Biological effects and dose-response assessment of diesel exhaust particles on in vitro early embryo development in mice.
An increased risk of early pregnancy loss in women briefly exposed to high levels of ambient particulate matter during the preconceptional period was recently observed. The effects of this exposure on early embryo development are unknown. This study was designed to assess the dose-response and biological effects of diesel exhaust particles (DEP) on in vitro embryo development using the in vitro fertilization (IVF) mouse model. Zygotes obtained from superovulated mice after IVF were randomly cultured in different DEP concentrations (0, 0.2, 2, and 20 microg/cm(2)) for 5 days and observed for their capacity to attach and develop on a fibronectin matrix until day 8. Main outcome measures included blastocyst rates 96 and 120 h after insemination, hatching discriminatory score, total cell count, proportion of cell allocation to inner cell mass (ICM) and trophectoderm (TE), ICM morphology, attachment rate and outgrowth area, apoptosis and necrosis rates, and Oct-4 and Cdx-2 expression. Multivariate analysis showed a negative dose-dependent effect on early embryo development and hatching process, blastocyst cell allocation, and ICM morphology. Although blastocyst attachment and outgrowth were not affected by DEP, a significant impairment of ICM integrity was observed in day 8 blastocysts. Cell death through apoptosis was significantly higher after DEP exposure. Oct-4 expression and the Oct-4/Cdx-2 ratio were significantly decreased in day 5 blastocysts irrespective of DEP concentration. Results suggest that DEP appear to play an important role in disrupting cell lineage segregation and ICM morphological integrity even at lower concentrations, compromising future growth and viability of the blastocyst.
Experimental Air Pollution Laboratory-LIM05, University of São Paulo School of Medicine, São Paulo, Brazil.
Daniela Aparecida Nicolosi Foltran
DA
Januário
Paulo Marcelo
PM
Perin
Mariangela
M
Maluf
Ana Julia
AJ
Lichtenfels
Paulo Hilário
PH
Nascimento Saldiva
D000818:Animals; D000071616:CDX2 Transcription Factor; D016923:Cell Death / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D047108:Embryonic Development / Q000187:drug effects*; D005307:Fertilization in Vitro; D020869:Gene Expression Profiling; D018398:Homeodomain Proteins / Q000235:genetics; D020287:In Situ Nick-End Labeling; D051379:Mice; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D001335:Vehicle Emissions / Q000633:toxicity*
D000071616:CDX2 Transcription Factor; C487514:Cdx2 protein, mouse; D018398:Homeodomain Proteins; D050814:Octamer Transcription Factor-3; D014157:Transcription Factors; D001335:Vehicle Emissions