Elevated tissue type plasminogen activator in human granulosa cells correlates with fertilizing capacity

Area of Science:

• Reproductive Biology
• Biochemistry
• Cell Biology

Background:

• Plasminogen activators are involved in ovulation and follicular rupture.
• Understanding molecular factors influencing human oocyte fertilization is crucial for in-vitro fertilization (IVF) success.

Purpose of the Study:

• To investigate the relationship between plasminogen activators, follicular fluid steroids, and human oocyte fertilizability.
• To determine if specific markers in granulosa cells and follicular fluid correlate with successful fertilization.

Main Methods:

• Granulosa cells from 49 human follicles (20 patients undergoing IVF) were analyzed for urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI).
• Follicular fluid steroid concentrations (estradiol [E2], progesterone [P], testosterone [T]) were measured.
• Enzyme levels and steroid content were correlated with oocyte fertilization outcomes.

Main Results:

• Follicles yielding fertilized oocytes showed significantly higher E2 and P levels and lower T levels compared to those with unfertilized oocytes.
• Granulosa cells from successfully fertilized oocytes had higher t-PA levels than those from unfertilized oocytes.
• No significant differences in u-PA or PAI levels were observed between groups.

Conclusions:

• Successful human oocyte fertilization is associated with elevated granulosa cell t-PA and high follicular fluid E2 and P levels.
• These findings suggest t-PA, E2, and P are potential biomarkers for predicting fertilization success in IVF.