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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

Freeze-fracture view of an epimastigote form of T. cruzi. The nuclear pores are evident.
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Figure 8: Freeze-fracture view of an epimastigote form of T. cruzi. The nuclear pores are evident.

Mentions: In trypomastigotes of T. cruzi, the nucleus is elongate and localized in the central portion of the cell. In spheromastigotes and epimastigotes it has a rounded shape. It has a typical nuclear membrane studded with pores (Fig. 8). Continuity between the outer nuclear membrane and the endoplasmic reticulum is evident. In favorable freeze-fracture preparations, large areas of the inner and the outer nuclear membranes are exposed. In the convex as well as in the concave faces of both membranes, intramembranous particles are randomly distributed. The nuclear pores, as seen in freeze-fracture replicas, have a mean diameter of 80 nm. In interphasic T. cruzi cells, the chromatic material agglomerates into masses at the periphery of the nucleus, below its inner membrane. Occasionally, these masses are also found in the more central region. The chromosomes are difficult to distinguish, because they do not condense at any stage of the life cycle. However, with the advent of the pulsed field electrophoresis, chromosomes have been identified. The genome of T. cruzi consists of 87 MB of DNA distributed among 30–40 chromosomal bands ranging from 0.45 to 4.0 (See ). In the center of the nucleus, or situated slightly eccentrically, the nucleolus may be found. During division, changes occur in the organization of the nuclear material. The nucleolus is dispersed during division, reappearing at the final phases of the cell division. At the beginning of the division process of T. cruzi, when the basal body is replicating, the first signs of division can be observed in the nucleus. The chromatin material localized below the inner nuclear membrane and the nucleolus disappear. Both are dispersed over the whole nucleus giving it a homogeneous aspect. Immediately after replication of the basal body, when the kinetoplast shows no morphological signs of division, microtubules appear inside the nucleus of trypanosomatids [36,37]. The nucleus, which has a spherical form, changes into a more oval one with the major axis perpendicular to the direction of the flagellum. Shortly thereafter, kinetoplast divides, the two newly formed structures move to the sides, and the nucleus becomes progressively elongated.


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

De Souza W - Kinetoplastid Biol Dis (2002)

Freeze-fracture view of an epimastigote form of T. cruzi. The nuclear pores are evident.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 8: Freeze-fracture view of an epimastigote form of T. cruzi. The nuclear pores are evident.
Mentions: In trypomastigotes of T. cruzi, the nucleus is elongate and localized in the central portion of the cell. In spheromastigotes and epimastigotes it has a rounded shape. It has a typical nuclear membrane studded with pores (Fig. 8). Continuity between the outer nuclear membrane and the endoplasmic reticulum is evident. In favorable freeze-fracture preparations, large areas of the inner and the outer nuclear membranes are exposed. In the convex as well as in the concave faces of both membranes, intramembranous particles are randomly distributed. The nuclear pores, as seen in freeze-fracture replicas, have a mean diameter of 80 nm. In interphasic T. cruzi cells, the chromatic material agglomerates into masses at the periphery of the nucleus, below its inner membrane. Occasionally, these masses are also found in the more central region. The chromosomes are difficult to distinguish, because they do not condense at any stage of the life cycle. However, with the advent of the pulsed field electrophoresis, chromosomes have been identified. The genome of T. cruzi consists of 87 MB of DNA distributed among 30–40 chromosomal bands ranging from 0.45 to 4.0 (See ). In the center of the nucleus, or situated slightly eccentrically, the nucleolus may be found. During division, changes occur in the organization of the nuclear material. The nucleolus is dispersed during division, reappearing at the final phases of the cell division. At the beginning of the division process of T. cruzi, when the basal body is replicating, the first signs of division can be observed in the nucleus. The chromatin material localized below the inner nuclear membrane and the nucleolus disappear. Both are dispersed over the whole nucleus giving it a homogeneous aspect. Immediately after replication of the basal body, when the kinetoplast shows no morphological signs of division, microtubules appear inside the nucleus of trypanosomatids [36,37]. The nucleus, which has a spherical form, changes into a more oval one with the major axis perpendicular to the direction of the flagellum. Shortly thereafter, kinetoplast divides, the two newly formed structures move to the sides, and the nucleus becomes progressively elongated.

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