Transient reduction of placental angiogenesis in PAI-1-deficient mice

Angiotensin-Converting Enzyme (ACE) Insertion/Deletion (I/D) Polymorphism as a Conjoint Regulator of Coagulation, Fibrinolytic, and RAAS Pathway in Infertility and Associated Pregnancy Complications

Despite the increase in assisted reproductive technologies, the high rates of infertility and pregnancy complications are a major concern to infertility specialists worldwide. Infertility may be attributed to pregnancy complications like thrombophilia, preeclampsia and fibrin-induced recurrent pregnancy loss (RPL). Renin-angiotensin-aldosterone system (RAAS) directly or indirectly causes preeclampsia and thrombophilia through the fibrinolytic pathway that ultimately leads to RPL or infertility. The underlying mechanisms of this interaction are still unclear. The present comprehensive review is intended to demonstrate the role and interaction of RAAS and fibrinolytic pathways in pregnancy complications. How this interaction can induce pregnancy complications, and ultimately infertility, is also discussed in the light of current evidence. This study also presents common markers that link RAAS and fibrinolytic processes in developing thrombophilia, preeclampsia and RPL. The common link in these pathways is ACE gene I/D polymorphism. Apart from ACE, PAI-1, VIIa, XIIa, AT1R, AT1AA, and TF are common molecules that can delineate the underlying causes of pregnancy complications and infertility.

Genetic Variations miR-10aA>T, miR-30cA>G, miR-181aT>C, and miR-499bA>G and the Risk of Recurrent Pregnancy Loss in Korean Women

This study investigated the genetic association between recurrent pregnancy loss (RPL) and microRNA (miRNA) polymorphisms in miR-10aA>T, miR-30cA>G, miR-181aT>C, and miR-499bA>G in Korean women. Blood samples were collected from 381 RPL patients and 281 control participants, and genotyping of miR-10aA>T, miR-30cA>G, miR-181aT>C, and miR-499bA>G was carried out by TaqMan miRNA RT-Real Time polymerase chain reaction (PCR). Four polymorphisms were identified, including miR-10aA>T, miR-30cA>G, miR-181aT>C, and miR-499bA>G. MiR-10a dominant model (AA vs. AT + TT) and miR-499bGG genotypes were associated with increased RPL risk (adjusted odds ratio [AOR] = 1.520, 95% confidence interval [CI] = 1.038−2.227, p = 0.032; AOR = 2.956, 95% CI = 1.168−7.482, p = 0.022, respectively). Additionally, both miR-499 dominant (AA vs. AG + GG) and recessive (AA + AG vs. GG) models were significantly associated with increased RPL risk (AOR = 1.465, 95% CI = 1.062−2.020, p = 0.020; AOR = 2.677, 95% CI = 1.066−6.725, p = 0.036, respectively). We further propose that miR-10aA>T, miR-30cA>G, and miR-499bA>G polymorphisms effects could contribute to RPL and should be considered during RPL patient evaluation.

The interaction effect of angiogenesis and endothelial dysfunction-related gene variants increases the susceptibility of recurrent pregnancy loss

PURPOSE

The role of genetic polymorphisms in the pathogenesis of recurrent pregnancy loss (RPL) has been studied intensively. Complex diseases, including miscarriage, are believed to have a polygenic basis, and gene-gene interactions can play a significant role in the etiology of the disease. This study was conducted to investigate the association of gene-gene interactions with angiogenesis, endothelial dysfunction-related gene polymorphisms, and RPL.

METHODS

A case-control study was conducted with 253 unrelated RPL patients with 2 or more spontaneous pregnancy losses and 339 healthy women with no history of pregnancy complications. Genotyping of single-nucleotide polymorphisms (SNPs) was performed using real-time polymerase chain reaction (real-time PCR), restriction fragment length polymorphism (RFLP), or allele-specific polymerase chain reaction methods.

RESULTS

The genotypes 677TT of the MTHFR gene, 936TT, 936CT, and 634CC, 634GC of the VEGF gene, and allele 894T of the NOS3 gene were associated with a predisposition to RPL in the Russian population. A significant role of additive and epistatic effects in the gene-gene interactions of the SNPs of SERPINE-1, ACE, NOS3, MTHFR, and VEGF genes in RPL was demonstrated.

CONCLUSIONS

The results showed that gene-gene interactions are important for RPL susceptibility. Additionally, analysis of the genotype combinations of several allelic variants provides more information on RPL risk than analysis of independent polymorphic markers.

Role of Plasminogen Activator Inhibitor Type 1 in Pathologies of Female Reproductive Diseases

Normal pregnancy is a state of hypercoagulability with diminishing fibrinolytic activity, which is mainly caused by an increase of plasminogen activator inhibitor type 1 (PAI-1). PAI-1 is the main inhibitor of plasminogen activators, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In human placentas, PAI-1 is expressed in extravillous interstitial trophoblasts and vascular trophoblasts. During implantation and placentation, PAI-1 is responsible for inhibiting extra cellular matrix (ECM) degradation, thereby causing an inhibition of trophoblasts invasion. In the present study, we have reviewed the literature of various reproductive diseases where PAI-1 plays a role. PAI-1 levels are increased in patients with recurrent pregnancy losses (RPL), preeclampsia, intrauterine growth restriction (IUGR), gestational diabetes mellitus (GDM) in the previous pregnancy, endometriosis and polycystic ovary syndrome (PCOS). In general, an increased expression of PAI-1 in the blood is associated with an increased risk for infertility and a worse pregnancy outcome. GDM and PCOS are related to the genetic role of the 4G/5G polymorphism of PAI-1. This review provides an overview of the current knowledge of the role of PAI-1 in reproductive diseases. PAI-1 represents a promising monitoring biomarker for reproductive diseases and may be a treatment target in the near future.

Cilioretinal artery: Vasculogenesis might be promoted by plasminogen activator inhibitor-1 5G allele

BACKGROUND

Cilioretinal arteries (CAs) represent enlargements of microscopic and early established collaterals formed via vasculogenesis between choroidal and retinal circulations. We aimed to investigate whether genetic tendency to thrombosis due to well-known gene polymorphisms may induce CA vasculogenesis in embryonic life.

METHODS

We assessed plasminogen activator inhibitor-1 (PAI-1) 4G/5G, methylenetetrahydrofolatereductase (MTHFR), FACTOR V LEIDEN and PROTHROMBIN gene polymorphisms on 130 patients [82/48 females/males; Median age: 57 (18-84) with visible CAs and 100 (64/36: female/male; Median age: 55 (19-90)] without visible CAs.

RESULTS

Using multiple logistic regression models, we found PAI-1 4G/5G; MTHFR (C677T and A1298C) polymorphisms to have significant effects on the probability of visible CAs, that having at least one 5G allele would increase the odds of having visible cilioretinal artery by 98.4% [Odds ratio: 1984 (95% CI: 1.320-3.000, p = 0.001)], and having at least one MTHFR C677T or A1298C allele would decrease the odds of having visible CAs by approximately 38% (OR = 0.618, 95% CI: 0.394-0.961, p = 0.035) or 44% (OR = 0.558, 95% CI: 0.354-0.871, p = 0.011), respectively.

CONCLUSIONS

This is the first study to test the existence of significant association between presence of enlarged and visible CAs and genetic factors predisposing to thrombosis, according to the literature. Here we suggest that not only the lack of genetic predisposition to thrombosis by MTHFR gene polymorphisms, but also the PAI-1 5G allele might promote vasculogenesis of CAs.

Plasminogen Activator Inhibitor-1 4G/5G Polymorphism is Associated with Reproductive Failure: Metabolic, Hormonal, and Immune Profiles

PROBLEM

Association between PAI-1 4G/5G polymorphism and reproductive failures has been postulated. We aimed to investigate its impact on metabolic, hormonal, and immune profiles of women with reproductive failures.

METHOD OF STUDY

A retrospective study was carried out in 208 women with a history of reproductive failure. Study patients were divided into three groups: women with repeated implantation failure (RIF, n = 40), recurrent pregnancy loss (RPL, n = 113), and both RIF and RPL (n = 55). Fertile controls were 92.

RESULTS

PAI-1 4G/4G was prevalent in RPL, RIF, and RIF/RPL groups when compared with controls (P = 0.003) and associated with increased risks of RIF, RPL, and RIF with RPL (OR = 4.5, 2.2 and 2.7). Women with PAI-1 4G/4G have significantly higher BMI, glucose, and PAI-1 levels and lower NK cytotoxicity when compared with women without PAI-1 4G/4G.

CONCLUSION

PAI-1 4G/5G polymorphism plays a major role in the pathogenesis of RPL and RIF by altering metabolic and immunological profiles.

Increased Umbilical Cord PAI-1 Levels in Placental Insufficiency Are Associated with Fetal Hypoxia and Angiogenesis

In intrauterine growth restriction (IUGR), a subset of pregnancies undergoes placental vascular dysregulation resulting in restricted blood flow and fetal hypoxemia. Altered transcription of hypoxic regulated plasminogen activator inhibitor 1 (PAI-1) has been associated with pregnancy complications and angiogenic regulation. Here we assessed circulating PAI-1 as an indicator of placental insufficiency. Venous umbilical PAI-1 of hypoxemic (VpO2 20 versus 35 mmHg, p < 0.0001) placental insufficient pregnancies (resistance index 0.9 versus 0.63, p < 0.05) (n = 18) was compared to controls (n = 12). PAI-1 was increased (~10-fold, p < 0.001) and had a positive predictive ratio of 6.7. Further, PAI-1 levels correlated to blood oxygen (r = -0.68, p < 0.0001). The plasma's angiogenic potency measured in vitro was associated with umbilical cord blood PAI-1 levels (r = 0.65, p < 0.01). This association was attenuated by PAI-1 inhibiting antibody (p < 0.001). The results demonstrate PAI-1 as a potential marker of placental insufficiency and identify its close association with pathological hypoxia and angiogenesis in a subset of growth restricted pregnancies.

Association between plasminogen activator inhibitor-1 gene polymorphisms and recurrent pregnancy loss: a systematic review and meta-analysis

Human plasminogen activator inhibitor-1 (PAI-1) is closely related to embryonic development and pregnancy success. The association between PAI-1 gene polymorphisms (PAI-1-844G/A and PAI-1-675G/A) and the risk of recurrent pregnancy loss (RPL) is controversial. Therefore, we perform this review to clarify the association between PAI-1 gene polymorphisms and RPL risk. We performed a systematic search for studies that described the effect of PAI-1 polymorphisms on RPL risk. The odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were considered under recessive genetic models. Furthermore, we conducted a subgroup analysis based on the studies' geographic regions of origin. Data were analyzed using Stata 11.2 software. Eighteen studies were included, and a high degree of statistical heterogeneity existed among the studies. In this study, we found a significant association between the PAI-1-675G/A polymorphism and the risk of RPL under the recessive model (OR = 1.70, 95% CI = 1.21-2.38). However, no significant association between the PAI-1-844G/A polymorphism and RPL was noted. PAI-1-675G/A (4G/5G) polymorphisms play a potential role in RPL. The screening of PAI-1 (4G/5G) gene mutations should be included during an RPL diagnostic workup, and patients should be treated using anticoagulant therapy during pregnancy if necessary.

Mast cells rescue implantation defects caused by c-kit deficiency

Various physiologically relevant processes are regulated by the interaction of the receptor tyrosine kinase (c-Kit) and its ligand stem cell factor (SCF), with SCF known to be the most important growth factor for mast cells (MCs). In spite of their traditional role in allergic disorders and innate immunity, MCs have lately emerged as versatile modulators of a variety of physiologic and pathologic processes. Here we show that MCs are critical for pregnancy success. Uterine MCs presented a unique phenotype, accumulated during receptivity and expanded upon pregnancy establishment. Kit^W-sh/W-sh mice, whose MC deficiency is based on restricted c-Kit gene expression, exhibited severely impaired implantation, which could be completely rescued by systemic or local transfer of wild-type bone marrow-derived MCs. Transferred wild-type MCs favored normal implantation, induced optimal spiral artery remodeling and promoted the expression of MC proteases, transforming growth factor-β and connective tissue growth factor. MCs contributed to trophoblast survival, placentation and fetal growth through secretion of the glycan-binding protein galectin-1. Our data unveil unrecognized roles for MCs at the fetomaternal interface with critical implications in reproductive medicine.

Unique expression patterns associated with preferential recruitment of immature myeloid cells into angiogenic versus dormant tumors

Cancer progression from microscopic dormant tumors into disseminated disease involves tumor angiogenesis, and is commonly referred to as the 'angiogenic switch'. CD11b(+)Gr1(+) immature myeloid cells (IMCs) were reported to promote angiogenesis and tumor progression. Here, we studied a model of tumor dormancy, in which Lewis Lung Carcinoma tumor cells were inoculated intra-abdominally into C57Bl/6J mice. Dormancy versus expansive growth was determined by the site of tumor implantation (lower vs upper abdomen). Global gene expression of IMCs was evaluated in different stages of recruitment, starting in the bone marrow, followed by the peripheral blood and finally in the vascular versus dormant tumors. We first demonstrated a ∼3 fold enrichment of IMCs within vascular tumors as compared with dormant tumors, correlating with tumor-infiltrating CD31(+) endothelial cells. Although their migration from the PB into dormant tumors led to differential expression of a relatively small number of genes, recruitment of IMCs into the upper tumors was associated with a profound transcriptional response. Importantly, a large set of proangiogenic genes were significantly upregulated in IMCs derived from vascular tumors compared with those derived from dormant tumors. We therefore, suggest that proangiogenic versus nonangiogenic transcriptional patterns is associated with the ability of IMCs to promote tumor angiogenesis.

Tissue plasminogen activator and plasminogen activator inhibitor 1 contribute to sonic hedgehog-induced in vitro cerebral angiogenesis

The molecular mechanisms underlying cerebral angiogenesis have not been fully investigated. Using primary mouse brain endothelial cells (MBECs) and a capillary-like tube formation assay, we investigated whether the sonic hedgehog (Shh) signaling pathway is coupled with the plasminogen/plasmin system in mediating cerebral angiogenesis. We found that incubation of MBECs with recombinant human Shh (rhShh) substantially increased the tube formation in naïve MBECs. This was associated with increases in tissue plasminogen activator (tPA) activation and reduction of plasminogen activator inhibitor 1 (PAI-1). Blockage of the Shh pathway with cyclopamine abolished the induction of tube formation and the effect of rhShh on tPA and PAI-1. Addition of PAI-1 reduced rhShh-augmented tube formation. Genetic ablation of tPA in MBECs impaired tube formation and downregulated of vascular endothelial growth factor (VEGF) and angiopoietin 1 (Ang1). Addition of rhShh to tPA−/− MBECs only partially restored the tube formation and upregulated Ang1, but not VEGF, although rhShh increased VEGF and Ang1 expression on wild-type MBECs. Complete restoration of tube formation in tPA−/− MBECs was observed only when both exogenous Shh and tPA were added. The present study provides evidence that tPA and PAI-1 contribute to Shh-induced in vitro cerebral angiogenesis.