Leptin in pregnancy and development: a contributor to adulthood disease?

Leptin deficiency, a potential mechanism for impaired fetal lung development in uteroplacental insufficiency?

Uteroplacental insufficiency (UPI) is a major cause of fetal growth restriction (FGR). Leptin, an adipokine, has been shown to play a vital role in fetal organogenesis. There is evidence reporting leptin deficiency in preterm and growth-restricted fetuses. In this issue of Pediatric Research, Yuliana et al. report leptin expression and lung development in UPI-induced FGR rats. UPI-induced FGR rats expressed decreased lung leptin and had impaired lung development, as shown by decreased surface area and lung volume. They also found a significant association between lung radial alveolar count, serum leptin, von Willebrand factor, and specific metabolites on metabolomic analyses. Previous studies on leptin supplementation in vivo have been associated with improvement in lung maturation; supporting the evidence, that leptin improves lung growth and development in FGR and may have future therapeutic potential in the improvement of respiratory outcomes in these infants. Future studies to support evidence of this association in humans are warranted.

Maternal Diet High in Linoleic Acid Alters Renal Branching Morphogenesis and mTOR/AKT Signalling Genes in Rat Fetal Kidneys

Linoleic acid (LA), an n-6 polyunsaturated fatty acid (PUFA), is obtained from the maternal diet during pregnancy, and is essential for normal fetal growth and development. A maternal high-LA (HLA) diet alters maternal and offspring fatty acids, maternal leptin and male/female ratio at embryonic (E) day 20 (E20). We investigated the effects of an HLA diet on embryonic offspring renal branching morphogenesis, leptin signalling, megalin signalling and angiogenesis gene expression. Female Wistar Kyoto rats were fed low-LA (LLA; 1.44% energy from LA) or high-LA (HLA; 6.21% energy from LA) diets during pregnancy and gestation/lactation. Offspring were sacrificed and mRNA from kidneys was analysed by real-time PCR. Maternal HLA decreased the targets involved in branching morphogenesis Ret and Gdnf in offspring, independent of sex. Furthermore, downstream targets of megalin, namely mTOR, Akt3 and Prkab2, were reduced in offspring from mothers consuming an HLA diet, independent of sex. There was a trend of an increase in the branching morphogenesis target Gfra1 in females (p = 0.0517). These findings suggest that an HLA diet during pregnancy may lead to altered renal function in offspring. Future research should investigate the effects an HLA diet has on offspring kidney function in adolescence and adulthood.

Selection of Leptin Surrogates by a General Phenotypic Screening Method for Receptor Agonists

There is a high demand for agonist biomolecules such as cytokine surrogates in both biological and medicinal research fields. These are typically sourced through natural ligand engineering or affinity-based screening, followed by individual functional validation. However, efficient screening methods for identifying rare hits within immense libraries are very limited. In this research article, we introduce a phenotypic screening method utilizing biological receptor activation-dependent cell survival (BRADS). This method offers a high-throughput, low-background, and cost-effective approach that can be implemented in virtually any biochemical laboratory setting. As a proof-of-concept, we successfully identified a surrogate for human leptin following a two-week cell culture process, without the need for specialized high-throughput equipment or reagents. This surrogate effectively emulates the activity of native human leptin in cell validation assays. Our findings not only underscore the effectiveness of BRADS but also suggest its potential applicability to a broad range of biological receptors, including Notch and GPCRs.

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks' gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

Effect of feeding frequency on reproductive performances and stress responses in gestating sows

The objective of this study was to investigate the influence of feeding frequency on a sow's reproductive performance and stress response during gestation. A total of twenty multiparous sows (Yorkshire × Landrace) were used in a completely randomized design based on their parity, body weight (BW), and backfat thickness (BFT), and the sows were allotted to two different feeding systems: 1) once daily feeding (OF) and 2) twice daily feeding (TF) in corn-soybean meal based diets. The gestation diet was formulated to contain 3,265 kcal of metabolizable energy (ME) / kg, 12.90% of crude protein (CP), and 0.75 % of total lysine. The lactation diet was formulated to contain 3,265 kcal of ME / kg, 16.80% of CP, and 1.08% of total lysine and provided ad libitum during lactation. In gestation, sow BFT and BF changes were not affected by feeding frequency, but higher BW and BW gain from day 35 to 90 and day 35 to 110 were observed in OF sow (p < 0.10). In lactation, feeding frequency did not influence on BW, BW gain, BFT, BF changes, average daily feed intake, and wean-to-estrus interval. Also, there were no differences in litter size, litter weight and piglet weight in lactating sows. OF sows had higher (p < 0.05; p < 0.10) protein, solid-not-fat, and total solid concentrations in colostrum compared to TF sows, while OF sows had a lower (p < 0.05) lactose concentration in colostrum compared to TF sows. Sows in OF showed significantly lower average daily water consumption (ADWC) from day 35 to 110 of gestation (p < 0.05). While there were no significant differences in stereotypic behaviors and salivary cortisol levels during gestation between treatments, the OF sows showed less time spending on the activity at day 105 (p < 0.05). In conclusion, reduced feeding frequency increased BW gain during gestation, decreased activation time, and changed the colostrum composition. This information may contribute to the understanding of the physiological and behavioral change of gestating sows by manipulating feeding frequency.

Minireview: Glucocorticoid-Leptin Crosstalk: Role of Glucocorticoid-Leptin Counterregulation in Metabolic Homeostasis and Normal Development

Glucocorticoids and leptin are two important hormones that regulate metabolic homeostasis by controlling appetite and energy expenditure in adult mammals. Also, glucocorticoids and leptin strongly counterregulate each other, such that chronic stress-induced glucocorticoids upregulate the production of leptin and leptin suppresses glucocorticoid production directly via action on endocrine organs and indirectly via action on food intake. Altered glucocorticoid or leptin levels during development can impair organ development and increase the risk of chronic diseases in adults, but there are limited studies depicting the significance of glucocorticoid-leptin interaction during development and its impact on developmental programming. In mammals, leptin-induced suppression of glucocorticoid production is critical during development, where leptin prevents stress-induced glucocorticoid production by inducing a period of short-hyporesponsiveness when the adrenal glands fail to respond to certain mild to moderate stressors. Conversely, reduced or absent leptin signaling increases glucocorticoid levels beyond what is appropriate for normal organogenesis. The counterregulatory interactions between leptin and glucocorticoids suggest the potential significant involvement of leptin in disorders that occur from stress during development.

Transcriptomic profiling reveals differential cellular response to copper oxide nanoparticles and polystyrene nanoplastics in perfused human placenta

The growing nanoparticulate pollution (e.g. engineered nanoparticles (NPs) or nanoplastics) has been shown to pose potential threats to human health. In particular, sensitive populations such as pregnant women and their unborn children need to be protected from harmful environmental exposures. However, developmental toxicity from prenatal exposure to pollution particles is not yet well studied despite evidence of particle accumulation in human placenta. Our study aimed to investigate how copper oxide NPs (CuO NPs; 10-20 nm) and polystyrene nanoplastics (PS NPs; 70 nm) impact on gene expression in ex vivo perfused human placental tissue. Whole genome microarray analysis revealed changes in global gene expression profile after 6 h of perfusion with sub-cytotoxic concentrations of CuO (10 µg/mL) and PS NPs (25 µg/mL). Pathway and gene ontology enrichment analysis of the differentially expressed genes suggested that CuO and PS NPs trigger distinct cellular response in placental tissue. While CuO NPs induced pathways related to angiogenesis, protein misfolding and heat shock responses, PS NPs affected the expression of genes related to inflammation and iron homeostasis. The observed effects on protein misfolding, cytokine signaling, and hormones were corroborated by western blot (accumulation of polyubiquitinated proteins) or qPCR analysis. Overall, the results of the present study revealed extensive and material-specific interference of CuO and PS NPs with placental gene expression from a single short-term exposure which deserves increasing attention. In addition, the placenta, which is often neglected in developmental toxicity studies, should be a key focus in the future safety assessment of NPs in pregnancy.

Potential mechanisms and modulators of food intake during pregnancy

Dietary choice during pregnancy is crucial not only for fetal development, but also for long-term health outcomes of both mother and child. During pregnancy, dramatic changes in endocrine, cognitive, and reward systems have been shown to take place. Interestingly, in different contexts, many of these mechanisms play a key role in guiding food intake. Here, we review how food intake may be impacted as a function of pregnancy-induced changes across species. We first summarize changes in endocrine and metabolic signaling in the course of pregnancy. Then, we show how these may be related to cognitive function and reward processing in humans. Finally, we link these to potential drivers of change in eating behavior throughout the course of pregnancy.

Parental obesity-induced changes in developmental programming

Many studies support the link between parental obesity and the predisposition to develop adult-onset metabolic syndromes that include obesity, high blood pressure, dyslipidemia, insulin resistance, and diabetes in the offspring. As the prevalence of obesity increases in persons of childbearing age, so does metabolic syndrome in their descendants. Understanding how parental obesity alters metabolic programs in the progeny, predisposing them to adult-onset metabolic syndrome, is key to breaking this cycle. This review explores the basis for altered metabolism of offspring exposed to overnutrition by focusing on critical developmental processes influenced by parental obesity. We draw from human and animal model studies, highlighting the adaptations in metabolism that occur during normal pregnancy that become maladaptive with obesity. We describe essential phases of development impacted by parental obesity that contribute to long-term alterations in metabolism in the offspring. These encompass gamete formation, placentation, adipogenesis, pancreas development, and development of brain appetite control circuits. Parental obesity alters the developmental programming of these organs in part by inducing epigenetic changes with long-term consequences on metabolism. While exposure to parental obesity during any of these phases is sufficient to alter long-term metabolism, offspring often experience multiple exposures throughout their development. These insults accumulate to increase further the susceptibility of the offspring to the obesogenic environments of modern society.

Adipose Tissue Development Relies on Coordinated Extracellular Matrix Remodeling, Angiogenesis, and Adipogenesis

Despite developing prenatally, the adipose tissue is unique in its ability to undergo drastic growth even after reaching its mature size. This development and subsequent maintenance rely on the proper coordination between the vascular niche and the adipose compartment. In this review, the process of adipose tissue development is broken down to explain (1) the ultrastructural matrix remodeling that is undertaken during simultaneous adipogenesis and angiogenesis, (2) the paracrine crosstalk involved during adipose development, (3) the mechanical regulators involved in adipose growth, and (4) the proteolytic and paracrine oversight for matrix remodeling during adipose development. It is crucial to gain a better understanding of the complex relationships that exist between adipose tissue and the vasculature during tissue development to provide insights into the pathological tissue expansion of obesity and to develop improved soft-tissue reconstruction techniques.

Leptin Levels of the Perinatal Period Shape Offspring's Weight Trajectories through the First Year of Age

Background: Leptin is a hormone regulating lifetime energy homeostasis and metabolism and its concentration is important starting from prenatal life. We aimed to investigate the association of perinatal leptin concentrations with growth trajectories during the first year of life. Methods: Prospective, longitudinal study, measuring leptin concentration in maternal plasma before delivery, cord blood (CB), and mature breast milk and correlating their impact on neonate’s bodyweight from birth to 1 year of age, in 16 full-term (FT), 16 preterm (PT), and 13 intrauterine growth-restricted (IUGR) neonates. Results: Maternal leptin concentrations were highest in the PT group, followed by IUGR and FT, with no statistical differences among groups (p = 0.213). CB leptin concentrations were significantly higher in FT compared with PT and IUGR neonates (PT vs. FT; IUGR vs. FT: p < 0.001). Maternal milk leptin concentrations were low, with no difference among groups. Maternal leptin and milk concentrations were negatively associated with all the neonates’ weight changes (p = 0.017 and p = 0.006), while the association with CB leptin was not significant (p = 0.051). Considering each subgroup individually, statistical analysis confirmed the previous results in PT and IUGR infants, with the highest value in the PT subgroup. In addition, this group’s results negatively correlated with CB leptin (p = 0.026) and showed the largest % weight increase. Conclusions: Leptin might play a role in neonatal growth trajectories, characterized by an inverse correlation with maternal plasma and milk. PT infants showed the highest correlation with hormone levels, regardless of source, seeming the most affected group by leptin guidance. Low leptin levels appeared to contribute to critical neonates’ ability to recover a correct body weight at 1 year. An eventual non-physiological “catch-up growth” should be monitored, and leptin perinatal levels may be an indicative tool. Further investigations are needed to strengthen the results.

Neonatal leptin antagonism improves metabolic programming of postnatally overnourished mice

BACKGROUND/OBJECTIVES

Alteration of the perinatal nutritional environment is an important risk factor for the development of metabolic diseases in later life. The hormone leptin plays a critical role in growth and development. Previous studies reported that postnatal overnutrition increases leptin secretion during the pre-weaning period. However, a direct link between leptin, neonatal overnutrition, and lifelong metabolic regulation has not been investigated.

METHODS

We used the small litter mouse model combined with neonatal leptin antagonist injections to examine whether attenuating leptin during early life improves lifelong metabolic regulation in postnatally overnourished mice.

RESULTS

Postnatally overnourished mice displayed rapid weight gain during lactation and remained overweight as adults. These mice also showed increased adiposity and perturbations in glucose homeostasis in adulthood. Neonatal administration of a leptin antagonist normalized fat mass and insulin sensitivity in postnatally overnourished mice. These metabolic improvements were associated with enhanced sensitivity of hypothalamic neurons to leptin.

CONCLUSIONS

Early postnatal overnutrition causes metabolic alterations that can be permanently attenuated with the administration of a leptin antagonist during a restricted developmental window.

A Review of the Relationship Between the Appetite-Regulating Hormone Leptin Present in Human Milk and Infant Growth

Objective: The relationship between leptin in human milk (HM) and infant growth is quite controversial. The aim of the present study was to review the epidemiological literature currently available on the relation between the appetite-regulating hormone leptin in HM with growth and infant weight gain. Also, to know if it influences on the center of satiety of the infant, and if this hormone has an effect in the self-regulation of food intake. Methods: A review of review and original research articles published from January 1, 2015 up to December 31, 2019 measuring leptin in HM and infant weight gain was performed in the PubMed and Embase databases. The literature showed a total of 237 articles, where the title and abstract were evaluated to eliminate duplicate citations and later exclusion criteria were established to discard articles. Eighteen articles met the inclusion criteria. Results: Six articles showed a relationship between leptin present in HM and infant weight. Five articles reported on leptin in HM and the effect on satiety and self-regulation of infant intake. Studies of leptin in infant serum blood were quite controversial. There is an inverse relationship between the leptin in HM and infant weight gain. Also, breastfed infants better self-regulate their intake and have a better relationship with food. The duration of breastfeeding directly influences on the growth of the infant due to the hormones present in the milk. However, these mechanisms are unclear, and the results are controversial. Conclusion: The evidence from the studies allowed us to establish that there is an association between leptin in HM and infant weight gain. However, there is still a lack of longitudinal studies, with a larger number of participants and well-established inclusion criteria about the relationship between leptin in HM exposure and the development of infant weight gain.

Maternal adaptations to food intake across pregnancy: Central and peripheral mechanisms

A sufficient and balanced maternal diet is critical to meet the nutritional demands of the developing fetus and to facilitate deposition of fat reserves for lactation. Multiple adaptations occur to meet these energy requirements, including reductions in energy expenditure and increases in maternal food intake. The central nervous system plays a vital role in the regulation of food intake and energy homeostasis and responds to multiple metabolic and nutrient cues, including those arising from the gastrointestinal tract. This review describes the nutrient requirements of pregnancy and the impact of over- and undernutrition on the risk of pregnancy complications and adult disease in progeny. The central and peripheral regulation of food intake is then discussed, with particular emphasis on the adaptations that occur during pregnancy and the mechanisms that drive these changes, including the possible role of the pregnancy-associated hormones progesterone, estrogen, prolactin, and growth hormone. We identify the need for deeper mechanistic understanding of maternal adaptations, in particular, changes in gut-brain axis satiety signaling. Improved understanding of food intake regulation during pregnancy will provide a basis to inform strategies that prevent maternal under- or overnutrition, improve fetal health, and reduce the long-term health and economic burden for mothers and offspring.

Roles of Endocannabinoids and Endocannabinoid-like Molecules in Energy Homeostasis and Metabolic Regulation: A Nutritional Perspective

The endocannabinoid system is involved in signal transduction in mammals. It comprises principally G protein-coupled cannabinoid receptors and their endogenous agonists, called endocannabinoids, as well as the enzymes and transporters responsible for the metabolism of endocannabinoids. Two arachidonic acid-containing lipid molecules, arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol, function as endocannabinoids. N-acylethanolamines and monoacylglycerols, in which the arachidonic acid chain is replaced with a saturated or monounsaturated fatty acid, are not directly involved in the endocannabinoid system but exhibit agonistic activities for other receptors. These endocannabinoid-like molecules include palmitoylethanolamide, oleoylethanolamide (OEA), and 2-oleoylglycerol. Endocannabinoids stimulate feeding behavior and the anabolism of lipids and glucose, while OEA suppresses appetite. Both central and peripheral systems are included in these nutritional and metabolic contexts. Therefore, they have potential in the treatment and prevention of obesity. We outline the structure, metabolism, and biological activities of endocannabinoids and related molecules, and focus on their involvement in energy homeostasis and metabolic regulation. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

RNA-Seq reveals changes in human placental metabolism, transport and endocrinology across the first-second trimester transition

The human placenta is exposed to major environmental changes towards the end of the first trimester associated with full onset of the maternal arterial placental circulation. Changes include a switch from histotrophic to hemotrophic nutrition, and a threefold rise in the intraplacental oxygen concentration. We evaluated their impact on trophoblast development and function using RNA-sequencing (RNA-Seq) and DNA-methylation analyses performed on the same chorionic villous samples at 7-8 (n=8) and 13-14 (n=6) weeks of gestation. Reads were adjusted for fetal sex. Most DEGs were associated with protein processing in the endoplasmic reticulum (ER), hormone secretion, transport, extracellular matrix, vasculogenesis, and reactive oxygen species metabolism. Transcripts higher in the first trimester were associated with synthesis and ER processing of peptide hormones, and glycolytic pathways. Transcripts encoding proteins mediating transport of oxygen, lipids, protein, glucose, and ions were significantly increased in the second trimester. The motifs of CBX3 and BCL6 were significantly overrepresented, indicating the involvement of these transcription factor networks in the regulation of trophoblast migration, proliferation and fusion. These findings are consistent with a high level of cell proliferation and hormone secretion by the early placenta to secure implantation in a physiological low-oxygen environment.

Association of high maternal blood alpha-fetoprotein level with risk of delivering small for gestational age: a meta-analysis

BACKGROUND

Early identification of pregnant women at risk of delivering small-for-gestational-age (SGA) infants is required to reduce the rates of mortality and morbidity in their whole life. This meta-analysis was performed to determine whether women with higher blood alpha-fetoprotein (AFP) levels are at increased risk of SGA.

METHODS

Studies identified by searching 11 databases, including PubMed, were assessed using the Newcastle-Ottawa Scale. Subgroup and meta-regression analyses and sensitivity analysis removing a potential outlier were performed. Publication bias was assessed using Egger's test.

RESULTS

A total of 39 good-quality cohort studies involving 93,968 women and their newborn infants or fetuses ensured both internal and external validity. Relative risk of SGA among women with higher in comparison to lower blood AFP levels was 2.021 (95% CI: 1.751-2.334). Maternal blood AFP levels showed a dose-response relationship with risk of SGA. Relative risk was higher with diagnosis of SGA by ultrasound than actual birth weight (P = 0.004). Sources of heterogeneity, subgroups, confounding factors, or potential outliers did not alter the interpretations without publication bias (P = 0.320).

CONCLUSIONS

Pregnant women with higher blood AFP levels are at increased risk of SGA compared to those with lower blood AFP levels.

IMPACT

Pregnant women with higher blood alpha-fetoprotein levels (AFP) levels are at increased risk of small for gestational age (SGA) compared to those with lower blood AFP levels. High-quality evidence showed a dose-response relationship of maternal blood AFP levels with risk of delivering SGA and was robust to sources of heterogeneity, subgroups, confounding factors, potential outliers, or publication bias. Politically and practically, monitoring of maternal blood AFP level is strongly recommended to identify women at risk of delivering SGA.

Infant body composition relationship to maternal adipokines and fat mass: the PONCH study

BACKGROUND

Infant adiposity is linked to both high maternal fat mass (FM) and excessive gestational FM gain, whereas the association with maternal adipokines is less clear. The aim was to determine how levels of maternal leptin, the soluble leptin receptor (sOB-R), adiponectin, and FM during pregnancy were linked to infant FM in normal-weight (NW) women and women with obesity (OB).

METHODS

Body composition and serum levels of leptin, adiponectin, and sOB-R were determined three times during pregnancy in 80 NW and 46 OB women. For infants, body composition was measured at 1 and 12 weeks of age.

RESULTS

Maternal leptin and sOB-R levels increased during pregnancy. For NW women, infant FM at 1 week was inversely associated with changes in maternal leptin and at 12 weeks inversely associated with absolute maternal sOB-R levels throughout pregnancy, as well as changes in sOB-R levels in early pregnancy. For OB women, infant FM at both 1 and 12 weeks were best explained by maternal FM.

CONCLUSIONS

Leptin and sOB-R, thought to regulate leptin bioavailability, are associated with fat accumulation in infants born to NW women. In OB women, maternal FM in early pregnancy is more important than leptin in determining infant fat accumulation.

IMPACT

In normal-weight women, the regulation of maternal leptin bioavailability during pregnancy has a role in infant fat mass accumulation. In women with obesity, however, pre-pregnancy maternal fat mass seems more important for infant fat mass. This is the first study of maternal adipokines and fat mass including longitudinal measurements in both mothers and their children. Understanding the relationship between maternal factors and infant fat mass is of great importance as obesity is programmed over the generations, and it is important to learn what regulates this programming.

The Role of Leptin in Fetal Growth during Pre-Eclampsia

Leptin is secreted by the placenta and has a multi-facetted role in the regulation of functions related to pregnancy. Metabolic disorders and insufficient homeostatic compensatory mechanisms involving leptin during pregnancy play a decisive role in the development of pre-eclampsia (PE) and give rise to compromised intrauterine growth conditions and aberrant birth weight of offspring. This review was compiled to elucidate the metabolic background of PE and its relationship with adverse intrauterine growth conditions through the examination of leptin as well as to describe possible mechanisms linking leptin to fetal growth restriction. This review illustrates that leptin in PE is dysregulated in maternal, fetal, and placental compartments. There is no single set of unifying mechanisms within the spectrum of PE, and regulatory mechanisms involving leptin are specific to each situation. We conclude that dysregulated leptin is involved in fetal growth at many levels through complex interactions with parallel pregnancy systems and probably throughout the entirety of pregnancy.

Impact of hyperleptinemia during placental ischemia-induced hypertension in pregnant rats

The prevalence of preeclampsia and obesity have increased. Although obesity is a major risk factor for preeclampsia, the mechanisms linking these morbidities are poorly understood. Circulating leptin levels increase in proportion to fat mass. Infusion of this adipokine elicits hypertension in nonpregnant rats, but less is known about how hyperleptinemia impacts blood pressure during placental ischemia, an initiating event in the pathophysiology of hypertension in preeclampsia. We tested the hypothesis that hyperleptinemia during reduced uterine perfusion pressure (RUPP) exaggerates placental ischemia-induced hypertension. On gestational day (GD) 14, Sprague-Dawley rats were implanted with osmotic mini-pumps delivering recombinant rat leptin (1 µg/kg/min iv) or vehicle concurrently with the RUPP procedure to induce placental ischemia or Sham. On GD 19, plasma leptin was elevated in Sham + Leptin and RUPP + Leptin. Leptin infusion did not significantly impact mean arterial pressure (MAP) in Sham. MAP was increased in RUPP + Vehicle vs. Sham + Vehicle. In contrast to our hypothesis, placental ischemia-induced hypertension was attenuated by leptin infusion. To examine potential mechanisms for attenuation of RUPP-induced hypertension during hyperleptinemia, endothelial-dependent vasorelaxation to acetylcholine was similar between Sham and RUPP; however, endothelial-independent vasorelaxation to the nitric oxide (NO)-donor, sodium nitroprusside, was increased in Sham and RUPP. These findings suggest that NO/cyclic guanosine monophosphate (cGMP) signaling was increased in the presence of hyperleptinemia. Plasma cGMP was elevated in Sham and RUPP hyperleptinemic groups compared with vehicle groups but plasma and vascular NO metabolites were reduced. These data suggest that hyperleptinemia during placental ischemia attenuates hypertension by compensatory increases in NO/cGMP signaling.NEW & NOTEWORTHY Ours is the first study to examine the impact of hyperleptinemia on the development of placental ischemia-induced hypertension using an experimental animal model.

How should we assess renal function in neonates and infants?

AIM

Review of current knowledge on assessing renal function in term and preterm neonates.

METHODS

Literature review and analysis of own data.

RESULTS

Prematurity, genetic, environmental and maternal factors may alter peak nephron endowment and life-long renal function. Nephrogenesis continues until 34-36 weeks of gestation, but it is altered with premature delivery. Variability of nephron endowment has a substantial impact on the clearance of renally excreted drugs. Postnatally, glomerular function rate (GFR) increases daily, doubles by two weeks, and slowly reaches full maturity at 18 months of age. Ideally, renal function biomarkers should be expressed as age-independent z-scores, and evidence suggests indexing these values to post-conceptual age rather than chronological age. Newborn and maternal serum creatinine correlate tightly for more than 72 hours after delivery, rendering this biomarker unsuitable for the assessment of neonatal renal function. Cystatin C does not cross the placenta and may be the preferred biomarker in the neonate. Here, we provide preliminary data on the natural evolution of the cystatin C eGFR in infancy.

CONCLUSION

Cystatin C may be superior for GFR estimation in neonates, but the best approach to drug dosing of renally excreted drugs remains to be established.

Association of Maternal Microbiota and Diet in Cord Blood Cytokine and Immunoglobulin Profiles

Mothers confer natural passive immunization to their infants through the transplacental pathway during the gestation period. The objective of the present study was to establish at birth the maternal and cord plasma concentration and relationship of immunoglobulins (Igs), cytokines (CKs), and adipokines. In addition, the impact of the maternal microbiota and diet was explored. The plasma profile of these components was different between mothers and babies, with the levels of many CKs, IgM, IgG2a, IgE, IgA, and leptin significantly higher in mothers than in the cord sample. Moreover, the total Igs, all IgG subtypes, IgE, and the Th1/Th2 ratio positively correlated in the mother–infant pair. Maternal dietary components such as monounsaturated fatty acids-polyunsaturated fatty acids and fiber were positively associated with some immune factors such as IgA in cord samples. The microbiota composition clustering also influenced the plasma profile of some factors (i.e., many CKs, some Ig, and adiponectin). In conclusion, we have established the concentration of these immunomodulatory factors in the maternal–neonatal pair at birth, some positive associations, and the influence of maternal diet and the microbiota composition, suggesting that the immune status during pregnancy, in terms of CKs and Igs levels, can influence the immune status of the infant at birth.

High Maternal Omega-3 Supplementation Dysregulates Body Weight and Leptin in Newborn Male and Female Rats: Implications for Hypothalamic Developmental Programming

Maternal diet is critical for offspring development and long-term health. Here we investigated the effects of a poor maternal diet pre-conception and during pregnancy on metabolic outcomes and the developing hypothalamus in male and female offspring at birth. We hypothesised that offspring born to dams fed a diet high in fat and sugar (HFSD) peri-pregnancy will have disrupted metabolic outcomes. We also determined if these HFSD-related effects could be reversed by a shift to a healthier diet post-conception, in particular to a diet high in omega-3 polyunsaturated fatty acids (ω3 PUFAs), since ω3 PUFAs are considered essential for normal neurodevelopment. Unexpectedly, our data show that there are minimal negative effects of maternal HFSD on newborn pups. On the other hand, consumption of an ω3-replete diet during pregnancy altered several developmental parameters. As such, pups born to high-ω3-fed dams weighed less for their length, had reduced circulating leptin, and also displayed sex-specific disruption in the expression of hypothalamic neuropeptides. Collectively, our study shows that maternal intake of a diet rich in ω3 PUFAs during pregnancy may be detrimental for some metabolic developmental outcomes in the offspring. These data indicate the importance of a balanced dietary intake in pregnancy and highlight the need for further research into the impact of maternal ω3 intake on offspring development and long-term health.

Leptin down-regulates KCC2 activity and controls chloride homeostasis in the neonatal rat hippocampus

The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.

Relative Contribution of Gestational Weight Gain, Gestational Diabetes, and Maternal Obesity to Neonatal Fat Mass

Maternal nutritional and metabolic status influence fetal growth. This study investigated the contribution of gestational weight gain (GWG), gestational diabetes (GDM), and maternal obesity to birthweight and newborn body fat. It is a secondary analysis of a prospective study including 204 women with a pregestational body mass index (BMI) of 18.5-24.9 kg/m² and 219 women with BMI ≥ 30 kg/m². GDM was screened in the second and third trimester and was treated by dietary intervention, and insulin if required. Maternal obesity had the greatest effect on skinfolds (+1.4 mm) and cord leptin (+3.5 ng/mL), but no effect on birthweight. GWG was associated with increased birthweight and skinfolds thickness, independently from GDM and maternal obesity. There was an interaction between third trimester weight gain and GDM on birthweight and cord leptin, but not with maternal obesity. On average, +1 kg in third trimester was associated with +13 g in birthweight and with +0.64 ng/mL in cord leptin, and a further 32 g and 0.89 ng/mL increase in diabetic mothers, respectively. Maternal obesity is the main contributor to neonatal body fat. There is an independent association between third trimester weight gain, birthweight, and neonatal body fat, enhanced by GDM despite intensive treatment.

The dynamical interplay of perinatal leptin with birthweight and 3-month weight, in full-term, preterm, IUGR mother-infant dyads

OBJECTIVE

To evaluate the dynamical interplay between perinatal leptin concentrations and neonatal weight evolution until 3 months of age.

METHODS

In a prospective observational study, maternal, cord blood and neonatal plasma leptin concentrations were correlated to birthweight and 3-month weight in 26 full-term, 20 preterm, and 17 intrauterine growth restriction (IUGR) mother-neonate couples.

RESULTS

The median of maternal, cord blood, neonatal leptin concentrations were significantly different among the three groups (p = 0.010; <0.001; =0.041 correspondingly). In the respect of the full-term group, higher concentrations were reported in preterm and IUGR mothers and lower concentrations in cord blood and neonatal plasma. The post-hoc comparisons showed that maternal concentrations were significantly higher in the IUGR group (p = 0.005 vs full-term), cord blood concentrations resulted always significantly lower (preterm, IUGR vs full-term p < 0.001) and neonatal concentrations were significantly lower in the preterm group (p = 0.018 vs full-term). Neonatal birthweight and 3-month weight were always significantly different among groups (p < 0.001), even if preterm and IUGR still had lower weight than full-term, the percent increasing of weight between birth and 3-month demonstrated that preterm and IUGR infants have grown significantly faster, (preterm, IUGR vs full-term p < 0.001). The univariable analysis showed a maternal leptin association with offspring' birthweight (R = -38%, p = 0.006) and with 3-month weight (R = -43%, p = 0.002). Accounting for confounders, these associations lost significance. Cord blood leptin concentrations positively correlated with birthweight and with 3-month weight (both, p < 0.001). The latter correlation, when adjusting for birthweight became negative (R = -43% p < 0.001).

CONCLUSION

Our results showed that maternal leptin levels lost their influence on neonatal weight when considering confounders. At 3-month, once birthweight adjusted, the percent increasing of weight was statistically larger in preterm and IUGR than the full-term group and the correlation between cord blood leptin and weight turned negative, from positive at birth. These data may be a clue for further investigation on the relationship between perinatal leptin concentrations and catch-up growth.

Temporal Leptin to Determine Cardiovascular and Metabolic Fate throughout the Life

Leptin links peripheral adiposity and the central nervous system (CNS) to regulate cardiometabolic physiology. Within the CNS, leptin receptor-expressing cells are a counterpart to circulating leptin, and leptin receptor-mediated neural networks modulate the output of neuroendocrine and sympathetic nervous activity to balance cardiometabolic homeostasis. Therefore, disrupted CNS leptin signaling is directly implicated in the development of metabolic diseases, such as hypertension, obesity, and type 2 diabetes. Independently, maternal leptin also plays a central role in the development and growth of the infant during gestation. Accumulating evidence points to the dynamic maternal leptin environment as a predictor of cardiometabolic fate in their offspring as it is directly associated with infant metabolic parameters at birth. In postnatal life, the degree of serum leptin is representative of the level of body adiposity/weight, a driving factor for cardiometabolic alterations, and therefore, the levels of blood leptin through the CNS mechanism, in a large part, are a strong determinant for future cardiometabolic fate. The current review focuses on highlighting and discussing recent updates for temporal dissection of leptin-associated programing of future cardiometabolic fate throughout the entire life.

Maternal excessive gestational weight gain as a risk factor for autism spectrum disorder in offspring: a systematic review

Background

Abnormal gestational weight gain (GWG) is a prenatal complication that may contribute to long-term behavioral and neurodevelopmental differences in offspring. This systematic review summarizes research on the association between maternal GWG and risk of autism spectrum disorder (ASD) in offspring.

Methods

Google and electronic databases, including PubMed, SCOPUS, Embase, Cochrane Library and Google Scholar, were searched for original human studies published in English through June 2020. Articles that examined the association between GWG and risk of ASD in offspring were included. Duplicate and irrelevant studies were removed; and data were obtained through critical analysis.

Results

Of 96 articles searched, eight studies were included in the final review. All studies (n = 7) investigating the association of maternal excessive GWG with risk of ASD in offspring indicated that high GWG was independently associated with an increased risk of ASD. Of five studies investigating the association of inadequate GWG with the risk of ASD, four indicated that low GWG was not associated with an increased risk of ASD. Of seven studies examining the association of maternal pre-pregnancy BMI or weight with the risk of ASD, five reported that maternal pre-pregnancy BMI or weight did not appear to be independently associated with risk of ASD. The GWG-ASD association is independent of maternal BMI and child’s intellectual disability, but offspring’s genetic susceptibility connection to the GWG-ASD association remains a topic of debate.

Conclusions

The findings suggest that maternal excessive GWG may be associated with increased risk of ASD in offspring. However, insufficient GWG does not appear to have such association.

Antioxidant Effects of N-Acetylcysteine Prevent Programmed Metabolic Disease in Mice

An adverse maternal in utero and lactation environment can program offspring for increased risk for metabolic disease. The aim of this study was to determine whether N-acetylcysteine (NAC), an anti-inflammatory antioxidant, attenuates programmed susceptibility to obesity and insulin resistance in offspring of mothers on a high-fat diet (HFD) during pregnancy. CD1 female mice were acutely fed a standard breeding chow or HFD. NAC was added to the drinking water (1 g/kg) of the treatment cohorts from embryonic day 0.5 until the end of lactation. NAC treatment normalized HFD-induced maternal weight gain and oxidative stress, improved the maternal lipidome, and prevented maternal leptin resistance. These favorable changes in the in utero environment normalized postnatal growth, decreased white adipose tissue (WAT) and hepatic fat, improved glucose and insulin tolerance and antioxidant capacity, reduced leptin and insulin, and increased adiponectin in HFD offspring. The lifelong metabolic improvements in the offspring were accompanied by reductions in proinflammatory gene expression in liver and WAT and increased thermogenic gene expression in brown adipose tissue. These results, for the first time, provide a mechanistic rationale for how NAC can prevent the onset of metabolic disease in the offspring of mothers who consume a typical Western HFD.

Leptin: Master Regulator of Biological Functions that Affects Breathing

Obesity is a global epidemic in developed countries accounting for many of the metabolic and cardiorespiratory morbidities that occur in adults. These morbidities include type 2 diabetes, sleep-disordered breathing (SDB), obstructive sleep apnea, chronic intermittent hypoxia, and hypertension. Leptin, produced by adipocytes, is a master regulator of metabolism and of many other biological functions including central and peripheral circuits that control breathing. By binding to receptors on cells and neurons in the brainstem, hypothalamus, and carotid body, leptin links energy and metabolism to breathing. In this comprehensive article, we review the central and peripheral locations of leptin's actions that affect cardiorespiratory responses during health and disease, with a particular focus on obesity, SDB, and its effects during early development. Obesity-induced hyperleptinemia is associated with centrally mediated hypoventilation with decrease CO₂ sensitivity. On the other hand, hyperleptinemia augments peripheral chemoreflexes to hypoxia and induces sympathoexcitation. Thus, "leptin resistance" in obesity is relative. We delineate the circuits responsible for these divergent effects, including signaling pathways. We review the unique effects of leptin during development on organogenesis, feeding behavior, and cardiorespiratory responses, and how undernutrition and overnutrition during critical periods of development can lead to cardiorespiratory comorbidities in adulthood. We conclude with suggestions for future directions to improve our understanding of leptin dysregulation and associated clinical diseases and possible therapeutic targets. Lastly, we briefly discuss the yin and the yang, specifically the contribution of relative adiponectin deficiency in adults with hyperleptinemia to the development of metabolic and cardiovascular disease. © 2020 American Physiological Society. Compr Physiol 10:1047-1083, 2020.

Comparison of leptin levels in neonates born to mothers with high or low gestational weight gain

Background Gestational weight gain (GWG) influences both fetal and maternal health. Leptin is a biomarker that may predict the early development of obesity and greater weight gain in childhood. Newborns with higher neonatal weight have been found to have higher leptin levels in umbilical cord blood (UCB). There are few studies that evaluate leptin levels in UCB according to GWG in women with a normal body mass index (BMI). The aim of the present study was to determine whether the levels of leptin in UCB in neonates born to mothers with a high GWG were higher, compared with levels in newborns whose mothers had a low GWG. Methods A cross-sectional analytic study was conducted on 65 primigravidas. They were under 30 years of age, had normal pregestational BMIs, no associated diseases and were classified as having high (n = 22) or low (n = 43) GWG. The neonatal UCB leptin levels were measured and both neonatal and maternal anthropometric evaluations were carried out. The quantitative variables were compared through the Mann-Whitney U test and Student's t test, as appropriate. Results UCB leptin levels were higher in the neonates whose mothers were in the high GWG group, compared with those born to mothers in the low GWG group (7.0 [1.9-11.4] vs. 2.9 [1.2-6.7] ng/mL, p = 0.020). When stratified by sex, that difference was maintained only in male neonates. Conclusions UCB leptin levels were higher in neonates born to mothers with a high GWG, compared with those in newborns whose mothers had a low GWG.

Effect of breed body-size on leptin amniotic fluid concentrations at term pregnancy in dogs

Because of the need to improve the knowledge about canine perinatology, and given the major role of fetal fluids in sustaining the course of pregnancy and fetal development, an in-depth analysis to better understand the role of some hormones in these compartments is essential. Among all, leptin is recognized to play a key role not only on the energetic homeostasis, but also at multiple levels, influencing the control of reproduction, food assumption and metabolism. Even if in humans and other species it is reported the presence of leptin receptors during fetal development, very little is known about the canine species, in which the role of leptin still needs to be fully understood. The present study aimed to assess the amniotic fluid leptin (AFL) concentrations at term pregnancy in healthy dogs, and to evaluate the possible influence played by breed body-size (after assessment of correlation with maternal bodyweight and placental weight), or other maternal (age, parity, and the so-called "litter effect") and neonatal (gender, birth weight, litter size) parameters on AFL concentrations, analyzed by ELISA test. The study was performed on 90 healthy, viable and normal weighted puppies, 39 small-sized (adult body weight < 10 kg) and 51 large-sized (adult body weight > 25 kg), born by 29 purebred, healthy bitches, submitted to elective Caesarean section because of breed-related or individual high risk for dystocia. The results showed that the mean AFL concentration in the small-sized puppies was significantly (p < 0.05) higher in comparison to large-sized puppies (867.48 vs 698.42 pg/ml), while all the other studied parameters did not show to influence AFL concentrations. In conclusions, the present study showed significant higher at term AFL concentrations in small-sized as compared to large-sized breeds, suggesting an influence of breed body-size on fetal metabolism, as previously reported for NEFA and IGF-I.

Fetal size and eating behaviour in childhood: a prospective cohort study

BACKGROUND

Although studies showed that an adverse intrauterine environment increases the obesity risk in adulthood, little is known about consequences of fetal growth and birth size for eating behaviour. We examined whether fetal and birth size are associated with childhood eating behaviour.

METHODS

Participants were 4350 mother-child dyads of the prospective cohort study Generation R. We assessed the relation between fetal and birth size measurements with child eating behaviour at age 4 years by maternal report on the Child Eating Behaviour Questionnaire. Child body mass index (BMI) was measured at age 2 years.

RESULTS

Per one standard deviation (SD) larger birthweight, children scored lower on Satiety Responsiveness [-0.29 points; 95% confidence interval (CI): -0.39; -0.18], higher on Food Responsiveness (0.28 points; 95% CI: 0.17; 0.39) and on Enjoyment of Food (0.21 points; 95% CI: 0.12; 0.31) at age 4 years. Similar associations were found in late pregnancy. Per one SD increase in fetal growth from late pregnancy to birth, children scored lower on Satiety Responsiveness (-0.15 points; 95% CI: -0.26; -0.04). Children within the 10% highest birthweight scored higher on food approach and lower on food avoidant scales, whereas associations in children within the 10% lowest birthweights were absent. Although child BMI partly mediated the association, direct effects of birthweight on appetitive traits remained.

CONCLUSIONS

This study indicates that fetal size, especially being large in utero, is associated with obesity-inducing eating behaviour. Our findings point to intrauterine influences on appetite and satiety, and contribute to understanding the complex aetiology of obesity.

Role of omega-6 and omega-3 fatty acids in fetal programming

Maternal nutrition plays a critical role in fetal development and can influence adult onset of disease. Linoleic acid (LA) and alpha-linolenic acid (ALA) are major omega-6 (n-6) and n-3 polyunsaturated fatty acids (PUFA), respectively, that are essential in our diet. LA and ALA are critical for the development of the fetal neurological and immune systems. However, in recent years, the consumption of n-6 PUFA has increased gradually worldwide, and elevated n-6 PUFA consumption may be harmful to human health. Consumption of diets with high levels of n-6 PUFA before or during pregnancy may have detrimental effects on fetal development and may influence overall health of offspring in adulthood. This review discusses the role of n-6 PUFA in fetal programming, the importance of a balance between n-6 and n-3 PUFAs in the maternal diet, and the need of further animal models and human studies that critically evaluate both n-6 and n-3 PUFA contents in diets.

The effect of high maternal linoleic acid on endocannabinoid signalling in rodent hearts

The endocannabinoid system (ECS), modulated by metabolites of linoleic acid (LA), is important in regulating cardiovascular function. In pregnancy, LA is vital for foetal development. We investigated the effects of elevated LA in H9c2 cardiomyoblasts in vitro and of a high linoleic acid (HLA, 6.21%) or low linoleic acid (LLA, 1.44%) diet during pregnancy in maternal and offspring hearts. H9c2 cell viability was reduced following LA exposure at concentrations between 300 and 1000 µM. HLA diet decreased cannabinoid receptor type 2 (CB2) mRNA expression in foetal hearts from both sexes. However, HLA diet increased CB2 expression in maternal hearts. The mRNA expression of fatty acid amide hydrolase (FAAH) in foetal hearts was higher in females than in males irrespective of diet and N-acyl phosphatidylethanolamine-specific phospholipase D (NAPE-PLD) mRNA expression showed an interaction between diet and sex. Data indicate that a high LA diet alters cell viability and CB2 expression, potentially influencing cardiac function during pregnancy and development of the offspring's heart.

Altered immune system in offspring of rat maternal vertical sleeve gastrectomy

Obesity in women results in reduced fertility and increased complications during pregnancy. Vertical sleeve gastrectomy (VSG) effectively reduces weight, type 2 diabetes, and dyslipidemia, but is also associated with preterm and small-for-gestational age births. The mechanism by which VSG influences fetal development remains unknown. Here we hypothesize that previously reported immune changes during rat VSG pregnancy are reflected long term in the immune system of the offspring. Offspring of VSG and sham dams were evaluated at postnatal day (PND) 21 and PND60. At PND21, VSG pups have lower numbers of circulating B lymphocytes compared with sham pups (P < 0.05) and have lower transcription of lymphocyte marker Ptprc (P < 0.01) in the spleen, while other lymphocyte populations measured are not different. Total plasma IgG is higher (P < 0.01) and C-reactive protein is lower (P < 0.05) in VSG offspring compared with sham offspring at PND21. The central nervous system of VSG pups is also affected at PND21, having higher expression of Il1b mRNA (P < 0.05) and higher immunoreactivity of microglia marker, IBA1, in the hypothalamus. At PND60, the immune-hematological differences are not present; however, mRNA expression of Il1b is elevated (P < 0.001) in the spleen of VSG offspring along with markers of T cells. These data suggest that the immune system of VSG offspring is compromised early in life, but rebounds after weaning and may even become hyperactive. Future work is needed to determine whether the immune system of VSG offspring is capable of mounting a proper defense and whether other aspects of development are affected.

Sex-specific effects of leptin administration to pregnant mice on the placentae and the metabolic phenotypes of offspring

Obesity during pregnancy has been shown to increase the risk of metabolic diseases in the offspring. However, the factors within the maternal milieu which affect offspring phenotypes and the underlying mechanisms remain unknown. The adipocyte hormone leptin plays a key role in regulating energy homeostasis and is known to participate in sex‐specific developmental programming. To examine the action of leptin on fetal growth, placental gene expression and postnatal offspring metabolism, we injected C57BL mice with leptin or saline on gestational day 12 and then measured body weights (BWs) of offspring fed on a standard or obesogenic diet, as well as mRNA expression levels of insulin‐like growth factors and glucose and amino acid transporters. Male and female offspring born to leptin‐treated mothers exhibited growth retardation before and a growth surge after weaning. Mature male offspring, but not female offspring, exhibited increased BWs on a standard diet. Leptin administration prevented the development of hyperglycaemia in the obese offspring of both sexes. The placentas of the male and female foetuses differed in size and gene expression, and leptin injection decreased the fetal weights of both sexes, the placental weights of the male foetuses and placental gene expression of the GLUT1 glucose transporter in female foetuses. The data suggest that mid‐pregnancy is an ontogenetic window for the sex‐specific programming effects of leptin, and these effects may be exerted via fetal sex‐specific placental responses to leptin administration.

Maternal serum and cord blood leptin concentrations at delivery

Introduction

Studies have demonstrated leptin involvement in the physiology and pathophysiology of pregnancy and suggest that leptin may be a prognostic marker for some complications of pregnancy although the association remains unclear. To date no studies have reported leptin reference intervals established in normal pregnancy, which could be used for interpreting the differences in leptin levels found in normal and pathological pregnancies.

Objective

To determine leptin concentrations at delivery, in maternal serum in normal pregnancy and in cord blood and to establish reference intervals for leptin.

Material and methods

The study was performed in 194 pregnant women without any comorbid health conditions. Leptin concentrations in maternal serum and in cord blood were measured by ELISA and subsequently analyzed by gestational age (weeks), maternal Body Mass Index (BMI), mode of delivery and infant gender and birth weight. For comparative analyses of normally distributed variables, parametric tests such as the Student–t were used to test the assumption of homogeneity or non-homogeneity of variance and a One-Way ANOVA when more than two groups were compared. The Pearson correlation coefficient was calculated to assess the correlation between normally distributed variables (p<0.05). The reference intervals for leptin were obtained by referring to the central 95% of laboratory test values.

Results

In normal pregnant women, the mean serum leptin concentration at delivery was 37.17 ± 28.07 ng/mL and the established reference interval was 33.19–41.14 ng/mL. The mean leptin concentration in cord blood was 14.78 ± 15.97 ng/mL and the established reference interval was 12.32–17.67 ng/mL. There was a statistically significant positive correlation between maternal serum and cord blood leptin concentrations (r = 0.37; p = 0.00). Mean leptin concentrations in cord blood increased with gestational age (p = 0.00). No statistically significant differences in maternal serum and cord blood leptin concentrations were found in regard to mode of delivery and neonatal gender. A statistically significant correlation was found between maternal serum leptin and third-trimester BMI (r = 0.22; p = 0.00), but there was no association between maternal BMI and cord blood leptin concentration. There was a statistically significant positive correlation between cord blood leptin concentration and birth weight (r = 0.23; p = 0.00).

Conclusions

Reference intervals for leptin in maternal serum and in cord blood established in normal pregnancy could be used in clinical practice for interpreting the differences in leptin concentrations found in normal pregnancy and in complications of pregnancy. The results indicate a strong association between maternal serum leptin levels and obesity and between cord blood leptin levels and birth weight.

Genetic variation, intrauterine growth, and adverse pregnancy conditions predict leptin gene DNA methylation in blood at birth and 12 months of age

BACKGROUND

Leptin regulates satiety and energy homoeostasis, and plays a key role in placentation in pregnancy. Previous studies have demonstrated regulation of leptin gene (LEP) expression and/or methylation in placenta and cord blood in association with early life exposures, but most have been small and have not considered the influence of genetic variation. Here, we investigated the relationship between maternal factors in pregnancy, infant anthropometry and LEP genetic variation with LEP promoter methylation at birth and 12 months of age.

METHODS

LEP methylation was measured in cord (n = 877) and 12-month (n = 734) blood in the Barwon Infant Study, a population-based pre-birth cohort. Infant adiposity at birth and 12-months was measured as triceps and subscapular skinfold thickness. Cross-sectional regression tested associations of methylation with pregnancy and anthropometry measures, while longitudinal regression tested if birth anthropometry predicted 12-month LEP methylation levels.

RESULTS

Male infants had lower LEP methylation in cord blood (-2.07% average methylation, 95% CI (-2.92, -1.22), p < 0.001). Genetic variation strongly influenced DNA methylation at a single CpG site, which was also negatively associated with birth weight (r = -0.10, p = 0.003). Pre-eclampsia was associated with lower cord blood methylation at another CpG site (-6.06%, 95% CI (-10.70, -1.42), p = 0.01). Gestational diabetes was more modestly associated with methylation at two other CpG units. Adiposity at birth was associated with 12-month LEP methylation, modified by rs41457646 genotype. There was no association of LEP methylation with 12-month anthropometric measures.

CONCLUSIONS

Infant sex, weight, genetic variation, and exposure to pre-eclampsia and gestational diabetes, are associated with LEP methylation in cord blood. Infant adiposity at birth predicts 12-month blood LEP methylation in a genotype-dependent manner. These findings are consistent with genetics and anthropometry driving altered LEP epigenetic profile and expression in infancy. Further work is required to confirm this and to determine the long-term impact of altered LEP methylation on health.

Neonatal Adipocytokines and Longitudinal Patterns of Childhood Growth

OBJECTIVE

Adipocytokines are markers of fetal metabolism, but their association with childhood growth is unclear. This study examined associations of neonatal adipocytokines with longitudinal childhood adiposity measures in a prospective cohort of pregnant women and their children.

METHODS

Leptin and adiponectin concentrations at delivery and children's BMI z scores between age 4 weeks and 8 years were measured. Differences in BMI z scores and rates of BMI z score change by leptin (n = 257) and adiponectin (n = 271) terciles were estimated.

RESULTS

Children in the middle (mean difference: 0.2; 95% CI: -0.1 to 0.4) and highest (0.4; 95% CI: 0.1 to 0.6) leptin terciles had greater BMI z scores than children in the lowest tercile. Associations were null after adjustment for birth weight z score. Children in the lowest adiponectin tercile had greater gains in BMI z score (change per year: 0.10; 95% CI: 0.08 to 0.13) than children in the middle (0.07; 95% CI: 0.04 to 0.09) and highest terciles (0.04; 95% CI: -0.01 to 0.05) (adiponectin × age interaction P < 0.001).

CONCLUSIONS

Lower adiponectin levels were associated with increased rates of BMI gains in the first 8 years of life. Though leptin was positively associated with BMI, this association may be confounded by birth weight.

Has the adipokine profile an influence on the catch-up growth type in small for gestational age infants?

Infants born small for gestational age (SGA) are at increased risk of perinatal morbidity, persistent short stature, and metabolic alterations in later life. Moreover, the post-natal growth pattern of SGA infants may be an important contributor to health outcomes later in life, which can be influenced by adipokines. The aims of this study were to compare plasma adipokine profiles (leptin, adiponectin, vaspin, chemerin, and nephroblastoma overexpressed (NOV/CCN3)) among SGA newborns aged 3 months, with low, normal, or high catch-up, to search for potential differences between males and females and to analyze the evolution of several adipokines in plasma from SGA newborns between 3 and 24 months. This prospective, longitudinal study was addressed in SGA Caucasian subjects at Hospital Universitario de Álava-Txagorritxu. We observed that infants with fast catch-up showed significantly lower birth weight than the other two groups. As far as adipokines are concerned, they could have an influence on catch-up type because differences among the three experimental groups were found. It may be proposed that health prognoses in infants with slow and fast catch-up are opposite, not only in adulthood but also during their first months. Finally, adipokine evolution patterns during the first 24 months of age differ, depending on the adipokine, and 24-month-old males show lower levels of leptin, adiponectin, and omentin than females.

Elevated maternal linoleic acid reduces circulating leptin concentrations, cholesterol levels and male fetal survival in a rat model

KEY POINTS

Linoleic acid consumption is increasing in Western populations. We investigated whether elevated linoleic acid in pregnancy was deleterious to mothers or offspring. Maternal and fetal body and organ weights were not affected by elevated linoleic acid consumption. Maternal lipids and leptin were altered following elevated linoleic acid consumption. Male offspring numbers were reduced following elevated linoleic acid consumption.

ABSTRACT

Dietary intakes of linoleic acid (LA) have increased dramatically in Western populations, including in women of reproductive age. Pro-inflammatory effects of LA may have detrimental effects on maternal and offspring outcomes. We aimed to investigate whether consumption of a maternal diet with elevated LA altered maternal inflammatory or metabolic markers during pregnancy, fetal growth and/or the sex ratio of the offspring. Female Wistar Kyoto rats consumed a diet high in LA (HLA) (6.21% of energy) or a diet low in LA (LLA) (1.44% of energy) for 10 weeks prior to mating and during pregnancy. Pregnant rats were killed at embryonic day 20 (E20). There were no differences in maternal or fetal body weights or organ weights in the HLA group compared to the LLA group. There was no difference in maternal circulating cytokine concentrations between dietary groups. In the maternal liver, IL-1α concentrations were significantly lower, and TNF-α and IL-7 significantly higher in the HLA group. Total plasma cholesterol, LDL-cholesterol, HDL cholesterol and the total:HDL cholesterol ratio were lower in dams fed the HLA diet. mRNA expression of sterol regulatory element binding transcription factor 1 (SREBF-1) and leptin in maternal adipose tissue was lower in the HLA group, as were circulating leptin concentrations. The proportion of male fetuses was lower and circulating prostaglandin E metabolite concentrations were increased in the HLA group. In conclusion, consumption of a maternal diet high in linoleic acid alters cholesterol metabolism and prostaglandin E metabolite concentrations, which may contribute to the reduced proportion of male offspring.

Maternal blood leptin concentration in small for gestational age: a meta-analysis

Monitoring leptin concentration in maternal blood would be useful for earlier identification of mothers at risk of delivering small for gestational age (SGA) neonates. This study was performed to examine whether maternal blood leptin concentrations are different between SGA neonates and healthy controls. Meta-analysis was performed to summarize the data of all English-language studies providing the numbers of SGA neonates, the numbers of healthy controls, and the means and standard deviations of maternal blood leptin concentrations in these two groups. The studies were collected by searching ten databases including PubMed (MEDLINE) and investigating the PubMed Related Citations and bibliographic references. The Newcastle-Ottawa Scale was used to assess study quality. Publication bias was assessed using Egger's test. The primary outcome of this study was the standardized mean difference (SMD) in maternal blood leptin concentration between SGA neonates and healthy controls. Thirty-two overall good-quality studies involving 1734 women and their neonates were extracted from 17 articles. Synthetic evidence did not indicate statistically significant SMD in maternal blood leptin concentration between SGA neonates and healthy controls (P = 0.172). Egger's test showed no publication bias (P = 0.309).Conclusion: Maternal blood leptin concentration is not significantly different between SGA neonates and healthy controls. What is Known: • Monitoring leptin concentration in maternal blood would be useful for earlier identification of mothers at risk of delivering small for gestational age (SGA) neonates. What is New: • The results of this meta-analysis including 1734 women and their neonates in 32 overall good-quality studies showed that maternal blood leptin concentration is not significantly different between SGA neonates and healthy controls.

miRNAs, target genes expression and morphological analysis on the heart in gestational protein-restricted offspring

Gestational protein restriction was associated with low birth weight, hypertension and higher prevalence of cardiac disorders in adults. Several mechanisms, including epigenetics, could be related with the cardiovascular phenotype on protein-restricted offspring. Thus, we investigated the morphological cardiac effects of gestational protein restriction and left ventricle miRNAs and target genes expression pattern in both 12-day and 16-week old gestational protein-restricted male offspring. Pregnant Wistar rats were allocated into two groups, according to protein supply during pregnancy: NP (normal protein diet- 17%) or LP (low protein diet-6%). Dams on the gestational protein-restricted diet had lower body weight gain and higher food intake. Gestational protein-restricted offspring had low birth weight, followed by rapidly body weight recovery, hypertension, and increased myocytes cross-sectional area and collagen fraction at 16-week old age. At 12-days old, miR-184, miR-192, miR-376c, miR-380-3p, miR-380-5p, miR-451, and miR-582-3p had increased expression, and miR-547 and miR-743a had decreased expression in the gestational protein-restricted left ventricle. At 16-week old, let-7b, miR-125a-3p, miR-142-3p, miR-182 and miR-188-5p had increased expression and let-7g, miR-107, miR-127, miR-181a, miR-181c, miR-184, miR-324-5p, miR-383, miR-423-5p and miR-484 had decreased expression in gestational protein-restricted left ventricle. Target predicted gene expression analysis showed higher expression of Dnmt3a, Oxct1, Rictor and Trps1 and lower expression of Bbs1 and Calml3 in 12-day old protein-restricted offspring. 16-week old protein-restricted offspring had higher expression of Adrbk1, Bbs1, Dnmt3a, Gpr22, Inppl1, and Oxct1 genes. In conclusion, gestational protein restriction was related to offspring low birth weight, increased systolic blood pressure and morphological heart alterations that could be related to early heart miRNA expression changes that perpetuate into adulthood and which are associated with the regulation of essential genes involved in cardiovascular development, heart morphology, function, and metabolism.

Obesity Disrupts Rhythmic Clock Gene Expression in Maternal Adipose Tissue during Rat Pregnancy

Obesity during pregnancy causes numerous maternal and fetal health complications, but the underlying mechanisms remain unclear. Adipose tissue dysfunction in obesity has previously been linked to disruption of the intrinsic adipose clock gene network that is crucial for normal metabolic function. This adipose clock also undergoes major change as part of the maternal metabolic adaptation to pregnancy, but whether this is affected by maternal obesity is unknown. Consequently, in this study we tested the hypothesis that obesity disturbs rhythmic gene expression in maternal adipose tissue across pregnancy. A rat model of maternal obesity was established by cafeteria (CAF) feeding, and adipose expression of clock genes and associated nuclear receptors ( Ppars and Pgc1α) was measured across days 15-16 and 21-22 of gestation (term = 23 days). CAF feeding suppressed the mesor and/or amplitude of adipose tissue clock genes (most notably Bmal1, Per2, and Rev-erbα) relative to chow-fed controls (CON) across both days of gestation. On day 15, the CAF diet also induced adipose Pparα, Pparδ, and Pgc1α rhythmicity but repressed that of Pparγ, while expression of Pparα, Pparδ, and Pgc1α was reduced at select time points. CAF mothers were hyperleptinemic at both stages of gestation, and at day 21 this effect was time-of-day dependent. Fetal plasma leptin exhibited clear rhythmicity, albeit with low amplitude, but interestingly these levels were unaffected by CAF feeding. Our data show that maternal obesity disrupts rhythmic expression of clock and metabolic genes in maternal adipose tissue and leads to maternal but not fetal hyperleptinemia.

A novel leptin receptor antagonist uncouples leptin's metabolic and immune functions

Leptin links body energy stores to high energy demanding processes like reproduction and immunity. Based on leptin's role in autoimmune diseases and cancer, several leptin and leptin receptor (LR) antagonists have been developed, but these intrinsically lead to unwanted weight gain. Here, we report on the uncoupling of leptin's metabolic and immune functions based on the cross talk with the epidermal growth factor receptor (EGFR). We show that both receptors spontaneously interact and, remarkably, that this complex can partially overrule the lack of LR activation by a leptin antagonistic mutein. Moreover, this leptin mutant induces EGFR phosphorylation comparable to wild-type leptin. Exploiting this non-canonical leptin signalling pathway, we identified a camelid single-domain antibody that selectively inhibits this LR-EGFR cross talk without interfering with homotypic LR signalling. Administration in vivo showed that this single-domain antibody did not interfere with leptin's metabolic functions, but could reverse the leptin-driven protection against starvation-induced thymic and splenic atrophy. These findings offer new opportunities for the design and clinical application of selective leptin and LR antagonists that avoid unwanted metabolic side effects.

Prenatal stress and models explaining risk for psychopathology revisited: Generic vulnerability and divergent pathways

The present review revisits three hypothesized models that potentially could explain how prenatal maternal stress influences fetal development, birth outcomes, and subsequent developmental psychopathology. These models were mostly based on animal models, and new evidence for these models from human studies is evaluated. Furthermore, divergent trajectories from prenatal exposure to adversities to offspring affected outcomes are reviewed, including the comparison of studies on prenatal maternal stress with research on maternal substance use and maternal malnutrition during pregnancy. Finally, new directions in research on the mechanism underlying prenatal stress effects on human offspring is summarized. While it is concluded that there is abundant evidence for the negative associations between prenatal maternal stress and offspring behavioral, brain, and psychopathological outcomes in humans, there is no consistent evidence for specific mechanisms or specific outcomes in relation to stress exposure in utero. Rather, principles of multifinality and equifinality best describe the consequences for the offspring, suggesting a generic vulnerability and different pathways from prenatal adversities to developmental psychopathology, which complicates the search for underlying mechanisms. New and promising directions for research are provided to get a better understanding of how prenatal stress gets under the skin to affect fetal development.

Impact of maternal pre-pregnancy overweight on infant overweight at 1 year of age: associations and sex-specific differences

BACKGROUND

Maternal overweight or obesity (OWOB) is linked to gestational diabetes, fetal macrosomia and higher rates of caesarean delivery.

OBJECTIVES

The study aims to assess whether maternal pre-pregnancy OWOB is associated with infant overweight in a sex-dependent manner, independent of microbiota-altering variables.

METHODS

Weight and length measurements of 955 mother-infant pairs were obtained from the Canadian Healthy Infant Longitudinal Development cohort. Maternal pre-pregnancy weight was defined as follows: normal, overweight (25 ≤ body mass index < 30) and obese (body mass index ≥ 30). Age and sex-adjusted weight-for-length z-scores >97th percentile were classified as infant overweight at age 1 year. Associations between pre-pregnancy and infant overweight were determined by linear and logistic regression, adjusting for covariates.

RESULTS

Maternal pre-pregnancy OWOB were associated with infant weight-for-length and overweight risk at 1 year. Except for pre-pregnancy obesity, these associations were not attenuated appreciably after adjustment for birth mode, exclusivity of breastfeeding, exposure to antibiotics and infant sex. Yet only boys born to mothers with obesity were three times more likely to become overweight at age 1 independent of microbiota-altering variables. Pre-pregnancy obesity was associated with weight-for-length in male and female infants.

CONCLUSIONS

Maternal pre-pregnancy OWOB increases the risk of infant overweight, and this association is more evident in male infants.

Serum adipokine levels and insulin resistance in the first trimester of pregnancy in adolescents and their relationship with neonatal weight

Introduction: The approach to the physiology of pregnancy based on adipokine behavior and the homeostasis-insulin resistance (HOMA-IR) model, along with their relationship to neonatal weight, has been poorly studied in adolescent pregnant women. Objective: To determine possible correlations between adipokines –leptin and adiponectin– and HOMA-IR in pregnant women aged 14 to 17 years, and first-trimester body mass index (BMI) and neonatal weight. Materials and methods: In the weeks 11 to 14 of gestation, the biochemical variables leptin, adiponectin, glycemia and insulin were measured and HOMA-IR was calculated. Maternal and neonatal anthropometric variables were obtained. Statistical analysis was performed with Pearson correlation and the p value. Results: We noticed a positive correlation of serum leptin levels with HOMA-IR in the first trimester of gestation (r=0.5, p≤0.000) and a negative correlation between adiponectin and HOMA-IR (r=-0.4; p=0.017), along with positive correlations between BMI and leptin, insulin and HOMA-IR (r=0.83 and p <0.000, r=0.56 and p≤0.000; r=0.54 and p≤0.000, respectively). In adolescent non-obese mothers with no history of dyslipidemia, there was a positive correlation between HOMA-IR and neonatal weight (r=0.43, p=0.012). Conclusions: Leptin and HOMA-IR showed a positive correlation, while adiponectin and HOMA-IR showed a negative correlation. Leptin and HOMA-IR were positively correlated with BMI. HOMA-IR correlated with the weight of neonates of non-obese adolescents without dyslipidemia.