DETECTION OF 2 TRANSFORMING GROWTH FACTOR-BETA-RELATED MORPHOGENS, BONE MORPHOGENETIC PROTEINS-4 AND PROTEINS-5, IN RNA OF MULTIPLE-SCLEROSIS AND CREUTZFELDT-JAKOB-DISEASE LESIONS

The bone morphogenetic proteins (BMPs) constitute a novel subfamily of the transforming growth factor type beta (TGF-beta) supergene family. Here we demonstrate, using polymerase chain reaction (PCR) BMP-4 and BMP-5 messages in RNA isolated from multiple sclerosis (MS) plaque tis sue. This is the first demonstration of BMP expression in an inflammat ory lesion in general, and in MS in particular. However, BMP-4 and BMP -5 messages could be detected in RNA isolated from a Morbus Creutzfeld t-Jakob (CJD) lesion. Even in normal brain, RNA expression of BMP-4, b ut not that of BMP-5, was detected. Therefore, BMP-5 gene expression s eems to be associated with MS and CJD lesions, whereas the BMP-4 gene appears to be constitutively expressed in the human brain. As TGF-beta s and BMPs are regulators of regenerative processes and contribute to regulation of chemoattraction and local immunoreactivity, BMP-4 and B MP-5 might be involved in aspects of MS lesion formation unknown so fa r. PCR analysis of human cell lines demonstrate BMP-4 and BMP-5 expres sion in leukocytic cells, suggesting that infiltrating leukocytes cont ribute at least in part to BMP-4 and BMP-5 mRNAs of the MS plaque.