TY  - JOUR
A1  - Keller, Johannes
A1  - Catala-Lehnen, Philip
A1  - Huebner, Antje K.
A1  - Jeschke, Anke
A1  - Heckt, Timo
A1  - Lueth, Anja
A1  - Krause, Matthias
A1  - Koehne, Till
A1  - Albers, Joachim
A1  - Schulze, Jochen
A1  - Schilling, Sarah
A1  - Haberland, Michael
A1  - Denninger, Hannah
A1  - Neven, Mona
A1  - Hermans-Borgmeyer, Irm
A1  - Streichert, Thomas
A1  - Breer, Stefan
A1  - Barvencik, Florian
A1  - Levkau, Bodo
A1  - Rathkolb, Birgit
A1  - Wolf, Eckhard
A1  - Calzada-Wack, Julia
A1  - Neff, Frauke
A1  - Gailus-Durner, Valerie
A1  - Fuchs, Helmut
A1  - de Angelis, Martin Hrabe
A1  - Klutmann, Susanne
A1  - Tsourdi, Elena
A1  - Hofbauer, Lorenz C.
A1  - Kleuser, Burkhard
A1  - Chun, Jerold
A1  - Schinke, Thorsten
A1  - Amling, Michael
T1  - Calcitonin controls bone formation by inhibiting the release of sphingosine 1-phosphate from osteoclasts
JF  - Nature Communications
N2  - The hormone calcitonin (CT) is primarily known for its pharmacologic action as an inhibitor of bone resorption, yet CT-deficient mice display increased bone formation. These findings raised the question about the underlying cellular and molecular mechanism of CT action. Here we show that either ubiquitous or osteoclast-specific inactivation of the murine CT receptor (CTR) causes increased bone formation. CT negatively regulates the osteoclast expression of Spns2 gene, which encodes a transporter for the signalling lipid sphingosine 1-phosphate (S1P). CTR-deficient mice show increased S1P levels, and their skeletal phenotype is normalized by deletion of the S1P receptor S1P(3). Finally, pharmacologic treatment with the nonselective S1P receptor agonist FTY720 causes increased bone formation in wild-type, but not in S1P(3)-deficient mice. This study redefines the role of CT in skeletal biology, confirms that S1P acts as an osteoanabolic molecule in vivo and provides evidence for a pharmacologically exploitable crosstalk between osteoclasts and osteoblasts.
Y1  - 2014
U6  - https://doi.org/10.1038/ncomms6215
SN  - 2041-1723
VL  - 5
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Unterberg, Marlies
A1  - Leffers, Larissa
A1  - Huebner, Florian
A1  - Humpf, Hans-Ulrich
A1  - Lepikhov, Konstantin
A1  - Walter, Joern
A1  - Ebert, Franziska
A1  - Schwerdtle, Tanja
T1  - Toxicity of arsenite and thio-DMA(V) after long-term (21 days) incubation of human urothelial cells: cytotoxicity, genotoxicity and epigenetics
JF  - Toxicology research
N2  - This study aims to further mechanistically understand toxic modes of action after chronic inorganic arsenic exposure. Therefore long-term incubation studies in cultured cells were carried out, to display chronically attained changes, which cannot be observed in the generally applied in vitro short-term incubation studies. Particularly, the cytotoxic, genotoxic and epigenetic effects of an up to 21 days incubation of human urothelial (UROtsa) cells with pico- to nanomolar concentrations of iAs(III) and its metabolite thio-DMA(V) were compared. After 21 days of incubation, cytotoxic effects were strongly enhanced in the case of iAs(III) and might partly be due to glutathione depletion and genotoxic effects on the chromosomal level. These results are in strong contrast to cells exposed to thio-DMA(V). Thus, cells seemed to be able to adapt to this arsenical, as indicated among others by an increase in the cellular glutathione level. Most interestingly, picomolar concentrations of both iAs(III) and thio-DMA(V) caused global DNA hypomethylation in UROtsa cells, which was quantified in parallel by 5-medC immunostaining and a newly established, reliable, high resolution mass spectrometry (HRMS)-based test system. This is the first time that epigenetic effects are reported for thio-DMA(V); iAs(III) induced epigenetic effects occur in at least 8000 fold lower concentrations as reported in vitro before. The fact that both arsenicals cause DNA hypomethylation at really low, exposure-relevant concentrations in human urothelial cells suggests that this epigenetic effect might contribute to inorganic arsenic induced carcinogenicity, which for sure has to be further investigated in future studies.
Y1  - 2014
U6  - https://doi.org/10.1039/c4tx00036f
SN  - 2045-452X
SN  - 2045-4538
VL  - 3
IS  - 6
SP  - 456
EP  - 464
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -