cAMP-dependent differential regulation of extracellular matrix (ECM) gene expression in cultured rat Schwann cells

cAMP-dependent regulation of the steady-state mRNA levels for the ECM components, laminin A, B1 and B2 chains, collagen types I, III and IV were examined by Northern blot analysis in cultured rat Schwann cells. ECM mRNAs of laminin B1 chain and collagen types I and IV were expressed at high levels in the control Schwann cells, while laminin B2 chain and collagen type III mRNA levels were low, and laminin A chain mRNA was not detectable. When Schwann cells were treated with forskolin or cAMP derivatives, the gene expression for the ECM molecules constituting the Schwann cell basement membrane, laminin B1 and B2 chains, and collagen type IV, was enhanced in time- and dose-dependent manners for exogenously administered forskolin or cAMP derivatives, while the mRNA levels for the ECM molecules, which are not the major components of the basement membrane, fibrillary collagen types I and III were significantly suppressed. This cAMP-dependent differential regulation of Schwann cell ECM gene expression may be related to the role of each ECM molecule in the peripheral nerve development and regeneration.