Figure 4.

Effects of paricalcitol treatment on mitogen-activated protein kinase- and Akt-signaling pathway activation in indoxyl sulfate-treated human renal proximal tubular epithelial (HK-2) cells. (A) Levels of phospho-extracellular signal-related kinase 1/2 (phospho-Erk1/2), phospho-c-Jun N-terminal domain kinase (phospho-Jnk), phospho-p38, and (B) phospho-Akt in HK-2 cells incubated with indoxyl sulfate after pretreatment with paricalcitol. Increased levels of phospho-Erk1/2, phospho-Jnk, phospho-p38, and phospho-Akt were attenuated by paricalcitol treatment. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; IS, indoxyl sulfate. ^ap < 0.05 vs. control, ^bp < 0.05 vs. indoxyl sulfate-treated HK-2 cells.