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Zhang Y, Dong Z, Gu F, Xu Y, Li Y, Sun W, Rao W, Du S, Zhu C, Wang Y, Wei F, Cai Q. Degradation of TRIM32 is induced by RTA for Kaposi's sarcoma-associated herpesvirus lytic replication. J Virol 2024; 98:e0000524. [PMID: 38717113 DOI: 10.1128/jvi.00005-24] [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: 01/03/2024] [Accepted: 04/05/2024] [Indexed: 06/14/2024] Open
Abstract
TRIM32 is often aberrantly expressed in many types of cancers. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked with several human malignancies, including Kaposi's sarcoma and primary effusion lymphomas (PELs). Increasing evidence has demonstrated the crucial role of KSHV lytic replication in viral tumorigenesis. However, the role of TRIM32 in herpesvirus lytic replication remains unclear. Here, we reveal that the expression of TRIM32 is upregulated by KSHV in latency, and reactivation of KSHV lytic replication leads to the inhibition of TRIM32 in PEL cells. Strikingly, RTA, the master regulator of lytic replication, interacts with TRIM32 and dramatically promotes TRIM32 for degradation via the proteasome systems. Inhibition of TRIM32 induces cell apoptosis and in turn inhibits the proliferation and colony formation of KSHV-infected PEL cells and facilitates the reactivation of KSHV lytic replication and virion production. Thus, our data imply that the degradation of TRIM32 is vital for the lytic activation of KSHV and is a potential therapeutic target for KSHV-associated cancers. IMPORTANCE TRIM32 is associated with many cancers and viral infections; however, the role of TRIM32 in viral oncogenesis remains largely unknown. In this study, we found that the expression of TRIM32 is elevated by Kaposi's sarcoma-associated herpesvirus (KSHV) in latency, and RTA (the master regulator of lytic replication) induces TRIM32 for proteasome degradation upon viral lytic reactivation. This finding provides a potential therapeutic target for KSHV-associated cancers.
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Affiliation(s)
- Yulin Zhang
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhongwei Dong
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Feng Gu
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yifei Xu
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ying Li
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Wen Sun
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Wutian Rao
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shujuan Du
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Caixia Zhu
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yuyan Wang
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Fang Wei
- ShengYushou Center of Cell Biology and Immunology, Joint International Research Laboratory of Metabolic & Development Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Qiliang Cai
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, Shanghai Institute of Infections Disease and Biosecurity, Shanghai Frontiers Science Center of Pathogenic Microorganism and Infection, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China
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Shi JH, Liu LN, Song DD, Liu WW, Ling C, Wu FX, Wang TT, Liu B, Cui NP, Qin Y, Ni ZY. TRAF3/STAT6 axis regulates macrophage polarization and tumor progression. Cell Death Differ 2023; 30:2005-2016. [PMID: 37474750 PMCID: PMC10406838 DOI: 10.1038/s41418-023-01194-1] [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: 01/02/2023] [Revised: 07/05/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023] Open
Abstract
Converting tumor-associated macrophages (TAMs) from the M2 to the M1 phenotype is considered an effective strategy for cancer therapy. TRAF3 is known to regulate NF-κB signaling. However, the role of TRAF3 in TAM polarization has not yet been completely elucidated. Here, we found that ablation of TRAF3 increased M1 markers, iNOS, FGR and SLC4A7, while down-regulated M2 markers, CD206, CD36 and ABCC3, expression levels in macrophages. Moreover, TRAF3 deficiency enhanced LPS-induced M1 and abolished IL-4-induced macrophage polarization. Next, quantitative ubiquitomics assays demonstrated that among the quantitative 7618 ubiquitination modification sites on 2598 proteins, ubiquitination modification of IL-4 responding proteins was the most prominently reduced according to enrichment analysis. STAT6, a key factor of IL-4 responding protein, K450 and K129 residue ubiquitination levels were dramatically decreased in TRAF3-deficient macrophages. Ubiquitination assay and luciferase assay demonstrated that TRAF3 promotes STAT6 ubiquitination and transcriptional activity. Site mutation analysis revealed STAT6 K450 site ubiquitination played a vital role in TRAF3-mediated STAT6 activation. Finally, B16 melanoma mouse model demonstrated that myeloid TRAF3 deficiency suppressed tumor growth and lung metastasis in vivo. Taken together, TRAF3 plays a vital role in M2 polarization via regulating STAT6 K450 ubiquitination in macrophages.
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Affiliation(s)
- Jian-Hong Shi
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China.
- Clinical Medical College, Hebei University, Baoding, 071000, Hebei, China.
- Hebei Collaborative Innovation Center of Tumor Microecological Metabolism Regulation, Baoding, 071000, Hebei, China.
- Hebei Key Laboratory of Cancer Radiotherapy and Chemotherapy, Baoding, 071000, Hebei, China.
| | - Li-Na Liu
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Clinical Medical College, Hebei University, Baoding, 071000, Hebei, China
| | - Dan-Dan Song
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Clinical Medical College, Hebei University, Baoding, 071000, Hebei, China
| | - Wen-Wen Liu
- Department of Breast Surgery, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
| | - Chen Ling
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Department of Medical Oncology, Hengyang Third People's Hospital, Hengyang, 421200, Hunan, China
| | - Fei-Xiang Wu
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Hebei Key Laboratory of Precise Imaging of Inflammation Related Tumors, Baoding, 071000, Hebei, China
| | - Ting-Ting Wang
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Clinical Medical College, Hebei University, Baoding, 071000, Hebei, China
| | - Bin Liu
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
- Hebei Collaborative Innovation Center of Tumor Microecological Metabolism Regulation, Baoding, 071000, Hebei, China
- Hebei Key Laboratory of Cancer Radiotherapy and Chemotherapy, Baoding, 071000, Hebei, China
| | - Nai-Peng Cui
- Hebei Collaborative Innovation Center of Tumor Microecological Metabolism Regulation, Baoding, 071000, Hebei, China
- Hebei Key Laboratory of Cancer Radiotherapy and Chemotherapy, Baoding, 071000, Hebei, China
- Department of Breast Surgery, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China
| | - Yan Qin
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, China.
- Hebei Collaborative Innovation Center of Tumor Microecological Metabolism Regulation, Baoding, 071000, Hebei, China.
- Hebei Key Laboratory of Precise Imaging of Inflammation Related Tumors, Baoding, 071000, Hebei, China.
| | - Zhi-Yu Ni
- Clinical Medical College, Hebei University, Baoding, 071000, Hebei, China.
- Hebei Collaborative Innovation Center of Tumor Microecological Metabolism Regulation, Baoding, 071000, Hebei, China.
- Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, 100000, Beijing, China.
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Combs LR, Combs J, McKenna R, Toth Z. Protein Degradation by Gammaherpesvirus RTAs: More Than Just Viral Transactivators. Viruses 2023; 15:730. [PMID: 36992439 PMCID: PMC10055789 DOI: 10.3390/v15030730] [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: 02/09/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is a member of the Gammaherpesvirus subfamily that encodes several viral proteins with intrinsic E3 ubiquitin ligase activity or the ability to hijack host E3 ubiquitin ligases to modulate the host's immune response and to support the viral life cycle. This review focuses specifically on how the immediate-early KSHV protein RTA (replication and transcription activator) hijacks the host's ubiquitin-proteasome pathway (UPP) to target cellular and viral factors for protein degradation to allow for robust lytic reactivation. Notably, RTA's targets are either potent transcription repressors or they are activators of the innate and adaptive immune response, which block the lytic cycle of the virus. This review mainly focuses on what is currently known about the role of the E3 ubiquitin ligase activity of KSHV RTA in the regulation of the KSHV life cycle, but we will also discuss the potential role of other gammaherpesviral RTA homologs in UPP-mediated protein degradation.
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Affiliation(s)
- Lauren R. Combs
- Department of Oral Biology, University of Florida College of Dentistry, 1395 Center Drive, Gainesville, FL 32610, USA
| | - Jacob Combs
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - Zsolt Toth
- Department of Oral Biology, University of Florida College of Dentistry, 1395 Center Drive, Gainesville, FL 32610, USA
- UF Genetics Institute, Gainesville, FL 32610, USA
- UF Health Cancer Center, Gainesville, FL 32610, USA
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4
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Gu F, Wang C, Wei F, Wang Y, Zhu Q, Ding L, Xu W, Zhu C, Cai C, Qian Z, Yuan Z, Robertson E, Cai Q. Correction: STAT6 degradation and ubiquitylated TRIML2 are essential for activation of human oncogenic herpesvirus. PLoS Pathog 2022; 18:e1010579. [PMID: 35648772 PMCID: PMC9159590 DOI: 10.1371/journal.ppat.1010579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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5
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RNA Microarray-Based Comparison of Innate Immune Phenotypes between Human THP-1 Macrophages Stimulated with Two BCG Strains. Int J Mol Sci 2022; 23:ijms23094525. [PMID: 35562916 PMCID: PMC9103163 DOI: 10.3390/ijms23094525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 04/13/2022] [Indexed: 12/10/2022] Open
Abstract
Currently, the only available vaccine against tuberculosis is Mycobacterium bovis Bacille Calmette-Guérin (BCG). Pulmonary tuberculosis protection provided by the vaccine varies depending on the strain, the patient’s age and the evaluated population. Although the adaptive immune responses induced by different BCG strains have been widely studied, little conclusive data is available regarding innate immune responses, especially in macrophages. Here, we aimed to characterize the innate immune responses of human THP-1-derived macrophages at the transcriptional level following a challenge with either the BCG Mexico (M.BCG) or Phipps (P.BCG) strains. After a brief in vitro characterization of the bacterial strains and the innate immune responses, including nitric oxide production and cytokine profiles, we analyzed the mRNA expression patterns and performed pathway enrichment analysis using RNA microarrays. Our results showed that multiple biological processes were enriched, especially those associated with innate inflammatory and antimicrobial responses, including tumor necrosis factor (TNF)-α, type I interferon (IFN-I) and IFN-γ. However, four DEGs were identified in macrophages infected with M.BCG compared to P. BCG. These findings indicated the proinflammatory stimulation of macrophages induced by both BCG strains, at the cytokine level and in terms of gene expression, suggesting a differential expression pattern of innate immune transcripts depending on the mycobacterial strain.
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Sandhu PK, Damania B. The regulation of KSHV lytic reactivation by viral and cellular factors. Curr Opin Virol 2022; 52:39-47. [PMID: 34872030 PMCID: PMC8844089 DOI: 10.1016/j.coviro.2021.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/03/2021] [Indexed: 02/03/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic herpesvirus that exhibits two distinct phases of infection in the host-latent and lytic. The quiescent latent phase is defined by limited expression of a subset of viral proteins and microRNAs, and an absence of virus production. KSHV periodically reactivates from latency to undergo active lytic replication, leading to production of new infectious virions. This switch from the latent to the lytic phase requires the viral protein regulator of transcription activator (RTA). RTA, along with other virally encoded proteins, is aided by host factors to facilitate this transition. Herein, we highlight the key host proteins that are involved in mediating RTA activation and KSHV lytic replication and discuss the cellular processes in which they function. We will also focus on the modulation of viral reactivation by the innate immune system, and how KSHV influences key immune signaling pathways to aid its own lifecycle.
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Affiliation(s)
- Praneet Kaur Sandhu
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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7
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Li J, Yang Y, Li Q, Wei S, Zhou Y, Yu W, Xue L, Zhou L, Shen L, Lu G, Chen L, Tao S. STAT6 contributes to renal fibrosis by modulating PPARα-mediated tubular fatty acid oxidation. Cell Death Dis 2022; 13:66. [PMID: 35046382 PMCID: PMC8770798 DOI: 10.1038/s41419-022-04515-3] [Citation(s) in RCA: 19] [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: 06/15/2021] [Revised: 12/14/2021] [Accepted: 01/10/2022] [Indexed: 12/13/2022]
Abstract
Lipid metabolism, especially fatty acid oxidation (FAO) dysfunction, is a major driver of renal fibrosis; however, the detailed regulatory mechanisms involved remain unclear. In this study, we showed that there existed an association between the signal transducer and activator of transcription 6 (STAT6) and tubular lipid metabolism in fibrotic kidneys. Specifically, STAT6 was activated along with the accumulation of lipids via the downregulation of FAO-related genes when mice were subjected to unilateral ureteral obstruction (UUO) or high-fat diet challenge. Tubular-specific depletion, or pharmacologic inhibitor of Stat6 in mice, and Stat6 knockdown in cultured tubular cells attenuated lipid accumulation and renal fibrosis by enhancing FAO. Mechanistically, STAT6 transcriptionally inhibited the expression of PPARα and its FAO-related target genes through a sis-inducible element located in the promoter region of the protein. In conclusion, our study demonstrates the mechanistic details of STAT6-mediated FAO dysregulation in the progression of renal fibrosis and provides a preclinical rationale for efforts to improve the management of renal fibrosis brought about by FAO dysregulation.
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Affiliation(s)
- Jianzhong Li
- Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
- Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, China
| | - Youjing Yang
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Qianmin Li
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Shuhui Wei
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Yujia Zhou
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Wangjianfei Yu
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Lian Xue
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Ling Zhou
- Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, China
| | - Lei Shen
- Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, China
| | - Guoyuan Lu
- Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, China
| | - Ling Chen
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China
| | - Shasha Tao
- Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China.
- School of Public Health, Medical College of Soochow University, 199 Ren'ai Road, Suzhou, 215123, China.
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8
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Proteomic Profiling Identifies Kaposi's Sarcoma-Associated Herpesvirus (KSHV)-Encoded LANA SIM-Associated Proteins in Hypoxia. mSystems 2021; 6:e0110921. [PMID: 34726485 PMCID: PMC8562486 DOI: 10.1128/msystems.01109-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypoxia signaling is a key regulator in the development and progression of many types of human malignancies, including viral cancers. The latency-associated nuclear antigen (LANA), encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) during latency, is a multifunctional protein that plays an essential role in viral episome maintenance and lytic gene silencing for inducing tumorigenesis. Although our previous studies have shown that LANA contains a SUMO-interacting motif (LANASIM), and hypoxia reduces SUMOylated KAP1 association with LANASIM, the physiological proteomic network of LANASIM-associated cellular proteins in response to hypoxia is still unclear. In this study, we individually established cell lines stably expressing wild-type LANA (LANAWT) and its SIM-deleted mutant (LANAdSIM) and treated them with or without hypoxia, followed by coimmunoprecipitation and mass spectrometry analysis to systemically identify the hypoxia-responsive profile of LANASIM-associated cellular proteins. We found that in hypoxia, the number of cellular proteins associated with LANAWT instead of LANAdSIM was dramatically increased. Functional network analysis revealed that two major pathways, which included cytoskeleton organization and DNA/RNA binding and processing pathways, were significantly enriched for 28 LANASIM-associated proteins in response to hypoxia. HNRNPU was one of the proteins consistently identified that interacted with LANASIM in different proteomic screening systems and responded to hypoxia. This study provides a proteomic profile of LANASIM-associated proteins in hypoxia and facilitates our understanding of the role of the collaboration between viral infection and the hypoxia response in inducing viral persistence and tumorigenesis. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) has been reported to be involved in the regulation of host proteins in response to hypoxic stress. LANA, one of the key latent proteins, contains a SUMO-interacting motif (LANASIM) and reduces the association with SUMOylated KAP1 upon hypoxic treatment. However, the physiological systematic network of LANASIM-associated cellular proteins in hypoxia is still unclear. Here, we revealed two major pathways, which included cytoskeleton organization and DNA/RNA binding and processing pathways, that were significantly enriched for 28 LANASIM-associated proteins in hypoxia. This discovery not only provides a proteomic profile of LANASIM-associated proteins in hypoxia but also facilitates our understanding of the collaboration between viral infection and hypoxic stress in inducing viral persistence and tumorigenesis.
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Li J, Yang Y, Wei S, Chen L, Xue L, Tian H, Tao S. Bixin Protects Against Kidney Interstitial Fibrosis Through Promoting STAT6 Degradation. Front Cell Dev Biol 2020; 8:576988. [PMID: 33313043 PMCID: PMC7704619 DOI: 10.3389/fcell.2020.576988] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 10/19/2020] [Indexed: 01/02/2023] Open
Abstract
Bixin, a natural carotenoid extracted from the seeds of Bixa orellana, has antioxidant and anti-inflammation effects. However, the pharmacological effects and underlying mechanisms of bixin in kidney interstitial fibrosis remain unknown. Partial epithelial-to-mesenchymal transition (EMT) of tubular cells has been linked to renal interstitial fibrosis. Here, we found that in the unilateral ureteral obstruction model, bixin administration could ameliorate kidney interstitial fibrosis. The expression of signal transducer and activator of transcription 6 (STAT6) was dramatically increased in renal tubular cells. Bixin treatment inhibited STAT6 induction. The activation of STAT6 signaling was essential for transforming growth factor β1, fibrotic markers, and EMT-related protein expression in HK2 cells, which was confirmed by using the Stat6-/- mice. Ubiquitination, but not the acetylation level of STAT6, was induced by bixin treatment and promoted the suppression of phosphorylation and stability of STAT6. P62-dependent autophagy might be involved in this process. The study demonstrated that bixin can be exploited therapeutically to alleviate renal interstitial fibrosis by targeting STAT6 signaling deactivation.
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Affiliation(s)
- Jianzhong Li
- Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Youjing Yang
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Shuhui Wei
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Ling Chen
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Lian Xue
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Hailin Tian
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Shasha Tao
- School of Public Health, Medical College of Soochow University, Suzhou, China
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The roles of post-translational modifications and coactivators of STAT6 signaling in tumor growth and progression. Future Med Chem 2020; 12:1945-1960. [DOI: 10.4155/fmc-2020-0224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Signal transducers and activators of transcription 6 (STAT6) are highly expressed in various tumors and associated with tumorigenesis, immunosuppression, proliferation, metastasis and poor prognosis in human cancers. In response to IL-4/13, STAT6 is phosphorylated, dimerizes and triggers transcriptional regulation after recruitment of coactivators to transcriptosome, such as CBP/p300, SRC-1, PARP-14 and PSF. Post-translational modifications, including phosphorylation, ubiquitination, ADP-ribosylation and acetylation, have been explored for molecular mechanisms of STAT6 in tumor development and management. STAT6 has been developed as a specific biomarker for distinguishing and diagnosing tumor phenotypes, although it is observed to be frequently mutated in metastatic tumors. In this article, we focus mainly on the structural characteristics of STAT6 and its role in tumor growth and progression.
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11
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Abstract
Viruses commonly antagonize the antiviral type I interferon response by targeting signal transducer and activator of transcription 1 (STAT1) and STAT2, key mediators of interferon signaling. Other STAT family members mediate signaling by diverse cytokines important to infection, but their relationship with viruses is more complex. Importantly, virus-STAT interaction can be antagonistic or stimulatory depending on diverse viral and cellular factors. While STAT antagonism can suppress immune pathways, many viruses promote activation of specific STATs to support viral gene expression and/or produce cellular conditions conducive to infection. It is also becoming increasingly clear that viruses can hijack noncanonical STAT functions to benefit infection. For a number of viruses, STAT function is dynamically modulated through infection as requirements for replication change. Given the critical role of STATs in infection by diverse viruses, the virus-STAT interface is an attractive target for the development of antivirals and live-attenuated viral vaccines. Here, we review current understanding of the complex and dynamic virus-STAT interface and discuss how this relationship might be harnessed for medical applications.
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Zhang X, Pavlicev M, Jones HN, Muglia LJ. Eutherian-Specific Gene TRIML2 Attenuates Inflammation in the Evolution of Placentation. Mol Biol Evol 2020; 37:507-523. [PMID: 31633784 PMCID: PMC6993854 DOI: 10.1093/molbev/msz238] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Evolution of highly invasive placentation in the stem lineage of eutherians and subsequent extension of pregnancy set eutherians apart from other mammals, that is, marsupials with short-lived placentas, and oviparous monotremes. Recent studies suggest that eutherian implantation evolved from marsupial attachment reaction, an inflammatory process induced by the direct contact of fetal placenta with maternal endometrium after the breakdown of the shell coat, and shortly before the onset of parturition. Unique to eutherians, a dramatic downregulation of inflammation after implantation prevents the onset of premature parturition, and is critical for the maintenance of gestation. This downregulation likely involved evolutionary changes on maternal as well as fetal/placental side. Tripartite-motif family-like2 (TRIML2) only exists in eutherian genomes and shows preferential expression in preimplantation embryos, and trophoblast-derived structures, such as chorion and placental disc. Comparative genomic evidence supports that TRIML2 originated from a gene duplication event in the stem lineage of Eutheria that also gave rise to eutherian TRIML1. Compared with TRIML1, TRIML2 lost the catalytic RING domain of E3 ligase. However, only TRIML2 is induced in human choriocarcinoma cell line JEG3 with poly(I:C) treatment to simulate inflammation during viral infection. Its knockdown increases the production of proinflammatory cytokines and reduces trophoblast survival during poly(I:C) stimulation, while its overexpression reduces proinflammatory cytokine production, supporting TRIML2’s role as a regulatory inhibitor of the inflammatory pathways in trophoblasts. TRIML2’s potential virus-interacting PRY/SPRY domain shows significant signature of selection, suggesting its contribution to the evolution of eutherian-specific inflammation regulation during placentation.
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Affiliation(s)
- Xuzhe Zhang
- Division of Human Genetics, Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.,March of Dimes Prematurity Research Center Ohio Collaborative, Cincinnati, OH
| | - Mihaela Pavlicev
- Division of Human Genetics, Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.,March of Dimes Prematurity Research Center Ohio Collaborative, Cincinnati, OH
| | - Helen N Jones
- Division of Pediatric Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.,Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Louis J Muglia
- Division of Human Genetics, Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.,March of Dimes Prematurity Research Center Ohio Collaborative, Cincinnati, OH
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13
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STUB1 is targeted by the SUMO-interacting motif of EBNA1 to maintain Epstein-Barr Virus latency. PLoS Pathog 2020; 16:e1008447. [PMID: 32176739 PMCID: PMC7105294 DOI: 10.1371/journal.ppat.1008447] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/30/2020] [Accepted: 03/01/2020] [Indexed: 12/31/2022] Open
Abstract
Latent Epstein-Barr virus (EBV) infection is strongly associated with several malignancies, including B-cell lymphomas and epithelial tumors. EBNA1 is a key antigen expressed in all EBV-associated tumors during latency that is required for maintenance of the EBV episome DNA and the regulation of viral gene transcription. However, the mechanism utilized by EBV to maintain latent infection at the levels of posttranslational regulation remains largely unclear. Here, we report that EBNA1 contains two SUMO-interacting motifs (SIM2 and SIM3), and mutation of SIM2, but not SIM3, dramatically disrupts the EBNA1 dimerization, while SIM3 contributes to the polySUMO2 modification of EBNA1 at lysine 477 in vitro. Proteomic and immunoprecipitation analyses further reveal that the SIM3 motif is required for the EBNA1-mediated inhibitory effects on SUMO2-modified STUB1, SUMO2-mediated degradation of USP7, and SUMO1-modified KAP1. Deletion of the EBNASIM motif leads to functional loss of both EBNA1-mediated viral episome maintenance and lytic gene silencing. Importantly, hypoxic stress induces the SUMO2 modification of EBNA1, and in turn the dissociation of EBNA1 with STUB1, KAP1 and USP7 to increase the SUMO1 modification of both STUB1 and KAP1 for reactivation of lytic replication. Therefore, the EBNA1SIM motif plays an essential role in EBV latency and is a potential therapeutic target against EBV-associated cancers. The Small Ubiquitin-related modifier (SUMO) modification of proteins is a reversible post-translational regulation involved in control of gene transcription, among other functions. Epstein-Barr virus (EBV) infects most people worldwide and contributes to the development of several types of cancers due to its ability to induce cell proliferation and survival. EBNA1 is expressed in all forms of EBV-associated tumors. In this study, we found that EBNA1 contains a SUMO-interacting motif (SIM) named EBNA1SIM, which is required for EBNA1 to exert inhibitory effects on a SUMO2-modified complex (SC2) including STUB1, KAP1 and USP7. Disruption of EBNA1SIM leads to loss of both EBNA1-mediated viral episome maintenance and lytic gene silencing. Importantly, hypoxia-mediated reactivation of viral lytic replication induces the EBNA1 dissociation from STUB1 in the SC2 complex. This discovery not only opens a new insight on the interplay between host and virus, but it also provides a therapeutic target specific against EBV-associated cancers.
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14
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Broussard G, Damania B. KSHV: Immune Modulation and Immunotherapy. Front Immunol 2020; 10:3084. [PMID: 32117196 PMCID: PMC7025529 DOI: 10.3389/fimmu.2019.03084] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is associated with KS, primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). To ensure its own survival and propagation, KSHV employs an extensive network of viral proteins to subvert the host immune system, resulting in lifelong latent infection. Modulation of cellular and systemic immune defenses allows KSHV to persist in the host, which may eventually lead to the progression of KSHV-associated cancers. Due to KSHV's reliance on modifying immune responses to efficiently infect its host, immunotherapy is an attractive option for treating KSHV-associated malignancies. In this review, we will focus on the mechanisms by which KSHV evades the immune system and the current immune-related clinical strategies to treat KSHV-associated disease.
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Affiliation(s)
- Grant Broussard
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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