TNF-α-induced sympathetic excitation requires EGFR and ERK1/2 signaling in cardiovascular regulatory regions of the forebrain

Peripherally or centrally administered TNF-α elicits a prolonged sympathetically mediated pressor response, but the underlying molecular mechanisms are unknown. Activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in cardiovascular regions of the brain has recently been recognized as a key mediator of sympathetic excitation, and ERK1/2 signaling is induced by activation of epidermal growth factor receptor (EGFR) tyrosine kinase activity. The present study examined the role of EGFR and ERK1/2 signaling in the sympathetic response to TNF-α. In urethane-anesthetized rats, intracarotid artery injection of TNF-α increased phosphorylation of EGFR and ERK1/2 in the subfornical organ (SFO) and the hypothalamic paraventricular nucleus (PVN); upregulated the gene expression of excitatory mediators in SFO and PVN; and increased blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA). A continuous intracerebroventricular infusion of the selective EGFR tyrosine kinase inhibitor AG1478 or the ERK1/2 inhibitor PD98059 significantly attenuated these responses. Bilateral PVN microinjections of TNF-α also increased phosphorylated ERK1/2 and the gene expression of excitatory mediators in PVN, along with increases in BP, HR, and RSNA, and these responses were substantially reduced by prior bilateral PVN microinjections of AG1478. These results identify activation of EGFR in cardiovascular regulatory regions of the forebrain as an important molecular mediator of TNF-α-driven sympatho-excitatory responses and suggest that EGFR activation of the ERK1/2 signaling pathway plays an essential role. These mechanisms likely contribute to sympathetic excitation in pathophysiological states like heart failure and hypertension, in which circulating and brain TNF-α levels are increased.NEW & NOTEWORTHY Proinflammatory cytokines contribute to the augmented sympathetic nerve activity in hypertension and heart failure, but the central mechanisms involved are largely unknown. The present study reveals that TNF-α transactivates EGFR in the subfornical organ and the hypothalamic paraventricular nucleus to initiate ERK1/2 signaling, upregulate the gene expression of excitatory mediators, and increase sympathetic nerve activity. These findings identify EGFR as a gateway to sympathetic excitation and a potential target for intervention in cardiovascular disease states.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:320

Enthalten in:

American journal of physiology. Heart and circulatory physiology - 320(2021), 2 vom: 01. Feb., Seite H772-H786

Sprache:

Englisch

Beteiligte Personen:

Wei, Shun-Guang [VerfasserIn]
Yu, Yang [VerfasserIn]
Felder, Robert B [VerfasserIn]

Links:

Volltext

Themen:

170449-18-0
Brain
EC 2.7.10.1
EC 2.7.11.24
Egfr protein, rat
ErbB Receptors
Hypothalamic paraventricular nucleus
Journal Article
Mapk1 protein, rat
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase 3
Proinflammatory cytokines
Protein Kinase Inhibitors
Quinazolines
RTKI cpd
Renin-angiotensin system
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.
Subfornical organ
Sympathetic nervous system
Tumor Necrosis Factor-alpha
Tyrphostins

Anmerkungen:

Date Completed 22.03.2021

Date Revised 26.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1152/ajpheart.00606.2020

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM319028860