Effects of amniotic fluid on proteases: a possible role of amniotic fluid in fetal wound healing

Fetuses are surrounded by amniotic fluid rich in nutrients and other factors essential to fetal development and possibly to its scarless wound healing. The purpose of this study was to determine whether amniotic fluid contains factors that regulate activities of major proteases involved in the process of wound healing (e.g., collagenase, hyaluronidase, elastase, and cathepsin B). Human amniotic fluid was assayed in vitro for inhibition or stimulation of the activity of these enzymes. Our results showed that amniotic fluid enhanced collagenase activity at a concentration of 66 micrograms protein (p < 0.01), but inhibited activities of hyaluronidase (132 micrograms protein; p < 0.05), elastase (170 micrograms protein; p < 0.05), and cathepsin B (19 micrograms protein; p < 0.01). This finding suggests that amniotic fluid could have an important role in flawless fetal wound healing by regulating these matrix-degrading enzymes.