Figure 5. PKCα, δ and ε stimulate Ezrin Thr567 phosphorylation in human obstructive cholestatic livers and HepG2 cells.
(A) PKCα, δ, and ε mRNA expression in the livers of obstructive cholestatic patients (n=30) and control patients (n=23) (fold of control group). (B) A representative Western blot of PKCα, δ, and ε protein expression, and (C) their densitometry (fold of control group, n=23 for control group, n=30 for obstructive cholestatic group). (D) The increased PKCα, PKCδ, and PKCε proteins were detected in the Ezrin pull-down complex, and (E) their corresponding densitometry analysis (fold of control group, n=15 for control group, n=21 for obstructive cholestatic group). (F)–(G) Modulating PKCα, δ, and ε activities affected Ezrin phosphorylation and MRP2 protein expression in stably transfected HepG2 cells. Cells were transfected with PKC wild-type (WT), dominant negative mutant (DN) and constitutively active mutant (CAT) constructs, or not transfected control (CTR). C1-C4, controls; O1-O5, obstructive cholestasis liver samples. *p< 0.01 versus controls.