Targeting allosteric site of AKT by 5,7-dimethoxy-1,4-phenanthrenequinone suppresses neutrophilic inflammation.

Abstract

BACKGROUND:

Acute lung injury (ALI) is a severe life-threatening inflammatory disease. Neutrophil activation is a major pathogenic factor in ALI. Protein kinase B (PKB)/AKT regulates diverse cellular responses, but the significance in neutrophilic inflammation and ALI remains unknown.

METHODS:

Human neutrophils and neutrophil-like differentiated HL-60 (dHL-60) cells were used to examine the anti-inflammatory effects of 5,7-dimethoxy-1,4-phenanthrenequinone (CLLV-1). The therapeutic potential of CLLV-1 was determined in a mouse model of lipopolysaccharide (LPS)-induced ALI.

FINDINGS:

CLLV-1 inhibited respiratory burst, degranulation, adhesion, and chemotaxis in human neutrophils and dHL-60 cells. CLLV-1 inhibited the phosphorylation of AKT (Thr308 and Ser473), but not of ERK, JNK, or p38. Furthermore, CLLV-1 blocked AKT activity and covalently reacted with AKT Cys310 in vitro. The AKT309-313 peptide-CLLV-1 adducts were determined by NMR or mass spectrometry assay. The alkylation agent-conjugated AKT (reduced form) level was also inhibited by CLLV-1. Significantly, CLLV-1 ameliorated LPS-induced ALI, neutrophil infiltration, and AKT activation in mice.

INTERPRETATION:

Our results identify CLLV-1 as a covalent allosteric AKT inhibitor by targeting AKT Cys310. CLLV-1 shows potent anti-inflammatory activity in human neutrophils and LPS-induced mouse ALI. Our findings provide a mechanistic framework for redox modification of AKT that may serve as a novel pharmacological target to alleviate neutrophilic inflammation.

• Authors: Po-Jen Chen, I-Ling Ko, Chia-Lin Lee, Hao-Chun Hu, Fang-Rong Chang, Yang-Chang Wu, Yann-Lii Leu, Chih-Ching Wu, Cheng-Yu Lin, Chang-Yu Pan, Yung-Fong Tsai, Tsong-Long Hwang
• Journal: EBioMedicine (EBioMedicine) Vol. 40 Pg. 528-540 (Feb 2019) ISSN: 2352-3964 [Electronic] Netherlands
• PMID: 30709770 (Publication Type: Journal Article)
• Copyright: Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.

Chemical References

• 5,7-dimethoxy-1,4-phenanthrenequinone
• Anti-Inflammatory Agents
• Phenanthrenes
• Quinones
• Reactive Oxygen Species
• Proto-Oncogene Proteins c-akt

Topics

• Allosteric Site
• Anti-Inflammatory Agents (chemistry, pharmacology)
• Cell Adhesion (drug effects)
• Chemotaxis, Leukocyte (immunology)
• HL-60 Cells
• Humans
• Models, Molecular
• Molecular Conformation
• Neutrophil Infiltration (drug effects)
• Neutrophils (drug effects, immunology, metabolism)
• Phenanthrenes (chemistry, pharmacology)
• Protein Binding
• Protein Interaction Domains and Motifs (drug effects)
• Proto-Oncogene Proteins c-akt (antagonists & inhibitors, chemistry, metabolism)
• Quinones (chemistry, pharmacology)
• Reactive Oxygen Species
• Structure-Activity Relationship