Biological processing of dinuclear ruthenium complexes in eukaryotic cells

Li, Xin, Heimann, Kirsten, Dinh, Xuyen Thi, Keene, F. Richard, and Collins, J. Grant (2016) Biological processing of dinuclear ruthenium complexes in eukaryotic cells. Molecular BioSystems, 12. pp. 3032-3045.

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (4MB) | Preview
View at Publisher Website: http://dx.doi.org/10.1039/c6mb00431h
 
9


Abstract

The biological processing – mechanism of cellular uptake, effects on the cytoplasmic and mitochondrial membranes, intracellular sites of localisation and induction of reactive oxygen species – of two dinuclear polypyridylruthenium(II) complexes has been examined in three eukaryotic cells lines. Flow cytometry was used to determine the uptake of [{Ru(phen)2}2{mu-bb12}]4+ (Rubb12) and [Ru(phen)2(mu-bb7)Ru(tpy)Cl]3+ {Rubb7-Cl, where phen = 1,10-phenanthroline, tpy = 2,2':6',2''-terpyridine and bbn = bis[4(4'-methyl- 2,2'-bipyridyl)]-1,n-alkane} in baby hamster kidney (BHK), human embryonic kidney (HEK-293) and liver carcinoma (HepG2) cell lines. The results demonstrated that the major uptake mechanism for Rubb12 and Rubb7-Cl was active transport, although with a significant contribution from carrier-assisted diffusion for Rubb12 and passive diffusion for Rubb7-Cl. Flow cytometry coupled with Annexin V/TO-PRO-3 double-staining was used to compare cell death by membrane damage or apoptosis. Rubb12 induced significant direct membrane damage, particularly with HepG2 cells, while Rubb7-Cl caused considerably less membrane damage but induced greater levels of apoptosis. Confocal microscopy, coupled with JC-1 assays, demonstrated that Rubb12 depolarises the mitochondrial membrane, whereas Rubb7-Cl had a much smaller affect. Cellular localisation experiments indicated that Rubb12 did not accumulate in the mitochondria, whereas significant mitochondrial accumulation was observed for Rubb7-Cl. The effect of Rubb12 and Rubb7-Cl on intracellular superoxide dismutase activity showed that the ruthenium complexes could induce cell death via a reactive oxygen species-mediated pathway. The results of this study demonstrate that Rubb12 predominantly kills eukaryotic cells by damaging the cytoplasmic membrane. As this dinuclear ruthenium complex has been previously shown to exhibit greater toxicity towards bacteria than eukaryotic cells, the results of the present study suggest that metal-based cationic oligomers can achieve selective toxicity against bacteria, despite exhibiting a non-specific membrane damage mechanism of action.

Item ID: 44763
Item Type: Article (Refereed Research - C1)
Keywords: dinuclear poypyridylruthenium(II); cellular uptake; cell localisation; eukaryotic cells; confocal microscopy; flow cytometry; membrane damage
Additional Information:

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material. https://creativecommons.org/licenses/by/3.0/

Open Access through the Royal Society of Chemistry Gold for Gold Open Access.

ISSN: 1742-2051
Date Deposited: 25 Jul 2016 23:50
FoR Codes: 03 CHEMICAL SCIENCES > 0302 Inorganic Chemistry > 030201 Bioinorganic Chemistry @ 60%
06 BIOLOGICAL SCIENCES > 0601 Biochemistry and Cell Biology > 060103 Cell Development, Proliferation and Death @ 20%
11 MEDICAL AND HEALTH SCIENCES > 1101 Medical Biochemistry and Metabolomics > 110103 Medical Biochemistry: Inorganic Elements and Compounds @ 20%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970103 Expanding Knowledge in the Chemical Sciences @ 60%
97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 20%
97 EXPANDING KNOWLEDGE > 970111 Expanding Knowledge in the Medical and Health Sciences @ 20%
Downloads: Total: 9
Last 12 Months: 4
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page