Abstract:

BACKGROUND: Fibroblasts cultured in 3-dimensional collagen gels will mediate collagen gels contraction, which is considered to be an in vitro model of tissue remodeling. PAR1 and PAR2 have been known to be involved in tissue remodeling through stimulating collagen gel contraction mediated by fibroblasts. Prostaglandin E2 (PGE2) is a predominant prostanoid mediating signal transduction of protease activated receptors, and it also plays an important role in contraction, proliferation, and chemotasis reaction of human fetal lung fibroblasts. However, whether protease activated receptors can modulate the PGE2 production from fibroblasts cultured in the 3-dimensional collagen gels is not known.
OBJECTIVE: To investigate whether PAR1 and PAR2 might have effect on PGE2 production from fibroblasts cultured in 3-dimensional collagen gels.
METHODS: Type Ⅰ collagen was extracted from tail tendon, and human fetal lung fibroblasts were cultured in vitro. Immunoblot was used to detect PAR1 and PAR2 expressions. Human fetal lung fibroblasts were cast into type I collagen gels, i.e., 3-dimensional culture of human fetal lung fibroblasts. After gelation, the human fetal lung fibroblasts were stimulated by PAR1 and PAR2 agonists, thrombin, trypsin, SLIGKV-NH2 and TFLLR-NH2. PGE2 was quantified in the supernatant using ELISA.
RESULTS AND CONCLUSION: Both PAR1 and PAR2 were demonstrated to express on human fetal lung fibroblasts. PGE2 release was detected under control condition. PAR1 nonselective agonist, PAR2 nonselective agonist, and SLIGKV-NH2 significantly stimulated PGE2 production (P < 0.01); however, TFLLR-NH2 remarkably inhibited PGE2 production in a dose-dependent manner (P < 0.01). The results demonstrated that PAR1 and PAR2 regulated prostaglandin E2 production in human fetal lung fibroblasts cultured in three-dimensional collagen gels.