• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.32-39
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• 2005

Polycyclic aromatic hydrocarbons (PAHs) are an important class of environmentally prevalent xenobiotics that exert complex effects on the biological system and characterized as probably carcinogenic materials. Single cell gel electrophoresis assays were performed in order to evaluate DNA damage occurring in the T-and B lymphocytes, spleens (T/B-cell), bone marrow, and livers of mouse exposed to mixture of PAHs (Benzo(a)pyrene, Benzo(e)pyrene, Fluoranthene, Pyrene) at dose of 400, 800, or 1600 mg/kg body weight for 2 days. DNA damage of the cells purified from mice was increased in dose dependent manner. In the blood cells and organs, DNA damage was also discovered to vary directly with PAHs. Especially T-cells had been damaged more than B-cell. Plasma proteomes were separated by 2-dimensional electrophoresis with pH 4-7 ranges of IPG Dry strips and many proteins showed significant up-and -down expressions with the dose dependent manner. Of these, significant 4 spots were identified using matrix-assisted laser desorption/ionization-time of fight (MALDI-TOF) mass spectrometry. Identified proteins were related to energy metabolism and signal transduction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.423-432
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• 1996

To investigate the effect of food habits on the bone state of the senior citizens, two groups were tested: one(111 senior citizens) was healthy ordinary senior citizens over 65 years old and the other(51 senior citizens) was patients distinguished as having osteoporosis. The present dietary intake was estimated by a 24-hr recall method, and individual history. For the data analysis, percentages and frequencies were calculated and χ²-test was undertaken to test the relation among values. The following results were obtained: patient group with osteoporosis was less in height and weight than the group of ordinary senior citizens(160.33cm, 59.99kg). It was much less than the average Korean senior citizens(158cm, 54.9kg). Food appetite in the group of patient was worse than that of ordinary senior citizens group. According to their dietary history(58.8%), the food intake pattern was most of vegetables(62.0%). Eventhough they haven't been intaken milk after recognizing of their osteoporosis(74.5%). Most of them didn't improve their food habits to help Ca metabolism. Also they have depress of their life(50%). All subjects certainly took insufficient energy, Ca, protein from their diets. Moreover the major source of Ca were vegetables, seaweeds and legumes.

• Journal of Photoscience
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• v.1 no.1
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• pp.9-14
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• 1994

Exposure of isolated intact mitochondria to near UV to visible light resulted in not only loss of respiration, the most well-documented phenomenon regarding phototoxic effects in the respiring organelles, but also lipid peroxidation of membranes and mitochondrial swelling; these turned out to be O$_2$-dependent and thus prevented by anaerobiosis, enhanced by a partial deuteration of the suspension medium, and suppressed by the presence of a singlet oxygen ($^1O_2$) scavenger. Measurements of the spectral dependence of such detrimental effects of light on mitochondrial structure and function revealed that all the resulting spectra bear a significant resemblance to the action spectrum for photogeneration of $^1O_2$ from mitochondrial membranes, which in turn carries the spectral characteristics of light absorption by mitochondrial Fe-S centers. Futhermore, destructing the Fe-S centers by a mercurial treatment of mitochondria brought about a striking reduction of the light-induced membrane peroxidation and swelling of mitochondria. These results are consistent with the suggestion that the impairment of functional, structural integrity of mitochondria caused by strong irradiation is directly related to the production of $^1O_2$ in mitochondria, photosensitized by the Fe-S centers. This paper also presents kinetic data which indicate that, among various membrane-bound protein systems associated with mitochondrial energy metabolism, the respiratory chain is the primary target for photodamage.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.1048-1060
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• 2005

Dietary acidifiers appear to be a possible alternative to feed antibiotics in order to improve performance of weaning pigs. It is generally known that dietary acidifiers lower gastric pH, resulting in increased activity of proteolytic enzymes, improved protein digestibility and inhibiting the proliferation of pathogenic bacteria in GI tract. It is also hypothesized that acidifiers could be related to reduction of gastric emptying rate, energy source in intestine, chelation of minerals, stimulation of digestive enzymes and intermediate metabolism. However, the exact mode of action still remains questionable. Organic acidifiers have been widely used for weaning pigs' diets for decades and most common organic acidifiers contain fumaric, citric, formic and/or lactic acid. Many researchers have observed that dietary acidifier supplementation improved growth performance and health status in weaning pigs. Recently inorganic acidifiers as well as organic acidifiers have drawn much attention due to improving performance of weaning pigs with a low cost. Several researchers introduced the use of salt form of acidifiers because of convenient application and better effects than pure state acids. However, considerable variations in results of acidifier supplementation have been reported in response of weaning pigs. The inconsistent responses to dietary acidifiers could be explained by feed palatability, sources and composition of diet, supplementation level of acidifier and age of animals.

• Journal of Microbiology
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• v.42 no.3
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• pp.174-180
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• 2004

A halophilic bacterium was isolated from fermented seafood. The 16S rDNA sequence identity between the isolate and Halomonas subglaciescola AJ306801 was above 95％. The isolate that did not grow in the condition without NaCl or in the condition with other sodium (Na$\^$+/) or chloride ions (Cl$\^$-/) instead of NaCl was named H. subglaciescola DH-l. Two mutants capable of growing without NaCl were obtained by random mutagenesis, of which their total soluble protein profiles were compared with those of the wild type by two-dimensional electrophoresis. The external compatible solutes (betaine and choline) and cell extract of the wild type did not function as osmoprotectants, and these parameters within the mutants did not enhance their growth in the saline environment. In the proton translocation test, rapid acidification of the reactant was not detected for the wild type, but it was detected for the mutant in the condition without NaCl. From these results, we derived the hypothesis that NaCl may be absolutely required for the energy metabolism of H. subglaciescola DH-l but not for its osmoregulation, and the mutants may have another modified proton translocation system that is independent of NaCl, except for those mutants with an NaCl-dependent system.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1245-1251
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• 2008

Oxalate decarboxylases (OXDCs) (E.C. 4.1.1.2) are enzymes catalyzing the conversion of oxalate to formate and $CO_2$. The OXDCs found in fungi and bacteria belong to a functionally diverse protein superfamily known as the cupins. Fungi-originated OXDCs are secretory enzymes. However, most bacterial OXDCs are localized in the cytosol, and may be involved in energy metabolism. In Agrobacterium tumefaciens C58, a locus for a putative oxalate decarboxylase is present. In the study reported here, an enzyme was overexpressed in Escherichia coli and showed oxalate decarboxylase activity. Computational analysis revealed the A. tumefaciens C58 OXDC contains a signal peptide mediating translocation of the enzyme into the periplasm that was supported by expression of signal-peptideless and full-length versions of the enzyme in A. tumefaciens C58. Further site-directed mutagenesis experiment demonstrated that the A. tumefaciens C58 OXDC is most likely translocated by a twin-arginine translocation (TAT) system.

• Korean Journal of Microbiology
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• v.20 no.4
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• pp.161-172
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• 1982

In order to compare the metabolic activities of methanol utilizing bacteria, Pseudomonas sp. grown in different carbon sources, changes in respiratory activities, prinicipal enzyme activities for the energy metabolism, and the macromolecular compositions of the cells grown on methanol or glucose were measured. 1. The respiratory activity of cells grown on methanol was higher than that of cells grown on glucose, while glucose exhibited the highest $O_2-consumption$ rate among the different respiratory substrates. 2. TRhe activity of hydroxy pyruvate reductase which participates in serine pathway was high in the cells grown on methanol. However, activities of NAD-linked alcohol dehydrogenase, formaldehyde dehydrogenase and formate dehydrogenase were slightly lower in the cells grown on glucose thant on methanol. 4. For succinic dehydrogenase and malic dehydrogenase which take part in TCA cycle, the specific activities were higher in the cells grown on methanol than in those grown on glucose. No activity of glucose-6-phosphate dehydrogenase, which participates in pentose monophosphate shunt, was detectable in the cells grown on either carbon sources. 5. Protein contents of the cells grown on methanol increased relatively compared with those of the cells grown on glucose. However, there are no changes in the contents of carbohydrate and nucleic acid.

• BMB Reports
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• v.56 no.12
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• pp.651-656
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• 2023

Senescence, a cellular process through which damaged or dysfunctional cells suppress the cell cycle, contributes to aging or age-related functional decline. Cell metabolism has been closely correlated with aging processes, and it has been widely recognized that metabolic changes underlie the cellular alterations that occur with aging. Here, we report that fatty acid oxidation (FAO) serves as a critical regulator of cellular senescence and uncover the underlying mechanism by which FAO inhibition induces senescence. Pharmacological or genetic ablation of FAO results in a p53-dependent induction of cellular senescence in human fibroblasts, whereas enhancing FAO suppresses replicative senescence. We found that FAO inhibition promotes cellular senescence through acetyl-CoA, independent of energy depletion. Mechanistically, increased formation of autophagosomes following FAO inhibition leads to a reduction in SIRT1 protein levels, thereby contributing to senescence induction. Finally, we found that inhibition of autophagy or enforced expression of SIRT1 can rescue the induction of senescence as a result of FAO inhibition. Collectively, our study reveals a distinctive role for the FAO-autophagy-SIRT1 axis in the regulation of cellular senescence.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.187-195
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• 2020

To understand the molecular mechanism involved in the survivability of cold-tolerant lactic acid bacteria was of great significance in food processing, since these bacteria play a key role in a variety of low-temperature fermented foods. In this study, the cold-stress response of probiotic Lactobacillus plantarum K25 isolated from Tibetan kefir grains was analyzed by iTRAQ proteomic method. By comparing differentially expressed (DE) protein profiles of the strain incubated at 10℃ and 37℃, 506 DE proteins were identified. The DE proteins involved in carbohydrate, amino acid and fatty acid biosynthesis and metabolism were significantly down-regulated, leading to a specific energy conservation survival mode. The DE proteins related to DNA repair, transcription and translation were up-regulated, implicating change of gene expression and more protein biosynthesis needed in response to cold stress. In addition, two-component system, quorum sensing and ABC (ATP-binding cassette) transporters also participated in cell cold-adaptation process. These findings provide novel insight into the cold-resistance mechanism in L. plantarum with potential application in low temperature fermented or preserved foods.

• Molecules and Cells
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• v.28 no.3
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• pp.175-181
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• 2009

In hypertriglyceridaemic individuals, atherosclerogenesis is associated with the increased concentrations of very low density lipoprotein (VLDL) and VLDL-associated remnant particles. In vitro studies have suggested that VLDL induces foam cells formation. To reveal the changes of the proteins expression in the process of foam cells formation induced by VLDL, we performed a proteomic analysis of the foam cells based on the stimulation of differentiated THP-1 cells with VLDL. Using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, 14 differentially expressed proteins, containing 8 up-regulated proteins and 6 down-regulated proteins were identified. The proteins are involved in energy metabolism, oxidative stress, cell growth, differentiation and apoptosis, such as adipose differentiation-related protein (ADRP), enolase, S100A11, heat shock protein 27 and so on. In addition, the expression of some selected proteins was confirmed by Western blot and RT-PCR analysis. The results suggest that VLDL not only induces lipid accumulation, but also brings about foam cells diverse characteristics by altering the expression of various proteins.