title: 1,3-Dinitrobenzene neurotoxicity - Passage effect in immortalized astrocytes.
abstract: Age-related disturbances in astrocytic mitochondrial function are linked to loss of neuroprotection and decrements in neurological function. The immortalized rat neocortical astrocyte-derived cell line, DI-TNC1, provides a convenient model for the examination of cellular aging processes that are difficult to study in primary cell isolates from aged brain. Successive passages in culture may serve as a surrogate of aging in which time-dependent adaptation to culture conditions may result in altered responses to xenobiotic challenge. To investigate the hypothesis that astrocytic mitochondrial homeostatic function is decreased with time in culture, low passage DI-TNC1 astrocytes (LP; #2-8) and high passage DI-TNC1 astrocytes (HP; #17-28) were exposed to the mitochondrial neurotoxicant 1,3-dinitrobenzene (DNB). Cells were exposed in either monoculture or in co-culture with primary cortical neurons. Astrocyte mitochondrial membrane potential, morphology, ATP production and proliferation were monitored in monoculture, and the ability of DI-TNC1 cells to buffer K(+)-induced neuronal depolarization was examined in co-cultures. In HP DI-TNC1 cells, DNB exposure decreased proliferation, reduced mitochondrial membrane potential and significantly decreased mitochondrial form factor. Low passage DI-TNC1 cells effectively attenuated K(+)-induced neuronal depolarization in the presence of DNB whereas HP counterparts were unable to buffer K(+) in DNB challenge. Following DNB challenge, LP DI-TNC1 cells exhibited greater viability in co-culture than HP. The data provide compelling evidence that there is an abrupt phenotypic change in DI-TNC1 cells between passage #9-16 that significantly diminishes the ability of DI-TNC1 cells to compensate for neurotoxic challenge and provide neuroprotective spatial buffering. Whether or not these functional changes have an in vivo analog in aging brain remains to be determined.
authors.affiliation: Nicholas School of the Environment, Duke University, 308 Research Drive, A354 Levine Science Research Center, Durham, NC 27708, USA.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Maurer
authors.affiliation: Toxicology Program, School of Public Health, Environmental Health Sciences Department, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
authors.forename: Jackelyn D
authors.initials: JD
authors.lastname: Latham
authors.affiliation: Toxicology Program, School of Public Health, Environmental Health Sciences Department, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
authors.forename: Rory W
authors.initials: RW
authors.lastname: Landis
authors.affiliation: Simulation Group, Samsung SDI, Suwon-si, Gyeonggi-do, Republic of Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Song
authors.affiliation: H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA.
authors.forename: Tamir
authors.initials: T
authors.lastname: Epstein
authors.affiliation: Toxicology Program, School of Public Health, Environmental Health Sciences Department, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA. Electronic address: philbert@umich.edu.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Philbert
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000375:Aging / Q000187:drug effects*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000648:ultrastructure; D001973:Bromodeoxyuridine / Q000378:metabolism; D002461:Cell Line, Transformed; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D004136:Dinitrobenzenes / Q000633:toxicity*; D004622:Embryo, Mammalian; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D016014:Linear Models; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009498:Neurotoxins / Q000633:toxicity*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004136:Dinitrobenzenes; D005904:Glial Fibrillary Acidic Protein; D009498:Neurotoxins; D000255:Adenosine Triphosphate; C017906:3-dinitrobenzene; D010751:Phosphopyruvate Hydratase; D001973:Bromodeoxyuridine
keywords: 1,3-Dinitrobenzene; Aging; Astrocytes; Mitochondria; Susceptibility