Division of Molecular Parasitology, Department of Biology, and Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine- University, Universitätsstr 1, Clinic for Gastroenterology, Hepatology, and Infectiology, Heinrich-Heine-University, Moorenstr 5, 40225 Düsseldorf, Germany.
Infect Immun. 2010 Apr;78(4):1642-9. doi: 10.1128/IAI.01159-09. Epub 2010 Jan 25.
Deletion of the taurine transporter gene (taut) results in lowered levels of taurine, the most abundant amino acid in mammals. Here, we show that taut-/- mice have lost their ability to self-heal blood-stage infections with Plasmodium chabaudi malaria. All taut-/- mice succumb to infections during crisis, while about 90% of the control taut(+/+) mice survive. The latter retain unchanged taurine levels even at peak parasitemia. Deletion of taut, however, results in the lowering of circulating taurine levels from 540 to 264 micromol/liter, and infections cause additional lowering to 192 micromol/liter. Peak parasitemia levels in taut-/- mice are approximately 60% higher than those in taut(+/+) mice, an elevation that is associated with increased systemic tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels, as well as with liver injuries. The latter manifest as increased systemic ammonia levels, a perturbed capacity to entrap injected particles, and increased expression of genes encoding TNF-alpha, IL-1beta, IL-6, inducible nitric oxide synthase (iNOS), NF-kappaB, and vitamin D receptor (VDR). Autopsy reveals multiorgan failure as the cause of death for malaria-infected taut-/- mice. Our data indicate that taut-controlled taurine homeostasis is essential for resistance to P. chabaudi malaria. Taurine deficiency due to taut deletion, however, impairs the eryptosis of P. chabaudi-parasitized erythrocytes and expedites increases in systemic TNF-alpha, IL-1beta, and ammonia levels, presumably contributing to multiorgan failure in P. chabaudi-infected taut-/- mice.
牛磺酸转运蛋白基因(taut)缺失导致牛磺酸水平降低,牛磺酸是哺乳动物中最丰富的氨基酸。在这里,我们表明 taut-/- 小鼠失去了自我治愈伯氏疟原虫疟原虫血期感染的能力。所有 taut-/- 小鼠在危机期间都屈服于感染,而大约 90%的对照 taut(+/+) 小鼠存活下来。后者即使在寄生虫高峰期也保持不变的牛磺酸水平。然而,taut 的缺失导致循环牛磺酸水平从 540 降至 264 微摩尔/升,感染导致进一步降至 192 微摩尔/升。taut-/- 小鼠的峰值寄生虫血症水平比 taut(+/+) 小鼠高约 60%,这种升高与系统性肿瘤坏死因子 alpha (TNF-alpha) 和白细胞介素-1beta (IL-1beta) 水平升高以及肝损伤有关。后者表现为系统氨水平升高、捕获注入颗粒的能力受损以及编码 TNF-alpha、IL-1beta、IL-6、诱导型一氧化氮合酶 (iNOS)、NF-kappaB 和维生素 D 受体 (VDR) 的基因表达增加。尸检显示多器官衰竭是疟疾感染 taut-/- 小鼠死亡的原因。我们的数据表明,taut 控制的牛磺酸动态平衡对于抵抗伯氏疟原虫疟疾至关重要。然而,由于 taut 缺失导致牛磺酸缺乏,会损害 P. chabaudi 寄生虫感染的红细胞的细胞内凋亡,并加速系统性 TNF-alpha、IL-1beta 和氨水平的升高,这可能导致 P. chabaudi 感染的 taut-/- 小鼠多器官衰竭。