Cerebrospinal Fluid Protein Biomarker Panel for Assessment of Neurotoxicity Induced by Kainic Acid in Rats

Abstract

Glutamate excitotoxicity plays a key role in the etiology of a variety of neurological, psychiatric, and neurodegenerative disorders. The goal of this study was to investigate spatiotemporal distribution in the brain and cerebrospinal fluid (CSF) concentrations of ubiquitin C-terminal hydrolase-1 (UCH-L1), glial fibrillary acidic protein (GFAP), αII-spectrin breakdown products (SBDP150, SBDP145, and SBDP120), and their relationship to neuropathology in an animal model of kainic acid (KA) excitotoxicity. Triple fluorescent labeling and Fluoro-Jade C staining revealed a reactive gliosis in brain and specific localization of degenerating neurons in hippocampus and entorhinal cortex of KA-treated rats. Immunohistochemistry showed upregulation of GFAP expression in hippocampus and cortex beginning 24h post KA injection and peaking at 48h. At these time points concurrent with extensive neurodegeneration all SBDPs were observed throughout the brain. At 24h post KA injection, a loss of structural integrity was observed in cellular distribution of UCH-L1 that correlated with an increase in immunopositive material in the extracellular matrix. CSF levels of UCH-L1, GFAP, and SBDPs were significantly increased in KA-treated animals compared with controls. The temporal increase in CSF biomarkers correlated with brain tissue distribution and neurodegeneration. This study provided evidence supporting the use of CSF levels of glial and neuronal protein biomarkers to assess neurotoxic damage in preclinical animal models that could prove potentially translational to the clinic. The molecular nature of these biomarkers can provide critical information on the underlying mechanisms of neurotoxicity that might facilitate the development of novel drugs and allow physicians to monitor drug safety.

In Vitro Neurotoxicity Resulting from Exposure of Cultured Neural Cells to Several Types of Nanoparticles

“…22 Our results indicated that the nanoparticles of nanotube, CB, and C60 caused in vitro neurotoxicity potential by inducing αII-SBDP of SBDP150/145, which have been demonstrated in previous studies as biomarkers for compound-induced neurodegeneration and neurotoxicity in rat. 23–25 While SBDP150/145/120 are useful as markers for in vitro evaluation of NP-induced neurotoxicity in our current studies, they are potential biomarkers to assess the NP-induced neurotoxicity in vivo.…”

Acute Temporal Profiles of Serum Levels of UCH-L1 and GFAP and Relationships to Neuronal and Astroglial Pathology following Traumatic Brain Injury in Rats

“…Increased levels of UCH-L1 in serum or CSF have been documented in several in vivo models of neuronal injuries such as TBI, stroke, hypothermic circulatory arrest and neurotoxicity [15][16][17][18] . Several studies have also shown increased GFAP levels in serum following experimental TBI 19, 20 .…”

“…CSF and serum samples were analyzed using GFAP and UCH-L1 Banyan Biomarker's proprietary sandwich ELISA as described in previous publications [9][10][11][12][13] antibody or streptavidin-HRP conjugates catalyzed the reaction with tetramethyl benzidine, and the product was quantitated by absorbance at 450nm using a microplate spectrophotometer (BMG, Optima FluoStar, Germany). Standard curves were generated using recombinant proteins corresponding to measured analyte for each assay and four-parameter non-linear regression analyses were applied to determine analyte quantity using SigmaPlot software (Systat, Chicago, IL).…”

Contributions of astrocytes to epileptogenesis following status epilepticus: Opportunities for preventive therapy?

“…Depending on the stimulus paradigms used to evoke SE in these models, spontaneous seizures can begin within days (Bumanglag and Sloviter, 2008; Norwood et al, 2010). In all of these models, considerable neuronal cell death is observed throughout the brain and astrocytes begin to exhibit signs of reactive gliosis soon after evoking SE (do Nascimento et al, 2012; Glushakova et al, 2012; Lauritzen et al, 2012a). …”