Preserved expression of fibroblast growth factor (FGF)-2 and FGF receptor 1 in brain and spinal cord of amyotrophic lateral sclerosis patients

Impaired trophic support of motor neurons appears to be an important pathogenic factor in amyotrophic lateral sclerosis (ALS). We investigated the mRNA expression of the pluripotent fibroblast growth factor 2 (FGF-2) and its receptors in post mortem spinal cord of ALS and control patients. FGF-2 and FGF receptor (FGFR) 1 and 2 transcripts were first studied in the spinal cord using RT-PCR. The cellular distribution of FGF-2 and FGFR mRNA in the spinal cord, motor cortex and brain stem was then assessed by in situ hybridization histochemistry. RT-PCR revealed the presence of FGF-2 and FGF receptor 1 and 2 transcripts with no obvious differences between ALS and control spinal cord. Comparing mRNA expression in the motoneuron-containing ventral horn with the clinically and neuropathologically spared dorsal horn of ALS spinal cord displayed similar expression levels. At the cellular level, we found a prominent neuronal expression of FGF-2 and FGFR1. Interestingly, both morphologically intact and damaged motoneurons showed positive staining for FGF-2 and FGFR1 transcripts. The distribution of cells expressing FGF-2 and FGFR1 transcripts showed no differences between ALS and controls. Our data suggest that FGF-2 and FGFR1 expression is preserved in the motor system in end stage ALS.