EFFECT OF SUBLETHAL DOSES OF CADMIUM, INORGANIC MERCURY AND METHYLMERCURY ON THE CELL MORPHOLOGY OF AN INSECT CELL LINE (AEDES ALBOPICTUS, C6/36)

Abstract

The effect of CdCl2 (44 microM), HgCl2 (3.7 microM), and MeHgCl (2 microM) on the morphology of Aedes albopictus C6/36 cells was studied at the light microscopical level. Treatment times and metal concentrations were in the sublethal range as determined by a fluorometric dye exclusion test. The three metal species had profound effects on the cell morphology. MeHgCl treatment induced the development of a large number of short, actin-supported, tangled filopodia. Both CdCl2 and HgCl2 induced long extensions. Pretreatment with colchicine but not with cytochalasin B prevented formation of these extensions which suggests that they were supported by microtubules. This was confirmed by immunostaining for microtubules. The extensions were relatively stable towards colchicine post-treatment. To authors' knowledge, this effect has not yet been described for heavy metals. The similarity with 20-hydroxyecdysone-treated cells and the occurrence of cytoplasmic feet in insect cells is discussed.

Cadmium induced endothelial dysfunction: Consequence of defective migratory pattern of endothelial cells in association with poor nitric oxide availability under cadmium challenge

“…Further, we concluded that Cd induced dense peripheral bands along with the stress fibers to induce polarization in the cytoskeleton, which ultimately forms membrane extensions such as filopodia and lamellipodia. A light microscopy study by Braeckman et al (1997) revealed that a Cd-dose of 44 mM induced long extensions in Aedes albopictus C6/36 cells.…”

Are Neuropathological Conditions Relevant to Ethylmercury Exposure?

“…For example, MeHg is 6-40 times more toxic than inorganic mercury in PC12 pheochromocytoma cells, as measured by viability (Parran et al 2001(Parran et al , 2003. While inorganic mercury and MeHg show nearly equivalent ability to kill cells (as measured by lethal dose 50 , referred to as LD 50 values, which correspond to the concentrations required to kill 50% of the cells) for viability in a mosquito derived cell line, MeHg is approximately 20 times more effective than inorganic mercury in inhibition of proliferation in these cells (Braeckman et al 1997). In addition, MeHg is 10 times more potent than inorganic mercury in depressing nerve fiber growth in chick dorsal root ganglia explants (Miura et al 2000).…”

Endocrine disruption in aquatic insects: a review

“…It should be remarked that also other compounds can induce cellular elongations. Braeckman et al (1997) observed cell elongations after treatment of cadmium. Apart from androst-4-ene-3,17-dione, vertebrate steroids were inactive at concentrations up to 1.0 mM.…”