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Karasik A, Lorenzi HA, DePass AV, Guydosh NR. Endonucleolytic RNA cleavage drives changes in gene expression during the innate immune response. Cell Rep 2024; 43:114287. [PMID: 38823018 PMCID: PMC11251458 DOI: 10.1016/j.celrep.2024.114287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 04/05/2024] [Accepted: 05/13/2024] [Indexed: 06/03/2024] Open
Abstract
Viral infection triggers several double-stranded RNA (dsRNA) sensors that lead to changes in gene expression in the cell. One of these sensors activates an endonuclease, ribonuclease L (RNase L), that cleaves single-stranded RNA. However, how the resultant widespread RNA fragmentation affects gene expression is not fully understood. Here, we show that this fragmentation induces the ribotoxic stress response via ZAKα, potentially through stalled ribosomes and/or ribosome collisions. The p38 and JNK pathways that are activated as part of this response promote outcomes that inhibit the virus, such as programmed cell death. We also show that RNase L limits the translation of stress-responsive genes. Intriguingly, we found that the activity of the generic endonuclease, RNase A, recapitulates many of the same molecular phenotypes as activated RNase L, demonstrating how widespread RNA cleavage can evoke an antiviral program.
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Affiliation(s)
- Agnes Karasik
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hernan A Lorenzi
- TriLab Bioinformatics Group, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew V DePass
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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2
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Bian J, Yan J, Chen C, Yin L, Liu P, Zhou Q, Yu J, Liang Q, He Q. Development of an immune-related diagnostic predictive model for oral lichen planus. Medicine (Baltimore) 2024; 103:e37469. [PMID: 38489725 PMCID: PMC10939522 DOI: 10.1097/md.0000000000037469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/10/2024] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
Oral lichen planus (OLP) was a chronic inflammatory disease of unknown etiology with a 1.4% chance of progressing to malignancy. However, it has been suggested in several studies that immune system disorders played a dominant role in the onset and progression of OLP. Therefore, this experiment aimed to develop a diagnostic prediction model for OLP based on immunopathogenesis to achieve early diagnosis and treatment and prevent cancer. In this study, 2 publicly available OLP datasets from the gene expression omnibus database were filtered. In the experimental group (GSE52130), the level of immune cell infiltration was assessed using MCPcounter and ssGSEA algorithms. Subsequently, differential expression analysis and gene set enrichment analysis were performed between the OLP and control groups. The resulting differentially expressed genes were intersected with immunologically relevant genes provided on the immunology database and analysis portal database (ImmPort) website to obtain differentially expressed immunologically relevant genes (DEIRGs). Furthermore, the gene ontology and kyoto encyclopedia of genes and genomes analyses were carried out. Finally, protein-protein interaction network and least absolute shrinkage and selection operator regression analyses constructed a model for OLP. Receiver operating characteristic curves for the experimental and validation datasets (GSE38616) were plotted separately to validate the model's credibility. In addition, real-time quantitative PCR experiment was performed to verify the expression level of the diagnostic genes. Immune cell infiltration analysis revealed a more significant degree of inflammatory infiltration in the OLP group compared to the control group. In addition, the gene set enrichment analysis results were mainly associated with keratinization, antibacterial and immune responses, etc. A total of 774 differentially expressed genes was obtained according to the screening criteria, of which 65 were differentially expressed immunologically relevant genes. Ultimately, an immune-related diagnostic prediction model for OLP, which was composed of 5 hub genes (BST2, RNASEL, PI3, DEFB4A, CX3CL1), was identified. The verification results showed that the model has good diagnostic ability. There was a significant correlation between the 5 hub diagnostic biomarkers and immune infiltrating cells. The development of this model gave a novel insight into the early diagnosis of OLP.
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Affiliation(s)
- Jiamin Bian
- School of Stomatology, North Sichuan Medical College, Nanchong, Sichuan, China
| | - Jiayu Yan
- School of Stomatology, North Sichuan Medical College, Nanchong, Sichuan, China
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
- Department of Stomatology, Sichuan Integrated Traditional and Western Medicine Hospital, Chengdu, Sichuan, China
| | - Chu Chen
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Li Yin
- Department of Stomatology, Sichuan Integrated Traditional and Western Medicine Hospital, Chengdu, Sichuan, China
| | - Panpan Liu
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Qi Zhou
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Jianfeng Yu
- Department of Stomatology, Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Qin Liang
- Department of Stomatology, Pengzhou Hospital of Traditional Chinese Medicine, Pengzhou, Sichuan, China
| | - Qingmei He
- Department of Neurological, Chongqing Shi Yong Chuan Hospital of Traditional Chinese Medicine, Chongqing, China
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3
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Ding K, Li H, Tai F, Duan J, Wang Q, Zhai R, Fu H, Ge C, Zheng X. Unraveling the Role of RNase L Knockout in Alleviating Immune Response Activation in Mice Bone Marrow after Irradiation. Int J Mol Sci 2024; 25:2722. [PMID: 38473966 PMCID: PMC10932110 DOI: 10.3390/ijms25052722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 02/09/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Ionizing radiation (IR) induces severe hematopoietic injury by causing DNA and RNA damage as well as activating the immune responses, necessitating the development of effective therapeutic strategies. Ribonuclease L (RNase L) as an innate immune response pathway is triggered by exogenous and endogenous abnormal dsRNA under viral infection and dyshomeostasis, thereby activating the immune responses. Thus, we investigated the effect of RNase L on irradiation-induced bone marrow damage using RNase L knockout (RNase L-/-) mice. Phenotypic analysis revealed that RNase L knockout mitigates irradiation-induced injury in the bone marrow. Further investigation into the mechanism of RNase L by RNA-seq, qRT-PCR, and CBA analysis demonstrated that RNase L deficiency counteracts the upregulation of genes related to immune responses induced by irradiation, including cytokines and interferon-stimulated genes. Moreover, RNase L deficiency inhibits the increased levels of immunoglobulins in serum induced by irradiation. These findings indicate that RNase L plays a role in the immune response induced by irradiation in the bone marrow. This study further enhances our understanding of the biological functions of RNase L in the immune response induced by irradiation and offers a novel approach for managing irradiation-induced bone marrow injury through the regulation of RNase L activation.
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Affiliation(s)
| | | | | | | | | | | | | | - Changhui Ge
- Beijing Key Laboratory for Radiobiology, Department of Experimental Hematology and Biochemistry, Beijing Institute of Radiation Medicine, Beijing 100850, China; (K.D.); (H.L.); (F.T.); (J.D.); (Q.W.); (R.Z.); (H.F.)
| | - Xiaofei Zheng
- Beijing Key Laboratory for Radiobiology, Department of Experimental Hematology and Biochemistry, Beijing Institute of Radiation Medicine, Beijing 100850, China; (K.D.); (H.L.); (F.T.); (J.D.); (Q.W.); (R.Z.); (H.F.)
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Karasik A, Lorenzi HA, DePass AV, Guydosh NR. Endonucleolytic RNA cleavage drives changes in gene expression during the innate immune response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555507. [PMID: 37693516 PMCID: PMC10491309 DOI: 10.1101/2023.09.01.555507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Viral infection triggers several dsRNA sensors that lead to changes in gene expression in the cell. One of these sensors activates an endonuclease, RNase L, that cleaves single stranded RNA. However, how the resultant widespread RNA fragmentation affects gene expression is not fully understood. Here we show that this fragmentation induces the Ribotoxic Stress Response via ZAKα, potentially through ribosome collisions. The p38 and JNK pathways that are activated as part of this response promote outcomes that inhibit the virus, such as programmed cell death. We also show that RNase L limits the translation of stress-responsive genes, including antiviral IFIT mRNAs and GADD34 that encodes an antagonist of the Integrated Stress Response. Intriguingly, we found the activity of the generic endonuclease, RNase A, recapitulates many of the same molecular phenotypes as activated RNase L, demonstrating how widespread RNA cleavage can evoke an antiviral program.
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Affiliation(s)
- Agnes Karasik
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Hernan A Lorenzi
- TriLab Bioinformatics Group, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Andrew V DePass
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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5
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Torices S, Teglas T, Naranjo O, Fattakhov N, Frydlova K, Cabrera R, Osborne OM, Sun E, Kluttz A, Toborek M. Occludin Regulates HIV-1 Infection by Modulation of the Interferon Stimulated OAS Gene Family. Mol Neurobiol 2023; 60:4966-4982. [PMID: 37209263 PMCID: PMC10199280 DOI: 10.1007/s12035-023-03381-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/04/2023] [Indexed: 05/22/2023]
Abstract
HIV-1-associated blood brain barrier (BBB) alterations and neurocognitive disorders are frequent clinical manifestations in HIV-1 infected patients. The BBB is formed by cells of the neurovascular unit (NVU) and sealed together by tight junction proteins, such as occludin (ocln). Pericytes are a key cell type of NVU that can harbor HIV-1 infection via a mechanism that is regulated, at least in part, by ocln. After viral infection, the immune system starts the production of interferons, which induce the expression of the 2'-5'-oligoadenylate synthetase (OAS) family of interferon stimulated genes and activate the endoribonuclease RNaseL that provides antiviral protection by viral RNA degradation. The current study evaluated the involvement of the OAS genes in HIV-1 infection of cells of NVU and the role of ocln in controlling OAS antiviral signaling pathway. We identified that ocln modulates the expression levels of the OAS1, OAS2, OAS3, and OASL genes and proteins and, in turn, that the members of the OAS family can influence HIV replication in human brain pericytes. Mechanistically, this effect was regulated via the STAT signaling. HIV-1 infection of pericytes significantly upregulated expression of all OAS genes at the mRNA level but selectively OAS1, OAS2, and OAS3 at the protein level. Interestingly no changes were found in RNaseL after HIV-1 infection. Overall, these results contribute to a better understanding of the molecular mechanisms implicated in the regulation of HIV-1 infection in human brain pericytes and suggest a novel role for ocln in controlling of this process.
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Affiliation(s)
- Silvia Torices
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA.
| | - Timea Teglas
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Oandy Naranjo
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Nikolai Fattakhov
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Kristyna Frydlova
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Rosalba Cabrera
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Olivia M Osborne
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Enze Sun
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Allan Kluttz
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street, Miami, FL, 11336, USA.
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Torices S, Teglas T, Naranjo O, Fattakhov N, Frydlova K, Cabrera R, Osborne OM, Sun E, Kluttz A, Toborek M. Occludin regulates HIV-1 infection by modulation of the interferon stimulated OAS gene family. RESEARCH SQUARE 2023:rs.3.rs-2501091. [PMID: 36778388 PMCID: PMC9915789 DOI: 10.21203/rs.3.rs-2501091/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
HIV-1-associated blood brain barrier (BBB) alterations and neurocognitive disorders are frequent clinical manifestations in HIV-1 infected patients. The BBB is formed by cells of the neurovascular unit (NVU) and sealed together by tight junction (TJ) proteins, such as occludin (ocln). Pericytes are a key cell type of NVU that can harbor HIV-1 infection via a mechanism that is regulated, at least in part, by ocln. After viral infection, the immune system starts the production of interferons, which induce the expression of the 2'-5'-oligoadenylate synthetase (OAS) family of interferon stimulated genes and activate the endoribonuclease RNaseL that provides antiviral protection by viral RNA degradation. The current study evaluated the involvement of the OAS genes in HIV-1 infection of cells of NVU and the role of ocln in controlling OAS antiviral signaling pathway. We identified that ocln modulates the expression levels of the OAS1, OAS2, OAS3, and OASL genes and proteins and, in turn, that the members of the OAS family can influence HIV replication in human brain pericytes. Mechanistically, this effect was regulated via the STAT signaling. HIV-1 infection of pericytes significantly upregulated expression of all OAS genes at the mRNA level but selectively OAS1, OAS2 and OAS3 at the protein level. Interestingly no changes were found in RNaseL after HIV-1 infection. Overall, these results contribute to a better understanding of the molecular mechanisms implicated in the regulation of HIV-1 infection in human brain pericytes and suggest a novel role for ocln in controlling of this process.
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Affiliation(s)
- Silvia Torices
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Timea Teglas
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Oandy Naranjo
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Nikolai Fattakhov
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Kristyna Frydlova
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Rosalba Cabrera
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Olivia M Osborne
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Enze Sun
- University of Miami Miller School of Medicine: University of Miami School of Medicine
| | - Allan Kluttz
- University of Miami Miller School of Medicine: University of Miami School of Medicine
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Prangley E, Korennykh A. 2-5A-Mediated decay (2-5AMD): from antiviral defense to control of host RNA. Crit Rev Biochem Mol Biol 2022; 57:477-491. [PMID: 36939319 PMCID: PMC10576847 DOI: 10.1080/10409238.2023.2181308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 10/18/2022] [Accepted: 02/13/2023] [Indexed: 03/21/2023]
Abstract
Mammalian cells are exquisitely sensitive to the presence of double-stranded RNA (dsRNA), a molecule that they interpret as a signal of viral presence requiring immediate attention. Upon sensing dsRNA cells activate the innate immune response, which involves transcriptional mechanisms driving inflammation and secretion of interferons (IFNs) and interferon-stimulated genes (ISGs), as well as synthesis of RNA-like signaling molecules comprised of three or more 2'-5'-linked adenylates (2-5As). 2-5As were discovered some forty years ago and described as IFN-induced inhibitors of protein synthesis. The efforts of many laboratories, aimed at elucidating the molecular mechanism and function of these mysterious RNA-like signaling oligonucleotides, revealed that 2-5A is a specific ligand for the kinase-family endonuclease RNase L. RNase L decays single-stranded RNA (ssRNA) from viruses and mRNAs (as well as other RNAs) from hosts in a process we proposed to call 2-5A-mediated decay (2-5AMD). During recent years it has become increasingly recognized that 2-5AMD is more than a blunt tool of viral RNA destruction, but a pathway deeply integrated into sensing and regulation of endogenous RNAs. Here we present an overview of recently emerged roles of 2-5AMD in host RNA regulation.
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Affiliation(s)
- Eliza Prangley
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Alexei Korennykh
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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Tang J, Dong B, Liu M, Liu S, Niu X, Gaughan C, Asthana A, Zhou H, Xu Z, Zhang G, Silverman RH, Huang H. Identification of Small Molecule Inhibitors of RNase L by Fragment-Based Drug Discovery. J Med Chem 2022; 65:1445-1457. [PMID: 34841869 PMCID: PMC10620946 DOI: 10.1021/acs.jmedchem.1c01156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The pseudokinase-endoribonuclease RNase L plays important roles in antiviral innate immunity and is also implicated in many other cellular activities. The inhibition of RNase L showed therapeutic potential for Aicardi-Goutières syndrome (AGS). Thus, RNase L is a promising drug target. In this study, using an enzyme assay and NMR screening, we discovered 13 inhibitory fragments against RNase L. Cocrystal structures of RNase L separately complexed with two different fragments were determined in which both fragments bound to the ATP-binding pocket of the pseudokinase domain. Myricetin, vitexin, and hyperoside, three natural products sharing similar scaffolds with the fragment AC40357, demonstrated a potent inhibitory activity in vitro. In addition, myricetin has a promising cellular inhibitory activity. A cocrystal structure of RNase L with myricetin provided a structural basis for inhibitor design by allosterically modulating the ribonuclease activity. Our findings demonstrate that fragment screening can lead to the discovery of natural product inhibitors of RNase L.
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Affiliation(s)
- Jinle Tang
- State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Beihua Dong
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ming Liu
- State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Shuyan Liu
- National Clinical Research Center for Infectious Diseases, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen 518112, China
| | - Xiaogang Niu
- College of Chemistry and Molecular Engineering, Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing 100871, China
| | - Christina Gaughan
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Abhishek Asthana
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Huan Zhou
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Zhengshuang Xu
- State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Guoliang Zhang
- National Clinical Research Center for Infectious Diseases, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen 518112, China
| | - Robert H. Silverman
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Hao Huang
- State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
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Karasik A, Jones GD, DePass AV, Guydosh NR. Activation of the antiviral factor RNase L triggers translation of non-coding mRNA sequences. Nucleic Acids Res 2021; 49:6007-6026. [PMID: 33556964 DOI: 10.1093/nar/gkab036] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/06/2021] [Accepted: 02/03/2021] [Indexed: 11/15/2022] Open
Abstract
Ribonuclease L (RNase L) is activated as part of the innate immune response and plays an important role in the clearance of viral infections. When activated, it endonucleolytically cleaves both viral and host RNAs, leading to a global reduction in protein synthesis. However, it remains unknown how widespread RNA decay, and consequent changes in the translatome, promote the elimination of viruses. To study how this altered transcriptome is translated, we assayed the global distribution of ribosomes in RNase L activated human cells with ribosome profiling. We found that RNase L activation leads to a substantial increase in the fraction of translating ribosomes in ORFs internal to coding sequences (iORFs) and ORFs within 5' and 3' UTRs (uORFs and dORFs). Translation of these alternative ORFs was dependent on RNase L's cleavage activity, suggesting that mRNA decay fragments are translated to produce short peptides that may be important for antiviral activity.
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Affiliation(s)
- Agnes Karasik
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD 20892, USA
| | - Grant D Jones
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew V DePass
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Maestri E, Duszka K, Kuznetsov VA. Immunity Depletion, Telomere Imbalance, and Cancer-Associated Metabolism Pathway Aberrations in Intestinal Mucosa upon Short-Term Caloric Restriction. Cancers (Basel) 2021; 13:cancers13133180. [PMID: 34202278 PMCID: PMC8267928 DOI: 10.3390/cancers13133180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 11/16/2022] Open
Abstract
Systems cancer biology analysis of calorie restriction (CR) mechanisms and pathways has not been carried out, leaving therapeutic benefits unclear. Using metadata analysis, we studied gene expression changes in normal mouse duodenum mucosa (DM) response to short-term (2-weeks) 25% CR as a biological model. Our results indicate cancer-associated genes consist of 26% of 467 CR responding differential expressed genes (DEGs). The DEGs were enriched with over-expressed cell cycle, oncogenes, and metabolic reprogramming pathways that determine tissue-specific tumorigenesis, cancer, and stem cell activation; tumor suppressors and apoptosis genes were under-expressed. DEG enrichments suggest telomeric maintenance misbalance and metabolic pathway activation playing dual (anti-cancer and pro-oncogenic) roles. The aberrant DEG profile of DM epithelial cells is found within CR-induced overexpression of Paneth cells and is coordinated significantly across GI tract tissues mucosa. Immune system genes (ISGs) consist of 37% of the total DEGs; the majority of ISGs are suppressed, including cell-autonomous immunity and tumor-immune surveillance. CR induces metabolic reprogramming, suppressing immune mechanics and activating oncogenic pathways. We introduce and argue for our network pro-oncogenic model of the mucosa multicellular tissue response to CR leading to aberrant transcription and pre-malignant states. These findings change the paradigm regarding CR's anti-cancer role, initiating specific treatment target development. This will aid future work to define critical oncogenic pathways preceding intestinal lesion development and biomarkers for earlier adenoma and colorectal cancer detection.
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Affiliation(s)
- Evan Maestri
- Department of Biochemistry and Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA;
- Department of Biology, SUNY University at Buffalo, Buffalo, NY 14260, USA
| | - Kalina Duszka
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria;
| | - Vladimir A. Kuznetsov
- Department of Biochemistry and Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA;
- Bioinformatics Institute, Biomedical Sciences Institutes A*STAR, Singapore 13867, Singapore
- Correspondence:
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11
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Sunitinib inhibits RNase L by destabilizing its active dimer conformation. Biochem J 2021; 477:3387-3399. [PMID: 32830849 DOI: 10.1042/bcj20200260] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/27/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023]
Abstract
The pseudokinase (PK) RNase L is a functional ribonuclease and plays important roles in human innate immunity. The ribonuclease activity of RNase L can be regulated by the kinase inhibitor sunitinib. The combined use of oncolytic virus and sunitinib has been shown to exert synergistic effects in anticancer therapy. In this study, we aimed to uncover the mechanism of action through which sunitinib inhibits RNase L. We solved the crystal structures of RNase L in complex with sunitinib and its analogs toceranib and SU11652. Our results showed that sunitinib bound to the ATP-binding pocket of RNase L. Unexpectedly, the αA helix linking the ankyrin repeat-domain and the PK domain affected the binding mode of sunitinib and resulted in an unusual flipped orientation relative to other structures in PDB. Molecular dynamics simulations and dynamic light scattering results support that the binding of sunitinib in the PK domain destabilized the dimer conformation of RNase L and allosterically inhibited its ribonuclease activity. Our study suggested that dimer destabilization could be an effective strategy for the discovery of RNase L inhibitors and that targeting the ATP-binding pocket in the PK domain of RNase L was an efficient approach for modulating its ribonuclease activity.
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Hanscom M, Loane DJ, Aubretch T, Leser J, Molesworth K, Hedgekar N, Ritzel RM, Abulwerdi G, Shea-Donohue T, Faden AI. Acute colitis during chronic experimental traumatic brain injury in mice induces dysautonomia and persistent extraintestinal, systemic, and CNS inflammation with exacerbated neurological deficits. J Neuroinflammation 2021; 18:24. [PMID: 33461596 PMCID: PMC7814749 DOI: 10.1186/s12974-020-02067-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/21/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Disruptions of brain-gut axis have been implicated in the progression of a variety of gastrointestinal (GI) disorders and central nervous system (CNS) diseases and injuries, including traumatic brain injury (TBI). TBI is a chronic disease process characterized by persistent secondary injury processes which can be exacerbated by subsequent challenges. Enteric pathogen infection during chronic TBI worsened cortical lesion volume; however, the pathophysiological mechanisms underlying the damaging effects of enteric challenge during chronic TBI remain unknown. This preclinical study examined the effect of intestinal inflammation during chronic TBI on associated neurobehavioral and neuropathological outcomes, systemic inflammation, and dysautonomia. METHODS Dextran sodium sulfate (DSS) was administered to adult male C57BL/6NCrl mice 28 days following craniotomy (Sham) or TBI for 7 days to induce intestinal inflammation, followed by a return to normal drinking water for an additional 7 to 28 days for recovery; uninjured animals (Naïve) served as an additional control group. Behavioral testing was carried out prior to, during, and following DSS administration to assess changes in motor and cognitive function, social behavior, and mood. Electrocardiography was performed to examine autonomic balance. Brains were collected for histological and molecular analyses of injury lesion, neurodegeneration, and neuroinflammation. Blood, colons, spleens, mesenteric lymph nodes (mLNs), and thymus were collected for morphometric analyses and/or immune characterization by flow cytometry. RESULTS Intestinal inflammation 28 days after craniotomy or TBI persistently induced, or exacerbated, respectively, deficits in fine motor coordination, cognition, social behavior, and anxiety-like behavior. Behavioral changes were associated with an induction, or exacerbation, of hippocampal neuronal cell loss and microglial activation in Sham and TBI mice administered DSS, respectively. Acute DSS administration resulted in a sustained systemic immune response with increases in myeloid cells in blood and spleen, as well as myeloid cells and lymphocytes in mesenteric lymph nodes. Dysautonomia was also induced in Sham and TBI mice administered DSS, with increased sympathetic tone beginning during DSS administration and persisting through the first recovery week. CONCLUSION Intestinal inflammation during chronic experimental TBI causes a sustained systemic immune response and altered autonomic balance that are associated with microglial activation, increased neurodegeneration, and persistent neurological deficits.
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Affiliation(s)
- Marie Hanscom
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA.
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
| | - Taryn Aubretch
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Jenna Leser
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Kara Molesworth
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Nivedita Hedgekar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Rodney M Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Gelareh Abulwerdi
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Terez Shea-Donohue
- Division of Translational Radiation Sciences (DTRS), Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
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IFN-γ restores the impaired function of RNase L and induces mitochondria-mediated apoptosis in lung cancer. Cell Death Dis 2019; 10:642. [PMID: 31501431 PMCID: PMC6733796 DOI: 10.1038/s41419-019-1902-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/17/2019] [Accepted: 08/11/2019] [Indexed: 11/24/2022]
Abstract
RNase L is an essential component in interferon (IFN)-mediated antiviral signaling that showed antitumor effects in cancer. Cancer immunotherapy based on interferon has achieved encouraging results that indicate an applicable potential for cancer therapy. Here we showed that function of RNase L, though highly upregulated, was functionally impaired both in nuclear and cytoplasm in lung cancer cells. In normal lung epithelial cells, RNase L activation induced by 2–5A promoted nuclear condensation, DNA cleavage, and cell apoptosis, while in lung cancer cells, these processes were inhibited and RNase L-mediated downregulation of fibrillarin, Topo I and hnRNP A1 was also impaired in lung cancer cells. Moreover, the impairment of RNase L in lung cancer cells was due to the elevated expression of RLI. Application of IFN-γ to lung cancer cells led to enhanced expression of RNase L that compensated the RLI inhibition and restored the cytoplasmic and nuclear function of RNase L, leading to apoptosis of lung cancer cells. Thus, the present study discovered the impaired function and mechanism of RNase L in lung cancer cells and proved the efficacy of IFN-γ in restoring RNase L function and inducing apoptosis in the lung cancer cell. These results indicated the RNase L as a therapeutic target in lung cancer cells and immunotherapy of IFN-γ may serve as an adjuvant to enhance the efficacy.
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Kim SC. RNase-L Deficiency-Associated Intractable Indeterminate Colitis in Children. Inflamm Bowel Dis 2019; 25:e106-e107. [PMID: 31077295 DOI: 10.1093/ibd/izz096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Affiliation(s)
- Soon Chul Kim
- Department of Pediatrics, Chonbuk National University Medical School and Hospital, Research Institute of Clinical Medicine of Chonbuk National University - Biomedical research Institute of Chonbuk National University Hospital, Jeonju, South Korea
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15
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Gusho E, Baskar D, Banerjee S. New advances in our understanding of the "unique" RNase L in host pathogen interaction and immune signaling. Cytokine 2016; 133:153847. [PMID: 27595182 PMCID: PMC7128181 DOI: 10.1016/j.cyto.2016.08.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 08/08/2016] [Accepted: 08/08/2016] [Indexed: 12/22/2022]
Abstract
Ever since the discovery of the existence of an interferon (IFN)-regulated ribonuclease, significant advances have been made in understanding the mechanism and associated regulatory effects of its action. What had been studied initially as a "unique" endoribonuclease is currently known as ribonuclease L (RNase L where "L" stands for latent). Some of the key developments include discovery of the RNase L signaling pathway, its structural characterization, and its molecular cloning. RNase L has been implicated in antiviral and antibacterial defense, as well as in hereditary prostate cancer. RNase L is activated by 2'-5' linked oligoadenylates (2-5A), which are synthesized by the oligoadenylate synthetases (OASs), a family of IFN-regulated pathogen recognition receptors that sense double-stranded RNAs. Activated RNase L cleaves single stranded RNAs, including viral RNAs and cellular RNAs. The catalytic activity of RNase L has been found to lead into the activation of several cellular signaling pathways, including those involved in autophagy, apoptosis, IFN-β production, NLRP3 inflammasome activation leading to IL-1β secretion, inhibition of cell migration, and cell adhesion. In this review, we will highlight the newest advances in our understanding of the catalytic role of RNase L in the context of different cellular pathways and extend the scope of these findings to discussion of potential therapeutic targets for antimicrobial drug development.
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Affiliation(s)
- Elona Gusho
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue Cleveland, OH 44195, USA
| | - Danika Baskar
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue Cleveland, OH 44195, USA; Pediatrics Division Office, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA(1)
| | - Shuvojit Banerjee
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue Cleveland, OH 44195, USA.
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16
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Abstract
Type I interferons (IFNs) are pleiotropic cytokines well recognized for their role in the induction of a potent antiviral gene program essential for host defense against viruses. They also modulate innate and adaptive immune responses. However, the role of type I IFNs in host defense against bacterial infections is enigmatic. Depending on the bacterium, they exert seemingly opposite and capricious functions. In this review, we summarize the effect of type I IFNs on specific bacterial infections and highlight the effector mechanisms regulated by type I IFNs in an attempt to elucidate new avenues to understanding their role.
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Affiliation(s)
- Gayle M Boxx
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Genhong Cheng
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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17
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Banerjee S. RNase L and the NLRP3-inflammasome: An old merchant in a new trade. Cytokine Growth Factor Rev 2016; 29:63-70. [PMID: 26987611 DOI: 10.1016/j.cytogfr.2016.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/27/2016] [Indexed: 12/12/2022]
Abstract
The type I/III interferon (IFN)-inducible 2'-5'- oligoadenylate synthetase (OAS)/endoribonuclease L (RNase L) is a classical innate immune pathway that has been implicated in antiviral and antibacterial defense and also in hereditary prostate cancer. The OAS/RNase L pathway is activated when OAS senses double-stranded RNA and catalyzes the synthesis of 2'-5' linked oligodenylates (2-5A) from ATP. 2-5A then binds and activates RNase L, resulting cleavage of single-stranded RNAs. RNase L cleavage products are capable of activating RIG-like receptors such as RIG-I and MDA5 that leads to IFN-β expression during viral infection. Our recent findings suggest that beside the RLR pathway, RNase L cleavage products can also activate the NLRP3-inflammasome pathway, which requires DHX33 (DExD/H-box helicase) and the mitochondrial adaptor protein MAVS. Here we discuss this newly identified role of OAS-RNase L pathway in regulation of inflammasome signaling as an alternative antimicrobial mechanism that has potential as a target for development of new broad-spectrum antimicrobial and anti-inflammatory therapies.
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Affiliation(s)
- Shuvojit Banerjee
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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18
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The Roles of RNase-L in Antimicrobial Immunity and the Cytoskeleton-Associated Innate Response. Int J Mol Sci 2016; 17:ijms17010074. [PMID: 26760998 PMCID: PMC4730318 DOI: 10.3390/ijms17010074] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/21/2015] [Accepted: 01/04/2016] [Indexed: 12/26/2022] Open
Abstract
The interferon (IFN)-regulated endoribonuclease RNase-L is involved in multiple aspects of the antimicrobial innate immune response. It is the terminal component of an RNA cleavage pathway in which dsRNA induces the production of RNase-L-activating 2-5A by the 2′-5′-oligoadenylate synthetase. The active nuclease then cleaves ssRNAs, both cellular and viral, leading to downregulation of their expression and the generation of small RNAs capable of activating retinoic acid-inducible gene-I (RIG-I)-like receptors or the nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasome. This leads to IFNβ expression and IL-1β activation respectively, in addition to broader effects on immune cell function. RNase-L is also one of a growing number of innate immune components that interact with the cell cytoskeleton. It can bind to several cytoskeletal proteins, including filamin A, an actin-binding protein that collaborates with RNase-L to maintain the cellular barrier to viral entry. This antiviral activity is independent of catalytic function, a unique mechanism for RNase-L. We also describe here the interaction of RNase-L with the E3 ubiquitin ligase and scaffolding protein, ligand of nump protein X (LNX), a regulator of tight junction proteins. In order to better understand the significance and context of these novel binding partners in the antimicrobial response, other innate immune protein interactions with the cytoskeleton are also discussed.
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19
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Brennan-Laun SE, Ezelle HJ, Li XL, Hassel BA. RNase-L control of cellular mRNAs: roles in biologic functions and mechanisms of substrate targeting. J Interferon Cytokine Res 2015; 34:275-88. [PMID: 24697205 DOI: 10.1089/jir.2013.0147] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
RNase-L is a mediator of type 1 interferon-induced antiviral activity that has diverse and critical cellular roles, including the regulation of cell proliferation, differentiation, senescence and apoptosis, tumorigenesis, and the control of the innate immune response. Although RNase-L was originally shown to mediate the endonucleolytic cleavage of both viral and ribosomal RNAs in response to infection, more recent evidence indicates that RNase-L also functions in the regulation of cellular mRNAs as an important mechanism by which it exerts its diverse biological functions. Despite this growing body of work, many questions remain regarding the roles of mRNAs as RNase-L substrates. This review will survey known and putative mRNA substrates of RNase-L, propose mechanisms by which it may selectively cleave these transcripts, and postulate future clinical applications.
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Affiliation(s)
- Sarah E Brennan-Laun
- 1 Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine , Baltimore, Maryland
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20
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Li XY, Guo HZ, Zhu J. Tumor suppressor activity of RIG-I. Mol Cell Oncol 2014; 1:e968016. [PMID: 27308362 PMCID: PMC4905202 DOI: 10.4161/23723548.2014.968016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/07/2014] [Accepted: 08/18/2014] [Indexed: 11/19/2022]
Abstract
Retinoic acid inducible gene-I (RIG-I), named for the observation that its mRNA expression is highly upregulated in the progression of all-trans retinoic acid (ATRA)-induced maturation of acute promyelocytic leukemia (APL) cells, has been well documented as a pivotal virus-associated molecular pattern recognition receptor (PRR) responsible for triggering innate immunity. Upon recognizing viral RNA ligands, RIG-I experiences a series of programmed conformational changes and modifications that unleash its activity through the formation of complexes with various binding partners. Such partners include the mitochondria membrane-anchored protein IPS-1 (also named MAVS/VISA/Cardif) that activates both the IRF3/7 and NF-κB pathways. These partnerships and resulting pathway activations underlie the synthesis of type I interferon and other inflammatory factors. Recent studies have demonstrated that RIG-I is also involved in the regulation of basic cellular processes outside of innate immunity against viral infections, such as hematopoietic proliferation and differentiation, maintenance of leukemic stemness, and tumorigenesis of hepatocellular carcinoma. In this review, we will highlight recent studies leading up to the recognition that RIG-I performs an essential function as a tumor suppressor and try to reconcile this activity of RIG-I with its well-known role in protecting cells against viral infection.
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Affiliation(s)
- Xian-Yang Li
- State Key Laboratory for Medical Genomics and Shanghai Institute of Hematology and Collaborative Innovation Center of Hematology; Rui-Jin Hospital; Shanghai Jiao-Tong University School of Medicine Shanghai, People's Republic of China; Department of Laboratory Medicine; Shanghai First People's Hospital; Shanghai Jiao-Tong University; Shanghai, People's Republic of China
| | - He-Zhou Guo
- State Key Laboratory for Medical Genomics and Shanghai Institute of Hematology and Collaborative Innovation Center of Hematology; Rui-Jin Hospital; Shanghai Jiao-Tong University School of Medicine Shanghai, People's Republic of China
| | - Jiang Zhu
- State Key Laboratory for Medical Genomics and Shanghai Institute of Hematology and Collaborative Innovation Center of Hematology; Rui-Jin Hospital; Shanghai Jiao-Tong University School of Medicine Shanghai, People's Republic of China
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21
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Brennan-Laun SE, Li XL, Ezelle HJ, Venkataraman T, Blackshear PJ, Wilson GM, Hassel BA. RNase L attenuates mitogen-stimulated gene expression via transcriptional and post-transcriptional mechanisms to limit the proliferative response. J Biol Chem 2014; 289:33629-43. [PMID: 25301952 DOI: 10.1074/jbc.m114.589556] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cellular response to mitogens is tightly regulated via transcriptional and post-transcriptional mechanisms to rapidly induce genes that promote proliferation and efficiently attenuate their expression to prevent malignant growth. RNase L is an endoribonuclease that mediates diverse antiproliferative activities, and tristetraprolin (TTP) is a mitogen-induced RNA-binding protein that directs the decay of proliferation-stimulatory mRNAs. In light of their roles as endogenous proliferative constraints, we examined the mechanisms and functional interactions of RNase L and TTP to attenuate a mitogenic response. Mitogen stimulation of RNase L-deficient cells significantly increased TTP transcription and the induction of other mitogen-induced mRNAs. This regulation corresponded with elevated expression of serum-response factor (SRF), a master regulator of mitogen-induced transcription. RNase L destabilized the SRF transcript and formed a complex with SRF mRNA in cells providing a mechanism by which RNase L down-regulates SRF-induced genes. TTP and RNase L proteins interacted in cells suggesting that RNase L is directed to cleave TTP-bound RNAs as a mechanism of substrate specificity. Consistent with their concerted function in RNA turnover, the absence of either RNase L or TTP stabilized SRF mRNA, and a subset of established TTP targets was also regulated by RNase L. RNase L deficiency enhanced mitogen-induced proliferation demonstrating its functional role in limiting the mitogenic response. Our findings support a model of feedback regulation in which RNase L and TTP target SRF mRNA and SRF-induced transcripts. Accordingly, meta-analysis revealed an enrichment of RNase L and TTP targets among SRF-regulated genes suggesting that the RNase L/TTP axis represents a viable target to inhibit SRF-driven proliferation in neoplastic diseases.
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Affiliation(s)
- Sarah E Brennan-Laun
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and
| | - Xiao-Ling Li
- the Genetics Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Heather J Ezelle
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and the Research Services, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, and
| | | | - Perry J Blackshear
- the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Gerald M Wilson
- From the Marlene and Stewart Greenebaum Cancer Center, Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Bret A Hassel
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and the Research Services, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, and
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Djaldetti M, Bessler H. Modulators affecting the immune dialogue between human immune and colon cancer cells. World J Gastrointest Oncol 2014; 6:129-38. [PMID: 24834143 PMCID: PMC4021329 DOI: 10.4251/wjgo.v6.i5.129] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 01/03/2014] [Accepted: 04/11/2014] [Indexed: 02/05/2023] Open
Abstract
The link between chronic inflammation and colorectal cancer has been well established. The events proceeding along tumorigenesis are complicated and involve cells activated at the cancer microenvironment, tumor infiltrating polymorphonuclears, immune cells including lymphocyte subtypes and peripheral blood mononuclear cells (PBMC), as well as tumor-associated macrophages. The immune cells generate inflammatory cytokines, several of them playing a crucial role in tumorigenesis. Additional factors, such as gene expression regulated by cytokines, assembling of tumor growth- and transforming factors, accelerated angiogenesis, delayed apoptosis, contribute all to initiation, development and migration of tumor cells. Oxygen radical species originating from the inflammatory area promote cell mutation and cancer proliferation. Tumor cells may over-express pro-inflammatory mediators that in turn activate immune cells for inflammatory cytokines production. Consequently, an immune dialogue emerges between immune and cancer cells orchestrated through a number of activated molecular pathways. Cytokines, encompassing migration inhibitory factor, transforming growth factor beta 1, tumor necrosis factor-α, Interleukin (IL)-6, IL-10, IL-12, IL-17, IL-23 have been reported to be involved in human cancer development. Some cytokines, namely IL-5, IL-6, IL-10, IL-22 and growth factors promote tumor development and metastasis, and inhibit apoptosis via activation of signal transducer activator transcription-3 transcription factor. Colon cancer environment comprises mesenchymal, endothelial and immune cells. Assessment of the interaction between components in the tumor environment and malignant cells requires a reconsideration of a few topics elucidating the role of chronic inflammation in carcinogenesis, the function of the immune cells expressed by inflammatory cytokine production, the immunomodulation of cancer cells and the existence of a cross-talk between immune and malignant cells leading to a balance in cytokine production. It is conceivable that the prevalence of anti-inflammatory cytokine production by PBMC in the affected colonic mucosa will contribute to the delay, or even to halt down malignant expansion. Targeting the interplay between immune and cancer cells by mediators capable to alter cytokine secretion toward increased anti-inflammatory cytokine release by PBMC and tumor associated macrophages, may serve as an additional strategy for treatment of malignant diseases. This review will focus on the inflammatory events preceding tumorigenesis in general, and on a number of modulators capable to affect colon cancer cell-induced production of inflammatory cytokines by PBMC through alteration of the immune cross-talk between PBMC and cancer cells.
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Enteropathogenic Escherichia coli inhibits type I interferon- and RNase L-mediated host defense to disrupt intestinal epithelial cell barrier function. Infect Immun 2014; 82:2802-14. [PMID: 24733098 DOI: 10.1128/iai.00105-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) primarily infects children in developing countries and causes diarrhea that can be deadly. EPEC pathogenesis occurs through type III secretion system (T3SS)-mediated injection of effectors into intestinal epithelial cells (IECs); these effectors alter actin dynamics, modulate the immune response, and disrupt tight junction (TJ) integrity. The resulting compromised barrier function and increased gastrointestinal (GI) permeability may be responsible for the clinical symptoms of infection. Type I interferon (IFN) mediates anti-inflammatory activities and serves essential functions in intestinal immunity and homeostasis; however, its role in the immune response to enteric pathogens, such as EPEC, and its impact on IEC barrier function have not been examined. Here, we report that IFN-β is induced following EPEC infection and regulates IEC TJ proteins to maintain barrier function. The EPEC T3SS effector NleD counteracts this protective activity by inhibiting IFN-β induction and enhancing tumor necrosis factor alpha to promote barrier disruption. The endoribonuclease RNase L is a key mediator of IFN induction and action that promotes TJ protein expression and IEC barrier integrity. EPEC infection inhibits RNase L in a T3SS-dependent manner, providing a mechanism by which EPEC evades IFN-induced antibacterial activities. This work identifies novel roles for IFN-β and RNase L in IEC barrier functions that are targeted by EPEC effectors to escape host defense mechanisms and promote virulence. The IFN-RNase L axis thus represents a potential therapeutic target for enteric infections and GI diseases involving compromised barrier function.
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Cooper DA, Jha BK, Silverman RH, Hesselberth JR, Barton DJ. Ribonuclease L and metal-ion-independent endoribonuclease cleavage sites in host and viral RNAs. Nucleic Acids Res 2014; 42:5202-16. [PMID: 24500209 PMCID: PMC4005677 DOI: 10.1093/nar/gku118] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ribonuclease L (RNase L) is a metal-ion–independent endoribonuclease associated with antiviral and antibacterial defense, cancer and lifespan. Despite the biological significance of RNase L, the RNAs cleaved by this enzyme are poorly defined. In this study, we used deep sequencing methods to reveal the frequency and location of RNase L cleavage sites within host and viral RNAs. To make cDNA libraries, we exploited the 2′, 3′-cyclic phosphate at the end of RNA fragments produced by RNase L and other metal-ion–independent endoribonucleases. We optimized and validated 2′, 3′-cyclic phosphate cDNA synthesis and Illumina sequencing methods using viral RNAs cleaved with purified RNase L, viral RNAs cleaved with purified RNase A and RNA from uninfected and poliovirus-infected HeLa cells. Using these methods, we identified (i) discrete regions of hepatitis C virus and poliovirus RNA genomes that were profoundly susceptible to RNase L and other single-strand specific endoribonucleases, (ii) RNase L-dependent and RNase L-independent cleavage sites within ribosomal RNAs (rRNAs) and (iii) 2′, 3′-cyclic phosphates at the ends of 5S rRNA and U6 snRNA. Monitoring the frequency and location of metal-ion–independent endoribonuclease cleavage sites within host and viral RNAs reveals, in part, how these enzymes contribute to health and disease.
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Affiliation(s)
- Daphne A Cooper
- Department of Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA, Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic, Cleveland, OH 44195, USA, Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA and Program in Molecular Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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Wen XD, Wang CZ, Yu C, Zhao L, Zhang Z, Matin A, Wang Y, Li P, Xiao SY, Du W, He TC, Yuan CS. Panax notoginseng attenuates experimental colitis in the azoxymethane/dextran sulfate sodium mouse model. Phytother Res 2013; 28:892-8. [PMID: 24142591 DOI: 10.1002/ptr.5066] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/09/2013] [Accepted: 09/03/2013] [Indexed: 12/14/2022]
Abstract
Patients suffering from inflammatory bowel disease are at a high risk of developing colorectal cancer. To assess the anticancer potential of botanicals, in this study, we evaluated the effects of Panax notoginseng on azoxymethane/dextran sulfate sodium (DSS)-induced colitis. One week after A/J mice received azoxymethane, the animals received DSS for 8 days or were supplemented with P. notoginseng extract, at 30 or 90 mg/kg. DSS-induced colitis was scored with the disease activity index. The severity of the inflammatory lesions was evaluated by a colon tissue histological assessment. The expression of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) were also explored. We observed that the effects of P. notoginseng on the reduction of colon inflammation, expressed in disease activity index score, were in a dose-related manner (p < 0.01). P. notoginseng inhibited the reduction of the colon length and the loss of bodyweight in dose-related manner (all p < 0.05). The histological assessment of the colitis and inflammatory-related immunohistochemical data also supported the pharmacological observations. Our data suggest that P. notoginseng is a promising candidate in preventing and treating colitis and inflammation-associated colon carcinogenesis.
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Affiliation(s)
- Xiao-Dong Wen
- Tang Center for Herbal Medicine Research, University of Chicago, Chicago, IL, 60637, USA; Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL, 60637, USA; State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
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