Excessive KLF2 impairs mesenchymal-epithelial transition efficiency and adhesion in endometrial stromal cells via AKT phosphorylation

Research question: What is the dynamic expression profile of Krüppel-like factor 2 (KLF2) during the progression of mesenchymal-epithelial transition (MET), and through which molecular mechanisms does KLF2 regulate transformation?

Design: This study examined changes in KLF2 expression during the in-vivo menstrual cycle using immunohistochemistry and an in-vitro decidualization cell model. KLF2 negative control (KLF2-NC) and KLF2 overexpression (KLF2-OE) models were constructed in primary and immortalized human endometrial stromal cells via lentiviral transfection. Mesenchymal and epithelial protein changes were detected in the KLF2-NC and KLF2-OE groups on different days of MET using immunofluorescent staining. Potential KLF2 binding sites were predicted through motif enrichment analysis, and the interaction between KLF2 expression and Akt phosphorylation during MET was analysed using co-immunoprecipitation (co-IP) and western blotting. Finally, the effects of excessive KLF2 expression on the expression of adhesion factor and the efficiency of adhesion of BeWo-spheroids were determined.

Results: The results showed that KLF2 demonstrated significantly higher expression during the proliferative phase compared with the decidual phase in normal human endometrial tissue (P = 0.0095). Furthermore, KLF2 expression showed a progressive decline during MET. KLF2 overexpression decreased epithelial gene expression. Further, co-IP and western blotting demonstrated that KLF2 affects the MET process by regulating Akt phosphorylation, affecting the expression of adhesion factor and the efficiency of adhesion.

Conclusions: This study found that KLF2 expression changes during the menstrual cycle, and excessive KLF2 is not conducive to Akt phosphorylation during MET in the decidual phase.

AKT; Adhesion; Endometrial stromal cells; KLF2; Mesenchymal–epithelial transition.