Figure 5.

Immunofluorescence staining of Jagged1, Notch3, ABCG2, CK19, and PCNA during recovery of injury induced by 5‐FU. (a) In the untreated rat tracheal epithelium, only a few cells were Jagged1‐positive. The number of Jagged1‐positive cells increased gradually, reaching its peak at about 6 h, and decreasing thereafter. (b) Few cells with nuclear localized Notch3 were detected in the untreated rat tracheal epithelium. After 5‐FU treatment, the proportion of cells of Notch3 nuclear‐positive increased significantly, and proportion peaked by about 6 h. By 48 h, the proportion had returned to normal levels. Most of cells with nuclear Notch3 neighboured Jagged1‐positive cells. (c) ABCG2 was mainly localized to the cell membrane and exhibited correlated with nuclear Notch3 localization. Most ABCG2‐positive cells also exhibited nuclear Notch3. (d) CK19‐positive cells were predominant in normal rat tracheal epithelium. After 5‐FU treatment, the number of CK19‐positive cells decreased sharply, then increased slowly, and returned almost to baseline levels by 48 h. (e) PCNA was localized to the cell nuclear. In normal rat tracheal epithelium, few cells were PCNA‐positive. After 5‐FU treatment, the number of PCNA‐positive cells increased and peaked by 6 h, then decreased gradually and returned to its normal levels by about 48 h (original magnification ×400).