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Zhang P, Yang J, Liu X, Huang C, Tao Y, Shen P, Bai Z, Xiao C, Zhou L, Li G, Zhang L, Zhou W, Gao Y. FBP1 orchestrates keratinocyte proliferation/differentiation and suppresses psoriasis through metabolic control of histone acetylation. Cell Death Dis 2024; 15:392. [PMID: 38834617 PMCID: PMC11150480 DOI: 10.1038/s41419-024-06706-6] [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: 10/26/2023] [Revised: 04/13/2024] [Accepted: 04/24/2024] [Indexed: 06/06/2024]
Abstract
Keratinocyte proliferation and differentiation in epidermis are well-controlled and essential for reacting to stimuli such as ultraviolet light. Imbalance between proliferation and differentiation is a characteristic feature of major human skin diseases such as psoriasis and squamous cell carcinoma. However, the effect of keratinocyte metabolism on proliferation and differentiation remains largely elusive. We show here that the gluconeogenic enzyme fructose-1,6-bisphosphatase 1 (FBP1) promotes differentiation while inhibits proliferation of keratinocyte and suppresses psoriasis development. FBP1 is identified among the most upregulated genes induced by UVB using transcriptome sequencing and is elevated especially in upper epidermis. Fbp1 heterozygous mice exhibit aberrant epidermis phenotypes with local hyperplasia and dedifferentiation. Loss of FBP1 promotes proliferation and inhibits differentiation of keratinocytes in vitro. Mechanistically, FBP1 loss facilitates glycolysis-mediated acetyl-CoA production, which increases histone H3 acetylation at lysine 9, resulting in enhanced transcription of proliferation genes. We further find that the expression of FBP1 is dramatically reduced in human psoriatic lesions and in skin of mouse imiquimod psoriasis model. Fbp1 deficiency in mice facilitates psoriasis-like skin lesions development through glycolysis and acetyl-CoA production. Collectively, our findings reveal a previously unrecognized role of FBP1 in epidermal homeostasis and provide evidence for FBP1 as a metabolic psoriasis suppressor.
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Affiliation(s)
- Pengfei Zhang
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Ju Yang
- Department of Dermatology, The General Hospital of Western Theater Command PLA, Chengdu, Sichuan, 610083, China
| | - Xiong Liu
- Department of Information, The PLA Center for Disease Control and Prevention, Beijing, China
| | - Congshu Huang
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Yuandong Tao
- Department of Pediatric Urology, The Seventh Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Pan Shen
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Zhijie Bai
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Chengrong Xiao
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Lei Zhou
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Gaofu Li
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Li Zhang
- Department of Information, The PLA Center for Disease Control and Prevention, Beijing, China
| | - Wei Zhou
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
| | - Yue Gao
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
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2
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Quintana JF, Sinton MC, Chandrasegaran P, Lestari AN, Heslop R, Cheaib B, Ogunsola J, Ngoyi DM, Kuispond Swar NR, Cooper A, Mabbott NA, Coffelt SB, MacLeod A. γδ T cells control murine skin inflammation and subcutaneous adipose wasting during chronic Trypanosoma brucei infection. Nat Commun 2023; 14:5279. [PMID: 37644007 PMCID: PMC10465518 DOI: 10.1038/s41467-023-40962-y] [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] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
African trypanosomes colonise the skin to ensure parasite transmission. However, how the skin responds to trypanosome infection remains unresolved. Here, we investigate the local immune response of the skin in a murine model of infection using spatial and single cell transcriptomics. We detect expansion of dermal IL-17A-producing Vγ6+ cells during infection, which occurs in the subcutaneous adipose tissue. In silico cell-cell communication analysis suggests that subcutaneous interstitial preadipocytes trigger T cell activation via Cd40 and Tnfsf18 signalling, amongst others. In vivo, we observe that female mice deficient for IL-17A-producing Vγ6+ cells show extensive inflammation and limit subcutaneous adipose tissue wasting, independently of parasite burden. Based on these observations, we propose that subcutaneous adipocytes and Vγ6+ cells act in concert to limit skin inflammation and adipose tissue wasting. These studies provide new insights into the role of γδ T cell and subcutaneous adipocytes as homeostatic regulators of skin immunity during chronic infection.
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Affiliation(s)
- Juan F Quintana
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK.
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
- Division of Immunology, Immunity to Infection and Respiratory Medicine, Lydia Becker Institute of Immunology and Inflammation. University of Manchester, Manchester, UK.
| | - Matthew C Sinton
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Praveena Chandrasegaran
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Agatha Nabilla Lestari
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Rhiannon Heslop
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Bachar Cheaib
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Translational Lung Research Center Heidelberg (TLRC), Center for Infectious Diseases, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - John Ogunsola
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Dieudonne Mumba Ngoyi
- Department of Parasitology, National Institute of Biomedical Research, Kinshasa, Democratic Republic of the Congo
| | - Nono-Raymond Kuispond Swar
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- Department of Parasitology, National Institute of Biomedical Research, Kinshasa, Democratic Republic of the Congo
| | - Anneli Cooper
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Neil A Mabbott
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Seth B Coffelt
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology (WCIP), University of Glasgow, Glasgow, UK.
- School of Biodiversity, One Health, Veterinary Medicine (SBOHVM), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Song Q, Guo JX, Ma YX, Ou T, Zhang J, Li HZ, Mi SQ, Zhang YZ, Oda H, Chen W. Taurine alleviated hepatic steatosis in oleic acid-treated-HepG2 cells and rats fed a high-fat diet. Heliyon 2023; 9:e16401. [PMID: 37274675 PMCID: PMC10238701 DOI: 10.1016/j.heliyon.2023.e16401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 04/21/2023] [Accepted: 05/16/2023] [Indexed: 06/06/2023] Open
Abstract
Taurine has been proven in many trials to alleviate the symptoms of metabolic associated fatty liver disease. Here its protective effect for hepatic steatosis and modulation of AMP-activated protein kinase and insulin signaling pathway were investigated. Steatotic HepG2 cell established with oleic acid (0.05 mmol/L), treated with taurine (5 mmol/L), dorsomorphin (10 μmol/L) for 24 h. Sprague Dawley rats were divided into regular and high-fat diet (HFD) groups, and their corresponding taurine (70 or 350 mg/kg BW/d) groups, fed for 8 weeks. In steatotic cell, taurine reduced the TG concentration and SREBP-1c, PPARγ, FAS, ACC, SCD1 protein levels, decreased phosphorylation of mTOR, IRS1 (Ser302), increased phosphorylation of AMPKα, LKB1, PI3K, Akt, ACC. While dorsomorphin eliminated taurine's TG-lowering effect. In HFD-fed rats, taurine reduced liver TG, serum TG, ALT, AST, IL-1β, IL-4, TNF-α. The effects of taurine on the main factors of fatty acid synthesis were mostly consistent with cell experiments, and the reduction of microRNAs (451, 33, 291b) was aligned with the improvement in LKB1 and AMPK expression in HFD rats. Taurine alleviated steatosis-induced inhibition of IRS1-PI3K-Akt pathway, but suppressed its positively regulated downstream factor mTOR. In parallel, taurine reduced steatosis by activating LKB1-AMPKα pathway via phosphorylation and no-phosphorylation manner, then inhibiting SREBP-1c directly or by suppressing mTOR phosphorylation.
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Affiliation(s)
- Qi Song
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
- Laboratory of Nutritional Biochemistry, Nagoya University, Nagoya, 464-8601, Japan
| | - Jun Xia Guo
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Yu Xun Ma
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Tong Ou
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Jing Zhang
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Hui Zi Li
- Department of Nutrition, PLA Rocket Force Characteristic Medical Center, Beijing, 100088, China
| | - Sheng Quan Mi
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Yan Zhen Zhang
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
| | - Hiroaki Oda
- Laboratory of Nutritional Biochemistry, Nagoya University, Nagoya, 464-8601, Japan
| | - Wen Chen
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, 100191, China
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Liu MC, Weng PW, Chen SC, Liu TH, Huang HW, Huang CT, Yang CT, Mishra VK, Yang MT. Immunologic, Anti-Inflammatory, and Anti-Muscle Damage Profile of Supplemented Vitamin D 3 in Healthy Adults on Strenuous Endurance Exercise. BIOLOGY 2023; 12:biology12050657. [PMID: 37237471 DOI: 10.3390/biology12050657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023]
Abstract
Reportedly, strenuous endurance exercise can depress the immune system and induce inflammation and muscle damage. Therefore, this double-blinded, matched-pair study aimed to investigate the impact of vitamin D3 supplementation on immune response (leukocyte, neutrophil, lymphocyte, CD4+, CD8+, CD19+, and CD56+ counts), inflammatory profile (TNF-α and IL-6), muscle damage (CK and LDH levels), as well as aerobic capacity after strenuous endurance exercise in 18 healthy men taking 5000 IU of vitamin D3 (n = 9) or placebo (n = 9) daily for 4 weeks. Total and differential blood leukocyte counts, levels of cytokines, and muscle damage biomarkers were determined before, immediately after, and 2, 4, and 24 h after exercise. The IL-6, CK, and LDH levels were significantly lower in vitamin D3 group at 2, 4, and 24 h post exercise (p < 0.05). Maximal and average heart rates during exercise were also significantly lower (p < 0.05). In the vitamin D3 group, the CD4+/CD8+ ratio after 4 weeks of supplementation was only significantly lower at post-0 than at baseline and significantly higher at post-2 than at baseline and post-0 (all p < 0.05). Taken together, 5000 IU of daily vitamin D3 supplementation for 4 weeks exhibited positive effects in terms of increased blood 25(OH)D levels, CD4+/CD8+ ratio (immune response), and aerobic capacity while inhibiting inflammatory cytokines and CK and LDH (muscle damage) in people performing strenuous endurance exercise.
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Affiliation(s)
- Ming-Che Liu
- School of Dental Technology, Taipei Medical University, Taipei 110301, Taiwan
- Clinical Research Center, Taipei Medical University Hospital, Taipei 110301, Taiwan
- Department of Urology, Taipei Medical University Hospital, Taipei 110301, Taiwan
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Research Center of Urology and Kidney, Taipei Medical University, Taipei 110301, Taiwan
| | - Pei-Wei Weng
- School of Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235041, Taiwan
- International Ph.D. Program in Biomedical Engineering, Taipei Medical University, Taipei 110301, Taiwan
| | - Sheng-Chang Chen
- School of Medicine, Taipei Medical University, Taipei 110301, Taiwan
| | - Ting-Hao Liu
- Center for General Education, Taipei Medical University, Taipei 110301, Taiwan
| | - Hsiang-Wei Huang
- Department of Medical Education, E-DA Hospital, Kaohsiung 824005, Taiwan
| | - Chang-Ti Huang
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei 110301, Taiwan
| | - Cheng-Tse Yang
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei 110301, Taiwan
| | | | - Ming-Ta Yang
- Clinical Research Center, Taipei Medical University Hospital, Taipei 110301, Taiwan
- Center for General Education, Taipei Medical University, Taipei 110301, Taiwan
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SCD1 is nutritionally and spatially regulated in the intestine and influences systemic postprandial lipid homeostasis and gut-liver crosstalk. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159195. [PMID: 35718096 DOI: 10.1016/j.bbalip.2022.159195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/21/2022] [Accepted: 06/01/2022] [Indexed: 01/27/2023]
Abstract
Stearoyl-CoA desaturase-1 is an endoplasmic reticulum (ER)-membrane resident protein that inserts a double bond into saturated fatty acids, converting them into their monounsaturated counterparts. Previous studies have demonstrated an important role for SCD1 in modulating tissue and systemic health. Specifically, lack of hepatic or cutaneous SCD1 results in significant reductions in tissue esterified lipids. While the intestine is an important site of lipid esterification and assimilation into the body, the regulation of intestinal SCD1 or its impact on lipid composition in the intestine and other tissues has not been investigated. Here we report that unlike other lipogenic enzymes, SCD1 is enriched in the distal small intestine and in the colon of chow-fed mice and is robustly upregulated by acute refeeding of a high-sucrose diet. We generated a mouse model lacking SCD1 specifically in the intestine (iKO mice). These mice have significant reductions not only in intestinal lipids, but also in plasma triacylglycerols, diacylglycerols, cholesterol esters, and free cholesterol. Additionally, hepatic accumulation of diacylglycerols is significantly reduced in iKO mice. Comprehensive targeted lipidomic profiling revealed a consistent reduction in the myristoleic (14:1) to myristic (14:0) acid ratios in intestine, liver, and plasma of iKO mice. Consistent with the reduction of the monounsaturated fatty acid myristoleic acid in hepatic lipids of chow fed iKO mice, hepatic expression of Pgc-1α, Sirt1, and related fatty acid oxidation genes were reduced in chow-fed iKO mice. Further, lack of intestinal SCD1 reduced expression of de novo lipogenic genes in distal intestine of chow-fed mice and in the livers of mice fed a lipogenic high-sucrose diet. Taken together, these studies reveal a novel pattern of expression of SCD1 in the intestine. They also demonstrate that intestinal SCD1 modulates lipid content and composition of not only intestinal tissues, but also that of plasma and liver. Further, these data point to intestinal SCD1 as a modulator of gut-liver crosstalk, potentially through the production of novel signaling lipids such as myristoleic acid. These data have important implications to understanding how intestinal SCD1 may modulate risk for post-prandial lipemia, hepatic steatosis, and related pathologies.
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Ascenzi F, De Vitis C, Maugeri-Saccà M, Napoli C, Ciliberto G, Mancini R. SCD1, autophagy and cancer: implications for therapy. J Exp Clin Cancer Res 2021; 40:265. [PMID: 34429143 PMCID: PMC8383407 DOI: 10.1186/s13046-021-02067-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/09/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Autophagy is an intracellular degradation system that removes unnecessary or dysfunctional components and recycles them for other cellular functions. Over the years, a mutual regulation between lipid metabolism and autophagy has been uncovered. METHODS This is a narrative review discussing the connection between SCD1 and the autophagic process, along with the modality through which this crosstalk can be exploited for therapeutic purposes. RESULTS Fatty acids, depending on the species, can have either activating or inhibitory roles on autophagy. In turn, autophagy regulates the mobilization of fat from cellular deposits, such as lipid droplets, and removes unnecessary lipids to prevent cellular lipotoxicity. This review describes the regulation of autophagy by lipid metabolism in cancer cells, focusing on the role of stearoyl-CoA desaturase 1 (SCD1), the key enzyme involved in the synthesis of monounsaturated fatty acids. SCD1 plays an important role in cancer, promoting cell proliferation and metastasis. The role of autophagy in cancer is more complex since it can act either by protecting against the onset of cancer or by promoting tumor growth. Mounting evidence indicates that autophagy and lipid metabolism are tightly interconnected. CONCLUSION Here, we discuss controversial findings of SCD1 as an autophagy inducer or inhibitor in cancer, highlighting how these activities may result in cancer promotion or inhibition depending upon the degree of cancer heterogeneity and plasticity.
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Affiliation(s)
- Francesca Ascenzi
- Department of Clinical and Molecular Medicine, Sant'Andrea Hospital, "Sapienza" University of Rome, 00161, Rome, Italy
| | - Claudia De Vitis
- Department of Clinical and Molecular Medicine, Sant'Andrea Hospital, "Sapienza" University of Rome, 00161, Rome, Italy
| | - Marcello Maugeri-Saccà
- Division of Medical Oncology 2, IRCCS "Regina Elena" National Cancer Institute, 00144, Rome, Italy
| | - Christian Napoli
- Department of Medical Surgical Sciences and Translational Medicine, "Sapienza" University of Rome, 00189, Rome, Italy
| | - Gennaro Ciliberto
- Scientific Direction, IRCCS "Regina Elena" National Cancer Institute, 00144, Rome, Italy
| | - Rita Mancini
- Department of Clinical and Molecular Medicine, Sant'Andrea Hospital, "Sapienza" University of Rome, 00161, Rome, Italy.
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7
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Wertz PW. Lipid Metabolic Events Underlying the Formation of the Corneocyte Lipid Envelope. Skin Pharmacol Physiol 2021; 34:38-50. [PMID: 33567435 DOI: 10.1159/000513261] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/22/2020] [Indexed: 11/19/2022]
Abstract
Cornified cells of the stratum corneum have a monolayer of an unusual lipid covalently attached to the outer surface. This is referred to as the corneocyte lipid envelope (CLE). It consists of a monolayer of ω-hydroxyceramides covalently attached to the outer surface of the cornified envelope. The CLE is essential for proper barrier function of the skin and is derived from linoleate-rich acylglucosylceramides synthesized in the viable epidermis. Biosynthesis of acylglucosylceramide and its conversion to the cornified envelope is complex. Acylglucosylceramide in the bounding membrane of the lamellar granule is the precursor of the CLE. The acylglucosylceramide in the limiting membrane of the lamellar granule may be oriented with the glucosyl moiety on the inside. Conversion of the acylglucosylceramide to the CLE requires removal of the glucose by action of a glucocerebrosidase. The ester-linked fatty acid may be removed by an as yet unidentified esterase, and the resulting ω-hydroxyceramide may become ester linked to the outer surface of the cornified envelope through action of transglutaminase 1. Prior to removal of ester-linked fatty acids, linoleate is oxidized to an epoxy alcohol through action of 2 lipoxygenases. This can be further oxidized to an epoxy-enone, which can spontaneously attach to the cornified envelope through Schiff's base formation. Mutations of genes coding for enzymes involved in biosynthesis of the CLE result in ichthyosis, often accompanied by neurologic dysfunction. The CLE is recognized as essential for barrier function of skin, but many questions about details of this essentiality remain. What are the relative roles of the 2 mechanisms of lipid attachment? What is the orientation of acylglucosylceramide in the bounding membrane of lamellar granules? Some evidence supports a role for CLE as a scaffold upon which intercellular lamellae unfold, but other evidence does not support this role. There is also controversial evidence for a role in stratum corneum cohesion. Evidence is presented to suggest that covalently bound ω-hydroxyceramides serve as a reservoir for free sphingosine that can serve in communicating with the viable epidermis and act as a potent broad-acting antimicrobial at the skin surface. Many questions remain.
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Monounsaturated Fatty Acids in Obesity-Related Inflammation. Int J Mol Sci 2020; 22:ijms22010330. [PMID: 33396940 PMCID: PMC7795523 DOI: 10.3390/ijms22010330] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 12/14/2022] Open
Abstract
Obesity is an important aspect of the metabolic syndrome and is often associated with chronic inflammation. In this context, inflammation of organs participating in energy homeostasis (such as liver, adipose tissue, muscle and pancreas) leads to the recruitment and activation of macrophages, which secrete pro-inflammatory cytokines. Interleukin-1β secretion, sustained C-reactive protein plasma levels and activation of the NLRP3 inflammasome characterize this inflammation. The Stearoyl-CoA desaturase-1 (SCD1) enzyme is a central regulator of lipid metabolism and fat storage. This enzyme catalyzes the generation of monounsaturated fatty acids (MUFAs)-major components of triglycerides stored in lipid droplets-from saturated fatty acid (SFA) substrates. In this review, we describe the molecular effects of specific classes of fatty acids (saturated and unsaturated) to better understand the impact of different diets (Western versus Mediterranean) on inflammation in a metabolic context. Given the beneficial effects of a MUFA-rich Mediterranean diet, we also present the most recent data on the role of SCD1 activity in the modulation of SFA-induced chronic inflammation.
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9
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Evans EA, Sayers SR, Kodji X, Xia Y, Shaikh M, Rizvi A, Frame J, Brain SD, Philpott MP, Hannen RF, Caton PW. Psoriatic skin inflammation induces a pre-diabetic phenotype via the endocrine actions of skin secretome. Mol Metab 2020; 41:101047. [PMID: 32599074 PMCID: PMC7452265 DOI: 10.1016/j.molmet.2020.101047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE Psoriasis is a chronic inflammatory skin disease that is thought to affect ∼2% of the global population. Psoriasis has been associated with ∼30% increased risk of developing type 2 diabetes (T2D), with numerous studies reporting that psoriasis is an independent risk-factor for T2D, separate from underlying obesity. Separately, studies of skin-specific transgenic mice have reported altered whole-body glucose homeostasis in these models. These studies imply a direct role for skin inflammation and dysfunction in mediating the onset of T2D in psoriasis patients, potentially via the endocrine effects of the skin secretome on key metabolic tissues. We used a combination of in vivo and ex vivo mouse models and ex vivo human imiquimod (IMQ) models to investigate the effects of psoriasis-mediated changes in the skin secretome on whole-body metabolic function. METHODS To induce psoriatic skin inflammation, mice were topically administered 75 mg of 5% IMQ cream (or Vaseline control) to a shaved dorsal region for 4 consecutive days. On day 5, mice were fasted for glucose and insulin tolerance testing, or sacrificed in the fed state with blood and tissues collected for analysis. To determine effects of the skin secretome, mouse skin was collected at day 5 from IMQ mice and cultured for 24 h. Conditioned media (CM) was collected and used 1:1 with fresh media to treat mouse explant subcutaneous adipose tissue (sAT) and isolated pancreatic islets. For human CM experiments, human skin was exposed to 5% IMQ cream for 20 min, ex vivo, to induce a psoriatic phenotype, then cultured for 24 h. CM was collected, combined 1:1 with fresh media and used to treat human sAT ex vivo. Markers of tissue inflammation and metabolic function were determined by qPCR. Beta cell function in isolated islets was measured by dynamic insulin secretion. Beta-cell proliferation was determined by measurement of Ki67 immunofluorescence histochemistry and BrDU uptake, whilst islet apoptosis was assessed by caspase 3/7 activity. All data is expressed as mean ± SEM. RESULTS Topical treatment with IMQ induced a psoriatic-like phenotype in mouse skin, evidenced by thickening, erythema and inflammation of the skin. Topical IMQ treatment induced inflammation and signs of metabolic dysfunction in sub-cutaneous and epidydimal adipose tissue, liver, skeletal muscle and gut tissue. However, consistent with islet compensation and a pre-diabetic phenotype, IMQ mice displayed improved glucose tolerance, increased insulin and c-peptide response to glucose, and increased beta cell proliferation. Treatment of sAT with psoriatic mouse or human skin-CM replicated the in vivo phenotype, leading to increased inflammation and metabolic dysfunction in mouse and human sAT. Treatment of pancreatic islets with psoriatic mouse skin-CM induced increases in beta-proliferation and apoptosis, thus partially replicating the in vivo phenotype. CONCLUSIONS Psoriasis-like skin inflammation induces a pre-diabetic phenotype, characterised by tissue inflammation and markers of metabolic dysfunction, together with islet compensation in mice. The in vivo phenotype is partially replicated by exposure of sAT and pancreatic islets to psoriatic-skin conditioned media. These results support the hypothesis that psoriatic skin inflammation, potentially via the endocrine actions of the skin secretome, may constitute a novel pathophysiological pathway mediating the development of T2D.
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Affiliation(s)
- Elizabeth A Evans
- Department of Diabetes, School of Life Course Sciences, King's College London, UK
| | - Sophie R Sayers
- Department of Diabetes, School of Life Course Sciences, King's College London, UK
| | - Xenia Kodji
- Section of Vascular Biology & Inflammation, School of Cardiovascular Medicine & Sciences, BHF Centre for Cardiovascular Sciences, King's College London, London, UK; A∗STAR - Agency for Science, Technology and Research - SRIS, Singapore
| | - Yue Xia
- Department of Diabetes, School of Life Course Sciences, King's College London, UK
| | - Mahum Shaikh
- Department of Diabetes, School of Life Course Sciences, King's College London, UK
| | - Alizah Rizvi
- Department of Diabetes, School of Life Course Sciences, King's College London, UK
| | - James Frame
- Anglia-Ruskin University, Chelmsford, Essex, UK; Springfield Hospital, Chelmsford, UK
| | - Susan D Brain
- Section of Vascular Biology & Inflammation, School of Cardiovascular Medicine & Sciences, BHF Centre for Cardiovascular Sciences, King's College London, London, UK
| | - Michael P Philpott
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Queen Mary University of London, London, UK
| | - Rosalind F Hannen
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Queen Mary University of London, London, UK
| | - Paul W Caton
- Department of Diabetes, School of Life Course Sciences, King's College London, UK.
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