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Li X, Tang X, Xiang Y, Zhao Z, Li Y, Ding Q, Zhang L, Xu J, Zhao L, Chen Y. N-glycosylation of SCAP exacerbates hepatocellular inflammation and lipid accumulation via ACSS2-mediated histone H3K27 acetylation. Am J Physiol Gastrointest Liver Physiol 2024. [PMID: 38591127 DOI: 10.1152/ajpgi.00273.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 03/25/2024] [Indexed: 04/10/2024]
Abstract
Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a widely expressed membrane glycoprotein that acts as an important modulator of lipid metabolism and inflammatory stress. N-glycosylation of SCAP has been suggested to modulate cancer development, but its role in NASH is poorly understood. In this study, the N-glycosylation of SCAP was analyzed by using sequential trypsin proteolysis and glycosidase treatment. The liver cell lines expressing wild-type and N-glycosylation sites mutated SCAP were constructed to investigate the N-glycosylation role of SCAP in regulating inflammation and lipid accumulation as well as the underlying mechanisms. The hepatic SCAP protein levels were significantly increased in C57BL/6J mice fed with western diet and sweet water (WD+SW) and diabetic db/db mice, which exhibited typical liver steatosis and inflammation. In vitro, the enhanced N-glycosylation increased the protein stability of SCAP and hence increased its total protein levels, while the ablation of N-glycosylation significantly decreased SCAP protein stability and alleviated lipid accumulation and inflammation in hepatic cell lines. Mechanistically, the presence of SCAP N-glycosylation increased not only the SREBP1-mediated acetyl-CoA synthetase 2 (ACSS2) transcription but also the AMPK-mediated S659 phosphorylation of ACCS2 protein, causing the enhanced ACSS2 levels in nucleus and hence increasing the histone H3K27 acetylation (H3K27ac), which is a key epigenetic modification associated with NASH. Modulating ACSS2 expression or its location in cytoplasm abolished the effects of SCAP N-glycosylation on H3K27ac and lipid accumulation and inflammation. In conclusion, SCAP N-glycosylation aggravates inflammation and lipid accumulation through enhancing ACSS2-mediated H3K27ac in hepatocytes.
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Affiliation(s)
- Xuemei Li
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaoqin Tang
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yue Xiang
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhibo Zhao
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yanping Li
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qiuying Ding
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Linkun Zhang
- Department of Endocrinology, First Affiliated Hospital of Chongqing Medical University, China
| | - Jingyuan Xu
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yao Chen
- Centre for health medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Chen J, Du H, Liu Z, Li T, Du H, Wang W, Aslam M, Chen W, Li P, Luo H, Fang H, Liu X. Endoplasmic reticulum-quality control pathway and endoplasmic reticulum-associated degradation mechanism regulate the N-glycoproteins and N-glycan structures in the diatom Phaeodactylum tricornutum. Microb Cell Fact 2022; 21:219. [PMID: 36266689 DOI: 10.1186/s12934-022-01941-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/02/2022] [Indexed: 11/10/2022] Open
Abstract
Tunicamycin inhibits the first step of protein N-glycosylation modification. However, the physiological, transcriptomic, and N-glycomic effects of tunicamycin on important marine diatom Phaeodactylum tricornutum are still unknown. In this study, comprehensive approaches were used to study the effects of tunicamycin stress. The results showed that cell growth and photosynthesis were significantly inhibited in P. tricornutum under the tunicamycin stress. The soluble protein content was significantly decreased, while the soluble sugar and neutral lipid were dramatically increased to orchestrate the balance of carbon and nitrogen metabolisms. The stress of 0.3 μg ml-1 tunicamycin resulted in the differential expression of ERQC and ERAD related genes. The upregulation of genes involved in ERQC pathway, the activation of anti-oxidases and the differential expression of genes related with ERAD mechanism might be important for maintaining homeostasis in cell. The identification of N-glycans, especially complex-type N-glycan structures enriched the N-glycan database of diatom P. tricornutum and provided important information for studying the function of N-glycosylation modification on proteins. As a whole, our study proposed working models of ERQC and ERAD will provide a solid foundation for further in-depth study of the related mechanism and the diatom expression system.
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Liao Z, Yang C, Jiang R, Zhu W, Zhang Y, Su J. Cyprinid-specific duplicated membrane TLR5 senses dsRNA as functional homodimeric receptors. EMBO Rep 2022; 23:e54281. [PMID: 35678424 DOI: 10.15252/embr.202154281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 05/02/2022] [Accepted: 05/13/2022] [Indexed: 12/30/2022] Open
Abstract
Membrane-embedded Toll-like receptor 5 (TLR5) functions as a homodimer to detect bacterial flagellin. Cyprinid grass carp (Ctenopharyngodon idella) encodes two TLR5 genes, CiTLR5a and CiTLR5b. Here, we show that cyprinid TLR5a and TLR5b homodimers unexpectedly bind the dsRNA analog poly(I:C) and regulate interferon (IFN) response in early endosomes and lysosomes. Although TLR5 homodimers also bind flagellin, an immune response to flagellin is only triggered by TLR5a/b heterodimer. Moreover, we demonstrate that two TLR5 paralogs have opposite effects on antiviral response: CiTLR5a slightly promotes and powerfully maintains, whereas CiTLR5b remarkably inhibits virus replication. We show that the ectodomain of CiTLR5 is required for dsRNA-induced IFN signaling, and we map the key poly(I:C) binding sites to G240 for CiTLR5a and to N547 for CiTLR5b. Furthermore, we reveal that differential N-glycosylation of CiTLR5a/b affects dsRNA-IFN signaling but has no role in flagellin-mediated NF-κB induction, with paralog-specific roles for CiTLR5a-T101 and corresponding CiTLR5b-I99. Moreover, we provide evidence that the ability to sense dsRNA represents a neofunctionalization specific for membrane-bound TLR5 in cyprinid, bridging viral and bacterial immune responses.
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Affiliation(s)
- Zhiwei Liao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Chunrong Yang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Rui Jiang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Wentao Zhu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Yongan Zhang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Jianguo Su
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
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Xie X, Du H, Chen J, Aslam M, Wang W, Chen W, Li P, Du H, Liu X. Global Profiling of N-Glycoproteins and N-Glycans in the Diatom Phaeodactylum tricornutum. Front Plant Sci 2021; 12:779307. [PMID: 34925422 PMCID: PMC8678454 DOI: 10.3389/fpls.2021.779307] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/05/2021] [Indexed: 05/04/2023]
Abstract
N-glycosylation is an important posttranslational modification in all eukaryotes, but little is known about the N-glycoproteins and N-glycans in microalgae. Here, N-glycoproteomic and N-glycomic approaches were used to unveil the N-glycoproteins and N-glycans in the model diatom Phaeodactylum tricornutum. In total, 863 different N-glycopeptides corresponding to 639 N-glycoproteins were identified from P. tricornutum. These N-glycoproteins participated in a variety of important metabolic pathways in P. tricornutum. Twelve proteins participating in the N-glycosylation pathway were identified as N-glycoproteins, indicating that the N-glycosylation of these proteins might be important for the protein N-glycosylation pathway. Subsequently, 69 N-glycans corresponding to 59 N-glycoproteins were identified and classified into high mannose and hybrid type N-glycans. High mannose type N-glycans contained four different classes, such as Man-5, Man-7, Man-9, and Man-10 with a terminal glucose residue. Hybrid type N-glycan harbored Man-4 with a terminal GlcNAc residue. The identification of N-glycosylation on nascent proteins expanded our understanding of this modification at a N-glycoproteomic scale, the analysis of N-glycan structures updated the N-glycan database in microalgae. The results obtained from this study facilitate the elucidation of the precise function of these N-glycoproteins and are beneficial for future designing the microalga to produce the functional humanized biopharmaceutical N-glycoproteins for the clinical therapeutics.
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Affiliation(s)
- Xihui Xie
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Hong Du
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Jichen Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Muhammad Aslam
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Faculty of Marine Sciences, Lasbela University of Agriculture, Water & Marine Sciences, Uthal, Pakistan
| | - Wanna Wang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Weizhou Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Ping Li
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Hua Du
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Xiaojuan Liu
- Guangdong Provincial Key Laboratory of Marine Biotechnology, STU-UNIVPM Joint Algal Research Center, College of Sciences, Institute of Marine Sciences, Shantou University, Shantou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
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Guo P, Li C, Ju Y, Liu E, Zhang H, Hu J, Meng S. [ N-glycosylation modification of heat shock protein gp96 affects its immunological function]. Sheng Wu Gong Cheng Xue Bao 2021; 37:4036-4046. [PMID: 34841803 DOI: 10.13345/j.cjb.200786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
N-glycosylation modification, one of the most common protein post-translational modifications, occurs in heat shock protein gp96. The purpose of this study is to investigate the effect of N-glycosylation modification on immunologic function of the recombinant gp96 using the mutant gp96 in N-glycosylation sites. Firstly, wild-type and mutant gp96 proteins were expressed by insect expression system and their glycosylation levels were detected. To determine the effect of N-glycosylation on gp96 antigen presentation function, the IFN-γ+ CD8+ T cells in gp96-immunized mice and secretion level of IFN-γ were examined by flow cytometry and ELISA. The ATPase activity of gp96 was further detected by the ATPase kit. Finally, the effect of N-glycosylation on adjuvant function of gp96 for influenza vaccine was investigated in immunized mice. It was found that total sugar content of mutant recombinant gp96 was reduced by 27.8%. Compared to the wild type recombinant gp96, mutations in N-glycosylation sites resulted in decreased antigen presentation ability and ATPase activity of gp96. Furthermore, influenza vaccine-specific T cell levels induced by mutant gp96 as adjuvant were dramatically reduced compared to those by wild type recombinant gp96. These results demonstrate that N-glycosylation modification is involved in regulation of ATPase activity and antigen presentation function of gp96, thereby affecting its adjuvant function. The results provide the technical bases for development of gp96- adjuvanted vaccines.
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Affiliation(s)
- Peng Guo
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changfei Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Ju
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Erlong Liu
- Heat Shock Biotechnology Co., Ltd., Beijing 100123, China
| | - Han Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Hu
- Cominghealth Biotechnology Co., Ltd., Beijing 100101, China
| | - Songdong Meng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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