Prostaglandin E2 affects proliferation and collagen synthesis by human patellar tendon fibroblasts.

OBJECTIVE

To determine the effect of prostaglandin E2 on proliferation and collagen synthesis by human patellar tendon fibroblasts.

DESIGN AND SETTING

Controlled laboratory study.

METHODS

Human patellar tendon fibroblasts were treated with different concentrations (1, 10, 100 ng/mL) of prostaglandin E2 in cultures. Fibroblasts without prostaglandin E2 treatment were used as the control group. The fibroblast proliferation and collagen synthesis were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and Sircol collagen assay, respectively.

MAIN OUTCOME MEASURED

Changes in proliferation and collagen production of human patellar tendon fibroblasts.

RESULTS

: At 1 ng/mL of prostaglandin E2, there was no significant effect on fibroblast proliferation compared with the control group. At concentrations of 10 ng/mL and 100 ng/mL prostaglandin E2, however, fibroblast proliferation significantly decreased, by 7.3% (P = 0.002) and 10.8% (P < 0.0001), respectively, compared with the control group. At 1 ng/mL of prostaglandin E2, collagen production of the tendon fibroblasts was unaffected. However, at both 10 ng/mL and 100 ng/mL prostaglandin E2, collagen production was significantly decreased, by 45.2% (P < 0.0001) and 45.7% (P < 0.0001), respectively, compared with the control group. The levels of collagen production between these 2 dosages did not differ significantly.

CONCLUSIONS

Prostaglandin E2 affects the proliferation of and collagen production by human patellar tendon fibroblasts in a dosage-dependent manner.

CLINICAL RELEVANCE

Based on these in vitro findings, we speculate that production of prostaglandin E2 in tendons might play some role in the acellularity and matrix disorganization seen in exercise-induced tendinopathy.