The cytoskeleton of the electric tissue of Electrophorus electricus, L.

The electric eel Electrophorus electricus is a fresh water teleost showing an electrogenic tissue that produces electric discharges. This electrogenic tissue is distributed in three well-defined electric organs which may be found symmetrically along both sides of the eel. These electric organs develop from muscle and exhibit several biochemical properties and morphological features of the muscle sarcolema. This review examines the contribution of the cytoskeletal meshwork to the maintenance of the polarized organization of the electrocyte, the cell that contains all electric properties of each electric organ. The cytoskeletal filaments display an important role in the establishment and maintenance of the highly specialized membrane model system of the electrocyte. As a muscular tissue, these electric organs expresses actin and desmin. The studies that characterized these cytoskeletal proteins and their implications on the electrophysiology of the electric tissues are revisited

The cytoskeleton of the electric tissue of Electrophorus electricus, L.

The electric eel Electrophorus electricus is a fresh water teleost showing an electrogenic tissue that produces electric discharges. This electrogenic tissue is distributed in three well-defined electric organs which may be found symmetrically along both sides of the eel. These electric organs develop from muscle and exhibit several biochemical properties and morphological features of the muscle sarcolema. This review examines the contribution of the cytoskeletal meshwork to the maintenance of the polarized organization of the electrocyte, the cell that contains all electric properties of each electric organ. The cytoskeletal filaments display an important role in the establishment and maintenance of the highly specialized membrane model system of the electrocyte. As a muscular tissue, these electric organs expresses actin and desmin. The studies that characterized these cytoskeletal proteins and their implications on the electrophysiology of the electric tissues are revisited

Distribution of cytoskeletal and adhesion proteins in adult zebrafish skeletal muscle

Submitted by Martha Martínez Silveira ([email protected]) on 2015-03-31T17:15:54Z No. of bitstreams: 1 Camara E Distribution of cytoskeletal and...........pdf: 7670751 bytes, checksum: 2b5045d146bc45a665558b865be8cea7 (MD5)Approved for entry into archive by Martha Martínez Silveira ([email protected]) on 2015-03-31T17:28:08Z (GMT) No. of bitstreams: 1 Camara E Distribution of cytoskeletal and...........pdf: 7670751 bytes, checksum: 2b5045d146bc45a665558b865be8cea7 (MD5)Made available in DSpace on 2015-03-31T17:28:08Z (GMT). No. of bitstreams: 1 Camara E Distribution of cytoskeletal and...........pdf: 7670751 bytes, checksum: 2b5045d146bc45a665558b865be8cea7 (MD5) Previous issue date: 2009Universidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, BrasilUniversidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, BrasilUniversidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, BrasilUniversidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Rio de Janeiro, RJ, BrasilThe organization of cytoskeletal and adhesion proteins in skeletal muscle is critical for its contractile function. Zebrafish has become a paramount model for studies of vertebrate biology, including muscle. However, only a few studies have been published using immunolabeling to specifically localize proteins in adult zebrafish muscle. To fully appreciate the distribution of cytoskeletal and adhesion proteins, and therefore to better correlate the adult muscle with its myogenesis, we used indirect immunofluorescence microscopy of frozen adult zebrafish skeletal muscle sections. Here we describe the fish muscle cytoskeletal architecture and location of the major myofibrillar proteins desmin, alpha-actinin, myosin, titin, troponin, tropomyosin and nebulin, the adhesion proteins vinculin and paxillin, and the extracellular matrix proteins laminin and fibronectin. Electron microscopical analysis in ultra-thin sections of adult zebrafish skeletal muscle showed bundles of collagen fibers and fibroblastic cells in the extracellular space of the myosept

Discovery of Putative Dual Inhibitor of Tubulin and EGFR by Phenotypic Approach on LASSBio-1586 Homologs

Combretastatin A-4 (CA-4, 1) is an antimicrotubule agent used as a prototype for the design of several synthetic analogues with anti-tubulin activity, such as LASSBio-1586 (2). A series of branched and unbranched homologs of the lead-compound 2, and vinyl, ethinyl and benzyl analogues, were designed and synthesized. A comparison between the cytotoxic effect of these homologs and 2 on different human tumor cell lines was performed from a cell viability study using MTT with 48 h and 72 h incubations. In general, the compounds were less potent than CA-4, showing CC50 values ranging from 0.030 μM to 7.53 μM (MTT at 72 h) and 0.096 μM to 8.768 μM (MTT at 48 h). The antimitotic effect of the target compounds was demonstrated by cell cycle analysis through flow cytometry, and the cellular mechanism of cytotoxicity was determined by immunofluorescence. While the benzyl homolog 10 (LASSBio-2070) was shown to be a microtubule stabilizer, the lead-compound 2 (LASSBio-1586) and the methylated homolog 3 (LASSBio-1735) had microtubule destabilizing behavior. Molecular docking studies were performed on tubulin protein to investigate their binding mode on colchicine and taxane domain. Surprisingly, the benzyl homolog 10 was able to modulate EGFR phosphorylate activity in a phenotypic model. These data suggest LASSBio-2070 (10) as a putative dual inhibitor of tubulin and EGFR. Its binding mode with EGFR was determined by molecular docking and may be useful in lead-optimization initiatives

The Wnt signaling pathway regulates Nalm-16 b-cell precursor acute lymphoblastic leukemic cell line survival and etoposide resistance

10 p. : il.B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most common malignancy in children. The Wnt signaling pathway has been found to be extensively involved in cancer onset and progression but its role in BCP-ALL remains controversial.Weevaluate the role of the Wnt pathway in maintenance of BCP-ALL cells and resistance to chemotherapy. Gene expression profile revealed that BCP-ALL cells are potentially sensitive to modulation of Wnt pathway. Nalm-16 and Nalm-6 cell lines displayed low levels of canonical activation, as reflected by the virtually complete absence of total b-catenin in Nalm-6 and the b-catenin cell membrane distribution in Nalm-16 cell line. Canonical activation with Wnt3a induced nuclear b-catenin translocation and led to BCP-ALL cell death. Lithium chloride (LiCl) also induced a cytotoxic effect on leukemic cells. In contrast, both Wnt5a and Dkk-1 increased Nalm-16 cell survival. Also, Wnt3a enhanced the in vitro sensitivity of Nalm-16 to etoposide (VP-16) while treatment with canonical antagonists protected leukemic cells from chemotherapy-induced cell death. Overall, our results suggest that canonical activation of the Wnt pathway may exerts a tumor suppressive effect, thus its inhibition may support BCP-ALL cell survival