Perinatal Oxidative Stress May Affect Fetal Ghrelin Levels in Humans

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

Uric acid participating in female reproductive disorders: a review

Uric acid (UA) is the end metabolic product of purine metabolism. Early on, UA was considered to be a metabolite with a certain antioxidant capacity. As research has progressed, other properties of UA have been explored, and its association with many diseases has been found. The association between UA and kidney disease and cardiovascular disease is well established; however, there is still a paucity of reviews on the association between UA and the female reproductive system. An increasing number of epidemiological studies have shown elevated serum UA levels in patients with polycystic ovary syndrome (PCOS), endometriosis, etc. Additionally, serum UA can be used as a predictor of pregnancy complications and adverse foetal outcomes. An increasing number of animal experiments and clinical studies have revealed possible mechanisms related to the involvement of UA in certain female reproductive disorders: oxidative stress, chronic inflammation, mitochondrial dysfunction, etc. This article reviews the current mainstream mechanisms regarding the pathogenesis of UA and the role of UA in certain specific female reproductive disorders (direct involvement in the development of certain diseases or enhancement of other risk factors) in the hope of contributing to clinical prevention, diagnosis, treatment and improvement in prognosis.

Prenatal and early postnatal food restrictions cause changes in brain oxidative status and orexigenic/anorexigenic hormones in the offspring of rats: prevention by quercetin and kaempferol

Brain oxidative signaling pathways have been identified as important targets for alleviating food deprivation-induced changes in metabolic gate-ways. Previous studies have shown that prenatal and early postnatal malnutrition alters leptin and ghrelin signaling via oxidative pathways. Thus, it has been hypothesized that agents with antioxidant properties might be beneficial for the mitigation of prenatal and early postnatal food scarcity-induced oxidative damage. Quercetin and kaempferol are natural bioflavonoids with proven antioxidant properties. In this study, we evaluated their effects on prenatal maternal food consumption, maternal and pup weights, biomarkers of orexigenic and anorexigenic hormones and oxidative stress in rats. Rats were allotted into different treatment groups (n ​= ​6) in three different experiments (prenatal, postnatal food-deprivations or both). Prenatal-food restriction (PrNFR) was induced by 50% of ad libitum accessible diet during pregnancy till parturition and postnatal-food restriction (PsNFR) was simulated by litter-enlargement to 16 pups per mother from postnatal day (PND) 2. Rats in each experiment were concurrently treated with vehicle (10 ​mL/kg), quercetin (50, 100 and 200 ​mg/kg, p.o.) or kaempferol (50, 100 and 200 ​mg/kg, p.o.) respectively. A third experimental group consisted of both protocols. Quercetin and kaempferol dose-dependently increased the body weights of pups exposed to PrNFR, PsNFR and PrNFR-PsNFR at PNDs 1-22 respectively. Both compounds increased maternal body weights but attenuated maternal food-intake at prenatal days 7 and 14 due by PrNFR. Quercetin and kaempferol reduced brain malondialdehyde concentrations and increased glutathione levels in PrNFR, PsNFR and PrNFR-PsNFR-exposed offspring of rats. Importantly, quercetin and kaempferol significantly (p ​< ​0.05) prevented PrNFR-, PsNFR- or PrNFR-PsNFR-induced alterations in leptin and ghrelin levels. Cumulatively, quercetin and kaempferol increased pup and maternal weights and attenuated maternal food-intake of rats submitted to PrNFR, PsNFR and PrNFR-PsNFR respectively, likely via nutrigenomic modulations of orexigenic/anorexigenic hormones and inhibition of brain oxidative stress.

Leptin and Ghrelin in Excessive Gestational Weight Gain-Association between Mothers and Offspring

Two-thirds of pregnant women exceed gestational weight gain recommendations. Excessive gestational weight gain (EGWG) appears to be associated with offspring's complications induced by mechanisms that are still unclear. The aim of this study was to investigate whether umbilical cord leptin (UCL) and ghrelin (UCG) concentrations are altered in full-term neonates born to EGWG mothers and whether neonatal anthropometric measurements correlate with UCL and UCG levels and maternal serum ghrelin and leptin as well as urine ghrelin concentrations. The study subjects were divided into two groups, 28 healthy controls and 38 patients with EGWG. Lower UCL and UCG levels were observed in neonates born to healthy mothers but only in male newborns. In the control group UCG concentrations correlated positively with neonatal birth weight, body length and head circumference. In the control group maternal serum ghrelin levels correlated negatively with neonatal birth weight, body length and head circumference as well as positively with chest circumference. In the EGWG group UCG concentrations correlated negatively with neonatal birth weight and birth body length. UCL correlated positively with birth body length in EGWG group and negatively with head circumference in the control group. In conclusion, EGWG is associated with disturbances in UCL and UCG concentrations.

FABP4 in Gestational Diabetes-Association between Mothers and Offspring

Fetuses exposed to gestational diabetes mellitus (GDM) have a higher risk of abnormal glucose homeostasis in later life. The molecular mechanisms of this phenomenon are still not fully understood. Fatty acid binding protein 4 (FABP4) appears to be one of the most probable candidates involved in the pathophysiology of GDM. The main aim of the study was to investigate whether umbilical cord serum FABP4 concentrations are altered in term neonates born to GDM mothers. Two groups of subjects were selected—28 healthy controls and 26 patients with GDM. FABP4, leptin, and ghrelin concentrations in the umbilical cord serum, maternal serum, and maternal urine were determined via an enzyme-linked immunosorbent assay. The umbilical cord serum FABP4 levels were higher in the GDM offspring and were directly associated with the maternal serum FABP4 and leptin levels, as well as the prepregnancy body mass index (BMI) and the BMI at and after delivery; however, they correlated negatively with birth weight and lipid parameters. In the multiple linear regression models, the umbilical cord serum FABP4 concentrations depended positively on the maternal serum FABP4 and negatively on the umbilical cord serum ghrelin levels and the high-density lipoprotein cholesterol. There are many maternal variables that can affect the level of FABP4 in the umbilical cord serum, thus, their evaluation requires further investigation.

Umbilical Cord SFRP5 Levels of Term Newborns in Relation to Normal and Excessive Gestational Weight Gain

Among the new adipokines, secreted frizzled-related protein 5 (SFRP5) is considered to prevent obesity and insulin resistance. The umbilical cord SFRP5 levels have not yet been investigated. The main aim of the study was to investigate whether the umbilical cord SFRP5 concentrations are altered in term neonates born to mothers with excessive gestational weight gain (EGWG). Two groups of subjects were selected depending on their gestational weight gain, i.e. 28 controls and 38 patients with EGWG. Umbilical cord and maternal serum SFRP5 levels were lower in the EGWG group. Umbilical cord SFRP5 concentrations were directly associated with the maternal serum SFRP5, hemoglobin A1c and lean tissue index, umbilical cord leptin levels, as well as newborns’ anthropometric measurements in the EGWG subjects. In multiple linear regression models performed in all the study participants, umbilical cord SFRP5 concentrations depended positively on the maternal serum SFRP5, ghrelin, and leptin levels and negatively on the umbilical cord ghrelin levels, low-density lipoprotein cholesterol, pre-pregnancy body mass index, and gestational weight gain. EGWG is associated with disturbances in SFRP5 concentrations. Obstetricians and midwives should pay attention to nutrition and weight management during pregnancy.

Cord blood insulin, IGF-I, IGF-II, leptin, adiponectin and ghrelin, and their associations with insulin sensitivity, β-cell function and adiposity in infancy

AIM

Vulnerability to insulin resistance and Type 2 diabetes may originate in early life, but little is known about whether any perinatal biomarkers are predictive of later metabolic health. We sought to assess whether cord blood insulin, insulin-like growth factor (IGF)-I, IGF-II, leptin, adiponectin and ghrelin are associated with metabolic health indicators in infancy.

METHODS

In a prospective singleton birth cohort, we assessed cord blood insulin, IGF-I, IGF-II, leptin, adiponectin and ghrelin concentrations in relation to the homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function (HOMA-β), fasting proinsulin-to-insulin ratio, BMIz-score, and the sum of triceps and subscapular skinfold thickness (an indicator of adiposity) in infants at age 1 year (n = 185).

RESULTS

Adjusting for maternal and infant characteristics, one standard deviation (sd) increase in cord blood adiponectin was associated with an 11.1% (95% confidence interval 1.8-19.5%) decrease in HOMA-β (P = 0.02) and a 13.6% (1.8-26.8%) increase in proinsulin-to-insulin ratio (P = 0.02), indicating worse β-cell function in infants at age 1 year. One sd increase in cord blood insulin was associated with a 0.5 (0.1-1.0) mm increase in skinfold thickness (P = 0.01). One sd increase in cord blood ghrelin was associated with a 0.2 (0.02-0.3) decrease in BMIz-score (P = 0.02) and a 0.5 (0.1-0.9) mm decrease (P = 0.02) in skinfold thickness. Cord blood IGF-I and IGF-II were not associated with the observed metabolic health indicators at age 1 year.

CONCLUSION

The study is the first to show that cord blood adiponectin may be negatively predictive of β-cell function, whereas cord blood ghrelin may be negatively predictive of adiposity in infancy.

Cord blood leptin and insulin levels in association with mitochondrial DNA content

Background

The developmental origins of health and disease theory states that a disturbance in the early life environment can contribute to disease risk in later life. Leptin and insulin are anorectic hormones involved in energy homeostasis and are crucial for foetal growth. Disturbances in the levels of these hormones contribute to obesity and diabetes. In adults, altered mitochondrial function is an important hallmark of metabolic disorders, including obesity and diabetes. However, the mitochondrial effects of early life metabolic variation are unexplored. We investigated whether there is an association between metabolic hormones and mitochondrial DNA (mtDNA) content in early life.

Methods

The study included 236 newborns from the FLEHS III birth cohort, Flanders (Belgium). Relative mtDNA content of cord blood leukocytes was determined using quantitative PCR. Cord blood levels of leptin and insulin were determined using immunoassays. We studied the association between these metabolic hormones and mtDNA content using multiple linear regression models, while accounting for covariates and potential confounders.

Results

Leptin and insulin levels were positively associated with cord blood mtDNA content. mtDNA content was respectively 4.49% (95% CI 1.15–7.93; p = 0.008) and 1.60% (95% CI 0.31–2.91; p = 0.02) higher for a interquartile range increase of respectively cord blood leptin and insulin levels. In a sensitivity analysis, we observed that insulin and leptin were independently associated to mtDNA content and that insulin was stronger associated to mtDNA content in boys than in girls.

Conclusion

Neonatal metabolic hormones were associated with cord blood mtDNA content, which suggests that in early life the variation of mtDNA content might accommodate or reflect changes in the metabolic status.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1599-z) contains supplementary material, which is available to authorized users.

Maternal serum uric acid levels in pregnancy and fetal growth

Objective: Studies of maternal serum uric acid (UA) in pregnancy focus primarily on high levels of UA, however, both low and high UA levels can be markers of oxidative stress, a biological state potentially linked to fetal growth. We therefore aimed to test whether low and high maternal serum UA levels during pregnancy are associated with atypical fetal growth (unusually small or large) measured as birthweight (BW) for gestational age.Methods: The Pregnancy Outcomes and Community Health Study enrolled 3019 pregnant women between their 16th-27th week of pregnancy from 52 clinics in five Michigan communities (1998-2004). Maternal UA levels were measured in blood collected at enrollment among a subcohort of 1291 participants. Infant BW and gestational age were used to calculate gestational age-specific BW Z-score. Infants were grouped as small (SGA = BW < 10th percentile), appropriate (AGA = BW 10th-90th percentile), or large (LGA) = BW > 90th percentile) for their gestational age. Analyses considered multiple potential confounders. Linear spline or multiple linear regression models were applied to evaluate the relationship between maternal UA levels and BW Z-score overall and within SGA, AGA, and LGA groups. Model robustness was tested through bootstrap, sensitivity analysis, and cross-validation techniques.Results: The relation between maternal UA levels and BW Z-score varied by infant group. Among SGA infants, the relation was nonlinear (J-shape): both extremes of UA had lower BW Z-score with a breakpoint of 0.267 mmol/L UA (adjusted regression coefficient β = 2.32, p = .01 for lower UA; adjusted β = -37.38, p < .01 for higher UA). Among AGA infants, there was no significant association, and among LGA infants, the relation was linear (adjusted β = 2.86, p = .03).Conclusions: Future research on maternal UA levels in pregnancy may benefit from considering both very low and high levels, and identifying in utero conditions associated with the two extremes.

Ghrelin Protects Human Lens Epithelial Cells against Oxidative Stress-Induced Damage

Oxidative stress has been recognized as an important mediator in the pathogenesis of age-related cataracts; using antioxidant supplements is one plausible strategy to protect the antioxidative defense system against oxidative stress. Ghrelin administration is expected to reduce ROS, preventing the onset of different diseases. The role of ghrelin, if any, in protecting against oxidative stress in HLECs has never been examined. In the present study, we investigated the effects of ghrelin against H₂O₂-induced oxidative stress and the associated molecular mechanisms in HLECs and rat lenses. The results showed that pretreatment with ghrelin reduced H₂O₂-induced cellular apoptosis and ROS accumulation, increased the expression levels of SOD and CAT, and decreased the expression level of MDA. The morphological examination showed that the ghrelin-treated lens organ culture maintained transparency. This is the first report to show that ghrelin can protect HLECs from H₂O₂-induced oxidative stress. Our findings suggest that ghrelin may prevent the progression of cataracts, which has treatment value for ophthalmologists.

Early and Late Postnatal Accelerated Growth Have Distinct Effects on Metabolic Health in Normal Birth Weight Infants

Accelerated growth in postnatal life in low birth weight infants has been associated with insulin resistance and metabolic syndrome-related disorders in later life. Postnatal accelerated growth in also common in normal birth weight infants, but little is known about the impact on metabolic health. In a prospective cohort study of 203 term normal birth weight infants, we evaluated the impacts of accelerated (Δweight Z score > 0.5) or decelerated (Δweight ΔZ < -0.5) growth during early (0-3 months) and late (3-12 months) postnatal life on metabolic health indicators at age 1-year. The primary outcomes were homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function [homeostasis model assessment of β-cell function (HOMA-β)], and fasting plasma lipids. Adjusting for maternal, paternal, and infant characteristics, accelerated growth during the first 3 months of life was associated with a 41.6% (95% confidence interval 8.9-84.2%) increase in HOMA-β, and a 8.3% (0.7-15.4%) decrease in fasting plasma total cholesterols, and was not associated with HOMA-IR in infants at age 1-year. Accelerated growth during 3-12 months was associated with a 30.9% (3.3-66.0%) increase in HOMA-IR and was not associated with HOMA-β. Neither accelerated nor decelerated growth was associated with fasting plasma triglycerides, high-density lipoprotein or low-density lipoprotein cholesterol concentrations in infants at age 1-year. Accelerated growth during early postnatal life may be beneficial for β-cell function, but during late postnatal life harmful for insulin sensitivity in normal birth weight infants.

[Increased prevalence of congenital dacryostenosis following cesarean section]

BACKGROUND

Congenital nasolacrimal duct obstruction (dacryostenosis) with a persisting membrane at Hasner's valve is the most common cause of persistent tear and ocular discharge in infants.

PURPOSE

To evaluate whether there is an association between congenital dacryostenosis and delivery via cesarean section.

MATERIAL AND METHODS

In a prospective study we examined 107 children (mean age 9.2 ± 7.1 months) with congenital dacryostenosis. We evaluated data about the mode of delivery (vaginal delivery versus cesarean section) and gestational age at the time of birth. Within the first 8 months of life children were treated by probing using local anesthesia, whereas older children were treated using general anesthesia. After the age of 11 months treatment included nasolacrimal duct intubation with a bicanalicular stent. Statistical analyses were performed using binomial tests, Fisher's exact test and the t-test.

RESULTS

In this study 51 children delivered by cesarean section were compared with 56 children delivered by spontaneous vaginal delivery. A total of 44 age-matched pairs from both groups were evaluated in order to eliminate confounding factors due to gestational age at delivery. Based on the published rate of cesarean sections from the same region of the State of Hesse between 2002-2004 we observed a statistically significant association between congenital dacryostenosis and delivery by cesarean section among the 88 age-matched patients (P = 0.009). Moreover, subgroup analysis revealed a significant association between congenital dacryostenosis and delivery by primary cesarean section (P = 0.00004). The prevalence of surgical treatment was not statistically different between both groups based on the mode of delivery (P = 0.8).

CONCLUSION

Our results suggest that delivery via cesarean section is associated with a significantly higher prevalence of congenital dacryostenosis.