Grafts of meningeal fibroblasts in adult rat spinal cord lesion promote axonal regrowth.

We have studied the morphological consequences of implantation into the injured adult rat spinal cord of fibroblasts derived from the meninges overlying the cerebral cortex. Our initial objective was to reproduce the well known post-traumatic fibroadhesive scar observed in the clinical situation. One month after implantation, instead of having formed a fibroadhesive scar, fibroblasts had promoted the regeneration of peptidergic axons originating from dorsal root afferents and, to a lesser extent, of supraspinal serotonergic fibers at the periphery of the grafts. Using RT-PCR we were able to identify in cultures of meningeal-derived fibroblasts mRNAs for beta-NGF, NT3, aFGF and bFGF, which suggests that the promoting effect on axonal regeneration of these cells is at least in part due to their capacity to synthesize neurotrophic factors.