• The Korean Journal of Physiology and Pharmacology
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• 제23권6호
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• pp.519-528
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• 2019

Mitochondrial dysfunction is closely associated with reactive oxygen species (ROS) generation and oxidative stress in cells. On the other hand, modulation of the cellular antioxidant defense system by changes in the mitochondrial DNA (mtDNA) content is largely unknown. To determine the relationship between the cellular mtDNA content and defense system against oxidative stress, this study examined a set of myoblasts containing a depleted or reverted mtDNA content. A change in the cellular mtDNA content modulated the expression of antioxidant enzymes in myoblasts. In particular, the expression and activity of glutathione peroxidase (GPx) and catalase were inversely correlated with the mtDNA content in myoblasts. The depletion of mtDNA decreased both the reduced glutathione (GSH) and oxidized glutathione (GSSG) slightly, whereas the cellular redox status, as assessed by the GSH/GSSG ratio, was similar to that of the control. Interestingly, the steady-state level of the intracellular ROS, which depends on the reciprocal actions between ROS generation and detoxification, was reduced significantly and the lethality induced by $H_2O_2$ was alleviated by mtDNA depletion in myoblasts. Therefore, these results suggest that the ROS homeostasis and antioxidant enzymes are modulated by the cellular mtDNA content and that the increased expression and activity of GPx and catalase through the depletion of mtDNA are closely associated with an alleviation of the oxidative stress in myoblasts.

• Molecular & Cellular Toxicology
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• 제5권3호
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• pp.243-249
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• 2009

Melamine, which is used to produce melamine resin for various industrial applications, has a high nitrogen content by mass. For this reason, it has been illegally added to foods to increase their apparent protein content. In the present investigation, melamine-induced oxidative damage of human lymphocyte DNA was evaluated by Comet assay. The in vitro oxidative DNA damage caused by melamine increased in a dose-dependent manner. This DNA damage was significantly inhibited by treatment with ascorbate. Moreover, the traditional Korean medicinal herb, named Acanthopanax, red ginseng and green tea markedly reduced the DNA damage. Various edible plant extracts also inhibited melamine-induced oxidative DNA damage in vitro. Melamine enhanced intracellular ROS generation, and this effect was suppressed by treatment with various antioxidants.

• Fisheries and Aquatic Sciences
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• 제10권1호
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• pp.24-29
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• 2007

Our objective was to clarify the cytogenetic characteristics, including karyotypes, cellular DNA content, and nuclear size of erythrocytes, of black plaice Pleuronectes obscurus, dotted gizzard shad Konosirus punctatus, and perch sculpin Pseudoblennius percoides, collected from the coastal areas of Jo Island, Busan, Korea. Karyotypes of P. obscurus and K. punctatus both had a diploid number of 48 and a fundamental number (FN) of 48, with a chromosome formula of 48T. The karyotype of p. percoides had a diploid number of 46 and FN of 56, with a chromosome formula of 10SM +36T. No sex-associated heteromorphic pairs were detected for any species. The variation in DNA values (P. obscurus=1.15 pg/nucleus, K. punctatus=1.56pg/nucleus, P. percoides=1.11 pg/nucleus) was positively related to variation in chromosome FN.

• Food Science and Biotechnology
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• 제14권3호
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• pp.350-354
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• 2005

The effect of the essential oil obtained from Chrysanthemum boreale Makino on the apoptosis of KB cells was investigated. Cytotoxicity and cellular DNA content were analyzed by MTT assay, flow cytometry, agarose gel electrophoresis, and Hoechst 33258 staining. The caspase-3 and poly (ADP-ribose) polymerase (PARP) proteins were estimated by Western blotting method. The various cytotoxic effects of the essential oil which are hallmarks of apoptosis, including DNA fragmentation, apoptotic body formation, and sub-G1 DNA content, all progressed in a dose-dependent manner. Treatment with an apoptosis-inducing concentration of the essential oil caused rapid and transient induction of caspase 3 activity. Further, the efficacious induction of PARP cleavage and caspase-3 activation was observed at an essential oil concentration of 0.1 and 0.2 mg/mL for 12 hr.

• The Korean Journal of Physiology
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• 제25권1호
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• pp.81-85
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• 1991

At the fifth day after right lung pneumonectomy in New-Zealand white rabbits $(0.8{\sim}1.1\;kg\;B.W.)$, phospholipid and protein concentration in the left lung lavage fluid were measured for clarification of the effect of unilateral pneumonectomy on the secretory function of the type II pneumocytes in growing rabbits. In an attempt to evaluate the effect of unilateral pneumonectomy on the compensatory growth of the residual lung, left lung weight and left lung weight-body weight ratio and DNA concentration, RNA/DNA and total DNA content in the left lung tissue were measured in pneumonectomized and in sham operated control rabbits. The lung weight of pneumonectomized rabbit was approximately two times heavier than that of the control rabbits. DNA concentration and RNA/DNA of the lung tissue were not changed but total DNA content was increased significantly. Phospholipid concentration in the lung lavage fluid of the pneumonectomized rabbits was over two times higher than that of control rabbits. from these experimental results, It is concluded that unilateral pneumonectomy in growing rabbits might cause to increase the secretion of pulmonary surfactant from type II pneumocyte of the residual lung. The cellular hyperplasia seems to be the primary response of the compensatory growing lung in unilateral pneumonectomized growing rabbits.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.477-481
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• 2003

The community escape response of Rhodobacter sphaeroides is exerted through the action of CerR and CerI, which code for a LuxR-type regulatory protein and acylhomoserine lactone synthase, respectively. Deletion of chromosomal DNA including cerR and cerI (mutant RI) or insertional interruption of cert (mutant AP3) resulted in two-fold increase in the cellular poly-${\beta}$-hydroxybutyrate (PHB) content In comparison with the wild-type under aerobic growth conditions. The PHB synthase (PhbC) activities of the cer mutants were doubled, and the enzyme expression was regulated at the level of phbC transcription. Thus, CerR, possibly in response to autoinducer (AI), appears to modulate the PHB content of aerobically grown cells by downregulating phbC transcription.

• 대한치과보철학회지
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• 제30권2호
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• pp.247-257
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• 1992

The present study quantitates the in vitro cytotoxicity of a variety of denture base acrylic resins using cell culture techniques combined with image analysis to measure nuclear area and DNA contents. In this study, a comparison was made among direct curing, heat curing and microwave curing resins. The results obtained from this study were as follows : 1. Morphologically, cell process and nucleus became prominent but macroscopic difference according to the resins were nit observed. In addition, increased cellular density around the specimen were observed. 2. In DNA contents measurements, $S-G_2M$ phase cell was 15.47%, 14.58% in control and heat curing resin on 1st day and the others group $21.39\sim33.36%$ were measured. 3. Nuclear area and DNA contents were increased on 3rd day except DNA content of the microwave curing resin group. These results suggest that denture base acrylic resins stimulate gingival fibroblasts in vitro, especially stimulation of direct curing resin is larger and longer than the others.

• 한국수산과학회지
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• 제49권5호
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• pp.628-634
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• 2016

We investigated the characteristics and rate of development of allotriploid embryos derived from a cross between female olive flounder Paralichthys olivaceus and male starry flounder Platichthys stellatus. The allotriploidy was induced by cold shocking fertilized eggs three minutes post-fertilization at 3°C for 45 minutes. The average cellular DNA content of the allotriploid embryos was 2.06±0.03 pg/cell, which is equal to the sum of the cellular DNA content of a diploid olive flounder (1.42 pg/cell) and a haploid starry flounder (0.66 pg/haploid cell). The first cleavage, midblastula, gastrula and Kupffer's vesicle appearance stages of the allotriploid eggs began at 1.5, 8, 13 and 26 hours after cold shocking at 18°C, respectively. The developmental rate of allotriploid eggs was equivalent to that of diploid and triploid olive flounder eggs at 10, 14 and 18°C. However, the hatching times of allotriploid eggs, 7 h at 10°C, 5 h at 14°C and 4 h at 18°C, were earlier than those of diploid and triploid olive flounder.

• Molecules and Cells
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• 제27권4호
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• pp.391-396
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• 2009

Image-based, high-content screening assays demand solutions for image segmentation and cellular compartment encoding to track critical events - for example those reported by GFP fusions within mitosis, signalling pathways and protein translocations. To meet this need, a series of nuclear/cytoplasmic discriminating probes have been developed: DRAQ5$^{TM}$ and CyTRAK Orange$^{TM}$. These are spectrally compatible with GFP reporters offering new solutions in imaging and cytometry. At their most fundamental they provide a convenient fluorescent emission signature which is spectrally separated from the commonly used reporter proteins (e.g. eGFP, YFP, mRFP) and fluorescent tags such as Alexafluor 488, fluorescein and Cy2. Additionally, they do not excite in the UV and thus avoid the complications of compound UV-autofluorescence in drug discovery whilst limiting the impact of background sample autofluorescence. They provide a convenient means of stoichiometrically labelling cell nuclei in live cells without the aid of DMSO and can equally be used for fixed cells. Further developments have permitted the simultaneous and differential labelling of both nuclear and cytoplasmic compartments in live and fixed cells to clearly render the precise location of cell boundaries which may be beneficial for quantitative expression measurements, cell-cell interactions and most recently compound in vitro toxicology testing.

• 미생물학회지
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• 제7권1호
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• pp.10-21
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• 1969

The effect of glucose and 2-thiobarbituric acid on the biosynthesis of cell constituents such as protein, carbohydrate, DNA, RNA, phospholipid and PCA-soluble phosphate compounds in Chlorella duing the life cycle was measured, and the changes in the content of these main cellular components of the algal cell were analyzed in connection with the nuclear and cytoplasmic divison. In the normal autotrophic synchronous culture the contents of protein, RNA, and DNA in the cell showed a chracteristic changes according to the progress of cell development, increasing more or less throughout all the life cycle. The synthesis of protein is more prominent in the division period nad that of DNA is more active in the ripening period, while the synthesis of RNA is more rapid in the growing and ripening periods than other developmental stages. The period of division cycle was little affected by glucose in the medium, although the synchrony of the growth and cellular division was disturbed and the n value increased. The cotents of protein, carbohydrate, RNA nad DNA of the cell were increased by the glucose treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment. The synthesis of protein, carbohydrate, DNA, RNA and phospholipid of the cell was also retarded by 2-thiobarbituric acid. In the autotrophic, mixotrophic and 2-thiobarbituric acid-treated cultures, each having different mode cytoplasmic division, a common general schema occurring in the cell during the life cycle may be drawn as follows. The ratio of RNA to protein attains maximum value in the $L_1$-cell stage prior to the nuclear division and thereafter decreases during the periods of ripening and division. The ratio of PCA-soluble phosphate compounds to protein increased from the begining of the culture to $L_4$-cell stage successively and thereafter decreased gradually during the division period, while the ratio of protein to DNA kept almost constant up to the division period and thereafter increased during the division period. Therefore, it is presumed that the increase in the ratio of RNA to protein is to be an inducer of nuclear division and that the cytoplasmic division is induced by the increase in the ratio of protein to DNA.