Department of Molecular Biology, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, 119 4th South Ring, Fengtai District, Beijing 100050, China.
Cells. 2020 Nov 3;9(11):2406. doi: 10.3390/cells9112406.
Tuberculosis, caused by , is one of the most severe diseases worldwide. The initial pulmonary localization of the pathogen often develops into systemic infection with high lethality. The present work investigated the role of sphingolipids, specifically the function of acid sphingomyelinase (Asm) and ceramide, in infection of murine macrophages in vitro and mice in vivo with Bacillus Calmette-Guérin (BCG). In vitro, we investigated macrophages from wild-type (wt) and Asm deficient (Asm) mice to define signaling events induced by BCG infection and mediated by Asm. We demonstrate that infection of wt macrophages results in activation of Asm, which increases reactive oxygen species (ROS) via stimulation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. ROS promote BCG degradation by cathepsin D. Asm deficiency in macrophages abrogates these effects. In vivo studies reveal that wt mice rapidly control BCG infection, while Asm mice fail to control the infection and kill the bacteria. Transplantation of wt macrophages into Asm mice reversed their susceptibility to BCG, demonstrating the importance of Asm in macrophages for defense against BCG. These findings indicate that Asm is important for the control of BCG infection.
结核病是由 引起的,是全球最严重的疾病之一。病原体在肺部的初始定位常常发展为全身性感染,具有很高的致死率。本研究调查了鞘脂类,特别是酸性鞘磷脂酶(Asm)和神经酰胺的功能,在体外感染鼠巨噬细胞和体内感染卡介苗(BCG)的小鼠中的作用。在体外,我们研究了野生型(wt)和 Asm 缺陷(Asm)小鼠的巨噬细胞,以确定 BCG 感染诱导的信号事件及其介导的 Asm。我们证明,wt 巨噬细胞的感染导致 Asm 的激活,通过刺激烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶增加活性氧(ROS)。ROS 通过组织蛋白酶 D 促进 BCG 降解。巨噬细胞中的 Asm 缺陷会消除这些作用。体内研究表明,wt 小鼠能迅速控制 BCG 感染,而 Asm 小鼠则不能控制感染并杀死细菌。将 wt 巨噬细胞移植到 Asm 小鼠中,逆转了它们对 BCG 的易感性,证明了 Asm 在巨噬细胞中对防御 BCG 的重要性。这些发现表明 Asm 对控制 BCG 感染很重要。