An endogenous 55 kDa TNF receptor mediates cell death in a neural cell line

• Published in: Brain research. Molecular brain research. Vol. 38; no. 2; pp. 222 - 232
• Main Authors: Sipe, Kimberly J., Srisawasdi, Dalin, Dantzer, Robert, Kelley, Keith W., Weyhenmeyer, James A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.1996; Elsevier
• Subjects: Analysis of Variance; Animals; Biological and medical sciences; Blotting, Northern; Cell Death - physiology; Cell Differentiation - physiology; Dactinomycin - pharmacology; DNA Fragmentation; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Isolated neuron and nerve. Neuroglia; Mice; Molecular Weight; Neurons - cytology; Neurons - physiology; Polymerase Chain Reaction - methods; Receptors, Tumor Necrosis Factor - physiology; Recombinant Proteins - pharmacology; Transcription, Genetic - drug effects; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha - pharmacology; Vertebrates: nervous system and sense organs; Cell line; Neuron; Cell death; Cytokine; Cytotoxicity; Sensitization; Tumor necrosis factor α; Biological receptor
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/0169-328X(95)00310-O

Tumor necrosis factor-α (TNF) is associated with developmental and injury-related events in the central nervous system (CNS). In the present study, we have examined the role of TNF on neurons using the clonal murine neuroblastoma line, N1E-115 (N1E). N1E cells represent a well-defined model for studying neuronal development since they can be maintained as either undifferentiated, mitotically active neuroblasts or as differentiated, mature neurons. Northern and reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that both undifferentiated and differentiated N1Es express transcripts for the 55 kDa TNF receptor (TNFR), but not the 75 kDa TNFR. The biological activity of the expressed TNF receptor was demonstrated by a dose dependent cytotoxicity to either recombinant murine or human TNF when the cells were incubated with the transcriptional inhibitor actinomycin D. The lack of the 75 kDa receptor mRNA expression and the dose dependent response to rHuTNF, an agonist specific for the murine 55 kDa receptor, suggest that the TNF induced cytotoxicity is mediated through the 55 kDa receptor in both the undifferentiated and differentiated N1Es. Light microscopic observations, flow cytometric analysis of hypodiploid DNA, and electrophoretic analysis of nucleosomal DNA fragmentation of N1Es treated with actinomycin D and TNF revealed features characteristic of both necrotic and apoptotic cell death. These findings demonstrate that blast and mature N1E cells express the 55 kDa TNF receptor which is responsible for inducing both necrotic and apoptotic death in these cells. The observation that actinomycin D renders N1E cells susceptible to the cytotoxic effects of TNF indicates that a sensitization step, such as removal of an endogenous protective factor or viral-mediated inhibition of transcription, may be necessary for TNF cytotoxicity in neurons.