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Chandrasekaran P, Weiskirchen S, Weiskirchen R. Perilipins: A family of five fat-droplet storing proteins that play a significant role in fat homeostasis. J Cell Biochem 2024; 125:e30579. [PMID: 38747370 DOI: 10.1002/jcb.30579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/18/2024] [Accepted: 04/30/2024] [Indexed: 06/12/2024]
Abstract
Lipid droplets are organelles with unique spherical structures. They consist of a hydrophobic neutral lipid core that varies depending on the cell type and tissue. These droplets are surrounded by phospholipid monolayers, along with heterogeneous proteins responsible for neutral lipid synthesis and metabolism. Additionally, there are specialized lipid droplet-associated surface proteins. Recent evidence suggests that proteins from the perilipin family (PLIN) are associated with the surface of lipid droplets and are involved in their formation. These proteins have specific roles in hepatic lipid droplet metabolism, such as protecting the lipid droplets from lipase action and maintaining a balance between lipid storage and utilization in specific cells. Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by the accumulation of lipid droplets in more than 5% of the hepatocytes. This accumulation can progress into metabolic dysfunction-associated steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The accumulation of hepatic lipid droplets in the liver is associated with the progression of MASLD and other diseases such as sarcopenic obesity. Therefore, it is crucial to understand the role of perilipins in this accumulation, as these proteins are key targets for developing novel therapeutic strategies. This comprehensive review aims to summarize the structure and characteristics of PLIN proteins, as well as their pathogenic role in the development of hepatic steatosis and fatty liver diseases.
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Affiliation(s)
| | - Sabine Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), Rheinisch-Westfälische Technische Hochschule (RWTH), University Hospital Aachen, Aachen, Germany
| | - Ralf Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), Rheinisch-Westfälische Technische Hochschule (RWTH), University Hospital Aachen, Aachen, Germany
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2
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Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, de Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circ Res 2023; 132:849-863. [PMID: 36876496 PMCID: PMC10065965 DOI: 10.1161/circresaha.122.321938] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/23/2023] [Indexed: 03/07/2023]
Abstract
BACKGROUND Removal of circulating plasma low-density lipoprotein cholesterol (LDL-C) by the liver relies on efficient endocytosis and intracellular vesicle trafficking. Increasing the availability of hepatic LDL receptors (LDLRs) remains a major clinical target for reducing LDL-C levels. Here, we describe a novel role for RNF130 (ring finger containing protein 130) in regulating plasma membrane availability of LDLR. METHODS We performed a combination of gain-of-function and loss-of-function experiments to determine the effect of RNF130 on LDL-C and LDLR recycling. We overexpressed RNF130 and a nonfunctional mutant RNF130 in vivo and measured plasma LDL-C and hepatic LDLR protein levels. We performed in vitro ubiquitination assays and immunohistochemical staining to measure levels and cellular distribution of LDLR. We supplement these experiments with 3 separate in vivo models of RNF130 loss-of-function where we disrupted Rnf130 using either ASO (antisense oligonucleotides), germline deletion, or AAV CRISPR (adeno-associated virus clustered regularly interspaced short palindromic repeats) and measured hepatic LDLR and plasma LDL-C. RESULTS We demonstrate that RNF130 is an E3 ubiquitin ligase that ubiquitinates LDLR resulting in redistribution of the receptor away from the plasma membrane. Overexpression of RNF130 decreases hepatic LDLR and increases plasma LDL-C levels. Further, in vitro ubiquitination assays demonstrate RNF130-dependent regulation of LDLR abundance at the plasma membrane. Finally, in vivo disruption of Rnf130 using ASO, germline deletion, or AAV CRISPR results in increased hepatic LDLR abundance and availability and decreased plasma LDL-C levels. CONCLUSIONS Our studies identify RNF130 as a novel posttranslational regulator of LDL-C levels via modulation of LDLR availability, thus providing important insight into the complex regulation of hepatic LDLR protein levels.
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Affiliation(s)
- Bethan L. Clifford
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
| | - Kelsey E. Jarrett
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
| | - Joan Cheng
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Angela Cheng
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Marcus Seldin
- Department of Biological Chemistry, University of California Irvine, CA, USA
| | - Pauline Morand
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | | | - Mary Chen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO, USA
| | - Angel Baldan
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO, USA
| | - Thomas Q. de Aguiar Vallim
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Elizabeth J. Tarling
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Lead contact
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Johnson AA, Shokhirev MN. Pan-Tissue Aging Clock Genes That Have Intimate Connections with the Immune System and Age-Related Disease. Rejuvenation Res 2021; 24:377-389. [PMID: 34486398 DOI: 10.1089/rej.2021.0012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In our recent transcriptomic meta-analysis, we used random forest machine learning to accurately predict age in human blood, bone, brain, heart, and retina tissues given gene inputs. Although each tissue-specific model utilized a unique number of genes for age prediction, we found that the following six genes were prioritized in all five tissues: CHI3L2, CIDEC, FCGR3A, RPS4Y1, SLC11A1, and VTCN1. Since being selected for age prediction in multiple tissues is unique, we decided to explore these pan-tissue clock genes in greater detail. In the present study, we began by performing over-representation and network topology-based enrichment analyses in the Gene Ontology Biological Process database. These analyses revealed that the immunological terms "response to protozoan," "immune response," and "positive regulation of immune system process" were significantly enriched by these clock inputs. Expression analyses in mouse and human tissues identified that these inputs are frequently upregulated or downregulated with age. A detailed literature search showed that all six genes had noteworthy connections to age-related disease. For example, mice deficient in Cidec are protected against various metabolic defects, while suppressing VTCN1 inhibits age-related cancers in mouse models. Using a large multitissue transcriptomic dataset, we additionally generate a novel, minimalistic aging clock that can predict human age using just these six genes as inputs. Taken all together, these six genes are connected to diverse aspects of aging.
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Affiliation(s)
| | - Maxim N Shokhirev
- Razavi Newman Integrative Genomics and Bioinformatics Core, Salk Institute for Biological Studies, La Jolla, California, USA
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4
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Herrera-Marcos LV, Sancho-Knapik S, Gabás-Rivera C, Barranquero C, Gascón S, Romanos E, Martínez-Beamonte R, Navarro MA, Surra JC, Arnal C, García-de-Jalón JA, Rodríguez-Yoldi MJ, Tena-Sempere M, Sánchez-Ramos C, Monsalve M, Osada J. Pgc1a is responsible for the sex differences in hepatic Cidec/Fsp27β mRNA expression in hepatic steatosis of mice fed a Western diet. Am J Physiol Endocrinol Metab 2020; 318:E249-E261. [PMID: 31846369 DOI: 10.1152/ajpendo.00199.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hepatic fat-specific protein 27 [cell death-inducing DNA fragmentation effector protein C (Cidec)/Fsp27] mRNA levels have been associated with hepatic lipid droplet extent under certain circumstances. To address its hepatic expression under different dietary conditions and in both sexes, apolipoprotein E (Apoe)-deficient mice were subjected to different experimental conditions for 11 wk to test the influence of cholesterol, Western diet, squalene, oleanolic acid, sex, and surgical castration on Cidec/Fsp27 mRNA expression. Dietary cholesterol increased hepatic Cidec/Fsp27β expression, an effect that was suppressed when cholesterol was combined with saturated fat as represented by Western diet feeding. Using the latter diet, neither oleanolic acid nor squalene modified its expression. Females showed lower levels of hepatic Cidec/Fsp27β expression than males when they were fed Western diets, a result that was translated into a lesser amount of CIDEC/FSP27 protein in lipid droplets and microsomes. This was also confirmed in low-density lipoprotein receptor (Ldlr)-deficient mice. Incubation with estradiol resulted in decreased Cidec/Fsp27β expression in AML12 cells. Whereas male surgical castration did not modify the expression, ovariectomized females did show increased levels compared with control females. Females also showed increased expression of peroxisome proliferator-activated receptor-γ coactivator 1-α (Pgc1a), suppressed by ovariectomy, and the values were significantly and inversely associated with those of Cidec/Fsp27β. When Pgc1a-deficient mice were used, the sex differences in Cidec/Fsp27β expression disappeared. Therefore, hepatic Cidec/Fsp27β expression has a complex regulation influenced by diet and sex hormonal milieu. The mRNA sex differences are controlled by Pgc1a.
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Affiliation(s)
- Luis V Herrera-Marcos
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
| | - Sara Sancho-Knapik
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
| | - Clara Gabás-Rivera
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Barranquero
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Sonia Gascón
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Eduardo Romanos
- Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
| | - Roberto Martínez-Beamonte
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - María A Navarro
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Joaquín C Surra
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Departamento de Producción Animal y Ciencia de los Alimentos, Escuela Politécnica Superior de Huesca Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Huesca, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Carmen Arnal
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Departamento de Patología Animal, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - José A García-de-Jalón
- Departamento de Patología Animal, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
| | - María J Rodríguez-Yoldi
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Manuel Tena-Sempere
- Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba e Instituto Maimónides de Investigación Biomédica de Córdoba, Córdoba, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Sánchez-Ramos
- Instituto de Investigaciones Biomedicas "Alberto Sols," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - María Monsalve
- Instituto de Investigaciones Biomedicas "Alberto Sols," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús Osada
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Instituto Agroalimentario de Aragón, Centro de Investigación y Tecnología Agroalimentaria de Aragón-Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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Abstract
PURPOSE OF REVIEW Obesity is a pandemic, yet preventable healthcare problem. Insulin resistance, diabetes mellitus, dyslipidemia, and cardiovascular complications are core manifestation of obesity. While adipose tissue is a primary site of energy storage, it is also an endocrine organ, secreting a large number of adipokines and cytokines. Nonetheless in obesity, the secretion of cytokines and free fatty acids increases significantly and is associated with the degree of adiposity and insulin resistance. Fat-specific protein 27 (FSP27) has emerged as one of the major proteins that promote physiological storage of fat in adipose tissue. RECENT FINDINGS Review of number of recent findings suggests that FSP27 plays a crucial role in physiological storage of fat within the adipose tissue especially in humans. However, in disease conditions such as obesity, FSP27 may contribute to ectopic fat accumulation in non-adipose tissue. More studies are required to highlight the tissue-specific role of FSP27, especially in humans.
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Affiliation(s)
- Shakun Karki
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, 88 East Newton St, Boston, MA, 02118, USA.
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6
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Wang J, Yan C, Xu C, Chua BT, Li P, Chen FJ. Polybasic RKKR motif in the linker region of lipid droplet (LD)-associated protein CIDEC inhibits LD fusion activity by interacting with acidic phospholipids. J Biol Chem 2018; 293:19330-19343. [PMID: 30361435 DOI: 10.1074/jbc.ra118.004892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/24/2018] [Indexed: 12/17/2022] Open
Abstract
Lipid droplets (LDs) are intracellular organelles and a central site for lipid synthesis, storage, and mobilization. The size of LDs reflects the dynamic regulation of lipid metabolism in cells. Previously, we found that cell death-inducing DFFA-like effector C (CIDEC) mediates LD fusion and growth by lipid transfer through LD-LD contact sites in adipocytes and hepatocytes. The CIDE-N domains of CIDEC molecules form homodimers, whereas the CIDE-C domain plays an important role in LD targeting and enrichment. Here, using targeted protein deletions and GFP expression coupled with fluorescence microscopy, we identified a polybasic RKKR motif in the linker region that connects the CIDE-N and CIDE-C domains of CIDEC and functions as a regulatory motif for LD fusion. We found that deletion of the linker region or mutation of the RKKR motif increases the formation of supersized LDs compared with LD formation in cells with WT CIDEC. This enhanced LD fusion activity required the interaction between CIDE-N domains. Mechanistically, we found that the RKKR motif interacts with acidic phospholipids via electrostatic attraction. Loss of this motif disrupted the protein-lipid interaction, resulting in enhanced lipid droplet fusion activity and thus formation of larger LDs. In summary, we have uncovered a CIDEC domain that regulates LD fusion activity, a finding that provides insights into the inhibitory regulation of LD fusion through CIDEC-lipid interactions.
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Affiliation(s)
- Jia Wang
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084
| | - Chengsong Yan
- the State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, and
| | - Chenqi Xu
- the State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, and
| | - Boon Tin Chua
- the Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
| | - Peng Li
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084,
| | - Feng-Jung Chen
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, .,the Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
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