RESUMO
Introduction: Maternal obesity poses risks for both mother and offspring during pregnancy, with underlying mechanisms remaining largely unexplored. Obesity is associated with microbial gut dysbiosis and low-grade inflammation, and also the diet has a major impact on these parameters. This study aimed to investigate how maternal obesity and diet contribute to changes in immune responses, exploring potential associations with gut microbiota dysbiosis and adverse pregnancy outcomes in mice. Methods: Before mating, C57BL/6 mice were assigned to either a high-fat-diet (HFD) or low-fat-diet (LFD) to obtain obese (n=17) and lean (n=10) mice. To distinguish between the effects of obesity and diet, 7 obese mice were switched from the HFD to the LFD from day 7 until day 18 of pregnancy ("switch group"), which was the endpoint of the study. T helper (Th) cell subsets were studied in the spleen, mesenteric lymph nodes (MLN) and Peyer's patches (PP), while monocyte subsets and activation status were determined in maternal blood (flow cytometry). Feces were collected before and during pregnancy (day 7,14,18) for microbiota analysis (16S rRNA sequencing). Pregnancy outcome included determination of fetal and placental weight. Results: Obesity increased splenic Th1 and regulatory T cells, MLN Th1 and PP Th17 cells and enhanced IFN-γ and IL-17A production by splenic Th cells upon ex vivo stimulation. Switching diet decreased splenic and PP Th2 cells and classical monocytes, increased intermediate monocytes and activation of intermediate/nonclassical monocytes. Obesity and diet independently induced changes in the gut microbiota. Various bacterial genera were increased or decreased by obesity or the diet switch. These changes correlated with the immunological changes. Fetal weight was lower in the obese than the lean group, while placental weight was lower in the switch than the obese group. Discussion: This study demonstrates that obesity and diet independently impact peripheral and intestinal immune responses at the end of pregnancy. Simultaneously, both factors affect specific bacterial gut genera and lead to reduced fetal or placental weight. Our data suggest that switching diet during pregnancy to improve maternal health is not advisable and it supports pre/probiotic treatment of maternal obesity-induced gut dysbiosis to improve maternal immune responses and pregnancy outcome.
Assuntos
Dieta Hiperlipídica , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Obesidade , Resultado da Gravidez , Animais , Gravidez , Feminino , Microbioma Gastrointestinal/imunologia , Camundongos , Dieta Hiperlipídica/efeitos adversos , Obesidade/imunologia , Obesidade/microbiologia , Disbiose/imunologia , Obesidade Materna/imunologiaRESUMO
CONTEXT: Circulating adiponectin levels are decreased in pregnant women with obesity or gestational diabetes, and this is believed to contribute to the insulin resistance and increased risk of fetal overgrowth associated with these conditions. However, the molecular mechanisms regulating adiponectin secretion from maternal adipose tissues in pregnancy are poorly understood. OBJECTIVE: We tested the hypothesis that obesity in pregnancy is associated with adipose tissue insulin resistance and increased adiponectin ubiquitination and degradation, caused by inflammation and endoplasmic reticulum (ER) stress. METHODS: Visceral adipose tissues were collected from lean and obese pregnant humans and mice. Total and ubiquitinated adiponectin, and markers of inflammation, ER stress, and insulin resistance were examined in adipose tissues. The role of insulin, inflammation, and ER stress in mediating adiponectin ubiquitination and degradation was examined using 3T3L-1 adipocytes. RESULTS: Obesity in pregnancy is associated with adipose tissue inflammation, ER stress, insulin resistance, increased adiponectin ubiquitination, and decreased total abundance of adiponectin. Adiponectin ubiquitination was increased in visceral fat of obese pregnant women as compared to lean pregnant women. We further observed that insulin prevents, whereas ER stress and inflammation promote, adiponectin ubiquitination and degradation in differentiated 3T3-L1 adipocytes. CONCLUSION: We have identified adiponectin ubiquitination as a key mechanism by which obesity diminishes adiponectin secretion in pregnancy. This information will help us better understand the mechanisms controlling maternal insulin resistance and fetal growth in pregnancy and may provide a foundation for the development of strategies aimed at improving adiponectin production in pregnant women with obesity or gestational diabetes.
Assuntos
Adiponectina/metabolismo , Diabetes Gestacional/metabolismo , Insulina/metabolismo , Obesidade Materna/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Adiponectina/análise , Adulto , Animais , Estudos de Coortes , Diabetes Gestacional/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Recém-Nascido , Resistência à Insulina/imunologia , Gordura Intra-Abdominal/imunologia , Gordura Intra-Abdominal/patologia , Masculino , Camundongos , Obesidade Materna/imunologia , Obesidade Materna/patologia , Gravidez , Proteólise , Ubiquitinação/imunologiaRESUMO
Obesity is prevalent among women of reproductive age and is associated with increased risk of developing multiple pregnancy disorders. Pregnancy must induce immune tolerance to avoid fetal rejection, while obesity can cause chronic inflammation through activating the immune system. Impaired maternal immuno-tolerance leads to pregnancy failure, such as recurrent spontaneous abortion (RSA), one of the most common complications during early pregnancy. How does maternal immune response change under obesity stress in normal pregnancy and RSA? In turn, is obesity affected by different gestational statuses? Limited information is presently available now. Our study investigated pregnancy outcomes and maternal immune responses in two murine models (normal pregnancy and spontaneous abortion models) after obesity challenge with a high-fat diet (HFD). Abortion-prone mice fed HFD had significantly higher weight gains during pregnancy than normal pregnant mice with HFD feeding. Nonetheless, the embryo implantation and resorption rates were comparable between HFD and normal chow diet (NCD)-fed mice in each model. Evaluation of immune cell subsets showed HFD-induced obesity drove the upregulation of activated NK cell-activating receptor (NKp46)+ NK cells and pro-inflammatory macrophages (MHCIIhigh Mφ) as well as CD4+ and CD8+ T cells in the normal pregnancy group. However, in the abortion-prone group, relative more immature NK cells with decreased activity phenotypes were found in obese mice. Moreover, there were increased DCreg (CD11bhigh DC) cells and decreased CD4+ and CD8+ T cells detected in the HFD abortion-prone mice relative to those fed the NCD diet. Our findings reveal how pregnancy obesity and maternal immune regulation are mutually influenced. It is worth noting that the abortion-prone model where active maternal immune status was intensified by obesity, in turn stimulated an overcompensation response, leading to an over-tolerized immune status, and predisposing to potential risks of perinatal complications.
Assuntos
Aborto Habitual/imunologia , Histocompatibilidade Materno-Fetal , Obesidade Materna/imunologia , Útero/imunologia , Aborto Habitual/metabolismo , Aborto Habitual/fisiopatologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Cultivadas , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Ganho de Peso na Gestação , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Obesidade Materna/metabolismo , Obesidade Materna/fisiopatologia , Fenótipo , Gravidez , Útero/metabolismo , Útero/fisiopatologiaRESUMO
Pregravid obesity has been shown to disrupt the development of the offspring's immune system and increase susceptibility to infection. While the mechanisms underlying the impact of maternal obesity on fetal myeloid cells are emerging, the consequences for T cells remain poorly defined. In this study, we collected umbilical cord blood samples from infants born to lean mothers and mothers with obesity and profiled CD4 T cells using flow cytometry and single cell RNA sequencing at resting and following ex vivo polyclonal stimulation. We report that maternal obesity is associated with higher frequencies of memory CD4 T cells suggestive of in vivo activation. Moreover, single cell RNA sequencing revealed expansion of an activated subset of memory T cells with maternal obesity. However, ex vivo stimulation of purified CD4 T cells resulted in poor cytokine responses, suggesting functional defects. These phenotypic and functional aberrations correlated with methylation and chromatin accessibility changes in loci associated with lymphocyte activation and T cell receptor signaling, suggesting a possible link between maternal obesogenic environment and fetal immune reprogramming. These observations offer a potential explanation for the increased susceptibility to microbial infection in babies born to mothers with obesity.
Assuntos
Biomarcadores , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Epigênese Genética , Sangue Fetal/citologia , Imunofenotipagem , Montagem e Desmontagem da Cromatina , Citocinas/metabolismo , Metilação de DNA , Feminino , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Obesidade Materna/sangue , Obesidade Materna/genética , Obesidade Materna/imunologia , Obesidade Materna/metabolismo , Gravidez , Análise de Célula Única/métodos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , TranscriptomaRESUMO
Overweight and obesity during pregnancy have been associated with increased birth weight, childhood obesity, and noncommunicable diseases in the offspring, leading to a vicious transgenerational perpetuating of metabolic derangements. Key components in intrauterine developmental programming still remain to be identified. Obesity involves chronic low-grade systemic inflammation that, in addition to physiological adaptations to pregnancy, may potentially expand to the placental interface and lead to intrauterine derangements with a threshold effect. Animal models, where maternal inflammation is mimicked by single injections with lipopolysaccharide (LPS) resembling the obesity-induced immune profile, showed increased adiposity and impaired metabolic homeostasis in the offspring, similar to the phenotype observed after exposure to maternal obesity. Cytokine levels might be specifically important for the metabolic imprinting, as cytokines are transferable from maternal to fetal circulation and have the capability to modulate placental nutrient transfer. Maternal inflammation may induce metabolic reprogramming at several levels, starting from the periconceptional period with effects on the oocyte going through early stages of embryonic and placental development. Given the potential to reduce inflammation through inexpensive, widely available therapies, examinations of the impact of chronic inflammation on reproductive and pregnancy outcomes, as well as preventive interventions, are now needed.
Assuntos
Desenvolvimento Infantil/fisiologia , Desenvolvimento Fetal/imunologia , Obesidade Materna/imunologia , Obesidade Infantil/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Animais , Criança , Modelos Animais de Doenças , Feminino , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Fenômenos Fisiológicos da Nutrição Materna/imunologia , Troca Materno-Fetal/imunologia , Redes e Vias Metabólicas/imunologia , Obesidade Materna/complicações , Obesidade Materna/metabolismo , Obesidade Materna/terapia , Obesidade Infantil/metabolismo , Obesidade Infantil/prevenção & controle , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/prevenção & controleRESUMO
PROBLEM: Prenatal exposure to metabolic dysregulation arising from maternal obesity can have negative health consequences in post-natal life. To date, the specific effects of maternal obesity on fetal immunity at a cellular level have not been well characterized. METHOD OF STUDY: Using cord blood mononuclear cells (CBMCs) and cord plasma (n = 9/group) isolated from infants born to women with a high body mass index (BMI>25kg/m2 ) compared to women with a normal BMI (18-25kg/m2 ), we evaluated differences in immune cell populations using single-cell mass cytometry (CyTOF). CBMCs were matched according to potentially confounding variables, such as maternal and gestational age, ethnicity, smoking status, and gravidity. Statistical results were adjusted for fetal sex. Data were analyzed by viSNE and FlowSOM softwares in Cytobank™ . RESULTS: In newborn CBMCs from women with high BMI, we observed changes in frequency and phenotype of immune cell populations, including significant increases in CD4+ T cells and decreases in myeloid cell populations. IL-12p40 and MDC concentrations were significantly elevated in the high BMI group compared to control. CONCLUSION: This study demonstrates an association between maternal obesity and fetal immunity. Our results warrant following long-term immunologic outcomes and associated clinical risks in children born to women with a high pre-pregnancy BMI.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Sangue Fetal/citologia , Células Mieloides/imunologia , Obesidade Materna/imunologia , Proteínas ADAM/metabolismo , Índice de Massa Corporal , Células Cultivadas , Feminino , Humanos , Recém-Nascido , Subunidade p40 da Interleucina-12/metabolismo , Masculino , Espectrometria de Massas , Fenótipo , Gravidez , Risco , Análise de Célula Única , Proteínas Supressoras de Tumor/metabolismo , Regulação para CimaRESUMO
Inflammation is often equated to the physiological response to injury or infection. Inflammatory responses defined by cytokine storms control cellular mechanisms that can either resolve quickly (i.e., acute inflammation) or remain prolonged and unabated (i.e., chronic inflammation). Perhaps less well-appreciated is the importance of inflammatory processes central to healthy pregnancy, including implantation, early stages of placentation, and parturition. Pregnancy juxtaposed with disease can lead to the perpetuation of aberrant inflammation that likely contributes to or potentiates maternal morbidity and poor fetal outcome. Maternal obesity, a prevalent condition within women of reproductive age, associates with increased risk of developing multiple pregnancy disorders. Importantly, chronic low-grade inflammation is thought to underlie the development of obesity-related obstetric and perinatal complications. While diverse subsets of uterine immune cells play central roles in initiating and maintaining healthy pregnancy, uterine leukocyte dysfunction as a result of maternal obesity may underpin the development of pregnancy disorders. In this review we discuss the current knowledge related to the impact of maternal obesity and obesity-associated inflammation on uterine immune cell function, utero-placental establishment, and pregnancy health.
Assuntos
Inflamação/patologia , Obesidade Materna/imunologia , Útero/imunologia , Animais , Feminino , Humanos , Modelos Biológicos , Placenta/patologia , GravidezRESUMO
: It was previously demonstrated that non-allergen-sensitized rodents born to mothers exposed to a high-fat diet (HFD) spontaneously develop lower respiratory compliance and higher respiratory resistance. In the present study, we sought to determine if mice born to mothers consuming HFD would exhibit changes in inflammatory response and lung remodeling when subjected to ovalbumin (OVA) sensitization/challenge in adult life. Mice born to dams consuming either HFD or standard chow had increased bronchoalveolar lavage (BAL) levels of IL-1ß, IL-4, IL-5, IL-10, IL-13, TNF-α and TGF-ß1 after challenge with OVA. IL-4, IL-13, TNF-α and TGF-ß1 levels were further increased in the offspring of HFD-fed mothers. Mice born to obese dams also had exacerbated values of leukocyte infiltration in lung parenchyma, eosinophil and neutrophil counts in BAL, mucus overproduction and collagen deposition. The programming induced by maternal obesity was accompanied by increased expression of miR-155 in peripheral-blood mononuclear cells and reduced miR-133b in trachea and lung tissue in adult life. Altogether, the present data support the unprecedented notion that the progeny of obese mice display exacerbated responses to sensitization/challenge with OVA, leading to the intensification of the morphological changes of lung remodeling. Such changes are likely to result from long-lasting changes in miR-155 and miR-133b expression.
Assuntos
Remodelação das Vias Aéreas , Citocinas/imunologia , Inflamação/imunologia , Obesidade Materna/imunologia , Hipersensibilidade Respiratória/imunologia , Animais , Líquido da Lavagem Broncoalveolar , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Eosinófilos/imunologia , Feminino , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , MicroRNAs/genética , Neutrófilos/imunologia , Ovalbumina , Gravidez , Células Th2/imunologiaRESUMO
Obesity is seen as a low grade inflammatory state, and is associated with adverse pregnancy outcomes. Disturbed macrophage characteristics might be essential in obesity associated pregnancy pathology via effects on the regulation of angiogenesis and placental development. This study aims to address the effects of maternal obesity on macrophage subsets in the decidua of women with term uncomplicated pregnancies. Macrophages were isolated from the decidua basalis and decidua parietalis of women with pre-gravid BMIâ¯<â¯25 (control) and BMIâ¯>â¯30 (obese). Macrophages were characterized and quantified using multi-color flow cytometry. Placentas of 10 obese and 10 control women after an uncomplicated term pregnancy were included. The decidua parietalis, but not decidua basalis, showed significantly lower levels of M1-type (HLA-DR+, CD163-) macrophages (pâ¯<â¯0.05) in obese women (4,3% of total macrophages) compared to control women (5,3% of total macrophages). The lower levels of M1 macrophages, considered to be pro-inflammatory, might indicate a mechanism to compensate for the pro-inflammatory environment in obese women to ensure healthy pregnancy outcomes.