Mitochondrial localization of non-histone protein HMGB1 during human endothelial cell– Toxoplasma gondii infection

• Published in: Cell biology international Vol. 32; no. 2; pp. 235 - 238
• Main Authors: Stumbo, Ana Carolina, Cortez, Erika, Rodrigues, Carlos Alberto, Henriques, Maria das Graças M.O., Porto, Luís Cristóvão, Barbosa, Helene S., Carvalho, Laís
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier Ltd 01-02-2008; Blackwell Publishing Ltd
• Subjects: Animals; Cell Line; Endothelial Cells - cytology; Endothelial Cells - metabolism; Fluorescent Dyes - metabolism; HMGB1; HMGB1 Protein - metabolism; Human endothelial cell; Humans; Mitochondria; Mitochondria - metabolism; Toxoplasma - pathogenicity; Toxoplasma gondii; Toxoplasmosis - metabolism; Human endothelial cell; Mitochondria; Toxoplasma gondii; HMGB1
• ISSN: 1065-6995; 1095-8355
• DOI: 10.1016/j.cellbi.2007.08.031

Toxoplasma gondii is an obligate intracellular pathogen, replicating only within a specialized membrane-bounded cytoplasmic vacuole, the parasitophorous vacuole (PV), which interacts with host cell mitochondria. High mobility group box 1 (HMGB1), a known nuclear transcription factor, also may be involved in pathological conditions, whose function is to signal tissue damage. Using confocal microscopy, we have investigated the localization of HMGB1 and the mitochondria performance during interaction between human umbilical vein endothelial cells (HUVEC) and
Toxoplasma. Immunofluorescence showed HMGB1 localization in HUVEC tubular mitochondria stained with Mito Tracker (MT). At 2
h post-infection, MT labeled spherical structures scattered throughout the cytoplasm and HMGB1 were still present. After 24
h of infection, long and tubular structures were localized around PVs and were double labeled by MT and HMGB1, suggesting a structural reorganization of the mitochondria over a long period of infection. For the first time, these results show there is HMGB1 in HUVEC mitochondria and that this protein could be playing a part in mitochondrial DNA events which are important for fission and fusion processes reported here during HUVEC-
T. gondii infection.