Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Symposium Abstracts
*University of Milan and IRCCS Maggiore Hospital Foundation, Milan, Italy; †University of Brescia, Brescia, Italy; and ‡Harvard School of Public Health, Boston, United States.
Inhalation of air particles and their metal components has been related to hypertension and cardiovascular disease in epidemiology studies. Metal components of air particles may contribute to cause hypertension and cardiovascular disease by promoting oxidative stress, due to decreased nitric oxide availability, inflammation, and modified vascular response. MiRNAs are highly conserved, non-coding small RNAs that regulate gene expression on the post-transcriptional level. miR-222 is an important regulator of pro-angiogenic endothelial cell function. miR-21 might be an important modulator of vascular disease and vessel remodelling.
To identify effects of exposure to metal-rich particulate on miR-21 and miR-222 expression in workers of an electric furnace steel plant with well characterized exposure.
We measured mir-21 and mir222 expression in blood RNA obtained from 63 workers on the first day of a workweek (baseline) and after three days of work (post exposure). The relative expression of miRNAs was measured by real-time PCR using RNU48 as endogenous controls. Relative quantification of miRNA expression was calculated using the 2-ΔΔCt method. We determined individual exposure to inhalable particles and metals for all subjects.
We found under-expression of miR-222 (Δmean = 1.9; P = 0.002) and miR-21 (Δmean = 1.1; P = 0.05), in post exposure measure when compared to baseline. Such decrease was negatively associated with exposure to airborne lead level for miR222 expression (β = −2.75, P = 0.01) while no association between MiR-21 and exposure to airborne particles and metals was observed.
Individuals exposed to inhalable metal-rich particles showed decreased expression of miRNAs related with cardiovascular functions.