Nucleotide-Binding Oligomerization Domain-Containing Protein 1 Regulates Inflammatory Response in Endometriosis

Background: Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) is known to play an important role in innate immunity, while the relationship between NOD1 and inflammatory response in endometriosis remains unknown. The present study aims to investigate the effects of NOD1 on inflammatory response in endometriosis. Methods: Immunohistochemistry staining, Western blot, and qRT-PCR were conducted to investigate the levels of NOD1 and inflammatory cytokines in the endometriotic lesions. A Spearman’s rank correlation analysis was conducted to determine the correlations of NOD1 and inflammatory cytokines (interleukin (IL)-6, tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein (MCP)-1). Human endometrial stromal cells (HESCs) were isolated and incubated with peritoneal fluid with or without ML130. Cell viability was determined by using an MTT assay. Results: A significant elevation in NOD1 and inflammatory cytokine was observed in ectopic endometrium. Interestingly, a positive correlation between NOD1 and inflammatory cytokines was observed. In addition, treatment with ML130 significantly suppressed cell viability and the production of inflammatory cytokines in the 20% peritoneal fluid treated ectopic HESCs. Conclusions: NOD1 is related to the inflammatory response that is involved in endometriosis.