RUNX1 GENE EXPRESSION CHANGES IN SMOKING WOMENS PLACENTAS

Introduction: Placenta can be affected by environmental factors such as exposure to cigarette smoke. This exposure in the fetal context is considered a risk factor for the development of short-term postnatal diseases such as asthma. Asthma is a inflammatory disease characterized by the predominant acquisition of CD4 T-lymphocytes of the Th2 type. Transcription factors such as GATA3 and STAT6 actively participate in the process of differentiation of virgin T lymphocytes towards the Th2 profile, while transcription factors such as STAT1, T-BET, RUNX1 and RUNX3 participate in the differentiation towards the Th1 profile. The objective of current study is to evaluate the expression profile of STAT1, T-BET, GATA3, RUNX1 and RUNX3 among placentas from smoking and non-smoking women and determine the impact of exposure to cigarette smoke during the gestation period. Methods: STAT1, T-BET, RUNX1 and RUNX3 protein and mRNA were determined by Immunohistochemistry and by real time PCR respectively. In this study, 34 paraffin-embedded placentas were evaluated (14 of female smokers and 20 of non-smokers). Additionaly global methylation was determined by ELISA. Resuts: In this study we demonstrated significant increases in RUNX1 transcription factor expression in placentas of female smokers compared to non-smoking women. Similarly, we observed significant increases in the mRNA expression of GATA3 and RUNX3. Finally, we identified a higher frequency of low birth weight infants in cases of exposure to cigarette smoke during pregnancy. Discussion: Our data contribute as a first approximation to the understanding of the genetic and clinical impact of environmental exposure during pregnancy and its importance in maternal and fetal health.