Effect of Maternal Tobacco Smoke Exposure on the Placental Transcriptome

Article Outline

• Abstract
• 1. Introduction
• 2. Materials and methods
  • 2.1. Study cohort
  • 2.2. Samples
  • 2.3. Microarray assay
  • 2.4. Quantitative real time polymerase chain reaction (qRT-PCR)
• 3. Results
  • 3.1. Placental transcriptome
  • 3.2. Effect of tobacco smoke on the placental transcriptome
  • 3.3. Validation of array data by qRT-PCR
• 4. Discussion
• Conflict of interest statement
• Acknowledgments
• AppendixSupporting data
• References
• Copyright

Abstract 

Smoking in pregnancy increases a woman's risk of preterm delivery resulting in serious neonatal health problems and chronic lifelong disabilities for the children (e.g., mental retardation, learning problems). To study the effects of tobacco smoke on the placental transcriptome, we performed gene expression profiling on placentas from women exposed to tobacco smoke in pregnancy (N = 12) and from those without significant exposure (N = 64).

Gene expression profiles were determined by Illumina HumanRef-8 v2 Expression BeadChips with 18,216 gene probes. Microarray data were normalized by quantile method and filtered for a detection P-value <0.01. Differential gene expression was determined by moderated t-statistic. A linear model was fitted for each gene given a series of arrays using lmFit function. Multiple testing correction was performed using the Benjamini and Hochberg method.

Abundant levels of transcripts were found for genes encoding placental hormones (CSH1, CSHL1), pregnancy-specific proteins (PSG3, PSG4, PAPPA), and hemoglobins (HBB, HBG, HBA). Comparative analysis of smokers vs nonsmokers revealed the differential expression of 241 genes (P < 0.05). In smoker cohort, we detected high up-regulation of xenobiotic genes (CYP1A1, CYP1B1, CYB5A, COX412), collagen genes (e.g., COL6A3, COL1A1, COL1A2), coagulation genes (F5, F13A1) as well as thrombosis-related genes (CD36, ADAMTS9, GAS6).

In smokers, we identified deregulated genes that show tissue non-specific induction and may be considered as general biomarkers of tobacco smoke exposure. Further, we also found genes specifically deregulated in the exposed placentas. Functional annotation analysis suggested processes and pathways affected by tobacco smoke exposure that may represent molecular mechanisms of smoke-induced placental abnormalities.

Keywords: Placenta, Gene expression, Tobacco smoke exposure

Back to Article Outline

1. Introduction 

Smoking is a major public health problem, even though number of unambiguous knowledge about its negative effect on human health is increasing. Cigarette smoke contains more than 2500 chemicals and certain of these are harmful to the developing fetus and cause adverse pregnancy outcomes. Epidemiological studies suggest that, depending on the population, 12–31% of pregnant women smoke [1], [2], [3], [4], although during the previous two decades maternal smoking has dropped by 60% in the developed countries [1]. Exposure to cigarette smoke during pregnancy is associated with slow pre- and postnatal-growth and nearly doubles a woman's risk of having a low birth weight baby (<2500 g) [1], [5], [6], [7]. A dose–response association was observed between number of cigarettes smoked by pregnant women and the risk of intrauterine growth retardation; similarly this relationship was confirmed even for secondhand smoking [7]. Tobacco exposure also increases the risk of preterm delivery resulting in serious health problems for the child during the neonatal period, leading to chronic lifelong disabilities (such as cerebral palsy, mental retardation and learning problems) and even death [8]. Prenatal nicotine exposure represents a significant risk factor for sudden infant death syndrome (SIDS), which is the leading cause of death of infants in the developed countries [9].

Maternal smoking also impairs placental development and anatomy. During pregnancy, cigarette smoking can affect placental nutrient function by reducing maternal uterine blood flow, leading to hypoxia [10]. Further, it can cause placenta previa (a low-placed placenta that covers part or all of the internal cervical os), placental abruption (in which the placenta peels away, partially or almost completely before delivery), resulting in bleeding during delivery and premature rupture of the placental membranes [11], [12].

Tobacco smoke-induced alterations in the transcriptome have been studied in human lung cells, peripheral blood cells and a mouse model [13], [14], [15], [16]. These studies showed that tobacco smoke causes significant changes in gene expression levels in the exposed tissues, indicating negative effects on the regulation of biological processes. However, there is limited information about the molecular mechanisms linking tobacco smoke exposure with placental complications.

Huuskonen et al. studied alterations in gene expression for xenobiotic- and steroid-metabolizing genes in a small set of term placentas of smoking women and identified induction of CYP1 family members (CYP1A1, CYP1B1 and CYP1A2) and the glutathione-S-transferase gene (GSTA1) [17]. However, CYP genes are also expressed constitutively in the placenta and show trimester-specific transcript levels: e.g., CYP1A1, 1A2, 2C, 2D6, 2E1, 2F1, 3A4, 3A5 and 3A7 are expressed in the first trimester [18]. Sitras et al. analyzed global placental gene expression in intrauterine growth restriction and studied the possible additional effects of preeclampsia [19]. They showed that placental insufficiency alters placental glucocorticoid metabolism, upregulates inflammatory response in placenta and shares common pathogenic mechanisms with severe early-onset preeclampsia. Surprisingly, smoking was found to be protective against preeclampsia in young women without pregestational hypertension [20]. Smoking in pregnancy is also associated with dysregulation of trophoblastic expression of molecules that govern cellular responses to oxygen tension. In this context, hypoxia and nicotine exposure dramatically impair expression of hypoxia-inducible (pVHL and HIF2α) and angiogenic factors (VEGFs) [21]. Moreover, passive exposure to tobacco smoke has almost the same detrimental effects as active smoking on placental development [21].

In this study, we performed gene expression profiling in term placentas from women who were exposed to tobacco smoke during pregnancy and compared these profiles with those of women without significant exposure. We also analyzed the affected biological processes and signaling pathways that may represent molecular mechanisms of placental defects caused by smoking.

Back to Article Outline

2. Materials and methods 

2.1. Study cohort 

The study comprised 76 women who gave birth to a baby at the Children Hospital of Motol in Prague between 17 June and 26 June 2007 (12 deliveries) and 8 October 2007 and 26 February 2008 (64 deliveries). The study was approved by the Institutional Review Board of the Faculty Hospital Motol. All participants provided written informed consent and completed a questionnaire including information about their smoking history in pregnancy (cigarette numbers per day, timing, exposure to secondhand smoking), life style (diet, alcohol drinking, area of residency), pregnancy history (use of medications, diseases), delivery course and newborn characteristics.

Tobacco smoke exposure during pregnancy was declared by 10 women (samples P105, P115, P131, P133, P139, P157, P162, P170, P174 and P179) in the questionnaire. The average numbers of cigarettes smoked per day in every trimester were seven in the first trimester, six in the second trimester and five in the third trimester. However, the questionnaire data might have been unreliable. Therefore, smoking status was further confirmed by measurement of plasma cotinine levels in women from venous and cord blood [22] and we found two additional women with excess levels (P137 and P150). The levels of DNA adducts and oxidative stress markers in the placentas have been described [22], [23]. Characteristics of women based on their smoking status are summarized in Table 1. The smoker cohort did not differ significantly from nonsmoker cohort in most parameters (BMI/P = 0.13, gestational age/P = 0.69, placental volume/P = 0.58, birth weight/P = 0.18), only maternal age showed significant difference at P < 0.01.

Table 1. Characteristics of women based on their smoking status.

Detailed information for particular subjects are available in the GEO database under the accession number GSE18044 (http://www.ncbi.nlm.nih.gov/geo/). Some information for subject P163 were not available.

2.2. Samples 

The placental samples were prepared according to a standard protocol [24]. Villus parenchymal sections were obtained by dissecting a 1.5-cm square segment (approximately 5 cm away from the site of cord insertion) and then splitting it into three equal parts: maternal (including the thin basal plate), middle and fetal (including the chorionic plate). The middle sections were frozen in RNA Later solution (Ambion, Austin, TX, USA) and stored at −20 °C until RNA isolation.

Total RNA was isolated from the tissue using RNeasy Mini Kits (Qiagen, Hilden, Germany) according to the manufacturer instructions. Integrity of the RNA was assayed using an Agilent 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA) and only samples with a score above 7.0 were processed.

2.3. Microarray assay 

Gene expression profiling was performed using HumanRef-8 v2 Expression BeadChips (Illumina, San Diego, CA, USA) as described [25]. Briefly, cRNA was generated from 200 ng of total RNA using Illumina TotalPrep RNA Amplification Kit (Ambion) with 14 h in vitro transcription reaction. Amplified cRNA (750 ng) was hybridized to the array according to the manufacturer's manual. Hybridized slides were scanned on an Illumina BeadArray Reader and bead level data were summarized by Illumina BeadStudio Software v2.

Bead summary data were imported into R statistical environment (http://www.r-project.org) and normalized using the quantile method in the Lumi package. Only probes with a detection P-value < 0.01 in more than 50% of arrays were included for further analyses. Differential gene expression was analyzed in the Limma package using moderated t-statistic. A linear model was fitted for each gene given a series of arrays using lmFit function [26]. Multiple testing correction was performed using the Benjamini and Hochberg method. Hierarchical clustering analysis of the samples and genes was performed using the average linkage and Euclidean distance.

Protein ANalysis THrough Evolutionary Relationships (PANTHER) Classification System (http://www.pantherdb.org/) was used to characterize placental transcriptome. The test list (7297 transcripts) was determined by data filtering for a detection P-value < 0.01 in all nonsmoker samples. Statistically significant overrepresentation of genes in the test list relative to the reference list was determined by binomial test. The list of transcripts represented on the Illumina HumanRef-8 v2 Expression BeadChip was used as the reference list. The P-values were adjusted with Bonferroni correction for multiple testing. Database for Annotation, Visualization and Integrated Discovery (DAVID) (http://david.abcc.ncifcrf.gov/) was used to extract biological meaning from the list of deregulated genes [27]. The enrichment score of each group was measured by the geometric mean of the EASE Scores (modified Fisher's exact test). EASE calculated overrepresentation with respect to the total number of genes assayed and annotated within each group on the background of Illumina HumanRef-8 v2 Expression BeadChips.

The complete microarray data were deposited in Gene Expression Omnibus (GEO) database under the accession number GSE18044 (http://www.ncbi.nlm.nih.gov/geo/).

2.4. Quantitative real time polymerase chain reaction (qRT-PCR) 

Transcript levels of selected genes from various functional categories were analyzed by qRT-PCR using TaqMan Gene Expression Assays (Hs00164383_m1: CYP1B1, Hs00261747_m1: COX412, Hs00173472_m1: PLA2G5, Hs00609865_m1: EDNRA, Hs00197387_m1: PROCR) (Applied Biosystems, Foster City, CA, USA) according to the manufacturer instructions. Briefly, 500 ng of total RNA was reverse transcribed using MMLV transcriptase under the following conditions: 70 °C for 5 min, 42 °C for 1 h and 95 °C for 2 min. The conditions for the PCR reaction were as follows: 95 °C for 10 min followed by 40 cycles of 95 °C for 15 s and 60 °C for 1 min using a Corbett RotorGene 3000 thermal cycler (Qiagen). The gene expression levels were normalized to β2-microglobulin (Hs99999907_m1, Applied Biosystems). This control gene showed stable expression across all samples in microarray data set and there was non-significant difference between smokers (avg. signal: 4147.6 ± 605) and controls (avg. signal: 4002.5 ± 1277) (P = 0.71). Relative fold changes of gene expression were calculated using the ΔΔCT method [28]. Differences between the mean gene expression levels of smokers and nonsmokers were evaluated using Student's t-test.

Back to Article Outline

3. Results 

3.1. Placental transcriptome 

Gene expression profiles were determined in 76 placental samples using Illumina HumRef8 Beadchips with 18,216 gene probes (gene annotation file at http://www.switchtoi.com/annotationfiles.ilmn). Out of these, 10,590 genes were expressed at a detectable level under described settings (see Materials and methods). The profiles of placental samples showed relatively consistent patterns of gene expression; 94.3% genes had standard deviation from the mean of <40%. This variation likely reflected inter-individual variability in population as well as effect of smoke exposure.

Abundant levels of transcript were found in genes encoding e.g. placental hormones (CSH1 and CSHL1), pregnancy-specific proteins (PSG3, PSG4, PSG5 and PAPPA), hemoglobins (HBB, HBG and HBA), translation factors (EEF1A1, RPS29 and TPT1), placental enzyme (ALPP) and placental growth factor (PGF). List of 100 genes with the highest transcript levels in all samples is summarized in SI Table 1.

The 7297 genes expressed in placentas of all nonsmokers were analyzed by PANTHER Classification System to determine Gene Ontology (GO) categories most represented in the gene list. The analysis showed significant over- and under- representation of the genes involved in protein and nucleic acid metabolism, protein biosynthesis, modification, and traffic. In terms of molecular function, the genes were mostly categorized as nucleic acid binding factors, ribosomal proteins, and proteins participating in membrane transport. Enriched biological processes and molecular functions of the placental genes are summarized in Table 2.

Table 2. Over- and under- represented biological processes and molecular functions of genes expressed in the placenta.

Major Gene Ontology (GO) categories of 7297 genes expressed in placentas of all nonsmokers were analyzed using the PANTHER Classification System. Counts of genes present in the GO category and expected count are shown. Cut-off value of statistical significance for GO enrichment in the gene list was set up to P ≤ 10⁻⁷.

3.2. Effect of tobacco smoke on the placental transcriptome 

The study cohort comprised 12 subjects exposed to tobacco smoke during pregnancy and 64 subjects without significant exposure. Comparative analysis of the gene expression profiles between smokers and nonsmokers determined differential expression of 241 genes at P < 0.05 (SI Table 2). Out of these, 178 genes were up-regulated and 63 genes down-regulated in placentas of smokers. Hierarchical clustering analysis of the subjects according to the differentially expressed genes did not group the smokers into one homogenous cluster (Fig. 1) but the cluster was mixed with few nonsmokers (P101, P161, P124, P136, P135 and P140). On the other hand, two smokers (P150 and P162) showed distinct expression profile and resembled the nonsmokers.

• 
  • View Large Image
  • Download to PowerPoint

• Fig. 1 

  Hierarchical clustering analysis of women exposed to tobacco smoke and those without exposure according to 100 differentially expressed genes with the lowest P value. Each column represents a separate sample and each row a single gene. The relative gene expressions are expressed by a gradient intensity of color. The lightest red indicates the lowest expression and the lightest green indicates maximal expression. The color bar at the top of the heat map indicates women categorized for smoking status: red indicates smokers and blue indicates nonsmokers.

In smokers, significantly increased levels of transcripts were observed in genes coding xenobiotic-metabolizing enzymes (CYP1A1, CYP1B1, CYB5A and COX412), collagen genes (COL6A3, COL1A1, COL1A2, COL6A1, COL3A1, COL4A1, COL5A1 and COL6A2), extracellular matrix genes (EFEMP1, MXRA5, SPON1, EFEMP2 and FRAS1), coagulation genes (F5, F13A1), endothelial genes (EDG2, EDNRA, LIPG, LYVE1 and PECAM1), vascular genes (CTHRC1, AGTR1) and inflammation genes (PLA2G5, AFAP1L2 and IL33). In contrast, the greatest reduction of expression was found in genes related to adipocytes (LEP, LPL), anion transport (SLCO4A1, SLC39A6 and SLC7A1), polyamine biosynthesis (AMD1), pregnancy maintenance (PROCR) and genotoxic stress (NEK11).

Functional annotation analysis of differently expressed genes in smokers revealed several biological processes (P < 0.0001), in which the genes are involved (Table 3). The processes were mainly related to development, metabolism, ion transport and adhesion. Using the KEGG database we analyzed signaling pathways that could be affected by tobacco smoke exposure and determined significant enrichment (P < 0.05) of the genes in pathways involving cell communication, extracellular matrix (ECM)–receptor interactions, focal adhesion and metabolism of amino acids.

Table 3. Enriched biological processes and pathways of 241 differently expressed genes in placentas of smokers.

Major Gene Ontology (GO) categories of 178 up-regulated and 63 down-regulated genes in placentas of smokers were analyzed using DAVID Database. Count of genes present in the GO category is shown. Cut-off value of statistical significance for GO enrichment in the gene list was P < 10⁻⁴ for up-regulated gene and P < 0.05 for down-regulated genes and pathways.

3.3. Validation of array data by qRT-PCR 

To validate microarray data we chose 5 genes (CYP1B1, COX412, PLA2G5, EDNRA and PROCR) from various functional categories. Transcript levels of these genes were assayed in all samples by qRT-PCR and relative ratios (smokers vs controls) were calculated. The ratios obtained by microarrays and qRT-PCR showed high correlation (r² = 0.95, P < 0.01). We confirmed up-regulated expression of CYP1B1 (12.8-fold, P < 0.01), COX412 (4.4-fold, P < 0.001), PLA2G5 (4.2-fold, P < 0.001) and EDNRA (6.2-fold, P < 0.001) and down-regulated expression of PROCR (0.8-fold, P = 0.13) in smoking women (Fig. 2).

• 
  • View Large Image
  • Download to PowerPoint

• Fig. 2 

  Gene expression of selected genes in controls and smokers detected by qRT-PCR. The values are expressed as 2−ΔΔCt and presented as the mean plus standard error. CTR-controls, SK-smokers, **p < 0.01.

Back to Article Outline

4. Discussion 

Smoking significantly increases the rate of low birth weight infants and intrauterine growth retardation [29]. These outcomes influence the subsequent health status of individuals as increased mortality and morbidity in childhood and an elevated risk of hypertension, coronary heart disease, stroke and type 2 diabetes in adulthood [30]. Tobacco smoke induces heritable genetic mutations in mice [31] and environmental tobacco smoke exposure during pregnancy can lead to respiratory symptoms and asthma by age 12–24 months [32]. More studies on the impact of smoking and/or air pollution on the placental transcriptome will bring us new information about factors affecting pregnancy and their possible impact for the future health status of neonates.

To determine the effects of tobacco smoke on the placental transcriptome we performed gene expression profiling in term placentas from women exposed to tobacco smoke in pregnancy (N = 12) and from those without significant exposure (N = 64). We are aware of the limited number of smoking subjects; however, health education in antenatal clinics has helped to decrease the population of smoking women in our region, as is obvious from the questionnaire data. We observed a decreasing trend of cigarette numbers smoked per day with the duration of pregnancy and only a few women reported smoking in all trimesters.

Gene expression profiles of the smokers showed specific patterns that discriminated them from the nonsmokers; however, profiles of six of the nonsmokers (P101, P161, P124, P136, P135 and P140) resembled those of smokers (Fig. 1). Questionnaire data showed that subject P135 declared exposure to passive smoking, but no cotinine was detected in her plasma. P136 declared stopping smoking in the first trimester and P140 had quit smoking before the pregnancy commenced. Further, two smokers (P150 and P162) showed distinct profiles and were clustered with nonsmokers. Subject P162 declared intensive alcohol consumption during all trimesters.

We defined smoking status of the women based on questionnaire data supported by cotinine plasma concentrations. However, the questionnaire data could have been unreliable and subjective. In this context, we rely on self-reported questionnaire data and especially smoking history is crucial for study design. Some nonsmokers in the smoker cluster declared smoking before or at the beginning of the pregnancy that may cause their assembly with smokers. We included to the smoker group only women smoking along whole pregnancy but tobacco smoke may have different effects on placenta in each trimester. However, we assume that active smoking is likely to cause irreversible changes of transcription regulation in placental cells that might be detectable later during pregnancy. Moreover, pregnancy represents long-term period that can be affected by many other factors.

Comparative analysis determined significantly altered expression levels of 241 genes in smokers compared with nonsmokers. As might be expected, the greatest increase of gene expression in smokers was detected in genes coding for xenobiotic-metabolizing enzymes CYP1A1 (2.5-fold) and CYP1B1 (12-fold). Other up-regulated xenobiotic genes were CYB5A and COX412. Cytochrome P450s comprise a superfamily of heme-thiolate proteins that have a central role in phase I drug metabolism. These are involved in the oxidative, peroxidative and reductive metabolism of such endogenous and xenobiotic substrates such as environmental pollutants, steroids, prostaglandins and fatty acids. Expression of the CYP1 family genes is induced by various xenobiotic compounds, suggesting that their deregulation in our smoker cohort is a direct effect of tobacco smoke exposure. Moreover, other studies have previously reported the up-regulation of CYP1A1 and CYP1B1 in human blood [33] and lung cells exposed to tobacco smoke [13] as well as in exposed placentas [17], [18].

Other genes whose deregulated expressions have been detected previously in tobacco smoke exposed tissues were GAS6 and AKR1C3 [13], [34]. In our study, these genes also showed altered placental transcript levels in the smokers. These genes and cytochrome P450 genes thus represent general biomarkers of smoking because they show non-specific tissue induction after tobacco smoke exposure.

Accumulation of thrombotic factors can highly increase the risk of placental abruption [35]. In this context, we identified significant up-regulation of coagulation genes (F5, F13A1) as well as thrombosis-related genes (CD36, ADAMTS9 and GAS6) in smokers. GAS6 plays a pivotal role in endothelial cell response to inflammatory stimuli by promoting the interaction of circulating cells with endothelium and amplifying local thrombosis [36], [37]. Altered expression of GAS6 after tobacco smoke exposure in lung cells has also been reported [33]. On the other hand, we found decreased expression of the PROCR gene that is expressed mainly on endothelial surface of blood vessels and in the placenta. This gene plays a role in pregnancy maintenance, because PROCR knockout mice experience placental thrombosis and early embryonic mortality [38]. In humans, mutations in the PROCR gene are associated with venous thromboembolism as well as late fetal losses [39], [40].

Decreased vascularization and hypoxia in the placenta represent other tobacco smoke-associated complications [11]. In our study, several vascular genes (EDG2, EDNRA, AGTR1 and CTHRC1) showed significantly altered expression in smokers. Using qRT-PCR we confirmed a 6-fold up-regulation of EDNRA expression in smokers compared with nonsmokers. This gene encodes a G-protein-coupled receptor of endothelins and its expression is induced by hypoxia in the rat placenta [41]. AGTR1, up-regulated in smokers, is a vasopressor hormone controlling blood pressure and its aberrant expression was found in human intrauterine growth restricted placentas [42]. Taken together, smoking clearly induced alterations of gene expression of vascular and coagulation genes and thus might contribute to placental insufficiency and/or fetal growth restriction.

Morphological defects of the placenta in smoking women have been well described: e.g., lower placental weight, abnormalities of the microvilli, focal syncytial necrosis and degenerated cytoplasmic organelles [43]. In concordance with the observation that smoking is associated with an increased collagen content in the placenta [11], we found multiple up-regulations of collagen genes (COL6A3, COL1A1, COL1A2, etc.) in the smokers, indicating a higher production of collagen.

Our results further suggest impaired extracellular environment in placentas of the exposed women because we detected deregulations of many genes associated with the ECM, such as ECM1, EFEMP, and FRAS1. Especially trophoblast differentiation and invasion are regulated by numerous ECM proteins and adhesion molecules expressed at the fetal–maternal interface [44]. Moreover, the functional annotation analysis determined significant enrichment of these deregulated genes in the pathway of cell communication, ECM–receptor interaction and focal adhesion, in which ECM genes play a regulatory role. These results show deregulation of the genes that may affect placenta at the structural level.

In mammals, imprinted genes (e.g., IGF2, MEST and PHLDA2) have an important role in feto–placental development [42]. They affect the growth, morphology and nutrient transfer capacity of the placenta and thus control nutrient supplies for fetal growth. We detected up-regulated expression of the imprinted gene PHLDA2 among these smokers. This is one of several genes in the imprinted domain of 11p15.5 and is considered an important tumor suppressor gene region. PHLDA2 regulates placental growth and its elevated placental expression is associated with low birth weight [45].

To our knowledge, this study reports the largest data set of gene expression profiles detected in placentas of pregnant women exposed to tobacco smoke and control subjects. We identified genes that are deregulated in various tissues after tobacco smoke and other chemical exposures such as polycyclic aromatic hydrocarbons and their derivatives (e.g., CYP1A1, CYP1B1, GAS6 and AKR1C3). The altered expression of these genes is likely directly linked to smoking, whereas the deregulation of other genes may be associated with stress-induced responses (e.g., deregulation of thrombotic, inflammation and vascular genes). Functional annotation analysis suggested processes and pathways affected by tobacco smoke exposure that may represent molecular mechanisms of smoke-induced placental abnormalities. Our findings support the concept that tobacco smoke causes alterations in the transcriptome that might contribute to placental insufficiency in smoking pregnant women.

Back to Article Outline

Conflict of interest statement 

No conflicts declared.

Back to Article Outline

Acknowledgments 

The authors wish to thank the gynecological staff of the University Hospital in Prague-Motol. We thank Mgr. Viktor Stranecky (Institute of Inherited Metabolic Disorders, 1st Medical Faculty of Charles University, Prague) for microarray data analyses. The work was supported by the Czech Ministry of Education Youth and Sports (Grant no. 2B06088).

Back to Article Outline

AppendixSupporting data 

Back to Article Outline

References 

1. Källén K. The impact of maternal smoking during pregnancy on delivery outcome. Eur J Public Health. 2001;11:329–333
   • View In Article
   • MEDLINE
   • CrossRef
2. Kvale K, Glysch RL, Gothard M, Aakko E, Remington P. Trends in smoking during pregnancy, Wisconsin 1990 to 1996. WMJ. 2000;99:63–67
   • View In Article
   • MEDLINE
3. Colman GJ, Joyce T. Trends in smoking before, during, and after pregnancy in ten states. Am J Prev Med. 2003;24:29–35
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (92 KB)
   • CrossRef
4. Ebrahim SH, Floyd RL, Merritt RK, Decoufle P, Holtzman D. Trends in pregnancy-related smoking rates in the United States, 1987–1996. JAMA. 2000;283:361–366
   • View In Article
   • MEDLINE
   • CrossRef
5. Barker DJ, Gluckman PD, Robinson JS. Conference report: fetal origins of adult disease–report of the First International Study Group, Sydney, 29–30 October 1994. Placenta. 1995;16:317–320
   • View In Article
   • Abstract
   • Full-Text PDF (320 KB)
   • CrossRef
6. Robinson JS, Moore VM, Owens JA, McMillen IC. Origins of fetal growth restriction. Eur J Obstet Gynecol Reprod Biol. 2000;92:13–19
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (99 KB)
   • CrossRef
7. Horta BL, Victora CG, Menezes AM, Halpern R, Barros FC. Low birth weight, preterm births and intrauterine growth retardation in relation to maternal smoking. Paediatr Perinat Epidemiol. 1997;11:140–151
   • View In Article
   • MEDLINE
8. Salihu HM, Wilson RE. Epidemiology of prenatal smoking and perinatal outcomes. Early Hum Dev. 2007;83:713–720
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (222 KB)
   • CrossRef
9. Chong DS, Yip PS, Karlberg J. Maternal smoking: an increasing unique risk factor for sudden infant death syndrome in Sweden. Acta Paediatr. 2004;93:471–478
   • View In Article
   • MEDLINE
   • CrossRef
10. Morrow RJ, Ritchie JW, Bull SB. Maternal cigarette smoking: the effects on umbilical and uterine blood flow velocity. Am J Obstet Gynecol. 1988;159:1069–1071
    • View In Article
    • MEDLINE
11. Jauniaux E, Burton GJ. Morphological and biological effects of maternal exposure to tobacco smoke on the feto-placental unit. Early Hum Dev. 2007;83:699–706
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (454 KB)
    • CrossRef
12. Kaminsky LM, Ananth CV, Prasad V, Nath C, Vintzileos AM New Jersey Placental Abruption Study Investigators. The influence of maternal cigarette smoking on placental pathology in pregnancies complicated by abruption. Am J Obstet Gynecol. 2007;197(275):e1–e5
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (79 KB)
    • CrossRef
13. Harvey BG, Heguy A, Leopold PL, Carolan BJ, Ferris B, Crystal RG. Modification of gene expression of the small airway epithelium in response to cigarette smoking. J Mol Med. 2007;85:39–53
    • View In Article
    • MEDLINE
    • CrossRef
14. Heguy A, O'Connor TP, Luettich K, Worgall S, Cieciuch A, Harvey BG, et al. Gene expression profiling of human alveolar macrophages of phenotypically normal smokers and nonsmokers reveals a previously unrecognized subset of genes modulated by cigarette smoking. J Mol Med. 2006;84:318–328
    • View In Article
    • MEDLINE
    • CrossRef
15. van Leeuwen DM, van Agen E, Gottschalk RW, Vlietinck R, Gielen M, van Herwijnen MH, et al. Cigarette smoke-induced differential gene expression in blood cells from monozygotic twin pairs. Carcinogenesis. 2007;28:691–697
    • View In Article
    • MEDLINE
    • CrossRef
16. Meng QR, Gideon KM, Harbo SJ, Renne RA, Lee MK, Brys AM, et al. Gene expression profiling in lung tissues from mice exposed to cigarette smoke, lipopolysaccharide, or smoke plus lipopolysaccharide by inhalation. Inhal Toxicol. 2006;18:555–568
    • View In Article
    • CrossRef
17. Huuskonen P, Storvik M, Reinisalo M, Honkakoski P, Rysä J, Hakkola J, et al. Microarray analysis of the global alterations in the gene expression in the placentas from cigarette-smoking mothers. Clin Pharmacol Ther. 2008;83:542–550
    • View In Article
    • CrossRef
18. Pasanen M. The expression and regulation of drug metabolism in human placenta. Adv Drug Deliv Rev. 1999;38:81–97
    • View In Article
    • CrossRef
19. Sitras V, Paulssen R, Leirvik J, Vårtun A, Acharya G. Placental gene expression profile in intrauterine growth restriction due to placental insufficiency. Reprod Sci. 2009;16:701–711
    • View In Article
    • CrossRef
20. Engel SM, Janevic TM, Stein CR, Savitz DA. Maternal smoking, preeclampsia, and infant health outcomes in New York City, 1995–2003. Am J Epidemiol. 2009;169:33–40
    • View In Article
    • CrossRef
21. Genbacev O, McMaster MT, Zdravkovic T, Fisher SJ. Disruption of oxygen-regulated responses underlies pathological changes in the placentas of women who smoke or who are passively exposed to smoke during pregnancy. Reprod Toxicol. 2003;17:509–518
    • View In Article
    • MEDLINE
    • CrossRef
22. Topinka J, Milcova A, Libalova H, Novakova Z, Rossner P, Balascak I, et al. Biomarkers of exposure to tobacco smoke and environmental pollutants in mothers and their transplacental transfer to the foetus. Part I: bulky DNA adducts. Mutat Res. 2009;669:13–19
    • View In Article
    • CrossRef
23. Rossner P, Milcova A, Libalova H, Novakova Z, Topinka J, Balascak I, et al. Biomarkers of exposure to tobacco smoke and environmental pollutants in mothers and their transplacental transfer to the foetus. Part II: oxidative damage. Mutat Res. 2009;669:20–26
    • View In Article
    • CrossRef
24. Sood R, Zehnder JL, Druzin ML, Brown PO. Gene expression patterns in human placenta. Proc Natl Acad Sci U S A. 2006;103:5478–5483
    • View In Article
    • MEDLINE
    • CrossRef
25. Merkerova M, Vasikova A, Bruchova H, Libalova H, Topinka J, Balascak I, et al. Differential gene expression in umbilical cord blood and maternal peripheral blood. Eur J Haematol. 2009;83:183–190
    • View In Article
    • CrossRef
26. Smyth GK. Linear models and empirical bayes methods for assessing differential expression in microarray experiments. Stat Appl Genet Mol Biol. 2004;3:Article3
    • View In Article
27. Dennis G, Sherman BT, Hosack DA, Yang J, Gao W, Lane HC, et al. DAVID: database for annotation, visualization, and integrated discovery. Genome Biol. 2003;4:P3
    • View In Article
    • CrossRef
28. Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCt method. Methods. 2001;25:402–408
    • View In Article
    • MEDLINE
    • CrossRef
29. Dejmek J, Solansky I, Podrazilova K, Sram RJ. The exposure of nonsmoking and smoking mothers to environmental tobacco smoke during different gestational phases and fetal growth. Environ Health Perspect. 2002;110:601–606
    • View In Article
    • MEDLINE
    • CrossRef
30. Barker DJ, Osmond C, Kajantie E, Eriksson JG. Growth and chronic disease: findings in the Helsinki Birth Cohort. Ann Hum Biol. 2009;26:1–14
    • View In Article
    • CrossRef
31. Yauk CL, Bernst ML, Williams A, Rowan-Carroll A, Douglas GR, Stampfli MR. Mainstream tobacco smoke causes paternal germ-line DNA mutation. Cancer Res. 2007;67:5103–5106
    • View In Article
    • MEDLINE
    • CrossRef
32. Miller RL, Garfinkel R, Horton M, Camann D, Perera FP, Whyatt RM, et al. Polycyclic aromatic hydrocarbons, environmental tobacco smoke, and respiratory symptoms in an inner-city birth cohort. Chest. 2004;126:1071–1078
    • View In Article
    • MEDLINE
    • CrossRef
33. Lampe JW, Stepaniants SB, Mao M, Radich JP, Dai H, Linsley PS, et al. Signatures of environmental exposures using peripheral leukocyte gene expression: tobacco smoke. Cancer Epidemiol Biomarkers Prev. 2004;13:445–453
    • View In Article
    • MEDLINE
34. Spira A, Beane J, Shah V, Liu G, Schembri F, Yang X, et al. Effects of cigarette smoke on the human airway epithelial cell transcriptome. Proc Natl Acad Sci U S A. 2004;101:10143–10148
    • View In Article
35. Eskes TK. Clotting disorders and placental abruption: homocysteine a new risk factor. Eur J Obstet Gynecol Reprod Biol. 2001;95:206–212
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (144 KB)
    • CrossRef
36. Maree AO, Jneid H, Palacios IF, Rosenfield K, MacRae CA, Fitzgerald DJ. Growth arrest specific gene (GAS) 6 modulates platelet thrombus formation and vascular wall homeostasis and represents an attractive drug target. Curr Pharm Des. 2007;13:2656–2661
    • View In Article
    • CrossRef
37. Tjwa M, Bellido-Martin L, Lin Y, et al. Gas6 promotes inflammation by enhancing interactions between endothelial cells, platelets, and leukocytes. Blood. 2008;111:4096–4105
    • View In Article
    • CrossRef
38. Gu JM, Crawley JT, Ferrell G, et al. Disruption of the endothelial cell protein C receptor gene in mice causes placental thrombosis and early embryonic lethality. J Biol Chem. 2002;277:43335–43343
    • View In Article
    • MEDLINE
    • CrossRef
39. Kaare M, Ulander VM, Painter JN, Ahvenainen T, Kaaja R, Aittomäki K. Variations in the thrombomodulin and endothelial protein C receptor genes in couples with recurrent miscarriage. Hum Reprod. 2007;22:864–868
    • View In Article
    • MEDLINE
    • CrossRef
40. Franchi F, Biguzzi E, Cetin I, Facchetti F, Radaelli T, Bozzo M, et al. Mutations in the thrombomodulin and endothelial protein C receptor genes in women with late fetal loss. Br J Haematol. 2001;114:641–646
    • View In Article
    • MEDLINE
    • CrossRef
41. Girsh E, Plaks V, Gilad AA, Nevo N, Schechtman E, Neeman M, et al. Cloprostenol, a prostaglandin F(2alpha) analog, induces hypoxia in rat placenta: BOLD contrast MRI. NMR Biomed. 2007;20:28–39
    • View In Article
    • MEDLINE
    • CrossRef
42. McMinn J, Wei M, Schupf N, Cusmai J, Johnson EB, Smith AC, et al. Unbalanced placental expression of imprinted genes in human intrauterine growth restriction. Placenta. 2006;27:540–549
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (651 KB)
    • CrossRef
43. Demir R, Demir AY, Yinanc M. Structural changes in placental barrier of smoking mother. A quantitative and ultrastructural study. Pathol Res Pract. 1994;190:656–667
    • View In Article
    • MEDLINE
    • CrossRef
44. Pollheimer J, Knöfler M. Signalling pathways regulating the invasive differentiation of human trophoblasts: a review. Placenta. 2005;26(Suppl. A:):S21–S30
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (498 KB)
    • CrossRef
45. Apostolidou S, Abu-Amero S, O'Donoghue K, Frost J, Olafsdottir O, Chavele KM, et al. Elevated placental expression of the imprinted PHLDA2 gene is associated with low birth weight. J Mol Med. 2007;85:379–387
    • View In Article
    • MEDLINE
    • CrossRef