Expression of autophagy-related proteins in cortical nodules of tuberous sclerosis complex

Abstract

Objective: To investigate the expression of LC3B, p-AMPKα and p27 in cortical tuberous sclerosis complex (TSC). Methods: Nineteen specimens of surgically resected TSC cortical tubers were collected at Xuanwu Hospital, Capital Medical University, from 2014 to 2017. The expression of the three proteins in the lesions and the adjacent relatively normal regions was detected by immunohistochemical staining (EnVision two-step method). Results: LC3B was mainly expressed in the dysmorphic neuron and giant cell in TSC cortical tubers and in the adjacent relatively normal neurons, and the expression was diffuse or perinuclear cytoplasmic. There was no significant difference in the average optical density between abnormal cells and neurons adjacent to the lesions (0.343±0.195 vs. 0.419±0.088, P>0.05). p-AMPKα was localized in the cytoplasm of dysmorphic neurons and giant cell in TSC cortical tubers. The average optical density of abnormal cells in the lesions was significantly higher than that of neurons adjacent to the lesions (0.306±0.123 vs. 0.233±0.654, P<0.05). P27 showed nuclear positivity, mainly expressed in the neurons and glial cells close to TSC cortical tubers, while the positive rate in the abnormal cells in TSC cortical tubers was low (15/19 vs. 7/19, P<0.05). Conclusion: There is no significant decrease in the level of autophagy in dysmorphic neurons and giant cells in TSC cortical tubers, which may be related to the compensatory mechanism of AMPK signaling pathway, but without activation of downstream p27.