The Influence Of ILK Signal Pathway In C2C12 Cells Proliferation

It is generally accepted that integrin-linked kinase (ILK) participates in multiple signal transduction pathways related to cell proliferation in various cells after activation of ILK depending on phospholipid inositol 3-kinase (PI3K). Our previous study found that muscle cell enhancement factor 2C (MEF2C) was fully activated when the phosphorylation activity of ILK was inhibited in the skeletal muscle cells of goats, which could enhance the binding of promoter of transcription factor and then regulating the expression of these genes. However, it is still unclear presently whether activation of ILK depends on PI3K and then regulates the activity of MEF2C in the process of cell proliferation of skeletal muscle cells.To investigate the effect of ILK signaling pathway during proliferation of C2C12 cells, we explored the activation ways and the regulation styles of ILK and MEF2C in the skeletal muscle.The restrain of skeletal muscle cell line C2C12 by Cpd22 is be observed in order to explore the change of ILK signaling pathway. In compared with the control, ILK phosphorylation level was decreased by 51.65%, MEF2C phosphorylation level was increased by 141.18%, MCK mRNA expression level was improved by 354.78% when ILK activity is inhibited. A result indicates that the expression level of ILK was decrease by 31.10% through electrotransfected ILK-interference vectors, ILK phosphorylation levels were decreased by 45.20% compared with the control group when ILK expression is suppressed, MEF2C phosphorylation were remarkable increased by 146.38%, the expression of MCK was increased by 182.99%, respectively The results in treatment of C2C12 with inhibitors or ILK-interference vectors both draw a conclusion that ILK negatively regulated MEF2C phosphorylation activity and MCK transcription activity.In order to research the function of PI3K in ILK signal pathway, we used PI3K inhibitors (LY294002) to treat C2C12. In compared with the control, ILK phosphorylation level was decreased by 54.44%, MEF2C phosphorylation level was decreased by 91.71%, and MCK mRNA expression was decreased by 41.56%. When we inhibitted of PI3K phosphorylation activity, further inhibitted the activity of ILK, in compared with the control, MEF2C phosphorylation level was increased by 113.60% and mRNA expression of MCK was increased by 170.97%, but the increasing level was lower than that of inhibited the ILK by Cpd22. Thus the activity of ILK depended on PI3K, however, we didn’t find the negatively regulation on MEF2C phosphorylation activity after inhibitted the activity of PI3K.The above results confirm that ILK negatively regulated MEF2C phosphorylation activity and transcription activity, but this regulation was independently of PI3K. The results supply evidences for the study of classical signaling pathway of PI3K-ILK in the process of cell proliferation.