Involvement of mTOR pathway in neurodegeneration in NSF-related developmental and epileptic encephalopathy

Autor: Takahiro Hayashi, Naoko Yano, Kengo Kora, Atsushi Yokoyama, Kanako Maizuru, Taisei Kayaki, Kinuko Nishikawa, Mitsujiro Osawa, Akira Niwa, Toshiki Takenouchi, Atsushi Hijikata, Tsuyoshi Shirai, Hisato Suzuki, Kenjiro Kosaki, Megumu K Saito, Junko Takita, Takeshi Yoshida
Rok vydání: 2023
Předmět:
Zdroj: Human Molecular Genetics. 32:1683-1697
ISSN: 1460-2083
0964-6906
DOI: 10.1093/hmg/ddad008
Popis: Membrane fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. During neurotransmitter exocytosis, SNARE proteins on a synaptic vesicle and the target membrane form a complex, resulting in neurotransmitter release. N-ethylmaleimide-sensitive factor (NSF), a homohexameric ATPase, disassembles the complex, allowing individual SNARE proteins to be recycled. Recently, the association between pathogenic NSF variants and developmental and epileptic encephalopathy (DEE) was reported; however, the molecular pathomechanism of NSF-related DEE remains unclear. Here, three patients with de novo heterozygous NSF variants were presented, of which two were associated with DEE and one with a very mild phenotype. One of the DEE patients also had hypocalcemia from parathyroid hormone deficiency and neuromuscular junction impairment. Using PC12 cells, a neurosecretion model, we show that NSF with DEE-associated variants impaired the recycling of vesicular membrane proteins and vesicle enlargement in response to exocytotic stimulation. In addition, DEE-associated variants caused neurodegenerative change and defective autophagy through overactivation of the mammalian/mechanistic target of rapamycin (mTOR) pathway. Treatment with rapamycin, an mTOR inhibitor or overexpression of wild-type NSF ameliorated these phenotypes. Furthermore, neurons differentiated from patient-derived induced pluripotent stem cells showed neurite degeneration, which was also alleviated by rapamycin treatment or gene correction using genome editing. Protein structure analysis of NSF revealed that DEE-associated variants might disrupt the transmission of the conformational change of NSF monomers and consequently halt the rotation of ATP hydrolysis, indicating a dominant negative mechanism. In conclusion, this study elucidates the pathomechanism underlying NSF-related DEE and identifies a potential therapeutic approach.
Databáze: OpenAIRE
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