The modern concept of thyroid disruptors includes synthetic chemicals and bioactive compounds from food that interfere with any aspect of the hypothalamus–pituitary–thyroid axis, thyroid hormone biosynthesis and secretion, blood and transmembrane transport, metabolism and local actions of thyroid hormones. This review highlights relevant disruptors that affect populations through their diet: directly from food itself (fish oil and polyunsaturated fatty acids, pepper, coffee, cinnamon and resveratrol/grapes), through vegetable cultivation (pesticides) and from containers for food storage and cooking (bisphenol A, phthalates and polybrominated diphenyl ethers). Due to the vital role of thyroid hormones during every stage of life, we review effects from the gestational period to adulthood, including evidence from in vitro studies, rodent models, human trials and epidemiological studies.
Karen Jesus Oliveira, Maria Isabel Chiamolera, Gisele Giannocco, Carmen Cabanelas Pazos-Moura and Tania Maria Ortiga-Carvalho
Gabriela Sm Paula, Marianna Wilieman, Karina Ribeiro Silva, Leandra Baptista, Sihem Boudina, Luana L Souza, Thais Bento-Bernardes, Karina Asensi, Regina Coeli dos Santos Goldenberg and Carmen Cabanelas Pazos-Moura
Neuromedin B, a bombesin-like peptide, and its receptor, are expressed in white adipose tissue with undefined roles. Female mice with disruption of neuromedin B receptor (NB-R) exhibited partial resistance to diet-induced obesity leading to our hypothesis that NB-R is involved in adipogenesis. Here we showed that adipose stem/stromal cells (ASC) from perigonadal fat of female NB-R knockout mice, exposed to a differentiation protocol in vitro, accumulated less lipid (45%) than wild-type, suggesting reduced capacity to differentiate under adipogenic input. To further explore mechanisms, preadipocytes 3T3-L1 cells were incubated in the presence of NB-R antagonist (PD168368) during the first three days in culture. Cells were analyzed in the end of the treatment (Day 3) and later when fully differentiated (Day 21). NB-R antagonist induced lower number of cells at day 3 and 21 (33-39%), reduced cell proliferation at day 3 (-53%) and reduced lipid accumulation at day 21 (-86%). The mRNA expressions of several adipocyte differentiation markers were importantly reduced at both days: CEBPb and PPARg, and Fabp4, Plin-1 and Adipoq, and additionally Lep mRNA at day 21. The antagonist had no effect when incubated with mature 3T3-L1 adipocytes. Therefore, genetically disruption of NB-R in mice ASC or pharmacological antagonism of NB-R in 3T3-L1 cells impairs adipogenesis. The mechanisms suggested by results in 3T3-L1 cells involve reduction of cell proliferation and of early genes expressions, leading to decreased number of mature adipocytes. We speculate that NB-R antagonism may be useful to limit the increase in adiposity due to pre-adipocyte differentiation