HDAC6 was up-regulated in <i>Pkd1</i> mutant renal epithelial cells and kidney tissues.

<p>(A) Western blotting analysis of the expression of HDAC6 in <i>Pkd1</i> wild-type (WT) and <i>Pkd1^null/null</i> (Null) MEK cells as well as in postnatal <i>Pkd1</i> heterozygous PH2 cells and homozygous PN24 cells. The expression of HDAC6 in the above cells was quantified from three independent immunoblots and was standardized to actin. ** <i>p < 0.01</i>. (B) The activity of HDAC6 in <i>Pkd1</i> wild-type (WT) and <i>Pkd1^null/null</i> (Null) MEK cells as well as in postnatal <i>Pkd1</i> heterozygous PH2 cells and homozygous PN24 cells. The activity of HDAC6 was increased about 7.8 fold in <i>Pkd1^null/null</i> (Null) MEK cells and 4.8 fold in postnatal <i>Pkd1</i> homozygous PN24 cells compared with that in <i>Pkd1</i> wild type MEK cells and postnatal <i>Pkd1</i> heterozygous PH2 cells, respectively. The HDAC6 activity assay was performed in three independent experiments. * <i>p < 0.05</i>, ** <i>p < 0.01</i>. (C) Western blotting analysis of the expression of HDAC6 in <i>Pkd1</i> wild type and <i>Pkd1</i> hypomorphic homozygous (<i>Pkd1^nl/nl</i>) kidney tissues collected at postnatal days 7, 14, and 21. The relative expression levels of HDAC6 in different kidneys were standardized to actin and were presented in the lower panel. (D) Immunohistochemistry of HDAC6 in kidney sections from <i>Pkd1</i> wild type and <i>Pkd1^nl/nl</i> mice harvested at postnatal day 28. Scale bar, 20 µm.