Exposure to CSF from sporadic amyotrophic lateral sclerosis patients induces morphological transformation of astroglia and enhances GFAP and S100β expression

We have earlier shown that cerebrospinal fluid (CSF) of amyotrophic lateral sclerosis (ALS) patients' produces selective degeneration of motor neurons, both in vitro as well as in vivo. The present study further evaluates the effect of ALS-CSF on the astrocytes in embryonic rat spinal cord cultures. We quantified the number of flat and process-bearing astrocytes in spinal cord cultures exposed to ALS-CSF and compared them against controls. In addition, GFAP and S100β expression were quantified by Western blot and measurement of immunofluorescence intensity respectively. We found higher number of process-bearing astrocytes in the cultures exposed to ALS-CSF. Both these proteins increased significantly in cultures exposed to ALS-CSF. Our results provide evidence that astroglia respond to toxic factor(s) present in ALS-CSF by undergoing morphological transformation from flat to process bearing which is further confirmed by elevated expression of GFAP and S100β. The above changes could possibly alter the microenvironment hastening the motor neuron degeneration.