Enter Your Search:
Results 1-2 (2)
Go to page number:
Select a Filter Below
American Journal of Respiratory Cell and Molecular Biology (1)
Free radical biology & medicine (1)
Dasgupta, Trisha (2)
Akhmedov, Alexander T. (1)
Factor, Phillip (1)
Hebbel, Robert P (1)
Jiang, Hong (1)
Kaul, Dhananjay K. (1)
McDonald, Jacob D. (1)
Miller, Rachel L. (1)
Panettieri, Reynold A. (1)
Perera, Frederica (1)
Qu, Anna (1)
Wu, Jie (1)
Year of Publication
Polycyclic Aromatic Hydrocarbons Impair Function of β2-Adrenergic Receptors in Airway Epithelial and Smooth Muscle Cells
Akhmedov, Alexander T.
McDonald, Jacob D.
Panettieri, Reynold A.
Miller, Rachel L.
American Journal of Respiratory Cell and Molecular Biology
Incomplete combustion produces a pollutant mixture that includes polycyclic aromatic hydrocarbons (PAHs). Previous work by the Columbia Center for Children's Environmental Health (CCCEH) and others linked exposure to PAH with symptoms of asthma and other adverse health effects in young children. Inhaled β2-adrenergic agonists are mainstays in the treatment of reactive airway diseases. These exogenous catecholamines engage membrane-bound β2-adrenergic receptors (β2AR) on airway epithelial and smooth muscle cells to cause airway dilation. We hypothesized that exposure to PAH might similarly interfere with the function of β2AR in airway epithelial or smooth muscle cells, reducing the efficacy of a medication important for the treatment of asthma symptoms. A PAH mixture was devised, based on ambient levels measured prenatally among a cohort of pregnant women participating at the CCCEH. Primary airway epithelial and smooth muscle cells were exposed to varying concentrations of the PAH mixture, and expression, function, and signaling of β2AR were assessed. Murine tracheal epithelial cells and human airway smooth muscle cells, after exposure to a PAH mixture, exhibited reduced expression and function of β2AR. These findings support our hypothesis that environmentally relevant PAHs can impede β2AR-mediated airway relaxation, and suggest a new paradigm where air pollutants not only contribute to the pathogenesis of childhood asthma, but also diminish responsiveness to standard therapy.
polycyclic aromatic hydrocarbons; β2-adrenergic receptors
Protective Effect of Arginine on Oxidative Stress in Transgenic Sickle Mouse Models
Hebbel, Robert P
Kaul, Dhananjay K.
Free radical biology & medicine
Sickle cell disease (SCD) is characterized by reperfusion injury and chronic oxidative stress. Oxidative stress and hemolysis in SCD result in inactivation of nitric oxide (NO) and depleted arginine levels. We hypothesized that augmenting NO production by arginine supplementation will reduce oxidative stress in SCD. To this end, we measured the effect of arginine (5% in mouse chow) on NO metabolites (NOx), lipid peroxidation (LPO) and selected antioxidants in transgenic sickle mouse models. Untreated transgenic sickle (NY1DD) mice (expressing ~75% βS-globin of all β-globins; mild pathology) and knockout sickle (BERK) mice (expressing exclusively hemoglobin S; severe pathology) showed reduced NOx levels and significant increases in the liver LPO compared with C57BL mice, with BERK mice showing maximal LPO increase in accordance with the disease severity. This was accompanied by reduced activity of antioxidants (glutathione [GSH], total superoxide dismutase [SOD], catalase and glutathione peroxidase [GPx]). However, GSH levels in BERK were higher than in NY1DD mice indicating a protective response to greater oxidative stress. Importantly, dietary arginine significantly increased NOx levels, reduced LPO and increased antioxidants in both sickle mouse models. In contrast, L-NAME, a potent non-selective NOS inhibitor, worsened the oxidative stress in NY1DD mice. Thus, attenuating effect of arginine on oxidative stress in SCD mice suggests its potential application in the management of this disease.
Sickle cell disease; oxidative stress; arginine; lipid peroxidation; antioxidants
Results 1-2 (2)
Go to page number:
Remove citation from clipboard
Add citation to clipboard
This will clear all selections from your clipboard. Do you wish proceed?
Clipboard is full! Please remove an item and try again.
PubMed Central Canada is a service of the
Canadian Institutes of Health Research
(CIHR) working in partnership with the National Research Council's
Canada Institute for Scientific and Technical Information
in cooperation with the
National Center for Biotechnology Information
U.S. National Library of Medicine
(NCBI/NLM). It includes content provided to the
PubMed Central International archive
by participating publishers.