• Journal of Chest Surgery
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• v.40 no.8
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• pp.529-535
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• 2007

Background: An imbalance between oxidants and antioxidants leads to oxidative stress, and this has been proposed to play an important role in the pathogenesis of lung neoplasm. Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/ref-1) is a multifunctional protein involved in DNA base excision repair and the redox regulation of many transcription factors. However, the alteration of the expressed levels of APE/ref-1 in non-small cell lung cancer is unknown. Material and Method: Forty-nine patients with surgically resected non-small cell lung cancer (NSCLC) were included in this study. Immunohistochemical staining with APE/ref-1 antibodies was performed, and their expressions were analyzed via Western blotting for specific antibodies. Result: APE/ref-1 was localized at the nucleus and mainly in the non-tumor region of the NSCLC tissue specimens; it was expressed in the cytoplasm and nucleus of the NSCLC. The nuclear and cytoplasmic expressions of APE/ref-1 in lung cancers were markedly up-regulated in the NSCLC, and this was correlated with the clinical stage. Catalase, as first-line antioxidant defense, was dramatically decreased in the NSCLC. Conclusion: Taken together, our results suggest that APE/ref-1, and especially cytoplasmic APE/ref-1, was upregulated in the lung cancer regions, and this may contribute to the compensatory defense system against oxidative stress. A low expression of catalase might have fundamental effects on the extracellular redox state of lung tumors, along with the potential consequences for the tumors.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.451-463
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• 2006

Background : Reactive oxygen species (ROS) take center stage as executers in ventilator-induced lung injury (VILI). The protein with DNA-damage scanning activity, poly (ADP-ribose) polymerase-1 (PARP1), signals DNA rupture and participates in base-excision repair. Paradoxically,overactivation of PARP1 in response to massive genotoxic injury such as ROS can induce cell death through ${\beta}$ -nicotinamide adenine dinucleotide ($NAD^+$) depletion, resulting in inflammation. The purpose of this study is to investigate the role of PARP1 and the effect of its inhibitor in VILI. Methods : Forty-eight male C57BL/6 mice were divided into sham, lung protective ventilation(LPV), VILI, and PARP1 inhibitor (PJ34)+VILI (PJ34+VILI) groups. Mechanical ventilator setting for the LPV group was $PIP\;15cmH_2O$ + $PEEP\;3cmH_2O$ + RR 90/min + 2 hours. The VILI and PJ34+VILI groups were ventilated on a setting of $PIP\;40cmH_2O$ + $PEEP\;0cmH_2O$ + RR 90/min + 2 hours. As a PARP1 inhibitor for the PJ34+VILI group, 20 mg/Kg of PJ34 was treated intraperitoneally 2 hours before mechanical ventilation. Wet-to-dry weight ratio and acute lung injury (ALI) score were measured to determine the degree of VILI. PARP1 activity was evaluated by using an immunohistochemical method utilizing biotinylated NAD. Myeloperoxidase (MPO) activity and the concentration of inflammatory cytokines such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-6 were measured in bronchoalveolar lavage fluid (BALF). Results : In the PJ34+VILI group, PJ34 pretreatment significantly reduced the degree of lung injury, compared with the VILI group (p<0.05). The number of cells expressing PARP1 activity was significantly increased in the VILI group, but significantly decreased in the PJ34+VILI group (p=0.001). In BALF, MPO activity, $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6 were also significantly lower in the PJ34+VILI group (all, p<0.05). Conclusion : PARP1 overactivation plays a major role in the mechanism of VILI. PARP1 inhibitor prevents VILI, and decreases MPO activity and inflammatory cytokines.