scholarly journals Innate STAT1-Dependent Genomic Response of Neurons to the Antiviral Cytokine Alpha Interferon

2005 ◽  
Vol 79 (13) ◽  
pp. 8295-8302 ◽  
Author(s):  
Jianping Wang ◽  
Iain L. Campbell

ABSTRACT Alpha/beta interferons (IFNs-α/β) are cytokines that play an essential role in the host defense against viral infection. Our previous studies have shown that the key IFN signaling molecule STAT1 is highly elevated and activated in central nervous system neurons during viral infection and in transgenic mice with astrocyte production of IFN-α (glial fibrillary acidic protein [GFAP]-IFN-α), suggesting that neurons are a very responsive target cell population for IFNs. To elucidate the genomic response of neurons to IFN-α, we undertook studies both in vitro and in vivo. Gene chip analysis was applied to RNA from IFN-α-treated or untreated primary cortical neuronal cultures derived from embryonic day 15 fetal wild-type or STAT1 knockout (KO) mice. The expression of 51 known and 5 unknown genes was increased significantly by more than twofold after exposure of wild-type but not STAT1 KO neurons to IFN-α. Some more highly expressed genes included IFN-induced 15-kDa protein, ubiquitin-specific protease 18, glucocorticoid attenuated response genes, IFN-induced GTPases, and the chemokine CXCL10. For several of these genes, the gene chip findings were confirmed by RNase protection assays. In addition, examination of the expression of some of these selected genes revealed that they were increased in neurons in the brain of either GFAP-IFN-α mice or mice infected with lymphocytic choriomeningitis virus. In conclusion, our study revealed a robust STAT1-dependent genomic response of neurons to IFN-α, highlighting an innate potential of these cells to defend against viral infection in the brain.

2019 ◽  
Vol 116 (50) ◽  
pp. 25322-25328 ◽  
Author(s):  
Yi Liu ◽  
Xiaopin Ma ◽  
Hisashi Fujioka ◽  
Jun Liu ◽  
Shengdi Chen ◽  
...  

Loss-of-function mutations in DJ-1 are associated with autosomal recessive early onset Parkinson’s disease (PD), yet the underlying pathogenic mechanism remains elusive. Here we demonstrate that DJ-1 localized to the mitochondria-associated membrane (MAM) both in vitro and in vivo. In fact, DJ-1 physically interacts with and is an essential component of the IP3R3-Grp75-VDAC1 complexes at MAM. Loss of DJ-1 disrupted the IP3R3-Grp75-VDAC1 complex and led to reduced endoplasmic reticulum (ER)-mitochondria association and disturbed function of MAM and mitochondria in vitro. These deficits could be rescued by wild-type DJ-1 but not by the familial PD-associated L166P mutant which had demonstrated reduced interaction with IP3R3-Grp75. Furthermore, DJ-1 ablation disturbed calcium efflux-induced IP3R3 degradation after carbachol treatment and caused IP3R3 accumulation at the MAM in vitro. Importantly, similar deficits in IP3R3-Grp75-VDAC1 complexes and MAM were found in the brain of DJ-1 knockout mice in vivo. The DJ-1 level was reduced in the substantia nigra of sporadic PD patients, which was associated with reduced IP3R3-DJ-1 interaction and ER-mitochondria association. Together, these findings offer insights into the cellular mechanism in the involvement of DJ-1 in the regulation of the integrity and calcium cross-talk between ER and mitochondria and suggests that impaired ER-mitochondria association could contribute to the pathogenesis of PD.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Lan Xiao ◽  
Vinay Sharma ◽  
Leila Toulabi ◽  
Xuyu Yang ◽  
Cheol Lee ◽  
...  

Abstract Stress causes release of glucocorticoids from the adrenals which then circulate to the brain. High concentrations glucocorticoid from chronic severe stress results in pathophysiology in the brain, including neuronal degeneration, cell death and cognitive dysfunction, leading to diseases such as Alzheimer Disease and Major Depressive Disorders. Neurotrophic/growth factors such as BDNF, NGF and NT3 have been linked to these pathological conditions. Carboxypeptidase E (CPE), a proneuropeptide/prohormone processing enzyme, also named neurotrophic factor-α1(NFα1) is highly expressed in the stress-vulnerable hippocampal CA3 neurons, and was shown to have neuroprotective activity from in vitro studies. Here we investigated if CPE-NFα1 functions in vivo, independent of its enzymatic activity, and the mechanism underlying its action. We generated knock-in mice expressing a non-enzymatic form of CPE, CPE-E342Q, but not wild-type CPE. The CPE-E342Q mice showed significantly decreased neuropeptide content and exhibited obesity, diabetes and infertility due to lack of prohormone processing activity, similar to CPE-KO mice. However, they showed no hippocampal CA3 degeneration, exhibited neurogenesis in the dentate gyrus, and displayed normal spatial learning and memory, similar to CPE wild-type mice, after weaning stress; unlike CPE-KO mice which showed hippocampal CA3 neuronal degeneration and cognitive deficits. Binding studies showed that radiolabeled CPE bound hippocampal cell membrane specifically, in a saturable manner. Binding of CPE and CPE-E342Q to hippocampal neurons activated Erk signaling and pre-treatment with either of these proteins protected neurons against H2O2- or glutamate-induced neurotoxcity by increasing BCL2 expression. In vitro and in vivo inhibitor studies demonstrated that this neuroprotective effect was independent of tyrosine kinase receptor signaling. Taken together, the data provide evidence that CPE-NFα1 is a unique neurotrophic factor which acts through a non-tyrosine kinase receptor to activate Erk-BCL2 signaling to protect hippocampal CA3 neurons against stress-induced neurodegeneration and maintaining normal cognitive functions in mice.


2008 ◽  
Vol 83 (3) ◽  
pp. 1173-1183 ◽  
Author(s):  
D. Curanović ◽  
M. G. Lyman ◽  
C. Bou-Abboud ◽  
J. P. Card ◽  
L. W. Enquist

ABSTRACT The attenuated pseudorabies virus (PRV) strain Bartha contains several characterized mutations that affect its virulence and ability to spread through neural circuits. This strain contains a small genomic deletion that abrogates anterograde spread and is widely used as a retrograde-restricted neural circuit tracer. Previous studies showed that the retrograde-directed spread of PRV Bartha is slower than that of wild-type PRV. We used compartmented neuronal cultures to characterize the retrograde defect and identify the genetic basis of the phenotype. PRV Bartha is not impaired in retrograde axonal transport, but transneuronal spread among neurons is diminished. Repair of the UL21 locus with wild-type sequence restored efficient transneuronal spread both in vitro and in vivo. It is likely that mutations in the Bartha UL21 gene confer defects that affect infectious particle production, causing a delay in spread to presynaptic neurons and amplification of infection. These events manifest as slower kinetics of retrograde viral spread in a neural circuit.


2019 ◽  
Author(s):  
Satoshi Taniguchi ◽  
Tomoki Yoshikawa ◽  
Masayuki Shimojima ◽  
Shuetsu Fukushi ◽  
Takeshi Kurosu ◽  
...  

ABSTRACTLymphocytic choriomeningitis virus (LCMV) is a prototypic arenavirus. The viral genome consists of two RNA segments, L and S. The 5’- and 3’-termini of both L and S segments are highly conserved among arenaviruses. These regions consist of 19 complementary base pairs and are essential for viral genome replication and transcription. In addition to these 19 nucleotides in the 5’- and 3’-termini, there are untranslated regions (UTRs) composed of 58 and 41 nucleotide residues in the 5’ and 3’ UTRs, respectively, in the LCMV S segment. Their functional roles, however, have yet to be elucidated. In this study, a reverse genetics and a minigenome system for the LCMV strain WE were established and used to analyze the function of these regions. The results obtained from these analyses, plus RNA secondary structure prediction, revealed that not only these 19 nucleotides but also the 20th–40th and 20th–38th nucleotides located downstream of the 19 nucleotides in the 5’- and 3’-termini, respectively, are heavily involved in viral genome replication and transcription. Furthermore, the introduction of mutations in these regions depressed viral propagation in vitro and enhanced attenuation in vivo. Conversely, recombinant LCMVs (rLCMVs), which had various deletions in the other UTRs, propagated as well as wild-type LCMV in vitro but were attenuated in vivo. Most mice previously infected with rLCMVs with mutated UTRs, when further infected with a lethal dose of wild-type LCMV, survived. These results suggest that rLCMVs with mutated UTRs could be candidates for an LCMV vaccine.IMPORTANCEThe function of untranslated regions (UTRs) of the arenavirus genome has not well been studied except for the 19 nucleotides of the 5’- and 3’-termini. In this study the function of the UTRs of the LCMV S segment was analyzed. It was found that not only the 19 nucleotides of the 5’- and 3’-termini but also the 20th–40th and 20th–38th nucleotides located downstream of the 19 nucleotides in the 5’- and 3’-termini, respectively, were involved in viral genome replication and transcription. Furthermore, other UTRs in the S segment were involved in virulence in vivo. The introduction of mutations to these regions makes it possible to establish attenuated LCMV and potentially develop LCMV vaccine candidates.


2006 ◽  
Vol 81 (2) ◽  
pp. 860-871 ◽  
Author(s):  
Christie Wacher ◽  
Marcus Müller ◽  
Markus J. Hofer ◽  
Daniel R. Getts ◽  
Regina Zabaras ◽  
...  

ABSTRACT The interferon (IFN)-stimulated genes (ISGs) ISG-49, ISG-54, and ISG-56 are highly responsive to viral infection, yet the regulation and function of these genes in vivo are unknown. We examined the simultaneous regulation of these ISGs in the brains of mice during infection with either lymphocytic choriomeningitis virus (LCMV) or West Nile virus (WNV). Expression of the ISG-49 and ISG-56 genes increased significantly during LCMV infection, being widespread and localized predominantly to common as well as distinct neuronal populations. Expression of the ISG-54 gene also increased but to lower levels and with a more restricted distribution. Although expression of the ISG-49, ISG-54, and ISG-56 genes was increased in the brains of LCMV-infected STAT1 and STAT2 knockout (KO) mice, this was blunted, delayed, and restricted to the choroid plexus, meninges, and endothelium. ISG-56 protein was regulated in parallel with the corresponding RNA transcript in the brain during LCMV infection in wild-type and STAT KO mice. Similar changes in ISG-49, ISG-54, and ISG-56 RNA levels and ISG-56 protein levels were observed in the brains of wild-type mice following infection with WNV. Thus, the ISG-49, ISG-54, and ISG-56 genes are coordinately upregulated in the brain during LCMV and WNV infection; this upregulation, in the case of LCMV, was totally (neurons) or partially (non-neurons) dependent on the IFN-signaling molecules STAT1 and STAT2. These findings suggest a dominant role for the ISG-49, ISG-54, and ISG-56 genes in the host response to different viruses in the central nervous system, where, particularly in neurons, these genes may have nonredundant functions.


Author(s):  
Tatsuki Koike ◽  
Cristian C. Constantinescu ◽  
Shuhei Ikeda ◽  
Toshiya Nishi ◽  
Eiji Sunahara ◽  
...  

Abstract Purpose Cholesterol 24-hydroxylase (CH24H) is a brain-specific enzyme that plays a major role in brain cholesterol homeostasis by converting cholesterol into 24S-hydroxycholesterol. The selective CH24H inhibitor soticlestat (TAK-935) is being pursued as a drug for treatment of seizures in developmental and epileptic encephalopathies. Herein, we describe the successful discovery and the preclinical validation of the novel radiolabeled CH24H ligand (3-[18F]fluoroazetidin-1-yl){1-[4-(4-fluorophenyl)pyrimidin-5-yl]piperidin-4-yl}methanone ([18F]T-008) and its tritiated analog, [3H]T-008. Methods In vitro autoradiography (ARG) studies in the CH24H wild-type (WT) and knockout (KO) mouse brain sections were conducted using [3H]T-008. PET imaging was conducted in two adult rhesus macaques using [18F]T-008. Each macaque received two test–retest baseline scans and a series of two blocking doses of soticlestat administered prior to [18F]T-008 to determine the CH24H enzyme occupancy. PET data were analyzed with Logan graphical analysis using plasma input. A Lassen plot was applied to estimate CH24H enzyme occupancy by soticlestat. Results In ARG studies, binding of [3H]T-008 was specific to CH24H in the mouse brain sections, which was not observed in CH24H KO or in wild-type mice after pretreatment with soticlestat. In rhesus PET studies, the rank order of [18F]T-008 uptake was striatum > cortical regions > cerebellum, which was consistent with CH24H distribution in the brain. Pre-blocking with soticlestat reduced the maximum uptake and increased the washout in all brain regions in a dose-dependent manner. Calculated global occupancy values for soticlestat at a dose of 0.89 mg/kg were 97–98%, indicating maximum occupancy. Conclusion The preclinical in vitro and in vivo evaluation of labeled T-008 demonstrates that [18F]T-008 is suitable for imaging CH24H in the brain and warrants further studies in humans. Graphical abstract


2021 ◽  
Author(s):  
Sambamurthy Chandrasekaran ◽  
Joshua A Kochanowsky ◽  
Emily F Merritt ◽  
Anita A Koshy

Dogma holds that Toxoplasma gondii persists in neurons because neurons cannot clear intracellular parasites, even with IFN-γ stimulation. As several recent studies questioned this idea, we used primary murine neuronal cultures from wild-type and transgenic mice in combination with IFN-γ stimulation and parental and transgenic parasites to reassess IFN-γ dependent neuronal clearance of intracellular parasites. We found that neurons respond to IFN-γ and that a subset of neurons clear intracellular parasites via immunity regulated GTPases. Whole neuron reconstructions from mice infected with parasites that trigger neuron GFP expression only after full invasion revealed that ~40% of these T. gondii-invaded neurons no longer harbor parasites. Finally, IFN-γ stimulated human stem cell derived neurons showed a ~ 50% decrease in parasite infection rate when compared to unstimulated cultures. This work highlights the capability of human and murine neurons to mount cytokine-dependent anti-T. gondii defense mechanisms in vitro and in vivo.


Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 965-972 ◽  
Author(s):  
Niels C. Adams ◽  
Toshifumi Tomoda ◽  
Margaret Cooper ◽  
Gunnar Dietz ◽  
Mary E. Hatten

The cortical regions of the brain are laminated as a result of directed migration of precursor cells along glia during development. Previously, we have used an assay system to identify astrotactin as a neuronal ligand for migration on glial fibers. To examine the function of astrotactin in vivo, we generated a null mutation by targeted gene disruption. The cerebella of astrotactin null mice are approximately 10% smaller than wild type. In vitro and in vivo cerebellar granule cell assays show a decrease in neuron-glial binding, a reduction in migration rates and abnormal development of Purkinje cells. Consequences of this are poorer balance and coordination. Thus, astrotactin functions in migration along glial processes in vivo, a process required for generating laminar structures and for the development of synaptic partner systems.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 834-834
Author(s):  
Asumi Yokota ◽  
Shinya Kimura ◽  
Satohiro Masuda ◽  
Eishi Ashihara ◽  
Yoshimasa Urasaki ◽  
...  

Abstract Central nervous system (CNS) relapse accompanying prolonged administration of imatinib mesylate, an Abl-specific tyrosine kinase inhibitor, has recently become apparent as an impediment to the therapy of Philadelphia-chromosome-positive (Ph+) leukemia. CNS relapse may be explained by limited penetration of imatinib into the cerebrospinal fluid due to presence of P-glycoprotein (P-gp) at blood-brain barrier. To overcome imatinib-resistance mechanisms such as bcr-abl gene amplification, point mutations within ABL kinase domain, and activation of Lyn, we recently developed a specific dual BCR-ABL/Lyn inhibitor, INNO-406 (formerly NS-187), which is 25–55 times more potent than imatinib in vitro and at least 10 times more potent in vivo (Blood106: 3948–3954, 2005). The aim of this study was to investigate the efficacy of INNO-406 in treating CNS Ph+ leukemia. The intracellular accumulation of [14C]INNO-406 in P-gp overexpressing LLC-GA5-COL150 cells was much less than that in parental LLC-PK1 cells. The addition of 10 mM cyclosporin A (CsA) increased the intracellular accumulation of [14C]INNO-406 in both LLC-PK1 cells and LLC-GA5-COL150 cells. The peak concentration of INNO-406 in the brain when 30 mg/kg INNO-406 was administered p.o. was 50 ng/ g (87 nM), representing only 10% of plasma drug level. These findings suggested that INNO-406 is also a substrate of P-gp, as is imatinib. However, the residual concentration of INNO-406 in the CNS was enough to inhibit the growth of Ph+ leukemic cells according to the in vitro data. To increase the concentration of INNO-406 in CNS, we next examined the combined effects of CsA. In the brain, the concentration of INNO-406 was doubled following prior administration of 50 mg/kg CsA. Since pharmacokinetic studies suggested the possible effects of INNO-406 against CNS Ph+ leukemia, we investigated in vivo anti-CNS Ph+ leukemia effects of INNO-406 alone and combination of INNO-406 and CsA using immunodeficient mice (nude or NOD/SCID) which received Ph+ leukemic cells into the cerebral ventricle. INNO-406 alone inhibited growth of leukemic cells harboring either wild type or mutated BCR-ABL such as E255K and M351T in CNS. Furthermore, CsA significantly enhanced anti-CNS Ph+ leukemia effects of INNO-406 in vivo not only against cells harboring wild type BCR-ABL but also against cells harboring BCR-ABL/M351T (Figure). In conclusion, INNO-406 was found to inhibit Ph+ leukemic cell growth in CNS in spite of efflux of the compound by P-gp, and CsA augmented the anti-CNS Ph+ leukemia effects of INNO-406. Phase I clinical study on INNO-406 was initiated in the U.S.A. in July 2006. The efficacy and safety of INNO-406 in the treatment of leukemias is expected to be verified by early-phase clinical trials. Figure Figure


2010 ◽  
Vol 84 (11) ◽  
pp. 5583-5593 ◽  
Author(s):  
Evgeni Gabev ◽  
Kurt Tobler ◽  
Carlos Abril ◽  
Monika Hilbe ◽  
Claudia Senn ◽  
...  

ABSTRACT Bovine herpesvirus 1 (BoHV-1) and BoHV-5 are closely related pathogens of cattle, but only BoHV-5 is considered a neuropathogen. We engineered intertypic gD exchange mutants with BoHV-1 and BoHV-5 backbones in order to address their in vitro and in vivo host ranges, with particular interest in invasion of the brain. The new viruses replicated in cell culture with similar dynamics and to titers comparable to those of their wild-type parents. However, gD of BoHV-5 (gD5) was able to interact with a surprisingly broad range of nectins. In vivo, gD5 provided a virulent phenotype to BoHV-1 in AR129 mice, featuring a high incidence of neurological symptoms and early onset of disease. However, only virus with the BoHV-5 backbone, independent of the gD type, was detected in the brain by immunohistology. Thus, gD of BoHV-5 confers an extended cellular host range to BoHV-1 and may be considered a virulence factor but does not contribute to the invasion of the brain.


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