Upregulation of α-SMA and ECM by gene transfer and ZnSO4 treatment in liver. (A) Detection of α-SMA by immunohistochemistry. Forty eight h after hydrodynamics-based injection of pPK9a, the mice were sacrificed and the liver sections were subjected to immunostaining. Dark brown granules represent α-SMA signals stained by α-SMA-specific antibody and indicated by arrows. (B) Detection of ECM and collagen by Masson's trichrome staining. The cytoplasm was stained red and collagen fibers in ECM were blue-green. The collagen signals were indicated by arrows. Representative liver sections of α-SMA and collagen from experimental I-IV groups: (I) Ringer's solution + pPK9a + ZnSO4 48 h. (II) Ringer's solution + ZnSO4. (III) Ringer's solution + pPK9a. (IV) Mice without hydrodynamics-based injection. Bar = 0.2 mm.