title: Dioscorin protects tight junction protein expression in A549 human airway epithelium cells from dust mite damage.
abstract: OBJECTIVE
  In addition to being an allergen, the trypsin activity of dust mite extract also destroys the tight junctions of bronchial epithelium. Such damage can lead to airway leakage, which increases airway exposure to allergens, irritants, and other pathogens. Dioscorin, the storage protein of yam, demonstrates anti-trypsin activity, as well as other potential anti-inflammatory effects. This study investigated the protective role of dioscorin for tight junctions.
  
  
  METHODS
  The immunofluorescence stains of zonula occludens (ZO-1), E-cadherin (EC) and desmoplakin (DP) proteins were compared. A cultured A549 cell line was used as a control and A549 cells were incubated with mite extract 100 mg/mL for 16 h, with or without dioscorin 100 mg/mL pretreatment for 8 h and with dioscorin 100 mg/mL alone for 16 h. Western blot was performed to detect changes in ZO-1, EC, and DP in the treated A549 cell lines.
  
  
  RESULTS
  Loss of tight junction protein expression (ZO-1, EC, DP) was demonstrated after 16-h mite extract incubation. The defect could be restored if cells were pretreated with dioscorin for 8 h. In addition, dioscorin did not cause damage to the A549 cell lines in terms of cell survival or morphology. Western blot showed no change in the amount of tight junction protein under various conditions.
  
  
  CONCLUSIONS
  Dioscorin is a potential protector of airway damage caused by mite extract.
authors.affiliation: Division of Immunology and Nephrology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan. linshienfu@yahoo.com.tw
authors.forename: Lin Shien
authors.initials: LS
authors.lastname: Fu
authors.forename: Ying Hsien
authors.initials: YH
authors.lastname: Ko
authors.forename: Kuo Wei
authors.initials: KW
authors.lastname: Lin
authors.forename: Jeng Yuan
authors.initials: JY
authors.lastname: Hsu
authors.forename: Jao Jia
authors.initials: JJ
authors.lastname: Chu
authors.forename: Chin Shiang
authors.initials: CS
authors.lastname: Chi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000096:biosynthesis; D002460:Cell Line; D051180:Desmoplakins / Q000096:biosynthesis; D005455:Fluorescent Antibody Technique; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis; D008856:Microscopy, Fluorescence; D010750:Phosphoproteins / Q000096:biosynthesis; D010940:Plant Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D039981:Pyroglyphidae; D020545:Respiratory Mucosa / Q000187:drug effects / Q000276:immunology / Q000469:parasitology*; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D015820:Cadherins; D051180:Desmoplakins; D008565:Membrane Proteins; D010750:Phosphoproteins; D010940:Plant Proteins; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; C095057:dioscorin protein, Dioscorea