Maternal cigarette smoking during pregnancy is associated with downregulation of miR-16, miR-21, and miR-146a in the placenta

Effects of maternal smoking on inflammation, autophagy/mitophagy, and miRNAs in endothelial cells: Influence of newborn sex

Maternal smoking (MS) during pregnancy is linked to well-documented adverse health effects for the mother and foetus, however the role of fetal sex was largely overlooked. Primary cultures of male and female human umbilical vein endothelial cells (MHUVECs and FHUVECs, respectively) were used. IL-6, IL-8, and TNF-α levels were measured in HUVECs supernatant. The expression of genes and proteins (oestrogen receptors (ERs), Hsp90, Beclin-1, p62, LC3, LAMP-1 and Parkin), as well as the expression of miR-29a-3p, miR-29b-3p, miR-126-3p, miR-133a-3p, and miR-146a-5p were analysed in cells obtained from foetuses born to non-smoking and smoking mothers. In HUVECs from foetuses born to non-smoking mothers, Beclin-1 protein was higher in MHUVECs (1.8 fold increase), while Parkin, Hsp90 proteins, and miR-146a-5p were elevated in FHUVECs (2.2, 2.6, and 2.1 fold increase, respectively), with no other significant differences. MS amplified these sex differences, with specific effects based on foetus sex. FHUVECs obtained from foetus born to smoking mothers showed higher levels of IL-8 (1399.36 ± 123.96 pg/ml for FHUVECs vs 655.11 ± 215.94; pg/ml for MHUVECs; P < 0.001), Hsp90 gene and protein (3.3 and 2.6 fold increase), and ERβ protein and Beclin-1 gene (2.1, and 4.9 fold increase), and lower levels of miR-29b-3p, miR-133a-3p, and miR-146a-5p than MHUVECs (0.27, 0.68, and 0.1 fold change, respectively). This study shows that primary HUVECs from fetuses born to smoking mothers retain a memory of smoking effects, with sex differences in gene expression, miRNA profiles, and autophagic responses, suggesting that maternal smoking impacts endothelial cell physiology in a sex-dependent manner.

MicroRNA expression in response to environmental hazards: Implications for health

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally and are increasingly recognized as sensitive biomarkers of environmental exposure. This review explores how various environmental hazards-including radiation, air pollutants, heavy metals, pesticides, phthalates, and pathogens-alter both cellular and circulating miRNA expression, influencing phenotypic plasticity and contributing to disease development. Environmental hazards can induce epigenetic modifications in miRNA profiles, disrupting key biological processes such as inflammation, oxidative stress, apoptosis, and DNA repair. These alterations are associated with a wide range of diseases. The review outlines miRNA biogenesis, function, and extracellular transport, highlighting their stability and tissue specificity as biomarkers of exposure and disease. It also examines the complexity of exposure-specific miRNA signatures, shaped by factors such as genetic background, co-exposures, and exposure duration, and discusses current challenges in their validation and clinical application. Overall, this review underscores the pivotal role of miRNAs in cellular responses to environmental hazards and their potential as diagnostic and therapeutic tools, with broad implications for environmental health and disease prevention.

Effect of Per and Poly-Fluoroalkyl Substances on Pregnancy and Child Development

BACKGROUND

Childhood obesity is significantly influenced by maternal exposure to Per and Poly-Fluoroalkyl Substances (PFAS) during pregnancy. PFAS exposure occurs through the Peroxisome Proliferator-Activated Receptor (PPAR-γ) receptor, leading to increased fat deposition and profound health effects in child growth and development. Despite ongoing investigations, the relationship between maternal serum PFAS concentration and child obesity requires further exploration.

OBJECTIVE

This study aimed to review the possible effects of Per and poly-fluoroalkyl substances exposure and their mechanism in overweight/obese children from pregnant ladies.

METHODS

A detailed literature survey was conducted using online databases, including Science Direct, Google Scholar, Scopus, Cochrane, and PubMed. The study focused on the diverse effects of PFAS on maternal and child health, with particular emphasis on neurological complications.

RESULTS

Child growth development depends upon breastfeeding and placenta health, which is disrupted by PFAS exposure, ultimately destroying the body mass index of the child. Neurotoxicity testing utilized the SH-SY5Y human-derived cell line as an in vitro model, revealing PFAS-induced increases in adipocyte number, reduced cell size, altered lipid conglomeration, increased adiposity, and changes in liver function. in vivo studies in mice and human cell lines indicated PPAR-γ and ER-α activation, leading to adiposity and weight gain through Estrogen signaling and Lipid metabolism. PFAS concentrations positively correlated in maternal sera, analyzed by liquid chromatography/quadrupole mass spectrometry.

CONCLUSION

PFAS, with a long half-life of 3.5-8.5 years, is commonly found in the serum of pregnant women, crossing the placenta barrier. This exposure disrupts placental homeostasis, negatively impacting mechanisms of action and potentially leading to deterioration in pregnancy and child health. Further research is needed to comprehensively understand the complex interplay between PFAS exposure and its implications for maternal and child well-being.

Elucidating tobacco smoke-induced craniofacial deformities: Biomarker and MAPK signaling dysregulation unraveled by cross-species multi-omics analysis

Tobacco smoke (TS), particularly secondhand and thirdhand smoke, poses a pervasive and intractable environmental hazard that promotes teratogenesis and the progression of craniofacial malformations, although the underlying mechanisms remain elusive. Using zebrafish larvae as a model, our research demonstrated a correlation between the increasing concentration of cigarette smoke extract (CSE) and the severity of craniofacial malformations, supported by Alcian blue staining and histological assessments. Through a combined mRNA-miRNA analysis and quantitative real-time PCR, we identified miR-96-5p, miR-152, miR-125b-2-3p, and miR-181a-3-3p as pivotal biomarkers in craniofacial cartilage development. Functional analyses revealed their association with the MAPK signaling pathway, oxidative stress (OS), and cell development, highlighting MAPK as a crucial mediator. Single-cell transcriptomics further disclosed aberrant MAPK activation in mesenchymal cells. Subsequent investigations in human embryonic palatal mesenchymal (HEPM) cells confirmed similar patterns of growth inhibition, apoptosis, and OS, and emphasized the cross-species consistency of these biomarkers and the over-activation of the MAPK signaling pathway. A comprehensive tri-omics analysis of HEPM cells identified pivotal genes, proteins, and metabolites within the MAPK pathway. This groundbreaking cross-species multi-omics study unveils novel biomarkers and MAPK pathway perturbations linked to TS-induced craniofacial developmental toxicity, promoting innovative clinical prediction, diagnosis, and interventional strategies to tackle TS-induced craniofacial malformations.

Tobacco Smoke Exposure and Lactation

Tobacco smoke exposure remains a significant public health concern, particularly for lactating women and their infants. Despite widespread awareness of the harms of smoking during pregnancy, many women continue to smoke postpartum, directly impacting lactation success and infant health. Studies have shown that nicotine, the primary component of tobacco smoke, inhibits prolactin production and the milk ejection reflex, resulting in a decreased milk supply and poor breastfeeding outcomes. Additionally, the presence of harmful chemicals in tobacco smoke, such as cadmium and lead, can accumulate in breast milk, exposing infants to toxic substances with potential long-term health implications. Maternity professionals play a crucial role in supporting smoking cessation efforts among postpartum women, providing evidence-based counseling, resources, and referrals to cessation programs. This review aims to provide an update for maternity professionals on the effects of tobacco smoke exposure on lactation and breastfeeding outcomes. In this review, we will explore the physiological mechanisms through which tobacco smoke components can interfere with lactation. Furthermore, we will discuss the challenges faced by lactating women who smoke, including increased risk of mastitis, reduced breastfeeding duration, and impaired infant growth and development. Finally, we will highlight emerging research on novel interventions to reduce the adverse effects of tobacco smoke exposure on lactation, including pharmacological treatments and behavioral interventions tailored to postpartum women.

To boldly go where no microRNAs have gone before: spaceflight impact on risk for small-for-gestational-age infants

In the era of renewed space exploration, comprehending the effects of the space environment on human health, particularly for deep space missions, is crucial. While extensive research exists on the impacts of spaceflight, there is a gap regarding female reproductive risks. We hypothesize that space stressors could have enduring effects on female health, potentially increasing risks for future pregnancies upon return to Earth, particularly related to small-for-gestational-age (SGA) fetuses. To address this, we identify a shared microRNA (miRNA) signature between SGA and the space environment, conserved across humans and mice. These miRNAs target genes and pathways relevant to diseases and development. Employing a machine learning approach, we identify potential FDA-approved drugs to mitigate these risks, including estrogen and progesterone receptor antagonists, vitamin D receptor antagonists, and DNA polymerase inhibitors. This study underscores potential pregnancy-related health risks for female astronauts and proposes pharmaceutical interventions to counteract the impact of space travel on female health.

Effect of environmental air pollutants on placental function and pregnancy outcomes: a molecular insight

Air pollution has become a major health concern, particularly for vulnerable populations such as the elderly, children, and pregnant women. Studies have reported a strong association between prenatal exposure to air pollutants and adverse pregnancy outcomes, including lower birth weight, reduced fetal growth, and an increased frequency of preterm births. This review summarizes the harmful effects of air pollutants, such as particulate matter, on pregnancy and outlines the mechanistic details associated with these adverse outcomes. Particulate pollutant matter may be able to cross the placenta barrier, and alterations in placental functions are central to the detrimental effects of these pollutants. In addition to associations with preeclampsia and gestational hypertension, air pollutants also induce oxidative stress, inflammation, and epigenetic alteration in the placenta. These pollutants can also affect placental homeostasis and endocrine function, contributing to pregnancy complications and possible transgenerational effects. Prenatal air pollution exposure has been linked to reduced cognitive and motor function in infants and newborns, increasing the predisposition to autism spectrum disorders and other neuropsychiatric disorders. This review also summarizes the use of various animal models to study the harmful effects of air pollution on pregnancy and postnatal outcomes. These findings provide valuable insight into the molecular events associated with the process and can aid in risk mitigation and adopting safety measures. Implementing effective environmental protocols and taking appropriate steps may reduce the global disease burden, particularly for developing nations with poor regulatory compliance and large populations of pregnant women.

Maternal smoking cessation in the first trimester still poses an increased risk of attention-deficit/hyperactivity disorder and learning disability in offspring

Background

Studies have found maternal smoking during pregnancy was linked to attention-deficit/hyperactivity disorder (ADHD) risk. It is unclear if maternal smoking cessation during pregnancy lowers ADHD and learning disability (LD) risk in offspring. This study aimed to explore the associations between maternal smoking cessation during pregnancy and ADHD and LD risk in offspring.

Methods

Data from the National Health and Nutrition Examination Survey 1999-2004 (8,068 participants) were used. Logistic regression was used to analyze the associations between maternal smoking and smoking cessation during pregnancy and ADHD and LD risk in offspring.

Results

Compared to non-smokers' offspring, maternal smoking during pregnancy increased the risk of ADHD (odds ratios [OR] = 2.07, 95% confidence interval [CI]: 1.67-2.56) and LD (OR = 1.93, 95% CI: 1.61-2.31) in offspring, even if mothers quit smoking later (ORADHD = 1.91, 95%CIADHD: 1.38-2.65, ORLD = 1.65, 95%CILD: 1.24-2.19). Further analysis of the timing of initiation of smoking cessation during pregnancy revealed that, compared to non-smokers' offspring, maternal quitting smoking in the first trimester still posed an increased risk of ADHD (OR = 1.72, 95% CI: 1.41-2.61) and LD (OR = 1.52, 95% CI: 1.06-2.17) in offspring. Maternal quitting smoking in the second or third trimester also had a significantly increased risk of ADHD (OR = 2.13, 95% CI: 1.26-3.61) and LD (OR = 1.82, 95% CI: 1.16-2.87) in offspring. Furthermore, maternal smoking but never quitting during pregnancy had the highest risk of ADHD (OR = 2.17, 95% CI: 1.69-2.79) and LD (OR = 2.10, 95% CI: 1.70-2.58) in offspring. Interestingly, a trend toward a gradual increase in the risk-adjusted OR for ADHD and LD risk was observed among the three groups: maternal quitting smoking in the first trimester, maternal quitting smoking in the second or third trimester, and maternal smoking but never quitting.

Conclusion

Maternal smoking cessation in the first trimester still poses an increased risk of ADHD and LD in offspring. Furthermore, it seems that the later the mothers quit smoking during pregnancy, the higher the risk of ADHD and LD in their offspring. Therefore, early intervention of maternal smoking in preconception and prenatal care is vital for offspring neurodevelopment.

Polycyclic aromatic hydrocarbons exposure and arterial stiffness-related plasma miRNAs: A panel study

The underlying mechanisms between polycyclic aromatic hydrocarbons (PAHs) exposure and arterial stiffness are poorly understood. We carried out a panel study involving three repeated surveys to examine the associations of individual and mixture of PAHs exposure with arterial stiffness-related miRNAs among 123 community adults. In linear mixed-effect (LME) models, we found that urinary 9-hydroxyfluorene (9-OHFlu), 2-hydroxyphenanthrene (2-OHPh), 9-hydroxyphenanthrene (9-OHPh) at lag 0 day were positively linked to miR-146a and/or miR-222. The Bayesian kernel machine regression (BKMR) analyses revealed positive overall associations of PAHs mixture at lag 0 day with miR-146a and miR-222, and urinary 9-OHFlu contributed the most. In addition, an inter-quartile range (IQR) increase in urinary 9-OHFlu at lag 0 day was associated with elevated miR-146a and miR-222 by 0.16 (95% CI: 0.02, 0.30) to 0.34 (95% CI: 0.13, 0.54). Accordingly, exposure to PAHs, especially 9-OHFlu at lag 0 day, was related to elevated arterial stiffness-related plasma miRNAs.

Ambient air pollution and adverse birth outcomes: A review of underlying mechanisms

Epidemiological data provide varying degrees of evidence for associations between prenatal exposure to ambient air pollutants and adverse birth outcomes (suboptimal measures of fetal growth, preterm birth and stillbirth). To assess further certainty of effects, this review examines the experimental literature base to identify mechanisms by which air pollution (particulate matter, nitrogen dioxide and ozone) could cause adverse effects on the developing fetus. It likely that this environmental insult impacts multiple biological pathways important for sustaining a healthy pregnancy, depending upon the composition of the pollutant mixture and the exposure window owing to changes in physiologic maturity of the placenta, its circulations and the fetus as pregnancy ensues. The current body of evidence indicates that the placenta is a target tissue, impacted by a variety of critical processes including nitrosative/oxidative stress, inflammation, endocrine disruption, epigenetic changes, as well as vascular dysregulation of the maternal-fetal unit. All of the above can disturb placental function and, as a consequence, could contribute to compromised fetal growth as well increasing the risk of stillbirth. Furthermore, given that there is often an increased inflammatory response associated with preterm labour, inflammation is a plausible mechanism mediating the effects of air pollution on premature delivery. In the light of increased urbanisation and an ever-changing climate, both of which increase ambient air pollution and negatively affect vulnerable populations such as pregnant individuals, it is hoped that the collective evidence may contribute to decisions taken to strengthen air quality policies, reductions in exposure to air pollution and subsequent improvements in the health of those not yet born.

Exploring the roles of noncoding RNAs in craniofacial abnormalities: A systematic review

Congenital craniofacial abnormalities are congenital anomalies of variable expressivity and severity with a recognizable set of abnormalities, which are derived from five identifiable primordial structures. They can occur unilaterally or bilaterally and include various malformations such as cleft lip with/without palate, craniosynostosis, and craniofacial microsomia. To date, the molecular etiology of craniofacial abnormalities is largely unknown. Noncoding RNAs (ncRNAs), including microRNAs, long ncRNAs, circular RNAs and PIWI-interacting RNAs, function as major regulators of cellular epigenetic hallmarks via regulation of various molecular and cellular processes. Recently, aberrant expression of ncRNAs has been implicated in many diseases, including craniofacial abnormalities. Consequently, this review focuses on the role and mechanism of ncRNAs in regulating craniofacial development in the hope of providing clues to identify potential therapeutic targets.

Nicotine-induced Genetic and Epigenetic Modifications in Primary Human Amniotic Fluid Stem Cells

BACKGROUND

Smoking during pregnancy has been linked to adverse health outcomes in offspring, but the underlying mechanisms are not fully understood. To date, the effect of maternal smoking has been tested in primary tissues and animal models, but the scarcity of human tissues limits experimental studies. Evidence regarding smoking-related molecular alteration and gene expression profiles in stem cells is still lacking.

METHODS

We developed a cell culture model of human amniotic fluid stem cells (hAFSCs) of nicotine (NIC) exposure to examine the impact of maternal smoking on epigenetic alterations of the fetus.

RESULTS

NIC 0.1 μM (equivalent to "light" smoking, i.e., 5 cigarettes/day) did not significantly affect cell viability; however, significant alterations in DNA methylation and N6-methyladenosine (m6A) RNA methylation in hAFSCs occurred. These epigenetic changes may influence the gene expression and function of hAFSCs. Furthermore, NIC exposure caused time-dependent alterations of the expression of pluripotency genes and cell surface markers, suggesting enhanced cell stemness and impaired differentiation potential. Furthermore, NICtreated cells showed reduced mRNA levels of key adipogenic markers and hypomethylation of the promoter region of the imprinted gene H19 during adipogenic differentiation, potentially suppressing adipo/lipogenesis. Differential expression of 16 miRNAs, with predicted target genes involved in various metabolic pathways and linked to pathological conditions, including cognitive delay and fetal growth retardation, has been detected.

CONCLUSION

Our findings highlight multi-level effects of NIC on hAFSCs, including epigenetic modifications, altered gene expression, and impaired cellular differentiation, which may contribute to long-term consequences of smoking in pregnancy and its potential impact on offspring health and development.

Epigenetic modification impacting brain functions: Effects of physical activity, micronutrients, caffeine, toxins, and addictive substances

Changes in gene expression are involved in many brain functions. Epigenetic processes modulate gene expression by histone modification and DNA methylation or RNA-mediated processes, which is important for brain function. Consequently, epigenetic changes are also a part of brain diseases such as mental illness and addiction. Understanding the role of different factors on the brain epigenome may help us understand the function of the brain. This review discussed the effects of caffeine, lipids, addictive substances, physical activity, and pollutants on the epigenetic changes in the brain and their modulatory effects on brain function.

Female-to-male differential transcription patterns of miRNA-mRNA networks in the livers of dioxin-exposed mice

Non-coding microRNAs (miRNAs) have important roles in regulating the expression of liver mRNAs in response to xenobiotic-exposure, but their roles concerning dioxins such as TCDD (2,3,7,8-Tetrachlorodibenzo-p-dioxin) are less clear. This report concerns the potential implication of liver (class I) and circulating (class II) miRNAs in hepatotoxicity of female and male mice after acute exposure to TCDD. The data show that, of a total of 38 types of miRNAs, the expression of eight miRNAs were upregulated in both female and male mice exposed to TCDD. Inversely, the expression of nine miRNAs were significantly downregulated in both animal genders. Moreover, certain miRNAs were preferentially induced in either females or males. The potential downstream regulatory effects of miRNAs on their target genes was evaluated by determining the expression of three group of genes that are potentially involved in cancer biogenesis, other diseases and in hepatotoxicity. It was found that certain cancer-related genes were more highly expressed females rather than males after exposure to TCDD. Furthermore, a paradoxical female-to-male transcriptional pattern was found for several disease-related and hepatotoxicity-related genes. These results suggest the possibility of developing of new miRNA-specific interfering molecules to address their dysfunctions as caused by TCDD.

The role of microRNAs in nicotine signaling

Cigarette smoking is a harmful habit that is widespread around the world. It is among the well-known lifestyle-related risk factors for many diseases. Nicotine, as its principal constituent, has various detrimental, and beneficial functions. Nicotinic acetylcholine receptors (nAChRs), which are present in nearly all body cells, are how nicotine works. Numerous investigations have demonstrated that nicotine causes abnormal microRNA expression (miRNAs). These short sequences of RNAs are known to regulate gene expression post-transcriptionally. A wide range of miRNAs are modulated by nicotine, and nicotine-induced miRNA changes could subsequently mediate nicotine's effect on gene expression regulation. We will focus on the reciprocal interaction between nAChRs and miRNAs and describe the essential targets of these dysregulated miRNAs after nicotine exposure and activation of nAChRs. It appears that crucial subcellular mechanisms implicated in nicotine's effects are miRNA-related pathways. It is crucial to investigate the molecular mechanism underlying the effects of nicotine as well as the dysregulation of miRNA following nAChR activation. The finding about epigenetic mechanisms of nicotine-induced effects may shed light on the establishment of new treatment strategies to prevent the harmful effects of nicotine and perhaps may augment the beneficial effects in diverse smoking-related diseases.

Epigenetic and Long-Term Effects of Nicotine on Biology, Behavior, and Health

Tobacco and nicotine use are associated with disease susceptibility and progression. Health challenges associated with nicotine and smoking include developmental delays, addiction, mental health and behavioral changes, lung disease, cardiovascular disease, endocrine disorders, diabetes, immune system changes, and cancer. Increasing evidence suggests that nicotine-associated epigenetic changes may mediate or moderate the development and progression of a myriad of negative health outcomes. In addition, nicotine exposure may confer increased lifelong susceptibility to disease and mental health challenges through alteration of epigenetic signaling. This review examines the relationship between nicotine exposure (and smoking), epigenetic changes, and maladaptive outcomes that include developmental disorders, addiction, mental health challenges, pulmonary disease, cardiovascular disease, endocrine disorders, diabetes, immune system changes, and cancer. Overall, findings support the contention that nicotine (or smoking) associated altered epigenetic signaling is a contributing factor to disease and health challenges.

Gut Microbiome and Small RNA Integrative-Omic Perspective of Meconium and Milk-FED Infant Stool Samples

The human gut microbiome plays an important role in health, and its initial development is conditioned by many factors, such as feeding. It has also been claimed that this colonization is guided by bacterial populations, the dynamic virome, and transkingdom interactions between host and microbial cells, partially mediated by epigenetic signaling. In this article, we characterized the bacteriome, virome, and smallRNome and their interaction in the meconium and stool samples from infants. Bacterial and viral DNA and RNA were extracted from the meconium and stool samples of 2- to 4-month-old milk-fed infants. The bacteriome, DNA and RNA virome, and smallRNome were assessed using 16S rRNA V4 sequencing, viral enrichment sequencing, and small RNA sequencing protocols, respectively. Data pathway analysis and integration were performed using the R package mixOmics. Our findings showed that the bacteriome differed among the three groups, while the virome and smallRNome presented significant differences, mainly between the meconium and stool of milk-fed infants. The gut environment is rapidly acquired after birth, and it is highly adaptable due to the interaction of environmental factors. Additionally, transkingdom interactions between viruses and bacteria can influence host and smallRNome profiles. However, virome characterization has several protocol limitations that must be considered.

The effects of maternal cigarette smoking on cadmium and lead levels, miRNA expression and biochemical parameters across the feto-placental unit

Several miRNAs have been previously identified to be associated with cigarette smoke and/or the toxic metals cadmium (Cd) and lead (Pb). The aim of this study was to investigate the associations of maternal cigarette smoking with cadmium (Cd) and lead (Pb) levels, candidate miRNA expression and biochemical parameters across the feto-placental unit. miRNAs were isolated according to protocols provided by manufacturer from 72 healthy postpartum women using Qiagens' kits based on phenol/guanidine samples lysis and silica-membrane purification of total RNA. Candidate miRNAs (miR-1537, miR-190b, miR-16, miR-21, and miR-146a) were quantified by real-time PCR. Biochemical parameters were analyzed in plasma samples by standardized and harmonized enzymatic methods using appropriate calibrators, while CRP was determined by immunoturbidimetric method. Concentration of Cd and Pb in whole blood and placenta samples were measured by inductively coupled plasma mass spectroscopy. Cd levels in smokers were higher in all of the analyzed compartments of the feto-placental unit, Pb in maternal blood and placenta than non-smokers. Smokers also had a higher expression of miR-16 in maternal and miR-146a in cord plasma, and lower expression of miR-21 in the placenta in comparison to non-smokers. Urate concentrations in the maternal plasma of smokers were lower than this value in non-smokers. The study has demonstrated that maternal smoking was associated with toxic metals (Cd and Pb) levels, urate concentration and alteration of miRNA expression. Given that the effects of maternal smoking on miRNA expression are inadequate, all compartments of the feto-placental unit should be analyzed to obtain a complete picture. This paper is the first to report on the results of expression of cellular and circulating miRNAs simultaneously in maternal and fetal compartments and in the placenta.

Epigenetics as a Biomarker for Early-Life Environmental Exposure

PURPOSE OF REVIEW

There is interest in evaluating the developmental origins of health and disease (DOHaD) which emphasizes the role of prenatal and early-life environments on non-communicable health outcomes throughout the life course. The ability to rigorously assess and identify early-life risk factors for later health outcomes, including those with childhood onset, in large population samples is often limited due to measurement challenges such as impractical costs associated with prospective studies with a long follow-up duration, short half-lives for some environmental toxicants, and lack of biomarkers that capture inter-individual differences in biologic response to external environments.

RECENT FINDINGS

Epigenomic patterns, and DNA methylation in particular, have emerged as a potential objective biomarker to address some of these study design and exposure measurement challenges. In this article, we summarize the literature to date on epigenetic changes associated with specific prenatal and early-life exposure domains as well as exposure mixtures in human observational studies and their biomarker potential. Additionally, we highlight evidence for other types of epigenetic patterns to serve as exposure biomarkers. Evidence strongly supports epigenomic biomarkers of exposure that are detectable across the lifespan and across a range of exposure domains. Current and future areas of research in this field seek to expand these lines of evidence to other environmental exposures, to determine their specificity, and to develop predictive algorithms and methylation scores that can be used to evaluate early-life risk factors for health outcomes across the life span.

Global microRNA and protein expression in human term placenta

Introduction

Description of the global expression of microRNAs (miRNAs) and proteins in healthy human term placentas may increase our knowledge of molecular biological pathways that are important for normal fetal growth and development in term pregnancy. The aim of this study was to explore the global expression of miRNAs and proteins, and to point out functions of importance in healthy term placentas.

Materials and methods

Placental samples (n = 19) were identified in a local biobank. All samples were from uncomplicated term pregnancies with vaginal births and healthy, normal weight newborns. Next-generation sequencing and nano-scale liquid chromatographic tandem mass spectrometry were used to analyse miRNA and protein expression, respectively.

Results

A total of 895 mature miRNAs and 6,523 proteins were detected in the placentas, of which 123 miRNAs and 346 proteins were highly abundant. The miRNAs were in high degree mapped to chromosomes 19, 14, and X. Analysis of the highly abundant miRNAs and proteins showed several significantly predicted functions in common, including immune and inflammatory response, lipid metabolism and development of the nervous system.

Discussion

The predicted function inflammatory response may reflect normal vaginal delivery, while lipid metabolism and neurodevelopment may be important processes for the term fetus. The data presented in this study, with complete miRNA and protein findings, will enhance the knowledge base for future research in the field of placental function and pathology.

Smoking and Its Consequences on Male and Female Reproductive Health

Smoking contributes to the death of around one in 10 adults worldwide. Specifically, cigarettes are known to contain around 4000 toxins and chemicals that are hazardous in nature. The negative effects of smoking on human health and interest in smoking-related diseases have a long history. Among these concerns are the harmful effects of smoking on reproductive health. Thirteen percent of female infertility is due to smoking. Female smoking can lead to gamete mutagenesis, early loss of reproductive function, and thus advance the time to menopause. It has been also associated with ectopic pregnancy and spontaneous abortion. Even when it comes to assisted reproductive technologies cycles, smokers require more cycles, almost double the number of cycles needed to conceive as non-smokers. Male smoking is shown to be correlated with poorer semen parameters and sperm DNA fragmentation. Not only active smokers but also passive smokers, when excessively exposed to smoking, can have reproductive problems comparable to those seen in smokers. In this book chapter, we will approach the effect of tobacco, especially tobacco smoking, on male and female reproductive health. This aims to take a preventive approach to infertility by discouraging smoking and helping to eliminate exposure to tobacco smoke in both women and men.

Non-coding RNAs and their cross-talks impacting reproductive health of women

Non-coding RNAs (ncRNAs) work as crucial posttranscriptional modulators of gene expression regulating a wide array of biological processes that impact normal physiology, including reproductive health. The health of women, especially reproductive health, is now a prime focus of society that ensures the females' overall physical, social, and mental well-being. Furthermore, there has been a growing cognizance of ncRNAs' possible applications in diagnostics and therapeutics of dreaded diseases. Hence, understanding the functions and mode of actions of ncRNAs in the context of women's health will allow us to develop effective prognostic and therapeutic strategies that will enhance the quality of life of women. Herein, we summarize recent progress on ncRNAs, such as microRNAs (miRNAs) and long ncRNAs (lncRNAs), and their implications in reproductive health by tying the knot with lifestyle factors that affect fertility complications, pregnancy outcomes, and so forth. We also discourse the interplay among the RNA species, especially miRNAs, lncRNAs, and protein-coding RNAs, through the competing endogenous RNA regulations in diseases of women associated with maternal and fetal health. This review provides new perspectives correlating ncRNAs, lifestyle, and reproductive health of women, which will attract future studies to improve women's lives. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

DNA methylation in former extremely low birth weight newborns: association with cardiovascular and endocrine function

BACKGROUND

There is increased risk of cardiovascular, metabolic, and hypertensive disorders in later life in the preterm population. We studied school-age children who had been born extremely premature who had undergone endocrine, cardiovascular, and anthropometric evaluations.

METHODS

School age measurements of salivary cortisol, adrenal androgens, blood pressure, and anthropometric markers were correlated with DNA methylation of 11-betahydroxysteroid dehydrogenase type 2 (11BHSD2), leptin, and the LINE1 repetitive DNA element.

RESULTS

We observed a modest correlation between log AUC for salivary cortisol and methylation of leptin in preterm infants and a negative correlation between methylation of region 1 of the glucocorticoid receptor (GR in term-born infants. There was an association between LINE1 methylation and cortisol response to awakening and a negative correlation between LINE1 and systolic blood pressure at 6-7 years. Methylation of the GR promoter region showed a positive association with systolic blood pressure at 6-7 years of age.

CONCLUSIONS

These results show that extremely preterm birth, followed by complex patterns of endocrine, cardiovascular, and metabolic exposures during early postnatal life, is associated with lasting changes in DNA methylation patterns in genes involved in hypothalamic pituitary adrenal axis function, adrenal hormonal regulation, and cardiometabolic risk.

IMPACT

Preterm infants have significant environmental and physiological exposures during early life that may have lasting impact on later function. Alterations in hypothalamic pituitary adrenal axis (HPA) function have been associated with these exposures. We examined the associated changes in DNA methylation of important genes involved in HPA function, metabolism, and global DNA methylation. The changes we saw in DNA methylation may help to explain associated cardiovascular, metabolic, and growth disturbance in these children in later life.

Western diet-induced shifts in the maternal microbiome are associated with altered microRNA expression in baboon placenta and fetal liver

Maternal consumption of a high-fat, Western-style diet (WD) disrupts the maternal/infant microbiome and contributes to developmental programming of the immune system and nonalcoholic fatty liver disease (NAFLD) in the offspring. Epigenetic changes, including non-coding miRNAs in the fetus and/or placenta may also underlie this risk. We previously showed that obese nonhuman primates fed a WD during pregnancy results in the loss of beneficial maternal gut microbes and dysregulation of cellular metabolism and mitochondrial dysfunction in the fetal liver, leading to a perturbed postnatal immune response with accelerated NAFLD in juvenile offspring. Here, we investigated associations between WD-induced maternal metabolic and microbiome changes, in the absence of obesity, and miRNA and gene expression changes in the placenta and fetal liver. After ~8-11 months of WD feeding, dams were similar in body weight but exhibited mild, systemic inflammation (elevated CRP and neutrophil count) and dyslipidemia (increased triglycerides and cholesterol) compared with dams fed a control diet. The maternal gut microbiome was mainly comprised of Lactobacillales and Clostridiales, with significantly decreased alpha diversity (P = 0.0163) in WD-fed dams but no community-wide differences (P = 0.26). At 0.9 gestation, mRNA expression of IL6 and TNF in maternal WD (mWD) exposed placentas trended higher, while increased triglycerides, expression of pro-inflammatory CCR2, and histological evidence for fibrosis were found in mWD-exposed fetal livers. In the mWD-exposed fetus, hepatic expression levels of miR-204-5p and miR-145-3p were significantly downregulated, whereas in mWD-exposed placentas, miR-182-5p and miR-183-5p were significantly decreased. Notably, miR-1285-3p expression in the liver and miR-183-5p in the placenta were significantly associated with inflammation and lipid synthesis pathway genes, respectively. Blautia and Ruminococcus were significantly associated with miR-122-5p in liver, while Coriobacteriaceae and Prevotellaceae were strongly associated with miR-1285-3p in the placenta; both miRNAs are implicated in pathways mediating postnatal growth and obesity. Our findings demonstrate that mWD shifts the maternal microbiome, lipid metabolism, and inflammation prior to obesity and are associated with epigenetic changes in the placenta and fetal liver. These changes may underlie inflammation, oxidative stress, and fibrosis patterns that drive NAFLD and metabolic disease risk in the next generation.

miRNA changes in the mouse placenta due to bisphenol A exposure

Aim: To determine small RNA expression changes in mouse placenta induced by bisphenol A (BPA) exposure. Methods: Exposing female mice to BPA two weeks prior to conception through gestational day 12.5; whereupon fetal placentas were collected, frozen in liquid nitrogen and stored at -80°C. Small RNAs were isolated and used for small RNA-sequencing. Results: 43 small RNAs were differentially expressed. Target mRNAs were closely aligned to those expressed by thymus and brain, and pathway enrichment analyses indicated that such target mRNAs regulate neurogenesis and associated neurodevelopment processes. Conclusions: BPA induces several small RNAs in mouse placenta that might provide biomarkers for BPA exposure. Further, the placenta might affect fetal brain development through the secretion of miRNAs.

Effect of E-cigarettes aerosol exposure during lactation in rats: Hormonal and biochemical aspects

Electronic cigarettes (e-cigarettes) have been marketed as a less lethal substitute for smoking traditional cigarettes. This study aims to investigate the impact of e-cigarettes aerosol exposure on lactating dams and pups, whose dams were exposed. Lactating dams received fresh air (control) or e-cigarettes aerosol during lactation (day 4-21). Maternal exposure to e-cigarettes aerosol during lactation induced significant reduction (P < 0.0001) in the fat content of the milk and serum Leptin level (P < 0.005) compared to control dams. Furthermore, pups whose dams were exposed to e-cigarettes during lactation showed an increased level of glucose, thyroxine and decreased level of insulin. The exposure to e-cigarettes aerosol during lactation altered the composition of milk as well as the hormonal and biochemical profile in dams and pups. This result, if observed in women using e-cigarettes, suggests that e-cigarettes' use during lactation may have consequences on the milk production and hormonal and biochemical profile in breastfeeding mothers and nursing babies.

Maternal smoking-induced lung injuries in dams and offspring via inflammatory cytokines

Maternal smoking during pregnancy can induce permanent changes in neonatal inflammation, which will result in lifelong implications. An original study of data from GSE96978, composed of 2 subseries (GSE96976 and GSE96977), investigated genome-wide changes in ELT cells, the lungs of mouse dams and their juvenile offspring and focused on finding an in vitro alternative as a human tissue-based replacement for the use of animals. Therefore, the study only analyzed the similarities of GO terms between ELT cells and dams. However, the relationship between differentially expressed genes (DEGs) in dams and offspring was not investigated. The present study aimed to identify the key molecules involved in maternal smoking-induced dam and offspring lung injuries. Data from GSE96977 were downloaded from Gene Expression Omnibus (GEO) data sets. In our study, differentially expressed genes (DEGs) in dams and offspring were reanalyzed using the limma package. The results of Gene Set Enrichment Analysis (GSEA) showed that the DEGs in the lungs of dams were significantly enriched in immune-related functions and those in the lungs of offspring were enriched in cell growth. Furthermore, a total of 90 DEGs shared in the dam and offspring datasets were screened out. In addition, most of these DEGs were enriched in cytokine and cytokine receptor interaction KEGG pathways. Furthermore, protein-protein interaction (PPI) network analysis screened out 4 core genes in cluster 1. In addition, the miRNAs related to these core genes were predicted, and mmu-miR-1903 was screened out. Taken together, our data indicate that inflammatory responses may play an important role in maternal smoking induced lung injuries in dams and offspring. Furthermore, mmu-miR-1903 is a potential epigenetic biomarker of lung inflammation in the offspring of dams who smoked during pregnancy. In conclusion, by screening shared differential genes, we only need to detect maternal genes to predict maternal smoking-induced lung injuries in offspring.

The importance of non-coding RNAs in environmental stress-related developmental brain disorders: A systematic review of evidence associated with exposure to alcohol, anesthetic drugs, nicotine, and viral infections

Brain development is a dynamic and lengthy process that includes cell proliferation, migration, neurogenesis, gliogenesis, synaptogenesis, and pruning. Disruption of any of these developmental events can result in long-term outcomes ranging from brain structural changes, to cognitive and behavioral abnormality, with the mechanisms largely unknown. Emerging evidence suggests non-coding RNAs (ncRNAs) as pivotal molecules that participate in normal brain development and neurodevelopmental disorders. NcRNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are transcribed from the genome but not translated into proteins. Many ncRNAs have been implicated as tuners of cell fate. In this review, we started with an introduction of the current knowledge of lncRNAs and miRNAs, and their potential roles in brain development in health and disorders. We then reviewed and discussed the evidence of ncRNA involvement in abnormal brain development resulted from alcohol, anesthetic drugs, nicotine, and viral infections. The complex connections among these ncRNAs were also discussed, along with potential overlapping ncRNA mechanisms, possible pharmacological targets for therapeutic/neuroprotective interventions, and potential biomarkers for brain developmental disorders.

The effects of thirdhand smoke on reproductive health

Tobacco smoke is an environmental pollutant that can cause follicle destruction and oocyte dysfunction. Thirdhand smoke (THS) is residual tobacco smoke existing in the environment long after cigarettes have been extinguished, which can react with other environmental compounds to produce secondary pollutants. THS contains a variety of toxic and harmful chemicals, such as nicotine and 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA), a logical biomarker of THS exposure. The health hazards of THS exposure and its components have been researched in recent years. In this review, we have summarized research progress on the effects of THS exposure on organs in mice and humans especially on the reproductive system. This review may help evaluate the health risks of THS, in particular reproduction and offspring health. We hope this review will guide public health education on the dangers of THS exposure and promotion of healthy living habits.

Alterations of epigenetic landscape in Down syndrome carrying pregnancies: A systematic review of case-control studies

OBJECTIVE

Great attention is currently paid to both the pathogenetic mechanisms and non-invasive prenatal diagnosis (NIPD) of Down syndrome (DS). It has been posited that dysregulation of epigenetic signatures including DNA methylation and microRNAs (miRNAs) crucially contribute to the pathomechanism of DS. Therefore, we aimed to perform a systematic review of case-control publications that have examined the differences in epigenetic landscape between pregnancies bearing euploid fetuses and those affected with DS to provide a focused insight into the pathophysiology of DS and also novel biomarkers for NIPD of DS.

STUDY DESIGN

Pertinent keywords were utilized to search into PubMed, Scopus, and Google Scholar. We enrolled studies that have compared the pattern of miRNAs expression profile or DNA methylation between pregnant women who carries DS fetuses and those with euploid fetuses.

RESULTS

An assessment of 599 articles resulted in, finally, 18 eligible studies (12 miRNAs and 6 DNA methylation). The most investigated miRNAs were those that are encoded by genes on chromosome 21 and more hypermethylation regions in DS fetuses than euploids with nearly evenly distribution on all chromosomes were found. Distinct mechanisms with potential therapeutic purposes have been put forward for the involvement of epigenetic perturbations in the etiopathogenesis of DS.

CONCLUSION

There is a disagreement in the recruiting of epigenetic biomarkers for NIPD of DS. This heterogeneity in results of the qualified publications emanates from confounding factors such as differences in demographic data of participants, analytical platforms, and study design. Hence, before harnessing epigenetic signatures for NIPD of DS, more experiments are required.

Epigenetic Alterations of Maternal Tobacco Smoking during Pregnancy: A Narrative Review

In utero exposure to maternal tobacco smoking is the leading cause of birth complications in addition to being associated with later impairment in child's development. Epigenetic alterations, such as DNA methylation (DNAm), miRNAs expression, and histone modifications, belong to possible underlying mechanisms linking maternal tobacco smoking during pregnancy and adverse birth outcomes and later child's development. The aims of this review were to provide an update on (1) the main results of epidemiological studies on the impact of in utero exposure to maternal tobacco smoking on epigenetic mechanisms, and (2) the technical issues and methods used in such studies. In contrast with miRNA and histone modifications, DNAm has been the most extensively studied epigenetic mechanism with regard to in utero exposure to maternal tobacco smoking. Most studies relied on cord blood and children's blood, but placenta is increasingly recognized as a powerful tool, especially for markers of pregnancy exposures. Some recent studies suggest reversibility in DNAm in certain genomic regions as well as memory of smoking exposure in DNAm in other regions, upon smoking cessation before or during pregnancy. Furthermore, reversibility could be more pronounced in miRNA expression compared to DNAm. Increasing evidence based on longitudinal data shows that maternal smoking-associated DNAm changes persist during childhood. In this review, we also discuss some issues related to cell heterogeneity as well as downstream statistical analyses used to relate maternal tobacco smoking during pregnancy and epigenetics. The epigenetic effects of maternal smoking during pregnancy have been among the most widely investigated in the epigenetic epidemiology field. However, there are still huge gaps to fill in, including on the impact on miRNA expression and histone modifications to get a better view of the whole epigenetic machinery. The consistency of maternal tobacco smoking effects across epigenetic marks and across tissues will also provide crucial information for future studies. Advancement in bioinformatic and biostatistics approaches is key to develop a comprehensive analysis of these biological systems.

Role of microRNAs in the pathophysiology of addiction

Addiction is a chronic and relapsing brain disorder characterized by compulsive seeking despite adverse consequences. There are both heritable and epigenetic mechanisms underlying drug addiction. Emerging evidence suggests that non-coding RNAs (ncRNAs) such as microRNAs (miRNAs), long non-coding RNAs, and circular RNAs regulate synaptic plasticity and related behaviors caused by substances of abuse. These ncRNAs modify gene expression and may contribute to the behavioral phenotypes of addiction. Among the ncRNAs, the most widely researched and impactful are miRNAs. The goal in this systematic review is to provide a detailed account of recent research involving the role of miRNAs in addiction. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions RNA in Disease and Development > RNA in Disease.

LINC01128 - miR-16 interaction regulates the migration and invasion of human chorionic trophoblast cells

Objective: Pre-eclampsia (PE) is a major complication of pregnancy, but its pathogenesis is unclear. This study explored the role of LINC01128 in the progression of PE, and its interaction with miR-16 on the behaviors of trophoblasts.Methods: The mRNA levels of LINC01128 and miR-16 in placental tissues and HTR-8/SVneo cells were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell Counting Kit (CCK)-8, wound healing assay and transwell assay were used to detect proliferation, migration and invasion. E-Cadherin, Vimentin, Matrix metalloproteinase 2 (MMP2) and MMP9 protein expressions were detected by Western blot. The correlation between LINC01128 and miR-16 was determined and verified by starBase and dual-luciferase assay.Results: The expression of LINC01128 was downregulated in PE. Overexpression of LINC01128 promoted LINC01128 expression, cell proliferation, migration, invasion and the expressions of Vimentin, MMP2 and MMP9, but inhibited the expression of E-Cadherin. SiLINC01128 showed opposite effects. MiR-16 interacted with LINC01128, and miR-16 was high-expressed in PE placentae. MiR-16 inhibitor promoted cell proliferation, migration, invasion and related protein expressions, but inhibited the expression of E-Cadherin. However, siLINC01128 inhibited the regulatory effect of miR-16 inhibitor on HTR-8/Svneo cells.Conclusion: LINC01128/miR-16 is involved in HTR-8/SVneo cells by regulating the migration and invasion of human chorionic trophoblast cells.

miRNA-138-5p suppresses cigarette smoke-induced apoptosis in testicular cells by targeting Caspase-3 through the Bcl-2 signaling pathway

Long-term cigarette smoking (CS) can cause testicular toxicity, which interferes with normal spermatogenesis and leads to male infertility. One possible mechanism for this is the activation of the apoptosis signaling pathway, which leads to the irreversible apoptosis of testicular cells. However, the exact mechanism for this is not completely understood. Cell viability, cell apoptosis, and lactate dehydrogenase release assays were performed to elucidate the function of micro RNA (miRNA) in the pathogenesis of male testicular cell injury induced by CS. The results suggested that testicular cell injury was associated with CS both in vitro and in vivo. CS extract (CSE)-treated Leydig and Sertoli cells showed noticeable apoptosis. Based on the results of Agilent miRNA microarray and bioinformatics analyses, miRNA-138-5p was used in subsequent experiments. Quantitative polymerase chain reaction and Western blot assays showed a negative correlation between miR-138-5p and Caspase-3 expression. Transfection of miR-138-5p mimic significantly inhibited apoptosis and downregulated the expression of Caspase-3 in TM3 and TM4 cells. Furthermore, a dual-luciferase reporter assay demonstrated that miR-138-5p directly targeted Caspase-3 to regulate the apoptosis of testicular cells mediated by CSE. In addition, overexpression of miR-138-5p markedly downregulated the expression of p53 and Bak, which played critical roles in the Bcl-2 pathway. These results demonstrate that miRNA-138-5p inhibits CS-induced apoptosis in testicular cells by targeting Caspase-3 through the Bcl-2 signaling pathway.

Effects of ethanol and nicotine co-administration on follicular atresia and placental histo-morphology in the first-generation mice pups during intrauterine development and lactation periods

This study is evaluating the effects of ethanol and nicotine exposure during pregnancy and lactation on placenta histology and follicular atresia in the first-generation (f1) mice pups. The experimental groups were 5 groups of NMRI pregnant mice, including: control, vehicle (received normal saline) ethanol (3 g/kg/day, 20 % v/v intraperitoneally), nicotine (1 mg/kg/day, subcutaneously), and ethanol plus nicotine which received both. Pregnant animals in each group were then divided into two groups, one group for examining the placenta that was treated for 18 days and the other group for the ovary of one-day-old (PND1) and fifty-six-day-old (PND56) female offspring who were treated for 42 days (during intrauterine development and lactation). After the autopsy procedure, histopathological and morphometrical observations were done. Data revealed that the exposed mice had a significant change in the placenta morphometry and histology as well as a marked increase in the number of ovarian TUNEL positive cells on postnatal days 1 and 56. Therefore, maternal exposure to alcohol and nicotine during developmental and lactation periods could lead to changes in the placenta properties as well as an increase in the apoptotic ovarian follicles in f1 mice pups.

Peroxisome Proliferator-Activated Receptors (PPAR), fatty acids and microRNAs: Implications in women delivering low birth weight babies

Low birth weight (LBW) babies are associated with neonatal morbidity and mortality and are at increased risk for noncommunicable diseases (NCDs) in later life. However, the molecular determinants of LBW are not well understood. Placental insufficiency/dysfunction is the most frequent etiology for fetal growth restriction resulting in LBW and placental epigenetic processes are suggested to be important regulators of pregnancy outcome. Early life exposures like altered maternal nutrition may have long-lasting effects on the health of the offspring via epigenetic mechanisms like DNA methylation and microRNA (miRNA) regulation. miRNAs have been recognized as major regulators of gene expression and are known to play an important role in placental development. Angiogenesis in the placenta is known to be regulated by transcription factor peroxisome proliferator-activated receptor (PPAR) which is activated by ligands such as long-chain-polyunsaturated fatty acids (LCPUFA). In vitro studies in different cell types indicate that fatty acids can influence epigenetic mechanisms like miRNA regulation. We hypothesize that maternal fatty acid status may influence the miRNA regulation of PPAR genes in the placenta in women delivering LBW babies. This review provides an overview of miRNAs and their regulation of PPAR gene in the placenta of women delivering LBW babies.Abbreviations: AA - Arachidonic Acid; Ago2 - Argonaute2; ALA - Alpha-Linolenic Acid; ANGPTL4 - Angiopoietin-Like Protein 4; C14MC - Chromosome 14 miRNA Cluster; C19MC - Chromosome 19 miRNA Cluster; CLA - Conjugated Linoleic Acid; CSE - Cystathionine γ-Lyase; DHA - Docosahexaenoic Acid; EFA - Essential Fatty Acids; E2F3 - E2F transcription factor 3; EPA - Eicosapentaenoic Acid; FGFR1 - Fibroblast Growth Factor Receptor 1; GDM - Gestational Diabetes Mellitus; hADMSCs - Human Adipose Tissue-Derived Mesenchymal Stem Cells; hBMSCs - Human Bone Marrow Mesenchymal Stem Cells; HBV - Hepatitis B Virus; HCC - Hepatocellular Carcinoma; HCPT - Hydroxycamptothecin; HFD - High-Fat Diet; Hmads - Human Multipotent Adipose-Derived Stem; HSCS - Human Hepatic Stellate Cells; IUGR - Intrauterine Growth Restriction; LA - Linoleic Acid; LBW - Low Birth Weight; LCPUFA - Long-Chain Polyunsaturated Fatty Acids; MEK1 - Mitogen-Activated Protein Kinase 1; MiRNA - MicroRNA; mTOR - Mammalian Target of Rapamycin; NCDs - NonCommunicable Diseases; OA - Oleic Acid; PASMC - Pulmonary Artery Smooth Muscle Cell; PLAG1 - Pleiomorphic Adenoma Gene 1; PPAR - Peroxisome Proliferator-Activated Receptor; PPARα - PPAR alpha; PPARγ - PPAR gamma; PPARδ - PPAR delta; pre-miRNA - precursor miRNA; RISC - RNA-Induced Silencing Complex; ROS - Reactive Oxygen Species; SAT - Subcutaneous Adipose Tissue; WHO - World Health Organization.

Comparison and optimisation of microRNA extraction from the plasma of healthy pregnant women

Circulating microRNA (miRNA) biomarkers are implicated in the diagnosis, monitoring and prediction of various disease processes. Before embarking upon biomarker discovery, miRNA extraction techniques must first be optimised in the biofluid and population under study. Using plasma from a healthy pregnant woman, it was attempted to optimise and compare the performance of two commercially available miRNA extraction kits; Qiagen (miRNeasy Serum/Plasma) and Promega (Maxwell^® RSC miRNA from Tissue or Plasma or Serum). Sample miRNA content (concentration and percentage) was assessed using Agilent Bioanalyzer Small RNA chips and reverse transcription-quantitative PCR (RT-qPCR) using four constitutively expressed miRNAs (hsa-miR-222-3p, hsa-let-7i-3p, hsa-miR-148-3p and hsa-miR-30e-5p). Quality control spike-ins monitored RNA extraction (UniSp2, 4 and 5) and cDNA synthesis (UniSp6, cel-miR-39-3p) efficiency. Optimisation approaches included: i) Starting volume of plasma; the addition of ii) Proteinase K; iii) a RNA bacteriophage carrier (MS2); and iv) a glycogen carrier. The two kits exhibited equivalence in terms of miRNA recovery based on Bioanalyzer and RT-qPCR ΔΔCq results. Optimisation attempts for both kits failed to improve upon miRNA content compared with standard methodology. Comparing the standard methodology, the Qiagen kit was more consistent (smaller variance of ΔCq values) compared with the Promega kit. The standard methodology of either kit would be suitable for the investigation of miRNA biomarkers in a healthy pregnant population.

The influence of lifestyle factors on miRNA expression and signal pathways: a review

The term 'lifestyle' includes different factors that contribute to the maintenance of a good health status. Increasing evidences suggest that lifestyle factors may influence epigenetic mechanisms, such as miRNAs expression. The dysregulation of miRNAs can modify the expression of genes and molecular pathways that may lead to functional alterations. This review summarizes human studies highlighting that diet, physical activity, smoking and alcohol consumption may affect the miRNA machinery and several biological functions. Most miRNAs are involved in molecular pathways that influence inflammation, cell cycle regulation and carcinogenesis resulting in the onset or progression of pathological conditions. Investigating these interactions will be pivotal for understanding the etiology of pathologic processes, the potential new treatment strategies and for preventing diseases.

Pre-amplification as a method for improvement of quantitative RT-PCR analysis of circulating miRNAs

Introduction

The assessment of circulating miRNAs is challenging and still limited due to their low concentrations, small size and lack of reference values in human biological samples. Pre-amplification of complementary DNAs may facilitate reliable miRNA quantification. The aim of our study was to evaluate the efficacy of pre-amplification as a step to increase the sensitivity of qPCR analysis for five candidate circulating miRNAs presumably related to toxic metals and cigarette smoke exposure: miR-1537, miR-190b, miR-16, miR-21, and miR-146a.

Materials and methods

Candidate miRNAs expression was analysed in plasma samples of 19 mother-newborn pairs. For isolation, transcription, pre-amplification and qPCR quantification kits and protocols by Qiagen (Hilden, Germany) were used. Paired t-test or Wilcoxon rank test were used to compare miRNAs expression levels with and without a pre-amplification step prior to qPCR, separately in maternal and cord plasma. Intraclass correlation (ICC) was calculated as an agreement measure between procedures for each miRNA.

Results

Pre-amplification facilitated the detection of all assayed miRNAs with an overall cycle threshold (C_T) improvement of 6.6 ± 0.89 (P < 0.05). Excellent ICCs (> 0.90) were found between data for preamplified and not preamplified miR-16, miR-21 and miR-146a. However, these correlations for low expressed miR-190b were moderate (0.79 in maternal; 0.61 in cord plasma) and poor for miR-1537 (0.49 in maternal; no correlation in cord plasma).

Conclusion

Pre-amplification is a useful, necessary step in the analysis of miR-1537 and miR-190b as a reliable procedure facilitating extracellular miRNA expression detection in human plasma by real-time PCR quantification.

A role for microRNAs in the epigenetic control of sexually dimorphic gene expression in the human placenta

Aim: The contribution of miRNAs as epigenetic regulators of sexually dimorphic gene expression in the placenta is unknown. Materials & methods: 382 placentas from the extremely low gestational age newborns (ELGAN) cohort were evaluated for expression levels of 37,268 mRNAs and 2,102 miRNAs using genome-wide RNA-sequencing. Differential expression analysis was used to identify differences in the expression based on the sex of the fetus. Results: Sexually dimorphic expression was observed for 128 mRNAs and 59 miRNAs. A set of 25 miRNA master regulators was identified that likely contribute to the sexual dimorphic mRNA expression. Conclusion: These data highlight sex-dependent miRNA and mRNA patterning in the placenta and provide insight into a potential mechanism for observed sex differences in outcomes.

Placental microRNAs: Responders to environmental chemicals and mediators of pathophysiology of the human placenta

MicroRNAs (miRNAs) are epigenetic modifiers that play an important role in the regulation of the expression of genes across the genome. miRNAs are expressed in the placenta as well as other organs, and are involved in several biological processes including the regulation of trophoblast differentiation, migration, invasion, proliferation, apoptosis, angiogenesis and cellular metabolism. Related to their role in disease process, miRNAs have been shown to be differentially expressed between normal placentas and placentas obtained from women with pregnancy/health complications such as preeclampsia, gestational diabetes mellitus, and obesity. This dysregulation indicates that miRNAs in the placenta likely play important roles in the pathogenesis of diseases during pregnancy. Furthermore, miRNAs in the placenta are susceptible to altered expression in relation to exposure to environmental toxicants. With relevance to the placenta, the dysregulation of miRNAs in both placenta and blood has been associated with maternal exposures to several toxicants. In this review, we provide a summary of miRNAs that have been assessed in the context of human pregnancy-related diseases and in relation to exposure to environmental toxicants in the placenta. Where data are available, miRNAs are discussed in their context as biomarkers of exposure and/or disease, with comparisons made across-tissue types, and conservation across studies detailed.

The impact of tobacco chemicals and nicotine on placental development

Despite decades of messages warning about the dangers of tobacco use in pregnancy, 10% to 15% of pregnant women continue to smoke. Furthermore, an increased popularity of electronic nicotine delivery systems (ENDS) over the past decade in women of childbearing age raises parallel concerns regarding the effects of vaporized nicotine use in pregnancy. While research using animal models which mimic tobacco smoke and nicotine exposure in pregnancy have largely replicated findings in humans, few studies focus directly on the effects of these exposures on the placenta. Because the placenta is a fetal derived tissue, and nicotine and other components of tobacco smoke are either processed by or transported directly through the placenta, such studies help us understand the risks of these exposures on the developing fetus. In this review, we summarize research on the placenta and placental-derived cells examining either tobacco smoke or nicotine exposure, including both histologic and subcellular (ie, epigenetic and molecular) modifications. Collectively, these studies reveal that tobacco and nicotine exposure are accompanied by some common and several unique molecular and epigenomic placental modifications. Consideration of the nature and sequelae of these molecular mediators of risk may help to better inform the public and more effectively curtail modifiable behavior.

Genome-wide miRNA profiling in plasma of pregnant women with down syndrome fetuses

Down syndrome (DS) is one of the most common causes of intellectual disability and new approaches allowing its rapid and effective prenatal detection are being explored. In this study, we investigated the diagnostic potential of plasma microRNAs (miRNAs). This study builds upon our previous study in DS placentas, where seven miRNAs were found to be significantly up-regulated. A total of 70 first-trimester plasma samples from pregnant women were included in the present study (35 samples with DS fetuses; 35 with euploid fetuses). Genome-wide miRNA profiling was performed in the pilot study using Affymetrix GeneChip™ miRNA 4.1 Array Strips (18 samples). Selected miRNAs were then analysed in the validation study using quantitative reverse transcription PCR (RT-qPCR; 52 samples). Based on the current pilot study results (12 miRNAs), our previous research on chorionic villi samples (7 miRNAs) and the literature (4 miRNAs), a group of 23 miRNAs was selected for the validation study. Although the results of the pilot study were promising, the validation study using the more sensitive RT-qPCR technique and a larger group of samples revealed no significant differences in miRNA profiles between the compared groups. Our results suggest that testing of the first-trimester plasma miRNAs is probably not suitable for non-invasive prenatal testing (NIPT). Different results could be theoretically achieved at later gestational ages; however, such a result probably would have limited use in clinical practice.

Influence of Second-Hand Smoke and Prenatal Tobacco Smoke Exposure on Biomarkers, Genetics and Physiological Processes in Children-An Overview in Research Insights of the Last Few Years

Children are commonly exposed to second-hand smoke (SHS) in the domestic environment or inside vehicles of smokers. Unfortunately, prenatal tobacco smoke (PTS) exposure is still common, too. SHS is hazardous to the health of smokers and non-smokers, but especially to that of children. SHS and PTS increase the risk for children to develop cancers and can trigger or worsen asthma and allergies, modulate the immune status, and is harmful to lung, heart and blood vessels. Smoking during pregnancy can cause pregnancy complications and poor birth outcomes as well as changes in the development of the foetus. Lately, some of the molecular and genetic mechanisms that cause adverse health effects in children have been identified. In this review, some of the current insights are discussed. In this regard, it has been found in children that SHS and PTS exposure is associated with changes in levels of enzymes, hormones, and expression of genes, micro RNAs, and proteins. PTS and SHS exposure are major elicitors of mechanisms of oxidative stress. Genetic predisposition can compound the health effects of PTS and SHS exposure. Epigenetic effects might influence in utero gene expression and disease susceptibility. Hence, the limitation of domestic and public exposure to SHS as well as PTS exposure has to be in the focus of policymakers and the public in order to save the health of children at an early age. Global substantial smoke-free policies, health communication campaigns, and behavioural interventions are useful and should be mandatory.

MicroRNAs and Xenobiotic Toxicity: An Overview

The advent of new technologies has paved the rise of various chemicals that are being employed in industrial as well as consumer products. This leads to the accumulation of these xenobiotic compounds in the environment where they pose a serious threat to both target and non-target species. miRNAs are one of the key epigenetic mechanisms that have been associated with toxicity by modulating the gene expression post-transcriptionally. Here, we provide a comprehensive view on miRNA biogenesis, their mechanism of action and, their possible role in xenobiotic toxicity. Further, we review the recent in vitro and in vivo studies involved in xenobiotic exposure induced miRNA alterations and the mRNA-miRNA interactions. Finally, we address the challenges associated with the miRNAs in toxicological studies.

MiRNA-146a Polymorphism Was Not Associated with Malaria in Southern India

Micro-RNAs (miRNAs) play a crucial role in immune regulation, and a common miRNA-146a polymorphism (rs2910164) increased the odds of falciparum malaria in pregnant African women. Here, we examined whether this association holds true in a different population, that is, 449 mainly male and adult malaria patients and 666 community controls in southwestern India. Plasmodium vivax malaria (67%) predominated over falciparum malaria (11%) and mixed species infections (22%). Overall, 59% of the study participants carried the miRNA-146a polymorphism. However, it was not associated with the odds of malaria, irrespective of parasite species. This underlines the importance of considering the complexities of clinical manifestations of malaria, genetic background, and parasite species when disentangling the role of human genetic variation, including those of miRNAs in malaria.

Placenta-specific plasma miR518b is a potential biomarker for preeclampsia

INTRODUCTION

MicroRNAs have a significant role in the pathogenesis of preeclampsia. Circulating microRNAs could represent a potential biomarker for preeclampsia. The aim of this study was to evaluate plasma miR210-3p and miR518b in preeclampsia and healthy pregnancy for the first time by digital droplet PCR (ddPCR).

METHODS

Thirty-six pregnant women (seventeen healthy pregnancies, nineteen preeclampsia patients) were involved from the Clinic for Gynaecology and Obstetrics "Narodni front" in Belgrade, Serbia. Plasma miR210-3p, miR518b and cel-miR-39 as a spike-in control were measured by ddPCR.

RESULTS

MiR518b was significantly elevated in preeclampsia compared to a healthy pregnancy (P = 0.034; 0.302(0.217-0.421) vs. 0.171(0.110-0.266)). MiR210-3p showed no significant difference between the two groups (P = 0.951). The adjustment of miR518b was made for a gestational age and smoking status and the difference between the preeclampsia and healthy pregnancy group was more significant (P = 0.026; 0.300(0.216-0.419) vs. 0.172(0.121-0.245)). Plasma miR-518b was significantly higher in the group of preeclampsia patients with proteinuria above the 75th percentile for the group (P = 0.033), in women who smoked (P = 0.039), and was positively related to uric acid in preeclampsia (P = 0.018, r = 0.536). Plasma miR518b was able to significantly discriminate between preeclampsia and healthy pregnancy, yielding AUC of 0.712 (95%CI:0.539-0.891), P = 0.028.

CONCLUSIONS

In this study plasma microRNA were measured for the first time in preeclampsia and healthy pregnancies with ddPCR. Placenta-specific miR-518b could serve as a potential biomarker for discriminating preeclampsia and healthy pregnancy, which should be confirmed on a larger study population. This study has failed to confirm the same potential for miR210-3p.

Maternal Tobacco Smoke Exposure Causes Sex-Divergent Changes in Placental Lipid Metabolism in the Rat

Maternal tobacco smoke exposure (MTS) affects fetal acquisition of long-chain polyunsaturated fatty acids (LCPUFA) and increases the risk of obesity and cardio-metabolic disease in the offspring. Alterations in fetal LCPUFA acquisition in maternal smoking are mediated by the placenta. The handling of LCPUFA by the placenta involves protein-mediated transfer and storage. Molecular mediators of placental LCPUFA handling include PPARγ and the fatty acid transport proteins. We previously demonstrated, in a rat model, that MTS results in programming of adult-onset obesity and metabolic disease in male, but not female, offspring. In this study, we test the hypothesis that in utero MTS exposure alters placental structure, placental LCPUFA handling, and fetal fatty acid levels, in a sex-divergent manner. We exposed pregnant rats to tobacco smoke from embryonic day 11 to term gestation. We measured placental and fetal fatty acid profiles, the systolic/diastolic ratio (SD ratio), placental histology, and expression of molecular mediators in the placenta. Our primary finding is that MTS alters fatty acid profiles in male, but not female fetuses and placenta, including increasing the ratio of omega-6 to omega-3 fatty acids. MTS also increased SD ratio in male, but not female placenta. In contrast, the expression of PPARγ and FATPs was upregulated in female, but not male placenta. We conclude that MTS causes sex-divergent changes in placental handling of LCPUFA in the rat. We speculate that our results demonstrate an adaptive response to MTS by the female placenta.

Environmental Influencers, MicroRNA, and Multiple Sclerosis

Multiple sclerosis (MS) is a complex neurological disorder characterized by an aberrant immune system that affects patients' quality of life. Several environmental factors have previously been proposed to associate with MS pathophysiology, including vitamin D deficiency, Epstein-Barr virus (EBV) infection, and cigarette smoking. These factors may influence cellular molecularity, interfering with cellular proliferation, differentiation, and apoptosis. This review argues that small noncoding RNA named microRNA (miRNA) influences these factors' mode of action. Dysregulation in the miRNAs network may deeply impact cellular hemostasis, thereby possibly resulting in MS pathogenicity. This article represents a literature review and an author's theory of how environmental factors may induce dysregulations in the miRNAs network, which could ultimately affect MS pathogenicity.

MicroRNAs as Epigenetic Targets of Cigarette Smoke During Embryonic Development

The adverse developmental effects of exposure to Cigarette Smoke (CS) during pregnancy are documented in this paper. These include low birth weight, congenital anomalies, preterm birth, fetal mortality and morbidity. The current biological thought now recognizes that epigenetics represents a fundamental contributing process in embryogenesis, and that the environment can have a profound effect on shaping the epigenome. It has become increasingly recognized that genes encoding microRNAs (miRNAs) might be potential loci for congenital disabilities. One means by which CS can cause developmental anomalies may be through epigenetic mechanisms involving altered miRNA expression. While several studies have focused on genes affected by CS during embryonic/ fetal development, there is a paucity of knowledge on the involvement of miRNAs in this process. This brief review summarizes the current state of knowledge in this area.