Characterization of aromatase expression in the spinal cord of an animal model of familial ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease involving motor neurons in the motor cortex, brainstem and spinal cord. ALS leads to progressive, aggravated muscle weakness and paralysis. Although the precise pathogenesis remains unknown, several studies have shown that estrogens exert neuroprotective effects during the course of the disease. Aromatase is the key enzyme in estrogen synthesis. In the present study, we used immunohistochemistry, immunofluorescence and western blotting to observe the characteristics of aromatase expression in the spinal cords of copper-zinc superoxide dismutase-1 (SOD1)-G93A transgenic mice. Under normal and nearly normal (pre-symptomatic stage) conditions, the motor neurons in the spinal anterior horn expressed aromatase. After disease onset, astrocytes began to express aromatase. The total level of aromatase expression decreased with disease progression. These findings may provide the basis for the pathogenesis of ALS through glial aromatization during the progression of this disease.