Related Experiment Videos
Human hepatoma cell line plasminogen activator.
The Journal of Laboratory and Clinical Medicine
|October 1, 1983
Summary
Hep G2 cells produce multiple forms of urokinase-like plasminogen activator (PA), primarily secreted into the cell medium. Cellular inhibitors can mask the detection of this cell-associated PA activity.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Background:
- The fibrinolytic system regulates blood clot breakdown.
- Hep G2 cells are a human hepatoma cell line known to synthesize fibrinolytic components.
- Plasminogen activator (PA) is a key enzyme in fibrinolysis.
Purpose of the Study:
- To investigate the capacity of Hep G2 cells to produce plasminogen activator (PA).
- To characterize the forms and localization of PA produced by Hep G2 cells.
- To identify potential factors affecting PA detection in Hep G2 cells.
Main Methods:
- Culturing Hep G2 cells and collecting conditioned medium and cell extracts.
- Assessing PA activity using SDS-polyacrylamide gel electrophoresis and isoelectric focusing.
- Utilizing specific antibodies (anti-urokinase, anti-tissue activator) and enzyme inhibitors (diisopropylfluorophosphate) for characterization.
- Investigating the effect of cell extracts on purified urokinase activity to detect inhibitors.
Main Results:
- PA activity accumulated in Hep G2 conditioned medium, with forms of Mr 100,000, 60,000, and 52,000 daltons identified.
- The secreted PA exhibited an isoelectric point (pI 8.6) identical to urokinase and was neutralized by anti-urokinase IgG.
- Cell extracts contained fibrinolytic inhibitors that masked latent, cell-associated PA activity, which was revealed after acidification.
Conclusions:
- Hep G2 cells produce multiple molecular weight forms of a urokinase-like plasminogen activator.
- The secreted PA is primarily found in the conditioned medium.
- Cellular fibrinolytic inhibitors can obscure the detection of cell-associated PA activity in Hep G2 cells.