ENRICHED ENVIRONMENT PRODUCES MOLECULAR AND PHYSIOLOGICAL CHANGES THAT PREVENTS INDUCED PRETERM DELIVERY IN A MICE MODEL

SCHANDER JULIETA; WOLFSON MANUEL; JURIOL LORENA; JENSEN FEDERICO; CORREA FERNANDO; FRANCHI ANA MARÍA

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica (SAIC), Reunión Conjunta de Sociedades de Biociencias.

Our group developed a murine model of preterm delivery (PTD) induced by the administration of bacterial lipopolysaccharide (LPS) that produces an 85% of PTD. The effects of environmental enrichment (EE), which are mainly positive, seem to be associated with an overall improvement in the psychological and physical wellbeing of animals. The aim of this work was to evaluate the effect of exposition to an EE for reducing PTD rate in our mouse model. EE protocol consisted in housing a group of ten 6-week old BALB/c females in larger cages containing a variety of objects that provide optimal conditions for social interaction, further exploration, visual, cognitive, and voluntary exercise activity. Standard conditions (control environment, CE) consisted of standard laboratory cages housing 4 animals. After 6 weeks females were mated with males in regular cages and then pregnant females returned to EE (or CE) cages till day 15th of pregnancy, when LPS (or saline solution) was administered to evaluate percentage of PTD. We observed that pretreatment with EE felt by 41% LPS-induced PTD and offspring born from these mothers had a normal development. We studied different inflammatory mediators in uterus, and observed an impact of EE in the expression levels of CD14 and TLR-4 that were significantly diminished. Similarly, we observed that EE treatment significantly prevented the increase of NOS activity induced by LPS. Moreover, we analyzed leukocyte infiltration and matrix metalloproteinase 2 and 9 activity in cervical tissue to evaluate signs of cervical ripening, and observed that LPS increased leukocyte infiltration in both groups, but MMP-9 activity was increased only in CE treated mice. Results were analyzed by one or two-way ANOVA as appropriate and comparisons were made by Tukey?s test. Collectively, our results showed a protective effect of the enrichment of the environment against an immune challenge during pregnancy that involves molecular and physiological changes.