TY - JOUR
T1 - Inhibition of lysyl oxidase by prostaglandin E2 via EP2/EP4 receptors in human amnion fibroblasts
T2 - Implications for parturition
AU - Liu, Chao
AU - Zhu, Ping
AU - Wang, Wangsheng
AU - Li, Wenjiao
AU - Shu, Qun
AU - Chen, Zi Jiang
AU - Myatt, Leslie
AU - Sun, Kang
PY - 2016/3/15
Y1 - 2016/3/15
N2 - The underlying mechanism leading to rupture of the membranes at parturition is not fully understood. Lysyl oxidase (LOX) cross-links collagen fibrils thereby increasing the tensile strength of the membranes. Thus, understanding the regulation of LOX expression may be of crucial importance for elucidation of the process of rupture of the fetal membranes. Prostaglandin E2 (PGE2), mainly produced in the amnion, plays crucial roles during human parturition. However it is not known whether PGE2 regulates LOX expression in the fetal membranes. Using primary human amnion fibroblasts, we showed that addition of PGE2 decreased LOX mRNA and protein levels, which were blocked by inhibition of EP2/EP4 receptors and the receptor-coupled cAMP/PKA pathway. EP2/EP4 receptor agonists and stimulators of the cAMP/PKA pathway consistently decreased LOX expression. Furthermore, PGE2 induced cyclo-oxygenase-2 (COX-2) expression, a key enzyme in PGE2 production, via an EP2 and EP4 receptor-coupled cAMP/PKA pathway. Small interfering RNA-mediated knock-down of COX-2 expression significantly increased the basal expression of LOX. In addition, an increase in COX-2 and a reciprocal decrease in LOX abundance occurred in amnion tissue following labor at term. In conclusion, we have revealed a feed-forward loop of induction of COX-2 and reduction in LOX expression by PGE2 acting via an EP2/EP4 receptor-coupled cAMP/PKA pathway in human amnion fibroblasts toward the end of gestation, which may play a significant role in the rupture of fetal membranes.
AB - The underlying mechanism leading to rupture of the membranes at parturition is not fully understood. Lysyl oxidase (LOX) cross-links collagen fibrils thereby increasing the tensile strength of the membranes. Thus, understanding the regulation of LOX expression may be of crucial importance for elucidation of the process of rupture of the fetal membranes. Prostaglandin E2 (PGE2), mainly produced in the amnion, plays crucial roles during human parturition. However it is not known whether PGE2 regulates LOX expression in the fetal membranes. Using primary human amnion fibroblasts, we showed that addition of PGE2 decreased LOX mRNA and protein levels, which were blocked by inhibition of EP2/EP4 receptors and the receptor-coupled cAMP/PKA pathway. EP2/EP4 receptor agonists and stimulators of the cAMP/PKA pathway consistently decreased LOX expression. Furthermore, PGE2 induced cyclo-oxygenase-2 (COX-2) expression, a key enzyme in PGE2 production, via an EP2 and EP4 receptor-coupled cAMP/PKA pathway. Small interfering RNA-mediated knock-down of COX-2 expression significantly increased the basal expression of LOX. In addition, an increase in COX-2 and a reciprocal decrease in LOX abundance occurred in amnion tissue following labor at term. In conclusion, we have revealed a feed-forward loop of induction of COX-2 and reduction in LOX expression by PGE2 acting via an EP2/EP4 receptor-coupled cAMP/PKA pathway in human amnion fibroblasts toward the end of gestation, which may play a significant role in the rupture of fetal membranes.
KW - Amnion
KW - Cyclooxygenase-2
KW - Lysyl oxidase
KW - Parturition
KW - Prostaglandin E2
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U2 - 10.1016/j.mce.2016.01.022
DO - 10.1016/j.mce.2016.01.022
M3 - Article
C2 - 26826430
AN - SCOPUS:84959326831
VL - 424
SP - 118
EP - 127
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
SN - 0303-7207
ER -