7 research outputs found
Propagation of CJD Prions in Primary Murine Glia Cells Expressing Human PrPc
There are various existing cell models for the propagation of animal prions. However, in vitro propagation of human prions has been a long-standing challenge. This study presents the establishment of a long-term primary murine glia culture expressing the human prion protein homozygous for methionine at codon 129, which allows in vitro propagation of CreutzfeldtâJakob disease (CJD) prions (variant CJD (vCJD) and sporadic CJD (sCJD) type MM2). Prion propagation could be detected by Western blotting of pathological proteinase K-resistant prion protein (PrPSc) from 120 days post exposure. The accumulation of PrPSc could be intensified by adding a cationic lipid mixture to the infectious brain homogenate at the time of infection. Stable propagation of human prions in a long-term murine glia cell culture represents a new tool for future drug development and for mechanistic studies in the field of human prion biology. In addition, our cell model can reduce the need for bioassays with human prions and thereby contributes to further implementation of the 3R principles aiming at replacement, reduction and refinement of animal experiments
Endogene neuronale VorlĂ€uferzellen unterdrĂŒcken das Wachstum von Glioblastomen
GesamtdissertationNeural precursor cells (NPCs) migrate towards glioblastoma in vivo and in
vitro. They are attracted by glioma cells independent of other cell types or
surrounding tissue. Young animals display prolonged survival after glioma
inoculation compared to older animals due to the larger amount of precursors,
which accumulate around the tumour. Young animals are naturally equipped with
a greater number of NPCs. Additionally subventricular proliferation is even
more restrained by the presence of a tumour only in adult animals. This
further reduction of dividing precursors in adult mice solely refers to
diminished proliferation rates since whole cell number and cell death rate was
not affected by glioblastoma. Survival times of old animals can be aligned to
the one of young mice by applying exogenous precursor cells. Proliferative
capacity of NPCs is determined by the age of the subventricular zone and is an
intrinsic and stable attribute. Neural precursors as well as NPC-conditioned
medium directly induce glioma cell death. The transcription factor activating
transcription factor-3 (ATF-3) is necessary and sufficient for the induction
of cell death. Differential gene expression and morphological changes after
administration of NPC-conditioned medium point to glioma cell death induced by
endoplasmic reticulum stress.Neuronale VorlÀuferzellen migrieren spezifisch zu Glioblastomen in vivo und in
vitro. Dieser Prozess findet unabhÀngig von anderen Zelltypen oder umgebendem
Gewebe statt. Junge MĂ€use verfĂŒgen nach Inokulierung von Gliomzellen ĂŒber eine
lĂ€ngere Ăberlebenszeit im Vergleich zu adulten Tieren. Dies lĂ€sst sich auf die
erhöhte Anzahl von VorlÀuferzellen, die um den Tumor herum akkumulieren,
zurĂŒckfĂŒhren. Junge Tiere besitzen von Natur aus eine höhere Anzahl von
neuronalen VorlÀuferzellen. Dazu kommt, dass die subventrikulÀre Proliferation
nur in adulten Tieren zusÀtzlich durch den Tumor negativ beeinflusst wird.
Diese Reduktion von sich teilenden subventrikulÀren VorlÀuferzellen in adulten
MĂ€usen beruht ausschlieĂlich auf einer verminderten Proliferationsrate da
sowohl Gesamtzellzahl und Zelltodrate vom Tumor unbeeinfluĂt blieben. Es
zeigte sich, dass adulte Tiere nach Gabe von exogenen VorlÀuferzellen die
Ăberlebenszeit junger Tiere erreichen. Das proliferative Potential von
neuronalen VorlÀuferzellen wird durch das Alter der subventrikulÀren Zone
determiniert und stellt eine intrinsische und stabile Eigenschaft dar.
Neuronale VorlÀuferzellen sowie VorlÀuferzell-konditioniertes Medium
induzieren Gliomzelltod unabhĂ€ngig von Ă€uĂeren Faktoren in vitro. Der
Transkriptionsfaktor activating transcription factor-3 (ATF-3) ist fĂŒr die
Induktion von Gliomzelltod notwendig und hinreichend. Differentielle
Genexpression und MorphologieÀnderung in Gliomzellen, induziert durch
VorlÀuferzell-konditioniertes Medium, lassen Zelltod durch endoplasmatischen
Stress vermuten
Neural precursor cells induce cell death of high-grade astrocytomas through stimulation of TRPV1
Primary astrocytomas of grade 3 or 4 according to the classification system of the World Health Organization (high-grade astrocytomas or HGAs) are preponderant among adults and are almost invariably fatal despite the use of multimodal therapy. Here we show that the juvenile brain has an endogenous defense mechanism against HGAs. Neural precursor cells (NPCs) migrate to HGAs, reduce glioma expansion and prolong survival time by releasing endovanilloids that activate the vanilloid receptor (transient receptor potential vanilloid subfamily member-1 or TRPV1) on HGA cells. TRPV1 is highly expressed in tumor and weakly expressed in tumor-free brain. TRPV1 stimulation triggers tumor cell death through the branch of the endoplasmic reticulum stress pathway that is controlled by activating transcription factor-3 (ATF3). The antitumorigenic response of NPCs is lost with aging. NPC-mediated tumor suppression can be mimicked in the adult brain by systemic administration of the synthetic vanilloid arvanil, suggesting that TRPV1 agonists have potential as new HGA therapeutics