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From the cell biology to the development of new chemotherapeutic approaches against trypanosomatids: dreams and reality.

De Souza W - Kinetoplastid Biol Dis (2002)

Bottom Line: These organisms are also of biological interest since they are able to change the morphology according to the environment where they live, through a process of reversible cell transformation, and possess structures and organelles that are not found in mammalian cells.In addition, the present knowledge of structures and organelles such as the nucleus, the plasma membrane, the sub-pellicular microtubules, the flagellum, the kinetoplast-mitochondrion complex, the peroxisome (glycosome), the acidocalcisome and the structures and organelles involved in the endocytic pathway, is reviewed from a cell biology perspective.The possible use of available data for the development of new anti parasite drugs is also discussed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCSBloco G, 21941900, Rio de JaneiroRJ, Brasil. wsouza@biof.ufrj.br

ABSTRACT
Members of the Trypanosomatidae family comprise a large number of species that are causative agents of important diseases such as sleeping sickness, Chagas' disease and Leishmaniasis. These organisms are also of biological interest since they are able to change the morphology according to the environment where they live, through a process of reversible cell transformation, and possess structures and organelles that are not found in mammalian cells. This review analyses the process of transformation, which takes place during the life cycle of Trypanosoma cruzi in the vertebrate and invertebrate hosts. Special attention is given to the interaction of the parasite with vertebrate cells. In addition, the present knowledge of structures and organelles such as the nucleus, the plasma membrane, the sub-pellicular microtubules, the flagellum, the kinetoplast-mitochondrion complex, the peroxisome (glycosome), the acidocalcisome and the structures and organelles involved in the endocytic pathway, is reviewed from a cell biology perspective. The possible use of available data for the development of new anti parasite drugs is also discussed.

No MeSH data available.


Related in: MedlinePlus

Different views of the attachment of the flagellum to the cell body of T. cruzi as seen in freeze-fracture replicas.
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Figure 13: Different views of the attachment of the flagellum to the cell body of T. cruzi as seen in freeze-fracture replicas.

Mentions: This fact makes the flagellum of T. cruzi a suitable model for the study of the natural growth and shortening of this structure. At the side of the axoneme of the flagellum of trypanosomatids there is a filamentous, lattice-like structure, which has been called paraflagellar or paraxial rod. The flagellum of trypanosomatids is usually attached to the cell body. This attachment occurs only in a determined region of the flagellum of trypanosomatids in which the flagellum emerges from the central portion. However, it is extensive in developmental stages in which it emerges laterally as occurs with epimastigote and trypomastigote forms. Such attachment is made by a junction, which has been considered to be of the desmosome type [Review in [41]]. When the flagellar movement starts, the wave propagates throughout the flagellum and upon reaching the region in which it is attached to the body of the parasite, induces an apparent movement of the body; giving the visual impression of an undulating membrane. The undulating membrane of trypanosomatids does not appear in thin sections as an actual structure, as it does in Trichomonadidae. Observations of thin sections of the attachment zone by electron microscopy show that the junctional complex is formed by a linear series of apposed macular densities, each measuring 25 nm in diameter and formed from an amorphous material spaced at intervals of 90 nm. Freeze-fracture studies indicate that there is a specialization of the T. cruzi flagellar membrane at the region of attachment of the flagellum to the cell body of epimastigote and trypomastigote forms. This appears as clusters of intramembranous particles spaced at more or less regular intervals (Fig. 13).


From the cell biology to the development of new chemotherapeutic approaches against trypanosomatids: dreams and reality.

De Souza W - Kinetoplastid Biol Dis (2002)

Different views of the attachment of the flagellum to the cell body of T. cruzi as seen in freeze-fracture replicas.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC119324&req=5

Figure 13: Different views of the attachment of the flagellum to the cell body of T. cruzi as seen in freeze-fracture replicas.
Mentions: This fact makes the flagellum of T. cruzi a suitable model for the study of the natural growth and shortening of this structure. At the side of the axoneme of the flagellum of trypanosomatids there is a filamentous, lattice-like structure, which has been called paraflagellar or paraxial rod. The flagellum of trypanosomatids is usually attached to the cell body. This attachment occurs only in a determined region of the flagellum of trypanosomatids in which the flagellum emerges from the central portion. However, it is extensive in developmental stages in which it emerges laterally as occurs with epimastigote and trypomastigote forms. Such attachment is made by a junction, which has been considered to be of the desmosome type [Review in [41]]. When the flagellar movement starts, the wave propagates throughout the flagellum and upon reaching the region in which it is attached to the body of the parasite, induces an apparent movement of the body; giving the visual impression of an undulating membrane. The undulating membrane of trypanosomatids does not appear in thin sections as an actual structure, as it does in Trichomonadidae. Observations of thin sections of the attachment zone by electron microscopy show that the junctional complex is formed by a linear series of apposed macular densities, each measuring 25 nm in diameter and formed from an amorphous material spaced at intervals of 90 nm. Freeze-fracture studies indicate that there is a specialization of the T. cruzi flagellar membrane at the region of attachment of the flagellum to the cell body of epimastigote and trypomastigote forms. This appears as clusters of intramembranous particles spaced at more or less regular intervals (Fig. 13).

Bottom Line: These organisms are also of biological interest since they are able to change the morphology according to the environment where they live, through a process of reversible cell transformation, and possess structures and organelles that are not found in mammalian cells.In addition, the present knowledge of structures and organelles such as the nucleus, the plasma membrane, the sub-pellicular microtubules, the flagellum, the kinetoplast-mitochondrion complex, the peroxisome (glycosome), the acidocalcisome and the structures and organelles involved in the endocytic pathway, is reviewed from a cell biology perspective.The possible use of available data for the development of new anti parasite drugs is also discussed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCSBloco G, 21941900, Rio de JaneiroRJ, Brasil. wsouza@biof.ufrj.br

ABSTRACT
Members of the Trypanosomatidae family comprise a large number of species that are causative agents of important diseases such as sleeping sickness, Chagas' disease and Leishmaniasis. These organisms are also of biological interest since they are able to change the morphology according to the environment where they live, through a process of reversible cell transformation, and possess structures and organelles that are not found in mammalian cells. This review analyses the process of transformation, which takes place during the life cycle of Trypanosoma cruzi in the vertebrate and invertebrate hosts. Special attention is given to the interaction of the parasite with vertebrate cells. In addition, the present knowledge of structures and organelles such as the nucleus, the plasma membrane, the sub-pellicular microtubules, the flagellum, the kinetoplast-mitochondrion complex, the peroxisome (glycosome), the acidocalcisome and the structures and organelles involved in the endocytic pathway, is reviewed from a cell biology perspective. The possible use of available data for the development of new anti parasite drugs is also discussed.

No MeSH data available.


Related in: MedlinePlus