scholarly journals Free Fatty Acid Receptors in Health and Disease

2020 ◽  
Vol 100 (1) ◽  
pp. 171-210 ◽  
Author(s):  
Ikuo Kimura ◽  
Atsuhiko Ichimura ◽  
Ryuji Ohue-Kitano ◽  
Miki Igarashi
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Future Research ◽  
Biological Responses ◽  
Free Fatty Acid Receptors ◽  
Chain Lengths ◽  
Chain Fatty Acids

Fatty acids are metabolized and synthesized as energy substrates during biological responses. Long- and medium-chain fatty acids derived mainly from dietary triglycerides, and short-chain fatty acids (SCFAs) produced by gut microbial fermentation of the otherwise indigestible dietary fiber, constitute the major sources of free fatty acids (FFAs) in the metabolic network. Recently, increasing evidence indicates that FFAs serve not only as energy sources but also as natural ligands for a group of orphan G protein-coupled receptors (GPCRs) termed free fatty acid receptors (FFARs), essentially intertwining metabolism and immunity in multiple ways, such as via inflammation regulation and secretion of peptide hormones. To date, several FFARs that are activated by the FFAs of various chain lengths have been identified and characterized. In particular, FFAR1 (GPR40) and FFAR4 (GPR120) are activated by long-chain saturated and unsaturated fatty acids, while FFAR3 (GPR41) and FFAR2 (GPR43) are activated by SCFAs, mainly acetate, butyrate, and propionate. In this review, we discuss the recent reports on the key physiological functions of the FFAR-mediated signaling transduction pathways in the regulation of metabolism and immune responses. We also attempt to reveal future research opportunities for developing therapeutics for metabolic and immune disorders.

scholarly journals Free fatty acid receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Celia Briscoe ◽  
Andrew Brown ◽  
Nick Holliday ◽  
Stephen Jenkinson ◽  
Graeme Milligan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Propanoic Acid ◽  
Pentanoic Acid ◽  
Free Fatty Acid Receptors ◽  
Long Chain

Free fatty acid receptors (FFA, nomenclature as agreed by the NC-IUPHAR Subcommittee on free fatty acid receptors [111, 24]) are activated by free fatty acids. Long-chain saturated and unsaturated fatty acids (including C14.0 (myristic acid), C16:0 (palmitic acid), C18:1 (oleic acid), C18:2 (linoleic acid), C18:3, (α-linolenic acid), C20:4 (arachidonic acid), C20:5,n-3 (EPA) and C22:6,n-3 (docosahexaenoic acid)) activate FFA1 [8, 50, 60] and FFA4 receptors [41, 48, 90], while short chain fatty acids (C2 (acetic acid), C3 (propanoic acid), C4 (butyric acid) and C5 (pentanoic acid)) activate FFA2 [9, 62, 86] and FFA3 [9, 62] receptors. The crystal structure for agonist bound FFA1 has been described [108].

scholarly journals The impact of short-chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon

2018 ◽  
Vol 315 (1) ◽  
pp. G53-G65 ◽  
Author(s):  
Charlotte Bayer Christiansen ◽  
Maria Buur Nordskov Gabe ◽  
Berit Svendsen ◽  
Lars Ove Dragsted ◽  
Mette Marie Rosenkilde ◽  
...  
Keyword(s):  
Energy Source ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Rat Colon ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Free Fatty Acid Receptors ◽  
Chain Fatty Acids

The colonic epithelium harbors a large number of endocrine cells, but little is known about the endocrine functions of the colon. However, the high density of glucagon like peptide-1 (GLP-1)- and peptide-YY (PYY)-secreting L cells is of great interest because of the potential antidiabetic and antiobesity effects of GLP-1 and PYY. Short-chain fatty acids (SCFAs) produced by local bacterial fermentation are suggested to activate the colonic free fatty acid receptors FFAR2 (GPR43) and FFAR3 (GPR41), stimulating the colonic L cells. We used the isolated perfused rat colon as a model of colonic endocrine secretion and studied the effects of the predominant SCFAs formed: acetate, propionate, and butyrate. We show that luminal and especially vascular infusion of acetate and butyrate significantly increases colonic GLP-1 secretion, and to a minor extent also PYY secretion, but only after enhancement of intracellular cAMP. Propionate neither affected GLP-1 nor PYY secretion whether administered luminally or vascularly. A FFAR2- and FFAR3–specific agonist [( S)-2-(4-chlorophenyl)-3,3-dimethyl- N-(5-phenylthiazol-2-yl)butamide (CFMB)/ AR420626 ] had no effect on colonic GLP-1 output, and a FFAR3 antagonist ( AR399519 ) did not decrease the SCFA-induced GLP-1 response. However, the voltage-gated Ca2+-channel blocker nifedipine, the KATP-channel opener diazoxide, and the ATP synthesis inhibitor 2,4-dinitrophenol completely abolished the responses. FFAR2 receptor studies confirmed low-potent partial agonism of acetate, propionate, and butyrate, compared with CFMB, which is a full agonist with ~750-fold higher potency than the SCFAs. In conclusion, SCFAs may increase colonic GLP-1/PYY secretion, but FFAR2/FFAR3 do not seem to be involved. Rather, SCFAs are metabolized and appear to function as a colonocyte energy source.NEW & NOTEWORTHY By the use of in situ isolated perfused rat colon we show that short-chain fatty acids (SCFAs) primarily are used as a colonocyte energy source in the rat, subsequently triggering glucagon like peptide-1 (GLP-1) secretion independent of the free fatty acid receptors FFAR2 and FFAR3. Opposite many previous studies on SCFAs and FFAR2/FFAR3 and GLP-1 secretion, this experimental model allows investigation of the physiological interactions between luminal nutrients and secretion from cells whose function depend critically on their blood supply as well as nerve and paracrine interactions.

scholarly journals Free Fatty Acid Receptors (FFARs) In Adipose: Physiological Role and Therapeutic Outlook

2021 ◽  
Author(s):  
Saeed Al Mahri ◽  
Shuja Shafi Malik ◽  
Maria Al Ibrahim ◽  
Esraa Haji ◽  
Ghida Dairi ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Metabolic Regulation ◽  
Physiological Role ◽  
Short Chain Fatty Acids ◽  
Whole Body ◽  
Chain Fatty Acids

Fatty acids (FFAs) are important biological molecules that serve as a major energy source and are key components of biological membranes. Besides, FFAs play important roles in metabolic regulation and contribute to the development and progression of metabolic disorders like diabetes. Recent studies have shown that FFAs can act as important ligands of G-protein coupled receptors (GPCRs) on the surface of cells and impact key physiological processes. Free fatty acid activated receptors include FFAR1 (GPR40), FFAR2 (GPR43), FFAR3 (GPR41) and FFAR4 (GPR120). FFAR2 and FFAR3are activated by short chain fatty acids like acetate, propionate and butyrate whereas FFAR1 and FFAR4 are activated by medium and long chain fatty acids like palmitate, oleate, linoleate and others. FFARs have generated considerable attention over the last few years and have become attractive pharmacological targets in the treatment of type 2 diabetes and metabolic syndrome. Several lines of evidence point to their importance in the regulation of whole-body metabolic homeostasis including adipose metabolism. Here we summarize our current understanding of the physiological functions of FFAR isoforms in adipose biology and explore the prospect of FFAR based therapies to treat patients with obesity and Type 2 Diabetes.

scholarly journals Fatty acid composition of milk fat in milk of Tzigay sheep and their F2 cross-breeds with Chios

2015 ◽  
Vol 31 (1) ◽  
pp. 45-53
Author(s):  
G. Gerchev ◽  
N. Naydenova ◽  
S. Slavkova ◽  
G. Mihaylova
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Milk Fat ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Milk Samples ◽  
Chain Fatty Acids

The study was conducted on aggregate milk samples, which were taken every month during the milking period from Tzigay sheep and their F2 cross-breeds of Chios, raised in the conditions of the Central Balkan Mountain. The fat extraction of milk samples was done by the Rose-Gottlieb method. Fatty acid composition was determined on a gas chromatograph with flame ionization detector and capillary column. The aim of the study was to follow the changes in the composition of fatty acids in the milk fat of milk of Tzigay sheep and their F2 cross-breeds. The saturated fatty acids in milk of the two groups had high values during both consecutive years, as they varied from 67.05% in milk of Tzigay sheep in the second lactation up to 70.87% at their F2 cross-breeds. The content of myristic acid was correspondingly 8.22-8.88% at Tzigay sheep and 8.45-8.74% at their F2 cross-breeds. The total amount of polyunsaturated fatty acids in the examined milk for the two types of sheep was comparatively low with near concentrations (4.39-5.20%) in the period of the two years. The milk of the two groups had high values of the correlation SFA/PUSFA (15.71 and 13.17) and low values of PUSFA/SFA (0.06-0.08). Mon?unsaturated fatty acids, represented mainly by the oleic acid (C18:1) varied during both periods from 21.92% to 25.32% and appeared as a substratum in the synthesis of CLA. The short-chain fatty acids (C4:0-C11:0) had higher values in Tzigay sheep in comparison with F2 cross-breeds of Chios. The long-chain fatty acids (C17iso-C25:0) maintained close concentration in the milk of Tzigay breed, while their content in the milk of F2 cross-breeds was increased.

scholarly journals Free Fatty acids receptors (FFAR2 and FFAR3) control cell proliferation by regulating cellular glucose uptake

2019 ◽  
Author(s):  
Mohammad Aziz ◽  
Saeed Al Mahri ◽  
Amal Alghamdi ◽  
Maaged AlAkiel ◽  
Monira Al Aujan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fatty Acids ◽  
Cell Proliferation ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Glucose Uptake ◽  
Microarray Data ◽  
Free Fatty Acid Receptors

Abstract Background Colorectal cancer is a worldwide problem which has been associated with changes in diet and lifestyle pattern. As a result of colonic fermentation of dietary fibres, short chain free fatty acids are generated which activate Free Fatty Acid Receptors 2 and 3 (FFAR2 and FFAR3). FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells. Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis. Methods Transcriptome analysis console was used to analyse microarray data from patients and cell lines. We employed shRNA mediated down regulation of FFAR2 and FFAR3 genes which was assessed using qRT-PCR. Assays for glucose uptake and cAMP generation was done along with immunofluorescence studies. For measuring cell proliferation, we employed real time electrical impedance based assay available from xCelligence. Results Microarray data analysis of colorectal cancer patient samples showed a significant down regulation of FFAR2 gene expression. This prompted us to study the FFAR2 in colorectal cancer. Since, FFAR3 shares significant structural and functional homology with FFAR2, we knocked down both these receptors in colorectal cancer cell line HCT 116. These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of GLUT1. Since, FFAR2 and FFAR3 signal through G protein subunit (Gαi), knockdown of these receptors was associated with increased cAMP. Inhibition of PKA did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway. Conclusion: Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of protein kinase A mediated cAMP signalling. Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes. This study paves the way to understand the mechanism of action of short chain free fatty acid receptors in colorectal cancer.

scholarly journals Acute postprandial effect of hydrogenated fish oil, palm oil and lard on plasma cholesterol, triacylglycerol and non-esterified fatty acid metabolism in normocholesterolaemic males

2006 ◽  
Vol 95 (4) ◽  
pp. 787-794 ◽  
Author(s):  
Marie M. Cantwell ◽  
Mary A.T. Flynn ◽  
Michael J. Gibney
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fish Oil ◽  
Palm Oil ◽  
Unsaturated Fatty Acids ◽  
Lipid Analysis ◽  
Plasma Cholesterol ◽  
Random Order ◽  
Postprandial Response ◽  
Chain Fatty Acids

The majority of research has focused on the association betweentransunsaturated fatty acids (TUFA) from hydrogenated vegetable oils and heart disease even though TUFA are also produced from hydrogenated fish oil. We compared the acute effect of three solid fats on postprandial cholesterol, triacylglycerol (TAG) and NEFA concentrations in normocholesterolaemic males. Eight healthy male volunteers consumed each of the three 40g fat meals (partially hydrogenated fish oil (PHFO), palm oil and lard) in random order and blood samples were drawn at 2, 4, 6 and 8h thereafter for lipid analysis. The postprandial response in plasma TAG, TAG-rich lipoprotein-TAG (TRL-TAG), total cholesterol and plasma NEFA, measured as the area under the postprandial curve, was not significantly different between the three meals (p>0·05), which varied in MUFA, PUFA and TUFA content. There was no marked elevation of longer-chain fatty acids (C20–22,cisortransisomers) into the TRL-TAG fraction following the PHFO meal even though they provided 40% of the total fatty acids in the PHFO meal. The postprandial TRL-TAG response to PHFO was expected to be higher, as it is higher in TUFA, lower in PUFA and similar in saturated fatty acid composition compared with the lard and palm oil test meals. The absence of a higher postprandial response following ingestion of PHFO could be as a result of reduced absorption and increased oxidation of long-chain fatty acids (bothcisandtransisomers)

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