Calbindin D-28 and microtubule-associated protein-2: their use as sensitive immunohistochemical markers of cerebellar neurotoxicity in a regulatory toxicity study.
The aim of this study was to develop an immunohistochemical (IHC) method for calbindin D-28 (CB-28) and microtubule-associated protein-2 (MAP-2) and evaluate their expression as markers in the detection, characterisation and grading of unexpected cerebellar toxicity in the rat. High power examination of H&E-stained brain sections of treated rats 2 days following a single oral dose of a novel compound revealed irregular vacuolation of the molecular layer and Purkinje cell degeneration. Animals killed after 14 days recovery showed Purkinje cell degeneration but vacuolation of the molecular layer was absent. In control animals, CB-28 and MAP-2 expression was high in Purkinje cell dendrites and cell bodies in the molecular layer. In treated animals, low power examination revealed loss of CB-28 and MAP-2 expression in degenerating neurons arranged in parasagittal stripes within the vermis. This is the first description of successful use of these two markers in a regulatory toxicity study using FFPE brain. In particular, CB-28 provides a sensitive method for characterising CNS toxicity which can be detected at low power enabling easier detection, screening and grading of neurotoxicity.
Department of Pathology, Safety Asssessment, GlaxoSmithKline Research and Development Ltd, Park Road, Ware, Herts SG12 0DP, UK. richard.i.haworth@gsk.com
Richard
R
Haworth
Nicola
N
McCormack
Simone
S
Selway
Andrew M
AM
Pilling
Tom C
TC
Williams
D000284:Administration, Oral; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D064026:Calbindins; D002491:Central Nervous System Agents / Q000633:toxicity*; D002531:Cerebellum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D007124:Immunoenzyme Techniques; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009410:Nerve Degeneration / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D011689:Purkinje Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D018675:Toxicity Tests / Q000379:methods*; D015262:Xenobiotics / Q000633:toxicity*
D015415:Biomarkers; D064026:Calbindins; D002491:Central Nervous System Agents; D008869:Microtubule-Associated Proteins; D064030:S100 Calcium Binding Protein G; D015262:Xenobiotics