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Sample records for activator inhibitor-1 defined

  1. Use of mouse models to study plasminogen activator inhibitor-1.

    PubMed

    Declerck, Paul J; Gils, Ann; De Taeye, Bart

    2011-01-01

    Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and therefore plays an important role in the plasminogen/plasmin system. PAI-1 is involved in a variety of cardiovascular diseases (mainly through inhibition of t-PA) as well as in cell migration and tumor development (mainly through inhibition of u-PA and interaction with vitronectin). PAI-1 is a unique member of the serpin superfamily, exhibiting particular unique conformational and functional properties. Since its involvement in various biological and pathophysiological processes PAI-1 has been the subject of many in vivo studies in mouse models. We briefly discuss structural and physiological differences between human and mouse PAI-1 that should be taken into account prior to extrapolation of data obtained in mouse models to the human situation. The current review provides an overview of the various models, with a focus on cardiovascular disease and cancer, using wild-type mice or genetically modified mice, either deficient in PAI-1 or overexpressing different variants of PAI-1. PMID:21683250

  2. Plasminogen activator inhibitor-1 in sputum and nasal fluids increases in asthmatics during common colds

    PubMed Central

    Cho, Seong H.; Hong, Seung J.; Chen, Haimei; Habib, Ali; Cho, David; Lee, Sun H.; Kang, Joseph; Ward, Theresa; Boushey, Homer A.; Schleimer, Robert P.; Avila, Pedro C.

    2014-01-01

    Capsule Summary This study showed that sputum and nasal lavage levels of plasminogen activator inhibitor-1 (PAI-1) rise during a common cold in asthmatic patients. This rise may contribute to the progression of airway remodeling. PMID:24373352

  3. Metabolic factors, adipose tissue, and plasminogen activator inhibitor-1 levels in Type 2 diabetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasminogen activator inhibitor-1 (PAI-1) production by adipose tissue is increased in obesity, and its circulating levels are high in type 2 diabetes. PAI-1 increases cardiovascular risk by favoring clot stability, interfering with vascular remodeling, or both. We investigated in obese diabetic per...

  4. Plasminogen Activator Inhibitor-1 Suppresses Profibrotic Responses in Fibroblasts from Fibrotic Lungs*

    PubMed Central

    Marudamuthu, Amarnath S.; Shetty, Shwetha K.; Bhandary, Yashodhar P.; Karandashova, Sophia; Thompson, Michael; Sathish, Venkatachalem; Florova, Galina; Hogan, Taryn B.; Pabelick, Christina M.; Prakash, Y. S.; Tsukasaki, Yoshikazu; Fu, Jian; Ikebe, Mitsuo; Idell, Steven; Shetty, Sreerama

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by progressive interstitial scarification. A hallmark morphological lesion is the accumulation of myofibroblasts or fibrotic lung fibroblasts (FL-fibroblasts) in areas called fibroblastic foci. We previously demonstrated that the expression of both urokinase-type plasminogen activator (uPA) and the uPA receptor are elevated in FL-fibroblasts from the lungs of patients with IPF. FL-fibroblasts isolated from human IPF lungs and from mice with bleomycin-induced pulmonary fibrosis showed an increased rate of proliferation compared with normal lung fibroblasts (NL-fibroblasts) derived from histologically “normal” lung. Basal expression of plasminogen activator inhibitor-1 (PAI-1) in human and murine FL-fibroblasts was reduced, whereas collagen-I and α-smooth muscle actin were markedly elevated. Conversely, alveolar type II epithelial cells surrounding the fibrotic foci in situ, as well as those isolated from IPF lungs, showed increased activation of caspase-3 and PAI-1 with a parallel reduction in uPA expression. Transduction of an adenovirus PAI-1 cDNA construct (Ad-PAI-1) suppressed expression of uPA and collagen-I and attenuated proliferation in FL-fibroblasts. On the contrary, inhibition of basal PAI-1 in NL-fibroblasts increased collagen-I and α-smooth muscle actin. Fibroblasts isolated from PAI-1-deficient mice without lung injury also showed increased collagen-I and uPA. These changes were associated with increased Akt/phosphatase and tensin homolog proliferation/survival signals in FL-fibroblasts, which were reversed by transduction with Ad-PAI-1. This study defines a new role of PAI-1 in the control of fibroblast activation and expansion and its role in the pathogenesis of fibrosing lung disease and, in particular, IPF. PMID:25648892

  5. Tissue Plasminogen Activator and Plasminogen Activator Inhibitor-1 Levels in Patients with Acute Paraquat Intoxication

    PubMed Central

    Seok, Su-Jin; Kim, Su-Ji; Gil, Hyo-Wook; Yang, Jong-Oh; Lee, Eun-Young

    2011-01-01

    To investigate the effects of reactive oxygen species (ROS) on tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) plasma levels, and their possible implications on clinical outcome, we measured tPA and PAI-1 levels in 101 patients with acute paraquat (PQ) intoxication. The control group consisted of patients who ingested non-PQ pesticides during the same period. tPA and PAI-1 levels were higher in the PQ group than in the controls. PQ levels were significantly correlated with ingested amount, timelag to hospital, tPA level, and hospitalization duration. tPA levels were correlated with PAI-1, fibrin degradation product (FDP), and D-dimer. D-dimer levels were lower in the PQ group than in the controls. Univariate analysis indicated the following significant determinants of death: age, ingested amount, PQ level, timelag to hospital, serum creatinine, lipase, pH, pCO2, HCO3-, WBC, FDP, PAI-1, and tPA. However, multivariate analysis indicated that only PQ level was significant independent factor predicting death. In conclusion, tPA and PAI-1 levels were higher, while D-dimer levels were lower in the PQ group than in the controls, implying that ROS stimulate tPA and PAI-1, but PAI-1 activity overrides tPA activity in this setting. Decreased fibrinolytic activity appears to be one of the clinical characteristics of acute PQ intoxication. PMID:21468253

  6. Kinetic analysis of the interaction between plasminogen activator inhibitor-1 and tissue-type plasminogen activator.

    PubMed Central

    Masson, C; Angles-Cano, E

    1988-01-01

    The kinetics of inhibition of tissue-type plasminogen activator (t-PA) by the fast-acting plasminogen activator inhibitor-1 (PAI-1) was investigated in homogeneous (plasma) and heterogeneous (solid-phase fibrin) systems by using radioisotopic and spectrophotometric analysis. It is demonstrated that fibrin-bound t-PA is protected from inhibition by PAI-1, whereas t-PA in soluble phase is rapidly inhibited (K1 = 10(7) M-1.s-1) even in the presence of 2 microM-plasminogen. The inhibitor interferes with the binding of t-PA to fibrin in a competitive manner. As a consequence the Kd of t-PA for fibrin (1.2 +/- 0.4 nM) increases and the maximal velocity of plasminogen activation by fibrin-bound t-PA is not modified. From the plot of the apparent Kd versus the concentration of PAI-1 a Ki value of 1.3 +/- 0.3 nM was calculated. The quasi-similar values for the dissociation constants between fibrin and t-PA (Kd) and between PAI-1 and t-PA (Ki), as well as the competitive type of inhibition observed, indicate that the fibrinolytic activity of human plasma may be the result of an equilibrium distribution of t-PA between both the amount of fibrin generated and the concentration of circulating inhibitor. Images Fig. 2. Fig. 3. PMID:3146972

  7. Plasminogen activator inhibitor-1 stimulates macrophage activation through Toll-like Receptor-4.

    PubMed

    Gupta, Kamlesh K; Xu, Zhi; Castellino, Francis J; Ploplis, Victoria A

    2016-08-26

    While inflammation is often associated with increased Plasminogen Activator Inhibitor-1 (PAI-1), the functional consequences of PAI-1 in inflammation have yet to be fully determined. The aim of this study was to establish the in vivo relevance of PAI-1 in inflammation. A mouse model of systemic inflammation was employed in wild-type (WT) and PAI-1 deficient (PAI-1(-/-)) mice. Mice survival, macrophage infiltration into the lungs, and plasma levels of pro-inflammatory cytokines were assessed after lipopolysaccharide (LPS) infusion. In vitro experiments were conducted to examine changes in LPS-induced inflammatory responses after PAI-1 exposure. PAI-1 was shown to regulate inflammation, in vivo, and affect macrophage infiltration into lungs. Further, PAI-1 activated macrophages, and increased pro-inflammatory cytokines at both the mRNA and protein levels in these cells. The effect of PAI-1 on macrophage activation was dose-dependent and LPS-independent. Proteolytic inhibitory activity and Lipoprotein Receptor-related Protein (LRP) and vitronectin (VN) binding functions, were not involved in PAI-1-mediated activation of macrophages. However, the effect of PAI-1 on macrophage activation was partially blocked by a TLR4 neutralizing antibody. Furthermore, PAI-1-induced Tumor Necrosis Factor-alpha (TNF-α) and Macrophage Inflammatory Protein-2 (MIP-2) expression was reduced in TLR4(-/-) macrophages compared to WT macrophages. These results demonstrate that PAI-1 is involved in the regulation of host inflammatory responses through Toll-like Receptor-4 (TLR4)-mediated macrophage activation. PMID:27317488

  8. Plasminogen Activator Inhibitor-1 in Cancer: Rationale and Insight for Future Therapeutic Testing.

    PubMed

    Placencio, Veronica R; DeClerck, Yves A

    2015-08-01

    Despite its function as an inhibitor of urokinase and tissue-type plasminogen activator (PA), PA inhibitor-1 (PAI-1) has a paradoxical protumorigenic role in cancer, promoting angiogenesis and tumor cell survival. In this review, we summarize preclinical evidence in support of the protumorigenic function of PAI-1 that has led to the testing of small-molecule PAI-1 inhibitors, initially developed as antithrombotic agents, in animal models of cancer. The review discusses the challenges and the opportunities that lay ahead to the development of efficacious and nontoxic PAI-1 inhibitors as anticancer agents. PMID:26180080

  9. Structural basis of specific inhibition of tissue-type plasminogen activator by plasminogen activators inhibitor-1

    PubMed Central

    Gong, Lihu; Liu, Min; Zeng, Tu; Shi, Xiaoli; Yuan, Cai; Andreasen, Peter A.; Huang, Mingdong

    2016-01-01

    Thrombosis is a leading cause of death worldwide [1]. Recombinant tissue-type plasminogen activator (tPA) is the FDA-approved thrombolytic drug for ischemic strokes, myocardial infarction and pulmonary embolism. tPA is a multi-domain serine protease of the trypsin-family [2] and catalyses the critical step in fibrinolysis [3], converting the zymogen plasminogen to the active serine protease plasmin, which degrades the fibrin network of thrombi and blood clots. tPA is rapidly inactivated by endogenous plasminogen activators inhibitor-1 (PAI-1) [4] (Fig. 1). Engineering on tPA to reduce its inhibition by PAI-1 without compromising its thrombolytic effect is a continuous effort [5]. Tenecteplase (TNK-tPA) is a newer generation of tPA variant showing slower inhibition by PAI-1 [6]. Extensive studies to understand the molecular interactions between tPA and PAI-1 have been carried out [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], however, the precise details at atomic resolution remain unknown. We report the crystal structure of tPA·PAI-1 complex here. The methods required to achieve these data include: (1) recombinant expression and purification of a PAI-1 variant (14-1B) containing four mutations (N150H, K154T, Q319L, and M354I), and a tPA serine protease domain (tPA-SPD) variant with three mutations (C122A, N173Q, and S195A, in the chymotrypsin numbering) [19]; (2) formation of a tPA-SPD·PAI-1 Michaëlis complex in vitro [19]; and (3) solving the three-dimensional structure for this complex by X-ray crystallography [deposited in the PDB database as 5BRR]. The data explain the specificity of PAI-1 for tPA and uPA [19], [20], and provide structural basis to design newer generation of PAI-1-resistant tPA variants as thrombolytic agents [19]. PMID:26909366

  10. Structural basis of specific inhibition of tissue-type plasminogen activator by plasminogen activators inhibitor-1.

    PubMed

    Gong, Lihu; Liu, Min; Zeng, Tu; Shi, Xiaoli; Yuan, Cai; Andreasen, Peter A; Huang, Mingdong

    2016-03-01

    Thrombosis is a leading cause of death worldwide [1]. Recombinant tissue-type plasminogen activator (tPA) is the FDA-approved thrombolytic drug for ischemic strokes, myocardial infarction and pulmonary embolism. tPA is a multi-domain serine protease of the trypsin-family [2] and catalyses the critical step in fibrinolysis [3], converting the zymogen plasminogen to the active serine protease plasmin, which degrades the fibrin network of thrombi and blood clots. tPA is rapidly inactivated by endogenous plasminogen activators inhibitor-1 (PAI-1) [4] (Fig. 1). Engineering on tPA to reduce its inhibition by PAI-1 without compromising its thrombolytic effect is a continuous effort [5]. Tenecteplase (TNK-tPA) is a newer generation of tPA variant showing slower inhibition by PAI-1 [6]. Extensive studies to understand the molecular interactions between tPA and PAI-1 have been carried out [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], however, the precise details at atomic resolution remain unknown. We report the crystal structure of tPA·PAI-1 complex here. The methods required to achieve these data include: (1) recombinant expression and purification of a PAI-1 variant (14-1B) containing four mutations (N150H, K154T, Q319L, and M354I), and a tPA serine protease domain (tPA-SPD) variant with three mutations (C122A, N173Q, and S195A, in the chymotrypsin numbering) [19]; (2) formation of a tPA-SPD·PAI-1 Michaëlis complex in vitro [19]; and (3) solving the three-dimensional structure for this complex by X-ray crystallography [deposited in the PDB database as 5BRR]. The data explain the specificity of PAI-1 for tPA and uPA [19], [20], and provide structural basis to design newer generation of PAI-1-resistant tPA variants as thrombolytic agents [19]. PMID:26909366

  11. Therapeutic Administration of Plasminogen Activator Inhibitor-1 Prevents Hypoxic–Ischemic Brain Injury in Newborns

    PubMed Central

    Yang, Dianer; Nemkul, Niza; Shereen, Ahmed; Jone, Alice; Dunn, R. Scott; Lawrence, Daniel A.; Lindquist, Diana

    2009-01-01

    Disruption of the integrity of the blood–brain barrier (BBB) is an important mechanism of cerebrovascular diseases, including neonatal cerebral hypoxia–ischemia (HI). Although both tissue-type plasminogen activator (tPA) and matrix metalloproteinase-9 (MMP-9) can produce BBB damage, their relationship in neonatal cerebral HI is unclear. Here we use a rodent model to test whether the plasminogen activator (PA) system is critical for MMP-9 activation and HI-induced brain injury in newborns. To test this hypothesis, we examined the therapeutic effect of intracerebroventricular injection of plasminogen activator inhibitor-1 (PAI-1) in rat pups subjected to unilateral carotid artery occlusion and systemic hypoxia. We found that the injection of PAI-1 greatly reduced the activity of both tPA and urokinase-type plasminogen activator after HI. It also blocked HI-induced MMP-9 activation and BBB permeability at 24 h of recovery. Furthermore, magnetic resonance imaging and histological analysis showed the PAI-1 treatment reduced brain edema, axonal degeneration, and cortical cell death at 24–48 h of recovery. Finally, the PAI-1 therapy provided a dose-dependent decrease of brain tissue loss at 7 d of recovery, with the therapeutic window at 4 h after the HI insult. Together, these results suggest that the brain PA system plays a pivotal role in neonatal cerebral HI and may be a promising therapeutic target in infants suffering hypoxic–ischemic encephalopathy. PMID:19587273

  12. Mechanism of Plasminogen Activator Inhibitor-1 regulation by Oncostatin M and Interleukin-1 in human astrocytes

    PubMed Central

    Kasza, Aneta; Kiss, Daniel L.; Gopalan, Sunita; Xu, Weili; Rydel, Russell E.; Koj, Aleksander; Kordula, Tomasz

    2015-01-01

    Glial cells that produce and respond to various cytokines mediate inflammatory processes in the brain. Here, we show that oncostatin M (OSM) and interleukin-1 (IL-1) regulate the expression of plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) in human astrocytes. Using the PAI-1 reporter constructs we show that the −58 to −51 proximal element mediates activation by both cytokines. This element is already bound by c-fos/c-jun heterodimers in unstimulated astrocytes, and treatment with cytokine strongly stimulates both expression of c-fos and binding of c-fos/c-jun heterodimers. In addition, IL-1 activates an inhibitory mechanism that downregulates PAI-1 expression after longer exposure to this cytokine. Overexpression of dominant-negative signal transducer and activator of transcription-1 (STAT1), STAT3, STAT5 and inhibitor of nuclear factor kB (IkB) suppressed OSM/IL-1-induced expression of the PAI-1 reporter construct. We conclude that OSM and IL-1 regulate the PAI-1 gene expression via up-regulating c-fos levels and subsequent binding of c-fos/c-jun heterodimers to the proximal element of the PAI-1 gene. PMID:12390531

  13. Abrogation of Plasminogen Activator Inhibitor-1-Vitronectin Interaction Ameliorates Acute Kidney Injury in Murine Endotoxemia

    PubMed Central

    Gupta, Kamlesh K.; Donahue, Deborah L.; Sandoval-Cooper, Mayra J.; Castellino, Francis J.; Ploplis, Victoria A.

    2015-01-01

    Sepsis-induced acute kidney injury (AKI) contributes to the high mortality and morbidity in patients. Although the pathogenesis of AKI during sepsis is poorly understood, it is well accepted that plasminogen activator inhibitor-1 (PAI-1) and vitronectin (Vn) are involved in AKI. However, the functional cooperation between PAI-1 and Vn in septic AKI has not been completely elucidated. To address this issue, mice were utilized lacking either PAI-1 (PAI-1−/−) or expressing a PAI-1-mutant (PAI-1R101A/Q123K) in which the interaction between PAI-1 and Vn is abrogated, while other functions of PAI-1 are retained. It was found that both PAI-1−/− and PAI-1R101A/Q123K mice are associated with decreased renal dysfunction, apoptosis, inflammation, and ERK activation as compared to wild-type (WT) mice after LPS challenge. Also, PAI-1−/− mice showed attenuated fibrin deposition in the kidneys. Furthermore, a lack of PAI-1 or PAI-1-Vn interaction was found to be associated with an increase in activated Protein C (aPC) in plasma. These results demonstrate that PAI-1, through its interaction with Vn, exerts multiple deleterious mechanisms to induce AKI. Therefore, targeting of the PAI-1-Vn interaction in kidney represents an appealing therapeutic strategy for the treatment of septic AKI by not only altering the fibrinolytic capacity but also regulating PC activity. PMID:25799354

  14. Novel Plasminogen Activator Inhibitor-1 Inhibitors Prevent Diabetic Kidney Injury in a Mouse Model

    PubMed Central

    Park, Jong Hee; Lee, Jung Hwa; Lee, Hi Bahl; Miyata, Toshio; Ha, Hunjoo

    2016-01-01

    Diabetic nephropathy is the leading cause of end-stage renal disease worldwide, but no effective therapeutic strategy is available. Because plasminogen activator inhibitor-1 (PAI-1) is increasingly recognized as a key factor in extracellular matrix (ECM) accumulation in diabetic nephropathy, this study examined the renoprotective effects of TM5275 and TM5441, two novel orally active PAI-1 inhibitors that do not trigger bleeding episodes, in streptozotocin (STZ)-induced diabetic mice. TM5275 (50 mg/kg) and TM5441 (10 mg/kg) were administered orally for 16 weeks to STZ-induced diabetic and age-matched control mice. Relative to the control mice, the diabetic mice showed significantly increased (p < 0.05) plasma glucose and creatinine levels, urinary albumin excretion, kidney-to-bodyweight ratios, glomerular volume, and fractional mesangial area. Markers of fibrosis and inflammation along with PAI-1 were also upregulated in the kidney of diabetic mice, and treatment with TM5275 and TM5441 effectively inhibited albuminuria, mesangial expansion, ECM accumulation, and macrophage infiltration in diabetic kidneys. Furthermore, in mouse proximal tubular epithelial (mProx24) cells, both TM5275 and TM5441 effectively inhibited PAI-1-induced mRNA expression of fibrosis and inflammation markers and also reversed PAI-1-induced inhibition of plasmin activity, which confirmed the efficacy of the TM compounds as PAI-1 inhibitors. These data suggest that TM compounds could be used to prevent diabetic kidney injury. PMID:27258009

  15. PGE2 Reduces MMP-14 and Increases Plasminogen Activator Inhibitor-1 in Cardiac Fibroblasts

    PubMed Central

    Kassem, Kamal M.; Clevenger, Margarette H.; Szandzik, David L.; Peterson, Edward; Harding, Pamela

    2014-01-01

    Prostaglandin E2 (PGE2) is elevated during cardiac injury and we have previously shown that mice lacking the PGE EP4 receptor display dilated cardiomyopathy (DCM) with increased expression of the membrane type matrix metalloproteinase, MMP-14. We thus hypothesized that PGE2 regulates expression of MMP-14 and also affects fibroblast migration. Primary cultures of neonatal rat ventricular fibroblasts (NVFs) were used to test the effects of PGE2. Gene and protein expression was assessed by real time RT-PCR and Western blot, MMP activity was determined by zymography and migration of NVF was assessed by motility in a transwell system. PGE2 reduced expression of MMP-14 and these effects were antagonized by an EP4 antagonist. An EP4 agonist mimicked the effect of PGE2. PGE2 also increased mRNA and protein levels of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of MMP activation. However, PGE2-stimulation of PAI-1 was mediated by the EP1/EP3 receptor and not EP4. Migration of NVF was assessed by motility in a transwell system. Treatment of NVFs with PGE2 reduced the number of cells migrating towards 10% FCS. Treatment with the EP2 agonist also reduced migration but did not affect MMP-14 expression or PAI-1. Our results suggest that PGE2 utilizes different receptors and mechanisms to ultimately decrease MMP expression and NVF migration. PMID:25263346

  16. PGE2 reduces MMP-14 and increases plasminogen activator inhibitor-1 in cardiac fibroblasts.

    PubMed

    Kassem, Kamal M; Clevenger, Margarette H; Szandzik, David L; Peterson, Edward; Harding, Pamela

    2014-10-01

    Prostaglandin E2 (PGE2) is elevated during cardiac injury and we have previously shown that mice lacking the PGE2 EP4 receptor display dilated cardiomyopathy (DCM) with increased expression of the membrane type matrix metalloproteinase, MMP-14. We thus hypothesized that PGE2 regulates expression of MMP-14 and also affects fibroblast migration. Primary cultures of neonatal rat ventricular fibroblasts (NVFs) were used to test the effects of PGE2. Gene and protein expression was assessed by real time RT-PCR and Western blot, MMP activity was determined by zymography and migration of NVF was assessed by motility in a transwell system. PGE2 reduced expression of MMP-14 and these effects were antagonized by an EP4 antagonist. An EP4 agonist mimicked the effect of PGE2. PGE2 also increased mRNA and protein levels of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of MMP activation. However, PGE2-stimulation of PAI-1 was mediated by the EP1/EP3 receptor and not EP4. Migration of NVF was assessed by motility in a transwell system. Treatment of NVFs with PGE2 reduced the number of cells migrating toward 10% FCS. Treatment with the EP2 agonist also reduced migration but did not affect MMP-14 expression or PAI-1. Our results suggest that PGE2 utilizes different receptors and mechanisms to ultimately decrease MMP expression and NVF migration. PMID:25263346

  17. Increased concentration of plasminogen activator inhibitor-1 and fibrinogen in individuals with metabolic syndrome.

    PubMed

    Palomo, Iván G; Gutiérrez, César L; Alarcón, Marcelo L; Jaramillo, Julio C; Segovia, Fabián M; Leiva, Elba M; Mujica, Verónica E; Icaza, Gloria N; Díaz, Nora S; Moore-Carrasco, Rodrigo

    2009-01-01

    Metabolic syndrome (MS) is closely linked to a generalized metabolic disorder referred to as insulin resistance. Disturbances in the hemostasis and fibrinolytic systems are a feature of MS. The aim of this study was to determine the concentration levels of fibrinogen and plasminogen activator inhibitor-1 (PAI-1) in a group of patients with MS with respect to a non-MS group, and to evaluate their possible relation with other risk factors in MS. The study was carried out in a total of 186 male and female non-smoking individuals aged 45-64 years, 93 with MS (ATP III criteria) and 93 without MS. Plasmatic levels of PAI-1 were measured by ELISA, and those of fibrinogen by the Claus method. The plasmatic levels of PAI-1 (men 49.2±19.8 vs. 35.0±12.2 ng/ml and women 42.0±19.7 vs. 31.6±14.6 ng/ml; p=0.0026) and fibrinogen (274.0±82.1 vs. 232.7±66.6 ng/ml; p=0.0002) were significantly higher in the MS group than in the non-MS group. PAI-1 was significantly associated with diastolic blood pressure, triglycerides and waist circumference. Fibrinogen was negatively associated with HDL-c. High plasmatic levels of PAI-1 and fibrinogen contribute to the cardiovascular risk that characterizes individuals with MS. PMID:21475821

  18. Plasminogen Activator Inhibitor-1 Controls Vascular Integrity by Regulating VE-Cadherin Trafficking

    PubMed Central

    Daniel, Anna E.; Timmerman, Ilse; Kovacevic, Igor; Hordijk, Peter L.; Adriaanse, Luc; Paatero, Ilkka; Belting, Heinz-Georg; van Buul, Jaap D.

    2015-01-01

    Background Plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, is expressed and secreted by endothelial cells. Patients with PAI-1 deficiency show a mild to moderate bleeding diathesis, which has been exclusively ascribed to the function of PAI-1 in down-regulating fibrinolysis. We tested the hypothesis that PAI-1 function plays a direct role in controlling vascular integrity and permeability by keeping endothelial cell-cell junctions intact. Methodology/Principal Findings We utilized PAI-039, a specific small molecule inhibitor of PAI-1, to investigate the role of PAI-1 in protecting endothelial integrity. In vivo inhibition of PAI-1 resulted in vascular leakage from intersegmental vessels and in the hindbrain of zebrafish embryos. In addition PAI-1 inhibition in human umbilical vein endothelial cell (HUVEC) monolayers leads to a marked decrease of transendothelial resistance and disrupted endothelial junctions. The total level of the endothelial junction regulator VE-cadherin was reduced, whereas surface VE-cadherin expression was unaltered. Moreover, PAI-1 inhibition reduced the shedding of VE-cadherin. Finally, we detected an accumulation of VE-cadherin at the Golgi apparatus. Conclusions/Significance Our findings indicate that PAI-1 function is important for the maintenance of endothelial monolayer and vascular integrity by controlling VE-cadherin trafficking to and from the plasma membrane. Our data further suggest that therapies using PAI-1 antagonists like PAI-039 ought to be used with caution to avoid disruption of the vessel wall. PMID:26714278

  19. Plasminogen Activator Inhibitor-1 in depression: Results from Animal and Clinical Studies

    PubMed Central

    Jiang, Haitang; Li, Xiaoli; Chen, Suzhen; Lu, Na; Yue, Yingying; Liang, Jinfeng; Zhang, Zhijun; Yuan, Yonggui

    2016-01-01

    Evidence suggests that plasminogen activator inhibitor-1 (PAI-1) is a stress-related factor, and serum PAI-1 levels are increased in patients with major depressive disorders (MDD). Herein, we analysed PAI-1 protein levels in the brain, cerebrospinal fluid (CSF) and serum of rodents exposed to chronic unpredictable mild stress or treated with escitalopram. In addition, we examined PAI-1 concentrations in serum obtained from 17 drug-free depressed patients before and after escitalopram treatment. We found that PAI-1 expression was increased in area 1 of the cingulate cortex and prelimbic cortex of the medial prefrontal cortex as well as in the hippocampal cornu ammonis 3 and dentate gyrus in stressed rats. A downregulation of PAI-1 following chronic escitalopram treatment was also found. PAI-1 levels were higher in the CSF and serum in stressed rats than in controls, although the difference did not reach statistical significance in the serum. Escitalopram treatment significantly decreased PAI-1 levels in the serum, but not in the CSF. MDD patients had significantly greater serum PAI-1 concentrations than controls. Our results suggest that PAI-1 is implicated in the pathophysiology of depression. PMID:27456456

  20. Plasminogen Activator Inhibitor-1 in depression: Results from Animal and Clinical Studies.

    PubMed

    Jiang, Haitang; Li, Xiaoli; Chen, Suzhen; Lu, Na; Yue, Yingying; Liang, Jinfeng; Zhang, Zhijun; Yuan, Yonggui

    2016-01-01

    Evidence suggests that plasminogen activator inhibitor-1 (PAI-1) is a stress-related factor, and serum PAI-1 levels are increased in patients with major depressive disorders (MDD). Herein, we analysed PAI-1 protein levels in the brain, cerebrospinal fluid (CSF) and serum of rodents exposed to chronic unpredictable mild stress or treated with escitalopram. In addition, we examined PAI-1 concentrations in serum obtained from 17 drug-free depressed patients before and after escitalopram treatment. We found that PAI-1 expression was increased in area 1 of the cingulate cortex and prelimbic cortex of the medial prefrontal cortex as well as in the hippocampal cornu ammonis 3 and dentate gyrus in stressed rats. A downregulation of PAI-1 following chronic escitalopram treatment was also found. PAI-1 levels were higher in the CSF and serum in stressed rats than in controls, although the difference did not reach statistical significance in the serum. Escitalopram treatment significantly decreased PAI-1 levels in the serum, but not in the CSF. MDD patients had significantly greater serum PAI-1 concentrations than controls. Our results suggest that PAI-1 is implicated in the pathophysiology of depression. PMID:27456456

  1. Plasminogen activator inhibitor-1 gene-deficient mice. II. Effects on hemostasis, thrombosis, and thrombolysis.

    PubMed Central

    Carmeliet, P; Stassen, J M; Schoonjans, L; Ream, B; van den Oord, J J; De Mol, M; Mulligan, R C; Collen, D

    1993-01-01

    The effects of plasminogen activator inhibitor-1 (PAI-1) gene inactivation on hemostasis, thrombosis and thrombolysis were studied in homozygous PAI-1-deficient (PAI-1-/-) mice, generated by homologous recombination in D3 embryonic stem cells. Diluted (10-fold) whole blood clots from PAI-1-/- and from PAI-1 wild type (PAI-1+/+) mice underwent limited but significantly different (P < 0.001) spontaneous lysis within 3 h (6 +/- 1 vs 3 +/- 1%, respectively). A 25-microliters 125I-fibrin-labeled normal murine plasma clot, injected into a jugular vein, was lysed for 47 +/- 5, 66 +/- 3, and 87 +/- 7% within 8 h in PAI-1+/+, heterozygous PAI-1-deficient (PAI-1+/-), and PAI-1-/- mice, respectively (P = 0.002 for PAI-1+/+ vs PAI-1-/- mice). Corresponding values after pretreatment with 0.5 mg/kg endotoxin in PAI-1+/+ and PAI-1-/- mice, were 35 +/- 5 and 91 +/- 3% within 4 h, respectively (P < 0.001). 11 out of 26 PAI-1+/+ but only 1 out of 25 PAI-1-/- mice developed venous thrombosis (P = 0.004) within 6 d after injection of 10 or 50 micrograms endotoxin in the footpad. Spontaneous bleeding or delayed rebleeding could not be documented in PAI-1-/- mice after partial amputation of the tail or of the caecum. Thus, disruption of the PAI-1 gene in mice appears to induce a mild hyperfibrinolytic state and a greater resistance to venous thrombosis but not to impair hemostasis. Images PMID:8254029

  2. Plasminogen Activator Inhibitor-1 Limits Liver Injury and Facilitates Regeneration after Acetaminophen Overdose

    PubMed Central

    Bajt, Mary Lynn; Yan, Hui-Min; Farhood, Anwar; Jaeschke, Hartmut

    2008-01-01

    Deficiency in plasminogen activator inhibitor-1 (PAI-1) gene expression is known to promote growth factor activation and regeneration in a number of hepatotoxicity models. To evaluate if PAI-1 has similar effects in acetaminophen (APAP) hepatotoxicity, wild-type (WT) and PAI-1 gene knockout mice (PAI-KO) were treated with 200 mg/kg APAP and liver injury and its repair were assessed. In WT animals, plasma alanine aminotransferase (ALT) activities increased during the first 12 h and then returned to baseline within 48 h. The area of necrosis increased in parallel to the ALT values, peaked between 12 and 24 h and was completely resolved by 96 h. The regenerative response of cells outside the necrotic area, as indicated by proliferating cell nuclear antigen protein and cyclin D1 gene expression, was observed within 24 h, peaked at 48 h and then declined but remained elevated until 96 h. Liver injury in response to APAP was similar in PAI-KO as in WT animals during the first 12 h. However, plasma ALT values and the area of necrosis further increased during the following 12 h with development of massive intrahepatic hemorrhage. Approximately, 50% of the PAI-KO animals did not survive. Although liver injury of the surviving animals was repaired, the regeneration process was delayed until 48 h. A potential reason for this delay may have been due to the more severe injury and/or the increased expression of the cell cycle inhibitor p21. Our data indicate that PAI activation limits liver injury and mortality during APAP hepatotoxicity by preventing excessive hemorrhage and thereby facilitating tissue repair. PMID:18469330

  3. Plasminogen activator inhibitor-1 limits liver injury and facilitates regeneration after acetaminophen overdose.

    PubMed

    Bajt, Mary Lynn; Yan, Hui-Min; Farhood, Anwar; Jaeschke, Hartmut

    2008-08-01

    Deficiency in plasminogen activator inhibitor-1 (PAI-1) gene expression is known to promote growth factor activation and regeneration in a number of hepatotoxicity models. To evaluate if PAI-1 has similar effects in acetaminophen (APAP) hepatotoxicity, wild-type (WT) and PAI-1 gene knockout mice (PAI-KO) were treated with 200 mg/kg APAP and liver injury and its repair were assessed. In WT animals, plasma alanine aminotransferase (ALT) activities increased during the first 12 h and then returned to baseline within 48 h. The area of necrosis increased in parallel to the ALT values, peaked between 12 and 24 h and was completely resolved by 96 h. The regenerative response of cells outside the necrotic area, as indicated by proliferating cell nuclear antigen protein and cyclin D(1) gene expression, was observed within 24 h, peaked at 48 h and then declined but remained elevated until 96 h. Liver injury in response to APAP was similar in PAI-KO as in WT animals during the first 12 h. However, plasma ALT values and the area of necrosis further increased during the following 12 h with development of massive intrahepatic hemorrhage. Approximately, 50% of the PAI-KO animals did not survive. Although liver injury of the surviving animals was repaired, the regeneration process was delayed until 48 h. A potential reason for this delay may have been due to the more severe injury and/or the increased expression of the cell cycle inhibitor p21. Our data indicate that PAI activation limits liver injury and mortality during APAP hepatotoxicity by preventing excessive hemorrhage and thereby facilitating tissue repair. PMID:18469330

  4. Low Molecular Weight Antagonists of Plasminogen Activator Inhibitor-1: Therapeutic Potential in Cardiovascular Disease.

    PubMed

    Simone, Tessa M; Higgins, Paul J

    2012-08-01

    Plasminogen activator inhibitor-1 (PAI-1; SERPINE1) is the major physiologic regulator of the plasmin-based pericellular proteolytic cascade, a modulator of vascular smooth muscle cell (VSMC) migration and a causative factor in cardiovascular disease and restenosis, particularly in the context of increased vessel transforming growth factor- β1 (TGF-β1) levels. PAI-1 limits conversion of plasminogen to plasmin (and, thereby, fibrin degradation) by inhibiting its protease targets urokinase and tissue-type plasminogen activators (uPA, tPA). PAI-1 also has signaling functions and binds to the low density lipoprotein receptor-related protein 1 (LRP1) to regulate LRP1-dependent cell motility that, in turn, contributes to neointima formation. PAI-1/uPA/uPA receptor/LRPI/integrin complexes are endocytosed with subsequent uPAR/LRP1/integrin redistribution to the leading edge, initiating an "adhesion-detachment-readhesion" cycle to promote cell migration. PAI-1 also interacts with LRP1 in a uPA/uPAR-independent manner triggering Jak/Stat1 pathway activation to stimulate cell motility. PAI-1 itself is a substrate for extracellular proteases and exists in a "cleaved" form which, while unable to interact with uPA and tPA, retains LRP1-binding and migratory activity. These findings suggest that there are multiple mechanisms through which inhibition of PAI-1 may promote cardiovascular health. Several studies have focused on the design, synthesis and preclinical assessment of PAI-1 antagonists including monoclonal antibodies, peptides and low molecular weight (LMW) antagonists. This review discusses the translational impact of LMW PAI-1 antagonists on cardiovascular disease addressing PAI-1-initiated signaling, PAI-1 structure, the design and characteristics of PAI-1-targeting drugs, results of in vitro and in vivo studies, and their clinical implications. PMID:23936868

  5. Enhancing the Function of CD34+ Cells by Targeting Plasminogen Activator Inhibitor-1

    PubMed Central

    Hazra, Sugata; Stepps, Valerie; Bhatwadekar, Ashay D.; Caballero, Sergio; Boulton, Michael E.; Higgins, Paul J.; Nikonova, Elena V.; Pepine, Carl J.; Thut, Catherine; Finney, Eva M.; Stone, David J.; Bartelmez, Stephen H.; Grant, Maria B.

    2013-01-01

    Previously, we showed that transient inhibition of TGF- β1 resulted in correction of key aspects of diabetes-induced CD34+ cell dysfunction. In this report, we examine the effect of transient inhibition of plasminogen activator inhibitor-1 (PAI-1), a major gene target of TGF-β1 activation. Using gene array studies, we examined CD34+ cells isolated from a cohort of longstanding diabetic individuals, free of microvascular complications despite suboptimal glycemic control, and found that the cells exhibited reduced transcripts of both TGF-β1 and PAI-1 compared to age, sex, and degree of glycemic control-matched diabetic individuals with microvascular complications. CD34+ cells from diabetic subjects with microvascular complications consistently exhibited higher PAI-1 mRNA than age-matched non-diabetic controls. TGF- β1 phosphorodiamidate morpholino oligo (PMO) reduced PAI-1 mRNA in diabetic (p<0.01) and non-diabetic (p=0.05) CD34+ cells. To reduce PAI-1 in human CD34+ cells, we utilized PAI-1 siRNA, lentivirus expressing PAI-1 shRNA or PAI-1 PMO. We found that inhibition of PAI-1 promoted CD34+ cell proliferation and migration in vitro, likely through increased PI3(K) activity and increased cGMP production. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34+ cells to injured acellular retinal capillaries was greater after PAI-1-PMO treatment compared with control PMO-treated cells. Targeting PAI-1 offers a promising therapeutic strategy for restoring vascular reparative function in defective diabetic progenitors. PMID:24223881

  6. High-fat diet enhances and plasminogen activator inhibitor-1 deficiency attenuates bone loss in mice with Lewis Lung carcinoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study determined the effects of a high-fat diet and plasminogen activator inhibitor-1 deficiency (PAI-1-/-) on bone structure in mice bearing Lewis lung carcinoma (LLC) in lungs. Reduction in bone volume fraction (BV/TV) by 22% and 21%, trabecular number (Tb.N) by 8% and 4% and bone mineral de...

  7. RNA aptamers as conformational probes and regulatory agents for plasminogen activator inhibitor-1.

    PubMed

    Madsen, Jeppe B; Dupont, Daniel M; Andersen, Thomas B; Nielsen, Anne F; Sang, Lu; Brix, Ditte M; Jensen, Jan K; Broos, Thomas; Hendrickx, Maarten L V; Christensen, Anni; Kjems, Jørgen; Andreasen, Peter A

    2010-05-18

    The hallmark of serpins is the ability to undergo the so-called "stressed-to-relaxed" switch during which the surface-exposed reactive center loop (RCL) becomes incorporated as strand 4 in central beta-sheet A. RCL insertion drives not only the inhibitory reaction of serpins with their target serine proteases but also the conversion to the inactive latent state. RCL insertion is coupled to conformational changes in the flexible joint region flanking beta-sheet A. One interesting serpin is plasminogen activator inhibitor-1 (PAI-1), a fast and specific inhibitor of the serine proteases tissue-type and urokinase-type plasminogen activator. Via its flexible joints' region, native PAI-1 binds vitronectin and relaxed, protease-complexed PAI-1 certain endocytosis receptors. From a library of 35-nucleotides long 2'-fluoropyrimidine-containing RNA oligonucleotides, we have isolated two aptamers binding PAI-1 by the flexible joint region with low nanomolar K(D) values. One of the aptamers exhibited measurable binding to native PAI-1 only, while the other also bound relaxed PAI-1. While none of the aptamers inhibited the antiproteolytic effect of PAI-1, both aptamers inhibited vitronectin binding and the relaxed PAI-1-binding aptamer also endocytosis receptor binding. The aptamer binding exclusively to native PAI-1 increased the half-life for the latency transition to more than 6 h, manyfold more than vitronectin. Contact with Lys124 in the flexible joint region was critical for strong inhibition of the latency transition and the lack of binding to relaxed PAI-1. We conclude that aptamers yield important information about the serpin conformational switch and, because they can compete with high-affinity protein-protein interactions, may provide leads for pharmacological intervention. PMID:20387790

  8. Angiotensinogen and Plasminogen Activator Inhibitor-1 Gene Polymorphism in Relation to Renovascular Disease

    SciTech Connect

    Reis, Kadriye Altok Onal, Baran; Gonen, Sevim; Arinsoy, Turgay; Erten, Yasemin; Ilgit, Erhan; Soylemezoglu, Oguz; Derici, Ulver; Guz, Galip; Bali, Musa; Sindel, Sukru

    2006-02-15

    The present study was designed to evaluate angiotensinogen (AGT) M235T and plasminogen activator inhibitor-1 (PAI-1) (4G/5G) polymorphisims in relation to the occurrence of atherosclerotic renal artery stenosis (ARAS) and recurrent stenosis. In this study, 30 patients were enrolled after angiographic demonstration of ARAS; 100 healthy subjects for AGT polymorphism and 80 healthy subjects for PAI-1 polymorphism were considered the control group. The patients were followed for a mean 46.1 {+-} 9.2 months. The patients had significantly higher frequencies of the MT genotype and the T allele than control group ({chi}{sup 2} = 18.2, p < 0.001 and {chi}{sup 2} = 11.5 p < 0.001). There were no significant differences in the PAI-1 genotype and allele findings when the data for all patients were compared with that for the controls ({chi}{sup 2}= 2.45, p = 0.29 and {chi}{sup 2} = 0.019, p = 0.89). There were no significant differences in the genotype and allele findings for the patients with and without restenosis (p > 0.05). The C-reactive protein (CRP) level was higher in the patients with restenosis than in the patients without restenosis (7.694 {+-} 0.39 mg/L and 1.56 {+-} 1.08 mg/L) (p = 0.001). Our results suggest that the M235T MT genotype and T allele might be associated with increased risk of atherosclerotic renal artery stenosis. The CRP level might be an independent predictor for recurrent stenosis.

  9. Leptin links with plasminogen activator inhibitor-1 in human obesity: the SABPA study.

    PubMed

    Pieterse, Chiné; Schutte, Rudolph; Schutte, Aletta E

    2015-07-01

    The relationship between obesity and the development of cardiovascular disease is well established. However, the underlying mechanisms contributing to vascular disease and increased cardiovascular risk in the obese remain largely unexplored. Since leptin exerts direct vascular effects, we investigated leptin and the relationship thereof with circulating markers of vascular damage, namely plasminogen activator inhibitor-1 antigen (PAI-1(ag)), von Willebrand factor antigen (vWF(ag)) and urinary albumin-to-creatinine ratio (ACR). The study included a bi-ethnic population of 409 African and Caucasian teachers who were stratified into lean (<0.5) and obese (⩾0.5) groups according to waist-to-height ratio. We obtained ambulatory blood pressure measurements and determined serum leptin levels, PAI-1(ag), vWF(ag) and ACR, as markers of vascular damage. The obese group had higher leptin (P<0.001) and PAI-1(ag) (P<0.001) levels and a tendency existed for higher vWF(ag) (P=0.068). ACR did not differ between the two groups (P=0.21). In single regression analyses positive associations existed between leptin and all markers of vascular damage (all P<0.001) only in the obese group. After adjusting for covariates and confounders in multiple regression analyses, only the association between leptin and PAI-1(ag) remained (R(2)=0.440; β=0.293; P=0.0021). After adjusting for gender, ethnicity and age, additional analyses indicated that leptin also associated with fibrinogen and clot lysis time in both lean and obese groups, which in turn is associated with 24- h blood pressure and pulse pressure. This result provides evidence that elevated circulating leptin may directly contribute to vascular damage, possibly through mechanism related to thrombotic vascular disease. PMID:25740294

  10. Genetics of Plasminogen Activator Inhibitor-1 (PAI-1) in a Ghanaian Population

    PubMed Central

    White, Marquitta J.; Kodaman, Nuri M.; Harder, Reed H.; Asselbergs, Folkert W.; Vaughan, Douglas E.; Brown, Nancy J.; Moore, Jason H.; Williams, Scott M.

    2015-01-01

    Plasminogen activator inhibitor 1 (PAI-1), a major modulator of the fibrinolytic system, is an important factor in cardiovascular disease (CVD) susceptibility and severity. PAI-1 is highly heritable, but the few genes associated with it explain only a small portion of its variation. Studies of PAI-1 typically employ linear regression to estimate the effects of genetic variants on PAI-1 levels, but PAI-1 is not normally distributed, even after transformation. Therefore, alternative statistical methods may provide greater power to identify important genetic variants. Additionally, most genetic studies of PAI-1 have been performed on populations of European descent, limiting the generalizability of their results. We analyzed >30,000 variants for association with PAI-1 in a Ghanaian population, using median regression, a non-parametric alternative to linear regression. Three variants associated with median PAI-1, the most significant of which was in the gene arylsulfatase B (ARSB) (p = 1.09 x 10−7). We also analyzed the upper quartile of PAI-1, the most clinically relevant part of the distribution, and found 19 SNPs significantly associated in this quartile. Of note an association was found in period circadian clock 3 (PER3). Our results reveal novel associations with median and elevated PAI-1 in an understudied population. The lack of overlap between the two analyses indicates that the genetic effects on PAI-1 are not uniform across its distribution. They also provide evidence of the generalizability of the circadian pathway’s effect on PAI-1, as a recent meta-analysis performed in Caucasian populations identified another circadian clock gene (ARNTL). PMID:26322636

  11. Polymorphism in methylenetetrahydrofolate reductase, plasminogen activator inhibitor-1, and apolipoprotein E in hemodialysis patients.

    PubMed

    Al-Muhanna, Fahad; Al-Mueilo, Samir; Al-Ali, Amein; Larbi, Emmanuel; Rubaish, Abdullah; Abdulmohsen, Mohammed Fakhry; Al-Zahrani, Alhussain; Al-Ateeq, Suad

    2008-11-01

    The methylenetetrahydrofolate reductase (MTHFR) gene polymorphism, apolipoprotein E (apo epsilon4) gene polymorphism and polymorphism of plasminogen activator inhibitor-1 (PAI-1) have been shown to be associated with end-stage renal disease (ESRD). To determine the prevalence of these mutations in Saudi patients with ESRD on hemodialysis, we studied the allelic frequency and genotype distribution in patients receiving hemodialysis and in a control group, all residing in the Eastern Province of Saudi Arabia. The genotypes were determined using allele specific hybridization procedures and were confirmed by restriction fragment length polymorphism. The T allele frequency and homozygous genotype of MTHFR in ESRD patients were 14% and 2.4%, respectively compared to 13.4% and 0%, respectively in the control group. The allele frequency and homozygous genotype of 4G/4G PAI-1 gene polymorphism were 46.4% and 4.8% respectively in ESRD patients compared to 57.1% and 32% respectively in the control group. The apo s4 allele frequency and homozygous genotype distribution in hemodialysis patients were 7% and 2.4%, respectively compared to 13% and 2% in the control group. Although allele frequency of C677T of MTHFR was statistically similar in the hemodialysis patients and in the control group, the homozygotes T allele genotype was over represented in the hemodialysis group compared to normal. The prevalence of PAI-1 4G/4G polymorphism in ESRD patients was lower when compared to the control group. The prevalence of apo s4 allele did not differ significantly between the two groups. The present results demonstrate that all three studied polymorphic mutations are present in our population and that they may contribute to the etiology of the disease in our area. PMID:18974580

  12. Modulation of plasminogen activator inhibitor 1 by Triton X-100--identification of two consecutive conformational transitions.

    PubMed

    Gils, A; Declerck, P J

    1998-08-01

    Plasminogen activator inhibitor-1 (PAI-1) is a unique member of the serpin superfamily because of its conformational and functional flexibility. In the present study, we have evaluated the influence of the non-ionic detergent Triton X-100 (TX-100) on the functional stability and conformational transitions of PAI-1. At 37 degrees C, TX-100 induced a concentration-dependent decrease of the functional half-life of PAI-1 resulting in half-lives of 177 +/- 54 min (mean +/- SD, n = 3), 19 +/- 2 min, 1.7 +/- 0.3 min and 0.53 +/- 0.03 min in the presence of 0.005, 0.010, 0.020 and 0.2% TX-100, respectively, compared to a half-life of 270 +/- 146 min in the absence of TX-100. Conformational analysis at various time points and at different temperatures (0 degrees C, 25 degrees C, 37 degrees C) revealed that this inactivation proceeds through the formation of a substrate-like intermediate followed by the formation of the latent form. Kinetic evaluation demonstrated that this conversion fits to two consecutive first-order transitions, i.e. active k1--> substrate k2--> latent. The k1 value was strongly dependent on the concentration of TX-100 (e.g. 0.002 +/- 0.0006 s(-1) and 0.029 +/- 0.003 s(-1) for 0.01% and 0.2% TX-100 at 37 degrees C) whereas the conversion of substrate to latent (k2) was virtually independent of the TX-100 concentration (i.e. 0.012 +/- 0.002 s(-1) and 0.011 +/- 0.001 s(-1) for 0.01 and 0.2% TX-100 at 37 degrees C). Experiments with a variety of other non-ionic amphiphilic compounds revealed that the amphiphilic character of the compound is, at least in part, responsible for the observed effects and strongly indicate that the currently reported mechanism of inactivation is of general importance for the conformational transitions in PAI-1. In conclusion, TX- 100 changes the initial conformation of PAI-1 resulting in altered functional properties. This observation allows us to develop a new model for the mechanism involved in the conformational flexibility of

  13. Recombinant Human Plasminogen Activator Inhibitor-1 Accelerates Odontoblastic Differentiation of Human Stem Cells from Apical Papilla.

    PubMed

    Jin, Bin; Choung, Pill-Hoon

    2016-05-01

    Dental caries, the most prevalent oral disease in dental patients, involves the phases of demineralization and destruction of tooth hard tissues like enamel, dentin, and cementum. Dentin is a major component of the root and is also the innermost layer that protects the tooth nerve, exposure of which results in pain. In this study, we used human stem cells from apical papilla (hSCAP), which are early progenitor cells, to examine the effects of recombinant human plasminogen activator inhibitor-1 (rhPAI-1) on odontogenic differentiation in vitro and in vivo. We demonstrated that rhPAI-1 promoted the proliferation and odontogenic differentiation of hSCAP and increased the expression levels of odontoblast-associated markers. We also observed that rhPAI-1 upregulated the expression of Smad4, nuclear factor I-C (NFI-C), Runx2, and osterix (OSX) during odontogenic differentiation. Notably, transplantation of rhPAI-1-treated hSCAP effectively induced odontoblastic differentiation and dentinal formation. And the differentiated odontoblast-like cells showed numerous odontoblast processes inserted in dentin tubules and arranged collagen fibers. Furthermore, odontoblast-associated markers were more highly expressed in the rhPAI-1-induced differentiated odontoblast-like cells compared with the control group. These markers were also more highly expressed in the newly formed dentin-like tissue of the rhPAI-1-treated group compared with the control group. Consistent with our in vitro results, the expression levels of Smad4, NFI-C, and OSX were also increased in the rhPAI-1-treated group compared with the control group. Taken together, these results suggest that rhPAI-1 promotes odontoblast differentiation and dentin formation of hSCAP, and Smad4/NFI-C/OSX may play critical roles in the rhPAI-1-induced odontogenic differentiation. Thus, dental stem cells from apical papilla combined with rhPAI-1 could lead to dentin regeneration in clinical implications. PMID:27046084

  14. Circadian fluctuations of tissue plasminogen activator antigen and plasminogen activator inhibitor-1 antigens in vasospastic angina.

    PubMed

    Sakata, K; Hoshino, T; Yoshida, H; Ono, N; Ohtani, S; Yokoyama, S; Mori, N; Kaburagi, T; Kurata, C; Urano, T

    1992-10-01

    To elucidate the circadian variation of fibrinolytic components in vasospastic angina, plasma levels of tissue plasminogen activator antigen (t-PA), free plasminogen activator inhibitor antigen (free PAI-1), t-PA/PAI-1 complex, and total PAI-1 were measured in venous plasma samples. Samples were taken every 6 hours (6:00 AM, noon, 6:00 PM, and midnight) for 24 hours in 14 patients with vasospastic angina, in 9 patients with exertional angina, and in 19 normal subjects. Twenty-four-hour Holter monitoring (Holter monitor, Del Mar Avionics, Irvine, Calif.) was also carried out in all subjects. All of the fibrinolytic components showed circadian variation, with a peak level at 6:00 AM in every study group except for the t-PA/PAI-1 complex in the group of patients with exertional angina. The values for all or the fibrinolytic components at each sampling time were higher in patients with coronary artery disease than in normal subjects. In particular, the mean value of free PAI-1 at 6:00 AM in patients with vasospastic angina was significantly higher than that in normal subjects and that in patients with exertional angina. This value of free PAI-1 in patients with vasospastic angina was closely associated with the duration of ischemic attacks. These results suggested that the circadian fluctuation of fibrinolytic components may be an important factor that leads to coronary thrombosis at the time of coronary spasm, especially in the early morning. PMID:1529901

  15. Association of plasminogen activator inhibitor-1 and angiotensin converting enzyme polymorphisms with recurrent pregnancy loss in Iranian women

    PubMed Central

    Shakarami, Fatemeh; Akbari, Mohammad Taghi; Zare Karizi, Shohreh

    2015-01-01

    Background: Recurrent pregnancy loss (RPL) defined by two or more failed pregnancies before 20 weeks of gestation. Several factors play a role in RPL including thrombophilic conditions which can be influenced by gene polymorphisms. Plasminogen activator inhibitor-1 (PAI-1) and angiotensin converting enzyme (ACE) genes are closely related to fibrinolytic process, embryonic development and pregnancy success. Objective: The aim of this study was to investigate the relationship between RPL and common polymorphisms in ACE and PAI-1 genes. Materials and Methods: In this case control study, 100 women with recurrent abortions (at least two) were selected as cases and 100 healthy women with two or more normal term deliveries without a history of abortion as controls. Total genomic DNA was isolated from blood leukocytes. The status of the PAI-1 4G/5G and ACE (D/I) polymorphism was determined by PCR-RFLP. Results: Homozygosity for PAI-1 4G polymorphism was seen in 17 cases (17%), and 5 controls (5%) (p=0.006) so patients with homozygote 4G mutation were significantly more prone to RPL in contrast to control group (OR: 4.63, % 95 CI: 1.55-13.84). In addition, 7 patients (7 %), and no one from the control group, were homozygote (I/I) for ACE polymorphism (p=0.034), suggesting no significant associations between ACE D allele or DD genotype and RPL. Conclusion: Considering these results, because 4G/4G polymorphism for PAI-1 gene could be a thrombophilic variant leading to abortion, analysis of this mutation and other susceptibility factors are recommended in patients with RPL. PMID:26644791

  16. The metalloprotease inhibitor 1,10-phenanthroline affects Schistosoma mansoni motor activity, egg laying and viability.

    PubMed

    Day, T A; Chen, G Z

    1998-04-01

    The Zn(2+)-chelating metalloprotease inhibitor 1,10-phenanthroline (phenanthroline, 5-150 microM) elicited dose-dependent contraction of the longitudinal and circular (transverse) musculature of adult male schistosomes. At the same concentrations, phenanthroline did not cause contraction of dispersed individual muscle fibres. The phenanthroline-induced contractions were reduced by the inclusion of 100 or 300 microM Zn2+ in the extracellular medium. Phenanthroline (0.5-150 microM) also inhibited the egg production of adult worm pairs in vitro, with a 98% reduction at 50 microM. When worm pairs were exposed to phenanthroline, the males detached from the dish and released the females, resulting in unpaired worms. At the higher concentrations (50 and 150 microM), the worms were killed in vitro. Worm burdens were reduced by over 50% in infected mice injected with phenanthroline (20 mg/kg/day for 4 days), but twice the dose resulted in only a 25% reduction. Phenanthroline injections also induced an hepatic shift and an unpairing of adult worms in infected mice, and the female worms appeared degenerate and lacked gut pigmentation. Mice fed a diet containing 0.3% phenanthroline received significant protection from infection when challenged with schistosome cercaria, where phenanthroline-fed mice had 94% fewer adult worms than control mice. The broad range of phenanthroline effects on schistosomes suggests broad and important functions for metalloproteases in these worms. PMID:9585934

  17. Regulation of plasminogen activator inhibitor-1 and urokinase by hyaluronan fragments in mouse macrophages.

    PubMed

    Horton, M R; Olman, M A; Bao, C; White, K E; Choi, A M; Chin, B Y; Noble, P W; Lowenstein, C J

    2000-10-01

    Pulmonary inflammation and fibrosis are characterized by increased turnover and production of the extracellular matrix as well as an impairment of lung fibrinolytic activity. Although fragments of the extracellular matrix component hyaluronan induce macrophage production of inflammatory mediators, the effect of hyaluronan on the fibrinolytic mediators plasminogen activator inhibitor (PAI)-1 and urokinase-type plasminogen activator (uPA) is unknown. This study demonstrates that hyaluronan fragments augment steady-state mRNA, protein, and inhibitory activity of PAI-1 as well as diminish the baseline levels of uPA mRNA and inhibit uPA activity in an alveolar macrophage cell line. Hyaluronan fragments alter macrophage expression of PAI-1 and uPA at the level of gene transcription. Similarly, hyaluronan fragments augment PAI-1 and diminish uPA mRNA levels in freshly isolated inflammatory alveolar macrophages from bleomycin-treated rats. These data suggest that hyaluronan fragments influence alveolar macrophage expression of PAI-1 and uPA and may be a mechanism for regulating fibrinolytic activity during lung inflammation. PMID:11000131

  18. The Role of Urokinase Plasminogen Activator and Plasmin Activator Inhibitor-1 on Vein Wall Remodeling in Experimental Deep Vein Thrombosis

    PubMed Central

    Baldwin, Joe F.; Sood, Vikram; Elfline, Megan A.; Luke, Cathy E.; Dewyer, Nicholas A.; Diaz, Jose A.; Myers, Dan D.; Wakefield, Thomas; Henke, Peter K.

    2012-01-01

    OBJECTIVE Deep vein thrombosis (DVT) resolution instigates an inflammatory response, resulting in vessel wall damage and scarring. Urokinase-plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor-1 (PAI-1), are integral components of the fibrinolytic system, essential for VT resolution. This study determined the vein wall response when exposed to increased and decreased plasmin activity. Methods A mouse inferior vena cava (IVC) ligation model in uPA −/− or PAI-1 −/− and their genetic wild types (B6/SvEv and C57/BL6, respectively) was used to create stasis thrombi, with tissue harvest at either 8 or 21d. Tissue analysis included gene expression of vascular smooth muscle cells (alpha SMA [αSMA], SM22) and endothelial marker (CD31), by real time PCR, ELISA, matrix metalloproteinase (MMP) -2 and 9 activity by zymography and vein wall collagen by picrosirius red histological analysis. A P < .05 was considered significant. RESULTS Thrombi were significantly larger in both 8d and 21d uPA −/− as compared to WT, and were significantly smaller in both 8 and 21d PAI-1 −/− as compared to WT. Correspondingly, 8d plasmin levels were reduced in half in uPA −/− and increased 3 fold in PAI-1 −/− when compared to respective WT thrombi (P < .05, N = 5 – 6). The endothelial marker CD31 was elevated 2 fold in PAI-1 −/− mice at 8d, but reduced 2.5 fold at 21d in uPA −/− as compared with WT (P = .02, N = 5 – 6), suggesting less endothelial preservation. Vein wall VSMC gene expression showed that 8d and 21d PAI-1 −/− mice had 2.3 and 3.8 fold more SM22 and 1.8 and 2.3 fold more αSMA expression than respective WT (P < .05, N = 5 – 7), as well as 1.8 fold increased αSMA (+) cells (N = 3 – 5, P ≤ .05). No significant difference in MMP2 or 9 activity was found in the PAI-1 −/− mice compared with WT, while 5.4 fold more MMP9 was present in 21d WT than 21d uPA −/− (P = .03, N = 5). Lastly, collagen was ~2 fold

  19. Reactivated recombinant plasminogen activator inhibitor-1 (rPAI-1) effectively prevents thrombolysis in vivo.

    PubMed

    Vaughan, D E; Declerck, P J; Van Houtte, E; De Mol, M; Collen, D

    1992-07-01

    The effects of human recombinant plasminogen activator inhibitor (rPAI-1) on thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) were studied in a rabbit model of jugular vein thrombosis. Two functionally distinct rPAI-1 preparations were used in these experiments, including latent rPAI-1 (approximately 2 units of t-PA neutralizing activity per micrograms protein) and reactivated rPAI-1 (approximately 150 units/micrograms). Simultaneous intravenous infusion over 4 h of 1.7 mg/kg of reactivated rPAI-1 (inhibitory capacity approximately 0.5 mg/kg rt-PA) with 0.5 mg/kg of rt-PA completely prevented lysis of a jugular venous thrombus, whereas an equivalent amount of latent PAI-1 did not significantly influence clot lysis. These findings demonstrate that reactivated human rPAI-1 efficiently neutralizes thrombolysis with rt-PA in vivo. Since previous studies have suggested that elevated endogenous levels of PAI-1 do not attenuate the thrombolytic potency of rt-PA in the endotoxin-treated model, we compared the stability of complexes formed by 125I-rt-PA with reactivated human rPAI-1 and with rabbit PAI-1 in vitro. Our findings indicate that both forms of PAI-1 form SDS-stable complexes following incubation with 125I-rt-PA. Thus, it seems likely that elevated levels of active PAI-1 can negate the thrombolytic effects of rt-PA in vivo and argues against the possibility that t-PA can dissociate from PAI-1 and have its activity restored in the presence of a thrombus.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1514173

  20. A Plasminogen Activator Inhibitor-1 Inhibitor Reduces Airway Remodeling in a Murine Model of Chronic Asthma

    PubMed Central

    Lee, Sun H.; Eren, Mesut; Vaughan, Douglas E.; Schleimer, Robert P.

    2012-01-01

    We previously reported that plasminogen activator inhibitor (PAI)-1 deficiency prevents collagen deposition in the airways of ovalbumin (OVA)-challenged mice. In this study, we explored the therapeutic utility of blocking PAI-1 in preventing airway remodeling, using a specific PAI-1 inhibitor, tiplaxtinin. C57BL/6J mice were immunized with intraperitoneal injections of OVA on Days 0, 3, and 6. Starting on Day 11, mice were challenged with phosphate-buffered saline or OVA by nebulization three times per week for 4 weeks. Tiplaxtinin was mixed with chow and administered orally from 1 day before the phosphate-buffered saline or OVA challenge. Lung tissues were harvested after challenge and characterized histologically for infiltrating inflammatory cells, mucus-secreting goblet cells, and collagen deposition. Airway hyperresponsiveness was measured using whole-body plethysmography. Tiplaxtinin treatment significantly decreased levels of PAI-1 activity in bronchoalveolar lavage fluids, which indicates successful blockage of PAI-1 activity in the airways. The number of infiltrated inflammatory cells was reduced by tiplaxtinin treatment in the lungs of the OVA-challenged mice. Furthermore, oral administration of tiplaxtinin significantly attenuated the degree of goblet cell hyperplasia and collagen deposition in the airways of the OVA-challenged mice, and methacholine-induced airway hyperresponsiveness was effectively reduced by tiplaxtinin in these animals. This study supports our previous findings that PAI-1 promotes airway remodeling in a murine model of chronic asthma, and suggests that PAI-1 may be a novel target of treatment of airway remodeling in asthma. PMID:22323366

  1. A plasminogen activator inhibitor-1 inhibitor reduces airway remodeling in a murine model of chronic asthma.

    PubMed

    Lee, Sun H; Eren, Mesut; Vaughan, Douglas E; Schleimer, Robert P; Cho, Seong H

    2012-06-01

    We previously reported that plasminogen activator inhibitor (PAI)-1 deficiency prevents collagen deposition in the airways of ovalbumin (OVA)-challenged mice. In this study, we explored the therapeutic utility of blocking PAI-1 in preventing airway remodeling, using a specific PAI-1 inhibitor, tiplaxtinin. C57BL/6J mice were immunized with intraperitoneal injections of OVA on Days 0, 3, and 6. Starting on Day 11, mice were challenged with phosphate-buffered saline or OVA by nebulization three times per week for 4 weeks. Tiplaxtinin was mixed with chow and administered orally from 1 day before the phosphate-buffered saline or OVA challenge. Lung tissues were harvested after challenge and characterized histologically for infiltrating inflammatory cells, mucus-secreting goblet cells, and collagen deposition. Airway hyperresponsiveness was measured using whole-body plethysmography. Tiplaxtinin treatment significantly decreased levels of PAI-1 activity in bronchoalveolar lavage fluids, which indicates successful blockage of PAI-1 activity in the airways. The number of infiltrated inflammatory cells was reduced by tiplaxtinin treatment in the lungs of the OVA-challenged mice. Furthermore, oral administration of tiplaxtinin significantly attenuated the degree of goblet cell hyperplasia and collagen deposition in the airways of the OVA-challenged mice, and methacholine-induced airway hyperresponsiveness was effectively reduced by tiplaxtinin in these animals. This study supports our previous findings that PAI-1 promotes airway remodeling in a murine model of chronic asthma, and suggests that PAI-1 may be a novel target of treatment of airway remodeling in asthma. PMID:22323366

  2. The role of plasminogen activator inhibitor-1 in gastric mucosal protection

    PubMed Central

    Kenny, Susan; Steele, Islay; Lyons, Suzanne; Moore, Andrew R.; Murugesan, Senthil V.; Tiszlavicz, Laszlo; Dimaline, Rod; Pritchard, D. Mark; Varro, Andrea

    2013-01-01

    Gastric mucosal health is maintained in response to potentially damaging luminal factors. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) disrupt protective mechanisms leading to bleeding and ulceration. The plasminogen activator system has been implicated in fibrinolysis following gastric ulceration, and an inhibitor of this system, plasminogen activator inhibitor (PAI)-1, is expressed in gastric epithelial cells. In Helicobacter pylori-negative patients with normal gastric histology taking aspirin or NSAIDs, we found elevated gastric PAI-1 mRNA abundance compared with controls; the increase in patients on aspirin was independent of whether they were also taking proton pump inhibitors. In the same patients, aspirin tended to lower urokinase plasminogen activator mRNA. Immunohistochemistry indicated PAI-1 localization to epithelial cells. In a model system using MKN45 or AGS-GR cells transfected with a PAI-1 promoter-luciferase reporter construct, we found no evidence for upregulation of PAI-1 expression by indomethacin, and, in fact, cyclooxygenase products such as PGE2 and PGI2 weakly stimulated expression. Increased gastric PAI-1 mRNA was also found in mice following gavage with ethanol or indomethacin, but plasma PAI-1 was unaffected. In PAI-1−/− mice, gastric hemorrhagic lesions in response to ethanol or indomethacin were increased compared with C57BL/6 mice. In contrast, in PAI-1-H/Kβ mice in which PAI-1 is overexpressed in parietal cells, there were decreased lesions in response to ethanol and indomethacin. Thus, PAI-1 expression is increased in gastric epithelial cells in response to mucosal irritants such as aspirin and NSAIDs probably via an indirect mechanism, and PAI-1 acts as a local autoregulator to minimize mucosal damage. PMID:23494120

  3. Age-dependent neonatal intracerebral hemorrhage in plasminogen activator inhibitor 1 knockout mice.

    PubMed

    Leroux, Philippe; Omouendze, Priscilla L; Roy, Vincent; Dourmap, Nathalie; Gonzalez, Bruno J; Brasse-Lagnel, Carole; Carmeliet, Peter; Leroux-Nicollet, Isabelle; Marret, Stéphane

    2014-05-01

    Intracerebral-intraventricular hemorrhages (ICH/IVH) in very preterm neonates are responsible for high mortality and subsequent disabilities. In humans, tissue plasminogen activator (t-PA) initiates fibrinolysis and activates endoluminal-endothelial receptors; dysfunction of the t-PA inhibitor (PAI-1) results in recurrent hemorrhages. We used PAI-1 knockout (PAI-1) mice to examine the role of t-PA in age-dependent intracranial hemorrhages as a possible model of preterm ICH/IVH. Intracortical injection of 2 μL of phosphate-buffered saline produced a small traumatic injury and a high rate of hemorrhage in PAI-1 pups at postnatal day 3 (P3) or P5, whereas it had no effect in wild-type neonates. This resulted in white matter and cortical lesions, ventricle enlargement, hyperlocomotion, and altered cortical levels of serotonin and dopamine in the adult PAI mice. N-methyl-D-aspartate receptor blockers, plasmin- and matrix metalloproteinases inhibitors reduced hemorrhage and tissue lesions. In contrast to P3 to P5, no significant hemorrhages were induced in P10 PAI-1 pups and there were no behavioral or neurochemical alterations in adulthood. These data suggest that microvascular immaturity up to P5 in mice is a determinant factor required for t-PA-dependent vascular rupture. Neonatal PAI-1 mice could be a useful ICH/IVH model for studying the ontogenic window of vascular immaturity and vascular protection against later neurodisabilities. PMID:24709679

  4. Plasminogen activator inhibitor 1: Mechanisms of its synergistic regulation by growth factors

    SciTech Connect

    Song, Xiaoling

    2010-01-01

    My research is on the synergistic regulation of PAI-1 by EGF and TGF-β. The mechanism of synergistic regulation of PAI-1 by EGF and TGF-β are addressed. Methods are described for effective identification of RNA accessible sites for antisense oligodexoxynucleotides (ODNs) and siRNA. In this study effective AS-ODN sequences for both Lcn2 and Bcl2 were identified by in vitro tiled microarray studies. Our results suggest that hybridization of ODN arrays to a target mRNA under physiological conditions might be used as a rapid and reliable in vitro method to accurately identify targets on mRNA molecules for effective antisense and potential siRNA activity in vivo.

  5. Adenosine kinase inhibitors. 1. Synthesis, enzyme inhibition, and antiseizure activity of 5-iodotubercidin analogues.

    PubMed

    Ugarkar, B G; DaRe, J M; Kopcho, J J; Browne, C E; Schanzer, J M; Wiesner, J B; Erion, M D

    2000-07-27

    Adenosine receptor agonists produce a wide variety of therapeutically useful pharmacologies. However, to date they have failed to undergo successful clinical development due to dose-limiting side effects. Adenosine kinase inhibitors (AKIs) represent an alternative strategy, since AKIs may raise local adenosine levels in a more site- and event-specific manner and thereby elicit the desired pharmacology with a greater therapeutic window. Starting with 5-iodotubercidin (IC50 = 0.026 microM) and 5'-amino-5'-deoxyadenosine (IC50 = 0.17 microM) as lead inhibitors of the isolated human AK, a variety of pyrrolo[2,3-d]pyrimidine nucleoside analogues were designed and prepared by coupling 5-substituted-4-chloropyrrolo[2,3-d]pyrimidine bases with ribose analogues using the sodium salt-mediated glycosylation procedure. 5'-Amino-5'-deoxy analogues of 5-bromo- and 5-iodotubercidins were found to be the most potent AKIs reported to date (IC50S < 0.001 microM). Several potent AKIs were shown to exhibit anticonvulsant activity in the rat maximal electric shock (MES) induced seizure assay. PMID:10956196

  6. Glioma-derived plasminogen activator inhibitor-1 (PAI-1) regulates the recruitment of LRP1 positive mast cells.

    PubMed

    Roy, Ananya; Coum, Antoine; Marinescu, Voichita D; Põlajeva, Jelena; Smits, Anja; Nelander, Sven; Uhrbom, Lene; Westermark, Bengt; Forsberg-Nilsson, Karin; Pontén, Fredrik; Tchougounova, Elena

    2015-09-15

    Glioblastoma (GBM) is a high-grade glioma with a complex microenvironment, including various inflammatory cells and mast cells (MCs) as one of them. Previously we had identified glioma grade-dependent MC recruitment. In the present study we investigated the role of plasminogen activator inhibitor 1 (PAI-1) in MC recruitment.PAI-1, a primary regulator in the fibrinolytic cascade is capable of forming a complex with fibrinolytic system proteins together with low-density lipoprotein receptor-related protein 1 (LRP1). We found that neutralizing PAI-1 attenuated infiltration of MCs. To address the potential implication of LRP1 in this process, we used a LRP1 antagonist, receptor-associated protein (RAP), and demonstrated the attenuation of MC migration. Moreover, a positive correlation between the number of MCs and the level of PAI-1 in a large cohort of human glioma samples was observed. Our study demonstrated the expression of LRP1 in human MC line LAD2 and in MCs in human high-grade glioma. The activation of potential PAI-1/LRP1 axis with purified PAI-1 promoted increased phosphorylation of STAT3 and subsequently exocytosis in MCs.These findings indicate the influence of the PAI-1/LRP1 axis on the recruitment of MCs in glioma. The connection between high-grade glioma and MC infiltration could contribute to patient tailored therapy and improve patient stratification in future therapeutic trials. PMID:26164207

  7. Toxicogenomic analysis of mainstream tobacco smoke-exposed mice reveals repression of plasminogen activator inhibitor-1 gene in heart.

    PubMed

    Halappanavar, Sabina; Stampfli, Martin R; Berndt-Weis, Lynn; Williams, Andrew; Douglas, George R; Yauk, Carole L

    2009-01-01

    Tobacco smoking is associated with cardiovascular pathology. However, the molecular mechanisms of tobacco smoke exposure that lead to initiation or exacerbation of cardiovascular disease are unclear. In this study, the effects of mainstream tobacco smoke (MTS) on global transcription in the heart were investigated. Male C57B1/CBA mice were exposed to MTS from 2 cigarettes daily, 5 days/wk for 6 or 12 wk. Mice were sacrificed immediately, or 6 wk following the last cigarette. High-density DNA microarrays were used to characterize global gene expression changes in whole heart. Fifteen genes were significantly differentially expressed following exposure to MTS. Among these genes, cytochrome P-450 1A1 (Cyp1A1) was upregulated by 12-fold, and Serpine-1 (plasminogen activator inhibitor-1, PAI-1) was downregulated by 1.7-fold. Concomitant increase in Cyp1A1 protein levels and decrease in total and active PAI-1 protein was observed in tissue extracts by Western blot assay and enzyme-linked immunosorbent assay (ELISA), respectively. Observed changes were transient and were partially reversed during break periods. Thus, gene expression profiling of heart tissue revealed a novel cardiovascular mechanism operating in response to MTS. Our results suggest a potential role for PAI-1 in MTS-induced cardiovascular pathology. PMID:18925475

  8. Mechanisms of conversion of plasminogen activator inhibitor 1 from a suicide inhibitor to a substrate by monoclonal antibodies.

    PubMed

    Komissarov, Andrey A; Declerck, Paul J; Shore, Joseph D

    2002-11-15

    We have delineated two different reaction mechanisms of monoclonal antibodies (mAbs), MA-8H9D4 and either MA-55F4C12 or MA-33H1F7, that convert plasminogen activator inhibitor 1 (PAI-1) to a substrate for tissue (tPA)- and urokinase plasminogen activators. MA-8H9D4 almost completely (98-99%) shifts the reaction to the substrate pathway by preventing disordering of the proteinase active site. MA-8H9D4 does not affect the rate-limiting constants (k(lim)) for the insertion of the reactive center loop cleaved by tPA (3.5 s(-1)) but decreases k(lim) for urokinase plasminogen activator from 25 to 4.0 s(-1). MA-8H9D4 does not cause deacylation of preformed PAI-1/proteinase complexes and probably acts prior to the formation of the final inhibitory complex, interfering with displacement of the acylated serine from the proteinase active site. MA-55F4C12 and MA-33H1F7 (50-80% substrate reaction) do not interfere with initial PAI-1/proteinase complex formation but retard the inhibitory pathway by decreasing k(lim) (>10-fold for tPA). Interaction of two mAbs with the same molecule of PAI-1 has been directly demonstrated for pairs MA-8H9D4/MA-55F4C12 and MA-8H9D4/MA-33H1F7 but not for MA-55F4C12/MA-33H1F7. The strong functional additivity observed for MA-8H9D4 and MA-55F4C12 demonstrates that these mAbs interact independently and affect different steps of the PAI-1 reaction mechanism. PMID:12223472

  9. TNF-alpha, but not IL-6, stimulates plasminogen activator inhibitor-1 expression in human subcutaneous adipose tissue.

    PubMed

    Plomgaard, Peter; Keller, Pernille; Keller, Charlotte; Pedersen, Bente Klarlund

    2005-06-01

    Plasminogen activator inhibitor-1 (PAI-1) is produced by adipose tissue, and elevated PAI-1 levels in plasma are a risk factor in the metabolic syndrome. We investigated the regulatory effects of TNF-alpha and IL-6 on PAI-1 gene induction in human adipose tissue. Twenty healthy men underwent a 3-h infusion of either recombinant human TNF-alpha (n = 8), recombinant human IL-6 (n = 6), or vehicle (n = 6). Biopsies were obtained from the subcutaneous abdominal adipose tissue at preinfusion, at 1, 2, and 3 h during the infusion, and at 2 h after the infusion. The mRNA expression of PAI-1 in the adipose tissue was measured using real-time PCR. The plasma levels of TNF-alpha and IL-6 reached 18 and 99 pg/ml, respectively, during the infusions. During the TNF-alpha infusion, adipose PAI-1 mRNA expression increased 2.5-fold at 1 h, 6-fold at 2 h, 9-fold at 3 h, and declined to 2-fold 2 h after the infusion stopped but did not change during IL-6 infusion and vehicle. These data demonstrate that TNF-alpha rather than IL-6 stimulates an increase in PAI-1 mRNA in the subcutaneous adipose tissue, suggesting that TNF-alpha may be involved in the pathogenesis of related metabolic disorders. PMID:15677734

  10. Plasminogen activator inhibitor-1 and type 2 diabetes: a systematic review and meta-analysis of observational studies

    PubMed Central

    Yarmolinsky, James; Bordin Barbieri, Natália; Weinmann, Tobias; Ziegelmann, Patricia K.; Duncan, Bruce B.; Inês Schmidt, Maria

    2016-01-01

    An emerging body of evidence has implicated plasminogen activator inhibitor-1 (PAI-1) in the development of type 2 diabetes (T2D), though findings have not always been consistent. We systematically reviewed epidemiological studies examining the association of PAI-1 with T2D. EMBASE, PubMed, Web of Science, and the Cochrane Library were searched to identify studies for inclusion. Fifty-two studies (44 cross-sectional with 47 unique analytical comparisons and 8 prospective) were included. In pooled random-effects analyses of prospective studies, a comparison of the top third vs. bottom third of baseline PAI-1 values generated a RR of T2D of 1.67 (95% CI 1.28–2.18) with moderate heterogeneity (I2 = 38%). Additionally, of 47 cross-sectional comparisons, 34(72%) reported significantly elevated PAI-1 among diabetes cases versus controls, 2(4%) reported significantly elevated PAI-1 among controls, and 11(24%) reported null effects. Results from pooled analyses of prospective studies did not differ substantially by study design, length of follow-up, adjustment for various putative confounding factors, or study quality, and were robust to sensitivity analyses. Findings from this systematic review of the available epidemiological literature support a link between PAI-1 and T2D, independent of established diabetes risk factors. Given the moderate size of the association and heterogeneity across studies, future prospective studies are warranted. PMID:26813008

  11. Plasminogen activator inhibitor-1 is elevated, but not essential, in the development of bleomycin-induced murine scleroderma

    PubMed Central

    Matsushita, M; Yamamoto, T; Nishioka, K

    2005-01-01

    Accumulative data have demonstrated that plasminogen activator inhibitor-1 (PAI-1) plays an important role in the extracellular matrix metabolism; however, the involvement of PAI-1 in scleroderma has not been fully elucidated. In this study, we investigated the role of PAI-1 in bleomycin-induced murine scleroderma. 100 µg of bleomycin was injected subcutaneously to the back skin of C3H/HeJ mice on alternate day for 4 weeks. Histopathological findings revealed that PAI-1 was positive in macrophage-like cells and fibroblastic cells in the dermis, in parallel with the induction of dermal sclerosis. PAI-1 mRNA expression in the whole skin was up-regulated at 1 and 4 weeks. The production of active PAI-1 protein in the lesional skin was significantly increased 3 and 4 weeks after bleomycin treatment. Next, we examined whether dermal sclerosis is induced by bleomycin in PAI-1-deficient (PAI-1–/–) mice. 10 µg of bleomycin was subcutaneously injected to PAI-1–/– and wild type (WT) mice 5 days per week for 4 weeks. Histological examination revealed that dermal sclerosis was similarly induced even in PAI-1–/– as well as WT mice. Dermal thickness and collagen contents in the skin were significantly increased by bleomycin injection in both PAI-1–/– and WT mice, and the rate of increase was similar. These data suggest that PAI-1 plays an important role, possibly via TGF-β pathway activation. However, the fact that PAI-1 deficiency did not ameliorate skin sclerosis suggest that PAI-1 is not the essential factor in the development of bleomycin-induced scleroderma, and more complex biochemical effects other than PA/plasmin system are greatly suspected. PMID:15730388

  12. Effects of Pharmacological Inhibition and Genetic Deficiency of Plasminogen Activator Inhibitor-1 in Radiation-Induced Intestinal Injury

    SciTech Connect

    Abderrahmani, Rym; Francois, Agnes; Buard, Valerie; Benderitter, Marc; Sabourin, Jean-Christophe; Crandall, David L.; Milliat, Fabien

    2009-07-01

    Purpose: To investigate effects of plasminogen activator inhibitor 1 (PAI-1) genetic deficiency and pharmacological PAI-1 inhibition with PAI-039 in a mouse model of radiation-induced enteropathy. Methods and Materials: Wild-type (Wt) and PAI-1{sup -/-} knockout mice received a single dose of 19 Gy to an exteriorized localized intestinal segment. Sham and irradiated Wt mice were treated orally with 1 mg/g of PAI-039. Histological modifications were quantified using a radiation injury score. Moreover, intestinal gene expression was monitored by real-time PCR. Results: At 3 days after irradiation, PAI-039 abolished the radiation-induced increase in the plasma active form of PAI-1 and limited the radiation-induced gene expression of transforming growth factor {beta}1 (TGF-{beta}1), CTGF, PAI-1, and COL1A2. Moreover, PAI-039 conferred temporary protection against early lethality. PAI-039 treatment limited the radiation-induced increase of CTGF and PAI-1 at 2 weeks after irradiation but had no effect at 6 weeks. Radiation injuries were less severe in PAI-1{sup -/-} mice than in Wt mice, and despite the beneficial effect, 3 days after irradiation, PAI-039 had no effects on microscopic radiation injuries compared to untreated Wt mice. Conclusions: A genetic deficiency of PAI-1 is associated with amelioration of late radiation enteropathy. Pharmacological inhibition of PAI-1 by PAI-039 positively impacts the early, acute phase increase in plasma PAI-1 and the associated radiation-induced gene expression of inflammatory/extracellular matrix proteins. Since PAI-039 has been shown to inhibit the active form of PAI-1, as opposed to the complete loss of PAI-1 in the knockout animals, these data suggest that a PAI-1 inhibitor could be beneficial in treating radiation-induced tissue injury in acute settings where PAI-1 is elevated.

  13. Effects of Lewis lung carcinoma on trabecular microstructural changes in wild-type and plasminogen activator inhibitor-1 deficient mice fed a high-fat diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bone is a major target organ of metastasis. The present study investigated the effects of Lewis lung carcinoma (LLC) on trabecular microstructural changes, using tomographic analysis, in distal femur and lumbar 4 vertebra from LLC-bearing wild-type and plasminogen activator inhibitor-1 (PAI-1) defi...

  14. Effects of a high-fat diet on spontaneous metastasis of Lewis lung carcinoma in plasminogen activator inhibitor-1 deficient and wild-type mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the effects of plasminogen activator inhibitor-1 (PAI-1) deficiency on spontaneous metastasis of Lewis lung carcinoma (LLC) in PAI-1 deficient (PAI-1-/-) and wildtype mice (C57BL/6J background) fed the AIN93G diet or that diet modified with 45% calories from fat. The high-fat diet i...

  15. Low-molecular-weight heparin modulates vein wall fibrotic response in a plasminogen activator inhibitor 1-dependent manner

    PubMed Central

    Obi, Andrea T.; Diaz, Jose A.; Ballard-Lipka, Nicole L.; Roelofs, Karen J.; Farris, Diana M.; Lawrence, Daniel A.; Henke, Peter K.; Wakefield, Thomas W.

    2014-01-01

    Background Treatment with low-molecular-weight heparin (LMWH) favorably alters the vein wall response to deep venous thrombosis (DVT), although the mechanisms remain unclear. Previous studies have suggested that LMWH alters the levels of circulating plasminogen activator inhibitor 1 (PAI-1), a known mediator of fibrosis, and may improve endogenous fibrinolysis. We hypothesized that LMWH favorably alters the vein wall response by binding of PAI-1 and acceleration of fibrinolysis. Methods Wild-type and PAI-1 −/− mice underwent treatment with LMWH after induction of occlusive DVT. Vein wall and plasma were harvested and analyzed by enzyme-linked immunosorbent assay, zymography, real-time polymerase chain reaction, and immunohistochemistry. Results Wild-type mice treated with LMWH exhibited diminished vein wall fibrosis (0.6 ± 0.6 vs 1.4 ± 0.2; P < .01; n = 5) and elevation of circulating PAI-1 (1776 ± 342 vs 567 ± 104 ρg/mL; P < .01; n = 5) compared with untreated controls after occlusive DVT. PAI-1−/− mice treated with LMWH were not similarly protected from fibrosis, despite improved thrombus resolution. Treatment with LMWH was associated with decreased intrathrombus interleukin-lβ (68.6 ± 31.0 vs 223.4 ± 28.9 ρg/mg total protein; P < .01; n = 5) but did not alter inflammatory cell recruitment to the vein wall. PAI-1 −/− mice exhibited significantly elevated intrathrombus (257.2 ± 51.5 vs 4.3 ± 3.8 ρg/mg total protein; n = 5) and vein wall interleukin-13 (187.2 ± 57.6 vs 9.9 ± 1.1 ρg/mg total protein; P < .05; n = 5) as well as vein wall F4/80 positively staining monocytes (53 ± 11 vs 16 ± 2 cells/5 high-power fields; P < .05; n = 4). Conclusions LMWH did not accelerate venous thrombosis resolution but did protect against vein wall fibrosis in a PAI-1-dependent manner in an occlusive DVT model. Lack of PAI-1 correlated with accelerated venous thrombosis resolution but no protection from fibrosis. PAI-1 inhibition as a treatment strategy

  16. Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis.

    PubMed

    Pelisch, Nicolas; Dan, Takashi; Ichimura, Atsuhiko; Sekiguchi, Hiroki; Vaughan, Douglas E; van Ypersele de Strihou, Charles; Miyata, Toshio

    2015-01-01

    Multiple sclerosis (MS) is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS). Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1) have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB). The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS. PMID:25915660

  17. Constitutively active phosphatase inhibitor-1 improves cardiac contractility in young mice but is deleterious after catecholaminergic stress and with aging

    PubMed Central

    Wittköpper, Katrin; Fabritz, Larissa; Neef, Stefan; Ort, Katharina R.; Grefe, Clemens; Unsöld, Bernhard; Kirchhof, Paulus; Maier, Lars S.; Hasenfuss, Gerd; Dobrev, Dobromir; Eschenhagen, Thomas; El-Armouche, Ali

    2010-01-01

    Phosphatase inhibitor-1 (I-1) is a distal amplifier element of β-adrenergic signaling that functions by preventing dephosphorylation of downstream targets. I-1 is downregulated in human failing hearts, while overexpression of a constitutively active mutant form (I-1c) reverses contractile dysfunction in mouse failing hearts, suggesting that I-1c may be a candidate for gene therapy. We generated mice with conditional cardiomyocyte-restricted expression of I-1c (referred to herein as dTGI-1c mice) on an I-1–deficient background. Young adult dTGI-1c mice exhibited enhanced cardiac contractility but exaggerated contractile dysfunction and ventricular dilation upon catecholamine infusion. Telemetric ECG recordings revealed typical catecholamine-induced ventricular tachycardia and sudden death. Doxycycline feeding switched off expression of cardiomyocyte-restricted I-1c and reversed all abnormalities. Hearts from dTGI-1c mice showed hyperphosphorylation of phospholamban and the ryanodine receptor, and this was associated with an increased number of catecholamine-induced Ca2+ sparks in isolated myocytes. Aged dTGI-1c mice spontaneously developed a cardiomyopathic phenotype. These data were confirmed in a second independent transgenic mouse line, expressing a full-length I-1 mutant that could not be phosphorylated and thereby inactivated by PKC-α (I-1S67A). In conclusion, conditional expression of I-1c or I-1S67A enhanced steady-state phosphorylation of 2 key Ca2+-regulating sarcoplasmic reticulum enzymes. This was associated with increased contractile function in young animals but also with arrhythmias and cardiomyopathy after adrenergic stress and with aging. These data should be considered in the development of novel therapies for heart failure. PMID:20071777

  18. Effect of dipeptidyl peptidase-4 inhibitor, vildagliptin on plasminogen activator inhibitor-1 in patients with diabetes mellitus.

    PubMed

    Tani, Shigemasa; Takahashi, Atsuhiko; Nagao, Ken; Hirayama, Atsushi

    2015-02-15

    Dipeptidyl peptidase-4 (DPP-4) inhibitors may affect the serum levels of plasminogen activator inhibitor-1 (PAI-1) associated with triglyceride (TG) metabolism, which is a prognostic factor for cardiovascular disease, in diabetic patients. We conducted an 8-week, prospective, randomized study in which we assigned type 2 diabetic patients who were inadequately controlled with antidiabetic therapy to the vildagliptin group (50 mg bid, n = 49) or the control group (n = 49). The primary efficacy parameter was the change in the serum level of PAI-1, and the secondary end point was the change in the serum levels of TG-rich lipoproteins. In the vildagliptin group, significant decrease of the serum PAI-1 level by 16.3% (p <0.0001) and significant decreases of the serum TG, remnant-like particle cholesterol, and apolipoprotein B levels by 12.1% (p = 0.002), 13.9% (p = 0.003), and 9.5% (p <0.0001), respectively, were observed. No such changes were observed in the control group. Multivariate regression analyses identified the absolute change from the baseline (Δ) of the PAI-1, but not that of the fasting blood glucose or hemoglobin A1c, as independent predictors of the ΔTG, Δ remnant-like particle cholesterol, and Δ apolipoprotein B. In conclusion, treatment of type 2 diabetes with vildagliptin might prevent the progression of atherosclerotic cardiovascular disease in diabetic patients by decreasing the serum PAI-1 levels and improving TG metabolism. PMID:25637323

  19. Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis

    PubMed Central

    Pelisch, Nicolas; Dan, Takashi; Ichimura, Atsuhiko; Sekiguchi, Hiroki; Vaughan, Douglas E.; van Ypersele de Strihou, Charles; Miyata, Toshio

    2015-01-01

    Multiple sclerosis (MS) is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS). Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1) have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB). The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS. PMID:25915660

  20. Fructose-induced steatosis in mice: role of plasminogen activator inhibitor-1, microsomal triglyceride transfer protein and NKT cells.

    PubMed

    Kanuri, Giridhar; Spruss, Astrid; Wagnerberger, Sabine; Bischoff, Stephan C; Bergheim, Ina

    2011-06-01

    Plasminogen activator inhibitor-1 (PAI-1) is an acute-phase protein known to be involved in alcoholic liver disease and hepatic fibrosis. In the present study, the hypothesis that PAI-1 is causally involved in the onset of fructose-induced hepatic steatosis was tested in a mouse model. Wild-type C57BL/6J and PAI-1⁻/⁻ mice were fed with 30% fructose solution or water for 8 weeks. Markers of hepatic steatosis, expression of PAI-1, apolipoprotein B (ApoB), cluster of differentiation 1d (CD1d), markers of natural killer T (NKT) cells, protein levels of phospho-c-Met and tumor necrosis factor-α (TNF-α) were determined. Activity of the microsomal triglyceride transfer protein (MTTP) was measured in liver tissue. In comparison with water controls, chronic intake of 30% fructose solution caused a significant increase in hepatic triglycerides, PAI-1 expression and plasma alanine aminotransferase levels in wild-type mice. This effect of fructose feeding was markedly attenuated in PAI-1⁻/⁻ mice. Despite no differences in portal endotoxin levels and hepatic TNF-α protein levels between fructose-fed groups, the protective effect of the loss of PAI-1 against the onset of fructose-induced steatosis was associated with a significant increase in phospho-c-Met, phospho Akt, expression of ApoB and activity of MTTP in livers of PAI-1⁻/⁻ mice in comparison with fructose-fed wild types. Moreover, in PAI-1⁻/⁻ mice, expressions of CD1d and markers of CD1d-reactive NKT cells were markedly higher than in wild-type mice; however, expression of markers of activation of CD1d-reactive NKT cells (eg, interleukin-15 and interferon-γ) were only found to be increased in livers of fructose-fed PAI-1⁻/⁻ mice. Taken together, these data suggest that PAI-1 has a causal role in mediating the early phase of fructose-induced liver damage in mice through signaling cascades downstream of Kupffer cells and TNF-α. PMID:21423135

  1. Skin abnormalities in mice transgenic for plasminogen activator inhibitor 1: implications for the regulation of desquamation and follicular neogenesis by plasminogen activator enzymes.

    PubMed

    Lyons-Giordano, B; Lazarus, G S

    1995-08-01

    Plasminogen activator enzymes have been implicated in the regulation of growth, migration, and differentiation which occur continually in normal epidermis and cyclically in the hair follicle. To elucidate further the importance of plasminogen activation in epidermal physiology, studies were conducted using mice transgenic for human plasminogen activator inhibitor 1 (PAI-1). The epidermis of the newborn (4-7 days) transgenic mice was flaky and showed delayed hair growth compared to that of their control littermates. Histologic analyses revealed a greatly thickened stratum corneum in the transgenics. By 2 weeks after birth, no differences in epidermal morphology were apparent between transgenic and control littermates. Using in situ hybridization, immunocytochemistry, and in situ reverse zymography techniques, epidermal PAI-1 expression was correlated temporally with the aberrant epidermal morphology. These data implicate plasminogen activator activity in the regulation of epidermal shedding and follicular neogenesis. PMID:7649363

  2. Regulatory role of microRNA-30b and plasminogen activator inhibitor-1 in the pathogenesis of cognitive impairment

    PubMed Central

    LI, XIUQIN; GAO, YONG; MENG, ZHAOYUN; ZHANG, CUI; QI, QINDE

    2016-01-01

    The present study aimed to investigate the role of plasminogen activator inhibitor-1 (PAI-1) in drug-induced early cognitive impairment and the underlying mechanism concerning microRNA (miR)-30b. A mouse model of cognitive impairment was established by intraperitoneal injection of scopolamine (2 mg/kg body weight) for 13 days. Behavioral performance was assessed using the Morris water maze (MWM) test. The mRNA expression levels of PAI-1 and miR-30b were detected using quantitative polymerase chain reaction (qPCR). The protein expression levels of PAI-1 in the hippocampus and blood were determined using western blot analysis and enzyme-linked immunosorbent assays. The MWM test demonstrated that, on days 3 and 4, the escape latency was significantly elevated in the model mice in comparison with control group (P<0.05). In addition, the length of swimming path was significantly increased (P<0.05), while the number of times of crossing the platform location was significantly reduced in the model mouse group (P<0.05) in comparison with the control group. qPCR demonstrated that the mRNA expression levels of PAI-1 in the model mice was significantly elevated in the hippocampus and blood in comparison with the control group (P<0.01). Furthermore, western blot analysis and enzyme-linked immunosorbent assay demonstrated that the protein expression levels of PAI-1 were significantly elevated in the hippocampus and blood in the model group, in comparison with the control group (P<0.05). Notably, the levels of miR-30b in the hippocampus and blood were significantly decreased in the model mice in comparison with the control group (P<0.01). To conclude, the expression levels of PAI-1 were significantly elevated in mice with scopolamine-induced cognitive impairment, which may be associated with the downregulation of miR-30b. The findings from the present study suggest that miR-30b may be involved in the regulation of PAI-1, which would contribute to the pathogenesis of cognitive

  3. The solution structure of the MANEC-type domain from hepatocyte growth factor activator inhibitor-1 reveals an unexpected PAN/apple domain-type fold.

    PubMed

    Hong, Zebin; Nowakowski, Michal; Spronk, Chris; Petersen, Steen V; Andreasen, Peter A; Koźmiński, Wiktor; Mulder, Frans A A; Jensen, Jan K

    2015-03-01

    A decade ago, motif at N-terminus with eight-cysteines (MANEC) was defined as a new protein domain family. This domain is found exclusively at the N-terminus of >400 multi-domain type-1 transmembrane proteins from animals. Despite the large number of MANEC-containing proteins, only one has been characterized at the protein level: hepatocyte growth factor activator inhibitor-1 (HAI-1). HAI-1 is an essential protein, as knockout mice die in utero due to placental defects. HAI-1 is an inhibitor of matriptase, hepsin and hepatocyte growth factor (HGF) activator, all serine proteases with important roles in epithelial development, cell growth and homoeostasis. Dysregulation of these proteases has been causatively implicated in pathological conditions such as skin diseases and cancer. Detailed functional understanding of HAI-1 and other MANEC-containing proteins is hampered by the lack of structural information on MANEC. Although many MANEC sequences exist, sequence-based database searches fail to predict structural homology. In the present paper, we present the NMR solution structure of the MANEC domain from HAI-1, the first three-dimensional (3D) structure from the MANEC domain family. Unexpectedly, MANEC is a new subclass of the PAN/apple domain family, with its own unifying features, such as two additional disulfide bonds, two extended loop regions and additional α-helical elements. As shown for other PAN/apple domain-containing proteins, we propose a similar active role of the MANEC domain in intramolecular and intermolecular interactions. The structure provides a tool for the further elucidation of HAI-1 function as well as a reference for the study of other MANEC-containing proteins. PMID:25510835

  4. Small Molecule Inhibitors of Plasminogen Activator Inhibitor-1 Elicit Anti-Tumorigenic and Anti-Angiogenic Activity

    PubMed Central

    Placencio, Veronica R.; Ichimura, Atsuhiko; Miyata, Toshio; DeClerck, Yves A.

    2015-01-01

    Numerous studies have shown a paradoxical positive correlation between elevated levels of plasminogen activator inhibitior-1 (PAI-1) in tumors and blood of cancer patients with poor clinical outcome, suggesting that PAI-1 could be a therapeutic target. Here we tested two orally bioavailable small molecule inhibitors of PAI-1 (TM5275 and TM5441) for their efficacy in pre-clinical models of cancer. We demonstrated that these inhibitors decreased cell viability in several human cancer cell lines with an IC50 in the 9.7 to 60.3 μM range and induced intrinsic apoptosis at concentrations of 50 μM. In vivo, oral administration of TM5441 (20 mg/kg daily) to HT1080 and HCT116 xenotransplanted mice increased tumor cell apoptosis and had a significant disruptive effect on the tumor vasculature that was associated with a decrease in tumor growth and an increase in survival that, however, were not statistically significant. Pharmacokinetics studies indicated an average peak plasma concentration of 11.4 μM one hour after oral administration and undetectable levels 23 hours after administration. The effect on tumor vasculature in vivo was further examined in endothelial cells (EC) in vitro and this analysis indicated that both TM5275 and TM5441 inhibited EC branching in a 3D Matrigel assay at concentrations where they had little effect on EC apoptosis. These studies bring novel insight on the activity of PAI-1 inhibitors and provide important information for the future design of inhibitors targeting PAI-1 as therapeutic agents in cancer. PMID:26207899

  5. Conformational Lability in Serine Protease Active Sites: Structures of Hepatocyte Growth Factor Activator (HGFA) Alone and with the Inhibitory Domain from HGFA Inhibitor-1B

    SciTech Connect

    Shia, Steven; Stamos, Jennifer; Kirchhofer, Daniel; Fan, Bin; Wu, Judy; Corpuz, Raquel T.; Santell, Lydia; Lazarus, Robert A.; Eigenbrot, Charles

    2010-07-20

    Hepatocyte growth factor activator (HGFA) is a serine protease that converts hepatocyte growth factor (HGF) into its active form. When activated HGF binds its cognate receptor Met, cellular signals lead to cell growth, differentiation, and migration, activities which promote tissue regeneration in liver, kidney and skin. Intervention in the conversion of HGF to its active form has the potential to provide therapeutic benefit where HGF/Met activity is associated with tumorigenesis. To help identify ways to moderate HGF/Met effects, we have determined the molecular structure of the protease domain of HGFA. The structure we determined, at 2.7 {angstrom} resolution, with no pseudo-substrate or inhibitor bound is characterized by an unconventional conformation of key residues in the enzyme active site. In order to find whether this apparently non-enzymatically competent arrangement would persist in the presence of a strongly-interacting inhibitor, we also have determined, at 2.6 {angstrom} resolution, the X-ray structure of HGFA complexed with the first Kunitz domain (KD1) from the physiological inhibitor hepatocyte growth factor activator inhibitor 1B (HAI-1B). In this complex we observe a rearranged substrate binding cleft that closely mirrors the cleft of other serine proteases, suggesting an extreme conformational dynamism. We also characterize the inhibition of 16 serine proteases by KD1, finding that the previously reported enzyme specificity of the intact extracellular region of HAI-1B resides in KD1 alone. We find that HGFA, matriptase, hepsin, plasma kallikrein and trypsin are potently inhibited, and use the complex structure to rationalize the structural basis of these results.

  6. Angiotensin II induces secretion of plasminogen activator inhibitor 1 and a tissue metalloprotease inhibitor-related protein from rat brain astrocytes

    SciTech Connect

    Olson, J.A. Jr.; Shiverick, K.T.; Ogilvie, S.; Buhi, W.C.; Raizada, M.K. )

    1991-03-01

    The present study investigates angiotensin (Ang) II effects on secretory protein synthesis in brain astrocytes cultured from neonatal and 21-day-old rats. Ang II-induced changes in the de novo synthesis of (35S)methionine-labeled secretory proteins were visualized using two-dimensional NaDodSO4/PAGE. Astrocytes from 21-day-old rat brain possess specific high-affinity receptors for Ang II. These cells express two Ang II-induced secretory proteins with Mr 55,000 (AISP-55K) and Mr 30,000 (AISP-30K), which were time- and dose-dependent (EC50, 1 nM). (Sar1, Ile8)Ang II (where Sar is sarcosine) inhibited Ang II-induced secretion of AISP-55K but not AISP-30K. N-terminal amino acid sequencing indicates that AISP-55K is identical to rat plasminogen activator inhibitor 1, whereas AISP-30K exhibits 72-81% identity to three closely related proteins: human tissue inhibitor of metalloproteases, a rat phorbol ester-induced protein, and the murine growth-responsive protein 16C8. Immunofluorescent staining with rat plasminogen activator inhibitor 1 antibody was induced in the majority of cells in culture after Ang II treatment of astrocytes from 21-day-old rat brains. Absence of this response to Ang II in astrocytes from neonatal rat brain provides evidence that this action of Ang II on astrocytes is developmentally regulated.

  7. Sunflower trypsin inhibitor-1.

    PubMed

    Korsinczky, Michael L J; Schirra, Horst Joachim; Craik, David J

    2004-10-01

    SFTI-1 is a bicyclic 14 amino acid peptide that was originally isolated from the seeds of the sunflower Helianthus annuus. It is a potent inhibitor of trypsin, with a sub-nanomolar K(i) value and is homologous to the active site region of the well-known family of serine protease inhibitors known as the Bowman-Birk trypsin inhibitors. It has a cyclic backbone that is cross-braced by a single disulfide bridge and a network of hydrogen bonds that result in a well-defined structure. SFTI-1 is amenable to chemical synthesis, allowing for the creation of synthetic variants. Alterations to the structure such as linearising the backbone or removing the disulfide bridge do not reduce the potency of SFTI-1 significantly, and minimising the peptide to as few as nine residues results in only a small decrease in reactivity. The creation of linear variants of SFTI-1 also provides a tool for investigating putative linear precursor peptides. The mechanism of biosynthesis of SFTI-1 is not yet known but it seems likely that it is a gene-coded product that has arisen from a precursor protein that may be evolutionarily related to classic Bowman-Birk inhibitors. PMID:15544530

  8. Plasminogen Activator Inhibitor-1 Mitigates Brain Injury in a Rat Model of Infection-Sensitized Neonatal Hypoxia–Ischemia

    PubMed Central

    Yang, Dianer; Sun, Yu-Yo; Nemkul, Niza; Baumann, Jessica M.; Shereen, Ahmed; Dunn, R. Scott; Wills-Karp, Marsha; Lawrence, Daniel A.; Lindquist, Diana M.; Kuan, Chia-Yi

    2013-01-01

    Intrauterine infection exacerbates neonatal hypoxic–ischemic (HI) brain injury and impairs the development of cerebral cortex. Here we used low-dose lipopolysaccharide (LPS) pre-exposure followed by unilateral cerebral HI insult in 7-day-old rats to study the pathogenic mechanisms. We found that LPS pre-exposure blocked the HI-induced proteolytic activity of tissue-type plasminogen activator (tPA), but significantly enhanced NF-κB signaling, microglia activation, and the production of pro-inflammatory cytokines in newborn brains. Remarkably, these pathogenic responses were all blocked by intracerebroventricular injection of a stable-mutant form of plasminogen activator protein-1 called CPAI. Similarly, LPS pre-exposure amplified, while CPAI therapy mitigated HI-induced blood-brain-barrier damage and the brain tissue loss with a therapeutic window at 4 h after the LPS/HI insult. The CPAI also blocks microglia activation following a brain injection of LPS, which requires the contribution by tPA, but not the urinary-type plasminogen activator (uPA), as shown by experiments in tPA-null and uPA-null mice. These results implicate the nonproteolytic tPA activity in LPS/HI-induced brain damage and microglia activation. Finally, the CPAI treatment protects near-normal motor and white matter development despite neonatal LPS/HI insult. Together, because CPAI blocks both proteolytic and nonproteolytic tPA neurotoxicity, it is a promising therapeutics of neonatal HI injury either with or without infection. PMID:22556277

  9. Protonation state of a single histidine residue contributes significantly to the kinetics of the reaction of plasminogen activator inhibitor-1 with tissue-type plasminogen activator.

    PubMed

    Komissarov, Andrey A; Declerck, Paul J; Shore, Joseph D

    2004-05-28

    Stopped-flow fluorometry was used to study the kinetics of the reactive center loop insertion occurring during the reaction of N-((2-(iodoacetoxy)ethyl)-N-methyl)amino-7-nitrobenz-2-oxa-3-diazole (NBD) P9 plasminogen activator inhibitor-1 (PAI-1) with tissue-(tPA) and urokinase (uPA)-type plasminogen activators and human pancreatic elastase at pH 5.5-8.5. The limiting rate constants of reactive center loop insertion (k(lim)) and concentrations of proteinase at half-saturation (K(0.5)) for tPA and uPA and the specificity constants (k(lim)/K(0.5)) for elastase were determined. The pH dependences of k(lim)/K(0.5) reflected inactivation of each enzyme due to protonation of His57 of the catalytic triad. However, the specificity of the inhibitory reaction with tPA and uPA was notably higher than that for the substrate reaction catalyzed by elastase. pH dependences of k(lim) and K(0.5) obtained for tPA revealed an additional ionizable group (pKa, 6.0-6.2) affecting the reaction. Protonation of this group resulted in a significant increase in both k(lim) and K(0.5) and a 4.6-fold decrease in the specificity of the reaction of tPA with NBD P9 PAI-1. Binding of monoclonal antibody MA-55F4C12 to PAI-1 induced a decrease in k(lim) and K(0.5) at any pH but did not affect either the pKa of the group or an observed decrease in k(lim)/K(0.5) due to protonation of the group. In contrast to tPA, the k(lim) and K(0.5) for the reactions of uPA with NBD P9 PAI-1 or its complex with the monoclonal antibody were independent of pH in the 6.5-8.5 range. Since slightly acidic pH is a feature of a number of malignant tumors, alterations in PAI-1/tPA kinetics could play a role in the cancerogenesis. Changes in the protonation state of His(188), which is placed closely to the S1 site and is unique for tPA, has been proposed to contribute to the observed pH dependences of k(lim) and K(0.5). PMID:15033993

  10. Hypoxia dysregulates the production of adiponectin and plasminogen activator inhibitor-1 independent of reactive oxygen species in adipocytes

    SciTech Connect

    Chen Baoying; Lam, Karen S.L.; Wang Yu; Wu Donghai; Lam, Michael C.; Shen Jiangang; Wong Laiching; Hoo, Ruby L.C.; Zhang Jialiang; Xu Aimin . E-mail: amxu@hkucc.hku.hk

    2006-03-10

    Low plasma levels of adiponectin (hypoadiponectinemia) and elevated circulating concentrations of plasminogen activator inhibitor (PAI)-1 are causally associated with obesity-related insulin resistance and cardiovascular disease. However, the mechanism that mediates the aberrant production of these two adipokines in obesity remains poorly understood. In this study, we investigated the effects of hypoxia and reactive oxygen species (ROS) on production of adiponectin and PAI-1 in 3T3-L1 adipocytes. Quantitative PCR and immunoassays showed that ambient hypoxia markedly suppressed adiponectin mRNA expression and its protein secretion, and increased PAI-1 production in mature adipocytes. Dimethyloxallyl glycine, a stabilizer of hypoxia-inducible factor 1{alpha} (HIF-1{alpha}), mimicked the hypoxia-mediated modulations of these two adipokines. Hypoxia caused a modest elevation of ROS in adipocytes. However, ablation of intracellular ROS by antioxidants failed to alleviate hypoxia-induced aberrant production of adiponectin and PAI-1. On the other hand, the antioxidants could reverse hydrogen peroxide (H{sub 2}O{sub 2})-induced dysregulation of adiponectin and PAI-1 production. H{sub 2}O{sub 2} treatment decreased the expression levels of peroxisome proliferator-activated receptor gamma (PPAR{gamma}) and CCAAT/enhancer binding protein (C/EBP{alpha}), but had no effect on HIF-1{alpha}, whereas hypoxia stabilized HIF-1{alpha} and decreased expression of C/EBP{alpha}, but not PPAR{gamma}. Taken together, these data suggest that hypoxia and ROS decrease adiponectin production and augment PAI-1 expression in adipocytes via distinct signaling pathways. These effects may contribute to hypoadiponectinemia and elevated PAI-1 levels in obesity, type 2 diabetes, and cardiovascular diseases.

  11. Cross-Talk between Human Mast Cells and Bronchial Epithelial Cells in Plasminogen Activator Inhibitor-1 Production via Transforming Growth Factor-β1

    PubMed Central

    Lee, Sun H.; Kato, Atsushi; Takabayashi, Tetsuji; Kulka, Marianna; Shin, Soon C.; Schleimer, Robert P.

    2015-01-01

    Previous reports suggest that plasminogen activator inhibitor-1 (PAI-1) promotes airway remodeling and that human and mouse mast cells (MCs) are an important source of PAI-1. In the present study we investigated MC–epithelial cell (EC) interactions in the production of PAI-1. We stimulated the human MC line LAD2 with IgE-receptor cross-linking and collected the supernatants. We incubated the human bronchial EC line BEAS-2B with the LAD2 supernatants and measured the level of PAI-1. When the supernatants from IgE-stimulated LAD2 were added to BEAS-2B, there was a significant enhancement of PAI-1 production by BEAS-2B. When we treated the MC supernatants with a transforming growth factor (TGF)-β1 neutralizing antibody, the MC-derived induction of PAI-1 from BEAS-2B was completely abrogated. Although TGF-β1 mRNA was constitutively expressed in resting LAD2, it was not highly induced by IgE-mediated stimulation. Nonetheless, active TGF-β1 protein was significantly increased in LAD2 after IgE-mediated stimulation. Active TGF-β1 produced by primary cultured human MCs was significantly reduced in the presence of a chymase inhibitor, suggesting a role of MC chymase as an activator of latent TGF-β1. This study indicates that stimulation of human MCs by IgE receptor cross-linking triggers activation of TGF-β1, at least in part via chymase, which in turn induces the production of PAI-1 by bronchial ECs. Our data suggest that human MCs may play an important role in airway remodeling in asthma as a direct source of PAI-1 and by activating bronchial ECs to produce further PAI-1 via a TGF-β1–mediated activation pathway. PMID:24987792

  12. Cross-talk between human mast cells and bronchial epithelial cells in plasminogen activator inhibitor-1 production via transforming growth factor-β1.

    PubMed

    Cho, Seong H; Lee, Sun H; Kato, Atsushi; Takabayashi, Tetsuji; Kulka, Marianna; Shin, Soon C; Schleimer, Robert P

    2015-01-01

    Previous reports suggest that plasminogen activator inhibitor-1 (PAI-1) promotes airway remodeling and that human and mouse mast cells (MCs) are an important source of PAI-1. In the present study we investigated MC-epithelial cell (EC) interactions in the production of PAI-1. We stimulated the human MC line LAD2 with IgE-receptor cross-linking and collected the supernatants. We incubated the human bronchial EC line BEAS-2B with the LAD2 supernatants and measured the level of PAI-1. When the supernatants from IgE-stimulated LAD2 were added to BEAS-2B, there was a significant enhancement of PAI-1 production by BEAS-2B. When we treated the MC supernatants with a transforming growth factor (TGF)-β1 neutralizing antibody, the MC-derived induction of PAI-1 from BEAS-2B was completely abrogated. Although TGF-β1 mRNA was constitutively expressed in resting LAD2, it was not highly induced by IgE-mediated stimulation. Nonetheless, active TGF-β1 protein was significantly increased in LAD2 after IgE-mediated stimulation. Active TGF-β1 produced by primary cultured human MCs was significantly reduced in the presence of a chymase inhibitor, suggesting a role of MC chymase as an activator of latent TGF-β1. This study indicates that stimulation of human MCs by IgE receptor cross-linking triggers activation of TGF-β1, at least in part via chymase, which in turn induces the production of PAI-1 by bronchial ECs. Our data suggest that human MCs may play an important role in airway remodeling in asthma as a direct source of PAI-1 and by activating bronchial ECs to produce further PAI-1 via a TGF-β1-mediated activation pathway. PMID:24987792

  13. Histone deacetylase inhibitor m-carboxycinnamic acid bis-hydroxamide attenuates plasminogen activator inhibitor-1 expression in human pleural mesothelial cells.

    PubMed

    Chung, Chi-Li; Sheu, Joen-Rong; Chen, Wei-Lin; Chou, Yung-Chen; Hsiao, Che-Jen; Hsiao, Shih-Hsin; Hsu, Ming-Jen; Cheng, Yu-Wen; Hsiao, George

    2012-04-01

    Plasminogen activator inhibitor-1 (PAI-1), primarily up-regulated by transforming growth factor (TGF)-β, is essential in the development of fibrosis. Histone deacetylase (HDAC) was shown to modulate gene expression and fibrogenesis in various tissues. However, the implications of HDAC in terms of PAI-1 expression and pleural fibrosis remain unclear. In this study, we examined the effects of m-carboxycinnamic acid bis-hydroxamide (CBHA), a hybrid-polar HDAC inhibitor, on the TGF-β1-induced expression of PAI-1 in a human pleural mesothelial cell line (MeT-5A). MeT-5A cells were treated with TGF-β1 in the presence or absence of CBHA. We assayed the expression and stability of PAI-1 mRNA and protein, PAI-1 promoter activity, the activation of Smad signaling, the protein-protein interactions of Smads with transcriptional cofactors Sp1 and coactivator p300, and the expression of the mRNA-stabilizing protein nucleolin. The results indicate that CBHA significantly inhibited TGF-β1-induced PAI-1 mRNA and protein expression, and attenuated PAI-1 promoter activity in MeT-5A cells. CBHA abrogated TGF-β1-induced Smad4 nuclear translocation, but not Smad2/3 activation. Furthermore, the association of Smad4 with p300, but not with Sp1, was disrupted by CBHA. Alternatively, CBHA suppressed TGF-β1-induced nucleolin expression, and thereby destabilized PAI-1 mRNA and decreased PAI-1 protein concentrations. These findings suggest that the inhibition of HDAC activity by CBHA may attenuate PAI-1 expression through the modulation of cellular signaling at multiple levels. Given the down-regulating effect of CBHA on PAI-1 expression, HDAC inhibitors should be tested further in animal models as potential therapeutic agents for pleural fibrosis. PMID:22033265

  14. Induction of plasminogen activator inhibitor 1 gene expression in murine liver by lipopolysaccharide. Cellular localization and role of endogenous tumor necrosis factor-alpha.

    PubMed Central

    Fearns, C.; Loskutoff, D. J.

    1997-01-01

    We previously demonstrated that lipopolysaccharide (LPS) induces plasminogen activator inhibitor 1 (PAI-1) gene expression primarily in endothelial cells in most organs of the mouse, with maximal induction by 3 hours. Here we show that induction in the liver occurs in a distinctly different pattern. For example, the increase in PAI-1 mRNA in liver was biphasic with an initial peak at 1 to 2 hours and a second peak at 6 to 8 hours. Moreover, in situ hybridization experiments revealed that PAI-1 mRNA was induced in both endothelial cells and hepatocytes. The endothelial cell response was monophasic and maximal between 1 and 4 hours, whereas the hepatocyte response was biphasic, peaking at 2 hours and again at 6 to 8 hours. To determine possible mechanisms involved in the induction of PAI-1 by LPS, we analyzed the tissues for changes in tumor necrosis factor (TNF)-alpha LPS caused a rapid induction of TNF-alpha mRNA in Kupffer cells, detectable within 15 minutes. Pretreatment of mice with anti-TNF antiserum before challenge with LPS reduced the subsequent increase in plasma levels of PAI-1 by 50 to 70% and significantly reduced the level of induction of PAI-1 mRNA in the liver at both early and late times. Pretreatment appeared to inhibit induction primarily within hepatocytes. These results suggest that LPS may induce PAI-1 in endothelial cells and hepatocytes by different mechanisms. Images Figure 3 Figure 4 Figure 7 PMID:9033272

  15. Effect of ascorbate on plasminogen activator inhibitor-1 expression and release from platelets and endothelial cells in an in-vitro model of sepsis.

    PubMed

    Swarbreck, Scott B; Secor, Dan; Ellis, Christopher G; Sharpe, Michael D; Wilson, John X; Tyml, Karel

    2015-06-01

    The microcirculation during sepsis fails due to capillary plugging involving microthrombosis. We demonstrated that intravenous injection of ascorbate reduces this plugging, but the mechanism of this beneficial effect remains unclear. We hypothesize that ascorbate inhibits the release of the antifibrinolytic plasminogen activator inhibitor-1 (PAI-1) from endothelial cells and platelets during sepsis. Microvascular endothelial cells and platelets were isolated from mice. Cells were cultured and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNFα), or thrombin (agents of sepsis), with/without ascorbate for 1-24 h. PAI-1 mRNA was determined by quantitative PCR. PAI-1 protein release into the culture medium was measured by ELISA. In platelets, PAI-1 release was measured after LPS, TNFα, or thrombin stimulation, with/without ascorbate. In endothelial cells, LPS and TNFα increased PAI-1 mRNA after 6-24 h, but no increase in PAI-1 release was observed; ascorbate did not affect these responses. In platelets, thrombin, but not LPS or TNFα, increased PAI-1 release; ascorbate inhibited this increase at low extracellular pH. In unstimulated endothelial cells and platelets, PAI-1 is released into the extracellular space. Thrombin increases this release from platelets; ascorbate inhibits it pH-dependently. The data suggest that ascorbate promotes fibrinolysis in the microvasculature under acidotic conditions in sepsis. PMID:25730478

  16. Defining Adapted Physical Activity: International Perspectives

    ERIC Educational Resources Information Center

    Hutzler, Yeshayahu; Sherrill, Claudine

    2007-01-01

    The purpose of this study was to describe international perspectives concerning terms, definitions, and meanings of adapted physical activity (APA) as (a) activities or service delivery, (b) a profession, and (c) an academic field of study. Gergen's social constructionism, our theory, guided analysis of multiple sources of data via qualitative…

  17. Inhibition of Plasminogen Activator Inhibitor-1 Attenuates Transforming Growth Factor-β-Dependent Epithelial Mesenchymal Transition and Differentiation of Fibroblasts to Myofibroblasts

    PubMed Central

    Omori, Keitaro; Hattori, Noboru; Senoo, Tadashi; Takayama, Yusuke; Masuda, Takeshi; Nakashima, Taku; Iwamoto, Hiroshi; Fujitaka, Kazunori; Hamada, Hironobu; Kohno, Nobuoki

    2016-01-01

    Transforming growth factor-β (TGF-β) is central during the pathogenesis of pulmonary fibrosis, in which the plasminogen activator inhibitor-1 (PAI-1) also has an established role. TGF-β is also known to be the strongest inducer of PAI-1. To investigate the link between PAI-1 and TGF-β in fibrotic processes, we evaluated the effect of SK-216, a PAI-1-specific inhibitor, in TGF-β-dependent epithelial-mesenchymal transition (EMT) and fibroblast to myofibroblast differentiation. In human alveolar epithelial A549 cells, treatment with TGF-β induced EMT, whereas co-treatment with SK-216 attenuated the occurrence of EMT. The inhibition of TGF-β-induced EMT by SK-216 was also confirmed in the experiment using murine epithelial LA-4 cells. Blocking EMT by SK-216 inhibited TGF-β-induced endogenous production of PAI-1 and TGF-β in A549 cells as well. These effects of SK-216 were not likely mediated by suppressing either Smad or ERK pathways. Using human lung fibroblast MRC-5 cells, we demonstrated that SK-216 inhibited TGF-β-dependent differentiation of fibroblasts to myofibroblasts. We also observed this inhibition by SK-216 in human primary lung fibroblasts. Following these in vitro results, we tested oral administration of SK-216 into mice injected intratracheally with bleomycin. We found that SK-216 reduced the degree of bleomycin-induced pulmonary fibrosis in mice. Although the precise mechanisms underlying the link between TGF-β and PAI-1 regarding fibrotic process were not determined, PAI-1 seems to act as a potent downstream effector on the pro-fibrotic property of TGF-β. In addition, inhibition of PAI-1 activity by a PAI-1 inhibitor exerts an antifibrotic effect even in vivo. These data suggest that targeting PAI-1 as a downstream effector of TGF-β could be a promising therapeutic strategy for pulmonary fibrosis. PMID:26859294

  18. Impact of statin therapy on plasma levels of plasminogen activator inhibitor-1. A systematic review and meta-analysis of randomised controlled trials.

    PubMed

    Sahebkar, Amirhossein; Catena, Cristiana; Ray, Kausik K; Vallejo-Vaz, Antonio J; Reiner, Željko; Sechi, Leonardo A; Colussi, GianLuca

    2016-07-01

    Elevated plasma levels of the pro-thrombotic and pro-inflammatory factor plasminogen activator inhibitor-1 (PAI-1) may contribute to the pathogenesis of atherosclerotic cardiovascular disease. Beyond their lipid-lowering effect, statins have been shown to modulate plasma PAI-1 levels but evidence from individual randomised controlled trials (RCTs) is controversial. Therefore, we aimed to assess the potential effects of statin therapy on plasma PAI-1 concentration through a meta-analysis of RCTs. We searched Medline and SCOPUS databases (up to October 3, 2014) to identify RCTs investigating the effect of statin therapy on plasma PAI-1 concentrations. We performed random-effects meta-analysis and assessed heterogeneity (I² test, subgroup and sensitivity analyses) and publication bias (funnel plot, Egger and "trim and fill" tests). Sixteen RCTs (comprising 19 treatment arms) were included and pooled analyses showed a significant effect of statins in reducing plasma PAI-1 concentrations (weighted mean difference WMD: -15.72 ng/ml, 95 % confidence interval [CI]: -25.01, -6.43,). In subgroup analysis, this effect remained significant in with lipophilic statins (atorvastatin and simvastatin) (WMD: -21.32 ng/ml, 95 % CI: -32.73, -9.91, I²=99 %) and particularly atorvastatin (WMD: -20.88 ng/mL, 95 % CI: -28.79, -12.97, I2=97 %). In the meta-regression analysis, the impact of statins on PAI-1 did not correlate with the administered dose, duration of treatment and changes in plasma LDL-cholesterol concentrations. Finally, evidence of publication bias was observed. In conclusion, taking into account the limit of heterogeneity between studies, the present meta-analysis suggests that statin therapy (mainly atorvastatin) significantly lowers plasma PAI-1 concentrations. PMID:27009446

  19. Fructose Rich Diet-Induced High Plasminogen Activator Inhibitor-1 (PAI-1) Production in the Adult Female Rat: Protective Effect of Progesterone

    PubMed Central

    Castrogiovanni, Daniel; Alzamendi, Ana; Ongaro, Luisina; Giovambattista, Andrés; Gaillard, Rolf C.; Spinedi, Eduardo

    2012-01-01

    The effect of progesterone (P4) on fructose rich diet (FRD) intake-induced metabolic, endocrine and parametrial adipose tissue (PMAT) dysfunctions was studied in the adult female rat. Sixty day-old rats were i.m. treated with oil alone (control, CT) or containing P4 (12 mg/kg). Rats ate Purina chow-diet ad libitum throughout the entire experiment and, between 100 and 120 days of age drank ad libitum tap water alone (normal diet; CT-ND and P4-ND) or containing fructose (10% w/v; CT-FRD and P4-FRD). At age 120 days, animals were subjected to a glucose tolerance test or decapitated. Plasma concentrations of various biomarkers and PMAT gene abundance were monitored. P4-ND (vs. CT-ND) rats showed elevated circulating levels of lipids. CT-FRD rats displayed high (vs. CT-ND) plasma concentrations of lipids, leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1). Lipidemia and adiponectinemia were high (vs. P4-ND) in P4-FRD rats. Although P4 failed to prevent FRD-induced hyperleptinemia, it was fully protective on FRD-enhanced plasma PAI-1 levels. PMAT leptin and adiponectin mRNAs were high in CT-FRD and P4-FRD rats. While FRD enhanced PMAT PAI-1 mRNA abundance in CT rats, this effect was absent in P4 rats. Our study supports that a preceding P4-enriched milieu prevented the enhanced prothrombotic risk induced by FRD-elicited high PAI-1 production. PMID:23016136

  20. Hesperetin and its sulfate and glucuronide metabolites inhibit TNF-α induced human aortic endothelial cell migration and decrease plasminogen activator inhibitor-1 (PAI-1) levels.

    PubMed

    Giménez-Bastida, Juan Antonio; González-Sarrías, Antonio; Vallejo, Fernando; Espín, Juan Carlos; Tomás-Barberán, Francisco A

    2016-01-01

    Epidemiological, clinical and preclinical studies have reported the protection offered by citrus consumption, mainly orange, against cardiovascular diseases, which is primarily mediated by the antiatherogenic and vasculoprotective effects of the flavanone hesperetin-7-O-rutinoside (hesperidin). However, flavanone aglycones or glycosides are not present in the bloodstream but their derived phase-II metabolites could be the actual bioactive molecules. To date, only a few studies have explored the effects of circulating hesperetin-derived metabolites (glucuronides and sulfates) on endothelial cells. Herein, we describe for the first time the effects of hesperetin 3'-O-glucuronide, hesperetin 7-O-glucuronide, hesperetin 3'-O-sulfate, hesperetin 7-O-sulfate and hesperetin on human aortic endothelial cell (HAEC) migration upon pro-inflammatory stimuli as an essential step to angiogenesis. Hesperetin and its derived metabolites, at physiologically relevant concentrations (1-10 μM), significantly attenuated cell migration in the presence of the pro-inflammatory cytokine TNF-α (50 ng mL(-1)), which was accompanied and perhaps mediated by a significant decrease in the levels of the thrombogenic plasminogen activator inhibitor-1 (PAI-1). However, hesperetin metabolites did not counteract the TNF-α-induced production of pro-inflammatory interleukin-6 (IL-6) and IL-8. We also study here for the first time, the metabolism of hesperetin and its derived metabolites by HAEC with and without a pro-inflammatory stimulus. All these results reinforce the concept according to which circulating phase-II hesperetin metabolites are critical molecules contributing to the cardioprotective effects upon consumption of citrus fruits such as orange. PMID:26456097

  1. Hepatocyte Growth Factor Activator Inhibitor-1 Is Induced by Bone Morphogenetic Proteins and Regulates Proliferation and Cell Fate of Neural Progenitor Cells

    PubMed Central

    Koivuniemi, Raili; Mäkelä, Johanna; Hokkanen, Marie-Estelle; Bruelle, Céline; Ho, Tho Huu; Ola, Roxana; Korhonen, Laura; Schröder, Jim; Kataoka, Hiroaki; Lindholm, Dan

    2013-01-01

    Background Neural progenitor cells (NPCs) in the developing neuroepithelium are regulated by intrinsic and extrinsic factors. There is evidence that NPCs form a self-supporting niche for cell maintenance and proliferation. However, molecular interactions and cell-cell contacts and the microenvironment within the neuroepithelium are largely unknown. We hypothesized that cellular proteases especially those associated with the cell surface of NPCs play a role in regulation of progenitor cells in the brain. Methodology/Principal Findings In this work, we show that NPCs, isolated from striatal anlage of developing rat brain, express hepatocyte growth factor activator inhibitor-1 and -2 (HAI-1 and HAI-2) that are cell surface-linked serine protease inhibitors. In addition, radial glia cells derived from mouse embryonic stem cells also express HAI-1 and HAI-2. To study the functional significance of HAI-1 and HAI-2 in progenitor cells, we modulated their levels using expression plasmids or silencing RNA (siRNA) transfected into the NPCs. Data showed that overexpression of HAI-1 or HAI-2 decreased cell proliferation of cultured NPCs, whilst their siRNAs had opposite effects. HAI-1 also influenced NPC differentiation by increasing the number of glial fibrillary acidic protein (GFAP) expressing cells in the culture. Expression of HAI-1 in vivo decreased cell proliferation in developing neuroepithelium in E15 old animals and promoted astrocyte cell differentiation in neonatal animals. Studying the regulation of HAI-1, we observed that Bone morphogenetic protein-2 (BMP-2) and BMP-4 increased HAI-1 levels in the NPCs. Experiments using HAI-1-siRNA showed that these BMPs act on the NPCs partly in a HAI-1-dependent manner. Conclusions This study shows that the cell-surface serine protease inhibitors, HAI-1 and HAI-2 influence proliferation and cell fate of NPCs and their expression levels are linked to BMP signaling. Modulation of the levels and actions of HAI-1 in NPCs may be of

  2. The biological activity of structurally defined inositol glycans

    PubMed Central

    Goel, Meenakshi; Azev, Viatcheslav N; d’Alarcao, Marc

    2009-01-01

    Background The inositol glycans (IGs) are glycolipid-derived carbohydrates produced by insulin-sensitive cells in response to insulin treatment. IGs exhibit an array of insulin-like activities including stimulation of lipogenesis, glucose transport and glycogen synthesis, suggesting that they may be involved in insulin signal transduction. However, because the natural IGs are structurally heterogeneous and difficult to purify to homogeneity, an understanding of the relationship between structure and biological activity has relied principally on synthetic IGs of defined structure. Discussion This article briefly describes what is known about the role of IGs in signal transduction and reviews the specific biological activities of the structurally defined IGs synthesized and tested to date. Conclusion A pharmacophore for IG activity begins to emerge from the reviewed data and the structural elements necessary for activity are summarized. PMID:20390053

  3. SNS Devices With Pinhole-Defined Active Regions

    NASA Technical Reports Server (NTRS)

    Hunt, Brian D.; Barner, Jeffrey B.

    1996-01-01

    Superconductor/normal conductor/superconductor (SNS) microbridge devices with pinhole-defined active regions undergoing development. Device includes thin, electrically insulating layer deposited epitaxially, with controlled formation of pinholes, on one of two superconducting layers. Normally conducting metal deposited epitaxially in pinholes and on insulating layer, forming electrical contact between two superconducting layers. Junction resistances and maximum junction voltages expected to be increased.

  4. Female mice are more susceptible to nonalcoholic fatty liver disease: sex-specific regulation of the hepatic AMP-activated protein kinase-plasminogen activator inhibitor 1 cascade, but not the hepatic endotoxin response.

    PubMed

    Spruss, Astrid; Henkel, Janin; Kanuri, Giridhar; Blank, Daniela; Püschel, Gerhard P; Bischoff, Stephan C; Bergheim, Ina

    2012-01-01

    As significant differences between sexes were found in the susceptibility to alcoholic liver disease in human and animal models, it was the aim of the present study to investigate whether female mice also are more susceptible to the development of non-alcoholic fatty liver disease (NAFLD). Male and female C57BL/6J mice were fed either water or 30% fructose solution ad libitum for 16 wks. Liver damage was evaluated by histological scoring. Portal endotoxin levels and markers of Kupffer cell activation and insulin resistance, plasminogen activator inhibitor 1 (PAI-1) and phosphorylated adenosine monophosphate-activated protein kinase (pAMPK ) were measured in the liver. Adiponectin mRNA expression was determined in adipose tissue. Hepatic steatosis was almost similar between male and female mice; however, inflammation was markedly more pronounced in livers of female mice. Portal endotoxin levels, hepatic levels of myeloid differentiation primary response gene (88) (MyD88) protein and of 4-hydroxynonenal protein adducts were elevated in animals with NAFLD regardless of sex. Expression of insulin receptor substrate 1 and 2 was decreased to a similar extent in livers of male and female mice with NAFLD. The less pronounced susceptibility to liver damage in male mice was associated with a superinduction of hepatic pAMPK in these mice whereas, in livers of female mice with NAFLD, PAI-1 was markedly induced. Expression of adiponectin in visceral fat was significantly lower in female mice with NAFLD but unchanged in male mice compared with respective controls. In conclusion, our data suggest that the sex-specific differences in the susceptibility to NAFLD are associated with differences in the regulation of the adiponectin-AMPK-PAI-1 signaling cascade. PMID:22952059

  5. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  6. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  7. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  8. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  9. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  10. NGF Upregulates the Plasminogen Activation Inhibitor-1 in Neurons via the Calcineurin/NFAT Pathway and the Down Syndrome-Related Proteins DYRK1A and RCAN1 Attenuate This Effect

    PubMed Central

    Stefos, Georgios C.; Soppa, Ulf; Dierssen, Mara; Becker, Walter

    2013-01-01

    Background Plasminogen activator inhibitor 1 (PAI-1) is a key regulator of the plasminogen activation system. Although several lines of evidence support a significant role of PAI-1 in the brain, the regulation of its expression in neurons is poorly understood. In the present study we tested the hypothesis that NGF induces the upregulation of PAI-1 via the calcineurin/nuclear factor of activated T cells (NFAT) pathway and analysed whether the overexpression of the Down syndrome-related proteins DYRK1A and RCAN1 modulated the effect of NGF on PAI-1 expression. Results NGF upregulated PAI-1 mRNA levels in primary mouse hippocampal neurons cultured for 3 days in vitro and in the rat pheochromocytoma cell line PC12. Reporter gene assays revealed that NGF activated the calcineurin/NFAT pathway in PC12 cells. Induction of PAI-1 by NGF was sensitive to the calcineurin inhibitor FK506 and the specific inhibition of NFAT activation by the cell permeable VIVIT peptide. Activation of calcineurin/NFAT signalling through other stimuli resulted in a much weaker induction of PAI-1 expression, suggesting that other NGF-induced pathways are involved in PAI-1 upregulation. Overexpression of either DYRK1A or RCAN1 negatively regulated NFAT-dependent transcriptional activity and reduced the upregulation of PAI-1 levels by NGF. Conclusion The present results show that the calcineurin/NFAT pathway mediates the upregulation of PAI-1 by NGF. The negative effect of DYRK1A and RCAN1 overexpression on NGF signal transduction in neural cells may contribute to the altered neurodevelopment and brain function in Down syndrome. PMID:23825664

  11. Crystal Structure of a Two-domain Fragment of Hepatocyte Growth Factor Activator Inhibitor-1: FUNCTIONAL INTERACTIONS BETWEEN THE KUNITZ-TYPE INHIBITOR DOMAIN-1 AND THE NEIGHBORING POLYCYSTIC KIDNEY DISEASE-LIKE DOMAIN.

    PubMed

    Hong, Zebin; De Meulemeester, Laura; Jacobi, Annemarie; Pedersen, Jan Skov; Morth, J Preben; Andreasen, Peter A; Jensen, Jan K

    2016-07-01

    Hepatocyte growth factor activator inhibitor-1 (HAI-1) is a type I transmembrane protein and inhibitor of several serine proteases, including hepatocyte growth factor activator and matriptase. The protein is essential for development as knock-out mice die in utero due to placental defects caused by misregulated extracellular proteolysis. HAI-1 contains two Kunitz-type inhibitor domains (Kunitz), which are generally thought of as a functionally self-contained protease inhibitor unit. This is not the case for HAI-1, where our results reveal how interdomain interactions have evolved to stimulate the inhibitory activity of an integrated Kunitz. Here we present an x-ray crystal structure of an HAI-1 fragment covering the internal domain and Kunitz-1. The structure reveals not only that the previously uncharacterized internal domain is a member of the polycystic kidney disease domain family but also how the two domains engage in interdomain interactions. Supported by solution small angle x-ray scattering and a combination of site-directed mutagenesis and functional assays, we show that interdomain interactions not only stabilize the fold of the internal domain but also stimulate the inhibitory activity of Kunitz-1. By completing our structural characterization of the previously unknown N-terminal region of HAI-1, we provide new insight into the interplay between tertiary structure and the inhibitory activity of a multidomain protease inhibitor. We propose a previously unseen mechanism by which the association of an auxiliary domain stimulates the inhibitory activity of a Kunitz-type inhibitor (i.e. the first structure of an intramolecular interaction between a Kunitz and another domain). PMID:27189939

  12. Expression of Progesterone Receptor Membrane Component 1 (PGRMC1), Progestin and AdipoQ Receptor 7 (PAQPR7), and Plasminogen Activator Inhibitor 1 RNA-Binding Protein (PAIRBP1) in Glioma Spheroids In Vitro

    PubMed Central

    Hlavaty, Juraj; Ertl, Reinhard; Miller, Ingrid; Gabriel, Cordula

    2016-01-01

    Objective. Some effects of progesterone on glioma cells can be explained through the slow, genomic mediated response via nuclear receptors; the other effects suggest potential role of a fast, nongenomic action mediated by membrane-associated progesterone receptors. Methods. The effects of progesterone treatment on the expression levels of progesterone receptor membrane component 1 (PGRMC1), plasminogen activator inhibitor 1 RNA-binding protein (PAIRBP1), and progestin and adipoQ receptor 7 (PAQR7) on both mRNA and protein levels were investigated in spheroids derived from human glioma cell lines U-87 MG and LN-229. Results. The only significant alteration at the transcript level was the decrease in PGRMC1 mRNA observed in LN-229 spheroids treated with 30 ng/mL of progesterone. No visible alterations at the protein levels were observed using immunohistochemical analysis. Stimulation of U-87 MG spheroids resulted in an increase of PGRMC1 but a decrease of PAIRBP1 protein. Double immunofluorescent detection of PGRMC1 and PAIRBP1 identified the two proteins to be partially colocalized in the cells. Western blot analysis revealed the expected bands for PGRMC1 and PAIRBP1, whereas two bands were detected for PAQR7. Conclusion. The progesterone action is supposed to be mediated via membrane-associated progesterone receptors as the nuclear progesterone receptor was absent in tested spheroids. PMID:27340667

  13. The High Affinity Binding Site on Plasminogen Activator Inhibitor-1 (PAI-1) for the Low Density Lipoprotein Receptor-related Protein (LRP1) Is Composed of Four Basic Residues.

    PubMed

    Gettins, Peter G W; Dolmer, Klavs

    2016-01-01

    Plasminogen activator inhibitor 1 (PAI-1) is a serpin inhibitor of the plasminogen activators urokinase-type plasminogen activator (uPA) and tissue plasminogen activator, which binds tightly to the clearance and signaling receptor low density lipoprotein receptor-related protein 1 (LRP1) in both proteinase-complexed and uncomplexed forms. Binding sites for PAI-1 within LRP1 have been localized to CR clusters II and IV. Within cluster II, there is a strong preference for the triple CR domain fragment CR456. Previous mutagenesis studies to identify the binding site on PAI-1 for LRP1 have given conflicting results or implied small binding contributions incompatible with the high affinity PAI-1/LRP1 interaction. Using a highly sensitive solution fluorescence assay, we have examined binding of CR456 to arginine and lysine variants of PAI-1 and definitively identified the binding site as composed of four basic residues, Lys-69, Arg-76, Lys-80, and Lys-88. These are highly conserved among mammalian PAI-1s. Individual mutations result in a 13-800-fold increase in Kd values. We present evidence that binding involves engagement of CR4 by Lys-88, CR5 by Arg-76 and Lys-80, and CR6 by Lys-69, with the strongest interactions to CR5 and CR6. Collectively, the individual binding contributions account quantitatively for the overall PAI-1/LRP1 affinity. We propose that the greater efficiency of PAI-1·uPA complex binding and clearance by LRP1, compared with PAI-1 alone, is due solely to simultaneous binding of the uPA moiety in the complex to its receptor, thereby making binding of the PAI-1 moiety to LRP1 a two-dimensional surface-localized association. PMID:26555266

  14. A Phytochemical-rich Multivitamin-multimineral Supplement Is Bioavailable and Reduces Serum Oxidized Low-density Lipoprotein, Myeloperoxidase, and Plasminogen Activator Inhibitor-1 in a Four-week Pilot trial of Healthy Individuals

    PubMed Central

    Desai, Anuradha; Lamb, Joseph J.; Chang, Jyh-Lurn; Darland, Gary; Konda, Veera R.

    2014-01-01

    Background: A multivitamin-multimineral supplement combined with a diverse blend of bioactive phytochemicals may provide additional antioxidant capacity and anti-inflammatory property for overall health. This convenient feature may be useful for individuals who want to increase their intake of phytochemicals. Methods: We conducted a pilot study in 15 healthy individuals (8 women and 7 men, mean age 41.7±14.9 years, mean body mass index 28.0±5.6) to investigate the effects of this novel formulation on biomarkers associated with oxidative stress and inflammation. After a 2-week diet that limited intake of fruits and vegetables to 2 servings/day, participants continued with the same restricted diet but began consuming 2 tablets of the study product for the subsequent 4 weeks. Fasting blood samples collected at Week 2 and Week 6 were analyzed and compared using paired t-tests for levels of carotenoids, folate, vitamin B12, homocysteine, oxidized low-density lipoprotein cholesterol (oxLDL), high-sensitivity C-reactive protein (hs-CRP), F2-isoprostane, plasminogen activator inhibitor-1 (PAI-1), and myeloperoxidase. Noninvasive peripheral arterial tonometry (EndoPAT) was also measured. Results: After 4 weeks of supplementation, plasma levels of carotenoids, folate, and vitamin B12, but not homocysteine, were significantly increased (P<.05). Serum levels of oxLDL, PAI-1 and myeloperoxidase were significantly reduced (P<.05), but F2-isoprostane, hs-CRP, and EndoPAT measures were unchanged compared with baseline. The study product was well tolerated. Conclusions: This nutritional supplement is bioavailable as indicated by the significant increase in plasma carotenoids, vitamin B12, and folate levels and may provide health benefits by significantly reducing serum levels of oxLDL, myeloperoxidase, and PAI-1 in healthy individuals. PMID:24808980

  15. Discussing and Defining Sexual Assault: A Classroom Activity

    ERIC Educational Resources Information Center

    Franiuk, Renae

    2007-01-01

    The author devised a classroom activity that facilitates discussion and increases awareness about sexual assault. Students read scenarios involving sexual situations that varied in ambiguity, then labeled whether the situations involved a sexual assault. Students also gave their definitions of sexual assault and completed an evaluation of the…

  16. Proteolytic activation defines distinct lymphangiogenic mechanisms for VEGFC and VEGFD

    PubMed Central

    Bui, Hung M.; Enis, David; Robciuc, Marius R.; Nurmi, Harri J.; Cohen, Jennifer; Chen, Mei; Yang, Yiqing; Dhillon, Veerpal; Johnson, Kathy; Zhang, Hong; Kirkpatrick, Robert; Traxler, Elizabeth; Alitalo, Kari

    2016-01-01

    Lymphangiogenesis is supported by 2 homologous VEGFR3 ligands, VEGFC and VEGFD. VEGFC is required for lymphatic development, while VEGFD is not. VEGFC and VEGFD are proteolytically cleaved after cell secretion in vitro, and recent studies have implicated the protease a disintegrin and metalloproteinase with thrombospondin motifs 3 (ADAMTS3) and the secreted factor collagen and calcium binding EGF domains 1 (CCBE1) in this process. It is not well understood how ligand proteolysis is controlled at the molecular level or how this process regulates lymphangiogenesis, because these complex molecular interactions have been difficult to follow ex vivo and test in vivo. Here, we have developed and used biochemical and cellular tools to demonstrate that an ADAMTS3-CCBE1 complex can form independently of VEGFR3 and is required to convert VEGFC, but not VEGFD, into an active ligand. Consistent with these ex vivo findings, mouse genetic studies revealed that ADAMTS3 is required for lymphatic development in a manner that is identical to the requirement of VEGFC and CCBE1 for lymphatic development. Moreover, CCBE1 was required for in vivo lymphangiogenesis stimulated by VEGFC but not VEGFD. Together, these studies reveal that lymphangiogenesis is regulated by two distinct proteolytic mechanisms of ligand activation: one in which VEGFC activation by ADAMTS3 and CCBE1 spatially and temporally patterns developing lymphatics, and one in which VEGFD activation by a distinct proteolytic mechanism may be stimulated during inflammatory lymphatic growth. PMID:27159393

  17. Defining Health Activism: From MADD to Mad Activists

    PubMed Central

    Huang, Jean

    2011-01-01

    Health Activism in the 20th Century: A History of Medicine Symposium at Yale University School of Medicine in October 2010 highlighted a variety of issues concerning the social history of medicine, including race, gender, sexual orientation, and disability. A watershed moment in a burgeoning interdisciplinary field, this symposium could pave the way for extensive future discourse. PMID:21451786

  18. Ion exchange defines the biological activity of titanate nanotubes.

    PubMed

    Rónavári, Andrea; Kovács, Dávid; Vágvölgyi, Csaba; Kónya, Zoltán; Kiricsi, Mónika; Pfeiffer, Ilona

    2016-05-01

    One-dimensional titanate nanotubes (TiONTs) were subjected to systematic ion exchange to determine the impact of these modifications on biological activities. Ion exchanged TiONTs (with Ag, Mg, Bi, Sb, Ca, K, Sr, Fe, and Cu ions) were successfully synthesized and the presence of the substituted ions was verified by energy dispersive X-ray spectroscopy (EDS). A complex screening was carried out to reveal differences in toxicity to human cells, as well as in antibacterial, antifungal, and antiviral activities between the various modified nanotubes. Our results demonstrated that Ag ion exchanged TiONTs exerted potent antibacterial and antifungal effects against all examined microbial species but were ineffective on viruses. Surprisingly, the antibacterial activity of Cu/TiONTs was restricted to Micrococcus luteus. Most ion exchanged TiONTs did not show antimicrobial activity against the tested bacterial and fungal species. Incorporation of various ions into nanotube architectures lead to mild, moderate, or even to a massive loss of human cell viability; therefore, this type of biological effect exerted by TiONTs can be greatly modulated by ion exchange. These findings further emphasize the contribution of ion exchange in determining not only the physical and chemical characteristics but also the bioactivity of TiONT against different types of living cells. PMID:26972521

  19. Twist1 activity thresholds define multiple functions in limb development

    PubMed Central

    Krawchuk, Dayana; Weiner, Shoshana J.; Chen, You-Tzung; Lu, Benson; Costantini, Frank; Behringer, Richard R.; Laufer, Ed

    2010-01-01

    Summary The basic helix-loop-helix transcription factor Twist1 is essential for normal limb development. Twist1−/− embryos die at midgestation. However, studies on early limb buds found that Twist1−/− mutant limb mesenchyme has an impaired response to FGF signaling from the apical ectodermal ridge, which disrupts the feedback loop between the mesenchyme and AER, and reduces and shifts anteriorly Shh expression in the zone of polarizing activity. We have combined Twist1 null, hypomorph and conditional alleles to generate a Twist1 allelic series that survives to birth. As Twist1 activity is reduced, limb skeletal defects progress from preaxial polydactyly to girdle reduction combined with hypoplasia, aplasia or mirror symmetry of all limb segments. With reduced Twist1 activity there is striking and progressive upregulation of ectopic Shh expression in the anterior of the limb, combined with an anterior shift in the posterior Shh domain, which is expressed at normal intensity, and loss of the posterior AER. Consequently limb outgrowth is initially impaired, before an ectopic anterior Shh domain expands the AER, promoting additional growth and repatterning. Reducing the dosage of FGF targets of the Etv gene family, which are known repressors of Shh expression in the anterior limb mesenchyme, strongly enhances the anterior skeletal phenotype. Conversely this and other phenotypes are suppressed by reducing the dosage of the Twist1 antagonist Hand2. Our data support a model whereby multiple Twist1 activity thresholds contribute to early limb bud patterning, and suggest how particular combinations of skeletal defects result from differing amounts of Twist1 activity. PMID:20732316

  20. Mutant p53: Multiple Mechanisms Define Biologic Activity in Cancer

    PubMed Central

    Kim, Michael Paul; Zhang, Yun; Lozano, Guillermina

    2015-01-01

    The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of alterations involve p53 missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may concomitantly gain novel functions, often with deleterious effects. Here, we review characterized mechanisms of mutant p53 gain of function in various model systems. In addition, we review mutant p53 addiction as emerging evidence suggests that tumors may depend on sustained mutant p53 activity for continued growth. We also discuss the role of p53 in stromal elements and their contribution to tumor initiation and progression. Lastly, current genetic mouse models of mutant p53 in various organ systems are reviewed and their limitations discussed. PMID:26618142

  1. 34 CFR 656.3 - What activities define a comprehensive or undergraduate National Resource Center?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 3 2014-07-01 2014-07-01 false What activities define a comprehensive or undergraduate....3 What activities define a comprehensive or undergraduate National Resource Center? A comprehensive... science, technology, engineering, and mathematics fields to achieve foreign language...

  2. 34 CFR 656.3 - What activities define a comprehensive or undergraduate National Resource Center?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false What activities define a comprehensive or undergraduate....3 What activities define a comprehensive or undergraduate National Resource Center? A comprehensive... science, technology, engineering, and mathematics fields to achieve foreign language...

  3. 26 CFR 1.103(n)-2T - Private activity bond defined (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Private activity bond defined (temporary). 1.103....103(n)-2T Private activity bond defined (temporary). Q-1: What is the definition of the term “private activity bond”? A-1: In general, for purposes of §§ 1.103(n)-1T through 1.103(n)-6T, the term...

  4. 26 CFR 1.103(n)-2T - Private activity bond defined (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Private activity bond defined (temporary). 1.103....103(n)-2T Private activity bond defined (temporary). Q-1: What is the definition of the term “private activity bond”? A-1: In general, for purposes of §§ 1.103(n)-1T through 1.103(n)-6T, the term...

  5. Defining Standards and Policies for Promoting Physical Activity in Afterschool Programs

    ERIC Educational Resources Information Center

    Beets, Michael W.; Wallner, Megan; Beighle, Aaron

    2010-01-01

    Background: National guidelines exist that define "quality" afterschool programs (3-6 pm, ASP). No widely adopted national standards/policies exist, however, for ASP providers for the promotion of physical activity (PA). To address this gap, state-level ASP organizations have developed or adopted standards/policies related to PA. The extent to…

  6. 34 CFR 656.3 - What activities define a comprehensive or undergraduate National Resource Center?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 3 2012-07-01 2012-07-01 false What activities define a comprehensive or undergraduate National Resource Center? 656.3 Section 656.3 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION NATIONAL RESOURCE CENTERS PROGRAM FOR FOREIGN LANGUAGE AND...

  7. 34 CFR 656.3 - What activities define a comprehensive or undergraduate National Resource Center?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 3 2013-07-01 2013-07-01 false What activities define a comprehensive or undergraduate National Resource Center? 656.3 Section 656.3 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION NATIONAL RESOURCE CENTERS PROGRAM FOR FOREIGN LANGUAGE AND...

  8. Human G109E-inhibitor-1 impairs cardiac function and promotes arrhythmias.

    PubMed

    Haghighi, Kobra; Pritchard, Tracy J; Liu, Guan-Sheng; Singh, Vivek P; Bidwell, Philip; Lam, Chi Keung; Vafiadaki, Elizabeth; Das, Parthib; Ma, Jianyong; Kunduri, Swati; Sanoudou, Despina; Florea, Stela; Vanderbilt, Erica; Wang, Hong-Shang; Rubinstein, Jack; Hajjar, Roger J; Kranias, Evangelia G

    2015-12-01

    A hallmark of human and experimental heart failure is deficient sarcoplasmic reticulum (SR) Ca-uptake reflecting impaired contractile function. This is at least partially attributed to dephosphorylation of phospholamban by increased protein phosphatase 1 (PP1) activity. Indeed inhibition of PP1 by transgenic overexpression or gene-transfer of constitutively active inhibitor-1 improved Ca-cycling, preserved function and decreased fibrosis in small and large animal models of heart failure, suggesting that inhibitor-1 may represent a potential therapeutic target. We recently identified a novel human polymorphism (G109E) in the inhibitor-1 gene with a frequency of 7% in either normal or heart failure patients. Transgenic mice, harboring cardiac-specific expression of G109E inhibitor-1, exhibited decreases in contractility, Ca-kinetics and SR Ca-load. These depressive effects were relieved by isoproterenol stimulation. Furthermore, stress conditions (2Hz +/- Iso) induced increases in Ca-sparks, Ca-waves (60% of G109E versus 20% in wild types) and after-contractions (76% of G109E versus 23% of wild types) in mutant cardiomyocytes. Similar findings were obtained by acute expression of the G109E variant in adult cardiomyocytes in the absence or presence of endogenous inhibitor-1. The underlying mechanisms included reduced binding of mutant inhibitor-1 to PP1, increased PP1 activity, and dephosphorylation of phospholamban at Ser16 and Thr17. However, phosphorylation of the ryanodine receptor at Ser2808 was not altered while phosphorylation at Ser2814 was increased, consistent with increased activation of Ca/calmodulin-dependent protein kinase II (CaMKII), promoting aberrant SR Ca-release. Parallel in vivo studies revealed that mutant mice developed ventricular ectopy and complex ventricular arrhythmias (including bigeminy, trigeminy and ventricular tachycardia), when challenged with isoproterenol. Inhibition of CaMKII activity by KN-93 prevented the increased propensity to

  9. Role of protein phosphatase-1 inhibitor-1 in cardiac physiology and pathophysiology

    PubMed Central

    Nicolaou, Persoulla; Hajjar, Roger J.; Kranias, Evangelia G.

    2009-01-01

    The type 1 protein phosphatase (PP1) is a critical negative regulator of Ca2+ cycling and contractility in the cardiomyocyte. In particular, it mediates restoration of cardiac function to basal levels, after β-adrenergic stimulation, by dephosphorylating key phospho-proteins. PP1 is a holoenzyme comprised of its catalytic and auxiliary subunits. These regulatory proteins dictate PP1's subcellular localization, substrate specificity and activity. Amongst them, inhibitor-1 is of particular importance since it has been implicated as an integrator of multiple neurohormonal pathways, which finely regulate PP1 activity, at the level of the sarcoplasmic reticulum (SR). In fact, perturbations in the regulation of PP1 by inhibitor-1 have been implicated in the pathogenesis of heart failure, suggesting that inhibitor-1-based therapeutic interventions may ameliorate cardiac dysfunction and remodeling in the failing heart. This review will discuss the current views on the role of inhibitor-1 in cardiac physiology, its possible contribution to cardiac disease and its potential as a novel therapeutic strategy. PMID:19481088

  10. RE-DEFINING THE ROLES OF SENSORS IN OBJECTIVE PHYSICAL ACTIVITY MONITORING

    PubMed Central

    Chen, Kong Y.; Janz, Kathleen F.; Zhu, Weimo; Brychta, Robert J.

    2011-01-01

    Background As physical activity researchers are increasingly using objective portable devices, this review describes current state of the technology to assess physical activity, with a focus on specific sensors and sensor properties currently used in monitors and their strengths and weakness. Additional sensors and sensor properties desirable for activity measurement and best practices for users and developers also are discussed. Best Practices We grouped current sensors into three broad categories for objectively measuring physical activity: associated body movement, physiology, and context. Desirable sensor properties for measuring physical activity and the importance of these properties in relationship to specific applications are addressed, and the specific roles of transducers and data acquisition systems within the monitoring devices are defined. Technical advancements in sensors, microcomputer processors, memory storage, batteries, wireless communication, and digital filters have made monitors more usable for subjects (smaller, more stable, and longer running time) and for researchers (less costly, higher time resolution and memory storage, shorter download time, and user-defined data features). Future Directions Users and developers of physical activity monitors should learn about the basic properties of their sensors, such as range, accuracy, precision, while considering the data acquisition/filtering steps that may be critical to data quality and may influence the desirable measurement outcome(s). PMID:22157770

  11. IMD-4690, a novel specific inhibitor for plasminogen activator inhibitor-1, reduces allergic airway remodeling in a mouse model of chronic asthma via regulating angiogenesis and remodeling-related mediators.

    PubMed

    Tezuka, Toshifumi; Ogawa, Hirohisa; Azuma, Masahiko; Goto, Hisatsugu; Uehara, Hisanori; Aono, Yoshinori; Hanibuchi, Masaki; Yamaguchi, Yoichi; Fujikawa, Tomoyuki; Itai, Akiko; Nishioka, Yasuhiko

    2015-01-01

    Plasminogen activator inhibitor (PAI)-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen, Dermatophagoides pteronyssinus (Dp). IMD-4690 was intraperitoneally administered during the challenge. Lung histopathology, hyperresponsiveness and the concentrations of mediators in lung homogenates were analyzed. The amount of active PAI-1 in the lungs was increased in mice treated with Dp. Administration with IMD-4690 reduced an active/total PAI-1 ratio. IMD-4690 also reduced the number of bronchial eosinophils in accordance with the decreased expressions of Th2 cytokines in the lung homogenates. Airway remodeling was inhibited by reducing subepithelial collagen deposition, smooth muscle hypertrophy, and angiogenesis. The effects of IMD-4690 were partly mediated by the regulation of TGF-β, HGF and matrix metalloproteinase. These results suggest that PAI-1 plays crucial roles in airway inflammation and remodeling, and IMD-4690, a specific PAI-1 inhibitor, may have therapeutic potential for patients with refractory asthma due to airway remodeling. PMID:25785861

  12. Defining Single Molecular Forces Required for Notch Activation Using Nano Yoyo.

    PubMed

    Chowdhury, Farhan; Li, Isaac T S; Ngo, Thuy T M; Leslie, Benjamin J; Kim, Byoung Choul; Sokoloski, Joshua E; Weiland, Elizabeth; Wang, Xuefeng; Chemla, Yann R; Lohman, Timothy M; Ha, Taekjip

    2016-06-01

    Notch signaling, involved in development and tissue homeostasis, is activated at the cell-cell interface through ligand-receptor interactions. Previous studies have implicated mechanical forces in the activation of Notch receptor upon binding to its ligand. Here we aimed to determine the single molecular force required for Notch activation by developing a novel low tension gauge tether (LTGT). LTGT utilizes the low unbinding force between single-stranded DNA (ssDNA) and Escherichia coli ssDNA binding protein (SSB) (∼4 pN dissociation force at 500 nm/s pulling rate). The ssDNA wraps around SSB and, upon application of force, unspools from SSB, much like the unspooling of a yoyo. One end of this nano yoyo is attached to the surface though SSB, while the other end presents a ligand. A Notch receptor, upon binding to its ligand, is believed to undergo force-induced conformational changes required for activating downstream signaling. If the required force for such activation is larger than 4 pN, ssDNA will unspool from SSB, and downstream signaling will not be activated. Using these LTGTs, in combination with the previously reported TGTs that rupture double-stranded DNA at defined forces, we demonstrate that Notch activation requires forces between 4 and 12 pN, assuming an in vivo loading rate of 60 pN/s. Taken together, our study provides a direct link between single-molecular forces and Notch activation. PMID:27167603

  13. Antimycobacterial activity of chemically defined natural substances from the Caribbean flora in Guadeloupe.

    PubMed

    Rastogi, N; Abaul, J; Goh, K S; Devallois, A; Philogène, E; Bourgeois, P

    1998-04-01

    Eight chemically defined, naturally occurring compounds were extracted from the tropical flora of the Caribbean island of Guadeloupe: pilocarpine, an alkaloid from Pilocarpus racemosus; heraclenol and isomeranzin, coumarins from Triphasia trifolia; lochnerin, an indole alkaloid from Rauwolfia biauriculata; ibogaine and voacangine, indole alkaloids from Tabernaemontana citrifolia; texalin, an oxazole from Amyris elemifera; and canellal, a sesquiterpene dialdehyde from Canella winterana. An essential oil fraction from Canella winterana was also tested. The antimycobacterial activity of these substances was tested against Mycobacterium tuberculosis, M. avium and M. kansasii using the Middlebrook 7H11 agar medium, the Bactec 460-TB radiometric methodology, and determination of bacterial viable counts. Three compounds, namely ibogaine, voacangine and texalin, showed antimycobacterial activity. Investigations on the structure-modification and structure-activity relationships of these compounds may help determine new targets for future drug development. PMID:9626931

  14. CXCR4 Activation Defines a New Subgroup of Sonic Hedgehog–Driven Medulloblastoma

    PubMed Central

    Sengupta, Rajarshi; Dubuc, Adrian; Ward, Stacey; Yang, Lihua; Northcott, Paul; Woerner, B. Mark; Kroll, Kirsten; Luo, Jingqin; Taylor, Michael D.; Wechsler-Reya, Robert J.; Rubin, Joshua B.

    2012-01-01

    Medulloblastoma prognosis tends to be poor, despite aggressive therapy, but defining molecular subgroups may identify patients who could benefit from targeted therapies. This study used human gene array and associated clinical data to identify a new molecular subgroup of medulloblastoma characterized by coactivation of the Sonic hedgehog (SHH) and CXCR4 pathways. SHH–CXCR4 tumors were more common in the youngest patients where they were associated with desmoplastic histology. In contrast to tumors activating SHH but not CXCR4, coactivated tumors exhibited greater expression of Math1 and cyclin D1. Treatment with the CXCR4 antagonist AMD3100 inhibited cyclin D1 expression and maximal tumor growth in vivo. Mechanistic investigations revealed that SHH activation stimulated CXCR4 cell surface localization and effector signaling activity, whereas SHH absence caused CXCR4 to assume an intracellular localization. Taken together, our findings define a new medulloblastoma subgroup characterized by a functional interaction between the SHH and CXCR4 pathways, and they provide a rationale to clinically evaluate combined inhibition of SHH and CXCR4 for medulloblastoma treatment. PMID:22052462

  15. HLA-A3 supermotif defined by quantitative structure-activity relationship analysis.

    PubMed

    Guan, Pingping; Doytchinova, Irini A; Flower, Darren R

    2003-01-01

    Activation of a cytotoxic T cell requires specific binding of antigenic peptides to major histocompatibility complex (MHC) molecules. This paper reports a study of peptides binding to members of the HLA-A3 superfamily using a recently developed 2D-QSAR method, called the additive method. Four alleles with high phenotype frequency were included in the study: A*0301, A*1101, A*3101 and A*6801. The influence of each of the 20 amino acids at each position of the peptide on binding was studied. A refined A3 supertype motif was defined in the study. PMID:12646688

  16. Essential requirement of cytochrome c release for caspase activation by procaspase-activating compound defined by cellular models

    PubMed Central

    Seervi, M; Joseph, J; Sobhan, P K; Bhavya, B C; Santhoshkumar, T R

    2011-01-01

    Mitochondrial cytochrome c (cyt. c) release and caspase activation are often impaired in tumors with Bcl-2 overexpression or Bax and Bak-defective status. Direct triggering of cell death downstream of Bax and Bak is an attractive strategy to kill such cancers. Small molecule compounds capable of direct caspase activation appear to be the best mode for killing such tumors. However, there is no precise model to screen such compounds. The currently employed cell-free systems possess the inherent drawback of lacking cellular contents and organelles that operate in integrating cell death signaling. We have developed highly refined cell-based approaches to validate direct caspase activation in cancer cells. Using this approach, we show that PAC-1 (first procaspase-activating compound), the first direct activator of procaspases identified in a cell-free system, in fact requires mitochondrial cyt. c release for triggering caspase activation similar to other antitumor agents. It can induce significant caspase activation and cell death in the absence of Bax and Bak, and in cells overexpressing Bcl-2 and Bcl-xL. This study for the first time defines precise criteria for the validation of direct caspase-activating compounds using specialized cellular models that is expected to accelerate the discovery of potential direct caspase activators. PMID:21900958

  17. Sequencing formally defined reactions for robotic activity: integrating RAPS and GAPPS

    NASA Astrophysics Data System (ADS)

    Slack, Marc G.

    1992-11-01

    Construction of robots which operate in unstructured environments has of late produced a number of approaches for transforming sensor readings into activity in the world. Most of these approaches provide no formal semantics for discussing the way in which the internal state of the robot maps to the desired state of the world. We have been investigating the use of the GAPPS programming language as a mechanism for defining robotic reactions. This work has resulted in the creation of reactive modules which mediate between discrete statements about world states to achieve or maintain and the required continuous activity. While relatively complex goals have been achieved with this approach, the syntax and semantics of the GAPPS language is inappropriate for complicated dynamically changing goals. As a result, we have begun investigating the use of Reactive Action Packages (RAPs) as a mechanism for sequencing the activation of GAPPS-based reactive skills. The motivation for using RAPs is twofold. First, the syntax and semantics of the RAPs language integrates smoothly with a traditional non-linear planning system, allowing the construction and execution of plans for increasingly complex tasks. Second, GAPPS-based reactions fulfill a missing component of a RAPs-based controller system, namely the transformation of discrete RAP primitives (e.g., (maintain grasp ?thing)) into continuous physical activity. This paper presents the approach we are taking and discusses some of the issues involved in integrating these two systems.

  18. The retrieval of self-defining memories is associated with the activation of specific working selves.

    PubMed

    Çili, Soljana; Stopa, Lusia

    2015-01-01

    This article presents two studies that investigated the impact of the retrieval of self-defining memories on individuals' sense of self. Participants recalled positive and/or negative self-defining memories, rated memory characteristics and completed measures focusing on different self-aspects. Study 1 found that participants reported higher state self-esteem after recalling a positive memory than after recalling a negative one. They also reported lower negative self-consistency and higher state self-concept clarity and positive self-consistency, but this result became non-significant after controlling for state self-esteem. Study 2 found that participants reported higher state self-esteem, a marginally higher proportion of recreation/exploration, goals and a marginally lower proportion of achievement goals after recalling a positive memory than after recalling a negative one. They also reported a higher proportion of self-cognitions referring to emotional states after recalling memories from which they had not abstracted meaning than after recalling memories from which they had done this. These findings suggest that the retrieval of vivid, emotional and highly self-relevant memories may be accompanied by the activation of specific self-representations or working selves. They also suggest that the experience of memory-related intrusive images may temporarily influence individuals' sense of self. The implications of these findings for clinical practice are discussed. PMID:24528183

  19. The Race against Protease Activation Defines the Role of ESCRTs in HIV Budding

    PubMed Central

    Bendjennat, Mourad; Saffarian, Saveez

    2016-01-01

    HIV virions assemble on the plasma membrane and bud out of infected cells using interactions with endosomal sorting complexes required for transport (ESCRTs). HIV protease activation is essential for maturation and infectivity of progeny virions, however, the precise timing of protease activation and its relationship to budding has not been well defined. We show that compromised interactions with ESCRTs result in delayed budding of virions from host cells. Specifically, we show that Gag mutants with compromised interactions with ALIX and Tsg101, two early ESCRT factors, have an average budding delay of ~75 minutes and ~10 hours, respectively. Virions with inactive proteases incorporated the full Gag-Pol and had ~60 minutes delay in budding. We demonstrate that during budding delay, activated proteases release critical HIV enzymes back to host cytosol leading to production of non-infectious progeny virions. To explain the molecular mechanism of the observed budding delay, we modulated the Pol size artificially and show that virion release delays are size-dependent and also show size-dependency in requirements for Tsg101 and ALIX. We highlight the sensitivity of HIV to budding “on-time” and suggest that budding delay is a potent mechanism for inhibition of infectious retroviral release. PMID:27280284

  20. De novo DNA demethylation and noncoding transcription define active intergenic regulatory elements.

    PubMed

    Schlesinger, Felix; Smith, Andrew D; Gingeras, Thomas R; Hannon, Gregory J; Hodges, Emily

    2013-10-01

    Deep sequencing of mammalian DNA methylomes has uncovered a previously unpredicted number of discrete hypomethylated regions in intergenic space (iHMRs). Here, we combined whole-genome bisulfite sequencing data with extensive gene expression and chromatin-state data to define functional classes of iHMRs, and to reconstruct the dynamics of their establishment in a developmental setting. Comparing HMR profiles in embryonic stem and primary blood cells, we show that iHMRs mark an exclusive subset of active DNase hypersensitive sites (DHS), and that both developmentally constitutive and cell-type-specific iHMRs display chromatin states typical of distinct regulatory elements. We also observe that iHMR changes are more predictive of nearby gene activity than the promoter HMR itself, and that expression of noncoding RNAs within the iHMR accompanies full activation and complete demethylation of mature B cell enhancers. Conserved sequence features corresponding to iHMR transcript start sites, including a discernible TATA motif, suggest a conserved, functional role for transcription in these regions. Similarly, we explored both primate-specific and human population variation at iHMRs, finding that while enhancer iHMRs are more variable in sequence and methylation status than any other functional class, conservation of the TATA box is highly predictive of iHMR maintenance, reflecting the impact of sequence plasticity and transcriptional signals on iHMR establishment. Overall, our analysis allowed us to construct a three-step timeline in which (1) intergenic DHS are pre-established in the stem cell, (2) partial demethylation of blood-specific intergenic DHSs occurs in blood progenitors, and (3) complete iHMR formation and transcription coincide with enhancer activation in lymphoid-specified cells. PMID:23811145

  1. Contact activation of blood coagulation on a defined kaolin/collagen surface in a microfluidic assay

    PubMed Central

    Zhu, Shu; Diamond, Scott L.

    2014-01-01

    Generation of active Factor XII (FXIIa) triggers blood clotting on artificial surfaces and may also enhance intravascular thrombosis. We developed a patterned kaolin (0 to 0.3 pg/μm2)/type 1 collagen fibril surface for controlled microfluidic clotting assays. Perfusion of whole blood (treated only with a low level of 4 μg/mL of the XIIa inhibitor, corn trypsin inhibitor) drove platelet deposition followed by fibrin formation. At venous wall shear rate (100 s−1), kaolin accelerated onset of fibrin formation by ~100 sec when compared to collagen alone (250 sec vs. 350 sec), with little effect on platelet deposition. Even with kaolin present, arterial wall shear rate (1000 s−1) delayed and suppressed fibrin formation compared to venous wall shear rate. A comparison of surfaces for extrinsic activation (tissue factor TF/collagen) versus contact activation (kaolin/collagen) that each generated equal platelet deposition at 100 s−1 revealed: (1) TF surfaces promoted much faster fibrin onset (at 100 sec) and more endpoint fibrin at 600 sec at either 100 s−1 or 1000 s−1, and (2) kaolin and TF surfaces had a similar sensitivity for reduced fibrin deposition at 1000 s−1 (compared to fibrin formed at 100 s−1) despite differing coagulation triggers. Anti-platelet drugs inhibiting P2Y1, P2Y12, cyclooxygenase-1 or activating IP-receptor or guanylate cyclase reduced platelet and fibrin deposition on kaolin/collagen. Since FXIIa or FXIa inhibition may offer safe antithrombotic therapy, especially for biomaterial thrombosis, these defined collagen/kaolin surfaces may prove useful in drug screening tests or in clinical diagnostic assays of blood under flow conditions. PMID:25303860

  2. De novo DNA demethylation and noncoding transcription define active intergenic regulatory elements

    PubMed Central

    Schlesinger, Felix; Smith, Andrew D.; Gingeras, Thomas R.; Hannon, Gregory J.; Hodges, Emily

    2013-01-01

    Deep sequencing of mammalian DNA methylomes has uncovered a previously unpredicted number of discrete hypomethylated regions in intergenic space (iHMRs). Here, we combined whole-genome bisulfite sequencing data with extensive gene expression and chromatin-state data to define functional classes of iHMRs, and to reconstruct the dynamics of their establishment in a developmental setting. Comparing HMR profiles in embryonic stem and primary blood cells, we show that iHMRs mark an exclusive subset of active DNase hypersensitive sites (DHS), and that both developmentally constitutive and cell-type-specific iHMRs display chromatin states typical of distinct regulatory elements. We also observe that iHMR changes are more predictive of nearby gene activity than the promoter HMR itself, and that expression of noncoding RNAs within the iHMR accompanies full activation and complete demethylation of mature B cell enhancers. Conserved sequence features corresponding to iHMR transcript start sites, including a discernible TATA motif, suggest a conserved, functional role for transcription in these regions. Similarly, we explored both primate-specific and human population variation at iHMRs, finding that while enhancer iHMRs are more variable in sequence and methylation status than any other functional class, conservation of the TATA box is highly predictive of iHMR maintenance, reflecting the impact of sequence plasticity and transcriptional signals on iHMR establishment. Overall, our analysis allowed us to construct a three-step timeline in which (1) intergenic DHS are pre-established in the stem cell, (2) partial demethylation of blood-specific intergenic DHSs occurs in blood progenitors, and (3) complete iHMR formation and transcription coincide with enhancer activation in lymphoid-specified cells. PMID:23811145

  3. Degradation of estradiol and ethinyl estradiol by activated sludge and by a defined mixed culture.

    PubMed

    Weber, Stefanie; Leuschner, Prisca; Kämpfer, Peter; Dott, Wolfgang; Hollender, Juliane

    2005-04-01

    The aerobic degradation of the natural hormone 17-beta-estradiol (E2) and the synthetic hormone 17-alpha-ethinyl estradiol (EE2) was investigated in batch experiments with activated sludge from a conventional and a membrane sewage treatment plant. E2 was converted to estrone (E1), the well known metabolite, and further completely transformed within 3 days. The turnover rates of E2 did not differ greatly between conventional and membrane activated sludge. EE2 was persistent in both sludges. By several transfers into fresh E2-medium an enrichment culture could be selected that used E2 as growth substrate. Further enrichment and isolation led to a defined mixed culture consisting of two strains, which were identified by a polyphasic approach as Achromobacter xylosoxidans and Ralstonia sp., respectively. The culture used E2 and E1 as growth substrates and transformed estriol (E3) and 16-alpha-hydroxyestrone but not the xenoestrogens bisphenol A, alpha-zearalenol, mestranol or EE2. The turnover rates of E2 were 0.025-0.1 microg h(-1) cfu(-1) and did not depend on the steroid concentration. PMID:15290133

  4. Measurement of membrane-bound human heme oxygenase-1 activity using a chemically defined assay system.

    PubMed

    Huber, Warren J; Marohnic, Christopher C; Peters, Michelle; Alam, Jawed; Reed, James R; Masters, Bettie Sue Siler; Backes, Wayne L

    2009-04-01

    Heme oxygenase (HO) catalyzes heme degradation in a reaction requiring NADPH-cytochrome P450 reductase (CPR). Although most studies with HO used a soluble 30-kDa form, lacking the C-terminal membrane-binding region, recent reports show that the catalytic behavior of this enzyme is very different if this domain is retained; the overall activity was elevated 5-fold, and the K(m) for CPR decreased approximately 50-fold. The goal of these studies was to accurately measure HO activity using a coupled assay containing purified biliverdin reductase (BVR). This allows measurement of bilirubin formation after incorporation of full-length CPR and heme oxygenase-1 (HO-1) into a membrane environment. When rat liver cytosol was used as the source of partially purified BVR, the reaction remained linear for 2 to 3 min; however, the reaction was only linear for 10 to 30 s when an equivalent amount of purified, human BVR (hBVR) was used. This lack of linearity was not observed with soluble HO-1. Optimal formation of bilirubin was achieved with concentrations of bovine serum albumin (0.25 mg/ml) and hBVR (0.025-0.05 microM), but neither supplement increased the time that the reaction remained linear. Various concentrations of superoxide dismutase had no effect on the reaction; however, when catalase was included, the reactions were linear for at least 4 to 5 min, even at high CPR levels. These results not only show that HO-1-generated hydrogen peroxide leads to a decrease in HO-1 activity but also provide for a chemically defined system to be used to examine the function of full-length HO-1 in a membrane environment. PMID:19131520

  5. 12 CFR 218.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... limitation, a fee paid— (A) For personal services, tax preparation, or real estate settlement services; (B... DEFINITION OF BROKER IN THE SECURITIES EXCHANGE ACT OF 1934 (REGULATION R) § 218.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.” (a) Defined...

  6. 12 CFR 218.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... limitation, a fee paid— (A) For personal services, tax preparation, or real estate settlement services; (B... DEFINITION OF BROKER IN THE SECURITIES EXCHANGE ACT OF 1934 (REGULATION R) § 218.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.” (a) Defined...

  7. 12 CFR 218.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... limitation, a fee paid— (A) For personal services, tax preparation, or real estate settlement services; (B... DEFINITION OF BROKER IN THE SECURITIES EXCHANGE ACT OF 1934 (REGULATION R) § 218.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.” (a) Defined...

  8. Non-native ligands define the active site of Pennisetum glaucum (L.) R. Br dehydroascorbate reductase.

    PubMed

    Krishna Das, Bhaba; Kumar, Amit; Maindola, Priyank; Mahanty, Srikrishna; Jain, S K; Reddy, Mallireddy K; Arockiasamy, Arulandu

    2016-05-13

    Dehydroascorbate reductase (DHAR), a member of the glutathione-S-transferase (GST) family, reduces dehydroascorbate (DHA) to ascorbate (AsA; Vitamin-C) in a glutathione (GSH)-dependent manner and in doing so, replenishes the critical AsA pool of the cell. To understand the enzyme mechanism in detail, we determined the crystal structure of a plant DHAR from Pennisetum glaucum (PgDHAR) using Iodide-Single Anomalous Dispersion (SAD) and Molecular replacement methods, in two different space groups. Here, we show PgDHAR in complex with two non-native ligands, viz. an acetate bound at the G-site, which resembles the γ-carboxyl moiety of GSH, and a glycerol at the H-site, which shares the backbone of AsA. We also show that, in the absence of bound native substrates, these non-native ligands help define the critical 'hook points' in the DHAR enzyme active site. Further, our data suggest that these non-native ligands can act as the logical bootstrapping points for iterative design of inhibitors/analogs for DHARs. PMID:27067046

  9. From molecular signal activation to locomotion: an integrated, multiscale analysis of cell motility on defined matrices.

    PubMed

    Pathak, Amit; Kumar, Sanjay

    2011-01-01

    The adhesion, mechanics, and motility of eukaryotic cells are highly sensitive to the ligand density and stiffness of the extracellular matrix (ECM). This relationship bears profound implications for stem cell engineering, tumor invasion and metastasis. Yet, our quantitative understanding of how ECM biophysical properties, mechanotransductive signals, and assembly of contractile and adhesive structures collude to control these cell behaviors remains extremely limited. Here we present a novel multiscale model of cell migration on ECMs of defined biophysical properties that integrates local activation of biochemical signals with adhesion and force generation at the cell-ECM interface. We capture the mechanosensitivity of individual cellular components by dynamically coupling ECM properties to the activation of Rho and Rac GTPases in specific portions of the cell with actomyosin contractility, cell-ECM adhesion bond formation and rupture, and process extension and retraction. We show that our framework is capable of recreating key experimentally-observed features of the relationship between cell migration and ECM biophysical properties. In particular, our model predicts for the first time recently reported transitions from filopodial to "stick-slip" to gliding motility on ECMs of increasing stiffness, previously observed dependences of migration speed on ECM stiffness and ligand density, and high-resolution measurements of mechanosensitive protrusion dynamics during cell motility we newly obtained for this study. It also relates the biphasic dependence of cell migration speed on ECM stiffness to the tendency of the cell to polarize. By enabling the investigation of experimentally-inaccessible microscale relationships between mechanotransductive signaling, adhesion, and motility, our model offers new insight into how these factors interact with one another to produce complex migration patterns across a variety of ECM conditions. PMID:21483802

  10. A Cautionary Tale About Conducting Research on Abstinence Education: How Do State Abstinence Coordinators Define "Sexual Activity?"

    ERIC Educational Resources Information Center

    Bailey, William; Young, Michael; Knickerbocker, Cliff; Doan, Tam

    2002-01-01

    Investigated how state coordinators of abstinence education programs defined "sexual activity." Researchers surveyed Title V abstinence education coordinators from the 50 states, the District of Columbia, and three territories. Of the 17 coordinators providing at least partial responses, none reported having a definition of sexual activity. The…

  11. Defining cure.

    PubMed

    Hilton, Paul; Robinson, Dudley

    2011-06-01

    This paper is a summary of the presentations made as Proposal 2-"Defining cure" to the 2nd Annual meeting of the ICI-Research Society, in Bristol, 16th June 2010. It reviews definitions of 'cure' and 'outcome', and considers the impact that varying definition may have on prevalence studies and cure rates. The difference between subjective and objective outcomes is considered, and the significance that these different outcomes may have for different stakeholders (e.g. clinicians, patients, carers, industry etc.) is discussed. The development of patient reported outcome measures and patient defined goals is reviewed, and consideration given to the use of composite end-points. A series of proposals are made by authors and discussants as to how currently validated outcomes should be applied, and where our future research activity in this area might be directed. PMID:21661023

  12. 17 CFR 247.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., including, without limitation, a fee paid— (A) For personal services, tax preparation, or real estate... AND DEFINITIONS RELATED TO THE EXCEPTIONS FOR BANKS FROM THE DEFINITION OF BROKER § 247.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.”...

  13. 17 CFR 247.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., including, without limitation, a fee paid— (A) For personal services, tax preparation, or real estate... AND DEFINITIONS RELATED TO THE EXCEPTIONS FOR BANKS FROM THE DEFINITION OF BROKER § 247.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.”...

  14. 17 CFR 247.721 - Defined terms relating to the trust and fiduciary activities exception from the definition of...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., including, without limitation, a fee paid— (A) For personal services, tax preparation, or real estate... AND DEFINITIONS RELATED TO THE EXCEPTIONS FOR BANKS FROM THE DEFINITION OF BROKER § 247.721 Defined terms relating to the trust and fiduciary activities exception from the definition of “broker.”...

  15. Progress in defining clinically meaningful changes for clinical trials in nonrenal manifestations of SLE disease activity.

    PubMed

    Choi, Chan-Bum; Liang, Matthew H; Bae, Sang-Cheol

    2016-01-01

    Since the 2002 Dusseldorf meeting, one new agent, Benlysta, has been approved by the US Food and Drug Administration for systemic lupus erythematosus. Experiences from the field in conducting trials of all the agents tested during this period have provided valuable practical insights. There has been incremental progress in defining the minimal clinically important difference (MCID) of key disease manifestations and the view is largely that of the health care providers and not that of the person suffering the disease. This basic methodological work on the MCID should improve the efficiency and the clinical relevance of future trials and their design. PMID:26732314

  16. Systematic Survey of Serine Hydrolase Activity in Mycobacterium tuberculosis Defines Changes Associated with Persistence.

    PubMed

    Ortega, Corrie; Anderson, Lindsey N; Frando, Andrew; Sadler, Natalie C; Brown, Robert W; Smith, Richard D; Wright, Aaron T; Grundner, Christoph

    2016-02-18

    The transition from replication to non-replication underlies much of Mycobacterium tuberculosis (Mtb) pathogenesis, as non- or slowly replicating Mtb are responsible for persistence and poor treatment outcomes. Therapeutic targeting of non-replicating populations is a priority for tuberculosis treatment, but few drug targets in non-replicating Mtb are currently known. Here, we directly measured the activity of the highly diverse and druggable serine hydrolases (SHs) during active replication and non-replication using activity-based proteomics. We predict SH activity for 78 proteins, including 27 proteins with unknown function, and identify 37 SHs that remain active in the absence of replication, providing a set of candidate persistence targets. Non-replication was associated with major shifts in SH activity. These activity changes were largely independent of SH abundance, indicating extensive post-translational regulation of SHs. By probing a large cross-section of druggable Mtb enzyme space during replication and non-replication, we identify new SHs and suggest new persistence targets. PMID:26853625

  17. Defining feasible bounds on muscle activation in a redundant biomechanical task; practical implications of redundancy

    PubMed Central

    Sohn, M. Hongchul; McKay, J. Lucas; Ting, Lena H.

    2013-01-01

    Measured muscle activation patterns often vary significantly from musculoskeletal model predictions that use optimization to resolve redundancy. Although experimental muscle activity exhibits both inter- and intra-subject variability we lack adequate tools to quantify the biomechanical latitude that the nervous system has when selecting muscle activation patterns. Here, we identified feasible ranges of individual muscle activity during force production in a musculoskeletal model to quantify the degree to which biomechanical redundancy allows for variability in muscle activation patterns. In a detailed cat hindlimb model matched to the posture of three cats, we identified the lower and upper bounds on muscle activity in each of 31 muscles during static endpoint force production across different force directions and magnitudes. Feasible ranges of muscle activation were relatively unconstrained across force magnitudes such that only a few (0∼13%) muscles were found to be truly “necessary” (e.g. exhibited non-zero lower bounds) at physiological force ranges. Most muscles were “optional” having zero lower bounds, and frequently had “maximal” upper bounds as well. Moreover, “optional” muscles were never selected by optimization methods that either minimized muscle stress, or that scaled the pattern required for maximum force generation. Therefore, biomechanical constraints were generally insufficient to restrict or specify muscle activation levels for producing a force in a given direction, and many muscle patterns exist that could deviate substantially from one another but still achieve the task. Our approach could be extended to identify the feasible limits of variability in muscle activation patterns in dynamic tasks such as walking. PMID:23489436

  18. Directed Endothelial Progenitor Differentiation from Human Pluripotent Stem Cells Via Wnt Activation Under Defined Conditions.

    PubMed

    Bao, Xiaoping; Lian, Xiaojun; Palecek, Sean P

    2016-01-01

    Efficient derivation of endothelial cells and their progenitors from human pluripotent stem cells (hPSCs) can facilitate studies of human vascular development, disease modeling, drug discovery, and cell-based therapy. Here we provide a detailed protocol for directing hPSCs to functional endothelial cells and their progenitors in a completely defined, growth factor- and serum-free system by temporal modulation of Wnt/β-catenin signaling via small molecules. We demonstrate a 10-day, two-stage process that recapitulates endothelial cell development, in which hPSCs first differentiate to endothelial progenitors that then generate functional endothelial cells and smooth muscle cells. Methods to characterize endothelial cell identity and function are also described. PMID:27590162

  19. Spontaneous cortical activity alternates between motifs defined by regional axonal projections.

    PubMed

    Mohajerani, Majid H; Chan, Allen W; Mohsenvand, Mostafa; LeDue, Jeffrey; Liu, Rui; McVea, David A; Boyd, Jamie D; Wang, Yu Tian; Reimers, Mark; Murphy, Timothy H

    2013-10-01

    Using millisecond-timescale voltage-sensitive dye imaging in lightly anesthetized or awake adult mice, we show that a palette of sensory-evoked and hemisphere-wide activity motifs are represented in spontaneous activity. These motifs can reflect multiple modes of sensory processing, including vision, audition and touch. We found similar cortical networks with direct cortical activation using channelrhodopsin-2. Regional analysis of activity spread indicated modality-specific sources, such as primary sensory areas, a common posterior-medial cortical sink where sensory activity was extinguished within the parietal association area and a secondary anterior medial sink within the cingulate and secondary motor cortices for visual stimuli. Correlation analysis between functional circuits and intracortical axonal projections indicated a common framework corresponding to long-range monosynaptic connections between cortical regions. Maps of intracortical monosynaptic structural connections predicted hemisphere-wide patterns of spontaneous and sensory-evoked depolarization. We suggest that an intracortical monosynaptic connectome shapes the ebb and flow of spontaneous cortical activity. PMID:23974708

  20. Spontaneous cortical activity alternates between motifs defined by regional axonal projections

    PubMed Central

    Mohajerani, Majid H.; Chan, Allen W.; Mohsenvand, Mostafa; LeDue, Jeffrey; Liu, Rui; McVea, David A.; Boyd, Jamie D.; Wang, Yu Tian; Reimers, Mark; Murphy, Timothy H.

    2014-01-01

    In lightly anaesthetized or awake adult mice using millisecond timescale voltage sensitive dye imaging, we show that a palette of sensory-evoked and hemisphere-wide activity motifs are represented in spontaneous activity. These motifs can reflect multiple modes of sensory processing including vision, audition, and touch. Similar cortical networks were found with direct cortical activation using channelrhodopsin-2. Regional analysis of activity spread indicated modality specific sources such as primary sensory areas, and a common posterior-medial cortical sink where sensory activity was extinguished within the parietal association area, and a secondary anterior medial sink within the cingulate/secondary motor cortices for visual stimuli. Correlation analysis between functional circuits and intracortical axonal projections indicated a common framework corresponding to long-range mono-synaptic connections between cortical regions. Maps of intracortical mono-synaptic structural connections predicted hemisphere-wide patterns of spontaneous and sensory-evoked depolarization. We suggest that an intracortical monosynaptic connectome shapes the ebb and flow of spontaneous cortical activity. PMID:23974708

  1. Defining How a Microbial Cell Senses and Responds to a Redox Active Environment

    SciTech Connect

    Kenneth H. Nealson

    2012-06-22

    This grant was for four years, and the work was designed to look at the mechanisms of extracellular electron transfer by the dissimilatory iron reducing bacteria Shewanella oneidensis MR-1, and other closely related Shewanella strains and species. During this work, we defined many of the basic physiological and biochemical properties of the Shewanella group, Much of which was summarized in review articles. We also finished and published the genome sequence of strain MR-1, the first of the shewanellae to have its genome sequenced. Control at the transcriptional and translational level was studied in collaboration with colleagues at PNNL and ANL. We utilized synchrotron X-ray radiation to image both the bacteria and the metal oxide particles via a technique called STXM, synchrotron X-ray absorption (ref. No.9), and X-ray microbeam analysis. We purified several of the cytochromes involved with metal reduction, and improved gene annotation of the MR-1 genome. The conductive appendages (nanowires) of MR-1 were described and characterized. Comparative genomics and biochemistry revealed that the pathway for the utilization of N-acetyl glucosamine in the various strains of Shewanella exhibited great variability, and had a number of previously unknown genes.

  2. Defining Active and Reasonable Efforts: Reasonable Efforts to Prevent Placement and Preserve Families.

    ERIC Educational Resources Information Center

    Hunner, Robert J.

    1986-01-01

    Describes development of guidelines to expand understanding of and compliance with both the reasonable efforts requirement of the Adoption Assistance and Child Welfare Act 1980 (P.L. 96-272) and active efforts requirement of the Indian Child Welfare Act 1978 (P.L. 95-608) to help keep Indian families together. (Author/BB)

  3. 26 CFR 1.183-2 - Activity not engaged in for profit defined.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... activities which constitute a trade or business of the taxpayer and under section 212 for expenses incurred... accepted business, economic, and scientific practices, or consultation with those who are expert therein... status such continued losses, if not explainable, as due to customary business risks or reverses, may...

  4. 26 CFR 1.183-2 - Activity not engaged in for profit defined.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... activities which constitute a trade or business of the taxpayer and under section 212 for expenses incurred... accepted business, economic, and scientific practices, or consultation with those who are expert therein... status such continued losses, if not explainable, as due to customary business risks or reverses, may...

  5. 26 CFR 1.183-2 - Activity not engaged in for profit defined.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... activities which constitute a trade or business of the taxpayer and under section 212 for expenses incurred... accepted business, economic, and scientific practices, or consultation with those who are expert therein... status such continued losses, if not explainable, as due to customary business risks or reverses, may...

  6. 26 CFR 1.183-2 - Activity not engaged in for profit defined.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... activities which constitute a trade or business of the taxpayer and under section 212 for expenses incurred... accepted business, economic, and scientific practices, or consultation with those who are expert therein... status such continued losses, if not explainable, as due to customary business risks or reverses, may...

  7. Histone modifications defining active genes persist after transcriptional and mitotic inactivation.

    PubMed

    Kouskouti, Antigone; Talianidis, Iannis

    2005-01-26

    We examined various histone modifications across the promoter and the coding regions of constitutively active hepatic genes in G0/G1-enriched, mitotically arrested and alpha-amanitin-blocked cells. Gene activation correlated with localized histone hyperacetylation, H3-K4 tri- or dimethylation and H3-K79 dimethylation and localized nucleosome remodeling at the promoter and the 5' portion of the coding regions. Nucleosomes at more downstream locations were monomethylated at H3-K4. CBP, PCAF, Brg-1, SNF2H and FACT were recruited to the coding regions in a gene-specific manner, in a similarly restricted promoter-proximal pattern. Elongator, however, associated with the more downstream regions. While all factors were dissociated from the chromatin after transcriptional inactivation by alpha-amanitin, the histone modifications remained stable. In mitotic cells, histone modifications on parental nucleosomes were preserved and were regenerated in a transcription-dependent manner at the newly deposited nucleosomes, as the cells entered the next G1 phase. The findings suggest that histone modifications may function as molecular memory bookmarks for previously active locations of the genome, thus contributing to the maintenance of active chromatin states through cell division. PMID:15616580

  8. Dynamic Protein Associations Define Two Phases of IL-1β Transcriptional Activation

    PubMed Central

    Zhang, Yue; Saccani, Simona; Shin, Hyunjin; Nikolajczyk, Barbara S.

    2010-01-01

    IL-1β is a key proinflammatory cytokine with roles in multiple diseases. Monocytes package the IL-1β promoter into a “poised architecture” characterized by a histone-free transcription start site and constitutive transcription factor associations. Upon LPS stimulation, multiple proteins inducibly associate with the IL-1β gene. To understand how the complex combination of constitutive and inducible transcription factors activate the IL-1β gene from a poised structure, we measured temporal changes in NF-κB and IFN regulatory factor (IRF) association with IL-1β regulatory elements. Association of the p65 subunit of NF-κB peaks 30–60 min post-monocyte stimulation, and it shortly precedes IRF-4 recruitment to the IL-1β enhancer and maximal mRNA production. In contrast, IRF-8/enhancer association decreases poststimulation. To test the importance of delayed IRF-4/enhancer association, we introduced a mutated PU.1 protein shown to prevent PU.1-mediated IRF-4 recruitment to the enhancer sequence. Mutated PU.1 initially increased IL-1β mRNA followed by decreased mRNA levels 2–3 h poststimulation. Taken together, these data support a dynamic model of IL-1β transcriptional activation in which a combination of IRF-8 and p65 drives the initial phase of IL-1β transcription, while PU.1-mediated IRF-4 recruitment to the enhancer is important for the second phase. We further demonstrate that activation of both NF-κB and IRF-4 depends on CK2 kinase activity. Because IRF-4/enhancer association requires CK2 but not p65 activation, we conclude that CK2 triggers the IRF-4 and p65 pathways independently to serve as a master regulator of IL-1β transcription. PMID:18566416

  9. Structural Waters Define a Functional Channel Mediating Activation of the GPCR, rhodopsin

    SciTech Connect

    Angel, T.; Gupta, S; Jastrzebska, B; Palczewski, K; Chance, M

    2009-01-01

    Structural water molecules may act as prosthetic groups indispensable for proper protein function. In the case of allosteric activation of G protein-coupled receptors (GPCRs), water likely imparts structural plasticity required for agonist-induced signal transmission. Inspection of structures of GPCR superfamily members reveals the presence of conserved embedded water molecules likely important to GPCR function. Coupling radiolytic hydroxyl radical labeling with rapid H2O18 solvent mixing, we observed no exchange of these structural waters with bulk solvent in either ground state or for the Meta II or opsin states. However, the radiolysis approach permitted labeling of selected side chain residues within the transmembrane helices and revealed activation-induced changes in local structural constraints likely mediated by dynamics of both water and protein. These results suggest both a possible general mechanism for water-dependent communication in family A GPCRs based on structural conservation, and a strategy for probing membrane protein structure.

  10. Model development with defined biological mechanisms for xenobiotic treatment activated sludge at steady state.

    PubMed

    Chong, Nyuk-Min

    2015-06-01

    Activated sludge treatment of a xenobiotic organic compound, much different from treatment of biogenic organics, must be modeled with interactions involving a two-part biomass of degrader and nondegrader, which selectively or competitively grow on a two-part substrate of input xenobiotic and its biogenic metabolites. A xenobiotic treatment model was developed which incorporates kinetics of the growth of degrader and nondegrader, the line dividing metabolites into xenobiotic and biogenic, yields of degrader and nondegrader from utilization of their parts of substrates, and kinetics of degrader reversion to nondegrader due to instability of the degradative element degraders carry. Experimental activated sludge operated for treatment of a xenobiotic generated data for calibration of the model. With the input of influent xenobiotic concentration, mean cell and hydraulic residence times, and calibrated parameters, the model readily outputs concentrations of degrader, nondegrader, and effluent biogenic residue that closely match the results obtained from experiments. PMID:25561268

  11. 26 CFR 1.103(n)-2T - Private activity bond defined (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... in section 103(b)(4) (C) or (D) apply? A-4: Section 103(n)(7)(C) provides that the term “private... activity bond”? A-1: In general, for purposes of §§ 1.103(n)-1T through 1.103(n)-6T, the term “private... from tax under section 103(a) (without application of section 103(n)). See § 1.103-7(b) for...

  12. Dual transcriptional activities of SIX proteins define their roles in normal and ectopic eye development.

    PubMed

    Anderson, Abigail M; Weasner, Bonnie M; Weasner, Brandon P; Kumar, Justin P

    2012-03-01

    The SIX family of homeodomain-containing DNA-binding proteins play crucial roles in both Drosophila and vertebrate retinal specification. In flies, three such family members exist, but only two, Sine oculis (So) and Optix, are expressed and function within the eye. In vertebrates, the homologs of Optix (Six3 and Six6) and probably So (Six1 and Six2) are also required for proper eye formation. Depending upon the individual SIX protein and the specific developmental context, transcription of target genes can either be activated or repressed. These activities are thought to occur through physical interactions with the Eyes absent (Eya) co-activator and the Groucho (Gro) co-repressor, but the relative contribution that each complex makes to overall eye development is not well understood. Here, we attempt to address this issue by investigating the role that each complex plays in the induction of ectopic eyes in Drosophila. We fused the VP16 activation and Engrailed repressor domains to both So and Optix, and attempted to generate ectopic eyes with these chimeric proteins. Surprisingly, we find that So and Optix must initially function as transcriptional repressors to trigger the formation of ectopic eyes. Both factors appear to be required to repress the expression of non-retinal selector genes. We propose that during early phases of eye development, SIX proteins function, in part, to repress the transcription of non-retinal selector genes, thereby allowing induction of the retina to proceed. This model of repression-mediated induction of developmental programs could have implications beyond the eye and might be applicable to other systems. PMID:22318629

  13. Defining filled and empty space: reassessing the filled space illusion for active touch and vision.

    PubMed

    Collier, Elizabeth S; Lawson, Rebecca

    2016-09-01

    In the filled space illusion, an extent filled with gratings is estimated as longer than an equivalent extent that is apparently empty. However, researchers do not seem to have carefully considered the terms filled and empty when describing this illusion. Specifically, for active touch, smooth, solid surfaces have typically been used to represent empty space. Thus, it is not known whether comparing gratings to truly empty space (air) during active exploration by touch elicits the same illusionary effect. In Experiments 1 and 2, gratings were estimated as longer if they were compared to smooth, solid surfaces rather than being compared to truly empty space. Consistent with this, Experiment 3 showed that empty space was perceived as longer than solid surfaces when the two were compared directly. Together these results are consistent with the hypothesis that, for touch, the standard filled space illusion only occurs if gratings are compared to smooth, solid surfaces and that it may reverse if gratings are compared to empty space. Finally, Experiment 4 showed that gratings were estimated as longer than both solid and empty extents in vision, so the direction of the filled space illusion in vision was not affected by the nature of the comparator. These results are discussed in relation to the dual nature of active touch. PMID:27233286

  14. Changes in everyday function among individuals with psychometrically defined Mild Cognitive Impairment in the ACTIVE Study

    PubMed Central

    Wadley, Virginia G.; Crowe, Michael; Marsiske, Michael; Cook, Sarah E.; Unverzagt, Frederick W.; Rosenberg, Adrienne L.; Rexroth, Daniel

    2007-01-01

    Objectives. Because many individuals with Mild Cognitive Impairment (MCI) will progress to a dementia diagnosis, this population is at high risk for losing functional independence. We examine trajectories of change in everyday function for individuals with cognitive deficits suggestive of MCI. Design. We utilized data from the longitudinal, multi-site Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, which allowed for post-hoc classification of MCI status at baseline using psycho metric definitions for amnestic MCI, non-amnestic MCI, multi-domain MCI, and no MCI. Setting. Six U.S. cities. Participants. 2832 volunteers (mean age 74 years; 26% African American) living independently, recruited from senior housing, community centers, and hospitals and clinics. Measurements. Mixed effect models examined changes in self-reported instrumental and basic activities of daily living (IADLs and ADLs) from the MDS Home Care Interview in 2,358 participants over a three-year period. Results. In models for IADL performance, IADL difficulty, and a Daily Functioning Composite, there was a significant time by MCI classification interaction for each MCI subtype, indicating that all MCI groups showed faster rates of decline in everyday function relative to cognitively normal participants with no MCI. Conclusion. Results demonstrate the importance of MCI as a clinical entity that not only predicts progression to dementia but also predicts functional declines in activities that are key to autonomy and quality of life. MCI classification guidelines should allow for functional changes in MCI, and clinicians should monitor for such changes. Preservation of function may serve as a meaningful outcome for intervention efforts. PMID:17661957

  15. An allosteric role for receptor activity-modifying proteins in defining GPCR pharmacology

    PubMed Central

    J Gingell, Joseph; Simms, John; Barwell, James; Poyner, David R; Watkins, Harriet A; Pioszak, Augen A; Sexton, Patrick M; Hay, Debbie L

    2016-01-01

    G protein-coupled receptors are allosteric proteins that control transmission of external signals to regulate cellular response. Although agonist binding promotes canonical G protein signalling transmitted through conformational changes, G protein-coupled receptors also interact with other proteins. These include other G protein-coupled receptors, other receptors and channels, regulatory proteins and receptor-modifying proteins, notably receptor activity-modifying proteins (RAMPs). RAMPs have at least 11 G protein-coupled receptor partners, including many class B G protein-coupled receptors. Prototypic is the calcitonin receptor, with altered ligand specificity when co-expressed with RAMPs. To gain molecular insight into the consequences of this protein–protein interaction, we combined molecular modelling with mutagenesis of the calcitonin receptor extracellular domain, assessed in ligand binding and functional assays. Although some calcitonin receptor residues are universally important for peptide interactions (calcitonin, amylin and calcitonin gene-related peptide) in calcitonin receptor alone or with receptor activity-modifying protein, others have RAMP-dependent effects, whereby mutations decreased amylin/calcitonin gene-related peptide potency substantially only when RAMP was present. Remarkably, the key residues were completely conserved between calcitonin receptor and AMY receptors, and between subtypes of AMY receptor that have different ligand preferences. Mutations at the interface between calcitonin receptor and RAMP affected ligand pharmacology in a RAMP-dependent manner, suggesting that RAMP may allosterically influence the calcitonin receptor conformation. Supporting this, molecular dynamics simulations suggested that the calcitonin receptor extracellular N-terminal domain is more flexible in the presence of receptor activity-modifying protein 1. Thus, RAMPs may act in an allosteric manner to generate a spectrum of unique calcitonin receptor

  16. New rabies virus variants for monitoring and manipulating activity and gene expression in defined neural circuits

    PubMed Central

    Osakada, Fumitaka; Mori, Takuma; Cetin, Ali H.; Marshel, James H.; Virgen, Beatriz; Callaway, Edward M.

    2011-01-01

    SUMMARY Glycoprotein-deleted (ΔG) rabies virus is a powerful tool for studies of neural circuit structure. Here we describe the development and demonstrate the utility of new resources that allow experiments directly investigating relationships between the structure and function of neural circuits. New methods and reagents allowed efficient production of twelve novel ΔG rabies variants from plasmid DNA. These new rabies viruses express useful neuroscience tools, including: the Ca++ indicator GCaMP3, for monitoring activity; Channelrhodopsin-2, for photoactivation; allatostatin receptor, for inactivation by ligand application; rtTA, ERT2CreERT2, or FLPo, for control of gene expression. These new tools allow neurons targeted based on their connectivity, to have their function assayed or their activity or gene expression manipulated. Combining these tools with in vivo imaging and optogenetic methods, and/or inducible gene expression in transgenic mice, will facilitate experiments investigating neural circuit development, plasticity, and function that have not been possible with existing reagents. PMID:21867879

  17. Nuclear Pore Proteins Nup153 and Megator Define Transcriptionally Active Regions in the Drosophila Genome

    PubMed Central

    Miura, Kota; Luscombe, Nicholas M.; Akhtar, Asifa

    2010-01-01

    Transcriptional regulation is one of the most important processes for modulating gene expression. Though much of this control is attributed to transcription factors, histones, and associated enzymes, it is increasingly apparent that the spatial organization of chromosomes within the nucleus has a profound effect on transcriptional activity. Studies in yeast indicate that the nuclear pore complex might promote transcription by recruiting chromatin to the nuclear periphery. In higher eukaryotes, however, it is not known whether such regulation has global significance. Here we establish nucleoporins as a major class of global regulators for gene expression in Drosophila melanogaster. Using chromatin-immunoprecipitation combined with microarray hybridisation, we show that Nup153 and Megator (Mtor) bind to 25% of the genome in continuous domains extending 10 kb to 500 kb. These Nucleoporin-Associated Regions (NARs) are dominated by markers for active transcription, including high RNA polymerase II occupancy and histone H4K16 acetylation. RNAi–mediated knock-down of Nup153 alters the expression of ∼5,700 genes, with a pronounced down-regulatory effect within NARs. We find that nucleoporins play a central role in coordinating dosage compensation—an organism-wide process involving the doubling of expression of the male X chromosome. NARs are enriched on the male X chromosome and occupy 75% of this chromosome. Furthermore, Nup153-depletion abolishes the normal function of the male-specific dosage compensation complex. Finally, by extensive 3D imaging, we demonstrate that NARs contribute to gene expression control irrespective of their sub-nuclear localization. Therefore, we suggest that NAR–binding is used for chromosomal organization that enables gene expression control. PMID:20174442

  18. Integrated Interpretation of Geophysical, Geotechnical, and Environmental Monitoring Data to Define Precursors for Landslide Activation

    NASA Astrophysics Data System (ADS)

    Uhlemann, S.; Chambers, J.; Merritt, A.; Wilkinson, P.; Meldrum, P.; Gunn, D.; Maurer, H.; Dixon, N.

    2014-12-01

    To develop a better understanding of the failure mechanisms leading to first time failure or reactivation of landslides, the British Geological Survey is operating an observatory on an active, shallow landslide in North Yorkshire, UK, which is a typical example of slope failure in Lias Group mudrocks. This group and the Whitby Mudstone Formation in particular, show one of the highest landslide densities in the UK. The observatory comprises geophysical (i.e., ERT and self-potential monitoring, P- and S-wave tomography), geotechnical (i.e. acoustic emission and inclinometer), and hydrological and environmental monitoring (i.e. weather station, water level, soil moisture, soil temperature), in addition to movement monitoring using real-time kinematic GPS. In this study we focus on the reactivation of the landslide at the end of 2012, after an exceptionally wet summer. We present an integrated interpretation of the different data streams. Results show that the two lobes (east and west), which form the main focus of the observatory, behave differently. While water levels, and hence pore pressures, in the eastern lobe are characterised by a continuous increase towards activation resulting in significant movement (i.e. metres), water levels in the western lobe are showing frequent drainage events and thus lower pore pressures and a lower level of movement (i.e. tens of centimetres). This is in agreement with data from the geoelectrical monitoring array. During the summer season, resistivities generally increase due to decreasing moisture levels. However, during the summer of 2012 this seasonal pattern was interrupted, with the reactivated lobe displaying strongly decreasing resistivities (i.e. increasing moisture levels). The self-potential and soil moisture data show clear indications of moisture accumulation prior to the reactivation, followed by continuous discharge towards the base of the slope. Using the different data streams, we present 3D volumetric images of

  19. Activity of Defined Mushroom Body Output Neurons Underlies Learned Olfactory Behavior in Drosophila

    PubMed Central

    Owald, David; Felsenberg, Johannes; Talbot, Clifford B.; Das, Gaurav; Perisse, Emmanuel; Huetteroth, Wolf; Waddell, Scott

    2015-01-01

    Summary During olfactory learning in fruit flies, dopaminergic neurons assign value to odor representations in the mushroom body Kenyon cells. Here we identify a class of downstream glutamatergic mushroom body output neurons (MBONs) called M4/6, or MBON-β2β′2a, MBON-β′2mp, and MBON-γ5β′2a, whose dendritic fields overlap with dopaminergic neuron projections in the tips of the β, β′, and γ lobes. This anatomy and their odor tuning suggests that M4/6 neurons pool odor-driven Kenyon cell synaptic outputs. Like that of mushroom body neurons, M4/6 output is required for expression of appetitive and aversive memory performance. Moreover, appetitive and aversive olfactory conditioning bidirectionally alters the relative odor-drive of M4β′ neurons (MBON-β′2mp). Direct block of M4/6 neurons in naive flies mimics appetitive conditioning, being sufficient to convert odor-driven avoidance into approach, while optogenetically activating these neurons induces avoidance behavior. We therefore propose that drive to the M4/6 neurons reflects odor-directed behavioral choice. PMID:25864636

  20. Diterpenes from rosemary (Rosmarinus officinalis): Defining their potential for anti-cancer activity.

    PubMed

    Petiwala, Sakina M; Johnson, Jeremy J

    2015-10-28

    Recently, rosemary extracts standardized to diterpenes (e.g. carnosic acid and carnosol) have been approved by the European Union (EU) and given a GRAS (Generally Recognized as Safe) status in the United States by the Food and Drug Administration (FDA). Incorporation of rosemary into our food system and through dietary selection (e.g. Mediterranean Diet) has increased the likelihood of exposure to diterpenes in rosemary. In consideration of this, a more thorough understanding of rosemary diterpenes is needed to understand its potential for a positive impact on human health. Three agents in particular have received the most attention that includes carnosic acid, carnosol, and rosmanol with promising results of anti-cancer activity. These studies have provided evidence of diterpenes to modulate deregulated signaling pathways in different solid and blood cancers. Rosemary extracts and the phytochemicals therein appear to be well tolerated in different animal models as evidenced by the extensive studies performed for approval by the EU and the FDA as an antioxidant food preservative. This mini-review reports on the pre-clinical studies performed with carnosic acid, carnosol, and rosmanol describing their mechanism of action in different cancers. PMID:26170168

  1. Inducible in vivo DNA footprints define sequences necessary for UV light activation of the parsley chalcone synthase gene.

    PubMed Central

    Schulze-Lefert, P; Dangl, J L; Becker-André, M; Hahlbrock, K; Schulz, W

    1989-01-01

    We began characterization of the protein--DNA interactions necessary for UV light induced transcriptional activation of the gene encoding chalcone synthase (CHS), a key plant defense enzyme. Three light dependent in vivo footprints appear on a 90 bp stretch of the CHS promoter with a time course correlated with the onset of CHS transcription. We define a minimal light responsive promoter by functional analysis of truncated CHS promoter fusions with a reporter gene in transient expression experiments in parsley protoplasts. Two of the three footprinted sequence 'boxes' reside within the minimal promoter. Replacement of 10 bp within either of these 'boxes' leads to complete loss of light responsiveness. We conclude that these sequences define the necessary cis elements of the minimal CHS promoter's light responsive element. One of the functionally defined 'boxes' is homologous to an element implicated in regulation of genes involved in photosynthesis. These data represent the first example in a plant defense gene of an induced change in protein--DNA contacts necessary for transcriptional activation. Also, our data argue strongly that divergent light induced biosynthetic pathways share common regulatory units. Images PMID:2566481

  2. Viral RNA patterns and high viral load reliably define oropharynx carcinomas with active HPV16 involvement.

    PubMed

    Holzinger, Dana; Schmitt, Markus; Dyckhoff, Gerhard; Benner, Axel; Pawlita, Michael; Bosch, Franz X

    2012-10-01

    Oropharyngeal squamous cell carcinomas (OPSCC) that are associated with human papilloma virus (HPV) infection carry a more favorable prognosis than those that are HPV-negative. However, it remains unclear which biomarker(s) can reliably determine which OPSCC specimens are truly driven by HPV infection. In this study, we analyzed 199 fresh-frozen OPSCC specimens for HPV DNA, viral load, RNA expression patterns typical for cervical carcinomas (CxCaRNA(+)), and the HPV-targeted tumor suppressor protein p16(INK4a) as markers for HPV infection. In this set of specimens, there was a 49% prevalence of DNA for the cancer-associated HPV type 16 (HPV(+)). However, there was only a 16% prevalence of high viral load and only a 20% prevalence of CxCaRNA(+), a marker of HPV16 carcinogenic activity. Among the CxCaRNA(+) tumors, 78% of the specimens exhibited overexpression of p16(INK4a), which also occurred in 14% of the HPV-negative tumors. Using a multivariate survival analysis with HPV negativity as the reference group, CxCaRNA(+) as a single marker conferred the lowest risk of death [HR = 0.28, 95% confidence interval (CI), 0.13-0.61] from oropharyngeal cancer, closely followed by high viral load (HR = 0.32, 95% CI, 0.14-0.73). In contrast, a weaker inverse association was found for OPSCC that were HPV(+) and p16(INK4a) high (HR = 0.55, 95% CI, 0.29-1.08). In summary, our findings argued that viral load or RNA pattern analysis is better suited than p16(INK4a) expression to identify HPV16-driven tumors in OPSCC patient populations. PMID:22991302

  3. The role of substrate specificity and metal binding in defining the activity and structure of an intracellular subtilisin.

    PubMed

    Gamble, Michael; Künze, Georg; Brancale, Andrea; Wilson, Keith S; Jones, D Dafydd

    2012-01-01

    The dimeric intracellular subtilisin proteases (ISPs) found throughout Gram-positive bacteria are a structurally distinct class of the subtilase family. Unlike the vast majority of subtilisin-like proteases, the ISPs function exclusively within the cell, contributing the majority of observed cellular proteolytic activity. Given that they are active within the cell, little is known about substrate specificity and the role of stress signals such as divalent metal ions in modulating ISP function. We demonstrate that both play roles in defining the proteolytic activity of Bacillus clausii ISP and propose the molecular basis of their effects. Enzyme kinetics reveal that one particular synthetic tetrapeptide substrate, Phe-Ala-Ala-Phe-pNA, is hydrolysed with a catalytic efficiency ∼100-fold higher than any other tested. Heat-denatured whole proteins were found to be better substrates for ISP than the native forms. Substrate binding simulations suggest that the S1, S2 and S4 sites form defined binding pockets. The deep S1 cavity and wide S4 site are fully occupied by the hydrophobic aromatic side-chains of Phe. Divalent metal ions, probably Ca(2+), are proposed to be important for ISP activity through structural changes. The presence of >0.01 mM EDTA inactivates ISP, with CD and SEC suggesting that the protein becomes less structured and potentially monomeric. Removal of Ca(2+) at sites close to the dimer interface and the S1 pocket are thought to be responsible for the effect. These studies provide a new insight into the potential physiological function of ISPs, by reconciling substrate specificity and divalent metal binding to associate ISP with the unfolded protein response under stress conditions. PMID:23650602

  4. Defining the role of tyrosine and rational tuning of oxidase activity by genetic incorporation of unnatural tyrosine analogs.

    PubMed

    Yu, Yang; Lv, Xiaoxuan; Li, Jiasong; Zhou, Qing; Cui, Chang; Hosseinzadeh, Parisa; Mukherjee, Arnab; Nilges, Mark J; Wang, Jiangyun; Lu, Yi

    2015-04-15

    While a conserved tyrosine (Tyr) is found in oxidases, the roles of phenol ring pKa and reduction potential in O2 reduction have not been defined despite many years of research on numerous oxidases and their models. These issues represent major challenges in our understanding of O2 reduction mechanism in bioenergetics. Through genetic incorporation of unnatural amino acid analogs of Tyr, with progressively decreasing pKa of the phenol ring and increasing reduction potential, in the active site of a functional model of oxidase in myoglobin, a linear dependence of both the O2 reduction activity and the fraction of H2O formation with the pKa of the phenol ring has been established. By using these unnatural amino acids as spectroscopic probe, we have provided conclusive evidence for the location of a Tyr radical generated during reaction with H2O2, by the distinctive hyperfine splitting patterns of the halogenated tyrosines and one of its deuterated derivatives incorporated at the 33 position of the protein. These results demonstrate for the first time that enhancing the proton donation ability of the Tyr enhances the oxidase activity, allowing the Tyr analogs to augment enzymatic activity beyond that of natural Tyr. PMID:25672571

  5. The IRE1/bZIP60 pathway and Bax inhibitor 1 suppress systemic accumulation of potyviruses and potexviruses in Arabidopsis and N. benthamiana plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inositol requiring enzyme (IRE1) is an endoplasmic reticulum (ER) stress sensor and when activated it splices the bZIP60 mRNA producing a truncated transcription factor that upregulates expression of genes involved in the unfolded protein response (UPR). Bax inhibitor 1 (BI-1) is another ER stre...

  6. Defining "Development".

    PubMed

    Pradeu, Thomas; Laplane, Lucie; Prévot, Karine; Hoquet, Thierry; Reynaud, Valentine; Fusco, Giuseppe; Minelli, Alessandro; Orgogozo, Virginie; Vervoort, Michel

    2016-01-01

    Is it possible, and in the first place is it even desirable, to define what "development" means and to determine the scope of the field called "developmental biology"? Though these questions appeared crucial for the founders of "developmental biology" in the 1950s, there seems to be no consensus today about the need to address them. Here, in a combined biological, philosophical, and historical approach, we ask whether it is possible and useful to define biological development, and, if such a definition is indeed possible and useful, which definition(s) can be considered as the most satisfactory. PMID:26969977

  7. Defining Overweight and Obesity

    MedlinePlus

    ... Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Defining Adult Overweight and ... Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs File Formats Help: How ...

  8. Brain-specific Angiogenesis Inhibitor-1 Signaling, Regulation, and Enrichment in the Postsynaptic Density*

    PubMed Central

    Stephenson, Jason R.; Paavola, Kevin J.; Schaefer, Stacy A.; Kaur, Balveen; Van Meir, Erwin G.; Hall, Randy A.

    2013-01-01

    Brain-specific angiogenesis inhibitor-1 (BAI1) is an adhesion G protein-coupled receptor that has been studied primarily for its anti-angiogenic and anti-tumorigenic properties. We found that overexpression of BAI1 results in activation of the Rho pathway via a Gα12/13-dependent mechanism, with truncation of the BAI1 N terminus resulting in a dramatic enhancement in receptor signaling. This constitutive activity of the truncated BAI1 mutant also resulted in enhanced downstream phosphorylation of ERK as well as increased receptor association with β-arrestin2 and increased ubiquitination of the receptor. To gain insights into the regulation of BAI1 signaling, we screened the C terminus of BAI1 against a proteomic array of PDZ domains to identify novel interacting partners. These screens revealed that the BAI1 C terminus interacts with a variety of PDZ domains from synaptic proteins, including MAGI-3. Removal of the BAI1 PDZ-binding motif resulted in attenuation of receptor signaling to Rho but had no effect on ERK activation. Conversely, co-expression with MAGI-3 was found to potentiate signaling to ERK by constitutively active BAI1 in a manner that was dependent on the PDZ-binding motif of the receptor. Biochemical fractionation studies revealed that BAI1 is highly enriched in post-synaptic density fractions, a finding consistent with our observations that BAI1 can interact with PDZ proteins known to be concentrated in the post-synaptic density. These findings demonstrate that BAI1 is a synaptic receptor that can activate both the Rho and ERK pathways, with the N-terminal and C-terminal regions of the receptor playing key roles in the regulation of BAI1 signaling activity. PMID:23782696

  9. Defining Infertility

    MedlinePlus

    ... of the American Society for Reproductive Medicine Defining infertility What is infertility? Infertility is “the inability to conceive after 12 months ... to conceive after 6 months is generally considered infertility. How common is it? Infertility affects 10%-15% ...

  10. Defining Risk.

    ERIC Educational Resources Information Center

    Tholkes, Ben F.

    1998-01-01

    Defines camping risks and lists types and examples: (1) objective risk beyond control; (2) calculated risk based on personal choice; (3) perceived risk; and (4) reckless risk. Describes campers to watch ("immortals" and abdicators), and several "treatments" of risk: avoidance, safety procedures and well-trained staff, adequate insurance, and a…

  11. Co-Activation of Epidermal Growth Factor Receptor and c-MET Defines a Distinct Subset of Lung Adenocarcinomas

    PubMed Central

    Matsubara, Daisuke; Ishikawa, Shumpei; Sachiko, Oguni; Aburatani, Hiroyuki; Fukayama, Masashi; Niki, Toshiro

    2010-01-01

    Epidermal growth factor receptor (EGFR) and MET are molecular targets for lung cancer treatment. The relationships between expression, activation, and gene abnormalities of these two targets are currently unclear. Here, we demonstrate that a panel of 40 lung cancer cell lines could be classified into two groups. Group I was characterized by (1) high phosphorylations of MET and EGFR, (2) frequent mutation or amplification of EGFR, MET, and human epidermal growth factor receptor-2 (HER2), (3) high expressions of bronchial epithelial markers (thyroid transcription factor-1 (TTF-1), MUC1, and Cytokeratin 7 (CK7)); and (4) high expressions of MET, human epidermal growth factor receptor-3, E-cadherin, cyclooxygenase-2, and laminin gamma2. In contrast, Group II exhibited little or no phosphorylation of MET and EGFR; no mutation or amplification of EGFR, MET, and HER2; were triple-negative for TTF-1, MUC1, and CK7; and showed high expressions of vimentin, fibroblast growth factor receptor-1, and transcription factor 8. Importantly, Group I was more sensitive to gefitinib and more resistant to cisplatin and paclitaxel than Group II. The clinical relevance was confirmed in publicly available data on 442 primary lung adenocarcinoma patients; survival benefits by postoperative chemotherapy were seen in only patients with tumors corresponding to Group II. Overall, co-activation of EGFR and MET defines a distinct subgroup of lung carcinoma with characteristic genetic abnormalities, gene expression pattern, and response to chemotherapeutic reagents. PMID:20934974

  12. Rhomboid Enhancer Activity Defines a Subset of Drosophila Neural Precursors Required for Proper Feeding, Growth and Viability

    PubMed Central

    Gresser, Amy L.; Gutzwiller, Lisa M.; Gauck, Mackenzie K.; Hartenstein, Volker; Cook, Tiffany A.; Gebelein, Brian

    2015-01-01

    Organismal growth regulation requires the interaction of multiple metabolic, hormonal and neuronal pathways. While the molecular basis for many of these are well characterized, less is known about the developmental origins of growth regulatory structures and the mechanisms governing control of feeding and satiety. For these reasons, new tools and approaches are needed to link the specification and maturation of discrete cell populations with their subsequent regulatory roles. In this study, we characterize a rhomboid enhancer element that selectively labels four Drosophila embryonic neural precursors. These precursors give rise to the hypopharyngeal sensory organ of the peripheral nervous system and a subset of neurons in the deutocerebral region of the embryonic central nervous system. Post embryogenesis, the rhomboid enhancer is active in a subset of cells within the larval pharyngeal epithelium. Enhancer-targeted toxin expression alters the morphology of the sense organ and results in impaired larval growth, developmental delay, defective anterior spiracle eversion and lethality. Limiting the duration of toxin expression reveals differences in the critical periods for these effects. Embryonic expression causes developmental defects and partially penetrant pre-pupal lethality. Survivors of embryonic expression, however, ultimately become viable adults. In contrast, post-embryonic toxin expression results in fully penetrant lethality. To better define the larval growth defect, we used a variety of assays to demonstrate that toxin-targeted larvae are capable of locating, ingesting and clearing food and they exhibit normal food search behaviors. Strikingly, however, following food exposure these larvae show a rapid decrease in consumption suggesting a satiety-like phenomenon that correlates with the period of impaired larval growth. Together, these data suggest a critical role for these enhancer-defined lineages in regulating feeding, growth and viability. PMID

  13. Rhomboid Enhancer Activity Defines a Subset of Drosophila Neural Precursors Required for Proper Feeding, Growth and Viability.

    PubMed

    Gresser, Amy L; Gutzwiller, Lisa M; Gauck, Mackenzie K; Hartenstein, Volker; Cook, Tiffany A; Gebelein, Brian

    2015-01-01

    Organismal growth regulation requires the interaction of multiple metabolic, hormonal and neuronal pathways. While the molecular basis for many of these are well characterized, less is known about the developmental origins of growth regulatory structures and the mechanisms governing control of feeding and satiety. For these reasons, new tools and approaches are needed to link the specification and maturation of discrete cell populations with their subsequent regulatory roles. In this study, we characterize a rhomboid enhancer element that selectively labels four Drosophila embryonic neural precursors. These precursors give rise to the hypopharyngeal sensory organ of the peripheral nervous system and a subset of neurons in the deutocerebral region of the embryonic central nervous system. Post embryogenesis, the rhomboid enhancer is active in a subset of cells within the larval pharyngeal epithelium. Enhancer-targeted toxin expression alters the morphology of the sense organ and results in impaired larval growth, developmental delay, defective anterior spiracle eversion and lethality. Limiting the duration of toxin expression reveals differences in the critical periods for these effects. Embryonic expression causes developmental defects and partially penetrant pre-pupal lethality. Survivors of embryonic expression, however, ultimately become viable adults. In contrast, post-embryonic toxin expression results in fully penetrant lethality. To better define the larval growth defect, we used a variety of assays to demonstrate that toxin-targeted larvae are capable of locating, ingesting and clearing food and they exhibit normal food search behaviors. Strikingly, however, following food exposure these larvae show a rapid decrease in consumption suggesting a satiety-like phenomenon that correlates with the period of impaired larval growth. Together, these data suggest a critical role for these enhancer-defined lineages in regulating feeding, growth and viability. PMID

  14. Tracking a defined route for O[subscript 2] migration in a dioxygen-activating diiron enzyme

    SciTech Connect

    Song, Woon Ju; Gucinski, Grant; Sazinsky, Matthew H.; Lippard, Stephen J.

    2011-09-08

    For numerous enzymes reactive toward small gaseous compounds, growing evidence indicates that these substrates diffuse into active site pockets through defined pathways in the protein matrix. Toluene/o-xylene monooxygenase hydroxylase is a dioxygen-activating enzyme. Structural analysis suggests two possible pathways for dioxygen access through the {alpha}-subunit to the diiron center: a channel or a series of hydrophobic cavities. To distinguish which is utilized as the O{sub 2} migration pathway, the dimensions of the cavities and the channel were independently varied by site-directed mutagenesis and confirmed by X-ray crystallography. The rate constants for dioxygen access to the diiron center were derived from the formation rates of a peroxodiiron(III) intermediate, generated upon treatment of the diiron(II) enzyme with O2. This reaction depends on the concentration of dioxygen to the first order. Altering the dimensions of the cavities, but not the channel, changed the rate of dioxygen reactivity with the enzyme. These results strongly suggest that voids comprising the cavities in toluene/o-xylene monooxygenase hydroxylase are not artifacts of protein packing/folding, but rather programmed routes for dioxygen migration through the protein matrix. Because the cavities are not fully connected into the diiron active center in the enzyme resting state, conformational changes will be required to facilitate dioxygen access to the diiron center. We propose that such temporary opening and closing of the cavities may occur in all bacterial multicomponent monooxygenases to control O{sub 2} consumption for efficient catalysis. Our findings suggest that other gas-utilizing enzymes may employ similar structural features to effect substrate passage through a protein matrix.

  15. A high-resolution lake sediment record of glacier activity from SE Greenland defines abrupt Holocene cooling events

    NASA Astrophysics Data System (ADS)

    Balascio, N. L.; Bradley, R. S.; D'Andrea, W. J.

    2013-12-01

    Orbital driven changes in high latitude summer insolation during the Holocene are responsible for the primary millennial-scale climate trends in the Arctic. Following deglaciation, maximum summer temperatures generally occurred during the early to mid-Holocene and declined through the late Holocene. Superimposed on this gradual cooling trend are centennial- and decadal-scale intervals that indicate more rapid perturbations of the arctic climate system. Highly resolved sedimentary records from terrestrial and marine sites help to better characterize climate system dynamics during the Holocene and investigate forcing and feedback mechanism that operate on different timescales. Reconstructing glacial activity can provide valuable paleoclimate information about trends in summer temperature and/or winter precipitation. Proglacial lakes contain sediment archives of meltwater input from glaciers and typically have high sedimentation rates preserving detailed information on glacial activity. However, interpreting proglacial sedimentary records can be difficult because 1) there may be significant input of sediment from non-glacial sources, 2) there is often a lack of organic material for radiocarbon dating, and 3) not all glaciers are sensitive to rapid climatic changes. Here we present a c. 10 cal ka BP record of glacier activity from Kulusuk Lake (65.6°N, 37.1°W; 202 m a.s.l.), a proglacial lake in southeast Greenland that is well constrained by radiocarbon dates and shows a clear signal of changes in glacial input throughout the Holocene. Kulusuk Lake is presently fed by meltwater from two cirque glaciers. It has a small catchment and no other significant source of sediment input. A 3.5 m sediment core contains distinct lithologic changes defined by grain size, magnetic susceptibility, organic content, and scanning XRF data. During the early Holocene, an overall decrease in meltwater input from 8.7-7.7 ka indicates the retreat of the glaciers in response to regional

  16. Defining RNA motif–aminoglycoside interactions via two-dimensional combinatorial screening and structure–activity relationships through sequencing

    PubMed Central

    Velagapudi, Sai Pradeep; Disney, Matthew D.

    2013-01-01

    RNA is an extremely important target for the development of chemical probes of function or small molecule therapeutics. Aminoglycosides are the most well studied class of small molecules to target RNA. However, the RNA motifs outside of the bacterial rRNA A-site that are likely to be bound by these compounds in biological systems is largely unknown. If such information were known, it could allow for aminoglycosides to be exploited to target other RNAs and, in addition, could provide invaluable insights into potential bystander targets of these clinically used drugs. We utilized two-dimensional combinatorial screening (2DCS), a library-versus-library screening approach, to select the motifs displayed in a 3 × 3 nucleotide internal loop library and in a 6-nucleotide hairpin library that bind with high affinity and selectivity to six aminoglycoside derivatives. The selected RNA motifs were then analyzed using structure–activity relationships through sequencing (StARTS), a statistical approach that defines the privileged RNA motif space that binds a small molecule. StARTS allowed for the facile annotation of the selected RNA motif–aminoglycoside interactions in terms of affinity and selectivity. The interactions selected by 2DCS generally have nanomolar affinities, which is higher affinity than the binding of aminoglycosides to a mimic of their therapeutic target, the bacterial rRNA A-site. PMID:23719281

  17. Defining RNA motif-aminoglycoside interactions via two-dimensional combinatorial screening and structure-activity relationships through sequencing.

    PubMed

    Velagapudi, Sai Pradeep; Disney, Matthew D

    2013-10-15

    RNA is an extremely important target for the development of chemical probes of function or small molecule therapeutics. Aminoglycosides are the most well studied class of small molecules to target RNA. However, the RNA motifs outside of the bacterial rRNA A-site that are likely to be bound by these compounds in biological systems is largely unknown. If such information were known, it could allow for aminoglycosides to be exploited to target other RNAs and, in addition, could provide invaluable insights into potential bystander targets of these clinically used drugs. We utilized two-dimensional combinatorial screening (2DCS), a library-versus-library screening approach, to select the motifs displayed in a 3×3 nucleotide internal loop library and in a 6-nucleotide hairpin library that bind with high affinity and selectivity to six aminoglycoside derivatives. The selected RNA motifs were then analyzed using structure-activity relationships through sequencing (StARTS), a statistical approach that defines the privileged RNA motif space that binds a small molecule. StARTS allowed for the facile annotation of the selected RNA motif-aminoglycoside interactions in terms of affinity and selectivity. The interactions selected by 2DCS generally have nanomolar affinities, which is higher affinity than the binding of aminoglycosides to a mimic of their therapeutic target, the bacterial rRNA A-site. PMID:23719281

  18. Gardnerella vaginalis Subgroups Defined by cpn60 Sequencing and Sialidase Activity in Isolates from Canada, Belgium and Kenya.

    PubMed

    Schellenberg, John J; Paramel Jayaprakash, Teenus; Withana Gamage, Niradha; Patterson, Mo H; Vaneechoutte, Mario; Hill, Janet E

    2016-01-01

    Increased abundance of Gardnerella vaginalis and sialidase activity in vaginal fluid is associated with bacterial vaginosis (BV), a common but poorly understood clinical entity associated with poor reproductive health outcomes. Since most women are colonized with G. vaginalis, its status as a normal member of the vaginal microbiota or pathogen causing BV remains controversial, and numerous classification schemes have been described. Since 2005, sequencing of the chaperonin-60 universal target (cpn60 UT) has distinguished four subgroups in isolate collections, clone libraries and deep sequencing datasets. To clarify potential clinical and diagnostic significance of cpn60 subgroups, we undertook phenotypic and molecular characterization of 112 G. vaginalis isolates from three continents. A total of 36 subgroup A, 33 B, 35 C and 8 D isolates were identified through phylogenetic analysis of cpn60 sequences as corresponding to four "clades" identified in a recently published study, based on sequencing 473 genes across 17 isolates. cpn60 subgroups were compared with other previously described molecular methods for classification of Gardnerella subgroups, including amplified ribosomal DNA restriction analysis (ARDRA) and real-time PCR assays designed to quantify subgroups in vaginal samples. Although two ARDRA patterns were observed in isolates, each was observed in three cpn60 subgroups (A/B/D and B/C/D). Real-time PCR assays corroborated cpn60 subgroups overall, but 13 isolates from subgroups A, B and D were negative in all assays. A putative sialidase gene was detected in all subgroup B, C and D isolates, but only in a single subgroup A isolate. In contrast, sialidase activity was observed in all subgroup B isolates, 3 (9%) subgroup C isolates and no subgroup A or D isolates. These observations suggest distinct roles for G. vaginalis subgroups in BV pathogenesis. We conclude that cpn60 UT sequencing is a robust approach for defining G. vaginalis subgroups within the

  19. Gardnerella vaginalis Subgroups Defined by cpn60 Sequencing and Sialidase Activity in Isolates from Canada, Belgium and Kenya

    PubMed Central

    Schellenberg, John J.; Paramel Jayaprakash, Teenus; Withana Gamage, Niradha; Patterson, Mo H.; Vaneechoutte, Mario; Hill, Janet E.

    2016-01-01

    Increased abundance of Gardnerella vaginalis and sialidase activity in vaginal fluid is associated with bacterial vaginosis (BV), a common but poorly understood clinical entity associated with poor reproductive health outcomes. Since most women are colonized with G. vaginalis, its status as a normal member of the vaginal microbiota or pathogen causing BV remains controversial, and numerous classification schemes have been described. Since 2005, sequencing of the chaperonin-60 universal target (cpn60 UT) has distinguished four subgroups in isolate collections, clone libraries and deep sequencing datasets. To clarify potential clinical and diagnostic significance of cpn60 subgroups, we undertook phenotypic and molecular characterization of 112 G. vaginalis isolates from three continents. A total of 36 subgroup A, 33 B, 35 C and 8 D isolates were identified through phylogenetic analysis of cpn60 sequences as corresponding to four “clades” identified in a recently published study, based on sequencing 473 genes across 17 isolates. cpn60 subgroups were compared with other previously described molecular methods for classification of Gardnerella subgroups, including amplified ribosomal DNA restriction analysis (ARDRA) and real-time PCR assays designed to quantify subgroups in vaginal samples. Although two ARDRA patterns were observed in isolates, each was observed in three cpn60 subgroups (A/B/D and B/C/D). Real-time PCR assays corroborated cpn60 subgroups overall, but 13 isolates from subgroups A, B and D were negative in all assays. A putative sialidase gene was detected in all subgroup B, C and D isolates, but only in a single subgroup A isolate. In contrast, sialidase activity was observed in all subgroup B isolates, 3 (9%) subgroup C isolates and no subgroup A or D isolates. These observations suggest distinct roles for G. vaginalis subgroups in BV pathogenesis. We conclude that cpn60 UT sequencing is a robust approach for defining G. vaginalis subgroups within

  20. PP1-mediated dephosphorylation of phosphoproteins at mitotic exit is controlled by inhibitor-1 and PP1 phosphorylation

    PubMed Central

    Wu, Judy Qiju; Guo, Jessie Yanxiang; Tang, Wanli; Yang, Chih-Sheng; Freel, Christopher D.; Chen, Chen; Nairn, Angus C.; Kornbluth, Sally

    2009-01-01

    Loss of Cdc2 activity following Cyclin B degradation is necessary, but not sufficient, for mitotic exit. Proteins phosphorylated by Cdc2 and downstream mitotic kinases must also be dephosphorylated. We report here that protein phosphatase-1 (PP1) is the major catalyst of mitotic phosphoprotein dephosphorylation. Suppression of PP1 during early mitosis is maintained through the dual inhibition of PP1 by Cdc2 phosphorylation and the binding of Inhibitor-1 (I1), which is facilitated by PKA-mediated I1 phosphorylation. As Cdc2 levels drop following Cyclin B degradation, autodephosphorylation of PP1 at the site of Cdc2 phosphorylation (T320) allows partial PP1 activation. This promotes PP1-regulated dephosphorylation of I1 at its activating site (T35), dissociation of the I1-PP1 complex, and full PP1 activation to promote mitotic exit. Thus, Cdc2 both phosphorylates multiple mitotic substrates and inhibits their PP1-mediated dephosphorylation. PMID:19396163

  1. Defining chaos

    SciTech Connect

    Hunt, Brian R.; Ott, Edward

    2015-09-15

    In this paper, we propose, discuss, and illustrate a computationally feasible definition of chaos which can be applied very generally to situations that are commonly encountered, including attractors, repellers, and non-periodically forced systems. This definition is based on an entropy-like quantity, which we call “expansion entropy,” and we define chaos as occurring when this quantity is positive. We relate and compare expansion entropy to the well-known concept of topological entropy to which it is equivalent under appropriate conditions. We also present example illustrations, discuss computational implementations, and point out issues arising from attempts at giving definitions of chaos that are not entropy-based.

  2. Entrectinib, a Pan-TRK, ROS1, and ALK Inhibitor with Activity in Multiple Molecularly Defined Cancer Indications.

    PubMed

    Ardini, Elena; Menichincheri, Maria; Banfi, Patrizia; Bosotti, Roberta; De Ponti, Cristina; Pulci, Romana; Ballinari, Dario; Ciomei, Marina; Texido, Gemma; Degrassi, Anna; Avanzi, Nilla; Amboldi, Nadia; Saccardo, Maria Beatrice; Casero, Daniele; Orsini, Paolo; Bandiera, Tiziano; Mologni, Luca; Anderson, David; Wei, Ge; Harris, Jason; Vernier, Jean-Michel; Li, Gang; Felder, Eduard; Donati, Daniele; Isacchi, Antonella; Pesenti, Enrico; Magnaghi, Paola; Galvani, Arturo

    2016-04-01

    Activated ALK and ROS1 tyrosine kinases, resulting from chromosomal rearrangements, occur in a subset of non-small cell lung cancers (NSCLC) as well as other tumor types and their oncogenic relevance as actionable targets has been demonstrated by the efficacy of selective kinase inhibitors such as crizotinib, ceritinib, and alectinib. More recently, low-frequency rearrangements of TRK kinases have been described in NSCLC, colorectal carcinoma, glioblastoma, and Spitzoid melanoma. Entrectinib, whose discovery and preclinical characterization are reported herein, is a novel, potent inhibitor of ALK, ROS1, and, importantly, of TRK family kinases, which shows promise for therapy of tumors bearing oncogenic forms of these proteins. Proliferation profiling against over 200 human tumor cell lines revealed that entrectinib is exquisitely potent in vitro against lines that are dependent on the drug's pharmacologic targets. Oral administration of entrectinib to tumor-bearing mice induced regression in relevant human xenograft tumors, including the TRKA-dependent colorectal carcinoma KM12, ROS1-driven tumors, and several ALK-dependent models of different tissue origins, including a model of brain-localized lung cancer metastasis. Entrectinib is currently showing great promise in phase I/II clinical trials, including the first documented objective responses to a TRK inhibitor in colorectal carcinoma and in NSCLC. The drug is, thus, potentially suited to the therapy of several molecularly defined cancer settings, especially that of TRK-dependent tumors, for which no approved drugs are currently available. Mol Cancer Ther; 15(4); 628-39. ©2016 AACR. PMID:26939704

  3. Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BAX inhibitor-1 (BI-1) is proposed to be a cell death suppressor conserved in both animals and plants. The ability of BI-1 genes to inhibit programmed cell death (PCD) has been well studied in animals, but the physiological importance of BI-1 in plant-microbe interactions remains unclear. This study...

  4. 20 CFR 404.418 - “Noncovered remunerative activity outside the United States,” defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... United States,â defined. 404.418 Section 404.418 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... (b) He carries on a trade or business outside the United States (other than the performance of... earnings from self-employment (see § 404.1052) if the trade or business were carried on in the...

  5. Defining GERD.

    PubMed Central

    Sontag, S. J.

    1999-01-01

    "It is not the death of GERD that I seek, but that it turns from its evil ways and follows the path of righteousness." The reflux world is fully aware of what GERD is and what GERD does. What the world does not know, however, is the answer to the most important yet least asked question surrounding GERD's raison-d'etre: Why is GERD here and why do we have it? What GERD is: abnormal gastric reflux into the esophagus that causes any type of mischief. What GERD does: causes discomfort and/or pain with or without destroying the mucosa; causes stricture or stenosis, preventing food from being swallowed; sets the stage for the development of esophageal adenocarcinoma; invades the surrounding lands to harass the peaceful oropharyngeal, laryngeal and broncho-pulmonary territories; reminds us that we are not only human, but that we are dust and ashes. Why GERD is here: We propose three separate and distinct etiologies of GERD, and we offer the following three hypotheses to explain why, after 1.5 million years of standing erect, we have evolved into a species (specifically Homosapiens sapiens) that is destined to live with the scourge of GERD. Hypothesis 1: congenital. The antireflux barrier, comprising the smooth-muscled lower esophageal sphincter, the skeletal-muscled right crural diaphragm and the phreno-esophageal ligament does not completely develop due to a developmental anomaly or incomplete gestation. Hypothesis 2: acute trauma: The antireflux barrier in adults suffering acute traumatic injury to the abdomen or chest is permanently disrupted by unexpected forces, such as motor vehicle accidents (with steering wheel crush impact), blows to the abdomen (from activities such as boxing, etc.), heavy lifting or moving (e.g., pianos, refrigerators) or stress positions (e.g., hand stands on parallel gym bars). The trauma creates a hiatal hernia that renders the antireflux mechanism useless and incapable of preventing GERD. Hypothesis 3: chronic trauma: The antireflux barrier

  6. Molecular interactions of the intrinsic activation complex of coagulation: binding of native and activated human factors IX and X to defined phospholipid vesicles.

    PubMed

    Burri, B J; Edgington, T S; Fair, D S

    1987-02-20

    The assembly of proteins of the intrinsic activation complex has been partially elucidated. In the present study we examine the association of gamma-carboxylated serine proteinase zymogens factors IX and X, and their proteolytically activated counterparts factors IXa and Xa to unilamellar lipid vesicles of defined composition using three types of physical measurement. Utilizing relative light scatter to estimate the dissociation constants for binding in the presence of calcium ions, it appears that factor IXa (0.93 +/- 0.37 microM) may preferentially associate with phospholipids relative to factor IX (0.35 +/- 0.08 microM). In contrast, factor X (0.34 +/- 0.14 microM), the substrate for factor IXa, appears to bind to phospholipid with a higher affinity than factor Xa (0.58 +/- 0.13 microM). These observations are compatible with the hypothesized dynamics where the forward 'traffic' is facilitated by favoring the association of factor IXa with factor X. The dissociation constants were estimated by molecular exclusion chromatography (1.1 - 2.5 microM) and do not reflect these relative and ordered differences in association with lipid vesicles. Quasi-elastic light scatter analyses indicate that each protein appears to saturate the same vesicle surface, consistent with competition for similar surface lipids, although the molecular shell formed by factor Xa (36 A) is smaller, suggesting that it has a different packing on the phospholipid surface than the other proteins (64-79 A). The pattern of preferential affinities for phospholipid is consistent with a kinetically functional forward traffic through the reaction precursors to products, and suggests that these preferential affinities may assist in the ordering of the four proteins in the intrinsic activation complex. PMID:3493031

  7. The Use of Cytochrome C Oxidase Enzyme Activity and Immunohistochemistry in Defining Mitochondrial Injury in Kidney Disease.

    PubMed

    Zsengellér, Zsuzsanna K; Rosen, Seymour

    2016-09-01

    The renal biopsy is a dynamic way of looking at renal disease, and tubular elements are an important part of this analysis. The mitochondria in 20 renal biopsies were examined by immunohistochemical (electron transport chain enzyme: cytochrome C oxidase IV [COX IV]) and enzyme histochemical methods (COX), both by light and electron microscopy. The distal convoluted tubules and thick ascending limbs showed the greatest intensity in the COX immunostains and enzyme activity in controls. The degree of mitochondrial COX protein and enzyme activity diminished as the tubules became atrophic. With proximal hypertrophic changes, there was great variation in both COX activity and protein expression. In contrast, in three cases of systemic lupus erythematosus, biopsied for high-grade proteinuria, the activity was consistently upregulated, whereas protein expression remained normal. These unexpected findings of heterogeneous upregulation in hypertrophy and the dyssynchrony of protein expression and activity may indicate mitochondrial dysregulation. Functional electron microscopy showed COX activity delineated by the intense mitochondrial staining in normal or hypertrophic proximal tubules. With atrophic changes, residual small mitochondria with diminished activity could be seen. With mitochondrial size abnormalities (enlargement and irregularity, adefovir toxicity), activity persisted. In the renal biopsy, mitochondrial analysis is feasible utilizing immunohistochemical and enzyme histochemical techniques. PMID:27578326

  8. Endosomal localization of phospholipase D 1a and 1b is defined by the C-termini of the proteins, and is independent of activity.

    PubMed

    Hughes, W E; Parker, P J

    2001-06-15

    The factors regulating the activity of cellular phospholipase D (PLD) have been well characterized; however, the cellular distribution of specific PLD isoforms and the factors defining localization are less clear. Two specific PLD1 isoforms, PLD1a and PLD1b, are shown in the present study to be localized in endosomal compartments with early endosomal autoantigen 1, internalizing epidermal growth factor receptor (ErbB1) and lysobisphosphatidic acid. Novel C-terminal splice variants of PLD1, PLD1a2 and PLD1b2, do not exhibit this endosomal localization. Studies using catalytically inactive and C-terminal deletion mutants of the four PLD1 isoforms led to the conclusion that the C-terminus plays an important part in the catalytic activity of PLD1, but that the endosomal localization of PLD1a and PLD1b is defined by the C-terminus and not catalytic activity. PMID:11389680

  9. In vitro assays for assessment of androgenic and estrogenic activity of defined mixtures and complex environment samples

    EPA Science Inventory

    Point sources of potentially endocrine active compounds to aquatic environments such as waste water treatment plants, pulp and paper mills, and animal feeding operations invariably contain complex mixtures of chemicals. The current study investigates the use of targeted in vitro ...

  10. A Defined Terminal Region of the E. coli Chromosome Shows Late Segregation and High FtsK Activity

    PubMed Central

    Meile, Jean-Christophe; Stouf, Mathieu; Capiaux, Hervé; Mercier, Romain; Lesterlin, Christian; Hallet, Bernard; Cornet, François

    2011-01-01

    Background The FtsK DNA-translocase controls the last steps of chromosome segregation in E. coli. It translocates sister chromosomes using the KOPS DNA motifs to orient its activity, and controls the resolution of dimeric forms of sister chromosomes by XerCD-mediated recombination at the dif site and their decatenation by TopoIV. Methodology We have used XerCD/dif recombination as a genetic trap to probe the interaction of FtsK with loci located in different regions of the chromosome. This assay revealed that the activity of FtsK is restricted to a ∼400 kb terminal region of the chromosome around the natural position of the dif site. Preferential interaction with this region required the tethering of FtsK to the division septum via its N-terminal domain as well as its translocation activity. However, the KOPS-recognition activity of FtsK was not required. Displacement of replication termination outside the FtsK high activity region had no effect on FtsK activity and deletion of a part of this region was not compensated by its extension to neighbouring regions. By observing the fate of fluorescent-tagged loci of the ter region, we found that segregation of the FtsK high activity region is delayed compared to that of its adjacent regions. Significance Our results show that a restricted terminal region of the chromosome is specifically dedicated to the last steps of chromosome segregation and to their coupling with cell division by FtsK. PMID:21799784

  11. Defining the Active Fraction of Daptomycin against Methicillin-Resistant Staphylococcus aureus (MRSA) Using a Pharmacokinetic and Pharmacodynamic Approach

    PubMed Central

    Garonzik, Samira M.; Lenhard, Justin R.; Forrest, Alan; Holden, Patricia N.; Bulitta, Jϋrgen B.; Tsuji, Brian T.

    2016-01-01

    Our objective was to study the pharmacodynamics of daptomycin in the presence of varying concentrations of human serum (HS) in vitro to quantify the fraction of daptomycin that is ‘active’. Time kill experiments were performed with daptomycin (0 to 256 mg/L) against two MRSA strains at log-phase growth, in the presence of HS (0%, 10%, 30%, 50%, 70%) combined with Mueller-Hinton broth. Daptomycin ≥ 2 mg/L achieved 99.9% kill within 8 h at all HS concentrations; early killing activity was slightly attenuated at higher HS concentrations. After 1 h, bacterial reduction of USA300 upon exposure to daptomycin 4 mg/L ranged from -3.1 to -0.5 log10CFU/mL in the presence of 0% to 70% HS, respectively. Bactericidal activity was achieved against both strains at daptomycin ≥ 4 mg/L for all fractions of HS exposure. A mechanism-based mathematical model (MBM) was developed to estimate the active daptomycin fraction at each %HS, comprising 3 bacterial subpopulations differing in daptomycin susceptibility. Time-kill data were fit with this MBM with excellent precision (r2 >0.95). The active fraction of daptomycin was estimated to range from 34.6% to 25.2% at HS fractions of 10% to 70%, respectively. Despite the reported low unbound fraction of daptomycin, the impact of protein binding on the activity of daptomycin was modest. The active fraction approach can be utilized to design in vitro experiments and to optimize therapeutic regimens of daptomycin in humans. PMID:27284923

  12. High Heregulin Expression Is Associated with Activated HER3 and May Define an Actionable Biomarker in Patients with Squamous Cell Carcinomas of the Head and Neck

    PubMed Central

    Shames, David S.; Carbon, Juliet; Walter, Kim; Jubb, Adrian M.; Kozlowski, Cleopatra; Januario, Tom; An, Do; Fu, Ling; Xiao, Yuanyuan; Raja, Rajiv; Jiang, Brittany; Malekafzali, Ashi; Stern, Howard; Settleman, Jeff; Wilson, Timothy R.; Hampton, Garret M.; Yauch, Robert L.; Pirzkall, Andrea; Amler, Lukas C.

    2013-01-01

    Purpose Tumors with oncogenic dependencies on the HER family of receptor tyrosine kinases (RTKs) often respond well to targeted inhibition. Our previous work suggested that many cell lines derived from squamous cell carcinomas of the head and neck (SCCHNs) depend on autocrine signaling driven by HER2/3 dimerization and high-level co-expression of HRG. Additionally, results from a Phase I trial of MEHD7495A, a dual-action antibody that blocks ligand binding to EGFR and HER3, suggest that high-level HRG expression was associated with clinical response in SCCHN patients. Here we explore the hypothesis that high-level HRG expression defines a subpopulation of SCCHNs with activated HER3. Experimental Design qRT-PCR expression profiling was performed on >750 tumors of diverse origin, including >150 therapy-naïve, primary, and recurrent SCCHNs. Activated HER3, defined by immunoprecipitation of phospho-HER3, was compared to HRG expression in SCCHN samples. Paracrine versus autocrine expression was evaluated using RNA-in situ hybridization. Results SCCHN tumors express the highest levels of HRG compared to a diverse collection of other tumor types. We show that high HRG expression is associated with activated HER3, whereas low HRG expression is associated with low HER3 activation in SCCHN tumors. Furthermore, HRG expression is higher in recurrent SCCHN compared to patient-matched therapy naïve specimens. Conclusions HRG expression levels define a biologically distinct subset of SCCHN patients. We propose that high-level expression of HRG is associated with constitutive activation of HER3 in SCCHN and thus defines an actionable biomarker for interventions targeting HER3. PMID:23468880

  13. In Vitro Assays for Assessment of Androgenic and Estrogenic Activity of Defined Mixtures and Complex Environmental Samples

    EPA Science Inventory

    Point sources of endocrine active compounds to aquatic environments such as waste water treatment plants, pulp and paper mills, and animal feeding operations invariably contain complex mixtures of chemicals. The current study investigates the use of targeted in vitro assays des...

  14. Defining the Active Ingredients of Interactive Computer Play Interventions for Children with Neuromotor Impairments: A Scoping Review

    ERIC Educational Resources Information Center

    Levac, Danielle; Rivard, Lisa; Missiuna, Cheryl

    2012-01-01

    Rehabilitation researchers who investigate complex interventions are challenged to describe the "active ingredients" of their interventions: the reason(s) why a treatment is expected to be effective. Interactive Computer Play (ICP) is an emerging complex intervention in rehabilitation practice and research. The purpose of this scoping review is to…

  15. Flavonol Activation Defines an Unanticipated Ligand-Binding Site in the Kinase-RNase Domain of IRE1

    SciTech Connect

    Wiseman, R. Luke; Zhang, Yuhong; Lee, Kenneth P.K.; Harding, Heather P.; Haynes, Cole M.; Price, Joshua; Sicheri, Frank; Ron, David

    2010-08-18

    Signaling in the most conserved branch of the endoplasmic reticulum (ER) unfolded protein response (UPR) is initiated by sequence-specific cleavage of the HAC1/XBP1 mRNA by the ER stress-induced kinase-endonuclease IRE1. We have discovered that the flavonol quercetin activates yeast IRE1's RNase and potentiates activation by ADP, a natural activating ligand that engages the IRE1 nucleotide-binding cleft. Enzyme kinetics and the structure of a cocrystal of IRE1 complexed with ADP and quercetin reveal engagement by quercetin of an unanticipated ligand-binding pocket at the dimer interface of IRE1's kinase extension nuclease (KEN) domain. Analytical ultracentrifugation and crosslinking studies support the preeminence of enhanced dimer formation in quercetin's mechanism of action. These findings hint at the existence of endogenous cytoplasmic ligands that may function alongside stress signals from the ER lumen to modulate IRE1 activity and at the potential for the development of drugs that modify UPR signaling from this unanticipated site.

  16. Analytic Hierarchy Process to Define the Most Important Factors and Related Technologies for Empowering Elderly People in Taking an Active Role in their Health.

    PubMed

    Fico, G; Gaeta, E; Arredondo, M T; Pecchia, L

    2015-09-01

    Successful management of health conditions in older population is determined by strategic involvement of a professional team of careers and by empowering patients and their caregivers to take over a central role and responsibility in the daily management of condition. Identifying, structuring and ranking the most important needs related to these aspects could pave the way for improved strategies in designing systems and technological solutions supporting user empowerment. This paper presents the preliminary results of a study aiming to elicit these needs. Healthcare professionals, working together in the European and Innovation Partnership on Active and Healthy Ageing (EIP-AHA) initiative, have defined a set of needs and factors that have been organized in two hierarchies around the concepts of patient activation and proactive and prepared care team, defined in the Chronic Care Model. The two hierarchies have been mapped, by a team of experts in computer science, with technologies and solutions that could facilitate the achievement of the identified needs. PMID:26254254

  17. Review of screening guidelines for non-AIDS-defining malignancies: evolving issues in the era of highly active antiretroviral therapy.

    PubMed

    Tyerman, Zachary; Aboulafia, David M

    2012-01-01

    HIV-associated morbidity and mortality have declined dramatically in the era of HAART. Through direct and indirect benefits of HAART, people with HIV/AIDS are living longer, developing less AIDS-defining cancers and more cancers commonly seen in the seronegative population. Herein, we review cancer screening strategies for people living with HIV and compare and contrast them with those of the general population. The most noticeable differences occur in anal and cervical cancer screening. Although anal cancer is uncommon in the general population, it is more prevalent in men who have sex with men and people at high risk for human papillomavirus infection, especially those infected with HIV. To address this, we recommend that a digital rectal exam and a visual inspection be performed annually. In addition, an anal Pap test should be performed soon after the diagnosis of HIV infection, with follow-up testing every six months until two normal tests. Abnormal cytological results are then investigated with high-resolution anoscopy and biopsy of suspicious lesions. In screening for cervical cancer, a Pap test should be performed during the anogenital exam after initial HIV diagnosis, with a second Pap six months later, then annually if the results are normal. A colposcopy should follow an abnormal result. Human papillomavirus testing as a screening method for cervical cancer in women with HIV can also be efficacious. In lung cancer screening, preliminary data suggest that low-dose computerized tomography may play an important role, but further research is needed. Screening for breast and colon cancer should follow guidelines for the general population. Early screening for prostate cancer based on a diagnosis of HIV lacks clear benefit. PMID:22297500

  18. A role for the thermal environment in defining co-stimulation requirements for CD4(+) T cell activation.

    PubMed

    Zynda, Evan R; Grimm, Melissa J; Yuan, Min; Zhong, Lingwen; Mace, Thomas A; Capitano, Maegan; Ostberg, Julie R; Lee, Kelvin P; Pralle, Arnd; Repasky, Elizabeth A

    2015-01-01

    Maintenance of normal core body temperature is vigorously defended by long conserved, neurovascular homeostatic mechanisms that assist in heat dissipation during prolonged, heat generating exercise or exposure to warm environments. Moreover, during febrile episodes, body temperature can be significantly elevated for at least several hours at a time. Thus, as blood cells circulate throughout the body, physiologically relevant variations in surrounding tissue temperature can occur; moreover, shifts in core temperature occur during daily circadian cycles. This study has addressed the fundamental question of whether the threshold of stimulation needed to activate lymphocytes is influenced by temperature increases associated with physiologically relevant increases in temperature. We report that the need for co-stimulation of CD4+ T cells via CD28 ligation for the production of IL-2 is significantly reduced when cells are exposed to fever-range temperature. Moreover, even in the presence of sufficient CD28 ligation, provision of extra heat further increases IL-2 production. Additional in vivo and in vitro data (using both thermal and chemical modulation of membrane fluidity) support the hypothesis that the mechanism by which temperature modulates co-stimulation is linked to increases in membrane fluidity and membrane macromolecular clustering in the plasma membrane. Thermally-regulated changes in plasma membrane organization in response to physiological increases in temperature may assist in the geographical control of lymphocyte activation, i.e., stimulating activation in lymph nodes rather than in cooler surface regions, and further, may temporarily and reversibly enable CD4+ T cells to become more quickly and easily activated during times of infection during fever. PMID:26131730

  19. Distinct Orai-coupling domains in STIM1 and STIM2 define the Orai-activating site

    PubMed Central

    Wang, Xizhuo; Wang, Youjun; Zhou, Yandong; Hendron, Eunan; Mancarella, Salvatore; Andrake, Mark D.; Rothberg, Brad S.; Soboloff, Jonathan; Gill, Donald L.

    2014-01-01

    STIM1 and STIM2 are widely expressed endoplasmic reticulum (ER) Ca2+ sensor proteins able to translocate within the ER membrane to physically couple with and gate plasma membrane Orai Ca2+ channels. Although structurally similar, we reveal critical differences in the function of the short STIM-Orai activating regions (SOAR) from STIM1 and STIM2. We narrowed these differences in Orai1 gating to a strategically exposed phenylalanine residue (Phe-394) in SOAR1, which in SOAR2 is substituted by a leucine residue. Remarkably, in full-length STIM1, replacement of Phe-394 with the dimensionally similar but polar histidine headgroup, prevents both Orai1 binding and gating, creating an Orai1 non-agonist. Thus, this residue is critical in tuning the efficacy of Orai activation. While STIM1 is a full Orai1-agonist, leucine-replacement of this crucial residue in STIM2 endows it with partial agonist properties, which may be critical for limiting Orai1 activation stemming from its enhanced sensitivity to store-depletion. PMID:24492416

  20. Distinct Orai-coupling domains in STIM1 and STIM2 define the Orai-activating site

    NASA Astrophysics Data System (ADS)

    Wang, Xizhuo; Wang, Youjun; Zhou, Yandong; Hendron, Eunan; Mancarella, Salvatore; Andrake, Mark D.; Rothberg, Brad S.; Soboloff, Jonathan; Gill, Donald L.

    2014-02-01

    STIM1 and STIM2 are widely expressed endoplasmic reticulum (ER) Ca2+ sensor proteins able to translocate within the ER membrane to physically couple with and gate plasma membrane Orai Ca2+ channels. Although they are structurally similar, we reveal critical differences in the function of the short STIM-Orai-activating regions (SOAR) of STIM1 and STIM2. We narrow these differences in Orai1 gating to a strategically exposed phenylalanine residue (Phe-394) in SOAR1, which in SOAR2 is substituted by a leucine residue. Remarkably, in full-length STIM1, replacement of Phe-394 with the dimensionally similar but polar histidine head group prevents both Orai1 binding and gating, creating an Orai1 non-agonist. Thus, this residue is critical in tuning the efficacy of Orai activation. While STIM1 is a full Orai1-agonist, leucine-replacement of this crucial residue in STIM2 endows it with partial agonist properties, which may be critical for limiting Orai1 activation stemming from its enhanced sensitivity to store-depletion.

  1. Associations between Physical Activity and Obesity Defined by Waist-To-Height Ratio and Body Mass Index in the Korean Population

    PubMed Central

    Lee, On; Lee, Duck-chul; Lee, Sukho; Kim, Yeon Soo

    2016-01-01

    Objective This study investigated the associations between physical activity and the prevalence of obesity determined by waist-to-height ratio (WHtR) and body mass index (BMI). Methods This is the first study to our knowledge on physical activity and obesity using a nationally representative sample of South Korean population from The Korea National Health and Nutrition Examination Survey. We categorized individuals into either non-obese or obese defined by WHtR and BMI. Levels of moderate-to-vigorous physical activity were classified as ‘Inactive’, ‘Active’, and ‘Very active’ groups based on the World Health Organization physical activity guidelines. Multivariable logistic regression was used to examine the associations between physical activity and the prevalence of obesity. Results Physical activity was significantly associated with a lower prevalence of obesity using both WHtR and BMI. Compared to inactive men, odds ratios (ORs) (95% confidence intervals [CIs]) for obesity by WHtR ≥0.50 were 0.69 (0.53–0.89) in active men and 0.76 (0.63–0.91) in very active men (p for trend = 0.007). The ORs (95% CIs) for obesity by BMI ≥25 kg/m2 were 0.78 (0.59–1.03) in active men and 0.82 (0.67–0.99) in very active men (p for trend = 0.060). The ORs (95% CIs) for obesity by BMI ≥30 kg/m2 were 0.40 (0.15–0.98) in active men and 0.90 (0.52–1.56) in very active men (p for trend = 0.978). Compared to inactive women, the ORs (95% CIs) for obesity by WHtR ≥0.50 were 0.94 (0.75–1.18) in active women and 0.84 (0.71–0.998) in very active women (p for trend = 0.046). However, no significant associations were found between physical activity and obesity by BMI in women. Conclusions We found more significant associations between physical activity and obesity defined by WHtR than BMI. However, intervention studies are warranted to investigate and compare causal associations between physical activity and different obesity measures in various populations

  2. The protective role of Bax Inhibitor-1 against chronic mild stress through the inhibition of monoamine oxidase A

    PubMed Central

    Lee, Hwa-Young; Lee, Geum-Hwa; Marahatta, Anu; Lin, Shun-Mei; Lee, Mi-Rin; Jang, Kyu Yun; Kim, Kyung Min; Lee, Hee Jae; Lee, Jae-Won; Bagalkot, Tarique Rajasaheb; Chung, Young-Chul; Lee, Yong-Chul; Kim, Hyung-Ryong; Chae, Han-Jung

    2013-01-01

    The anti-apoptotic protein Bax inhibitor-1 (BI-1) is a regulator of apoptosis linked to endoplasmic reticulum (ER) stress. It has been hypothesized that BI-1 protects against neuron degenerative diseases. In this study, BI-1−/− mice showed increased vulnerability to chronic mild stress accompanied by alterations in the size and morphology of the hippocampi, enhanced ROS accumulation and an ER stress response compared with BI-1+/+ mice. BI-1−/− mice exposed to chronic mild stress showed significant activation of monoamine oxidase A (MAO-A), but not MAO-B, compared with BI-1+/+ mice. To examine the involvement of BI-1 in the Ca2+-sensitive MAO activity, thapsigargin-induced Ca2+ release and MAO activity were analyzed in neuronal cells overexpressing BI-1. The in vitro study showed that BI-1 regulates Ca2+ release and related MAO-A activity. This study indicates an endogenous protective role of BI-1 under conditions of chronic mild stress that is primarily mediated through Ca2+-associated MAO-A regulation. PMID:24292328

  3. The transcriptional PPARβ/δ network in human macrophages defines a unique agonist-induced activation state

    PubMed Central

    Adhikary, Till; Wortmann, Annika; Schumann, Tim; Finkernagel, Florian; Lieber, Sonja; Roth, Katrin; Toth, Philipp M.; Diederich, Wibke E.; Nist, Andrea; Stiewe, Thorsten; Kleinesudeik, Lara; Reinartz, Silke; Müller-Brüsselbach, Sabine; Müller, Rolf

    2015-01-01

    Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is a lipid ligand-inducible transcription factor with established metabolic functions, whereas its anti-inflammatory function is poorly understood. To address this issue, we determined the global PPARβ/δ-regulated signaling network in human monocyte-derived macrophages. Besides cell type-independent, canonical target genes with metabolic and immune regulatory functions we identified a large number of inflammation-associated NFκB and STAT1 target genes that are repressed by agonists. Accordingly, PPARβ/δ agonists inhibited the expression of multiple pro-inflammatory mediators and induced an anti-inflammatory, IL-4-like morphological phenotype. Surprisingly, bioinformatic analyses also identified immune stimulatory effects. Consistent with this prediction, PPARβ/δ agonists enhanced macrophage survival under hypoxic stress and stimulated CD8+ T cell activation, concomitantly with the repression of immune suppressive target genes and their encoded products CD274 (PD-1 ligand), CD32B (inhibitory Fcγ receptor IIB) and indoleamine 2,3-dioxygenase 1 (IDO-1), as well as a diminished release of the immune suppressive IDO-1 metabolite kynurenine. Comparison with published data revealed a significant overlap of the PPARβ/δ transcriptome with coexpression modules characteristic of both anti-inflammatory and pro-inflammatory cytokines. Our findings indicate that PPARβ/δ agonists induce a unique macrophage activation state with strong anti-inflammatory but also specific immune stimulatory components, pointing to a context-dependent function of PPARβ/δ in immune regulation. PMID:25934804

  4. Using constitutive activity to define appropriate high-throughput screening assays for orphan g protein-coupled receptors.

    PubMed

    Ngo, Tony; Coleman, James L J; Smith, Nicola J

    2015-01-01

    Orphan G protein-coupled receptors represent an underexploited resource for drug discovery but pose a considerable challenge for assay development because their cognate G protein signaling pathways are often unknown. In this methodological chapter, we describe the use of constitutive activity, that is, the inherent ability of receptors to couple to their cognate G proteins in the absence of ligand, to inform the development of high-throughput screening assays for a particular orphan receptor. We specifically focus on a two-step process, whereby constitutive G protein coupling is first determined using yeast Gpa1/human G protein chimeras linked to growth and β-galactosidase generation. Coupling selectivity is then confirmed in mammalian cells expressing endogenous G proteins and driving accumulation of transcription factor-fused luciferase reporters specific to each of the classes of G protein. Based on these findings, high-throughput screening campaigns can be performed on the already miniaturized mammalian reporter system. PMID:25563179

  5. Can we define an asymptotic value for the ice active surface site density for heterogeneous ice nucleation?

    NASA Astrophysics Data System (ADS)

    Niedermeier, Dennis; Augustin-Bauditz, Stefanie; Hartmann, Susan; Wex, Heike; Ignatius, Karoliina; Stratmann, Frank

    2015-05-01

    The immersion freezing behavior of droplets containing size-segregated, monodisperse feldspar particles was investigated. For all particle sizes investigated, a leveling off of the frozen droplet fraction was observed reaching a plateau within the heterogeneous freezing temperature regime (T >- 38°C). The frozen fraction in the plateau region was proportional to the particle surface area. Based on these findings, an asymptotic value for ice active surface site density ns, which we named ns⋆, could be determined for the investigated feldspar sample. The comparison of these results with those of other studies not only elucidates the general feasibility of determining such an asymptotic value but also shows that the value of ns⋆ strongly depends on the method of the particle surface area determination. However, such an asymptotic value might be an important input parameter for atmospheric modeling applications. At least it shows that care should be taken when ns is extrapolated to lower or higher temperature.

  6. Can we define an asymptotic value for the ice active surface site density for heterogeneous ice nucleation?

    NASA Astrophysics Data System (ADS)

    Niedermeier, Dennis; Augustin-Bauditz, Stefanie; Hartmann, Susan; Wex, Heike; Ignatius, Karoliina; Stratmann, Frank

    2015-04-01

    The formation of ice in atmospheric clouds has a substantial influence on the radiative properties of clouds as well as on the formation of precipitation. Therefore much effort has been made to understand and quantify the major ice formation processes in clouds. Immersion freezing has been suggested to be a dominant primary ice formation process in low and mid-level clouds (mixed-phase cloud conditions). It also has been shown that mineral dust particles are the most abundant ice nucleating particles in the atmosphere and thus may play an important role for atmospheric ice nucleation (Murray et al., 2012). Additionally, biological particles like bacteria and pollen are suggested to be potentially involved in atmospheric ice formation, at least on a regional scale (Murray et al., 2012). In recent studies for biological particles (SNOMAX and birch pollen), it has been demonstrated that freezing is induced by ice nucleating macromolecules and that an asymptotic value for the mass density of these ice nucleating macromolecules can be determined (Hartmann et al., 2013; Augustin et al., 2013, Wex et al., 2014). The question arises whether such an asymptotic value can also be determined for the ice active surface site density ns, a parameter which is commonly used to describe the ice nucleation activity of e.g., mineral dust. Such an asymptotic value for ns could be an important input parameter for atmospheric modeling applications. In the presented study, we therefore investigated the immersion freezing behavior of droplets containing size-segregated, monodisperse feldspar particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS). For all particle sizes considered in the experiments, we observed a leveling off of the frozen droplet fraction reaching a plateau within the heterogeneous freezing temperature regime (T > -38°C) which was proportional to the particle surface area. Based on these findings, we could determine an asymptotic value for the ice

  7. Defining torpor in free-ranging bats: experimental evaluation of external temperature-sensitive radiotransmitters and the concept of active temperature.

    PubMed

    Willis, C K R; Brigham, R M

    2003-07-01

    A variety of definitions involving body temperature (Tb), metabolic rate and behavior have been used to define torpor in mammals and birds. This problem is confounded in some studies of free-ranging animals that employ only skin temperature (Tsk), a measure that approximates but may not precisely reflect Tb. We assess the accuracy of Tsk in the context of a recent definition for torpor called active temperature. We compared the active temperatures of individual big brown bats (Eptesicus fuscus), which aggregate in cavities, with solitary, foliage-roosting hoary bats (Lasiurus cinereus). In captive big brown bats, we compared Tsk and core Tb at a range of ambient temperatures for clustered and solitary roosting animals, compared Tsk and Tb during arousal from torpor, and quantified the effect of flight on warming from torpor. Hoary bats had significantly lower active temperatures than big brown bats despite having the same normothermic Tsk. Tsk was significantly lower than Tb during normothermia but often greater than Tb during torpor. Flight increased the rate of warming from torpor. This effect was more pronounced for Tsk than Tb. This suggests that bats could rely on heat generated by flight muscles to complete the final stages of arousal. Using active temperature to define torpor may underestimate torpor due to ambient cooling of external transmitters or animals leaving roosts while still torpid. Conversely, active temperature may also overestimate shallow torpor use if it is recorded during active arousal when shivering and non-shivering thermogenesis warm external transmitters. Our findings illuminate the need for laboratory studies that quantify the relationship between metabolic rate and Tsk over a range of ambient temperatures. PMID:12764630

  8. Structurally well-defined macrophage activating factor derived from vitamin D3-binding protein has a potent adjuvant activity for immunization.

    PubMed

    Yamamoto, N; Naraparaju, V R

    1998-06-01

    Freund's adjuvant produced severe inflammation that augments development of antibodies. Thus, mixed administration of antigens with adjuvant was not required as long as inflammation was induced in the hosts. Since macrophage activation for phagocytosis and antigen processing is the first step of antibody development, inflammation-primed macrophage activation plays a major role in immune development. Therefore, macrophage activating factor should act as an adjuvant for immunization. The inflammation-primed macrophage activation process is the major macrophage activating cascade that requires participation of serum vitamin D3-binding protein (DBP; human DBP is known as Gc protein) and glycosidases of B and T lymphocytes. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase efficiently generated the most potent macrophage activating factor (designated GcMAF) we have ever encountered. Administration of GcMAF (20 or 100 pg/mouse) resulted in stimulation of the progenitor cells for extensive mitogenesis and activation of macrophages. Administration of GcMAF (100 pg/mouse) along with immunization of mice with sheep red blood cells (SRBC) produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days. Thus, GcMAF has a potent adjuvant activity for immunization. Although malignant tumours are poorly immunogenic, 4 days after GcMAF-primed immunization of mice with heat-killed Ehrlich ascites tumour cells, the ascites tumour was no longer transplantable in these mice. PMID:9682967

  9. Transcriptional regulation of the cyclin-dependent kinase inhibitor 1A (p21) gene by NFI in proliferating human cells

    PubMed Central

    Ouellet, Stéphane; Vigneault, François; Lessard, Maryse; Leclerc, Steeve; Drouin, Régen; Guérin, Sylvain L.

    2006-01-01

    The cyclin-dependent kinase inhibitor 1A (CDKN1A), also known as p21 (WAF1/CIP1) modulates cell cycle, apoptosis, senescence and differentiation via specific protein–protein interactions with the cyclins, cyclin-dependent kinase (Cdk), and many others. Expression of the p21 gene is mainly regulated at the transcriptional level. By conducting both ligation-mediated PCR (LMPCR) and chromatin immunoprecipitation (ChIP) in vivo, we identified a functional target site for the transcription factor, nuclear factor I (NFI), in the basal promoter from the p21 gene. Transfection of recombinant constructs bearing mutations in the p21 NFI site demonstrated that NFI acts as a repressor of p21 gene expression in various types of cultured cells. Inhibition of NFI in human skin fibroblasts through RNAi considerably increased p21 promoter activity suggesting that NFI is a key repressor of p21 transcription. Over-expression of each of the four NFI isoforms in HCT116 cells established that each of them contribute to various extend to the repression of the p21 gene. Most of all, over-expression of NFI-B in doxorubicin, growth-arrested HCT116 increased the proportion of cells in the S-phase of the cell cycle whereas NFI-A and NFI-X reduced it, thereby establishing a role for NFI in the cell cycle dependent expression of p21. PMID:17130157

  10. Correlation Between Radiation Dose to {sup 18}F-FDG-PET Defined Active Bone Marrow Subregions and Acute Hematologic Toxicity in Cervical Cancer Patients Treated With Chemoradiotherapy

    SciTech Connect

    Rose, Brent S.; Liang Yun; Lau, Steven K.; Jensen, Lindsay G.; Yashar, Catheryn M.; Hoh, Carl K.; Mell, Loren K.

    2012-07-15

    Purpose: To test the hypothesis that radiation dose to {sup 18}F-fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG-PET)-defined active bone marrow (BM{sub ACT}) subregions is correlated with hematologic toxicity in cervical cancer patients treated with chemoradiotherapy. Methods and Materials: The conditions of 26 women with cervical cancer who underwent {sup 18}F-FDG-PET before treatment with concurrent cisplatin and intensity-modulated radiation therapy were analyzed. BM{sub ACT} was defined as the subregion of total bone marrow (BM{sub TOT}) with a standardized uptake value (SUV) equal to or above the mean for that individual. Inactive bone marrow (BM{sub INACT}) was defined as BM{sub TOT} - BM{sub ACT}. Generalized linear modeling was used to test the correlation between BM{sub ACT} and BM{sub INACT} dose-volume metrics and hematologic nadirs, particularly white blood cell count (WBC) and absolute neutrophil count (ANC). Results: Increased BM{sub ACT} mean dose was significantly associated with decreased log(WBC) nadir ({beta} = -0.04; 95% CI, -0.07to -0.01; p = 0.009), decreased log(ANC) nadir ({beta} = -0.05; 95% CI, -0.08 to -0.02; p = 0.006), decreased hemoglobin nadir ({beta} = -0.16; 95% CI, -0.27 to -0.05; p = 0.010), and decreased platelet nadir ({beta} = -6.16; 95% CI, -9.37 to -2.96; p < 0.001). By contrast, there was no association between BM{sub INACT} mean dose and log(WBC) nadir ({beta} = -0.01; 95% CI, -0.06 to 0.05; p = 0.84), log(ANC) nadir ({beta} = -0.03; 95% CI, -0.10 to 0.04; p = 0.40), hemoglobin nadir ({beta} = -0.09; 95% CI, -0.31 to 0.14; p = 0.452), or platelet nadir ({beta} = -3.47; 95% CI, -10.44 to 3.50; p = 0.339). Conclusions: Irradiation of BM subregions with higher {sup 18}F-FDG-PET activity was associated with hematologic toxicity, supporting the hypothesis that reducing dose to BM{sub ACT} subregions could mitigate hematologic toxicity. Future investigation should seek to confirm these findings and to identify

  11. Defining the paramedic process.

    PubMed

    Carter, Holly; Thompson, James

    2015-01-01

    The use of a 'process of care' is well established in several health professions, most evidently within the field of nursing. Now ingrained within methods of care delivery, it offers a logical approach to problem solving and ensures an appropriate delivery of interventions that are specifically suited to the individual patient. Paramedicine is a rapidly advancing profession despite a wide acknowledgement of limited research provisions. This frequently results in the borrowing of evidence from other disciplines. While this has often been useful, there are many concerns relating to the acceptable limit of evidence transcription between professions. To date, there is no formally recognised 'process of care'-defining activity within the pre-hospital arena. With much current focus on the professional classification of paramedic work, it is considered timely to formally define a formula that underpins other professional roles such as nursing. It is hypothesised that defined processes of care, particularly the nursing process, may have features that would readily translate to pre-hospital practice. The literature analysed was obtained through systematic searches of a range of databases, including Ovid MEDLINE, Cumulative Index to Nursing and Allied Health. The results demonstrated that the defined process of care provides nursing with more than just a structure for practice, but also has implications for education, clinical governance and professional standing. The current nursing process does not directly articulate to the complex and often unstructured role of the paramedic; however, it has many principles that offer value to the paramedic in their practice. Expanding the nursing process model to include the stages of Dispatch Considerations, Scene Assessment, First Impressions, Patient History, Physical Examination, Clinical Decision-Making, Interventions, Re-evaluation, Transport Decisions, Handover and Reflection would provide an appropriate model for pre

  12. Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

    PubMed Central

    Wu, Mingyi; Xu, Li; Zhao, Longyan; Xiao, Chuang; Gao, Na; Luo, Lan; Yang, Lian; Li, Zi; Chen, Lingyun; Zhao, Jinhua

    2015-01-01

    Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan) contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants. PMID:25871288

  13. Bax inhibitor 1, a modulator of calcium homeostasis, confers affective resilience.

    PubMed

    Hunsberger, Joshua G; Machado-Vieira, Rodrigo; Austin, Daniel R; Zarate, Carlos; Chuang, De-Maw; Chen, Guang; Reed, John C; Manji, Husseini K

    2011-07-27

    The endoplasmic reticulum (ER) is a critical site for intracellular calcium storage as well as protein synthesis, folding, and trafficking. Disruption of these processes is gaining support for contributing to heritable vulnerability of certain diseases. Here, we investigated Bax inhibitor 1 (BI-1), an anti-apoptotic protein that primarily resides in the ER and associates with B-cell lymphoma 2 (Bcl-2) and Bcl-XL, as an affective resiliency factor through its modulation of calcium homeostasis. We found that transgenic (TG) mice with BI-1 reinforced expression, via the neuronal specific enolase promoter, showed protection against the learned helplessness (LH) paradigm, an animal model to test stress coping. TG mice were also protected against anhedonia following both serotonin and catecholamine depletion as measured in two different models, the female urine sniffing test and the saccharine preference test. In addition, we used primary mouse cortical cultures to explore the ability of BI-1 to influence calcium homeostasis under basal conditions and also following challenge with thapsigargin (THPS), an inhibitor of sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) that disrupts calcium homeostasis. TG neurons showed decreased basal cytosolic calcium levels and decreased Ca(2+) cytosolic accumulation following challenge with THPS as compared to WT neuronal cultures. Together, these data suggest that BI-1, through its actions on calcium homeostasis, may confer affective resiliency in multiple animal models of depression and anhedonia. PMID:21718971

  14. Bax Inhibitor-1 regulates hepatic lipid accumulation via ApoB secretion

    PubMed Central

    Lee, Hwa Young; Lee, Geum-Hwa; Bhattarai, Kashi Raj; Park, Byung-Hyun; Koo, Seung-Hoi; Kim, Hyung-Ryong; Chae, Han Jung

    2016-01-01

    In this study, we explored the effects of Bax Inhibitor-1 (BI-1) on ApoB aggregation in high-fat diet (HFD)-induced hepatic lipid accumulation. After 1 week on a HFD, triglycerides and cholesterol accumulated more in the liver and were not effectively secreted into the plasma, whereas after 8 weeks, lipids were highly accumulated in both the liver and plasma, with a greater effect in BI-1 KO mice compared with BI-1 WT mice. ApoB, a lipid transfer protein, was accumulated to a greater extent in the livers of HFD-BI-1 KO mice compared with HFD-BI-1 WT mice. Excessive post-translational oxidation of protein disulfide isomerase (PDI), intra-ER ROS accumulation and folding capacitance alteration were also observed in HFD-BI-1 KO mice. Higher levels of endoplasmic reticulum (ER) stress were consistently observed in KO mice compared with the WT mice. Adenovirus-mediated hepatic expression of BI-1 in the BI-1 KO mice rescued the above phenotypes. Our results suggest that BI-1-mediated enhancement of ApoB secretion regulates hepatic lipid accumulation, likely through regulation of ER stress and ROS accumulation. PMID:27297735

  15. Characterization of BAX inhibitor-1 as a novel leukemia-associated antigen.

    PubMed

    Schmidt, S M; König, T; Bringmann, A; Held, S; von Schwarzenberg, K; Heine, A; Holderried, T A W; Stevanovic, S; Grünebach, F; Brossart, P

    2009-10-01

    Using dendritic cells (DCs) electroporated with whole RNA isolated from blasts of a patient with acute myeloid leukemia (AML), we were able to generate leukemia-specific cytotoxic T lymphocytes (CTLs) capable of recognizing the leucemic cells. To identify T-cell epitopes mediating lysis of malignant cells, peptides were eluted from the patient's blasts and analyzed by mass spectrometry (LC/MS)-based peptide sequencing. Using this approach, an HLA-A24-binding peptide derived from Bax inhibitor-1 (BI-1), a regulator of apoptosis pathways, was identified as an epitope recognized by the generated CTLs. To further characterize this novel antigenic peptide, CTLs were induced using DCs electroporated with RNA coding for BI-1 or pulsed with the cognate peptide. These CTLs generated from healthy donors in vitro efficiently lysed the patient's blasts as well as other HLA-matched leukemic cells. In conclusion, we identified a BI-1 peptide as a novel immunogenic tumor-associated antigen (TAA) in AML. In vitro induction of BI-1-specific CTLs by RNA transfection or pulsing of DCs with the synthetically generated peptide was a feasible and highly effective method to generate leukemia-specific CTLs. As BI-1 is (over-) expressed in a broad variety of malignancies, it may represent an interesting novel TAA in the context of cancer vaccines. PMID:19609282

  16. Expression of Arabidopsis Bax Inhibitor-1 in transgenic sugarcane confers drought tolerance.

    PubMed

    Ramiro, Daniel Alves; Melotto-Passarin, Danila Montewka; Barbosa, Mariana de Almeida; Santos, Flavio Dos; Gomez, Sergio Gregorio Perez; Massola Júnior, Nelson Sidnei; Lam, Eric; Carrer, Helaine

    2016-09-01

    The sustainability of global crop production is critically dependent on improving tolerance of crop plants to various types of environmental stress. Thus, identification of genes that confer stress tolerance in crops has become a top priority especially in view of expected changes in global climatic patterns. Drought stress is one of the abiotic stresses that can result in dramatic loss of crop productivity. In this work, we show that transgenic expression of a highly conserved cell death suppressor, Bax Inhibitor-1 from Arabidopsis thaliana (AtBI-1), can confer increased tolerance of sugarcane plants to long-term (>20 days) water stress conditions. This robust trait is correlated with an increased tolerance of the transgenic sugarcane plants, especially in the roots, to induction of endoplasmic reticulum (ER) stress by the protein glycosylation inhibitor tunicamycin. Our findings suggest that suppression of ER stress in C4 grasses, which include important crops such as sorghum and maize, can be an effective means of conferring improved tolerance to long-term water deficit. This result could potentially lead to improved resilience and yield of major crops in the world. PMID:26872943

  17. Bax Inhibitor-1 regulates hepatic lipid accumulation via ApoB secretion.

    PubMed

    Lee, Hwa Young; Lee, Geum-Hwa; Bhattarai, Kashi Raj; Park, Byung-Hyun; Koo, Seung-Hoi; Kim, Hyung-Ryong; Chae, Han Jung

    2016-01-01

    In this study, we explored the effects of Bax Inhibitor-1 (BI-1) on ApoB aggregation in high-fat diet (HFD)-induced hepatic lipid accumulation. After 1 week on a HFD, triglycerides and cholesterol accumulated more in the liver and were not effectively secreted into the plasma, whereas after 8 weeks, lipids were highly accumulated in both the liver and plasma, with a greater effect in BI-1 KO mice compared with BI-1 WT mice. ApoB, a lipid transfer protein, was accumulated to a greater extent in the livers of HFD-BI-1 KO mice compared with HFD-BI-1 WT mice. Excessive post-translational oxidation of protein disulfide isomerase (PDI), intra-ER ROS accumulation and folding capacitance alteration were also observed in HFD-BI-1 KO mice. Higher levels of endoplasmic reticulum (ER) stress were consistently observed in KO mice compared with the WT mice. Adenovirus-mediated hepatic expression of BI-1 in the BI-1 KO mice rescued the above phenotypes. Our results suggest that BI-1-mediated enhancement of ApoB secretion regulates hepatic lipid accumulation, likely through regulation of ER stress and ROS accumulation. PMID:27297735

  18. Bax inhibitor 1 regulates ER-stress-induced ROS accumulation through the regulation of cytochrome P450 2E1.

    PubMed

    Kim, Hyung-Ryong; Lee, Geum-Hwa; Cho, Eun Yi; Chae, Soo-Wan; Ahn, Taeho; Chae, Han-Jung

    2009-04-15

    This study investigated the molecular mechanism by which Bax inhibitor 1 (BI1) abrogates the accumulation of reactive oxygen species (ROS) in the endoplasmic reticulum (ER). Electron uncoupling between NADPH-dependent cytochrome P450 reductase (NPR) and cytochrome P450 2E1 (P450 2E1) is a major source of ROS on the ER membrane. ER stress produced ROS accumulation and lipid peroxidation of the ER membrane, but BI1 reduced this accumulation. Under ER stress, expression of P450 2E1 in control cells was upregulated more than in BI1-overexpressing cells. In control cells, inhibiting P450 2E1 through chemical or siRNA approaches suppressed ROS accumulation, ER membrane lipid peroxidation and the resultant cell death after ER stress. However, it had little effect in BI1-overexpressing cells. In addition, BI1 knock down also increased ROS accumulation and expression of P450 2E1. In a reconstituted phospholipid membrane containing purified BI1, NPR and P450 2E1, BI1 dose-dependently decreased the production of ROS. BI1 bound to NPR with higher affinity than P450 2E1. Furthermore, BI1 overexpression reduced the interaction of NPR and P450 2E1, and decreased the catalytic activity of P450 2E1, suggesting that the flow of electrons from NPR to P450 2E1 can be modulated by BI1. In summary, BI1 reduces the accumulation of ROS and the resultant cell death through regulating P450 2E1. PMID:19339548

  19. Glycodendrimersomes from Sequence-Defined Janus Glycodendrimers Reveal High Activity and Sensor Capacity for the Agglutination by Natural Variants of Human Lectins.

    PubMed

    Zhang, Shaodong; Xiao, Qi; Sherman, Samuel E; Muncan, Adam; Ramos Vicente, Andrea D M; Wang, Zhichun; Hammer, Daniel A; Williams, Dewight; Chen, Yingchao; Pochan, Darrin J; Vértesy, Sabine; André, Sabine; Klein, Michael L; Gabius, Hans-Joachim; Percec, Virgil

    2015-10-21

    A library of eight amphiphilic Janus glycodendrimers (Janus-GDs) presenting D-lactose (Lac) and a combination of Lac with up to eight methoxytriethoxy (3EO) units in a sequence-defined arrangement was synthesized via an iterative modular methodology. The length of the linker between Lac and the hydrophobic part of the Janus-GDs was also varied. Self-assembly by injection from THF solution into phosphate-buffered saline led to unilamellar, monodisperse glycodendrimersomes (GDSs) with dimensions predicted by Janus-GD concentration. These GDSs provided a toolbox to measure bioactivity profiles in agglutination assays with sugar-binding proteins (lectins). Three naturally occurring forms of the human adhesion/growth-regulatory lectin galectin-8, Gal-8S and Gal-8L, which differ by the length of linker connecting their two active domains, and a single amino acid mutant (F19Y), were used as probes to study activity and sensor capacity. Unpredictably, the sequence of Lac on the Janus-GDs was demonstrated to determine bioactivity, with the highest level revealed for a Janus-GD with six 3EO groups and one Lac. A further increase in Lac density was invariably accompanied by a substantial decrease in agglutination, whereas a decrease in Lac density resulted in similar or lower bioactivity and sensor capacity. Both changes in topology of Lac presentation of the GDSs and seemingly subtle alterations in protein structure resulted in different levels of bioactivity, demonstrating the presence of regulation on both GDS surface and lectin. These results illustrate the applicability of Janus-GDs to dissect structure-activity relationships between programmable cell surface models and human lectins in a highly sensitive and physiologically relevant manner. PMID:26421463

  20. Neogenin, Defined as a GD3-associated Molecule by Enzyme-mediated Activation of Radical Sources, Confers Malignant Properties via Intracytoplasmic Domain in Melanoma Cells.

    PubMed

    Kaneko, Kei; Ohkawa, Yuki; Hashimoto, Noboru; Ohmi, Yuhsuke; Kotani, Norihiro; Honke, Koichi; Ogawa, Mitsutaka; Okajima, Tetsuya; Furukawa, Keiko; Furukawa, Koichi

    2016-08-01

    To investigate mechanisms for increased malignant properties in malignant melanomas by ganglioside GD3, enzyme-mediated activation of radical sources and subsequent mass spectrometry were performed using an anti-GD3 antibody and GD3-positive (GD3+) and GD3-negative (GD3-) melanoma cell lines. Neogenin, defined as a GD3-neighbored molecule, was largely localized in lipid/rafts in GD3+ cells. Silencing of neogenin resulted in the reduction of cell growth and invasion activity. Physical association between GD3 and neogenin was demonstrated by immunoblotting of the immunoprecipitates with anti-neogenin antibody from GD3+ cell lysates. The intracytoplasmic domain of neogenin (Ne-ICD) was detected in GD3+ cells at higher levels than in GD3- cells when cells were treated by a proteasome inhibitor but not when simultaneously treated with a γ-secretase inhibitor. Exogenous GD3 also induced increased Ne-ICD in GD3- cells. Overexpression of Ne-ICD in GD3- cells resulted in the increased cell growth and invasion activity, suggesting that Ne-ICD plays a role as a transcriptional factor to drive malignant properties of melanomas after cleavage with γ-secretase. γ-Secretase was found in lipid/rafts in GD3+ cells. Accordingly, immunocyto-staining revealed that GD3, neogenin, and γ-secretase were co-localized at the leading edge of GD3+ cells. All these results suggested that GD3 recruits γ-secretase to lipid/rafts, allowing efficient cleavage of neogenin. ChIP-sequencing was performed to identify candidates of target genes of Ne-ICD. Some of them actually showed increased expression after expression of Ne-ICD, probably exerting malignant phenotypes of melanomas under GD3 expression. PMID:27288875

  1. Controllable assembly of well-defined monodisperse Au nanoparticles on hierarchical ZnO microspheres for enhanced visible-light-driven photocatalytic and antibacterial activity

    NASA Astrophysics Data System (ADS)

    Wang, Yuan; Fang, Hua-Bin; Zheng, Yan-Zhen; Ye, Rongqin; Tao, Xia; Chen, Jian-Feng

    2015-11-01

    A high-efficiency visible-light-driven photocatalyst composed of homogeneously distributed Au nanoparticles (AuNPs) well-defined on hierarchical ZnO microspheres (ZMS) via a controllable layer-by-layer self-assembly technique is demonstrated. The gradual growth of the characteristic absorption bands of Au loaded on ZnO in the visible light region with an increasing number of assemblies indicates the enhancement of the light harvesting ability of the ZMS/Au composites as well as the reproducibility and controllability of the entire assembly process. Results on the photoelectrochemical performance characterized by EIS and transient photocurrent response spectra indicate that the ZMS/Au composites possess increased photoinduced charge separation and transfer efficiency compared to the pure ZMS film. As a result, the hybrid composites exhibited enhanced decomposition activity for methylene blue and salicylic acid as well as antibacterial activity in killing S. aureus and E. coli under visible light irradiation. It can be noted that well-distributed Au components even at a rather low Au/ZnO weight ratio of ~1.2% also exhibited extraordinary photocatalysis. Such a facile and controllable self-assembly approach may be viable for preparing high-performance visible-light-driven ZMS/Au photocatalysts in a simple and controllable way, and consequently, the technology may extend to other plasmon-enhanced heterostructures made of nanostructured semiconductors and noble metals for great potential application in environmental protection.A high-efficiency visible-light-driven photocatalyst composed of homogeneously distributed Au nanoparticles (AuNPs) well-defined on hierarchical ZnO microspheres (ZMS) via a controllable layer-by-layer self-assembly technique is demonstrated. The gradual growth of the characteristic absorption bands of Au loaded on ZnO in the visible light region with an increasing number of assemblies indicates the enhancement of the light harvesting ability of

  2. An olive pollen protein with allergenic activity, Ole e 10, defines a novel family of carbohydrate-binding modules and is potentially implicated in pollen germination

    PubMed Central

    2005-01-01

    CBMs (carbohydrate-binding modules) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. They have been frequently identified by amino acid sequence alignments, but only a few have been experimentally established to have a carbohydrate-binding activity. A small olive pollen protein, Ole e 10 (10 kDa), has been described as a major inducer of type I allergy in humans. In the present study, the ability of Ole e 10 to bind several polysaccharides has been analysed by affinity gel electrophoresis, which demonstrated that the protein bound 1,3-β-glucans preferentially. Analytical ultracentrifugation studies confirmed binding to laminarin, at a protein/ligand ratio of 1:1. The interaction of Ole e 10 with laminarin induced a conformational change in the protein, as detected by CD and fluorescence analyses, and an increase of 3.6 °C in the thermal denaturation temperature of Ole e 10 in the presence of the glycan. These results, and the absence of alignment of the sequence of Ole e 10 with that of any classified CBM, indicate that this pollen protein defines a novel family of CBMs, which we propose to name CBM43. Immunolocalization of Ole e 10 in mature and germinating pollen by transmission electron microscopy and confocal laser scanning microscopy demonstrated the co-localization of Ole e 10 and callose (1,3-β-glucan) in the growing pollen tube, suggesting a role for this protein in the metabolism of carbohydrates and in pollen tube wall re-formation during germination. PMID:15882149

  3. ERBB receptor feedback inhibitor 1: identification and regulation by estrogen in chickens.

    PubMed

    Ahn, Suzie E; Jeong, Wooyoung; Kim, Ji-Hye; Lim, Whasun; Kim, Jinyoung; Bazer, Fuller W; Han, Jae Yong; Song, Gwonhwa

    2012-01-01

    The ERBB receptor feedback inhibitor 1 (ERRFI1) is a scaffolding adaptor protein, that plays a pivotal role in the epidermal growth factor receptor (EGFR) cell signaling cascade as a negative regulator affecting many important physiological processes. It was recently reported that ERRFI1 is a critical regulator of the response of the endometrium to estrogen regulation of tissue homeostasis in mice. But, very little is known about ERRF11 and hormonal regulation of the ERRFI1 gene in chickens. Therefore, in the present study, ERRFI1 gene was cloned and its differential expression profile analyzed at different embryonic stages, in various adult organs, and in oviducts from estrogen-treated chickens. Chicken ERRFI1 has an open-reading frame of 2848 nucleotides that encode for a protein of 465 amino acids that has considerable homology to mammalian ERRFI1 proteins (>62% identity). Importantly, ERRFI1 mRNA is abundantly distributed in various organs from chickens. We then determined that DES (diethylstilbestrol, a synthetic nonsteroidal estrogen) induced ERRFI1 mRNA and protein predominantly in luminal and glandular epithelial cells of the oviduct. Further, we determined whether microRNAs, specifically miR-200b, miR-429 and miR-1639, influence ERRFI1 expression via its 3'UTR and found that it does not directly target the 3'UTR of ERRFI1 mRNA. Therefore, it is unlikely that post-transcriptional regulation influences ERRFI1 expression in the chicken oviduct. In conclusion, our results indicate that ERRFI1 is a novel estrogen-stimulated gene expressed in epithelial cells of the chicken oviduct that likely plays an important role in oviduct growth and differentiation during early development of the chicken. PMID:22137914

  4. Overexpression of BAX INHIBITOR-1 Links Plasma Membrane Microdomain Proteins to Stress1[OPEN

    PubMed Central

    Ishikawa, Toshiki; Aki, Toshihiko; Yanagisawa, Shuichi; Uchimiya, Hirofumi; Kawai-Yamada, Maki

    2015-01-01

    BAX INHIBITOR-1 (BI-1) is a cell death suppressor widely conserved in plants and animals. Overexpression of BI-1 enhances tolerance to stress-induced cell death in plant cells, although the molecular mechanism behind this enhancement is unclear. We recently found that Arabidopsis (Arabidopsis thaliana) BI-1 is involved in the metabolism of sphingolipids, such as the synthesis of 2-hydroxy fatty acids, suggesting the involvement of sphingolipids in the cell death regulatory mechanism downstream of BI-1. Here, we show that BI-1 affects cell death-associated components localized in sphingolipid-enriched microdomains of the plasma membrane in rice (Oryza sativa) cells. The amount of 2-hydroxy fatty acid-containing glucosylceramide increased in the detergent-resistant membrane (DRM; a biochemical counterpart of plasma membrane microdomains) fraction obtained from BI-1-overexpressing rice cells. Comparative proteomics analysis showed quantitative changes of DRM proteins in BI-1-overexpressing cells. In particular, the protein abundance of FLOTILLIN HOMOLOG (FLOT) and HYPERSENSITIVE-INDUCED REACTION PROTEIN3 (HIR3) markedly decreased in DRM of BI-1-overexpressing cells. Loss-of-function analysis demonstrated that FLOT and HIR3 are required for cell death by oxidative stress and salicylic acid, suggesting that the decreased levels of these proteins directly contribute to the stress-tolerant phenotypes in BI-1-overexpressing rice cells. These findings provide a novel biological implication of plant membrane microdomains in stress-induced cell death, which is negatively modulated by BI-1 overexpression via decreasing the abundance of a set of key proteins involved in cell death. PMID:26297139

  5. Loss of Calmodulin Binding to Bax Inhibitor-1 Affects Pseudomonas-mediated Hypersensitive Response-associated Cell Death in Arabidopsis thaliana*

    PubMed Central

    Kawai-Yamada, Maki; Hori, Zenta; Ogawa, Taro; Ihara-Ohori, Yuri; Tamura, Katsunori; Nagano, Minoru; Ishikawa, Toshiki; Uchimiya, Hirofumi

    2009-01-01

    Bax inhibitor-1 (BI-1) is a cell death suppressor protein conserved across a variety of organisms. The Arabidopsis atbi1-1 plant is a mutant in which the C-terminal 6 amino acids of the expressed BI-1 protein have been replaced by T-DNA insertion. This mutant BI-1 protein (AtBI-CM) produced in Escherichia coli can no longer bind to calmodulin. A promoter-reporter assay demonstrated compartmentalized expression of BI-1 during hypersensitive response, introduced by the inoculation of Pseudomonas syringae possessing the avrRTP2 gene, Pst(avrRPT2). In addition, both BI-1 knockdown plants and atbi1-1 showed increased sensitivity to Pst(avrRPT2)-induced cell death. The results indicated that the loss of calmodulin binding reduces the cell death suppressor activity of BI-1 in planta. PMID:19674971

  6. In vitro activity of telithromycin and quinupristin/dalfopristin against methicillin-resistant coagulase-negative staphylococci with defined resistance genotypes.

    PubMed

    Novotná, G; Spízek, J; Janata, J

    2007-01-01

    We determined the activities of new antibiotics telithromycin (ketolide) and quinupristin/dalfopristin (streptogramins) against 88 macrolide and/or lincosamide resistant coagulase-negative staphylococci (CoNS) isolates with defined resistance gene status. Telithromycin susceptibility was determined only in erythromycin-sensitive isolates (15) indicating the same mechanisms of resistance. In contrast, all erythromycin-resistant isolates (73) were either constitutively resistant to telithromycin (13 isolates with constitutive erm genes) or demonstrated telithromycin D-shaped zone (60 isolates with inducible msr(A) and/or erm). However, the level of inducible resistance conferred by msr(A) (35 isolates) was borderline even after induction by erythromycin. No quinupristin/dalfopristin resistant isolate was observed if tested by disk-diffusion method (DDM) but 18 isolates were intermediate (MIC = 1-3 mg/L) and two isolates resistant (MIC = 8 mg/L) if tested by E-test. All these isolates were resistant to streptogramin A and harbored vga(A) gene (1 isolate) or vga(A)LC gene (19 isolates). MICs for quinupristin/dalfopristin were higher for isolates with combination of streptogramin A resistance and constitutive MLSB resistance (MIC = 3-8 mg/L in 4 isolates) than for streptogramin A-resistant isolates susceptible to streptogramin B (MIC = 0.5-2 mg/L in 16 isolates). In addition to S. haemolyticus, vga(A)LC was newly identified in S. epidermidis and S. warnerii indicating its widespread occurrence in CoNS. Misidentification of low-level resistant isolates by DDM may contribute to dissemination of streptogramin A resistance. PMID:18450221

  7. Mitochondrial Division Inhibitor 1 Ameliorates Mitochondrial Injury, Apoptosis, and Motor Dysfunction After Acute Spinal Cord Injury in Rats.

    PubMed

    Li, Gang; Jia, Zhiqiang; Cao, Yang; Wang, Yansong; Li, Haotian; Zhang, Zhenyu; Bi, Jing; Lv, Gang; Fan, Zhongkai

    2015-07-01

    Mitochondrial division inhibitor 1 (Mdivi-1) is the most effective pharmacological inhibitor of mitochondrial fission. Spinal cord injury (SCI) is a common and serious trauma, which lacks efficient treatment. This study aimed to detect the role of Mdivi-1 in neuronal injury and its underlying mechanism after acute SCI (ASCI) in rats. Western blot analysis showed that Bax levels on the mitochondrial outer membrane, and release of cytochrome C (cytC) and apoptosis-inducing factor (AIF) from the mitochondria began to increase significantly at 4 h after ASCI, then peaked at 16 h, and declined significantly from 16 to 24 h. However, the mitochondrial levels of Bcl-2 increased significantly at 2 h, peaked at 4 h, and subsequently significantly decreased from 4 to 24 h after ASCI. In addition, Mdivi-1(1.2 mg/kg) significantly suppressed the translocation of dynamin-related protein 1 (Drp1) and Bax to the mitochondria, mitochondrial depolarization, decrease of ATP and reduced Glutathione, increase of the Malondialdehyde, cytC release, and AIF translocation at 16 h and 3 days after ASCI, and also inhibited the caspase-3 activation and decrease of the percentage of apoptotic cells at 16 h, 3 and 10 days, further, ameliorated the motor dysfunction greatly from 3 to 10 days after ASCI in rats. This neuroprotective effect was dose-dependent. However, Mdivi-1(1.2 mg/kg) had no effects on the translocation of Bcl-2 and fission protein 1 on the mitochondria, and did not affect the expression of total Drp1 at 16 h after ASCI. Our experimental findings indicated that Mdivi-1 can protect rats against ASCI, and that its underlying mechanism may be associated with inhibition of Drp1 translocation to the mitochondria, alleviation of mitochondrial dysfunction and oxidative stress, and suppression of caspase-dependent and -independent apoptosis. PMID:25968480

  8. Defining the Anthropocene

    NASA Astrophysics Data System (ADS)

    Lewis, Simon; Maslin, Mark

    2016-04-01

    Time is divided by geologists according to marked shifts in Earth's state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Should the Anthropocene - the idea that human activity is a force acting upon the Earth system in ways that mean that Earth will be altered for millions of years - be defined as a geological time-unit at the level of an Epoch? Here we appraise the data to assess such claims, first in terms of changes to the Earth system, with particular focus on very long-lived impacts, as Epochs typically last millions of years. Can Earth really be said to be in transition from one state to another? Secondly, we then consider the formal criteria used to define geological time-units and move forward through time examining whether currently available evidence passes typical geological time-unit evidence thresholds. We suggest two time periods likely fit the criteria (1) the aftermath of the interlinking of the Old and New Worlds, which moved species across continents and ocean basins worldwide, a geologically unprecedented and permanent change, which is also the globally synchronous coolest part of the Little Ice Age (in Earth system terms), and the beginning of global trade and a new socio-economic "world system" (in historical terms), marked as a golden spike by a temporary drop in atmospheric CO2, centred on 1610 CE; and (2) the aftermath of the Second World War, when many global environmental changes accelerated and novel long-lived materials were increasingly manufactured, known as the Great Acceleration (in Earth system terms) and the beginning of the Cold War (in historical terms), marked as a golden spike by the peak in radionuclide fallout in 1964. We finish by noting that the Anthropocene debate is politically loaded, thus transparency in the presentation of evidence is essential if a formal definition of the Anthropocene is to avoid becoming a debate about bias. The

  9. Defining an emerging disease.

    PubMed

    Moutou, F; Pastoret, P-P

    2015-04-01

    Defining an emerging disease is not straightforward, as there are several different types of disease emergence. For example, there can be a 'real' emergence of a brand new disease, such as the emergence of bovine spongiform encephalopathy in the 1980s, or a geographic emergence in an area not previously affected, such as the emergence of bluetongue in northern Europe in 2006. In addition, disease can emerge in species formerly not considered affected, e.g. the emergence of bovine tuberculosis in wildlife species since 2000 in France. There can also be an unexpected increase of disease incidence in a known area and a known species, or there may simply be an increase in our knowledge or awareness of a particular disease. What all these emerging diseases have in common is that human activity frequently has a role to play in their emergence. For example, bovine spongiform encephalopathy very probably emerged as a result of changes in the manufacturing of meat-and-bone meal, bluetongue was able to spread to cooler climes as a result of uncontrolled trade in animals, and a relaxation of screening and surveillance for bovine tuberculosis enabled the disease to re-emerge in areas that had been able to drastically reduce the number of cases. Globalisation and population growth will continue to affect the epidemiology of diseases in years to come and ecosystems will continue to evolve. Furthermore, new technologies such as metagenomics and high-throughput sequencing are identifying new microorganisms all the time. Change is the one constant, and diseases will continue to emerge, and we must consider the causes and different types of emergence as we deal with these diseases in the future. PMID:26470448

  10. Interpolation and Definability

    NASA Astrophysics Data System (ADS)

    Gabbay, Dov M.; Maksimova, Larisa L.

    This chapter is on interpolation and definability. This notion is not only central in pure logic, but has significant meaning and applicability in all areas where logic itself is applied, especially in computer science, artificial intelligence, logic programming, philosophy of science and natural language. The notion may sometimes appear to the reader as too technical/mathematical but it does also have a general meaning in terms of expressibility and definability.

  11. A role for the anaphase-promoting complex inhibitor Emi2/XErp1, a homolog of early mitotic inhibitor 1, in cytostatic factor arrest of Xenopus eggs

    PubMed Central

    Tung, Jeffrey J.; Hansen, David V.; Ban, Kenneth H.; Loktev, Alexander V.; Summers, Matthew K.; Adler, John R.; Jackson, Peter K.

    2005-01-01

    Unfertilized vertebrate eggs are arrested in metaphase of meiosis II with high cyclin B/Cdc2 activity to prevent parthenogenesis. Until fertilization, exit from metaphase is blocked by an activity called cytostatic factor (CSF), which stabilizes cyclin B by inhibiting the anaphase-promoting complex (APC) ubiquitin ligase. The APC inhibitor early mitotic inhibitor 1 (Emi1) was recently found to be required for maintenance of CSF arrest. We show here that exogenous Emi1 is unstable in CSF-arrested Xenopus eggs and is destroyed by the SCFβTrCP ubiquitin ligase, suggesting that endogenous Emi1, an apparent 44-kDa protein, requires a stabilizing factor. However, anti-Emi1 antibodies crossreact with native Emi2/Erp1/FBXO43, a homolog of Emi1 and conserved APC inhibitor. Emi2 is stable in CSF-arrested eggs, is sufficient to prevent CSF release, and is rapidly degraded in a Polo-like kinase 1-dependent manner in response to calcium-mediated egg activation. These results identify Emi2 as a candidate CSF maintenance protein. PMID:15753281

  12. Defining Airflow Obstruction

    PubMed Central

    Eschenbacher, William L.

    2016-01-01

    Airflow obstruction has been defined using spirometric test results when the forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio is below a fixed cutoff (<70%) or lower limits of normal (LLN) from reference equations that are based on values from a normal population. However, similar to other positive or abnormal diagnostic test results that are used to identify the presence of disease, perhaps airflow obstruction should be defined based on the values of FEV1/FVC for a population of individuals with known disease such as chronic obstructive pulmonary disease (COPD). Unfortunately, we do not know such a distribution of values of FEV1/FVC for patients with COPD since there is no gold standard for this syndrome or condition. Yet, we have used this physiologic definition of airflow obstruction based on a normal population to identify patients with COPD. In addition, we have defined airflow obstruction as either being present or absent. Instead, we should use a different approach to define airflow obstruction based on the probability or likelihood that the airflow obstruction is present which in turn would give us the probability or likelihood of a disease state such as COPD. PMID:27239557

  13. Defining Equality in Education

    ERIC Educational Resources Information Center

    Benson, Ronald E.

    1977-01-01

    Defines equality of education in three areas: 1) by the degree of integration of school systems; 2) by a comparison of material resources and assets in education; and 3) by the effects of schooling as measured by the mean scores of groups on standardized tests. Available from: College of Education, 107 Quadrangle, Iowa State University, Ames, Iowa…

  14. Defining Supports Geometry

    ERIC Educational Resources Information Center

    Stephan, Michelle L.; McManus, George E.; Dickey, Ashley L.; Arb, Maxwell S.

    2012-01-01

    The process of developing definitions is underemphasized in most mathematics instruction. Investing time in constructing meaning is well worth the return in terms of the knowledge it imparts. In this article, the authors present a third approach to "defining," called "constructive." It involves modifying students' previous understanding of a term…

  15. On Defining Mass

    ERIC Educational Resources Information Center

    Hecht, Eugene

    2011-01-01

    Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement…

  16. Defining Effective Teaching

    ERIC Educational Resources Information Center

    Layne, L.

    2012-01-01

    The author looks at the meaning of specific terminology commonly used in student surveys: "effective teaching." The research seeks to determine if there is a difference in how "effective teaching" is defined by those taking student surveys and those interpreting the results. To investigate this difference, a sample group of professors and students…

  17. Defining structural limit zones

    NASA Technical Reports Server (NTRS)

    Merchant, D. H.

    1978-01-01

    Method for defining limit loads uses probability distribution of largest load occurring during given time intervals. Method is compatible with both deterministic and probabilistic structural design criteria. It also rationally accounts for fact that longer structure is exposed to random loading environment, greater is possibility that it will experience extreme load.

  18. Defining Faculty Work.

    ERIC Educational Resources Information Center

    Gray, Peter J.; Diamond, Robert M.

    1994-01-01

    A process of planned change is proposed for redefining college faculty work. Legitimate faculty work is defined in broad terms, and information sources and methods for collecting information to support redefinition are identified. The final step in the redefinition process is the development of new mission statements for the institution and its…

  19. Defined by Limitations

    ERIC Educational Resources Information Center

    Arriola, Sonya; Murphy, Katy

    2010-01-01

    Undocumented students are a population defined by limitations. Their lack of legal residency and any supporting paperwork (e.g., Social Security number, government issued identification) renders them essentially invisible to the American and state governments. They cannot legally work. In many states, they cannot legally drive. After the age of…

  20. Regulation of the Action of Early Mitotic Inhibitor 1 on the Anaphase-promoting Complex/Cyclosome by Cyclin-dependent Kinases*

    PubMed Central

    Moshe, Yakir; Bar-On, Ortal; Ganoth, Dvora; Hershko, Avram

    2011-01-01

    Cell cycle regulation is characterized by alternating activities of cyclin-dependent kinases (CDKs) and of the ubiquitin ligase anaphase promoting complex/cyclosome (APC/C). During S-phase APC/C is inhibited by early mitotic inhibitor 1 (Emi1) to allow the accumulation of cyclins A and B and to prevent re-replication. Emi1 is degraded at prophase by a Plk1-dependent pathway. Recent studies in which the degradation pathway of Emi1 was disrupted have shown that APC/C is activated at mitotic entry despite stabilization of Emi1. These results suggested the possibility of additional mechanisms other than degradation of Emi1, which release APC/C from inhibition by Emi1 upon entry into mitosis. In this study we report one such mechanism, by which the ability of Emi1 to inhibit APC/C is negatively regulated by CDKs. We show that in Plk1-inhibited cells Emi1 is stabilized and phosphorylated, that Emi1 is phosphorylated by CDKs in mitotic but not S-phase cell extracts, and that Emi1 phosphorylation by mitotic cell extracts or purified CDKs markedly reduces the ability of Emi1 to bind and to inhibit APC/C. Finally, we show that the addition of extracts from S-phase cells to extracts from mitotic cells protects Emi1 from CDK-mediated inactivation. PMID:21454540

  1. Identification of two catalytic residues in RAG1 that define a single active site within the RAG1/RAG2 protein complex.

    PubMed

    Fugmann, S D; Villey, I J; Ptaszek, L M; Schatz, D G

    2000-01-01

    During V(D)J recombination, the RAG1 and RAG2 proteins cooperate to catalyze a series of DNA bond breakage and strand transfer reactions. The structure, location, and number of active sites involved in RAG-mediated catalysis have as yet not been determined. Using protein secondary structure prediction algorithms, we have identified a region of RAG1 with possible structural similarities to the active site regions of transposases and retroviral integrases. Based on this information, we have identified two aspartic acid residues in RAG1 (D600 and D708) that function specifically in catalysis. The results support a model in which RAG1 contains a single, divalent metal ion binding active site structurally related to the active sites of transposases/integrases and responsible for all catalytic functions of the RAG protein complex. PMID:10678172

  2. Defining the level of human immunodeficiency virus type 1 (HIV-1) protease activity required for HIV-1 particle maturation and infectivity.

    PubMed Central

    Rosé, J R; Babé, L M; Craik, C S

    1995-01-01

    The human immunodeficiency virus type 1 (HIV-1) protease is the enzyme required for processing of the Gag and Gag-Pol polyproteins to yield mature, infectious virions. Although the complete absence of proteolytic activity prevents maturation, the level of activity sufficient for maturation and subsequent infectivity has not been determined. Amino acid substitutions that reduce catalytic activity without affecting substrate recognition have been engineered into the active site of the HIV-1 protease. The catalytic efficiency (kcat) of the HIV-1 protease is decreased 4-fold when threonine 26 is replaced by serine (T26S) and approximately 50-fold when alanine 28 is replaced by serine (A28S). Genes containing these mutations were cloned into a proviral vector for analysis of their effects on virion maturation and infectivity. The results show that virions containing the T26S protease variant, in which only 25% of the protease is active, are very similar to wild-type virions, although slight reductions in infectivity are observed. Virions containing the A28S protease variant are not infectious, even though a limited amount of polyprotein processing does occur. There appears to be a linear correlation between the level of protease activity and particle infectivity. Our observations suggest that a threshold of protease activity exists between a 4-fold and 50-fold reduction, below which processing is insufficient to yield infectious particles. Our data also suggest that a reduction of protease activity by 50-fold or greater is sufficient to prevent the formation of infectious particles. PMID:7535864

  3. The p16(INK4A)/pRb pathway and telomerase activity define a subgroup of Ph+ adult Acute Lymphoblastic Leukemia associated with inferior outcome.

    PubMed

    Chien, Wei W; Catallo, Régine; Chebel, Amel; Baranger, Laurence; Thomas, Xavier; Béné, Marie-Christine; Gerland, Luc M; Schmidt, Aline; Beldjord, Kheira; Klein, Nathalie; Escoffre-Barbe, Martine; Leguay, Thibaut; Huguet, Françoise; Larosa, Fabrice; Hayette, Sandrine; Plesa, Adriana; Ifrah, Norbert; Dombret, Hervé; Salles, Gilles; Chassevent, Agnès; Ffrench, Martine

    2015-04-01

    Adult Acute Lymphoblastic Leukemia (ALL) therapies have been improved by pediatric-like approaches. However, treatment failures and relapses are common and new markers are needed to identify patients with poor prognosis in prospective trials. The p16(INK4A)/CDK4-6/pRb pathway and telomerase activity, which are implicated in cell activation and aging, were analyzed to identify new prognostic markers. Proteins of the p16(INK4A)/CDK4-6/pRb pathway and telomerase activity were analyzed in 123 adult B-cell precursor (BCP) ALL cases included in the GRAALL/GRAAPH trials. We found a significantly increased expression of p16(INK4A) in BCP-ALLs with MLL rearrangement. Telomerase activity was significantly lower in Philadelphia chromosome-negative/IKAROS-deleted (BCR-ABL1(-)/IKAROS(del)) cases compared to Philadelphia chromosome-positive (BCR-ABL1+) BCP-ALLs. In BCR-ABL1+ ALLs, high CDK4 expression, phosphorylated pRb (p-pRb) and telomerase activity were significantly associated with a shorter disease-free survival (DFS) and event-free survival (EFS). Enhanced p16(INK4A) expression was only related to a significantly shorter DFS. In vitro analyses of normal stimulated lymphocytes after short- and long-term cultures demonstrated that the observed protein variations of poor prognosis in BCR-ABL1+ ALLs may be related to cell activation but not to cell aging. For these patients, our findings argue for the development of therapeutic strategies including the addition of new lymphocyte activation inhibitors to current treatments. PMID:25675863

  4. Defining Dynamic Route Structure

    NASA Technical Reports Server (NTRS)

    Zelinski, Shannon; Jastrzebski, Michael

    2011-01-01

    This poster describes a method for defining route structure from flight tracks. Dynamically generated route structures could be useful in guiding dynamic airspace configuration and helping controllers retain situational awareness under dynamically changing traffic conditions. Individual merge and diverge intersections between pairs of flights are identified, clustered, and grouped into nodes of a route structure network. Links are placed between nodes to represent major traffic flows. A parametric analysis determined the algorithm input parameters producing route structures of current day flight plans that are closest to todays airway structure. These parameters are then used to define and analyze the dynamic route structure over the course of a day for current day flight paths. Route structures are also compared between current day flight paths and more user preferred paths such as great circle and weather avoidance routing.

  5. Defining the Structural Parameters that Confer Anticonvulsant Activity by the Site-by-Site Modification of (R)-N′-Benzyl 2- Amino-3-methylbutanamide

    PubMed Central

    King, Amber; De Ryck, Marc; Kaminski, Rafal; Valade, Anne; Stables, James P.; Kohn, Harold

    2011-01-01

    Primary Amino Acid Derivatives (PAADs) (N′-benzyl 2-substituted 2-amino acetamides) are structurally related to Functionalized Amino Acids (FAAs) (N′-benzyl 2- substituted 2-acetamido acetamides) but differ by the absence of the terminal N-acetyl group. Both classes exhibit potent anticonvulsant activities in the maximal electroshock seizure animal model and the reported structure-activity relationships (SARs) of PAADs and FAAs differ in significant ways. Recently, we documented that PAAD efficacy was associated with a hydrocarbon moiety at the C(2)-carbon, while in the FAAs, a substituted heteroatom one atom removed from the C(2)-center was optimal. Previously in this issue, we showed that PAAD activity was dependent upon the electronic properties of the 4′-N′-benzylamide substituent, while FAA activity was insensitive to electronic changes at this site. In this study, we prepared analogs of (R)-N′-benzyl 2-amino-3-methylbutanamide to identify the structural components for maximal anticonvulsant activity. We demonstrated that the SAR of PAADs and FAAs diverged at the terminal amide site and that PAADs had considerably more structural latitude in the types of units that could be incorporated at this position, suggesting that these compounds function according to different mechanism(s). PMID:21861466

  6. Quantification of pulmonary thallium-201 activity after upright exercise in normal persons: importance of peak heart rate and propranolol usage in defining normal values

    SciTech Connect

    Brown, K.A.; Boucher, C.A.; Okada, R.D.; Strauss, H.W.; Pohost, G.M.

    1984-06-01

    Fifty-nine normal patients (34 angiographically normal and 25 clinically normal by Bayesian analysis) underwent thallium-201 imaging after maximal upright exercise. Lung activity was quantitated relative to myocardial activity and a lung/myocardial activity ratio was determined for each patient. Stepwise regression analysis was then used to examine the influence of patient clinical characteristics and exercise variables on the lung/myocardium ratio. Peak heart rate during exercise and propranolol usage both showed significant negative regression coefficients (p less than 0.001). No other patient data showed a significant relation. Using the regression equation and the estimated variance, a 95% confidence level upper limit of normal could be determined for a give peak heart rate and propranolol status. Sixty-one other patients were studied to validate the predicted upper limits of normal based on this model. None of the 27 patients without coronary artery disease had an elevated lung/myocardial ratio, compared with 1 of 8 with 1-vessel disease (difference not significant), 6 of 14 with 2-vessel disease (p less than 0.005), and 6 of 12 with 3-vessel disease (p less than 0.0001). Thus, lung activity on upright exercise thallium-201 studies can be quantitated relative to myocardial activity, and is inversely related to peak heart rate and propranolol use. Use of a regression analysis allows determination of a 95% confidence upper limit of normal to be anticipated in an individual patient.

  7. Activating Mutations in PIK3CB Confer Resistance to PI3K Inhibition and Define a Novel Oncogenic Role for p110β.

    PubMed

    Nakanishi, Yoshito; Walter, Kimberly; Spoerke, Jill M; O'Brien, Carol; Huw, Ling Y; Hampton, Garret M; Lackner, Mark R

    2016-03-01

    Activation of the PI3K pathway occurs commonly in a wide variety of cancers. Experience with other successful targeted agents suggests that clinical resistance is likely to arise and may reduce the durability of clinical benefit. Here, we sought to understand mechanisms underlying resistance to PI3K inhibition in PTEN-deficient cancers. We generated cell lines resistant to the pan-PI3K inhibitor GDC-0941 from parental PTEN-null breast cancer cell lines and identified a novel PIK3CB D1067Y mutation in both cell lines that was recurrent in cancer patients. Stable expression of mutant PIK3CB variants conferred resistance to PI3K inhibition that could be overcome by downstream AKT or mTORC1/2 inhibitors. Furthermore, we show that the p110β D1067Y mutant was highly activated and induced PIP3 levels at the cell membrane, subsequently promoting the localization and activation of AKT and PDK1 at the membrane and driving PI3K signaling to a level that could withstand treatment with proximal inhibitors. Finally, we demonstrate that the PIK3CB D1067Y mutant behaved as an oncogene and transformed normal cells, an activity that was enhanced by PTEN depletion. Collectively, these novel preclinical and clinical findings implicate the acquisition of activating PIK3CB D1067 mutations as an important event underlying the resistance of cancer cells to selective PI3K inhibitors. PMID:26759240

  8. Electron beam lithographically-defined scanning electrochemical-atomic force microscopy probes: fabrication method and application to high resolution imaging on heterogeneously active surfaces.

    PubMed

    Dobson, Phillip S; Weaver, John M R; Burt, David P; Holder, Mark N; Wilson, Neil R; Unwin, Patrick R; Macpherson, Julie V

    2006-09-01

    This paper describes in detail the use of electron beam lithography (EBL) to successfully batch microfabricate combined scanning electrochemical-atomic force microscopy (SECM-AFM) probes. At present, the process produces sixty probes at a time, on a 1/4 of a three-inch wafer. Using EBL, gold triangular-shaped electrodes can be defined at the tip apex, with plasma enhanced chemical vapor deposited silicon nitride serving as an effective insulating layer, at a thickness of 75 nm. The key features of the fabrication technique and the critical steps are discussed. The capability of these probes for SECM-AFM imaging in both tapping and constant distance mode is illustrated with dual topographical-electrochemical scans over an array of closely-spaced 1 microm diameter Pt disc electrodes, held at a suitable potential to generate an electroactive species at a transport-limited rate. As highlighted herein, understanding diffusion to heterogeneous electrode surfaces, including array electrodes, is currently topical and we present preliminary data highlighting the use of SECM-AFM as a valuable tool for the investigation of diffusion and reactivity at high spatial resolution. PMID:19817052

  9. Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the Sigma54 (RpoN) regulon of Salmonella Typhimurium LT2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Sigma54, or RpoN, is an alternative s factor found widely in eubacteria. A significant complication in analysis of the global sigma54 regulon in a bacterium is that the sigma54 RNA polymerase holoenzyme requires interaction with an active bacterial enhancer-binding protein (bEBP) to init...

  10. Bioactivity and Bioavailability of Ginsenosides Are Dependent on the Glycosidase Activities of the A/J Mouse Intestinal Microbiome Defined by Pyrosequencing

    PubMed Central

    Niu, Tao; Smith, Diane; Yang, Zhen; Gao, Song; Yin, Taijun; Jiang, Zhi-Hong; You, Ming; Gibbs, Richard A.; Petrosino, Joseph F.; Hu, Ming

    2015-01-01

    Purpose The ability of bacteria in the intestinal microbiome to convert naturally occurring primary ginsenosides in red ginseng extract or RGE to active secondary ginsenosides was investigated. Methods The anti-proliferative activity of ginsenosides was tested using the mouse lung cancer LM1 cells. Their permeabilities were evaluated in Caco-2 cell monolayers. Systemic exposure of secondary ginsenosides was determined in A/J mice. 16S rRNA gene pyrosequencing was used to determine membership and abundance of bacteria in the intestinal microbiome. Results Secondary ginsenoside C-K exhibited higher anti-proliferative activity and permeability than primary ginsenosides, and significant amounts of secondary ginsenosides (F2 and C-K) were found in the blood of A/J mice following oral administration of the primary ginsenoside Rb1. Because mammalian cells did not hydrolyze ginsenoside, we determined the ability of bacteria to hydrolyze ginsenosides and found that the primary ginsenoside Rb1 underwent stepwise hydrolysis to Rd, F2, and then C-K. Formation of F2 from Rd was the rate-limiting step in the biotransformation of Rb1 to C-K. Conclusion This is the first study to characterize the A/J mouse intestinal microbiome and reveal the presence of certain bacterial families capable of efficiently converting inactive primary ginsenosides to active secondary ginsenosides in vivo. PMID:23254888