Epigenetic Alterations and Exposure to Air Pollutants: Protocol for a Birth Cohort Study to Evaluate the Association Between Adverse Birth Outcomes and Global DNA Methylation

Consequences of the exposome to gestational diabetes mellitus

The exposome is the cumulative measure of environmental influences and associated biological responses throughout the lifespan, including those from the environment, diet, behaviour, and endogenous processes. The exposome concept and the 2030 Agenda for the Sustainable Development Goals (SDGs) from the United Nations are the basis for understanding the aetiology and consequences of non-communicable diseases, including gestational diabetes mellitus (GDM). Pregnancy may be developed in an environment with adverse factors part of the immediate internal medium for fetus development and the external medium to which the pregnant woman is exposed. The placenta is the interface between maternal and fetal compartments and acts as a protective barrier or easing agent to transfer exposome from mother to fetus. Under and over-nutrition in utero, exposure to adverse environmental pollutants such as heavy metals, endocrine-disrupting chemicals, pesticides, drugs, pharmaceuticals, lifestyle, air pollutants, and tobacco smoke plays a determinant role in the development of GDM. This phenomenon is worsened by metabolic stress postnatally, such as obesity which increases the risk of GDM and other diseases. Clinical risk factors for GDM development include its aetiology. It is proposed that knowledge-based interventions to change the potential interdependent ecto-exposome and endo-exposome could avoid the occurrence and consequences of GDM.

Air Pollution and Perinatal Health in the Eastern Mediterranean Region: Challenges, Limitations, and the Potential of Epigenetics

PURPOSE OF REVIEW

Even though the burden of disease attributable to air pollution is high in the Eastern Mediterranean Region (EMR), the number of studies linking environmental exposures to negative health outcomes remains scarce and limited in scope. This review aims to assess the literature on exposure to air pollutants and perinatal health in the EMR and to explain the potential of epigenetics in exploring the processes behind adverse birth outcomes.

RECENT FINDINGS

In the last three decades, hundreds of studies and publications tackled the health effects of air pollution on birth outcomes and early life development, but only a small number of these studies was conducted in the EMR. The existing literature is concentrated in specific geographic locations and is focused on a limited number of exposures and outcomes. Main limitations include inconsistent and poorly funded air quality monitoring, inappropriate study designs, imprecise and/or unreliable assessments of exposures, and outcomes. Even though the studies establish associations between air pollutants and adverse birth outcomes, the mechanisms through which these processes take place are yet to be fully understood. A likely candidate to explain these processes is epigenetics; however, epigenetics research on the impact of air pollution in EMR is still in its infancy. This review highlights the need for future research examining perinatal health and air pollutants, especially the epigenetic processes that underlie the adverse birth outcomes, to better understand them and to develop effective recommendations and intervention strategies.

Particulate Matter-Induced Cardiovascular Dysfunction: A Mechanistic Insight

Air pollution and particulate matter (PM) are significant factors for adverse health effects most prominently cardiovascular disease (CVD). PM is produced from various sources, which include both natural and anthropogenic. It is composed of biological components, organic compounds, minerals, and metals, which are responsible for inducing inflammation and adverse health effects. However, the adverse effects are related to PM size distribution. Finer particles are a significant cause of cardiovascular events. This review discusses the direct and indirect mechanisms of PM-induced CVD like myocardial infarction, the elevation of blood pressure, cardiac arrhythmias, atherosclerosis, and thrombosis. The two potential mechanisms are oxidative stress and systemic inflammation. Prenatal exposure has also been linked with cardiovascular outcomes later in life. Moreover, we also mentioned the epidemiological studies that strongly associate PM with CVD.

Maternal exposure to air pollution and umbilical asprosin concentration, a novel insulin-resistant marker

Air pollution exposure during pregnancy has been associated with abnormal glucose hemostasis in the fetus, which may result in the programming of type 2 diabetes mellitus (T2DM) development in future life. Therefore, we investigated the association of maternal exposure to particulate matters (PMs) and traffic indicators with umbilical asprosin concentration, a novel insulin-resistant inducing adipokine, in newborns. Accordingly, 759 mother-newborn pairs from Sabzevar, Iran (2018-2019) participated in our study. Maternal exposure to PM₁, PM_2.5 and PM₁₀ concentrations was estimated using spatial-temporal models developed for the study area. The associations of exposure to traffic indicators (total street length in 100, 300 and 500 m buffers around home and proximity of mothers to nearest major roads) and air pollution with umbilical asprosin concentration were estimated using linear regression models, adjusted for potential confounders. The median (interquartile range (IQR)) of umbilical asprosin concentration was 30.4 (19.1) ng/mL. In fully adjusted models, each one IQR increase in PM₁₀ and PM_2.5 were associated with 26.43 ng/mL (95% CI: 10.97, 41.88) and 31.76 ng/mL (95% CI: 15.66, 47.86) increase in umbilical asprosin concentration, respectively. A similarity result was observed for total street length in 100 m buffer. An increase in proximity to major roads was associated with a decrease of -21.48 ng/mL (95% CI: 33.29, -9.67) in umbilical asprosin concentration. Our results suggested that maternal exposure to air pollution during pregnancy could increase the umbilical asprosin concentration. These novel findings may improve our understanding of the mechanisms whereby air pollutants impaired glucose hemostasis during the fetal period.

Ambient air pollution exposure during pregnancy and gestational diabetes mellitus in Shenyang, China: a prospective cohort study

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. Reports of the association between air pollution exposure and GDM have been inconsistent in previous studies. We conducted a cohort study to investigate the associations between air pollution exposure and GDM in the city of Shenyang in Northeast China for the first time. We studied interactions with different air pollutant exposures and conducted a stratified analysis according to folic acid intake, age, body mass index (BMI), primiparity, and sleep quality. We found significant associations between prenatal exposure to NO_x and SO₂ and the development of GDM during the second trimester: the largest effect on GDM was exposure to SO₂ (odds ratio (OR): 1.77, 95% confidence interval (CI): 1.23-2.56) in the largest quartile compared with the lowest quartile. Significant interactions between age, BMI, parity, sleep quality, and air pollution exposures were observed; stratified analysis showed stronger associations between GDM and high air pollutant exposure in pregnant women with older age, larger BMI, poorer sleep quality, and more parity. We found that air pollution exposure during the second trimester was significantly associated with GDM in a prospective birth cohort study in Northeast China. SO₂, oxynitride (NOX, NO₂, NO), CO, and O₃ all showed a linear trend effect on GDM. Interactions between prenatal air pollution exposure and other factors, such as age at pregnancy, BMI before pregnancy, primiparity, folic acid intake, and sleep quality, during the second trimester might exist.

Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment

PURPOSE

To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study.

METHODS

We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails-hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017.

RESULTS

overall 838 eligible pregnant women were approached. The participation rate was 206(25%) in our study and about 185(90%) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100%),193(93%), 205(99%), and 205(99%), respectively. These values dropped to 65(54%), 83(69%), 84(70%), and 84(70%) for the remaining participants 120(58%) in the third trimester, respectively. Also, we gathered milk samples from 125(60%) of mothers at two to three months after delivery.

CONCLUSION

Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn's urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers.

Endocrinology and Metabolism Research Institute from inception to maturity: an overview of 25-year activity

Endocrinology and Metabolism Research Institute (EMRI) was founded in 1993. EMRI progressed step by step from inception and reached to its maturation during the past 25 years. EMRI has expanded and progressed in different aspects including human resources and infrastructures (laboratories and new technologies) and has obtained the first rank in the country in endocrinology research. It has also collaborated with regional and international organizations such as World Health Organization (WHO), International Osteoporosis Foundation (IOF), and American Association of Clinical Endocrinologists (AACE). This article provides an overview of EMRI activities during a quarter of a century.

Moral reasons to edit the human genome: picking up from the Nuffield report

In July 2018, the Nuffield Council of Bioethics released its long-awaited report on heritable genome editing (HGE). The Nuffield report was notable for finding that HGE could be morally permissible, even in cases of human enhancement. In this paper, we summarise the findings of the Nuffield Council report, critically examine the guiding principles they endorse and suggest ways in which the guiding principles could be strengthened. While we support the approach taken by the Nuffield Council, we argue that detailed consideration of the moral implications of genome editing yields much stronger conclusions than they draw. Rather than being merely 'morally permissible', many instances of genome editing will be moral imperatives.

Solidarity after nature: From biopolitics to cosmopolitics

What is sustaining the divide between nature and nurture, even though sciences like epigenetics have been challenging it for at least two decades? Evelyn Fox Keller asked this question and considered it a logical problem rooted in terminological confusion within the sciences. In this article, we propose a complementary diagnosis of the problem: the nature-nurture divide is (re-)mobilized when society faces questions of inclusion and solidarity. With examples stemming from the fields of insurance and health care, immigration policy and epigenetics, we demonstrate how the nature-nurture divide is performed through techniques of classification for a politics of solidarity. We identify a common operation to these different examples that we coin 'biopolitical imputation'. We use this term to draw attention to how (Western) societal institutions, including science, create solvable problems out of complex situations, defining human actors and their agency along the lines of the nature-nurture divide as a moral guide. We argue that the tenacity of the nature-nurture divide is therefore not only a logical problem needing better scientific concepts, but also a cosmopolitical problem asking for a more profound reflection on the ontology and ethics of solidarity in order to move beyond the biopolitics of nature versus nurture.

Air pollution during pregnancy and placental adaptation in the levels of global DNA methylation

BACKGROUND

Health in early life is crucial for health later in life. Exposure to air pollution during embryonic and early-life development can result in placental epigenetic modification and foetus reprogramming, which can influence disease susceptibility in later life. Objectives: The aim of this paper was to investigate the placental adaptation in the level of global DNA methylation and differential gene expression in the methylation cycle in new-borns exposed to high fine particulate matter in the foetal stage.

STUDY DESIGN

This is a nested case-control study. We enrolled pregnant healthy women attending prenatal care clinics in Tehran, Iran, who were residents of selected polluted and unpolluted regions, before the 14th week of pregnancy. We calculated the regional background levels of particle mass- particles with aerodynamics diameter smaller than 2.5 μm (PM2.5) and 10 μm (PM10)-of two regions of interest. At the time of delivery, placental tissue was taken for gene expression and DNA methylation analyses. We also recorded birth outcomes (the new-born's sex, birth date, birth weight and length, head and chest circumference, gestational age, Apgar score, and level of neonatal care required).

RESULTS

As regards PM2.5 and PM10 concentrations in different time windows of pregnancy, there were significantly independent positive correlations between PM10 and PM2.5 in the first trimester of all subjects and placental global DNA methylation levels (p-value = 0.01, p-value = 0.03, respectively). The gene expression analysis showed there was significant correlation between S-adenosylmethionine expression and PM2.5 (p = 0.003) and PM10 levels in the first trimester (p = 0.03).

CONCLUSION

Our data showed prenatal exposures to air pollutants in the first trimester could influence placental adaptation by DNA methylation.