MCP-1 promotes ILK phosphorylation at Ser246 during endometriosis development and affects the pregnancy outcome.

In women with endometriosis, monocyte chemoattractant protein 1 (MCP-1) or chemokine (C-C motif) ligand 2 (CCL2) is elevated in serum, peritoneal fluid, and endometriotic lesions, though its exact role in endometriosis is still unknown. The MCP-1 downstream molecule integrin-linked kinase (ILK) is involved in several cellular events. Our recent findings suggest that MCP-1 promotes an inflammatory response via ILK in a mouse endometriosis model. MCP-1 also favors human endometriotic cell aggregation, colonization, migration, and invasion, which are reversed by the ILK inhibitor compound (CPD) 22 (600 nM). Furthermore, the inflammatory response to MCP-1 is reduced by ILK inhibition (CPD22, 20 mg/kg body weight) in a mouse model. We studied MCP-1/chemokine (C-C motif) receptor type (CCR)2-mediated ILK signaling in endometriosis and observed a positive association of ILK and CCR2 with endometriosis in patients. Our immunoprecipitation and molecular docking studies confirmed ILK interaction with CCR2 under a high MCP-1 level in Hs832(C).TCs (human endometriotic cells). MCP-1 promotes ILK-Ser246 phosphorylation in endometriotic cells in human and mouse models. The mouse model shows the same inflammatory markers as seen in human endometriosis and mimics some of the aspects of the inflammatory reaction. Targeting ILK by CDP22 (20 mg/kg) suppresses endometriosis progression in the mouse model. Altered MCP-1-ILK signaling leads to poor pregnancy outcomes in the mouse model. Further, our in silico results suggest that CPD22 stabilizes the interaction with Asp234 and His318 residues of ILK and inhibits the Ser246 phosphorylation. In conclusion, MCP-1 activates ILK at the Ser246 residue and leads to lesion development/progression, reflecting the therapeutic importance of ILK for endometriosis management through the mouse model.