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We investigated the role of tumor necrosis factor (TNF)-alpha in the onset of neuronal and glial apoptosis after traumatic spinal cord crush injury in rats. A few TUNEL-positive cells were first observed within and surrounding the lesion area 4 h after injury, with the largest number observed 24-48 h after injury. Double-labeling of cells using cell(More)
Two cysteine protease families, caspase and calpain, are known to participate in cell death. We investigated whether a stress-specific protease activation pathway exists, and to what extent Bcl-2 plays a role in preventing drug-induced protease activity and cell death in a dopaminergic neuronal cell line, MN9D. Staurosporine (STS) induced caspase-dependent(More)
In this study, we examined the possibility that MPTP and 6-hydroxydopamine (6-OHDA) act on distinct cell death pathways in a murine dopaminergic neuronal cell line, MN9D. First, we found that cells treated with 6-OHDA accompanied ultrastructural changes typical of apoptosis, whereas MPP+ treatment induced necrotic manifestations. Proteolytic cleavage of(More)
Certain natural products and Asian herbal remedies have been used in Asia to attenuate neurodegenerative diseases, including senile dementia. We have examined derivatives of several natural products for potential neuroprotective activity in an in vitro test system. In the present study, we assayed a number of compounds that were isolated from Panax ginseng(More)
In higher vertebrates, reactive gliosis resulting from injury to the central nervous system (CNS) is characterized by a rapid increase in immunoreactivity (IR) to glial fibrillary acidic protein (GFAP). Little is known about the extracellular signals that initiate the increase in GFAP-IR following CNS injury. We demonstrated recently [T.H. Oh, G.J.(More)
Buffering extracellular pH at the site of a spinal cord crush-injury may stimulate axonal regeneration in rats (1; Guth et al., Exp. Neurol. 88: 44-55, 1985). We demonstrated in cultured astrocytes that acidic pH initiates a rapid increase in immunoreactivity for GFAP (GFAP-IR), a hallmark of reactive gliosis (2; Oh et al., Glia 13: 319-322, 1995). We(More)
To further characterize MPP(+)-induced cell death and to explore the role of Bcl-2-related proteins in this death paradigm, we utilized a mesencephalon-derived dopaminergic neuronal cell line (MN9D) stably transfected with human bcl-2 (MN9D/Bcl-2), its C-terminal deletion mutant (MN9D/Bcl-2Delta22), murine bax (MN9D/Bax), or a control vector (MN9D/Neo). As(More)
An MN9D dopaminergic neuronal cell line overexpressing calbindin-D28K (MN9D/Calbindin) was established in order to investigate directly the potential role of calcium-binding protein in neuronal differentiation. Overexpression of calbindin-D28K in MN9D cells resulted in significant increases in the number of neurites, the length of primary neurites, and the(More)
We have studied the reactive responses of both astrocytes and microglia to dopaminergic denervation of the striatum by MPTP. Following MPTP treatment, increased GFAP immunoreactivity reached a peak at 2 days and persisted for at least 6 weeks. Immunoreactivity to vimentin was also markedly increased in astrocytes 48 h after MPTP treatment. Striatal laminin(More)
Astroglia in cultures of dissociated neonatal rat optic nerves were studied by light microscopy, immunocytochemistry and electron microscopy to determine whether intermediate filaments play a role in defining the multipolar morphology of the mature astrocyte. Immature, polygonal astroblasts contained few glial filaments, in spite of exhibiting positive(More)