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Fan H, Song C, Zhang J. Sarm1 Controls the MYD88-Mediated Inflammatory Responses in Inflammatory Bowel Disease via the Regulation of TRAF3 Recruitment. Immunol Invest 2024; 53:800-812. [PMID: 38651786 DOI: 10.1080/08820139.2024.2343889] [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] [Indexed: 04/25/2024]
Abstract
BACKGROUND Sterile alpha and TIR motif-containing 1 (Sarm1) is known as a negative regulator of inflammatory responses. However, its role in inflammatory bowel disease (IBD) is still unclear. OBJECTIVE This study aimed to explore the function of Sarm1 in IBD and its underlying mechanisms. Sarm1 and tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) knockout (KO) micewere established. METHODS The colitis was induced using dextran sulfate sodium (DSS). Bone marrow-derived macrophages (BMDMs) were isolated and stimulated with lipopolysaccharides (LPS) or cytidine phosphate guanosine(CpG). Inflammatory cytokines were measured viaELISA. qPCR and Western blotting were used to determine the levels of the mRNA and protein expression, respectively. RESULTS It was demonstrated that reduced expression of Sarm1 was correlated with the severity of IBD in ulcerative colitis patients, and also with the reduction of pro-inflammatory cytokines in the mouse model induced by DSS. It was further observed that Sarm1 KO enhanced the induction of pro-inflammatory cytokines in both animal and in vitro cell models. Sarm1 deficiency in macrophages increased the severity of colitis in the mouse model induced by DSS. Moreover, Sarm1 regulatedTRAF3 recruitment to myeloid differentiation primary response protein 88 (MyD88), which in turn controlled the MYD88-mediated inflammatory responses. CONCLUSIONS In summary, our data suggest that Sarm1 controls the MYD88-mediated inflammatory responses in IBD via its regulation of TRAF3 recruitment.
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Affiliation(s)
- Huijuan Fan
- Department of Gastroenterology, The Second Affiliated Hospital, Air Force Medical University, Xi'an, Shaanxi, China
| | - Chun Song
- Department of Gastroenterology, The Second Affiliated Hospital, Air Force Medical University, Xi'an, Shaanxi, China
| | - Jingyu Zhang
- Department of Gastroenterology, The Second Affiliated Hospital, Air Force Medical University, Xi'an, Shaanxi, China
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Jiang J, Li Y, Li KQ, Shen YJ, Li F, Wang YL, Jiang YH, Zou PF. Functional characterization of RIP2 in large yellow croaker (Larimichthys crocea), a protein involved in the host antiviral responses via NF-κΒ, IRF3/7 related signaling. FISH & SHELLFISH IMMUNOLOGY 2024; 145:109374. [PMID: 38218422 DOI: 10.1016/j.fsi.2024.109374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/15/2024]
Abstract
As an adaptor protein functions essentially in the activation of NF-κΒ and MAPK signaling pathways mediated by NOD1 and NOD2, RIP2 plays important roles in the host innate immune responses. In the present study, the RIP2 ortholog termed Lc-RIP2 was identified and characterized in large yellow croaker (Larimichthys crocea). It was revealed that Lc-RIP2 is consisted of an open reading frame (ORF) of 1695 bp, encoding a protein of 564 aa, with an N-terminal kinase domain and a C-terminal caspase activation and recruitment domain (CARD). Subcellular localization assays demonstrated that Lc-RIP2 was a cytosolic protein, which was broadly distributed in the examined tissues/organs, and could be induced in response to poly I:C, LPS, PGN, and Pseudomonas plecoglossicida stimulations in vivo according to qRT-PCR analysis. Notably, Lc-RIP2 overexpression in vitro was sufficient to abolish SVCV proliferation in EPC cells, and could significantly induce the activation of NF-κB, IRF3, IRF7, and IFN1 promoters. In addition, luciferase assays found that Lc-RIP2 could cooperate with Lc-MAVS, Lc-TRAF3, Lc-TRAF6, Lc-IRF3, and Lc-IRF7 in NF-κB activation, associate with Lc-TRIF, Lc-MAVS, Lc-TRAF3, Lc-IRF3, and Lc-IRF7 in IRF3 activation, enhance Lc-TRIF, Lc-MAVS, Lc-TRAF3, and Lc-TRAF6 mediated IRF7 activation, and Lc-IRF3 mediated IFN1 activation, whereas suppress NF-κB activation when co-expressed with Lc-TRIF. Co-immunoprecipitation (Co-IP) assays also demonstrated that Lc-RIP2 interacts separately with Lc-TRIF, Lc-MAVS, Lc-TRAF3, Lc-TRAF6, Lc-IRF3, and Lc-IRF7. It is thus collectively indicated that Lc-RIP2 function dominantly in the regulation of the host innate immune signaling.
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Affiliation(s)
- Jing Jiang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China
| | - Ying Li
- Key Laboratory of Estuarine Ecological Security and Environmental Health, Tan Kah Kee College, Xiamen University, Zhangzhou, Fujian Province, 363105, China
| | - Kai Qing Li
- College of the Environment and Ecology, Xiamen University, Xiamen, Fujian Province, 361102, China
| | - Ying Jia Shen
- College of the Environment and Ecology, Xiamen University, Xiamen, Fujian Province, 361102, China
| | - Fang Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Yi Lei Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China
| | - Yong Hua Jiang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China
| | - Peng Fei Zou
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China.
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