Meconium Transferrin and Ferritin as Markers of Homeostasis in the Developing Fetus

The molecular mechanisms regulating homeostasis in the developing fetus have not been satisfactorily elucidated. Meconium contains substances accumulated in the fetal intestines. Measurements of transferrin and ferritin concentrations in meconium and assessment of transferrin-ferritin relationships could enhance knowledge about specific processes of the intrauterine period involving the two proteins and their effects on the development and growth of the fetus. Transferrin and ferritin concentrations were measured by ELISA in the homogenates of first meconium portions from 125 neonates. Higher birth weight was associated with lower ferritin concentrations in meconium (r = -0.22, p = 0.015). In neonates with a birth weight of more than 3750 g, there was a positive correlation between transferrin and ferritin concentrations (r = 0.51, p = 0.003). With meconium transferrin concentrations above 43.52 µg/g, a negative correlation between transferrin and ferritin was established (r = -0.37, p = 0.036), while with transferrin concentrations below 43.52 µg/g, the correlations between the birth weight and the meconium transferrin and ferritin concentrations were negative (r = -0.61, p < 0.001 and r = -0.43, p = 0.017, respectively). Measurements of transferrin and ferritin in meconium specimens create a new use for these common biomarkers to improve our understanding of the effects of homeostasis in utero on the fetal development and growth. Establishing reference ranges of meconium transferrin and ferritin concentrations and their association with the clinical parameters during pregnancy could aid in the assessment of the impact of intrauterine life on the health status of the neonate and its adaptation to extrauterine life.

Maternal and fetal origins of offspring blood pressure: statistical analysis using genetic correlation and genetic risk score-based Mendelian randomization

BACKGROUND

Epidemiological studies demonstrated that adverse in utero environment was associated with increased risk of offspring high blood pressure, by using birthweight as the proxy of maternal intrauterine exposure; however, the nature of such association remains less understood.

METHODS

With maternal/fetal-specific summary statistics of birthweight (n = 297 356 for own birthweight and n = 210 248 for offspring birthweight) and summary statistics of blood pressure [i.e. systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP)] (n = 757 601), we evaluated the genetic correlation between fetal-specific birthweight and blood pressure using cross-trait linkage disequilibrium score regression, and next detected pleiotropic genes for them with a pleiotropy mapping method called mixture-adjusted intersect-union pleiotropy test. Furthermore, we conducted a genetic risk score (GRS)-based Mendelian randomization analysis in parent-offspring pairs (n = 6031) of the UK Biobank cohort, to assess the causal relation between maternal-specific GRS and blood pressure conditioning on fetal genotypes.

RESULTS

We found fetal-specific birthweight had a negative genetic correlation with DBP (ρ^g = -0.174, P = 1.68 × 10-10), SBP (ρ^g = -0.198, P = 8.09 × 10-12), and PP (ρ^g = -0.152, P = 6.04 × 10-8), and detected 143, 137 and 135 pleiotropic genes shared between fetal-specific birthweight and PP, SBP and DBP, respectively. These genes often exhibited opposite genetic effects, and were more likely to be differentially expressed in pancreas, liver, heart, brain, whole blood and muscle skeletal tissues. A causal negative association of maternal-specific birthweight was identified with SBP (P = 2.20 × 10-2) and PP (P = 7.67 × 10-3) but not DBP (P = 0.396) in mother-offspring pairs, after accounting for the influence of fetal-specific GRS; and the two significant relations were robust against the horizontal pleiotropy of instruments and the confounding influence of gestational duration and preterm birth. However, these causal associations could not be detected in father-offspring pairs.

CONCLUSIONS

This study revealed common genetic components underlying birthweight and blood pressure, and provided important insight into aetiology and early prevention of high blood pressure.

Pre- and Postnatal Determinants Shaping the Microbiome of the Newborn in the Opinion of Pregnant Women from Silesia (Poland)

Pre- and postnatal factors influence the formation of the newborn's microbiome as early as birth and the intrauterine period has a substantial impact on the composition of the baby's gastrointestinal microbiota and its subsequent development. This study intends to measure pregnant women's knowledge of the importance of microbiota for the health of the newborn. The sample was selected based on defined inclusion and exclusion criteria. The assessment of women's knowledge was assessed by the Kolmogorov-Smirnov and Kruskal-Wallis statistical tests. This study population comprised 291 adult pregnant women with a mean age of 28.4 ± 4.7 years. A total of 34% (n = 99), 35% (n = 101), and 31.3% (n = 91) were at the 1-3 trimester, respectively. The results showed that 36.4% of the women were aware that the intrauterine period changes the makeup of the gastrointestinal microbiota, whereas 5.8% exhibited awareness of the composition of the child's normal gut microbiota. Most of the women surveyed-(72.1%)-know that colonization of the tract occurs as early as the birth period. Women with student status (those who will pursue higher education in the future) and those who had given birth to the most children exhibited higher levels of knowledge.

Development of pups born to rats established as a model of underweight Japanese women and the onset of impaired glucose tolerance

An increasing number of Japanese women of childbearing age are underweight (BMI <18.5), but the association between this and the increased number of low-birth-weight babies born remains unclear. Here, a rat model was established to mimic the undernutrition (85% of the energy required for those with normal activity levels) experienced by such women and to evaluate the associated impaired glucose tolerance. The undernourished Wistar rat group showed increased serum corticosterone level reflecting stress, and greater adrenal weight and size. It also showed greater insulin resistance, higher expression of FOXO-1, a transcription factor related to muscle atrophy, and lower expression of p-Akt, an insulin-dependent signaling factor. Overall, this work shows the key role of undernutrition during pregnancy as a cause of impaired glucose tolerance and increased diabetes risk in offspring. The findings of this study may inform preemptive measures to prevent the development of metabolic syndrome in offspring of undernourished mothers.

Is birthweight influenced equally by maternal and paternal anthropometry?

OBJECTIVES

To elucidate the influence of parental biometric factors on fetal birthweight (BW).

STUDY DESIGN

This prospective study was conducted between 2015 and 2017 in Hadassah University Hospital. Inclusion criteria included singletons that were born to healthy mothers at 37-41 weeks' gestation and had no growth abnormality or congenital malformation. Maternal and paternal head circumference, weight, and height were measured. Other data including neonatal head circumference and neonatal birthweight were also collected. Neonatal head circumference and birthweight percentiles were converted to sex-specific ranks according to the neonatal Intergrowth 21 charts (rank = 1 for percentile <3, rank = 2 for percentile 3-10, etc.).

RESULTS

One hundred and ninety-nine trios (mother, father, and neonate) were included in the final analysis. In univariate analysis, maternal head circumference (p = .006), maternal height (p = .001), maternal weight before pregnancy (p < .001), maternal weight at term (p < .001), gestational weight gain (p = .009), paternal height (p = .018), neonatal head circumference (p < .001), and neonatal head circumference percentile rank (p < .001) were significant predictors of neonatal birthweight percentile rank. In multivariate regression, the three factors that were significant independent predictors of neonatal birthweight percentile rank were maternal weight before pregnancy (p = .047), maternal weight at term (p = .01), and neonatal head circumference percentile rank (p < .001). No interaction was found between neonatal sex and any of the tested variables. Neonatal sex-specific multivariate analysis showed that maternal height (p = .013), gestational weight gain (p = .005), and neonatal head circumference percentile rank (p < .001) were predictors of birthweight percentile rank in males. Maternal weight at term (p < .001) and neonatal head circumference percentile rank (p < .001) were predictors of birthweight percentile rank in females.

CONCLUSIONS

Maternal height and weight parameters as well as neonatal head circumference percentile rank were found to be independent predictors of birthweight percentile rank. Paternal parameters did not show any significant association in multivariable analysis. The biological regulation of fetal size is assumed to be the result of strong evolutionary selection. As the fetus must pass through the mother's birth canal, there should be a natural match between maternal and fetal size to ensure the successful birth and survival of mother and offspring.

The jury is still out on the existence of a placental microbiome

The human microbiome is crucial for regulating normal development, but the exact point when it is established remains unknown. A sterile placenta was traditionally considered a prerequisite for a healthy pregnancy, but studies have revealed that the placenta harbours microbial communities, even under normal conditions. However, reports have failed to provide evidence for the consistent presence of bacteria in the normal human placenta, challenging the in utero colonisation hypothesis. This mini review examines our understanding of the potential placental microbial colonisation in normal healthy pregnancies. This may impact the metabolic and immune functions of the growing foetus and have long-term consequences.

Increasing mTORC1 Pathway Activity or Methionine Supplementation during Pregnancy Reverses the Negative Effect of Maternal Malnutrition on the Developing Kidney

BACKGROUND

Low nephron number at birth is associated with a high risk of CKD in adulthood because nephrogenesis is completed in utero. Poor intrauterine environment impairs nephron endowment via an undefined molecular mechanism. A calorie-restricted diet (CRD) mouse model examined the effect of malnutrition during pregnancy on nephron progenitor cells (NPCs).

METHODS

Daily caloric intake was reduced by 30% during pregnancy. mRNA expression, the cell cycle, and metabolic activity were evaluated in sorted Six2 NPCs. The results were validated using transgenic mice, oral nutrient supplementation, and organ cultures.

RESULTS

Maternal CRD is associated with low nephron number in offspring, compromising kidney function at an older age. RNA-seq identified cell cycle regulators and the mTORC1 pathway, among other pathways, that maternal malnutrition in NPCs modifies. Metabolomics analysis of NPCs singled out the methionine pathway as crucial for NPC proliferation and maintenance. Methionine deprivation reduced NPC proliferation and lowered NPC number per tip in embryonic kidney cultures, with rescue from methionine metabolite supplementation. Importantly, in vivo, the negative effect of caloric restriction on nephrogenesis was prevented by adding methionine to the otherwise restricted diet during pregnancy or by removing one Tsc1 allele in NPCs.

CONCLUSIONS

These findings show that mTORC1 signaling and methionine metabolism are central to the cellular and metabolic effects of malnutrition during pregnancy on NPCs, contributing to nephrogenesis and later, to kidney health in adulthood.

Significance and effects of prenatal and postnatal microbiome in the period of early individual development and options for interventional treatment

Összefoglaló. A humán mikrobiom az emberi szervezetben és az emberi testfelszínen élő mikrobaközösségek összessége, amelyek többsége a gyomor-bél rendszerben él. Ezek a mikrobaközösségek számos és sokféle baktériumot tartalmaznak, gombákat, vírusokat, archeákat és protozoonokat. Ez a mikrobiális közösség, vagy mikrobiota, a gazdaszervezetben nagyrészt egymással kölcsönösségi viszonyban tenyészik, és gondoskodik a bélben a tápanyagok anyagcseréjéről, kalibrálja az anyagcsere-működést, tanítja az immunrendszert, fenntartja a közösség integritását, és véd a kórokozók ellen. A majdan megszületendő magzat a megfelelő tápanyagellátását az anyai véráramból kapja, és így az anyai szervezetben a mikrobiota indukálta baktériumkomponensek vagy metabolitok hatékonyan átvihetők a magzatba. Az anyai mikrobiális közösségek - ideértve a praenatalis bélrendszeri, hüvelyi, száj- és bőrmikrobiomot - a terhesség alatt valójában kifejezett változásokon mennek keresztül, amelyek befolyásolhatják az egészség megőrzését, és hozzájárulhatnak a közismert betegségek kialakulásához. A magzat nem steril, és immunológiai szempontból sem naiv, hanem az anya révén környezeti ingerek hatásaitól befolyásolva kölcsönhatásba lép az anyai immunrendszerrel. Számos anyai tényező - beleértve a hormonokat, a citokineket és a mikrobiomot - módosíthatja az intrauterin környezetet, ezáltal befolyásolva a magzati immunrendszer fejlődését. A fokozott stresszben élő anyák csecsemőinél nagyobb az allergia és a gyomor-bél rendszeri rendellenességek aránya. A várandós étrendje is befolyásolja a magzati mikrobiomot a méh közvetítésével. A bélflóránk, vagyis a mikrobiom, a belünkben élő mikrobák összessége és szimbiózisa, amelynek kényes egyensúlya már csecsemőkorban kialakul, és döntően meghatározza az intestinalis barrier és a bélasszociált immunrendszer működését. A probiotikumok szaporodásához szükséges prebiotikummal is befolyásolható a bélflóra. A pre- és a probiotikum kombinációja a szimbiotikum. Az anyatej a patogénekkel szemben protektív hatású, részben azáltal, hogy emeli a Bifidobacterium-számot az újszülött bélflórájában. A dysbiosis a kommenzális, egészséges bélflóra megváltozása. Ennek szerepét feltételezik funkcionális gastrointestinalis kórképekben, egyre több pszichiátriai és neurológiai kórképben is, mint az autizmus-spektrumzavar. Orv Hetil. 2021; 162(19): 731-740. Summary. The human microbiome is the totality of microbe communities living in the human body and on the human body surface, most of which live in the gastrointestinal tract. These microbe communities contain many and varied bacteria, fungi, viruses, archaea and protozoa. This microbial community or microbiota in the host is largely reciprocal and takes care of nutrient metabolism in the gut, calibrates metabolism, teaches the immune system, maintains community integrity, and protects against pathogens. The fetus to be born is adequately supplied with nutrients from the maternal bloodstream, and thus microbial-induced bacterial components or metabolites can be efficiently transferred to the fetus in the maternal body. Maternal microbial communities, including prenatal intestinal, vaginal, oral, and dermal microbiomes, actually undergo pronounced changes during pregnancy that can affect health maintenance and contribute to the development of well-known diseases. The fetus is not sterile or immunologically naïve, but interacts with the maternal immune system through the effects of environmental stimuli through the mother. Many maternal factors, including hormones, cytokines, and the microbiome, can modify the intrauterine environment, thereby affecting the development of the fetal immune system. Infants of mothers under increased stress have higher rates of allergies and gastrointestinal disorders. The diet of the gravida also affects the fetal microbiome through the uterus. Our intestinal flora, or microbiome, is the totality and symbiosis of the microbes living in them, the delicate balance of which is established in infancy and decisively determines the functioning of the intestinal barrier and the intestinal associated immune system. The prebiotic required for the proliferation of probiotics can also affect the intestinal flora. The combination of pre- and probiotic is symbiotic. Breast milk has a protective effect against pathogens, in part by raising the number of Bifidobacteria in the intestinal flora of the newborn. Dysbiosis is a change in the commensal, healthy gut flora. Its role is hypothesized in functional gastrointestinal disorders, as well as in more and more psychiatric and neurological disorders such as the autism spectrum disorder. Orv Hetil. 2021; 162(19): 731-740.

Cord blood androgen levels of females from same sex and opposite sex twins - A pilot study

OBJECTIVE

Opposite-sex twins have shown behavioural and reproductive differences between females and males. These differences may be determined by higher intrauterine levels of androgens among females that were exposed to a male co-twin. The aim of this study was to compare cord blood androgen levels in females from same-sex and opposite-sex twins.

DESIGN

A prospective study. In this pilot study, we compared cord blood androgens (DHEA-S, Δ-4 androstenedione, total testosterone-TT) and sex hormone-binding globulin (SHBG) levels in 20 females from same sex and 20 females from opposite-sex dichorionic diamniotic twins. We used generalized estimating equation (GEE) modelling to assess differences in cord blood androgens between females from same-sex twin pregnancies and females from opposite-sex twin pregnancies.

PATIENTS

Twenty opposite-sex twin pairs (female-male twins) and 20 same-sex twin pairs (female-female).

MEASUREMENTS

Cord blood total testosterone, Δ-4 androstenedione, DHEA-S and sex hormone-binding globulin (SHBG) levels.

RESULTS

No difference in the levels of androgens as Δ-4 androstenedione, total testosterone and SHBG was identified between females that were exposed to a female co-twin compared with females that were exposed to a male co-twin. DHEA-S levels were significantly lower among females from opposite-sex twins compared with females from same-sex twins.

CONCLUSIONS

Our preliminary data do not support the hypothesis that females exposed to male co-twins are exposed to higher levels of androgens in utero compared with females exposed to female co-twins. Further studies are needed to explain the reported behavioural and reproductive differences among opposite-sex twins.

Pre-pregnancy obesity and childhood malignancies: A population-based cohort study

OBJECTIVE

Exploring the effect of maternal obesity during pregnancy on the long-term health of offspring is of great importance. The aim of this study was to evaluate the association between maternal pre-pregnancy obesity and future risk of childhood malignancies.

STUDY DESIGN

A population-based cohort analysis comparing the risk for long-term childhood malignancies (up to the age of 18 years) in children born (1991-2014) to mothers with and without pre-pregnancy obesity (body mass index > 30) was conducted in July 2017. Childhood malignancies were predefined based on ICD-9 codes, as recorded in the hospital medical files. Children with congenital malformations and multiple gestations were excluded from the analysis. The Kaplan-Meier survival curve was constructed to compare cumulative oncological morbidity in both groups over time. The Cox proportional hazards model was used to control for confounders.

RESULTS

During the study period, 241 273 infants met the inclusion criteria; 3268 were born to mothers with pre-pregnancy obesity. Children of obese women had significantly increased risk for several childhood malignancies (including brain tumors) as well as increased risk for total hospitalizations with malignancy diagnoses, even after controlling for several confounders (adjusted HR 1.90, 95% CI 1.07-3.37, P = 0.028). Cumulative incidence of oncological morbidity was also significantly increased over time in the studied group (log-rank P = 0.023).

CONCLUSION

Maternal pre-pregnancy obesity is significantly associated with an increased long-term risk for general childhood malignancies, and specifically brain tumors in the offspring. These results are important when counseling mothers regarding potential future risks and recommended lifestyle modifications.

Intrauterine growth restriction: screening and diagnosis using animal models

Intrauterine growth restriction (IUGR) is a serious condition of multifactorial origin, mainly caused by maternal malnutrition, multiple gestation associated with nutrient competition, abuse of nocive substances and infections. The diagnosis of such syndrome is complex, as its own manifestations can mask its occurrence, requiring a thorough assessment of body weight and size. Moreover, it is not responsive to any kind of treatment. There is evidence that IUGR may predispose the individual to several pathologies, such as diabetes, hypertension and metabolic syndrome in adulthood, and it has also been linked to thrifty phenotype hypothesis. Thus, a healthy lifestyle is needed to better prevent those pathologies. Given the world high prevalence and importance of IUGR, mainly in developing countries, this review is focused on discussing how different animal models contribute to the biological screening and diagnosis of this condition.

Pakistan Developmental Origins of Health and Disease (DOHaD) Society: addressing the 'DO' component of DOHaD

Adverse intrauterine environment could serve as an important stimulus for postnatal altered health status and for increased susceptibility to long-term non-communicable diseases (NCDs). The notion is now recognized as the Developmental Origins of Health and Disease (DOHaD), which was first proposed by Sir David Barker. Since then, several scientific disciplines have strived to measure the magnitude of the early fetal programming and later risk of diseases. Pakistan, with striking figures of morbidity and mortality from NCDs, is currently tackling with double burden of diseases and requires planned efforts to counteract the threat of NCDs. Considering the growing needs and available evidences, Pakistan DOHaD Society was officially instigated in September 2016. The Society aims to explicitly address the association of life in utero with future health and disease and to endorse early screening and interventions to reduce the burden of NCDs, mental health issues and learning disorders along the life course. It has shown significant progress toward investigating the influence of adverse in utero environment such as diabetes, maternal under-nutrition and pre-eclampsia on fetal programming under two major research lines, that is, cardiovascular and cerebrovascular programming. The Society has been successful in disseminating its research findings through several esteemed international scientific conferences. Pakistan DOHaD Society encourages scientific community for collaborative research aimed at improving the quality of life during early childhood, adolescence and adulthood through provision of appropriate pre-pregnancy and antenatal interventions targeted to address at-risk in utero conditions.

Gestational caloric restriction with micronutrients supplementation does not delay development and promotes feeding behavior benefits

Introduction: Caloric restriction (CR) has been proven to promote a series of health benefits from yeast to primates. Nowadays, increasing rates of obesity certainly encourage researchers to evaluate CR effects and establish it as a therapeutic approach. Maternal obesity is also a concern, and studies in the developmental origins of health and disease (DOHaD) have shown the importance of interventions during pregnancy, especially those involving maternal nutrition. On the other hand, undernutrition during pregnancy leads to increased weight gain, disturbed feeding behavior and dysfunctional metabolism in adulthood.Methods: In this way, we utilized moderate CR (20% compared to control consumption) in pregnant Wistar rats as intervention, with malnutrition control by micronutrients supplementation. We assessed CR effects on offspring's developmental milestones, feeding behavior, exploratory behavior, and memory on adolescence (PND21) and adulthood (PND60).Results: We did not find alterations on litter size or birth weight, although CR pups were leaner at adult ages. Importantly, no delay in development was observed. Besides, female pups showed earlier suction reflex and male pups showed earlier response to the negative geotaxis. CR pups also showed less preference for palatable food (Froot Loops®) at adult age, which could be decisive on obesity tendency. Locomotor activity was increased by CR on PND60 and there was no effect on memory at all.Discussion: Our results on development and behavior demonstrate that gestational CR may be a helpful health strategy if malnutrition is well controlled, with potential clinical impact.

Low Birth Weight and Kidney Function in Middle-Aged Men and Women: The Netherlands Epidemiology of Obesity Study

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR)<60mL/min/1.73m², is a risk factor for cardiovascular morbidity and mortality. Little is known about low birth weight and risk for CKD in middle-aged adults in the general population. We estimated the causal association between birth weight and eGFR in a Dutch cohort of middle-aged men and women.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

6,671 participants in the Netherlands Epidemiology of Obesity (NEO) Study. Replication study using data for 133,814 participants studied by the CKDGen consortium.

EXPOSURE

Birth weight was self-reported and also based on an instrumental variable, 59 birth weight-associated genetic variants, derived from an independent data source.

OUTCOME

eGFR at the age of 45 to 65 years.

ANALYTICAL APPROACH

We assessed the association between self-reported birth weight and eGFR in the NEO Study using multivariable linear regression, adjusted for age, sex, education, smoking, and alcohol use. The effect of the instrument on eGFR was estimated using separate 2-sample Mendelian randomization analyses: one using individual data from the NEO cohort and one using summary data from the CKDGen consortium.

RESULTS

At baseline, mean eGFR was 86±12.4 (SD) mL/min/1.73m². After multivariable adjustment, self-reported birth weight was not associated with kidney function in middle age. Two-sample Mendelian randomization analysis showed that in the NEO cohort, for each 500-g lower birth weight defined using genetic variants, there was a 3.7 (95% CI, 0.5-6.9)-mL/min/1.73m² lower eGFR at the age of 45 to 65 years. However, using CKDGen summary-level data, there was a smaller nonsignificant relationship between birth weight and eGFR.

LIMITATIONS

Birth weight was self-reported.

CONCLUSIONS

Lower birth weight defined using genetic variants was associated with lower eGFRs in Dutch middle-aged adults. However, this finding was not replicated within the CKDGen consortium.

Intrauterine Microbiota: Missing, or the Missing Link?

The intrauterine environment provides a key interface between the mother and the developing fetus during pregnancy, and is a target for investigating mechanisms of fetal programming. Studies have demonstrated an association between prenatal stress and neurodevelopmental disorders. The role of the intrauterine environment in mediating this effect is still being elucidated. In this review, we discuss emerging preclinical and clinical evidence suggesting the existence of microbial communities in utero. We also outline possible mechanisms of bacterial translocation to the intrauterine environment and immune responses to the presence of microbes or microbial components. Lastly, we overview the effects of intrauterine inflammation on neurodevelopment. We hypothesize that maternal gestational stress leads to disruptions in the maternal oral, gut, and vaginal microbiome that may lead to the translocation of bacteria to the intrauterine environment, eliciting an inflammatory response and resulting in deficits in neurodevelopment.

Protein and peptide profiles in neonatal meconium

AIM

The proteins accumulated in the meconium reflect the intrauterine environment and are naturally excreted by a neonate. The identification and classification of individual meconium proteins may be a valuable source of information about physiological and pathological processes in utero.

METHODS

Proteomic analysis was used to study the protein composition in pooled 50 serial meconium portions from 10 neonates. The proteins were classified based on the gene ontology database. The amounts and relative number of proteins (%) in the identified categories and their subcategories were assessed.

RESULTS

A total of 946 proteins identified in meconium, including 430 represented by two or more peptides were classified into three categories: biological process (n = 401), molecular function (n = 386) and cellular component (n = 422). The highest number of proteins (>25% of the total) was found in the subcategories: developmental processes, signaling, transport, response to stimulus, regulation, metabolic processes, ion binding, extracellular region, membrane and cytoplasm.

CONCLUSION

The composition of meconium proteins identified in this study may be a rich source of new biomarkers for use in neonatology with a potential to predict later development.

Exposure to different intrauterine environments: implications for telomere attrition in early life

Objective: Studies focusing on telomere attrition in newborns and what factors could be involved in this issue are sparse; most reports have been in adult populations. Thereby, the aim of this study was to present an overview of what is currently known about the relationship between environmental exposure of the fetus during pregnancy and telomere length outcomes in early life. Methods: The MEDLINE (via PubMed) and Bireme databases were searched for studies published until 1 June 2016. Studies that reported telomere length measurement from birth to age 1 year were included. Results: Fifteen articles were selected that evaluated possible relationships between maternal smoking, hyperglycemia, hypertension, sleep apnea, psychological stress, folate concentration in early pregnancy, and radiation, in addition to small-for-gestational-age status and preterm birth. We found that sleep apnea, psychological stress, and folate concentration in early pregnancy were associated with telomere shortening in the newborn. No association was found with radiation, small-for-gestational-age status, or preterm birth. Results for maternal smoking, hyperglycemia, and hypertension were conflicting, and further studies should be considered. Conclusion: The actual clinical implications of these findings have yet to be investigated.

Prenatal Lipopolysaccharide Exposure Promotes Dyslipidemia in the Male Offspring Rats

Inflammation is critical to the pathogenesis of cardiovascular diseases (CVDs). We have uncovered intrauterine inflammation induced by lipopolysaccharide (LPS) increases CVDs in adult offspring rats. The present study aimed to explore the role of prenatal exposure to LPS on the lipid profiles in male offspring rats and to further assess their susceptibility to high fat diet (HFD). Maternal LPS (0.79 mg/kg) exposure produced a significant increase in serum and hepatic levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, aspartate amino transferase as well as liver morphological abnormalities in 8-week-old offspring rats. Meanwhile, disturbed gene expressions involved in hepatic lipid metabolism and related signaling pathways were found, especially the up-regulated very-low density lipoprotein receptor (VLDLR) and down-regulated transmembrane 7 superfamily member 2 (TM7SF2). Following HFD treatment, however, the lipid profile shifts and liver dysfunction were exacerbated compared to the offsprings treated with prenatal LPS exposure alone. Compared with that in control offsprings, the hepatic mitochondria (Mt) in offspring rats solely treated with HFD exhibited remarkably higher ATP level, enforced Complex IV expression and a sharp reduction of its activity, whereas the offsprings from LPS-treated dams showed the loss of ATP content, diminished membrane potential, decline in protein expression and activity of mitochondrial respiratory complex IV, increased level of MtDNA deletion as well. Furthermore, treatment with HFD deteriorated these mitochondrial disorders in the prenatally LPS-exposed offspring rats. Taken together, maternal LPS exposure reinforces dyslipidemia in response to a HFD in adult offsprings, which should be associated with mitochondrial abnormalities and disturbed gene expressions of cholesterol metabolism.

The Association of Intrapair Birth-Weight Differences With Internalizing and Externalizing Behavior Problems

Problem behaviors are of increasing public health concern. Twin studies have revealed substantial genetic and environmental influences on children's behavior, and examining birth-weight difference could allow the identification of the specific contribution of multiple non-shared prenatal environmental factors. The Twins and Multiple Births Association Heritability Study, a UK, volunteer-based study, recruited mothers of twins aged 18 months to 5 years; 960 twins (480 pairs) were included in the analysis. Twins' mothers answered questions relative to their pregnancy and their twins' characteristics, and completed the Child Behavior Checklist (CBCL) 1½-5. The association between the absolute birth-weight difference and each CBCL scale's score difference was analyzed by means of multiple linear regressions. Expected mean CBCL score differences were calculated. In monozygotic (MZ) twins, statistically and clinically significant associations were found between intrapair birth-weight difference and difference in total problems, internalizing problems, and emotional reactiveness. No significant results were observed neither in dizygotic (DZ) twins when analyzed as a separate group nor in MZ and DZ twins combined. The results of the present study suggest that with increasing the absolute birth-weight difference, the intrapair difference in total problems, internalizing behaviors and emotionality increases, with smaller twins being at major risk for later behavior problems. Moreover, these results suggest a causal association between birth weight and behavior development.

DNA methylation profiles in sibling pairs discordant for intrauterine exposure to maternal gestational diabetes

Intrauterine exposure to hyperglycemia is reported to confer increased metabolic risk in later life, supporting the 'developmental origins of health and disease' hypothesis. Epigenetic alterations are suggested as one of the possible underlying mechanisms. In this study, we compared pairwise DNA methylation differences between siblings whose intrauterine exposure to maternal gestational diabetes (GDM) were discordant. Methylation of peripheral blood DNA of 18 sibling pairs was measured using Infinium HumanMethylation450 BeadChip assays. Of the 465,447 CpG sites analyzed, 12 showed differential methylation (false discovery rate <0.15), including markers within genes associated with monogenic diabetes (HNF4A) or obesity (RREB1). The overall methylation at HNF4A showed inverse correlations with mRNA expression levels, though non significant. In a gene set enrichment analysis, metabolism and signal transduction pathways were enriched. In conclusion, we found DNA methylation markers associated with intrauterine exposure to maternal GDM, including those within genes previously implicated in diabetes or obesity.

Comparison of associations of maternal peri-pregnancy and paternal anthropometrics with child anthropometrics from birth through age 7 y assessed in the Danish National Birth Cohort

BACKGROUND

Maternal prepregnancy adiposity may influence child adiposity beyond the transmitted genetic effects, which, if true, may accelerate the obesity epidemic, but the evidence for this mechanism is inconsistent.

OBJECTIVE

The aim was to assess whether the associations of maternal body mass index (BMI) with child anthropometric measurements from birth through infancy and at 7 y of age exceed those of paternal associations.

DESIGN

In the Danish National Birth Cohort, information on parental and child anthropometric measures is available for 30,655 trio families from maternal interviews during pregnancy and the postpartum period and from a 7-y follow-up. By using multiple linear and logistic regression models of child SD (z) scores of weight and BMI at birth, 5 mo, 12 mo, and 7 y of age, and of child overweight at age 7 y, we compared associations with maternal prepregnancy and postpartum BMI z scores and with paternal BMI z scores.

RESULTS

When comparing maternal-child and paternal-child BMI z score associations, the strongest associations were observed with mothers' BMI at birth [maternal and paternal BMI z scores: 0.143 (95% CI: 0.130, 0.155) and 0.017 (95% CI: 0.005, 0.029), respectively] and throughout infancy, but the relative difference in the associations declined by child age [for BMI z score at child age 7 y per maternal and paternal BMI z scores: 0.208 (95% CI: 0.196, 0.220) and 0.154 (95% CI: 0.143, 0.166), respectively]. At 7 y of age, ORs of child overweight were 2.30 (95% CI: 1.99, 2.67) by maternal overweight and 1.96 (95% CI: 1.74, 2.21) by paternal overweight. There were no differences between the results based on maternal BMI before and after pregnancy or on child's weight adjusted for length or height.

CONCLUSIONS

The associations of child weight and BMI with maternal BMI were stronger than with paternal BMI. The differences between the associations were strong at birth but declined with child aging.

Striking differences in estimates of infant adiposity by new and old DXA software, PEAPOD and skin-folds at 2 weeks and 1 year of life

BACKGROUND

Infant adiposity better predicts childhood obesity/metabolic risk than weight, but technical challenges fuel controversy over the accuracy of adiposity estimates.

OBJECTIVE

We prospectively measured adiposity (%fat) in term newborns (NB) at 2 weeks (n = 41) and 1 year (n = 30).

METHODS

%fat was measured by dual X-ray absorptiometry (DXA), PEAPOD and skin-folds (SF). DXAs were analyzed using Hologic Apex software 3.2(DXAv1) and a new version 5.5.2(DXAv2).

RESULTS

NB %fat by DXAv2 was 55% higher than DXAv1 (14.2% vs. 9.1%), 45% higher than SF (9.8%), and 36% higher than PEAPOD (10.4%). Among NB, Pearson correlations were 0.73-0.89, but agreement (intra-class correlations) poor between DXAv2 and DXAv1 (0.527), SF (0.354) and PEAPOD (0.618). At 1 year, %fat by DXAv2 was 51% higher than DXAv1 (33.6% vs. 22.4%), and twice as high compared with SF (14.6%). Agreement was poor between DXAv2 and DXAv1 (0.204), and SF (0.038). The absolute increase in %fat from 2 weeks to 1 year was 19.7% (DXAv2), 13.6% (DXAv1) and only 4.8% by SF.

CONCLUSION

Analysis of the same DXA scans using new software yielded considerably higher adiposity estimates at birth and 1 year compared with the previous version. Using different modalities to assess body composition longitudinally is problematic. Standardization is gravely needed to determine how early life exposures affect childhood obesity/metabolic risk.

Preventing Obesity Across Generations: Evidence for Early Life Intervention

To prevent the intergenerational transfer of obesity and end the current epidemic, interventions are needed across the early life stages, from preconception to prenatal to infancy through the age of 2 years. The foundation for obesity is laid in early life by actions and interactions passed from parent to child that have long-lasting biologic and behavioral consequences. The purpose of this paper is to examine the best evidence about (a) factors in parents and offspring that promote obesity during the early life stages, (b) the social determinants and dimensions of obesity in early life, (c) promising and effective interventions for preventing obesity in early life, and (d) opportunities for future research into strategies to disrupt the intergenerational cycle of obesity that begins early in life. The pathway for halting the intergenerational obesity epidemic requires the discovery and development of evidence-based interventions that can act across multiple dimensions of influence on early life.

Does epigenetic dysregulation of pancreatic islets contribute to impaired insulin secretion and type 2 diabetes?

β cell dysfunction is central to the development and progression of type 2 diabetes (T2D). T2D develops when β cells are not able to compensate for the increasing demand for insulin caused by insulin resistance. Epigenetic modifications play an important role in establishing and maintaining β cell identity and function in physiological conditions. On the other hand, epigenetic dysregulation can cause a loss of β cell identity, which is characterized by reduced expression of genes that are important for β cell function, ectopic expression of genes that are not supposed to be expressed in β cells, and loss of genetic imprinting. Consequently, this may lead to β cell dysfunction and impaired insulin secretion. Risk factors that can cause epigenetic dysregulation include parental obesity, an adverse intrauterine environment, hyperglycemia, lipotoxicity, aging, physical inactivity, and mitochondrial dysfunction. These risk factors can affect the epigenome at different time points throughout the lifetime of an individual and even before an individual is conceived. The plasticity of the epigenome enables it to change in response to environmental factors such as diet and exercise, and also makes the epigenome a good target for epigenetic drugs that may be used to enhance insulin secretion and potentially treat diabetes.

You are what you eat: O-linked N-acetylglucosamine in disease, development and epigenetics

PURPOSE OF REVIEW

The O-linked N-acetylglucosamine (O-GlcNAc) modification is both responsive to nutrient availability and capable of altering intracellular cellular signalling. We summarize data defining a role for O-GlcNAcylation in metabolic homeostasis and epigenetic regulation of development in the intrauterine environment.

RECENT FINDINGS

O-GlcNAc transferase (OGT) catalyzes nutrient-driven O-GlcNAc addition and is subject to random X-inactivation. OGT plays key roles in growth factor signalling, stem cell biology, epigenetics and possibly imprinting. The O-GlcNAcase, which removes O-GlcNAc, is subject to tight regulation by higher order chromatin structure. O-GlcNAc cycling plays an important role in the intrauterine environment wherein OGT expression is an important biomarker of placental stress.

SUMMARY

Regulation of O-GlcNAc cycling by X-inactivation, epigenetic regulation and nutrient-driven processes makes it an ideal candidate for a nutrient-dependent epigenetic regulator of human disease. In addition, O-GlcNAc cycling influences chromatin modifiers critical to the regulation and timing of normal development including the polycomb repression complex and the ten-eleven translocation proteins mediating DNA methyl cytosine demethylation. The pathway also impacts the hypothalamic-pituitary-adrenal axis critical to intrauterine programming influencing disease susceptibility in later life.

A statistical framework for testing the causal effects of fetal drive

Maternal genetic and phenotypic characteristics (e.g., metabolic and behavioral) affect both the intrauterine milieu and lifelong health trajectories of their fetuses. Yet at the same time, fetal genotype may affect processes that alter pre and postnatal maternal physiology, and the subsequent health of both fetus and mother. We refer to these latter effects as 'fetal drive.' If fetal genotype is driving physiologic, metabolic, and behavioral phenotypic changes in the mother, there is a possibility of differential effects with different fetal genomes inducing different long-term effects on both maternal and fetal health, mediated through intrauterine environment. This proposed mechanistic path remains largely unexamined and untested. In this study, we offer a statistical method to rigorously test this hypothesis and make causal inferences in humans by relying on the (conditional) randomization inherent in the process of meiosis. For illustration, we apply this method to a dataset from the Framingham Heart Study.

Altered thyroid hormone profile in offspring after exposure to high estradiol environment during the first trimester of pregnancy: a cross-sectional study

BACKGROUND

The increasing number of babies conceived by in vitro fertilization and embryo transfer (IVF-ET) shifts concern from pregnancy outcomes to long-time health of offspring. Maternal high estradiol (E2) is a major characteristic of IVF-ET and lasts throughout the first trimester of pregnancy. The fetal thyroid develops during this period and may thus be affected by exposure to the supra-physiological E2. The aim of this study is to investigate whether the high E2 maternal environment in the first trimester increases the risk of thyroid dysfunction in children born following IVF-ET.

METHODS

A cross-sectional survey design was used to carry out face-to-face interviews with consecutive children attending the hospital. A total of 949 singletons born after fresh embryo transfer (ET) (n=357), frozen ET (n=212), and natural conception (NC) (n=380), aged 3 to 10 years old, were included. All children were thoroughly examined. Meanwhile, another 183 newborns, including 55 fresh ET, 48 frozen ET, and 80 NC were studied. Levels of serum T3, FT3, T4, FT4, and TSH and levels of maternal E2 at different stages of the first trimester were examined.

RESULTS

The mean serum E2 levels of women undergoing fresh ET during the first trimester of pregnancy were significantly higher than those of the women undergoing frozen ET or following NC. The thyroid hormone profile, especially the levels of T4, FT4, and TSH, were significantly increased in 3- to 10-year-old children conceived by fresh ET compared to NC. The same tendency was confirmed in newborns. However, levels of T4 and TSH in the frozen ET group were nearer to that of the NC group. Furthermore, levels of T4 and FT4 in fresh ET were positively correlated with maternal serum levels of E2 during early pregnancy.

CONCLUSIONS

The maternal high E2 environment in the first trimester is correlated with increased risk of thyroid dysfunction. Frozen ET could reduce risks of thyroid damage in children conceived by IVF. Further studies are needed to confirm these findings and to better determine the underlying molecular mechanisms and clinical significance.

TRIAL REGISTRATION

ChicCTR-OCC-14004682 (22-05-2014).

Maternal insulin resistance and transient hyperglycemia impact the metabolic and endocrine phenotypes of offspring

Studies in both humans and rodents suggest that maternal diabetes leads to a higher risk of the fetus developing impaired glucose tolerance and obesity during adulthood. However, the impact of hyperinsulinemia in the mother on glucose homeostasis in the offspring has not been fully explored. We aimed to determine the consequences of maternal insulin resistance on offspring metabolism and endocrine pancreas development using the LIRKO mouse model, which exhibits sustained hyperinsulinemia and transient increase in blood glucose concentrations during pregnancy. We examined control offspring born to either LIRKO or control mothers on embryonic days 13.5, 15.5, and 17.5 and postpartum days 0, 4, and 10. Control offspring born to LIRKO mothers displayed low birth weights and subsequently rapidly gained weight, and their blood glucose and plasma insulin concentrations were higher than offspring born to control mothers in early postnatal life. In addition, concentrations of plasma leptin, glucagon, and active GLP-1 were higher in control pups from LIRKO mothers. Analyses of the endocrine pancreas revealed significantly reduced β-cell area in control offspring of LIRKO mothers shortly after birth. β-Cell proliferation and total islet number were also lower in control offspring of LIRKO mothers during early postnatal days. Together, these data indicate that maternal hyperinsulinemia and the transient hyperglycemia impair endocrine pancreas development in the control offspring and induce multiple metabolic alterations in early postnatal life. The relatively smaller β-cell mass/area and β-cell proliferation in these control offspring suggest cell-autonomous epigenetic mechanisms in the regulation of islet growth and development.

Postnatal stability, tissue, and time specific effects of AHRR methylation change in response to maternal smoking in pregnancy

The intrauterine environment has the potential to "program" the developing fetus in a way that can be potentially deleterious to later health. While in utero environmental/stochastic factors are known to influence DNA methylation profile at birth, it has been difficult to assign specific examples of epigenetic variation to specific environmental exposures. Recently, several studies have linked exposure to smoking with DNA methylation change in the aryl hydrocarbon receptor repressor (AHRR) gene in blood. This includes hypomethylation of AHRR in neonatal blood in response to maternal smoking in pregnancy. The role of AHRR as a negative regulator of pathways involved in pleiotropic responses to environmental contaminants raises the possibility that smoking-induced hypomethylation is an adaptive response to an adverse in utero environmental exposure. However, the tissue specificity of the response to maternal smoking, and the stability of the methylation changes early in life remain to be determined. In this study we analyzed AHRR methylation in three cell types-cord blood mononuclear cells (CBMCs), buccal epithelium, and placenta tissue-from newborn twins of mothers who smoked throughout pregnancy and matched controls. Further, we explored the postnatal stability of this change at 18 months. Our results confirm the previous association between maternal smoking and AHRR methylation in neonatal blood. In addition, this study expands the region of AHRR methylation altered in response to maternal smoking during pregnancy and reveals the tissue-specific nature of epigenetic responses to environmental exposures in utero. Further, the evidence for postnatal stability of smoking-induced epigenetic change supports a role for epigenetics as a mediator of long-term effects of specific in utero exposures in humans. Longitudinal analysis of further specific exposures in larger cohorts is required to examine the extent of this phenomenon in humans.

Gestational diabetes mellitus, programing and epigenetics

Gestational diabetes mellitus (GDM) is a common medical complication in pregnancy. Offspring exposed to maternal hyperglycemia have a higher birth weight and are prone to develop metabolic disease in adult life. The intrauterine environmental or nutritional status seems to be involved in the fetal programing. The concept of "Developmental Origins of Health and Disease" (DOHaD) has been widely accepted and it brings new insights into the molecular pathogenesis of human diseases. The underlying mechanism is still under discussion and epigenetic mechanisms may provide an explanation for the phenomenon. The aim of this review is to illustrate the role of epigenetic modifications in the development of insulin resistance in metabolic diseases induced by adverse intrauterine exposures. Changes in epigenetic mechanism may be an early event in pathogenesis and progression of the metabolic disease in humans. Studies on epigenetic modifications contribute to our understanding of long-term effects of in utero exposure and shed light on the disease prevention and treatment by modulating epigenetic changes.

Differential methylation in glucoregulatory genes of offspring born before vs. after maternal gastrointestinal bypass surgery

Obesity and overnutrition during pregnancy affect fetal programming of adult disease. Children born after maternal bariatric gastrointestinal bypass surgery (AMS) are less obese and exhibit improved cardiometabolic risk profiles carried into adulthood compared with siblings born before maternal surgery (BMS). This study was designed to analyze the impact of maternal weight loss surgery on methylation levels of genes involved in cardiometabolic pathways in BMS and AMS offspring. Differential methylation analysis between a sibling cohort of 25 BMS and 25 AMS (2-25 y-old) offspring from 20 mothers was conducted to identify biological functions and pathways potentially involved in the improved cardiometabolic profile found in AMS compared with BMS offspring. Links between gene methylation and expression levels were assessed by correlating genomic findings with plasma markers of insulin resistance (fasting insulin and homeostatic model of insulin resistance). A total of 5,698 genes were differentially methylated between BMS and AMS siblings, exhibiting a preponderance of glucoregulatory, inflammatory, and vascular disease genes. Statistically significant correlations between gene methylation levels and gene expression and plasma markers of insulin resistance were consistent with metabolic improvements in AMS offspring, reflected in genes involved in diabetes-related cardiometabolic pathways. This unique clinical study demonstrates that effective treatment of a maternal phenotype is durably detectable in the methylome and transcriptome of subsequent offspring.

Maternal gestational androgens are associated with decreased juvenile play in white-faced marmosets (Callithrix geoffroyi)

Exposure to androgens during prenatal development shapes both physiological and behavioral developmental trajectories. Notably, in rhesus macaques, prenatal androgen exposure has been shown to increase rough-and-tumble play, a prominent behavioral feature in males during the juvenile period in primates. While macaques are an Old World, polygamous species with marked sexually dimorphic behavior, New World callitrichine primates (marmosets and tamarins) live in cooperative breeding groups and are considered to be socially monogamous and exhibit minimal sexual dimorphism in social play, which suggests that androgen may affect this species in different ways compared to macaques. In addition, we previously described considerable variation in maternal androgen production during gestation in marmosets. Here we tested the association between this variation and variation in offspring rough-and-tumble play patterns in both males and females. We measured testosterone and androstenedione levels in urine samples collected from pregnant marmoset mothers and then observed their offspring's play behavior as juveniles (5-10 months of age). In contrast to findings in rhesus macaques, hierarchical regression analyses showed that higher gestational testosterone levels, primarily in the second semester, were associated with decreased rough-and-tumble play in juveniles, and this relationship appears to be driven more so by males than females. We found no reliable associations between gestational androstenedione and juvenile play behavior. Our findings provide evidence to suggest that normative variation in levels of maternal androgen during gestation may influence developmental behavioral trajectories in marmosets in a way that contradicts previous findings in Old World primates.

Fetal environment, epigenetics, and pediatric renal disease

The notion that some adult diseases may have their origins in utero has recently captured scientists' attention. Some of these effects persist across generations and may involve epigenetic mechanisms. Epigenetic modifications, DNA methylation together with covalent modifications of histones, alter chromatin density and accessibility of DNA to cellular machinery, modulating the transcriptional potential of the underlying DNA sequence. Here, we will discuss the different epigenetic modifications and their potential role in and contribution to renal disease development.

Investigating parent of origin effects in studies of type 2 diabetes and obesity

The role of parent-of-origin effects (POE) in the etiology of complex diseases such as type 2 diabetes (T2DM) and obesity is currently of intense interest, but still largely unclear. POE are transmittable genetic effects whereby the expression of the phenotype in the offspring depends upon whether the transmission originated from the mother or father. In mammals, POE can be caused by genetic imprinting, intrauterine effects, or maternally inherited mitochondrial genes. In this paper, we describe the different mechanisms underlying POE, characterize known examples of POE in rare forms of diabetes, and review the evidence from linkage and association studies for POE in T2DM and obesity. Finally, we summarize some of the new and established statistical and experimental approaches commonly used to detect POE. Through this paper, we hope emphasizes the potentially significant importance of POE in the etiology of T2DM and obesity.

Intrauterine environment, mammary gland mass and breast cancer risk

Two intimately linked hypotheses on breast cancer etiology are described. The main postulate of the first hypothesis is that higher levels of pregnancy estrogens and other hormones favor the generation of a higher number of susceptible stem cells with compromised genomic stability. The second hypothesis postulates that the mammary gland mass, as a correlate of the number of cells susceptible to transformation, is an important determinant of breast cancer risk. A simple integrated etiological model for breast cancer is presented and it is indicated that the model accommodates most epidemiological aspects of breast cancer occurrence and natural history.