Effects of polyunsaturated fatty acids on intestinal cell proliferation

摘要

The effect of the polyunsaturated fatty acids, linoleic acid (LA), arachidonic acid (AA) and conjugated dienoic linoleic acid (CLA) on IEC-6 cells (rat intestinal cell) proliferation and cell transduction have been determined in vitro. IEC-6 cells proliferation was assessed by cell growth and [~3H]-thymidine incorporation analysis. At 10 #mu#M concentration, the proliferation of cells supplemented with AA or LA was significantly higher than that of CLA. [~3H]-thymidine uptake showed the same results. LA and AA increased [~3H]-thymidine uptake more than CLA. The stimulatory effect of LA or AA was even more pronounced in the presence of IGF. Both cell number analysis and [~3H]-thymidine incorporation revealed that IEC-6 cell proliferation was influenced differently by exogenous free fatty acids, in which AA or LA stimulated IEC-6 cell proliferation and CLA inhibited it. Tyrosine phosphorylation provides a key switch to regulate cellular activity in response to extracellular stimuli. At 20 pM and 10 pM, AA with IGF-1 stimulated protein tyrosine phosphorylation in IEC-6 cells, but LA's impact was less than that of AA. CLA and CLA with IGF-1 inhibited protein tyrosine phosphorylation in IEC-6 cells. These results suggest there is a possible correlation between cell proliferation and IGF receptor tyrosine kinase activity driven by AA.