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1.
Sci Rep ; 6: 37172, 2016 11 16.
Article in English | MEDLINE | ID: mdl-27849017

ABSTRACT

Engulfment and cell motility 1 (ELMO1) functions as a guanine exchange factor for Rac1 and was recently found to protect endothelial cells from apoptosis. Genome wide association studies suggest that polymorphisms within human elmo1 act as a potential contributing factor for the development of diabetic nephropathy. Yet, the function of ELMO1 with respect to the glomerulus and how this protein contributes to renal pathology was unknown. Thus, this study aimed to identify the role played by ELMO1 in renal development in zebrafish, under hyperglycaemic conditions, and in diabetic nephropathy patients. In zebrafish, hyperglycaemia did not alter renal ELMO1 expression. However, hyperglycaemia leads to pathophysiological and functional alterations within the pronephros, which could be rescued via ELMO1 overexpression. Zebrafish ELMO1 crispants exhibited a renal pathophysiology due to increased apoptosis which could be rescued by the inhibition of apoptosis. In human samples, immunohistochemical staining of ELMO1 in nondiabetic, diabetic and polycystic kidneys localized ELMO1 in glomerular podocytes and in the tubules. However, ELMO1 was not specifically or distinctly regulated under either one of the disease conditions. Collectively, these results highlight ELMO1 as an important factor for glomerular protection and renal cell survival via decreasing apoptosis, especially under diabetic conditions.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Apoptosis , Diabetes Mellitus, Experimental/embryology , Kidney/embryology , Zebrafish Proteins/metabolism , Zebrafish/embryology , Adaptor Proteins, Signal Transducing/genetics , Animals , Animals, Genetically Modified , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/pathology , Humans , Kidney/pathology , Zebrafish/genetics , Zebrafish Proteins/genetics
2.
Diabetes ; 65(1): 149-63, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26450995

ABSTRACT

High glucose in vivo and in vitro induces neural tube defects (NTDs). CITED2 (CBP/p300-interacting transactivator with ED-rich tail 2) is essential for neural tube closure. We explored the regulatory mechanism underlying CITED2 expression and its relationship with miRNA and endoplasmic reticulum (ER) stress. miR-200b levels were increased by maternal diabetes or high glucose in vitro, and this increase was abrogated by transgenic overexpression of superoxide dismutase 1 (SOD1) or an SOD1 mimetic. CITED2 was the target of miR-200b and was downregulated by high glucose. Two miR-200b binding sites in the 3'-untranslated region of the CITED2 mRNA were required for inhibiting CITED2 expression. The miR-200b mimic and a CITED2 knockdown mimicked the stimulative effect of high glucose on unfolded protein response (UPR) and ER stress, whereas the miR-200b inhibitor and CITED2 overexpression abolished high glucose-induced UPR signaling, ER stress, and apoptosis. The ER stress inhibitor, 4-phenylbutyrate, blocked CITED2 knockdown-induced apoptosis. Furthermore, the miR-200b inhibitor reversed high glucose-induced CITED2 downregulation, ER stress, and NTDs in cultured embryos. Thus, we showed a novel function of miR-200b and CITED2 in high glucose-induced UPR and ER stress, suggesting that miR-200b and CITED2 are critical for ER homeostasis and NTD formation in the developing embryo.


Subject(s)
Diabetes Mellitus, Experimental/embryology , Endoplasmic Reticulum Stress/genetics , MicroRNAs/genetics , Neural Tube Defects/embryology , RNA, Messenger/metabolism , Repressor Proteins/genetics , Trans-Activators/genetics , Unfolded Protein Response/genetics , 3' Untranslated Regions , Animals , Apoptosis/genetics , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/metabolism , Embryo, Mammalian , Female , Gene Knockdown Techniques , Immunoblotting , In Situ Nick-End Labeling , In Vitro Techniques , Mice , Mice, Transgenic , Neural Stem Cells , Neural Tube Defects/genetics , Neural Tube Defects/metabolism , Phenylbutyrates/pharmacology , Pregnancy , Repressor Proteins/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase-1 , Trans-Activators/metabolism
3.
J Matern Fetal Neonatal Med ; 28(4): 403-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24766077

ABSTRACT

OBJECTIVE: To evaluate the effects of folic acid (FA)-induced renal failure in young offspring of diabetic mothers. METHODS: The offspring of streptozotocin-induced diabetic dams were divided into four groups: CC (controls receiving vehicle); DC (diabetics receiving vehicle); CA (controls receiving FA solution, 250 mg/kg) and DA (diabetics receiving FA solution, 250 mg/kg). Renal function tests and morphometry results were analyzed. RESULTS: An increase in creatinine and urea levels was observed in CA and DA groups at two and five months. FA administration caused a significant reduction in the number of glomeruli in the offspring of diabetic dams. The diabetes group treated with FA had fewer glomeruli compared to controls at two and five months. FA caused an increase in the area of the urinary space both in controls and offspring of diabetic dams at two and five months. The number of glomeruli and area of the urinary space at two months were negatively correlated. CONCLUSIONS: Fetal programing promotes remarkable changes in kidney morphology and function in offspring. We suggest that the morphological changes in the kidneys are more pronounced when fetal programing is associated with newly acquired diseases, e.g. renal failure induced by FA.


Subject(s)
Acute Kidney Injury/embryology , Acute Kidney Injury/pathology , Diabetes Mellitus, Experimental/pathology , Fetal Development , Pregnancy in Diabetics/pathology , Prenatal Exposure Delayed Effects/pathology , Acute Kidney Injury/physiopathology , Animals , Blood Pressure , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/physiopathology , Female , Fetal Development/drug effects , Heart Rate , Kidney/physiopathology , Kidney Function Tests , Pregnancy , Pregnancy in Diabetics/physiopathology , Prenatal Exposure Delayed Effects/physiopathology , Rats , Rats, Wistar , Streptozocin
4.
J Diabetes Res ; 2014: 354094, 2014.
Article in English | MEDLINE | ID: mdl-25133191

ABSTRACT

Diabetic retinopathy (DR) is the leading cause of blindness among the American working population. The purpose of this study is to establish a new diabetic animal model using a cone-dominant avian species to address the distorted color vision and altered cone pathway responses in prediabetic and early diabetic patients. Chicken embryos were injected with either streptozotocin (STZ), high concentration of glucose (high-glucose), or vehicle at embryonic day 11. Cataracts occurred in varying degrees in both STZ- and high glucose-induced diabetic chick embryos at E18. Streptozotocin-diabetic chicken embryos had decreased levels of blood insulin, glucose transporter 4 (Glut4), and phosphorylated protein kinase B (pAKT). In STZ-injected E20 embryos, the ERG amplitudes of both a- and b-waves were significantly decreased, the implicit time of the a-wave was delayed, while that of the b-wave was significantly increased. Photoreceptors cultured from STZ-injected E18 embryos had a significant decrease in L-type voltage-gated calcium channel (L-VGCC) currents, which was reflected in the decreased level of L-VGCCα1D subunit in the STZ-diabetic retinas. Through these independent lines of evidence, STZ-injection was able to induce pathological conditions in the chicken embryonic retina, and it is promising to use chickens as a potential new animal model for type I diabetes.


Subject(s)
Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Type 1/embryology , Diabetic Retinopathy/embryology , Prediabetic State/embryology , Animals , Blood Glucose/metabolism , Calcium Channels, L-Type/metabolism , Cataract/blood , Cataract/chemically induced , Cataract/embryology , Chick Embryo , Color Vision , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/chemically induced , Diabetic Retinopathy/blood , Diabetic Retinopathy/chemically induced , Diabetic Retinopathy/physiopathology , Embryo Culture Techniques , Glucose , Glucose Transporter Type 4/metabolism , Insulin/blood , Phosphorylation , Prediabetic State/blood , Prediabetic State/chemically induced , Proto-Oncogene Proteins c-akt/metabolism , Retinal Cone Photoreceptor Cells/metabolism , Retinal Cone Photoreceptor Cells/pathology , Streptozocin , Time Factors
5.
Gene ; 516(2): 218-27, 2013 Mar 10.
Article in English | MEDLINE | ID: mdl-23287646

ABSTRACT

Congenital heart defects (CHD) are one of the most common defects in offspring of diabetic mothers. There is a clear association between maternal diabetes and CHD; however the underlying molecular mechanism remains unknown. We hypothesized that maternal diabetes affects with the expression of early developmental genes that regulate the essential developmental processes of the heart, thereby resulting in the pathogenesis of CHD. We analyzed genome-wide expression profiling in the developing heart of embryos from diabetic and control mice by using the oligonucleotide microarray. Microarray analysis revealed that a total of 878 genes exhibited more than 1.5 fold changes in expression level in the hearts of experimental embryos in either E13.5 or E15.5 compared with their respective controls. Expression pattern of genes that is differentially expressed in the developing heart was further examined by the real-time reverse transcriptase-polymerase chain reaction. Several genes involved in a number of molecular signaling pathways such as apoptosis, proliferation, migration and differentiation in the developing heart were differentially expressed in embryos of diabetic pregnancy. It is concluded that altered expression of several genes involved in heart development may contribute to CHD in offspring of diabetic mothers.


Subject(s)
Gene Expression Regulation, Developmental , Heart/embryology , Pregnancy in Diabetics , Transcriptome , Animals , Cluster Analysis , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/genetics , Female , Male , Mice , Microarray Analysis , Myocardium/metabolism , Pregnancy , Pregnancy in Diabetics/genetics , Prenatal Exposure Delayed Effects/genetics , Streptozocin , Validation Studies as Topic
6.
Birth Defects Res A Clin Mol Teratol ; 94(10): 770-81, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22786762

ABSTRACT

Maternal diabetes and obesity are independent risk factors for neural tube defects, although it is unclear whether the effects are mediated by common pathogenic mechanisms. In this manuscript, we report a genome-wide survey of histone acetylation in neurulation stage embryos from mouse pregnancies with different metabolic conditions: maternal diabetes, and maternal consumption of a high fat content diet. We find that maternal diabetes, and independently, exposure to high-fat diet, are associated with increases and decreases of H3 and H4 histone acetylation in the embryo. Intriguingly, changes of H3K27 acetylation marks are significantly enriched near genes known to cause neural tube defects in mouse mutants. These data suggest that epigenetic changes in response to diet and metabolic condition may contribute to increased risk for neural tube defects in diabetic and obese pregnancies. Importantly, the responses to high-fat diet and maternal diabetes were distinct, suggesting that perturbed embryonic development under these conditions is mediated by different molecular pathways. This conclusion is supported by morphometric analyses that reveal a trend for maternal diabetes to delay embryonic development in the C57BL/6 strain, while high-fat diet appears to be associated with accelerated development. Taken together, our results link changes in histone acetylation to metabolic conditions during pregnancy, and implicate distinct epigenetic mechanisms in susceptibility to neural tube defects under conditions of maternal diabetes and obesity.


Subject(s)
Embryonic Development/genetics , Epigenesis, Genetic/physiology , Pregnancy in Diabetics/genetics , Algorithms , Animals , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/etiology , Diabetes, Gestational/genetics , Diet, High-Fat , Dietary Fats , Embryo, Mammalian , Embryonic Development/drug effects , Epigenomics , Female , Male , Mice , Mice, Inbred C57BL , Pregnancy , Pregnancy in Diabetics/pathology , Prenatal Exposure Delayed Effects/genetics , Streptozocin
7.
Cell Mol Neurobiol ; 32(6): 1031-7, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22410672

ABSTRACT

Compelling evidence shows that the offspring subjected to uncontrolled hyperlycemia during gestation display behavioral, neurochemical, and cellular abnormalities during adulthood. However, the molecular mechanisms underlying these defects remain elusive. Previous studies have shown an increased rate of apoptosis and a decreased index of neuronal proliferation associated with diabetic embryopathy. The aim of the present study was to determine whether impairments in apoptotic related proteins also occur in the developing central nervous system from non-malformed embryos exposed to uncontrolled gestational hyperglycemia. Pregnant rats injected with either streptozotocin or vehicle were killed on gestational day 19. Offspring brains were quickly removed to evaluate protein expression by Western blotting. Embryonic brains from diabetic rats exhibited a decrease in the cell survival p-Akt expression (52.83 ± 24.35%) and in the pro-apoptotic protein Bax (56.16 ± 6.47%). Moreover, the anti-apoptotic protein Bcl-2 showed a non-significant increase while there were no changes in Procaspase 3 or cleaved Caspase 3 proteins. The cytoskeleton proteins NF-200 and GFAP were also examined. Neither NF-200 nor GFAP showed differences in embryonic brains from diabetic rats compared to controls. Altogether, these results indicate that both proliferation and apoptotic pathways are decreased in the brain from the developing offspring of diabetic rats. Since selective neuronal apoptosis, as well as selective cell proliferation, are specifically involved in brain organogenesis, it is possible that simultaneous impairments during the perinatal period contribute to the long lasting alterations observed in the adult brain.


Subject(s)
Apoptosis , Brain/embryology , Brain/pathology , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/pathology , Down-Regulation , Signal Transduction , Animals , Blood Glucose/metabolism , Brain/enzymology , Caspase 3/metabolism , Cell Proliferation , Cytoskeleton/metabolism , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/complications , Female , Fetus/metabolism , Glial Fibrillary Acidic Protein/metabolism , Hyperglycemia/complications , Hyperglycemia/pathology , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Sprague-Dawley
8.
Folia Histochem Cytobiol ; 49(2): 325-34, 2011.
Article in English | MEDLINE | ID: mdl-21744335

ABSTRACT

In various tissues, glucocorticoids (GCs) are known to downregulate glucose transport systems; however, their effects on glucose transporters (GLUTs) in the placenta of a diabetic rat are unknown. Glucocorticoid hormone action within the cell is regulated by the glucocorticoid receptor (GR). Thus, this study was designed to investigate the relationship between GR and glucose transporter expression in the placenta of the diabetic rat. Our immunohistochemical results indicated that GR and glucose transporter protein 1 (GLUT 1) are expressed ubiquitously in the trophoblast and endothelial cells of the labyrinthine zone, where maternal fetal transport takes place in the rat placenta. Expression of GR in the junctional zone of the rat placenta was detected in giant cells, and in some spongiotrophoblast cells, but not in the glycogen cells. GLUT 1 was present, especially in glycogen cells during early pregnancy, and in the spongiotrophoblast cells of the junctional zone during late pregnancy. Amounts of GR and GLUT 1 protein were increased towards the end of gestation both in the control and the diabetic placenta. However, at days 17 and 19 of gestation, only the placental GR protein was significantly increased in the streptozotocin-induced diabetic rats compared to control rats. Diabetes led to a significant decrease in placental weight at gestation day 15. In contrast, at gestational days 17 and 21, the weights of the diabetic placenta were significantly increased as compared with the controls. Moreover, diabetes induced fetus intrauterine growth retardation at gestational days 13, 17 and 21. In conclusion, the localization pattern of GR and GLUT 1 proteins in the same cell types led us to believe that there might be a relationship between GR and GLUT 1 expressions at the cellular level. GLUT 1 does not play a pivotal role in diabetic pregnancies. However, placental growth abnormalities during diabetic pregnancy may be related to the amount of GR.


Subject(s)
Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/metabolism , Glucose Transporter Type 1/metabolism , Placenta/embryology , Placenta/metabolism , Receptors, Glucocorticoid/metabolism , Animals , Blood Glucose/metabolism , Body Weight , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/complications , Female , Fetus/metabolism , Hyperglycemia/blood , Hyperglycemia/complications , Hyperglycemia/embryology , Immunoblotting , Immunohistochemistry , Placenta/pathology , Pregnancy , Protein Transport , Rats , Streptozocin
9.
Rev Invest Clin ; 61(1): 41-52, 2009.
Article in Spanish | MEDLINE | ID: mdl-19507474

ABSTRACT

Human epidemiological and experimental animal studies have shown that suboptimal environments in the womb and during early neonatal life alter growth and may program offspring susceptibility to lifelong health problems. One of the most interesting and significant feature of developmental programming is the evidence that adverse consequences of altered intrauterine environments can be passed from first generation to second generation offspring. To obtain the transgenerational phenotype, a negative environment is required during fetal or early neonatal life, the physiologic phenotype or disease can be transmitted through the germ line and the subsequent generations are not directly exposed to the environmental factor. The hypothesis has become well accepted by compelling animal studies that define the outcome of specific challenges such as: 1) nutrient restriction or overfeeding during pregnancy and lactation; 2) uterine blood flow restriction; 3) fetal exposure to inappropriately high levels of glucocorticoids, and 4) experimental maternal diabetes. Maternal protein restriction in the rat adversely affects glucose metabolism of male and female second generation offspring in a gender and developmental time window-specific manner. Other studies have proved transgenerational passage of effects resulting from treatment of pregnant rats with dexamethasone by either maternal or paternal lines. First generation female diabetic offspring of F0 rats treated with streptozotocin during pregnancy had F2 offspring with altered glucose and carbohydrate metabolism. The studies suggest that the mechanisms involved in developmental programming are likely epigenetic rather than due to DNA sequence mutations. Many individuals all over the world experience undernutrition, stress, hyperglycemia and other negative environmental factors during pregnancy and/or lactation. Insult during this critical period of development may induce malprogramming and adversely alter not only the F1 generation but also future generations. Preventing or treating these conditions will help to minimize the risk of transmission of metabolic diseases to future generations.


Subject(s)
Metabolic Diseases/etiology , Prenatal Exposure Delayed Effects , Animals , Birth Weight , Diabetes Mellitus, Experimental/embryology , Diabetes, Gestational/metabolism , Diet , Disease Susceptibility , Epigenesis, Genetic , Female , Fetal Growth Retardation/etiology , Fetal Macrosomia/etiology , Glucocorticoids/adverse effects , Humans , Hyperinsulinism/embryology , Hyperinsulinism/metabolism , Infant, Newborn , Lactation , Male , Malnutrition/complications , Malnutrition/embryology , Metabolic Diseases/embryology , Metabolic Diseases/genetics , Metabolic Syndrome/embryology , Metabolic Syndrome/genetics , Metabolic Syndrome/metabolism , Models, Biological , Oxazoles/toxicity , Pregnancy , Pregnancy Complications/metabolism , Rats , Rats, Wistar
10.
Reprod Toxicol ; 28(4): 521-9, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19539026

ABSTRACT

UNLABELLED: Fetal growth restriction (FGR) describes newborns that were born small for gestational age. The etiology of FGR is unknown, but it is assumed that it is the consequences of both genetic and environmental factors, and that one of the important environmental factors is oxidative stress. In this study we used the Cohen diabetic (CD) rats (sensitive and resistant strains) and the original Sabra strain fed either high sucrose low copper diet-HSD or regular diet-RD to evaluate the genetic and environmental factors contributing to FGR. In addition, we treated the pregnant rats with antioxidants (vitamins C and E added to their food) to evaluate the effects of antioxidants in the prevention of FGR and in changing the redox state of the fetuses. METHODS: The study was performed on term 21-day-old fetuses of the three strains fed RD or HSD. Fetal and placental weight and fetal crown rump length were measured. Heart, kidneys, brain and liver were also weighted and studied. The fetal and placental redox status was investigated by studying the levels of Malondialdehyde (MDA) to determine the lipid peroxidation damage and by measuring the activity of catalase (CAT) and superoxide dismutase (SOD) enzymes. Similar studies were performed following the addition of 0.1% of vitamins C and E to the diet. RESULTS: FGR in the Cohen diabetic rats is a consequence of genetic (6-20% reduction in fetal weight in the CDr and CDs compared to Sabra) and environmental (11-36% reduction in fetal weight while on HSD) factors, with greater susceptibility in the CDs diabetic rats. Increased lipid peroxidation was observed in some of the organs only in HSD, however not only in the sensitive strain. In each organ, different patterns of anti oxidant capacity were observed. The addition of antioxidants to the food significantly reduced the signs of enhanced oxidative stress in all animals but partially restored normal fetal growth only in the diabetic CDs rats. This may imply that in this model oxidative stress is apparently not a major contributor to FGR. CONCLUSIONS: Cohen diabetic rats are a good model for the study of the interaction of genetic and environmental factors in the development of FGR. Maternal nutrition can influence the antioxidant capacity of the fetal organs which is modified by antioxidants. However, FGR in our model does not seem to result primarily from enhanced oxidative stress, as it is only partially affected by the antioxidant treatment. Thus, the repeated observations of oxidative stress in SGA infants may be a resulting metabolic alteration of FGR and not the main cause.


Subject(s)
Antioxidants/metabolism , Diabetes Mellitus, Experimental/genetics , Fetal Growth Retardation/metabolism , Models, Animal , Oxidative Stress , Animals , Animals, Outbred Strains , Ascorbic Acid/metabolism , Catalase/metabolism , Copper/administration & dosage , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/metabolism , Diet , Female , Lipid Peroxidation , Malondialdehyde/metabolism , Organ Size , Oxidation-Reduction , Rats , Rats, Inbred Strains , Rats, Wistar , Sucrose/administration & dosage , Superoxide Dismutase/metabolism , Vitamin E/metabolism
11.
Anat Histol Embryol ; 38(3): 169-76, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19245670

ABSTRACT

Newborn children of diabetic mothers have an increased morbidity and mortality because of respiratory distress syndrome. We study lung histogenesis during intrauterine development of offspring of diabetic Sprague-Dawley rats at 18, 19 and 21 days of gestation (DG). Pregnant rats were grouped into diabetic (streptozotocin-induced), citrate, and control groups; five female and five male offspring were selected randomly from each group at 18, 19 and 21 DG, and a biopsy of the lung was taken and processed in paraffin for histological examination. The biopsy for the transmission electron microscopy (TEM) analysis was taken at 21 days. A delay in alveolization of the offspring at 18, 19 and 21 days of the diabetic group was observed, which was confirmed at TEM level, and also less quantity of protein D associated to surfactant in diabetic group was detected (P < 0.001). The foetuses of the diabetic group presented a delay in lung histogenesis and in differentiation of the type II pneumocytes cells, but conserved the proportion with a decrease in 50% of pneumocytes, accompanied by a diminish of protein D associated to surfactant factor.


Subject(s)
Diabetes Mellitus, Experimental/embryology , Fetal Organ Maturity/physiology , Lung/embryology , Pulmonary Surfactant-Associated Protein D/metabolism , Animals , Diabetes Mellitus, Experimental/physiopathology , Female , Gestational Age , Lung/cytology , Lung/ultrastructure , Male , Microscopy, Electron, Transmission , Pregnancy , Pregnancy in Diabetics , Pulmonary Surfactants/metabolism , Rats , Rats, Sprague-Dawley
13.
Birth Defects Res A Clin Mol Teratol ; 82(10): 710-9, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18937363

ABSTRACT

BACKGROUND: Congenital defects are a major complication of diabetic pregnancy, and the leading cause of infant death in the first year of life. Caudal dysgenesis, occurring up to 200-fold more frequently in children born to diabetic mothers, is a hallmark of diabetic pregnancy. Given that there is also an at least threefold higher risk for heart defects and NTDs, it is important to identify the underlying molecular mechanisms for aberrant embryonic development. METHODS: We have investigated gene expression in a transgenic mouse model of caudal dysgenesis, and in a pharmacological model using situ hybridization and quantitative real-time PCR. RESULTS: We identified altered expression of several molecules that control developmental processes and embryonic growth. CONCLUSIONS: The results from our models point towards major implication of altered Wnt signaling in the pathogenesis of developmental anomalies associated with embryonic exposure to maternal diabetes.


Subject(s)
Diabetes Mellitus, Experimental/embryology , Fetal Diseases/metabolism , Neural Tube Defects/etiology , Pregnancy in Diabetics , Signal Transduction , Wnt Proteins/metabolism , Animals , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/genetics , Disease Models, Animal , Embryo, Mammalian/metabolism , Female , Fetal Diseases/pathology , Mice , Mice, Transgenic , Neural Tube Defects/metabolism , Pregnancy , Wnt Proteins/genetics
14.
Diabetes ; 57(12): 3344-52, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18728230

ABSTRACT

OBJECTIVE: To characterize normal and malformed embryos within the same litters from control and diabetic rats for expression of genes related to metabolism of reactive oxygen species (ROS) or glucose as well as developmental genes. RESEARCH DESIGN AND METHODS: Embryos from nondiabetic and streptozotocin-induced diabetic rats were collected on gestational day 11 and evaluated for gene expression (PCR) and distribution of activated caspase-3 and glutathione peroxidase (Gpx)-1 by immunohistochemistry. RESULTS: Maternal diabetes (MD group) caused growth retardation and an increased malformation rate in the embryos of MD group rats compared with those of controls (N group). We found decreased gene expression of Gpx-1 and increased expression of vascular endothelial growth factor-A (Vegf-A) in malformed embryos of diabetic rats (MDm group) compared with nonmalformed littermates (MDn group). Alterations of messenger RNA levels of other genes were similar in MDm and MDn embryos. Thus, expression of copper zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and sonic hedgehog homolog (Shh) were decreased, and bone morphogenetic protein-4 (Bmp-4) was increased, in the MD embryos compared with the N embryos. In MDm embryos, we detected increased activated caspase-3 immunostaining in the first visceral arch and cardiac area and decreased Gpx-1 immunostaining in the cardiac tissue; both findings differed from the caspase/Gpx-1 immunostaining of the MDn and N embryos. CONCLUSIONS: Maternal diabetes causes growth retardation, congenital malformations, and decreased general antioxidative gene expression in the embryo. In particular, enhanced apoptosis of the first visceral arch and heart, together with decreased cardiac Gpx-1 levels, may compromise the mandible and heart and thus cause an increased risk of developing congenital malformation.


Subject(s)
Chromosome Aberrations/embryology , Diabetes Mellitus, Experimental/embryology , Glutathione Peroxidase/metabolism , Mandible/pathology , Myocardium/enzymology , Animals , Caspase 3/metabolism , Diabetes Mellitus, Experimental/enzymology , Disease Models, Animal , Female , Mandible/enzymology , Pregnancy , Rats , Reactive Oxygen Species/metabolism
15.
Toxicol Pathol ; 36(4): 529-51, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18467681

ABSTRACT

Type 2 diabetes mellitus (TTDM) is characterized by progressive loss of glucose control through multifactorial mechanisms. The search for an understanding of TTDM has relied on animal models since the realization of the importance of the pancreas in controlling plasma glucose concentration. Rodent models of TTDM are developed to express hyperglycemia and not islet degeneration per se. Degeneration of the islets of Langerhans with beta-cell loss is secondary to insulin resistance and is regarded as the more important lesion. Despite this, differences between models are seen in the development and progression of islet degeneration. Assessing the differences between the models is important to appreciate the various aspects of TTDM and understand their advantages as well as their deficiencies. Relevant animal models of TTDM provide opportunities to investigate important physiological and cell biological processes that may ultimately lead to development of targeted therapies. This article reviews the importance, advantages, and limitations of rodent models of TTDM in relation to the histopathological changes that characterize islet degeneration. Pathophysiological mechanisms that contribute to islet degeneration are also discussed and are placed into the context of changes in islet histological appearances.


Subject(s)
Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 2/pathology , Islets of Langerhans/pathology , Rodentia , Animals , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/etiology , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 2/embryology , Diabetes Mellitus, Type 2/etiology , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Gene Expression , Humans , Insulin Resistance , Islets of Langerhans/embryology , Streptozocin , Transgenes
16.
Reprod Toxicol ; 23(4): 486-98, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17482424

ABSTRACT

We aimed to investigate the extent to which maternal diabetes with or without folic acid (FA) supplementation affects mRNA levels and protein distribution of ROS scavenging enzymes, vascular endothelial growth factor-A (Vegf-A), folate binding protein-1 (Folbp-1), and apoptosis-associated proteins in the yolk sacs of rat embryos on gestational days 10 and 11. Commencing at conception and throughout pregnancy, half of the streptozotocin-diabetic and half of the control rats received daily FA injections. Maternal diabetes impaired vascular morphology and decreased CuZnSOD and GPX-1 gene expression in yolk sacs. Maternal diabetes also increased the levels of CuZnSOD protein, increased the Bax/Bcl-2 protein ratio and decreased Vegf-A protein distribution. FA treatment normalized vascular morphology, decreased mRNA levels of all three SOD isoforms and increased Vegf-A mRNA levels, rectified CuZnSOD protein distribution and Bax/Bcl-2 ratio. A teratogenic diabetic environment produces a state of vasculopathy, oxidative stress, and mild apoptosis in the yolk sac. FA administration normalizes vascular morphology, diminishes apoptotic rate, and increases Vegf-A gene expression and protein distribution in the yolk sac of diabetic rats.


Subject(s)
Antioxidants/pharmacology , Apoptosis/drug effects , Diabetes Mellitus, Experimental/drug therapy , Folic Acid/pharmacology , Oxidoreductases/metabolism , Pregnancy in Diabetics/drug therapy , Vascular Endothelial Growth Factor A/metabolism , Yolk Sac/drug effects , Animals , Antioxidants/therapeutic use , Caspase 3/metabolism , Catalase/metabolism , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Female , Folic Acid/therapeutic use , Gene Expression Regulation, Developmental/drug effects , Gestational Age , Glutathione Peroxidase/metabolism , Glycine N-Methyltransferase/metabolism , Oxidoreductases/genetics , Pregnancy , Pregnancy in Diabetics/genetics , Pregnancy in Diabetics/metabolism , Pregnancy in Diabetics/pathology , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Superoxide Dismutase/metabolism , Vascular Endothelial Growth Factor A/genetics , Yolk Sac/enzymology , Yolk Sac/pathology , bcl-2-Associated X Protein/metabolism
17.
Mol Hum Reprod ; 13(2): 103-10, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17148578

ABSTRACT

Maternal diabetes significantly increases the risk of congenital malformations, and the mechanisms involved are not yet clarified. This study was designed to address peroxisome proliferator-activated receptor delta (PPARdelta) involvement in diabetic embryopathy. We investigated the concentrations of PPARdelta and its endogenous agonist prostaglandin (PG)I(2), as well as the effect of PPARdelta activation on lipid metabolism and PGE(2) concentrations in embryos from control and streptozotocin-induced diabetic rats during early organogenesis. Embryos from diabetic rats showed decreased concentrations of PPARdelta and its endogenous agonist PGI(2) when compared with controls. In embryos from control rats, the addition of the PPARdelta activators (cPGI(2) and PGA(1)) increased embryonic phospholipid levels and de novo phospholipid synthesis studied using (14)C-acetate as a tracer. PGE(2) formed from arachidonate released from phospholipid stores was also up-regulated by PPARdelta activators. In embryos from diabetic rats, reduced phospholipid synthesis and PGE(2) content were observed, and clearly up-regulated by cPGI(2) additions to values similar to those found in control embryos. These data suggest that PPARdelta may play an important role in lipid metabolic and signalling pathways during embryo organogenesis, developmental pathways that are altered in embryos from diabetic rats, possibly as a result of a reduction in levels of PPARdelta and its endogenous activator PGI(2).


Subject(s)
Diabetes Mellitus, Experimental/embryology , Epoprostenol/metabolism , Fetal Diseases/metabolism , Lipid Metabolism , Organogenesis , PPAR delta/metabolism , Pregnancy, Animal , Animals , Dinoprostone/analysis , Embryo Culture Techniques , Embryo, Mammalian/anatomy & histology , Embryo, Mammalian/metabolism , Epoprostenol/pharmacology , Female , Fetal Development/drug effects , Fetal Diseases/chemically induced , Lipid Metabolism/drug effects , Male , PPAR delta/physiology , Pregnancy , Pregnancy in Diabetics , Rats , Rats, Wistar , Signal Transduction , Streptozocin
18.
Birth Defects Res A Clin Mol Teratol ; 76(2): 107-14, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16470537

ABSTRACT

BACKGROUND: We have previously shown that oxidative stress is important in the pathogenesis of diabetes-induced anomalies in Cohen Diabetic sensitive (CDs) rat embryos and seems to interplay with genetic factors. We investigated the role of genetic factors related to the antioxidant defense mechanism in CDs rat embryos. METHODS: We studied 11.5- and 12.5-day embryos of Cohen Diabetic resistant (CDr) and CDs rats that were fed a regular diet (RD), and hence not diabetic, compared to rats fed a high-sucrose low-copper diet (HSD) where only the CDs animals became diabetic. Embryos were monitored for growth and congenital anomalies. mRNA of catalase (CAT), glutathione peroxidase (GSHpx), CuZn-SOD (SOD-superoxide dismutase), and Mn-SOD and the extent of nuclear factor kappa B (NF-kappaB) activation were assessed. RESULTS: Embryos of CDs dams fed RD were significantly smaller and had an increased rate of NTDs compared to embryos of CDr dams fed RD. When CDs dams were fed HSD, >50% of the CDs embryos were dead and 44% of the live embryos had NTDs. Live 11.5-day old embryos of CDs dams fed RD had a statistically significant increase in CAT, CuZn-SOD, and GSHpx mRNA levels compared with the levels in the CDr embryos from dams fed RD. CDs embryos from dams fed HSD showed significant overactivation of NF-kappaB compared with CDr embryos from dams fed HSD (in which activation was decreased), without any increase in the expression of SOD, CAT, and GSHpx. CONCLUSIONS: This study demonstrates that one of the genetic differences between the CDr and CDs strains fed RD is an increased expression of genes encoding for antioxidant enzymes in the CDs but inability for upregulation in diabetes. In addition, while activation of NF-kappaB is decreased in CDr on HSD, it is increased in the CDs. These differences may play a role in the increased sensitivity of the CDs embryos to diabetic-induced teratogenicity.


Subject(s)
Antioxidants/metabolism , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/genetics , Enzymes/genetics , Gene Expression Regulation, Developmental/drug effects , NF-kappa B/metabolism , Animals , Catalase/genetics , Copper/administration & dosage , Copper/deficiency , Diabetes Mellitus, Experimental/metabolism , Diet , Female , Gene Expression Regulation, Developmental/physiology , Glutathione Peroxidase/genetics , Male , Pregnancy , Pregnancy Outcome , Rats , Reactive Oxygen Species/metabolism , Sucrose/administration & dosage , Sucrose/adverse effects , Superoxide Dismutase/genetics
19.
Int J Obes (Lond) ; 30(5): 739-50, 2006 May.
Article in English | MEDLINE | ID: mdl-16418759

ABSTRACT

OBJECTIVE: We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. DESIGN: Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. MEASUREMENTS: Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitamin A, E and C concentrations, and (iii) antioxidant enzymes activities in erythrocytes. The plasma lipid concentrations and fatty acid composition were also determined. RESULTS: Diabetes increased plasma triglyceride and cholesterol concentrations, whereas macrosomia was associated with enhanced plasma cholesterol and triglyceride levels, which diminished by feeding n-3 PUFA diet. N-3 PUFA diet also reduced increased plasma TBARS and corrected the decreased ORAC values in diabetic rats and their macrosomic offspring. EPAX diet increased the diminished vitamin A levels in diabetic mothers and vitamin C concentrations in macrosomic pups. Also, this diet improved the decreased erythrocyte superoxide dismutase and glutathione peroxidase activities in diabetic and macrosomic animals. CONCLUSION: Diabetes and macrosomia were associated with altered lipid metabolism, antioxidant enzyme activities and vitamin concentrations. N-3 PUFA diet improved hyperlipidemia and restored antioxidant status in diabetic dams and MAC offspring.


Subject(s)
Antioxidants/metabolism , Diabetes Mellitus/drug therapy , Fatty Acids, Omega-3/administration & dosage , Pregnancy in Diabetics/drug therapy , Animals , Animals, Newborn , Ascorbic Acid/blood , Biomarkers/blood , Diabetes Mellitus/embryology , Diabetes Mellitus/metabolism , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/embryology , Diabetes Mellitus, Type 2/metabolism , Erythrocytes/enzymology , Fatty Acids/blood , Female , Fetal Macrosomia/metabolism , Free Radical Scavengers/metabolism , Glutathione Peroxidase/blood , Lipid Peroxidation , Lipids/blood , Pregnancy , Pregnancy in Diabetics/metabolism , Rats , Rats, Wistar , Superoxide Dismutase/blood , Thiobarbituric Acid Reactive Substances/analysis , Vitamin A/blood , Vitamin E/blood
20.
Dev Biol ; 292(1): 25-33, 2006 Apr 01.
Article in English | MEDLINE | ID: mdl-16442519

ABSTRACT

Nitric oxide (NO) participates in a diverse array of biological functions in mammalian organ systems. Depending on the biochemical environment, the production of NO may result in cytoprotection or cytotoxicity. The paradoxical actions of NO arise from the complexities generated by the redox milieu, NO concentration/bioavailability, and tissue/cell context, which ultimately result in the wide range of regulatory roles observed. Additionally, in physiological versus pathological states, NO often displays diametrically opposing affects in several organ systems. Here, we will discuss the roles of NO during reproduction, organ system development, in particular, the cardiovascular system, and its potential implications in diabetes-induced fetal defects.


Subject(s)
Cardiovascular System/embryology , Cardiovascular System/metabolism , Nitric Oxide/physiology , Animals , Cardiovascular System/pathology , Cardiovascular System/physiopathology , Diabetes Mellitus, Experimental/embryology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Experimental/physiopathology , Humans , Mice
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