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SHR0534 is being developed for type-2 diabetes mellitus. Herein the tolerability, safety, pharmacokinetics and pharmacodynamics of SHR0534 in healthy Chinese subjects were assessed in a phase-I, randomized, double-blind, placebo-controlled, single- and multiple-ascending dose study. Forty subjects were randomized 4:1 to receive SHR0534 at the dose of 10, 25, 50 or 100 mg, or placebo, and another eleven subjects were allocated to either the 5 mg group or the placebo group at an 8:3 ratio. All subjects received a single dose on day 1, followed by a 9-day washout and once-daily administrations for 14 consecutive days. Serial samples were collected, and vital signs, electrocardiograms, laboratory tests, urinalysis and adverse events (AEs) were recorded. All doses of SHR0534 were safe and well tolerated with infrequent, generally mild-to-moderate AEs and no serious AEs in the study. SHR0534 was absorbed with a

Free fatty acid receptor-1 (FFA1) agonists have been considered for a long time as a potentially new class for the treatment of type 2 diabetes mellitus. Phenylpropanoic acid is the preferred scaffold in the development of FFA1 receptor agonists. This review analyzes the effect of structural fragments of phenylpropanoic acid-based agonists on receptor affinity, selectivity, biocompatibility, and metabolic stability. Current trends in the design of FFA1 receptor agonists are discussed.

Free fatty acid receptor 1 (FFA1) and FFA4 belong to a family of free fatty acid (FFA) receptors. FFA1- and FFA4-mediated signaling regulates a variety of malignant properties in cancer cells. It is known that stromal cells in the tumor microenvironment promote tumor progression. In the present study, to assess the roles of FFA1 and FFA4 in cellular functions modulated by endothelial cells, highly migratory MG63-CR7(F2) cells were generated from osteosarcoma MG-63 cells, using endothelial F2 cell supernatants. Expression levels of

We examined whether the acetylenic fatty acids 6-octadecynoic acid (6-ODA) and 9-octadecynoic acid (9-ODA) perform as ligands for free fatty acid receptors of medium- and long-chain fatty acids FFAR1 and FFAR4, previously called GPR40 and GPR120, respectively. Phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 was increased through FFAR1 but not through FFAR4 expressed in HEK 293 cells, suggesting that 6-ODA and 9-ODA function as an FFAR1 ligand, but not as an FFAR4 ligand. Activation of ERK in FFAR1-expressing HEK293 cells by 6-ODA and 9-ODA peaked at 10 min after stimulation followed by a slow decrease, similar to ERK activation by rosiglitazone, which peaked at 10 min after stimulation and lasted longer. Glucose-dependent production of insulin from MIN6 insulinoma cells was induced by 6-ODA and 9-ODA in an FFAR1-dependent manner. In this process, 6-ODA and 9-ODA stimulated the production of insulin not in the first phase that occurred within 10 min after stimulation but in the second phase. F-actin-remodeling that reflects insulin granule recruiting to the plasma membrane in the second phase of insulin secretion by 6-ODA and 9-ODA suggested that they have an FFAR1-dependent function in insulin secretion from MIN6 cells.

Objective: Investigate the involvement of the fatty acids receptor GPR40 in the assembly and activation of NADPH oxidase and the implications on pancreatic β-cell function. Methods: BRIN-BD11 β-cells were exposed to GPR40 agonist (GW9508) or linoleic acid in different glucose concentrations. Superoxide and H2O2 were analyzed, respectively, by DHE fluorescence and by fluorescence of the H2O2 sensor, roGFP2-Orp1. Protein contents of p47phox in plasma membrane and cytosol were analyzed by western blot. NADPH oxidase role was evaluated by p22phox siRNA or by pharmacological inhibition with VAS2870. NOX2 KO islets were used to measure total cytosolic calcium and insulin secretion. Results: GW9508 and linoleic acid increased superoxide and H2O2 contents at 5.6 and 8.3 mM of glucose. In addition, in 5.6 mM, but not at 16.7 mM of glucose, activation of GPR40 led to the translocation of p47phox to the plasma membrane. Knockdown of p22phox abolished the increase in superoxide after GW9508 and linoleic acid. No differences in insulin secretion were found between wild type and NOX2 KO islets treated with GW9508 or linoleic acid. Discussion: We report for the first time that acute activation of GPR40 leads to NADPH oxidase activation in pancreatic β-cells, without impact on insulin secretion.

Citrus fruits and juices have been studied extensively for their potential involvement in the prevention of various diseases. Flavanones, the characteristic polyphenols of citrus species, are the primarily compounds responsible for these studied health benefits. Using in silico and in vitro methods, we are exploring the possible antidiabetic action of narirutin, a flavanone family member. The goal of the in silico research was to anticipate how narirutin would interact with eight distinct receptors implicated in diabetes control and complications, namely, dipeptidyl-peptidase 4 (DPP4), protein tyrosine phosphatase 1B (PTP1B), free fatty acid receptor 1 (FFAR1), aldose reductase (AldR), glycogen phosphorylase (GP), alpha-amylase (AAM), peroxisome proliferator-activated receptor gamma (PPAR-γ), alpha-glucosidase (AGL), while the in vitro study looked into narirutin’s possible inhibitory impact on alpha-amylase and alpha-glucosidase. The results indicate that the studied citrus flavanone interacted remarkably with most of the receptors and had an excellent inhibitory activity during the in vitro tests suggesting its potent role among the different constituent of the citrus compounds in the management of diabetes and also its complications.

GPR40 (FFAR1) is a promising target for the managing type 2 diabetes (T2D). The most advanced GPR40 agonist TAK-875 exhibited satisfactory glucose-lowering effects in phase II and III studies. However, the phase III studies of TAK-875 revealed drug-induced liver injury (DILI). It is unknown whether DILI is a consequence of a specific GPR40 agonist or is an inherent feature of all GPR40 agonists. CPL207280 is a novel GPR40 agonist that improves diabetes in Zucker Diabetic Fatty (ZDF) rats, Goto Kakizaki (GK) rats and db/db mice. In this report, the DILI-related toxicity of CPL207280 was compared directly with that of TAK-875. In vitro studies evaluating hepatic biliary transporter inhibition, mitochondrial function, and metabolic profiling were performed in hepatocytes from different species. The long term toxicity of CPL207280 was studied in vivo in rats and monkeys. Activity of CPL207280 was one order of magnitude lesser than that of TAK-875 for the inhibition of bile acid transporters. CPL207280 had a negligible effect on the hepatic mitochondria. In contrast to TAK-875, which was metabolized through toxic glucuronidation, CPL207280 was metabolized mainly through oxidation. No deleterious hepatic effects were observed in chronically treated healthy and diabetic animals. The study presents promising data on the feasibility of creating a liver-safe GPR40 agonist. Additionally, it can be concluded that DILI is not a hallmark of GPR40 agonists; it is linked to the intrinsic properties of an individual agonist.

The free fatty acid receptor 1 (FFAR1) is a class A G-protein coupled receptor and a validated target to develop antidiabetic drugs. The present work describes the quantitative structure–activity relationship (QSAR) study of a series of 4-alkynyldihydrocinnamic acid analogs to rationalize their FFAR1 agonist activity. The various physicochemical and structural descriptors were derived from Molecular Operating Environment (MOE, 2011). The variable selection and model development were carried out using Combinatorial Protocol in Multiple Linear Regressions (CP-MLR) approach. The identified QSAR models highlighted the significance of solvent accessible surface area and associated hydrophobicity to the biological activity. The chemical features to improve hydrophobicity of 4-alkynyldihydrocinnamic acid analogs have been discussed. Keywords: Free fatty acid receptor 1, GPR40, QSAR, CP-MLR, Physicochemical property

The G-protein-coupled receptor 40 (GPR40) is an attractive molecular target for the treatment of type 2 diabetes mellitus. Previously, based on the natural oleic acid substrate, an exogenous ligand for this receptor, named AV1, was synthesized. In this context, here we validated the activity of AV1 as a full agonist, while the corresponding catechol analogue, named AV2, was investigated for the first time. The ligand-protein interaction between this new molecule and the receptor was highlighted in the lower portion of the GPR40 groove that generally accommodates DC260126. The functional assays performed have demonstrated that AV2 is a suitable GPR40 partial agonist, showing a therapeutic potential and representing a useful tool in the management of type 2 diabetes.

GPR40 (FFAR1 or FFA1) is a G protein-coupled receptor, primarily expressed in pancreatic islet β-cells and intestinal enteroendocrine cells. When activated by fatty acids, GPR40 elicits increased insulin secretion from islet β-cells only in the presence of elevated glucose levels. Towards this end, studies were undertaken towards discovering a novel GPR40 Agonist whose mode of action is via Positive Allosteric Modulation of the GPR40 receptor (AgoPAM). Efforts were made to identify a suitable GPR40 AgoPAM tool molecule to investigate mechanism of action and de-risk liver toxicity of GPR40 AgoPAMs due to reactive acyl-glucuronide (AG) metabolites.

The free fatty acid receptor 1 (FFA1) is considered as a promising anti-diabetic target based on its function of glucose-stimulated insulin secretion. The previously reported compound 2 is a highly potent FFA1 agonist, but it might be suffered from poor pharmacokinetic properties because the phenylpropanoic acid is vulnerable to β-oxidation. To identify orally available analogs, we tried to block the route of β-oxidation by incorporating deuterium at phenylpropionic acid moiety. As expected, the deuterium-based analogs 3 and 4 exhibited better pharmacokinetic properties than parent compound 2. Although the difference of potency between compound 2 and 3 is quite small, the glucose-lowering effect of deuterium analog 3 was better than that of compound 2. Meanwhile, compound 3 docked well into the same binding pocket of TAK-875, and formed almost identical interactions of TAK-875 in binding site. Different from glibenclamide, a lower risk of hypoglycemia was observed in compound 3 even at the high dose of 60 mg/kg.

Background Fatty acids (FAs), and especially monounsaturated FAs (MUFAs) stimulate GLP-1 release. However, lipotoxicity is indicated in GLP-1 secreting cells following long-term exposure to elevated levels of saturated FAs (SFAs) in vivo and in vitro, where in vitro studies indicate that cosupplementation with MUFAs confers lipoprotection. SFAs and MUFAs differentially affect the fate of cells in ways that depend on the cell type, concentration and ratio of the FAs. The present study was designed to further elucidate the mechanisms underlying the effects of SFAs/MUFAs on GLP-1-producing cells in terms of lipotoxicity/lipoprotection and GLP-1 secretion. Methods Cultured GLP-1 secreting cells were exposed to hyperlipidemia simulated by SFA-albumin complexes where the molar ratio was 2:1. The cellular response to simulated hyperlipidemia was assessed in the presence/absence of MUFA cosupplementation by determining intracellular ceramide, ROS, neutral lipid accumulation, and cellular respiration. The role for cellular respiration in GLP-1 secretion in response to SFAs/MUFAs was assessed. Results Generation of intracellular ceramide mediate a detrimental increased in ROS production following long term exposure to SFAs in GLP-1-secreting cells. Cosupplementation with MUFAs increases cellular respiration, triglyceride synthesis, and the expression of ceramide kinase, while reducing ceramide synthesis and attenuating ROS production, caspase-3 activity and DNA fragmentation. Further, acute secretory effects of unsaturated FAs are independent of FAO, but mediated by a FFAR1 induced increase in cellular respiration. Conclusion This study demonstrates novel data supporting effects of MUFAs on the ceramide biosynthetic pathway, triglyceride storage respiration and secretion in GLP-1 secreting cells. These findings may be of value for nutritional interventions, as well as for identification of novel targets, to help preserve L-cell mass and potentiate GLP-1 secretion in diabesity.

The aim was to characterize a phenolic-rich water extract from the pericarp of an improved genotype of Apache red maize (RPE) and evaluate its ability to activate the type 2 diabetes markers free fatty acid receptor 1 (GPR40) and glucokinase (GK) in vitro. The extract contained mainly phenolic acids, anthocyanins, and other flavonoids. RPE inhibited α-amylase (IC50 = 88.3 μg/mL), α-glucosidase (IC50 = 169.3 μg/mL), and reduced glucose transport in a Caco-2 cell monolayer (up to 25%). Furthermore, RPE activated GPR40 (EC50 = 77.7 μg/mL) in pancreatic INS-1E cells and GK (EC50 = 43.4 μg/mL) in liver HepG2 cells, potentially through allosteric modulation. RPE activated GPR40-related insulin secretory pathway and activated the glucose metabolism regulator AMPK (up to 78%). Our results support the hypothesis that foods with a high concentration of anthocyanins and phenolic acids, such as in the selected variety of maize used, could ameliorate obesity and type 2 diabetes comorbidities.

Free fatty acid 1 (FFA1/GPR40) has attracted extensive attention as a novel target for the treatment of type 2 diabetes for its role in the enhancement of insulin secretion with glucose dependency. Aiming to develop novel potent FFA1 agonists, a new series of phenylpropionic acid derivatives were designed and synthesized on the basis of the modification of chemical cement of TAK-875, AMG-837, and LY2881835. Among them, most promising compounds 7, 14, and 15 were obtained with EC50 values of 82, 79, and 88 nM, exhibiting a powerful agonistic activity compared to TAK-875 (95.1 nM). During Oral glucose tolerance test in normal mice, compound 7, 14, and 15 had significant glucose-lowering effect at the dose of 50 mg/kg. Furthermore, compound 15 (50 mg/kg) also significantly improved in glucose tolerance in type 2 diabetic mice. Herein, we reported the discovery and optimization of a series of potent FFA1 agonists. The discovery supported further exploration surrounding this scaffold.

Insulin plays a significant role in carbohydrate homeostasis as the blood glucose lowering hormone. Glucose-induced insulin secretion (GSIS) is augmented by glucagon-like peptide (GLP-1), a gastrointestinal peptide released in response to ingesting nutriments. The secretion of insulin and GLP-1 is mediated by the binding of nutrients to G protein-coupled receptors (GPCRs) expressed by pancreatic β-cells and enteroendocrine cells, respectively. Therefore, insulin secretagogues and incretin mimetics currently serve as antidiabetic treatments. This study demonstrates the potency of synthetic isoprenoid derivatives of lysophosphatidylcholines (LPCs) to stimulate GSIS and GLP-1 release. Murine insulinoma cell line (MIN6) and enteroendocrinal L cells (GLUTag) were incubated with LPCs bearing geranic acid (1-GA-LPC), citronellic acid (1-CA-LPC), 3,7-dimethyl-3-vinyloct-6-enoic acid (GERA-LPC), and (E)-3,7,11-trimethyl- 3-vinyldodeca-6,10-dienoic acid (1-FARA-LPC). Respective free terpene acids were also tested for comparison. Besides their insulin- and GLP-1-secreting capabilities, we also investigated the cytotoxicity of tested compounds, the ability to intracellular calcium ion mobilization, and targeted GPCRs involved in maintaining lipid and carbohydrate homeostasis. We observed the high cytotoxicity of 1-GERA-LPC and 1-FARA-LPC in contrast 1-CA-LPC and 1-GA-LPC. Moreover, 1-CA-LPC and 1-GA-LPC demonstrated the stimulatory effect on GSIS and 1-CA-LPC augmented GLP-1 secretion. Insulin and GLP-1 release appeared to be GPR40-, GPR55-, GPR119- and GPR120-dependent.

Crohn's disease (CD) is an inflammatory bowel disease (IBD) which is characterized by chronic and relapsing inflammation of the gastrointestinal (GI) tract. The etiology of CD is unknown, but factors such as epithelial barrier dysfunction, immune system imbalance, microbiota dysbiosis and environmental influences are thought to be involved in its pathogenesis. Recent studies have shown that short chain fatty acids (SCFAs) and long chain fatty acids (LCFAs) play a vital role in pathophysiology and development of CD by various mechanisms affecting pro- and anti-inflammatory mediators, and maintaining the intestinal homeostasis and regulation of gene expression. SCFAs and LCFAs activate signaling cascades that control immune functions through interaction with cell surface free fatty acid receptors (FFARs), i.e. FFAR1, FFAR2, FFAR3, and FFAR4. This review highlights the role of fatty acids in maintenance of intestinal and immune homeostasis and supports the supplementation of fatty acids as a promising adjunctive treatment for CD.

Fatty acids (FAs) are considered not only as a basic nutrient, but are also recognized as signaling molecules acting on various types of receptors. The receptors activated by FAs include the family of rhodopsin-like receptors: GPR40 (FFAR1), GPR41 (FFAR3), GPR43 (FFAR2), GPR120 (FFAR4), and several other, less characterized G-protein coupled receptors (GPR84, GPR109A, GPR170, GPR31, GPR132, GPR119, and Olfr78). The ubiquitously distributed FFAR4 can be activated by saturated and unsaturated medium- and long-chain fatty acids (MCFAs and LCFAs), as well as by several synthetic agonists (e.g., TUG-891). The stimulation of FFAR4 using selective synthetic agonists proved to be promising strategy of reduction of inflammatory reactions in various tissues. In this paper, we summarize the evidence showing the mechanisms of the potential beneficial effects of FFAR4 stimulation in atherosclerosis. Based partly on our own results, we also suggest that an important mechanism of such activity may be the modulatory influence of FFAR4 on the phenotype of macrophage involved in atherogenesis.

Free fatty acid receptor 1 (FFAR1 or GPR40) has attracted attention for the treatment of type 2 diabetes mellitus, and various small-molecule agonists have been developed. However, most FFAR1 agonists as well as endogenous ligands, such as linoleic acids, have high lipophilicity, and their high lipophilicity is related to off-target toxicity. Therefore, we need to focus on new ligand candidates with less toxicity. In this study, we screened peptides with FFAR1 agonist activity as new ligand candidates. First, we used phage display to identify peptides with high affinity to FFAR1. Next, the agonist activities of peptides determined by the phage display were evaluated by the TGF-α shedding assay. Finally, to improve the FFAR1 agonist activity of the peptide, we performed an inclusive single amino acid substitution and sequence analysis. Logistic regression (LR) analysis using 120 physiochemical properties was performed to predict peptides with high FFAR1 agonist activity. STTGTQY determined by phage display promoted glucose-stimulated insulin secretion in pancreatic MIN6 cells. Furthermore, STKGTF predicted by the LR analysis showed high insulin secretion at low concentrations compared to STTGTQY. The results of this study suggest that peptides could be new candidates as FFAR1 agonists.

Branched fatty acid esters of hydroxy fatty acids (FAHFAs) are endogenous lipids with antidiabetic and anti-inflammatory effects. Each FAHFA family consists of esters with different acyl chains and multiple isomers with branch points at different carbons. Some FAHFAs, including palmitic acid hydroxy stearic acids (PAHSAs), improve insulin sensitivity and glucose tolerance in mice by enhancing glucose-stimulated insulin secretion (GSIS), insulin-stimulated glucose transport, and insulin action to suppress hepatic glucose production and reducing adipose tissue inflammation. However, little is known about the biological effects of other FAHFAs. Here, we investigated whether PAHSAs, oleic acid hydroxy stearic acid, palmitoleic acid hydroxy stearic acid, and stearic acid hydroxy stearic acid potentiate GSIS in β-cells and human islets, insulin-stimulated glucose uptake in adipocytes, and anti-inflammatory effects in immune cells. We also investigated whether they activate G protein–coupled receptor 40, which mediates the effects of PAHSAs on insulin secretion and sensitivity in vivo. We show that many FAHFAs potentiate GSIS, activate G protein–coupled receptor 40, and attenuate LPS-induced chemokine and cytokine expression and secretion and phagocytosis in immune cells. However, fewer FAHFAs augment insulin-stimulated glucose uptake in adipocytes. S-9-PAHSA, but not R-9-PAHSA, potentiated GSIS and glucose uptake, while both stereoisomers had anti-inflammatory effects. FAHFAs containing unsaturated acyl chains with higher branching from the carboxylate head group are more likely to potentiate GSIS, whereas FAHFAs with lower branching are more likely to be anti-inflammatory. This study provides insight into the specificity of the biological actions of different FAHFAs and could lead to the development of FAHFAs to treat metabolic and immune-mediated diseases.

Pancreatic β-cell insulin secretion, which responds to various secretagogues and hormonal regulations, is reviewed here, emphasizing the fundamental redox signaling by NADPH oxidase 4- (NOX4-) mediated H2O2 production for glucose-stimulated insulin secretion (GSIS). There is a logical summation that integrates both metabolic plus redox homeostasis because the ATP-sensitive K+ channel (KATP) can only be closed when both ATP and H2O2 are elevated. Otherwise ATP would block KATP, while H2O2 would activate any of the redox-sensitive nonspecific calcium channels (NSCCs), such as TRPM2. Notably, a 100%-closed KATP ensemble is insufficient to reach the −50 mV threshold plasma membrane depolarization required for the activation of voltage-dependent Ca2+ channels. Open synergic NSCCs or Cl− channels have to act simultaneously to reach this threshold. The resulting intermittent cytosolic Ca2+-increases lead to the pulsatile exocytosis of insulin granule vesicles (IGVs). The incretin (e.g., GLP-1) amplification of GSIS stems from receptor signaling leading to activating the phosphorylation of TRPM channels and effects on other channels to intensify integral Ca2+-influx (fortified by endoplasmic reticulum Ca2+). ATP plus H2O2 are also required for branched-chain ketoacids (BCKAs); and partly for fatty acids (FAs) to secrete insulin, while BCKA or FA β-oxidation provide redox signaling from mitochondria, which proceeds by H2O2 diffusion or hypothetical SH relay via peroxiredoxin “redox kiss” to target proteins.

Metabolomics has been increasingly applied to biomarker discovery, as untargeted metabolic profiling represents a powerful exploratory tool for identifying causal links between biomarkers and disease phenotypes. In the present work, we used untargeted metabolomics to investigate plasma specimens of rats, dogs, and mice treated with small-molecule drugs designed for improved glycemic control of type 2 diabetes mellitus patients via activation of GPR40. The in vivo pharmacology of GPR40 is not yet fully understood. Compounds targeting this receptor have been found to induce drug-induced liver injury (DILI). Metabolomic analysis facilitating an integrated UPLC-TWIMS-HRMS platform was used to detect metabolic differences between treated and non-treated animals within two 4-week toxicity studies in rat and dog, and one 2-week toxicity study in mouse. Multivariate statistics of untargeted metabolomics data subsequently revealed the presence of several significantly upregulated endogenous compounds in the treated animals whose plasma level is known to be affected during DILI. A specific bile acid metabolite useful as endogenous probe for drug–drug interaction studies was identified (chenodeoxycholic acid-24 glucuronide), as well as a metabolic precursor indicative of acidic bile acid biosynthesis (7α-hydroxy-3-oxo-4-cholestenoic acid). These results correlate with typical liver toxicity parameters on the individual level.

Extracellular vesicles (EVs) are vesicles secreted by normal and malignant cells that are implicated in tumor progression. Linoleic acid (LA) is an essential polyunsaturated fatty acid that induces migration, invasion and an increase in phospholipase D activity in breast cancer cells. In this study, we determined whether stimulation of MDA-MB-231 breast cancer cells with LA induces the secretion of EVs, which can mediate cell processes related with angiogenesis in human umbilical vein endothelial cells (HUVECs). Our findings demonstrate that treatment of MDA-MB-231 cells with 90 μM LA for 48 h induce an increase in the number of EVs released. Moreover, EVs from MDA-MB-231 stimulated with 90 μM LA induce FAK and Src activation and migration via FAK and Src activity, whereas the secretion of these EVs is through FFAR1 and FFAR4 activation in HUVECs. The EVs from MDA-MB-231 cells treated with LA also increase proliferation, invasion, MMP-9 secretion, an increase of MMP-2 secretion and formation of new tubules in HUVECs. In summary, we demonstrate, for the first time, that treatment with LA induces the release of EVs from MDA-MB-231 cells that induce cellular processes involved with angiogenesis in HUVECs.

Glucagon like peptide-1 (GLP-1) is an incretin hormone, secreted from L-cells of distal ileum and colon in response to nutrient ingestion in human. GLP-1 plays a major role in gut motility, appetite regulation, and insulin secretion. Dipeptidyl peptidase-4 (DPP4), a serine peptidase, cleaves N-terminal dipeptides of GLP-1, rendering it inactive and responsible for its short half-life. DPP4 is widely expressed in numerous tissues in a membrane bound or soluble form. The enteroendocrine cell lines STC-1 and GLUTag are extensively used as models for in vitro studies, however, the basic parallel characterization between these cell lines is still missing. Previously, we demonstrated that these cell lines exhibit different responses to α-linolenic acid (αLA)-induced GLP-1 secretion. Therefore, we examined the basal and stimulated GLP-1 and DPP4 secretion between the two cell lines. GPR120 and GPR40 are known to bind long chain fatty acids. We found that STC-1 cells secreted significantly more basal and αLA-induced GLP-1 than GLUTag cells. In addition, STC-1 secreted DPP4 and expressed higher amounts of DPP4 and GPR120 than GLUTag cells, while GLUTag cells expressed higher GPR40 protein levels than STC-1 cells. Interestingly, the secreted soluble DPP4 did not change the active GLP-1 concentrations in the buffer group, and only 5.5 % of GLP-1 was degraded in the αLA stimulated group. These results suggested that STC-1 cells have a higher potential to secrete GLP-1 and DPP4 than GLUTag cells, and the membrane bound DPP4 may play a more significant role in the inactivation of GLP-1 secretion.

Diabetes mellitus is a worldwide health problem with high rates of mortality and morbidity. Management of diabetes mellitus by dietary components is achievable especially at the initial stage of the disease. Several studies confirmed the antidiabetic activities of simple phenolic acids and lysophosphatidylcholine (LPC). The main goal of this study was to identify new potential insulin secretion modulators obtained by combining the structures of two natural compounds, namely O-methyl derivatives of phenolic acids and phospholipids. LPC and phosphatidylcholine bearing methoxylated aromatic carboxylic acids were tested as potential agents able to improve glucose-stimulated insulin secretion (GSIS) and intracellular calcium mobilization in MIN6 &beta, pancreatic cell line. Our results show that LPC with covalently bonded molecule of p-anisic acid at the sn-1 position was able to induce GSIS and intracellular calcium flux. Notably, 1-anisoyl-2-hydroxy-sn-glycero-3-phosphocholine did not affect the viability of MIN6 cells, suggesting its potential safe use. Furthermore, we have shown that three G protein coupled receptors, namely GPR40, GPR55, and GPR119, are targeted by this LPC derivative.

Six derivatives of 3-phenylpropionic acid bearing various natural and natural-like, spatially defined peripheral motifs have been synthesized and evaluated in vitro for free fatty acid receptor 1 (FFA1) activation. Two frontrunner compounds (bearing a bornyl and cytosine groups) were evaluated in an oral glucose tolerance test in mice where both demonstrated the ability to sustain blood glucose levels following a glucose challenge. The bornyl compound displayed a somewhat superior, dose-dependent efficacy and, therefore, can be regarded as a lead compounds for further development as a therapeutic agent for type 2 diabetes mellitus. Its high affinity to FFA1 was rationalized by docking experiments.

Fasiglifam (TAK-875) a G-protein coupled receptor 40 (GPR40) agonist, significantly improves hyperglycemia without hypoglycemia and weight gain, the major side effects of conventional anti-diabetics. Unfortunately, during multi-center Phase 3 clinical trials, unexpected liver toxicity resulted in premature termination of its development. Here, we investigated whether TAK-875 directly inflicts toxicity on hepatocytes and explored its underlying mechanism of toxicity. TAK-875 decreased viability of 2D and 3D cultures of HepG2, a human hepatocarcinoma cell line, in concentration- (＞50 µM) and time-dependent manners, both of which corresponded with ROS generation. An antioxidant, N-acetylcysteine, attenuated TAK-875-mediated hepatotoxicity, which confirmed the role of ROS generation. Of note, knockdown of GPR40 using siRNA abolished the hepatotoxicity of TAK-875 and attenuated ROS generation. In contrast, TAK-875 induced no cytotoxicity in fibroblasts up to 500 µM. Supporting the hepatotoxic potential of TAK-875, exposure to TAK-875 resulted in increased mortality of zebrafish larvae at 25 µM. Histopathological examination of zebrafish exposed to TAK-875 revealed severe hepatotoxicity as manifested by degenerated hypertrophic hepatocytes with cytoplasmic vacuolation and acentric nuclei, confirming that TAK-875 may induce direct hepatotoxicity and that ROS generation may be involved in a GPR40-dependent manner.

Key metabolites act through specific G protein-coupled receptors (GPCRs) as extracellular signals of fuel availability and metabolic stress. Here, we focus on the succinate receptor SUCNR1/GPR91 and the long chain fatty acid receptor FFAR1/GPR40, for which 3D structural information is available. Like other small polar acidic metabolites, succinate is excreted from the cell by transporter proteins to bind to an extracellular, solvent-exposed pocket in SUCNR1. Non-metabolite pharmacological tool compounds are currently being designed based on the structure of the SUCNR1 binding pocket. In FFAR1, differently signaling lipid mimetics bind in two distinct membrane-exposed sites corresponding to each of the lipid bilayer leaflets. Conceivably endogenous lipid ligands gain access to these sites by way of the membrane and probably occupy both sites under physiological circumstances. Design of polar agonists for a dynamic, solvent-exposed pocket in FFAR1 underlines the possibility of structure-based approaches for development of novel tool compounds even in lipid sensing metabolite GPCRs.

Fatty and hydroxycarboxylic acids are one of the main intermediates of energy metabolism in ruminants and critical in the milk production of cattle. High production demands on a dairy farm can induce nutritional imbalances and metabolism disorders, which have been widely associated with the onset of sterile inflammatory processes and increased susceptibility to infections. The literature suggests that short-chain fatty acids (SCFA), long-chain fatty acids (LCFA) and hydroxycarboxylic acids are relevant modulators of the host innate inflammatory response. For instance, increased SCFA and lactate levels are associated with subacute ruminal acidosis (SARA) and the activation of pro-inflammatory processes mediated by diverse leukocyte and vascular endothelial cells. As such, free LCFA and the ketone body β-hydroxybutyrate are significantly increased in the plasma 1-2 weeks postpartum, coinciding with the time period in which cows are more susceptible to acquiring infectious diseases that the host innate immune system should actively oppose. Today, many of these pro-inflammatory responses can be related to the activation of specific G protein-coupled receptors, including GPR41/FFA3 and GPR43/FFA2 for SCFA; GPR40/FFA1 and GPR120/FFA4 for LCFA, GPR109A/HCA2 for ketone body β-hydroxybutyrate, and GPR81/HCA1 for lactate, all expressed in different bovine tissues. The activation of these receptors modulates the release of intracellular granules [e.g., metalloproteinase-9 (MMP-9) and lactoferrin], radical oxygen species (ROS) production, chemotaxis, and the production of relevant pro-inflammatory mediators. The article aimed to review the role of natural ligands and receptors and the resulting impact on the host innate immune reaction of cattle and, further, to address the most recent evidence supporting a potential connection to metabolic disorders.

The free fatty acid receptor 1 (FFA1) is a potential target due to its function in enhancing of glucose-stimulated insulin secretion. The FFA1 agonist GW9508 has great potential for the treatment of type 2 diabetes mellitus, but it has been suffering from high plasma clearance probably because the phenylpropanoic acid is vulnerable to β-oxidation. To identify orally available analog without influence on the unique pharmacological mechanism of GW9508, we tried to interdict the metabolically labile group by incorporating two deuterium atoms at the α-position of phenylpropionic acid affording compound 4 (HWL-066). As expected, HWL-066 revealed a lower clearance (CL = 0.23 L-1 hr-1 kg-1 ), higher maximum concentration (Cmax = 5907.47 μg/L), and longer half-life (T1/2 = 3.50 hr), resulting in a 2.8-fold higher exposure than GW9508. Moreover, the glucose-lowering effect of HWL-066 was far better than that of GW9508 and comparable with TAK-875. Different from glibenclamide, no side-effect of hypoglycemia was observed in mice after oral administrating HWL-066 (80 mg/kg).

The secretion of insulin from β-cells depends on extracellular factors, in particular glucose and other small molecules, some of which act on G-protein–coupled receptors. Fatty acids (FAs) have been discussed as exogenous secretagogues of insulin for decades, especially after the FA receptor GPR40 (G-protein–coupled receptor 40) was discovered. However, the role of FAs as endogenous signaling factors has not been investigated until now. In the present work, we demonstrate that lowering endogenous FA levels in β-cell medium by stringent washing or by the application of FA-free (FAF) BSA immediately reduced glucose-induced oscillations of cytosolic Ca2+ ([Ca2+]i oscillations) in MIN6 cells and mouse primary β-cells, as well as insulin secretion. Mass spectrometry confirmed BSA-mediated removal of FAs, with palmitic, stearic, oleic, and elaidic acid being the most abundant species. [Ca2+]i oscillations in MIN6 cells recovered when BSA was replaced by buffer or as FA levels in the supernatant were restored. This was achieved by recombinant lipase–mediated FA liberation from membrane lipids, by the addition of FA-preloaded FAF-BSA, or by the photolysis of cell-impermeant caged FAs. Our combined data support the hypothesis of FAs as essential endogenous signaling factors for β-cell activity and insulin secretion.

Type-2 diabetes mellitus is a progressive cluster of metabolic disorders, representing a global public health burden affecting more than 366 million people worldwide. We recently reported the discovery of three series of novel agents showing balanced activity on two metabolic receptors, peroxisome proliferator activated receptor-γ (PPAR-γ) and free fatty acid receptor 1 (FFAR1), also known as GPCR40. Our designing strategy relied on linking the thiazolidinedione head with known GPCR privilege structures. To further investigate this concept, two new scaffolds, the benzhydrol- and indole-based chemotypes, were introduced here in. Our optimization campaign resulted in three compounds; 15a, 15c, and 15d, with affinities in the low micromolar range on both targets. In vivo study of selected test compounds, revealed that 15c possesses a significant anti-hyperglycemic and anti-hyperlipidemic activities superior to rosiglitazone in fat-fed animal models. Molecular docking analysis was conducted to explain the binding modes of both series. These compounds could lead to the development of the unique antidiabetic agent acting as insulin sensitizer as well as insulin secretagogue.

Tight junctions play key roles in the regulation of airway epithelial barrier function and promotion of tight junction integrity is beneficial to lung health. G-protein coupled receptor (GPR) 40 has been identified as a receptor of polyunsaturated fatty acids. This study aimed to investigate the function of GPR40 in regulating tight junction assembly in human airway epithelial cells (Calu-3 cells) using GW9508, a GPR40 agonist. Immunoblotting and immunofluorescence analyses showed that Calu-3 cells expressed both types of polyunsaturated fatty acid receptors including GPR40 and GPR120. Intracellular Ca(2+) measurements confirmed that GW9508 stimulated GPR40, but not GPR120. In Ca(2+) switch assays, GW9508 promoted the recovery of transepithelial electrical resistance and re-localization of zonula occludens (ZO)-1 to intercellular areas. These effects were suppressed by inhibitors of GPR40 and phospholipase C (PLC). Interestingly, GW9508 enhanced tight junction assembly in an AMP-activated protein kinase (AMPK)-dependent manner. The effect of GW9508 on inducing tight junction assembly was also confirmed in 16HBE14o- cells. Our results indicate that GPR40 stimulation by GW9508 leads to AMPK activation via calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ). Collectively, this study reveals an unprecedented role of GPR40 in facilitating airway epithelial tight junction assembly via PLC-CaMKKβ-AMPK pathways. GPR40 represents a novel regulator of airway epithelial integrity and its stimulation may be beneficial in the treatment of airway diseases.

The free fatty acid receptor 1 (FFA1) plays an important role in amplifying insulin secretion in a glucose dependent manner. We have previously reported a series of FFA1 agonists with thiazole scaffold exemplified by compound 1, and identified a small hydrophobic subpocket partially occupied by the methyl group of compound 1. Herein, we describe further structure optimization to better fit the small hydrophobic subpocket by replacing the small methyl group with other hydrophobic substituents. All of these efforts resulted in the identification of compound 6, a potent FFA1 agonist (EC50 = 39.7 nM) with desired ligand efficiency (0.24) and ligand lipophilicity efficiency (4.7). Moreover, lead compound 6 exhibited a greater potential for decreasing the hyperglycemia levels than compound 1 during an oral glucose tolerance test. In summary, compound 6 is a promising FFA1 agonist for further investigation, and the structure-based study promoted our understanding for the binding pocket of FFA1.

The discovery of a novel series of N-arylpyrroles as agonists of GPR120 (FFAR4) is discussed. One lead compound is a potent GPR120 agonist, has good selectivity for related receptor GPR40 (FFAR1), has acceptable PK properties, and is active in 2 models of Type 2 Diabetes in mice.

The free fatty acid receptor 1 (FFA1) is being considered to be a novel anti-diabetic target based on its role in amplifying insulin secretion. We have previously identified several series of FFA1 agonists with different heterocyclic scaffolds. Herein, we describe the structural exploration of other heterocyclic scaffolds directed by drug-like physicochemical properties. Further structure-based design and chiral resolution provided the most potent compound 11 (EC50 = 7.9 nM), which exhibited improved lipophilicity (LogD7.4: 1.93), ligand efficiency (LE = 0.32) and ligand lipophilicity efficiency (LLE = 6.2). Moreover, compound 11 revealed an even better pharmacokinetic property than that of TAK-875 in terms of plasma clearance, maximum concentration, and plasma exposure. Although robust agonistic activity and PK profiles for compound 11, the glucose-lowering effects in vivo is not ideal, and the exact reason for in vitro/in vivo difference was worthy for further exploration.

Compound 12 is a GPR40 agonist that realizes the full magnitude of efficacy possible via GPR40 receptor agonism. In vitro and in vivo studies demonstrated superior glucose lowering by 12 compared to fasiglifam (TAK-875), in a glucose dependent manner. The enhanced efficacy observed with the full agonist 12 was associated with both direct and indirect stimulation of insulin secretion.

The free fatty acid receptor 1 (FFA1) is a potential target due to its function in enhancement of glucose-stimulated insulin secretion. Takeda’s compound 1 has robustly in vitro activity for FFA1, but it has been suffered from poor pharmacokinetic (PK) profiles because the phenylpropanoic acid is vulnerable to β-oxidation. To identify orally available agonists, we tried to interdict the metabolically labile group by incorporating two deuterium atoms at the α-position of phenylpropionic acid. Interestingly, the differences of physicochemical properties between hydrogen and deuterium are quite small, but there are many differences in the structure-activity relationship between phenylpropionic acid series and present deuterated series. Further optimizations of deuterated series led to the discovery of compound 18, which exhibited a superior balance in terms of in vitro activity, lipophilicity, and solubility. Better still, compound 18 revealed a lower clearance (CL = 0.44 L/h/kg), higher maximum concentration (Cmax = 7584.27 μg/L), and longer half-life (T1/2 = 4.16 h), resulting in a >23-fold exposure than compound 1. In subsequent in vivo pharmacodynamic studies, compound 18 showed a robustly glucose-lowering effect in rodent without the risk of hypoglycemia.

The progress made so far in the elucidation of the structure of free fatty acid receptor 1 (FFAR1) and its secondary and ternary complexes with partial and full allosteric ligands led to the discovery of various putative binding regions on the FFAR1 surface. Attempts to develop FFAR1 agonists culminated with the identification of TAK-875 (1), whose phase 3 clinical trials were terminated due to potential liver toxicity. In the search of safer agonists, numerous classes of new compounds were designed, synthesized, and tested. Chemical decoration of the scaffolds was rationalized to reach a good balance between lipophilicity, activity, and toxicity. Today, targeting FFAR1 with positive modulators represents an attractive pharmacological tool for the treatment of type 2 diabetes mellitus (T2DM), mainly because of the lack of hypoglycaemic side effects associated with several antidiabetic drugs currently available. Moreover, considering the involvement of FFAR1 in many physio-pathological processes, its agonists are also emerging as possible therapeutic tools for alleviating organ inflammation and fibrosis, as well as for the treatment of CNS disorders, such as Alzheimer's disease and dementia.

G-protein coupled receptor 40 (GPR40) has been considered to be an attractive drug target for the treatment of type 2 diabetes because of its role in free fatty acids-mediated enhancement of glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. A series of indole-5-propanoic acid compounds were synthesized, and their GPR40 agonistic activities were evaluated by nuclear factor of activated T-cells reporter assay and GSIS assay in the MIN-6 insulinoma cells. Three compounds, 8h (EC50 = 58.6 nM), 8i (EC50 = 37.8 nM), and 8o (EC50 = 9.4 nM), were identified as potent GPR40 agonists with good GSIS effects.

G-protein-coupled receptor 40 (GPR40) was recently identified as an interesting target for treatment of type 2 diabetes. The high level of expression in pancreatic beta cells and the dependence of glucose on stimulating the secretion of insulin led to great excitement in this field. The identification of this target was followed by the development of a series of agonists with great potential for the treatment of diabetes. All known agonists have the presence of a pharmacophoric carboxylic acid group in their structure, which makes several polar interactions at the binding site of this receptor. In this report, we provide a review of the structure-activity relationships of GPR40 agonists with a focus on the main strategies of medicinal chemistry used to develop each one of the main structural patterns exploited for this purpose. Additionally, we provide a general model for the design of GPR40 ligands that can help researchers to follow up some strategies and implement them in the development of novel agonists of this receptor.

An earlier reported series of 1,2,4-thiadiazole-based agonists of FFA1 (GPR40) was evolved into two structurally distinct series of compounds. One of the series (structurally related to known FFA1 agonist GW9508) displayed low micromolar potency while the other (representing a truncated version of the earlier reported potent FFA1 agonists) was, surprisingly, found to be devoid of agonist potency. In silico docking of representative compounds into the crystal structure of FFA1 revealed possible structural grounds for the observed SAR.

GPR40 and GPR120 are fatty acid sensors that play important roles in glucose and energy homeostasis. GPR40 potentiates glucose-dependent insulin secretion and demonstrated in clinical studies robust glucose lowering in type 2 diabetes. GPR120 improves insulin sensitivity in rodents, albeit its mechanism of action is not fully understood. Here, we postulated that the antidiabetic efficacy of GPR40 could be enhanced by coactivating GPR120. A combination of GPR40 and GPR120 agonists in db/db mice, as well as a single molecule with dual agonist activities, achieved superior glycemic control compared with either monotherapy. Compared with a GPR40 selective agonist, the dual agonist improved insulin sensitivity in ob/ob mice measured by hyperinsulinemic-euglycemic clamp, preserved islet morphology, and increased expression of several key lipolytic genes in adipose tissue of Zucker diabetic fatty rats. Novel insights into the mechanism of action for GPR120 were obtained. Selective GPR120 activation suppressed lipolysis in primary white adipocytes, although this effect was attenuated in adipocytes from obese rats and obese rhesus, and sensitized the antilipolytic effect of insulin in rat and rhesus primary adipocytes. In conclusion, GPR120 agonism enhances insulin action in adipose tissue and yields a synergistic efficacy when combined with GPR40 agonism.

GPR40 is generally known to signal through Gq. However, in transfected cells, certain synthetic agonists can make the receptor signal also through Gs and cAMP (Hauge et al., 2015). Here we find that, in colonic crypt cultures, the GLP-1 secretion induced by such Gq + Gs GPR40 agonists is indeed inhibited by blockers of both Gq and Gs and is eliminated by combining these. This in contrast to Gq-only GPR40 agonists which only are affected by the Gq inhibitor. Importantly, Gq-only GPR40 agonists in combination with low doses of selective synthetic agonists for Gs coupled receptors, e.g. GPR119 and TGR5 provide more than additive GLP-1 secretion both ex vivo and in vivo in mice. It is concluded that under physiological circumstances triglyceride metabolites, i.e. long chain fatty acids and 2-monoacyl glycerol plus bile acids, act synergistically through their respective receptors, GPR40, GPR119 and TGR5 to stimulate GLP-1 secretion robustly by combining Gq and Gs signaling pathways.

Background: Enhanced IAPP production may contribute to islet amyloid formation in type 2 diabetes. The objective of this study was to determine the effects of the saturated fatty acid palmitate on IAPP levels in human β-cells. Methods: EndoC-βH1 cells and human islets were cultured in the presence of sodium palmitate. Effects on IAPP/insulin mRNA expression and secretion were determined using real-time qPCR/ELISA. Pharmacological activators and/or inhibitors and RNAi were used to determine the underlying mechanisms. Results: We observed that EndoC-βH1 cells exposed to palmitate for 72 h displayed decreased expression of Pdx-1 and MafA and increased expression of thioredoxin-interacting protein (TXNIP), reduced insulin mRNA expression and glucose-induced insulin secretion, as well as increased IAPP mRNA expression and secretion. Further, these effects were independent of fatty acid oxidation, but abolished in response to GPR40 inhibition/downregulation. In human islets both a high glucose concentration and palmitate promoted increased IAPP mRNA levels, resulting in an augmented IAPP/insulin mRNA ratio. This was paralleled by elevated IAPP/insulin protein secretion and content ratios. Conclusions: Addition of exogenous palmitate to human β-cells increased the IAPP/insulin expression ratio, an effect contributed to by activation of GPR40. These findings may be pertinent to our understanding of the islet amyloid formation process.

Clinical studies indicate that partial agonists of the G-protein-coupled, free fatty acid receptor 1 GPR40 enhance glucose-dependent insulin secretion and represent a potential mechanism for the treatment of type 2 diabetes mellitus. Full allosteric agonists (AgoPAMs) of GPR40 bind to a site distinct from partial agonists and can provide additional efficacy. We report the 3.2-Å crystal structure of human GPR40 (hGPR40) in complex with both the partial agonist MK-8666 and an AgoPAM, which exposes a novel lipid-facing AgoPAM-binding pocket outside the transmembrane helical bundle. Comparison with an additional 2.2-Å structure of the hGPR40-MK-8666 binary complex reveals an induced-fit conformational coupling between the partial agonist and AgoPAM binding sites, involving rearrangements of the transmembrane helices 4 and 5 (TM4 and TM5) and transition of the intracellular loop 2 (ICL2) into a short helix. These conformational changes likely prime GPR40 to a more active-like state and explain the binding cooperativity between these ligands.

The pathophysiological actions of fatty acids (FAs) on Alzheimer’s disease (AD), which are possibly mediated by genomic effects, are widely known; however, their non-genomic actions remain elusive. The aim of this study was to investigate the non-genomic mechanism of extra-cellular palmitic acid (PA) regulating beta-amyloid peptide (Aβ) production, which may provide a link between obesity and the occurrence of AD. In an obese mouse model, a high-fat diet (HFD) significantly increased the expression levels of APP and BACE1 as well as the AD pathology in the mouse brain. We further found that PA conjugated with bovine serum albumin (PA-BSA) increased the expression of APP and BACE1 and the production of Aβ through the G protein-coupled receptor 40 (GPR40) in SK-N-MC cells. PA-BSA coupling with GPR40 significantly induced Akt activation which is required for mTOR/p70S6K1-mediated HIF-1α expression and NF-κB phosphorylation facilitating the transcriptional activity of the APP and BACE1 genes. In addition, silencing of APP and BACE1 expression significantly decreased the production of Aβ in SK-N-MC cells treated with PA-BSA. In conclusion, these results show that extra-cellular PA coupled with GPR40 induces the expression of APP and BACE1 to facilitate Aβ production via the Akt-mTOR-HIF-1α and Akt-NF-κB pathways in SK-N-MC cells.

The free fatty acid receptor 1 (FFA1/GPR40) has attracted extensive attention as a novel antidiabetic target. Aiming to explore the chemical space of FFA1 agonists, a new series of lead compounds with amide linker were designed and synthesized by combining the scaffolds of NIH screened lead compound 1 and GW9508. Among them, the optimal lead compound 17 exhibited a considerable agonistic activity (45.78%) compared to the NIH screened compound 1 (15.32%). During OGTT in normal mice, the compound 17 revealed a significant glucose-lowering effect (-23.7%) at the dose of 50mg/kg, proximity to the hypoglycemic effect (-27.8%) of Metformin (200mg/kg). In addition, the compound 17 (100mg/kg) also exhibited a significant improvement in glucose tolerance with a 29.1% reduction of glucose AUC0-2h in type 2 diabetic mice. All of these results indicated that compound 17 was considered to be a promising lead structure suitable for further optimization.

GPR40 is a G-protein-coupled receptor expressed primarily in pancreatic islets and intestinal L-cells that has been a target of significant recent therapeutic interest for type II diabetes. Activation of GPR40 by partial agonists elicits insulin secretion only in the presence of elevated blood glucose levels, minimizing the risk of hypoglycemia. GPR40 agoPAMs have shown superior efficacy to partial agonists as assessed in a glucose tolerability test (GTT). Herein, we report the discovery and optimization of a series of potent, selective GPR40 agoPAMs. Compound 24 demonstrated sustained glucose lowering in a chronic study of Goto Kakizaki rats, showing no signs of tachyphylaxis for this mechanism.

Fatty acids activate GPR40 and K+ channels to modulate β-cell function. Herein, we describe the design and synthesis of FAAzo-10, a light-controllable GPR40 agonist based on Gw-9508. FAAzo-10 is a potent GPR40 agonist in the trans-configuration and can be inactivated on isomerization to cis with UV-A light. Irradiation with blue light reverses this effect, allowing FAAzo-10 activity to be cycled ON and OFF with a high degree of spatiotemporal precision. In dissociated primary mouse β-cells, FAAzo-10 also inactivates voltage-activated and ATP-sensitive K+ channels, and allows us to control glucose-stimulated Ca2+ oscillations in whole islets with light. As such, FAAzo-10 is a useful tool to study the complex effects, with high specificity, which FA-derivatives such as Gw-9508 exert at multiple targets in mouse β-cells.