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Inhibition of cell apoptosis is an increasingly important factor in modulating airway inflammation in asthma, which is related to environmental pollutants. To investigate the effects of sulfur dioxide (SO2) on the mRNA and protein expressions of apoptosis-related genes in lungs from asthmatic rats, male Wistar rats were challenged by ovalbumin (OVA) or SO2 (2 ppm) inhalation alone or together. Examinations were performed 24 h after the last treatment. The mRNA and protein levels of p53, bax, and bcl-2 were analyzed in lungs using real-time reverse transcription-polymerase chain reaction (RT-PCR) assay and Western blot analysis, respectively. The results indicated that increases of bcl-2 or decreases of p53 and bax mRNA and protein levels were not significant in lungs of rats exposed to SO2 alone, compared with controls, but elevated or reduced levels of these genes appeared in lungs of asthmatic rats exposed to SO2 plus OVA, compared with controls, suggesting that SO2 exposure could result in OVA-induced increases or decreases of transcription and translation levels of these apoptosis-related genes in rat lungs, and may have relations to airway inflammation in asthma. The regulation mechanism of apoptosis in asthma disease exposure to SO2 needs further study. [ABSTRACT FROM AUTHOR]

Epidemiological studies suggested that ambient fine particulate matter (PM 2.5 ) exposure was associated with cardiovascular disease. However, the underlying mechanism, especially the mitochondrial damage mechanism, of PM 2.5 -induced heart acute injury is still unclear. In this study, the alterations of mitochondrial morphology and mitochondrial fission/fusion gene expression, oxidative stress, calcium homeostasis and inflammation in hearts of rats exposed to PM 2.5 with different dosages (0.375, 1.5, 6.0 and 24.0 mg/kg body weight) were investigated. The results indicated that the PM 2.5 exposure induced pathological changes and ultra-structural damage in hearts such as mitochondrial swell and cristae disorder. Furthermore, PM 2.5 exposure significantly increased specific mitochondrial fission/fusion gene (Fis1, Mfn1, Mfn2, Drp1 and OPA1) expression in rat hearts. These changes were accompanied by decreases of activities of superoxide dismutase (SOD), Na + K + -ATPase and Ca 2+ -ATPase and increases of levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) as well as levels of pro-inflammatory mediators including TNF-α, IL-6 and IL-1β in rat hearts. The results implicate that mitochondrial damage, oxidative stress, cellular homeostasis imbalance and inflammation are potentially important mechanisms for the PM 2.5 -induced heart injury, and may have relations with cardiovascular disease. [ABSTRACT FROM AUTHOR]