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Hazell Pickering S, Abdelhalim M, Collas P, Briand N. Alternative isoform expression of key thermogenic genes in human beige adipocytes. Front Endocrinol (Lausanne) 2024; 15:1395750. [PMID: 38859907 PMCID: PMC11163967 DOI: 10.3389/fendo.2024.1395750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/07/2024] [Indexed: 06/12/2024] Open
Abstract
Background The beneficial effect of thermogenic adipocytes in maintaining body weight and protecting against metabolic disorders has raised interest in understanding the regulatory mechanisms defining white and beige adipocyte identity. Although alternative splicing has been shown to propagate adipose browning signals in mice, this has yet to be thoroughly investigated in human adipocytes. Methods We performed parallel white and beige adipogenic differentiation using primary adipose stem cells from 6 unrelated healthy subjects and assessed differential gene and isoform expression in mature adipocytes by RNA sequencing. Results We find 777 exon junctions with robust differential usage between white and beige adipocytes in all 6 subjects, mapping to 562 genes. Importantly, only 10% of these differentially spliced genes are also differentially expressed, indicating that alternative splicing constitutes an additional layer of gene expression regulation during beige adipocyte differentiation. Functional classification of alternative isoforms points to a gain of function for key thermogenic transcription factors such as PPARG and CITED1, and enzymes such as PEMT, or LPIN1. We find that a large majority of the splice variants arise from differential TSS usage, with beige-specific TSSs being enriched for PPARγ and MED1 binding compared to white-specific TSSs. Finally, we validate beige specific isoform expression at the protein level for two thermogenic regulators, PPARγ and PEMT. Discussion These results suggest that differential isoform expression through alternative TSS usage is an important regulatory mechanism for human adipocyte thermogenic specification.
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Affiliation(s)
- Sarah Hazell Pickering
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Mohamed Abdelhalim
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Immunology and Transfusion Medicine, Oslo University Hospital, Oslo, Norway
| | - Nolwenn Briand
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
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Castellá M, Mestres-Arenas A, Gavaldà-Navarro A, Blasco-Roset A, Quesada-López T, Romero-Carramiñana I, Giralt M, Villarroya F, Cereijo R. The splicing factor SF3B1 is involved in brown adipocyte thermogenic activation. Biochem Pharmacol 2024; 220:116014. [PMID: 38158020 DOI: 10.1016/j.bcp.2023.116014] [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] [Received: 10/31/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
The ability of alternative splicing mechanisms to control gene expression is increasingly being recognized as relevant for adipose tissue function. The expression of SF3B1, a key component of the SF3B complex directly involved in spliceosome formation, was previously reported to be significantly induced in brown adipose tissue under cold-induced thermogenic activation. Here, we identify that noradrenergic cAMP-mediated thermogenic stimulation increases SF3B1 expression in brown and beige adipocytes. We further show that pladienolide-B, a drug that binds SF3B1 to inhibit pre-mRNA splicing by targeting the SF3B complex, down-regulates key components of the thermogenic machinery (e.g., UCP1 gene expression), differentially alters the expression of alternative splicing-regulated transcripts encoding molecular actors involved in the oxidative metabolism of brown adipocytes (e.g., peroxisome proliferator-activated receptor-gamma co-activator-alpha [PGC-1α] and cytochrome oxidase subunit 7a genes), and impairs the respiratory activity of brown adipocytes. Similar alterations were found in brown adipocytes with siRNA-mediated knockdown of SF3B1 protein levels. Our findings collectively indicate that SF3B1 is a key factor in the appropriate thermogenic activation of differentiated brown adipocytes. This work exemplifies the importance of splicing processes in adaptive thermogenesis and suggests that pharmacological tools, such as pladienolide-B, may be used to modulate brown adipocyte thermogenic activity.
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Affiliation(s)
- Moisés Castellá
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain
| | - Alberto Mestres-Arenas
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain
| | - Aleix Gavaldà-Navarro
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain
| | - Albert Blasco-Roset
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain
| | - Tania Quesada-López
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain; Institut d'Investigació Biomèdica Sant Pau (IIB-SANT PAU), and Department of Infectious Diseases, Hospital de la Santa Creu i Sant Pau, 08041 Barcelona, Spain
| | - Inés Romero-Carramiñana
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM); Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid; and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, 28049 Madrid, Spain
| | - Marta Giralt
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain
| | - Francesc Villarroya
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain.
| | - Rubén Cereijo
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona; Institut de Biomedicina de la Universitat de Barcelona (IBUB); and Institut de Recerca de Sant Joan de Déu, 08028 Barcelona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, 28029 Madrid, Spain.
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