Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, NIH, Hamilton, Montana, USA.
Ionis Pharmaceuticals Inc., Carlsbad, California, USA.
JCI Insight. 2019 Jul 30;5(16):131175. doi: 10.1172/jci.insight.131175.
Prion disease is a fatal, incurable neurodegenerative disease of humans and other mammals caused by conversion of cellular prion protein (PrP; PrPC) into a self-propagating neurotoxic conformer (prions; PrPSc). Strong genetic proofs of concept support lowering PrP expression as a therapeutic strategy. Antisense oligonucleotides (ASOs) can provide a practical route to lowering one target mRNA in the brain, but their development for prion disease has been hindered by three unresolved questions from prior work: uncertainty about mechanism of action, unclear potential for efficacy against established prion infection, and poor tolerability of drug delivery by osmotic pumps. Here we test antisense oligonucleotides (ASOs) delivered by bolus intracerebroventricular injection to intracerebrally prion-infected wild-type mice. Prophylactic treatments given every 2-3 months extended survival times 61-98%, and a single injection at 120 days post-infection, near the onset of clinical signs, extended survival 55% (87 days). In contrast, a non-targeting control ASO was ineffective. Thus, PrP lowering is the mechanism of action of ASOs effective against prion disease in vivo, and infrequent, or even single, bolus injections of ASOs can slow prion neuropathogenesis and markedly extend survival, even when initiated near clinical signs. These findings should empower development of PrP-lowering therapy for prion disease.
朊病毒病是一种致命的、无法治愈的人类和其他哺乳动物神经退行性疾病，由细胞朊蛋白（PrP；PrPC）转化为自我传播的神经毒性构象（朊病毒；PrPSc）引起。强有力的遗传概念验证支持降低 PrP 表达作为一种治疗策略。反义寡核苷酸（ASO）可以为降低大脑中一种靶 mRNA 提供一种实用途径，但由于之前工作中的三个未解决的问题，它们在朊病毒病中的发展受到了阻碍：作用机制的不确定性、对已建立的朊病毒感染的疗效的潜在影响不明确以及渗透压泵给药的耐受性差。在这里，我们测试了通过脑室内推注给药的反义寡核苷酸（ASO）在脑内感染朊病毒的野生型小鼠中的作用。每 2-3 个月给予一次预防性治疗可将存活时间延长 61-98%，在感染后 120 天（接近临床症状发作时）单次注射可将存活时间延长 55%（87 天）。相比之下，非靶向对照 ASO 则无效。因此，降低 PrP 是 ASO 对体内朊病毒病有效的作用机制，即使在接近临床症状时开始，不频繁甚至单次推注 ASO 也可以减缓朊病毒神经病变并显著延长存活时间。这些发现应该为开发针对朊病毒病的降低 PrP 治疗提供支持。
