Effect of drugs affecting microtubular assembly on microtubules, phospholipid synthesis and physiological indices (signalling, growth, motility and phagocytosis) inTetrahymena pyriformis

Abstract

Structural changes of microtubules, incorporation of radioactively labelled components into phospholipids, cell motility, growth and phagocytosis were studied under the effect of four drugs affecting microtubular assembly: colchicine, nocodazole, vinblastine and taxol. Although the first three agents influence microtubules in the direction of depolymerization and the fourth stabilizes them, their effects on the structure of microtubules cannot be explained by this. Using confocal microscopy after an acetylated anti-tubulin label, in nocodazole- and colchicine-treated cells, the basal body cages disappear and longitudinal microtubules (LM) became thinner without changing transversal microtubules (TM). After taxol treatment LM also became thinner, however TM disappeared. Under the effect of vinblastine TM became thinner, without influencing LM. These drugs influence the incorporation of components ([(3)H]-serine, [(3)H]-palmitic acid and (32)P) into phospholipids, however their effect is equivocal and cannot be consequently coupled with the effect on the microtubules. Nocodazole, vinblastine and taxol significantly reduced the cell's motility, however colchicine did so to a lesser degree. Vinblastine and nocodazole totally inhibited, and taxol significantly decreased cell growth, while colchicine in a lower concentration increased the multiplication of cells. Phagocytosis was not significantly influenced after 1 min, but after 5 min all the agents studied (except colchicine) significantly inhibited phagocytosis. After 15 and 30 min each molecule caused highly significant inhibition. The experiments demonstrate that drugs affecting microtubular assembly dynamics influence differently the diverse (longitudinal, transversal etc.) microtubular systems of Tetrahymena and also differently influence microtubule-dependent physiological processes. The latter are more dependent on microtubular dynamics than are changes in phospholipid signalling.

A Simple Microscopy Assay to Teach the Processes of Phagocytosis and Exocytosis

“…Previous studies have shown that microtubules in Tetrahymena are present at the cytoproct, the site of egestion, although their function is poorly defined (Allen and Wolf, 1974, 1979; Kovacs and Csaba, 2006; Sugita et al , 2009). Our data suggest that while egestion was slower with colchicine (time did not have a significant effect, p = 0.3554) than without ( p = 0.0063), there was no significant difference in the rates ( p = 0.4840) (Figure 4).…”

Effects of taxol treatment on the microtubular system and mitochondria of Tetrahymena

“…It was demonstrated in our previous experiments that two types of cytoplasmic microtubule bands (longitudinal and transversal) react differently to drugs affecting microtubular structures (Kovács and Pintér, 2001;Kovács and Csaba, 2005a). E.g.…”

“…In our previous experiments we obtained data on the connection of microtubular and signaling systems in Tetrahymena (Kovács and Pintér, 2001;Kovács et al, 2000), and on the effect of drugs affecting microtubular assembly to different kinds of microtubules in this unicellular organism (Kovács and Csaba, 2005a). The aim of the present study is to obtain additional data: 1./ on the alterations of different microtubular structures of Tetrahymena; 2./ on the alteration of posttranslational modification (e.g.…”

Assessment of microtubule depolymerization property of flavonoids isolated from Tanacetum gracile in breast cancer cells by biochemical and molecular docking approach

“…Microtubules are critical elements for a variety of fundamental cellular functions, including formation and maintenance of cell shape, transportation of vesicles and protein complexes, and regulation of motility and cell division [15]. Most of the anti-microtubule agents e.g., nocodazole, vinorelbine, colchicine and paclitaxel first bind with microtubules; thereby deregulate microtubule dynamics, activate mitotic spindle checkpoint and induces cell apoptosis [16][17][18]. It has been confirmed that suppression of microtubule dynamics and interference of microtubule polymerization or depolymerization, is an effective tool to block mitosis and kill tumor cells [19,20].…”