TY  - JOUR
A1  - Briese, Michael
A1  - Saal-Bauernschubert, Lena
A1  - Lüningschrör, Patrick
A1  - Moradi, Mehri
A1  - Dombert, Benjamin
A1  - Surrey, Verena
A1  - Appenzeller, Silke
A1  - Deng, Chunchu
A1  - Jablonka, Sibylle
A1  - Sendtner, Michael
T1  - Loss of Tdp-43 disrupts the axonal transcriptome of motoneurons accompanied by impaired axonal translation and mitochondria function
JF  - Acta Neuropathologica Communications
N2  - Protein inclusions containing the RNA-binding protein TDP-43 are a pathological hallmark of amyotrophic lateral sclerosis and other neurodegenerative disorders. The loss of TDP-43 function that is associated with these inclusions affects post-transcriptional processing of RNAs in multiple ways including pre-mRNA splicing, nucleocytoplasmic transport, modulation of mRNA stability and translation. In contrast, less is known about the role of TDP-43 in axonal RNA metabolism in motoneurons. Here we show that depletion of Tdp-43 in primary motoneurons affects axon growth. This defect is accompanied by subcellular transcriptome alterations in the axonal and somatodendritic compartment. The axonal localization of transcripts encoding components of the cytoskeleton, the translational machinery and transcripts involved in mitochondrial energy metabolism were particularly affected by loss of Tdp-43. Accordingly, we observed reduced protein synthesis and disturbed mitochondrial functions in axons of Tdp-43-depleted motoneurons. Treatment with nicotinamide rescued the axon growth defect associated with loss of Tdp-43. These results show that Tdp-43 depletion in motoneurons affects several pathways integral to axon health indicating that loss of TDP-43 function could thus make a major contribution to axonal pathomechanisms in ALS.
KW  - amyotrophic lateral sclerosis
KW  - Tdp-43
KW  - axonal transcriptome
KW  - nicotinamide
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230322
VL  - 8
ER  - 
TY  - JOUR
A1  - Jessen, Christina
A1  - Kreß, Julia K. C.
A1  - Baluapuri, Apoorva
A1  - Hufnagel, Anita
A1  - Schmitz, Werner
A1  - Kneitz, Susanne
A1  - Roth, Sabine
A1  - Marquardt, André
A1  - Appenzeller, Silke
A1  - Ade, Casten P.
A1  - Glutsch, Valerie
A1  - Wobser, Marion
A1  - Friedmann-Angeli, José Pedro
A1  - Mosteo, Laura
A1  - Goding, Colin R.
A1  - Schilling, Bastian
A1  - Geissinger, Eva
A1  - Wolf, Elmar
A1  - Meierjohann, Svenja
T1  - The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression
JF  - Oncogene
N2  - The transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H\(_2\)O\(_2\) or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma.
KW  - NRF2
KW  - melanoma malignancy
KW  - COX2 expression
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235064
SN  - 0950-9232
VL  - 39
ER  - 
TY  - JOUR
A1  - Weißbach, Susann
A1  - Heredia-Guerrero, Sofia Catalina
A1  - Barnsteiner, Stefanie
A1  - Großhans, Lukas
A1  - Bodem, Jochen
A1  - Starz, Hanna
A1  - Langer, Christian
A1  - Appenzeller, Silke
A1  - Knop, Stefan
A1  - Steinbrunn, Torsten
A1  - Rost, Simone
A1  - Einsele, Hermann
A1  - Bargou, Ralf Christian
A1  - Rosenwald, Andreas
A1  - Stühmer, Thorsten
A1  - Leich, Ellen
T1  - Exon-4 Mutations in KRAS Affect MEK/ERK and PI3K/AKT Signaling in Human Multiple Myeloma Cell Lines
JF  - Cancers
N2  - Approximately 20% of multiple myeloma (MM) cases harbor a point mutation in KRAS. However, there is still no final consent on whether KRAS-mutations are associated with disease outcome. Specifically, no data exist on whether KRAS-mutations have an impact on survival of MM patients at diagnosis in the era of novel agents. Direct blockade of KRAS for therapeutic purposes is mostly impossible, but recently a mutation-specific covalent inhibitor targeting KRAS\(^{p.G12C}\) entered into clinical trials. However, other KRAS hotspot-mutations exist in MM patients, including the less common exon-4 mutations. For the current study, the coding regions of KRAS were deep-sequenced in 80 newly diagnosed MM patients, uniformely treated with three cycles of bortezomib plus dexamethasone and cyclophosphamide (VCD)-induction, followed by high-dose chemotherapy and autologous stem cell transplantation. Moreover, the functional impact of KRAS\(^{p.G12A}\) and the exon-4 mutations p.A146T and p.A146V on different survival pathways was investigated. Specifically, KRAS\(^{WT}\), KRAS\(^{p.G12A}\), KRAS\(^{p.A146T}\), and KRAS\(^{p.A146V}\) were overexpressed in HEK293 cells and the KRAS\(^{WT}\) MM cell lines JJN3 and OPM2 using lentiviral transduction and the Sleeping Beauty vector system. Even though KRAS-mutations were not correlated with survival, all KRAS-mutants were found capable of potentially activating MEK/ERK- and sustaining PI3K/AKT-signaling in MM cells.
KW  - multiple myeloma
KW  - KRAS
KW  - MEK/ERK-signaling
KW  - AKT-signaling
KW  - amplicon sequencing
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200617
SN  - 2072-6694
VL  - 12
IS  - 2
ER  -