Seul-Ki Park

The effects of TiO2 nanoparticles on the protein expression in mouse lung

In this study, the differentially expressed proteins by titanium dioxide nanoparticles (TiO2 NPs) in mouse lung were examined via proteomic approach to better understand the molecular mechanism by which TiO2 NPs could induce toxicities at the protein level. We identified eight proteins that exhibited more than two-fold changes in expression by TiO2 NPs. Of these, five proteins, named cytoplasmic aconitase, L-lactate dehydrogenase A chain, carbonic anhydrase 1, pyruvate kinase isoform M2 and peroxiredoxin 6 displayed increased intensities in TiO2 NP-exposed lungs, while three proteins, named heat shock protein, moesin and apolipoprotein A-1 precursor, showed reduced intensities.

Proteomic profiling of hempseed proteins from Cheungsam

Proteomic profiling of hempseed proteins from a non-drug type of industrial hemp (Cannabis sativa L.), Cheungsam, was conducted using two-dimensional gel electrophoresis and mass spectrometry. A total of 1102 protein spots were resolved on pH 3-10 immobilized pH gradient strips, and 168 unique protein spots were identified. The proteins were categorized based on function, including involvement in energy regulation (23%), metabolism (18%), stress response (16%), unclassified (12%), cytoskeleton (11%), binding function (5%), and protein synthesis (3%). These proteins might have important biological functions in hempseed, such as germination, storage, or development.

Proteomic profiling of the differentially expressed proteins by TiO2 nanoparticles in mouse kidney

We investigated the proteins showing differential expression in response to TiO2 nanoparticles in mouse kidney using a proteomic approach to better understand the molecular mechanism by which TiO2 nanoparticles-induced nephrotoxicity at the protein level. More than 1,100 protein spots in mouse kidney were detected by the two-dimensional gel eletrophoresis and comparative analysis revealed that the expression of 11 proteins were changed by more than 2 fold in response to TiO2 nanoparticles. Of these, 10 were up-regulated and 1 was down-regulated upon treatment with TiO2 nanoparticles.

Electrolyzed-reduced water increases resistance to oxidative stress, fertility, and lifespan via insulin/IGF-1-like signal in C. elegans

Electrolyzed-reduced water (ERW) scavenges reactive oxygen species and is a powerful anti-oxidant. A positive correlation between oxidative stress and aging has been proved in many model organisms. In Caenorhabditis elegans, many long-lived mutants showed reduced fertility as a trade off against longevity phenotype. We aimed to study the effect of ERW on oxidative stress, fertility and lifespan of C. elegans. We also investigated the genetic pathway involved in the effect of ERW on resistance to oxidative stress and lifespan. We compared lifespan and fertility of worms in media prepared with distilled water and ERW. ERW significantly extended lifespan and increased the number of progeny produced. Then the effect of ERW on resistance to oxidative stress and lifespan of long-lived mutants was determined. ERW increased resistance to oxidative stress and lifespan of eat-2, a genetic model of dietary restriction, but had no effect on those of age-1, which is involved in insulin/insulin-like growth factor (IGF)-1-like signal. In addition, knockdown of daf-16, the downstream mediator of insulin/IGF-1-like signal, completely prevented the effect of ERW on lifespan. These findings suggest that ERW can extend lifespan without accompanying reduced fertility and modulate resistance to oxidative stress and lifespan via insulin/IGF-1-like signal in C. elegans.

Toxicoproteomic identification of TiO2 nanoparticle-induced protein expression changes in mouse brain

A proteomic analysis of the proteins in mouse brain that were differentially expressed in response to TiO2 nanoparticles was conducted to better understand the molecular mechanism of TiO2 nanoparticle-induced brain toxicity at the protein level. A total of 990 proteins from mouse brain were resolved by two-dimensional gel electrophoresis. A comparative proteomic analysis revealed that the expression levels of 11 proteins were changed by more than 2-fold in response to TiO2 nanoparticles: eight proteins were upregulated and three were downregulated by TiO2 nanoparticles. In addition, the activities of several antioxidative enzymes and acetylcholine esterase were reduced in TiO2 nanoparticle-exposed mouse brain. The protein profile alterations seem to be due to an indirect effect of TiO2 nanoparticles, because TiO2 nanoparticles were not detected in the brain in this investigation.

Electrolyzed-reduced water confers increased resistance to environmental stresses

Electrolysis of water produces reduced water at the cathode and oxidized water at the anode. Electrolyzed-reduced water (ERW) has an extremely negative oxidation-reduction potential. ERW scavenges cellular reactive oxygen species (ROS) and suppresses single-strand breaks of plasmid DNA in bacteria. Here, we examined the effect of ERW on resistance to oxidative stress both in vitro and in vivo. Oxidative DNA damage in human lymphocytes was significantly alleviated by ERW by reducing cellular ROS levels. Caenorhabditis elegans grown in media prepared with ERW had increased resistance to oxidative stress caused by paraquat. We observed a significant effect of ERW on response to other stressors, including heat shock and UV-irradiation in C. elegans. These data indicate that the powerful anti-oxidant activity of ERW is due to its radical-scavenging activity and show, for the first time, that ERW could increase thermotolerance and resistance to UV-irradiation. These results suggest that ERW aids resistance to various environmental stresses.

Proteomic analysis of hepatotoxicity induced by titanium nanoparticles in mouse liver

Differentially expressed proteins in mouse liver caused by toxicity of titanium nanoparticles (TiO2 NPs) were screened. More than 1,400 protein spots in mouse liver were detected by twodimensional gel electrophoresis, and 15 proteins that showed greater than 2-fold expressional changes in response to TiO2 NPs were identified by liquid chromatography-tandem mass spectrometry. Of these, 12 proteins were down-regulated and 3 proteins were up-regulated upon treatment with TiO2 NPs. The 15 differentially expressed proteins could be used for detection of inflammation, apoptosis, and antioxidative reaction for treatment of acute hepatic damage by TiO2 NPs.

Protein expression profiling in the liver of rats exposed to phenanthrene

Phenanthrene (PH) is a group of polycyclic aromatic hydrocarbons from various ambient sources. In this study, a proteomic approach was used to characterize protein expression profiling in rat livers exposed to phenanthrene. A 1.5-fold or greater change in the expression levels of ten proteins was observed after PH exposure. In response to a PH dose equivalent to 10% of the LD50, six proteins were upregulated and four were downregulated. At a PH dose equivalent to 50% of the LD50, upregulation of five proteins and downregulation of five proteins were found. Of these, validation of the differential expression of phenylalanine hydroxylase and glutathione S-transferase was performed by western blot, and the western blot results confirmed the proteomics-based expression levels.

Electrolyzed-reduced water mitigates amyloid beta toxicity via DAF-16 in C. elegans

Alzheimer’s disease is an age-related neurodegenerative disease. Extracellular aggregation of amyloid beta is a well-known hallmark of Alzheimer’s disease and believed to be critical for the development of Alzheimer’s disease. Lots of efforts have been put on finding an intervention alleviating amyloid beta toxicity. Electrolyzed-reduced water is generated near cathode by electrolysis of water and shown to have strong anti-oxidant and lifespan-extending activities in C. elegans. Here, we examined the effect of electrolyzed-reduced water on amyloid beta toxicity and investigated underlying cellular mechanism involved. Worms grown in media prepared with electrolyzedreduced water showed delayed amyloid beta-induced paralysis and age-related decline in motility. DAF-16, a FOXO transcription factor modulating insulin/IGF-1-like signal, is required for the protection against amyloid beta toxicity. These findings indicate that electrolyzed-reduced water can prevent amyloid beta toxicity via DAF-16 and suggest that electrolyzedreduced water could be utilized for the development of therapeutic intervention to Alzheimer’s disease.