Quantitative analysis of human endogenous retrovirus-K transcripts in postmortem premotor cortex fails to confirm elevated expression of HERV-K RNA in amyotrophic lateral sclerosis
Quantitative analysis of human endogenous retrovirus-K transcripts in postmortem premotor cortex fails to confirm elevated expression of HERV-K RNA in amyotrophic lateral sclerosis
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DOI：
10.1186/s40478-019-0698-2
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发表时间：
2019-03-18
影响因子：
7.1
通讯作者：
McCormick, Adele L.
中科院分区：
文献类型：
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作者：
Garson, Jeremy A.;Usher, Louise;McCormick, Adele L.
在过去的二十年中，许多研究已经证明了逆转录病毒酶逆转录酶在散发性肌萎缩侧索硬化症（ALS）患者血清中的活性。已知的人类外源性逆转录病毒（如HIV-1）已被排除为该活性的可能来源，因此研究人员认为可能涉及人类内源性逆转录病毒（HERV）。在观察到ALS患者皮质和脊髓神经元中HERV-K表达升高以及在体外和转基因小鼠中证明HERV-K包膜蛋白神经毒性后，HERV-K（HML-2）是最新提出的逆转录病毒候选药物。这种逆转录病毒假说是一个有吸引力的假说，尤其是因为它提出了ALS可能通过抗逆转录病毒药物治疗的可能性。在本研究中，我们试图独立证实ALS脑中HERV-K RNA水平升高的观察结果。从34例ALS患者和23例对照者的死后运动前区皮质中提取总RNA。根据MIQE指南，使用HERV-K gag、pol和env引物组进行定量实时逆转录PCR（RT-qPCR）。通过2（-Ct）方法分析数据，针对两个参考基因GAPDH和XPNPEP 1进行归一化。ALS患者运动前皮质中HERV-K RNA表达水平的几何平均值与非ALS对照组中的表达水平无差异。我们的研究结果没有证实最近报道的皮质HERV-K RNA水平升高与ALS之间的关联，因此对这种内源性逆转录病毒在ALS发病机制中的作用提出了质疑。这项研究的结果可能对正在进行的旨在用抗逆转录病毒药物抑制HERV-K活性的临床试验产生影响。
Over the past two decades a number of studies have demonstrated activity of the retroviral enzyme reverse transcriptase in the serum of patients with sporadic amyotrophic lateral sclerosis (ALS). Known human exogenous retroviruses such as HIV-1 have been eliminated as possible sources of this activity and investigators have therefore considered the possibility that human endogenous retroviruses (HERVs) might be involved. HERV-K (HML-2) is the most recent retroviral candidate to be proposed following the observation of elevated HERV-K expression in cortical and spinal neurons of ALS patients and the demonstration of HERV-K envelope protein neurotoxicity in vitro and in transgenic mice. This retroviral hypothesis is an attractive one, not least because it raises the possibility that ALS might become treatable using antiretroviral drugs. In the present study we have attempted independent confirmation of the observation that HERV-K RNA levels are elevated in ALS brain. Total RNA was extracted from the postmortem premotor cortex of 34 patients with ALS and 23 controls. Quantitative real-time reverse transcription PCR (RT-qPCR) was performed according to the MIQE guidelines using HERV-K gag, pol and env primer sets. Data was analysed by the 2(-Ct) method with normalisation against two reference genes, GAPDH and XPNPEP1. Geometric mean HERV-K RNA expression levels in the premotor cortex of ALS patients were not found to be different from the expression levels in non-ALS controls. Our findings do not confirm the recently reported association between elevated cortical HERV-K RNA levels and ALS, and thus raise doubts about the role of this endogenous retrovirus in ALS pathogenesis. The results of this study may have implications for ongoing clinical trials aiming to suppress HERV-K activity with antiretroviral drugs.