@article{BandyraSaidPfeifferetal.2012,
  author    = {Bandyra, Katarzyna J. and Said, Nelly and Pfeiffer, Verena and G{\´o}rna, Maria W. and Vogel, J{\"o}rg and Luisi, Ben F.},
  title     = {The Seed Region of a Small RNA Drives the Controlled Destruction of the Target mRNA by the Endoribonuclease RNase E},
  series = {Molecular Cell},
  volume    = {47},
  journal   = {Molecular Cell},
  number    = {6},
  doi       = {10.1016/j.molcel.2012.07.015},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126202},
  pages     = {943-953},
  year      = {2012},
  abstract  = {Numerous small non-coding RNAs (sRNAs) in bacteria modulate rates of translation initiation and degradation of target mRNAs, which they recognize through base-pairing facilitated by the RNA chaperone Hfq. Recent evidence indicates that the ternary complex of Hfq, sRNA and mRNA guides endoribonuclease RNase E to initiate turnover of both the RNAs. We show that a sRNA not only guides RNase E to a defined site in a target RNA, but also allosterically activates the enzyme by presenting a monophosphate group at the 5′-end of the cognate-pairing "seed." Moreover, in the absence of the target the 5′-monophosphate makes the sRNA seed region vulnerable to an attack by RNase E against which Hfq confers no protection. These results suggest that the chemical signature and pairing status of the sRNA seed region may help to both 'proofread' recognition and activate mRNA cleavage, as part of a dynamic process involving cooperation of RNA, Hfq and RNase E.},
  language  = {en}
}
@article{PfeifferGoetzXiangetal.2013,
  author    = {Pfeiffer, Verena and G{\"o}tz, Rudolf and Xiang, Chaomei and Camarero, Guadelupe and Braun, Attila and Zhang, Yina and Blum, Robert and Heinsen, Helmut and Nieswandt, Bernhard and Rapp, Ulf R.},
  title     = {Ablation of BRaf Impairs Neuronal Differentiation in the Postnatal Hippocampus and Cerebellum},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0058259},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130304},
  pages     = {e58259},
  year      = {2013},
  abstract  = {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.},
  language  = {en}
}
@phdthesis{Pfeiffer2018,
  author    = {Pfeiffer, Marion Verena},
  title     = {Die Rolle von CRAF bei der adulten hippocampalen Neurogenese},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-98220},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Der gyrus dentatus im Hippocampus ist die prim{\"a}re Zielregion kortikaler Afferenzen des Enthorinalen Cortex. Im Laufe seiner Entwicklung erlangt der gyrus dentatus durch die Etablierung einer neurogenen Nische (terti{\"a}re Matrix) die F{\"a}higkeit fortw{\"a}hrender postnataler Neurogenese. Diese wird durch eine Vielzahl von Mediatoren wie Transkriptionsfaktoren gesteuert, die die Proliferation und Zelldifferenzierung, aber auch das {\"U}berleben der hippocampalen neuralen Vorl{\"a}uferzellen (NPCs, neural progenitor cells) kontrollieren. In S{\"a}ugetieren steuern die homologen RAF Kinasen ARAF, BRAF und CRAF die mitogene Kaskade, die bei der adulten Neurogenese von elementarer Bedeutung ist. In dieser Studie wurde untersucht ob die Nullmutation von CRAF eine Auswirkung auf die postnatale und adulte hippocampale Neurogenese hat. Unsere Analysen von BRAF- und CRAF-defizienten M{\"a}usen zeigen in der fr{\"u}hen Embryonalentwicklung gemeinsame Funktionen beider Kinasen, weshalb das Fehlen einer Kinase bis zu bestimmten embryonalen Entwicklungszeitpunkten durch die jeweils andere Kinase kompensiert werden kann. Letalit{\"a}tsstudien zeigen jedoch, dass BRAF und CRAF bei sp{\"a}teren Entwicklungsstadien jeweils unabh{\"a}ngig f{\"u}r das {\"U}berleben von Tieren relevant sind. CRAF Nullmutanten werden nicht nach der erwarteten Mendelschen Frequenz geboren und nahezu 70\% der Tiere sterben bereits kurz nach der Geburt. Die maximale beobachtete Lebenserwartung adulter CRAFko Tiere lag bei postnatal Tag 55. CRAFko M{\"a}use haben eine reduzierte K{\"o}rpergr{\"o}ße, ver{\"a}nderte Hautfarbe und einen eye-open-at-birth-Ph{\"a}notyp. Verhaltensexperimente in unserer Arbeitsgruppe zeigten an heterozygoten CRAF M{\"a}usen einen Einfluss von CRAF auf das Angst - und Lernverhalten, was einen Einfluss von CRAF auf die Neurogenese-vermittelte hippocampale Funktion andeutete. Tats{\"a}chlich konnte hier die Expression von CRAF im postnatalen Gehirn von M{\"a}usen immunhistologisch wie auch proteinbiochemisch nachgewiesen werden. Im Hippocampus zeigte sich, dass ein Funktionsverlust von CRAF zu einer erh{\"o}hten Anzahl mitotisch aktiver NPCs f{\"u}hrt, die massive Zellzyklusver{\"a}nderungen aufweisen. Zudem wurde eine fehlerhafte Reorganisation der terti{\"a}ren Matrix beobachtet. NPCs CRAF-defizienter Tiere befinden sich vermehrt im Hilus und bleiben in der Entwicklung zu reifen K{\"o}rnerzellen im D Zell-Vorl{\"a}uferstadium stecken. Weitere Analysen zeigen, dass diese fehlplatzierten NPCs teilweise {\"u}ber apoptotische Signalwege eliminiert werden. Als Resultat dieser Entwicklungsst{\"o}rung ist der gyrus dentatus CRAF-defizienter Tiere verkleinert und es kann eine verlangsamte neuronale Differenzierung NPC-abgeleiteter Neurone beobachtet werden. Diese Befunde zeigen erstmals einen CRAF-spezifischen Einfluss auf die Regulation elementarer, zellul{\"a}rer Eigenschaften neuronaler Vorl{\"a}uferzellen des Hippocampus.},
  subject      = {Hippocampus},
  language  = {de}
}
@article{KleefeldtBoemmelBroedeetal.2019,
  author    = {Kleefeldt, Florian and B{\"o}mmel, Heike and Broede, Britta and Thomsen, Michael and Pfeiffer, Verena and W{\"o}rsd{\"o}rfer, Philipp and Karnati, Srikanth and Wagner, Nicole and Rueckschloss, Uwe and Erg{\"u}n, S{\"u}leyman},
  title     = {Aging-related carcinoembryonic antigen-related cell adhesion molecule 1 signaling promotes vascular dysfunction},
  series = {Aging Cell},
  volume    = {2019},
  journal   = {Aging Cell},
  number    = {18},
  doi       = {10.1111/acel.13025},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201231},
  pages     = {e13025},
  year      = {2019},
  abstract  = {Aging is an independent risk factor for cardiovascular diseases and therefore of particular interest for the prevention of cardiovascular events. However, the mechanisms underlying vascular aging are not well understood. Since carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is crucially involved in vascular homeostasis, we sought to identify the role of CEACAM1 in vascular aging. Using human internal thoracic artery and murine aorta, we show that CEACAM1 is upregulated in the course of vascular aging. Further analyses demonstrated that TNF-α is CEACAM1-dependently upregulated in the aging vasculature. Vice versa, TNF-α induces CEACAM1 expression. This results in a feed-forward loop in the aging vasculature that maintains a chronic pro-inflammatory milieu. Furthermore, we demonstrate that age-associated vascular alterations, that is, increased oxidative stress and vascular fibrosis, due to increased medial collagen deposition crucially depend on the presence of CEACAM1. Additionally, age-dependent upregulation of vascular CEACAM1 expression contributes to endothelial barrier impairment, putatively via increased VEGF/VEGFR-2 signaling. Consequently, aging-related upregulation of vascular CEACAM1 expression results in endothelial dysfunction that may promote atherosclerotic plaque formation in the presence of additional risk factors. Our data suggest that CEACAM1 might represent an attractive target in order to delay physiological aging and therefore the transition to vascular disorders such as atherosclerosis.},
  language  = {en}
}