{"doi":"10.1016/j.jbc.2021.100300","title":"Interaction of RIPK1 and A20 modulates MAPK signaling in murine acetaminophen toxicity","abstract":"Acetaminophen (APAP)-induced liver necrosis is a form of regulated cell death (RCD) in which APAP activates the mitogen-activated protein kinases (MAPKs) and specifically the c-Jun-N-terminal kinase (JNK) pathway, leading to necrotic cell death. Previously, we have shown that receptor interacting protein kinase-1 (RIPK1) knockdown is also protective against APAP RCD upstream of JNK. However, whether the kinase or platform function of RIPK1 is involved in APAP RCD is not known. To answer this question, we used genetic mouse models of targeted hepatocyte RIPK1 knockout (RIPK1HepCKO) or kinase dead knock-in (RIPK1D138N) and adult hepatocyte specific knockout of the cytoprotective protein A20 (A20HepCKO), known to interact with RIPK1, to study its potential involvement in MAPK signaling. We observed no difference in injury between WT and RIPK1D138N mice post APAP. However, RIPK1HepCKO was protective. We found that RIPK1HepCKO mice had attenuated pJNK activation, while A20 was simultaneously upregulated. Conversely, A20HepCKO markedly worsened liver injury from APAP. Mechanistically, we observed a significant upregulation of apoptosis signal-regulating kinase 1 (ASK1) and increased JNK activation in A20HepCKO mice compared with littermate controls. We also demonstrated that A20 coimmunoprecipitated (co-IP) with both RIPK1 and ASK1, and that in the presence of RIPK1, there was less A20-ASK1 association than in its absence. We conclude that the kinase-independent platform function of RIPK1 is involved in APAP toxicity. Adult RIPK1HepCKO mice are protected against APAP by upregulating A20 and attenuating JNK signaling through ASK1, conversely, A20HepCKO worsens injury from APAP. Acetaminophen (APAP)-induced liver necrosis is a form of regulated cell death (RCD) in which APAP activates the mitogen-activated protein kinases (MAPKs) and specifically the c-Jun-N-terminal kinase (JNK) pathway, leading to necrotic cell death. Previously, we have shown that receptor interacting protein kinase-1 (RIPK1) knockdown is also protective against APAP RCD upstream of JNK. However, whether the kinase or platform function of RIPK1 is involved in APAP RCD is not known. To answer this question, we used genetic mouse models of targeted hepatocyte RIPK1 knockout (RIPK1HepCKO) or kinase dead knock-in (RIPK1D138N) and adult hepatocyte specific knockout of the cytoprotective protein A20 (A20HepCKO), known to interact with RIPK1, to study its potential involvement in MAPK signaling. We observed no difference in injury between WT and RIPK1D138N mice post APAP. However, RIPK1HepCKO was protective. We found that RIPK1HepCKO mice had attenuated pJNK activation, while A20 was simultaneously upregulated. Conversely, A20HepCKO markedly worsened liver injury from APAP. Mechanistically, we observed a significant upregulation of apoptosis signal-regulating kinase 1 (ASK1) and increased JNK activation in A20HepCKO mice compared with littermate controls. We also demonstrated that A20 coimmunoprecipitated (co-IP) with both RIPK1 and ASK1, and that in the presence of RIPK1, there was less A20-ASK1 association than in its absence. We conclude that the kinase-independent platform function of RIPK1 is involved in APAP toxicity. Adult RIPK1HepCKO mice are protected against APAP by upregulating A20 and attenuating JNK signaling through ASK1, conversely, A20HepCKO worsens injury from APAP. Acetaminophen (APAP) remains the leading cause of acute liver failure in the United States (1Lee W.M. Acetaminophen (APAP) hepatotoxicity-Isn't it time for APAP to go away?.J. Hepatol. 2017; 67: 1324-1331Abstract Full Text Full Text PDF PubMed Scopus (114) Google Scholar). APAP's reactive metabolite, NAPQI, is inactivated by glutathione (GSH). Upon GSH depletion, NAPQI covalently binds to intracellular proteins causing organelle stress (2Dara L. Kaplowitz N. Drug induced liver injury.in: Arias I.M. Alter H.J. Boyer J.L. Cohen D.E. Shafritz D.A. Thorgeirsson S. Wolkoff A.W. The Liver: Biology a","journal":"Journal of Biological Chemistry","year":2021,"id":186193,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":24,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9539,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":743506,"name":"Katherine Donovan","orcid":"0000-0002-8757-4415","position":1,"is_corresponding":false},{"id":235953,"name":"Layla Shojaie","orcid":"0000-0002-5020-5181","position":2,"is_corresponding":false},{"id":744188,"name":"Heather S. Johnson","orcid":null,"position":3,"is_corresponding":false},{"id":238720,"name":"Janet Kwok","orcid":null,"position":4,"is_corresponding":false},{"id":261046,"name":"Jo Suda","orcid":null,"position":5,"is_corresponding":false},{"id":743507,"name":"Brian T. Lee","orcid":"0000-0002-0621-4304","position":6,"is_corresponding":false},{"id":744189,"name":"Mariam Aghajan","orcid":null,"position":7,"is_corresponding":false},{"id":590109,"name":"Ling Shao","orcid":"0000-0002-0285-9287","position":8,"is_corresponding":false},{"id":743508,"name":"Zhang‐Xu Liu","orcid":"0000-0001-7290-3506","position":9,"is_corresponding":false},{"id":235955,"name":"Lily Dara","orcid":"0000-0002-0121-7186","position":10,"is_corresponding":false},{"id":235954,"name":"Andrea Iorga","orcid":"0000-0001-7809-9184","position":0,"is_corresponding":true}],"reference_count":45,"raw_metadata":null,"created_at":"2026-07-18T23:48:42.632147Z","pmid":"33460648","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}