RESUMO
The aim of this study was to examine the impact of maternal obesity on the reproductive capacity of the female offspring (F1) and on the early development of the second generation (F2). To this end, rats were fed either standard (SD) or cafeteria (CD) diet. CD rats and their offspring were divided into 2 groups: rats with 18% and ≥25% overweight (CD18 and CD25, respectively) and offspring from CD18 and CD25 rats (OCD18 and OCD25, respectively). Both OCD groups achieved greater weight gain than controls, without changes in the serum levels of glucose, cholesterol or triglycerides. However, they showed increased gonadal cholesterol concentration and fat content compared to controls. Female OCD groups showed a slight prolongation of the estrous cycle and different pattern of changes in the weight gain during pregnancy. The OCD25 group displayed an increased fertility index and preimplantation losses, and changes in some fetal measurements. Some OCD25 dams gave birth to a larger litter of pups and displayed a lower viability index and lactation rate than controls. OCD25 dams also showed an increase in estradiol and a decrease in testosterone and anti-Müllerian hormone. OCD25 rats showed increased mRNA levels of steroidogenenic enzymes. The offspring from OCD25 females (F2OCD25 offspring) showed early vaginal opening and higher ovulation rate in females, and lower ano-genital distances in males, compared to controls. In conclusion, these results reflect that maternal obesity impacts on the reproductive health of successive generations, probably as a result of epigenetic changes in different systems, including germ cells.
Assuntos
Obesidade Materna , Efeitos Tardios da Exposição Pré-Natal , Reprodução , Animais , Feminino , Gravidez , Obesidade Materna/metabolismo , Ratos , Masculino , Dieta Hiperlipídica/efeitos adversos , Testosterona/sangue , Ciclo Estral , Dieta/efeitos adversos , Estradiol/sangue , Obesidade/metabolismo , Obesidade/etiologiaRESUMO
The gut plays a crucial role in metabolism by regulating the passage of nutrients, water and microbial-derived substances to the portal circulation. Additionally, it produces incretins, such as glucose-insulinotropic releasing peptide (GIP) and glucagon-like derived peptide 1 (GLP1, encoded by gcg gene) in response to nutrient uptake. We aimed to investigate whether offspring from overweight rats develop anomalies in the barrier function and incretin transcription. We observed pro-inflammatory related changes along with a reduction in Claudin-3 levels resulting in increased gut-permeability in fetuses and offspring from overweight rats. Importantly, we found decreased gip mRNA levels in both fetuses and offspring from overweight rats. Differently, gcg mRNA levels were upregulated in fetuses, downregulated in female offspring and unchanged in male offspring from overweight rats. When cultured with high glucose, intestinal explants showed an increase in gip and gcg mRNA levels in control offspring. In contrast, offspring from overweight rats did not exhibit any response in gip mRNA levels. Additionally, while females showed no response, male offspring from overweight rats did exhibit an upregulation in gcg mRNA levels. Furthermore, female and male offspring from overweight rats showed sex-dependent anomalies when orally challenged with a glucose overload, returning to baseline glucose levels after 120 min. These results open new research questions about the role of the adverse maternal metabolic condition in the programming of impairments in glucose homeostasis, enteroendocrine function and gut barrier function in the offspring from overweight mothers and highlight the importance of a perinatal maternal healthy metabolism.
Assuntos
Polipeptídeo Inibidor Gástrico , Sobrepeso , Ratos , Masculino , Feminino , Animais , Sobrepeso/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Incretinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glucose/metabolismo , Peptídeos/metabolismo , Homeostase , RNA Mensageiro/genéticaRESUMO
The aim of this study was to evaluate the paternal programming of sex-dependent alterations in fetoplacental growth and placental lipid metabolism regulated by peroxisome proliferator-activated receptor (PPAR) target genes in F1 diabetic males born from F0 pregestational diabetic rats. F1 control and diabetic male rats were mated with control female rats. On day 21 of gestation, F2 male and female fetoplacental growth, placental lipid levels, and protein and mRNA levels of genes involved in lipid metabolism and transport were evaluated. Fetal but not placental weight was increased in the diabetic group. Triglyceride, cholesterol and free fatty acid levels were increased in placentas of male fetuses from the diabetic group. The mRNA levels of Pparα and Pparγ coactivator 1α (Pgc-1α) were increased only in placentas of male fetuses from the diabetic group. Protein levels of PPARα and PGC-1α were decreased only in placentas of male fetuses from the diabetic group. No differences were found in Pparγ mRNA and protein levels in placentas from the diabetic group. The mRNA levels of genes involved in lipid synthesis showed no differences between groups, whereas the mRNA levels of genes involved in lipid oxidation and transport were increased only in placentas of male fetuses from the diabetic group. In conclusion, paternal diabetes programs fetal overgrowth and sex-dependent effects on the regulation of lipid metabolism in the placenta, where only placentas of male fetuses show an increase in lipid accumulation and mRNA expression of enzymes involved in lipid oxidation and transport pathways.
Assuntos
Diabetes Mellitus Experimental , Diabetes Gestacional , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Gestacional/genética , Diabetes Gestacional/metabolismo , Feminino , Macrossomia Fetal/metabolismo , Humanos , Masculino , PPAR alfa/genética , PPAR alfa/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Placenta/metabolismo , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Triglicerídeos/metabolismoRESUMO
In gestational diabetes mellitus (GDM) pregnancies, a compromised fetal liver may impact offspring's metabolic health. Here, we aimed to address prooxidant, proinflammatory and profibrotic markers in the livers from GDM rats and their fetuses, and to analyze the expression of miR-122 (a relevant microRNA in liver pathophysiology) in fetal and maternal plasma of GDM rats, as well as in the fetal livers of neonatal streptozotocin-induced (nSTZ) diabetic rats, the rats that generate GDM through intrauterine programming. GDM and nSTZ rats were evaluated on day 21 of pregnancy. We found increased nitric oxide production and lipoperoxidation in the livers from GDM rats and their fetuses compared to controls. Livers from GDM fetuses also showed increased levels of connective tissue growth factor and matrix metalloproteinase-2. The expression of miRNA-122 was downregulated in the plasma from GDM rats and their male fetuses, as well as in the livers from male fetuses of nSTZ diabetic rats. miR-122 levels were regulated both in vitro through PPARγ activation and in vivo through a maternal diet enriched in PPAR ligands. Our findings revealed a prooxidant/proinflammatory environment in the livers from GDM rats and their fetuses and a dysregulation of miR-122, likely relevant in the programming of offspring's diseases.
Assuntos
Diabetes Mellitus Experimental/genética , Diabetes Gestacional/genética , Feto/embriologia , Regulação da Expressão Gênica , Inflamação/genética , Fígado/embriologia , MicroRNAs/sangue , Útero/patologia , Animais , Biomarcadores/metabolismo , MicroRNA Circulante/sangue , MicroRNA Circulante/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Gestacional/sangue , Diabetes Gestacional/metabolismo , Modelos Animais de Doenças , Feminino , Inflamação/sangue , Peroxidação de Lipídeos , Masculino , Metaloproteinase 2 da Matriz/metabolismo , MicroRNAs/genética , Óxido Nítrico/biossíntese , Azeite de Oliva , Oxidantes/metabolismo , Gravidez , Ratos Wistar , EstreptozocinaRESUMO
Maternal obesity programs liver derangements similar to those of NAFLD. Our main goal was to evaluate whether these liver anomalies were related to aberrant PPARα function. Obesity was induced in female Albino-Wistar rats by a fatty diet (FD rats). Several parameters related to NAFLD were evaluated in both plasma and livers from fetuses of 21 days of gestation and 140-day-old offspring. FD fetuses and offspring developed increased levels of AST and ALT, signs of inflammation and oxidative and nitrative stress-related damage. FD offspring showed dysregulation of Plin2, CD36, Cyp4A, Aco, Cpt-1, Hadha and Acaa2 mRNA levels, genes involved in lipid metabolism and no catabolic effect of the PPARα agonist clofibrate. These results suggest that the FD offspring is prone to develop fatty liver, a susceptibility that can be linked to PPARα dysfunction, and that this could in turn be related to the liver impairments programmed by maternal obesity.
Assuntos
Dieta Hiperlipídica , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/metabolismo , Animais , Clofibrato/farmacologia , Feminino , Feto/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Fígado/embriologia , Fígado/patologia , Fígado/fisiopatologia , Masculino , PPAR alfa/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos WistarRESUMO
Maternal diabetes programs cardiovascular alterations in the adult offspring but the mechanisms involved remain unclarified. Here, we addresed whether maternal diabetes programs cardiac alterations related to extracellular matrix remodeling in the adult offspring, as well as the role of forkhead box transcription factor 1 (FOXO1) in the induction of these alterations. The heart from adult offspring from control and streptozotocin-induced diabetic rats was evaluated. Increased glycemia, triglyceridemia and insulinemia and markers of cardiomyopathy were found in the offspring from diabetic rats. In the heart, an increase in active FOXO1 and mRNA levels of its target genes, Mmp-2 and Ctgf, genes related to an altered extracellular matrix remodeling, together with an increase in collagen deposition and a decrease in the connexin43 levels, were found in the offspring from diabetic rats. Altogether, these results suggest an important role of FOXO1 activation in the cardiac alterations induced by intrauterine programming in maternal diabetes.
Assuntos
Doenças Cardiovasculares/metabolismo , Diabetes Gestacional/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Biomarcadores/metabolismo , Peso Corporal , Colágeno/metabolismo , Conexina 43/metabolismo , Matriz Extracelular/metabolismo , Feminino , Metaloproteinase 2 da Matriz/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Miocárdio/metabolismo , Miocárdio/patologia , Tamanho do Órgão , Fosforilação , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Serina-Treonina Quinases TOR/metabolismoRESUMO
STUDY QUESTION: What are the consequences of inhibiting mTOR, the mechanistic target of rapamycin (mTOR), and the peroxisome proliferator activated receptor gamma (PPARγ) and PPARδ pathways in the early post-implantation period on decidual function, embryo viability and feto-placental growth in the rat? SUMMARY ANSWER: mTOR inhibition from Days 7 to 9 of pregnancy in rats caused decidual PPARγ and PPARδ upregulation on Day 9 of pregnancy and resulted in embryo resorption by Day 14 of pregnancy. PPARγ and PPARδ inhibition differentially affected decidual mTOR signaling and levels of target proteins relevant to lipid histotrophic nutrition and led to reduced feto-placental weights on Day 14 of pregnancy. WHAT IS KNOWN ALREADY: Although mTOR, PPARγ and PPARδ are nutrient sensors important during implantation, the role of these signaling pathways in decidual function and how they interact in the early post-implantation period are unknown. Perilipin 2 (PLIN2) and fatty acid binding protein 4 (FABP4), two adipogenic proteins involved in lipid histotrophic nutrition, are targets of mTOR and PPAR signaling pathways in a variety of tissues. STUDY DESIGN, SIZE, DURATION: Rapamycin (mTOR inhibitor, 0.75 mg/kg, sc), T0070907 (PPARγ inhibitor, 0.001 mg/kg, sc), GSK0660 (PPARδ inhibitor, 0.1 mg/kg, sc) or vehicle was injected daily to pregnant rats from Days 7 to 9 of pregnancy and the studies were performed on Day 9 of pregnancy (n = 7 per group) or Day 14 of pregnancy (n = 7 per group). PARTICIPANTS/MATERIALS, SETTING, METHODS: On Day 9 of pregnancy, rat decidua were collected and prepared for western blot and immunohistochemical studies. On Day 14 of pregnancy, the resorption rate, number of viable fetuses, crown-rump length and placental and decidual weights were determined. MAIN RESULTS AND THE ROLE OF CHANCE: Inhibition of mTOR in the early post-implantation period led to a reduction in FABP4 protein levels, an increase in PLIN2 levels and an upregulation of PPARγ and PPARδ in 9-day-pregnant rat decidua. Most embryos were viable on Day 9 of pregnancy but had resorbed by Day 14 of pregnancy. This denotes a key function of mTOR in the post-implantation period and suggests that activation of PPAR signaling was insufficient to compensate for impaired nutritional/survival signaling induced by mTOR inhibition. Inhibition of PPARγ signaling resulted in decreased decidual PLIN2 and FABP4 protein expression as well as in inhibition of decidual mTOR signaling in Day 9 of pregnancy. This treatment also reduced feto-placental growth on Day 14 of pregnancy, revealing the relevance of PPARγ signaling in sustaining post-implantation growth. Moreover, following inhibition of PPARδ, PLIN2 levels were decreased and mTOR complex 1 and 2 signaling was altered in decidua on Day 9 of pregnancy. On Day 14 of pregnancy, PPARδ inhibition caused reduced feto-placental weight, increased decidual weight and increased resorption rate, suggesting a key role of PPARδ in sustaining post-implantation development. LARGE SCALE DATA: Not applicable. LIMITATIONS, REASONS FOR CAUTION: This is an in vivo animal study and the relevance of the results for humans remains to be established. WIDER IMPLICATIONS OF THE FINDINGS: The early post-implantation period is a critical window of development and changes in the intrauterine environment may cause embryo resorption and lead to placental and fetal growth restriction. mTOR, PPARγ and PPARδ signaling are decidual nutrient sensors with extensive cross-talk that regulates adipogenic proteins involved in histotrophic nutrition and important for embryo viability and early placental and fetal development and growth. STUDY FUNDING/COMPETING INTEREST(S): Funding was provided by the Agencia Nacional de Promoción Científica y Tecnológica de Argentina (PICT 2014-411 and PICT 2015-0130), and by the International Cooperation (Grants CONICET-NIH-2014 and CONICET-NIH-2017) to A.J. and T.J. The authors have no conflicts of interest.
Assuntos
Decídua/fisiologia , PPAR delta/fisiologia , PPAR gama/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Decídua/metabolismo , Desenvolvimento Embrionário , Proteínas de Ligação a Ácido Graxo/metabolismo , Feminino , Desenvolvimento Fetal , Imuno-Histoquímica , PPAR delta/genética , PPAR delta/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Gravidez , Ratos Wistar , Transdução de Sinais , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
BackgroundInsulin-like growth factor 2 (IGF2) is a key determinant of fetal growth, and the altered expression of IGF2 is implicated in fetal growth disorders and maternal metabolic derangements including gestational diabetes. Here we studied how increased levels of IGF2 in late pregnancy affect fetal growth.MethodsWe employed a rat model of repeated intrafetal IGF2 administration in late pregnancy, i.e., during GD19-GD21, and measured the consequences on fetal organ weight and expression of insulin/IGF-axis components.ResultsIGF2 treatment tended to increase fetal weight, but only weight increase of the fetal stomach reached significance (+33±9%; P<0.01). Sex-dependent data analysis revealed a sexual dimorphism of IGF2 action. In male fetuses, IGF2 administration significantly increased fetal weight (+13±3%; P<0.05) and weight of fetal stomach (+42±10%; P<0.01), intestine (+26±5%; P<0.05), liver (+13±4%; P<0.05), and pancreas (+25±8%; P<0.05). Weights of heart, lungs, and kidneys were unchanged. In female fetuses, IGF2 increased only stomach weight (+26±9%; P<0.05). Furthermore, gene expression of insulin/IGF axis in the heart, lungs, liver, and stomach was more sensitive toward IGF2 treatment in male than in female fetuses.ConclusionData suggest that elevated circulating IGF2 in late pregnancy predominantly stimulates organ growth of the digestive system, and male fetuses are more susceptible toward the IGF2 effects than female fetuses.
Assuntos
Sistema Digestório/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Fator de Crescimento Insulin-Like II/fisiologia , Animais , Feminino , Humanos , Insulina/metabolismo , Masculino , Tamanho do Órgão , Gravidez , Prenhez , Ratos , Ratos Wistar , Fatores Sexuais , Distribuição TecidualRESUMO
Gestational diabetes mellitus (GDM) is a prevalent disease that impairs fetal metabolism and development. We have previously characterized a rat model of GDM induced by developmental programming. Here, we analyzed lipid content, the levels of the three PPAR isotypes and the expression of microRNAs that regulate PPARs expression in the liver of male and female fetuses of control and GDM rats on day 21 of pregnancy. We found increased levels of triglycerides and cholesterol in the livers of male fetuses of GDM rats compared to controls, and, oppositely, reduced levels of triglycerides, cholesterol, phospholipids and free fatty acids in the livers of female fetuses of GDM rats compared to controls. Although GDM did not change PPARα levels in male and female fetal livers, PPARγ was increased in the liver of male fetuses of GDM rats, a change that occurred in parallel to a reduction in the expression of miR-130, a microRNA that targets PPARγ. In livers of female fetuses of GDM rats, no changes in PPARγ and miR-130 were evidenced, but PPARδ was increased, a change that occurred in parallel to a reduction in the expression of miR-9, a microRNA that targets PPARδ, and was unchanged in the liver of male fetuses of GDM and control rats. These results show clear sex-dependent changes in microRNAs that target different PPAR isotypes in relation to changes in the levels of their targets and the differential regulation of lipid metabolism evidenced in fetal livers of GDM pregnancies.
Assuntos
Diabetes Gestacional/metabolismo , Feto/metabolismo , Metabolismo dos Lipídeos , Fígado/embriologia , MicroRNAs/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Caracteres Sexuais , Animais , Feminino , Regulação da Expressão Gênica , Metabolismo dos Lipídeos/genética , Lipídeos/biossíntese , Masculino , MicroRNAs/genética , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos WistarRESUMO
Maternal diabetes programs metabolic and cardiovascular diseases in the offspring. Here, we demonstrated increased pro-oxidant/pro-inflammatory markers in the heart of 2-day-old offspring of diabetic rats, previous to the induction of metabolic alterations. At a pre-pubertal stage, sex-dependent changes were evidenced in the diabetic group, as only males showed increased glycemia as well as increased concentrations of nitrated proteins, matrix metalloproteinase-9 and peroxisome proliferator activated receptor α (PPARα) in the heart. Differently, the heart of male and female offspring of diabetic rats showed increased levels of connective tissue growth factor (CTGF). Maternal treatments with idebenone, a mitochondrial antioxidant, led to reductions in all the pro-oxidant and pro-inflammatory markers evaluated and in PPARα protein expression in the heart of the offspring of diabetic rats. The results of the present study highlight the gender dependence and the role of oxidative stress in the diabetes-induced intrauterine programming of heart alterations.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Miocárdio/metabolismo , Animais , Antioxidantes/farmacologia , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Feminino , Masculino , Troca Materno-Fetal , Metaloproteinase 9 da Matriz/metabolismo , Mitocôndrias , Óxido Nítrico/metabolismo , Estresse Oxidativo , PPAR alfa/metabolismo , Gravidez , Ratos Wistar , Ubiquinona/análogos & derivados , Ubiquinona/farmacologiaRESUMO
We aimed to analyze if an overload of saturated fat in maternal diet induced lipid metabolic impairments in livers from rat fetuses that persist in the offspring and to identify potential mechanisms involving fetal leptin resistance. Female rats were fed either a diet enriched in 25% of saturated fat (SFD rats) or a regular diet (controls). Fetuses of 21days of gestation and offspring of 21 and 140days of age were obtained and plasma and liver were kept for further analysis. Livers from a group of control and SFD fetuses were cultured in the presence or absence of leptin. Leptin or vehicle was administered to control fetuses during the last days of gestation and, on day 21, fetal livers and plasma were obtained. Lipid levels were assessed by thin-layer chromatography and mRNA gene expression of CPT1, ACO and PPARα by RT-PCR. Liver lipid levels were increased and CPT1 and ACO were down-regulated in fetuses and offspring from SFD rats compared to controls. After the culture with leptin, control fetal livers showed increased ACO and CPT1 expression and decreased lipid levels, while fetal livers from SFD rats showed no changes. Fetal administration of leptin induced a decrease in ACO and no changes in CPT1 expression. In summary, our results suggest that a saturated fat overload in maternal diet induces fetal leptin resistance in liver lipid catabolism, which might be contributing to liver lipid alterations that are sustained in the offspring.
Assuntos
Gorduras na Dieta/administração & dosagem , Leptina/fisiologia , Fígado/embriologia , Animais , Feminino , Homeostase , Fígado/metabolismo , Masculino , Ratos , Ratos WistarRESUMO
BACKGROUND: Diabetes in pregnancy affects fetal growth and development. The insulin/insulin-like growth factors (IGF) system comprising insulin, IGF, their receptors, and binding proteins, has been implicated in fetal growth regulation. This study tested the hypothesis that maternal diabetes alters the fetal insulin/IGF system in a tissue-specific manner. METHODS: Wistar rats were rendered diabetic by neonatal administration of streptozotocin and mated with control rats. At day 21 of gestation, the weights of fetuses, placentas, and fetal organs (heart, lung, liver, stomach, intestine, and pancreas) were determined. Maternal and fetal plasma concentrations of insulin, IGF1, and IGF2 were measured by ELISA, and expression of IGF1, IGF2, IGF1R, IGF2R, IR, IGFBP1, BP2, and BP3 in placenta and fetal organs by qPCR. RESULTS: The well-known increase in fetal growth in this model of mild diabetes is accompanied by elevated insulin and IGF1 levels and alterations of the insulin/IGF system in the fetus and the placenta. These alterations were organ and gene specific. The insulin/IGF system was generally upregulated, especially in the fetal heart, while it was downregulated in fetal lung. CONCLUSION: In our model of mild diabetes, the effect of maternal diabetes on fetal weight and fetal insulin/IGF system expression is organ specific with highly sensitive organs such as lung and heart, and organs that were less affected, such as stomach.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Insulina/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal , Diabetes Gestacional/metabolismo , Modelos Animais de Doenças , Feminino , Pulmão , Gravidez , Prenhez , Ratos , Ratos Wistar , Distribuição TecidualRESUMO
The fetal lung is affected by maternal diabetes. Nuclear receptor PPARα regulates nitric oxide (NO) overproduction in different tissues. We aimed to determine whether fetal lung PPARα expression is altered by maternal diabetes, and if there are gender-dependent changes in PPARα regulation of NO production in the fetal lung. Fetal lungs from control and diabetic rats were explanted on day 21 of gestation and evaluated for PPARα expression and NO production. Fetuses were injected with the PPARα ligand LTB(4) on days 19, 20 and 21, and the fetal lung explanted on day 21 to evaluate PPARα and the inducible isoform of NO synthase (iNOS). Besides, pregnant rats were fed with olive oil- and safflower oil-supplemented diets, enriched in PPAR ligands, for evaluation of fetal lung NO production and PPARα expression. We found reduced PPARα concentrations only in the lung from male fetuses from the diabetic group when compared to controls, although maternal diabetes led to NO overproduction in both male and female fetal lungs. Fetal activation of PPARα led to changes in lung PPARα expression only in female fetuses, although this treatment increased iNOS expression in both male and female fetuses in the diabetic group. Diets supplemented with olive oil and not with safflower oil led to a reduction in NO production in male and female fetal lungs. In conclusion, there are gender-dependent changes in PPARα expression and signaling in the fetal lung from diabetic rats, although PPARα activation prevents maternal diabetes-induced lung NO overproduction in both male and female fetuses.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Feto/metabolismo , Pulmão/metabolismo , Óxido Nítrico/metabolismo , PPAR alfa/metabolismo , Gravidez em Diabéticas/metabolismo , Animais , Glicemia , Dieta , Feminino , Sangue Fetal/metabolismo , Peso Fetal , Feto/efeitos dos fármacos , Feto/patologia , Regulação da Expressão Gênica no Desenvolvimento , Leucotrieno B4/administração & dosagem , Pulmão/patologia , Masculino , Troca Materno-Fetal , Azeite de Oliva , Tamanho do Órgão , PPAR alfa/genética , Óleos de Plantas/administração & dosagem , Gravidez , Fenômenos Fisiológicos da Nutrição Pré-Natal , Ratos , Ratos Wistar , Óleo de Cártamo/administração & dosagem , Fatores Sexuais , Transdução de Sinais , Triglicerídeos/sangueRESUMO
Matrix metalloproteinases (MMPs) are proteolytic enzymes related to a proinflammatory environment in several diseases, including diabetes, which can be activated by reactive nitrogen species. This work aimed to determine MMP-2 and MMP-9 activities and nitration in term placentas from type 2 diabetic patients and verify the hypothesis that peroxynitrites are positive regulators of placental MMP-2 and MMP-9 activities. For this purpose, term placentas from healthy and type 2 diabetic patients were analyzed for MMP-2 and MMP-9 levels and activities, protein nitration, and nitration of MMP-2 and MMP-9. Villous explants were cultured in the presence of peroxynitrites for further evaluation of MMP-2 and MMP-9 activities. We found that MMP-2 and MMP-9 activities were increased in term placentas from diabetic patients. These changes were found even when MMP-2 protein concentrations were diminished and MMP-9 protein concentrations were not changed in the diabetic group. Increased protein nitration and specific nitration of MMP-2 and MMP-9 were found in term placentas from diabetic patients. Peroxynitrites were able to increase the activity of placental MMP-2 and MMP-9. Taken together, this study has shown for first time that peroxynitrites can nitrate and activate MMP-2 and MMP-9 in the placenta, a nitrative pathway possibly related to MMPs overactivity in the placentas from type 2 diabetic patients.
Assuntos
Diabetes Mellitus Tipo 1/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Ácido Peroxinitroso/farmacologia , Placenta/enzimologia , Gravidez em Diabéticas/enzimologia , Adulto , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Peroxidação de Lipídeos , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Placenta/metabolismo , Gravidez , Técnicas de Cultura de TecidosRESUMO
Maternal diabetes increases the risks for embryo malformations. Matrix metalloproteinase-2 (MMP-2) and MMP-9 are two relevant MMPs for embryo development. Here, we addressed whether changes in these MMPs and in tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-2 are altered in embryos and decidua from type 1 diabetic rats during early organogenesis. Our results demonstrate MMP-2 and MMP-9 overactivities and overexpression, together with increases in lipid peroxidation and nitric oxide production in embryos and decidua from diabetic animals. There is a concomitant increase in the inhibitory activity of TIMP-1 and TIMP-2 in embryos and decidua, and an increase in protein expression of embryonic TIMP-1 and TIMP-2. In situ zymography demonstrated MMPs overactivities despite increased TIMPs in embryos and decidua in maternal diabetes during early organogenesis. This study reveals that maternal diabetes leads to profound alterations in MMPs/TIMPs balance during embryo organogenesis, the gestational period during which most malformations are induced.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Embrião de Mamíferos/metabolismo , Metaloproteinases da Matriz/metabolismo , Organogênese , Gravidez em Diabéticas/metabolismo , Inibidores Teciduais de Metaloproteinases/metabolismo , Animais , Decídua/química , Decídua/enzimologia , Decídua/metabolismo , Embrião de Mamíferos/química , Embrião de Mamíferos/enzimologia , Feminino , Peroxidação de Lipídeos , Metaloproteinase 2 da Matriz/análise , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/análise , Metaloproteinase 9 da Matriz/metabolismo , Metaloproteinases da Matriz/análise , Óxido Nítrico/biossíntese , Gravidez , Ratos , Ratos Wistar , Inibidor Tecidual de Metaloproteinase-1/análise , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/análise , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Inibidor Tecidual de Metaloproteinase-3/análise , Inibidor Tecidual de Metaloproteinase-3/metabolismo , Inibidores Teciduais de Metaloproteinases/análiseRESUMO
Maternal diabetes impairs fetoplacental metabolism and growth. Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor capable of regulating lipid metabolism and inflammatory pathways. In this study, we analyzed whether placental and fetal PPARα activation regulates lipid metabolism and nitric oxide (NO) production in term placentas from diabetic rats. Diabetes was induced by neonatal streptozotocin administration. On day 21 of pregnancy, placentas from control and diabetic rats were cultured in the presence of PPARα agonists (clofibrate and leukotriene B(4) (LTB(4))) for further evaluation of levels, synthesis, and peroxidation of lipids as well as NO production. Besides, on days 19, 20, and 21 of gestation, fetuses were injected with LTB(4), and the placentas were explanted on day 21 of gestation for evaluation of placental weight and concentrations of placental lipids, lipoperoxides, and NO metabolites. We found that placentas from diabetic rats showed reduced PPARα concentrations. They presented no lipid overaccumulation but reduced lipid synthesis, parameters negatively regulated by PPARα activators. Lipid peroxidation and NO production, increased in placentas from diabetic rats, were negatively regulated by PPARα activators. Fetal PPARα activation in diabetic rats does not change placental lipid concentrations but reduced placental weight and NO production. In conclusion, PPARα activators regulate lipid metabolism and NO production in term placentas from diabetic rats, an activation that regulates placental growth and can partly be exerted by the developing fetus.
Assuntos
Clofibrato/farmacologia , Diabetes Mellitus Experimental/fisiopatologia , Leucotrieno B4/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Óxido Nítrico/metabolismo , PPAR alfa/agonistas , Placenta/efeitos dos fármacos , Animais , Colesterol/metabolismo , Diabetes Mellitus Experimental/metabolismo , Feminino , Feto/efeitos dos fármacos , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Tamanho do Órgão , PPAR alfa/metabolismo , Fosfolipídeos/metabolismo , Placenta/metabolismo , Placenta/fisiopatologia , Gravidez , Ratos , Ratos Wistar , Triglicerídeos/metabolismoRESUMO
BACKGROUND: peroxisome proliferator-activated receptor α (PPARα) is a crucial regulator of liver lipid metabolism. As maternal diabetes impairs foetal lipid metabolism and growth, we aimed to determine whether PPARα activation regulates lipid metabolism in the foetal liver from diabetic rats as well as foetal weight and foetal liver weight. METHODS: diabetes was induced by neonatal streptozotocin administration (90 mg/kg). For ex vivo studies, livers from 21-day-old foetuses from control and diabetic rats were explanted and incubated in the presence of PPARα agonists (clofibrate and leukotriene B(4) ) for further evaluation of lipid levels (by thin layer chromatography and densitometry), de novo lipid synthesis (by (14) C-acetate incorporation) and lipid peroxidation (by thiobarbituric reactive substances evaluation). For in vivo studies, foetuses were injected through the uterine wall with leukotriene B(4) on days 19, 20 and 21 of gestation. On day 21 of gestation, foetal liver concentrations of lipids and lipoperoxides were evaluated. RESULTS: foetuses from diabetic rats showed increased body weight and liver weight, as well as accumulation of triglycerides and cholesteryl esters, increased de novo lipid synthesis and lipid peroxidation in the liver when compared to controls. Ex vivo studies showed that PPARα ligands reduced both the concentrations and synthesis of the lipid species studied and lipid peroxidation in the foetal liver from diabetic rats. In vivo experiments showed that leukotriene B(4) reduced the concentrations of triglycerides, cholesteryl esters and phospholipids, as well as lipid peroxidation, foetal weight and foetal liver weight in diabetic rats. CONCLUSIONS: PPARα activation regulates the impaired foetal liver lipid metabolism, prevents hepatomegaly and reduces foetal overgrowth induced by maternal diabetes.
Assuntos
Diabetes Mellitus Experimental/patologia , Feto/citologia , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , PPAR alfa/metabolismo , Animais , Peso Corporal , Núcleo Celular/metabolismo , Diabetes Mellitus Experimental/metabolismo , Feminino , Leucotrieno B4/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/citologia , Gravidez , Ratos , Ratos Wistar , Triglicerídeos/metabolismoRESUMO
Nitration-induced protein damage in the placenta leads to impaired blood flow and deficient feto-placental exchange in diabetic pregnancies. This work studied the effect of nitric oxide and peroxynitrite on Cu/Zn SOD activity in rat placentas and evaluated whether Cu/Zn SOD is nitrated in the placenta from diabetic rats at mid-gestation. Protein nitration was evaluated by EIA, Cu/Zn SOD activity by inhibition of the epinephrine auto-oxidation, Cu/Zn SOD expression by western blot and specific nitration by immunoprecipitation. This study found higher levels of protein nitration (p < 0.001), diminished Cu/Zn SOD activity and enhanced protein expression (p < 0.01) in placentas from diabetic rats. Placental Cu/Zn SOD activity was inhibited by peroxynitrite (p < 0.01). Besides, nitration of Cu/Zn SOD was elevated in placentas from diabetic rats (p < 0.01). These results show that rat Cu/Zn SOD can be nitrated, a modification that could lead to the depressed activity of this enzyme found in placentas from diabetic rats.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Placenta/enzimologia , Superóxido Dismutase/biossíntese , Sequência de Aminoácidos , Animais , Bovinos , Diabetes Mellitus Experimental/induzido quimicamente , Feminino , Humanos , Técnicas In Vitro , Masculino , Dados de Sequência Molecular , Óxido Nítrico/metabolismo , Ácido Peroxinitroso/farmacologia , Placenta/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Alinhamento de Sequência , Estreptozocina , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
The worldwide increase in the incidence of diabetes, the increase in type 2 diabetes in women at reproductive ages, and the cross-generation of the intrauterine programming of type 2 diabetes are the bases for the growing interest in the use of experimental diabetic models in order to gain insight into the mechanisms of induction of developmental alterations in maternal diabetes. In this scenario, experimental models that present the most common features of diabetes in pregnancy are highly required. Several important aspects of human diabetic pregnancies such as the increased rates of spontaneous abortions, malformations, fetoplacental impairments, and offspring diseases in later life can be approached by using the appropriate animal models. The purpose of this review is to give a practical and critical guide into the most frequently used experimental models in diabetes and pregnancy, discuss their advantages and limitations, and describe the aspects of diabetes and pregnancy for which these models are thought to be adequate. This review provides a comprehensive view and an extensive analysis of the different models and phenotypes addressed in diabetic animals throughout pregnancy. The review includes an analysis of the surgical, chemical-induced, and genetic experimental models of diabetes and an evaluation of their use to analyze early pregnancy defects, induction of congenital malformations, placental and fetal alterations, and the intrauterine programming of metabolic diseases in the offspring's later life.
Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Modelos Animais de Doenças , Gravidez em Diabéticas/fisiopatologia , Animais , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Gravidez , Gravidez em Diabéticas/metabolismoRESUMO
AIMS: Maternal diabetes impairs placental development and metabolism. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors relevant in metabolic homeostasis. We investigated the concentrations of PPARdelta and its endogenous agonist prostacyclin (PGI2), as well as the effects of carbaprostacylin (cPGI(2,) a PPARdelta agonist) on lipid metabolism in placentas from control and streptozotocin-induced diabetic rats on day 13.5 of gestation. MAIN METHODS: The placentas were explanted to evaluate PPARdelta expression and PGI2 concentrations, and cultured with cPGI2 for further analysis of lipid metabolism (concentrations and (14)C-acetate derived synthesis of triglycerides, cholesteryl esters, phospholipids, cholesterol and free fatty acids; release of glycerol and lipid peroxidation). KEY FINDINGS: Reduced PGI2 concentrations were found in the placentas from diabetic rats when compared to controls. cPGI2 additions reduced the concentrations and synthesis of several lipid species, increased lipid catabolism and reduced lipid peroxidation in the placenta. These effects were more marked in diabetic tissues, which presented alterations in the lipid metabolic parameters evaluated. cPGI2 additions increased placental PPARdelta and acyl-CoA oxidase expression, which are changes possibly involved in the catabolic effects observed. SIGNIFICANCE: The present study reveals the capability of cPGI2 to regulate placental lipid metabolism and PPARdelta expression, and suggests that preserving appropriate PGI2 concentrations in the placenta may help to metabolize maternal derived lipid overload in diabetic gestations.