Impact of antenatal corticotherapy on lipid metabolism and macrophage profile in lactation : study in animals and humans

Orientador: Gabriel Forato AnhêDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: A lactação representa um período no qual há um desvio energético do organismo materno para a glândula mamária a fim de prover a prole. Os glicocorticoides, utilizados para diminuir comorbidades associadas ao parto pré-termo, são considerados seguros e eficazes, porém pouco se sabe sobre o seu efeito no metabolismo lipídico e no perfil de macrófagos durante o período de lactação. Dessa maneira, o objetivo desse estudo foi avaliar o impacto da corticoterapia durante a gestação para o metabolismo lipídico e perfil de macrófagos no leite e na glândula mamária. Para atingir esse objetivo, os animais foram divididos em grupos que utilizaram apenas dexametasona ou em associação com a pioglitazona durante a gestação, ou que não utilizaram nenhum tratamento. Foram estudados genes do perfil de ativação de macrófagos além de genes envolvidos no metabolismo lipídico durante a lactação através da Reação em Cadeia da Polimerase (PCR). Ainda realizamos dosagens bioquímicas de triglicerídeos no leite e no sangue das mães e dos filhotes. Outras dosagens bioquímicas também foram realizadas, como glicemia e colesterol. Também foram avaliados o consumo alimentar, a ingestão hídrica e a evolução de pesos das mães, assim como a evolução de pesos da prole. Além disso, o teste de produção de VLDL foi realizado para se avaliar o papel hepático no desvio energético para a glândula mamária. De voluntárias humanas, foram coletados o soro e o leite da mãe e o soro do recém- nascido de pacientes que utilizaram betametasona durante a gestação (grupo Caso) ou que não utilizaram (grupo Controle) para avaliações por PCR e dosagens bioquímicas. Os nossos resultados em animais demonstraram que o glicocorticoide no final da gestação causa um aumento da subpopulação de macrófagos M2, que pode estar associado à uma deficiência de PPAR? e de seus genes alvos (LPL, CD36 e CideA). Essa deficiência modifica o desvio energético fisiológico que ocorre durante a lactação, aumentando as concentrações de triglicerídeos no soro em paralelo à sua diminuição no leite, conforme mostrado pelo desafio oral com ácidos graxos. Foi observado no leite das voluntárias um aumento de macrófagos M2 e um diminuição de triglicerídeos, de acordo com os resultados observados em animais. Sendo assim, podemos inferir que o uso da corticoterapia antenatal pode acarretar a diminuição de triglicerídeos no leite materno através de um desvio da polarização de macrófagos para o eixo M2Abstract: Lactation represents a period in which there is an energy shift from the maternal organism to the mammary gland to provide offspring. Glucocorticoids, used to reduce comorbidities associated with preterm delivery, are considered safe and effective, but little is known about their effect on lipid metabolism and macrophage profile during lactation. Thus, the aim of this study was to evaluate the impact of corticosteroid therapy during pregnancy on lipid metabolism and macrophage profile in milk and mammary gland. To achieve this goal, the animals were divided into groups that used only dexamethasone or in combination with pioglitazone during pregnancy, or did not use any treatment. We studied macrophage profile genes involved in lipid metabolism during lactation through Polymerase Chain Reaction (PCR), as well as biochemical dosages of triglycerides in the milk and blood of mothers and pups. Other biochemical dosages were also performed, such as blood glucose and cholesterol. The dietary intake, water intake and weight evolution of the mothers, as well as the weight evolution of the offspring were also evaluated. In addition, the VLDL production test was performed to evaluate the hepatic role in energy deviation to the mammary gland. From human volunteers, mother's serum and milk and newborn¿s serum were collected from patients who used betamethasone during pregnancy (Case group) or who did not use it (Control group) for PCR evaluations and biochemical dosages. Our results in animals have shown that late gestational glucocorticoid causes increased subpopulation of M2 macrophages, which may be associated with a deficiency of PPAR? and its target genes (LPL, CD36 and CideA). This deficiency modifies the physiological energy deviation that occurs during lactation, increasing serum triglyceride concentrations in parallel with its decrease in milk, as shown by oral fatty acid challenge. An increase in M2 macrophages and a decrease in triglycerides were observed in the volunteers' milk, according to the results observed in animals. Thus, we can conclude that the use of antenatal corticosteroid therapy can lead to a decrease in triglycerides in breast milk through a deviation of macrophage polarization to the M2 axisMestradoFarmacologiaMestra em Farmacologia164897/2017-8CNP

Dexamethasone programs lower fatty acid absorption and reduced PPAR-γ and fat/CD36 expression in the jejunum of the adult rat offspring

The progeny of rats born and breastfed by mothers receiving dexamethasone (DEX) during pregnancy exhibits permanent reduction in body weight and adiposity but the precise mechanisms related to this programming are not fully understood. In order to clarify this issue, the present study investigated key aspects of lipoprotein production and lipid metabolism by the liver and the intestine that would explain the reduced adiposity seen in the adult offspring exposed to DEX in utero. Female Wistar rats were treated with DEX (0.1 mg/kg/day) between the 15th and the 21st days of pregnancy, while control mothers were treated with vehicle. Male offspring born to control mothers were nursed by either adoptive control mothers (CTL/CTL) or DEX-treated mothers (CTL/DEX). Male offspring born to DEX-treated mothers were nursed by either control mothers (DEX/CTL) or adoptive DEX-treated mothers (DEX/DEX). We found that only the male DEX/DEX offspring had reduced adiposity. Additionally, male DEX/DEX progeny had lower circulating triacylglycerol (TAG) levels only in fed-state. The four groups of offspring presented similar energy expenditure, respiratory quotient and very low-density lipoprotein (VLDL) production. On the other hand, DEX/DEX rats displayed reduced TAG levels after gavage with olive oil and reduced expression of fatty acid translocase Cd36 (Fat/Cd36) and peroxisome proliferator-activated receptor γ (Pparg) in the jejunum. Altogether, our study supports the notion that reduced fat absorption by the jejunum may contribute to the lower adiposity of the adult offspring born and breastfed by mothers treated with DEX during pregnancy265CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão tem2013/07607-8; 2015/23285-6; 2016/13138-9; 2019/03196-0; 2019/19488-0; 2020/06397-

Agomelatine reduces circulating triacylglycerides and hepatic steatosis in fructose-treated rats

Agomelatine (AGO) is an antidepressant drug with agonistic activity at melatonin receptor 1 (MT1) and MT2 and with neutral antagonistic activity at serotonin receptor 5-HT2C. Although experimental studies show that melatonin reduces hypertriglyceridemia and hepatic steatosis induced by excessive fructose intake, no studies have tested if AGO exerts similar actions. To address this issue we have treated male Wistar rats with fructose (15% in the drinking water) and/or AGO (40 mg/kg/day) for two weeks. AGO reduced body weight gain, feeding efficiency and hepatic lipid levels without affecting caloric intake in fructose-treated rats. AGO has also decreased very low-density lipoprotein (VLDL) production and circulating TAG levels after an oral load with olive oil. Accordingly, treatment with AGO reduced the hepatic expression of fatty acid synthase (Fasn), a limiting step for hepatic de novo lipogenesis (DNLG). The expression of apolipoprotein B (Apob) and microsomal triglyceride transfer protein (Mttp) in the ileum, two crucial proteins for intestinal lipoprotein production, were also downregulated by treatment with AGO. Altogether, the present data show that AGO mimics the metabolic benefits of melatonin when used in fructose-treated rats. This study also suggests that it is relevant to evaluate the potential of AGO to treat metabolic disorders in future clinical trials