The Multifaceted Role of Plasminogen in Cancer.

Fibrinolytic factors like plasminogen, tissue-type plasminogen activator (tPA), and urokinase plasminogen activator (uPA) dissolve clots. Though mere extracellular-matrix-degrading enzymes, fibrinolytic factors interfere with many processes during primary cancer growth and metastasis. Their many receptors give them access to cellular functions that tumor cells have widely exploited to promote tumor cell survival, growth, and metastatic abilities. They give cancer cells tools to ensure their own survival by interfering with the signaling pathways involved in senescence, anoikis, and autophagy. They can also directly promote primary tumor growth and metastasis, and endow tumor cells with mechanisms to evade myelosuppression, thus acquiring drug resistance. In this review, recent studies on the role fibrinolytic factors play in metastasis and controlling cell-death-associated processes are presented, along with studies that describe how cancer cells have exploited plasminogen receptors to escape myelosuppression.

Dual mutation (MTHFR A1298C with PAI (4G) mutation) manifesting with bilateral lower limb gangrene in a neonate.

Neonates are at highest risk of thrombosis among paediatric patients. The relative prothrombotic state in a well neonate is compensated by other factors preventing spontaneous thrombosis; however, in a neonate with genetic predisposition, the balance is tilted predisposing them to a life-threatening thrombotic episode. We describe a rare case of methylenetetrahydrofolate reductase A1298C (homozygous) mutation along with plasminogen activator inhibitor (4G) mutation in a neonate who developed bilateral lower limb gangrene following thrombosis of the iliac vessels without any triggering factor. The neonate underwent thrombectomy as debulking measure along with thrombolytic therapy followed by unfractionated heparin and low-molecular-weight heparin which is still being continued along with oral aspirin. The neonate had to undergo amputation of both the involved lower limbs in view of dry gangrene. This case highlights that the dual mutations causing the prothrombotic state predispose the individual to the spontaneous life-threatening thrombotic episode as compared with the single mutation.

Analysis of thrombophilic gene mutations in coronary artery ectasia.

OBJECTIVE: Coronary artery ectasia (CAE) is defined as localized or diffuse dilatation in the coronary artery lumen of at least 1.5 times the diameter of adjacent healthy reference segments. The etiology of CAE is still unknown, but the most likely cause is atherosclerosis. The aim of this study was to evaluate several gene polymorphisms that are thought to have an effect on the development of coronary atherosclerosis and have been shown to cause thrombophilia in CAE patients. METHODS: The factor V Leiden (G1691A), factor V H1299R, prothrombin G20210A, factor XIII V34L, beta-fibrinogen-455 G>A, plasminogen activator inhibitor (PAI)-1 4G/5G, and methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C polymorphisms were evaluated in 66 patients with CAE and 32 individuals with normal coronary arteries. RESULTS: Comparison of the CAE and control groups revealed that the clinical features and the frequency of polymorphism in the thrombophilic genes were similar in both groups. However, when heterozygous and/or homozygous polymorphism was compared between groups, it was found that there was a significantly higher finding of thrombophilic gene polymorphism in the CAE group (p=0.023). CONCLUSION: Thrombophilic gene polymorphism may be associated with the formation and clinical presentation of CAE.

Comparison between thrombophilic gene polymorphisms among high risk patients.

INTRODUCTION: The purpose of this study was to compare the role of the thrombophilic variants among two groups of high risk patients with vascular disorders and recurrent pregnancy loss. METHODS: 200 patients, including 76 with thrombotic accidents and 124 with two or more idiopathic recurrent miscarriage during the first trimester, were tested for the presence of Factor V (F V) Leiden G1691A, Factor II (F II) G20210A, plasminogen activator inhibitor (PAI) 4G/5G, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms using Real time polymerase chain reaction (RT - PCR) in the Laboratory of Medical Genetics, Varna, Bulgaria between June 2016 and May 2019. Frequencies of thrombophilic gene polymorphisms were compared among the two populations and to the expected genotype frequencies. RESULTS: Individuals with a history of vascular disorders had a significantly higher frequency of F V Leiden variant compared to women with recurrent miscariage. There was no statistical difference between the analyzed patients for the other three thrombophilic polymorphisms. The allelic frequencies and the expected genotype frequencies of the F V, F II and MTHFR polymorphisms were calculated according to Hardy-Weinberg equilibrium. The percentages of the homozygotes for F V and F II were higher than expected in the two groups of patients. For the MTHFR there was no difference. CONCLUSION: F V Leiden remains the strongest risk factor for vascular disorders and recurrent pregnancy loss. Screening for this variant should be recommended to patients with thrombotic accidents and women with repeated miscarriage. The role of F II, PAI and MTHFR remains controversial.

First Report of an Acute, Obstructive Thrombosis of a Melody Valve Used for Transcatheter Pulmonary Replacement.

Transcatheter pulmonary valve (TPV) replacement is an effective therapy of right ventricular outflow tract conduit dysfunction. Acute complications after TPV implantation include infective endocarditis, stent fracture, and device dislocation. We present a novel, life-threatening complication: an acute, noninfectious TPV thrombosis. Within 24 hours after implantation of a Melody system (Medtronic, Inc, Minneapolis, MN), the patient developed an acute TPV thrombosis characterized by severe TPV stenosis on echocardiography and contrast filling defects on computed tomography pulmonary angiography images. Genetic testing revealed heterozygous prothrombin G20210A polymorphism and homozygous 4G/4G polymorphism of the plasminogen-activator-inhibitor. The patient recovered after surgical valve replacement with a pulmonary homograft.

Differences during the first lactation between cows cloned by somatic cell nuclear transfer and noncloned cows.

Lactation performance is dependent on both the genetic characteristics and the environmental conditions surrounding lactating cows. However, individual variations can still be observed within a given breed under similar environmental conditions. The role of the environment between birth and lactation could be better appreciated in cloned cows, which are presumed to be genetically identical, but differences in lactation performance between cloned and noncloned cows first need to be clearly evaluated. Conflicting results have been described in the literature, so our aim was to clarify this situation. Nine cloned Prim' Holstein cows were produced by the transfer of nuclei from a single fibroblast cell line after cell fusion with enucleated oocytes. The cloned cows and 9 noncloned counterparts were raised under similar conditions. Milk production and composition were recorded monthly from calving until 200d in milk. At 67d in milk, biopsies were sampled from the rear quarter of the udder, their mammary epithelial cell content was evaluated, and mammary cell renewal, RNA, and DNA were then analyzed in relevant samples. The results showed that milk production did not differ significantly between cloned and noncloned cows, but milk protein and fat contents were less variable in cloned cows. Furthermore, milk fat yield and contents were lower in cloned cows during early lactation. At around 67 DIM, milk fat and protein yields, as well as milk fat, protein, and lactose contents, were also lower in cloned cows. These lower yields could be linked to the higher apoptotic rate observed in cloned cows. Apoptosis is triggered by insulin-like factor growth binding protein 5 (IGFBP5) and plasminogen activator inhibitor (PAI), which both interact with CSN1S2. During our experiments, CSN1S2 transcript levels were lower in the mammary gland of cloned cows. The mammary cell apoptotic rate observed in cloned cows may have been related to the higher levels of DNA (cytosine-5-)-methyltransferase 1 (DNMT1) transcripts, coding for products that maintain the epigenetic status of cells. We conclude, therefore, that milk production in cloned cows differs slightly from that of noncloned cows. These differences may be due, in part, to a higher incidence of subclinical mastitis. They were associated with differences in cell apoptosis and linked to variations in DNMT1 mRNA. However, milk protein and fat contents were more similar among cloned cows than among noncloned cows.

Prevention of experimental postoperative peritoneal adhesions through the intraperitoneal administration of tanshinone IIA.

Postoperative adhesions develop after nearly every abdominal surgery. The formation of adhesions is associated with the inflammatory response, fibrinolytic system, and extracellular matrix deposition in response to injury. Tanshinone IIA is one of the major extracts obtained from Salvia miltiorrhiza, which has anti-inflammatory effects on many diseases. Postoperative adhesions were induced by injuring the parietal peritoneum and cecum in Wistar rats, followed by the administration of various dosages of tanshinone IIA. The adhesion scores for each group were collected seven days after the initial laparotomy. The activity of the tissue-type plasminogen activator in the peritoneal lavage fluid was measured. The messenger ribonucleic acid expression levels of the tissue-type plasminogen activator, plasminogen activator inhibitor-1, and cyclooxygenase-2 in the ischaemic tissues were measured by quantitative real-time polymerase chain reaction. The intraperitoneal administration of tanshinone IIA is effective for the prevention of the formation of postoperative adhesions in rats. Tanshinone IIA increased fibrinolytic activity in the peritoneal lavage fluid and tissue-type plasminogen activator messenger ribonucleic acid expression in ischaemic peritoneal tissues but decreased the plasminogen activator inhibitor and cyclooxygenase-2 messenger ribonucleic acid expression significantly. These results revealed that tanshinone IIA was a potent postoperative adhesion preventer by enhancing fibrinolytic activity and decreasing cyclooxygenase-2 activity.

Lack of association between polymorphisms of thrombogenic genes and disease susceptibility in rheumatoid arthritis.

Rheumatoid arthritis (RA) is associated with increased mortality due to cardiovascular disease (CVD). Abnormalities in coagulation have been linked with CVD in general and RA population. The aim of our study is to determine whether particular single nucleotide polymorphisms thought to be involved in the regulation of coagulation are over-represented in patients with RA compared to controls. We compared the frequency of atherothrombotic polymorphisms (Factor V Leiden, fibrinogen G455A, prothrombin G20210A and plasminogen activator inhibitor 4G5G) in 322 RA patients [231 females, mean age 61.5 ± 12, median disease duration 10 years (IQR = 14)] with 441 local controls. No significant differences were observed in genotype or allele frequencies either between RA and controls or between the disease subgroups studied. Whereas these polymorphisms may be of importance at the level of individual patients, they are unlikely to be clinically important on a population basis.

The urokinase plasminogen activator system in breast cancer invasion and metastasis.

The urokinase plasminogen activator system, which is a serine protease family include urokinase-type plasminogen activator (uPA), the uPA receptor and plasminogen activator inhibitors (PAIs). uPA catalyzes the transformation of plasminogen to its active form plasmin, which is able to degrade the extracellular matrix (ECM) and basement membranes, directly or indirectly through activating pro-matrix metalloproteinases (pro-MMPs), promoting cancer cell metastasis and invasion. Both uPA and PAI-1 are poor prognosis markers in primary breast cancer. Evidence has been presented that the uPA system facilitates breast cancer metastasis by several different mechanisms, such as the Ras-ERK pathway and p38 MAPK pathway. This review focuses on uPA system, summarizes their biological effects, highlights the molecular mechanism and pathway, and discusses the role of uPA system in the prevention and treatment of human breast cancers.

Association of tissue plasminogen activator and plasminogen activator inhibitor polymorphism with myocardial infarction: a meta-analysis.

INTRODUCTION: To investigate whether t-PA Alu repeat insertion/deletion (I/D) and PAI-1 4G/5G genetic variations are associated with the risk of MI. METHODS: We conducted a meta-analysis to assess the association between the t-PA I/D and PAI-1 4G/5G polymorphisms and risk of MI. We also performed subgroup analyses based on ethnicity (Caucasian, Asian, and African), gender and age. Forty one eligible studies including 12,461 cases and 14,993 controls were identified to evaluate the impact of PAI-1 4G/5G polymorphism on MI. Seven studies investigated the relationship between t-PA I/D and MI. RESULTS: This meta-analysis revealed that the PAI-1 4G allele (4G/4G and 4G/5G genotype) was associated with an increased risk of MI compared with the 5G allele in the overall population (OR=1.094, 95% CI=1.021 - 1.172, p=0.011). The relative risks of MI for 4G/4G genotype was increased when compared to 5G/5G genotype and 5G allele, with odds ratio at 1.157 (95% CI 1.015 - 1.320, p=0.029) and 1.126 (95% CI =1.015 - 1.249, p=0.025). However, the results show that the 4G/5G polymorphism risk for MI was not associated with ethnicity stratification as Caucasian, Asian or African population. No substantial differences in the genotype distributions were observed in the MI group and control group along the lines of gender and age. After multivariable analysis t-PA I/D polymorphism showed no consistent association with MI. CONCLUSIONS: This study suggests that the 4G/5G polymorphism of PAI-1 may be a risk factor for MI in overall populations.

Inhibition of Mycobacterium tuberculosis-induced signalling by transforming growth factor-ß in human mononuclear phagocytes.

Tuberculosis (TB) is associated with excessive production and bioactivation of transforming growth factor bets (TGF-ß) in situ. Here, modification of expression of components of plasminogen/plasmin pathway in human monocytes (MN) by inhibitors of TGF-ß signalling was examined. Smad3 siRNA effectively inhibited TGF-ß-induced urokinase plasminogen activator receptor (uPAR). Agents known to interfere with TGF-ß signalling, including the Smad inhibitors SIS3 and erythromycin derivatives, and ALK5 receptor inhibitor (SB 431542) in inhibition of uPAR expression in response to Mycobacterium tuberculosis (MTB) were examined. Inhibition by SIS3 only inhibited uPAR mRNA significantly. SIS3 may prove to be an effective adjunct to TB therapy.

Impact of uPA system gene polymorphisms on the susceptibility of environmental factors to carcinogenesis and the development of clinicopathology of oral cancer.

BACKGROUND: The levels of urokinase plasminogen activator (uPA) system in tumor tissues are implicated as prognostic biomarkers in a wide range of malignancies. However, their possible impact on the risk and prognosis of oral cancer and the susceptibility of environmental carcinogens to oral cancer remains poorly investigated. METHODS: The genetic polymorphisms of uPA, uPA receptor (uPAR), and plasminogen activator inhibitor (PAI)-1 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 253 patients with oral cancer and 344 healthy controls. RESULTS: There was no significant effect of uPA system genes on the susceptibility of oral cancer; however, the impact of uPA system gene polymorphisms on the susceptibility of betel nut and tobacco consumptions to oral cancer was revealed, except for that of uPAR gene polymorphism on tobacco consumption. Patients with oral cancer with at least one 5G allele of PAI-1 gene have a low risk for the development of clinical stage III or IV (p ≤ 0.05) and lymph node metastasis (p ≤ 0.05) compared with those with 4G/4G homozygotes. CONCLUSIONS: Our results suggest that the combination of uPA system gene polymorphisms and environmental carcinogens was related to the risk of oral cancer, and the genetic polymorphism of PAI-1 was associated with a low risk to the clinicopathological development of oral cancer.

Functional stability of endothelial cells on a novel hybrid scaffold for vascular tissue engineering.

Porous and pliable conduits made of biodegradable polymeric scaffolds offer great potential for the development of blood vessel substitutes but they generally lack signals for cell proliferation, survival and maintenance of a normal phenotype. In this study we have prepared and evaluated porous poly(ε-caprolactone) (PCL) integrated with fibrin composite (FC) to get a biomimetic hybrid scaffold (FC PCL) with the biological properties of fibrin, fibronectin (FN), gelatin, growth factors and glycosaminoglycans. Reduced platelet adhesion on a human umbilical vein endothelial cell-seeded hybrid scaffold as compared to bare PCL or FC PCL was observed, which suggests the non-thrombogenic nature of the tissue-engineered scaffold. Analysis of real-time polymerase chain reaction (RT-PCR) after 5 days of endothelial cell (EC) culture on a hybrid scaffold indicated that the prothrombotic von Willebrand factor and plasminogen activator inhibitor (PAI) were quiescent and stable. Meanwhile, dynamic expressions of tissue plasminogen activator (tPA) and endothelial nitric oxide synthase indicated the desired cell phenotype on the scaffold. On the hybrid scaffold, shear stress could induce enhanced nitric oxide release, which implicates vaso-responsiveness of EC grown on the tissue-engineered construct. Significant upregulation of mRNA for extracellular matrix (ECM) proteins, collagen IV and elastin, in EC was detected by RT-PCR after growing them on the hybrid scaffold and FC-coated tissue culture polystyrene (FC TCPS) but not on FN-coated TCPS. The results indicate that the FC PCL hybrid scaffold can accomplish a remodeled ECM and non-thrombogenic EC phenotype, and can be further investigated as a scaffold for cardiovascular tissue engineering.

Spatiotemporal expression of the serine protease inhibitor, SERPINE2, in the mouse placenta and uterus during the estrous cycle, pregnancy, and lactation.

BACKGROUND: SERPINE2, also known as glia-derived nexin or protease nexin-1, belongs to the serine protease inhibitor (SERPIN) superfamily. It is one of the potent serpins that modulates the activity of the plasminogen activator (PA) and was implicated in tissue remodeling. In this study, we investigated the expression patterns of SERPINE2 in the mouse placenta and uterus during the estrous cycle, pregnancy, and lactation. METHODS: SERPINE2 was purified from mouse seminal vesicle secretion using liquid chromatography (LC) and identified by LC/tandem mass spectrometry. The antiserum against the SERPINE2 protein was raised in rabbits. To reveal the uterine and placental expression of SERPINE2, tissues at various stages were collected for real-time PCR quantification, Western blotting, and immunohistochemical staining. RESULTS: Serpine2 mRNA was the major PA inhibitor in the placenta and uterus during the estrous cycle, pregnancy, and lactation, although Serpine1 mRNA had higher expression levels than Serpine2 mRNA in the placenta. Plat seemed to be the major PA in the mouse uterus and placenta. Antiserum against the SERPINE2 protein specifically recognized two forms of SERPINE2 and an extra 75-kDa protein, which was probably a complex of SERPINE2 with a certain protease, from among thousands of protein components in the tissue extract as demonstrated by Western blotting. In the uterus, SERPINE2 was primarily localized in luminal and glandular epithelial cells but it also was detected in circular and longitudinal smooth muscle cells during the estrous cycle and lactation. It was prominently expressed in decidual stroma cells, the metrial gland, and endometrial epithelium of the pregnant uterus. In the placenta, SERPINE2 was expressed in trophoblasts of the labyrinth and spongiotrophoblasts. However, its expression was remarkably reduced in giant cells which existed in the giant cell-decidual junction zone. In contrast, prominent expression of SERPINE2 seemed to be detected on clusters of glycogen cells near the junction zone. In addition, yolk sac membranes also showed high expression of SERPINE2. CONCLUSIONS: These findings indicate that SERPINE2 is a major PA inhibitor in the placenta and uterus during the estrous cycle, pregnancy, and lactation. It may participate in the PA-modulated tissue remodeling process in the mouse placenta and uterus.

Secretion of fibrinolytic enzymes facilitates human mesenchymal stem cell invasion into fibrin clots.

Adult human mesenchymal stem cells (hMSC) are involved in wound healing and regeneration of mesodermal tissue, but the underlying homing mechanisms are not well understood. Fibrin clot formation is associated with most wound healing processes and potentially guides the recruitment of hMSC. The objective of this study is the investigation of a fibrinolytic capacity, which is required for hMSC to migrate into a wounded tissue and thus to contribute to tissue regeneration. Using RT-PCR, semiquantitative real-time PCR and ELISA, we detected key components of the fibrinolytic cascade, including the urokinase plasminogen activator (uPA) and its receptor (uPAR), the tissue plasminogen activator (tPA) and the plasminogen activator inhibitor (PAI), suggesting a strong fibrinolytic activity of hMSC. To test this activity in a functional assay, we cultured fibrin-embedded hMSC in vitro for 7 days. The cells efficiently dissolved the surrounding fibrin mesh into the fibrin degradation products, the fibrinopeptides. The fibrinolytic activity of hMSC and human dermal fibroblasts, known to be critically involved in skin wound extracellular matrix remodeling, was similar. Our results suggest that a high intrinsic fibrinolytic capacity of hMSC mediates the invasion into a fibrin clot of a wounded tissue.

Interaction analyses of human monocytes co-cultured with different forms of Aspergillus fumigatus.

Monocytes play a major role in the cellular defence against Aspergillus fumigatus in immunocompromised patients. To obtain a better understanding of the mechanisms involved in this interaction, phagocytosis and gene expression profiling of human monocytes was carried out after incubation with A. fumigatus resting, swollen and germinating conidia and hyphae (for 3, 6 and 9 h). The majority of monocytes phagocytosed up to three conidia during the first 3 h of incubation. Microarray analysis showed an increased expression level of immune-relevant genes, which was dependent on the germination state of the fungus and the incubation period. Among these genes, those encoding interleukin-8, macrophage inflammatory protein 3-alpha (CCL20) and monocyte chemotactic protein-1 (CCL2) were found to be potential key regulators involved in the A. fumigatus-induced immune response. In addition, A. fumigatus was found to be an inducer of the genes encoding urokinase type plasminogen activator (uPA), urokinase type plasminogen activator receptor (uPAR),plasminogen activator inhibitor (PAI), pentraxin-3 (PTX3) and intercellular adhesion molecule-1 (ICAM-1), which, in combination, may contribute to thrombosis and local lung tissue injury.

Gene polymorphisms related to angiogenesis, inflammation and thrombosis that influence risk for oral cancer.

Genetic association studies have implicated functional DNA polymorphisms in genes encoding factors related to angiogenesis, inflammation and thrombosis with increased risk for oral squamous cell carcinoma (OSCC). This study examines possible interactions between nine such genotype polymorphisms and their combinatory effect in assessing the OSCC risk in a European population. OSCC cases (N=162) and healthy controls (N=168) of comparable age, gender, and ethnicity (Greeks and Germans) were studied. Multivariate logistic regression models were constructed in order to assess the contribution of homozygous or heterozygous variant genotypes of polymorphisms MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), MMP-9 (-1562C/T), TIMP-2 (-418C/G), VEGF (+936C/T), GPI-alpha (+807C/T), PAI-1 (4G/5G), ACE (intron 16D/I) and TAFI (+325C/T) upon overall, early and advanced stages of OSCC. Four out of nine polymorphisms affecting PAI-1, MMP-9, TIMP-2 and ACE expression contributed significantly in OSCC prediction in the various logistic regression models. Based on these findings and previous reports, possible interactions of the implicated factors leading to OSCC development, as well as an algorithm of risk estimation are discussed.

Genetic polymorphisms in venous thrombosis and pulmonary embolism after total hip arthroplasty: a pilot study.

UNLABELLED: Deep venous thrombosis (DVT) after major orthopaedic surgery is a substantial concern. We asked whether the single or combined presence of thrombophilic genetic polymorphisms might further increase the already high risk for venous thrombosis and pulmonary embolism (PE) after THA. We therefore compared the prevalence of factor V Leiden, prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, and plasminogen activator inhibitor 4G/5G polymorphisms between 50 patients with symptomatic DVT within 3 weeks after elective THA and an asymptomatic control group of 85 patients. We found no major difference for the presence of a single mutation between the groups. Factor V Leiden and homozygous MTHFR C667T mutations were of borderline significance with odds ratios (95% confidence intervals) of 3.73 (0.89-15.63) and 2.93 (0.92-9.29), respectively. Patients with homozygous or combined heterozygous status of MTHFR C677T and A1298C mutation had a higher frequency of DVT after elective THA (odds ratio, 2.86; 95% confidence interval, 1.32-6.35) than those with wild-type. The presence of a single mutation may not further increase the already high risk for symptomatic DVT after THA, whereas combinations of mutations of distinct polymorphisms might be important. However, prospective studies with a larger number of patients are needed before we would recommend preoperative screening. LEVEL OF EVIDENCE: Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Effects of nicotine and lipopolysaccharide on the expression of matrix metalloproteinases, plasminogen activators, and their inhibitors in human osteoblasts.

OBJECTIVE: Lipopolysaccharide (LPS) from periodontopathic bacteria can initiate alveolar bone loss through the induction of host-derived cytokines. Smoking increases the risk and severity of periodontitis. We examined the effects of nicotine and LPS on the expression of matrix metalloproteinases (MMPs), plasminogen activators (PAs), and their inhibitors, including tissue inhibitors of metalloproteinases (TIMPs) and PA inhibitor-1 (PAI-1), in osteoblasts. METHODS: The cells were cultured with or without 10(-4) M nicotine and 100 ng/ml LPS for 12 days or with 100 microg/ml polymyxin B, 10(-4) M D-tubocurarine, 10 micromol/ml NS398, or 10(-6) M celecoxib in the presence of either nicotine or LPS for 12 days. The gene and protein expression levels for MMPs, PAs, TIMPs, and PAI-1 were examined using real-time PCR and ELISAs, respectively. PGE(2) production was determined using an ELISA. RESULTS: The addition of nicotine and/or LPS to the culture medium increased the expression of MMP-1, -2, and -3 and tissue-type PA (tPA); decreased the expression of TIMP-1, -3, and -4; and did not affect expression of TIMP-2 or PAI-1. In the presence of d-tubocurarine or polymyxin B, neither nicotine nor LPS stimulated the expression of MMP-1. In the presence of NS398 or celecoxib, the stimulatory effects of nicotine and LPS on MMP-1 expression were unchanged, but they were unable to stimulate PGE(2) production. CONCLUSION: These results suggest that nicotine and LPS stimulate the resorption process that occurs during turnover of osteoid by increasing the production of MMPs and tPA and by decreasing the production of TIMPs. Furthermore, they suggest that the stimulatory effect of nicotine and LPS on PGE(2) production is independent of their stimulatory effect on MMP-1 expression.

Role of tissue-type plasminogen activator in salicylic acid-induced sloughing of human corn tissue.

BACKGROUND: Plasminogen activators (PAs) and their regulatory counterparts, PA inhibitors (PAIs), play a role in normal differentiation processes and various pathophysiologic conditions of the epidermis. Normal desquamation of corneocytes from the skin3s surface may, in part, be regulated by the balanced activities of tissue-type PA (tPA) and PAI-2. Salicylic acid (SA) is commonly used to remove the hyperkeratotic tissue of corns, calluses, and verrucae, and it may disrupt intercellular adhesion structures; however, its exact mechanism of keratolytic action is poorly defined. We sought to determine the effects of SA by comparing the levels of PA and PAI messenger RNA (mRNA) in normal skin, untreated corns, and SA-treated corns. METHODS: Untreated and SA-treated human corn tissue samples were obtained from patients electing surgery to repair bony defects that underlay their lesions. Histopathologic examination of corns was performed by staining the tissue sections with hematoxylin and eosin and by light microscopy. Polymerase chain reaction was used to compare mRNA expression of PAs and PAIs in normal skin, untreated corns, and SA-treated corns. RESULTS: We demonstrated lower tPA and higher PAI-2 mRNA levels in corn tissue compared with normal skin. In corn tissue treated with SA, the expression of tPA mRNA increased and of PAI-2 mRNA decreased to the levels found in normal skin. CONCLUSION: An altered balance in tPA and PAI-2 levels contributes to the induction of hyperkeratotic corn tissue and suggests that the keratolytic action of SA is associated with its ability to stimulate proteinase-meditated desquamation processes.