Oxycodone alleviates mifepristone-stimulated human endometrial stromal cell injury by activating the Keap1/Nrf2/HO-1 signaling pathway.

Abstract

Endometrial injury is a common disease in women caused by intrauterine inflammation, infections, and endocrine disorders. Human endometrial stromal cells (hEndoSCs) can maintain endometrial homeostasis and play an important role in repairing endometrial injury. Mifepristone, a steroidal anti-progesterone drug, is widely used in the field of reproductive medicine worldwide. Mifepristone-induced hEndoSC injury has been used to study endometrial injury in vitro. At present, the pathogenesis and potential regulatory mechanisms of oxycodone in endometrial injury remain unknown. We aimed to evaluate the functions of oxycodone in mifepristone-stimulated hEndoSC injury and analyze its potential molecular mechanism. hEndoSC viability, cytotoxicity, and apoptosis were analyzed using the methyl thiazolyl tetrazolium assay, the lactate dehydrogenase assay, and flow cytometry, respectively. Furthermore, the levels of cleaved-Caspase3, Keap1, Nrf2, HO-1, and NQO1 were assessed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and the release of inflammatory cytokines was determined using the enzyme-linked immunosorbent assay. We observed that oxycodone had no adverse effects on hEndoSCs; rather, it protected hEndoSCs against mifepristone-induced endometrial damage, as confirmed by the enhanced cell viability, reduced number of apoptotic cells, decreased Caspase3 activity and inflammatory cytokine secretion, and increased Keap1/Nrf2/HO-1 pathway-related protein expression. In addition, we found that the protective effects of oxycodone on mifepristone-induced hEndoSC injury were inhibited by ML385 (a Keap1/Nrf2/HO-1 inhibitor). In summary, we confirmed that oxycodone alleviates mifepristone-induced hEndoSC injury by activating the Keap1/Nrf2/HO-1 signaling pathway.