title: Microglial disruption in young mice with early chronic lead exposure.
abstract: The mechanisms by which early chronic lead (Pb) exposure alter brain development have not been identified. We examined neuroimmune system effects in C57BL/6J mice with Pb exposure, including levels that may be common among children in lower socioeconomic income environments. Pups were exposed via dams' drinking water from birth to post-natal day 28 to low, high or no Pb conditions. We compared gene expression of neuroinflammatory markers (study 1); and microglial mean cell body volume and mean cell body number in dentate gyrus, and dentate gyrus volume (study 2). Blood Pb levels in exposed animals at sacrifice (post-natal day 28) ranged from 2.66 to 20.31μg/dL. Only interleukin-6 (IL6) differed between groups and reductions were dose-dependent. Microglia cell body number also differed between groups and reductions were dose-dependent. As compared with controls, microglia cell body volume was greater but highly variable in only low-dose animals; dentate gyri volumes in low- and high-dose animals were reduced. The results did not support a model of increased neuroinflammation. Instead, early chronic exposure to Pb disrupted microglia via damage to, loss of, or lack of proliferation of microglia in the developing brains of Pb-exposed animals.
authors.affiliation: Department of Public Health Sciences, College of Health Sciences, University of Texas, El Paso, USA. casobin@utep.edu
authors.forename: Christina
authors.initials: C
authors.lastname: Sobin
authors.forename: Mayra Gisel Flores
authors.initials: MG
authors.lastname: Montoya
authors.forename: Natali
authors.initials: N
authors.lastname: Parisi
authors.forename: Tanner
authors.initials: T
authors.lastname: Schaub
authors.forename: Miguel
authors.initials: M
authors.lastname: Cervantes
authors.forename: Rodrigo X
authors.initials: RX
authors.lastname: Armijos
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D015415:Biomarkers / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002908:Chronic Disease; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005819:Genetic Markers; D007774:Lactation / Q000187:drug effects; D007855:Lead Poisoning / Q000473:pathology*; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009942:Organometallic Compounds / Q000493:pharmacokinetics / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines; D005819:Genetic Markers; D009942:Organometallic Compounds; D012333:RNA, Messenger; C008261:lead acetate