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Ecotoxicology and Human Environmental Health

Personal fine particulate matter constituents, increased systemic inflammation and the role of DNA hypomethylation Xiaoning Lei, Renjie Chen, Cuicui Wang, Jingjin Shi, Zhuohui Zhao, Weihua Li, Beizhan Yan, Steve Chillrud, Jing Cai, and Haidong Kan Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.9b02305 • Publication Date (Web): 20 Jul 2019 Downloaded from pubs.acs.org on July 23, 2019

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Environmental Science & Technology

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Personal fine particulate matter constituents, increased systemic inflammation

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and the role of DNA hypomethylation

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Xiaoning Lei1 ，Renjie Chen1, Cuicui Wang1 ，Jingjin Shi1 ，Zhuohui Zhao1 ，

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Weihua Li2, Beizhan Yan3, Steve Chillrud3, Jing Cai 1,4*，Haidong Kan 1,2*

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1. School of Public Health, Key Lab of Public Health Safety of the Ministry of

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Education and NHC Key Laboratory of Health Technology Assessment, Fudan

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University, Shanghai, China

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2. Key Laboratory of Reproduction Regulation of National Population and Family

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Planning Commission, Shanghai Institute of Planned Research, Institute of

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Reproduction and Development, Fudan University, Shanghai, China 3. Division of Geochemistry, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, USA

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4. Shanghai Key Laboratory of Meteorology and Health, Shanghai 200030, China

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*Correspondence: Dr. Haidong Kan, Department of Environmental Health,

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School of Public Health, Fudan University, P.O. Box 249, 130 Dong-An Road,

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Shanghai 200032, China. E-mail: [email protected]; or Dr. Jing Cai,

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Department of Environmental Health, School of Public Health, Fudan University,

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P.O. Box 249, 130 Dong-An Road, Shanghai 200032, China. E-mail:

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[email protected]

ACS Paragon Plus Environment


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ABSTRACT Limited evidence is available on the effects of various fine particulate

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matter (PM2.5) components on inflammatory cytokines and DNA methylation. We

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examined whether 16 PM2.5 components are associated with changes in four blood

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biomarkers, i.e. Tumor Necrosis Factor-α (TNF-α), Soluble Cluster of Differentiation

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40 Ligand (sCD40L), soluble Intercellular Adhesion Molecule-1 (sICAM-1) and

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Fibrinogen, as well as their corresponding DNA methylation levels in a panel of 36

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healthy college students in Shanghai, China. We used linear mixed-effect models to

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evaluate the associations, with controls of potential confounders. We further conducted

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mediation analysis to evaluate the potential mediation effects of components on

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inflammatory markers through change in DNA methylation. We observed that several

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components were consistently associated with TNF-α and Fibrinogen as well as their

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DNA hypomethylation. For example, an interquartile range increase in personal

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exposure to PM2.5-lead (Pb) was associated with 65.20% (95% CI: 37.07, 99.10)

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increase in TNF-α and 2.66 (95% CI: 37.07, 99.10) decrease in TNF-α methylation,

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30.51% (95% CI: 0.72, 69.11) increase in Fibrinogen and 1.25 (95% CI: 0.67, 1.83)

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decrease in F3 methylation. PM2.5 components were significantly associated with

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sICAM-1 methylation but not with sICAM-1 protein. DNA methylation mediated 19.89%

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- 41.75% of the elevation in TNF-α expression by various PM2.5 constituents. Our

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findings provide clues on personal PM2.5 constituents exposure may contribute to

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increased systemic inflammation through DNA hypomethylation.

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

INTRODUCTION

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Extensive epidemiological studies have linked PM2.5 exposure with the

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hospitalization and mortality of various cardiovascular diseases (CVDs) 1, 2. Systemic

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inflammation has been considered as one of common underlying pathological pathways

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by which PM2.5 affects cardiovascular health3, 4. Previous studies found that short-term

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exposure to total PM2.5 mass may lead to the upregulation of inflammatory cytokines5.

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However, the involved biological mechanism remains a matter of speculation.

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Epigenetic alternations can influence the expression of genes without modifying the

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genetic code6, and typically DNA hypomethylation may be involved in the

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development of a wide range of CVDs 7. Our previous panel study hinted that DNA

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methylation plays an important role in mediating the effect of total PM2.5 mass exposure

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on inflammatory pathways8.

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The cardiovascular effect of integrated PM2.5 have been largely evaluated9, 10, but

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which constituents are most responsible for these effects remain unidentified. It is

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partially due to the lack of methodology for accurate exposure assessment.

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Traditionally, PM2.5 exposure assessment relied on fixed monitoring network sites or

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stationary indoor monitors which usually generate temporally aggregated and averaged

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data for a certain spatial unit11. However, these methods ignore spatial heterogeneity

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and difference of activity-patterns among individuals, which could induce bias to the

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results of health study. The bias thus could be magnified for health effect evaluation of

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specific PM2.5 constituents, given that PM2.5 composition normally vary with individual

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and regions12.



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Therefore, we conducted personal monitoring in a panel of healthy college students

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in Shanghai, China. We aim to identify the key PM2.5 chemical components responsible

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for the effects of total PM2.5 exposure on circulating cytokines relevant to systemic

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inflammation. Moreover, we further explored the mediation effects of specific-gene

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methylation in the association between inflammatory protein expression and personal

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PM2.5 constituent exposure.

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

MATERIALS AND METHODS

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Study population and design. This longitudinal panel study was carried out during

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the period from December 17, 2014 to July 11, 2015. We excluded 1) participants with

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any diagnosed cardiopulmonary diseases (including asthma, rhinitis et al. n=2); 2) past

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or current smoker or alcohol addict (n=0); 3) those who are taking any

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medication/supplements (n=1) and participants experienced infection within 1 month

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of baseline physical exam (n=1). Eventually, 36 healthy students from two universities

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located at downtown area of Shanghai were recruited in this study. To control for the

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aforementioned potential confounders, all participants were asked to record the

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information on any use of medications, health conditions, alcohol drinking and physical

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activity during the follow ups. During the study period, we scheduled 4 rounds repeated

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measurements for personal exposure and health endpoints, with at least 2-week interval.

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The study protocol was approved (IRB No. 2014-TYSQ-09-1) by the Institutional

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Review Board of the School of Public Health of Fudan university, and written informed

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consent form was obtained from each subject. Detail information about the study design

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have been described in our previous publication 13.


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Exposure measurements. For each visit, all subjects were instructed to wear a

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designed sampling vest, which equipped with HOBO data loggers (Onset Computer

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Corporation, Pocasset, Massachusetts) and MicroPEM (RTI International, Research

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Triangle Park, NC, USA). HOBO data loggers were applied to record personal

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temperature and relative humidity every half-hour. MicroPEM with a 0.50 ( ± 0.05)

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L/min flow rate was used to log real-time PM2.5 concentrations every 10 seconds based

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on an on-board micro-nephelometer and collect a Teflon filter (FPTPMP325, Zefon,

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USA) sample through a one-stage PM2.5 impactor. Under such a low flow rate, we

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collected a 72-h integrated filter samples for each personal measurement to ensure

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sufficient amount of loading mass for chemical constitutes analysis.

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Fourteen elements were measured via polarized-energy dispersive x-ray fluorescence

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as described by Ngo14, including arsenic (As), barium (Ba), calcium (Ca), chromium

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(Cr), copper (Cu), iron (Fe), potassium(K), manganese (Mn), phosphorus (P), lead (Pb),

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silicon (Si), strontium (Sr), titanium (Ti), zinc (Zn). Elemental carbon (EC)

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concentrations were measured at Columbia University using a multi-wavelength optical

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measurements15. In the absence of measurements of personal organic carbon (OC) due

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to the limitations of our instruments and technology, we obtained hourly concentrations

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of OC measured at a fixed-site of Environmental Science Research Institute (ESRI) of

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Shanghai which was 0.6 km away from the residence of our participants. The ambient

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OC was then used as a surrogate of OC exposure. Ambient OC concentrations were

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measured by a semi-continuous OC/EC analyzer (Model 4G, Sunset Laboratory, OR,

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USA). More detailed quality assurance/quality control procedures of component



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measurements were routinely conducted as described in Supplementary Information (SI)

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materials and methods and our previous publication 16.

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DNA methylation and biomarker measurements. For each visit, we collected

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venous peripheral blood samples after 72-h personal sampling for DNA methylation

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and biomarkers measurements. According to our previous studies 8, 17, we selected four

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inflammatory proteins, including Tumor Necrosis Factor-α (TNF-α), Intercellular

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Adhesion Molecule-1 (ICAM-1) and soluble Cluster of Differentiation 40 Ligand

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(sCD40L), and Fibrinogen. The serum levels of TNF-α, ICAM-1 and Fibrinogen

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protein

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cytokine/chemokine kit (Millipore Corporation, Billerica, MA, USA). sCD40L

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expression was determined using enzyme-linked immune sorbent assays as our

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previous paper1.

were

detected

by Millipore

MILLIPLEX™

MAP

human

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We measured DNA methylation levels of TNF-α, ICAM-1 and sCD40L at two to five

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CpG positions. For Fibrinogen protein, we measured DNA methylation levels of F3

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instead, as done in previous studies

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corresponding methylation loci for examining. In addition, Bind et al

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that F3 hypomethylation may participate in pathways leading to increased Fibrinogen

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in response to air pollution. The locations of the amplified region and each candidate

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CpG loci are listed in SI Table S1. Information about the primer sequences are provided

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in SI Table S2. Two milliliters plasma samples were used for DNA extraction using the

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QIAmp DNA Mini Kit (Qiagen, Hilden, Germany), and the concentration of purified

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DNA was determined using a ND1000 spectrophotometer (NanoDrop Technologies

17, 18,

because Fibrinogen does not have


18

documented

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Inc., Wilmington, DE, USA). We modified aliquots of 300 ng of DNA with sodium

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bisulfite using the EpiTect Fast DNA Bisulfite Kit (Qiagen, Hilden, Germany) in a final

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elution volume of 10 μL M-Elution buffer. DNA methylation level was evaluated using

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highly quantitative bisulfite-PCR pyrosequencing by the PyroMark system (Qiagen,

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Hilden, Germany). The methylation degree of each CpG dinucleotide was presented as

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the percentage of methylated cytosines over the sum of methylated and un-methylated

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cytosines at position 5 (%5mC). More details of DNA methylation and cytokine

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measurements have been reported in elsewhere 8, 17 and SI materials and methods.

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Statistical analysis. We used linear mixed-effect (LME) model to estimate

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association between constituent-specific PM2.5 concentrations and inflammatory

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markers as well as DNA methylation. All cytokine concentrations were natural log-

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transformed before statistical analysis to better approximate a normal distribution. In

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the basic single-constituent model, PM2.5 constituents entered the model as fixed-effect

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independent variables one at a time, and several covariates including age, gender, body

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mass index (BMI), 24-h temperature, 24-h relative humidity, and season were also

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incorporated as fixed-effect predictors. In addition, a random participant-specific

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intercept was introduced to explain the within-subject correlations of repeated

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measurements. Moreover, a “constituent-PM2.5 joint model” with the adjustment of

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total PM2.5 mass (72-h average) was also built to estimate the effects of constituents

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independent of PM2.5. The Benjamini-Hochberg false discovery rate (FDR) was used

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for the correction of simultaneous multiple comparisons in dealing with multiple the

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constituent-specific associations estimating.



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All LME models were conducted using the package “lme4” in R (version 3.5.0, R

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development Core Team). The effect estimation for blood biomarkers and methylation

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were expressed as mean the percent changes and the absolute changes with their 95%

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confidence intervals (CIs) associated with an interquartile-range (IQR) increase in

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PM2.5 constituent concentrations. Statistical tests were two-sided, and P-value ≤ 0.05

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and ≤ 0.10 were considered “significant” and “marginal significant”, respectively.

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We also conducted mediation analyses to evaluate the potential mediation effects of

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DNA methylation on the association between a component and an inflammatory

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biomarker. For this analysis, we used existing “mediation” package in R. Detail

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information about the methods and materials are described in SI methods and materials.

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RESULTS

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Descriptive statistics. Details of the descriptive characteristics of 36 subjects were

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shown in SI Table S3. The female accounted for nearly 61% (22/36). The average (±

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standard deviation, SD) age of our participants was 24 ± 2 years and the average (±

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SD) BMI was 21 ± 3 kg/m2, respectively (SI Table S3). Results from self-reported

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questionnaires showed that none of them participated in strenuous physical activity,

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smoked, drank alcohol, took medication or supplements during the study period.

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Because one participant missed the last visit, a total of 143 valid measurements on both

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exposure and health were eventually collected.

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Table 1 provides the summary statistics of personal PM2.5 constituents, temperature

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and relative humidity. During the study period, the 72-h mean (±SD) mass

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concentration of total PM2.5 was 45.73 (±31.63) μg/m3. Concentrations of PM2.5


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constituents vary considerably. Carbonaceous components (OC and EC) were the most

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abundant composition with a mean (±SD) of 8.00 (±4.92) μg/m3 and 6.14 (±2.84) μg/m3,

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respectively. Among elements of PM2.5, Fe was the most major component with a mean

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(±SD) of 0.85 (±0.45) μg/m3, followed by Si with 0.67 (±0.0.35) μg/m3. Our findings

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were comparable to previous studies reported in Hong Kong12 and Beijing19. In addition,

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we observed correlations among constituents varied with constituents but they were all

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statistically significant at 1% levels (SI Table S4).

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Table 2 provides descriptive statistics for 4 circulating inflammatory cytokine and

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average DNA methylation. Mean (±SD) concentrations of TNF-α, sCD40L, Fibrinogen,

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and ICAM-1 were 4.22 (±5.27) pg/mL, 121.50 (±86.61) pg/mL, 3.03 (±3.58) μg/mL,

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and 172.80 (±98.31) ng/mL, respectively8. The methylation levels and correlation

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coefficients of CpG loci pairs for TNF-α, ICAM-1, CD40L genes have been reported in

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our previous work8, and the corresponding detail information for F3 refers to SI Table

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S5 and SI Figure. S1. Mean (±SD) level of TNF-α, CD40L, F3, and ICAM-1 genes at

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different CpG locus were 17.28 (±6.60) %5mC, 48.25 (±12.46) %5mC, 3.67

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(±2.62) %5mC and 3.49 (±2.29) %5mC, respectively. Although the methylated

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proportions differed across candidate loci, they were highly correlated with each other

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(all correlation coefficients ranged from 0.58 to 0.92, P  0.05). They may share most

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of the same functional complexes and traits, we hence introduced the average

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methylation levels across sites into the model. The correlation coefficients for the 4

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proteins versus the DNA methylation levels at corresponding upstream candidate CpG

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sites are shown in SI Table S6. Significant negative correlations were found between



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TNF-α methylation and TNF-α protein, between F3 methylation and Fibrinogen protein.

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Regression results. The effect on 4 circulating inflammatory biomarkers varied with

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constituents and with biomarkers. The percent changes in four inflammatory proteins

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per an IQR increase in specific 16 PM2.5 constituents' concentrations are illustrated in

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Figure 1. We observed significantly positive associations of all PM2.5 chemical

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components with at least one circulating biomarker. sICAM-1 protein was not

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associated with any constituent; in contrast, TNF-a protein was significantly correlated

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with all PM2.5 constituents. Especially, an IQR increase in personal exposure to Pb was

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associated with increases of 42.43% (95% confidence interval (CI): 4.27, 94.57) (P =

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0.03) and 65.20% (95% CI: 37.07, 99.10) (P  0.01) in sCD40L and TNF-α,

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respectively. an IQR elevate in personal exposure to Si was associated with increases

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of 44.46% (95% CI: 16.12, 79.71) in Fibrinogen.

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Figure 2 presents the changes in DNA methylation associated with increase in 72-h

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average concentration of PM2.5 constituents. We observed that elevation in all 16

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components significantly associated with immediate decrease in at least one circulating

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inflammatory methylation, except Cr negatively linked associated with sICAM-1

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methylation with marginal significance (P = 0.10). For example, an IQR increase in

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personal exposure to K and Pb were associated with decreases of 1.28 (95%CI: 0.45,

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2.11) (P  0.01) and 1.25 (95%CI: 0.67, 1.84) (P  0.01) in CD40L methylation and F3

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methylation (%5mC), respectively. Si was associated with both 1.21 (95%CI: 0.65, 1.76)

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(P  0.01) and 3.25 (95%CI: 1.67, 4.82) (P  0.01) decrease in sICAM-1 and TNF-α

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methylation (%5mC), respectively.


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Notably, after correcting for multiple comparisons (Table S7), we found robust

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associations between PM2.5 constituents and TNF-α cytokines; while, the important

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associations between PM2.5 constituents and sCD40L cytokines as well as CD40L

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methylation turned to be borderline significant or insignificant. The magnitude of the

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associations between PM2.5 constituents and Fibrinogen, ICAM-1 cytokines as well as

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DNA methylation slightly attenuated, and the 95% CIs became wider. Furthermore,

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except the sCD40L protein, the significant associations between PM2.5 constituents and

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other inflammation markers as well as methylation of candidate genes did not

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substantially change in the constituent-PM2.5 joint model (SI Figures S2 and S3).

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Average methylation level of TNF-α (Pearson r= -0.46, P < 0.01) and F3 (Pearson

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r= -0.21, P

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0.10).

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

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DISCUSSION Previously, we have reported positive associations between integrated PM2.5



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exposure and the levels of inflammatory cytokines in this group of participants8. Our

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current results identified specific constituents of PM2.5 exposure substantially

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contributed to those association, which has implications for developing air pollution

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abatement strategies to maximize public health benefits. Moreover, this study linked

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PM2.5 constituents to inflammation methylation on genes related to inflammation

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pathways and the mediation analysis provided further insight into potential importance

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of the association between PM2.5 exposure and gene-specific methylation.

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Systemic inflammation has been suggested as a common underlying pathway of 20.

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cardiovascular diseases caused by PM2.5 exposure

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informative set of circulatory cytokines (TNF-α, sICAM-1, sCD40L and Fibrinogen)

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which are well-established indicators of systemic inflammation and could predict

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cardiovascular disease risk

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concentrations 23; however, the results are not consistent 24. The inconsistency of the

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observations may be partially due to the outdoor fixed-site measurements that were

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used to assess exposure in these studies which may cause exposure misclassification25.

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In our study, personal sampling was conducted to minimize the bias. Our observation

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that TNF-α and sCD40L were associated with a set of PM2.5 components, further

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confirmed that our previous findings of acute inflammation following personal

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exposure to total PM2.58. In contrast, none of components were identified to be

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significantly associated with sICAM-1. It suggests that other components (such as ion

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fraction) that weren’t examined in this study may be responsible for sICAM-1

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expression; i.e. Bind et al26 observed that exposure to sulfate could cause sICAM-1

21, 22.

In this study, we selected an

These biomarkers have been linked with PM2.5


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protein overexpression.

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We found consistent positive associations between the following PM2.5 components

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and selected inflammatory biomarkers in both basic single-constituent model and

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constituent-PM2.5 joint model. EC was found to be associated with sCD40L, Fibrinogen

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and TNF-α increase. The effect on TNF-α and Fibrinogen remained robust after

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accounting for multiple comparisons and adjustment for PM2.5, supporting the finding

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from our prior study in a panel of 28 urban residents in Shanghai 23. Similar results were

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reported elsewhere

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exhaust. Lall et al. found that 2.8 µg/m3 increased in traffic-related PM2.5 exposures

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were positively associated with same day total cardiovascular admissions (RR = 1.041;

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95% CI, 1.005–1.077) across disease-specific subcategories: stroke and heart failure 30.

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Thus, our results suggest that the traffic emission might be partly responsible for the

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influence of PM2.5 exposure on the cardiovascular system disease through inflammatory

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response.

27-29.

In the metropolis cities, EC is a strong marker of vehicle

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Although crustal elements constitute only accounts for a small portion of PM2.5 mass,

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five of them were observed to have stronger influences on inflammatory biomarkers,

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including K, Ca, P, Si and Sr. Similar effects were also found in transition metals (Cu

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and Ti) and heavy metals (As and Pb). Among these elements, K and P could trace the

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biomass burning, Pb and As are widely recognized as markers of sources industry and

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mobile combustion31, while Ca, Sr and Si mostly are attributed to emissions from mixed

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sources of construction dust, soil and industry process

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with the previous findings. For example, Wu et al. found that a significant increase in

32, 33.


Our analyses are in line


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Fibrinogen is associated with dust and soil source high loading of Ca, Ba, Sr and Ti in

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Beijing among a panel of 40 healthy university students34. Toxicological and

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pathological studies documented significant associations of Cu, Ca, K, Si and Ti with

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inflammatory responses and these components may possess the ability to induce toxic

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effects in cardiopulmonary system35,

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cardiovascular hospitalization rates were associated with increased concentrations of

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road dust factor, which showed high explained variations and concentrations for Si, Ca,

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Ti and Cu37, 38. Thus, our findings provide evidence that exposure to the aforementioned

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trace elements could increase cardiovascular risks. These results also highlight that

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specific sources pollution (i.e., dust, motor vehicles, biomass combustion, and industry)

293

should be of particular concern.

36.

Rich et al. reported that increased acute

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It is not clear how the systemic inflammation and the adverse cardiovascular

295

outcomes are triggered by PM2.5 exposure. A recent research has identified that DNA

296

methylation can be a potential biological mechanism to explain adverse health effects

297

from air pollution37. This hypothesis could be supported by our observation that similar

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set of compositions was associated with hypomethylation of genes coding TNF-α and

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F3 proteins. Our mediation analysis further confirmed that decreased TNF-α

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methylation potentially mediated the elevated level of TNF-α protein of several PM2.5

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constituent exposure, including EC, As, Ca, Cu, K, P, Pb, Si, Sr, Ti and Zn. Especially,

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the mediation effects for these compositions were more than 30%. However, mediated

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effect of F3 methylation was not significant, which may be due to the much smaller

304

variation of F3 methylation (2.62 vs. 6.60 for TNF-α methylation). We didn’t observe


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any mediation effects of sCD40L and sICAM-1, which may be impacted by other

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biological processes.

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The current study has several strengths. First, this longitudinal panel study

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measured PM2.5 chemical components in individual levels, which offers an accurate

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exposure assessment. Second, this study simultaneously evaluated the variation of

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circulating gene-specific methylation and the expression of the associated inflammatory

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cytokine after PM2.5 constituent exposure, which provides a unique opportunity to

312

preliminary assess the potential mediation of methylation epigenetic in the

313

cardiovascular effects of PM2.5. Third, all the participants were healthy nonsmoking

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young college students in the present study, which minimizes the impacts of several

315

confounders, such as unhealthy lifestyle, medication use, chronic disease, ect.

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Several limitations still exist in our study. First, because the personal exposure

317

measurement is expensive and burdensome, we only recruited 36 participants, which

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somewhat limited our statistical power and precision. Second, OC concentrations

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monitored at fixed-site were used to substitute personal OC exposure levels, which may

320

slight the attenuate the accurate of assessment on the relationships between OC fraction

321

and biomarkers. Third, we only obtained the 72-h concentrations of personal PM2.5

322

constituent exposure, other exposure time windows (e.g. 24-h) thus cannot be tested in

323

this study. Finally, we didn’t evaluate the effects of ions (e.g. SO42-, NO3-) and gaseous

324

air pollutant (SO2, NO2 and O3) due to the limitation of instruments, which might also

325

influence DNA methylation and the protein levels.

326

In summary, this longitudinal panel study highlighted that TNF-α hypomethylation



327

might play a modest mediate role in the effects of personal exposure to carbon and trace

328

element components exposure (EC, As, Ca, Cu, K, P, Pb, Si, Sr, Ti and Zn) on increased

329

TNF-α expression. Our results provide evidence for the speculation that methylation

330

epigenetic regulation may be one of the key physiological mechanism linking PM2.5

331

exposure and adverse cardiovascular outcome. More epidemiological and toxicological

332

studies with comprehensive analysis of the exposure, biomarker variables, organ and

333

tissue responses to specific PM2.5 constituents and mixtures are required to replicate our

334

findings, and to decipher the biological mechanism in the future.

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

336

Supporting Information

337

Table S1. Locations of the amplified region and each CpG position relative to the

338

transcription start site. Table S2. Primers used for DNA methylation analysis. Table S3.

339

Description of the 36 study participants in Shanghai, China, 2014–2015. Table S4.

340

Pearson correlation coefficients of the 72-h average concentrations of personal

341

exposure fine particulate matter (PM2.5) and constituents variables. Table S5.

342

Descriptive statistics on F3 methylations for 5 CpG Loci. Table S6. Pearson correlation

343

coefficients for the 4 proteins versus the DNA methylation levels. Table S7. False

344

discovery rate (FDR) - value in blood biomarkers and DNA methylation associated with

345

an interquartile range increase in PM2.5 constituents after correcting for multiple

346

comparisons. Table S8. The mediated effects of F3 methylation in the associations

347

between personal PM2.5 compositions exposure and Fibrinogen protein. Figure S1.

348

Correlations between F3 DNA methylation at the individual CpG site. Figure S2.

ASSOCIATED CONTENT


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Percent changes in 4 inflammation proteins associated with an interquartile range

350

increase in personal 72-h average concentrations of PM2.5 constituents in the

351

constituents-PM2.5 adjust model. Figure S3. Changes in DNA methylation (5%mC) of

352

4 inflammation genes associated with an interquartile range increase in personal 72-h

353

average concentrations of PM2.5 constituents in the constituents-PM2.5 adjust model. SI

354

Material and Methods. SI References. (PDF)

355



AUTHOR INFORMATION

356

Corresponding Author

357

*Phone/fax: +86 (21) 54237908; e-mail: [email protected].

358

*Phone/fax: +86 (21) 54237908; e-mail: [email protected]

359

Notes

360

The authors declare no competing financial interest.

361



ACKNOWLEDGMENTS

362

The study was supported by the National Key Research and Development Program

363

of China (2016YFC0206504), National Natural Science Foundation of China

364

(91543114) and the Open Foundation of Shanghai Key Laboratory of

365

Meteorological and Health (QXJK201802).

366



367

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368

Global Association of Air Pollution and Cardiorespiratory Diseases: A Systematic Review,

369

Meta-Analysis, and Investigation of Modifier Variables. Am J Public Health 2018, 108, (S2),

370

S123-S130.

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501

Table 1. Descriptive statistics on personal PM2.5 and PM2.5 chemical constituents,

502

and weather variables for the study participants (n=36) in Shanghai, China,

503

2014–2015a

504 Variables

Mean

SD

Min

Median

Max

IQR

PM2.5, μg/m3

45.73

31.63

8.43

36.18

139.95

32.92

OC, μg/m3

8.00

4.92

1.07

6.91

25.22

5.75

EC, μg/m3

6.14

2.84

1.06

5.73

15.33

3.11

Ca, ng/m3

393.13

196.83

78.12

352.53

1145.61

192.99

K, ng/m3

Carbonaceous fractions

Crustal elements 550.21

377.78

51.57

442.86

1856.69

296.93

Sr,

ng/m3

2.63

1.99

0.00

2.29

9.39

1.92

Ba,

ng/m3

31.97

19.02

7.41

26.84

108.79

15.35

Si, ng/m3

666.87

350.94

74.09

622.59

1588.21

489.50

P, ng/m3

17.56

10.61

2.57

15.60

87.86

11.62

Fe, ng/m3

848.07

450.93

116.77

754.74

2492.30

518.56

Zn, ng/m3

159.33

114.85

23.03

126.31

713.79

100.58

Cu, ng/m3

18.74

11.19

3.80

16.56

90.81

10.80

Ti,

ng/m3

21.10

10.07

1.94

20.85

45.44

11.98

Cr,

ng/m3

7.88

5.28

0.71

7.06

30.84

5.10

Mn, ng/m3

64.89

32.93

11.30

60.06

205.23

41.90

As, ng/m3

2.43

2.04

0.00

1.80

10.18

2.37

Pb, ng/m3

38.79

34.11

0.37

28.35

145.08

31.20

Temperature, °C

22.44

4.64

10.24

24.60

28.54

6.81

Relative humidity, %

55.13

11.13

31.04

54.20

75.96

17.58

b Temperature,

°C

22.40

4.37

10.50

24.16

29.22

6.35

humidity, %

55.31

9.80

26.31

56.48

75.66

6.44

Transition metals

Heavy metals

b Relative

505

a Definition of abbreviations: SD, standard deviation; IQR, interquartile range.

506

b Data are presented as the 24-h average of weather conditions before blood sample collection.


Page 25 of 29


507

Table 2. Descriptive statistics on inflammation-related DNA methylations and

508

cytokines for the study participants (n=36) in Shanghai, China, 2014–2015a Variables

Mean

SD

4.22

5.27

ICAM-1, ng/mL

172.80

sCD40L, pg/mL

Min

Median

Max

0.66

2.44

38.88

98.31

24.92

143.80

574.40

121.50

86.61

0.33

111.00

372.00

3.03

3.58

0.88

1.88

26.83

17.28

6.60

6.61

15.14

35.43

ICAM-1 methylation, %5mC

3.49

2.29

0.00

2.91

8.88

CD40L methylation, %5mC

48.25

12.46

25.73

55.71

63.64

F3 methylation, %5mC

3.67

2.62

0.00

2.92

9.40

Cytokines TNF-α, pg/mL

Fibrinogen, μg/mL Gene-specific methylation TNF-α methylation, %5mC

509

a Definition of abbreviations: SD, standard deviation; TNF-α, TNF encoding tumor necrosis factor-

510

α; ICAM-1, ICAM1 encoding intercellular adhesion molecule-1; sCD40L, CD40LG encoding

511

soluble cluster of differentiation 40 (CD40) ligand; F3, F3 encoding tissue factor.



Page 26 of 29

512

Table 3. The mediated effects of TNF-α methylation in the associations between

513

personal PM2.5 compositions exposure and TNF-α protein

514 Pathway

PM2.5 constituents → TNF-α methylation → TNF-α protein Mean（%） 95% CI Lower（%） 95% CI Upper（%）

EC

29.34

-7.90

76.00

P-value 0.10

As

33.50

9.30

69.00

0.02

Ca

41.75

-0.53

139.00

0.05

Cu

19.89

3.89

39.00

0.03

K

27.00

13.10

48.00

0.00

P

26.53

6.84

48.00

0.02

Pb

25.21

9.88

48.00

0.00

Si

34.70

17.50

59.00

0.00

Sr

27.18

6.27

57.00

0.01

Ti

32.40

12.10

74.00

0.00

Zn

20.27

0.43

40.00

0.04

515 516


Page 27 of 29


517 518

Figure 1. Percent changes in 4 inflammation proteins associated with an

519

interquartile range increase in personal 72-h average concentrations of PM2.5

520

constituents in the single-constituent model. Abbreviations: TNF-α, tumor necrosis

521

factor alpha; sICAM-1, soluble intercellular adhesion molecule-1; sCD40L, soluble

522

cluster of differentiation 40 (CD40) ligand; CF, carbonaceous fractions; HM, heavy

523

metals.

524



525 526

Figure 2. Changes in DNA methylation (5%mC) of 4 inflammation genes

527

associated with an interquartile range increase in personal 72-h average

528

concentrations of PM2.5 constituents in the single-constituent model. Abbreviations:

529

TNF-α, tumor necrosis factor alpha; sICAM-1, soluble intercellular adhesion molecule-

530

1; CD40L, cluster of differentiation 40 (CD40) ligand; F3: tissue factor; CF,

531

carbonaceous fractions; HM, heavy metals.

532


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84x47mm (300 x 300 DPI)


Personal Fine Particulate Matter Constituents ... - ACS Publications

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