Expression of the plasminogen system in the physiological mouse ovary and in the pathological polycystic ovary syndrome (PCOS) state.

BACKGROUND: The fibrinolytic system and its inhibitors play a number of roles, apart from their function in blood haemostasis and thrombosis, namely in ovarian folliculogenesis and in ovulation. Plasminogen is converted to active plasmin at the time of follicular rupture through a decrease in plasminogen activator inhibitor-1 (PAI-1) and an increase in plasminogen activators. Oligo-/anovulation and follicle arrest are key characteristics of PCOS, but studies evaluating fibrinolytic/proteolytic markers within human or animal PCOS ovaries are lacking. We aimed to investigate and compare the expression and distribution of the plasminogen system markers in PCOS and control ovaries. METHODS: A hyperandrogenised PCOS mouse model was used that mimics the ovarian, endocrine and metabolic features of the human condition. Immunohistochemistry and digital image analysis were used to investigate and compare fibrinolytic/proteolytic markers plasminogen, plasminogen/plasmin, tissue plasminogen activator, urokinase plasminogen activator and inhibitor PAI-1 in PCOS and control ovaries. Student's t-test was used to compare data sets for normally distributed data and Wilcoxon-Mann Whitney test for non-normally distributed data. RESULTS: We noted differences in the ovarian distribution of PAI-1 that was expressed throughout the PCOS ovary, unlike the peripheral distribution observed in control ovaries. Plasminogen was present in small follicles only in PCOS ovaries but not in small follicles of control ovaries. When we assessed and compared PAI-1 expression within follicles of different developmental stages we also noted significant differences for both the PCOS and control ovaries. While we noted differences in distribution and expression within specific ovarian structures, no differences were noted in the overall ovarian expression of markers assessed between acyclical PCOS mice and control mice at the diestrus stage of the estrous cycle. CONCLUSIONS: Our novel study, that comprehensively assessed the fibrinolytic/proteolytic system in the mouse ovary, showed the expression, differential localisation and a potential role for the plasminogen system in the physiological mouse ovary and in PCOS. Androgens may be involved in regulating expression of the ovarian plasminogen system. Further studies evaluating these markers at different time-points of ovulation may help to further clarify both physiological and potential pathological actions these markers play in ovulatory processes distorted in PCOS.

Differential Effects on Haemostatic Markers by Metformin and the Contraceptive Pill: A Randomized Comparative Trial in PCOS.

Background Polycystic ovarian syndrome (PCOS) affects up to 18% of reproductive-aged women with increased risks of cardiovascular disease and venous thromboembolic disease, related to metabolic and hormonal features, obesity and an apparent hypofibrinolytic state, possibly exacerbated by current PCOS treatments. Objective To investigate and compare haemostatic impacts of common pharmacological treatments and explore relationships with hormonal and metabolic variables in PCOS. Patients/Methods This mechanistic sub-study using biobanked samples from a 6-month randomized comparative trial of pharmacological treatments assessed pro- and anti-thrombotic markers and overall haemostatic activity. Overweight women of mean age 33.9 ± 6.7 years and mean BMI (body mass index) of 36.5 ± 7.0 kg/m2 with PCOS (n = 60) were randomized to either metformin, higher-dose oral contraceptive pill (OCP) or low-dose OCP + spironolactone (OCP + S). Primary outcome measures included changes in plasminogen activator inhibitor 1 (PAI-1), asymmetric dimethylarginine (ADMA), prothrombin fragments 1 and 2 (PF1 and 2), plasminogen, tissue plasminogen activator (tPA), thrombin activatable fibrinolysis inhibitor (TAFI) and thrombin generation (TG). Results PAI-1 activity fell in all groups, ADMA fell in higher-dose OCP, PF1 and 2 increased with metformin and higher-dose OCP, TG rose and tPA fell in both OCP groups, plasminogen increased in all and TAFI increased after higher-dose OCP. Conclusion Endothelial function (primary haemostasis) improved with higher dose with some improvement in low-dose OCP + S and metformin. Aberrant coagulation was noted in both OCP groups, but not with metformin. Fibrinolysis was reduced with higher-dose OCP. Our work suggests an additional dimension of treatment (haemostatic system effects) that favours metformin treatment over the OCP in PCOS.

Comprehensive Assessment of the Hemostatic System in Polycystic Ovarian Syndrome.

Polycystic ovarian syndrome (PCOS) affects 12 to 19% of women and has reproductive and metabolic features (endothelial dysfunction, increased diabetes, and cardiovascular risk factors). It also appears to have altered coagulation and fibrinolysis with a prothrombotic state with epidemiological evidence of increased venous thromboembolism. We aimed to comprehensively assess hemostasis in women with PCOS versus control women. In an established case-control cohort of lean, overweight, and obese women with (n = 107) and without PCOS (n = 67), with existing measures of plasminogen activator inhibitor 1 (PAI-1), asymmetric dimethylarginine (ADMA), hormonal, and metabolic markers, we also assessed prothrombin fragments 1 and 2 (PF1 & 2), plasminogen, tissue plasminogen activator (tPA), and thrombin generation (TG). Higher levels of ADMA (0.70 vs. 0.39 µmol/L, p < 0.01), PAI-1 (4.80 vs. 3.66 U/mL, p < 0.01), and plasminogen (118.39 vs. 108.46%, p < 0.01) were seen in PCOS versus controls, and persisted after adjustment for age and body mass index (BMI). PF1 & 2 was marginally lower (180.0 vs. 236.0 pmol/L, p = 0.05), whereas tPA and TG were not different between groups, after adjustment for age and BMI. Significant relationships were observed between hormonal and metabolic factors with ADMA and PAI-1. We demonstrate impaired fibrinolysis in PCOS. In the context of abnormal endothelial function and known hormonal and metabolic abnormalities, this finding may underpin an increased risk of cardiovascular disease and venous thrombosis in PCOS.