1
|
Rahunen R, Tulppo M, Rinne V, Lepojärvi S, Perkiömäki JS, Huikuri HV, Ukkola O, Junttila J, Hukkanen J. Liver X Receptor Agonist 4β-Hydroxycholesterol as a Prognostic Factor in Coronary Artery Disease. J Am Heart Assoc 2024; 13:e031824. [PMID: 38390795 PMCID: PMC10944077 DOI: 10.1161/jaha.123.031824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/05/2024] [Indexed: 02/24/2024]
Abstract
BACKGROUND Regardless of progress in treatment of coronary artery disease (CAD), there is still a significant residual risk of death in patients with CAD, highlighting the need for additional risk stratification markers. Our previous study provided evidence for a novel blood pressure-regulating mechanism involving 4β-hydroxycholesterol (4βHC), an agonist for liver X receptors, as a hypotensive factor. The aim was to determine the role of 4βHC as a prognostic factor in CAD. METHODS AND RESULTS The ARTEMIS (Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection) cohort consists of 1946 patients with CAD. Men and women were analyzed separately in quartiles according to plasma 4βHC. Basic characteristics, medications, ECG, and echocardiography parameters as well as mortality rate were analyzed. At baseline, subjects with a beneficial cardiovascular profile, as assessed with traditional markers such as body mass index, exercise capacity, prevalence of diabetes, and use of antihypertensives, had the highest plasma 4βHC concentrations. However, in men, high plasma 4βHC was associated with all-cause death, cardiac death, and especially sudden cardiac death (SCD) in a median follow-up of 8.8 years. Univariate and comprehensively adjusted hazard ratios for SCD in the highest quartile were 3.76 (95% CI, 1.6-8.7; P=0.002) and 4.18 (95% CI, 1.5-11.4; P=0.005), respectively. In contrast, the association of cardiac death and SCD in women showed the lowest risk in the highest 4βHC quartile. CONCLUSIONS High plasma 4βHC concentration was associated with death and especially SCD in men, while an inverse association was detected in women. Our results suggest 4βHC as a novel sex-specific risk marker of cardiac death and especially SCD in chronic CAD. REGISTRATION INFORMATION clinicaltrials.gov. Identifier NCT01426685.
Collapse
Affiliation(s)
- Roosa Rahunen
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Biocenter OuluUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Mikko Tulppo
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | | | - Samuli Lepojärvi
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Juha S. Perkiömäki
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Heikki V. Huikuri
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Olavi Ukkola
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Juhani Junttila
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Biocenter OuluUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| | - Janne Hukkanen
- Research Unit of Biomedicine and Internal MedicineUniversity of OuluOuluFinland
- Biocenter OuluUniversity of OuluOuluFinland
- Medical Research Center OuluOulu University Hospital and University of OuluOuluFinland
| |
Collapse
|
2
|
Resetar M, Tietcheu Galani BR, Tsamo AT, Chen Y, Schachner D, Stolzlechner S, Mawouma Pagna JI, Beniddir MA, Kirchmair J, Dirsch VM. Flindissone, a Limonoid Isolated from Trichilia prieuriana, Is an LXR Agonist. JOURNAL OF NATURAL PRODUCTS 2023; 86:1901-1909. [PMID: 37526502 PMCID: PMC10463221 DOI: 10.1021/acs.jnatprod.3c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Indexed: 08/02/2023]
Abstract
In this study, the ability of six limonoids from Trichilia prieuriana (Meliaceae) to activate the liver X receptor (LXR) was assessed. One of these limonoids, flindissone, was shown to activate LXR by reporter-gene assays. Flindissone is a ring-intact limonoid, structurally similar to sterol-like LXR ligands. In endogenous cellular settings, flindissone showed an activity profile that is characteristic of LXR agonists. It induced cholesterol efflux in THP-1 macrophages by increasing the cholesterol transporter ABCA1 and ABCG1 gene expression. In HepG2 cells, flindissone induced the expression of IDOL, an LXR-target gene that is associated with the downregulation of the LDL receptor. However, unlike synthetic and similarly to sterol-based LXR agonists, flindissone did not induce the expression of the SREBP1c gene, a major transcription factor regulating de novo lipogenesis. Additionally, flindissone also appeared to be able to inhibit post-translational activation of SREBP1c. The results presented here reveal a natural product as a new LXR agonist and point to an additional property of T. prieuriana and other plant extracts containing flindissone.
Collapse
Affiliation(s)
- Mirta Resetar
- Department
of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Borris R. Tietcheu Galani
- Department
of Biological Sciences, Faculty of Science, University of Ngaoundere, PO Box 454, Ngaoundere, Adamawa, Cameroon
| | - Armelle T. Tsamo
- Department
of Organic Chemistry, Faculty of Science, University of Yaounde I, PO Box 812, Yaounde, Cameroon
| | - Ya Chen
- Department
of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Daniel Schachner
- Department
of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Stefanie Stolzlechner
- Center
for Cancer Research, Medical University
of Vienna, Borschkegasse 8a, 1090 Vienna, Austria
| | - Julio I. Mawouma Pagna
- Department
of Organic Chemistry, Faculty of Science, University of Yaounde I, PO Box 812, Yaounde, Cameroon
| | - Mehdi A. Beniddir
- Équipe
“Chimie des Substances Naturelles” BioCIS, CNRS, Université Paris-Saclay, 17 Avenue des Sciences, 91400 Orsay, France
| | - Johannes Kirchmair
- Department
of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Verena M. Dirsch
- Department
of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| |
Collapse
|
3
|
Bahman F, AlSaeed H, Albeloushi S, Al-Mulla F, Ahmad R, Al-Rashed F. The role of TLR2 in exercise-induced immunomodulation in normal weight individuals. Sci Rep 2023; 13:10703. [PMID: 37400578 DOI: 10.1038/s41598-023-37811-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/28/2023] [Indexed: 07/05/2023] Open
Abstract
Toll-like receptors (TLRs) have been targeted for therapeutic drug development for several disorders, including cardiovascular diseases (CVD), and diabetes mellitus. Daily levels physical activity (PA) has been purported to influence the systemic circulation of cytokines, affecting the overall activation of TLRs and influencing the inflammatory milieu. Objective and self-reported daily PA was tracked in 69 normal-weight adults. Freedson's cut-offs categorized daily PA intensity into the 25th lowest, medium, and top percentiles. Monocytic TLR2 expression was quantified by flow cytometry in fresh whole blood. Cross-sectional associations between flow cytometry measured TLR2+ subsets and clinical biomarkers were evaluated. PA increased circulation of TLR2+ monocytes. TLR2 expression was adversely corelated with reduced diastolic blood pressure (DBP), triglyceride (TG), and matrix metallopeptidase 9 (MMP9) levels. However, regression analysis indicated that only TG levels were independently linked with TLR2+ subsets in circulation in active participants. Higher daily levels of physical activity are associated with improved cardiovascular blood markers and elevated circulatory monocytic TLR2+ subsets. These findings suggest that TLR2 may play a role in modulating CVD risk factors in individuals leading physically active lifestyles.
Collapse
Affiliation(s)
- Fatemah Bahman
- Immunology and Microbiology Department, Dasman Diabetes Institute, Al-Soor Street, P.O. Box 1180, 15462, Dasman, Kuwait
| | - Halemah AlSaeed
- Immunology and Microbiology Department, Dasman Diabetes Institute, Al-Soor Street, P.O. Box 1180, 15462, Dasman, Kuwait
| | - Shaima Albeloushi
- Immunology and Microbiology Department, Dasman Diabetes Institute, Al-Soor Street, P.O. Box 1180, 15462, Dasman, Kuwait
| | - Fahd Al-Mulla
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, 15462, Dasman, Kuwait
| | - Rasheed Ahmad
- Immunology and Microbiology Department, Dasman Diabetes Institute, Al-Soor Street, P.O. Box 1180, 15462, Dasman, Kuwait
| | - Fatema Al-Rashed
- Immunology and Microbiology Department, Dasman Diabetes Institute, Al-Soor Street, P.O. Box 1180, 15462, Dasman, Kuwait.
| |
Collapse
|
4
|
Kim H, Park C, Kim TH. Targeting Liver X Receptors for the Treatment of Non-Alcoholic Fatty Liver Disease. Cells 2023; 12:cells12091292. [PMID: 37174692 PMCID: PMC10177243 DOI: 10.3390/cells12091292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 04/29/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) refers to a range of conditions in which excess lipids accumulate in the liver, possibly leading to serious hepatic manifestations such as steatohepatitis, fibrosis/cirrhosis and cancer. Despite its increasing prevalence and significant impact on liver disease-associated mortality worldwide, no medication has been approved for the treatment of NAFLD yet. Liver X receptors α/β (LXRα and LXRβ) are lipid-activated nuclear receptors that serve as master regulators of lipid homeostasis and play pivotal roles in controlling various metabolic processes, including lipid metabolism, inflammation and immune response. Of note, NAFLD progression is characterized by increased accumulation of triglycerides and cholesterol, hepatic de novo lipogenesis, mitochondrial dysfunction and augmented inflammation, all of which are highly attributed to dysregulated LXR signaling. Thus, targeting LXRs may provide promising strategies for the treatment of NAFLD. However, emerging evidence has revealed that modulating the activity of LXRs has various metabolic consequences, as the main functions of LXRs can distinctively vary in a cell type-dependent manner. Therefore, understanding how LXRs in the liver integrate various signaling pathways and regulate metabolic homeostasis from a cellular perspective using recent advances in research may provide new insights into therapeutic strategies for NAFLD and associated metabolic diseases.
Collapse
Affiliation(s)
- Hyejin Kim
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Chaewon Park
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Tae Hyun Kim
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
- Drug Information Research Institute, Sookmyung Women's University, Seoul 04310, Republic of Korea
- Muscle Physiome Research Center, Sookmyung Women's University, Seoul 04310, Republic of Korea
| |
Collapse
|
5
|
Rossetti C, Laraia L. Thermal Proteome Profiling Reveals Distinct Target Selectivity for Differentially Oxidized Oxysterols. ACS Chem Biol 2022; 17:1677-1684. [PMID: 35763711 DOI: 10.1021/acschembio.2c00383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxysterols are produced physiologically by many species; however, their distinct roles in regulating human physiology have not been studied systematically. The role of differing oxidation states and sites in mediating their biological functions is also unclear. As oxysterols have been associated with atherosclerosis, neurodegeneration, and cancer, a better understanding of their protein targets is desirable. To address this, we mapped the oxysterol interactome with three A- and B-ring oxidized sterols as well as 25-hydroxy cholesterol using thermal proteome profiling, validating selected targets with the cellular thermal shift assay and isothermal dose response fingerprinting. This revealed that the site of oxidation has a profound impact on target selectivity, with each oxysterol possessing an almost unique set of target proteins. Overall, targets clustered in pathways relating to vesicular transport and phosphoinositide metabolism, suggesting that while individual oxysterols bind to a unique set of proteins, the processes they modulate are highly interconnected.
Collapse
Affiliation(s)
- Cecilia Rossetti
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kgs. Lyngby, Denmark
| | - Luca Laraia
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kgs. Lyngby, Denmark
| |
Collapse
|
6
|
Passarelli MN, McDonald JG, Thompson BM, Arega EA, Palys TJ, Rees JR, Barry EL, Baron JA. Association of demographic and health characteristics with circulating oxysterol concentrations. J Clin Lipidol 2022; 16:345-355. [PMID: 35461764 PMCID: PMC10882644 DOI: 10.1016/j.jacl.2022.03.012] [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: 11/24/2021] [Revised: 03/21/2022] [Accepted: 03/28/2022] [Indexed: 11/22/2022]
Abstract
BACKGOUND Circulating oxysterols, cholesterol metabolites with important signaling functions, are increasingly being recognized as candidate biomarkers for several diseases, but associations with demographic and health characteristics remain poorly described. OBJECTIVE This study aims to characterize associations of major circulating oxysterols with sex, age, race/ethnicity, body mass index (BMI), lifestyle factors, and use of common medications. METHODS We measured plasma concentrations of 27-hydroxycholesterol (27-OHC), 25-hydroxycholesterol (25-OHC), 24(S)-hydroxycholesterol (24(S)-OHC), 7ɑ-hydroxycholesterol (7ɑ-OHC), and 4β-hydroxycholesterol (4β-OHC) from 1,440 participants of a completed clinical trial for the chemoprevention of colorectal adenomas. Adjusted percent difference in means were calculated using linear regression. RESULTS Women had 18% (95% CI, 14%, 22%) lower 27-OHC and 21% (15%, 27%) higher 4β-OHC than men. Blacks had 15% (7%, 23%) higher 4β-OHC than Non-Hispanic Whites, and Asian or Pacific Islanders had 19% (2%, 35%) higher 7ɑ-OHC than Non-Hispanic Whites. Individuals of BMI ≥35 kg/m2 had 33% (25%, 41%) lower 4β-OHC than those <25 kg/m2. Current smokers had 15% (5%, 24%) higher 7ɑ-OHC than never smokers, and daily alcohol drinkers had 17% (10%, 24%) higher 7ɑ-OHC than never drinkers. Statin use was associated with lower concentrations of all 5 oxysterols. Differences in mean <15% were found for characteristics such as age, total dietary energy intake, physical activity, diabetes, and anti-inflammatory drug use. CONCLUSION Circulating oxysterols are uniquely associated with multiple demographic and health characteristics.
Collapse
Affiliation(s)
- Michael N Passarelli
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
| | - Jeffrey G McDonald
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bonne M Thompson
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Enat A Arega
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Thomas J Palys
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Judy R Rees
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Elizabeth L Barry
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - John A Baron
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| |
Collapse
|
7
|
Rahunen R, Kummu O, Koivukangas V, Hautajärvi H, Hakkola J, Rysä J, Hukkanen J. Pregnane X Receptor‒4β-Hydroxycholesterol Axis in the Regulation of Overweight- and Obesity-Induced Hypertension. J Am Heart Assoc 2022; 11:e023492. [PMID: 35229613 PMCID: PMC9075316 DOI: 10.1161/jaha.121.023492] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Mechanisms mediating hypertensive effects of overweight and obesity have not been fully elucidated. We showed previously that activation of pregnane X receptor (PXR) by rifampicin elevates 24-hour blood pressure (BP) and plasma 4β-hydroxycholesterol (4βHC), agonist for liver X receptor (LXR). Methods and Results In combined "PXR activation data set" (n=62) of 4 clinical trials, 1 week rifampicin dosing increased office systolic BP (SBP) by 3.1 mm Hg, DBP 1.8 mm Hg, and mean arterial pressure 2.2 mm Hg in comparison with placebo (P<0.01). Plasma 4βHC had negative correlation with SBP both in rifampicin (r=-0.46, P=0.0002) and placebo (r=-0.45, P=0.0003) arms, although 4βHC was elevated >3-fold by rifampicin. In "non-intervention data set" (n=102) of patients with obesity and healthy volunteers (body mass index, 19.2-55.2 kg/m2), 4βHC had negative correlations (P<0.00001) with office SBP (r=-0.51), diastolic BP (r=-0.50), and mean arterial pressure (r=-0.54). Lean women had higher 4βHC than men, with increasing weight repressing 4βHC (r=-0.62, P<0.00001) in both sexes. In multiple linear regression analysis, the only statistically significant predictor for SBP was 4βHC. Six-day PXR agonist dosing elevated SBP in rats (n=7-8/group). PXR activation elevated 4βHC and after PXR agonist was withdrawn and elevated 4βHC was left to act alone, SBP was reduced on days 7 to 14 in comparison with control rats. Conclusions PXR activation elevates SBP. Elevated circulating 4βHC lowers SBP in rats, and higher 4βHC is an independent predictor of lower SBP in humans. PXR-4βHC-LXR is novel BP-regulating pathway deregulated in overweight and obesity by repressed 4βHC, with implications for sex-specific BP regulation. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00985270, NCT01293422, NCT01690104, NCT02329405, and NCT01330251.
Collapse
Affiliation(s)
- Roosa Rahunen
- Research Unit of Internal Medicine University of Oulu Finland.,Biocenter Oulu University of Oulu Finland.,Medical Research Center Oulu Oulu University Hospital and University of Oulu Finland
| | - Outi Kummu
- Biocenter Oulu University of Oulu Finland.,Medical Research Center Oulu Oulu University Hospital and University of Oulu Finland.,Research Unit of Biomedicine Pharmacology and Toxicology University of Oulu Finland
| | - Vesa Koivukangas
- Medical Research Center Oulu Oulu University Hospital and University of Oulu Finland.,Department of Surgery Oulu University Hospital and University of Oulu Finland
| | - Heidi Hautajärvi
- Admescope Ltd. Oulu Finland.,Now with Finnish Customs Laboratory Finland
| | - Jukka Hakkola
- Biocenter Oulu University of Oulu Finland.,Medical Research Center Oulu Oulu University Hospital and University of Oulu Finland.,Research Unit of Biomedicine Pharmacology and Toxicology University of Oulu Finland
| | - Jaana Rysä
- School of Pharmacy Faculty of Health Sciences University of Eastern Finland Kuopio Finland
| | - Janne Hukkanen
- Research Unit of Internal Medicine University of Oulu Finland.,Biocenter Oulu University of Oulu Finland.,Medical Research Center Oulu Oulu University Hospital and University of Oulu Finland
| |
Collapse
|
8
|
Integrative analysis reveals multiple modes of LXR transcriptional regulation in liver. Proc Natl Acad Sci U S A 2022; 119:2122683119. [PMID: 35145035 PMCID: PMC8851562 DOI: 10.1073/pnas.2122683119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2022] [Indexed: 02/08/2023] Open
Abstract
The nuclear receptors liver X receptor (LXR) α and β play crucial roles in hepatic metabolism. Many genes induced in response to pharmacologic LXR agonism have been defined; however, the transcriptional consequences of loss of LXR binding to its genomic targets are less well characterized. Here, we addressed how deletion of both LXRα and LXRβ from mouse liver (LXR double knockout [DKO]) affects the transcriptional regulatory landscape by integrating changes in LXR binding, chromatin accessibility, and gene expression. Many genes involved in fatty acid metabolism showed reduced expression and chromatin accessibility at their intergenic and intronic regions in LXRDKO livers. Genes that were up-regulated with LXR deletion had increased chromatin accessibility at their promoter regions and were enriched for functions not linked to lipid metabolism. Loss of LXR binding in liver reduced the activity of a broad set of hepatic transcription factors, inferred through changes in motif accessibility. By contrast, accessibility at promoter nuclear factor Y (NF-Y) motifs was increased in the absence of LXR. Unexpectedly, we also defined a small set of LXR targets for direct ligand-dependent repression. These genes have LXR-binding sites but showed increased expression in LXRDKO liver and reduced expression in response to the LXR agonist. In summary, the binding of LXRs to the hepatic genome has broad effects on the transcriptional landscape that extend beyond its canonical function as an activator of lipid metabolic genes.
Collapse
|
9
|
Hayashi Y, Lee-Okada HC, Nakamura E, Tada N, Yokomizo T, Fujiwara Y, Ichi I. Ablation of fatty acid desaturase 2 (FADS2) exacerbates hepatic triacylglycerol and cholesterol accumulation in polyunsaturated fatty acid-depleted mice. FEBS Lett 2021; 595:1920-1932. [PMID: 34008174 DOI: 10.1002/1873-3468.14134] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 04/22/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022]
Abstract
Deficiency of polyunsaturated fatty acids (PUFAs) is known to induce hepatic steatosis. However, it is not clearly understood which type of PUFA is responsible for the worsening of steatosis. This study observed a marked accumulation of hepatic triacylglycerol and cholesterol in fatty acid desaturase 2 knockout (FADS2-/- ) mice lacking both C18 and ≥ C20 PUFAs that were fed a PUFA-depleted diet. Hepatic triacylglycerol accumulation was associated with enhanced sterol regulatory element-binding protein (SREBP)-1-dependent lipogenesis and decreased triacylglycerol secretion into the plasma via very-low-density lipoprotein (VLDL). Furthermore, upregulation of cholesterol synthesis contributed to increased hepatic cholesterol content in FADS2-/- mice. These results suggest that ≥ C20 PUFAs synthesized by FADS2 are important in regulating hepatic triacylglycerol and cholesterol accumulation during PUFA deficiency.
Collapse
Affiliation(s)
- Yuri Hayashi
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Hyeon-Cheol Lee-Okada
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Eri Nakamura
- Laboratory of Genome Research, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Norihiro Tada
- Laboratory of Genome Research, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoko Fujiwara
- Institute for Human Life Innovation, Ochanomizu University, Tokyo, Japan.,Natural Science Division, Faculty of Core Research, Ochanomizu University, Tokyo, Japan
| | - Ikuyo Ichi
- Institute for Human Life Innovation, Ochanomizu University, Tokyo, Japan.,Natural Science Division, Faculty of Core Research, Ochanomizu University, Tokyo, Japan
| |
Collapse
|