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1.
Cell Death Dis ; 15(6): 404, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38858355

ABSTRACT

Senescent cells exhibit a diverse spectrum of changes in their morphology, proliferative capacity, senescence-associated secretory phenotype (SASP) production, and mitochondrial homeostasis. These cells often manifest with elongated mitochondria, a hallmark of cellular senescence. However, the precise regulatory mechanisms orchestrating this phenomenon remain predominantly unexplored. In this study, we provide compelling evidence for decreases in TIA-1, a pivotal regulator of mitochondrial dynamics, in models of both replicative senescence and ionizing radiation (IR)-induced senescence. The downregulation of TIA-1 was determined to trigger mitochondrial elongation and enhance the expression of senescence-associated ß-galactosidase, a marker of cellular senescence, in human foreskin fibroblast HS27 cells and human keratinocyte HaCaT cells. Conversely, the overexpression of TIA-1 mitigated IR-induced cellular senescence. Notably, we identified the miR-30-5p family as a novel factor regulating TIA-1 expression. Augmented expression of the miR-30-5p family was responsible for driving mitochondrial elongation and promoting cellular senescence in response to IR. Taken together, our findings underscore the significance of the miR-30-5p/TIA-1 axis in governing mitochondrial dynamics and cellular senescence.


Subject(s)
Cellular Senescence , MicroRNAs , Mitochondria , Mitochondrial Dynamics , T-Cell Intracellular Antigen-1 , Humans , MicroRNAs/metabolism , MicroRNAs/genetics , Cellular Senescence/radiation effects , Cellular Senescence/genetics , Mitochondrial Dynamics/genetics , T-Cell Intracellular Antigen-1/metabolism , T-Cell Intracellular Antigen-1/genetics , Mitochondria/metabolism , Fibroblasts/metabolism , Fibroblasts/radiation effects , Cell Line , Keratinocytes/metabolism , Keratinocytes/radiation effects , Keratinocytes/cytology , Signal Transduction , Radiation, Ionizing
2.
Neuromuscul Disord ; 33(12): 983-987, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38016875

ABSTRACT

Welander distal myopathy typically manifests in late adulthood and is caused by the founder TIA1 c.1150G>A (p.Glu384Lys) variant in families of Swedish and Finnish descent. Recently, a similar phenotype has been attributed to the digenic inheritance of TIA1 c.1070A>G (p.Asn357Ser) and SQSTM1 c.1175C>T (p.Pro392Leu) variants. We describe two unrelated Spanish patients presenting with slowly progressive gait disturbance, distal-predominant weakness, and mildly elevated creatine kinase (CK) levels since their 6th decade. Electromyography revealed abnormal spontaneous activity and a myopathic pattern. Muscle magnetic resonance imaging (MRI) showed marked fatty replacement in distal leg muscles. A muscle biopsy, performed on one patient, revealed myopathic changes with rimmed vacuoles. Both patients carried the TIA1 p.Asn357Ser and SQSTM1 p.Pro392Leu variants. Digenic inheritance is supported by evidence from unrelated pedigrees and a plausible biological interaction between both proteins in protein quality control processes. Recent functional studies and additional case descriptions further support this. Clinical suspicion is necessary to seek both variants.


Subject(s)
Distal Myopathies , Muscular Diseases , Adult , Humans , Distal Myopathies/pathology , Electromyography , Muscle, Skeletal/pathology , Muscular Diseases/genetics , Sequestosome-1 Protein/genetics , T-Cell Intracellular Antigen-1/genetics
3.
Cell Mol Biol (Noisy-le-grand) ; 69(14): 9-14, 2023 Dec 20.
Article in English | MEDLINE | ID: mdl-38279501

ABSTRACT

As the most common subtype of lung cancer, non-small cell lung cancer (NSCLC)is responsible for a large proportion of global cancer-caused deaths. The implication of long non-coding RNAs (lncRNAs) as tumor-suppressor or carcinogenic genes in NSCLC has been widely documented. Our study sought to investigate the performance of lncRNA RAMP2 antisense RNA1 (RAMP2-AS1) in NSCLC. GEPIA bioinformatics tool and RT-qPCR were applied for assessing the expression of RAMP2-AS1 and its neighboring gene receptor activity-modifying protein 2 (RAMP2) in NSCLC. Functional assays including CCK-8 assay, colony formation assay as well as caspase-3 activity analysis and Transwell invasion assays were applied for detecting the biological phenotypes of NSCLC cells. Interaction among RAMP2-AS1, RAMP2 and T-cell intracellular antigen 1cytotoxic granule associated RNA binding protein (TIA1) was evaluated by RNA immunoprecipitation and pulldown assays. We found that RAMP2-AS1 and RAMP2 were downregulated in NSCLC. Overexpression of RAMP2-AS1 hampered proliferation and invasion, whereas induced apoptosis of NSCLC cells. Mechanistically, RAMP2-AS1 interacted with TIA1 to stabilize the mRNA of RAMP2. In conclusion, we first uncovered that RAMP2-AS1 stabilized RAPM2 mRNA through TIA1 to inhibit the progression of NSCLC, providing new insight to improve the treatment efficacy of NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , MicroRNAs , RNA, Long Noncoding , Humans , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , RNA, Messenger/genetics , Receptor Activity-Modifying Protein 2/genetics , Receptor Activity-Modifying Protein 2/metabolism , Cell Line, Tumor , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , Cell Movement/genetics , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism
4.
F1000Res ; 12: 745, 2023.
Article in English | MEDLINE | ID: mdl-38638178

ABSTRACT

A member of the RNA-binding protein family, T-cell intracellular antigen-1 (TIA1) regulates mRNA translation and splicing as well as cellular stress by promoting stress granule formation. Variants of the TIA1 gene have implications in neurogenerative disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Reproducible research on TIA1 would be enhanced with the availability of high-quality anti-TIA1 antibodies. In this study, we characterized twelve TIA1 commercial antibodies for Western Blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. We identified many high-performing antibodies and encourage readers to use this report as a guide to select the most appropriate antibody for their specific needs.


Subject(s)
RNA-Binding Proteins , T-Cell Intracellular Antigen-1/genetics , Blotting, Western , Fluorescent Antibody Technique , Immunoprecipitation
5.
Cell Rep ; 41(12): 111869, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36543128

ABSTRACT

B cell lymphopoiesis requires dynamic modulation of the B cell transcriptome for timely coordination of somatic mutagenesis and DNA repair in progenitor B (pro-B) cells. Here, we show that, in pro-B cells, the RNA-binding proteins T cell intracellular antigen 1 (TIA1) and TIA1-like protein (TIAL1) act redundantly to enable developmental progression. They are global splicing regulators that control the expression of hundreds of mRNAs, including those involved in DNA damage repair. Mechanistically, TIA1 and TIAL1 bind to 5' splice sites for exon definition, splicing, and expression of DNA damage sensors, such as Chek2 and Rif1. In their absence, pro-B cells show exacerbated DNA damage, altered P53 expression, and increased cell death. Our study uncovers the importance of tight regulation of RNA splicing by TIA1 and TIAL1 for the expression of integrative transcriptional programs that control DNA damage sensing and repair during B cell development.


Subject(s)
Lymphopoiesis , Poly(A)-Binding Proteins , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism , Poly(A)-Binding Proteins/metabolism , Lymphopoiesis/genetics , RNA Splicing , RNA Splice Sites , DNA Repair , DNA Damage
6.
Proc Natl Acad Sci U S A ; 119(38): e2122523119, 2022 09 20.
Article in English | MEDLINE | ID: mdl-36112647

ABSTRACT

T cell intracellular antigen-1 (TIA-1) plays a central role in stress granule (SG) formation by self-assembly via the prion-like domain (PLD). In the TIA-1 PLD, amino acid mutations associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) or Welander distal myopathy (WDM), have been identified. However, how these mutations affect PLD self-assembly properties has remained elusive. In this study, we uncovered the implicit pathogenic structures caused by the mutations. NMR analysis indicated that the dynamic structures of the PLD are synergistically determined by the physicochemical properties of amino acids in units of five residues. Molecular dynamics simulations and three-dimensional electron crystallography, together with biochemical assays, revealed that the WDM mutation E384K attenuated the sticky properties, whereas the ALS mutations P362L and A381T enhanced the self-assembly by inducing ß-sheet interactions and highly condensed assembly, respectively. These results suggest that the P362L and A381T mutations increase the likelihood of irreversible amyloid fibrillization after phase-separated droplet formation, and this process may lead to pathogenicity.


Subject(s)
Amino Acids , Amyotrophic Lateral Sclerosis , Prions , Protein Aggregation, Pathological , T-Cell Intracellular Antigen-1 , Amino Acids/chemistry , Amino Acids/genetics , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Distal Myopathies/genetics , Distal Myopathies/metabolism , Humans , Mutation , Prions/chemistry , Protein Aggregation, Pathological/genetics , Protein Conformation, beta-Strand/genetics , Protein Domains/genetics , T-Cell Intracellular Antigen-1/chemistry , T-Cell Intracellular Antigen-1/genetics
7.
Pathol Res Pract ; 235: 153957, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35653925

ABSTRACT

BACKGROUND: CRNDE is known to be an important predictive factor of prognosis in many tumors; however, its role in cisplatin resistance is still unknown in ovarian cancer. The aim of the current research was to investigate the association between CRNDE and cisplatin resistance. MATERIALS AND METHODS: QRT-PCR and in situ hybridization assay were employed to detect the expression of CRNDE in ovarian cancer cells and tissues; CCK8 assay, AnnexinV-FITC apoptosis assay and Trans-well assay, to determine the cell proliferation, apoptosis and invasion; and RNA-pull down assay, mass spectrometry analysis, gene microarray to search the targeted gene of CRNDE and SRSF1. Association of CRNDE with SRSF1 was determined in ovarian cancer cells and nude mice. RESULTS: It was found that CRNDE and SRSF1 expression were higher in the cisplatin resistant ovarian cancer cells than their control cells. High expression of CRNDE and SRSF1 led to cisplatin resistance. While inhibition of CRNDE or SRSF1 sensitized ovarian cancer to cisplatin in vitro and in vivo. Moreover, as indicated in RIP assay, SRSF1 was potentially the targeted gene of CRNDE, and CRNDE promoting SRSF1 expression to induce cisplatin resistance; as indicated in gene microassay, there was significantly positive correlation between SRSF1 and TIA1, and SRSF1 promoting TIA1 expression. CONCLUSION: In conclusion, CRNDE induced cisplatin resistance in ovarian cancer through SRSF1/TIA1 signaling pathway; thus, CRNDE inhibitor or SRSF1 inhibitor combined with cisplatin might act as a novel promising approach to ovarian cancer.


Subject(s)
MicroRNAs , Ovarian Neoplasms , RNA, Long Noncoding/genetics , Animals , Carcinoma, Ovarian Epithelial/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Cisplatin/pharmacology , Cisplatin/therapeutic use , Drug Resistance, Neoplasm/genetics , Female , Gene Expression Regulation, Neoplastic , Humans , Mice , Mice, Nude , MicroRNAs/genetics , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Serine-Arginine Splicing Factors/genetics , Signal Transduction , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism
8.
Int J Mol Sci ; 23(3)2022 Jan 26.
Article in English | MEDLINE | ID: mdl-35163320

ABSTRACT

T-cell intracellular antigen 1 (TIA1) is an RNA-binding protein that is expressed in many tissues and in the vast majority of species, although it was first discovered as a component of human cytotoxic T lymphocytes. TIA1 has a dual localization in the nucleus and cytoplasm, where it plays an important role as a regulator of gene-expression flux. As a multifunctional master modulator, TIA1 controls biological processes relevant to the physiological functioning of the organism and the development and/or progression of several human pathologies. This review summarizes our current knowledge of the molecular aspects and cellular processes involving TIA1, with relevance for human pathophysiology.


Subject(s)
Cell Nucleus , RNA-Binding Proteins , T-Cell Intracellular Antigen-1 , Cell Nucleus/metabolism , Cytoplasm/metabolism , Humans , RNA-Binding Proteins/metabolism , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism , T-Lymphocytes/metabolism
9.
Fish Shellfish Immunol ; 121: 478-486, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35085738

ABSTRACT

T-cell intracellular antigen (TIA)-1 is a prion-related RNA-binding protein involved in splicing and translational repression, and regulates translation in response to stress conditions by isolating target mRNAs in stress granules (SGs). However, little is known about the potential roles of fish TIA-1 and how it works in viral infection. In this study, the TIA-1 (EcTIA-1) homolog from orange-spotted grouper (Epinephelus coioides) was cloned and characterized. The open reading frame (ORF) sequence of EcTIA-1 encoded a 388 amino acid protein with predicted molecular mass of 42.73 kDa. EcTIA-1 contains three conserved domains of RNA recognition motif (RRM) that may interact with RNA via its second and third RRMs. Overexpression of EcTIA-1 inhibited red-spotted grouper nervous necrosis virus (RGNNV) replication and positively regulated interferon immune response, which was increased by knockdown of EcTIA-1. RGNNV induced formation of SGs in cells with EcTIA-1 overexpression. These results provide a novel insight into understanding the roles of fish TIA-1 in response to RNA viruses.


Subject(s)
Bass , DNA Virus Infections , Fish Diseases , RNA Virus Infections , T-Cell Intracellular Antigen-1/immunology , Animals , Bass/genetics , Bass/immunology , DNA Virus Infections/immunology , DNA Virus Infections/veterinary , Fish Diseases/immunology , Fish Diseases/virology , Fish Proteins/genetics , Fish Proteins/immunology , Immunity, Innate , Necrosis , Nodaviridae , RNA Virus Infections/genetics , RNA Virus Infections/veterinary , T-Cell Intracellular Antigen-1/genetics
10.
Cells ; 10(9)2021 09 18.
Article in English | MEDLINE | ID: mdl-34572124

ABSTRACT

Early life radiation exposure causes abnormal brain development, leading to adult depression. However, few studies have been conducted to explore pre- or post-natal irradiation-induced depression-related neuropathological changes. Relevant molecular mechanisms are also poorly understood. We induced adult depression by irradiation of mice at postnatal day 3 (P3) to reveal hippocampal neuropathological changes and investigate their molecular mechanism, focusing on MicroRNA (miR) and its target mRNA and protein. P3 mice were irradiated by γ-rays with 5Gy, and euthanized at 1, 7 and 120 days after irradiation. A behavioral test was conducted before the animals were euthanized at 120 days after irradiation. The animal brains were used for different studies including immunohistochemistry, CAP-miRSeq, Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) and western blotting. The interaction of miR-34a-5p and its target T-cell intracytoplasmic antigen-1 (Tia1) was confirmed by luciferase reporter assay. Overexpression of Tia1 in a neural stem cell (NSC) model was used to further validate findings from the mouse model. Irradiation with 5 Gy at P3 induced depression in adult mice. Animal hippocampal pathological changes included hypoplasia of the infrapyramidal blade of the stratum granulosum, aberrant and impaired cell division, and neurogenesis in the dentate gyrus. At the molecular level, upregulation of miR-34a-5p and downregulation of Tia1 mRNA were observed in both animal and neural stem cell models. The luciferase reporter assay and gene transfection studies further confirmed a direct interaction between miR-43a-5p and Tia1. Our results indicate that the early life γ-radiation-activated miR-43a-5p/Tia1 pathway is involved in the pathogenesis of adult depression. This novel finding may provide a new therapeutic target by inhibiting the miR-43a-5p/Tia1 pathway to prevent radiation-induced pathogenesis of depression.


Subject(s)
Dentate Gyrus/pathology , Depression/pathology , Gamma Rays/adverse effects , Gene Expression Regulation, Neoplastic/radiation effects , MicroRNAs/genetics , Neurogenesis , T-Cell Intracellular Antigen-1/metabolism , Animals , Apoptosis , Cell Proliferation , Dentate Gyrus/radiation effects , Depression/etiology , Depression/metabolism , Mice , Mice, Inbred BALB C , T-Cell Intracellular Antigen-1/genetics
11.
Mol Biol Rep ; 48(9): 6349-6361, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34410578

ABSTRACT

BACKGROUND: Neuronal development is a tightly controlled process involving multi-layered regulatory mechanisms. While transcriptional pathways regulating neurodevelopment are well characterized, post-transcriptional programs are still poorly understood. TIA1 is an RNA-binding protein that can regulate splicing, stability, or translation of target mRNAs, and has been shown to play critical roles in stress response and neurodevelopment. However, the identity of mRNAs regulated by TIA1 during neurodevelopment under unstressed conditions is still unknown. METHODS AND RESULTS: To identify the mRNAs targeted by TIA1 during the first stages of human neurodevelopment, we performed RNA immunoprecipitation-sequencing (RIP-seq) on human embryonic stem cells (hESCs) and derived neural progenitor cells (NPCs), and cortical neurons under unstressed conditions. While there was no change in TIA1 protein levels, the number of TIA1 targeted mRNAs decreased from pluripotent cells to neurons. We identified 2400, 845, and 330 TIA1 mRNA targets in hESCs, NPC, and neurons, respectively. The vast majority of mRNA targets in hESC were genes associated with neurodevelopment and included autism spectrum disorder-risk genes that were not bound in neurons. Additionally, we found that most TIA1 mRNA targets have reduced ribosomal engagement levels. CONCLUSION: Our results reveal TIA1 mRNA targets in hESCs and during human neurodevelopment, indicate that translation repression is a key process targeted by TIA1 binding and implicate TIA1 function in neuronal differentiation.


Subject(s)
Neurogenesis/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction/genetics , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism , Autism Spectrum Disorder/genetics , Binding Sites , Cell Differentiation/genetics , Cell Line , Gene Knockdown Techniques , Human Embryonic Stem Cells/metabolism , Humans , Immunoprecipitation/methods , Neural Stem Cells/metabolism , Neurons/metabolism , Protein Binding , RNA, Small Interfering/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Ribosomes/metabolism , Sequence Analysis, RNA/methods , Transfection
12.
Methods Mol Biol ; 2312: 253-276, 2021.
Article in English | MEDLINE | ID: mdl-34228295

ABSTRACT

Recent studies revealed the biological significance of dynamic multicomponent assemblies of biomolecules inside living cells. Protein and nucleic acid assemblies are biomolecular condensates or non-membrane-bound organelles that have attracted increasing attention. Synthetic tools that manipulate the dynamic assembly/disassembly process of the structures are useful in elucidating both biophysical mechanisms of their assembly/disassembly and physiological roles of the condensates. In this report, general protocols to form and observe synthetic polymer-based condensates in living cells are described using the tool iPOLYMER. Taking advantage of the modular design of the tool, both chemical and light stimuli can induce formation of synthetic condensates inside living cells, which are observed by laser-scanning confocal microscopy. The experimental design described herein should help those who conduct experiments on synthetic manipulation of biomolecular condensates using iPOLYMER and other tools for synthetic manipulation of condensates. Technical notes for using iPOLYMER, including basic protocols of chemical- or light-inducible dimerization techniques (CID/LID), choice of proper control experiments, and advantages/disadvantages are also presented.


Subject(s)
Cell Engineering , Cytoplasmic Granules/genetics , Gene Expression Regulation , Molecular Mimicry , Optogenetics , Peptides/genetics , RNA/genetics , Synthetic Biology , T-Cell Intracellular Antigen-1/genetics , Animals , COS Cells , Cell Culture Techniques , Chlorocebus aethiops , Cytoplasmic Granules/metabolism , Gene Expression Regulation/drug effects , Gene Expression Regulation/radiation effects , HEK293 Cells , Humans , Hydrogels , Light , Microscopy, Confocal , Microscopy, Fluorescence , Peptides/metabolism , Protein Domains , RNA/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Sirolimus/pharmacology , T-Cell Intracellular Antigen-1/metabolism , Transfection
13.
Brain Res ; 1768: 147589, 2021 10 01.
Article in English | MEDLINE | ID: mdl-34310938

ABSTRACT

T-cell restriction intracellular antigen 1 (TIA1) is an RNA-binding protein that is a major component of stress granules (SGs). The low complexity domain (LCD) of TIA1 plays a central role in facilitating SGs assembly through liquid-liquid phase separation (LLPS). Disruption of the LLPS process has been associated with several diseases. It has recently been shown that the proline-rich domain affects the LLPS process of some proteins (such as UBQLN2 and Tau). Thus, proline may regulate LLPS. The LCD of TIA1 contains 11 proline residues, and several proline-related mutations have been shown to cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here, we demonstrated that TIA1 can undergo phase separation in cells. Additionally, disease-associated proline-to-leucine (P-L) mutations, which altered droplet morphology, facilitated the liquid-to-solid phase transition of TIA1 into solid-like amyloid fibrils. The changes in the physical properties of the P-L mutation altered the behavior of TIA1 in vivo and led to abnormal SGs kinetics, resulting in the formation of the pathological inclusions of ALS. Prolines are the key residues for regulating the LLPS of TIA1.


Subject(s)
Cytoplasmic Granules/metabolism , Protein Aggregates/genetics , T-Cell Intracellular Antigen-1/genetics , Amyloid/genetics , Cytoplasmic Granules/physiology , Inclusion Bodies/pathology , Liquid-Liquid Extraction , Mutation/genetics , Proline/metabolism , Protein Aggregates/physiology , Protein Aggregation, Pathological , Protein Domains/genetics , Stress Granules/genetics , Stress Granules/metabolism , T-Cell Intracellular Antigen-1/metabolism
14.
RNA ; 27(2): 174-189, 2021 02.
Article in English | MEDLINE | ID: mdl-33199441

ABSTRACT

Stress granules (SGs) are stress-induced RNA-protein assemblies formed from a complex transcriptome of untranslating ribonucleoproteins (RNPs). Although RNAs can be either enriched or depleted from SGs, the rules that dictate RNA partitioning into SGs are unknown. We demonstrate that the SG-enriched NORAD RNA is sufficient to enrich a reporter RNA within SGs through the combined effects of multiple elements. Moreover, artificial tethering of G3BP1, TIA1, or FMRP can target mRNAs into SGs in a dose-dependent manner with numerous interactions required for efficient SG partitioning, which suggests individual protein interactions have small effects on the SG partitioning of mRNPs. This is supported by the observation that the SG transcriptome is largely unchanged in cell lines lacking the abundant SG RNA-binding proteins G3BP1 and G3BP2. We suggest the targeting of RNPs into SGs is due to a summation of potential RNA-protein, protein-protein, and RNA-RNA interactions with no single interaction dominating RNP recruitment into SGs.


Subject(s)
Cytoplasmic Granules/metabolism , DNA Helicases/metabolism , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/metabolism , RNA Recognition Motif Proteins/metabolism , RNA, Long Noncoding/metabolism , RNA, Messenger/metabolism , Ribonucleoproteins/metabolism , Transcriptome , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Biological Transport , Cell Line, Tumor , DNA Helicases/genetics , Fibroblasts/cytology , Fibroblasts/metabolism , Fragile X Mental Retardation Protein/genetics , Fragile X Mental Retardation Protein/metabolism , Genes, Reporter , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Humans , Luciferases/genetics , Luciferases/metabolism , Poly-ADP-Ribose Binding Proteins/genetics , Protein Binding , Protein Interaction Mapping , RNA Helicases/genetics , RNA Recognition Motif Proteins/genetics , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Ribonucleoproteins/genetics , Stress, Physiological/genetics , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism
15.
J Virol ; 94(22)2020 10 27.
Article in English | MEDLINE | ID: mdl-32878892

ABSTRACT

Yellow fever virus (YFV) is an RNA virus primarily targeting the liver. Severe YF cases are responsible for hemorrhagic fever, plausibly precipitated by excessive proinflammatory cytokine response. Pathogen recognition receptors (PRRs), such as the cytoplasmic retinoic acid inducible gene I (RIG-I)-like receptors (RLRs), and the viral RNA sensor protein kinase R (PKR), are known to initiate a proinflammatory response upon recognition of viral genomes. Here, we sought to reveal the main determinants responsible for the acute cytokine expression occurring in human hepatocytes following YFV infection. Using a RIG-I-defective human hepatoma cell line, we found that RIG-I largely contributes to cytokine secretion upon YFV infection. In infected RIG-I-proficient hepatoma cells, RIG-I was localized in stress granules. These granules are large aggregates of stalled translation preinitiation complexes known to concentrate RLRs and PKR and are so far recognized as hubs orchestrating RNA virus sensing. Stable knockdown of PKR in hepatoma cells revealed that PKR contributes to both stress granule formation and cytokine induction upon YFV infection. However, stress granule disruption did not affect the cytokine response to YFV infection, as assessed by small interfering RNA (siRNA)-knockdown-mediated inhibition of stress granule assembly. Finally, no viral RNA was detected in stress granules using a fluorescence in situ hybridization approach coupled with immunofluorescence. Our findings suggest that both RIG-I and PKR mediate proinflammatory cytokine induction in YFV-infected hepatocytes, in a stress granule-independent manner. Therefore, by showing the uncoupling of the cytokine response from the stress granule formation, our model challenges the current view in which stress granules are required for the mounting of the acute antiviral response.IMPORTANCE Yellow fever is a mosquito-borne acute hemorrhagic disease caused by yellow fever virus (YFV). The mechanisms responsible for its pathogenesis remain largely unknown, although increased inflammation has been linked to worsened outcome. YFV targets the liver, where it primarily infects hepatocytes. We found that two RNA-sensing proteins, RIG-I and PKR, participate in the induction of proinflammatory mediators in human hepatocytes infected with YFV. We show that YFV infection promotes the formation of cytoplasmic structures, termed stress granules, in a PKR- but not RIG-I-dependent manner. While stress granules were previously postulated to be essential platforms for immune activation, we found that they are not required for the production of proinflammatory mediators upon YFV infection. Collectively, our work uncovered molecular events triggered by the replication of YFV, which could prove instrumental in clarifying the pathogenesis of the disease, with possible repercussions for disease management.


Subject(s)
DEAD Box Protein 58/metabolism , Yellow fever virus/metabolism , eIF-2 Kinase/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , Carcinoma, Hepatocellular , Cell Line , Cell Line, Tumor , Cytokines/metabolism , DEAD Box Protein 58/deficiency , DEAD Box Protein 58/genetics , DNA Helicases/genetics , Gene Knockdown Techniques , Haplorhini , Hepatocytes/virology , Humans , Poly-ADP-Ribose Binding Proteins/genetics , RNA Helicases/genetics , RNA Recognition Motif Proteins/genetics , RNA, Small Interfering , RNA, Viral/genetics , RNA-Binding Proteins/genetics , Receptors, Immunologic , T-Cell Intracellular Antigen-1/genetics , Transcriptome , eIF-2 Kinase/genetics
16.
Cells ; 9(7)2020 06 27.
Article in English | MEDLINE | ID: mdl-32605035

ABSTRACT

: The family Hantaviridae within the Bunyavirales order comprises tri-segmented negative sense RNA viruses, many of which are rodent-borne emerging pathogens associated with fatal human disease. In contrast, hantavirus infection of corresponding rodent hosts results in inapparent or latent infections, which can be recapitulated in cultured cells that become persistently infected. In this study, we used Tula virus (TULV) to investigate the location of hantavirus replication during early, peak and persistent phases of infection, over a 30-day time course. Using immunofluorescent (IF) microscopy, we showed that the TULV nucleocapsid protein (NP) is distributed within both punctate and filamentous structures, with the latter increasing in size as the infection progresses. Transmission electron microscopy of TULV-infected cell sections revealed these filamentous structures comprised aligned clusters of filament bundles. The filamentous NP-associated structures increasingly co-localized with the Golgi and with the stress granule marker TIA-1 over the infection time course, suggesting a redistribution of these cellular organelles. The analysis of the intracellular distribution of TULV RNAs using fluorescent in-situ hybridization revealed that both genomic and mRNAs co-localized with Golgi-associated filamentous compartments that were positive for TIA. These results show that TULV induces a dramatic reorganization of the intracellular environment, including the establishment of TULV RNA synthesis factories in re-modelled Golgi compartments.


Subject(s)
Orthohantavirus/pathogenicity , Animals , Orthohantavirus/genetics , Humans , In Situ Hybridization, Fluorescence , Phylogeny , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism , Virus Replication/genetics , Virus Replication/physiology
17.
J Affect Disord ; 260: 597-603, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31541970

ABSTRACT

BACKGROUND: The TIA1 gene encodes a prion-related RNA-binding protein that regulates stress-dependent synaptic plasticity and fear memory in mice. It is unknown whether genetic variation in human TIA1 is associated with differences in stress- and fear-related behavior in people. METHODS: A longitudinal, population-based survey was conducted in Sweden to collect information on demographics, socioeconomic status, exposure to stressful life events and psychiatric symptoms. DNA samples were obtained from study participants to allow genotyping of single-nucleotide polymorphisms in the human TIA1 locus. RESULTS: We identified a single-nucleotide polymorphism in the human TIA1 gene that interacts with exposure to previous-year stressful life events to predict the development of pathological anxiety symptoms in a non-clinical cohort. LIMITATIONS: Sample population is limited in both size and scope, and we did not perform functional analysis of allelic variants of TIA1. CONCLUSIONS: TIA1 may represent a susceptibility locus for stress-dependent psychopathology. These studies support an evolutionarily conserved role of TIA1 in the mammalian brain, and may provide molecular and genetic insight into the development of stress-related psychiatric conditions such as PTSD and anxiety.


Subject(s)
Anxiety Disorders/genetics , Polymorphism, Single Nucleotide , Stress, Psychological/genetics , T-Cell Intracellular Antigen-1/genetics , Adult , Alleles , Anxiety Disorders/psychology , Cohort Studies , Female , Gene-Environment Interaction , Genotyping Techniques , Humans , Life Change Events , Longitudinal Studies , Male , Middle Aged , Risk Factors , Stress, Psychological/psychology , Sweden , Young Adult
18.
Cell Rep ; 29(13): 4377-4388.e4, 2019 12 24.
Article in English | MEDLINE | ID: mdl-31875547

ABSTRACT

Pathological aggregation of RNA binding proteins (RBPs) is associated with dysregulation of RNA splicing in PS19 P301S tau transgenic mice and in Alzheimer's disease brain tissues. The dysregulated splicing particularly affects genes involved in synaptic transmission. The effects of neuroprotective TIA1 reduction on PS19 mice are also examined. TIA1 reduction reduces disease-linked alternative splicing events for the major synaptic mRNA transcripts examined, suggesting that normalization of RBP functions is associated with the neuroprotection. Use of the NetDecoder informatics algorithm identifies key upstream biological targets, including MYC and EGFR, underlying the transcriptional and splicing changes in the protected compared to tauopathy mice. Pharmacological inhibition of MYC and EGFR activity in neuronal cultures tau recapitulates the neuroprotective effects of TIA1 reduction. These results demonstrate that dysfunction of RBPs and RNA splicing processes are major elements of the pathophysiology of tauopathies, as well as potential therapeutic targets for tauopathies.


Subject(s)
RNA Splicing/genetics , Tauopathies/genetics , Alzheimer Disease/genetics , Animals , Brain/metabolism , Down-Regulation/genetics , ErbB Receptors/metabolism , Female , Heterozygote , Humans , Male , Mice, Inbred C57BL , Mice, Transgenic , Nerve Degeneration/genetics , Nerve Degeneration/pathology , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins c-myc/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Sex Characteristics , Spliceosomes/metabolism , Synapses/metabolism , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism
19.
Neuron ; 104(2): 290-304.e8, 2019 10 23.
Article in English | MEDLINE | ID: mdl-31378567

ABSTRACT

Phase separation into liquid-like compartments is an emerging property of proteins containing prion-like domains (PrLDs), yet the in vivo roles of phase separation remain poorly understood. TIA proteins contain a C-terminal PrLD, and mutations in the PrLD are associated with several diseases. Here, we show that the C. elegans TIAR-2/TIA protein functions cell autonomously to inhibit axon regeneration. TIAR-2 undergoes liquid-liquid phase separation in vitro and forms granules with liquid-like properties in vivo. Axon injury induces a transient increase in TIAR-2 granule number. The PrLD is necessary and sufficient for granule formation and inhibiting regeneration. Tyrosine residues within the PrLD are important for granule formation and inhibition of regeneration. TIAR-2 is also serine phosphorylated in vivo. Non-phosphorylatable TIAR-2 variants do not form granules and are unable to inhibit axon regeneration. Our data demonstrate an in vivo function for phase-separated TIAR-2 and identify features critical for its function in axon regeneration.


Subject(s)
Axons/metabolism , Caenorhabditis elegans Proteins/metabolism , Nerve Regeneration/physiology , RNA Recognition Motif Proteins/metabolism , Animals , Axons/physiology , Caenorhabditis elegans , Caenorhabditis elegans Proteins/genetics , Cell Compartmentation , Cytoplasmic Granules , Protein Domains , RNA Recognition Motif Proteins/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , T-Cell Intracellular Antigen-1/genetics , T-Cell Intracellular Antigen-1/metabolism
20.
FEBS J ; 286(24): 4937-4950, 2019 12.
Article in English | MEDLINE | ID: mdl-31408583

ABSTRACT

Apoptosis of vascular endothelial cells (VEC) is the main form of vascular injury that is closely linked to numerous cardiovascular diseases. Therefore, it is important to find new factors that can suppress VEC apoptosis. By using long noncoding RNA (lncRNA) microarray analysis, we found a new read-through lncRNA, MROH7-TTC4, which acted as an apoptosis inhibitor in VECs. Furthermore, by using the inhibitor (ABO) of annexin A7 (ANXA7) GTPase, we discovered that ANXA7 translocated into nucleus and interacted with 5'→3' exoribonuclease (XRN2). The decreased XRN2 phosphorylation induced by ANXA7 GTPase activity inhibition, promoted MROH7-TTC4 expression. Moreover, T-cell intracellular antigen-1 (TIA1), a binding protein of MROH7-TTC4, processed it into MROH7 and TTC4 that could inhibit VEC apoptosis. Here, we conclude that inhibiting ANXA7 GTPase activity promotes the interaction of ANXA7 and XRN2 in nucleus, which regulates the read-through transcription of MROH7-TTC4, and TIA1 is responsible for the process of MROH7-TTC4 that inhibits apoptosis through MROH7 and TTC4.


Subject(s)
Annexin A7/metabolism , RNA, Long Noncoding/metabolism , T-Cell Intracellular Antigen-1/metabolism , Tumor Suppressor Proteins/metabolism , Annexin A7/genetics , Apoptosis/genetics , Apoptosis/physiology , Blotting, Western , Chromatin Immunoprecipitation , Human Umbilical Vein Endothelial Cells , Humans , Immunoprecipitation , In Situ Nick-End Labeling , Phosphorylation , RNA, Long Noncoding/genetics , Real-Time Polymerase Chain Reaction , T-Cell Intracellular Antigen-1/genetics , Tumor Suppressor Proteins/genetics
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