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Panezai J, van Dyke T. Polyunsaturated Fatty Acids and Their Immunomodulatory Actions in Periodontal Disease. Nutrients 2023; 15:nu15040821. [PMID: 36839179 PMCID: PMC9965392 DOI: 10.3390/nu15040821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/20/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023] Open
Abstract
Polyunsaturated fatty acids (PUFAs) are a diverse set of molecules with remarkable contributions to human physiology. They not only serve as sources of fuel but also cellular structural components as well as substrates that provide bioactive metabolites. A growing body of evidence demonstrates their role in inflammation. Inflammation in the presence of a polymicrobial biofilm contributes to the pathology of periodontitis. The role PUFAs in modulating immuno-inflammatory reactions in periodontitis is only beginning to be uncovered as research continues to unravel their far-reaching immunologic implications.
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Affiliation(s)
- Jeneen Panezai
- Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Microbiology, Faculty of Life Sciences and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta 87300, Pakistan
| | - Thomas van Dyke
- Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA 02142, USA
- Centre for Clinical and Translational Research, The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Oral Medicine, Infection and Immunity, Harvard Faculty of Medicine, Boston, MA 02115, USA
- Correspondence:
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Izquierdo-Lahuerta A. The Parathyroid Hormone-Related Protein/Parathyroid Hormone 1 Receptor Axis in Adipose Tissue. Biomolecules 2021; 11:biom11111570. [PMID: 34827568 PMCID: PMC8615885 DOI: 10.3390/biom11111570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 10/10/2021] [Accepted: 10/20/2021] [Indexed: 12/02/2022] Open
Abstract
Adipose tissue is an organ that shows great plasticity and is able to adapt to the conditions to which the body is subdued. It participates in the regulation of energetic homeostasis and has endocrine functions. Recent studies have shown how the parathyroid hormone-related protein (PTHrP)/Parathyroid Hormone Receptor 1 (PTH1R) axis participates in the regulation of adipogenesis, opposing the action of Peroxisome proliferator-activated receptor gamma (PPARγ). In addition to this, PTHrP is overexpressed in adipose tissue in situations of wear and tear of the body, favoring browning and lipolysis in this tissue. It is also overexpressed in adipose tissue in stressful situations but in the opposite direction, in obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM). In conclusion, the PTHrP/PTH1R axis has a main role in adipose tissue, participating in its differentiation and remodeling. PTHrP might be used in obesity treatment and its complications for its ability to reprogram adipogenesis and adipose tissue expansion, WAT browning and for the improvement of the insulin sensitivity. In addition, PTHrP could even be used as a marker of placental status and maternal adaptations to prevent future metabolic problems in mothers and children, as well as in the treatment of bone-related diseases such as osteoporosis.
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Affiliation(s)
- Adriana Izquierdo-Lahuerta
- Area of Biochemistry and Molecular Biology, Department of Basic Sciences of Health, Faculty of Sciences of Health, Campus of Alcorcón, University Rey Juan Carlos, 28922 Madrid, Spain
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Metabolomic Analysis Reveals Changes in Plasma Metabolites in Response to Acute Cold Stress and Their Relationships to Metabolic Health in Cold-Acclimatized Humans. Metabolites 2021; 11:metabo11090619. [PMID: 34564435 PMCID: PMC8468536 DOI: 10.3390/metabo11090619] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/08/2021] [Indexed: 11/29/2022] Open
Abstract
Cold exposure results in activation of metabolic processes required for fueling thermogenesis, potentially promoting improved metabolic health. However, the metabolic complexity underlying this process is not completely understood. We aimed to analyze changes in plasma metabolites related to acute cold exposure and their relationship to cold-acclimatization level and metabolic health in cold-acclimatized humans. Blood samples were obtained before and acutely after 10–15 min of ice-water swimming (<5 °C) from 14 ice-water swimmers. Using mass spectrometry, 973 plasma metabolites were measured. Ice-water swimming induced acute changes in 70 metabolites. Pathways related to amino acid metabolism were the most cold-affected and cold-induced changes in several amino acids correlated with cold-acclimatization level and/or metabolic health markers, including atherogenic lipid profile or insulin resistance. Metabolites correlating with cold-acclimatization level were enriched in the linoleic/α-linolenic acid metabolic pathway. N-lactoyl-tryptophan correlated with both cold-acclimatization level and cold-induced changes in thyroid and parathyroid hormones. Acute cold stress in cold-acclimatized humans induces changes in plasma metabolome that involve amino acids metabolism, while the linoleic and α-linolenic acid metabolism pathway seems to be affected by regular cold exposure. Metabolites related to metabolic health, thermogenic hormonal regulators and acclimatization level might represent prospective molecular factors important in metabolic adaptations to regular cold exposure.
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Alhabeeb H, Kord-Varkaneh H, Tan SC, Găman MA, Otayf BY, Qadri AA, Alomar O, Salem H, Al-Badawi IA, Abu-Zaid A. The influence of omega-3 supplementation on vitamin D levels in humans: a systematic review and dose-response meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr 2020; 62:3116-3123. [PMID: 33356450 DOI: 10.1080/10408398.2020.1863905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Inconsistencies exist with regard to the influence of omega-3 supplementation on 25-hydroxyvitamin D (25(OH)D) levels, which could be attributed to many factors, such as the duration and dose of omega-3 supplementation, and individuals' baseline 25(OH)D levels. Therefore, to address the inconsistencies, we conducted a systematic review and dose-response meta-analysis to accurately determine the effect of omega-3 supplementation on 25(OH)D levels in humans. METHODS We performed a comprehensive literature search in Web of Science, PubMed/Medline, Scopus, and Embase databases from inception up to January 2020. We included only randomized controlled trials (RCTs). We used weighted mean difference (WMD) with 95% confidence interval (CI) to assess the influence of omega-3 supplementation on serum 25(OH)D levels using the random-effects model. RESULTS Our pooled results of 10 RCTs demonstrated an overall significant increase in 25(OH)D levels following omega-3 intake (WMD = 3.77 ng/ml, 95% CI: 1.29, 6.25). In addition, 25(OH)D levels were significantly increased when the intervention duration lasted >8 weeks and when the baseline serum 25(OH)D level was ˂20 ng/ml. Moreover, omega-3 intake ≤1000 mg/day resulted in higher 25(OH)D levels compared to omega-3 intake >1000 mg/day. CONCLUSION In conclusion, omega-3 supplementation increased 25(OH)D concentrations, particularly with dosages ≤1000 mg/day and intervention durations >8 weeks.
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Affiliation(s)
- Habeeb Alhabeeb
- Clinical Research, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Hamed Kord-Varkaneh
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shing Cheng Tan
- UKM Medical Molecular Biology Institute, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | | | | | | | - Osama Alomar
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Hany Salem
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ismail A Al-Badawi
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ahmed Abu-Zaid
- Department of Pharmacology, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Bao M, Zhang K, Wei Y, Hua W, Gao Y, Li X, Ye L. Therapeutic potentials and modulatory mechanisms of fatty acids in bone. Cell Prolif 2019; 53:e12735. [PMID: 31797479 PMCID: PMC7046483 DOI: 10.1111/cpr.12735] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/02/2019] [Accepted: 11/05/2019] [Indexed: 02/05/2023] Open
Abstract
Bone metabolism is a lifelong process that includes bone formation and resorption. Osteoblasts and osteoclasts are the predominant cell types associated with bone metabolism, which is facilitated by other cells such as bone marrow mesenchymal stem cells (BMMSCs), osteocytes and chondrocytes. As an important component in our daily diet, fatty acids are mainly categorized as long‐chain fatty acids including polyunsaturated fatty acids (LCPUFAs), monounsaturated fatty acids (LCMUFAs), saturated fatty acids (LCSFAs), medium‐/short‐chain fatty acids (MCFAs/SCFAs) as well as their metabolites. Fatty acids are closely associated with bone metabolism and associated bone disorders. In this review, we summarized the important roles and potential therapeutic implications of fatty acids in multiple bone disorders, reviewed the diverse range of critical effects displayed by fatty acids on bone metabolism, and elucidated their modulatory roles and mechanisms on specific bone cell types. The evidence supporting close implications of fatty acids in bone metabolism and disorders suggests fatty acids as potential therapeutic and nutritional agents for the treatment and prevention of metabolic bone diseases.
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Affiliation(s)
- Minyue Bao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Kaiwen Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yangyini Wei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Weihan Hua
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yanzi Gao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xin Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ling Ye
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Tsuji T, Matsumoto M, Nakamura M, Miyamoto T, Yagi M, Fujita N, Okada E, Nagoshi N, Tsuji O, Watanabe K. Metabolite profiling of plasma in patients with ossification of the posterior longitudinal ligament. J Orthop Sci 2018; 23:878-883. [PMID: 30075996 DOI: 10.1016/j.jos.2018.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/30/2018] [Accepted: 07/02/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND Metabolomics is one of the "omics" technologies, and is a comprehensive analysis of small molecule metabolites which include amino acid, nucleotides, carbohydrates and fatty acid. The purpose of the present study was to compare the differences of metabolite profiling between patients with ossification of the posterior longitudinal ligament (OPLL) and control subjects. METHODS We analyzed plasma metabolites in patients with cervical OPLL (n = 10) and in control subjects (n = 10). Ionic metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) and lipophilic metabolites were analyzed using liquid chromatograph time-of-flight mass spectrometry (LC-TOFMS). RESULTS A total of 259 metabolites (144 metabolites in CE-TOFMS and 115 metabolites in LC-TOFMS) were detected. Among the 259 metabolites, six metabolites, namely acylcarnitine (AC) (14:0), palmitoylcarnitine, AC (18:2), fatty acid (FA) (24:2), thyroxine, thiaproline were significantly larger in OPLL group, even in analyzes excluding patients with diabetes mellitus and hyperlipidemia. CONCLUSIONS We examined the metabolite profiling in patients with OPLL for the first time and detected six metabolites showing suggestive association with disease. These results of the present study could lead to new insights into clarifying the molecular pathomechanisms of OPLL.
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Affiliation(s)
- Takashi Tsuji
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Orthopaedic Surgery, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan; Department of Orthopaedic Surgery, Kitasato University Kitasato Institute Hospital, 5-9-1 Shirokane, Minato, Tokyo, 108-8642, Japan.
| | - Morio Matsumoto
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Masaya Nakamura
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Takeshi Miyamoto
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Mitsuru Yagi
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Nobuyuki Fujita
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Eijiro Okada
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Narihito Nagoshi
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Osahiko Tsuji
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Kota Watanabe
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
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Mao L, Wang M, Li Y, Liu Y, Wang J, Xue C. Docosahexaenoic acid‐containing phosphatidylcholine induced osteoblastic differentiation by modulating key transcription factors. J Food Biochem 2018. [DOI: 10.1111/jfbc.12661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Lei Mao
- College of Food Science and Engineering Ocean University of China Qingdao China
| | - Meiling Wang
- College of Food Science and Engineering Ocean University of China Qingdao China
| | - Yuanyuan Li
- College of Food Science and Engineering Ocean University of China Qingdao China
| | - Yaxuan Liu
- College of Food Science and Engineering Ocean University of China Qingdao China
| | - Jingfeng Wang
- College of Food Science and Engineering Ocean University of China Qingdao China
| | - Changhu Xue
- College of Food Science and Engineering Ocean University of China Qingdao China
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Das M, Das S. Docosahexaenoic Acid (DHA) Induced Morphological Differentiation of Astrocytes Is Associated with Transcriptional Upregulation and Endocytosis of β 2-AR. Mol Neurobiol 2018; 56:2685-2702. [PMID: 30054857 DOI: 10.1007/s12035-018-1260-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/17/2018] [Indexed: 12/24/2022]
Abstract
Docosahexaenoic acid (DHA), an important ω-3 fatty acid, is abundantly present in the central nervous system and is important in every step of brain development. Much of this knowledge has been based on studies of the role of DHA in the function of the neurons, and reports on its effect on the glial cells are few and far between. We have previously reported that DHA facilitates astrocyte differentiation in primary culture. We have further explored the signaling mechanism associated with this event. It was observed that a sustained activation of the extracellular signal-regulated kinase (ERK) appeared to be critical for DHA-induced differentiation of the cultured astrocytes. Prior exposure to different endocytic inhibitors blocked both ERK activation and differentiation of the astrocytes during DHA treatment suggesting that the observed induction of ERK-2 was purely endosomal. Unlike the β1-adrenergic receptor (β1-AR) antagonist, atenolol, pre-treatment of the cells with the β2-adrenergic receptor (β2-AR) antagonist, ICI-118,551 inhibited the DHA-induced differentiation process, indicating a downstream involvement of β2-AR in the differentiation process. qRT-PCR and western blot analysis demonstrated a significant induction in the mRNA and protein expression of β2-AR at 18-24 h of DHA treatment, suggesting that the induction of β2-AR may be due to transcriptional upregulation. Moreover, DHA caused activation of PKA at 6 h, followed by activation of downstream cAMP response element-binding protein, a known transcription factor for β2-AR. Altogether, the observations suggest that DHA upregulates β2-AR in astrocytes, which undergo endocytosis and signals for sustained endosomal ERK activation to drive the differentiation process.
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Affiliation(s)
- Moitreyi Das
- Neurobiology Division, Cell Biology & Physiology Department, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India
| | - Sumantra Das
- Neurobiology Division, Cell Biology & Physiology Department, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
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Baia LC, Van den Berg E, Vervloet MG, Heilberg IP, Navis G, Bakker SJL, Geleijnse JM, Kromhout D, Soedamah-Muthu SS, De Borst MH. Fish and omega-3 fatty acid intake in relation to circulating fibroblast growth factor 23 levels in renal transplant recipients. Nutr Metab Cardiovasc Dis 2014; 24:1310-1316. [PMID: 25063539 DOI: 10.1016/j.numecd.2014.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/16/2014] [Accepted: 06/15/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIMS A high circulating fibroblast growth factor 23 (FGF23) level is an independent risk factor for cardiovascular mortality in renal transplant recipients and the general population. N-3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) may contribute to cardiovascular risk reduction. We investigated whether fish and EPA-DHA intake are related to FGF23 levels in renal transplant recipients. METHODS AND RESULTS We performed a cross-sectional analysis in 619 stable renal transplant recipients (mean age 53 years, 57% male, estimated glomerular filtration rate [eGFR] 53 ± 20 mL/min/1.73 m(2)). Dietary intake was assessed by a 177-item food frequency questionnaire. Serum intact FGF23 was measured by ELISA. We examined differences in FGF23 levels across categories of fish and EPA-DHA intake using analysis of variance models adjusted for age, sex, dietary and lifestyle factors and key determinants of FGF23. Patients consumed on average 15 g of fish and 139 mg EPA-DHA/day. Median FGF23 was 62 pg/mL (IQR 43-98 pg/mL). Higher dietary EPA-DHA and fish intake were associated with lower serum FGF23 levels. Subgroup analyses revealed that particularly in patients with reduced renal function (eGFR <60 mL/min/1.73 m(2)), adjusted FGF23 levels (114, 79, 75 pg/mL, P = 0.0001) were inversely associated with tertiles of EPA-DHA intake. Similarly, we observed an inverse association between fish consumption and serum FGF23 levels in adjusted analyses. CONCLUSION A higher intake of fish and dietary n-3 fatty acids (EPA-DHA) is related to lower circulating FGF23 levels in renal transplant recipients. Further research is needed to assess the causality of this association and the clinical implications.
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Affiliation(s)
- L C Baia
- Department of Nephrology, University Medical Center Groningen and University of Groningen, The Netherlands; Department of Nephrology, Federal University of São Paulo, São Paulo, Brazil
| | - E Van den Berg
- Department of Nephrology, University Medical Center Groningen and University of Groningen, The Netherlands
| | - M G Vervloet
- Department of Nephrology, VU University Medical Center Amsterdam, The Netherlands
| | - I P Heilberg
- Department of Nephrology, Federal University of São Paulo, São Paulo, Brazil
| | - G Navis
- Department of Nephrology, University Medical Center Groningen and University of Groningen, The Netherlands
| | - S J L Bakker
- Department of Nephrology, University Medical Center Groningen and University of Groningen, The Netherlands
| | - J M Geleijnse
- Division of Human Nutrition, Wageningen University, The Netherlands
| | - D Kromhout
- Division of Human Nutrition, Wageningen University, The Netherlands
| | | | - M H De Borst
- Department of Nephrology, University Medical Center Groningen and University of Groningen, The Netherlands.
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Candelario J, Chachisvilis M. Activity of Bradykinin B2 Receptor Is Regulated by Long-Chain Polyunsaturated Fatty Acids. PLoS One 2013; 8:e68151. [PMID: 23826374 PMCID: PMC3694885 DOI: 10.1371/journal.pone.0068151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/26/2013] [Indexed: 01/22/2023] Open
Abstract
The molecular and cellular mechanisms by which long-chain polyunsaturated fatty acids (LCPUFA) exert their beneficial effects on cardiovascular health remain obscure. While both LCPUFA and bradykinin (BK) signaling pathway play a role in the cardiovascular system, any direct link between the two is yet to be established. Using picosecond time-resolved fluorescence microscopy and a genetically engineered bradykinin B2 receptor (B2R) sensor (B2K-CC), we detected LCPUFA-induced conformational responses in the B2R similar to those caused by its cognate ligand, BK. The selective B2R antagonist (HOE-140) blocked the eicosapentaenoic acid (EPA, C20∶5, n-3) induced conformational response of the B2K-CC. Further analysis suggests that LCPUFA are capable of direct, B2R-dependent activation of extracellular ligand-regulated kinases (ERK). From a wide range of fatty acids studied, varying in chain length, saturation, and position of double bonds, EPA, docosahexaenoic (DHA, C22∶6, n-3), docosadienoic (DDA, C22∶2, n-6), and dihomo-gamma linoleic (DGLA, C20∶3, n-6) fatty acids caused the highest ERK phosphorylation. EPA or DHA dependent ERK phosphorylation was inhibited by the selective B2R antagonist. We show that LCPUFA stimulates downstream signaling by B2R such as B2R-dependent phosphorylation and expression regulation of endothelial nitric-oxide synthase (eNOS). Further analysis indicated that LCPUFA also alters levels of the eNOS transcription factor, kruppel-like factor 2 (KLF2). Moreover we show that EPA increases membrane fluidity on the same time scale as B2R conformational response, suggesting that partitioning of LCPUFA into bilayer is a primary step required for receptor activation. In summary our data show that LCPUFA activate B2R receptor at nanomolar concentrations suggesting a novel molecular mechanism by which fatty acids may affect the cardiovascular system.
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Affiliation(s)
- Jose Candelario
- La Jolla Bioengineering Institute, San Diego, California, United States of America
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