PLAU Research Articles

A Noncanonical Role for Plasminogen Activator Inhibitor Type 1 in Obesity-Induced Diabetes

Obesity is a major risk factor for type 2 diabetes because of chronic hepatic inflammation and resultant insulin resistance. Hepatocyte growth factor (HGF) is responsible for resetting hepatic homeostasis after injury following activation by urokinase-type plasminogen activator (u-PA; encoded by the PLAU gene). Plasminogen activator inhibitor type-1 (PAI-1; encoded by the SERPINE1 gene), a u-PA inhibitor and antifibrinolytic agent, is often elevated in obesity and is linked to cardiovascular events. We hypothesized that, in addition to its role in preventing fibrinolysis, elevated PAI-1 inhibits HGF's activation by u-PA and the resultant anti-inflammatory and hepatoprotective properties. Wild-type and PAI-1 knockout (KO) mice on a high-fat diet both became significantly heavier than lean controls; however, the obese KO mice demonstrated improved glucose metabolism compared with wild-type mice.Obese KO mice also exhibited an increase in conversion of latent single-chain HGF to active two-chain HGF, coinciding with an increase in the phosphorylation of the HGF receptor (HGFR or MET, encoded by the MET gene), as well as dampened inflammation. These results strongly suggest that, in addition to its other functions, PAI-mediated inhibition of HGF activation prohibits theresolution of inflammation in the context of obesity-induced type 2 diabetes.

Evaluation of Tumor Regulatory Genes and Apoptotic Pathways in The Cytotoxic Effect of Cytochalasin H on Malignant Human Glioma Cell Line (U87MG).

Objective The aim of current study was to provide a proof-of-concept on the mechanism of PLAU and PCDH10 gene expressions and caspases-3, -8, and -9 activities in the apoptotic pathway after treatment of malignant human glioma cell line (U87MG) with cytochalasin H. Materials and Methods In the present experimental study, we have examined cytochalasin H cytotoxic activities as a new therapeutic agent on U87MG cells in vitro for the first time. The cells were cultured and treated with 10-5-10-9M of cytochalasin H for 24, 48 and 72 hours. The assessment of cell viability was carried out by (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazoliumbromide (MTT) assay at 578 nm. The data are the average of three independent tests. mRNA expression changes of PLAU and PCDH10 were then evaluated by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). The fluorometric of caspases-3, -8, and -9 activities were carried out. The morphology changes in the U87MG cells were observed by fluorescence microscope. Results MTT assay showed that cytochalasin H (10-5 M) inhibited the U87MG cancer cells proliferation after 48 hours. Analysis of qRT-PCR showed that the PLAU expression was significantly decreased in comparison with the control (P<0.05). The expression of PCDH10 also showed a significant increase when compared to the control (P<0.001). Fluorescence microscope indicated morphological changes due to apoptosis in U87MG cancer cells, after treatment with cytochalasin H (10-5M, 48 hours). The fluorometric evaluation of caspase-3, -8, and -9 activities showed no significant difference between the caspases and the control group. ConclusionThis study shows the effect of caspase-independent pathways of the programmed cell death on the U87MG cancer cell line under cytochalasin H treatment. Further studies are needed to explore the exact mechanism.

Ultrasound mediates iRGD targeted liposome-microbubble complex for thrombolytic therapy in vitro

Objective To fabricate iRGD targeted liposome-microbubble complex containing uPA (iRGD-LMC), and to improve the thrombolytic efficiency and reduce the risk of thrombolysis by iRGD-LMC combining with ultrasound targeted microbubbles destruction (UTMD) to release drug into the thrombus site with the help of microbubble cavitation effect. Methods Biotinylated iRGD-MBs were fabricated by thin-film rehydration method.Biotinylated liposomes containing uPA were fabricated by freeze-thaw method and were conjugated to the biotinylated iRGD-MBs surface through biotin-avidin linkage. The iRGD-LMC was subjected to confocal microscopy to determine the particle morphology. The concentration, average diameter and size distribution were determined by particle sizing instrument. The uPA loading efficiency was measured by BCA Protein Assay Kit. Ultrasound imaging was performed using a Vevo 2100 ultrasound imaging system. The iRGD-LMC was irradiated by different ultrasound time and intensity to release drug. Thrombolytic effect in vitro of iRGD-LMC combined with UTMD was observed on the thrombosis model which was extracted from mouse blood. Results iRGD-LMC was successfully prepared. iRGD-LMC was exhibited a well-defined spherical morphology and homogeneous distribution, like ordinary microbubbles. The concentration of iRGD-LMC was (0.51±0.03)×109/ml and average diameter was (2.62±0.12) μm. Drugs loading efficiency was (3 878.5±97.8) μg uPA per 108 microbubbles. iRGD-LMC could achieve contrast-enhanced ultrasound imaging in vitro. The thrombolytic effect of iRGD-LMC+ US group (87.66±1.69)% was the best in vitro, and had significant difference with others groups (P<0.05), followed by iRGD-LMC group (53.32±4.86)% and uPA group (51.09±9.01)%, Compared with PBS group, US group (23.56±9.46)% had thrombolytic effect. Conclusions iRGD-LMC is successfully prepared, which has the advantages of high drug loading of liposomes and good acoustic properties of microbubbles. iRGD-LMC combined with UTMD achieves a significant thrombolytic effect in vitro. Key words: Ultrasound targeted microbubble destruction; Urinary plasminogen activator; Thrombolytic therapy; iRGD-LMC

NKX2-2 Suppresses Osteosarcoma Metastasis and Proliferation by Downregulating Multiple Target Genes.

Osteosarcoma is the most common primary malignant bone tumor. However, our understanding of the molecular mechanism underlying its pathogenesis is incomplete. Studies have shown that aberrant expression of NK homeobox (NKX) genes may be involved in the oncogenesis of various cancers. Here, through migration screening assay, we found that a series of NKX genes inhibit the migration of osteosarcoma cells. Among these genes, NKX2-2 is a bona fide tumor suppressor for osteosarcoma. Overexpression of NKX2-2 decreases the migration, invasion, proliferation and colony formation of osteosarcoma cells in vitro and suppresses tumor growth and metastasis in vivo. Moreover, based on the results from both in vitro and in vivo studies, the transcriptional activation domain of NKX2-2 is important for its tumor suppressor function. Mechanistically, we revealed that NKX2-2 acts as a tumor suppressor partially by mediating the transcriptional downregulation of COL5A2, PLAU, SEMA7A and S1PR1 genes. In summary, our studies of NKX2-2 revealed new molecular mechanisms underlying osteosarcoma proliferation and metastasis and may provide a series of potential therapeutic targets for osteosarcoma.

JMJD3 and NF-\u03baB-dependent activation of Notch1 gene is required for keratinocyte migration during skin wound healing

It has been shown that epigenetic regulation plays an important role in skin wound healing. We previously found that histone H3K27me3 demethylase JMJD3 regulates inflammation and cell migration in keratinocyte wound healing. In this study, we identified Notch1 as a direct target of JMJD3 and NF-κB in wounded keratinocytes using in vitro cell and in vivo animal models. We found that Notch1 is up-regulated in the wound edge and its expression is dependent on JMJD3 and NF-κB in wounded keratinocytes. We also found that Notch1 activates the expression of RhoU and PLAU gene, which are critical regulators of cell migration. Consistently, depletion or inactivation of Notch1 resulted in decreased filopodia formation, increased focal adhesion and actin stress fiber, leading to reduced keratinocyte migration and skin wound healing. Thus, our findings provide the molecular mechanism involving JMJD3/NF-κB-Notch pathway in keratinocyte wound healing.

EXPRESSION OF CANCER-ASSOCIATED GENES IN PROSTATE TUMORS

Prostate cancer is one of the most common male cancers in Western countries and takes the third place in morbidity in Ukraine. It is a highly heterogeneous disease. To analyze relative expression levels of the TGFB1, IL1B, FOS, EFNA5, TAGLN, PLAU, and EPDR1 genes in malignant and non-malignant prostate tissues. Total RNA was isolated from 16 prostate adenomas, 37 prostate adenocarcinomas, and 29 conventionally normal prostate tissues. To analyze relative gene expression levels the quantitative real-time polymerase chain reaction was performed. The significant alterations in the relative expression levels were found in all analyzed sample groups for 4 genes: FOS, EFNA5, IL1B, and TGFB1. We have found that FOS and EFNA5 were more frequently overexpressed in carcinomas with Gleason score ≤ 7, compared with adenomas. On contrary, PLAU expression levels were decreased more frequently in prostate cancers, compared with conventionally normal tissues. Noteworthy, we found positive correlation between IL1B expression level and PSA (for patients with slight PSA increase, no more than 20.0 ng/ml). The EFNA5, FOS, IL1B, PLAU, and TGFB1 genes that showed significant expression alterations in prostate tumors, compared with conventionally normal prostate tissue, may play role in prostate cancer development and should be further investigated.

Vitronectin and Urokinase-Type Plasminogen Activator Gene Expression Levels Are Increased in Patients with Coronary Artery In-Stent Restenosis.

Neointimal hyperplasia is known as a main factor contributing to in-stent restenosis (ISR). Monocytes may play a central role in vessel restenosis process after stent implantation. The aim of this study was to investigate the relationships between the urokinase-type plasminogen activator (PLAU) and vitronectin (Vtn) gene expression levels in peripheral blood mononuclear cell samples isolated from whole blood of 66 patients undergoing coronary artery angiography (22 controls, stenosis < 0.05%; 22 with stent no-restenosis and stenosis < 70%; and 22 with ISR and stenosis > 70%). The Vtn and PLAU gene expression levels were measured by real-time quantitative polymerase chain reaction technique. The age- and gender-independent increases in the expression levels of Vtn (17-fold; p < 0.001) and PLAU (27-fold; p < 0.0001) genes were found in the patients with ISR as compared with the control group. The results suggested that the Vtn and PLAU genes may be involved in the coronary artery ISR.

Epigenetic silencing of triple negative breast cancer hallmarks by Withaferin A

Triple negative breast cancer (TNBC) is characterized by poor prognosis and a DNA hypomethylation profile. Withaferin A (WA) is a plant derived steroidal lactone which holds promise as a therapeutic agent for treatment of breast cancer (BC). We determined genome-wide DNA methylation changes in weakly-metastatic and aggressive, metastatic BC cell lines, following 72h treatment to a sub-cytotoxic concentration of WA. In contrast to the DNA demethylating agent 5-aza-2’-deoxycytidine (DAC), WA treatment of MDA-MB-231 cells rather tackles an epigenetic cancer network through gene-specific DNA hypermethylation of tumor promoting genes including ADAM metallopeptidase domain 8 (ADAM8), urokinase-type plasminogen activator (PLAU), tumor necrosis factor (ligand) superfamily, member 12 (TNFSF12), and genes related to detoxification (glutathione S-transferase mu 1, GSTM1), or mitochondrial metabolism (malic enzyme 3, ME3). Gene expression and pathway enrichment analysis further reveals epigenetic suppression of multiple cancer hallmarks associated with cell cycle regulation, cell death, cancer cell metabolism, cell motility and metastasis. Remarkably, DNA hypermethylation of corresponding CpG sites in PLAU, ADAM8, TNSF12, GSTM1 and ME3 genes correlates with receptor tyrosine-protein kinase erbB-2 amplification (HER2)/estrogen receptor (ESR)/progesterone receptor (PR) status in primary BC tumors. Moreover, upon comparing differentially methylated WA responsive target genes with DNA methylation changes in different clinical subtypes of breast cancer patients in the cancer genome atlas (TCGA), we found that WA silences HER2/PR/ESR-dependent gene expression programs to suppress aggressive TNBC characteristics in favor of luminal BC hallmarks, with an improved therapeutic sensitivity. In this respect, WA may represent a novel and attractive phyto-pharmaceutical for TNBC treatment.

Single cell digital polymerase chain reaction on self-priming compartmentalization chip.

Single cell analysis provides a new framework for understanding biology and disease, however, an absolute quantification of single cell gene expression still faces many challenges. Microfluidic digital polymerase chain reaction (PCR) provides a unique method to absolutely quantify the single cell gene expression, but only limited devices are developed to analyze a single cell with detection variation. This paper describes a self-priming compartmentalization (SPC) microfluidic digital polymerase chain reaction chip being capable of performing single molecule amplification from single cell. The chip can be used to detect four single cells simultaneously with 85% of sample digitization. With the optimized protocol for the SPC chip, we first tested the ability, precision, and sensitivity of our SPC digital PCR chip by assessing β-actin DNA gene expression in 1, 10, 100, and 1000 cells. And the reproducibility of the SPC chip is evaluated by testing 18S rRNA of single cells with 1.6%-4.6% of coefficient of variation. At last, by detecting the lung cancer related genes, PLAU gene expression of A549 cells at the single cell level, the single cell heterogeneity was demonstrated. So, with the power-free, valve-free SPC chip, the gene copy number of single cells can be quantified absolutely with higher sensitivity, reduced labor time, and reagent. We expect that this chip will enable new studies for biology and disease.

Characterization and mechanisms of photoageing-related changes in skin. Damages of basement membrane and dermal structures.

Sun-exposed skin is characterized by superficial changes such as wrinkles, sagging and pigmentary changes, and also many internal changes in the structure and function of epidermis, basement membrane (BM) and dermis. These changes (so-called photoageing) are predominantly induced by the ultraviolet (UV) component of sunlight. Epidermis of UV-irradiated skin produced several enzymes such as matrix metalloproteinases (MMPs), urinary plasminogen activator (uPA)/plasmin and heparanase, which degrade dermal collagen fibres and elastic fibres in the dermis, and components of epidermal BM. The BM at the dermal-epidermal junction (DEJ) controls dermal-epidermal signalling and plays an important role in the maintenance of a healthy epidermis and dermis. BM is repetitively damaged in sun-exposed skin compared with unexposed skin, leading to epidermal and dermal deterioration and accelerated skin ageing. UV exposure also induces an increase in vascular endothelial growth factor (VEGF), an angiogenic factor, while thrombospondin-1 (TSP-1), an anti-angiogenic factor, is decreased; these changes induce angiogenesis in papillary dermis with increased migration of elastase-positive leucocytes, leading to dermal elastic fibre damage. Elastic fibres, such as oxytalan fibres in papillary dermis, are associated with not only skin resilience, but also skin surface texture, and elastic fibre formation by fibroblasts is facilitated by increased expression of fibulin-5. Thus, induction of fibulin-5 expression is a damage-repair mechanism, and fibulin-5 is an early marker of photoaged skin. UV-induced skin damage is cumulative and leads to premature ageing of skin. However, appropriate daily skincare may ameliorate photoageing by inhibiting processes causing damage and enhancing repair processes.

Genetic Basis of Irritant Susceptibility in Health Care Workers.

The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) within genes involved in inflammation, skin barrier integrity, signaling/pattern recognition, and antioxidant defense with irritant susceptibility in a group of health care workers. The 536 volunteer subjects were genotyped for selected SNPs and patch tested with three model irritants: sodium lauryl sulfate (SLS), sodium hydroxide (NaOH), and benzalkonium chloride (BKC). Genotyping was performed on genomic DNA using Illumina Goldengate custom panels. The ACACB (rs2268387, rs16934132, rs2284685), NTRK2 (rs10868231), NTRK3 (rs1347424), IL22 (rs1179251), PLAU (rs2227564), EGFR (rs6593202), and FGF2 (rs308439) SNPs showed an association with skin response to tested irritants in different genetic models (all at P < 0.001). Functional annotations identified two SNPs in PLAU (rs2227564) and ACACB (rs2284685) genes with a potential impact on gene regulation. In addition, EGF (rs10029654), EGFR (rs12718939), CXCL12 (rs197452), and VCAM1 (rs3917018) genes showed an association with hand dermatitis (P < 0.005). The results demonstrate that genetic variations in genes related to inflammation and skin homeostasis can influence responses to irritants and may explain inter-individual variation in the development of subsequent contact dermatitis.

All-trans retinoic acid improves iodine uptake of thyroid cancer cells via repressing transcriptional activity of β-catenin

To determine whether all-trans retinoic acid (ATRA) could improve iodine uptake via repressing transcriptional activity of β-catenin in thyroid cancer cells. Three kinds of treatment models were firstly established with alcohol, ATRA, and transfection of β-catenin shRNA in undifferentiated human thyroid cancer cell line-SW1736.Then the expressions of sodium iodide symporter (NIS), β-catenin and its regulating factors, epithelial-mensechymal transition (EMT)-phenotype, invasion and metastasis associated proteins were further measured in above three cell models.After that, the influence of ATRA on the functional expression of NIS, iodine uptake potency, tumor growth curve and treatment effect inducing by radioactive iodine was comparatively analyzed in vitro and in vivo trials. After treated with ATRA, transcriptional activity of β-catenin decreased by downregulating phosphorylation of β-catenin Ser45, Y654 and GSK-3β Ser9. Additionally, ATRA effectively upregulated the protein level of NIS, and reversed EMT phenotype in alcohol treated cells, with absence in epithelial expression of E-cadherin and cytokeratin 18, as well as abnormal expression of Vimentin, urinary plasminogen activator (uPA), uPAR and Fibronectin.Compared with alcohol-treated group, both in vitro proliferation and invasion potential of ATRA treated cells markedly decreased (all P<0.05), and iodine uptake in vitro increased about 3.5-folds (P=0.007). In ATRA-treated animal model, tumor growth potential and tumor mass were significantly inhibited by radio-iodine ((131)I) treatment (all P<0.05). ATRA can increase functional expression of NIS via downregulating transcriptional activity of β-catenin and promote isotope sensitivity to radio-iodine in human undifferentiated thyroid cancer.

Establishment of a rat model of lumbar facet joint osteoarthritis using intraarticular injection of urinary plasminogen activator

Lumbar facet joint (LFJ) osteoarthritis (OA) is an important etiology of low back pain. Several animal models of LFJ OA have been established using intraarticular injection of various chemicals. This study aimed to establish a rat model of LFJ OA using urinary plasminogen activator (uPA). Sprague-Dawley rats were treated with intraarticular injection in the L5-L6 facet joints with uPA (OA group, n = 40) or normal saline (vehicle group, n = 40). Mechanical and thermal hyperalgesia in the ipsilateral hind paws were evaluated using von Frey hairs and a thermoalgesia instrument, respectively. Toluidine blue staining, hematoxylin-eosin staining, and immunohistochemical examination of the LFJ was performed. Treatment with uPA induced cartilage damage, synovitis, and proliferation of synovial cells in the fact joints. The OA group showed significantly higher hyperalgesia in the hind paws in comparison with the vehicle group and normal controls (P < 0.05). Expression of IL-1β, TNF-α, and iNOS in the LFJ cartilage in the OA group was significantly increased (P < 0.05). A rat model of LFJ OA was successfully established using intraarticular injection of uPA. This animal model is convenient and shows good resemblance to human OA pathology.

Extensive heterogeneity of human urokinase, as detected by two-dimensional mapping.

Urokinase (uPA, urinary plasminogen activator) is a serine protease belonging to the peptidase S1 family. Specifically, uPA cleaves the zymogen plasminogen into the active form (plasmin), which then degrades the fibrin clots. It is widely used as a fibrinolytic agent in thrombolytic therapy and it is also used clinically as a thrombolytic agent. It can be administered to improve the drainage of complicated pleural effusions and empyemas and it is the most effective drug in myocardial infarction. The enzyme was originally identified in human urine for its ability to catalyze the transformation of plasminogen into its active form (plasmin), which degrades fibrin and extracellular matrix components. The present report deals with the analysis and characterization of this preparation.

Gene expression abnormalities in histologically normal breast epithelium from patients with luminal type of breast cancer.

The gene expression profile of breast cancer has been described as a great breakthrough on the way to comprehend differences in cancer origin, behavior and therapy. However, gene expression profile in histologically normal epithelium (HNEpi) which could harbor genetic abnormalities predisposing breast tissue to develop malignancy was minor scope for scientists in the past. Thus, we aimed to analyze gene expressions in HNEpi and breast cancer tissue (BCTis) in order to establish its value as potential diagnostic marker for cancer development. We evaluated a panel of disease-specific genes in luminal type (A/B) of breast cancer and tumor surrounding HNEpi by qRT-PCR Array in 32 microdissected samples. There was 20.2 and 2.4% deregulation rate in genes with at least 2-fold or 5-fold over-expression between luminal (A/B) type breast carcinomas and tumor surrounding HNEpi, respectively. The high-grade luminal carcinomas showed higher number of deregulated genes compared to low-grade cases (50.6 vs. 23.8% with at least 2-fold deregulation rate). The main overexpressed genes in HNEpi were KLK5, SCGB1D2, GSN, EGFR and NGFR. The significant differences in gene expression between BCTis and HNEpi samples were revealed for BAG1, C3, CCNA2, CD44, FGF1, FOSL1, ID2, IL6R, NGFB, NGFR, PAPPA, PLAU, SERPINB5, THBS1 and TP53 gene (p < 0.05) and BCL2L2, CTSB, ITGB4, JUN, KIT, KLF5, SCGB1D2, SCGB2A1, SERPINE1 (p < 0.01), and EGFR, GABRP, GSN, MAP2K7 and THBS2 (p < 0.001), and GSN, KLK5 (p < 0.0001). The ontological gene analyses revealed high deregulations in gene group directly associated with breast cancer prognosis and origin.

Abstract 3: Imaging of stromal cells during hepatocellular metastasis formation in the RFP-MUP-uPA mouse

Abstract Major urinary protein-urokinase type plasminogen activator (MUP-uPA) transgenic mice develop liver disease. We have developed the RFP-MUP-uPA mice, by crossing MUP-uPA mice with transgenic mice ubiquitously-expressing RFP. Hepatocyte RFP fluorescence in this model is very strong. In addition, RFP fluorescence of stromal cells is very bright enabling the portal vein and sinusoid structures to be clearly visualized. Huh7 liver cancer cells expressing green fluorescent protein (GFP) were injected in the spleen of MUP-uPA transgenic mice. The vessels of the MUP-uPA liver are filled with Huh7-GFP cells as imaged in live mice 3h after cell injection. Huh7-GFP cells formed tumor colonies in the liver 28 days after cell transplantation to the spleen. The Huh7-GFP cells were visualized in the liver with the Olympus FV1000 confocal microscope. In large metastatic liver tumors in RFP-MUP-uPA mice, stroma cells derived from the host animal appeared around and into the edge of Huh7-GFP tumors. In contrast, in small metastatic liver tumors, there were no stromal cells observed. The stromal cells were observed in the spleen primary tumor, as well as kidney and the lung metastasis in addition to the large liver tumors. This model enables imaging the effects of uPA on liver metastasis and stromal recruitment enabling the metastasis to progress. Citation Format: Atsushi Suetsugu, Hisanobu Ogata, Yukihiko Hiroshima, Masashi Momiyama, Yosuke Osawa, Hisataka Moriwaki, Shigetoyo Saji, Michael Karin, Robert M. Hoffman. Imaging of stromal cells during hepatocellular metastasis formation in the RFP-MUP-uPA mouse. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3. doi:10.1158/1538-7445.AM2014-3

Global gene expression profiling in three tumor cell lines subjected to experimental cycling and chronic hypoxia.

Hypoxia is one of the most important features of the tumor microenvironment, exerting an adverse effect on tumor aggressiveness and patient prognosis. Two types of hypoxia may occur within the tumor mass, chronic (prolonged) and cycling (transient, intermittent) hypoxia. Cycling hypoxia has been shown to induce aggressive tumor cell phenotype and radioresistance more significantly than chronic hypoxia, though little is known about the molecular mechanisms underlying this phenomenon. The aim of this study was to delineate the molecular response to both types of hypoxia induced experimentally in tumor cells, with a focus on cycling hypoxia. We analyzed in vitro gene expression profile in three human cancer cell lines (melanoma, ovarian cancer, and prostate cancer) exposed to experimental chronic or transient hypoxia conditions. As expected, the cell-type specific variability in response to hypoxia was significant. However, the expression of 240 probe sets was altered in all 3 cell lines. We found that gene expression profiles induced by both types of hypoxia were qualitatively similar and strongly depend on the cell type. Cycling hypoxia altered the expression of fewer genes than chronic hypoxia (6,132 vs. 8,635 probe sets, FDR adjusted p<0.05), and with lower fold changes. However, the expression of some of these genes was significantly more affected by cycling hypoxia than by prolonged hypoxia, such as IL8, PLAU, and epidermal growth factor (EGF) pathway-related genes (AREG, HBEGF, and EPHA2). These transcripts were, in most cases, validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Our results indicate that experimental cycling hypoxia exerts similar, although less intense effects, on the examined cancer cell lines than its chronic counterpart. Nonetheless, we identified genes and molecular pathways that seem to be preferentially regulated by cyclic hypoxia.

SuPAR and Team Nephrology.

Primary focal segmental glomerulosclerosis (FSGS) accounts for nearly 10 % of patients who require renal replacement therapy. Elevated circulating levels of soluble urokinase receptor (suPAR) have been identified as a biomarker to discriminate primary FSGS from other glomerulopathies. Subsequent reports have questioned the diagnostic utility of this test. In a study in BMC Medicine, Huang et al. demonstrate that urinary soluble urokinase receptor (suPAR) excretion assists in distinguishing primary FSGS from other glomerular diseases, and that high plasma suPAR concentrations are not directly linked to a decline in glomerular filtration rate (GFR). This observation suggests that further investigation of suPAR is warranted in patients with FSGS. It should be interpreted in light of a recent report that B7-1 is expressed in the podocytes of a subset of patients with FSGS, and that blocking this molecule may represent the first successful targeted intervention for this disease. These advances highlight the rapid pace of scientific progress in the field of nephrology. Nephrologists should work together, share resources, and expedite the design of protocols to evaluate these novel biomarkers in a comprehensive and scientifically valid manner.Please see related article http://www.biomedcentral.com/1741-7015/12/81.

El polimorfismo de un solo nucleótido PLAU P141L se asocia con el grado de circulación colateral en pacientes con enfermedad arterial coronaria

Introduction and objectivesUrokinase-type plasminogen activator, which is encoded by the PLAU gene, plays a prominent role during collateral arterial growth. We investigated whether the PLAU P141L (C > T) polymorphism, which causes a mutation in the kringle domain of the protein, is associated with coronary collateral circulation in a cohort of 676 patients with coronary artery disease. MethodsThe polymorphism was genotyped in blood samples using a TaqMan-based genotyping assay, and collateral circulation was assessed by the Rentrop method. Multivariate logistic regression models adjusted by clinically relevant variables to estimate odds ratios were used to examine associations of PLAU P141L allelic variants and genotypes with collateral circulation. ResultsPatients with poor collateral circulation (Rentrop 0-1; n = 547) showed a higher frequency of the TT genotype than those with good collateral circulation (Rentrop 2-3; n = 129; P = .020). The T allele variant was also more common in patients with poor collateral circulation (P = .006). The odds ratio of having poorly developed collaterals in patients bearing the T allele (adjusted for clinically relevant variables) was statistically significant under the dominant model (odds ratio =1.83 [95% confidence interval, 1.16-2.90]; P = .010) and the additive model (odds ratio =1.73 [95% confidence interval, 1.14-2.62]; P = .009). ConclusionsAn association was found between coronary collateral circulation and the PLAU P141L polymorphism. Patients with the 141L variant are at greater risk of developing poor coronary collateral circulation.Full English text available from: www.revespcardiol.org/en

The PLAU P141L Single Nucleotide Polymorphism Is Associated With Collateral Circulation in Patients With Coronary Artery Disease

Introduction and objectivesUrokinase-type plasminogen activator, which is encoded by the PLAU gene, plays a prominent role during collateral arterial growth. We investigated whether the PLAU P141L (C > T) polymorphism, which causes a mutation in the kringle domain of the protein, is associated with coronary collateral circulation in a cohort of 676 patients with coronary artery disease. MethodsThe polymorphism was genotyped in blood samples using a TaqMan-based genotyping assay, and collateral circulation was assessed by the Rentrop method. Multivariate logistic regression models adjusted by clinically relevant variables to estimate odds ratios were used to examine associations of PLAU P141L allelic variants and genotypes with collateral circulation. ResultsPatients with poor collateral circulation (Rentrop 0-1; n = 547) showed a higher frequency of the TT genotype than those with good collateral circulation (Rentrop 2-3; n = 129; P = .020). The T allele variant was also more common in patients with poor collateral circulation (P = .006). The odds ratio of having poorly developed collaterals in patients bearing the T allele (adjusted for clinically relevant variables) was statistically significant under the dominant model (odds ratio = 1.83 [95% confidence interval, 1.16-2.90]; P = .010) and the additive model (odds ratio = 1.73 [95% confidence interval, 1.14-2.62]; P = .009). ConclusionsAn association was found between coronary collateral circulation and the PLAU P141L polymorphism. Patients with the 141L variant are at greater risk of developing poor coronary collateral circulation.