Browsing by Author "Hu, Dan-Ning"

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Effects of Lutein on Hyperosmoticity-Induced Upregulation of IL-6 in Cultured Corneal Epithelial Cells and Its Relevant Signal Pathways
(2016-01-01)
Chao, Shih-Chun
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Nien, Chan-Wei
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Iacob, Codrin
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Hu, Dan-Ning
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Huang, Sheng-Chieh
Dry eye is a common disorder characterized by deficiency of tear. Hyperosmoticity of tear stimulates inflammation and damage of ocular surface tissues and plays an essential role in the pathogenesis of dry eye. Cultured human corneal epithelial (CE) cells were used for the study of effects of lutein and hyperosmoticity on the secretion of IL-6 by CE cells. Cell viability of CE cells was not affected by lutein at 1-10 mu M as determined by MTT assay. Hyperosmoticity significantly elevated the secretion of IL-6 by CE cells as measured by ELISA analysis. The constitutive secretion of IL-6 was not affected by lutein. Lutein significantly and dose-dependently inhibited hyperosmoticity-induced secretion of IL-6. Phosphorylated-(p)-p38 MAPK, p-JNK levels in cell lysates and NF-kappa B levels in cell nuclear extracts were increased by being exposed to hyperosmotic medium. JNK, p38, and NF-kappa B inhibitors decreased hyperosmoticity-induced secretion of IL-6. Lutein significantly inhibited hyperosmoticity-induced elevation of NF-kappa B, p38, and p-JNK levels. We demonstrated that lutein inhibited hyperosmoticity-induced secretion of IL-6 in CE cells through the deactivation of p38, JNK, and NF-kappa B pathways. Lutein may be a promising agent to be explored for the treatment of dry eye.
Incidence of Non-Traumatic Subconjunctival Hemorrhage in a Nationwide Study in Taiwan from 2000 to 2011
(2015-07-16)
Hu, Dan-Ning
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Mou, Chih-Hsin
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Chao, Shih-Chun
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Lin, Ching-Yang
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Nien, Chan-Wei
Objective To determine the nationwide incidence of non-traumatic subconjunctival hemorrhage (NTSCH) in Taiwan from 2000-2011 and to analyze the risk factors for NTSCH using a case-control analysis. Methods This is a population-based cohort administrative database study. Randomly selected 1,000,000 residents from the Taiwan National Health Insurance Research Database in 2000 and followed for 12 years to determine the population incidence of NTSCH. Individuals with the first diagnosis of subconjunctival hemorrhage were identified by the corresponding International Classification of Diseases code (ICD) 372.72. Traumatic subconjunctival hemorrhages (ICD-9 codes 921, 871, 850-854 and 959.01) were excluded. The association of NTSCH with various demographic factors, comorbidities and use of medications was studied by a population based case-control analysis using data of 2008-2011. Results A total of 67,720 patients with a first-time diagnosis of NTSCH were identified during the 12 years period. The mean annual incidence was 65 per 10,000 individuals (crude incidence) and 60 per 10,000 individuals (age-and sex-standardized incidence). The incidence rate of NTSCH was higher in women than in men, [men-women ratio: 0.80 (95% confidence interval: 0.78-0.81)]. The age-specific incidence decreased from childhood to the group of teenagers, after which it increased to a maximal value of 136.2 per 10,000 people in the age group of 60-69 years. Case-control analysis showed that comorbidities of hypertension, purpura and thrombocytopenia, and the use of aspirin were significantly associated with the risk of NTSCH. Conclusions This study indicates that NTSCH is a common eye disease that occurs once in 167 individuals in a general East Asian population per year. It occurs more often in women than in men and the age-specific incidence peaked in the age group of 60-69 years. Hypertension, purpura and thrombocytopenia, and the use of aspirin are the major risk factors for NTSCH.
Inhibition effect of curcumin on UVB-induced secretion of pro-inflammatory cytokines from corneal limbus epithelial cells
(2017-06-18)
Chao, Shih-Chun
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Hu, Dan-Ning
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Roberts, Joan
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Shen, Xilun
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Lee, Chia-Yi
AIM: To study the effects of curcumin on the secretion of interleukin (IL) -6 and IL-8 by corneal limbus epithelial cells. METHODS: Human corneal limbus epithelial cells were isolated and cultured from donor eyes and irradiated by UVB at different dosages with or without curcumin. MTT test was used for studying the effects of UVB and curcumin on the cell viability. The role of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-kappa B) pathways on the UVB-induced secretion of IL-6 and IL-8 were tested by addition of their inhibitors to the culture with or without UVB-radiation. Levels of various signal pathways, IL-6 and IL-8 in the cells and in the conditioned culture medium were measured by ELISA analysis. RESULTS: UVB at 20 mJ/cm(2) or less and curcumin at 20 mu mol/L or less did not affect the cell viability of cultured limbus epithelial cells (P>0.05). UVB irradiation at 10 and 20 mJ/cm(2) induced a significant increase of secretion of IL-6 and IL-8 and upregulated NF-kappa B and phosphorylated MAPK pathways of cultured limbus epithelial cells (P<0.05). Various signal pathway inhibitors, including SP600125 (JNK inhibitor), SB203580 (p38 MAPK inhibitor) and BAY11-7082 (NF-kappa B inhibitor) significantly decreased the UVB-induced secretion of IL-6 and IL-8 secretion (P<0.05). Curcumin at 5-20 mu mol/L significantly inhibited UVB-induced secretion of IL-6 and IL-8 by limbus epithelial cells in a dose-dependent manner; while curcumin alone did not affect the secretion of IL-6 and IL-8. The upregulation of NF-kappa B and MAPK pathways induced by UVB treatment was significantly inhibited by curcumin, suggesting that NF-kappa B and MAPK pathways are involved in the inhibitory effect of curcumin on UVB-induced production of IL-6 and IL-8. CONCLUSION: Curcumin may be a promising agent to be explored for the prevention and treatment of pterygium.
Overexpression of urokinase-type plasminogen activator in pterygia and pterygium fibroblasts
(2011-01-06)
Chao, Shih-Chun
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Hu, Dan-Ning
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Yang, Pei-Yu
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Lin, Ching-Yang
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Yang, Shun-Fa
Purpose: Urokinase-type plasminogen activator (uPA) is a protease involved in tissue remodeling and cell migration. Little is known about the expression of uPA in pterygium. The purpose of this study was to investigate the expression of uPA mRNA and activities in various stages of surgically excised pterygia specimens and cultured pterygium fibroblasts and to compare them with normal conjunctival tissues and fibroblasts. Methods: The expression of uPA mRNA and activity in 15 pterygium tissues and cultured fibroblasts from pterygium were measured using quantitative RT-PCR and zymography. Five normal conjunctiva specimens and cultured conjunctival fibroblasts were tested as the controls. Results: The expression of uPA mRNA and activities in pterygia and pterygium fibroblasts were significantly greater than those of the normal samples (p<0.05) and were closely related to the progression of pterygium. The amounts of uPA mRNA and activities in early, moderate, and advanced pterygia were 100%, 208%, and 311% and 100%, 157%, and 280% of the early stage specimens, respectively. The amounts of uPA mRNA and the activities in cultured pterygium fibroblasts isolated from early, moderate, and advanced pterygium specimens were 100%, 219%, and 457% and 100%, 198% and 355% of early stage fibroblasts, respectively. Conclusions: Overexpression of uPA was present in pterygium and their fibroblasts. The expression of uPA by pterygium increased significantly following the progression of the pterygium. The increased expression of uPA may covert plasminogen to plasmin, degrade extracellular matrixes, stimulate cell migration, induce angiogenesis, and plays an important role in the development and progression of pterygium.
Subtoxic Levels of Apigenin Inhibit Expression and Secretion of VEGF by Uveal Melanoma Cells via Suppression of ERK1/2 and PI3K/Akt Pathways
(2013)
Chao, Shih-Chun
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Huang, Sheng-Chieh
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Hu, Dan-Ning
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Lin, Hung-Yu
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資訊工程學系
The effects of apigenin on the expression of VEGF in uveal melanoma cells have not been reported. We studied this effect and relevant signaling pathways in two human uveal melanoma cell lines (SP6.5 and C918). ELISA assay revealed that the constitutive secretion of VEGF by uveal melanoma cells was 21-fold higher than that in normal uveal melanocytes. Apigenin at subtoxic levels (1-5 mu M) significantly suppressed the secretion of VEGF in a dose-and time-dependent manner in melanoma cells. VEGF levels in the conditioned culture media from SP6.5 and C918 cell lines treated with 5 mu M apigenin for 24 h reduced to 29% and 21% of those in cells not treated with apigenin, respectively. RT-PCR analysis found that apigenin also decreased the expression of VEGF mRNA in melanoma cells. ELISA study of various signal pathways showed that apigenin significantly decreased phosphorylated Akt and ERK1/2 but increased phosphorylated JNK1/2 and p38 MAPK levels in melanoma cells. PI3K/Akt or ERK1/2 inhibitors significantly decreased, but JNK1/2 and p38 MAPK inhibitors did not influence the secretion of VEGF by melanoma cells, suggesting that apigenin suppresses the secretion of VEGF mainly through the inhibition of PI3K/Akt and ERK1/2 pathways.
Ultraviolet-A Irradiation Upregulated Urokinase-Type Plasminogen Activator in Pterygium Fibroblasts through ERK and JNK Pathways
(2013-02-01)
Chao, Shih-Chun
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Hu, Dan-Ning
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Yang, Pei-Yu
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Lin, Ching-Yang
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Nien, Chan-Wei
PURPOSE. Effects of ultraviolet (UV) B on the pterygium and its cells have been studied previously, whereas little is known on the effects of UVA. Urokinase-type plasminogen activator (uPA) is a protease involved in tissue remodeling and cell migration, and its levels are increased in pterygium. The purpose of our study was to investigate the effects of UVA on the expression of uPA in cultured pterygium fibroblasts. METHODS. Cultured fibroblasts from early-stage pterygia and normal conjunctiva were irradiated with different dosages of UVA and compared to nonirradiated cells. uPA activities in the medium and uPA mRNA in the cells were measured by casein zymography and RT-PCR, respectively. Total and phosphorylated p38 mitogen-activated protein kinase (MAPK), extracellular signal-related kinase (ERK), and c-Jun N-terminal kinase (JNK) levels of cells treated with and without UVA were measured by Western blotting. Inhibitors of p38 (SB203580), ERK (UO1026), and JNK (SP600125) were added before the irradiation of UVA to test their effects. RESULTS. UVA irradiation increased the uPA mRNA levels in pterygium fibroblasts and the uPA activities in cultured medium, which was accompanied with an increase in phosphorylated ERK and JNK. The ERK and JNK inhibitor, but not p38 MAPK inhibitors, significantly decreased the UVA-induced expression of uPA by pterygium fibroblasts. Normal conjunctival fibroblasts were less sensitive to UVA irradiation compared to the pterygium fibroblasts. CONCLUSIONS. UVA stimulated the production of uPA, a key factor in the modulation of extracellular matrixes, inflammatory processes, and angiogenesis. This may have a role in the development and progression of pterygium. (Invest Ophthalmol Vis Sci. 2013;54:999-1007) DOI:10.1167/iovs.12-10469