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Table 4 Mediation effect of TNF-α, IL-1β, and IL-6 on individual biosensor genes in 106 non-CBPs and 82 CBPsa

From: Occupational exposure to carbon black nanoparticles increases inflammatory vascular disease risk: an implication of an ex vivo biosensor assay

Biosensor Variable IQR in
non-CBPs 		Factor – biosensor associationa   Carbon black – biosensor associationa   Mediation effectb
Estimate (SE) P Estimate (SE) P   PM Pperm
ICAM Carbon black exposure      −0.392 (0.168) (c)c 0.021    
  TNF-α (pg/ml) 94.3 −0.229 (0.069) (b) 0.0011   0.025 (0.206) (c’) 0.903   1.00 0.006
  IL-1β (pg/ml) 6.2 −0.154 (0.023) (b) < 0.0001   −0.184 (0.154) (c’) 0.235   0.53 0.004
  IL-6 (pg/ml) 52.1 −0.076 (0.034) (b) 0.029   −0.143 (0.201) (c’) 0.478   0.64 0.05
  CRP (mg/L) 0.75 −0.028 (0.024) (b) 0.243   −0.338 (0.174) (c’) 0.054   NM  
  MIP-1β (ng/ml) 1.05 −0.065 (0.038) (b) 0.083   −0.231 (0.191) (c’) 0.230   NM  
VCAM Carbon black exposure      −0.689 (0.227) (c)c 0.0027    
  TNF-α (pg/ml) 94.3 −0.313 (0.093) (b) 0.0009   −0.120 (0.278) (c’) 0.667   0.83 0.004
  IL-1β (pg/ml) 6.2 −0.016 (0.035) (b) 0.639   −0.667 (0.232) (c’) 0.0045   NM  
  IL-6 (pg/ml) 52.1 −0.123 (0.046) (b) 0.008   −0.282 (0.270) (c’) 0.297   0.59 0.038
  CRP (mg/L) 0.75 −0.063 (0.032) (b) 0.050   −0.566 (0.234) (c’) 0.016   0.18 0.092
  MIP-1β (ng/ml) 1.05 −0.083 (0.051) (b) 0.104   −0.484 (0.258) (c’) 0.062   NM  
CCL2 Carbon black exposure      −0.567 (0.221) (c)c 0.011    
  TNF-α (pg/ml) 94.3 −0.319 (0.090) (b) 0.0005   0.014 (0.270) (c’) 0.959   1.00 0.004
  IL-1β (pg/ml) 6.2 0.000072 (0.034) (b) 0.998   −0.567 (0.226) (c’) 0.013   NM  
  IL-6 (pg/ml) 52.1 −0.082 (0.045) (b) 0.073   −0.298 (0.265) (c’) 0.264   0.47 0.068
  CRP (mg/L) 0.75 −0.031 (0.031) (b) 0.319   −0.505 (0.229) (c’) 0.0287   NM  
  MIP-1β (ng/ml) 1.05 −0.061 (0.050) (b) 0.223   −0.417 (0.252) (c’) 0.100   NM  
CXCL8 Carbon black exposure      −3.181 (0.421) (c)c < 0.0001    
  TNF-α (pg/ml) 94.3 −0.751 (0.168) (b) < 0.0001   −1.814 (0.504) (c’) 0.0004   0.43 < 0.002
  IL-1β (pg/ml) 6.2 −0.039 (0.064) (b) 0.550   −3.129 (0.430) (c’) < 0.0001   NM  
  IL-6 (pg/ml) 52.1 −0.347 (0.083) (b) < 0.0001   −2.038 (0.487) (c’) < 0.0001   0.36 < 0.002
  CRP (mg/L) 0.75 −0.070 (0.059) (b) 0.240   −3.044 (0.436) (c’) < 0.0001   NM  
  MIP-1β (ng/ml) 1.05 −0.311 (0.092) (b) 0.0009   −2.418 (0.468) (c’) < 0.0001   0.24 0.006
CCL5 Carbon black exposure      −0.479 (0.145) (c)c 0.0012    
  TNF-α (pg/ml) 94.3 −0.268 (0.058) (b) < 0.0001   0.008 (0.174) (c’) 0.963   1.00 < 0.002
  IL-1β (pg/ml) 6.2 −0.061 (0.022) (b) 0.0057   −0.397 (0.146) (c’) 0.0071   0.17 0.01
  IL-6 (pg/ml) 52.1 −0.069 (0.030) (b) 0.020   −0.251 (0.174) (c’) 0.150   0.48 0.01
  CRP (mg/L) 0.75 −0.039 (0.020) (b) 0.054   −0.402 (0.150) (c’) 0.008   0.16 0.056
  MIP-1β (ng/ml) 1.05 −0.104 (0.032) (b) 0.0014   −0.224 (0.162) (c’) 0.168   0.53 0.002
  1. CBP Carbon black packer, IQR Inter-quartile range, SE Standard error, GLM Generalized linear model
  2. aGLM was used to assess the association (c’) between carbon black exposure and delta Ct of selected biosensor genes with age, overweight and obesity, current smoking status, packyears, passage of cells, and cytokines or chemokines (b) included as covariate for adjustment. Non-transformed data of cytokine and chemokine levels were used in GLM. c’ and b should be referred to Fig. 1
  3. bThe proportion mediated effect size that quantifies the proportion of a total effect mediated was calculated using the following equation: (c-c’) / c. The database was permuted for 500 times to generate a null distribution of c-c’. Pperm was calculated as the number of permuted databases generating a c-c’ that is less than observed value divided by 500. c should be referred to Fig. 1
  4. cGLM was used to assess the association between carbon black and delta Ct of selected biosensor genes in 106 non-CBPs and 82 CBPs with adjustment for age, overweight and obesity, current smoking status, and packyears, and passage of cells. c should be referred to Fig. 1
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Particle and Fibre Toxicology

ISSN: 1743-8977

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