Synthesis, Activity, and Docking Study of Novel Phenylthiazole-Carboxamido Acid Derivatives as FFA2 Agonists

Circulating expression patterns of TL1A and FFAR2 in patients with stable and unstable angina

Background and aim

The primary factor in sudden cardiac death is coronary artery disease. We intended to discover the diagnostic worth of circulating tumor necrosis factor like cytokine 1A (TL1A) and free fatty acid receptor 2 (FFAR2) as early, noninvasive indicators for individuals with stable angina (SA) and unstable angina (UA).

Methods

In all, 90 people were enrolled in the current case–control study: 30 patients with SA, 30 patients with UA, and 30 healthy volunteers. Circulating TL1A and FFAR2 gene expression levels were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). FBG, TC, TG, and HDL-C were assessed by spectrophotometry, while hs-CRP and troponin T were measured by ELISA.

Results

Circulating TL1A expression was significantly elevated in SA (P < 0.001) and UA patients (P < 0.001) as compared to controls and also was significantly higher in UA patients (P < 0.001) as compared to SA patients. Circulating FFAR2 expression was significantly decreased in SA (P < 0.001) and UA patients (P < 0.001) in comparison with controls and was significantly lowered in UA patients (P = 0.001) in comparison with SA patients. Our results show that TL1A and FFAR2 were sensitive and specific biomarkers for discriminating SA patients from controls. Moreover, TL1A and FFAR2 displayed a remarkable ability to distinguish UA from SA. Multivariate regression analysis revealed that TL1A, FFAR2, FBG, TC, TG, LDL-C, and Troponin T were independent risk factors for SA, while TL1A, TG, and hs-CRP were independent risk factors for UA. TL1A has a significant positive correlation with LDL-C (r = 0.406, P = 0.001), hs-CRP (r = 0.673, P < 0.001), and troponin T (r = 0.653, P < 0.001). There was a significant inverse relationship between FFAR2 and each of TL1A (r = − 0.858, P < 0.001), FBG (r = − 0.325, P = 0.011), TC(r = − 0.306, P = 0.017), TG (r = − 0.368, P = 0.004), LDL-C (r = − 0.413, P = 0.001), hs-CRP (r = − 0.737, P < 0.001), and troponin T (r = − 0.715, P < 0.001).

Conclusion

Gene expression of TL1A and FFAR2 is a good new blood-based molecular indicator for early detection of SA and UA. Early detection of a possible UA is crucial for initiating appropriate treatment that results in better patient health.

Low Expression of FFAR2 in Peripheral White Blood Cells May Be a Genetic Marker for Early Diagnosis of Acute Myocardial Infarction

Objective

To find molecular markers for the diagnosis of acute myocardial infarction (AMI), this research further verified the relationship between the expression level of FFAR2 gene and AMI by expanding the sample size based on the previous gene chip results.

Methods

Peripheral venous leukocytes were collected from 113 patients with AMI and 94 patients with noncoronary artery disease as the experimental group and the control group, respectively. Real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of the FFAR2 gene. Western blot analysis was applied to detect the relative expression of the FFAR2 gene at the level of protein. Furthermore, the relationship between gene expression and clinical data was also analyzed and compared.

Results

The level of expression of FFAR2 gene in peripheral blood of patients with AMI was significantly lower than that of the control group (0.33 [0.04–1.08], 0.62 [0.07–1.86], respectively; p < 0.05), which was 0.53 times that of the control group. Western blot results presented that the FFAR2 protein level in the peripheral blood of the AMI group was lower than that of the control group (0.114; p=0.004). Analyzing clinical data of the subjects indicated that the average age of the AMI group was significantly higher than the age of control group (p < 0.01). Also, the fasting blood glucose level was higher (p < 0.01), and the high-density lipoprotein cholesterol (HDL-C) level was lower (p=0.03). The FFAR2 mRNA level correlated positively with the HDL-C level (p < 0.01). Logistic regression analysis suggested that the low expression of the FFAR2 gene in peripheral blood may be a risk factor for AMI independent of age, family history of diabetes, fasting blood glucose level, and HDL-C level (p=0.025). Compared with the high FFAR2 expression group, the risk of AMI in the low FFAR2 expression group was 6.308 times higher.

Conclusion

The expression level of the FFAR2 gene in peripheral blood of patients with AMI was significantly lower than that in the control group. Low expression of the FFAR2 gene in peripheral blood is an independent risk factor for AMI. Hence, it may also be a potential biomarker to predict AMI.

Free Fatty Acid Receptors and Cancer: From Nutrition to Pharmacology

The effects of fatty acids on cancer cells have been studied for decades. The roles of dietary long-chain n-3 polyunsaturated fatty acids, and of microbiome-generated short-chain butyric acid, have been of particular interest over the years. However, the roles of free fatty acid receptors (FFARs) in mediating effects of fatty acids in tumor cells have only recently been examined. In reviewing the literature, the data obtained to date indicate that the long-chain FFARs (FFA1 and FFA4) play different roles than the short-chain FFARs (FFA2 and FFA3). Moreover, FFA1 and FFA4 can in some cases mediate opposing actions in the same cell type. Another conclusion is that different types of cancer cells respond differently to FFAR activation. Currently, the best-studied models are prostate, breast, and colon cancer. FFA1 and FFA4 agonists can inhibit proliferation and migration of prostate and breast cancer cells, but enhance growth of colon cancer cells. In contrast, FFA2 activation can in some cases inhibit proliferation of colon cancer cells. Although the available data are sometimes contradictory, there are several examples in which FFAR agonists inhibit proliferation of cancer cells. This is a unique response to GPCR activation that will benefit from a mechanistic explanation as the field progresses. The development of more selective FFAR agonists and antagonists, combined with gene knockout approaches, will be important for unraveling FFAR-mediated inhibitory effects. These inhibitory actions, mediated by druggable GPCRs, hold promise for cancer prevention and/or therapy.

Ligands at the Free Fatty Acid Receptors 2/3 (GPR43/GPR41)

A large number of reviews and commentaries have highlighted the potential role of the short-chain fatty acid receptors GPR41 (FFA3) and, particularly, GPR43 (FFA2) as an interface between the intestinal microbiota and metabolic and inflammatory disorders. However, short-chain fatty acids have very modest potency and display limited selectivity between these two receptors, and studies on receptor knockout mice have resulted in non-uniform conclusions; therefore, selective and high-potency/high-affinity synthetic ligands are required to further explore the contribution of these receptors to health and disease. Currently no useful orthosteric ligands of FFA3 have been reported and although a number of orthosteric FFA2 agonists and antagonists have been described, a lack of affinity of different chemotypes of FFA2 antagonists at the mouse and rat orthologs of this receptor has hindered progress. Selective allosteric regulators of both FFA2 and FFA3 have provided tools to address a number of basic questions in both in vitro and ex vivo preparations, but at least some of the positive modulators appear to be biased and able to regulate only a subset of the functional capabilities of the short-chain fatty acids. Significant further progress is required to provide improved tool compounds to better assess potential translational opportunities of these receptors for short-chain fatty acids.