Haemoglobin adducts as biomarkers of exposure to tobacco-related nitrosamines

Abstract

A sensitive gas chromatography/mass spectrometry (GC/MS) method was developed to measure nitrosamineÁhaemoglobin adducts (HPB-Hb) (4-hydroxy-3-pyridinyl-1-butanone) at trace levels in red blood cells of smoking and non-smoking mothers and their newborn babies. GC/MS methods with chemical ionization (CI) of methane reagent gas in both positive and negative ion mode as well as electron ionization (EI) were studied to determine differences in sensitivity among the various ionization methods. Detection limits using both positive and negative chemical ionization modes were found to be 30 fmol HPB, whereas detection using electron impact modes yielded a detection limit of 80 fmol HBP. In order to apply the various methods of detection to tobacco-exposed samples from human populations, we characterized adduct levels in maternal as well as paired fetal samples obtained from mothers exposed to tobacco smoke during pregnancy. Maternal samples were characterized using serum cotinine levels and were classified as non-smokers, passively smoke-exposed women, less than one pack per day smokers and greater than one pack per day smokers. Paired maternal and fetal blood samples were obtained at delivery for qualitative and qualitative analysis of nitrosamine adducts. Comparative derivatization of HPB released under alkaline hydrolysis conditions was performed using O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) and 2,3,4,5,6-pentafluorobenzoylchloride (PFBC). Both negative CI and positive CI modes of analysis were compared to the more widely accepted EI modes of mass spectrometric analysis. These results suggest that both NICI and PICI modes of detection offer a greater sensitivity of adduct characterization when compared with EI ionization techniques and that either NICI or PICI modes are preferably applicable towards the detection of human biomarker assessment of tobacco-related nitrosamines.

Early limited nitrosamine exposures exacerbate high fat diet-mediated type 2 diabetes and neurodegeneration

“…Although the NDEA exposure was delivered within a brief window during the human equivalent of childhood or early adolescence, its adverse effects on the brain were sustained into adulthood, similar to the findings with respect to the i.c.-STZ model [19,22]. Conceivably, such prolonged and possibly progressive deficits may occur because nitrosamines promote formation of DNA and protein adducts [105-107] that can serve as persistent sources of oxidative stress, and cause further DNA damage and protein dysfunction.…”

Nitrosamine exposure exacerbates high fat diet-mediated type 2 diabetes mellitus, non-alcoholic steatohepatitis, and neurodegeneration with cognitive impairment

“…A second point is that, although the NDEA was delivered within a brief window early in life, its impact on cognitive function was sustained in the adults, similar to the effects of ic-STZ treatment [22,25]. The mechanism underlying these prolonged and possibly progressive deficits may reside in the fact that nitrosamines promote the formation of adducts that can serve as persistent sources of oxidative stress, DNA damage, and protein mal-folding or dysfunction [8,9,26,88], and ultimately lead to epigenetic changes in gene expression.…”

Mass spectrometry of peptides and proteins from human blood

“…Oxidation levels of blood proteins may reveal physiological conditions (Aldini et al, 2006(Aldini et al, , 2008Morgan et al, 2007;Bruschi et al, 2008) and might be detected by biotin hydrazide to selectively derivatize carbonyl groups in oxidized proteins followed by avidin affinity chromatography (Mirzaei et al, 2008). Protein adducts may form in response to physiological processes (Szapacs et al, 2006(Szapacs et al, , 2008 or may be indicative of the presence of specific mutagens, toxins, drug binding, or chemical weapons (Yike et al, 2006;Carol-Visser et al, 2008;Lohmann, Hayen, & Karst, 2008;Myers & Ali, 2008;Scholl & Groopman, 2008;Smith et al, 2008;Noort et al, 2008a,b;Will, Wolters, & Sheldrick, 2008;Zhang et al, 2008a;Moreno-Gordaliza et al, 2009;Preston et al, 2009;Winther et al, 2009). Protein serotonylation may have a physiological function since transglutaminase activity was observed as a cystamine-inhibitable incorporation of the free amine pentylamine-biotin into arterial proteins integral to contractility and the cytoskeleton (Schaub et al, 2009).…”