Julian M. Marshall

Plasminogen activators in ectopic and uterine endometrium

OBJECTIVE To investigate the expression of the plasminogen activator (PA)-plasmin system components in ectopic endometrium and in uterine endometrium from women with and without endometriosis. DESIGN Plasminogen, PAs (urokinase and tissue plasminogen activator), and PA inhibitors (1 and 2) were detected by immunohistochemistry using a alkaline phosphatase staining method. RESULTS No differences in staining were found between uterine endometrium of women with endometriosis and women without endometriosis with any of the antibodies used. However, we did find differences between uterine and ectopic endometrium. Although the expression of the components of the PA-plasmin system reflected the cyclic changes in the hormonal levels in uterine endometrium, ectopic endometrium maintained a very high level of plasminogen and urokinase in every sample. We were unable to detect the presence of PA inhibitors in either uterine or ectopic endometrium. CONCLUSIONS There is no evidence that uterine endometrium from women with endometriosis is originally more able to implant than that of women without the disease because of an increase in their PA expression. The high levels of urokinase and plasminogen in ectopic endometrium may reflect a more invasive nature of the endometriotic implants in the peritoneal cavity.

The compact domain conformation of human Glu-plasminogen in solution

A complete understanding of the accelerating mechanisms of plasminogen activation and fibrinolysis necessarily requires structural information on the conformational forms of plasminogen. Given the absence of high-resolution structural data on plasminogen the use of lower resolution approaches has been adopted. Two such approaches have previously indicated a compact conformation of Glu-plasminogen (Tranqui, L., Prandini, M., and Chapel, A. (1979) Biol. Cellulaire, 34, 39-42; Bányai, L. and Patthy, L. (1985) Biochim. Biophys. Acta, 832, 224-227) whereas a third has suggested a fairly extended conformation (Mangel, W., Lin, B. and Ramakrishnan, V. (1990) Science, 248, 69-73). Native Glu-plasminogen has been investigated using small-angle X-ray scattering (SAXS) experiments. It is concluded that this molecule in solution is compact (radius of gyration, RG 3.05 +/- 0.02 nm and maximum intramolecular distance, Im 9.1 +/- 0.3 nm) and that the data are consistent with the right-handed spiral structure observed using electron microscopy by Tranqui et al. (1979). A spiral structure of native plasminogen would have important implications for the conformational response of plasminogen to fibrin and concomitant stimulation of plasminogen activation.

Glycoprotein glycosylation and the immunosuppressive effects of human pregnancy serum

Pregnancy serum contains a factor or factors which suppress T lymphocyte proliferation, although the identity of the factor(s) is still unclear. We have demonstrated that the immunosuppressive activity of pregnancy sera can be destroyed by treatment with periodate which oxidises protein-linked oligosaccharides. Similar effects have been noted with uromodulin, a potent immunosuppressive glycoprotein initially isolated from pregnancy urine. We find, however, that uromodulin is present in both pregnancy and non-pregnancy sera, and that removal of uromodulin from pregnancy serum by lectin affinity chromatography is not associated with loss of activity, ruling out this glycoprotein as the immunosuppressive factor. The possible role of protein-linked oligosaccharides of other serum glycoproteins in causing the pregnancy-related immunosuppression is discussed.

A comparative analysis of two preparations of human chorionic gonadotrophin

A biophysical analysis of two pharmaceutical preparations of human chorionic gonadotrophin (Endo and Profasi) demonstrated that both contained high hCG specific activity. HCG protein analysis by occlusion HPLC and SDS gel electrophoresis showed similar profiles for both products. Although the purified protein components of both preparations were similar their were differences in the contents of the unpurified preparations. The Endo preparation exhibited greater inter-vial variability and contained an unidentified aromatic substance which interacted with the desalting column.