The identification of tyrosine-nitrated human serum albumin in airborne particulate matter from Japan
Introduction
It has been suggested that daily exposure to atomospheric particulate matter (PM2.5, PM10) may cause premature mortality, cardiovascular mortality, and respiratory mortality (Bruewer et al., 2005; Liu et al., 2019). Although the complexity of how PMs enter the human body through the respiratory system is becoming clearer, but the molecular mechanism of their toxicity is not fully understood (Horie et al., 2012). Generally, the factors contributing to the health effects and toxicity of PM are thought to be related to the contaminants contained in the particles.
PM samples in urban areas have been chemically characterized for inorganic ions, total carbon (elemental or black carbon), elements (mineral dust and trace elements from anthropogenic sources), polycyclic aromatic hydrocarbons (PAHs), and biological products (endotoxin) (Brook et al., 2010). In the atmosphere, cellular debris and various proteins form bio-aerosol particles, or PMs, and react with organic or inorganic materials (Jaenicke et al., 2005). The bio-aerosol particles in atmospheric PM include viruses, pollen, fungal spores, bacteria, and debris from vertebrates (e.g., humans), and other biota (e.g., plants and insects) (Castillo et al., 2012). Among these bio-aerosol particles, various proteins such as the debris from keratinocytes have been identified (Clark et al., 1973; Fox et al., 2008). In fact, proteins may account for up to ~5% or 0.5–2% of urban PM (Franze et al., 2005; Abe et al., 2006), and their considerably high protein content in PM has been found to have physicochemical effects on atmospheric particles. It has previously been demonstrated that the protein in PM proteins may contribute to allergic airway inflammation in mice (Ogino et al., 2014a, 2014b, 2018). Additionally, PM2.5 easily induces allergic airway inflammation in the presence of HSA, a non-allergen, illustrating another of its action mechanisms other than as an adjuvant (Nagaoka et al., 2019). Chemically modified tyrosine-nitrated proteins in atmospheric PM have also been measured, and the results suggest that protein reactions with environmental pollutants such as ozone and NOx (Ito et al., 2018), and the generation of 3-nitrotyrosine (3-NT) in the tyrosine residues of proteins is associated with allergies (Gruijthuijsen et al., 2006).
This study was initiated by the unexpected detection of an antibody against PM2.5-bound protein in experimental asthmatic mice (Ogino et al., 2014b). We identified a PM protein using immunoglobulin G (IgG) serum from experimentally asthmatic mice, and evaluated the biochemical characteristics of the identified proteins in PM.
Section snippets
Sources of airborne PM
The total suspended particles (TSP) were collected as previously reported (Ogino et al., 2014a). These samples were collected from seven locations in Japan (Table S1). PM2.5 was collected from low-volume air samplers (Okayama City and Fukue Island of Nagasaki Prefecture) (Ogino et al., 2014b), or cyclone system (Okayama City) (Ogino et al., 2017). TSP and PM2.5, on the filters and cyclone particles of PM2.5, were handled by gloved hands and then frozen at −30 °C. For the TSP and PM2.5, filters
Immunoreactive proteins against PM2.5 in mice serum with PM2.5-induced allergic airway inflammation
A PM2.5 filter was randomly selected for each month from 2010 to 2011, and the precipitate fraction of PM2.5 following elution was analyzed for western blots using the serum from mice for antiserum, which demonstrated acute airway inflammation (Ogino et al., 2014b). The PM content (30 μg) was electrophoresed by SDS-PAGE, and the immunoblot is shown in Fig. 1A. There was a single immunoreactive band near the molecular weight of 50 kDa.
Proteomic analysis and protein sequence analysis
Immunoprecipitation was performed with TSP proteins and
Discussion and conclusion
There have been a few reports on the presence of proteins in atmospheric PM and aerosols (Clark et al., 1973; Castillo et al., 2012), and plant and bacterial proteins have also reported as bio-aerosols (Liu F et al., 2016). As for human sources, skin fragments and human K10 epithelial keratin have been detected in atmospheric PM (Fox et al., 2008), but there was no previous evidence for the presence of HSA in atmospheric PM.
We were convinced of the presence of candidate HSA by proteomic and
Authors' contributions
Noriyoshi Ogino; Investigation, Writing – original draft. Keiki Ogino; Conceptualization, Data curation, Formal analysis, Funding acquisition, Project administration, Writing – review & editing. Masamitsu Eitoku; Supervision. Narufumi Suganuma; Project administration. Kenjiro Nagaoka; Methodology. Yasuhiro Kuramitsu; Methodology.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
We thank Emeritus Prof. Kazuyuki Nakamura of Yamaguchi University for his help with the proteomic analysis. We thank Prof. Hiroyuki Nakamura of Kanazawa University, Emeritus Prof. Hiroyuki Katsunuma of Tokyo Medical University, Specially Appointed Prof. Nakaji of Hirosaki University, and Assoc. Prof. Yasushi Obase of Nagasaki University for their help with the TSP/PM2.5 sampling in Kanazawa City, Tokyo, Nagasaki City, and Fukue Island. We thank Dr. Masayuki Kubo of the US Environmental
References (24)
- et al.
Relationship of particulate matter and ozone with 3-nitrotyrosine in the atmosphere
Environ. Pollut.
(2018) - et al.
Further studies on the reaction of amines and proteins with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole
Anal. Chim. Acta
(1985) - et al.
Protein amino acids as markers for biological sources in urban aerosols
Environ. Chem. Lett.
(2006) - et al.
Particulate matter air pollution and cardiovascular disease. An update to the scientific statement from the American Heart Association
Circulation
(2010) - et al.
Interferon-gamma induces internalization of epithelial tight junction proteins via a micropinocytosis-like process
Faseb. J.
(2005) - et al.
Exploring the feasibility of bioaerosol analysis as a novel fingerprinting technique
Anal. Bioanal. Chem.
(2012) - et al.
Fluorescence dye cocktail for multiplex drug-site mapping on human serum albumin
ASC Comb Sci
(2013) - et al.
Identification of skin in airborne particulate matter
Nature
(1973) - et al.
Human K10 epithelial keratin is the most abundant protein in airborne dust of both occupied and unoccupied school rooms
J. Environ. Monit.
(2008) - et al.
Enzyme immunoassays for the investigation of protein nitration by air pollutants
Analyst
(2003)
Protein nitration by polluted air
Environ. Sci. Technol.
Nitration enhances the allergic potential of proteins
Int. Arch. Allergy Immunol.
Cited by (2)
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