Fig. 1.

Mainstream tobacco smoke (MTS) induces γ-OH-PdG and α-meth-γ-OH-PdG in lung and γ-OH-PdG in bladder, but not in heart and liver. Polyphenol E (PPE) can prevent this TS effect. Two groups of mice (20 mice per group) were fed a control diet or diet containing 0.1% PPE. Ten mice from each group were either exposed to filtered air (FA) or MTS for 12 wk, as described in the text. Genomic DNAs from lung, heart, liver, and bladder tissues were prepared as described (34). PdG formation in these tissues was analyzed by an immunochemical method using a monoclonal antibody against PdG and quantum dot-labeled secondary antibody, as previously described (33). Each sample was measured two to four times. Typical slot blot hybridization results (Upper, antibody reaction; Lower, input DNA) are shown in A, and the quantification results are shown in B. Lines represent the geometric average values. ****P < 0.0001, ***P < 0.001, and *P < 0.05. PdG adduct formation in the lung and bladder tissues was further analyzed by a ³²P-postlabeling 2D-TLC/HPLC method, as previously described (34). (C) Typical 2D-TLC chromatographic autoradiograms. (D) The spots circled in C were extracted and further analyzed by an HPLC method (34). The elution positions of the standard γ-OH-PdG adduct and the α-meth-γ-OH-PdG adducts are indicated by the arrows. Note: MTS induced γ-OHPdG and α-meth-γ-OH-PdG in lung and γ-OH-PdG in bladder tissues, but not in heart and liver tissues. PPE prevented both types of DNA adduct formation in lung and bladder tissues in mice exposed to MTS, but PPE did not affect PdG adduct formation in lung and bladder tissues of the control mice. FA, mice exposed to FA; MTS, mice exposed to MTS; MTS + PPE, mice fed with diet with PPE and exposed to MTS; Std, standard DNA with different PdG levels.