Zhang, Y.* ; Jiang, D. ; Li, H.* ; Sun, Y.* ; Jiang, X.* ; Gong, S.* ; Qian, Z.* ; Tao, J.*
Melanocortin type 4 receptor-mediated inhibition of A-type K+ current enhances sensory neuronal excitability and mechanical pain sensitivity in rats.
J. Biol. Chem. 294, 5496-5507 (2019)
alpha-Melanocyte-stimulating hormone (-MSH) has been shown to be involved in nociception, but the underlying molecular mechanisms remain largely unknown. In this study, we report that -MSH suppresses the transient outward A-type K+ current (I-A) in trigeminal ganglion (TG) neurons and thereby modulates neuronal excitability and peripheral pain sensitivity in rats. Exposing small-diameter TG neurons to -MSH concentration-dependently decreased I-A. This -MSH-induced I-A decrease was dependent on the melanocortin type 4 receptor (MC4R) and associated with a hyperpolarizing shift in the voltage dependence of A-type K+ channel inactivation. Chemical inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin or of class I PI3Ks with the selective inhibitor CH5132799 prevented the MC4R-mediated I-A response. Blocking G(i/o)-protein signaling with pertussis toxin or by dialysis of TG neurons with the G-blocking synthetic peptide QEHA abolished the -MSH-mediated decrease in I-A. Further, -MSH increased the expression levels of phospho-p38 mitogen-activated protein kinase, and pharmacological or genetic inhibition of p38 abrogated the -MSH-induced I-A response. Additionally, -MSH significantly increased the action potential firing rate of TG neurons and increased the sensitivity of rats to mechanical stimuli applied to the buccal pad area, and both effects were abrogated by I-A blockade. Taken together, our findings suggest that -MSH suppresses I-A by activating MC4R, which is coupled sequentially to the G complex of the G(i/o)-protein and downstream class I PI3K-dependent p38 signaling, thereby increasing TG neuronal excitability and mechanical pain sensitivity in rats.
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Electrophysiology ; Patch Clamp ; Potassium Channel ; Signal Transduction ; G-protein-coupled Receptor (gpcr) ; Ion Channel ; Pain ; Cell Signaling ; A-type K Plus Current ; Alpha-melanocyte-stimulating Hormone ; Melanocortin Type 4 Receptor (mc4r) ; Neuronal Excitability ; Trigeminal Ganglion Neurons ; Pain Perception ; Nociception ; Action Potential; Melanocyte-stimulating Hormone; Kv4.2 Potassium Channel; Protein-kinase; Neuropathic Pain; Phosphatidylinositol 3-kinase; Ganglion Neurons; Calcium-channels; P38 Mapk; Activation; Expression
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2019
Prepublished im Jahr
HGF-Berichtsjahr
2019
ISSN (print) / ISBN
0021-9258
e-ISSN
1083-351X
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 294,
Heft: 14,
Seiten: 5496-5507
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
American Society for Biochemistry and Molecular Biology
Verlagsort
9650 Rockville Pike, Bethesda, Md 20814-3996 Usa
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30202 - Environmental Health
Forschungsfeld(er)
Lung Research
PSP-Element(e)
G-554000-001
Förderungen
Copyright
Erfassungsdatum
2019-03-13