Visfatin expression is elevated in normal human pregnancy

Visfatin is a novel-secreted 52kDa adipokine that appears to mimic the action of insulin, inducing glucose transport into mammalian cells. We examined visfatin expression in a cohort of pregnant women to determine if pregnancy influenced visfatin gene expression, circulating levels of visfatin, or local concentrations of visfatin in either omental fat or placenta. Samples of female omental fat, blood and placenta were collected over a 2-year period and frozen at -80 degrees C until they were employed in a series of various assays. Samples were collected during delivery in pregnant women, at hysterectomy in lean women and at bariatric surgery in obese and obese diabetic women. Visfatin expression and concentrations were measured in four cohorts of women: lean controls, pregnant women at term, obese (BMI>40) and obese diabetic women (BMI>40). Visfatin expression was seven times higher in omental fat of pregnant women than in lean women. Immunohistochemistry (IHC) demonstrated that the visfatin gene transcript was translated to protein. An immunoblot confirmed that visfatin protein was much higher in pregnant women than in obese women. Serum visfatin was 20.8ng/ml (n=7) in lean women as compared to 40.3ng/ml in pregnant women (n=4); thus the increased visfatin mRNA levels in omental fat were not reflected in increased serum visfatin. We measured visfatin mRNA content of human placenta and found that placenta expresses substantial amounts of visfatin. GAP-DH, a housekeeping gene that is highly expressed in most human cells had a threshold value (Ct) of 20.9 versus a Ct of 22.4 for visfatin. Again, IHC confirmed that placental visfatin mRNA was translated into visfatin protein. [(3)H] 2-deoxyglucose transport was measured in partially differentiated 3T3-L1 preadipocytes. At a concentration of 2nM, visfatin and insulin produced nearly identical increases in glucose transport. Taken together, these data suggest there is a selective increase in visfatin gene expression in pregnant women at term. Since visfatin also potently and efficaciously induced glucose transport in a cell culture model, any hypothetical role for visfatin in pregnancy should include the possibility that it may function in regulation of maternal/fetal glucose metabolism or distribution.

Preconception planning: are we making progress?

According to the American Diabetes Association, unplanned pregnancies in women with diabetes could lead to abnormal metabolic control, which causes fetal and maternal complications. Preconception planning can decrease these risks. This article reports on the progress in preconception planning over the past 2 years.

Identification of genes differentially expressed in mouse fetuses from streptozotocin-induced diabetic pregnancy by cDNA subtraction

Epidemiological studies have shown that the risks of fetal malformation such as neural tube defects increase in diabetic pregnancy. To explore the mechanism of fetal malformation induced by diabetes, cDNA subtraction using mouse embryos (E9.5) of diabetic dams and those of controls was performed to identify differentially expressed genes. The expression level of genes identified by cDNA subtraction was further verified by quantitative RT-PCR using E8.5 embryos, and differential expression of 4 genes, Brcc3, Commd3, Ddx1, and SET was confirmed. We also analyzed the expression level of neural tube defect-related genes, and found that Folbp1, EphrinA5 and Sox10 were differentially expressed. Altered expression of these genes mostly persisted throughout the later stages of the development (E10.5-14.5). Hierarchical clustering analysis showed correlation between expression levels of these genes, suggesting that these genes cooperatively play a role in embryonic development. Our results suggest that an altered gene expression profile in embryos underlies the development of congenital malformation in diabetic pregnancies.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. On day 21 of pregnancy, the adult rats (weighing approximately 250 +/- 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 +/- 0.2) and SOD (G3 = 223.0 +/- 84.7; G4 = 146.1 +/- 40.8), and decreased fetal CAT activity (G3 = 22.4 +/- 10.6; G4 = 34.4 +/- 14.1) and GSH-t (G3 = G4 = 0.3 +/- 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 +/- 0.2 and SOD = 274.1 +/- 80.3; fetal CAT = 92.6 +/- 82.7 and GSH-t = 0.6 +/- 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Continuous Subcutaneous Glucose Monitoring System in diabetic mothers during labour and postnatal glucose adaptation of their infants

AIMS

To assess a new technique for continuous monitoring of glucose concentration during labour in diabetic mothers. A second objective was to study maternal glucose levels in relation to postnatal glucose adaptation and the need for intravenous (IV) glucose treatment in the newborn infant.

METHODS

Fifteen pregnant women with insulin-treated diabetes mellitus participated in this prospective pilot study. To measure their glucose control during labour we used the Continuous Subcutaneous Glucose Monitoring System (CGMS; Medtronic, Minneapolis, MN, USA) to calculate the mean glucose concentration and the area under the curve (AUC) in the last 120 min before delivery. All infants of these women were transferred to the neonatal care unit for early oral feeding and blood glucose measurements up to 14 h after delivery. Infants received IV glucose if blood glucose values were repeatedly < 2.2 mmol/l.

RESULTS

All women coped well with the CGMS monitoring. AUC 0-120 min before delivery, mean glucose concentration 0-120 min before delivery and cord plasma insulin level were all significantly associated with the need for IV glucose in the newborn children.

CONCLUSIONS

In this study we found an association between maternal glucose concentrations during labour and postnatal glucose adaptation and need for IV glucose treatment in the infants. Online monitoring of glucose levels during delivery might help us to achieve maternal normoglycaemia and further reduce the risk of postnatal hypoglycaemia in the offspring.

Serum lipoprotein composition, lecithin cholesterol acyltransferase and tissue lipase activities in pregnant diabetic rats and their offspring receiving enriched n-3 PUFA diet

The effects of dietary n-3 polyunsaturated fatty acids on lipoprotein concentrations and on lipoprotein lipase (LPL), hepatic triglyceride lipase (HTGL) and lecithin cholesterol acyltransferase (LCAT) activities were studied in streptozotocin-induced diabetic rats during pregnancy and in their macrosomic offspring from birth to adulthood. Pregnant diabetic and control rats were fed Isio-4 diet (vegetable oil) or EPAX diet (concentrated marine omega-3 EPA/DHA oil), the same diets were consumed by pups at weaning. Compared with control rats, diabetic rats showed, during pregnancy, a significant elevation in very low density lipoprotein (VLDL) and low and high density lipoprotein (LDL-HDL(1))-triglyceride, cholesterol and apoprotein B100 concentrations and a reduction in apoprotein A-I levels. HTGL activity was high while LPL and LCAT activities were low in these rats. The macrosomic pups of Isio-4-fed diabetic rats showed a significant enhancement in triglyceride and cholesterol levels at birth and during adulthood with a concomitant increase in lipase and LCAT activities. EPAX diet induces a significant diminution of VLDL and LDL-HDL(1) in mothers and in their macrosomic pups, accompanied by an increase in cholesterol and apoprotein A-I levels in HDL(2-3) fraction. It also restores LPL, HTGL and LCAT activities to normal range. EPAX diet ameliorates considerably lipoprotein disorders in diabetic mothers and in their macrosomic offspring.

Effect of Bauhinia forficata aqueous extract on the maternal-fetal outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bauhinia forficata Link, commonly known as "paw-of-cow", is widely used in Brazilian folk medicine for the treatment of diabetes.

AIM OF THIS STUDY

To evaluate the effect of Bauhinia forficata treatment on maternal-fetal outcome and antioxidant systems of streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Virgin female Wistar rats were injected with 40 mg/kg streptozotocin before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats at increasing doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. At day 21 of pregnancy the rats were anaesthetized with ether and a maternal blood sample was collected for the determination superoxide dismutase (SOD) and reduced glutathione (GSH). The gravid uterus was weighed with its contents and fetuses were analyzed.

RESULTS AND CONCLUSION

The data showed that the diabetic dams presented an increased glycemic level, resorption, placental weight, placental index, and fetal anomalies, and reduced GSH and SOD determinations, live fetuses, maternal weight gain, gravid uterine weight, and fetal weight. It was also verified that Bauhinia forficata treatment had no hypoglycemic effect, did not improve maternal outcomes in diabetic rats, but it contributed to maintain GSH concentration similarly to non-diabetic groups, suggesting relation with the decreased incidence of visceral anomalies.

One-cell zygote transfer from diabetic to nondiabetic mouse results in congenital malformations and growth retardation in offspring

Fetuses of type 1 and 2 diabetic women experience higher incidences of malformations and fetal death as compared with nondiabetics, even when they achieve adequate glycemic control during the first trimester. We hypothesize that maternal diabetes adversely affects the earliest embryonic stage after fertilization and programs the fetus to experience these complications. To test this hypothesis, we transferred either one-cell mouse zygotes or blastocysts from either streptozotocin-induced diabetic or control mice into nondiabetic pseudopregnant female recipients. We then evaluated the fetuses at embryonic d 14.5 to assess fetal growth and the presence or absence of malformations. We found that fetuses from the diabetic mice transferred at the blastocyst stage but also as early as the one-cell zygote stage displayed significantly higher rates of malformations consistent with neural tube closure problems and abdominal wall and limb deformities. In addition, both these groups of fetuses were significantly growth retarded. To determine if this phenomenon was due to high glucose concentrations, two-cell embryos were cultured to a blastocyst stage in 52 mm D-glucose or L-glucose as an osmotic control, transferred into nondiabetic pseudopregnant mice, and examined at embryonic d 14.5. These embryos did not demonstrate any evidence of malformations, however, they did experience significantly higher rates of resorptions, lower implantation rates, and they were significantly smaller at embryonic d 14.5. In summary, exposure to maternal diabetes during oogenesis, fertilization, and the first 24 h was enough to program permanently the fetus to develop significant morphological changes.

[Morphological and immunohistochemical peculiarities of placental terminal villi in a physiological and gestosis-complicated pregnancy and in pregnancy in patients with type I diabetes and gestosis]

Using the methods of light microscopy and immunohistochemistry, the structural organization of terminal placental villi was studied in a physiological and gestosis-complicated pregnancy, as well as in women with type I diabetes mellitus and gestosis. The studies have revealed both morphological and immunohistochemical differences in the ratio of structural components in the terminal placental villi, including decreased diameter of the villi, increased degree of capillarization, reduced proportion of the connective tissue, increased type I, II, III, and VI collagen content in the connective tissue extracellular matrix and the decreased type IV collagen content in basement membranes in gestosis-complicated pregnancy. These changes were more expressed in the combination of gestosis and type I diabetes mellitus. It was found that the compensatory processes in gestosis are predominantly provided by syncytiotrophoblast, while in type I diabetes mellitus they were due to the increased capillarization of the terminal villi.

Glucose metabolism in pregnancy and embryogenesis

PURPOSE OF REVIEW

It has been known for decades that diabetic women have somewhat decreased fertility and that their offspring have an increased risk of being born with developmental abnormalities. We review results from studies examining the impact of maternal hyperglycemia and diabetes on oocyte and early embryo development. We focus on the effects of the maternal milieu on metabolism, cell signaling and the regulation of glucose-transporter expression in the developing oocyte and embryo.

RECENT FINDINGS

Offspring of diabetic mothers have metabolic disease at higher rates than can be explained by genetic inheritance alone. Oocytes from hyperglycemic animals display several abnormalities and are of lower quality than oocytes from control animals. There appears to be a decrease in glucose transport in embryos exposed to a hyperglycemic environment, which may lead to programmed cell death.

SUMMARY

Maternal hyperglycemia and diabetes have detrimental effects on the developing embryo at several stages of development. Although the exact pathophysiology of the developmental defects seen in infants born to diabetic mothers remains unclear, the role of glucose transport and regulation seems to play a critical role in early growth and development.

Role of lipids and fatty acids in macrosomic offspring of diabetic pregnancy

Diabetic pregnancy frequently results in macrosomia or fetal obesity. It seems that the anomalies in carbohydrate and lipid metabolism in macrosomic infants of diabetic mothers are due to maternal hyperglycemia, which leads to fetal hyperinsulinemia. We have developed a rat model of macrosomic offspring and assessed the onset of obesity in these animals. The macrosomic offspring born to diabetic mothers are prone to the development of glucose intolerance and obesity as a function of age. It seems that in utero programming during diabetic pregnancy creates a "metabolic memory" which is responsible for the development of obesity in macrosomic offspring. We have demonstrated that the metabolism of lipids, and altered anti-oxidant status and immune system are implicated in the etiopathology of obesity in these animals. We have reported beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) in obese animals, born to diabetic dams.

Maternal diabetes adversely affects AMP-activated protein kinase activity and cellular metabolism in murine oocytes

Maternal diabetes is associated with an increased risk of miscarriages and congenital anomalies. Preovulatory oocytes in murine models also experience maturational delay and greater granulosa cell apoptosis. The objective of this study was to examine whether maternal diabetes influences preovulatory oocyte metabolism and impacts meiotic maturation. Streptozotocin-induced diabetic B6SJLF1 mice were superovulated, and oocytes were collected at 0, 2, and 6 h after human chorionic gonadotropin (hCG) injection. Individual oocyte concentrations of ATP, 5'-AMP, glycogen, and fructose-1,6-phosphate (FBP) and enzyme activities of glucose-6-phosphate dehydrogenase (G6PDH), adenylate kinase, hydroxyacyl-CoA dehydrogenase (Hadh2), and glutamic pyruvate transaminase (Gpt2) were measured. Protein levels of phosphorylated AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) were also measured. ATP levels were significantly lower in oocytes from diabetic mice, and the percent change in the AMP-to-ATP ratio was significantly higher in these oocytes. In contrast, activities of Hadh2 and Gpt2, two enzymes activated by AMPK, were significantly less in these oocytes. Additionally, glycogen and FBP levels, both endogenous inhibitors of AMPK, were elevated. Phosphorylated ACC, a downstream target of AMPK, and phosphorylated AMPK were both decreased in diabetic oocytes, thus confirming decreased AMPK activity. Finally, addition of the activator AICAR to the in vitro maturation assay restored AMPK activity and corrected the maturation defect experienced by the oocytes from diabetic mice. In conclusion, maternal diabetes adversely alters cellular metabolism leading to abnormal AMPK activity in murine oocytes. Increasing AMPK activity in these oocytes during the preovulatory phase reverses the metabolic changes and corrects delays in meiotic maturation.

Influence of maternal diabetes mellitus on fetal iron status

OBJECTIVE

To determine the effects of maternal diabetes on fetal iron status using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood.

METHODS

Iron, ferritin, erythropoietin, STfR and haemoglobin concentration were measured and TfR-F index calculated in 97 maternal/cord blood pairs. Forty-nine women had type 1 diabetes (diagnosed before pregnancy) and these were compared with forty-eight non- diabetic controls. The women with type 1 diabetes were recruited consecutively from attendance at the joint antenatal endocrine clinic while the control group of women was recruited from consecutive attendance at the remaining antenatal clinics.

RESULTS

The infants of the diabetic women had significantly lower levels of ferritin (47 vs 169 mug/l; p<0.01) and higher STfR (17.4 vs 12.9 mg/l; p<0.01) and TfR-F index (10.4 vs 5.8; p<0.01) than controls. They were also significantly more acidotic at birth (7.25 vs 7.30; p<0.01), were born at an earlier gestation (36.7 vs 39.7 weeks; p<0.01) and had higher z Scores for weight (0.53 vs 0.02; p = 0.016).

CONCLUSIONS

Maternal diabetes causes depletion of fetal iron stores and is associated with higher fetal iron demands as indicated by higher STfR level and TfR-F index in cord blood.

Effect of a high-fat diet on diabetic mother rats and their offspring through three generations

Pregnant diabetic Wistar rats were fed a high-fat diet starting at the first gestational day. The effect of the high-fat diet on the growth of the female, her offspring, and the offspring's offspring was studied. Pregnant rats (first generation) were divided into the Diabetic streptozotocin-induced group and the control group. Diabetic streptozotocin-induced rats and control rats were fed either a control diet (5% fat in diet) or high-fat diet (32% fat in diet), and observed up to the third generation. In each generation, after weaning, the pups were fed the respective diet. The fat content was mainly animal lard. Diabetic rats fed the high-fat diet were infertile, and the pregnant first-generation and diabetic rats fed the control diet had a stillbirth rate of 27.5 +/- 22.0% (mean +/- SE). In the first generation, the diabetic rats fed the control diet had a significantly lower body weight increase during the pregnancy than the control rats fed the control diet. The second-generation diabetic rats fed the control diet had a high blood glucose level at birth, and their triglyceride level was higher than that in the other two groups. The third-generation diabetic rats fed the control diet had a triglyceride level higher than that of control rats. Delivery was most difficult in diabetic rats fed the high-fat diet. Pups of diabetic rats fed the control diet had growth retardation and increased blood glucose levels. We conclude that when the mother rat had diabetes, the next generation was also affected.

The influence of L-arginine on blood pressure, vascular nitric oxide and renal morphometry in the offspring from diabetic mothers

The present study was designed to evaluate the effects of L-arginine (L-arg) supplementation on blood pressure, vascular nitric oxide content, and renal morphometry in the adult offspring from diabetic mothers. Diabetes mellitus was induced in female rats with a single dose of streptozotocin (50 mg/kg), before mating. The offspring was divided into four groups: group C (controls); group DO (diabetic offspring); group CA (controls receiving 2% L-arg solution dissolved in 2% sucrose in the drinking water) and group DA (DO receiving the L-arg solution). Oral supplementation began after weaning and continued until the end of the experiments. In DO, hypertension was observed, from 3 mo on. In DA, pressure levels were not different from C and CA. In 6-mo-old animals, basal NO production (assessed by DAF-2) was significantly depressed in DO in comparison to controls. The NO production was significantly increased after stimulation with Ach or BK in all groups, the increase being greater in control than in DO rats. L-arg was able to improve the NO production and to prevent the glomerular hypertrophy in the DO. Our data suggest that the bioavailability of NO is reduced in the DO, because L-arg corrected both the hypertension and glomerular hypertrophy.

Fulminant type 1 diabetes during pregnancy: A case report and review of the literature

Fulminant type 1 diabetes, classified as a subtype of nonautoimmune type 1 diabetes, may result in severe complications for both mother and fetus due to the sudden onset of diabetic ketoacidosis. Little is known about the clinical features of pregnancy with fulminant type 1 diabetes. We present a case of fulminant type 1 diabetes during pregnancy, along with a review of the published literature. A 31-year-old Japanese woman presented with sudden onset of nausea and vomiting at 36 weeks' gestation and was provisionally diagnosed with acute gastroenteritis. She was referred to us for investigation of exaggerated general fatigue and intrauterine fetal death. Based on blood and urinary examinations, she was diagnosed with diabetic ketoacidosis, caused by fulminant type 1 diabetes. Although her ketoacidosis was improved, insulin therapy was needed. Awareness of this disease can lead to prompt diagnosis and treatment and consequently, improved maternal and fetal prognosis.

Diabetic pregnancy in rats leads to impaired glucose metabolism in offspring involving tissue-specific dysregulation of 11beta-hydroxysteroid dehydrogenase type 1 expression

Population-based studies have shown that the offspring of diabetic mothers have an increased risk of developing obesity, insulin resistance, type 2 diabetes and hypertension in later life. To investigate mechanism for the high incidence of metabolic diseases in the offspring of diabetic mothers, we focused on the tissue-specific glucocorticoid regulation by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) and studied offspring born to streptozotocin-induced diabetic rats. The body weights of newborn rats from diabetic mothers were heavier than those from control mothers. Offspring born to diabetic mothers demonstrated insulin resistance and mild glucose intolerance after glucose loading at 10 weeks and showed significantly increased 11beta-HSD1 mRNA and enzyme activity in adipose tissue at 12 weeks of age without obvious obesity. Hepatic 11beta-HSD1 mRNA was also elevated. We propose that the 11beta-HSD1 in adipose tissue and liver may play a key role in the development of metabolic syndrome in the offspring of diabetic mothers. Tissue-specific glucocorticoid dysregulation provides a candidate mechanism for the high incidence of metabolic diseases in the offspring of diabetic mothers. Therefore early analyses before apparent obesity are needed to elucidate the molecular mechanisms that may be programmed during the fetal period.

Expression of matrix metalloproteinases MMP-2 and MMP-9 is altered during nephrogenesis in fetuses from diabetic rats

Remodeling of extracellular matrix (ECM) is an important physiological feature of normal growth and development. Recent studies have emphasized the role of matrix metalloproteinases (MMP-2 and MMP-9) in normal mouse nephrogenesis. We have demonstrated previously in the rat that in utero exposure to maternal diabetes impairs renal development leading to a 30% reduction in the nephron number. Transforming growth factor-beta1 (TGF-beta1) and connective tissue growth factor (CTGF) are known to mediate high glucose effects on matrix degradation. The aim of the present study was to address the expression of type IV collagenase and TGF-beta1/CTGF systems in rat kidney during normal development and after in utero exposure to maternal diabetes. Both MMP-2 and MMP-9 mRNA metanephric expressions and activities were dramatically downregulated in kidneys issued from diabetic fetuses and in metanephros cultured in the presence of high glucose concentration. TGF-beta1 and CTGF expressions were significantly enhanced in diabetic fetal kidneys and in high glucose cultured metanephroi. Conditioned media obtained from metanephroi grown with high glucose concentration upregulated functional TGF-beta activity in transfected ATDC5 cells. In conclusion, in impaired nephrogenesis resulting from in utero exposure to maternal diabetes, alteration of both type IV collagenase and TGF-beta1/CTGF systems may lead to abnormal remodeling of ECM, which may, in turn, induce defects in ureteral bud branching leading to the observed reduction in the nephron number with consequences later in life: progression of chronic renal disease and hypertension.

Oxidant release is dramatically increased by elevated glucose concentrations in neutrophils from pregnant women

OBJECTIVE

To evaluate the mechanism of oxidative stress at glucose levels accompanying diabetic pregnancy. Specifically, we hypothesize that elevated glucose overwhelms hexose monophosphate shunt (HMS) down-regulation observed during pregnancy.

METHODS

Peripheral blood cells from normal healthy pregnant women were exposed to heightened glucose levels to provide an in vitro model of the effects of diabetic pregnancy. Changes in NAD(P)H, reactive oxygen species (ROS) and nitric oxide (NO) production were evaluated in single cells.

RESULTS

Altered metabolic dynamics, as judged by NAD(P)H autofluorescence of neutrophils from both pregnant and non-pregnant women, were observed during incubation with 14 mM glucose, a pathophysiologic level. In parallel, increased production of ROS and NO was observed. The ROS and NO levels attained in cells from pregnant women were greater than those observed in cells from non-pregnant women. Inhibitors of the HMS and NAD(P)H oxidase blocked these effects. These metabolic and oxidant changes required approximately one minute, suggesting that transient glucose spikes during pregnancy could trigger this response.

CONCLUSIONS

Elevated glucose levels enhance HMS activity and oxidant production in cells from pregnant women. This mechanism may be generally applicable in understanding the role of diabetes in materno-fetal health.

Embryonic oxidative stress as a mechanism of teratogenesis with special emphasis on diabetic embryopathy

Reactive oxygen species (ROS) are involved in the etiology of numerous diseases including cardio-vascular diseases and diabetes mellitus. There is evidence that several teratogens affect the developing embryo by increasing its oxidative stress and, because of its relatively weak antioxidant defense, especially at the early stages of organogenesis, result in severe embryonic damage. This mechanism seems to operate in diabetes-induced embryonic damage as well as in the mechanism of teratogenicity caused by ionizing radiation, hypoxia, alcohol and cocaine use and cigarette smoking. We studied the role of oxidative stress in diabetic induced embryopathy, both in vivo and in vitro. Under diabetic condition there was a significant decrease in the activity of endogenous antioxidant enzymes and of vitamins C and E in the embryos and their yolk sacs. The lowest activity was observed in the malformed experimental embryos when compared to experimental embryos without anomalies. Similar results were obtained in the Cohen diabetic rats, where the diabetic prone (CDs) rats were unable to increase their antioxidant enzyme activity in spite of the diabetes. Studies performed by other investigators show similar results. Human and animal studies show that the main mechanism of fetal damage induced by high levels of ionizing irradiation, cocaine and alcohol abuse, hypoxia and cigarette smoking is also by increased embryonic oxidative stress. Similarly, several drugs exert their teratogenic activity via embryonic oxidative stress. Abnormal placentation may also cause enhanced placental oxidative stress, resulting in embryonic death, preeclampsia or congenital anomalies. Inability of the developing embryo to cope with that stress may result in embryonic death and/or congenital anomalies. Animal studies also show that a variety of antioxidants are effective in decreasing the damaging effects of heightened oxidative stress induced by teratogens. Effective antioxidants, which might also be of clinical use, include vitamins C and E, carotenoids, folic acid, as well as synthetic products. Appropriate clinical studies with antioxidants in pregnancies of high risk to develop oxidative stress are needed, since non-toxic antioxidants might prove an efficient and inexpensive way to reduce the rate of some serious and sometimes fatal congenital anomalies.

No loss of genomic imprinting of IGF-II and H19 in placentas of diabetic pregnancies with fetal macrosomia

OBJECTIVES

Fetal macrosomia is a common complication of maternal diabetes mellitus and is associated with substantial morbidity, but the precise cellular and molecular mechanisms that induce fetal macrosomia are not well understood. The imprinted genes IGF-II and H19 are crucial for placental development and fetal growth. The term placentas from diabetic pregnancies express more insulin-like growth factor II (IGF-II) than those from normal pregnancies. Deregulation of their imprinting status is observed in the macrosomia-associated syndrome, the Beckwith-Wiedemann syndrome. The aim of this study was to determine whether loss of imprinting hence biallelic expression was also a hallmark of macrosomia in diabetic pregnancies.

DESIGN AND METHODS

IGF-II and H19 maternal and paternal expressions were studied in placentas from two groups of type 1 diabetic mothers: one with macrosomic babies and the other with babies of normal weight. Maternal or paternal allele specific expressions were defined by using DNA polymorphic markers of the IGF-II and H19 genes. RFLP analysis was performed on PCR products from genomic DNA of the father, the mother and the child, and on RT-PCR products from placental mRNA.

RESULTS

RFLP analysis showed that the IGF-II gene remains paternally expressed and the H19 gene remains maternally expressed in all placentas examined, independently of the birth weight status.

CONCLUSIONS

These results suggest that, in contrast with Beckwith-Wiedemann syndrome-associated macrosomia, loss of imprinting for IGF-II or H19 is not a common feature of diabetic pregnancies associated with macrosomia.

Folic acid supplementation affects ROS scavenging enzymes, enhances Vegf-A, and diminishes apoptotic state in yolk sacs of embryos of diabetic rats

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.

A 10-year retrospective analysis of pregnancy outcome in pregestational Type 2 diabetes: comparison of insulin and oral glucose-lowering agents

AIMS

To review the use of oral glucose-lowering agents (OGLA) in pregnant women with Type 2 diabetes mellitus.

METHODS

Retrospective analysis of outcomes and their predictors in singleton pregnancies > or = 24 weeks managed at Groote Schuur hospital, Cape Town, South Africa from 1991 to 2000. There were 379 pregnancies, subdivided into three groups according to therapy: OGLA alone, converted from OGLA to insulin, insulin alone or converted from diet alone to insulin. The OGLA used were metformin and glibenclamide.

RESULTS

Mean glycated haemoglobin (HbA(1c)) was similar at booking and throughout pregnancy in all groups. In the OGLA alone, converted from OGLA to insulin and insulin alone/converted from diet alone to insulin groups, fetal anomaly rates were comparable: 5.7%, 2.0% and 0.0%, P = 0.2, respectively; whereas perinatal mortality rates (per 1000 births) were: 125, 28, 33, P = 0.003, respectively. Booking HbA(1c) was independently associated with fetal anomaly [odds ratio (OR) 1.48; 95% confidence interval (CI) 1.11, 1.97; P = 0.006]. The specific OGLA used in the first trimester was not associated with the occurrence of fetal anomaly. Last HbA(1c) (OR 1.65; 95% CI 1.16, 2.42; P = 0.005) and fetal anomaly (OR 15.18; 95% CI 2.43, 93.37; P = 0.005) were independently associated with perinatal mortality. Conversion from OGLA to insulin was protective for perinatal mortality compared with OGLA alone treatment (OR 0.220; 95% CI 0.061, 0.756; P = 0.024). No perinatal mortality was observed in women on metformin alone.

CONCLUSIONS

These data suggest that metformin and glibenclamide are not teratogenic but that it is advisable to replace OGLA, in particular glibenclamide, with insulin when women book for pregnancy care to reduce perinatal mortality rates.

Diabetes alters the mRNA expression of insulin-like growth factors and their receptors in the mouse fallopian tube and uterus during the preimplantation stages

The possible role of insulin-like growth factors (IGFs) and their receptors (IGFRs) in the pathogenesis of diabetic embryopathy was investigated. Sexually mature female ICR mice of 6-8 weeks old were made diabetic by a single intraperitoneal injection with 200 mg/kg streptozotocin ten days prior to mating. Fallopian tubes and uterine tissues were obtained from the superovulated diabetic and normal mice 48, 72 and 96 hours following human chorionic gonadotropin (hCG) injection. The mRNA expression of IGF-1 and IGF-2 as well as their receptors was determined in the tissues using Real-time Polymerase Chain Reaction (Real-time PCR). The mRNA expression of IGF-1 in the fallopian tube and uterus of the diabetic mice was significantly lower 72 and 96 hours after hCG treatment, respectively, as compared to the controls. The mRNA expression of IGF-1R at 96 hours post-hCG treatment was significantly higher in the fallopian tube and lower in the uterus of the diabetic mice as compared to the controls. The mRNA expression IGF-2 in the fallopian tube was significantly higher 48 and 96 hours after hCG treatment, but was lower in the uterus of diabetic mice 96 hours after hCG treatment as compared to controls. The mRNA expression of IGF-2R in the diabetic mice was significantly higher 48 and 96 hours (the fallopian tube) and 48 hours (uterus) after hCG treatments as compared to the controls. In conclusion, an alteration in mRNA expression of IGFs and their receptors in the diabetic mice as observed in this study could possibly result in diabetic embryopathy.

Insulin-like growth factor-1 receptor expression in the placentae of diabetic and normal pregnancies

BACKGROUND

Septal hypertrophic cardiomyopathy (sHCM) is a characteristic anomaly of the infant of diabetic mother (IDM). Insulin-like growth factor-1 (IGF-1) has been identified as a mediator of tissue overgrowth and we have previously shown that maternal IGF-1 levels were significantly elevated among neonates with asymmetrical sHCM. IGF-1 does not cross the placenta; it exerts physiologic action through binding to the IGF-1 receptor (IGF-1R). Localisation and expression of IGF-1R in term diabetic pregnancies are largely unclear. We have studied IGF-1R in the placentae of diabetic and normal pregnancies and this receptor expression in association with neonates with sHCM.

METHODS

IGF-1R localization and expression in the placentae of six diabetic pregnancies associated with neonatal sHCM were compared with six each of randomly selected diabetic and normal pregnancies without neonatal sHCM by immunohistochemistry. The staining for IGF-1R in the deciduas, cytotrophoblasts, syncytiotrophoblasts and villous endothelium for these 18 samples were assessed and scored by two pathologists who were blinded to the respective diagnoses.

RESULTS

Placental IGF-1R staining was negative in the villous endothelium for all three groups. IGF-1R staining was present in deciduas, cytotrophoblasts and syncytiotrophoblasts but the staining was weaker in the entire group of infants with sHCM compared to those without sHCM.

CONCLUSIONS

IGF-1R is localized in all cell types of the placenta except in villous endothelium. Weaker placental IGF-1R staining in the placentae of diabetic pregnancies associated with sHCM suggests reduced expression of IGF-1R. This may be a down-regulatory response to elevated maternal IGF with neonatal sHCM outcome.

Placental triglyceride accumulation in maternal type 1 diabetes is associated with increased lipase gene expression

Maternal diabetes can cause fetal macrosomia and increased risk of obesity, diabetes, and cardiovascular disease in adulthood of the offspring. Although increased transplacental lipid transport could be involved, the impact of maternal type 1 diabetes on molecular mechanisms for lipid transport in placenta is largely unknown. To examine whether maternal type 1 diabetes affects placental lipid metabolism, we measured lipids and mRNA expression of lipase-encoding genes in placentas from women with type 1 diabetes (n = 27) and a control group (n = 21). The placental triglyceride (TG) concentration and mRNA expression of endothelial lipase (EL) and hormone-sensitive lipase (HSL) were increased in placentas from women with diabetes. The differences were more pronounced in women with diabetes and suboptimal metabolic control than in women with diabetes and good metabolic control. Placental mRNA expression of lipoprotein lipase and lysosomal lipase were similar in women with diabetes and the control group. Immunohistochemistry showed EL protein in syncytiotrophoblasts facing the maternal blood and endothelial cells facing the fetal blood in placentas from both normal women and women with diabetes. These results suggest that maternal type 1 diabetes is associated with TG accumulation and increased EL and HSL gene expression in placenta and that optimal metabolic control reduces these effects.

Characterization of differential gene expression profiles in diabetic embryopathy using DNA microarray analysis

OBJECTIVE

The molecular mechanisms by which maternal diabetes impairs embryogenesis are not established. This study aimed to determine the developmental genes and molecular pathways that are involved in diabetic embryopathy, by comparing gene expression profiles in the yolk sacs between the embryos of diabetic and control rats by using DNA microarray analysis.

STUDY DESIGN

Diabetes was induced in female rats by injecting streptozotocin (65 mg/kg) intravenously. Glucose levels were controlled by subcutaneously implanting insulin pellets. The female rats were mated with normal male rats. At gestation day 4, the insulin pellets were removed from a group of animals, making them hyperglycemic. The animals with insulin pellets served as controls. At gestational day 12, embryos were explanted, and yolk sacs were collected. Total RNA, free of DNA contamination, was extracted from the yolk sacs. Complementary DNA probes were synthesized, labeled with Cy3 and Cy5 fluorescent dyes, and used to hybridize rat oligo-array containing 10,000 genes. Data were analyzed by using 1-sample t test on log2 ratios, with P < .05 representing a significant difference. The changes in expression levels of important genes were verified with the use of a real-time polymerase chain reaction (PCR).

RESULTS

Five microarray experiments produced consistent results. A total of 101 genes were found to be differentially expressed between the embryos of diabetic and control rats. Analyses that used PathwayAssist (Ariadne Genomics, Rockville, MD) revealed a number of potential signaling pathways and genes involved in insulin signaling and stress response (insulin 2, insulin-binding protein 1, GST pi1), cell growth (GAP43, CSF1R, HGF), calcium signaling (calbindin 3, CBP A6), and PKC signaling (PKCBP beta15, FABP5), in concert with prior biochemical and molecular findings.

CONCLUSION

These observations show significant alterations in expression of developmental and stress response genes in diabetic embryopathy, and demonstrate, for the first time, that the yolk sac cells express insulin during early development. In addition, these data also demonstrate that hyperglycemia induces altered gene expression, resulting in aberrant cell signaling, morphogenesis, and embryopathy.

Metabolic hormones profile in 2 weeks old healthy infants of diabetic mothers

OBJECTIVE

To determine the concentration of plasma leptin and other metabolic hormones in offspring of diabetic and none diabetic mothers after 2 weeks of age. The relationship between leptin and metabolic hormones was also investigated.

METHODS

Included in the study were 79 newborns from the Neonatal Unit at King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia from January 2004-January 2005. The newborns were categorized into 3 main groups: the control group, consisting of 32 infants of non-diabetic mothers; the gestational diabetes mothers (GDM) group, consisting of 26 infants; and the frank diabetic mothers (FDM), consisting of 21 infants. Infants of diabetic mothers were further subdivided into those of dietary (d) or insulin (i) dependent mothers. Plasma leptin, insulin, cortisol and free thyroxin levels were measured by enzyme link immunosorbent assay.

RESULTS

No significant difference in plasma leptin was observed between the studied groups. The GDM-d and FDM-d showed lower glucose versus controls (p<0.001 and p<0.05). There was significant correlation between leptin and glucose in the GDM group (r=0.18, p< 0.05) and with insulin in GDM-d on diet control (r=0.37, p< 0.01).

CONCLUSION

After 2 weeks of life, no difference in plasma leptin between infants of diabetic and non-diabetic mothers was observed, which may be important for the stimulation of feeding behavior and acquisition of energy homeostasis. Significant association between plasma leptin and insulin in offspring of GDM supports the hypothesis that functional adipoinsular axis might exist in term newborns.

Maternal diabetes in vivo and high glucose concentration in vitro increases apoptosis in rat embryos

Apoptosis may be involved in diabetes-induced embryonic dysmorphogenesis. We estimated the occurrence of apoptosis in embryos of a rat model for diabetic pregnancy. We found decreased Bcl-2, increased Bax and cleaved Caspase 3 proteins in embryos from diabetic rats. Moreover, we found increased activation of Caspase 3 in cells from embryos previously exposed to a diabetes-like environment (in vivo, in vitro) compared to cells from control embryos, which was normalized by supplementation of N-acetylcysteine or apoptosis inhibitor. We detected increased propidium iodide uptake in embryonic cells exposed to maternal diabetes, a finding confirmed by vital staining. Additionally, we found increased dysmorphogenesis in embryos exposed to a diabetic environment in vivo and in vitro. Exposure to a diabetic milieu during organogenesis increases apoptosis in embryonic cells and dysmorphogenesis in embryos. Enhanced apoptotic rate may have a role in diabetic embryopathy by inducing disturbed embryonic maturation, increased rates of resorptions and congenital malformations.

Diabetic Pregnancies: The Challenge of Developing in a Pro-Inflammatory Environment

The maternal diabetic environment alters the embryo and the feto-placental development. The results of these alterations are: increased embryo resorption and malformation rates, placental dysfunction, fetal alterations that lead to increased neonatal morbidity and mortality rates, and also diseases that will be evident later in the adult life of the newborn. The etiology of these many maternal diabetes-induced complications are not yet understood in full. In this review the role of maternal diabetes as an inductor of a pro-inflammatory environment that impairs embryo and placental development is discussed. An overproduction of pro-inflammatory agents is found in the uterus during implantation and the developing embryo and placenta from experimental models of diabetes, as well as in placenta from diabetic women. In these tissues there are increases in reactive oxygen species, pro-inflammatory cytokines and prostaglandins, nitric oxide and peroxynitrites. These pro-inflammatory agents lead to the intrauterine activation of matrix metalloproteinases, proteases involved in remodeling the extracellular matrix during implantation and feto-placental development. Many of these pro-inflammatory agents have overlapping mechanisms of action and cross regulatory pathways that propagate the inflammatory processes. Antioxidants, PPARgamma activators, and NF-kappaB inhibitors are able to reduce the concentrations of these agents in intrauterine gestational tissues. This article reviews the current understanding of maternal diabetes-induced changes in pro-inflammatory and anti-inflammatory pathways that affect the embryo and placental development in maternal diabetes, and stresses the need of a strict maternal control of the pathology to prevent deleterious consequences in the offspring.

Maternal diabetes and the fetal heart

Maternal diabetes mellitus significantly affects the fetal heart and fetal-placental circulation in both structure and function. The influence of pre-conceptional diabetes begins during embryonic development in the first trimester, with altered cardiac morphogenesis and placental development. It continues to have an influence on the fetal circulation through the second and third trimesters and into the perinatal and neonatal period.

Embryopathy in experimental diabetic gestation: assessment of PGE2 level, gene expression of cyclooxygenases and apoptosis

The causes of, and predisposing conditions for, increased congenital anomalies in embryos of experimental diabetic gestation are not fully identified. In the present study, some possible factors involved in diabetes-induced embryopathy are explored. The concentration of PGE2, the gene expression of cyclooxygenases (COX-1 and COX-2) and level of apoptosis (measured by caspase-3 activity) are assessed during organogenesis in the embryos of streptozotocin-induced diabetic rats. The concentrations of PGE2 in the embryos of diabetic rats were lower than controls, with the lowest values in malformed embryos and their associated membranes (yolk sacs). The pattern of change in PGE2 was similar in the embryos of the control and diabetic groups, which showed a steady decline between days 9 and 11 of gestation. These changes in PGE2 were accompanied by a small decrease in COX-1 expression in all embryos and associated membranes during the same gestational period. Expression of COX-2, which was below normal in diabetic embryos, decreased between days 9 and 11 of gestation in all groups. In the membranes of non-malformed embryos, COX-2 expression peaked on day 10 of gestation. It was found that there was little or no detectable COX-2 expression in the membranes of malformed embryos on day 9 of gestation and although its expression was detectable on the following days it was much lower than in the other groups. Caspase-3 activity increased substantially between days 9 and 11 of gestation. Embryos from the experimentally diabetic group showed higher activity than did controls, with the largest increases in the malformed embryos. It would appear that COX-2 expression and PGE2 concentration (in both embryo and associated membranes) play a significant role in organ formation. The data presented here suggest that an unhealthy placenta may be instrumental in the development of malformed embryos.

Vascular endothelial growth factor, its receptors, and the tie receptors in the placental bed of women with preeclampsia, diabetes, and intrauterine growth retardation

Placental bed vascular function is compromised in pregnancies complicated by preeclampsia (PE), intrauterine growth retardation (IUGR), and maternal diabetes mellitus (DM). We performed an immunohistochemical analysis of vascular endothelial growth factor (VEGF), its receptors (VEGFR) -1 and -2, and the Tie-1 and -2 receptors in cryostat tissue sections of the placental bed from healthy women (n = 5) and women with PE (n = 5), IUGR (n = 5), and DM (n = 5). VEGF immunoreactivity was stable between the study groups. VEGFR-1 immunoreactivity in the myometrial vascular smooth muscle cells was strongest in the controls. In the myometrial cells, the strongest VEGFR-2 immunoreactivity was seen in women with IUGR. In the decidual vascular endothelial cells, the strongest Tie-1 immunoreactivity was observed in healthy women and in those with DM. Alterations in the placental bed expression of VEGFR-1, VEGFR -2, and Tie-1, but not of VEGF and Tie-2, may be associated with PE, IUGR, or DM.

Effect of pregnancy on the pharmacokinetics of metformin

AIMS

To determine the effects of pregnancy on metformin pharmacokinetics.

METHODS

Seven women with Type 2 diabetes mellitus taking metformin throughout pregnancy were studied on two occasions, once at 28-36 weeks gestation and once at least 8 weeks postpartum. Serum metformin concentrations were determined across a dosing interval using high-performance liquid chromatography. The areas under the serum concentration-time curve from 0 to 4 h post-dose (AUC0-4) and 0 to 8 h post-dose (AUC0-8) where possible, were compared in the pregnant and non-pregnant state.

RESULTS

Metformin concentrations were lower in pregnancy in six subjects, with a mean (95% CI) AUC0-4 that was 69% (53.6, 84.8) of the postpartum value. The AUC0-4 of one subject was higher in pregnancy at 142% of the postpartum value. Overall, the mean (95% CI) AUC0-4 during pregnancy for all seven subjects was 80% (51.3, 107.8) of the postpartum value (P = 0.053, two-tailed t-test; P = 0.027, one-tailed t-test).

CONCLUSION

These results are consistent with our hypothesis that the clearance of metformin increases in pregnancy as a result of enhanced renal elimination. A larger study is required to establish whether metformin dose adjustments are required in late pregnancy to maintain therapeutic effect.

Peroxynitrites and impaired modulation of nitric oxide concentrations in embryos from diabetic rats during early organogenesis

Maternal diabetes significantly increases the risk of congenital malformation, a syndrome known as diabetic embryopathy. Nitric oxide (NO), implicated in embryogenesis, has been found elevated in embryos from diabetic rats during organogenesis. The developmental signaling molecules endothelin-1 (ET-1) and 15-deoxy delta(12,14)prostaglandin J2 (15dPGJ2) downregulate embryonic NO levels. In the presence of NO and superoxide, formation of the potent oxidant peroxynitrite may occur. Therefore, we investigated peroxynitrite-induced damage, ET-1 and 15dPGJ2 concentrations, and the capability of ET-1, 15dPGJ2 and prostaglandin E2 (PGE2) to regulate NO production in embryos from severely diabetic rats (streptozotocin-induced before pregnancy). We found intense nitrotyrosine immunostaining (an index of peroxynitrite-induced damage) in neural folds, neural tube and developing heart of embryos from diabetic rats (P < 0.001 vs controls). We also found reduced ET-1 (P < 0.001) and 15dPGJ2 (P < 0.001) concentrations in embryos from diabetic rats when compared with controls. In addition, the inhibitory effect of ET-1, 15dPGJ2 and PGE2 on NO production found in control embryos was not observed in embryos from severely diabetic rats. In conclusion, both the demonstrated peroxynitrite-induced damage and the altered levels and function of multiple signaling molecules involved in the regulation of NO production provide supportive evidence of nitrosative stress in diabetic embryopathy.

Preterm delivery in normoalbuminuric, diabetic women without preeclampsia: The role of metabolic control

OBJECTIVE

The aim of this study was to examine the importance of glycemic regulation on the risk of preterm delivery in women with normoalbuminuria and no preeclampsia later in pregnancy.

STUDY DESIGN AND METHODS

A prospective study of 71 women with type 1 diabetes mellitus where complete data were collected on HbA1c, insulin dose, and albumin excretion rate from week 12 and every second week hereafter. Fundus photography was performed and diurnal blood pressure measured three times during pregnancy.

RESULTS

The preterm rate was 23% and women delivering preterm showed higher HbA1c throughout pregnancy. At regression analysis HbA1c was the strongest predictor for preterm delivery from week 6 to 32, also when including insulin dose, BMI, age, duration of diabetes, and diurnal blood pressure. The risk of delivering preterm was more than 40% when HbA1c was above 7.7% in week 8. Diurnal blood pressure was not found associated with preterm delivery.

CONCLUSION

The quality of glycemic regulation in the early and mid-pregnancy is a major, independent risk factor for preterm delivery in normoalbuminuric diabetic women without preeclampsia.

N-3 Fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring

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.

[Selenium and glutathion peroxidase enzyme levels in diabetic patients with early spontaneous abortions]

The incidence of spontaneous abortions in women with type 1 diabetes mellitus varies between 10-30%. The etiology of this is still unclear despite numerous experimental studies. Pregnancy is a condition of increased oxidative stress due to impaired balance between pro- and antioxidants. Glutathion and related enzymes perform the best antioxidant protection. Some authors point to a possible correlation between spontaneous abortions and low plasma Se levels as well as low intracellular activity of glutathion peroxidase enzyme. Others report that Hb A1-c, values over 1SD above normal increase the risk of spontaneous abortions with 3% and Hb A1-C values between 10-12% are critically high for the occurrence of spontaneous abortions. The purpose of the study was to evaluate the levels of Se and glutathion peroxidase enzyme (Gl-Px) in pregnant women with type 1 diabetes mellitus in the first trimester of pregnancy and to find out is there a correlation between glycemic control of diabetes and the incidence of spontaneous abortions.

DESCRIPTION OF PROJECT

75 pregnant women enrolled in an- 1 year prospective study divided in 3 groups according to pregnancy outcome: gr. 1 - n = 30 with type diabetes mellitus, no abortions, gr.2 - n = 16 with type diabetes mellitus with first trimester spontaneous abortion and gr. 3 - n = 29 healthy pregnant women. Women with type 1 diabetes mellitus were divided into three subgr. according to glycemic control - subgr. 1 - n = 12 (Hb A1-c < 7%), subgr.2 - n = 18 (Hb A1-c > 7< 8%), subgr.3 - n = 16 (Hb A1-c > 8%). Gl-Px activity was determined in Er hemolisate with test reagents of Randox Ransel, with ref.values 27.5 - 73 U/g Hb. Selen concentration was determined in whole blood sample by atomic absorption spectrophotometry with ref. values 0.12-1.1 micromol/l. HbA 1-C was measured by affinity chromatography with ref. values 4.5-6.3%. Statistical methods used were: dispersion, correlation analysis - SPSS package version 11.01.01.

RESULTS

Basic Se levels were low in all pregnant women in early pregnancy. The metabolic control level did not influence the levels of Se in pregnant women with diabetes mellitus type1. Gl -Px activity was within the normal limits in all women. There was no correlation between Se levels and Gl -Px activity in pregnant diabetics with and without abortions. There was a correlation between Se levels and Gl -Px activity only in healthy pregnant women. Pregnant women with poor glycemic control had higher incidence of spontaneous abortions.

CONCLUSIONS

We could not support the hypothesis of reduced antioxidant protection (low Se and Gl-Px levels) as a causative factor in the pathogenesis of spontaneous abortions in diabetic patients. Our study results showed that poor metabolic control of diabetes (high Hb A1-c) in the first trimester of pregnancy had a primary role in the occurrence of early abortions. We could speculate that the early hyperglycemic maternal-fetal environment most probably plays a role of an additional stress to the developing embryo.

eNOS, COX-2, and prostacyclin production are impaired in endothelial cells from diabetics

The vascular endothelium is a well-recognized target of damage for factors leading to increased cardiovascular risk. Among the agents playing an important role in cardiovascular homeostasis, nitric oxide and prostacyclin represent key markers of endothelial integrity. In the present work, we report for the first time the reduced expression of both endothelial nitric oxide synthase and cyclooxygenase-2 (COX-2) proteins, as well as decreased prostacyclin production, in unstimulated human endothelial cells from insulin-dependent diabetic mothers when compared to cells from non-diabetic, control subjects. According to a major role of COX-2 as a source of prostacyclin production even in unstimulated endothelial cells, prostacyclin production was concentration-dependently inhibited by the selective COX-2 inhibitor SC236. Overall, our results suggest a possible link between reduced endothelial COX-2 and NO-synthase expression and the increased risk of cardiovascular diseases affecting diabetic patients, and point to the use of endothelial cells from diabetic patients as a tool for investigating early dysfunction in pathological endothelium.

Unfavorable effect of type 1 and type 2 diabetes on maternal and fetal essential fatty acid status: a potential marker of fetal insulin resistance

BACKGROUND

Pregestational maternal diabetes increases obesity and diabetes risks in the offspring. Both conditions are characterized by insulin resistance, and diabetes is associated with low membrane arachidonic (AA) and docosahexaenoic (DHA) acids.

OBJECTIVE

We investigated whether type 1 and type 2 diabetes in pregnancy compromise maternal and fetal membrane essential fatty acids (FAs).

DESIGN

We studied 39 nondiabetic (control subjects), 32 type 1 diabetic, and 17 type 2 diabetic pregnant women and the infants they delivered. Maternal and cord blood samples were obtained at midgestation and at delivery, respectively. Plasma triacylglycerols and choline phosphoglycerides and red blood cell (RBC) choline and ethanolamine phosphoglyceride FAs were assessed.

RESULTS

The difference in maternal plasma triacylglycerol FAs between groups was not significant. However, the type 1 diabetes group had lower plasma choline phosphoglyceride DHA (3.7 +/- 0.9%; P < 0.01) than did the control group (5.2 +/- 1.6%). Likewise, RBC DHA was lower in the type 1 [choline: 3.4 +/- 1.5% (P < 0.01); ethanolamine: 5.9 +/- 2.5% (P < 0.05)] and type 2 [choline: 3.5 +/- 1.6% (P < 0.05)] diabetes groups than in the control group (choline: 5.5 +/- 2.2%; ethanolamine: 7.5 +/- 2.5%). Cord AA and DHA were lower in the plasma (type 1: P < 0.01) and RBC (type 2: P < 0.05) choline phosphoglycerides of the diabetics than of the control subjects, and cord RBC ethanolamine phosphoglycerides were lower in DHA (P < 0.05) in both diabetes groups than in the control group.

CONCLUSIONS

Diabetes (either type) compromises maternal RBC DHA and cord plasma and RBC AA and DHA. The association of these 2 FAs with insulin sensitivity may mean that the current finding explains the higher incidence of insulin resistance and diabetes in the offspring of diabetic women.

[Effect of lipid peroxidation and antioxidant defence system on the development of hemorrhagic complications in neonates of mothers with diabetes mellitus]

217 postmortem protocols of autopsies have been analyzed to study percentage of hemorrhagic complications. The analyzes allowed to determine frequency and localization hemorrhages happened in children bourn by mothers suffering from diabetes mellitus. The most detected localizations of hemorrhages are follows: ependyma (38.8%), ventricles of brain (30.8%), parenchyma of brain (30.8%) as well as frequently have been observed pleura, epicardium and adrenal glands hemorrhages.

Increased periconceptual maternal glycated haemoglobin in diabetic mothers reduces fetal long axis cardiac function

OBJECTIVE

To compare ventricular long axis function in fetuses of diabetic mothers (FDM) with contemporaneously studied normal controls (N) and to assess the effect of pre-pregnancy diabetic control on these measurements.

DESIGN

Long axis function was compared in 41 FDM and 159 N fetuses in a cross sectional observational study.

SETTING

Fetal medicine unit.

METHODS AND RESULTS

Echocardiography confirmed structural normality. Pulsed wave valvar Doppler velocimetry, lengthening and shortening myocardial velocities, and amplitude of ventricular long axis movement were recorded at the base of the left and right ventricular free walls and septum. Periconceptual diabetic control was assessed by haemoglobin A1c (HbA1c) in early pregnancy. Doppler and myocardial velocities were negatively related and myocardial thickness was positively related with HbA1c. In both cohorts all variables except mitral and tricuspid late filling (A wave) velocities were dependent on gestational age. FDM gestational age related values were higher for most variables and robust analysis of covariance showed significantly different maturation patterns in mitral valve E:A ratio (p = 0.036) and pulmonary velocity (p = 0.04), late lengthening myocardial velocities (left p = 0.016 and right p = 0.066), left myocardial shortening velocities (p = 0.008), and left free wall (p = 0.03) and septal (p = 0.04) amplitude of motion. FDM septal thickness was significantly increased throughout gestation (p < 0.0001).

CONCLUSION

Periconceptual diabetic control influences fetal cardiac performance and myocardial hypertrophy but, unlike the pathophysiology of adult ventricular hypertrophy, is accompanied by functional adaptation. It is unlikely to explain the increased rate of late stillbirth observed in diabetic pregnancies.

A diabetes-like environment increases malformation rate and diminishes prostaglandin E(2) in rat embryos: reversal by administration of vitamin E and folic acid

BACKGROUND

Offspring of women with diabetes are at increased risk for congenital malformations and disturbed growth compared with infants from nondiabetic pregnancies. The precise biological process behind these effects is not yet completely clarified. Previous studies have suggested that diabetic embryopathy is associated with increased level of oxidative stress and disturbed arachidonic acid metabolism. The aim of the present study was to investigate whether a diabetes-like environment both in vivo and in vitro increases embryonic levels of isoprostanes and alters embryonic prostaglandin E(2) (PGE(2)) concentration. Furthermore, we studied whether vitamin E and folic acid treatment rectify such alterations.

METHODS

Embryos from diabetic and nondiabetic rats at gestational days (GDs) 10 and 11 were used. In the in vitro experiments, we used whole embryo culture, which mimics pregnancy. GD 9 embryos from nondiabetic rats were cultured for either 24 hr (corresponding to GD 10) or 48 hr (corresponding to GD 11) and exposed to 10 or 30 mM glucose concentration with or without folic acid.

RESULTS

Embryos from diabetic rats and embryos cultured in a high glucose concentration showed increased malformation rates. Dietary treatment with vitamin E in vivo and supplementation of folic acid in the culture medium with 30 mM glucose in vitro decreased the malformation rate, decreased embryonic isoprostane levels, and increased PGE(2) concentration.

CONCLUSIONS

Diabetes-induced oxidative stress and disturbance of PGE(2) production may contribute to the embryonic dysmorphogenesis in the offspring of diabetic rodents and, thereby, may also have a role in human diabetic embryopathy.

Embryopathy in experimental diabetic gestation: assessment of oxidative stress and antioxidant defence

Maternal diabetes is associated with an increased rate of congenital fetal anomaly. In the present study, diabetes was induced by streptozotocin in female rats one week prior to conception and the embryos were examined during organogenesis. Experimental diabetes is associated with over-production of free radicals and disturbed antioxidant defence, particularly in malformed embryos. Oxidative stress is demonstrated by increased MDA accumulation and reduced glutathione levels. Despite large differences in the reduced/oxidised glutathione ratios during organogenesis in the control, diabetic non-malformed and malformed embryo groups, the half-cell redox potential was constant for each group during the experimental period. Calculated redox potentials indicated that although embryo cells from the control and diabetic mother groups were of the same chronological age, the stages of development were different. Increased oxidative stress in rat embryos was associated with increased glutathione peroxidases and glutathione-S-transferase activity. This may, in part, provide an explanation for the observed accumulation of oxidised glutathione in malformed embryos. Moreover, decreased levels of vitamin C and selenium were observed. Increased oxidative stress and perturbations in antioxidant defence contribute to the high incidence of congenital anomalies in experimental diabetic gestation.

Control of aging and longevity by IGF-I signaling

Animal models have established the IGF-I signaling pathway as a key modulator of aging in rodents and invertebrates. Considerable evidence suggests that reduced exposure of tissue to IGF-I is associated with an extended lifespan in these species. In humans, IGF-I is linked to various age-related diseases that are limiting factors for youthful longevity. On one hand, reduced IGF-I activity is associated with significant morbidity in adulthood with an increased risk of developing cardiovascular disease, diabetes, osteoporosis and neurodegenerative diseases. On the other hand, elevated IGF-I levels have been linked to cancer risk given the role of IGF in mediating normal and malignant tissue growth. Thus, IGF is clearly involved in modulating disease of aging; however, the mechanism appears to be complex and interdependent on additional modulating factors. It is attractive to hypothesize that maximal human survival depends on tight regulation of the GH-IGF axis and maintenance of optimal IGF-I action in order to prevent morbidities associated with either deficient or excessive state. Specifically, it is possible that lower levels of IGF-I during early adulthood followed by higher levels of IGF-I later in life may be most beneficial for human longevity by addressing age-specific morbidities.

The insulin-like growth factor system and Type 1 diabetic retinopathy during pregnancy

AIMS/HYPOTHESIS

To find out whether the levels of insulin-like growth factor-I (IGF-I), IGF binding protein-1 (IGFBP-1), highly phosphorylated IGFBP-1 (hpIGFBP-1), and IGF binding protein-3 (IGFBP-3) are related to the progression of diabetic retinopathy (DR) during pregnancy and postpartum.

METHODS

In a prospective study of 42 pregnant women with Type 1 diabetes and 9 nondiabetic controls, DR was graded from fundus photographs. Levels of serum total IGF-I and two different phosphoisoform patterns of IGFBP-1 and IGFBP-3 were measured during the first and third trimester of pregnancy and 3 months postpartum.

RESULTS

Both the levels of serum total IGF-I (P<.0001) and IGFBP-3 (P=.003) were lower in the diabetic than in the nondiabetic women during pregnancy and postpartum (repeated-measures ANOVA between the groups). Additionally, the IGF-I and IGFBP-3 levels tended to be lower in the diabetic women with more severe DR at baseline than in those with less severe DR. There were no statistically significant differences in the levels of IGF-I and IGFBP-3 in the diabetic women with progression of DR compared with those without. No statistical differences appeared in the IGFBP-1 phosphoisoform patterns between the groups.

CONCLUSIONS/INTERPRETATION

In diabetic women, mean serum levels of IGF-1 and IGFBP-3 are lower than in nondiabetic controls during pregnancy and/or postpartum. Because there was no clear connection between the IGF system and progression of DR during pregnancy, it is unlikely that these substances mediate the tendency of DR to progress during pregnancy.

Adiponectin and human pregnancy

Adiponectin is an adipose tissue-derived plasma protein that is involved in regulation of insulin resistance and glucose hemostasis. Human pregnancy is characterized by an increase in insulin resistance. Therefore, it is only natural that the role of adiponectin, a modulator of insulin resistance, is subject to investigation during gestation. Furthermore, conditions associated with increased insulin resistance, such as gestational diabetes and preeclampsia, may be influenced by this hormone. Adiponectin, a key modulator of insulin action and glucose metabolism, both known to regulate fetal growth, is a plausible candidate for regulation of intrauterine fetal development. In this review, we summarize the recent studies describing the relationship between adiponectin, pregnancy, and fetal growth.

[Correlation between amniotic fluid index (AFI) and glucose concentration in amniotic fluid, glycaemia, glycosylated haemoglobin concentration during normal pregnancy and pregnancy complicated by insulin-dependent diabetes mellitus]

INTRODUCTION

In spite of confirming an association between type I diabetes of pregnancy with hydramnios, in the most recent studies there is still no clarity about which of the maternal or foetal metabolic parameters linked with amniotic fluid volume play the most important role.

AIM

To determine which of the maternal or foetal metabolic parameters has the closest association with amniotic fluid volume.

MATERIAL AND METHODS

The research was performed in two groups: normal healthy pregnant women (n=43) and group of pregnant women with insulin-dependent diabetes mellitus (n=17) and their newborns. We measured: amniotic fluid index, glucose level in serum and in amniotic fluid, in newborn serum, HbA1c level in serum of women and newborns.

RESULTS

We found statistically significant higher values of amniotic fluid index 16.3 +/- 5.2 cm (p<0.01), glucose level in amniotic fluid 2.7 +/- 0.3 mmol/l (p<0.01), serum glucose level before delivery 8.4 +/- 1.6 mmol/l (p<0.001), glycosylated haemoglobin in serum levels 7.9 +/- 0.4% (p<0.05), levels of glucose and glycosylated haemoglobin in serum newborns 3.4 +/- 0.3 mmol/l (p<0.05), 7.7 +/- 0.4% (p<0.001) in patients with insulin-dependent diabetes mellitus as compared with these values in the group of healthy parturient women and their newborn infants. Performed correlation study shows statistical correlation between amniotic fluid index and glycosylated hemoglobin serum levels in the group of women with insulin-dependent diabetes mellitus (p<0.05), t=0.56.

CONCLUSION

We conclude that long hyperglycemia or increased HbA1c level have an important role in amniotic fluid index increase in patients with insulin-dependent diabetes mellitus.

Increased renal tubular reabsorption of calcium and magnesium by the offspring of diabetic rat pregnancy

Diabetic pregnancy has a marked influence on offspring calcium and magnesium homeostasis. Urinary excretion of calcium and magnesium is reduced, yet offspring of diabetic pregnancy exhibit hypomagnesemia and hypocalcemia. The aim of this study was to measure renal hemodynamic and tubular function in the offspring of diabetic (OD) and control, nondiabetic (OC) rats at 4 and 8 wk of age to determine the glomerular and tubular mechanisms through which renal calcium and magnesium handling are programmed in utero. The fraction of filtered calcium that was excreted was significantly lower in OD at both 4 and 8 wk of age [8 wk: OC (n = 6), 11.8 +/- 2.9 versus OD (n = 5), 4.3 +/- 0.6%; p < 0.05] and that of magnesium was lower at 8 wk of age [OC (n = 6), 42.4 +/- 7.5 versus OD (n = 5), 13.0 +/- 1.7%; p < 0.01]. This increased reabsorption occurred despite an elevated GFR in OD. These findings clearly indicate that tubular reabsorptive mechanisms for calcium and magnesium are increased markedly in OD. Serum PTH concentration was reduced in 8-wk-old OD [OC (n = 7), 539.4 +/- 142.1 versus OD (n = 9), 174.3 +/- 69.4 pg/ml; p < 0.05], consistent with previous reports in human infants. Taken together, these observations suggest that the basis for the altered renal magnesium and calcium handling in OD involves increased tubular transport activity and possibly increased sensitivity of these mechanisms to PTH.