Tert-Butyl Hydroperoxide Stimulated Apoptosis Independent of Prostaglandin E 2 and IL-6 in the HTR-8/SVneo Human Placental Cell Line

• Published in: Reproductive sciences (Thousand Oaks, Calif.) Vol. 27; no. 11; p. 2104
• Main Authors: Loch-Caruso, Rita, Korte, Cassandra S, Hogan, Kelly A, Liao, Sarah, Harris, Craig
• Format: Journal Article
• Language: English
• Published: United States 01.11.2020
• Subjects: Apoptosis - drug effects; Cell Line; Dinoprostone - metabolism; Female; Humans; Interleukin-6 - metabolism; Placenta - drug effects; Placenta - metabolism; Pregnancy; Reactive Oxygen Species - metabolism; tert-Butylhydroperoxide - administration & dosage; Trophoblasts - drug effects; Trophoblasts - metabolism; Oxidative stress; Prostaglandins; Reactive oxygen species; Trophoblasts; Apoptosis
• ISSN: 1933-7205

Significant gaps exist in our knowledge of how cellular redox status, sometimes referred to as oxidative stress, impacts placental trophoblasts. The present study used tert-butyl hydroperoxide (TBHP) as a known generator of reactive oxygen species (ROS) in the extravillous trophoblast cell line HTR-8/SVneo to examine the role of cellular redox disruption of prostaglandin E (PGE ) and the cytokine IL-6 in cell death. Cells were exposed to 0, 12.5, 25, or 50 μM TBHP for 4, 8, and 24 h to ascertain effects on cell viability, caspase 3/7 activity, PGE release, PTGS2 mRNA expression, and IL-6 release. Experiments with inhibitors included the cyclooxygenase inhibitor indomethacin, mitogen-activated protein kinase inhibitors (PD169316, U0126, or SP600125), or treatments to counter expected consequences of TBHP-stimulated generation of ROS (deferoxamine [DFO], butylated hydroxyanisole [BHA], and N,N'-diphenyl-1,4-phenylenediamine [DPPD]) using 24-h exposure to 50 μM TBHP. Cell viability, measured by ATP content, decreased 24% relative to controls with a 24-h exposure to 50 μM TBHP, but not at lower TBHP concentrations nor at earlier time points. Exposure to 50 μM TBHP increased caspase 3/7 activity, an indicator of apoptosis, after 8 and 24 h. Antioxidant treatment markedly reduced TBHP-stimulated caspase 3/7 activity, PGE release, and IL-6 release. TBHP-stimulated IL-6 release was blocked by PD169316 but unaltered by indomethacin. These data suggest that TBHP-stimulated IL-6 release and caspase 3/7 activation were independent of PGE yet were interrupted by treatments with known antioxidant properties, providing new insight into relationships between PGE , IL-6, and apoptosis under conditions of chemically induced cellular oxidation.