通过U7 snRNA介导的外原跳转来拯救衰变肌肉
Aurélie Goyenvalle1, Adeline Vulin, Françoise Fougerousse
1Généthon & CNRS UMR 8115, 1, rue de l'Internationale, Evry, France.
概括
这项研究表明,在mdx小鼠中,使用AAV介导的外显子跳转,持续产生功能性消毒素. 这种方法有效地通过恢复肌肉中的肌蛋白水平来纠正杜恩肌肉发育不良.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 神经肌肉疾病 神经肌肉疾病
背景情况:
- 杜氏肌肉发育不良 (DMD) 是一种严重的遗传疾病,由发育不良基因突变引起.
- 大多数 Dystrophin 基因突变导致框架转移或过早停止密码,导致缺席或非功能性的 Dystrophin 蛋白质.
- 引子跳转是一种治疗策略,可以恢复双蛋白读取框架,潜在地产生功能蛋白质.
研究的目的:
- 为了实现持续的,有针对性的异构体跳跃突变异构体在素信使RNA (mRNA) 中.
- 为了评估基因治疗后功能性消毒蛋白的持续生产.
- 评估在小鼠模型中纠正杜恩肌肉衰竭病理学的治疗疗效.
主要方法:
- 利用一种腺相关病毒 (AAV) 载体,提供与修饰的U7小核RNA相关的反感序列.
- 将AAV载体单剂量给mdx小鼠,这是杜申尼肌肉发育不良的模型.
- 监测持续的外跳转,双蛋白恢复和肌肉发育不良症状的纠正.
主要成果:
- 实现了持续且高效的外因子跳转,将突变的外因子从双氨酸mRNA中去除.
- 在多个肌肉群体的生理水平上证明了功能性消毒蛋白的持续生产.
- 在接受治疗的mdx小鼠中观察到肌肉缩现型的显著纠正.
结论:
- 单次使用AAV介导的外因子跳转是一种可行的策略,用于治疗杜申氏肌肉发育不良.
- 这种方法使得功能性消毒素的持续恢复和疾病的纠正.
- 这些发现支持这种基因治疗在DMD患者中临床应用的潜力.
相关概念视频
Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
The Unfolded Protein Response
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
Export of Misfolded Proteins out of the ER
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
Regulation of the Unfolded Protein Response
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...


