RESUMEN
Microorganisms can support environmental restoration by biodegradation of hydrocarbons but the mechanism of this process has been not described in detail yet. We present the effect of benzene derivatives on Raoultella ornithinolytica M03 cell composition. Comparison of the cell response after short-term and long-term stress revealed significant differences in surface properties, fatty acid composition and proteins profile. R. ornithinolytica M03 after long-term stress was characterized by lower cell surface hydrophobicity and much higher inner membrane permeability. Also decrease in the content of branched and unsaturated fatty acids was observed. Cells after short- and long-term stress were characterized by analyses of changes related to thirty-nine proteins participating in various metabolic pathways. The presence of benzene derivatives resulted in modifications in the abundance of proteins involved in determination of cell shape and ability to ion transport, lipid biosynthesis, amino-acid biosynthesis, tRNA ligases, chaperone and TCA cycle proteins, gluconeogenesis, transcription and nucleotide synthesis. Uptake and transport associated proteins, cell properties and membrane stability were also found to differ in the cells after short- and long-term stress suggesting the use of different mechanisms for transport and biodegradation of benzene derivatives and modification of cell response depending on the length of exposure to the stressor. BIOLOGICAL SIGNIFICANCE: This is the first comprehensive study whose results may contribute to a better understanding of the changes occurring during short- and long-term contact with benzene derivatives. After long term stress R. ornithinolytica M03 was characterized by lower cell surface hydrophobicity and much higher inner membrane permeability and decrease in the content of branched and unsaturated fatty acids. We identified changes related to multiple proteins engaged in various metabolic pathways such as biogenesis of cell membrane/wall, amino-acid biosynthesis, nucleotide and protein synthesis, gluconeogenesis and tRNA ligases. Changes in proteins participating in uptake and transport associated proteins, cell properties and membrane stability indicate modifications in transport and biodegradation of benzene derivatives, connected with the length of exposure to the stressor. The provided results seem to constitute an important aspect of remediation techniques.
Asunto(s)
Proteínas Bacterianas/metabolismo , Derivados del Benceno/metabolismo , Enterobacteriaceae/metabolismo , Ácidos Grasos/metabolismo , Biodegradación AmbientalRESUMEN
BACKGROUND AND PURPOSE: Parkinson's disease (PD) is usually diagnosed clinically from classical motor symptoms, while definitive diagnosis is made postmortem, based on the presence of Lewy bodies and nigral neuron cell loss. α-Synuclein (ASYN), the main protein component of Lewy bodies, clearly plays a role in the neurodegeneration that characterizes PD. Additionally, mutation in the SNCA gene or copy number variations are associated with some forms of familial PD. Here, the objective of the study was to evaluate whether olesoxime, a promising neuroprotective drug can prevent ASYN-mediated neurotoxicity. EXPERIMENTAL APPROACH: We used here a novel, mechanistically approachable and attractive cellular model based on the inducible overexpression of human wild-type ASYN in neuronally differentiated human neuroblastoma (SHSY-5Y) cells. This model demonstrates gradual cellular degeneration, coinciding temporally with the appearance of soluble and membrane-bound ASYN oligomers and cell death combining both apoptotic and non-apoptotic pathways. KEY RESULTS: Olesoxime fully protected differentiated SHSY-5Y cells from cell death, neurite retraction and cytoplasmic shrinkage induced by moderate ASYN overexpression. This protection was associated with a reduction in cytochrome c release from mitochondria and caspase-9 activation suggesting that olesoxime prevented ASYN toxicity by preserving mitochondrial integrity and function. In addition, olesoxime displayed neurotrophic effects on neuronally differentiated SHSY-5Y cells, independent of ASYN expression, by promoting their differentiation. CONCLUSIONS AND IMPLICATIONS: Because ASYN is a common underlying factor in many cases of PD, olesoxime could be a promising therapy to slow neurodegeneration in PD.