Background:
Recurrent miscarriage (RM) affects 1%–3% of pregnancies. However, in almost 50% of cases, the cause is unknown. Increasing evidence have shown that benzo(a)pyrene [B(a)P], a representative of polycyclic aromatic hydrocarbons (PAHs), is correlated with miscarriage. However, the underlying mechanisms of B(a)P/benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE)-induced trophoblast cell dysfunctions and miscarriage remain largely unknown.
Objective:
The objective was to discover the role(s) of a novel lncRNA,
lnc-HZ09
, in the regulation of BPDE-inhibited migration and invasion of trophoblast cells and the occurrence of miscarriage.
Method:
Human trophoblast cells were treated with 0, 0.25, 0.5,
BPDE with or without corresponding
lnc-HZ09
silencing or overexpression. Using these cells, we evaluated cell migration and invasion, the mRNA and protein levels of members of the PLD1/RAC1/CDC42 pathway, the regulatory roles of lnc-HZ09 in PLD1 transcription and mRNA stability, and lnc-HZ09 transcription and stability. Human villous tissues were collected from RM (
) group and their matched healthy control (HC,
) group. We evaluated the levels of BPDE-DNA adducts, lnc-HZ09, and the mRNA and protein expression of members of the PLD1/RAC1/CDC42 pathway, and correlated their relative expression levels. We further constructed 0, 0.05 or
B(a)P-induced mouse miscarriage model (each
), in which the mRNA and protein expression of members of the Pld1/Rac1/Cdc42 pathway were measured.
Results:
We identified a novel
lnc-HZ09
. Human trophoblast cells treated with
lnc-HZ09
exhibited less cell migration and invasion. In addition, the levels of this lncRNA were higher in villous tissues from women with recurrent miscarriage than those from healthy individuals. SP1-mediated PLD1 mRNA levels were lower, and HuR-mediated PLD1 mRNA stability was less in trophoblast cells overexpressing
lnc-HZ09
. However, trophoblast cells treated with MSX1 had higher levels of
lnc-HZ09
, and METTL3-mediated m6A methylation on
lnc-HZ09
resulted in greater
lnc-HZ09
RNA stability. In BPDE-treated human trophoblast cells and in RM villous tissues, MSX1-mediated
lnc-HZ09
transcription and METTL3-mediated
lnc-HZ09
stability were both greater. In our mouse miscarriage model, B(a)P-treated mice had lower mRNA and protein levels of members of the Pld1/Rac1/Cdc42 pathway.
Discussion:
These results suggest that in human trophoblast cells, BPDE exposure up-regulated
lnc-HZ09
level, suppressed PLD1/RAC1/CDC42 pathway, and inhibited migration and invasion, prov...