Premium
Assessing Gliogenesis in a Murine Multifactorial Brain Injury Model System
Author(s) -
Domowicz Miriam S.,
Wadlington Natasha L.,
Henry Judith G.,
Diaz Kasandra,
Munoz Miranda J.,
Schwartz Nancy B.
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.183.3
Subject(s) - oligodendrocyte , astrocyte , microglia , glial fibrillary acidic protein , biology , gliosis , in situ hybridization , pathology , myelin basic protein , medicine , endocrinology , central nervous system , myelin , inflammation , immunohistochemistry , gene expression , biochemistry , gene
Brain injury in humans caused by trauma, intrauterine infections, hypoxia and/or ischemia, pre‐maturity or low birth weight, during the perinatal period which coincides with glial cell (astrocyte and oligodendrocyte) maturation in the brain, often has devastating neurological consequences such as epilepsy, cerebral palsy, and behavioral and cognitive problems. Due to the variety of risk factors associated with these neurodevelopmental disorders, we are using a multifactorial injury model to examine the effects on differentiation and maturation of the two glial subtypes. The model consists of penetrating perinatal traumatic brain injury, with or without intraperitoneal injection of lipopolysaccharide (LPS) as a model of remote pathogen exposure. Postnatal‐day‐6 (P6) mouse pups underwent sham, LPS‐alone, stab‐alone, or stab‐plus‐LPS treatments. At different ages after injury, the pups were harvested and gene‐expression changes for astrocyte, neuron, oligodendrocyte, and precursor‐cell markers were assessed using mRNA in situ hybridization (ISH) and qPCR. In general, the injured (ipsilateral) side exhibited enlarged ventricles, occasional disruption of the cortex structure and sporadic cysts; whereas the uninjured (contralateral) side remained unaffected overall, comparable to sham‐treated animals. Astrocyte‐precursor and mature‐astrocyte marker mRNA levels increased in the stab‐alone and stab‐plus‐LPS treated animals. Microglial/macrophage markers CD208 and CD68 levels, increased in the ipsilateral sides of stab and stab‐plus LPS animals by P10, but the differences resolved by P15. Decreased mRNA expression of mature oligodendrocyte markers, proteolipid protein 1 (PLP) and myelin basic protein (MBP) and the neuronal marker Class III beta‐tubulin (TUBB3), was observed only on the ipsilateral side in stab‐treated pups by ISH. Interestingly, ectopic expression of the neural stem cell marker SRY(sex‐determining region Y)‐box 2 (SOX2), astrocyte precursor SOX9, and the oligodendrocyte precursor marker oligodendrocyte transcription factor (OLIG2) mRNAs were observed in the ipsilateral side following stab injuries with or without LPS treatment at P10. By fluorescent ISH, partial colocalization of SOX2, OLIG2 and SOX9 mRNAs with GFAP‐positive cells was confirmed. These data suggest that shortly following traumatic injury, concomitant with the decrease in mature oligodendrocyte and neuronal marker expression, neural stem cells and glial precursor populations may be attempting to repopulate the injury region. Support or Funding Information Supported by U.S. Public Health Service Grants HD009402 and GM066522