The F-actin cytoskeleton of Cryptococcus neoformans is known to comprise actin cables, cortical patches and cytokinetic ring. Here, we describe a new F-actin structure in fungi, a perinuclear F-actin collar ring around the cell nucleus, by fluorescent microscopic imaging of rhodamine phalloidin-stained F-actin. Perinuclear F-actin rings form in Cryptococcus neoformans treated with the microtubule inhibitor Nocodazole or with the drug solvent dimethyl sulfoxide (DMSO) or grown in yeast extract peptone dextrose (YEPD) medium, but they are absent in cells treated with Latrunculin A. Perinuclear F-actin rings may function as 'funicular cabin' for the cell nucleus, and actin cables as intracellular 'funicular' suspending nucleus in the central position in the cell and moving nucleus along the polarity axis along actin cables.
- MeSH
- aktiny analýza MeSH
- bicyklické sloučeniny heterocyklické farmakologie MeSH
- buněčné jádro ultrastruktura MeSH
- Cryptococcus neoformans účinky léků fyziologie ultrastruktura MeSH
- dimethylsulfoxid farmakologie MeSH
- elektronová mikroskopie MeSH
- faloidin analogy a deriváty MeSH
- fluorescenční mikroskopie MeSH
- mikrofilamenta ultrastruktura MeSH
- mikrotubuly účinky léků MeSH
- modulátory tubulinu farmakologie MeSH
- mořské toxiny farmakologie MeSH
- nokodazol farmakologie MeSH
- rhodaminy MeSH
- scavengery volných radikálů farmakologie MeSH
- thiazolidiny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Cryptococcus neoformans is an obligate aerobic pathogenic yeast causing lung infection typically followed by spread to the central nervous system. During pathogenesis, it relies on well-established virulence factors. This review focuses on the emerging role of cryptococcal adaptation to hypoxia in pathogenesis. METHODS AND RESULTS: We examined the MedLine database for information on the cryptococcal hypoxia response. While several recent papers describe components of two presumable hypoxia-sensing pathways including description of their target genes, a link of this system to the hypoxic tuning of proliferation is still missing. In addition, an interpretation of this knowledge in respect to the general picture of microbial pathogenesis is lacking. CONCLUSIONS: There seems to be a striking parallel between biofilm formation in bacteria, which results in chronic dormant infection with the potential for acute outbreaks, and the dormant state of primary infection followed by secondary outbreaks in C. neoformans. We propose a hypothesis that cryptococcal response to hypoxia might be the driving force for developing a state of dormant infection which is characterized by slowed proliferation and extensive changes in transcriptome and phenotype. This state enables C. neoformans to survive in host and possibly develop life-threatening acute outbreaks later. Hence, conventional well-aerated planktonic culture is not a good in vitro model for studying the pathogenesis of infection and we advocate the development of a more adequate model. Our further conclusion is that the ability of the immune system and antifungal agents to cope with hypoxia-adapted cells is crucial for the successful eradication of cryptococcal infection.
- MeSH
- antifungální látky terapeutické užití MeSH
- Cryptococcus neoformans fyziologie patogenita účinky léků MeSH
- kryptokoková meningitida MeSH
- kryptokokóza MeSH
- lidé MeSH
- virulence MeSH
- zdroje nemoci MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
