Experimental Studies Of The Effects Of Laminin And Type Ⅰ, Ⅳ Collagen On Nerve Axonal Growth

Neuronal responses to extracellular matrix ( ECM) constituents are likely to play an important role in nervous system development and regeneration. Laminin and type I, IV collagen are the main components of the ECM. In our studies, the effects of these three proteins on the injured peripheral nerve, Schwann cells and spinal cord neurons were determined. Laminin and type IV collagen could promote nerve regeneration, improve the results of vein repair on nerve defects in vivo, They could also stimulate the attachment, proliferation of Schwann cells and support the neurites outgrowth of spinal cord neurons in vitro. Laminin seemed have better effects than collagen IV on increasing the number of myelined axons that grew in venous conduits and promoting neurites enlongation. We did not find collagen I enhanced the regeneration of peripheral nerve in vivo. Schwann cells showed poor proliferation to collagen I compared to LM and collagen IV. The neurites outgrowth length of spinal cord neurons were shorter on collagen I substrate than that on Laminin substrate. These results suggest that different substrates have distinct effects on never regeneration. To overcome the obstacle of fibroblasts contamination in Schwann cell culture procedure, Geneticin was used to seletively kill the fibroblasts. Treatment of mixed cultures with this drug at a concentration of 100μg/ml for 4-5 days resulted in pure cultures of normal Schwann cells. We found that Schwann cells contain GFAP, staining with the anti-GFAP antibody could distinguish Schwann cells from fibroblasts.