Delivery of Therapeutic siRNA to the CNS Using Cationic and Anionic Liposomes.
Delivery of Therapeutic siRNA to the CNS Using Cationic and Anionic Liposomes.
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DOI：
10.3791/54106
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发表时间：
2016-07-23
期刊：
影响因子：
--
通讯作者：
Zabel MD
中科院分区：
文献类型：
--
作者：
Bender HR;Kane S;Zabel MD
Prion疾病是当正常的细胞Prion蛋白(PrPC)被一种异常构象的抗蛋白酶异构体PrPRes错误折叠时引起的。在野生动物种群中出现的Pron疾病及其对人类健康的影响越来越大，因此迫切需要找到治疗或治愈这些疾病的方法。最近的研究发现，许多抗PrP的化合物可以抑制感染性PrPRes异构体或下调正常细胞内的Prion蛋白。然而，这些化合物中的大多数都不能通过血脑屏障有效地抑制脑组织中PrPRes的形成，也不能特异性地针对神经元PrPC。此外，这些化合物往往具有多种非靶标作用，而且往往毒性太高，不能用于动物或人类受试者。因此，我们认为，血管内靶向神经元PrPC的siRNA是一种更安全、更有效的抗Prion化合物。我们使用阳离子或阴离子聚乙二醇化脂质体来保护siRNA免受血清降解和从单核吞噬细胞系统(MPS)中的消除。对于我们的复合脂质体配方，带负电荷的siRNA首先静电结合到阳离子脂质体上。一个带正电荷的多肽(RVG-9r)被添加到siRNA中，它特异性地靶向脂质体-siRNA-肽复合体(LSPC)穿过血脑屏障(BBB)到达中枢神经系统(CNS)中表达乙酰胆碱的神经元。对于我们的微囊化脂质体配方，阳离子和阴离子脂质用含有PrP siRNA的溶液进行再水化，这导致siRNA被包裹在阳离子或阴离子脂质体中。由于siRNA和阴离子脂都带负电荷，PrP siRNA与组蛋白样蛋白硫酸鱼精蛋白孵育，以实现阴离子脂质体的包裹。此外，我们还通过碳二亚胺反应将RVG-9R神经肽共价键合到脂质体的聚乙二醇基上，以将siRNA/脂质体复合体靶向CNS。我们称之为多肽寻址的脂质体包裹的治疗性siRNA(Palets)。利用这些配方，我们成功地将PrP siRNA传递给了ACHR表达的神经元，并降低了中枢神经系统神经元的PrPC表达。LSPC和Palet允许将PrP siRNA和潜在的其他小分子疗法有效地输送到中枢神经系统，以治疗神经退行性疾病。对siRNA等能够跨越血脑屏障(BBB)的治疗药物输送系统的优化，将为普恩和其他神经退行性疾病提供更多的治疗选择。使用带有神经靶向多肽的阳离子/阴离子脂质体作为中枢神经系统的递送系统，使siRNA能够穿过血脑屏障。
Prion diseases are caused when the normal, cellular prion protein (PrPC) is recruited to misfold by an abnormally conformed protease resistant isomer called PrPRes. The emergence of prion diseases in wildlife populations and its increasing impact on human health has led to an urgency to find a therapeutic or a cure for these diseases. Recent studies have found numerous anti-prion compounds that can either inhibit the infectious PrPRes isomer or down regulate the normal cellular prion protein. However, most of these compounds cannot cross the blood brain barrier to effectively inhibit PrPRes formation in brain tissue, or specifically target neuronal PrPC. Also, these compounds tend to have multiple off-target effects, and are often too toxic to use in animal or human subjects. Therefore, we propose that siRNA delivered intravascularly and targeted towards neuronal PrPC is a safer and more effective anti-prion compound. We use cationic or anionic PEGylated liposomes to protect the siRNA from serum degradation and elimination from the mononuclear phagocyte system (MPS). For our complexed liposome formulation, negatively charged siRNA is first electrostatically bound to the cationic liposome. A positively charged peptide (RVG-9r) is added to the siRNA that specifically targets the liposome-siRNA-peptide complexes (LSPCs) across the blood brain barrier (BBB) to acetylcholine expressing neurons in the central nervous system (CNS). For our encapsulated liposome formulations, the cationic and anionic lipids are rehydrated with a solution that contains the PrP siRNA, which results in encapsulation of the siRNA within the cationic or anionic liposomes. Since the siRNA and the anionic lipids are both negatively charged, the PrP siRNA is incubated with the histone-like protein protamine sulfate to achieve encapsulation within anionic liposomes. Also, we have covalently bonded the RVG-9r neuropeptide to the PEG groups of the encapsulated liposomes using a carbodiimide reaction to target the siRNA/liposome complexes to the CNS. We call the resulting liposomes peptide addressed liposome encapsulated therapeutic siRNA (PALETS). Using these formulations, we have successfully delivered PrP siRNA to AchR-expressing neurons, and decreased the PrPC expression of neurons in the CNS. LSPCs and PALETS allow for the efficient delivery of PrP siRNA, and potentially other small molecule therapeutics, to the CNS to treat neurodegenerative diseases. The optimization of a delivery system for therapeutics, like siRNA, capable of crossing the blood brain barrier (BBB) would allow for more treatment options for prion and other neurodegenerative diseases. The use of cationic/anionic liposomes with a neuro-targeting peptide as a CNS delivery system allows siRNA to cross the BBB.
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影响因子：
2.8
作者：
Graham, AJ;Ray, MA;Court, JA
通讯作者：
Court, JA
DOI：
10.1073/pnas.88.2.375
发表时间：
1991-01-01
影响因子：
11.1
作者：
DIEDRICH, JF;BENDHEIM, PE;HAASE, AT
通讯作者：
HAASE, AT
影响因子：
16.2
作者：
Mallucci, Giovanna R.;White, Melanie D.;Collinge, John
通讯作者：
Collinge, John
影响因子：
16.2
作者：
MOSER, M;COLELLO, RJ;OESCH, B
通讯作者：
OESCH, B
影响因子：
5.1
作者：
Li, S;Rizzo, MA;Huang, L
通讯作者：
Huang, L