TY  - JOUR
A1  - Gulbins, Erich
A1  - Palmada, Monica
A1  - Reichel, Martin
A1  - Lueth, Anja
A1  - Boehmer, Christoph
A1  - Amato, Davide
A1  - Mueller, Christian P.
A1  - Tischbirek, Carsten H.
A1  - Groemer, Teja W.
A1  - Tabatabai, Ghazaleh
A1  - Becker, Katrin Anne
A1  - Tripal, Philipp
A1  - Staedtler, Sven
A1  - Ackermann, Teresa F.
A1  - van Brederode, Johannes
A1  - Alzheimer, Christian
A1  - Weller, Michael
A1  - Lang, Undine E.
A1  - Kleuser, Burkhard
A1  - Grassme, Heike
A1  - Kornhuber, Johannes
T1  - Acid sphingomyelinase-ceramide system mediates effects of antidepressant drugs
JF  - Nature medicine
N2  - Major depression is a highly prevalent severe mood disorder that is treated with antidepressants. The molecular targets of antidepressants require definition. We investigated the role of the acid sphingomyelinase (Asm)-ceramide system as a target for antidepressants. Therapeutic concentrations of the antidepressants amitriptyline and fluoxetine reduced Asm activity and ceramide concentrations in the hippocampus, increased neuronal proliferation, maturation and survival and improved behavior in mouse models of stress-induced depression. Genetic Asm deficiency abrogated these effects. Mice overexpressing Asm, heterozygous for acid ceramidase, treated with blockers of ceramide metabolism or directly injected with C16 ceramide in the hippocampus had higher ceramide concentrations and lower rates of neuronal proliferation, maturation and survival compared with controls and showed depression-like behavior even in the absence of stress. The decrease of ceramide abundance achieved by antidepressant-mediated inhibition of Asm normalized these effects. Lowering ceramide abundance may thus be a central goal for the future development of antidepressants.
Y1  - 2013
U6  - https://doi.org/10.1038/nm.3214
SN  - 1078-8956
VL  - 19
IS  - 7
SP  - 934
EP  - +
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Bernhard, Nadine
A1  - Moskwa, Lisa-Marie
A1  - Schmidt, Karsten
A1  - Oeser, Ralf Andreas
A1  - Aburto, Felipe
A1  - Bader, Maaike Y.
A1  - Baumann, Karen
A1  - von Blanckenburg, Friedhelm
A1  - Boy, Jens
A1  - van den Brink, Liesbeth
A1  - Brucker, Emanuel
A1  - Buedel, Burkhard
A1  - Canessa, Rafaella
A1  - Dippold, Michaela A.
A1  - Ehlers, Todd
A1  - Fuentes, Juan P.
A1  - Godoy, Roberto
A1  - Jung, Patrick
A1  - Karsten, Ulf
A1  - Koester, Moritz
A1  - Kuzyakov, Yakov
A1  - Leinweber, Peter
A1  - Neidhardt, Harald
A1  - Matus, Francisco
A1  - Mueller, Carsten W.
A1  - Oelmann, Yvonne
A1  - Oses, Romulo
A1  - Osses, Pablo
A1  - Paulino, Leandro
A1  - Samolov, Elena
A1  - Schaller, Mirjam
A1  - Schmid, Manuel
A1  - Spielvogel, Sandra
A1  - Spohn, Marie
A1  - Stock, Svenja
A1  - Stroncik, Nicole
A1  - Tielboerger, Katja
A1  - Uebernickel, Kirstin
A1  - Scholten, Thomas
A1  - Seguel, Oscar
A1  - Wagner, Dirk
A1  - Kühn, Peter
T1  - Pedogenic and microbial interrelations to regional climate and local topography
BT  - New insights from a climate gradient (arid to humid) along the Coastal Cordillera of Chile
JF  - Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution
N2  - The effects of climate and topography on soil physico-chemical and microbial parameters were studied along an extensive latitudinal climate gradient in the Coastal Cordillera of Chile (26 degrees-38 degrees S). The study sites encompass arid (Pan de Azucar), semiarid (Santa Gracia), mediterranean (La Campana) and humid (Nahuelbuta) climates and vegetation, ranging from arid desert, dominated by biological soil crusts (biocrusts), semiarid shrubland and mediterranean sclerophyllous forest, where biocrusts are present but do have a seasonal pattern to temperate-mixed forest, where biocrusts only occur as an early pioneering development stage after disturbance. All soils originate from granitic parent materials and show very strong differences in pedogenesis intensity and soil depth. Most of the investigated physical, chemical and microbiological soil properties showed distinct trends along the climate gradient. Further, abrupt changes between the arid northernmost study site and the other semi-arid to humid sites can be shown, which indicate non-linearity and thresholds along the climate gradient. Clay and total organic carbon contents (TOC) as well as Ah horizons and solum depths increased from arid to humid climates, whereas bulk density (BD), pH values and base saturation (BS) decreased. These properties demonstrate the accumulation of organic matter, clay formation and element leaching as key-pedogenic processes with increasing humidity. However, the soils in the northern arid climate do not follow this overall latitudinal trend, because texture and BD are largely controlled by aeolian input of dust and sea salts spray followed by the formation of secondary evaporate minerals. Total soil DNA concentrations and TOC increased from arid to humid sites, while areal coverage by biocrusts exhibited an opposite trend. Relative bacterial and archaeal abundances were lower in the arid site, but for the other sites the local variability exceeds the variability along the climate gradient. Differences in soil properties between topographic positions were most pronounced at the study sites with the mediterranean and humid climate, whereas microbial abundances were independent on topography across all study sites. In general, the regional climate is the strongest controlling factor for pedogenesis and microbial parameters in soils developed from the same parent material. Topographic position along individual slopes of limited length augmented this effect only under humid conditions, where water erosion likely relocated particles and elements downward. The change from alkaline to neutral soil pH between the arid and the semi-arid site coincided with qualitative differences in soil formation as well as microbial habitats. This also reflects non-linear relationships of pedogenic and microbial processes in soils depending on climate with a sharp threshold between arid and semi-arid conditions. Therefore, the soils on the transition between arid and semi-arid conditions are especially sensitive and may be well used as indicators of long and medium-term climate changes. Concluding, the unique latitudinal precipitation gradient in the Coastal Cordillera of Chile is predestined to investigate the effects of the main soil forming factor - climate - on pedogenic processes.
KW  - Climate
KW  - Topography
KW  - Soil texture
KW  - Total organic carbon
KW  - Carbon isotope ratio (delta C-13(TOC))
KW  - Microbial abundance
Y1  - 2018
U6  - https://doi.org/10.1016/j.catena.2018.06.018
SN  - 0341-8162
SN  - 1872-6887
VL  - 170
SP  - 335
EP  - 355
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Repasch, Marisa
A1  - Scheingross, Joel S.
A1  - Hovius, Niels
A1  - Vieth-Hillebrand, Andrea
A1  - Mueller, Carsten W.
A1  - Höschen, Carmen
A1  - Szupiany, Ricardo N.
A1  - Sachse, Dirk
T1  - River organic carbon fluxes modulated by hydrodynamic sorting of particulate organic matter
JF  - Geophysical research letters
N2  - Rivers regulate the global carbon cycle by transferring particulate organic carbon (POC) from terrestrial landscapes to marine sedimentary basins, but the processes controlling the amount and composition of fluvially exported POC are poorly understood. We propose that hydrodynamic sorting processes modify POC fluxes during fluvial transit. We test this hypothesis by studying POC transported along a similar to 1,200 km reach of the Rio Bermejo, Argentina. Nanoscale secondary ion mass spectrometry revealed that POC was either fine, mineral-associated organic matter, or coarse discrete organic particles. Mineral-associated POC is more resistant to oxidation and has a lower particle settling velocity than discrete POC. Consequently, hydraulic sorting and downstream fining amplify the proportion of fine, mineral-associated POC from similar to 55% to similar to 78% over 1,220 km of downstream transit. This suggests that mineral-associated POC has a greater probability of export and preservation in marine basins than plant detritus, which may be oxidized to CO2 during transit.
KW  - compound-specific stable isotopes
KW  - carbon fluxes
KW  - rivers
KW  - NanoSIMS;
KW  - sediment transport
KW  - hydrodynamic sorting
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL096343
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  -