Advanced glycation end product (AGE)-receptor for AGE (RAGE) signaling and up-regulation of Egr-1 in hypoxic macrophages.
Receptor for advanced glycation end product (RAGE)-dependent signaling has been implicated in ischemia/reperfusion injury in the heart, lung, liver, and brain. Because macrophages contribute to vascular perturbation and tissue injury in hypoxic settings, we tested the hypothesis that RAGE regulates early growth response-1 (Egr-1) expression in hypoxia-exposed macrophages. Molecular analysis, including silencing of RAGE, or blockade of RAGE with sRAGE (the extracellular ligand-binding domain of RAGE), anti-RAGE IgG, or anti-AGE IgG in THP-1 cells, and genetic deletion of RAGE in peritoneal macrophages, revealed that hypoxia-induced up-regulation of Egr-1 is mediated by RAGE signaling. In addition, the observation of increased cellular release of RAGE ligand AGEs in hypoxic THP-1 cells suggests that recruitment of RAGE in hypoxia is stimulated by rapid production of RAGE ligands in this setting. Finally, we show that mDia-1, previously shown to interact with the RAGE cytoplasmic domain, is essential for hypoxia-stimulated regulation of Egr-1, at least in part through protein kinase C betaII, ERK1/2, and c-Jun NH(2)-terminal kinase signaling triggered by RAGE ligands. Our findings highlight a novel mechanism by which an extracellular signal initiated by RAGE ligand AGEs regulates Egr-1 in a manner requiring mDia-1.
Xu
Yunlu
Y
Division of Surgical Science, Department of Surgery, Columbia University Medical Center, New York, New York 10032, USA.
Toure
Fatouma
F
Qu
Wu
W
Lin
Lili
L
Song
Fei
F
Shen
Xiaoping
X
Rosario
Rosa
R
Garcia
Joel
J
Schmidt
Ann Marie
AM
Yan
Shi-Fang
SF
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D051766:Early Growth Response Protein 1 / Q000235:genetics*; D000080865:Formins; D006801:Humans; D008024:Ligands; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000378:metabolism*; D015398:Signal Transduction; D015854:Up-Regulation
D002352:Carrier Proteins; C491464:Diap1 protein, mouse; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D000080865:Formins; D008024:Ligands; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic