Pereira M C, Costa M, Chagas Filho C, de Meirelles M N
Department of Ultrastructure and Cellular Biology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil.
J Submicrosc Cytol Pathol. 1993 Oct;25(4):559-69.
The cytoskeletal organization of normal and Trypanosoma cruzi-infected mouse embryo heart muscle cells (HMC) in primary culture was investigated using immunofluorescence and transmission electron microscopy. Fluorescent probes revealed that in the early stages of infection, up to 24 h, the HMC cytoskeleton appeared to accommodate the intracellular parasites perinuclearly, with only a few cells displaying a slight disturbance in the distribution of filaments. However, as the infection progressed (48 to 72 h), microtubules and desmin filaments were disrupted. Breakdown of myofibrils occurred in regions where the parasites were present, followed by formation of actin polygons. Using Triton X-100 treated whole cell mount, we obtained a striking preservation of the three-dimensional architecture of the cytoskeleton. Combining electron spectroscopic imaging (ESI) with contrast tuning, we detected a highly interconnected cytoskeletal network in normal cells, and a loose network in infected cells. Bundles of filaments running under and over the parasites were also observed. Our results demonstrate that T. cruzi infection induces myofibrillar breakdown and destruction of several cytoskeleton filaments in heart muscle cells.
利用免疫荧光和透射电子显微镜技术，研究了原代培养的正常小鼠胚胎心肌细胞（HMC）和克氏锥虫感染的小鼠胚胎心肌细胞的细胞骨架组织。荧光探针显示，在感染的早期阶段，即长达24小时时，HMC细胞骨架似乎在细胞核周围容纳细胞内寄生虫，只有少数细胞的细丝分布出现轻微紊乱。然而，随着感染的进展（48至72小时），微管和结蛋白细丝被破坏。在存在寄生虫的区域，肌原纤维发生分解，随后形成肌动蛋白多边形。使用经Triton X - 100处理的全细胞装片，我们获得了细胞骨架三维结构的显著保存。将电子光谱成像（ESI）与对比度调节相结合，我们在正常细胞中检测到高度互连的细胞骨架网络，而在感染细胞中则检测到松散的网络。还观察到在寄生虫下方和上方运行的细丝束。我们的结果表明，克氏锥虫感染会诱导心肌细胞中的肌原纤维分解和几种细胞骨架细丝的破坏。
