5-HT2A receptor induces ERK phosphorylation and proliferation through ADAM-17 tumor necrosis factor-alpha-converting enzyme (TACE) activation and heparin-bound epidermal growth factor-like growth factor (HB-EGF) shedding in mesangial cells.
In this study, we present multiple lines of evidence to support a critical role for heparin-bound EGF (epidermal growth factor)-like growth factor (HB-EGF) and tumor necrosis factor-alpha-converting enzyme (TACE) (ADAM17) in the transactivation of EGF receptor (EGFR), ERK phosphorylation, and cellular proliferation induced by the 5-HT(2A) receptor in renal mesangial cells. 5-hydroxy-tryptamine (5-HT) resulted in rapid activation of TACE, HB-EGF shedding, EGFR activation, ERK phosphorylation, and longer term increases in DNA content in mesangial cells. ERK phosphorylation was attenuated by 1) neutralizing EGFR antibodies and the EGFR kinase inhibitor, AG1478, 2) neutralizing HB-EGF, but not amphiregulin, antibodies, heparin, or CM197, and 3) pharmacological inhibitors of matrix-degrading metalloproteinases or TACE small interfering RNA. Exogenously administered HB-EGF stimulated ERK phosphorylation. Additionally, TACE was co-immunoprecipitated with HB-EGF. Small interfering RNA against TACE also blocked 5-HT-induced increases in ERK phosphorylation, HB-EGF shedding, and DNA content. In aggregate, this work supports a pathway map that can be depicted as follows: 5-HT --> 5-HT(2A) receptor --> TACE --> HB-EGF shedding --> EGFR --> ERK --> increased DNA content. To our knowledge, this is the first time that TACE has been implicated in 5-HT-induced EGFR transactivation or in proliferation induced by a G protein-coupled receptor in native cells in culture.
Göőz
Monika
M
Nephrology, Rheumatology and Endocrinology Divisions, Department of Medicine of the Medical University of South Carolina and the Medical and Research Services of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29425. Electronic address: beckm@musc.edu.
Göőz
Pal
P
Nephrology, Rheumatology and Endocrinology Divisions, Department of Medicine of the Medical University of South Carolina and the Medical and Research Services of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29425.
Luttrell
Louis M
LM
Nephrology, Rheumatology and Endocrinology Divisions, Department of Medicine of the Medical University of South Carolina and the Medical and Research Services of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29425.
Raymond
John R
JR
Nephrology, Rheumatology and Endocrinology Divisions, Department of Medicine of the Medical University of South Carolina and the Medical and Research Services of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29425.
D051722:ADAM Proteins / Q000378:metabolism*; D000072198:ADAM17 Protein; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology*; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D050527:Mesangial Cells / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A / Q000502:physiology*; D015533:Transcriptional Activation
C587885:Hbegf protein, rat; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D044402:Receptor, Serotonin, 5-HT2A; D004815:Epidermal Growth Factor; D006493:Heparin; D048049:Extracellular Signal-Regulated MAP Kinases; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606464:Adam17 protein, rat