Functional Analysis of the Histidine N-Methyltransferase SETD3 in Endometriosis

Endometriosis is a disease associated with pain symptoms and reduced fertility, characterized by the presence of endometrial tissue outside the uterus. SETD3 is an actin-specific histidine N-methyltransferase that regulates actin stability and flexibility. Here, we investigate the effects of altered SETD3 expression on cytoskeletal function and endometriotic cell motility. SETD3 expression in endometriotic lesions was analyzed using EndometDB, and in uteri of the superfertile Dummerstorf mouse line FL1 by RT-qPCR. The functional impact of siRNA-mediated SETD3 depletion on endometriotic 12Z cells and primary endometriotic stroma cells was studied in vitro. Cell motility, contractility, invasiveness, morphology and gene expression were analyzed by RT-qPCR, Western blotting, immunofluorescence, scratch wound, collagen contraction and Matrigel invasion assays. In patient tissue, SETD3 expression was slightly increased in deep endometriotic lesions, whereas SETD3 was downregulated 1.6-fold in the uteri of superfertile mice. SETD3 depletion delayed cell motility, reduced invasiveness of 12Z cells, and reduced the capability to contract collagen gels. Cytoskeletal gene expression was moderately changed. Our data suggest that the histidine N-methyltransferase SETD3 contributes to cytoskeletal remodeling that plays a key role in cell migration and invasion. A dysregulation of SETD3 could therefore be related to the pathogenesis of endometriosis, particularly in deep endometriosis.