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Meng G, Tang X, Yang Z, Zhao Y, Curtis JM, McMullen TPW, Brindley DN. Dexamethasone decreases the autotaxin-lysophosphatidate-inflammatory axis in adipose tissue: implications for the metabolic syndrome and breast cancer. FASEB J 2018; 33:1899-1910. [PMID: 30192654 DOI: 10.1096/fj.201801226r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lysophosphatidate (LPA) signaling through 6 receptors is regulated by the balance of LPA production by autotaxin (ATX) vs. LPA degradation by lipid phosphate phosphatases (LPPs). LPA promotes an inflammatory cycle by increasing the synthesis of cyclooxygenase-2 and multiple inflammatory cytokines that stimulate further ATX production. We aimed to determine whether the anti-inflammatory glucocorticoid (GC) dexamethasone (Dex) functions partly by decreasing the ATX-LPA inflammatory cycle in adipose tissue, a major site of ATX secretion. Treatment of human adipose tissue with 10-1000 nM Dex decreased ATX secretion, increased LPP1 expression, and decreased mRNA expressions of IL-6, TNF-α, peroxisome proliferator-activated receptor (PPAR)-γ, and adiponectin. Cotreatment with rosiglitazone (an insulin sensitizer), insulin, or both abolished Dex-induced decreases in ATX and adiponectin secretion, but did not reverse Dex-induced decreases in secretions of 20 inflammatory cytokines and chemokines. Dex-treated mice exhibited lower ATX activity in plasma, brain, and adipose tissue; decreased mRNA levels for LPA and sphingosine 1-phosphate (S1P) receptors in brain; and decreased plasma concentrations of LPA and S1P. Our results establish a novel mechanism for the anti-inflammatory effects of Dex through decreased signaling by the ATX-LPA-inflammatory axis. The GC action in adipose tissue has implications for the pathogenesis of insulin resistance and obesity in metabolic syndrome and breast cancer treatment.-Meng, G., Tang, X., Yang, Z., Zhao, Y., Curtis, J. M., McMullen, T. P. W., Brindley, D. N. Dexamethasone decreases the autotaxin-lysophosphatidate-inflammatory axis in adipose tissue: implications for the metabolic syndrome and breast cancer.
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Affiliation(s)
- Guanmin Meng
- Signal Transduction Research Group, Department of Biochemistry, Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada
| | - Xiaoyun Tang
- Signal Transduction Research Group, Department of Biochemistry, Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada
| | - Zelei Yang
- Signal Transduction Research Group, Department of Biochemistry, Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada
| | - YuanYuan Zhao
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada; and
| | - Jonathan M Curtis
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada; and
| | - Todd P W McMullen
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - David N Brindley
- Signal Transduction Research Group, Department of Biochemistry, Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada
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Rock EM, Limebeer CL, Parker LA. Anticipatory nausea in animal models: a review of potential novel therapeutic treatments. Exp Brain Res 2014; 232:2511-34. [DOI: 10.1007/s00221-014-3942-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/31/2014] [Indexed: 11/24/2022]
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