14796
2016
eng
e0167033
11
11
article
1
2017-05-05
--
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PTH1R Mutants Found in Patients with Primary Failure of Tooth Eruption Disrupt G-Protein Signaling
Aim
Primary failure of tooth eruption (PFE) is causally linked to heterozygous mutations of the parathyroid hormone receptor (PTH1R) gene. The mutants described so far lead to exchange of amino acids or truncation of the protein that may result in structural changes of the expressed PTH1R. However, functional effects of these mutations have not been investigated yet.
Materials and Methods
In HEK293 cells, PTH1R wild type was co-transfected with selected PTH1R mutants identified in patients with PFE. The effects on activation of PTH-regulated intracellular signaling pathways were analyzed by ELISA and Western immunoblotting. Differential effects of wild type and mutated PTH1R on TRESK ion channel regulation were analyzed by electrophysiological recordings in Xenopus laevis oocytes.
Results
In HEK293 cells, activation of PTH1R wild type increases cAMP and in response activates cAMP-stimulated protein kinase as detected by phosphorylation of the vasodilator stimulated phosphoprotein (VASP). In contrast, the PTH1R mutants are functionally inactive and mutant PTH1R/Gly452Glu has a dominant negative effect on the signaling of PTH1R wild type. Confocal imaging revealed that wild type PTH1R is expressed on the cell surface, whereas PTH1R/Gly452Glu mutant is mostly retained inside the cell. Furthermore, in contrast to wild type PTH1R which substantially augmented K+ currents of TRESK channels, coupling of mutated PTH1R to TRESK channels was completely abolished.
Conclusions
PTH1R mutations affect intracellular PTH-regulated signaling in vitro. In patients with primary failure of tooth eruption defective signaling of PTH1R mutations is suggested to occur in dento-alveolar cells and thus may lead to impaired tooth movement.
PLoS One
10.1371/journal.pone.0167033
urn:nbn:de:bvb:20-opus-147967
PLoS ONE 11(11): e0167033. https://doi.org/10.1371/journal.pone.0167033
Hariharan Subramanian
Frank Döring
Sina Kollert
Natalia Rukoyatkina
Julia Sturm
Stepan Gambaryan
Angelika Stellzig-Eisenhauer
Philipp Meyer-Marcotty
Martin Eigenthaler
Erhard Wischmeyer
eng
uncontrolled
phosphorylation
eng
uncontrolled
xenopus oocytes
eng
uncontrolled
calcium signaling
eng
uncontrolled
intracellular receptors
eng
uncontrolled
mutation
eng
uncontrolled
teeth
eng
uncontrolled
tooth eruption
eng
uncontrolled
transfection
Chirurgie und verwandte medizinische Fachrichtungen
open_access
Institut für Klinische Biochemie und Pathobiochemie
Physiologisches Institut
Poliklinik für Kieferorthopädie
Förderzeitraum 2016
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/14796/Subramanian_journal.pone.0167033.pdf
14831
2015
eng
12548
5
article
1
2017-05-10
--
--
Activation of TRESK channels by the inflammatory mediator lysophosphatidic acid balances nociceptive signalling
In dorsal root ganglia (DRG) neurons TRESK channels constitute a major current component of the standing outward current IK\(_{SO}\). A prominent physiological role of TRESK has been attributed to pain sensation. During inflammation mediators of pain e.g. lysophosphatidic acid (LPA) are released and modulate nociception. We demonstrate co-expression of TRESK and LPA receptors in DRG neurons. Heterologous expression of TRESK and LPA receptors in Xenopus oocytes revealed augmentation of basal K\(^{+}\) currents upon LPA application. In DRG neurons nociception can result from TRPV\(_{1}\) activation by capsaicin or LPA. Upon co-expression in Xenopus oocytes LPA simultaneously increased both depolarising TRPV\(_{1}\) and hyperpolarising TRESK currents. Patch-clamp recordings in cultured DRG neurons from TRESK[wt] mice displayed increased IK\(_{SO}\) after application of LPA whereas under these conditions IK\(_{SO}\) in neurons from TRESK[ko] mice remained unaltered. Under current-clamp conditions LPA application differentially modulated excitability in these genotypes upon depolarising pulses. Spike frequency was attenuated in TRESK[wt] neurons and, in contrast, augmented in TRESK[ko] neurons. Accordingly, excitation of nociceptive neurons by LPA is balanced by co-activation of TRESK channels. Hence excitation of sensory neurons is strongly controlled by the activity of TRESK channels, which therefore are good candidates for the treatment of pain disorders.
Scientific Reports
10.1038/srep12548
urn:nbn:de:bvb:20-opus-148312
Scientific Reports 5:12548 (2015). DOI: 10.1038/srep12548
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Sina Kollert
Benjamin Dombert
Frank Döring
Erhard Wischmeyer
eng
uncontrolled
protein coupled receptors
eng
uncontrolled
molecular mechanisms
eng
uncontrolled
neuropathic pain
eng
uncontrolled
migraine
eng
uncontrolled
initiation
eng
uncontrolled
modulation
eng
uncontrolled
cells
eng
uncontrolled
sensory neurons
eng
uncontrolled
domain K\(^{+}\) channels
eng
uncontrolled
2-pore potassium channel
Medizin und Gesundheit
open_access
Institut für Klinische Neurobiologie
Physiologisches Institut
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/14831/013_Kollert_Scientific_Reports.pdf