Gadd153 和 NF-κB 相互作用调节 27-羟胆固醇诱导的人神经母细胞瘤 SH-SY5Y 细胞中 BACE1 和 β-淀粉样蛋白产生增加。
Gadd153 and NF-κB crosstalk regulates 27-hydroxycholesterol-induced increase in BACE1 and β-amyloid production in human neuroblastoma SH-SY5Y cells.
机构信息
Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
出版信息
PLoS One. 2013 Aug 9;8(8):e70773. doi: 10.1371/journal.pone.0070773. eCollection 2013.
β-amyloid (Aβ) peptide, accumulation of which is a culprit for Alzheimer's disease (AD), is derived from the initial cleavage of amyloid precursor protein by the aspartyl protease BACE1. Identification of cellular mechanisms that regulate BACE1 production is of high relevance to the search for potential disease-modifying therapies that inhibit BACE1 to reduce Aβ accumulation and AD progression. In the present study, we show that the cholesterol oxidation product 27-hydroxycholesterol (27-OHC) increases BACE1 and Aβ levels in human neuroblastoma SH-SY5Y cells. This increase in BACE1 involves a crosstalk between the two transcription factors NF-κB and the endoplasmic reticulum stress marker, the growth arrest and DNA damage induced gene-153 (gadd153, also called CHOP). We specifically show that 27-OHC induces a substantial increase in NF-κB binding to the BACE1 promoter and subsequent increase in BACE1 transcription and Aβ production. The NF-κB inhibitor, sc514, significantly attenuated the 27-OHC-induced increase in NF-κB-mediated BACE1 expression and Aβ genesis. We further show that the 27-OHC-induced NF-κB activation and increased NF-κB-mediated BACE1 expression is contingent on the increased activation of gadd153. Silencing gadd153 expression with siRNA alleviated the 27-OHC-induced increase in NF-κB activation, NF-κB binding to the BACE1 promoter, and subsequent increase in BACE1 transcription and Aβ production. We also show that increased levels of BACE1 in the triple transgenic mouse model for AD is preceded by gadd153 and NF-κB activation. In summary, our study demonstrates that gadd153 and NF-κB work in concert to regulate BACE1 expression. Agents that inhibit gadd153 activation and subsequent interaction with NF-κB might be promising targets to reduce BACE1 and Aβ overproduction and may ultimately serve as disease-modifying treatments for AD.
β-淀粉样蛋白(Aβ)肽的积累是阿尔茨海默病(AD)的罪魁祸首,它是由天冬氨酸蛋白酶 BACE1 对淀粉样前体蛋白的初始切割产生的。鉴定调节 BACE1 产生的细胞机制对于寻找潜在的疾病修饰疗法具有重要意义,这些疗法可以抑制 BACE1 以减少 Aβ 积累和 AD 进展。在本研究中,我们表明胆固醇氧化产物 27-羟胆固醇(27-OHC)增加了人神经母细胞瘤 SH-SY5Y 细胞中的 BACE1 和 Aβ 水平。这种 BACE1 的增加涉及到两个转录因子 NF-κB 和内质网应激标志物生长停滞和 DNA 损伤诱导基因 153(gadd153,也称为 CHOP)之间的串扰。我们特别表明,27-OHC 诱导 NF-κB 与 BACE1 启动子结合的大量增加,随后 BACE1 转录和 Aβ 产生增加。NF-κB 抑制剂 sc514 显著减弱了 27-OHC 诱导的 NF-κB 介导的 BACE1 表达和 Aβ 生成增加。我们进一步表明,27-OHC 诱导的 NF-κB 激活和增加的 NF-κB 介导的 BACE1 表达依赖于 gadd153 的激活增加。用 siRNA 沉默 gadd153 表达减轻了 27-OHC 诱导的 NF-κB 激活、NF-κB 与 BACE1 启动子结合以及随后 BACE1 转录和 Aβ 产生增加。我们还表明,AD 的三转基因小鼠模型中 BACE1 水平的增加先于 gadd153 和 NF-κB 的激活。总之,我们的研究表明,gadd153 和 NF-κB 协同作用调节 BACE1 的表达。抑制 gadd153 激活及其与 NF-κB 的后续相互作用的药物可能是减少 BACE1 和 Aβ 过度产生的有希望的靶点,并可能最终成为 AD 的疾病修饰治疗方法。