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Ag O, Ld O, Mv C, Dspsf G, Ti L, Santos-Fávero BC, Ad L, Pauletti BA, Ap L, Mc B, J A, Lca R, Hf C, Em C, J K, V P, J A, Lr S. Interaction between poly-A binding protein PABPC4 and nuclear receptor corepressor NCoR1 modulates a metabolic stress response. J Biol Chem 2023; 299:104702. [PMID: 37059182 PMCID: PMC10203745 DOI: 10.1016/j.jbc.2023.104702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/16/2023] Open
Abstract
Mitochondria are organelles known primarily for generating ATP via the oxidative phosphorylation process. Environmental signals are sensed by whole organisms or cells and markedly affect this process, leading to alterations in gene transcription and, consequently, changes in mitochondrial function and biogenesis. The expression of mitochondrial genes is finely regulated by nuclear transcription factors, including nuclear receptors and their coregulators. Among the best-known coregulators is the nuclear receptor corepressor 1 (NCoR1). Muscle-specific knockout of NCoR1 in mice induces an oxidative phenotype, improving glucose and fatty acid metabolism. However, the mechanism by which NCoR1 is regulated remains elusive. In this work, we identified the Poly A Binding Protein (PABPC4) as a new NCoR1 interactor. Unexpectedly, we found that silencing of PABPC4 induced an oxidative phenotype in both C2C12 and MEF cells as indicated by increased oxygen consumption, mitochondria content, and reduced lactate production. Mechanistically, we demonstrated that PABPC4 silencing increased the ubiquitination and consequent degradation of NCoR1, leading to the derepression of PPAR-regulated genes. As a consequence, cells with PABPC4 silencing had a greater capacity to metabolize lipids, reduced intracellular lipid droplets and reduced cell death. Interestingly, in conditions known to induce mitochondrial function and biogenesis, both mRNA expression and PABPC4 protein content were markedly reduced. Our study, therefore, suggests that the lowering of PABPC4 expression may represent an adaptive event required to induce mitochondrial activity in response to metabolic stress in skeletal muscle cells. As such, the NCoR1-PABPC4 interface might be a new road to the treatment of metabolic diseases.
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Affiliation(s)
- Oliveira Ag
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Oliveira Ld
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cruz Mv
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Guimarães Dspsf
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Lima Ti
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil; Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - B C Santos-Fávero
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Luchessi Ad
- Laboratory of Biotechnology, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - B A Pauletti
- Brazilian National Laboratory for Biosciences (LNBio), Center for Research in Energy and Materials (CNPEM), Campinas, São Paulo, Brazil
| | - Leme Ap
- Brazilian National Laboratory for Biosciences (LNBio), Center for Research in Energy and Materials (CNPEM), Campinas, São Paulo, Brazil
| | - Bajgelman Mc
- Brazilian National Laboratory for Biosciences (LNBio), Center for Research in Energy and Materials (CNPEM), Campinas, São Paulo, Brazil
| | - Afonso J
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Pecuária Sudeste, São Carlos, Brazil
| | - Regitano Lca
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Pecuária Sudeste, São Carlos, Brazil
| | - Carvalho Hf
- Laboratory of Extracellular Matrix and Gene Regulation, Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Carneiro Em
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Kobarg J
- Faculty of Pharmaceutic Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Perissi V
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Auwerx J
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Silveira Lr
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology (IB), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
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Isolation, culture, and immunostaining of neonatal rat ventricular myocytes. STAR Protoc 2021; 2:100950. [PMID: 34820638 PMCID: PMC8599495 DOI: 10.1016/j.xpro.2021.100950] [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] [Indexed: 12/02/2022] Open
Abstract
Isolation and culture of ventricular cardiomyocytes from neonatal rats (NRVMs) is a powerful model to study neonatal cardiac development, cell cycle regulation, and cardiac physiology and pathology in vitro. Here, we present our modified enzymatic digestion protocol followed by two-step discontinuous Percoll gradient centrifugation to isolate a high yield of viable ventricular cardiomyocytes from neonatal rats. Finally, here we describe an immunostaining protocol for cytosolic and nuclear staining of NRVMs. For complete details on the use and execution of this protocol, please refer to Pereira et al. (2020). Isolate a high yield of viable ventricular cardiomyocytes from neonatal rats (NRVMs) NRVMs can be maintained in culture for several days Enzymatic digestion of cardiac tissue and Percoll gradient separation Detailed subsection of immunofluorescence for nuclear and cytosolic staining
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