• Biomedical Science Letters
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• v.12 no.4
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• pp.349-354
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• 2006

Induction of apoptosis allows the organism to get rid of abnormal cells and also of tumor cells. Understanding the mechanism involved in Ultraviolet radiation (UV) induced apoptosis may improve its therapeutic efficacy. In this study, we present expression of poly (ADP-ribose) polymerase (PARP) during apoptosis induced by UV in HeLa $S_3$ cells. Four different assays were performed in this study: morphological assessment of apoptotic cells and cell viability, DNA fragmentation analysis by agarose gel electrophoresis, quantitative assay of fragmented DNA, and expression of PARP by the western blot analysis. The percentages of apoptotic HeLa $S_3$ cells irradiated with $75J/m^2$ UV was increased continuously from 3 hrs incubation. DNA ladder pattern was appeared at 6 hrs. The amount of nucleosomal DNA fragments in cells treated UV increased from 3 to 12 hrs incubation and gradually decreased. The cleavage of PARP in HeLa $S_3$ cells irradiated with UV was induced, and the cleavage of PARP was more delayed in the cells pretreated with $5J/m^2$ UV and subsequently irradiated with $75J/m^2$ UV. than that in the cells only irradiated with $75J/m^2$ UV. Thus these data suggest that the cleavage of PARP relates with DNA fragmentation associated with apoptosis.

• Journal of Photoscience
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• v.7 no.2
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• pp.53-58
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• 2000

We performed the cloning of a chalcone synthase (CHS) gene, the key enzyme in the anthocyanin biosynthesis, from the cDNA library constructed with grape suspension cells irradiated UV-B. The PCR fragment was used to cloning the CHS gene. One CHS cDNA clone containing an open reading frame and a partial stilbene synthase (STS)cDNA, the stilbene-type phytoalexin, were isolated. The CHS cDNA clone (VCHS) showed 87% sequence homology with VvCHS (V.vinifea) and 72.3% identity with VSTSY(V.vinifea). its amino acid sequences were longer than any other CHS genes as 454 residues. Two genes were weakly expressed in white light irradiated cells, but highly induced in UV-B irradiated condition during 32 hours. Interestingly, the STS was quickly and abundantly expressed from 2 hours when supplemented with jasmonic acid (JA) and the maximum expression was observed at 4 hours and then gradually decreased. But, the additional UV-B or white light quickly degraded the STS expression than only JA treated grape suspension cells. The CHS also was rapidly induced with JA and the synergistical effect was observed at the addigional light treatment of UV-B or white light. These results are indicated that CHS and STS have different response mechanisms against the environmental stresses.

• Journal of Radiation Protection and Research
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• v.20 no.2
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• pp.71-78
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• 1995

To develop methods to reduce radiation risk and apply such knowledge to improvement of radiation protection, the effects of cobaltous chloride known as bioantimutagen on the function of E. coli RecA protein involved in the repair of DNA damage were examined. The results demonstrated two distinct effects of cobaltous chloride on the RecA protein function necessary for the strand exchange reaction. Cobaltous chloride enhanced the ability of RecA protein to displace SSB protein from single-stranded DNA and the duplex DNA-dependent ATPase activity. RecA protein was preferentially bound with UV-irradiated supercoiled DNA as compared with nonirradiated DNA The binding of RecA protein to UV-irradiated supercoiled DNA was enhanced in a dose-dependent manner. It is likely that studies on the factors affecting repair efficiency and the DNA repair proteins may provide information on the repair of ionizing radiation-induced DNA damage and the mechanism for DNA radioprotection.

• Journal of Photoscience
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• v.9 no.2
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• pp.186-189
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• 2002

Many of the adverse effects of solar UV exposure appear to be directly attributable to damage to epidermal DNA. In particular, cyclobutane pyrimidine dimers (CPD) may initiate mutagenic changes as well as induce signal transduction responses that lead to a loss of skin immune surveillance and micro-destruction of skin structure. Our approach is to reverse the DNA damage using prokaryotic DNA repair enzymes delivered into skin using specially engineered liposomes. T4 endonuclease V encapsulated in liposomes (T4N5 liposome lotion) enhanced DNA repair by shifting repair of CPD from the nucleotide excision to the base excision repair pathway. Following topical application to humans, increased repair limited UV-induction of cytokines, many of which are immunosuppressive. In a recent clinical study, topical treatment of UV-irradiated human skin with T4N5 liposome lotion reduced the suppression of the nickel sulfate contact hypersensitivity response. Similarly, the photoreactivating enzyme enhances repair by directly reversing CPDs after absorbing activating light. Here also treatment of UV-irradiated human skin with photoreactivating enzyme in liposomes and photoreactivating light restored the response to the contact allergen nickel sulfate. These findings confirm in humans the observation in mice that UV induced suppression of contact hypersensitivity is caused in part by CPDs. We have tested the ability of T4N5 liposome lotion to prevent UV-induced skin cancer in patients with xeroderma pigmentosum (XP), who have an elevated incidence of skin cancer resulting from a genetic defect in DNA repair. Daily use of the lotion for one year in a group of 20 XP patients reduced the average number of actinic keratoses by 68% and basal cell cancers by 30% compared to 9 patients in the placebo control group. Delivery of DNA repair enzymes to skin is a promising new approach to photoprotection.

• Journal of Photoscience
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• v.9 no.2
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• pp.482-484
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• 2002

UV irradiation activates various intracellular signaling pathways causing cell death in a DNA damage-dependent and an independent manner. As DNA photoproducts, major forms of DNA damage, are maximally formed by UV light at 260-nm, short wavelength UV (UVC) is more harmful than middle wavelength UV (UVB). However, the differences or similarities in responses of DNA damage-independent intracellular signaling molecules to UVB and UVC are not elucidated. We examined activation of signaling molecules towards apoptosis in normal human fibroblastic cells after irradiation with UVB or UVC at a dose generating the equal amount of DNA photoproducts. Both UVB and UVC induced transient phosphorylation of ERK and sustained phosphorylation of p38. Phosphorylation of p53 at Ser15 and at Ser392 residues were also observed, which were inhibited by a phosphoinositide 3-kinase inhibitor, wortmannin. In contrast, an antioxidant N-acetyl-cysteine and a p38 inhibitor SB203580 suppressed only Ser392 phosphorylation, suggesting that UV-induced oxidative stress and p38 activation were involved in the phosphorylation of this site. The apoptic signals such as mitochondrial cytochrome C release and annexin V binding were then observed. Overall, no difference was found in chronological responses of p53, MAPK, and apoptosis between UVB-irradiated and UVC-irradiated cells. These results suggested that DNA damage-independent intracellular signaling molecules similarly responded to UVB and UVC when the equal level of DNA photoproducts were generated.

• Archives of Pharmacal Research
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• v.11 no.3
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• pp.225-229
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• 1988

A ginseng protein fraction which has been reported to have radiation protective effect was purified from Korean ginseng and its effects on relative survival and chromosome aberration were studied in UV irradiated CHO-K1 cells. When the protein fraction $(100\;{\mu}g/ml)$ was added to the cells before UV irradiation at 4\;J/$m^2$,, the survival rates were increased to 53.8% from 40.6% in control. Addition of the protein $(100\;{\mu}g/ml)$ after UV irradiation at 4 and $8\;J/m^2$ raised the rates to 85.4 and 24.0% from 79.2 and 11.5% in control, respectively. When the ginseng protein $(800\;{\mu}g/ml)$ was added to the cells exposed to UV light at 10, 20, $30\;J/m^2$, the frequencies of chromosome aberration (CA) were reduced significantly to almost same level regardless of the UV dose increment and there was no significant difference between pre- and post-treatment. When the concentration of ginseng protein was increased from 200 to $800\;{\mu}g/ml$, at UV dose of 10, 20, $30\;J/m^2$ each, the CA frequencies were decreased consistently as the dose of ginseng protein increased, at all UV doses tested. Similar effects were observed in both cases of pre- and post-treatment. The data suggest that the protein may reduce cell damage caused by UV light, especially damage to DNA molecule, or play a role in repair processes of damaged DNA, to increase cell survival and reduce chromosome aberrations.

• Journal of Photoscience
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• v.9 no.2
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• pp.182-185
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• 2002

There are 3 UV DNA repair endonuclease activities in mammalian cells that cleave UV -irradiated DNA. Interestingly, mammalian UV endonuclease III with MW of 26.7kD has a lyase activity on AP sites. It also cleaves the phosphodiester bond within a cyclobutane pyrimidine dimer. Genomic analysis of human repair endonuclease III gene revealed that this gene has 100% sequence identity with ribosomal protein S3 (rpS3). Therefore, rpS3 seems to function both in translation and in DNA repair. This gene of about 6.1 kb contains 6 introns and 7 exons, and the first and fifth introns of human rpS3 gene contain functional U15 small nucleolar (sno) RNAs which appear to be involved in ribosome assembly. It is to be noted that the column profile of the endonuclease activity of rpS3 appears to be altered in Xeroderma Pigmentosum (XP) group D cells compared to normal cells indicating that this protein is involved in XP disease as well. XP is a human disease characterized by high sensitivity of skin by UV- or sun-light irradiation and by high frequency of developing skin cancers. We also report here that rpS3 protein is involved in other cellular functions.

• Molecules and Cells
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• v.42 no.11
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• pp.794-803
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• 2019

Ultraviolet light (UV)-induced cellular response has been studied by numerous investigators for many years. Long noncoding RNAs (lncRNAs) are emerging as new regulators of diverse cellular process; however, little is known about the role of lncRNAs in the cellular response to UV treatment. Here, we demonstrate that levels of lncRNA-HOTTIP significantly increases after UV stimulation and regulates the UV-mediated cellular response to UV through the coordinate activation of its neighboring gene Hoxa13 in GC-1 cells (spermatogonia germ cell line). UV-induced, G2/M-phase arrest and early apoptosis can be regulated by lncRNA-HOTTIP and Hoxa13. Furthermore, lncRNA-HOTTIP can up-regulate ${\gamma}-H_2AX$ and p53 expression via Hoxa13 in UV-irradiated GC-1 cells. In addition, p53 has the ability to regulate the expression of both lncRNA-HOTTIP and Hoxa13 in vitro and in vivo. Our results provide new data regarding the role lncRNAs play in the UV response in spermatogenic cells.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.155-161
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• 2000

Unfortunately, there is no technique which is stable and repetitive to produce transgenic chicken, although various ways of gene transfer including PGC-and embryonic cell-mediated gene transfer, DNA microinjection, virus inoculation and sperm cells have been employed. The aims of this study were 세 develop and establish such a stable, repetitive and efficient way of gene transfer giving a faithful gene expression during development after the reconstruction of embryo in an UV-irradiated egg. A dual reporter plasmid (pJJ9), a fusion gene containing lacZ and GFP driven by a CMV promoter was used to exploit either merits of both reporting markers. lacZ with strong signal or GFP with vital marking. Electroporated embryonic blastodermal cells (EBCs) in the presence of the pJJ9 DNA faithfully showed 377 bp PCR product and lacZ or GFP expressions in the identical cells in vitro of in vivo. Furthermore, analyses of expression pattern of the foreign DNA demonstrated that microinjected EBCs cells into the UV-irradiated recipient egg should participate in normal developmental process, for example, proliferation and differentiation into various tissues. Thirty percentages of the manipulated eggs showed lacZ expression in their tissues. These results together with the specific procedures used in this study should facilitate avian transgenesis.

• BMB Reports
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• v.31 no.4
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• pp.405-408
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• 1998

Endonuclease-sensitive sites detected by T4 endonuclease V or UvrABC nuclease treatments were compared in the dihydrofolate reductase gene of UV-irradiated Chinese hamster ovary B-11 cells. The number of endonuclease-sensitive sites detected by T4 endonuclease V treatment followed by NaOH denaturation was twice that of formamide denaturation. Repeated treatment of damaged genomic DNA with T4 endonuclease V resulted in no further increase in the number of endonuclease-sensitive sites detected. The numbers of endonuclease-sensitive sites detected by UvrABC nuclease using each denaturation condition were similar. Sequential treatment with the two endonucleases using formamide denaturation resulted in twice the number of endonuclease-sensitive sites detected by treatment of each nuclease alone. Due to a lack of AP endonuclease activity these results suggest the presence of T4 endonuclease V-sensitive sites which could be complemented by alkaline gel separation or by UvrABC nuclease treatment.