A Study On The Mechanisms Of Chronic Inflammation Of Vascular Endothelial Cells Induced By Saturated Fatty Acids

Obese people have a higher risk of diabetes and cardiovascular disease than normal people.After detecting,the content of free fatty acids in obese people is significantly higher than that of normal people,especially the content of saturated fatty acids.We speculate that excessive saturated fatty acids will cause chronic inflammation in the body and further induce metabolic syndrome such as diabetes and cardiovascular disease.Chronic inflammation is the main mechanism of cardiovascular and cerebrovascular diseases,so this article aims to explore the pathogenesis of chronic inflammation induced by saturated fatty acids in vascular endothelial cells.Methods and results: We treated vascular endothelial cells with a variety of saturated fatty acids,extracted cytoplasmic and nuclear proteins,and detected protein expression levels by Western blotting.We found that saturated fatty acids can continuously increase the low level of NF-?B p65 in the nucleus,which is different from the transiently high level of NF-?B p65 stimulated by LPS.Compared with the acute inflammatory response induced by LPS,saturated fatty acids induce more like a chronic inflammatory response.The experimental results show that the four saturated fatty acids do not cause changes in NF-?B inhibitory protein ?(I?B?)in the nucleus and cytoplasm,and the I?B kinase(IKK)inhibitor,IKK16,cannot prevent these four saturated fatty acids from inducing nuclear NF-?B p65 rises at low levels.Based on the above experimental results of I?B? and IKK,it was verified that the activation of NF-?B by saturated fatty acids did not pass through the NF-?B classical signaling pathway.We speculate that saturated fatty acids may be involved in the synthesis of diacylglycerol(DAG)as a second messenger;the results show that the two inhibitors of DAG synthesis rate-limiting enzyme(GPAT),FGS67 and NEM,can inhibit myristateinduced NF-?B p65 from entering the nucleus.Subsequently,after pre-treating cells with two inhibitors of PKC,Sotrastaurin and Go6983,both were observed to block myristate-induced accumulation of NF-?B p65 in the nucleus.At the same time,myristic acid will reduce the expression of PKC? and HDAC5,and sotrastaurin can reverse this situation,and HDAC5 inhibitor LMK235 will continue to maintain this state induced by myristic acid.In order to analyze the relationship between PKC? and HDAC5,we packaged the lentivirus to make it carry the shRNA of the PKC? gene,which is used to infect cells,interfere with the cell's PKC? RNA,and reduce its expression.It was found through experiments that the expression of HDAC5 in the PKC? knockdown group was also greatly reduced,and this effect was enhanced after the addition of tetradecanoic acid;at the same time,the knockdown of PKC? caused the expression of total p65 in the nucleus of cells to be up-regulated,while acetylation p65(L310)was not up-regulated,but the expression of total p65 and acetylated p65(L310)was significantly enhanced by the addition of myristic acid.Conclusion: We found that the continuous activation of the saturated fatty acid-induced transcription factor NF-?B was not activated by I?B phosphorylation in the classical pathway,but entered the cell to synthesize DAG to activate the PKC family(except PKC?).Activated PKC molecules will inhibit PKC?,the low level of PKC? will make HDAC5 also in a low-level state,so that NF-?B p65 cannot be deacetylated in time and stays in the nucleus,and maintains a certain level of acetylation.It continues to specifically bind to specific DNA binding sites and activate the purpose.Gene transcription continues to exacerbate the inflammatory response.This article proposes a new mechanism specific to chronic inflammation,which has important guiding significance for the treatment of chronic inflammation-related diseases.