Expression of the beta-trace protein in human pachymeninx as revealed by in situ hybridization and immunocytochemistry

Abstract

In the pachymeninx (dura mater) from human spinal cord and brain, expression of mRNA for the beta-trace protein (beta-trace) was studied by in situ hybridization with digoxigenin-labeled cRNA probes. The localization of the protein was investigated using monoclonal and polyclonal antibodies, respectively. Very strong hybridization signals were observed in the fibroblasts of the pachymeninx. The results obtained by in situ hybridization were essentially confirmed by immunocytochemistry. By immunoblotting of proteins solubilized from the dura mater, strong immunoreactions were found with a polyclonal beta-trace antibody. Furthermore, beta-trace was quantified in human ventricular and lumbar cerebrospinal fluid (CSF) by use of an immunonephelometric assay. The beta-trace concentration in human lumbar CSF was elevated 11-fold as compared with ventricular CSF. Beta-trace determined in lumbar CSF most probably originates from fibroblasts of the pachymeninx. According to the bi- or probably multifunctional features of beta-trace, various sites of mRNA expression and protein synthesis exist in the human central nervous system (CNS). The major ones are the fibroblasts of the pachymeninx, and as previously shown, the epithelial layer of the choroid plexus.