title: Inhibition of zymosan-induced cytokine and chemokine expression in human corneal fibroblasts by triptolide.
abstract: OBJECTIVE
  To investigate the effects of triptolide on proinflammatory cytokine and chemokine expression induced by the fungal component zymosan in cultured human corneal fibroblasts (HCFs).
  
  
  METHODS
  HCFs were cultured in the absence or presence of zymosan or triptolide. The release of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1) into culture supernatants was measured with enzyme-linked immunosorbent assays. The cellular abundance of the mRNAs for these proteins was determined by reverse transcription and real-time polymerase chain reaction analysis. The phosphorylation of mitogen-activated protein kinases (MAPKs) and the endogenous nuclear factor-κB (NF-κB) inhibitor IκB-α was examined by immunoblot analysis. The release of lactate dehydrogenase (LDH) activity from HCFs was measured with a colorimetric assay.
  
  
  RESULTS
  Triptolide inhibited the zymosan-induced release of IL-6, IL-8, and MCP-1 from HCFs in a concentration- and time-dependent manner. It also inhibited the zymosan-induced up-regulation of IL-6, IL-8, and MCP-1 mRNA abundance in these cells. Furthermore, triptolide attenuated zymosan-induced phosphorylation of the MAPKs extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 as well as the phosphorylation and degradation of IκB-α. Triptolide did not exhibit cytotoxicity for HCFs.
  
  
  CONCLUSIONS
  Triptolide inhibited proinflammatory cytokine and chemokine production by HCFs exposed to zymosan, with this action likely being mediated by suppression of MAPK and NF-κB signaling pathways. This compound might thus be expected to limit the infiltration of inflammatory cells into the cornea associated with fungal infection.
authors.affiliation: Department of Ophthalmology, First Hospital of Jilin University, Changchun 130021, Jilin Province, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, First Hospital of Jilin University, Changchun 130021, Jilin Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Pathology, First Hospital of Jilin University, Changchun 130021, Jilin Province, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, Changchun 130021, Jilin Province, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, First Hospital of Jilin University, Changchun 130021, Jilin Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jia
keywords: corneal fibroblast; fungal keratitis; inflammation; triptolide; zymosan