Preparation of nuclear extracts from myelinating Schwann cells

Myelination of peripheral nerve fibres is performed by Schwann cells and is associated with the coordinate upregulation of lipid synthesis and multipl e genes encoding myelin-specific proteins. Both the decision to enter into a myelinating phenotype and subsequently, the quantity of myelin that each Schwann cell elaborates appear to be controlled by axonal signals. Understa nding of the relevant signaling pathways and the downstream transcription f actors and cis elements that confer myelin gene expression is notably limit ed. In large part, this has resulted direcly from a lack of methods for obt aining nuclear extracts from myelinating Schwann cells thus precluding the application of numerous powerful molecular techniques. In this report, we d escribe a method that overcomes this limitation for the myelinating Schwann cells in the sciatic nerves of the mouse. During the evolution of the meth od, its effectiveness was monitored using an oligonucleotide containing the binding site for KROX-20, a transcription factor known to be present in my elinating Schwann cells. Following technical development, the optimized pro tocol has proven to be entirely reliable and thus novel experimental strate gies now can be applied to the investigation of the molecular mechanisms co ntrolling gene expression in peripheral nerves. (C) 1999 Elsevier Science B .V. All rights reserved.