Association of serum folate levels during pregnancy and prenatal depression

OBJECTIVE

To evaluate the association between serum folate levels during pregnancy and prenatal depression and the extent to which obesity may modify this relationship.

METHODS

This secondary data analysis leveraged data from a previous study of pregnant Kaiser Permanente Northern California participants who completed a survey and provided a serum sample between 2011 and 2013. Serum folate was assessed using the Center for Disease Control's Total Folate Serum/Whole Blood Microbiological Assay Method. A score of 15 or greater on the Center for Epidemiologic Studies Depression Scale was defined as prenatal depression. We used Poisson regression to estimate risk of prenatal depression given prenatal serum folate status (low/medium tertiles vs. high tertile) in the full sample and in subsamples of women with pre-pregnancy body mass index in the (a) normal range and (b) overweight/obese range.

RESULTS

Of the sample, 13% had prenatal depression. Combined low/medium folate tertiles was associated with prenatal depression (adjusted relative risk [aRR] = 1.97, 95% confidence interval [CI]: 0.93-4.18), although results did not reach statistical significance. This relationship was stronger among women with overweight/obesity than women with normal weight (aRR: 2.61, 95% CI: 1.01-6.71 and aRR: 1.50, 95% CI: 0.34-6.66, respectively).

CONCLUSION

Results suggest an association between lower pregnancy folate levels and prenatal depression that may be stronger among women with overweight or obesity. Future studies need to clarify the temporal sequence of these associations.

The impact of micronutrient supplementation in alcohol-exposed pregnancies on reaction time responses of preschoolers in Ukraine

The potential of micronutrients to ameliorate the impact of prenatal alcohol exposure (PAE) on attentional regulation skills was explored in a randomized clinical trial conducted in Ukraine. Women who differed in prenatal alcohol use were recruited during pregnancy and assigned to one of three groups [No study-provided supplements, Multivitamin/Mineral Supplement (MVM), or MVM plus Choline]. Their offspring were seen in the preschool period and a reaction time task was administered. Participants were asked to press a response button as quickly as possible as 30 stimuli from the same category (animals) were presented consecutively and then followed by six stimuli from a novel category (vehicles). Number correct, mean latency of the response over trials, and variability in the latency were analyzed separately by sex. During the initial animal trials, boys whose mothers received MVM during pregnancy had more correct responses and reduced response latency compared to boys whose mothers had no MVM treatment. During vehicle trials, maternal choline supplementation was associated with increased response speed in males without a PAE history. Females receiving supplements did not show the same benefits from micronutrient supplementation and were more adversely impacted by prenatal alcohol exposure. Relationships between maternal levels of choline, betaine, and dimethylglycine (DMG) and task performance were also assessed. Although no effects were found for choline after adjusting for multiple comparisons, lower baseline DMG level was associated with greater accuracy and shorter latency of responses in the initial animal trials and shorter latency in the vehicle trials in female preschoolers. Level of betaine in Trimester 3 was associated with reduced variability in the latency of male responses during the animal trials. Maternal micronutrient supplementation in pregnancy appears to improve preschool reaction time performance, but the effects varied as a function of sex and PAE exposure status.

Altered Maternal Plasma Fatty Acid Composition by Alcohol Consumption and Smoking during Pregnancy and Associations with Fetal Alcohol Spectrum Disorders

Objective: Polyunsaturated fatty acids are vital for optimal fetal neuronal development. The relationship between maternal alcohol consumption and smoking with third trimester plasma fatty acids were examined and their association with Fetal Alcohol Spectrum Disorders (FASD).Methods: Moderate to heavy alcohol-using and low/unexposed comparison women were recruited during mid-pregnancy from two prenatal clinics in Ukraine. The participants' infants underwent physical and neurobehavioral exams prior to one-year of age and classified as having FASD by maternal alcohol consumption and neurobehavioral scores. A subset of mother-child pairs was selected representing three groups of cases and controls: Alcohol-Exposed with FASD (AE-FASD, n = 30), Alcohol-Exposed Normally Developing (AE-ND, n = 33), or Controls (n = 46). Third trimester maternal plasma samples were analyzed for fatty acids and levels were compared across groups.Results: The percent of C18:0 (p < 0.001), arachidonic acid (AA, C20:4n-6, p = 0.017) and C22:5n-6 (p = 0.001) were significantly higher in AE-FASD women than controls or AE-ND women. Alcohol-exposed women who smoked had lower C22:5n-3 (p = 0.029) and docosahexaenoic acid (DHA, C22:6n-3, p = 0.005) and higher C22:5n-6 (p = 0.013) than women consuming alcohol alone or abstainers.Conclusion: Alterations in fatty acid profiles were observed in moderate to heavy alcohol-consuming mothers with infants classified with FASD compared to alcohol-exposed normally developing infants or controls.

Vitamin D Deficiency in Pregnant Ukrainian Women: Effects of Alcohol Consumption on Vitamin D Status

OBJECTIVE

Heavy alcohol consumption can alter vitamin D status; however, the relationships between alcohol consumption and vitamin D concentrations in pregnant women have not been well studied. The aim of this study was to investigate the vitamin D status in a population of alcohol-exposed (N = 180) and low/unexposed control (N = 179) Ukrainian pregnant women.

METHODS

Women who attended prenatal care facilities in 2 regions of Ukraine (Rivne and Khmelnytsky) for a routine prenatal visit were screened for the study. At the time of enrollment (20.4 ± 7.0 weeks of gestation), blood samples and alcohol consumption data (during a typical week around conception and the most recent 2 weeks) were collected. Vitamin D status was assessed by 25-hydroxyvitamin D [25(OH)D] concentrations.

RESULTS

A high prevalence of suboptimal vitamin D status in pregnant Ukrainian women was observed. Overall, 50.1% and 33.4% of the women were classified as vitamin D deficient [25(OH)D < 20 ng/mL] or insufficient [25(OH)D ≥ 20 ng/mL and ≤30 ng/mL], respectively, based on 2011 Endocrine Society guidelines. Alcohol-exposed women had significantly lower 25(OH)D concentrations than low/unexposed women in Spring (p = 0.006) and Winter (p = 0.022). When vitamin D concentrations were grouped into sunny season (Summer + Fall) compared to not sunny season (Winter + Spring), there was a significant ethanol by season interaction (p = 0.0028), with alcohol-drinking women having lower circulating vitamin D compared to low/unexposed women in seasons of low sun availability.

CONCLUSIONS

These data suggest that when vitamin D concentrations are generally low (e.g., during seasons of low sun availability), alcohol consumption during pregnancy has a negative impact on vitamin D status.

The impact of micronutrient supplementation in alcohol-exposed pregnancies on information processing skills in Ukrainian infants

The potential of micronutrients to ameliorate the impact of prenatal alcohol exposure (PAE) was explored in a clinical trial conducted in Ukraine. Cardiac orienting responses (ORs) during a habituation/dishabituation learning paradigm were obtained from 6 to 12 month-olds to assess neurophysiological encoding and memory. Women who differed in prenatal alcohol use were recruited during pregnancy and assigned to a group (No study-provided supplements, multivitamin/mineral supplement, or multivitamin/mineral supplement plus choline supplement). Heart rate was collected for 30 s prior to stimulus onset and 12 s post-stimulus onset. Difference values (∆HR) for the first 3 trials of each condition were aggregated for analysis. Gestational blood samples were collected to assess maternal nutritional status and changes as a function of the intervention. Choline supplementation resulted in a greater ∆HR on the visual habituation trials for all infants and for the infants with no PAE on the dishabituation trials. The latency of the response was reduced in both conditions for all infants whose mothers received choline supplementation. Change in gestational choline level was positively related to ∆HR during habituation trials and levels of one choline metabolite, dimethylglycine (DMG), predicted ∆HR during habituation trials and latency of responses. A trend was found between DMG and ∆HR on the dishabituation trials and latency of the response. Supplementation did not affect ORs to auditory stimuli. Choline supplementation when administered together with routinely recommended multivitamin/mineral prenatal supplements during pregnancy may provide a beneficial impact to basic learning mechanisms involved in encoding and memory of environmental events in alcohol-exposed pregnancies as well as non- or low alcohol-exposed pregnancies. Changes in maternal nutrient status suggested that one mechanism by which choline supplementation may positively impact brain development is through prevention of fetal alcohol-related depletion of DMG, a metabolic nutrient that can protect against overproduction of glycine, during critical periods of neurogenesis.

Vitamin D and maternal and child health: overview and implications for dietary requirements

The essentiality of vitamin D for normal growth and development has been recognized for over 80 years, and vitamin D fortification programs have been in place in the United States for more than 70 years. Despite the above, vitamin D deficiency continues to be a common finding in certain population groups. Vitamin D deficiency has been suggested as a potential risk factor for the development of preeclampsia, and vitamin D deficiency during infancy and early childhood is associated with an increased risk for numerous skeletal disorders, as well as immunological and vascular abnormalities. Vitamin D deficiency can occur through multiple mechanisms including the consumption of diets low in this vitamin and inadequate exposure to environmental ultraviolet B rays. The potential value of vitamin D supplementation in high-risk pregnancies and during infancy and early childhood is discussed. Currently, there is vigorous debate concerning what constitutes appropriate vitamin D intakes during early development as exemplified by differing recommendations from the Institute of Medicine Dietary Reference Intake report and recent recommendations by the Endocrine Society. As is discussed, a major issue that needs to be resolved is what key biological endpoint should be used when making vitamin D recommendations for the pregnant woman and her offspring.

Influence of copper on early development: prenatal and postnatal considerations

Copper (Cu) is an essential nutrient whose requirement is increased during pregnancy and lactation. These represent times of critical growth and development, and the fetus and neonate are particularly vulnerable to deficiencies of this nutrient. Genetic mutations that predispose the offspring to inadequate stores of Cu can be life threatening as is observed in children with Menkes disease. During the last decade, severe Cu deficiency, once thought to be a rare condition, has been reported in the literature at an increasing frequency. Secondary Cu deficiencies can be induced by a variety of ways such as excessive zinc or iron intake, certain drugs, and bariatric surgery. Premature and low birth weight infants can be born with low Cu stores. A number of mechanisms can contribute to the teratogenicity of Cu including decreased activity of select cuproenzymes, increased oxidative stress, decreased nitric oxide availability, altered iron metabolism, abnormal extracellular matrix protein crosslinking, decreased angiogenesis and altered cell signaling among others. The brain, heart, and vessels as well as tissues such as lung, skin and hair, and systems including the skeletal, immune, and blood systems, are negatively affected by suboptimal Cu during development. Additionally, persistent structural, biochemical, and functional adverse effects in the offspring are noted even when Cu supplementation is initiated after birth, supporting the concept that adequate Cu nutriture during pregnancy and lactation is critical for normal development. Although Cu-containing IUDs are an effective method for increasing intrauterine Cu concentrations and for reducing the risk of pregnancy, high amounts of dietary Cu are not thought to represent a direct developmental risk.

The plausibility of maternal nutritional status being a contributing factor to the risk for fetal alcohol spectrum disorders: the potential influence of zinc status as an example

There is increasing evidence that human pregnancy outcome can be significantly compromised by suboptimal maternal nutritional status. Poor diet results in a maternal-fetal environment in which the teratogenicity of other insults such as alcohol might be amplified. As an example, there is evidence that zinc (Zn) can interact with maternal alcohol exposure to influence the risk for fetal alcohol spectrum disorders (FASD). Studies with experimental animals have shown that the teratogenicity of alcohol is increased under conditions of Zn deficiency, whereas its teratogenicity is lessened when animals are given Zn-supplemented diets or Zn injections before the alcohol exposure. Alcohol can precipitate an acute-phase response, resulting in a subsequent increase in maternal liver metallothionein, which can sequester Zn and lead to decreased Zn transfer to the fetus. Importantly, the teratogenicity of acute alcohol exposure is reduced in metallothionein knockout mice, which can have improved Zn transfer to the conceptus relative to wild-type mice. Consistent with the above, Zn status has been reported to be low in alcoholic women at delivery. Preliminary data from two basic science and clinical nutritional studies that are ongoing as part of the international Collaborative Initiative on Fetal Alcohol Spectrum Disorders support the potential role of Zn, among other nutritional factors, relative to risk for FASD. Importantly, the nutrient levels being examined in these studies are relevant to general clinical populations and represent suboptimal levels rather than severe deficiencies. These data suggest that moderate deficiencies in single nutrients can act as permissive factors for FASD, and that adequate nutritional status or intervention through supplementation may provide protection from some of the adverse effects of prenatal alcohol exposure.

Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial

BACKGROUND

Epidemiological data shows low dietary magnesium(Mg) may be related to incidence and progression of asthma.

OBJECTIVE

To determine if long term(6.5 month) treatment with oral Mg would improve asthma control and increase serum measures of Mg status in men and women with mild-to-moderate asthma.

SUBJECTS

55 males and females aged 21 to 55 years with mild to moderate asthma according to the 2002 National Heart, Lung, and Blood Institute(NHLBI) and Asthma Education and Prevention Program(NAEPP) guidelines and who used only beta-agonists or inhaled corticosteroids(ICS) as asthma medications were enrolled.

DESIGN

Subjects were randomly assigned to consume 340 mg(170 mg twice a day) of Mg or a placebo for 6.5 months.

MEASUREMENTS

Multiple measures of Mg status including serum, erythrocyte, urine, dietary, ionized and IV Mg were measured.

OBJECTIVE

markers of asthma control were: methacholine challenge test(MCCT) and pulmonary function test(PFT) results. Subjective validated questionnaires on asthma quality of life(AQLQ) and control(ACQ) were completed by participants. Markers of inflammation, including c-reactive protein(CRP) and exhaled nitric oxide(eNO) were determined.

RESULTS

The concentration of methacholine required to cause a 20% drop in forced expiratory volume in in minute(FEV(1)) increased significantly from baseline to month 6 within the Mg group. Peak expiratory flow rate(PEFR) showed a 5.8% predicted improvement over time(P = 0.03) in those consuming the Mg. There was significant improvement in AQLQ mean score units(P < 0.01) and in overall ACQ score only in the Mg group(P = 0.05) after 6.5 months of supplementation. Despite these improvements, there were no significant changes in any of the markers of Mg status.

CONCLUSION

Adults who received oral Mg supplements showed improvement in objective measures of bronchial reactivity to methacholine and PEFR and in subjective measures of asthma control and quality of life.

Multiple Measures of Magnesium Status Are Comparable in Mild Asthma and Control Subjects

Magnesium (Mg) may be a significant factor in asthma management. There is debate about how to best assess Mg status. We evaluated multiple indices of Mg status and lung function in 52 people with mild to moderate asthma and 47 controls. Mg measures included serum total, ionized and erythrocyte Mg, intravenous Mg load retention and dietary recall. Methacholine challenge and pulmonary function tests were used to assess diagnosis and severity of asthma. Mg status was similar in asthma and controls, and was not correlated to lung function. Total serum Mg closely reflected ionized Mg and offers a useful clinical diagnostic monitor.

Low nitric oxide: a key factor underlying copper-deficiency teratogenicity

Copper (Cu)-deficiency-induced teratogenicity is characterized by major cardiac, brain, and vascular anomalies; however, the underlying mechanisms are poorly understood. Cu deficiency decreases superoxide dismutase activity and increases superoxide anions, which can interact with nitric oxide (NO), reducing the NO pool size. Given the role of NO as a developmental signaling molecule, we tested the hypothesis that low NO levels, secondary to Cu deficiency, represent a developmental challenge. Gestation day 8.5 embryos from Cu-adequate (Cu+) or Cu-deficient (Cu-) dams were cultured for 48 h in Cu+ or Cu- medium, respectively. We report that NO levels were low in conditioned medium from Cu-/Cu- embryos and yolk sacs, compared to Cu+/Cu+ controls under basal conditions and with NO synthase (NOS) agonists. The low NO production was associated with low endothelial NOS phosphorylation at serine 1177 and cyclic guanosine-3',5'-monophosphate (cGMP) concentrations in the Cu-/Cu- group. The altered NO levels in Cu-deficient embryos are functionally significant, as the administration of the NO donor DETA/NONOate increased cGMP and ameliorated embryo and yolk sac abnormalities. These data support the concept that Cu deficiency limits NO availability and alters NO-dependent signaling, which contributes to abnormal embryo and yolk sac development.

Effects of copper deficiency on mouse yolk sac vasculature and expression of angiogenic mediators

BACKGROUND

Cu deficiency results in embryonic defects and yolk sac (YS) vasculature abnormalities. In diverse model systems, Cu treatment modulates angiogenesis, perhaps by influencing the activity of angiogenic mediators such as vascular endothelial growth factor (VEGF). Conversely, Cu chelators can suppress angiogenesis.

METHODS

Gestation day (GD) 8.5 embryos from mice fed Cu-adequate (Cu+) or Cu-deficient (Cu-) diets were cultured in Cu+ or Cu- medium for 48 hr. Growth and development were evaluated, and YS vessel diameters were measured. Using RT-PCR and immunohistochemistry, the mRNA and protein expressions of VEGF, Flt-1, Flk-1, Angiopoietin-1 (Ang-1), and Tie-2 were analyzed.

RESULTS

Cu+/Cu+ embryos developed normally, whereas Cu-/Cu- embryos showed a high incidence of developmental anomalies. Cu-/Cu- YS had a high proportion of vessels that were large in diameter compared to the Cu+/Cu+ YS. The mRNA expression of angiogenic mediators in Cu-/Cu- YS was similar to that in Cu+/Cu+ YS. The protein expression of VEGF in the Cu-/Cu- YS without any vessel defects, and Tie-2 in the Cu-/Cu- YS with both vessel defects and blood islands was significantly lower than that in the Cu+/Cu+ YS. The protein expression of Flt-1, Flk-1 and Ang-1 was similar among groups regardless of the presence, or type, of vessel defects.

CONCLUSIONS

Results from the current study support the concept that Cu is required for the normal development of YS vasculature. Our data suggest that the impaired vascularization of Cu-deficient YS cannot be explained fully by the altered protein expression of the angiogenic growth factors reported here.

Abnormal development and increased 3-nitrotyrosine in copper-deficient mouse embryos

Copper-deficient rat embryos are characterized by brain and heart anomalies, low superoxide dismutase activity, and high superoxide anion concentrations. One consequence of increased superoxide anions can be the formation of peroxynitrite, a strong biological oxidant. To investigate developmentally important features of copper deficiency, GD 8.5 mouse embryos from copper-adequate and copper-deficient dams were cultured in media that were adequate or deficient in copper. After 48 h, copper-deficient embryos exhibited brain and heart anomalies, and a high incidence of yolk sac vasculature abnormalities compared to controls. Immunohistochemistry of 4-hydroxynonenal and 8-hydroxy-2'-deoxyguanosine for lipid and DNA damage, respectively, was similar between groups. In contrast, 3-nitrotyrosine, taken as a measure of protein nitration, was markedly higher in the neuroepithelium of the anterior neural tube of copper-deficient embryos than in controls. Repletion of copper-deficient media with copper, or supplementation with copper-zinc superoxide dismutase, Tiron, or glutathione peroxidase did not ameliorate the abnormal development, but did decrease 3-nitrotyrosine in neuroepithelium of copper-deficient embryos. These data support the concept that while copper deficiency compromises oxidant defense and increases protein nitration, additional mechanisms, e.g., altered nitric oxide metabolism may contribute to copper-deficiency-induced teratogenesis.

Copper, oxidative stress, and human health

Copper (Cu), a redox active metal, is an essential nutrient for all species studied to date. During the past decade, there has been increasing interest in the concept that marginal deficits of this element can contribute to the development and progression of a number of disease states including cardiovascular disease and diabetes. Deficits of this nutrient during pregnancy can result in gross structural malformations in the conceptus, and persistent neurological and immunological abnormalities in the offspring. Excessive amounts of Cu in the body can also pose a risk. Acute Cu toxicity can result in a number of pathologies, and in severe cases, death. Chronic Cu toxicity can result in liver disease and severe neurological defects. The concept that elevated ceruloplasmin is a risk factor for certain diseases is discussed. In this paper, we will review recent literature on the potential causes of Cu deficiency and Cu toxicity, and the pathological consequences associated with the above. Finally, we will review some of the potential biochemical lesions that might underlie these pathologies. Given that oxidative stress is a characteristic of Cu deficiency, the role of Cu in the oxidative defense system will receive special attention. The concept that excess Cu may be a precipitating factor in Alzheimer's disease is discussed.

Diabetes and dietary copper alter 67Cu metabolism and oxidant defense in the rat

Perturbations in copper (Cu) metabolism are a characteristic of diabetes, for example, elevated plasma Cu and compromised oxidant defense related to diabetes-induced effects on Cu-containing enzymes. Herein, the redistribution of Cu in selected tissues is described in response to diabetic and nondiabetic states in rats that were fed diets adequate in (12 mg Cu/kg of diet) or deficient in (no added Cu) Cu. Diabetes was induced by intravenous administration of streptozotocin (40 mg/kg body weight). After 5 weeks, rats were gavaged with (67)Cu (0.74 MBq per rat) using the Cu-deficient diet as a vehicle (suspended 1:3 in water) and killed at various time points. The use of (67)Cu allowed for the assessment of short-term Cu distribution and its comparison to the steady-state Cu distribution, as determined by direct Cu analysis. In contrast to control rats, the adaptive mechanisms for Cu homeostasis in diabetic rats were impaired. In general, measures of Cu retention were reduced in diabetic rats compared to corresponding values for control rats. Moreover, diabetic rats had low copper, zinc superoxide dismutase activity that was reduced even further when diabetic rats were fed with low-Cu diets. However, liver and kidney metallothionein and plasma ceruloplasmin levels were elevated in diabetic rats compared to control rats. Such diabetes-related metabolic alterations were taken as measures of increased oxidative stress and inflammation, which may have implications in the progression of diabetes-related pathologies.

Metavanadate causes cellular accumulation of copper and decreased lysyl oxidase activity

Selected indices of copper metabolism in weanling rats and fibroblast cultures were progressively altered in response to increased levels of sodium metavanadate. In diets, vanadium was added in amounts ranging from 0 to 80 microg V/g of diet, that is, 0-1.6 micromol V/g of diet. In fibroblast cultures, vanadium ranged from 0 to 400 nmol V/ml. The inhibition of P-ATPase-7A activity by metavanadate, important to copper egress from cells, was a primary focus. In skin, and tendon, the copper concentration was increased in response to increased dietary levels of metavanadate, whereas lysyl oxidase activity, a secreted cuproprotein, was reduced. The reduction in lysyl oxidase activity was also accompanied by reduced redox cycling potential of isolated fractions of lysyl oxidase, presumably due to reduced lysyltyrosyl quinone (LTQ) formation at the active site of lysyl oxidase. In contrast, liver copper concentrations and plasma ceruloplasmin activity were not affected by metavanadate exposure. However, semicarbazide-sensitive benzylamine oxidase (SCBO) activity, which was taken as an indirect measure of vascular adhesive protein-1 (VAP-1), was increased. In cultured fibroblasts, cellular copper was also increased and lysyl oxidase decreased in response to metavanadate. Moreover, the steady-state levels of atp7a and lysyl oxidase mRNAs were not affected by addition of metavanadate to culture medium up to 200 nmol/ml. Taken together, these data suggest that pathways involving copper egress and lysyl oxidase activation are particularly sensitive to metavanadate exposure through processes that are predominately posttranslational.

The plausibility of micronutrient deficiencies being a significant contributing factor to the occurrence of pregnancy complications

Numerous studies support the concept that a major cause of pregnancy complications can be suboptimal embryonic and fetal nutrition. Although the negative effects of diets low in energy on pregnancy outcome are well documented, less clear are the effects of diets that are low in one or more essential micronutrients. However, several observational and intervention studies suggest that diets low in essential vitamins and minerals can pose a significant reproductive risk in diverse human populations. Although maternal nutritional deficiencies typically occur as a result of low dietary intakes of essential nutrients, nutritional deficiencies at the level of the conceptus can arise through multiple mechanisms. Evidence from experimental animals supports the concept that in addition to primary deficiencies, secondary embryonic and fetal nutritional deficiencies can be caused by diverse factors including genetics, maternal disease, toxicant insults and physiological stressors that can trigger a maternal acute phase response. These secondary responses may be significant contributors to the occurrence of birth defects. An implication of the above is that the frequency and severity of pregnancy complications may be reduced through an improvement in the micronutrient status of the mother.

Developmental consequences of trace mineral deficiencies in rodents: acute and long-term effects

Approximately 3% of infants born have at least one serious congenital malformation. In the U.S., an average of 10 infants per thousand die before 1 y of life; about half of these deaths can be attributed to birth defects, low birth weight or prematurity. Although the causes of developmental abnormalities are clearly multifactorial in nature, we suggest that a common factor contributing to the occurrence of developmental abnormalities is suboptimal mineral nutrition during embryonic and fetal development. Using zinc and copper as examples, evidence is presented that nutritional deficiencies can rapidly affect the developing conceptus and result in gross structural abnormalities. Deficits of zinc or copper can result in rapid changes in cellular redox balance, tissue oxidative stress, inappropriate patterns of cell death, alterations in the migration of neural crest cells and changes in the expression of key patterning genes. In addition to well-recognized malformations, mineral deficiencies during perinatal development can result in behavioral, immunological and biochemical abnormalities that persist into adulthood. Although these persistent defects can in part be attributed to subtle morphological abnormalities, in other cases they may be secondary to epigenetic or developmental changes in DNA methylation patterns. Epigenetic defects combined with subtle morphological abnormalities can influence an individual's risk for certain chronic diseases and thus influence his or her risk for morbidity and mortality later in life.

Copper-deficient rat embryos are characterized by low superoxide dismutase activity and elevated superoxide anions

The teratogenicity of copper (Cu) deficiency may result from increased oxidative stress and oxidative damage. Dams were fed either control (8.0 microg Cu/g) or Cu-deficient (0.5 microg Cu/g) diets. Embryos were collected on Gestational Day 12 for in vivo studies or on Gestational Day 10 and cultured for 48 h in Cu-deficient or Cu-adequate media for in vitro studies. Superoxide dismutase (SOD), glutathione peroxidase (GPX), and glutathione reductase (GR) activities were measured in control and Cu-deficient embryos as markers of the oxidant defense system. Superoxide anions were measured as an index of exposure to reactive oxygen species (ROS). No differences were found in GPX or GR activities among treatment groups. However, SOD activity was lower and superoxide anion concentrations higher in Cu-deficient embryos cultured in Cu-deficient serum compared to control embryos cultured in control serum. Even so, Cu-deficient embryos had similar CuZnSOD protein levels as controls. In the in vitro system, Cu-deficient embryos had a higher frequency of malformations and increased staining for superoxide anions in the forebrain, heart, forelimb, and somites compared to controls. When assessed for lipid and DNA oxidative damage, conjugated diene concentrations were similar among the groups, but a tendency was observed for Cu-deficient embryos to have higher 8-hydroxy-2'-deoxyguanosine concentrations than controls. Thus, Cu deficiency resulted in embryos with malformations and reduced SOD enzyme activity. Increased ROS concentrations in the Cu-deficient embryo may cause oxidative damage and contribute to the occurrence of developmental defects.

Effect of butyl benzyl phthalate on reproduction and zinc metabolism

Butyl benzyl phthalate (BBP) has been shown to be teratogenic. One mechanism contributing to the teratogenicity of several developmental toxicants, is chemical-induced changes in maternal zinc (Zn) metabolism which result in an increased synthesis of maternal liver metallothionein (Mt), and a subsequent reduction in Zn delivery to the conceptus. We investigated the effects of maternal BBP exposure on maternal-fetal Zn metabolism in Wistar rats. In study I, dams were gavaged with BBP (0,250,1000,1500 or 2000 mg/kg) on gestation days (GD) 11 through 13, and killed on GD 20. Maternal toxicity was evident in the three highest dose groups. Embryo/fetal death and small pup weights and lengths were noted in the 2000 mg BBP/kg group. Fetuses in the 1500 and 2000 mg/kg groups were characterized by poor skeletal ossification, and a high frequency of cleft palate. Rib anomalies were observed in the three highest dose groups. Maternal liver Mt concentrations were only slightly elevated in the 1500 and 2000 mg/kg groups. In study II, dams treated as above, were gavaged with 65Zn and killed 18 h later. While the 2000 mg/kg group had high percentages of 65Zn in some maternal tissues, sequestration of 65Zn in maternal liver was not evident. Thus, BBP is not a strong inducer of Mt, and the teratogenicity of BBP does not appear to be due to alterations in maternal and/or embryonic Zn metabolism.

Lysyl oxidase and P-ATPase-7A expression during embryonic development in the rat

Lysyl oxidase activity is critical for the assembly and cross-linking of extracellular matrix proteins, such as collagen and elastin. Moreover, lysyl oxidase activity is sensitive to changes in copper status and genetic perturbations in copper transport, e.g., mutations in the P-type ATPase gene, ATP7A, associated with cellular copper transport. Lysyl oxidase may also serve as a vehicle for copper transport from extracellular matrix cells. Herein, we demonstrate that sufficient lysyl oxidase functional activity is present in the rat embryo at gestation day (GD) 9 to be detected in conventional enzyme assays. Estimation of embryonic lysyl oxidase functional activity, however, required partial purification in order to remove inhibitors. From GD 9 to GD 15, lysyl oxidase activity was relatively constant when expressed per unit of protein or DNA. In contrast, the steady-state levels of lysyl oxidase and ATP7A mRNA, measured by RT-PCR and expressed relative to total RNA and cyclophilin mRNA, increased approximately fourfold from GD 9 to 15. The pattern of temporal expression for ATP7A was consistent with its possible role in copper delivery to lysyl oxidase.

Activation of chick tendon lysyl oxidase in response to dietary copper

Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons and aortae. Whether copper deficiency (0 added copper) or copper supplementation (16 microg copper/g of diet) caused changes in the molecular weight of protein(s) in tendon corresponding to lysyl oxidase was addressed. The average molecular weight of the peak corresponding to lysyl oxidase in tendon and aorta from copper-deficient birds was 28,386 Da +/- 86, whereas the average molecular weight of corresponding protein in tendon from copper-supplemented birds was 28,639 Da +/- 122. We propose that the shift in molecular weight is due in part to copper binding and the formation of lysyl tyrosyl quinone, the cofactor at the active site of lysyl oxidase.