Figure 4.

(A and B) Induction of ER stress in cultured HK-2 cells. Cells were treated for 24 h with 20 and 40 nM TG (A) or with 25 and 50 ng/ml TM (B) or DMSO as vehicle control (see the Concise Methods section for details). Total RNA was isolated, and the expression of HSPA5, HYOU1, and XBP1 was quantified by real-time RT-PCR. Data represent means of fold changes normalized against the respective controls (n = 3 for each condition). *P < 0.05, **P < 0.01 versus DMSO.