Results PCR PUFAs are natural ligands of GPR120 and GPR40. mRNA for GPR120 was detected in normal tissue both from ileum and colon, and in the Caco 2 cell line. On the other hand, GPR40 was only detected in the ileum and colon, which made Caco 2 cells a suitable system to spe cifically study PUFA induced activation of GPR120. PUFAs elevate the cytosolic Ca2 selleckchem concentration Studies describing GPR120 signalling in different cellular systems, including intestinal epithelial cells, have revealed that GPR120 is coupled to Gq. However, GPR120 has not been described in Caco 2 cells previously. Since i can be used as a measure of Gq activity, we investigated whether stimulation with EPA, DHA and AA was able to enhance i in Caco 2 cells. Figure 2 shows that treatment with 200 uM EPA, DHA or AA transiently increased i in Caco 2 cells.

During treatment with the different PUFAs, the max imum increase of F360 F380, which monitors i were 52. 2 2. 4% compared to untreated cells with EPA, 48. 9 1. 8% with DHA, and 51. 5 2. 6% with AA, and there Inhibitors,Modulators,Libraries were no significant differences between the re sponses to the three fatty acids. However, Figure 2C shows that the time to peak of i during treatment Inhibitors,Modulators,Libraries with 200 uM EPA was 33. 4 4. 4 sec, and significantly faster than the time to peak of i after treatment with 200 uM DHA which was 61. 8 6. 7 sec. The time to peak of i after treatment with 200 uM AA was 45. 4 7. 7 sec, and was not significantly different from the time to peak of i after treatment with 200 uM DHA or EPA. The time from the start of treatment with the different PUFAs, until the increase in i started, was also measured.

Figure 2D shows that the delay after treatment 200 uM EPA was 22. 5 4. 3 sec, and significantly shorter compared to treatment with both 200 uM DHA and 200 uM AA. The delay after treatment with 200 uM DHA and AA were 42. 2 5. 9 sec Inhibitors,Modulators,Libraries and 51. 2 6. 4 sec respectively. Activation of MAP kinase ERK1 2 Since differences were observed in the ability of the PUFAs to enhance cytosolic Ca2 levels, we wanted to investigate whether Inhibitors,Modulators,Libraries such differences could also be detected in other signalling pathways. GPR120 is known to activate MAP kinase ERK1 2 in different cellular sys tems, and we therefore investigated if triggering of GPR120 with EPA, DHA or AA would activate ERK1 2 in Caco 2 cells. Figure 3A shows that treatment with 100 uM EPA, DHA or AA in 20 min enhanced ERK1 2 activity significantly in Caco 2 cells.

Interest ingly, the activation induced Inhibitors,Modulators,Libraries by 100 uM DHA at 20 min was stronger compared to treatment with EPA selleck inhibitor and AA, although not statistically significant using densitometry. Treatment with 100 uM EPA or DHA resulted in similar kinetics in the activation of ERK1 2, while AA gave a slower response. GPCRs can activate MAP kinase ERK1 2 through dif ferent mechanisms.