Mouse Adenovirus Type 1 Early Region 1A Effects on the Blood-Brain Barrier.
Mouse Adenovirus Type 1 Early Region 1A Effects on the Blood-Brain Barrier.
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DOI：
10.1128/msphere.00079-16
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发表时间：
2016-03
期刊：
影响因子：
4.8
通讯作者：
Spindler KR
中科院分区：
文献类型：
--
作者：
Tirumuru N;Pretto CD;Castro Jorge LA;Spindler KR
脑炎可由病毒引起，由于大脑的重要性质和缺乏治疗选择，它可能危及生命。MAV-1在其自然宿主中产生病毒性脑炎，为研究与脑炎发展有关的因素提供了一个模型。MAV-1感染破坏了感染小鼠脑内血脑屏障，增加了脑内基质金属蛋白酶的活性。我们调查了腺病毒的主要转录调节因子E1a蛋白是否与MAV-1感染引起的任何特定表型有关。在所检测的一些功能中，E1a突变病毒表现出与野生型病毒相似的行为。然而，在缺乏E1a蛋白产生的病毒中，一种基质金属蛋白酶的mRNA表达水平较高。这突显了脑炎的复杂性质，并表明E1a可能对宿主基因具有转录效应，这些基因对脑炎的发展至关重要。小鼠腺病毒1型(MAV-1)感染内皮细胞，破坏血脑屏障(BBB)，引起近交系和近交系小鼠脑炎。使用一个不产生早期区域1A蛋白E1A的病毒突变体，我们研究了这种已知的病毒转录调节因子的活性是否需要BBB破坏和其他与脑炎相关的表型。野生型(Wt)病毒和E1a变异病毒导致受感染小鼠大脑中荧光素钠的渗透性水平相似。在血脑屏障完整性的体外测试中，wt和突变病毒在原代小鼠脑内皮细胞单层引起类似的跨内皮细胞电阻下降。这些结果表明，E1a蛋白不会破坏动物或培养细胞的血脑屏障完整性。Wt和E1a突变病毒感染小鼠后，两种已知与血脑屏障破坏相关的基质金属蛋白酶MMP2和MMP9的活性均有类似的增加，而MMP2或MMP9mRNA的稳态表达没有增加。相反，MMP3转录本的数量在感染这两种病毒时增加，并且在缺乏E1a蛋白产生的突变病毒感染时增加到更高的水平。在模拟病毒、野生型病毒和变异型病毒感染中，紧密连接蛋白的稳定表达水平没有差异。因此，在所检测的参数中，MAV-1E1A蛋白并不能显著影响血脑屏障的完整性，尽管它减少了感染后大脑中诱导的MMP3 mRNA的稳定表达。重要性脑炎可由病毒引起，由于大脑的重要性质和缺乏治疗选择，它可能危及生命。MAV-1在其自然宿主中产生病毒性脑炎，为研究与脑炎发展有关的因素提供了一个模型。MAV-1感染破坏了感染小鼠脑内血脑屏障，增加了脑内基质金属蛋白酶的活性。我们调查了腺病毒的主要转录调节因子E1a蛋白是否与MAV-1感染引起的任何特定表型有关。在所检测的一些功能中，E1a突变病毒表现出与野生型病毒相似的行为。然而，在缺乏E1a蛋白产生的病毒中，一种基质金属蛋白酶的mRNA表达水平较高。这突显了脑炎的复杂性质，并表明E1a可能对宿主基因具有转录效应，这些基因对脑炎的发展至关重要。
Encephalitis can be caused by viruses, and it is potentially life-threatening because of the vital nature of the brain and the lack of treatment options. MAV-1 produces viral encephalitis in its natural host, providing a model for investigating factors involved in development of encephalitis. MAV-1 infection disrupts the BBB and increases activity of matrix metalloproteinases in brains of infected mice. We investigated whether the major transcriptional regulator of adenoviruses, E1A protein, is responsible for any of the specific phenotypes that result from MAV-1 infection. For some of the functions assayed, an E1A mutant virus behaved like wild-type virus. However, expression of mRNA for one matrix metalloproteinase was higher in the virus lacking E1A protein production. This highlights the complex nature of encephalitis and suggests that E1A may have transcriptional effects on host genes important for the development of encephalitis. Mouse adenovirus type 1 (MAV-1) infects endothelial cells and disrupts the blood-brain barrier (BBB), causing encephalitis in inbred and outbred mice. Using a virus mutant that does not produce the early region 1A protein E1A, we investigated whether the activity of this known viral transcriptional regulator is needed for BBB disruption and other phenotypes associated with encephalitis. The wild-type (wt) virus and E1A mutant virus caused similar levels of permeability of sodium fluorescein in brains of infected mice. In an in vitro assay of BBB integrity, wt and mutant virus caused similar decreases in transendothelial electrical resistance in primary mouse brain endothelial cell monolayers. These results indicate that E1A protein does not contribute to disruption of BBB integrity in animals or cultured cells. Both wt and E1A mutant virus infection of mice led to similar increases in the activity of two matrix metalloproteinases known to correlate with BBB disruption, MMP2 and MMP9, while causing no increase in the steady-state expression of MMP2 or MMP9 mRNA. In contrast, the amount of MMP3 transcripts increased upon infection by both viruses and to a higher level in infections by the mutant virus lacking E1A protein production. There was no difference in the levels of steady-state expression of mRNA for tight junction proteins among mock virus, wt virus, and mutant virus infections. Thus, the MAV-1 E1A protein does not measurably affect BBB integrity in the parameters assayed, although it reduces the amount of MMP3 mRNA steady-state expression induced in brains upon infection. IMPORTANCE Encephalitis can be caused by viruses, and it is potentially life-threatening because of the vital nature of the brain and the lack of treatment options. MAV-1 produces viral encephalitis in its natural host, providing a model for investigating factors involved in development of encephalitis. MAV-1 infection disrupts the BBB and increases activity of matrix metalloproteinases in brains of infected mice. We investigated whether the major transcriptional regulator of adenoviruses, E1A protein, is responsible for any of the specific phenotypes that result from MAV-1 infection. For some of the functions assayed, an E1A mutant virus behaved like wild-type virus. However, expression of mRNA for one matrix metalloproteinase was higher in the virus lacking E1A protein production. This highlights the complex nature of encephalitis and suggests that E1A may have transcriptional effects on host genes important for the development of encephalitis.