Phosphatase and tensin homolog deficiency induces M2 macrophage polarization by promoting glycolytic activity in endometrial stromal cells

Endometriosis is a common gynecological disorder, whose pathogenesis remains incompletely understood. Macrophages, a key type of immune cell, are pivotal in the context of endometriosis. This study seeks to explore the interactions between endometriotic cells and macrophages. Quantitative real-time PCR (qRT-PCR) and Western blot experiments were employed to detect phosphatase and tensin homolog (PTEN) expression. Glucose consumption, lactate production, extracellular acidification rate, and oxygen consumption rate levels were used to assess cellular glycolytic capacity. The interaction between conditioned media from ectopic endometrial stromal cells (EESCs) and macrophages was investigated through co-culture experiments. The expression of M2 macrophage marker proteins and inflammatory factors was detected via qRT-PCR, immunofluorescence staining, and enzyme-linked immunosorbent assay. Cellular functions were evaluated using Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine (EdU), and wound healing assays. We found that PTEN deficiency promoted the glycolytic activity of EESCs. Simultaneously, it significantly promoted the macrophages' polarization toward the M2 phenotype, demonstrated by increased expression of M2 markers (differentiation 206 (CD206), CD163, and (C-C motif) ligand 22 (CCL22)). Further studies revealed that PTEN-deficient EESCs increased the level of CCL2 via promoting glycolytic activity, which was reversed by glycolytic inhibitor. Moreover, lactate and conditioned media from overexpressed CCL2 EESCs facilitated M2 polarization of macrophages, while 2-deoxy-d-glucose reversed the promoting effect. Furthermore, lactate-facilitated macrophages promoted the proliferation and migration abilities of EESCs. PTEN deficiency induces M2 macrophage polarization by promoting glycolytic activity in EESCs, which deepens the knowledge of the pathophysiology of endometriosis and provides novel insights into its treatment.