1,3-Dinitrobenzene (DNB) induces a selective, focal edematous lesion in the brainstem astrocytes of rats reminiscent of lesions induced by vitamin B, deficiency and chemicals that produce central nervous system (CNS) energy deprivation syndromes. Preliminary data collected in our laboratories provide compelling evidence that selective regional astrocyte vulnerability to DNB is mediated by opening of the mitochondrial permeability transition pore (mt-PTP) with subsequent formation of reactive oxygen species (ROS). It is well established in the literature that the mt-PTP is stabilized in the closed conformation by Bc1-2 and BC1-XL and maintained in the open state by Bax. The central hypothesis of this proposal is that regional expression of Bc1-2 family molecules regulates the differential susceptibility of astrocytes to chemicals that induce oxidative stress. Addressing the following specific questions will test the hypothesis: 1) Does DNB induce translocation of Bax to astrocytic mitochondria? 2) Does modulation of expression of mt-PTP agonist (Bax) or antagonist (Bc1-2/Bcl-XL) proteins alter the toxicity of DNB in astrocytes? 3) Does alteration of the expression of Bax, Bc1-2 or BC1 XL proteins modulate astrocytic sensitivity in vivo? 4) Does DNB induce transient regional inhibition of SDH in neurons and astrocytes in vivo and in vitro, and is the inhibition of SDH linked to induction of the mt-PTP? 5) Does opening of the mt-PTP increase cellular calcium loads thereby altering the ability of cortical and brainstem astrocytes to spatially buffer physiologic ions and maintain cell volume and viability? The Specific Aims will address the functional consequences of altered expression of selected Bc1-2 family proteins and their translocation to the mitochondrial compartment. Enriched primary cortical and brainstem astrocyte cultures will be used as a well characterized in vitro model of DNB-induced encephalopathy. These studies utilize emerging techniques in real-time confocal and high-resolution laser scanning confocal microscopy developed in the laboratory of the PI and collaborators. The recent development of nano-optochemical sensing technology in our laboratories permits a degree of spatial resolution and quantitative measurement of ionic transients hitherto unavailable. Data obtained from the proposed studies will provide a greater understanding of molecular and pathophysiologic mechanisms underlying the selective vulnerability of neuron and astrocyte populations to neurotoxicants and neurodegenerative change.

National Institute of Health (NIH)
National Institute of Environmental Health Sciences (NIEHS)
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Special Emphasis Panel (ZRG1-IFCN-1 (02))
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Lawler, Cindy P
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University of Michigan Ann Arbor
Public Health & Prev Medicine
Schools of Public Health
Ann Arbor
United States
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Maurer, Laura L; Latham, Jackelyn D; Landis, Rory W et al. (2016) 1,3-Dinitrobenzene neurotoxicity - Passage effect in immortalized astrocytes. Neurotoxicology 53:74-84
Russ, K A; Elvati, P; Parsonage, T L et al. (2016) C60 fullerene localization and membrane interactions in RAW 264.7 immortalized mouse macrophages. Nanoscale 8:4134-44
Kubik, Laura L; Philbert, Martin A (2015) The role of astrocyte mitochondria in differential regional susceptibility to environmental neurotoxicants: tools for understanding neurodegeneration. Toxicol Sci 144:7-16
Kubik, Laura L; Landis, Rory W; Remmer, Henriette et al. (2015) 1,3-dinitrobenzene induces age- and region-specific oxidation to mitochondria-related proteins in brain. Toxicol Sci 145:48-58
Dixon, Angela R; Philbert, Martin A (2015) Morphometric assessment of toxicant induced neuronal degeneration in full and restricted contact co-cultures of embryonic cortical rat neurons and astrocytes: using m-Dinitrobezene as a model neurotoxicant. Toxicol In Vitro 29:564-74
Song, Dong Hoon; Park, Jonghyun; Philbert, Martin A et al. (2014) Effects of local pH on the formation and regulation of cristae morphologies. Phys Rev E Stat Nonlin Soft Matter Phys 90:022702
Steiner, Stephen R; Milton, Evan; Philbert, Martin A (2013) A comparative study of protein carbonylation and mitochondrial dysfunction using the neurotoxicants 1,3-dinitrobenzene, 3-nitropropionic acid, and 3-chloropropanediol. Neurotoxicology 37:74-84
Song, Dong Hoon; Park, Jonghyun; Maurer, Laura L et al. (2013) Biophysical significance of the inner mitochondrial membrane structure on the electrochemical potential of mitochondria. Phys Rev E Stat Nonlin Soft Matter Phys 88:062723
Wang, Yipei; Liu, Xin; Schneider, Brandon et al. (2012) Mixed inhibition of adenosine deaminase activity by 1,3-dinitrobenzene: a model for understanding cell-selective neurotoxicity in chemically-induced energy deprivation syndromes in brain. Toxicol Sci 125:509-21
Nie, Guochao; Hah, Hoe Jin; Kim, Gwangseong et al. (2012) Hydrogel nanoparticles with covalently linked coomassie blue for brain tumor delineation visible to the surgeon. Small 8:884-91

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