title: Detection and comparison of matrix metalloproteinase in primary and recurrent pterygium fibroblasts.
abstract: OBJECTIVE
  To detect and compare the levels of matrix metalloproteinases (MMPs) secreted by primary and recurrent human pterygium fibroblasts (HPFs).
  
  
  METHODS
  Primary and recurrent HPFs as well as human conjunctival fibroblasts (HCF) were cultured in RPMI 1640 medium at the same conditions. The protein levels of MMP-1, MMP-3 and MMP-9 were determined by enzyme-linked immune sorbent assay (ELISA), respectively.
  
  
  RESULTS
  1) The protein level of MMP-1 in serum-free supernatant from cultured primary and recurrent HPFs was higher than that in normal HCFs (P<0.05); similarly, the protein level of MMP-1 in serum-free supernatant from cultured primary HPFs was higher than that in recurrent HCFs (P<0.05). 2) The protein level of MMP-3 in serum-free supernatant from cultured primary HPFs was higher than that in normal HCFs (P<0.05); meanwhile, the protein level of MMP-3 in serum-free supernatant from cultured recurrent HPFs was lower when compared with that in primary HPFs and normal HCFs (P<0.05). 3) MMP-9 was not detected in primary and recurrent HPFs in the conditioned medium.
  
  
  CONCLUSIONS
  The protein levels of MMP-1 and MMP-3 in supernatant secreted by primary HPFs are different from recurrent HPFs. Different pathological mechanisms may exist between primary and recurrent pterygia.
authors.affiliation: Department of Ophthalmolgy, the Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, Guangdong Province, China.
authors.forename: Mei-Xia
authors.initials: MX
authors.lastname: An
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Wu
authors.forename: Shao-Chun
authors.initials: SC
authors.lastname: Lin