Browsing by Author "Zhang, Junfeng Jim"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    DNA Methylation in Babies Born to Nonsmoking Mothers Exposed to Secondhand Smoke during Pregnancy: An Epigenome-Wide Association Study.
    (Environmental health perspectives, 2021-05-19) Fuemmeler, Bernard F; Dozmorov, Mikhail G; Do, Elizabeth K; Zhang, Junfeng Jim; Grenier, Carole; Huang, Zhiqing; Maguire, Rachel L; Kollins, Scott H; Hoyo, Cathrine; Murphy, Susan K

    Background

    Maternal smoking during pregnancy is related to altered DNA methylation in infant umbilical cord blood. The extent to which low levels of smoke exposure among nonsmoking pregnant women relates to offspring DNA methylation is unknown.

    Objective

    This study sought to evaluate relationships between maternal prenatal plasma cotinine levels and DNA methylation in umbilical cord blood in newborns using the Infinium HumanMethylation 450K BeadChip.

    Methods

    Participants from the Newborn Epigenetics Study cohort who reported not smoking during pregnancy had verified low levels of cotinine from maternal prenatal plasma (0 ng/mL to <4 ng/mL), and offspring epigenetic data from umbilical cord blood were included in this study (n=79). Multivariable linear regression models were fit to the data, controlling for cell proportions, age, race, education, and parity. Estimates represent changes in response to any 1-ng/mL unit increase in exposure.

    Results

    Multivariable linear regression models yielded 29,049 CpGs that were differentially methylated in relation to increases in cotinine at a 5% false discovery rate. Top CpGs were within or near genes involved in neuronal functioning (PRKG1, DLGAP2, BSG), carcinogenesis (FHIT, HSPC157) and inflammation (AGER). Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest cotinine was related to methylation of gene pathways controlling neuronal signaling, metabolic regulation, cell signaling and regulation, and cancer. Further, enhancers associated with transcription start sites were enriched in altered CpGs. Using an independent sample from the same study population (n=115), bisulfite pyrosequencing was performed with infant cord blood DNA for two genes within our top 20 hits (AGER and PRKG1). Results from pyrosequencing replicated epigenome results for PRKG1 (cg17079497, estimate=-1.09, standard error (SE)=0.45, p=0.018) but not for AGER (cg09199225; estimate=-0.16, SE=0.21, p=0.44).

    Discussion

    Secondhand smoke exposure among nonsmoking women may alter DNA methylation in regions involved in development, carcinogenesis, and neuronal functioning. These novel findings suggest that even low levels of smoke exposure during pregnancy may be sufficient to alter DNA methylation in distinct sites of mixed umbilical cord blood leukocytes in pathways that are known to be altered in cord blood from pregnant active smokers. https://doi.org/10.1289/EHP8099.
  • Thumbnail Image
    ItemOpen Access
    Effect of Prenatal Smoke Exposure on Birth Weight: The Moderating Role of Maternal Depressive Symptoms.
    (Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco, 2018-12-24) Schechter, Julia; Do, Elizabeth K; Zhang, Junfeng Jim; Hoyo, Cathrine; Murphy, Susan K; Kollins, Scott H; Fuemmeler, Bernard
    Introduction:Both prenatal smoke exposure and depression have been linked to lower birth weight, a risk factor for morbidity and mortality. Few studies have looked at the interaction between these risk factors and none have used a biomarker to objectively measure prenatal smoke exposure. The current study sought to examine independent and interactive effects of cotinine and depression on birth weight. The effect of race was also explored. Method:Data were drawn from a prospective study of pregnant women (N=568) in the southeastern U.S. Maternal demographic, health information, depressive symptoms, and birth data were collected via self-report and medical record abstraction. Prenatal blood samples were assayed for cotinine. Results:Controlling for covariates, multiple regression analyses indicated that both cotinine and depressive symptoms independently predicted lower birth weight and a significant interaction was also observed. Upon probing the interaction, a negative association between cotinine levels and birth weight was found in the context of higher depression but not lower depression scores. Similarly, logistic regression analyses revealed a significant interaction between cotinine and depression, such that cotinine predicted having a baby < 2500 g among women who fell above the indicated cut-off score. African American women had the highest levels of cotinine and lowest weight babies; however, race was not a significant moderator. Conclusions:Results suggest prenatal smoke exposure has a greater negative effect on birth weight for women endorsing co-occurring depressive symptoms. Findings can inform targeted interventions and assist medical providers with identifying women at increased risk for poor perinatal outcomes. Implications:Despite the common occurrence of smoking during pregnancy and prenatal depression, the interaction between these risk factors on birth weight has rarely been examined. Further, the extant results have been mixed, likely due in part to difficulties in measurement. The current study was the first to use prenatal cotinine to assess bias-free, continuous levels of prenatal smoke exposure. Results indicate that prenatal cotinine was a significant predictor of birth weight only in the context of maternal depressive symptoms. These findings have important implications for mitigating negative perinatal outcomes for pregnant women and their children.
  • Thumbnail Image
    ItemOpen Access
    Gestational age modifies the association between exposure to fine particles and fetal death: findings from a nationwide epidemiological study in the contiguous United States.
    (Environmental health : a global access science source, 2023-09) Tong, Mingkun; Lin, Weiwei; Liu, Hengyi; Gong, Jicheng; Zhang, Junfeng Jim; Xue, Tao

    Backgrounds

    The vulnerability of fetuses differs at different developmental stages, in response to environmental stressors such as fine particulate matter (PM2.5), a ubiquitous air pollutant. Whether gestational age (GA) modifies the association between prenatal fine particulate matter (PM2.5) exposure and fetal death remains unclear.

    Methods

    We selected approximately 47.8 million eligible United States (US) livebirth and fetal death (defined as a termination at a GA of 20-43 weeks) records from 1989 to 2004. For each record, we took the level of prenatal exposure to PM2.5 as the average concentration in the mother's residential county during the entire gestational period, or a specific trimester (i.e., GA-specific exposure), according to well-established estimates of monthly levels across the contiguous US. First, we evaluated the associations between PM2.5 exposure and fetal death at a specific GA (i.e., GA-specific outcome) using five different logit models (unadjusted, covariate-adjusted, propensity-score, double robust, and diagnostic-score models). Double robust model was selected as the main model due to its advantages in causal inference. Then, we conducted meta-analyses to pool the estimated GA-specific associations, and explored how the pooled estimates varied with GA.

    Results

    According to the meta-analysis, all models suggested gestational PM2.5 exposure was associated with fetal death. However, there was slight heterogeneity in the estimated effects, as different models revealed a range of 3.6-10.7% increase in the odds of fetal death per 5-µg/m3 increment of PM2.5. Each 5-µg/m3 increase in PM2.5 exposure during the entire gestation period significantly increased the odds of fetal death, by 8.1% (95% confidence interval [CI]: 5.1-11.2%). In terms of GA-specific outcomes, the odds of fetal death at a GA of 20-27, 28-36, or ≥ 37 weeks increased by 11.0% (5.9-16.4%), 5.2% (0.4-10.1%), and 8.3% (2.5-14.5%), respectively. In terms of GA-specific exposure, the odds of fetal death increased by 6.0% (3.9-8.2%), 4.1% (3.9-8.2%), and 4.3% (0.5-8.2%) with 5-µg/m3 increases in PM2.5 exposure during the first, second, and third trimester, respectively. The association had the largest effect size (odds ratio = 1.098, 95% CI: 1.061-1.137) between PM2.5 exposure during early gestation (i.e., first trimester) and early fetal death (i.e., 20-27 weeks).

    Conclusions

    Prenatal exposure to PM2.5 was significantly associated with an increased risk of fetal death. The association was varied by gestational-age-specific exposures or outcomes, suggesting gestation age as a potential modifier on the effect of PM2.5. The fetus was most vulnerable during the early stage of development to death associated with PM2.5 exposure.