Regulation Of Plasminogen Activator Inhibitor-1 Expression Research Articles

PAI-1 genetic polymorphisms influence septic patients' outcomes by regulating neutrophil activity.

Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathophysiology of sepsis, but the exact mechanism remains debatable. In this study, we investigated the associations among the serum levels of PAI-1, the incidence of 4G/5G promoter PAI-1 gene polymorphisms, immunological indicators, and clinical outcomes in septic patients. A total of 181 patients aged 18-80 years with sepsis between November 2016 and August 2018 in the intensive care unit in the Xinhua Hospital were recruited in this retrospective study, with 28-day mortality as the primary outcome. The initial serum level of PAI-1 and the presence of rs1799768 single nucleotide polymorphisms (SNPs) were examined. Univariate logistic regression and multivariate analyses were performed to determine the factors associated with different genotypes of PAI-1, serum level of PAI-1, and 28-day mortality. The logistic analysis suggested that a high serum level of PAI-1 was associated with the rs1799768 SNP of PAI-1 (4G/4G and 4G/5G) (Odds ratio [OR]: 2.49; 95% confidence interval [CI]: 1.09, 5.68). Furthermore, a high serum level of PAI-1 strongly influenced 28-day mortality (OR 3.36; 95% CI 1.51, 7.49). The expression and activation of neutrophils (OR 0.96; 95% CI 0.93, 0.99), as well as the changes in the expression patterns of cytokines and chemokine-associated neutrophils (OR: 1.00; 95% CI: 1.00, 1.00), were both regulated by the genotype of PAI-1. Genetic polymorphisms of PAI-1 can influence the serum levels of PAI-1, which might contribute to mortality by affecting neutrophil activity. Thus, patients with severe sepsis might clinically benefit from enhanced neutrophil clearance and the resolution of inflammation via the regulation of PAI-1 expression and activity.

Transcriptomic study of high‑glucose effects on human skin fibroblast cells.

Skin ulcers are a common complication of diabetes mellitus (DM). Fibroblasts are located within the dermis of skin tissue and can be damaged by diabetes. However, the underlying mechanism of how DM affects fibroblasts remains elusive. To understand the effects of DM on fibroblasts, the current study mimicked DM by high‑glucose (HG) supplementation in the culture medium of human foreskin primary fibroblast cells, and the analysis of transcriptomic changes was conducted. RNA sequencing‑based transcriptome analysis identified that, upon HG stress, 463 genes were upregulated and 351 genes downregulated (>1.5‑fold changes; P<0.05). These altered genes were distributed into 20 different pathways. In addition, gene ontology (GO) analysis indicated that 31 GO terms were enriched. Among the pathways identified, nuclear factor κB (NF‑κB) pathway genes were highly expressed, and the addition of Bay11‑7082, a typical NF‑κB signaling inhibitor, blocked the previously observed alterations in plasminogen activator inhibitor 1 (PAI1), an inflammation marker and frizzled class receptor 8 (FZD8), a Wnt signaling gene, expression that resulted from HG stress. Furthermore, an inhibitor of Wnt signaling diminished the role of Bay11‑7082 in the regulation of PAI1 expression under HG conditions, suggesting that Wnt signaling may function downstream of the NF‑κB pathway to protect fibroblast cells from HG stress. To the best of our knowledge, the current study is the first analysis of transcriptomic responses under HG stress in human fibroblasts. The data provided here may aid the understanding of the molecular mechanisms by which fibroblast cells are damaged in the skin of patients with DM.

The history and current status of anti-sperm antibody research

we have studied the implication of bone morphogenetic proteins (BMP) in the ovarian physiology. In the present study,weexhibit ourdata regarding (1) folliculogenesis, (2) ovulation and (3) polycystic ovary syndrome (PCOS), especially from the point of the relationship between ovarian cells and immune-competent cells. Folliculogenesis:Although the formation of an individual capillary network in the theca cell layer is required for ovarian folliculogenesis, the mechanism has not been clarified. We found that theca cell derived BMP-7 stimulated VEGF secretion levels in GC significantly. In endothelial cells, BMP-7 increased the cell number and induced VEGF receptor mRNA. BMP-7 might work to form vasculature around follicles via induction of VEGF expression in GC and increased sensitivity of endothelial cells to VEGF. Ovulation: As granulocyte colony-stimulating factor (G-CSF) is known to be a candidate for a treatment of luteinized unruptured follicle (LUF), neutrophils might be involved in ovulatory process. BMP cytokine is known to regulate ovulation, as BMP-6 null mice exhibit a decrease in the number of ovulatory follicleswithout effect on either themorphology or the dynamics of follicular development. We found that BMP-6 significantly increased growthregulated oncogene (GRO)levels in human GC. On the other hand, BMP-6 suppressed the relative expression of the protease inhibitors, secretory leukocyte peptidase inhibitor (SLPI) in GC. BMP-6 might play a role in ovulation by increasing the accumulation of neutrophils in the ovulatory follicle and suppressing the effect of protease inhibitor. PCOS: Plasminogen activator inhibitor-1 (PAI-1), the main physiological inhibitor of plasminogen activation, is elevated in women with PCOS and has been linked to PCOS in a mouse model of the disease. We have found that TGFand TNFwhich are involved in the etiology of PCOS, increased PAI-1 secretion levels by cultured GC. Insulin sensitizing drugs suppressed TGFand TNFmRNA expression in peritoneal fluid mononuclear cells. Our data suggested that insulin sensitizing agentsmayprovide a potential therapy for PCOS via down regulation of PAI-1 expression indirectly. To understand the etiology of PCOS, the regulation of immune-competent cells should be taken into consideration.

Novel regulatory mechanism and functional implication of plasminogen activator inhibitor-1 (PAI-1) expression in CpG-ODN-stimulated macrophages

Macrophages are activated by recognizing bacterial DNA and CpG-oligodeoxynucleotides (CpG-ODNs) through Toll-like receptor-9 (TLR-9). Plasminogen activator inhibitor-1 (PAI-1) has been shown to be an important factor in inflammation-induced macrophage migration which is essential for defense functions. The aim of this study was to demonstrate the molecular mechanism associated with the regulation of PAI-1 expression and its biological significance in CpG-ODN-stimulated mouse macrophages. Our results clearly show that PAI-1 expression in macrophages was highly up-regulated by CpG-ODN-stimulation in vitro and in vivo. The TLR-9-mediated stimulation of PAI-1 expression was independent of the NF-κB pathway and involved the synergistic activation of Sp1 and Elk-1 by the MEK1/2-ERK and JNK signaling pathways. The elevated PAI-1 expression resulted in significantly enhanced transmigration of RAW264.7 cells through vitronectin but not through fibronectin. We suggest that CpG-ODN plays a role in regulating macrophage migration by stimulating the expression of PAI-1, and the migration is modulated depending on the microenvironmental extracellular matrix components.

The adaptor protein Ruk/CIN85 activates plasminogen activator inhibitor-1 (PAI-1) expression via hypoxia-inducible factor-1α

Increased levels of plasminogen activator inhibitor-1 (PAI-1) indicate an enhanced risk of ischaemic/hypoxic cardiovascular events and a poor prognosis. The expression of PAI-1 can be induced by various stimuli including hypoxia, insulin and insulin-like growth factor 1 (IGF-1). The hypoxia-inducible factor-1 (HIF-1) is critical for hypoxia or insulin/IGF-1 mediated PAI-1 induction, but the components involved in merging the signals are not known so far. The adaptor/scaffold protein Ruk/CIN85 may be a candidate since it plays important roles in the regulation of processes associated with cardiovascular and oncological diseases such as downregulation of receptor tyrosine kinases, apoptosis, adhesion and invasion. Therefore, it was the aim of this study to investigate the involvement of Ruk/CIN85 in the regulation of PAI-1 expression. It was found that Ruk/CIN85 induced PAI-1 mRNA and protein expression both under normoxia and hypoxia. The induction of PAI-1 expression by Ruk/CIN85 occurred at the transcriptional level since the half-life of PAI-1 mRNA was not affected in cells overexpressing Ruk/CIN85 and reporter gene assays using wild-type and mutant human PAI-1 promoter luciferase constructs showed that the hypoxia responsive element was responsible for Ruk/CIN85 effects. Further, knocking down HIF-1alpha abolished not only the hypoxia-dependent but also the Ruk/CIN85-dependent PAI-1 induction. In addition, transient or stable overexpression of Ruk/CIN85 also induced HIF-1alpha protein levels and HIF-1 activity and knocking down Ruk/CIN85 reversed these effects. Thereby, Ruk/CIN85 interfered with the proline hydroxylation-dependent HIF-1alpha protein destabilisation. Together, these results provide the first evidence that Ruk/CIN85 induces PAI-1 expression via modulation of HIF-1alpha stability.

Green tea polyphenols inhibit plasminogen activator inhibitor-1 expression and secretion in endothelial cells

Compelling epidemiological evidence suggests that the consumption of green tea is associated with beneficial effects in prevention of cardiovascular diseases. Plasminogen activator inhibitor-1 (PAI-1) is known to play a pivotal role in cardiovascular diseases including arteriosclerosis and hypertension. Increased PAI-1 was found in atherosclerotic lesions, and high PAI-1 plasma levels were associated with coronary heart disease. To determine the effect and molecular mechanism of green tea polyphenols (GTPs) on the regulation of PAI-1 expression in endothelial cells, bovine aortic endothelial cells were incubated with GTPs, and PAI-1 expressions were measured by western blot and enzyme-linked immunosorbent assay, respectively. GTPs significantly reduced PAI-1 expression and secretion in a time-dependent and dose-dependent manner. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin markedly reversed GTPs repression of PAI-1 expression. In addition, the GTP-induced inhibitory effect was associated with an increased of activation of the protein kinase Akt. These results suggest that GTPs inhibit PAI-1 expression and its release from endothelial cells through the PI3K/Akt pathway, which may contribute to cardiovascular protection.

Nox4 mediates the expression of plasminogen activator inhibitor-1 via p38 MAPK pathway in cultured human endothelial cells

Introduction Plasminogen Activator Inhibitor-1 (PAI-1) is the most potent endogenous inhibitor of fibrinolysis which is implicated in the pathogenesis of myocardial infarction and metabolic syndrome. The formation of reactive oxygen species (ROS) plays an important role in the pathology of vascular disorders and has been shown to increase PAI-1 expression by endothelial cells. Growing evidence indicates that NADPH oxidase and in particular the constitutively active Nox4-p22 phox complexes are major sources of ROS in endothelial cells. The aim of the present study was to characterize the role of NADPH oxidase and in particular Nox4 in the regulation of PAI-1 expression in cultured Human Umbilical Venous Endothelial Cells (HUVECs). Methods and Results N-acetylcysteine (NAC, scavenger of ROS), diphenylene iodonium chloride (DPI, inhibitor of flavoproteins), M40403 (superoxyde dismutase mimic) and S17834 (inhibitor of NADPH oxidase) inhibited PAI-1 release and promoter activity in HUVECs. Specific knock down of Nox4 mRNA by siRNA caused a decrease in ROS production and NADPH oxidase activity. Moreover, Nox4 silencing decreased PAI-1 expression, release and activity as well as p38 MAPK pathways and NFκB activation. These signalling pathways are also involved in PAI-1 release. Conclusions The NADPH oxidase inhibitors DPI and S 17834 as well as Nox4 silencing decreased PAI-1 synthesis in human cultured endothelial cells demonstrating the involvement of the constitutively active Nox4-containing NADPH oxidase in ROS-mediated PAI-1 transcription via p38 MAPK pathways. NADPH oxidase targeting with inhibitors such as S17834 could be an interesting strategy to decrease both oxidative stress and PAI-1 synthesis.

The impact of the PAI-1 4G/5G polymorphism on the outcome of patients with ALI/ARDS

Intoduction Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with worse outcome in ALI/ARDS. A single guanosine insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene, may play an important role in the regulation of PAI-1 expression. The objective of the study was to evaluate the effect of this polymorphism on the outcome of critically ill patients with ALI/ARDS. Materials and Methods 52 consecutive ventilated patients with ALI/ARDS were studied. Bronchoalveolar lavage was performed within 48 hours from diagnosis. Measurement of plasma and BALF PAI-1 activity and D-dimers levels, and 4G/5G genotyping of PAI-1 were carried out. The primary outcome was 28-day mortality, and secondary outcomes included organ dysfunction and ventilator-free days. Results 17 patients were homozygotes for the 4G allele. Severity scores were not different between subgroups upon study enrollment. 28-day mortality was 70.6% and 42.9% for the 4G-4G and the non-4G-4G patients, respectively (p = 0.06). PAI-1 activity levels and D-dimer in plasma and BALF were not significantly different between the 4G-4G and the non-4G-4G subgroups. In the multivariate analysis, genotype 4G/4G was the only variable independently associated with 28-day mortality (Odds Ratio = 9.95, 95% CI: 1.79-55.28, p = 0.009). Furthermore, genotype 4G/4G and plasma PAI-1 activity levels were independently negatively associated with ventilator free days (p = 0.033 and p = 0.008, respectively). Conclusions ALI/ARDS patients, homozygous for the 4G allele of the PAI-1 gene, experienced higher 28-day mortality. This genotype was associated with a reduction in the number of days of unassisted ventilation and was inversely associated with the number of days without organ failure.

Oxidative Stress, Plasminogen Activator Inhibitor 1, and Lung Fibrosis

Fibrosis is characterized by excessive accumulation of extracellular matrix (ECM) in basement membranes and interstitial tissues, resulting from increased synthesis or decreased degradation of ECM or both. The plasminogen activator/plasmin system plays an important role in ECM degradation, whereas the plasminogen activator inhibitor 1 (PAI-1) is a physiologic inhibitor of plasminogen activators. PAI-1 expression is increased in the lung fibrotic diseases and in experimental fibrosis models. The deletion of the PAI-1 gene reduces, whereas the overexpression of PAI-1 enhances, the susceptibility of animals to lung fibrosis induced by different stimuli, indicating an important role of PAI-1 in the development of lung fibrosis. Many growth factors, including transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), as well as other chemicals/agents, induce PAI-1 expression in cultured cells and in vivo. Reactive oxygen and nitrogen species (ROS/RNS) have been shown to mediate the induction of PAI-1 by many of these stimuli. This review summarizes some recent findings that help us to understand the role of PAI-1 in the development of lung fibrosis and ROS/RNS in the regulation of PAI-1 expression during fibrogenesis.

Metabolic, hormonal and environmental regulation of plasminogen activator inhibitor-1 (PAI-1) expression: Lessons from the liver

Plasminogen activator inhibitor-1 (PAI-1) controls the regulation of the fibrinolytic system in blood by inhibiting both urokinase-type and tissue-type plasminogen activators. Enhanced levels of PAI-1 are found in patients with type 2 diabetes mellitus which is associated with a dysbalance in glucose and lipid homeostasis. Especially a defective insulin response in the liver contributes to the development of hyperglycemia, dyslipidemia and peripheral insulin resistance and may contribute to hepatic over-expression of PAI-1 in diabetes type 2. Furthermore, a substantial upregulation of PAI-1 expression has also been shown in a variety of liver injury models. Thus, the liver appears to be not only a major site of PAI-1 synthesis in response to hormonal changes, but also in response to a variety of other pathological events. PAI-1 expression in liver largely depends on activation of signalling pathways and transcriptional regulators which may be the basis for a new level of cross-talk between different signalling pathways and thus may represent attractive therapeutic candidates. This article will primarily focus on the regulation of PAI-1 expression in liver cells and discuss potential cross-talks between metabolic, hormonal and environmental signals.

Natriuretic factors and nitric oxide suppress plasminogen activator inhibitor-1 expression in vascular smooth muscle cells. Role of cGMP in the regulation of the plasminogen system.

Increased expression of plasminogen activator inhibitor-1 (PAI-1) has been reported in atherosclerotic and balloon-injured vessels. Little is known regarding the factors and mechanisms that may negatively regulate PAI-1 expression. In this report, the effect of cGMP-coupled vasoactive hormones, including natriuretic factors and nitric oxide, on the regulation of PAI-1 expression in vascular smooth muscle cells was examined. Atrial natriuretic factor 1-28 (ANF) and C-type natriuretic factor-22 (CNP) reduced angiotensin II (Ang II)- and platelet-derived growth factor-stimulated PAI-1 mRNA expression in rat aortic smooth muscle cells by 50% to 70%, with corresponding reductions in PAI-1 protein release. Treatment of human aortic smooth muscle cells with CNP similarly inhibited both platelet-derived growth factor-induced PAI-1 mRNA expression and PAI-1 protein release by 50%. Dose-response studies revealed that the inhibitory effects of CNP and ANF on PAI-1 expression were concentration dependent, with IC50s of approximately 1 nmol/L for both natriuretic peptides. Ang II-stimulated PAI-1 expression was also inhibited by the nitric oxide donor S-nitroso-N-acetylpenicillamine. The membrane-permeant cGMP analogue 8-Br-cGMP reduced Ang II-stimulated PAI-1 expression by 60%, and an inhibitor of soluble guanylyl cyclase (1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one) significantly impaired the inhibitory effects of S-nitroso-N-acetylpenicillamine on Ang II-stimulated PAI-1 expression. Studies of PAI-1 mRNA stability in cells treated with actinomycin D showed that ANF did not alter PAI-1 mRNA half-life, suggesting that natriuretic factors reduce PAI-1 transcription. These data show that natriuretic factors and nitric oxide, via a cGMP-dependent mechanism, inhibit PAI-1 synthesis in vascular smooth muscle cells. Thus, cGMP-coupled vasoactive hormones may play an important role in suppressing vascular PAI-1 expression.