Maternal iron supplementation attenuates the impact of perinatal copper deficiency but does not eliminate hypotriiodothyroninemia nor impaired sensorimotor development

Treatment for benign thyroid nodules with a combination of natural extracts

Benign thyroid nodules are among the most common endocrine disorders. Recent advances in diagnostic imaging and pathology have significantly contributed to better risk stratification of thyroid nodules. However, current treatment options, beyond surgical approaches are limited. The following placebo-controlled study presents, to the best of our knowledge, the first results of a non-invasive therapy for benign thyroid nodules. The efficacy and safety of a supplement containing spirulina, curcumin and Boswellia in euthyroid patients with benign thyroid nodules, was assessed by a 3 month, double-blind, placebo-controlled study which was completed by 34 patients. Patients with benign (FNAB documented) single thyroid nodules between 2 and 5 cm were evaluated in a prospective placebo-controlled cross-over trial, across 12 weeks (3 visits with six-week intervals). At each visit, the target thyroid nodule was recorded in two dimensions. In addition, plasma levels of thyroid stimulating hormone, free thyroxine and copper were assessed. The mean initial nodule area at V1 was 4.38±3.14 cm², at V2 3.87±2.79 cm², and at V3 3.53±2.84 cm²; P<0.04. Administration of the active substances (n=34) was followed by a mean area decrease of 0.611 cm²±0.933 (SD), while placebo administration (n=29) was followed by a mean decrease of 0.178 cm²±0.515 (SD), (P=0.027). The presented findings suggest that the combination of spirulina-curcumin-Boswellia is effective in reducing the size of benign thyroid nodules. However, additional studies are needed in order to elucidate the exact mechanisms through which the suggested supplement facilitates a decrease in the size of benign thyroid nodules.

Evaluation of serum ferritin and thyroid function in the second trimester of pregnancy

Ferritin is a universal intracellular protein that acts as an iron carrier. Several studies have indicated that iron deficiency affects thyroid function in non-pregnant women. Our objective was to assess the relationship between serum ferritin levels and thyroid function in pregnant women during the second trimester. Pregnant women with sufficient iodine intake and normal antithyroid antibodies during the second trimester were recruited from the obstetric outpatient department of the Fifth People's Hospital of Fudan University. Serum ferritin (SF) levels, thyroid function, anti-thyroid antibodies and vitamin B12 were determined by electrochemiluminescence immunoassay kit. Maternal serum iron (Fe), unsaturated iron binding capacity (UIBC), hemoglobin (Hb), creatinine (Cr), fasting blood glucose (FBG), and alanine aminotransferase (ALT) were also evaluated. Stepwise regressions performed to evaluate the associations between SF and other maternal parameters. In the second trimester, 11.4% pregnant women had a SF concentration less than 12 μg/L, and 7.6% pregnant women were anemic. SF levels were negatively correlated with serum TSH levels (r = -0.219, p < 0.05), and positively correlated with FT4 levels (r = 0.203, p < 0.05). Linear regression analysis showed only SF, age, week of gestation were significant predictors of regression with TSH as the dependent variable (β: -0.007, -0.059, and 0.118 respectively; all p < 0.05). However consistent relation between the SF levels and FT4 was not observed in stepwise linear regression. Maternal iron status is a determinant of TSH concentrations during pregnancy in pregnant women during the second trimester.

Fetal and neonatal iron deficiency but not copper deficiency increases vascular complexity in the developing rat brain

OBJECTIVES

Anemia caused by nutritional deficiencies, such as iron and copper deficiencies, is a global health problem. Iron and copper deficiencies have their most profound effect on the developing fetus/infant, leading to brain development deficits and poor cognitive outcomes. Tissue iron depletion or chronic anemia can induce cellular hypoxic signaling. In mice, chronic hypoxia induces a compensatory increase in brain blood vessel outgrowth. We hypothesized that developmental anemia, due to iron or copper deficiencies, induces angiogenesis/vasculogenesis in the neonatal brain.

METHODS

To test our hypothesis, three independent experiments were performed where pregnant rats were fed iron- or copper-deficient diets from gestational day 2 through mid-lactation. Effects on the neonatal brain vasculature were determined using quantitative real-time polymerase chain reaction to assess mRNA levels of angiogenesis/vasculogenesis-associated genes and GLUT1 immunohistochemistry to assess brain blood vessel density and complexity.

RESULTS

Iron deficiency, but not copper deficiency, increased mRNA expression of brain endothelial cell- and angiogenesis/vasculogenesis-associated genes (i.e. Glut1, Vwf, Vegfa, Ang2, Cxcl12, and Flk1) in the neonatal brain, suggesting increased cerebrovascular density. Iron deficiency also increased hippocampal and cerebral cortical blood vessel branching by 62 and 78%, respectively.

DISCUSSION

This study demonstrates increased blood vessel complexity in the neonatal iron-deficient brain, which is likely due to elevated angiogenic/vasculogenic signaling. At least initially, this is probably an adaptive response to maintain metabolic substrate homeostasis in the developing iron-deficient brain. However, this may also contribute to long-term neurodevelopmental deficits.

Maternal dietary intake during pregnancy has longstanding consequences for the health of her offspring

Over the past 100 years, advances in pharmaceutical and medical technology have reduced the burden of communicable disease, and our appreciation of the mechanisms underlying the development of noncommunicable disease has broadened. During this time, a number of studies, both in humans and animal models, have highlighted the importance of maintaining an optimal diet during pregnancy. In particular, a number of studies support the hypothesis that suboptimal maternal protein and fat intake during pregnancy can have long-term effects on the growing fetus, and increase the likelihood of these offspring developing cardiovascular, renal, or metabolic diseases in adulthood. More recently, it has been shown that dietary intake of a number of micronutrients may offset or reverse the deleterious effects of macronutrient imbalance. Furthermore, maternal fat intake has also been identified as a major contributor to a healthy fetal environment, with a beneficial role for unsaturated fats during development as well as a beneficial impact on cell membrane physiology. Together these studies indicate that attempts to optimise maternal nutrition may prove to be an efficient and cost-effective strategy for preventing the development of cardiovascular, renal, or metabolic diseases.

Fetal and neonatal iron deficiency reduces thyroid hormone-responsive gene mRNA levels in the neonatal rat hippocampus and cerebral cortex

Copper (Cu), iron (Fe), and thyroid hormone (TH) deficiencies produce similar defects in late brain development including hypomyelination of axons and impaired synapse formation and function, suggesting that these micronutrient deficiencies share a common mechanism contributing to these derangements. We previously demonstrated that fetal/neonatal Cu and Fe deficiencies lower circulating TH concentrations in neonatal rats. Fe deficiency also reduces whole-brain T(3) content, suggesting impaired TH action in the developing Fe-deficient brain. We hypothesized that fetal/neonatal Cu and Fe deficiencies will produce mild or moderate TH deficiencies and will impair TH-responsive gene expression in the neonatal cerebral cortex and hippocampus. To test this hypothesis, we rendered pregnant Sprague Dawley rats Cu-, Fe-, or TH-deficient from early gestation through postnatal d 10 (P10). Mild and moderate TH deficiencies were induced by 1 and 3 ppm propylthiouracil treatment, respectively. Cu deficiency did not significantly alter serum or tissue TH concentrations or TH-responsive brain mRNA expression. Fe deficiency significantly lowered P10 serum total T(3) (45%), serum total T(4) (52%), whole brain T(3) (14%), and hippocampal T(3) (18%) concentrations, producing a mild TH deficiency similar to 1 ppm propylthiouracil treatment. Fe deficiency lowered Pvalb, Enpp6, and Mbp mRNA levels in the P10 hippocampus. Fe deficiency also altered Hairless, Dbm, and Dio2 mRNA levels in the P10 cerebral cortex. These results suggest that some of the brain defects associated with Fe deficiency may be mediated through altered thyroidal status and the concomitant alterations in TH-responsive gene transcription.

Copper deficiency has minimal impact on ferroportin expression or function

Interactions between copper and iron homeostasis have been known since the nineteenth century when anemia in humans was first described due to copper limitation. However, the mechanism remains unknown. Intestinal and liver iron concentrations are usually higher following copper deficiency (CuD). This may be due to impaired function of the multicopper oxidases hephaestin or ceruloplasmin (Cp), respectively. However, iron retention could be due to altered ferroportin (Fpn), the essential iron efflux transporter in enterocytes and macrophages. Fpn mRNA is controlled partially by intracellular iron and IRE dependence. CuD should augment Fpn based on iron level. Some argue that Fpn stability is controlled partially by membrane ferroxidase (GPI-Cp). CuD should result in lower Fpn since GPI-Cp expression and function is reduced. Fpn turnover is controlled by hepcidin. CuD results in variable Hamp (hepcidin) expression. Fpn mRNA and protein level were evaluated following dietary CuD in rats and mice. To correlate with Fpn expression, measurements of tissue iron were conducted in several rodent models. Following CuD there was little change in Fpn mRNA. Previous work indicated that under certain circumstances Fpn protein was augmented in liver and spleen following CuD. Fpn levels in CuD did not correlate with either total iron or non-heme iron (NHI), as iron levels in CuD liver were higher and in spleen lower than copper adequate controls. Fpn steady state levels appear to be regulated by a complex set of factors. Changes in Fpn do not explain the anemia of CuD.

Suppressed hepcidin expression correlates with hypotransferrinemia in copper-deficient rat pups but not dams

Copper deficiency leads to anemia but the mechanism is unknown. Copper deficiency also leads to hypoferremia, which may limit erythropoiesis. The hypoferremia may be due to limited function of multicopper oxidases (MCO) hephaestin in enterocytes or GPI-ceruloplasmin in macrophages of liver and spleen whose function as a ferroxidase is thought essential for iron transfer out of cells. Iron release may also be limited by ferroportin (Fpn), the iron efflux transporter. Fpn may be lower following copper deficiency because of impaired ferroxidase activity of MCO. Fpn is also dependent on the liver hormone hepcidin as Fpn is degraded when hepcidin binds to Fpn. Anemia and hypoferremia both down regulate hepcidin by separate mechanisms. Current studies confirmed and extended earlier studies with copper-deficient (CuD) rats that suggested low hepicidin resulted in augmented Fpn. However, current studies in CuD dams failed to confirm a correlation that hepcidin expression was associated with low transferrin receptor 2 (TfR2) levels and also challenged the dogma that holotransferrin can explain the correlation with hepcidin. CuD dams exhibited hypoferremia, low liver TfR2, anemia in some rats, yet no depression in Hamp expression, the hepcidin gene. Normal levels of GDF-15, the putative erythroid cytokine that suppresses hepcidin, were detected in plasma of CuD and iron-deficient (FeD) dams. Importantly, FeD dams did display greatly lower Hamp expression. Normal hepcidin in these CuD dams is puzzling since these rats may need extra iron to meet needs of lactation and the impaired iron transfer noted previously.

Rapid alteration in rat red blood cell copper chaperone for superoxide dismutase after marginal copper deficiency and repletion

There is increased incidence of human copper deficiency (CuD). A sensitive and reliable blood biomarker may reveal additional cases of marginal deficiency. Two experiments were designed to test the hypothesis that the copper chaperone for superoxide dismutase (CCS) would be a robust marker after marginal CuD. Experiment 1 used weanling male Sprague-Dawley rats that were offered a CuD diet for 4 weeks, and samples were evaluated after 1, 2, and 4 weeks and compared with copper-adequate (CuA) controls. Furthermore, iron-deficient rats were included for comparison after 2 weeks of depletion. Red blood cell and plasma cuproenzymes were evaluated through Western blot analysis. Superoxide dismutase (Sod1) and ceruloplasmin protein were found to be altered by both iron and CuD, whereas CCS and CCS/Sod1 ratio were found to only be altered only in CuD rats and, importantly, after only 1 week of treatment. Two weeks on CuA diet restored cuproenzyme levels to control values after 4 weeks of CuD depletion. In experiment 2, marginal CuD (CuM) rats were compared with CuA and CuD rats after 2 weeks of treatment. Superoxide dismutase, ceruloplasmin, and CCS/Sod1 abundances were lower in CuM and CuD groups compared with CuA rats, but there was no statistical difference between CuM and CuD rats. However, CCS was statistically different between all groups, and abundance highly correlated with liver copper concentration. Results suggest that red blood cell CCS may be an excellent biomarker for diagnosis of rapid and marginal CuD.

Erythrocyte copper chaperone for superoxide dismutase is increased following marginal copper deficiency in adult and postweanling mice

A sensitive and reliable biomarker has yet to be identified for marginal copper deficiency in humans. The need for such a biomarker is critical, because increased cases of human copper deficiency evolve following bariatric surgery and other secondary factors besides diet. Four experiments were devised to induce marginal copper deficiency through copper-deficient (CuD) diets (5 wk for mice and 4 wk for rats). In Expt. 1 and 2, male postweanling mice were raised in either solid-bottom plastic cages (Expt. 1) or stainless steel hanging cages (Expt. 2) and compared. Postweanling rats (Expt. 3) and adult mice (Expt. 4) were also studied using stainless steel cages. Copper-adequate controls were fed a semipurified diet containing 9 mg Cu/kg. CuD rats exhibited the most severe changes in biomarkers due to copper limitation, including major reductions in plasma ceruloplasmin (Cp) and erythrocyte superoxide dismutase (Sod1) and augmentation in copper chaperone for Sod1 (CCS). The CuD mice in Expt. 2 were more deficient than the CuD mice in Expt. 1, likely due to coprophagia differences. In fact, the CuD mice in Expt. 1 had unaltered Sod1 or Cp levels. Importantly though, these marginally deficient mice and CuD adult mice that had no changes in Cp activity or liver copper level had robust augmentation of CCS. Erythrocyte CCS was the only consistent biomarker to change in copper deficiency for all dietary groups, suggesting that CCS may be an excellent biomarker for human confirmation of marginal copper deficiency.