Abstract:

Aim: Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder affecting motor neurons. The loss-of-function mutations seen in the Als2 gene lead to ALS. The interaction between alsin, Als2 encoded protein, and UXT has been documented in vitro. UXT is a cofactor in NF-κB pathway. Our aim is to investigate the effect of Als2 silencing in NF-κB in primary motor neurons. Method: Spinal motor neurons isolated from adult BalbC mice were characterized immunocytochemically by anti-ChAT and anti-βIII tubulin primary antibodies. Als2 was silenced by RNAi and expressions of UXT, A20 and IL8 were determined by qRT-PCR. TNF-α, an NF-κB activator, was also applied and alterations in the expressions of A20 and IL8 were measured. Data were statistically evaluated by Student t-test. Results: Als2 expression decreased 74.3% by RNAi in immunocytochemically characterized spinal motor neurons (p<0.0001). UXT expression reduced by 40% (p<0.0001), decrease in IL8 expression was 84.4% (p<0.0001), whereas A20 expression increased by 65% (p<0.0001). When TNF-α was applied, IL8 expression increased by 17-fold, but the increase in A20 was only 29.5%. Conclusion: The gene expressional correlation between Als2 and UXT has been proven. The decreases in Als2 and UXT cause a reduction in IL8 expression, whereas expression of A20 increases. This indicates that Als2 silencing might reduce inflammatory response while activating pro-apoptotic signals. When NF-κB pathway has been activated by TNF-α, a considerable increase in IL8 has been observed. These data provide a confirmation and elaboration of a connection between Als2, UXT and NF-κB pathway in primary spinal motor neurons.

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