13 research outputs found
Novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation
Journal ArticleA novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm) and submicron (250 nm) silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF), and detection by light scattering
A novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation
A novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm) and submicron (250 nm) silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF), and detection by light scattering
Inhibition of TRPA1, Endoplasmic Reticulum Stress, Human Airway Epithelial Cell Damage, and Ectopic <i>MUC5AC</i> Expression by Vasaka (<i>Adhatoda vasica</i>; Malabar Nut) Tea
This study tested whether a medicinal plant, Vasaka, typically consumed as a tea to treat respiratory malaise, could protect airway epithelial cells (AECs) from wood smoke particle-induced damage and prevent pathological mucus production. Wood/biomass smoke is a pneumotoxic air pollutant. Mucus normally protects the airways, but excessive production can obstruct airflow and cause respiratory distress. Vasaka tea pre- and co-treatment dose-dependently inhibited mucin 5AC (MUC5AC) mRNA induction by AECs treated with wood smoke particles. This correlated with transient receptor potential ankyrin-1 (TRPA1) inhibition, an attenuation of endoplasmic reticulum (ER) stress, and AEC damage/death. Induction of mRNA for anterior gradient 2, an ER chaperone/disulfide isomerase required for MUC5AC production, and TRP vanilloid-3, a gene that suppresses ER stress and wood smoke particle-induced cell death, was also attenuated. Variable inhibition of TRPA1, ER stress, and MUC5AC mRNA induction was observed using selected chemicals identified in Vasaka tea including vasicine, vasicinone, apigenin, vitexin, isovitexin, isoorientin, 9-oxoODE, and 9,10-EpOME. Apigenin and 9,10-EpOME were the most cytoprotective and mucosuppressive. Cytochrome P450 1A1 (CYP1A1) mRNA was also induced by Vasaka tea and wood smoke particles. Inhibition of CYP1A1 enhanced ER stress and MUC5AC mRNA expression, suggesting a possible role in producing protective oxylipins in stressed cells. The results provide mechanistic insights and support for the purported benefits of Vasaka tea in treating lung inflammatory conditions, raising the possibility of further development as a preventative and/or restorative therapy
Effects of fuel components and combustion particle physicochemical properties on toxicological responses of lung cells
<p>The physicochemical properties of combustion particles that promote lung toxicity are not fully understood, hindered by the fact that combustion particles vary based on the fuel and combustion conditions. Real-world combustion-particle properties also continually change as new fuels are implemented, engines age, and engine technologies evolve. This work used laboratory-generated particles produced under controlled combustion conditions in an effort to understand the relationship between different particle properties and the activation of established toxicological outcomes in human lung cells (H441 and THP-1). Particles were generated from controlled combustion of two simple biofuel/diesel surrogates (methyl decanoate and dodecane/biofuel-blended diesel (BD), and butanol and dodecane/alcohol-blended diesel (AD)) and compared to a widely studied reference diesel (RD) particle (NIST SRM2975/RD). BD, AD, and RD particles exhibited differences in size, surface area, extractable chemical mass, and the content of individual polycyclic aromatic hydrocarbons (PAHs). Some of these differences were directly associated with different effects on biological responses. BD particles had the greatest surface area, amount of extractable material, and oxidizing potential. These particles and extracts induced cytochrome P450 1A1 and 1B1 enzyme mRNA in lung cells. AD particles and extracts had the greatest total PAH content and also caused CYP1A1 and 1B1 mRNA induction. The RD extract contained the highest relative concentration of 2-ring PAHs and stimulated the greatest level of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNFα) cytokine secretion. Finally, AD and RD were more potent activators of TRPA1 than BD, and while neither the TRPA1 antagonist HC-030031 nor the antioxidant N-acetylcysteine (NAC) affected CYP1A1 or 1B1 mRNA induction, both inhibitors reduced IL-8 secretion and mRNA induction. These results highlight that differences in fuel and combustion conditions affect the physicochemical properties of particles, and these differences, in turn, affect commonly studied biological/toxicological responses.</p
Activation of Transient Receptor Potential Ankyrin‑1 (TRPA1) in Lung Cells by Wood Smoke Particulate Material
Cigarette smoke, diesel exhaust,
and other combustion-derived particles
activate the calcium channel transient receptor potential ankyrin-1
(TRPA1), causing irritation and inflammation in the respiratory tract.
It was hypothesized that wood smoke particulate and select chemical
constituents thereof would also activate TRPA1 in lung cells, potentially
explaining the adverse effects of wood and other forms of biomass
smoke on the respiratory system. TRPA1 activation was assessed using
calcium imaging assays in TRPA1-overexpressing HEK-293 cells, mouse
primary trigeminal neurons, and human adenocarcinoma (A549) lung cells.
Particles from pine and mesquite smoke were less potent agonists of
TRPA1 than an equivalent mass concentration of an ethanol extract
of diesel exhaust particles; pine particles were comparable in potency
to cigarette smoke condensate, and mesquite particles were the least
potent. The fine particulate (PM < 2.5 μm) of wood smoke
were the most potent TRPA1 agonists and several chemical constituents
of wood smoke particulate, 3,5-<i>ditert</i>-butylphenol,
coniferaldehyde, formaldehyde, perinaphthenone, agathic acid, and
isocupressic acid, were TRPA1 agonists. Pine particulate activated
TRPA1 in mouse trigeminal neurons and A549 cells in a concentration-dependent
manner, which was inhibited by the TRPA1 antagonist HC-030031. TRPA1
activation by wood smoke particles occurred through the electrophile/oxidant-sensing
domain (i.e., C621/C641/C665/K710), based on the inhibition of cellular
responses when the particles were pretreated with glutathione; a role
for the menthol-binding site of TRPA1 (S873/T874) was demonstrated
for 3,5-<i>ditert</i>-butylphenol. This study demonstrated
that TRPA1 is a molecular sensor for wood smoke particulate and several
chemical constituents thereof, in sensory neurons and A549 cells,
suggesting that TRPA1 may mediate some of the adverse effects of wood
smoke in humans
Activation of TRPV3 by Wood Smoke Particles and Roles in Pneumotoxicity
Wood/biomass
smoke particulate materials (WBSPM) are pneumotoxic,
but the mechanisms by which these materials affect lung cells are
not fully understood. We previously identified transient receptor
potential (TRP) ankyrin-1 as a sensor for electrophiles in WBSPM and
hypothesized that other TRP channels expressed by lung cells might
also be activated by WBSPM, contributing to pneumotoxicity.
Screening TRP channel activation by WBSPM using calcium flux assays
revealed TRPV3 activation by materials obtained from burning multiple
types of wood under fixed conditions. TRPV3 activation by WBSPM was
dependent on the chemical composition, and the pattern of activation
and chemical components of PM agonists was different from that of
TRPA1. Chemical analysis of particle constituents by gas chromatography–mass
spectrometry and principal component analysis indicated enrichment
of cresol, ethylphenol, and xylenol analogues, plus several
other chemicals among the most potent samples. 2,3-, 2,4-, 2,5-, 2,6-,
3,4-, and 3,5-xylenol, 2-, 3-, and 4-ethylphenol, 2-methoxy-4-methylphenol,
and 5,8-dihydronaphthol were TRPV3 agonists exhibiting preferential
activation versus TRPA1, M8, V1, and V4. The concentration of 2,3-
and 3,4-xylenol in the most potent samples of pine and mesquite smoke
PM (<3 μm) was 0.1–0.3% by weight, while that of 5,8-dihydronaphthol
was 0.03%. TRPV3 was expressed by several human lung epithelial cell
lines, and both pine PM and pure chemical TRPV3 agonists found in
WBSPM were more toxic to TRPV3-over-expressing cells via TRPV3 activation.
Finally, mice treated sub-acutely with pine particles exhibited an
increase in sensitivity to inhaled methacholine involving TRPV3. In
summary, TRPV3 is activated by specific chemicals in WBSPM, potentially
contributing to the pneumotoxic properties of certain WBSPM
Transient receptor potential vanilloid1 (TRPV1) is a mediator of lung toxicity for coal fly ash particulate material
ABSTRACT Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 Ͼ diesel exhaust PM Ͼ crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4␣ (C4␣), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue