TY  - JOUR
A1  - Hassouna, I.
A1  - Ott, C.
A1  - Wüstefeld, L.
A1  - Offen, N.
A1  - Neher, R. A.
A1  - Mitkovski, M.
A1  - Winkler, D.
A1  - Sperling, S.
A1  - Fries, L.
A1  - Goebbels, S.
A1  - Vreja, I. C.
A1  - Hagemeyer, N.
A1  - Dittrich, M.
A1  - Rossetti, M. F.
A1  - Kröhnert, K.
A1  - Hannke, K.
A1  - Boretius, S.
A1  - Zeug, A.
A1  - Höschen, C.
A1  - Dandekar, T.
A1  - Dere, E.
A1  - Neher, E.
A1  - Rizzoli, S. O.
A1  - Nave, K.-A.
A1  - Sirén, A.-L.
A1  - Ehrenreich, H.
T1  - Revisiting adult neurogenesis and the role of erythropoietin for neuronal and oligodendroglial differentiation in the hippocampus
JF  - Molecular Psychiatry
N2  - Recombinant human erythropoietin (EPO) improves cognitive performance in neuropsychiatric diseases ranging from schizophrenia and multiple sclerosis to major depression and bipolar disease. This consistent EPO effect on cognition is independent of its role in hematopoiesis. The cellular mechanisms of action in brain, however, have remained unclear. Here we studied healthy young mice and observed that 3-week EPO administration was associated with an increased number of pyramidal neurons and oligodendrocytes in the hippocampus of similar to 20%. Under constant cognitive challenge, neuron numbers remained elevated until >6 months of age. Surprisingly, this increase occurred in absence of altered cell proliferation or apoptosis. After feeding a \(^{15}\)N-leucine diet, we used nanoscopic secondary ion mass spectrometry, and found that in EPO-treated mice, an equivalent number of neurons was defined by elevated \(^{15}\)N-leucine incorporation. In EPO-treated NG2-Cre-ERT2 mice, we confirmed enhanced differentiation of preexisting oligodendrocyte precursors in the absence of elevated DNA synthesis. A corresponding analysis of the neuronal lineage awaits the identification of suitable neuronal markers. In cultured neurospheres, EPO reduced Sox9 and stimulated miR124, associated with advanced neuronal differentiation. We are discussing a resulting working model in which EPO drives the differentiation of non-dividing precursors in both (NG2+) oligodendroglial and neuronal lineages. As endogenous EPO expression is induced by brain injury, such a mechanism of adult neurogenesis may be relevant for central nervous system regeneration.
KW  - neural stem-cells
KW  - recombinat-human-erythropoietin
KW  - cognitive functions
KW  - pyramidal neurons
KW  - nervous-sytem
KW  - brain-injury
KW  - mouse-brain
KW  - progenitors
KW  - mice
KW  - memory
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186669
VL  - 21
IS  - 12
ER  - 
TY  - JOUR
A1  - Böhm, J.
A1  - Scherzer, S.
A1  - Shabala, S.
A1  - Krol, E.
A1  - Neher, E.
A1  - Mueller, T. D.
A1  - Hedrich, R.
T1  - Venus flytrap HKT1-type channel provides for prey sodium uptake into carnivorous plant without conflicting with electrical excitability
JF  - Molecular Plant
N2  - The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na\(^+\)- and K\(^+\)-permeable mutants function as ion channels rather than K\(^+\) transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na\(^+\)-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.
KW  - sodium channel
KW  - HKT1
KW  - Dionaea muscipula
KW  - action potential
KW  - glands
KW  - sodium uptake
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-189803
VL  - 9
IS  - 3
ER  -