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

Zhonghua Bing Li Xue Za Zhi. 2019 Nov 8;48(11):856-860. doi: 10.3760/cma.j.issn.0529-5807.2019.11.005.
[Article in Chinese]

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.

目的: 探讨结节性硬化综合征(tuberous sclerosis complex,TSC)皮质结节中自噬及相关调节通路上的蛋白LC3B、p-AMPKα及p27的表达情况。 方法: 收集2014至2017年在首都医科大学宣武医院手术切除的19例TSC皮质结节标本。采用免疫组织化学染色(EnVision二步法)对3种蛋白分别在病灶及病灶旁相对正常脑组织的表达情况进行检测,并进行统计学分析。 结果: LC3B主要表达于TSC皮质结节病灶中形态异常神经元和巨大细胞内以及病灶旁相对正常的神经元内,为胞质内弥漫阳性或核周阳性。对病灶中形态异常神经元和巨大细胞及病灶旁神经元的平均吸光度进行比较,差异无统计学意义[(0.343±0.195)比(0.419±0.088),P>0.05]。p-AMPKα定位于TSC皮质结节中形态异常神经元和巨大细胞的细胞质,病灶中异常细胞的平均吸光度明显高于病灶旁神经元的平均吸光度[(0.306±0.123)比(0.233±0.654),P<0.05]。p27为细胞核阳性,主要表达于TSC皮质结节病灶旁的神经元以及胶质细胞,而TSC皮质结节病灶中的异常细胞阳性表达率低(7/19比15/19,P<0.05)。 结论: TSC皮质结节病灶中异常细胞内自噬水平并没有明显下降,可能与AMPK信号通路激活的代偿机制相关,而这种代偿机制的发生可能是AMPK通过激活其下游p27以外的途径来实现的。.

Keywords: Autophagy; Immunohistochemistry; Tuberous sclerosis.

MeSH terms

  • AMP-Activated Protein Kinase Kinases
  • Autophagy-Related Proteins / metabolism*
  • Cerebral Cortex / pathology
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism*
  • Humans
  • Microtubule-Associated Proteins / metabolism*
  • Neuroglia / metabolism
  • Neurons / metabolism
  • Protein Kinases / metabolism*
  • Tuberous Sclerosis / metabolism*

Substances

  • Autophagy-Related Proteins
  • CDKN1B protein, human
  • MAP1LC3B protein, human
  • Microtubule-Associated Proteins
  • Cyclin-Dependent Kinase Inhibitor p27
  • Protein Kinases
  • AMP-Activated Protein Kinase Kinases