a key regulator of mitochondrial fragmentation, can be a disease-modifying therapeutic target for AD, we examined the effects of Drp1 inhibitor on mitochondrial and synaptic dysfunctions induced by oligomeric amyloid-β (Aβ) in neurons and neuropathology and cognitive functions in Aβ precursor protein/presenilin 1 double-transgenic AD mice. Inhibition of Drp1 alleviates mitochondrial fragmentation, loss of mitochondrial membrane potential, reactive oxygen species production, ATP reduction, and synaptic depression in Aβ-treated neurons. Furthermore, Drp1 inhibition significantly improves learning and memory and prevents mitochondrial fragmentation, lipid peroxidation, BACE1 expression, and Aβ deposition in the brain in the AD model. These results provide evidence that Drp1 plays an important role in Aβ-mediated and AD-related neuropathology and in cognitive decline in an AD animal model. Therefore, inhibiting excessive Drp1-mediated mitochondrial fission may be an efficient therapeutic avenue for AD.SIGNIFICANCE STATEMENT Mitochondrial fission relies on the evolutionary conserved dynamin-related protein 1 (Drp1). Drp1 activity and mitochondria fragmentation are significantly elevated in the brains of sporadic Alzheimer's disease (AD) cases. In the present study, we first demonstrated that the inhibition of Drp1 restored amyloid-β (Aβ)-mediated mitochondrial dysfunctions and synaptic depression in neurons and significantly reduced lipid peroxidation, BACE1 expression, and Aβ deposition in the brain of AD mice. As a result, memory deficits in AD mice were rescued by Drp1 inhibition. These results suggest that neuropathology and combined cognitive decline can be attributed to hyperactivation of Drp1 in the pathogenesis of AD. Therefore, inhibitors of excessive mitochondrial fission, such as Drp1 inhibitors, may be a new strategy for AD.

Rescue of Pink1 Deficiency by Stress-Dependent Activation of Autophagy.

  • Zhang Y
  • Cell Chem Biol
  • 2017 Apr 20

Literature context:


Abstract:

Stimulating autophagy is a promising therapeutic strategy for slowing the progression of neurodegenerative disease. Neurons are insensitive to current approaches based on mTOR inhibition for activating autophagy, and instead may rely on the Parkinson's disease-associated proteins PINK1 and PARKIN to activate the autophagy-lysosomal pathway in response to mitochondrial damage. We developed a multifactorial zebrafish drug-screening platform combining Pink1 deficiency with an environmental toxin to compromise mitochondrial function and trigger dopaminergic neuron loss. Using a phenotypic screening strategy, we identified a series of piperazine phenothiazines, including trifluoperazine, which rescued Pink1 deficiency by activating autophagy selectively in stressed zebrafish and human cells. We show that trifluoperazine acts downstream of, or parallel to, PINK1/PARKIN to stimulate transcription factor EB nuclear translocation and the expression of autophagy-lysosomal target genes. These data suggest that stress-dependent pharmacological reactivation of autophagy could prevent the loss of vulnerable neurons to slow neurodegeneration.

The interactome of the copper transporter ATP7A belongs to a network of neurodevelopmental and neurodegeneration factors.

  • Comstra HS
  • Elife
  • 2017 Mar 29

Literature context:


Abstract:

Genetic and environmental factors, such as metals, interact to determine neurological traits. We reasoned that interactomes of molecules handling metals in neurons should include novel metal homeostasis pathways. We focused on copper and its transporter ATP7A because ATP7A null mutations cause neurodegeneration. We performed ATP7A immunoaffinity chromatography and identified 541 proteins co-isolating with ATP7A. The ATP7A interactome concentrated gene products implicated in neurodegeneration and neurodevelopmental disorders, including subunits of the Golgi-localized conserved oligomeric Golgi (COG) complex. COG null cells possess altered content and subcellular localization of ATP7A and CTR1 (SLC31A1), the transporter required for copper uptake, as well as decreased total cellular copper, and impaired copper-dependent metabolic responses. Changes in the expression of ATP7A and COG subunits in Drosophila neurons altered synapse development in larvae and copper-induced mortality of adult flies. We conclude that the ATP7A interactome encompasses a novel COG-dependent mechanism to specify neuronal development and survival.

Funding information:
  • NIDDK NIH HHS - R01 DK093386()
  • NIEHS NIH HHS - P30 ES019776()
  • NIGMS NIH HHS - R01 GM083144()
  • NIH HHS - P40 OD018537()
  • NINDS NIH HHS - R21 NS088503()

Mutations in Human Accelerated Regions Disrupt Cognition and Social Behavior.

  • Doan RN
  • Cell
  • 2016 Oct 6

Literature context:


Abstract:

Comparative analyses have identified genomic regions potentially involved in human evolution but do not directly assess function. Human accelerated regions (HARs) represent conserved genomic loci with elevated divergence in humans. If some HARs regulate human-specific social and behavioral traits, then mutations would likely impact cognitive and social disorders. Strikingly, rare biallelic point mutations-identified by whole-genome and targeted "HAR-ome" sequencing-showed a significant excess in individuals with ASD whose parents share common ancestry compared to familial controls, suggesting a contribution in 5% of consanguineous ASD cases. Using chromatin interaction sequencing, massively parallel reporter assays (MPRA), and transgenic mice, we identified disease-linked, biallelic HAR mutations in active enhancers for CUX1, PTBP2, GPC4, CDKL5, and other genes implicated in neural function, ASD, or both. Our data provide genetic evidence that specific HARs are essential for normal development, consistent with suggestions that their evolutionary changes may have altered social and/or cognitive behavior. PAPERCLIP.

Monomeric Alpha-Synuclein Exerts a Physiological Role on Brain ATP Synthase.

  • Ludtmann MH
  • J. Neurosci.
  • 2016 Oct 12

Literature context:


Abstract:

Misfolded α-synuclein is a key factor in the pathogenesis of Parkinson's disease (PD). However, knowledge about a physiological role for the native, unfolded α-synuclein is limited. Using brains of mice lacking α-, β-, and γ-synuclein, we report that extracellular monomeric α-synuclein enters neurons and localizes to mitochondria, interacts with ATP synthase subunit α, and modulates ATP synthase function. Using a combination of biochemical, live-cell imaging and mitochondrial respiration analysis, we found that brain mitochondria of α-, β-, and γ-synuclein knock-out mice are uncoupled, as characterized by increased mitochondrial respiration and reduced mitochondrial membrane potential. Furthermore, synuclein deficiency results in reduced ATP synthase efficiency and lower ATP levels. Exogenous application of low unfolded α-synuclein concentrations is able to increase the ATP synthase activity that rescues the mitochondrial phenotypes observed in synuclein deficiency. Overall, the data suggest that α-synuclein is a previously unrecognized physiological regulator of mitochondrial bioenergetics through its ability to interact with ATP synthase and increase its efficiency. This may be of particular importance in times of stress or PD mutations leading to energy depletion and neuronal cell toxicity. SIGNIFICANCE STATEMENT: Misfolded α-synuclein aggregations in the form of Lewy bodies have been shown to be a pathological hallmark in histological staining of Parkinson's disease (PD) patient brains. It is known that misfolded α-synuclein is a key driver in PD pathogenesis, but the physiological role of unfolded monomeric α-synuclein remains unclear. Using neuronal cocultures and isolated brain mitochondria of α-, β-, and γ-synuclein knock-out mice and monomeric α-synuclein, this current study shows that α-synuclein in its unfolded monomeric form improves ATP synthase efficiency and mitochondrial function. The ability of monomeric α-synuclein to enhance ATP synthase efficiency under physiological conditions may be of importance when α-synuclein undergoes the misfolding and aggregation reported in PD.

Carnosic acid suppresses the production of amyloid-β 1-42 by inducing the metalloprotease gene TACE/ADAM17 in SH-SY5Y human neuroblastoma cells.

  • Meng P
  • Neurosci. Res.
  • 2013 Feb 19

Literature context:


Abstract:

A hallmark of Alzheimer's disease (AD) is the aggressive appearance of plaques of amyloid beta (Aβ) peptides, which result from the sequential cleavage of amyloid precursor protein (APP) by the β- and γ-secretases. Aβ production is evaded by alternate cleavage of APP by the α- and γ-secretases. Carnosic acid (CA) has been proven to activate the transcription factor Nrf2, a main regulator of the antioxidant response. We investigated the effects of CA on the production of Aβ 1-42 peptide (Aβ42) and on the expressions of the related genes in SH-SY5Y human neuroblastoma cells. The treatment of cells with CA suppressed Aβ42 secretion (61% suppression at 30μM). CA treatment enhanced the mRNA expressions of an α-secretase TACE (tumor necrosis factor-α-converting enzyme, also called a disintegrin and metalloproteinase-17, ADAM17) significantly and another α-secretase ADAM10 marginally; however, the β-secretase BACE1 (β-site APP-cleaving enzyme-1) was not increased by CA. Knockdown of TACE by siRNA reduced soluble-APPα secretion enhanced by CA and partially recovered the CA-suppressed Aβ42 secretion. These results suggest that CA reduces Aβ42 production by activating TACE without promoting BACE1 in human neuroblastoma cells. The use of CA may have a potential in the prevention of Aβ-mediated diseases, particularly AD.

Funding information:
  • NINDS NIH HHS - NS 38809(United States)

Using BAC transgenesis in zebrafish to identify regulatory sequences of the amyloid precursor protein gene in humans.

  • Shakes LA
  • BMC Genomics
  • 2012 Sep 4

Literature context:


Abstract:

BACKGROUND: Non-coding DNA in and around the human Amyloid Precursor Protein (APP) gene that is central to Alzheimer's disease (AD) shares little sequence similarity with that of appb in zebrafish. Identifying DNA domains regulating expression of the gene in such situations becomes a challenge. Taking advantage of the zebrafish system that allows rapid functional analyses of gene regulatory sequences, we previously showed that two discontinuous DNA domains in zebrafish appb are important for expression of the gene in neurons: an enhancer in intron 1 and sequences 28-31 kb upstream of the gene. Here we identify the putative transcription factor binding sites responsible for this distal cis-acting regulation, and use that information to identify a regulatory region of the human APP gene. RESULTS: Functional analyses of intron 1 enhancer mutations in enhancer-trap BACs expressed as transgenes in zebrafish identified putative binding sites of two known transcription factor proteins, E4BP4/ NFIL3 and Forkhead, to be required for expression of appb. A cluster of three E4BP4 sites at -31 kb is also shown to be essential for neuron-specific expression, suggesting that the dependence of expression on upstream sequences is mediated by these E4BP4 sites. E4BP4/ NFIL3 and XFD1 sites in the intron enhancer and E4BP4/ NFIL3 sites at -31 kb specifically and efficiently bind the corresponding zebrafish proteins in vitro. These sites are statistically over-represented in both the zebrafish appb and the human APP genes, although their locations are different. Remarkably, a cluster of four E4BP4 sites in intron 4 of human APP exists in actively transcribing chromatin in a human neuroblastoma cell-line, SHSY5Y, expressing APP as shown using chromatin immunoprecipitation (ChIP) experiments. Thus although the two genes share little sequence conservation, they appear to share the same regulatory logic and are regulated by a similar set of transcription factors. CONCLUSION: The results suggest that the clock-regulated and immune system modulator transcription factor E4BP4/ NFIL3 likely regulates the expression of both appb in zebrafish and APP in humans. It suggests potential human APP gene regulatory pathways, not on the basis of comparing DNA primary sequences with zebrafish appb but on the model of conservation of transcription factors.

Funding information:
  • NIMH NIH HHS - NIMH MH42834(United States)