Insights into inflammatory gene expression in endometriosis: a comparative evaluation of tissue biopsy samples

Endometriosis is a chronic inflammatory disorder characterized by ectopic growth of endometrial-like tissue. Cytokines play pivotal roles in coordinating tissue inflammation and immune responses. Therefore, some pro- and anti-inflammatory cytokines may be involved or altered in endometriosis were assessed in this study.

The expression levels of the reference gene ribosomal protein lateral stalk subunit P (RPLP) and interest genes, including interleukin 17 (IL-17), IL-23, IL-25, vascular endothelial growth factor (VEGF), and forkhead box P3 (FoxP3), were measured in the endometriotic tissues of 25 individuals with endometriosis and in the endometrial tissues of 25 control individuals. The cDNA was synthesized from the extracted RNAs, and these expression levels were analyzed using Real-time PCR.

VEGF and FoxP3 were not expressed in endometriotic tissues, while non-endometriotic tissues in control group showed significant levels (VEGF: 4.41 × 10³±1.38 × 10³, FoxP3: 12.3 × 10³±4.18 × 10³; both P = 0.001). IL-17, IL-23, and IL-25 were not detected in either group. The RPLP was only expressed, indicating the presence of some viable active cells in this tissue, which was significantly lower than in controls (P = 0.001). The undetectable level of VEGF in endometriosis suggests that there was no active angiogenesis.

Accordingly, in endometriosis tissue, lymphocytes might be absent or not play a significant role, but the expression of the structural RPLP indicates the presence of some viable, active cells in this tissue. The roles of the immune system and angiogenesis are multidimensional, involved in different stages, from inflammation to immune tolerance. This underscores the importance of other growth factors, which require careful assessment and individualized treatment strategies to address each patient's specific needs.