Browsing by Author "Yang, Pei-Yu"

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Overexpression of urokinase-type plasminogen activator in pterygia and pterygium fibroblasts
(2011-01-06)
Chao, Shih-Chun
;
Hu, Dan-Ning
;
Yang, Pei-Yu
;
Lin, Ching-Yang
;
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.
Swimming Pool Associated Vittaforma-Like Microsporidia Linked to Microsporidial Keratoconjunctivitis Outbreak, Taiwan
(2019-11-01)
Chen, Jung-Sheng
;
Hsu, Tsui-Kang
;
Hsu, Bing-Mu
;
Chao, Shih-Chun
;
Huang, Tung-Yi
We analyzed 2 batches of environmental samples after a microsporidial keratoconjunctivitis outbreak in Taiwan. Results indicated a transmission route from a parking lot to a foot washing pool to a swimming pool and suggested that accumulation of mud in the foot washing pool during the rainy season might be a risk factor.
Ultraviolet-A Irradiation Upregulated Urokinase-Type Plasminogen Activator in Pterygium Fibroblasts through ERK and JNK Pathways
(2013-02-01)
Chao, Shih-Chun
;
Hu, Dan-Ning
;
Yang, Pei-Yu
;
Lin, Ching-Yang
;
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