Phorbol Ester-dependent Activation of Peroxiredoxin I Gene Expression via a Protein Kinase C, Ras, p38 Mitogen-activated Protein Kinase Signaling Pathway

Abstract

The antioxidant protein peroxiredoxin (Prx) I is a thioredoxin peroxidase that is involved in the regulation of proliferation and differentiation of mammalian cells. Here, it is shown that Prx I gene expression was induced transcriptionally by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) in cultured rat liver tissue macrophages and RAW264.7 monocytic cells. TPA-dependent induction of Prx I gene expression was mediated by two proximal activator protein-1 sites of the rat Prx I promoter region that were nuclear targets of c-Jun as determined by transfection studies with luciferase reporter gene constructs and electrophoretic mobility shift assays. The transcription factor Nrf2, however, was not involved in the regulation of Prx I promoter activity. Prx I gene induction by TPA was decreased by protein kinase C inhibitors and overexpressed dominant negative forms of Ras and MEKK1, but not Raf-1. The p38 MAPK inhibitor SB202190 and overexpression of dominant negative mutants of MAPK kinase 4 (MKK4), MKK6, and p38 inhibited the TPA-dependent induction of Prx I gene transcription. In contrast, inhibitors of the JNK, SP600125, and the NF-B signaling pathway, caffeic acid phenethyl ester, respectively, as well as overexpressed dominant negative MKK7 and I B, had no effect on the up-regulation of Prx I reporter gene activity by TPA. Cotransfection of wild-type p38␣ and p38␤, but not that of p38␥ and p38␦, increased Prx I promoter activity. The data indicate that a protein kinase C, Ras, MEKK1, p38 MAPK signaling pathway plays a major role for the transcriptional up-regulation of Prx I gene expression.

Prostaglandin E2 Induces Breast Cancer–Related Aromatase Promoters via Activation of p38 and c-Jun NH2-Terminal Kinase in Adipose Fibroblasts

“…EPACs are guanine nucleotide exchange factors for the small G protein Rap1 (26). cAMP-dependent and phorbol ester/ PKC-dependent activations of p38, JNK, and ERK have been reported (18,21,(27)(28)(29)(30)(31). For example, h-adrenergic stimulation of p38 is blocked by a PKA inhibitor in brown adipocytes.…”

Induction of Prdx1 and Prdx6 in Liver Cells by Serum and TPA

“…Although the mechanism by which it elicits these two effects is unclear, the requirement of ROS in TPA-induced toxicity has been demonstrated (Lin et al, 2006). Induction of Prdx1 by TPA in H2.35 cells is not surprising given a prior study reporting Prdx1 induction by TPA in rat liver tissue macrophages and monocytic cells through a PKC/Ras/p38MAPK pathway (Hess et al, 2003). While this study reported nearly eight-fold induction by six hours, our results suggest a more modest effect on Prdx1 in H2.35 cells.…”

“…In addition to the previously mentioned consensus sequences, two putative AP1 sites are found between 340 and 470 nucleotides upstream of the transcription start site. It is worth noting that the TPA-dependent induction of Prdx1 reported by Hess et al was mediated by two proximal AP-1 sites targeted by c-Jun (Hess et al, 2003). The investigation of these potential regulatory elements and the corresponding DNA binding proteins will provide greater insight into the transcriptional regulation of Prdx6.…”

“…These data indicate that Prdx6 is more highly elevated in proliferating vs. quiescent cells as compared to Prdx1. Since Prdx1 is regulated by TPA in other cells (Hess et al, 2003), we also examined the regulation of Prdx1 and Prdx6 by TPA in H2.35 cells. As shown in Figure 1B, TPA also induced the expression of both genes, but with a much greater effect on Prdx6.…”

“…Originally named PAG (proliferation associated gene) in human (Prospéri et al, 1993), Prdx1 is overexpressed during cell proliferation and is transcriptionally induced by serum in human mammary epithelial cells (Prospéri et al, 1993). Prdx1 is also induced by the tumor promoter phorbol-12-myristate-13-acetate (TPA) in liver tissue macrophages (Hess et al, 2003). Since liver tissue is susceptible to high levels of ROS associated with normal cellular physiology and acute and chronic injury (Novo and M, 2008), we sought to compare Prdx1 and Prdx6 induction by serum and phorbol ester in H2.35 cells.…”