Senescence of Primary Amniotic Cells via Oxidative DNA Damage

Abstract

ObjectiveOxidative stress is a postulated etiology of spontaneous preterm birth (PTB) and preterm prelabor rupture of the membranes (pPROM); however, the precise mechanistic role of reactive oxygen species (ROS) in these complications is unclear. The objective of this study is to examine impact of a water soluble cigarette smoke extract (wsCSE), a predicted cause of pregnancy complications, on human amnion epithelial cells.MethodsAmnion cells isolated from fetal membranes were exposed to wsCSE prepared in cell culture medium and changes in ROS levels, DNA base and strand damage was determined by using 2′7′-dichlorodihydro-fluorescein and comet assays as well as Fragment Length Analysis using Repair Enzymes (FLARE) assays, respectively. Western blot analyses were used to determine the changes in mass and post-translational modification of apoptosis signal-regulating kinase (ASK1), phospho-p38 (P-p38 MAPK), and p19arf. Expression of senescence-associated β-galectosidase (SAβ-gal) was used to confirm cell ageing in situ.ResultsROS levels in wsCSE-exposed amnion cells increased rapidly (within 2 min) and significantly (p<0.01) at all-time points, and DNA strand and base damage was evidenced by comet and FLARE assays. Activation of ASK1, P-p38 MAPK and p19Arf correlated with percentage of SAβ-gal expressing cells after wsCSE treatment. The antioxidant N-acetyl-L-cysteine (NAC) prevented ROS-induced DNA damage and phosphorylation of p38 MAPK, whereas activation of ASK1 and increased expression of p19Arf were not significantly affected by NAC.ConclusionsThe findings support the hypothesis that compounds in wsCSE induces amnion cell senescence via a mechanism involving ROS and DNA damage. Both pathways may contribute to PTB and pPROM. Our results imply that antioxidant interventions that control ROS may interrupt pathways leading to pPROM and other causes of PTB.

Chorioamniotic membrane senescence: a signal for parturition?

“…Pathologic activation of premature senescence of fetoplacental tissues and SASP may be a predisposing factor to preterm birth and premature rupture of membranes, even in the absence of infection. 15,46 Future studies can validate this concept of premature senescence as a pathologic mechanism leading to adverse pregnancy outcome. …”

“…In vitro, we have shown induction of senescence by oxidative stress in fetal cells. 15,46 SASP markers generated from senescent fetal cells may constitute sterile intrauterine inflammation and function as a signal to promote labor. Therefore, the primary objective of this study is to investigate senescence-related morphologic and biochemical changes in chorioamniotic membranes in women who experienced term labor.…”

The influence of oxidative stress and autophagy cross regulation on pregnancy outcome

“…This induction of oxidative stress was demonstrated to provoke telomere reduction, cell cycle arrest, and senescence via activation of the p38MAPK pathway. In contrast, LPS treatment mainly activated the classic NF-kB inflammatory pathway (Menon et al 2013;Behnia et al 2016). Elevated levels of oxidative stress markers have been described in the maternal-fetal compartment from women in PTL and in deliveries preceded by PPROM (Bredeson et al 2014;Dutta et al 2016).…”

Positive and negative effects of cellular senescence during female reproductive aging and pregnancy

“…Hence, cellular senescence in fetal membranes is suggested to promote pregnancy complications. Indeed, increasing the number of senescent cells in fetal membranes, such as those induced by cigarette smoke extract, is thought to cause PTB (Menon et al 2013).…”