Linda Chamorro

Ulcerative colitis (UC) is a highly frequent inflammatory bowel disease (IBD), which causes are unknown. We have shown that the offspring gestated under thyroxine (T4) deficiency, condition named hypothyroxinemia (HTX), shows inflammatory features at the intestine. Moreover, the offspring gestated under HTX (HTX-offspring) suffers strong experimental autoimmune disease. Suggesting that gestational HTX could imprint their offspring with a high immune response after an inflammatory challenge. Thus, we think that the HTX-offspring will be more prone to suffer IBD. To analyze this hypothesis C57BL6 pregnant mice were induced with gestational HTX during E10 to E15 by giving them methimazole in the tap-drinking water. Then, UC was induced to the HTX-offspring or control at postnatal P55 by giving them dextran sodium sulphate (DSS) in the tap-drinking water for six days. Body weight, pathological score of IBD and hidden blood in stool were analyzed daily. Then, mice were sacrificed at day 10 to evaluate their inflammatory response. For that histological analysis were performed in the intestine; the content of cytokines in serum and intestine by ELISA and the populations of innate and adaptive immune cells at the intestine and spleen by flow cytometry. Our results shown that the male and female offspring developed an opposite immune response to UC. The female HTX-offspring were more resistant and the male HTX-offspring were more sensitive to UC compared to their respective female and male control groups. Thus, our results suggest that the immune response of an individual can be set up during gestation and that the normal level of maternal T4 during gestation is fundamental for the proper function of the offspring immune system.