Dynamic changes in and time sequence of ultraviolet B-induced apoptosis in rat corneal epithelial cells / Alterações dinâmicas na sequência temporal da apoptose induzida por radiação ultravioleta B em células epiteliais da córnea de ratos

ABSTRACT Purpose: To systematically examine the dynamic changes and time sequence in corneal epithelial cell apoptosis after excessive ultraviolet B irradiation. Methods: Ultraviolet B (144 mJ/cm2) was used to irradiate rat corneal epithelial cells for 2 h. Cell morphology was observed on differential interference contrast microscopy, and the numbers of the different kinds of apoptotic cells were counted using the ImageJ software. Cell viability was measured with the 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide method. Cell apoptotic rate and loss of mitochondrial membrane potential were detected using flow cytometric analyses. The expression levels of 3 apoptotic genes were measured with real-time quantitative polymerase chain reaction at different time points within 0-24 h after irradiation. Results: After 144-mJ/cm2 ultraviolet B irradiation for 2 h, the expression levels of caspase-8 and Bax were highest at 0 h; furthermore, the mitochondrial membrane potential decreased at 0 h and remained constant for 6 h in a subsequent culture. At 6 h, caspase-3 was activated. The decrease in cell viability and increase in apoptotic rate peaked at 6 h. The caspase-3 expression level decreased within 12-24 h, which led to a decline in apoptotic rate and change in apoptotic stage. Conclusions: The corneal epithelial cells exhibited rapid apoptosis after ultraviolet B irradiation, which was associated with both extrinsic and intrinsic pathways.

RESUMO Objetivos: Explorar sistematicamente as mudanças dinâmicas e a sequência temporal no processo de apoptose de células epiteliais corneanas após excesso de irradiação com ultravioleta B. Métodos: A radiação ultravioleta B (144 mJ/cm2) foi utilizada para irradiar células epiteliais da córnea de rato durante 2h. A morfologia celular foi observada por meio de microscópio de contraste de interferência diferencial, e os números de diferentes tipos de células apoptóticas foram contados e registrados pelo software ImageJ. A viabilidade celular foi medida pelo método brometo de 3- (4, 5-dimetil-2-tiazolil) -2, 5-difenil-2-H-tetrazólio. A taxa apoptótica celular e a perda do potencial da membrana mitocondrial foram detectadas por meio de análises citométricas de fluxo. Os níveis de expressão de três genes apoptóticos foram medidos por reação em cadeia da polimerase quantitativa em tempo real em diferentes momentos dentro de 0-24 h após a irradiação. Resultados: Após 144 mJ/cm2 de irradiação com ultravioleta B por 2h, os níveis de expressão de caspase-8 e Bax foram maiores em 0h; o potencial da membrana mitocondrial diminuiu a 0h e permaneceu constante por 6h na cultura subsequente. Às 6h, a caspase-3 foi ativada. A diminuição da viabilidade celular e o aumento da taxa apoptótica atingiu o pico em 6h. A expressão de caspase-3 diminuiu dentro de 12 - 24 h, levando a um declínio na taxa apoptótica e alteração no estágio apoptótico. Conclusões: As células epiteliais da córnea apresentaram uma apoptose rápida após excesso de irradiação com ultravioleta B, e esse processo foi associado tanto à via extrínseca como à via intrínseca.

Dietary effect of green tea extract on epidermal levels of skin pH related factors, lactate dehydrogenase protein expression and activity in UV-irradiated hairless mice / 한국영양학회지

PURPOSE: Skin pH, an indicator of skin health, is maintained by various organic factors, which include lactate, free amino acid (FAA), and free fatty acid (FFA). As skin ages or with illness, skin pH becomes less acidic, and functional food has been developed to maintain the acidic pH of skin. In this study, we determined the dietary effect of green tea extract (GTE) on skin pH of photo-aged mice, as measured by epidermal levels of lactate, FAA, and FFA. The protein expression and activity of lactate dehydrogenase (LDH), an enzyme of pyruvate reduction for lactate generation, was further determined. METHODS: Albino hairless mice were fed a control diet (group UV+) or a diet with 1% GTE (group GTE) in parallel with UV irradiation for 10 weeks. A normal control group was fed a control diet without UV irradiation for 10 weeks (group UV-). RESULTS: Skin pH was higher (less acidic) in group UV+ than in group UV-. In parallel, epidermal levels of lactate and FFA, as well as of LDH protein expression and activity, were reduced in group UV+. Dietary supplementation of GTE (group GTE) reduced skin pH to similar to the level of group UV-, and inversely increased epidermal levels of lactate, LDH protein expression and activity, but not of FFA. Although epidermal levels of FAA were similar in groups UV- and UV+, it was increased in group GTE to a level higher than in group UV-. In further analysis of major FFA, epidermal levels of palmitic acid [16:0], oleic acid [18:1(n-9)], and linoleic acid [18:2(n-6), but not of stearic acid [18:0] in group GTE were similar to or lower than those in group UV+. CONCLUSION: Dietary GTE normalized skin pH with increased levels of lactate and FAA, as well as with increased protein expression and activity of LDH in the epidermis of UVB irradiated hairless mice.

Comparison of Melanoma Subtypes among Korean Patients by Morphologic Features and Ultraviolet Exposure

BACKGROUND: Genetic alterations have been identified in melanomas according to different levels of sun exposure. Whereas the conventional morphology-based classification provides a clue for tumor growth and prognosis, the new classification by genetic alterations offers a basis for targeted therapy. OBJECTIVE: The purpose of this study is to demonstrate the biological behavior of melanoma subtypes and compare the two classifications in the Korean population. METHODS: A retrospective chart review was performed on patients found to have malignant melanoma in Severance Hospital from 2005 to 2012. Age, sex, location of the tumor, histologic subtype, tumor depth, ulceration, lymph node invasion, visceral organ metastasis, and overall survival were evaluated. RESULTS: Of the 206 cases, the most common type was acral melanoma (n=94, 45.6%), followed by nonchronic sun damage-induced melanoma (n=43, 20.9%), and mucosal melanoma (n=40, 19.4%). Twenty-one patients (10.2%) had the chronic sun-damaged type, whereas eight patients (3.9%) had tumors of unknown primary origin. Lentigo maligna melanoma was newly classified as the chronic sun-damaged type, and acral lentiginous melanoma as the acral type. More than half of the superficial spreading melanomas were newly grouped as nonchronic sun-damaged melanomas, whereas nodular melanoma was rather evenly distributed. CONCLUSION: The distribution of melanomas was largely similar in both the morphology-based and sun exposure-based classifications, and in both classifications, mucosal melanoma had the worst 5-year survival owing to its tumor thickness and advanced stage at the time of diagnosis.

Dietary effect of royal jelly supplementation on epidermal levels of hydration, filaggrins, free amino acids and the related enzyme expression in UV irradiated hairless mice

Ultraviolet (UV) irradiation reduces epidermal hydration, which is paralleled by the reduction of natural moisturizing factors (NMFs). Of various NMFs, free amino acids (AAs) are major constituents generated by filaggrin degradation. In this study, we attempted to determine whether dietary supplementation of royal jelly (RJ) in UV-irradiated mice can alters epidermal levels of hydration, filaggrins, and free AAs as well as of peptidylarginine deiminase-3 (PAD3), an enzyme involved in filaggrin degradation processes. Albino hairless mice were fed either a control diet (group UV+: UV irradiated control) or diets with 1% RJ harvested from different areas in Korea (groups RJ1, RJ2, and RJ3) or imported from China (group RJ4) for six weeks in parallel with UV irradiation. A normal control group (group UV-) was fed a control diet without UV irradiation for six weeks. Reduced epidermal levels of hydration, total filaggrins, and PAD3 were observed in group UV+; in group RJ1, these levels were increased to a level similar to that of group UV-. In addition, profilaggrins, two repeat intermediates (2RI), a precursor with two filaggrin repeats, and filaggrin were increased. Although no alteration of AAs was observed in any of the groups, and glutamate and serine, major AAs of NMF in group RJ1 were higher than in group UV+. Despite the increased levels of PAD3, epidermal levels of hydration, filaggrins, glutamate, and serine in groups RJ2, RJ3, and RJ4 were similar to those in group UV+. Dietary supplementation of RJ1 improves epidermal hydration in parallel with enhanced expression and degradation of filaggrin, but not by increased protein expression of PAD3, along with increased generation of glutamate and serine.

Isolation and characterization of an Ashbya gossypii mutant for improved riboflavin production

The use of the filamentous fungus, Ashbya gossypii, to improve riboflavin production at an industrial scale is described in this paper. A riboflavin overproducing strain was isolated by ultraviolet irradiation. Ten minutes after spore suspensions of A. gossypii were irradiated by ultraviolet light, a survival rate of 5.5% spores was observed, with 10% of the surviving spores giving rise to riboflavin-overproducing mutants. At this time point, a stable mutant of the wild strain was isolated. Riboflavin production of the mutant was two fold higher than that of the wild strain in flask culture. When the mutant was growing on the optimized medium, maximum riboflavin production could reach 6.38 g/l. It has even greater promise to increase its riboflavin production through dynamic analysis of its growth phase parameters, and riboflavin production could reach 8.12 g/l with pH was adjusted to the range of 6.0-7.0 using KH2PO4 in the later growth phase. This mutant has the potential to be used for industrial scale riboflavin production.

The Role of Nuclear Factor Kappa B on Lens Epithelial Cells after Ultraviolet B Irradiation

PURPOSE: This study was performed to determine the role of nuclear factor kappa B (NF-kappa B) on the lens epithelial cell death after ultraviolet (UV) irradiation. METHODS: Simian virus 40 transfected human lens epithelial cells (HLE B-3 cells) were used in this study. UVB located at 10cm from the bottom was irradiated during 1, 2, 3 and 4 minutes. To measure the cytotoxicity MTT assay was used. Translocation of NF-kappa B was examined by immunocytochemistry with anti NF-kappa B p65 antibody and electrophoretic mobility shift assay (EMSA). To confirm the role of NF-kappa B, the cells were pretreated with sulfasalazine, a specific inhibitor of NF-kappa B, for 30 minutes before irradiation, and cytotoxicity and translocation of NF-kappa B were evaluated. RESULTS: UV irradiation produced a progressive cytotoxic effect in cultured HLE B-3 cells after 1 minute and maximum cytotoxicity was reached after 3 minutes irradiation. When HLE B-3 cells were irradiated with UVB, the translocation of NF-kappa B was observed in immunocytochemistry. These translocations were peaked 6 hours after UV irradiation in EMSA. In HLE B-3 cells pretreated with sulfasalazine, the translocation of NF-kappa B was blocked. The cellular death after UV irradiation was markedly blocked by sulfasalazine. UV irradiation can translocate NF-kappa B and sulfasalazine is a useful blocking agent in this pathway. In addition, sulfasalazine can prevent cellular death after UV irradiation. CONCLUSIONS: These findings suggest that NF-kappa B plays an important role in cellular death after UV irradiation.

Regulation of Human Beta-Defensin 3(hBD-3) in Human Keratinocyte(HaCaT) Cell Lines

BACKGROUND: The large surfaces of the skin are often initial site of contact between microorganism and human. The skin are coated with epidermis and epithelial cells can recognize microorganism and mount a fast defense through the production of various inducible antibiotic peptides. This leads to chracteristic broad spectrum of antimicrobial activity against bacteria, fungi, and viruses. Recent studies introduce us new peptides with antimicrobial activity such as P,-defensins and cathelicidins. They are expressed on the epithelia and polymorphonuclear leukocytes, which are first lines of defence from various invasive environments. Futhermore, they are considered very interesting and important endogenous antibiotics. Our previous study has shown that the expression of human defensin(hBD-2) mRNA, which is potent antibiotic peptide against Gram-negative bacteria(P. aeruginosa), was upregulated with ultraviolet(UV) irradiation, tumor necrosis factor-α(TNF-α) and lipopolysaccharide(LPS) in HaCaT cells. A novel hBD-3, 5-kDa, nonhemolytic antimicrobial peptide, was demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes in especially, multiresistant S. aureus. We have analyzed the expression patterns of hBD-3 in HaCaT cell lines. OBJECTIVE: This research have done in order to evaluate the expression and regulation of hBD-3 mRNA in human keratinocyte cell lines. METHODS: HaCaT cell lines were used to all culture experiments. Cultured human keratinocytes were stimulated with UV irradiation or TNF-α or LPS to determine whether hBD-3 mRNA production occurred. Reverse transcription-polymerase chain reaction (RT-PCR) was per-formed to amplify hBD-3 cDNA from stimulated keratinocytes in a time dependant manner, and densitometry was used to verify the specificity of RT-PCR amplication products. RESULTS: Expression of hBD-3 was upregulated with UV irradiation, TNF-α and LPS in Ha-CaT cells compared to control CONCLUSIONS: Human keratinocytes are capable to induce hBD-3 mRNA, as well as hBD-2, in response to UV irradiation, TNF-α and LPS. suggesting that these cells could play an important role against the bacterial infection and UV light damage in human skin.

The Translocation of Nuclaer Factor Kappa B on Corneal Epithelial Cells after Ultraviolet B Irrradiation

PURPOSE: To seek the role of nuclear factor kappa B (NF-kB) on the corneal epithelial cell death after ultraviolet (UV) irradiation. METHODS: Human corneal epithelial cells transfected by Simian Virus 40 were used in this study. UVB(312 nm) located at 10cm distance from bottom (0.6 mW/cm2 ) was irradiated for 10, 20, 30, and 40 seconds. To measure the cytotoxicity, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method was used. Translocation of NF-KB was examined by immunocytochemistry with anti NF-K B p65 antibody and Electrophoretic Mobility Shift Assay (EMSA). To confirm the role of NF-KB , sulfasalazine, a specific inhibitor of NF-KB (0.5 mmole), was pretreated for 30 minutes before irradiatrion, and cytotoxicity and translocation of NF-KB was evaluated. RESULTS: UV irradiation resulted in a significant decrease in viability of cultured human corneal epithelial cells, especially after 20 second duration. When HCECs were irradiated with UVB, the translocation of N F -KB was observed in immunocytochemistry. These translocation was peaked 2 hours after UV irradiation in EMSA. In HCECs pretreated with sulfasalazine, either the cellular death or the translocation of NF-KB was blocked. CONCLUSION: UV irradiation can translocate NF-KB on the cultured human corneal epithelial cells. The cellular death after UV irradiation was blocked by sulfasalazine, a potent inhibitor of translocation of NF-KB. These findings suggest that NF-KB plays an important role in cellular death after UV irradiation.

Behavior of Fibroblasts on a Porous Hyaluronic Acid Incorporated Collagen Matrix

A hyaluronic acid (HA) incorporated porous collagen matrix was fabricated at -70 degree C by lyophilization. The HA incorporated collagen matrix showed increased pore size in comparison with collagen matrix. Biodegradability and mechanical properties of matrices were controllable by varying the ultraviolet (UV) irradiation time for cross-linking collagen molecules. Addition of HA to collagen matrix did not effect ultimate tensile stress after UV irradiation. HA incorporated collagen matrices demonstrated a higher resistance against the collagenase degradation than collagen matrix. In an in vitro investigation of cellular behavior using dermal fibroblasts on the porous matrix, HA incorporated collagen matrix induced increased dermal fibroblast migration and proliferation in comparison with collagen matrix. These results suggest that the HA incorporated collagen porous matrix assumes to enhance dermal fibroblast adaptation and regenerative potential.

Preliminary study on the antiultraviolet irradiation active substances of mycosporine-like amino acids from four kinds of Antarctic ice microalgae / 中国海洋药物

Objective To study on bioactive chemical compounds against ultraviolet irradiation in antarctic ice microalgae.Methods Four kinds of Antarctic ice microalgae were cultured under the conditions of low temperature,illumination,UV-A and UV-B irradiation.The chemical compounds were extracted by methanol and analyzed by spectrophotometer and HPLC/MS.The molecular structures were elucidated according to these data.The chemical compounds were irradated by sunshine to observe the speed of degradation and to estimate the bioactivity.Results There were five active compounds in Chlorophyceae L-4 and 7 active compounds in Diatom HF-9,in which 6 compounds belong to MAAs(mycosporine-like amino acids) and were of more bioactivity against ultraviolet irradiation.Conclusion MAAs from of Antarctic ice microalgae play an important role in resisting ultraviolet irradiation.

Synthesis of actinomycin-insensitive RNA during the first postirradiation mitotic cycle, in the synchronously mitotic plasmodia of Physarum polycephalum.

A sucrose density gradient analysis of 3H-uridine pulse-labelled RNA from the first postirradiation mitotic cycle of Physarum polycephalum shows that all the density classes of RNA synthesized during this period are resistant to the peptide-antibiotic, actinomycin D. In fact, the synthesis is found to be greater in the presence of the drug. The heterogenously sedimenting synthetic activity here may represent a single species of RNA and its precursors or more than one kind of RNA. Further characterization of this RNA is meaningful in view of the actinomycin insensitivity of the postirradiation mitotic cycle itself to this antibiotic.

Reduction of ultraviolet-induced mitotic delay by caffeine in G2-phase irradiated plasmodia of Physarum polycephalum.

Synchronously mitotic surface Plasmodia of Physarum polycephalum were ultraviolet- irradiated at different times during G2-phase (– 4 h to – 20 min with respect to metaphase), and treated immediately thereafter with varying concentrations of caffeine. It was observed that ultraviolet-induced mitotic delay is reduced significantly by this methylxanthine. In plasmodia irradiated between – 4 and – 1 h with respect to metaphase, the effect was concentration-dependent and the need for a certain threshold dose for obtaining the reduction in delay was apparent. However, higher doses than this were fairly toxic when applied at this part of the cycle and led to more mitotic delay than that obtained with UV alone. The most striking observation made during this study was the phase-specific precipitous effect seen in those plasmodia irradiated at about 20 min before mitosis which almost eliminated the long delay due to ultraviolet-irradiation. These results are discussed in the context of some of the known effects of ultraviolet and caffeine on a mitosis-promoting factor. It is proposed that the significant reduction of ultravioletinduced mitotic delay reported here is due to the reactivation of the ultraviolet-inactivated mitosis-promoting factor by caffeine. Alternatively, it is possible that caffeine may prevent the inactivation of this factor by ultraviolet.

Elucidation of the Inhibitory Immune Mechanism of the Contact Hypersensitivity in Mice Induced by Ultraviolet Irradiation / 대한피부과학회지

Normal C3H/HeN strain mice exposed to low-dose ultraviolet radiation(4 * 400 J/m) demonstrated a reduction in contact sensitization potential which locaiized to the skin area of direct UVR exposure(local suppression), where high-dose exposure of UVR(1*30.000 J/m) caused systemic suppression of CH induction, regardless of the application site of 2,4-dinitro-l-fluorobenzene(DNFB). There seemed to be two different mechanisms that are responsible for CH reaction induced by UVR. One of them, local suppression of low-dose UVR resulted from blocking the afferent phase of immune response by the functiona] inactivation of the epidermal Langerhans cells ; it was associated with lack of CH effector cells in the peripheral lymph nodes, an enhanced splenic suppressor cell acitvity, and could not be reversed by indomethacin treatment. The other, systemic suppression of high-dose UVR was mediated by enhancement of prostaglandin E(PGE); it was associated with prevention of the egress of effector cells within the regional lymph node which was caused by blocking the efferent lymphatics, and elevated plasma level of PGE. And depressed CH response was reversed when treated by indomethacin.

Quantitation of Sunburn Cell Production in Mouse Skin by Ultarviolet Irradiation / 대한피부과학회지

In this study, a total of 115 ICR male albino haired mice were used and divided into two groups(A & B) for experiment. In group A(65 mice), quantiatation of sunburn cell(SBC) production and its distribution according to the time course after ultraviolet irradiation was measured. In group B(50mice), quantitation of dose-response experiments for SBC production after ultraviolet irradiation was measured. The results were as follows: ]. SBCs were recognized by 2 hours after irradiation. There was a tendency to increase from 2 hours to 24 hours and decrease from then to l week after irradiation, 2. The increase of SBCs in lower epidermis 2 hours io 8 hours after exposure and in upper epidermis 24 hours after irradiation were statistically significant (p<0. 05). SBG number in all layers declined from 36 hours to 1 week after exposure. 3. The linear relationship which observed(y=8.09+0.85x, R=0.87) suggests a dose-response relationship between UVB dose and SBC number.