Conclusion
HMGB-1 activates the NF-κB pathway via TLR4 to increase cell proliferation, invasion, and the production of various inflammatory markers in HESCs. Thus, HMGB-1, TLR4, and NF-κB may represent potential therapeutic targets for the treatment of endometriosis.
Methods
Ectopic endometrial specimens were retrieved from patients with ovarian endometrioma having laparoscopy. Ectopic HESCs were treated with H2O2 and recombinant HMGB-1 to induce oxidative stress. The effect of oxidative stress on cell proliferation and invasion was demonstrated. Receptors for HMGB-1 in NF-κB pathway (TLR4, RAGE), angiogenic molecule (VEGF), adhesion molecules (ICAM-1, E-cadherin), and inflammatory cytokines were measured simultaneously to the oxidative stress.
Objective
To investigate whether high-mobility group box-1 induces cell proliferation, invasion and mediates inflammation in ectopic human endometrial stromal cells through Toll-like receptor 4.
Results
Ectopic HESCs showed markedly decreased cell viability with the increased release of HMGB-1 following treatment with H2O2. When ectopic HESCs were stressed by rHMGB-1, cell proliferation and cell migration numbers increased significantly in a dose-dependent manner. Increased TLR4 and RAGE mRNA and protein expression levels were noted to rHMGB-1 treatment in a dose-dependent manner. VEGF synthesis was also increased by rHMGB-1 treatment. The gene expression of ICAM-1 was upregulated, whereas that of E-cadherin was downregulated with rHMGB-1 treatment. Interleukin-6, IL-1β, tumor necrosis factor-alpha, and IL-10 were increased significantly by rHMGB-1 treatment. Inversely, after transfection of small interfering RNA against TLR4, rHMGB treatment resulted in decreased cell proliferation and invasion.