Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, 02-109, Poland.
Department of (Neuro)Pathology, Academic Medical Center, Amsterdam, 1105 AZ, The Netherlands.
Acta Neuropathol Commun. 2015 Jul 30;3:48. doi: 10.1186/s40478-015-0225-z.
Tuberous sclerosis complex (TSC) is a genetic disease resulting from mutation in TSC1 or TSC2 and subsequent hyperactivation of mammalian Target of Rapamycin (mTOR). Common TSC features include brain lesions, such as cortical tubers and subependymal giant cell astrocytomas (SEGAs). However, the current treatment with mTOR inhibitors has critical limitations. We aimed to identify new targets for TSC pharmacotherapy.
The results of our shRNA screen point to glutamate-cysteine ligase catalytic subunit (GCLC), a key enzyme in glutathione synthesis, as a contributor to TSC-related phenotype. GCLC inhibition increased cellular stress and reduced mTOR hyperactivity in TSC2-depleted neurons and SEGA-derived cells. Moreover, patients' brain tubers showed elevated GCLC and stress markers expression. Finally, GCLC inhibition led to growth arrest and death of SEGA-derived cells.
We describe GCLC as a part of redox adaptation in TSC, needed for overgrowth and survival of mutant cells, and provide a potential novel target for SEGA treatment.
结节性硬化症(TSC)是一种由 TSC1 或 TSC2 基因突变引起的遗传性疾病,进而导致哺乳动物雷帕霉素靶蛋白(mTOR)过度激活。常见的 TSC 特征包括脑部病变,如皮质结节和室管膜下巨细胞星形细胞瘤(SEGA)。然而,目前使用 mTOR 抑制剂治疗存在重大局限性。我们旨在寻找治疗 TSC 的新靶点。
我们的 shRNA 筛选结果表明,谷氨酸-半胱氨酸连接酶催化亚基(GCLC),即谷胱甘肽合成的关键酶,是 TSC 相关表型的一个贡献因素。GCLC 抑制增加了 TSC2 耗竭神经元和 SEGA 衍生细胞的细胞应激,并降低了 mTOR 的过度活性。此外,患者的脑结节显示出 GCLC 和应激标志物表达升高。最后,GCLC 抑制导致 SEGA 衍生细胞的生长停滞和死亡。
我们将 GCLC 描述为 TSC 中氧化还原适应的一部分,是突变细胞过度生长和存活所必需的,并为 SEGA 的治疗提供了一个潜在的新靶点。