Apigenin inhibits tumor necrosis factor α-induced cell proliferation and prostaglandin E2 synthesis by inactivating NFκB in endometriotic stromal cells.

Apigenin suppressed tumor necrosis factor α-induced cell proliferation and prostaglandin E2 expression via the attenuation of nuclear factor κB pathway in endometriotic stromal cells in vitro. Apigenin reduced the mitogenic activity and inflammatory reaction in endometriotic stromal cells.

The role of survivin in the resistance of endometriotic stromal cells to drug-induced apoptosis.

BACKGROUND: Decreased susceptibility of endometrial tissue to apoptosis may contribute to the pathogenesis of endometriosis. We investigate the role of survivin in the pathophysiology of endometriosis through the ability of ectopic and eutopic endometrial stromal cells (ESCs) to resist apoptosis. METHODS: Ectopic ESCs were obtained from ovarian chocolate cysts in patients undergoing laparoscopic surgery (n = 22). Eutopic ESCs were isolated from endometrial tissue of cyclic premenopausal women undergoing hysterectomy for fibroids (n = 22). Purified stromal cells were studied in vitro. The number of surviving cells and activation of caspases were assessed by WST-8 assay and immunoblotting. Expression of inhibitor of apoptosis proteins (IAP) family members: cIAP1 (birc2), cIAP2 (birc3), XIAP (birc4), survivin (birc5) were examined using cDNA array and real-time RT-PCR. Effects of gene silencing by small inhibitor RNAs (siRNA) were examined by WST-8-assay, Annexin-V staining and immunoblotting. RESULTS: After staurosporine (SS) treatment, 55% of eutopic ESCs survived versus 70% of ectopic ESCs. Procaspase-3 or -7 was more intensely activated by SS treatment in eutopic than in ectopic ESCs (P < 0.01). mRNAs for IAP-family genes, such as cIAP-1, XIAP and survivin, were highly expressed in ectopic ESCs before SS treatment. The fold induction of survivin expression after SS treatment was higher in ectopic than eutopic ESCs (2.8 +/- 0.27 versus 0.69 +/- 0.07, respectively). Survivin gene silencing in SS-treated ectopic ESCs led to an increase of apoptotic cells (P < 0.05, versus control siRNA). CONCLUSIONS: We demonstrated that survivin plays a critical role in susceptibility of ESCs to apoptosis. Our results indicate that a survivin inhibitor may be effective as a novel treatment for endometriosis.

TAK1 activation for cytokine synthesis and proliferation of endometriotic cells.

Endometriosis causes pelvic pain and infertility in women of reproductive age. We explored TNFalpha-induced specific signaling pathways and gene expressions in endometriotic stromal cells (ESCs). Based on the data of the pathway specific cDNA array, we analyzed the role of TAK1, which is believed to work as a common mediator for NF-kappaB and MAPK pathways. Using the NF-kappaB pathway array, we found that TNFalpha upregulated ICAM-3, IL-6, IL-8, TAK1, JNK2, RelA, and TLR4 expressions. TNFalpha augmented the phosphorylation of TAK1. By transfection of TAK1 siRNA, TNFalpha-induced phosphorylation of IkappaBalpha, JNK1/2, and p38MAPK, as well as IL-6 or IL-8 expression, were repressed. TAK1 silencing in TNFalpha-pretreated ESCs caused a decrease in the proportion of cells in S-phase, and reduced TNFalpha-promoted BrdU incorporation. We provide the first evidence that TNFalpha and its downstream TAK1, which are key mediators for NF-kappaB and MAPK pathways, may be involved in the pathogenesis of endometriosis.