Mitochondrial damage will hinder the energy production of cells and produce excessive ROS (reactive oxygen species), resulting in cell death through autophagy or apoptosis. In this paper, four cyclometalated iridium(III) complexes (Ir1: [Ir(piq)2L]PF6; Ir2: [Ir(bzq)2L]PF6; Ir3: [Ir(dfppy)2L]PF6; Ir4: [Ir(thpy)2L]PF6; piq = 1-phenylisoquinoline; bzq = benzo[h]quinoline; dfppy = 2-(2,4-difluorophenyl)pyridine;thpy = 2-(2-thienyl)pyridine; L = 1,10-phenanthroline-5-amine) were synthesized and characterized. Cytotoxicity tests show that these complexes have excellent cytotoxicity to cancer cells, and mechanism studies indicatethat these complexes can specifically target mitochondria. Complexes Ir1 and Ir2 can damage the function of mitochondria, subsequently increasing intracellular levels of ROS, decreasing MMP (mitochondrial membrane potential), and interfering with ATP energy production, which leads to autophagy and apoptosis. Furthermore, autophagy induced by Ir1 and Ir2 can promote cell death in coordination with apoptosis. Surprisingly, these four complexes also showed moderate antibacterial activity to S. aureusand P. aeruginosa.
Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Coordination Complexes/pharmacology , Iridium/chemistry , Mitochondria/metabolism , A549 Cells , Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Movement/drug effects , Coordination Complexes/chemistry , Humans , Magnetic Resonance Spectroscopy/methods , Membrane Potential, Mitochondrial/drug effects , Pseudomonas aeruginosa/drug effects , Quinolines/chemistry , Reactive Oxygen Species/metabolism , Spectrometry, Mass, Electrospray Ionization/methods , Staphylococcus aureus/drug effects
As the "powerhouse" of a cell, mitochondria maintain energy homeostasis, synthesize ATP via oxidative phosphorylation, generate ROS signaling molecules, and modulate cell apoptosis. Herein, three Re(I) complexes bearing guanidinium derivatives have been synthesized and characterized. All of these complexes exhibit moderate anticancer activity in HepG2, HeLa, MCF-7, and A549 cancer cells. Mechanism studies indicate that complex 3, [Re(CO)3(L)(Im)](PF6)2, can selectively localize in the mitochondria and induce cancer cell death through mitochondria-associated pathways. In addition, complex 3 can effectively depress the ability of cell migration, cell invasion, and colony formation.
Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Guanidine/chemistry , Mitochondria/drug effects , Mitochondria/metabolism , Rhenium/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Humans , Ligands , Neoplasm Invasiveness , Structure-Activity Relationship
Quantitative evaluation on the vegetation recovery after the earthquake is of great scienti-fic significance for local ecological system rebuilding and regional social-economic sustainable deve-lopment. By taking the Longxi River Basin in Dujiangyan of Sichuan Province as an example, and employing the MODIS-NDVI time-series data, this paper illustrated the dynamic changes of the ve-getation cover rates in Longxi River basin before and after the 5.12 Wenchuan Earthquake by using Landsat data, and then time-space characters of the recovery rates of the damaged vegetation was quantified structurally by referring the factors of river-system and terrain. The results showed that the recovery of impaired vegetation coverage worked well from a holistic point of view, but the response of vegetation coverage to earthquake disaster showed a lagging-phenomenon. The recovery rate of damaged vegetation was significantly correlated to its distance to surrounding river systems, elevation, slope degree, and slope aspect. This finding could provide technical supports for decision-makers to intervene the recovering process after earthquake.
Earthquakes , Ecosystem , Plant Development , Plants , China , Disasters , Environmental Monitoring , Rivers , Spatio-Temporal Analysis
