Expression of chondroitin 6-sulfotransferase mRNA and the sulfation product in post-crush sciatic nerves of adult rats

Abstract

Our study of homogenates of post-crush, regenerating sciatic nerves of adult rats found increased chondroitin sulfate (CS)-containing forms that were distinguishable by 6-sulfation. We hypothesize that chondroitin 6-sulfotransferase (C6ST) is upregulated to yield the 6-sulfated CS isoforms in the environment of the injured nerves. RT-PCR analysis of total RNA recovered from the nerve homogenates showed increase in the C6ST signal in comparison to that of the housekeeping glyceraldehyde-3-phosphate and the change peaked at 14 days post-crush. This was in phase with the changes we observed in 6-sulfated CS glycoforms. We then generated DIG-labeled RNA probes for in situ hybridization of C6ST transcripts in cryo-sections of the post-crush nerve. The anti-sense probe located C6ST transcripts in myelinated fibres but the sense probe showed negative results. In the normal intact nerve, the granular positivity appeared organized in the rim of myelinated fibres whereas in the crushed nerve, the granular positivity appeared profusely distributed in fibres undergoing myelinic reorganization. The observed expression patterns suggest that cells resident in the normal tissue were activated to condition the microenvironment for post-traumatic tissue reorganization. Supported by HKU7249/97M