Vivi M Heine

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Although it is known that the methylation of DNA in 5' promoters suppresses gene expression, the role of DNA methylation in gene bodies is unclear. In mammals, tissue- and cell type-specific methylation is present in a small percentage of 5' CpG island (CGI) promoters, whereas a far greater proportion occurs across gene bodies, coinciding with highly(More)
Whether the brain tumor medulloblastoma originates from stem cells or restricted progenitor cells is unclear. To investigate this, we activated oncogenic Hedgehog (Hh) signaling in multipotent and lineage-restricted central nervous system (CNS) progenitors. We observed that normal unipotent cerebellar granule neuron precursors (CGNPs) derive from hGFAP(+)(More)
Acute stress suppresses new cell birth in the hippocampus in several species. Relatively little is known, however, on how chronic stress affects the turnover, i.e. proliferation and apoptosis, of the rat dentate gyrus (DG) cells, and whether the stress effects are lasting. We investigated how 3 weeks of chronic unpredictable stress would influence the(More)
Inappropriate activation of the Hedgehog (Hh) signaling pathway has been implicated in a diverse spectrum of cancers, and its pharmacological blockade has emerged as an anti-tumor strategy. While nearly all known Hh pathway antagonists target the transmembrane protein Smoothened (Smo), small molecules that suppress downstream effectors could more(More)
Neurogenesis and apoptosis in the hippocampal dentate gyrus (DG) occur during development and adulthood. However, little is known about how these two processes relate to each other during aging. In this study, we examined apoptosis, proliferation, migration, and survival of newborn cells in the young (2 weeks), young-adult (6 weeks), middle-aged (12(More)
It has become increasingly clear that the increase in corticosteroid levels, e.g. after a brief stressor induce molecular and cellular changes in brain, including the hippocampal formation. These effects eventually result in behavioral adaptation. Prolonged exposure to stress, though, may lead to mal-adaptation and even be a risk factor for diseases like(More)
Various chronic stress paradigms decrease new cell proliferation in the hippocampal dentate gyrus, yet the exact underlying mechanism is still unclear. In the first gap (G1) phase of the cell cycle, both stimulatory and inhibitory signals derived from the extracellular environment converge. Corticosteroids, which increase during stress and are well-known(More)
Glucocorticoids (GCs) are administered to human fetuses at risk of premature delivery and to infants with life-threatening respiratory and cardiac conditions. However, there are ongoing concerns about adverse effects of GC treatment on the developing human brain, although the precise molecular mechanisms underlying GC-induced brain injury are unclear. Here,(More)
Two-day-old (P2) rat pups were subjected to either a global hypoxia or to electrocoagulation of the right carotid artery followed by 2.5 h hypoxia. Cellular and regional injury in the cerebellum (CB) was studied at 1, 2 and 19 days using immunohistology. Following hypoxia and hypoxia-ischemia, all neuronal populations of the CB were damaged in a subset of(More)
Recent evidence has shown that cell proliferation in the adult hippocampal dentate gyrus occurs in tight clusters located near the vasculature. Also, changes in neurogenesis often appear parallel to changes in angiogenesis. Moreover, both these processes share similar modulating factors, like vascular endothelial growth factor (VEGF) and its receptor Flk-1.(More)