%0 Journal Article
%T Secondhand smoke in combination with ambient air pollution exposure is associated with increasedx CpG methylation and decreased expression of IFN-¦Ã in T effector cells and Foxp3 in T regulatory cells in children
%A Arunima Kohli
%A Marco A Garcia
%A Rachel L Miller
%A Christina Maher
%A Olivier Humblet
%A S Hammond
%A Kari Nadeau
%J Clinical Epigenetics
%D 2012
%I BioMed Central
%R 10.1186/1868-7083-4-17
%X Subjects 7¨C18£¿years old were recruited from Fresno (high AAP; n£¿=£¿62) and Stanford, CA (low AAP; n£¿=£¿40) and divided into SHS-exposed (Fresno: n£¿=£¿31, Stanford: n£¿=£¿6) and non-SHS-exposed (nSHS; Fresno: n£¿=£¿31, Stanford: n£¿=£¿34) groups. T cells purified from peripheral blood were assessed for levels of DNA methylation and expression of IFN-¦Ã (in effector T cells) or Foxp3 (in regulatory T cells).Analysis showed a significant increase in mean % CpG methylation of IFN-¦Ã and Foxp3 associated with SHS exposure (IFN-¦Ã: FSHS 62.10%, FnSHS 41.29%, p£¿<£¿0.05; SSHS 46.67%, SnSHS 24.85%, p£¿<£¿0.05; Foxp3: FSHS 74.60%, FnSHS 54.44%, p£¿<£¿0.05; SSHS 62.40%, SnSHS 18.41%, p£¿<£¿0.05) and a significant decrease in mean transcription levels of both genes (IFN-¦Ã: FSHS 0.75, FnSHS 1.52, p£¿<£¿0.05; SHS 2.25, nSHS 3.53, p£¿<£¿0.05; Foxp3: FSHS 0.75, FnSHS 3.29, p£¿<£¿0.05; SSHS 4.8, SnSHS 7.2, p£¿<£¿0.05). AAP was also associated with hypermethylation (IFN-¦Ã: FSHS vs. SSHS, p£¿<£¿0.05; FnSHS vs. SnSHS, p£¿<£¿0.05; Foxp3: FSHS vs. SSHS, p£¿<£¿0.05; FnSHS vs. SnSHS, p£¿<£¿0.05) and decreased transcription of both genes (IFN-¦Ã: FSHS vs. SSHS, p£¿<£¿0.05; FnSHS vs. SnSHS, p£¿<£¿0.05; Foxp3: FSHS vs. SSHS, p£¿<£¿0.05; FnSHS vs. SnSHS, p£¿<£¿0.05). Average methylation between AAP- and SHS-only exposures was not significantly different (IFN-¦Ã: p£¿=£¿0.15; Foxp3: p£¿=£¿0.27), nor was Foxp3 expression (p£¿=£¿0.08); IFN-¦Ã expression was significantly decreased in AAP-only subjects (p£¿<£¿0.05).Exposures to SHS and AAP are associated with significant hypermethylation and decreased expression of IFN-¦Ã in Teffs and Foxp3 in Tregs. Relative contributions of each exposure to DNA modification and asthma pathogenesis warrant further investigation.Exposure to secondhand smoke (SHS) is associated with a number of adverse health effects, including cancer, cardiovascular disease, and increased frequency and severity of respiratory disease [1]. Per the US Surgeon General¡¯s 2006 report, any exposure to SHS results in increased health risks [1
%K Secondhand smoke
%K Ambient air pollution
%K IFN-¦Ã
%K Foxp3
%K Methylation
%K Epigenetic regulation
%K Pediatrics
%K T effectors
%K T regulatory cells
%U http://www.clinicalepigeneticsjournal.com/content/4/1/17