TY  - JOUR
A1  - Zanucco, Emanuele
A1  - Götz, Rudolf
A1  - Potapenko, Tamara
A1  - Carraretto, Irene
A1  - Ceteci, Semra
A1  - Ceteci, Fatih
A1  - Seeger, Werner
A1  - Savai, Rajkumar
A1  - Rapp, Ulf R.
T1  - Expression of B-RAF V600E in Type II Pneumocytes Causes Abnormalities in Alveolar Formation, Airspace Enlargement and Tumor Formation in Mice
JF  - PLOS ONE
N2  - Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation.
KW  - obstructive pulmonary-disease
KW  - lung-cancer
KW  - somatic mutations
KW  - epithelial-cells
KW  - mouse models
KW  - protein
KW  - kinase
KW  - inflammation
KW  - activation
KW  - pathway
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137061
VL  - 6
IS  - 12
ER  - 
TY  - JOUR
A1  - Pfeiffer, Verena
A1  - Götz, Rudolf
A1  - Xiang, Chaomei
A1  - Camarero, Guadelupe
A1  - Braun, Attila
A1  - Zhang, Yina
A1  - Blum, Robert
A1  - Heinsen, Helmut
A1  - Nieswandt, Bernhard
A1  - Rapp, Ulf R.
T1  - Ablation of BRaf Impairs Neuronal Differentiation in the Postnatal Hippocampus and Cerebellum
JF  - PLoS ONE
N2  - This study focuses on the role of the kinase BRaf in postnatal brain development. Mice expressing truncated, non-functional BRaf in neural stem cell-derived brain tissue demonstrate alterations in the cerebellum, with decreased sizes and fuzzy borders of the glomeruli in the granule cell layer. In addition we observed reduced numbers and misplaced ectopic Purkinje cells that showed an altered structure of their dendritic arborizations in the hippocampus, while the overall cornus ammonis architecture appeared to be unchanged. In male mice lacking BRaf in the hippocampus the size of the granule cell layer was normal at postnatal day 12 (P12) but diminished at P21, as compared to control littermates. This defect was caused by a reduced ability of dentate gyrus progenitor cells to differentiate into NeuN positive granule cell neurons. In vitro cell culture of P0/P1 hippocampal cells revealed that BRaf deficient cells were impaired in their ability to form microtubule-associated protein 2 positive neurons. Together with the alterations in behaviour, such as autoaggression and loss of balance fitness, these observations indicate that in the absence of BRaf all neuronal cellular structures develop, but neuronal circuits in the cerebellum and hippocampus are partially disturbed besides impaired neuronal generation in both structures.
KW  - granule cells
KW  - hippocampus
KW  - neurons
KW  - neuronal dendrites
KW  - embryos
KW  - dentate gyrus
KW  - neuronal differentiation
KW  - cerebellum
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130304
VL  - 8
IS  - 3
ER  -